FreeBSD/Linux Kernel Cross Reference
sys/dev/sym/sym_hipd.c

     /*-
      *  Device driver optimized for the Symbios/LSI 53C896/53C895A/53C1010
      *  PCI-SCSI controllers.
      *
      *  Copyright (C) 1999-2001  Gerard Roudier <groudier@free.fr>
      *
      *  This driver also supports the following Symbios/LSI PCI-SCSI chips:
      *      53C810A, 53C825A, 53C860, 53C875, 53C876, 53C885, 53C895,
      *      53C810,  53C815,  53C825 and the 53C1510D is 53C8XX mode.
     *
     *
     *  This driver for FreeBSD-CAM is derived from the Linux sym53c8xx driver.
     *  Copyright (C) 1998-1999  Gerard Roudier
     *
     *  The sym53c8xx driver is derived from the ncr53c8xx driver that had been
     *  a port of the FreeBSD ncr driver to Linux-1.2.13.
     *
     *  The original ncr driver has been written for 386bsd and FreeBSD by
     *          Wolfgang Stanglmeier        <wolf@cologne.de>
     *          Stefan Esser                <se@mi.Uni-Koeln.de>
     *  Copyright (C) 1994  Wolfgang Stanglmeier
     *
     *  The initialisation code, and part of the code that addresses
     *  FreeBSD-CAM services is based on the aic7xxx driver for FreeBSD-CAM
     *  written by Justin T. Gibbs.
     *
     *  Other major contributions:
     *
     *  NVRAM detection and reading.
     *  Copyright (C) 1997 Richard Waltham <dormouse@farsrobt.demon.co.uk>
     *
     *-----------------------------------------------------------------------------
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. The name of the author may not be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
     * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #define SYM_DRIVER_NAME "sym-1.6.5-20000902"
    
    /* #define SYM_DEBUG_GENERIC_SUPPORT */
    /* #define CAM_NEW_TRAN_CODE */
    
    #include <sys/param.h>
    
    /*
     *  Driver configuration options.
     */
    #include "opt_sym.h"
    #include <dev/sym/sym_conf.h>
    
    
    #include <sys/systm.h>
    #include <sys/malloc.h>
    #include <sys/endian.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/mutex.h>
    #include <sys/module.h>
    #include <sys/bus.h>
    
    #include <sys/proc.h>
    
    #include <dev/pci/pcireg.h>
    #include <dev/pci/pcivar.h>
    
    #include <machine/bus.h>
    #include <machine/resource.h>
    #include <sys/rman.h>
    
    #include <cam/cam.h>
    #include <cam/cam_ccb.h>
    #include <cam/cam_sim.h>
    #include <cam/cam_xpt_sim.h>
    #include <cam/cam_debug.h>
    
    #include <cam/scsi/scsi_all.h>
   #include <cam/scsi/scsi_message.h>
   
   #include <vm/vm.h>
   #include <vm/vm_param.h>
   #include <vm/pmap.h>
   
   /* Short and quite clear integer types */
   typedef int8_t    s8;
   typedef int16_t   s16;
   typedef int32_t   s32;
   typedef u_int8_t  u8;
   typedef u_int16_t u16;
   typedef u_int32_t u32;
   
   /*
    *  From 'cam.error_recovery_diffs.20010313.context' patch.
    */
   #ifdef  CAM_NEW_TRAN_CODE
   #define FreeBSD_New_Tran_Settings
   #endif  /* CAM_NEW_TRAN_CODE */
   
   /*
    *  Driver definitions.
    */
   #include <dev/sym/sym_defs.h>
   #include <dev/sym/sym_fw.h>
   
   /*
    *  IA32 architecture does not reorder STORES and prevents
    *  LOADS from passing STORES. It is called `program order'
    *  by Intel and allows device drivers to deal with memory
    *  ordering by only ensuring that the code is not reordered
    *  by the compiler when ordering is required.
    *  Other architectures implement a weaker ordering that
    *  requires memory barriers (and also IO barriers when they
    *  make sense) to be used.
    */
   
   #if     defined __i386__ || defined __amd64__
   #define MEMORY_BARRIER()        do { ; } while(0)
   #elif   defined __alpha__
   #define MEMORY_BARRIER()        alpha_mb()
   #elif   defined __powerpc__
   #define MEMORY_BARRIER()        __asm__ volatile("eieio; sync" : : : "memory")
   #elif   defined __ia64__
   #define MEMORY_BARRIER()        __asm__ volatile("mf.a; mf" : : : "memory")
   #elif   defined __sparc64__
   #define MEMORY_BARRIER()        __asm__ volatile("membar #Sync" : : : "memory")
   #else
   #error  "Not supported platform"
   #endif
   
   /*
    *  A la VMS/CAM-3 queue management.
    */
   
   typedef struct sym_quehead {
           struct sym_quehead *flink;      /* Forward  pointer */
           struct sym_quehead *blink;      /* Backward pointer */
   } SYM_QUEHEAD;
   
   #define sym_que_init(ptr) do { \
           (ptr)->flink = (ptr); (ptr)->blink = (ptr); \
   } while (0)
   
   static __inline struct sym_quehead *sym_que_first(struct sym_quehead *head)
   {
           return (head->flink == head) ? NULL : head->flink;
   }
   
   static __inline struct sym_quehead *sym_que_last(struct sym_quehead *head)
   {
           return (head->blink == head) ? NULL : head->blink;
   }
   
   static __inline void __sym_que_add(struct sym_quehead * new,
           struct sym_quehead * blink,
           struct sym_quehead * flink)
   {
           flink->blink    = new;
           new->flink      = flink;
           new->blink      = blink;
           blink->flink    = new;
   }
   
   static __inline void __sym_que_del(struct sym_quehead * blink,
           struct sym_quehead * flink)
   {
           flink->blink = blink;
           blink->flink = flink;
   }
   
   static __inline int sym_que_empty(struct sym_quehead *head)
   {
           return head->flink == head;
   }
   
   static __inline void sym_que_splice(struct sym_quehead *list,
           struct sym_quehead *head)
   {
           struct sym_quehead *first = list->flink;
   
           if (first != list) {
                   struct sym_quehead *last = list->blink;
                   struct sym_quehead *at   = head->flink;
   
                   first->blink = head;
                   head->flink  = first;
   
                   last->flink = at;
                   at->blink   = last;
           }
   }
   
   #define sym_que_entry(ptr, type, member) \
           ((type *)((char *)(ptr)-(size_t)(&((type *)0)->member)))
   
   
   #define sym_insque(new, pos)            __sym_que_add(new, pos, (pos)->flink)
   
   #define sym_remque(el)                  __sym_que_del((el)->blink, (el)->flink)
   
   #define sym_insque_head(new, head)      __sym_que_add(new, head, (head)->flink)
   
   static __inline struct sym_quehead *sym_remque_head(struct sym_quehead *head)
   {
           struct sym_quehead *elem = head->flink;
   
           if (elem != head)
                   __sym_que_del(head, elem->flink);
           else
                   elem = NULL;
           return elem;
   }
   
   #define sym_insque_tail(new, head)      __sym_que_add(new, (head)->blink, head)
   
   static __inline struct sym_quehead *sym_remque_tail(struct sym_quehead *head)
   {
           struct sym_quehead *elem = head->blink;
   
           if (elem != head)
                   __sym_que_del(elem->blink, head);
           else
                   elem = NULL;
           return elem;
   }
   
   /*
    *  This one may be useful.
    */
   #define FOR_EACH_QUEUED_ELEMENT(head, qp) \
           for (qp = (head)->flink; qp != (head); qp = qp->flink)
   /*
    *  FreeBSD does not offer our kind of queue in the CAM CCB.
    *  So, we have to cast.
    */
   #define sym_qptr(p)     ((struct sym_quehead *) (p))
   
   /*
    *  Simple bitmap operations.
    */
   #define sym_set_bit(p, n)       (((u32 *)(p))[(n)>>5] |=  (1<<((n)&0x1f)))
   #define sym_clr_bit(p, n)       (((u32 *)(p))[(n)>>5] &= ~(1<<((n)&0x1f)))
   #define sym_is_bit(p, n)        (((u32 *)(p))[(n)>>5] &   (1<<((n)&0x1f)))
   
   /*
    *  Number of tasks per device we want to handle.
    */
   #if     SYM_CONF_MAX_TAG_ORDER > 8
   #error  "more than 256 tags per logical unit not allowed."
   #endif
   #define SYM_CONF_MAX_TASK       (1<<SYM_CONF_MAX_TAG_ORDER)
   
   /*
    *  Donnot use more tasks that we can handle.
    */
   #ifndef SYM_CONF_MAX_TAG
   #define SYM_CONF_MAX_TAG        SYM_CONF_MAX_TASK
   #endif
   #if     SYM_CONF_MAX_TAG > SYM_CONF_MAX_TASK
   #undef  SYM_CONF_MAX_TAG
   #define SYM_CONF_MAX_TAG        SYM_CONF_MAX_TASK
   #endif
   
   /*
    *    This one means 'NO TAG for this job'
    */
   #define NO_TAG  (256)
   
   /*
    *  Number of SCSI targets.
    */
   #if     SYM_CONF_MAX_TARGET > 16
   #error  "more than 16 targets not allowed."
   #endif
   
   /*
    *  Number of logical units per target.
    */
   #if     SYM_CONF_MAX_LUN > 64
   #error  "more than 64 logical units per target not allowed."
   #endif
   
   /*
    *    Asynchronous pre-scaler (ns). Shall be 40 for
    *    the SCSI timings to be compliant.
    */
   #define SYM_CONF_MIN_ASYNC (40)
   
   /*
    *  Number of entries in the START and DONE queues.
    *
    *  We limit to 1 PAGE in order to succeed allocation of
    *  these queues. Each entry is 8 bytes long (2 DWORDS).
    */
   #ifdef  SYM_CONF_MAX_START
   #define SYM_CONF_MAX_QUEUE (SYM_CONF_MAX_START+2)
   #else
   #define SYM_CONF_MAX_QUEUE (7*SYM_CONF_MAX_TASK+2)
   #define SYM_CONF_MAX_START (SYM_CONF_MAX_QUEUE-2)
   #endif
   
   #if     SYM_CONF_MAX_QUEUE > PAGE_SIZE/8
   #undef  SYM_CONF_MAX_QUEUE
   #define SYM_CONF_MAX_QUEUE   PAGE_SIZE/8
   #undef  SYM_CONF_MAX_START
   #define SYM_CONF_MAX_START (SYM_CONF_MAX_QUEUE-2)
   #endif
   
   /*
    *  For this one, we want a short name :-)
    */
   #define MAX_QUEUE       SYM_CONF_MAX_QUEUE
   
   /*
    *  Active debugging tags and verbosity.
    */
   #define DEBUG_ALLOC     (0x0001)
   #define DEBUG_PHASE     (0x0002)
   #define DEBUG_POLL      (0x0004)
   #define DEBUG_QUEUE     (0x0008)
   #define DEBUG_RESULT    (0x0010)
   #define DEBUG_SCATTER   (0x0020)
   #define DEBUG_SCRIPT    (0x0040)
   #define DEBUG_TINY      (0x0080)
   #define DEBUG_TIMING    (0x0100)
   #define DEBUG_NEGO      (0x0200)
   #define DEBUG_TAGS      (0x0400)
   #define DEBUG_POINTER   (0x0800)
   
   #if 0
   static int sym_debug = 0;
           #define DEBUG_FLAGS sym_debug
   #else
   /*      #define DEBUG_FLAGS (0x0631) */
           #define DEBUG_FLAGS (0x0000)
   
   #endif
   #define sym_verbose     (np->verbose)
   
   /*
    *  Insert a delay in micro-seconds and milli-seconds.
    */
   static void UDELAY(int us) { DELAY(us); }
   static void MDELAY(int ms) { while (ms--) UDELAY(1000); }
   
   /*
    *  Simple power of two buddy-like allocator.
    *
    *  This simple code is not intended to be fast, but to
    *  provide power of 2 aligned memory allocations.
    *  Since the SCRIPTS processor only supplies 8 bit arithmetic,
    *  this allocator allows simple and fast address calculations
    *  from the SCRIPTS code. In addition, cache line alignment
    *  is guaranteed for power of 2 cache line size.
    *
    *  This allocator has been developped for the Linux sym53c8xx
    *  driver, since this O/S does not provide naturally aligned
    *  allocations.
    *  It has the advantage of allowing the driver to use private
    *  pages of memory that will be useful if we ever need to deal
    *  with IO MMUs for PCI.
    */
   
   #define MEMO_SHIFT      4       /* 16 bytes minimum memory chunk */
   #define MEMO_PAGE_ORDER 0       /* 1 PAGE  maximum */
   #if 0
   #define MEMO_FREE_UNUSED        /* Free unused pages immediately */
   #endif
   #define MEMO_WARN       1
   #define MEMO_CLUSTER_SHIFT      (PAGE_SHIFT+MEMO_PAGE_ORDER)
   #define MEMO_CLUSTER_SIZE       (1UL << MEMO_CLUSTER_SHIFT)
   #define MEMO_CLUSTER_MASK       (MEMO_CLUSTER_SIZE-1)
   
   #define get_pages()             malloc(MEMO_CLUSTER_SIZE, M_DEVBUF, M_NOWAIT)
   #define free_pages(p)           free((p), M_DEVBUF)
   
   typedef u_long m_addr_t;        /* Enough bits to bit-hack addresses */
   
   typedef struct m_link {         /* Link between free memory chunks */
           struct m_link *next;
   } m_link_s;
   
   typedef struct m_vtob {         /* Virtual to Bus address translation */
           struct m_vtob   *next;
           bus_dmamap_t    dmamap; /* Map for this chunk */
           m_addr_t        vaddr;  /* Virtual address */
           m_addr_t        baddr;  /* Bus physical address */
   } m_vtob_s;
   /* Hash this stuff a bit to speed up translations */
   #define VTOB_HASH_SHIFT         5
   #define VTOB_HASH_SIZE          (1UL << VTOB_HASH_SHIFT)
   #define VTOB_HASH_MASK          (VTOB_HASH_SIZE-1)
   #define VTOB_HASH_CODE(m)       \
           ((((m_addr_t) (m)) >> MEMO_CLUSTER_SHIFT) & VTOB_HASH_MASK)
   
   typedef struct m_pool {         /* Memory pool of a given kind */
           bus_dma_tag_t    dev_dmat;      /* Identifies the pool */
           bus_dma_tag_t    dmat;          /* Tag for our fixed allocations */
           m_addr_t (*getp)(struct m_pool *);
   #ifdef  MEMO_FREE_UNUSED
           void (*freep)(struct m_pool *, m_addr_t);
   #endif
   #define M_GETP()                mp->getp(mp)
   #define M_FREEP(p)              mp->freep(mp, p)
           int nump;
           m_vtob_s *(vtob[VTOB_HASH_SIZE]);
           struct m_pool *next;
           struct m_link h[MEMO_CLUSTER_SHIFT - MEMO_SHIFT + 1];
   } m_pool_s;
   
   static void *___sym_malloc(m_pool_s *mp, int size)
   {
           int i = 0;
           int s = (1 << MEMO_SHIFT);
           int j;
           m_addr_t a;
           m_link_s *h = mp->h;
   
           if (size > MEMO_CLUSTER_SIZE)
                   return NULL;
   
           while (size > s) {
                   s <<= 1;
                   ++i;
           }
   
           j = i;
           while (!h[j].next) {
                   if (s == MEMO_CLUSTER_SIZE) {
                           h[j].next = (m_link_s *) M_GETP();
                           if (h[j].next)
                                   h[j].next->next = NULL;
                           break;
                   }
                   ++j;
                   s <<= 1;
           }
           a = (m_addr_t) h[j].next;
           if (a) {
                   h[j].next = h[j].next->next;
                   while (j > i) {
                           j -= 1;
                           s >>= 1;
                           h[j].next = (m_link_s *) (a+s);
                           h[j].next->next = NULL;
                   }
           }
   #ifdef DEBUG
           printf("___sym_malloc(%d) = %p\n", size, (void *) a);
   #endif
           return (void *) a;
   }
   
   static void ___sym_mfree(m_pool_s *mp, void *ptr, int size)
   {
           int i = 0;
           int s = (1 << MEMO_SHIFT);
           m_link_s *q;
           m_addr_t a, b;
           m_link_s *h = mp->h;
   
   #ifdef DEBUG
           printf("___sym_mfree(%p, %d)\n", ptr, size);
   #endif
   
           if (size > MEMO_CLUSTER_SIZE)
                   return;
   
           while (size > s) {
                   s <<= 1;
                   ++i;
           }
   
           a = (m_addr_t) ptr;
   
           while (1) {
   #ifdef MEMO_FREE_UNUSED
                   if (s == MEMO_CLUSTER_SIZE) {
                           M_FREEP(a);
                           break;
                   }
   #endif
                   b = a ^ s;
                   q = &h[i];
                   while (q->next && q->next != (m_link_s *) b) {
                           q = q->next;
                   }
                   if (!q->next) {
                           ((m_link_s *) a)->next = h[i].next;
                           h[i].next = (m_link_s *) a;
                           break;
                   }
                   q->next = q->next->next;
                   a = a & b;
                   s <<= 1;
                   ++i;
           }
   }
   
   static void *__sym_calloc2(m_pool_s *mp, int size, char *name, int uflags)
   {
           void *p;
   
           p = ___sym_malloc(mp, size);
   
           if (DEBUG_FLAGS & DEBUG_ALLOC)
                   printf ("new %-10s[%4d] @%p.\n", name, size, p);
   
           if (p)
                   bzero(p, size);
           else if (uflags & MEMO_WARN)
                   printf ("__sym_calloc2: failed to allocate %s[%d]\n", name, size);
   
           return p;
   }
   
   #define __sym_calloc(mp, s, n)  __sym_calloc2(mp, s, n, MEMO_WARN)
   
   static void __sym_mfree(m_pool_s *mp, void *ptr, int size, char *name)
   {
           if (DEBUG_FLAGS & DEBUG_ALLOC)
                   printf ("freeing %-10s[%4d] @%p.\n", name, size, ptr);
   
           ___sym_mfree(mp, ptr, size);
   
   }
   
   /*
    * Default memory pool we donnot need to involve in DMA.
    */
   /*
    * With the `bus dma abstraction', we use a separate pool for
    * memory we donnot need to involve in DMA.
    */
   static m_addr_t ___mp0_getp(m_pool_s *mp)
   {
           m_addr_t m = (m_addr_t) get_pages();
           if (m)
                   ++mp->nump;
           return m;
   }
   
   #ifdef  MEMO_FREE_UNUSED
   static void ___mp0_freep(m_pool_s *mp, m_addr_t m)
   {
           free_pages(m);
           --mp->nump;
   }
   #endif
   
   #ifdef  MEMO_FREE_UNUSED
   static m_pool_s mp0 = {0, 0, ___mp0_getp, ___mp0_freep};
   #else
   static m_pool_s mp0 = {0, 0, ___mp0_getp};
   #endif
   
   
   /*
    * Actual memory allocation routine for non-DMAed memory.
    */
   static void *sym_calloc(int size, char *name)
   {
           void *m;
           /* Lock */
           m = __sym_calloc(&mp0, size, name);
           /* Unlock */
           return m;
   }
   
   /*
    * Actual memory allocation routine for non-DMAed memory.
    */
   static void sym_mfree(void *ptr, int size, char *name)
   {
           /* Lock */
           __sym_mfree(&mp0, ptr, size, name);
           /* Unlock */
   }
   
   /*
    * DMAable pools.
    */
   /*
    * With `bus dma abstraction', we use a separate pool per parent
    * BUS handle. A reverse table (hashed) is maintained for virtual
    * to BUS address translation.
    */
   static void getbaddrcb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
   {
           bus_addr_t *baddr;
           baddr = (bus_addr_t *)arg;
           *baddr = segs->ds_addr;
   }
   
   static m_addr_t ___dma_getp(m_pool_s *mp)
   {
           m_vtob_s *vbp;
           void *vaddr = NULL;
           bus_addr_t baddr = 0;
   
           vbp = __sym_calloc(&mp0, sizeof(*vbp), "VTOB");
           if (!vbp)
                   goto out_err;
   
           if (bus_dmamem_alloc(mp->dmat, &vaddr,
                                 BUS_DMA_NOWAIT, &vbp->dmamap))
                   goto out_err;
           bus_dmamap_load(mp->dmat, vbp->dmamap, vaddr,
                           MEMO_CLUSTER_SIZE, getbaddrcb, &baddr, BUS_DMA_NOWAIT);
           if (baddr) {
                   int hc = VTOB_HASH_CODE(vaddr);
                   vbp->vaddr = (m_addr_t) vaddr;
                   vbp->baddr = (m_addr_t) baddr;
                   vbp->next = mp->vtob[hc];
                   mp->vtob[hc] = vbp;
                   ++mp->nump;
                   return (m_addr_t) vaddr;
           }
   out_err:
           if (baddr)
                   bus_dmamap_unload(mp->dmat, vbp->dmamap);
           if (vaddr)
                   bus_dmamem_free(mp->dmat, vaddr, vbp->dmamap);
           if (vbp) {
                   if (vbp->dmamap)
                           bus_dmamap_destroy(mp->dmat, vbp->dmamap);
                   __sym_mfree(&mp0, vbp, sizeof(*vbp), "VTOB");
           }
           return 0;
   }
   
   #ifdef  MEMO_FREE_UNUSED
   static void ___dma_freep(m_pool_s *mp, m_addr_t m)
   {
           m_vtob_s **vbpp, *vbp;
           int hc = VTOB_HASH_CODE(m);
   
           vbpp = &mp->vtob[hc];
           while (*vbpp && (*vbpp)->vaddr != m)
                   vbpp = &(*vbpp)->next;
           if (*vbpp) {
                   vbp = *vbpp;
                   *vbpp = (*vbpp)->next;
                   bus_dmamap_unload(mp->dmat, vbp->dmamap);
                   bus_dmamem_free(mp->dmat, (void *) vbp->vaddr, vbp->dmamap);
                   bus_dmamap_destroy(mp->dmat, vbp->dmamap);
                   __sym_mfree(&mp0, vbp, sizeof(*vbp), "VTOB");
                   --mp->nump;
           }
   }
   #endif
   
   static __inline m_pool_s *___get_dma_pool(bus_dma_tag_t dev_dmat)
   {
           m_pool_s *mp;
           for (mp = mp0.next; mp && mp->dev_dmat != dev_dmat; mp = mp->next);
           return mp;
   }
   
   static m_pool_s *___cre_dma_pool(bus_dma_tag_t dev_dmat)
   {
           m_pool_s *mp = NULL;
   
           mp = __sym_calloc(&mp0, sizeof(*mp), "MPOOL");
           if (mp) {
                   mp->dev_dmat = dev_dmat;
                   if (!bus_dma_tag_create(dev_dmat, 1, MEMO_CLUSTER_SIZE,
                                  BUS_SPACE_MAXADDR_32BIT,
                                  BUS_SPACE_MAXADDR,
                                  NULL, NULL, MEMO_CLUSTER_SIZE, 1,
                                  MEMO_CLUSTER_SIZE, 0,
                                  busdma_lock_mutex, &Giant, &mp->dmat)) {
                           mp->getp = ___dma_getp;
   #ifdef  MEMO_FREE_UNUSED
                           mp->freep = ___dma_freep;
   #endif
                           mp->next = mp0.next;
                           mp0.next = mp;
                           return mp;
                   }
           }
           if (mp)
                   __sym_mfree(&mp0, mp, sizeof(*mp), "MPOOL");
           return NULL;
   }
   
   #ifdef  MEMO_FREE_UNUSED
   static void ___del_dma_pool(m_pool_s *p)
   {
           struct m_pool **pp = &mp0.next;
   
           while (*pp && *pp != p)
                   pp = &(*pp)->next;
           if (*pp) {
                   *pp = (*pp)->next;
                   bus_dma_tag_destroy(p->dmat);
                   __sym_mfree(&mp0, p, sizeof(*p), "MPOOL");
           }
   }
   #endif
   
   static void *__sym_calloc_dma(bus_dma_tag_t dev_dmat, int size, char *name)
   {
           struct m_pool *mp;
           void *m = NULL;
   
           /* Lock */
           mp = ___get_dma_pool(dev_dmat);
           if (!mp)
                   mp = ___cre_dma_pool(dev_dmat);
           if (mp)
                   m = __sym_calloc(mp, size, name);
   #ifdef  MEMO_FREE_UNUSED
           if (mp && !mp->nump)
                   ___del_dma_pool(mp);
   #endif
           /* Unlock */
   
           return m;
   }
   
   static void
   __sym_mfree_dma(bus_dma_tag_t dev_dmat, void *m, int size, char *name)
   {
           struct m_pool *mp;
   
           /* Lock */
           mp = ___get_dma_pool(dev_dmat);
           if (mp)
                   __sym_mfree(mp, m, size, name);
   #ifdef  MEMO_FREE_UNUSED
           if (mp && !mp->nump)
                   ___del_dma_pool(mp);
   #endif
           /* Unlock */
   }
   
   static m_addr_t __vtobus(bus_dma_tag_t dev_dmat, void *m)
   {
           m_pool_s *mp;
           int hc = VTOB_HASH_CODE(m);
           m_vtob_s *vp = NULL;
           m_addr_t a = ((m_addr_t) m) & ~MEMO_CLUSTER_MASK;
   
           /* Lock */
           mp = ___get_dma_pool(dev_dmat);
           if (mp) {
                   vp = mp->vtob[hc];
                   while (vp && (m_addr_t) vp->vaddr != a)
                           vp = vp->next;
           }
           /* Unlock */
           if (!vp)
                   panic("sym: VTOBUS FAILED!\n");
           return vp ? vp->baddr + (((m_addr_t) m) - a) : 0;
   }
   
   
   /*
    * Verbs for DMAable memory handling.
    * The _uvptv_ macro avoids a nasty warning about pointer to volatile
    * being discarded.
    */
   #define _uvptv_(p) ((void *)((vm_offset_t)(p)))
   #define _sym_calloc_dma(np, s, n)       __sym_calloc_dma(np->bus_dmat, s, n)
   #define _sym_mfree_dma(np, p, s, n)     \
                                   __sym_mfree_dma(np->bus_dmat, _uvptv_(p), s, n)
   #define sym_calloc_dma(s, n)            _sym_calloc_dma(np, s, n)
   #define sym_mfree_dma(p, s, n)          _sym_mfree_dma(np, p, s, n)
   #define _vtobus(np, p)                  __vtobus(np->bus_dmat, _uvptv_(p))
   #define vtobus(p)                       _vtobus(np, p)
   
   
   /*
    *  Print a buffer in hexadecimal format.
    */
   static void sym_printb_hex (u_char *p, int n)
   {
           while (n-- > 0)
                   printf (" %x", *p++);
   }
   
   /*
    *  Same with a label at beginning and .\n at end.
    */
   static void sym_printl_hex (char *label, u_char *p, int n)
   {
           printf ("%s", label);
           sym_printb_hex (p, n);
           printf (".\n");
   }
   
   /*
    *  Return a string for SCSI BUS mode.
    */
   static const char *sym_scsi_bus_mode(int mode)
   {
           switch(mode) {
           case SMODE_HVD: return "HVD";
           case SMODE_SE:  return "SE";
           case SMODE_LVD: return "LVD";
           }
           return "??";
   }
   
   /*
    *  Some poor and bogus sync table that refers to Tekram NVRAM layout.
    */
   #ifdef SYM_CONF_NVRAM_SUPPORT
   static const u_char Tekram_sync[16] =
           {25,31,37,43, 50,62,75,125, 12,15,18,21, 6,7,9,10};
   #endif
   
   /*
    *  Union of supported NVRAM formats.
    */
   struct sym_nvram {
           int type;
   #define SYM_SYMBIOS_NVRAM       (1)
   #define SYM_TEKRAM_NVRAM        (2)
   #ifdef  SYM_CONF_NVRAM_SUPPORT
           union {
                   Symbios_nvram Symbios;
                   Tekram_nvram Tekram;
           } data;
   #endif
   };
   
   /*
    *  This one is hopefully useless, but actually useful. :-)
    */
   #ifndef assert
   #define assert(expression) { \
           if (!(expression)) { \
                   (void)panic( \
                           "assertion \"%s\" failed: file \"%s\", line %d\n", \
                           #expression, \
                           __FILE__, __LINE__); \
           } \
   }
   #endif
   
   /*
    *  Some provision for a possible big endian mode supported by
    *  Symbios chips (never seen, by the way).
    *  For now, this stuff does not deserve any comments. :)
    */
   
   #define sym_offb(o)     (o)
   #define sym_offw(o)     (o)
   
   /*
    *  Some provision for support for BIG ENDIAN CPU.
    */
   
   #define cpu_to_scr(dw)  htole32(dw)
   #define scr_to_cpu(dw)  le32toh(dw)
   
   /*
    *  Access to the chip IO registers and on-chip RAM.
    *  We use the `bus space' interface under FreeBSD-4 and
    *  later kernel versions.
    */
   
   
   #if defined(SYM_CONF_IOMAPPED)
   
   #define INB_OFF(o)      bus_space_read_1(np->io_tag, np->io_bsh, o)
   #define INW_OFF(o)      bus_space_read_2(np->io_tag, np->io_bsh, o)
   #define INL_OFF(o)      bus_space_read_4(np->io_tag, np->io_bsh, o)
   
   #define OUTB_OFF(o, v)  bus_space_write_1(np->io_tag, np->io_bsh, o, (v))
   #define OUTW_OFF(o, v)  bus_space_write_2(np->io_tag, np->io_bsh, o, (v))
   #define OUTL_OFF(o, v)  bus_space_write_4(np->io_tag, np->io_bsh, o, (v))
   
   #else   /* Memory mapped IO */
   
   #define INB_OFF(o)      bus_space_read_1(np->mmio_tag, np->mmio_bsh, o)
   #define INW_OFF(o)      bus_space_read_2(np->mmio_tag, np->mmio_bsh, o)
   #define INL_OFF(o)      bus_space_read_4(np->mmio_tag, np->mmio_bsh, o)
   
   #define OUTB_OFF(o, v)  bus_space_write_1(np->mmio_tag, np->mmio_bsh, o, (v))
   #define OUTW_OFF(o, v)  bus_space_write_2(np->mmio_tag, np->mmio_bsh, o, (v))
   #define OUTL_OFF(o, v)  bus_space_write_4(np->mmio_tag, np->mmio_bsh, o, (v))
   
   #endif  /* SYM_CONF_IOMAPPED */
   
   #define OUTRAM_OFF(o, a, l)     \
           bus_space_write_region_1(np->ram_tag, np->ram_bsh, o, (a), (l))
   
   
   /*
    *  Common definitions for both bus space and legacy IO methods.
    */
   #define INB(r)          INB_OFF(offsetof(struct sym_reg,r))
   #define INW(r)          INW_OFF(offsetof(struct sym_reg,r))
   #define INL(r)          INL_OFF(offsetof(struct sym_reg,r))
   
   #define OUTB(r, v)      OUTB_OFF(offsetof(struct sym_reg,r), (v))
   #define OUTW(r, v)      OUTW_OFF(offsetof(struct sym_reg,r), (v))
   #define OUTL(r, v)      OUTL_OFF(offsetof(struct sym_reg,r), (v))
   
   #define OUTONB(r, m)    OUTB(r, INB(r) | (m))
   #define OUTOFFB(r, m)   OUTB(r, INB(r) & ~(m))
   #define OUTONW(r, m)    OUTW(r, INW(r) | (m))
   #define OUTOFFW(r, m)   OUTW(r, INW(r) & ~(m))
   #define OUTONL(r, m)    OUTL(r, INL(r) | (m))
   #define OUTOFFL(r, m)   OUTL(r, INL(r) & ~(m))
   
   /*
    *  We normally want the chip to have a consistent view
    *  of driver internal data structures when we restart it.
    *  Thus these macros.
    */
   #define OUTL_DSP(v)                             \
           do {                                    \
                   MEMORY_BARRIER();               \
                   OUTL (nc_dsp, (v));             \
           } while (0)
   
   #define OUTONB_STD()                            \
           do {                                    \
                   MEMORY_BARRIER();               \
                   OUTONB (nc_dcntl, (STD|NOCOM)); \
           } while (0)
   
   /*
    *  Command control block states.
    */
   #define HS_IDLE         (0)
   #define HS_BUSY         (1)
   #define HS_NEGOTIATE    (2)     /* sync/wide data transfer*/
   #define HS_DISCONNECT   (3)     /* Disconnected by target */
   #define HS_WAIT         (4)     /* waiting for resource   */
   
   #define HS_DONEMASK     (0x80)
   #define HS_COMPLETE     (4|HS_DONEMASK)
   #define HS_SEL_TIMEOUT  (5|HS_DONEMASK) /* Selection timeout      */
   #define HS_UNEXPECTED   (6|HS_DONEMASK) /* Unexpected disconnect  */
   #define HS_COMP_ERR     (7|HS_DONEMASK) /* Completed with error   */
   
   /*
    *  Software Interrupt Codes
    */
   #define SIR_BAD_SCSI_STATUS     (1)
   #define SIR_SEL_ATN_NO_MSG_OUT  (2)
   #define SIR_MSG_RECEIVED        (3)
   #define SIR_MSG_WEIRD           (4)
   #define SIR_NEGO_FAILED         (5)
   #define SIR_NEGO_PROTO          (6)
   #define SIR_SCRIPT_STOPPED      (7)
   #define SIR_REJECT_TO_SEND      (8)
   #define SIR_SWIDE_OVERRUN       (9)
   #define SIR_SODL_UNDERRUN       (10)
   #define SIR_RESEL_NO_MSG_IN     (11)
   #define SIR_RESEL_NO_IDENTIFY   (12)
   #define SIR_RESEL_BAD_LUN       (13)
   #define SIR_TARGET_SELECTED     (14)
   #define SIR_RESEL_BAD_I_T_L     (15)
   #define SIR_RESEL_BAD_I_T_L_Q   (16)
   #define SIR_ABORT_SENT          (17)
   #define SIR_RESEL_ABORTED       (18)
   #define SIR_MSG_OUT_DONE        (19)
   #define SIR_COMPLETE_ERROR      (20)
   #define SIR_DATA_OVERRUN        (21)
   #define SIR_BAD_PHASE           (22)
   #define SIR_MAX                 (22)
   
   /*
    *  Extended error bit codes.
    *  xerr_status field of struct sym_ccb.
    */
   #define XE_EXTRA_DATA   (1)     /* unexpected data phase         */
   #define XE_BAD_PHASE    (1<<1)  /* illegal phase (4/5)           */
   #define XE_PARITY_ERR   (1<<2)  /* unrecovered SCSI parity error */
   #define XE_SODL_UNRUN   (1<<3)  /* ODD transfer in DATA OUT phase */
   #define XE_SWIDE_OVRUN  (1<<4)  /* ODD transfer in DATA IN phase */
   
  /*
   *  Negotiation status.
   *  nego_status field of struct sym_ccb.
   */
  #define NS_SYNC         (1)
  #define NS_WIDE         (2)
  #define NS_PPR          (3)
  
  /*
   *  A CCB hashed table is used to retrieve CCB address
   *  from DSA value.
   */
  #define CCB_HASH_SHIFT          8
  #define CCB_HASH_SIZE           (1UL << CCB_HASH_SHIFT)
  #define CCB_HASH_MASK           (CCB_HASH_SIZE-1)
  #define CCB_HASH_CODE(dsa)      (((dsa) >> 9) & CCB_HASH_MASK)
  
  /*
   *  Device flags.
   */
  #define SYM_DISC_ENABLED        (1)
  #define SYM_TAGS_ENABLED        (1<<1)
  #define SYM_SCAN_BOOT_DISABLED  (1<<2)
  #define SYM_SCAN_LUNS_DISABLED  (1<<3)
  
  /*
   *  Host adapter miscellaneous flags.
   */
  #define SYM_AVOID_BUS_RESET     (1)
  #define SYM_SCAN_TARGETS_HILO   (1<<1)
  
  /*
   *  Device quirks.
   *  Some devices, for example the CHEETAH 2 LVD, disconnects without
   *  saving the DATA POINTER then reselects and terminates the IO.
   *  On reselection, the automatic RESTORE DATA POINTER makes the
   *  CURRENT DATA POINTER not point at the end of the IO.
   *  This behaviour just breaks our calculation of the residual.
   *  For now, we just force an AUTO SAVE on disconnection and will
   *  fix that in a further driver version.
   */
  #define SYM_QUIRK_AUTOSAVE 1
  
  /*
   *  Misc.
   */
  #define SYM_SNOOP_TIMEOUT (10000000)
  #define SYM_PCI_IO      PCIR_BAR(0)
  #define SYM_PCI_MMIO    PCIR_BAR(1)
  #define SYM_PCI_RAM     PCIR_BAR(2)
  #define SYM_PCI_RAM64   PCIR_BAR(3)
  
  /*
   *  Back-pointer from the CAM CCB to our data structures.
   */
  #define sym_hcb_ptr     spriv_ptr0
  /* #define sym_ccb_ptr  spriv_ptr1 */
  
  /*
   *  We mostly have to deal with pointers.
   *  Thus these typedef's.
   */
  typedef struct sym_tcb *tcb_p;
  typedef struct sym_lcb *lcb_p;
  typedef struct sym_ccb *ccb_p;
  typedef struct sym_hcb *hcb_p;
  
  /*
   *  Gather negotiable parameters value
   */
  struct sym_trans {
  #ifdef  FreeBSD_New_Tran_Settings
          u8 scsi_version;
          u8 spi_version;
  #endif
          u8 period;
          u8 offset;
          u8 width;
          u8 options;     /* PPR options */
  };
  
  struct sym_tinfo {
          struct sym_trans current;
          struct sym_trans goal;
          struct sym_trans user;
  };
  
  #define BUS_8_BIT       MSG_EXT_WDTR_BUS_8_BIT
  #define BUS_16_BIT      MSG_EXT_WDTR_BUS_16_BIT
  
  /*
   *  Global TCB HEADER.
   *
   *  Due to lack of indirect addressing on earlier NCR chips,
   *  this substructure is copied from the TCB to a global
   *  address after selection.
   *  For SYMBIOS chips that support LOAD/STORE this copy is
   *  not needed and thus not performed.
   */
  struct sym_tcbh {
          /*
           *  Scripts bus addresses of LUN table accessed from scripts.
           *  LUN #0 is a special case, since multi-lun devices are rare,
           *  and we we want to speed-up the general case and not waste
           *  resources.
           */
          u32     luntbl_sa;      /* bus address of this table    */
          u32     lun0_sa;        /* bus address of LCB #0        */
          /*
           *  Actual SYNC/WIDE IO registers value for this target.
           *  'sval', 'wval' and 'uval' are read from SCRIPTS and
           *  so have alignment constraints.
           */
  /**/   u_char  uval;           /* -> SCNTL4 register           */
  /*1*/   u_char  sval;           /* -> SXFER  io register        */
  /*2*/   u_char  filler1;
  /*3*/   u_char  wval;           /* -> SCNTL3 io register        */
  };
  
  /*
   *  Target Control Block
   */
  struct sym_tcb {
          /*
           *  TCB header.
           *  Assumed at offset 0.
           */
  /**/   struct sym_tcbh head;
  
          /*
           *  LUN table used by the SCRIPTS processor.
           *  An array of bus addresses is used on reselection.
           */
          u32     *luntbl;        /* LCBs bus address table       */
  
          /*
           *  LUN table used by the C code.
           */
          lcb_p   lun0p;          /* LCB of LUN #0 (usual case)   */
  #if SYM_CONF_MAX_LUN > 1
          lcb_p   *lunmp;         /* Other LCBs [1..MAX_LUN]      */
  #endif
  
          /*
           *  Bitmap that tells about LUNs that succeeded at least
           *  1 IO and therefore assumed to be a real device.
           *  Avoid useless allocation of the LCB structure.
           */
          u32     lun_map[(SYM_CONF_MAX_LUN+31)/32];
  
          /*
           *  Bitmap that tells about LUNs that haven't yet an LCB
           *  allocated (not discovered or LCB allocation failed).
           */
          u32     busy0_map[(SYM_CONF_MAX_LUN+31)/32];
  
          /*
           *  Transfer capabilities (SIP)
           */
          struct sym_tinfo tinfo;
  
          /*
           * Keep track of the CCB used for the negotiation in order
           * to ensure that only 1 negotiation is queued at a time.
           */
          ccb_p   nego_cp;        /* CCB used for the nego                */
  
          /*
           *  Set when we want to reset the device.
           */
          u_char  to_reset;
  
          /*
           *  Other user settable limits and options.
           *  These limits are read from the NVRAM if present.
           */
          u_char  usrflags;
          u_short usrtags;
  };
  
  /*
   *  Global LCB HEADER.
   *
   *  Due to lack of indirect addressing on earlier NCR chips,
   *  this substructure is copied from the LCB to a global
   *  address after selection.
   *  For SYMBIOS chips that support LOAD/STORE this copy is
   *  not needed and thus not performed.
   */
  struct sym_lcbh {
          /*
           *  SCRIPTS address jumped by SCRIPTS on reselection.
           *  For not probed logical units, this address points to
           *  SCRIPTS that deal with bad LU handling (must be at
           *  offset zero of the LCB for that reason).
           */
  /**/   u32     resel_sa;
  
          /*
           *  Task (bus address of a CCB) read from SCRIPTS that points
           *  to the unique ITL nexus allowed to be disconnected.
           */
          u32     itl_task_sa;
  
          /*
           *  Task table bus address (read from SCRIPTS).
           */
          u32     itlq_tbl_sa;
  };
  
  /*
   *  Logical Unit Control Block
   */
  struct sym_lcb {
          /*
           *  TCB header.
           *  Assumed at offset 0.
           */
  /**/   struct sym_lcbh head;
  
          /*
           *  Task table read from SCRIPTS that contains pointers to
           *  ITLQ nexuses. The bus address read from SCRIPTS is
           *  inside the header.
           */
          u32     *itlq_tbl;      /* Kernel virtual address       */
  
          /*
           *  Busy CCBs management.
           */
          u_short busy_itlq;      /* Number of busy tagged CCBs   */
          u_short busy_itl;       /* Number of busy untagged CCBs */
  
          /*
           *  Circular tag allocation buffer.
           */
          u_short ia_tag;         /* Tag allocation index         */
          u_short if_tag;         /* Tag release index            */
          u_char  *cb_tags;       /* Circular tags buffer         */
  
          /*
           *  Set when we want to clear all tasks.
           */
          u_char to_clear;
  
          /*
           *  Capabilities.
           */
          u_char  user_flags;
          u_char  current_flags;
  };
  
  /*
   *  Action from SCRIPTS on a task.
   *  Is part of the CCB, but is also used separately to plug
   *  error handling action to perform from SCRIPTS.
   */
  struct sym_actscr {
          u32     start;          /* Jumped by SCRIPTS after selection    */
          u32     restart;        /* Jumped by SCRIPTS on relection       */
  };
  
  /*
   *  Phase mismatch context.
   *
   *  It is part of the CCB and is used as parameters for the
   *  DATA pointer. We need two contexts to handle correctly the
   *  SAVED DATA POINTER.
   */
  struct sym_pmc {
          struct  sym_tblmove sg; /* Updated interrupted SG block */
          u32     ret;            /* SCRIPT return address        */
  };
  
  /*
   *  LUN control block lookup.
   *  We use a direct pointer for LUN #0, and a table of
   *  pointers which is only allocated for devices that support
   *  LUN(s) > 0.
   */
  #if SYM_CONF_MAX_LUN <= 1
  #define sym_lp(np, tp, lun) (!lun) ? (tp)->lun0p : 0
  #else
  #define sym_lp(np, tp, lun) \
          (!lun) ? (tp)->lun0p : (tp)->lunmp ? (tp)->lunmp[(lun)] : 0
  #endif
  
  /*
   *  Status are used by the host and the script processor.
   *
   *  The last four bytes (status[4]) are copied to the
   *  scratchb register (declared as scr0..scr3) just after the
   *  select/reselect, and copied back just after disconnecting.
   *  Inside the script the XX_REG are used.
   */
  
  /*
   *  Last four bytes (script)
   */
  #define  QU_REG scr0
  #define  HS_REG scr1
  #define  HS_PRT nc_scr1
  #define  SS_REG scr2
  #define  SS_PRT nc_scr2
  #define  HF_REG scr3
  #define  HF_PRT nc_scr3
  
  /*
   *  Last four bytes (host)
   */
  #define  actualquirks  phys.head.status[0]
  #define  host_status   phys.head.status[1]
  #define  ssss_status   phys.head.status[2]
  #define  host_flags    phys.head.status[3]
  
  /*
   *  Host flags
   */
  #define HF_IN_PM0       1u
  #define HF_IN_PM1       (1u<<1)
  #define HF_ACT_PM       (1u<<2)
  #define HF_DP_SAVED     (1u<<3)
  #define HF_SENSE        (1u<<4)
  #define HF_EXT_ERR      (1u<<5)
  #define HF_DATA_IN      (1u<<6)
  #ifdef SYM_CONF_IARB_SUPPORT
  #define HF_HINT_IARB    (1u<<7)
  #endif
  
  /*
   *  Global CCB HEADER.
   *
   *  Due to lack of indirect addressing on earlier NCR chips,
   *  this substructure is copied from the ccb to a global
   *  address after selection (or reselection) and copied back
   *  before disconnect.
   *  For SYMBIOS chips that support LOAD/STORE this copy is
   *  not needed and thus not performed.
   */
  
  struct sym_ccbh {
          /*
           *  Start and restart SCRIPTS addresses (must be at 0).
           */
  /**/   struct sym_actscr go;
  
          /*
           *  SCRIPTS jump address that deal with data pointers.
           *  'savep' points to the position in the script responsible
           *  for the actual transfer of data.
           *  It's written on reception of a SAVE_DATA_POINTER message.
           */
          u32     savep;          /* Jump address to saved data pointer   */
          u32     lastp;          /* SCRIPTS address at end of data       */
          u32     goalp;          /* Not accessed for now from SCRIPTS    */
  
          /*
           *  Status fields.
           */
          u8      status[4];
  };
  
  /*
   *  Data Structure Block
   *
   *  During execution of a ccb by the script processor, the
   *  DSA (data structure address) register points to this
   *  substructure of the ccb.
   */
  struct sym_dsb {
          /*
           *  CCB header.
           *  Also assumed at offset 0 of the sym_ccb structure.
           */
  /**/   struct sym_ccbh head;
  
          /*
           *  Phase mismatch contexts.
           *  We need two to handle correctly the SAVED DATA POINTER.
           *  MUST BOTH BE AT OFFSET < 256, due to using 8 bit arithmetic
           *  for address calculation from SCRIPTS.
           */
          struct sym_pmc pm0;
          struct sym_pmc pm1;
  
          /*
           *  Table data for Script
           */
          struct sym_tblsel  select;
          struct sym_tblmove smsg;
          struct sym_tblmove smsg_ext;
          struct sym_tblmove cmd;
          struct sym_tblmove sense;
          struct sym_tblmove wresid;
          struct sym_tblmove data [SYM_CONF_MAX_SG];
  };
  
  /*
   *  Our Command Control Block
   */
  struct sym_ccb {
          /*
           *  This is the data structure which is pointed by the DSA
           *  register when it is executed by the script processor.
           *  It must be the first entry.
           */
          struct sym_dsb phys;
  
          /*
           *  Pointer to CAM ccb and related stuff.
           */
          union ccb *cam_ccb;     /* CAM scsiio ccb               */
          u8      cdb_buf[16];    /* Copy of CDB                  */
          u8      *sns_bbuf;      /* Bounce buffer for sense data */
  #define SYM_SNS_BBUF_LEN        sizeof(struct scsi_sense_data)
          int     data_len;       /* Total data length            */
          int     segments;       /* Number of SG segments        */
  
          /*
           *  Miscellaneous status'.
           */
          u_char  nego_status;    /* Negotiation status           */
          u_char  xerr_status;    /* Extended error flags         */
          u32     extra_bytes;    /* Extraneous bytes transferred */
  
          /*
           *  Message areas.
           *  We prepare a message to be sent after selection.
           *  We may use a second one if the command is rescheduled
           *  due to CHECK_CONDITION or COMMAND TERMINATED.
           *  Contents are IDENTIFY and SIMPLE_TAG.
           *  While negotiating sync or wide transfer,
           *  a SDTR or WDTR message is appended.
           */
          u_char  scsi_smsg [12];
          u_char  scsi_smsg2[12];
  
          /*
           *  Auto request sense related fields.
           */
          u_char  sensecmd[6];    /* Request Sense command        */
          u_char  sv_scsi_status; /* Saved SCSI status            */
          u_char  sv_xerr_status; /* Saved extended status        */
          int     sv_resid;       /* Saved residual               */
  
          /*
           *  Map for the DMA of user data.
           */
          void            *arg;   /* Argument for some callback   */
          bus_dmamap_t    dmamap; /* DMA map for user data        */
          u_char          dmamapped;
  #define SYM_DMA_NONE    0
  #define SYM_DMA_READ    1
  #define SYM_DMA_WRITE   2
          /*
           *  Other fields.
           */
          u32     ccb_ba;         /* BUS address of this CCB      */
          u_short tag;            /* Tag for this transfer        */
                                  /*  NO_TAG means no tag         */
          u_char  target;
          u_char  lun;
          ccb_p   link_ccbh;      /* Host adapter CCB hash chain  */
          SYM_QUEHEAD
                  link_ccbq;      /* Link to free/busy CCB queue  */
          u32     startp;         /* Initial data pointer         */
          int     ext_sg;         /* Extreme data pointer, used   */
          int     ext_ofs;        /*  to calculate the residual.  */
          u_char  to_abort;       /* Want this IO to be aborted   */
  };
  
  #define CCB_BA(cp,lbl)  (cp->ccb_ba + offsetof(struct sym_ccb, lbl))
  
  /*
   *  Host Control Block
   */
  struct sym_hcb {
          /*
           *  Global headers.
           *  Due to poorness of addressing capabilities, earlier
           *  chips (810, 815, 825) copy part of the data structures
           *  (CCB, TCB and LCB) in fixed areas.
           */
  #ifdef  SYM_CONF_GENERIC_SUPPORT
          struct sym_ccbh ccb_head;
          struct sym_tcbh tcb_head;
          struct sym_lcbh lcb_head;
  #endif
          /*
           *  Idle task and invalid task actions and
           *  their bus addresses.
           */
          struct sym_actscr idletask, notask, bad_itl, bad_itlq;
          vm_offset_t idletask_ba, notask_ba, bad_itl_ba, bad_itlq_ba;
  
          /*
           *  Dummy lun table to protect us against target
           *  returning bad lun number on reselection.
           */
          u32     *badluntbl;     /* Table physical address       */
          u32     badlun_sa;      /* SCRIPT handler BUS address   */
  
          /*
           *  Bus address of this host control block.
           */
          u32     hcb_ba;
  
          /*
           *  Bit 32-63 of the on-chip RAM bus address in LE format.
           *  The START_RAM64 script loads the MMRS and MMWS from this
           *  field.
           */
          u32     scr_ram_seg;
  
          /*
           *  Chip and controller indentification.
           */
          device_t device;
  
          /*
           *  Initial value of some IO register bits.
           *  These values are assumed to have been set by BIOS, and may
           *  be used to probe adapter implementation differences.
           */
          u_char  sv_scntl0, sv_scntl3, sv_dmode, sv_dcntl, sv_ctest3, sv_ctest4,
                  sv_ctest5, sv_gpcntl, sv_stest2, sv_stest4, sv_scntl4,
                  sv_stest1;
  
          /*
           *  Actual initial value of IO register bits used by the
           *  driver. They are loaded at initialisation according to
           *  features that are to be enabled/disabled.
           */
          u_char  rv_scntl0, rv_scntl3, rv_dmode, rv_dcntl, rv_ctest3, rv_ctest4,
                  rv_ctest5, rv_stest2, rv_ccntl0, rv_ccntl1, rv_scntl4;
  
          /*
           *  Target data.
           */
  #ifdef __amd64__
          struct sym_tcb  *target;
  #else
          struct sym_tcb  target[SYM_CONF_MAX_TARGET];
  #endif
  
          /*
           *  Target control block bus address array used by the SCRIPT
           *  on reselection.
           */
          u32             *targtbl;
          u32             targtbl_ba;
  
          /*
           *  CAM SIM information for this instance.
           */
          struct          cam_sim  *sim;
          struct          cam_path *path;
  
          /*
           *  Allocated hardware resources.
           */
          struct resource *irq_res;
          struct resource *io_res;
          struct resource *mmio_res;
          struct resource *ram_res;
          int             ram_id;
          void *intr;
  
          /*
           *  Bus stuff.
           *
           *  My understanding of PCI is that all agents must share the
           *  same addressing range and model.
           *  But some hardware architecture guys provide complex and
           *  brain-deaded stuff that makes shit.
           *  This driver only support PCI compliant implementations and
           *  deals with part of the BUS stuff complexity only to fit O/S
           *  requirements.
           */
          bus_space_handle_t      io_bsh;
          bus_space_tag_t         io_tag;
          bus_space_handle_t      mmio_bsh;
          bus_space_tag_t         mmio_tag;
          bus_space_handle_t      ram_bsh;
          bus_space_tag_t         ram_tag;
  
          /*
           *  DMA stuff.
           */
          bus_dma_tag_t   bus_dmat;       /* DMA tag from parent BUS      */
          bus_dma_tag_t   data_dmat;      /* DMA tag for user data        */
          /*
           *  BUS addresses of the chip
           */
          vm_offset_t     mmio_ba;        /* MMIO BUS address             */
          int             mmio_ws;        /* MMIO Window size             */
  
          vm_offset_t     ram_ba;         /* RAM BUS address              */
          int             ram_ws;         /* RAM window size              */
  
          /*
           *  SCRIPTS virtual and physical bus addresses.
           *  'script'  is loaded in the on-chip RAM if present.
           *  'scripth' stays in main memory for all chips except the
           *  53C895A, 53C896 and 53C1010 that provide 8K on-chip RAM.
           */
          u_char          *scripta0;      /* Copies of script and scripth */
          u_char          *scriptb0;      /* Copies of script and scripth */
          vm_offset_t     scripta_ba;     /* Actual script and scripth    */
          vm_offset_t     scriptb_ba;     /*  bus addresses.              */
          vm_offset_t     scriptb0_ba;
          u_short         scripta_sz;     /* Actual size of script A      */
          u_short         scriptb_sz;     /* Actual size of script B      */
  
          /*
           *  Bus addresses, setup and patch methods for
           *  the selected firmware.
           */
          struct sym_fwa_ba fwa_bas;      /* Useful SCRIPTA bus addresses */
          struct sym_fwb_ba fwb_bas;      /* Useful SCRIPTB bus addresses */
          void            (*fw_setup)(hcb_p np, const struct sym_fw *fw);
          void            (*fw_patch)(hcb_p np);
          const char      *fw_name;
  
          /*
           *  General controller parameters and configuration.
           */
          u_short device_id;      /* PCI device id                */
          u_char  revision_id;    /* PCI device revision id       */
          u_int   features;       /* Chip features map            */
          u_char  myaddr;         /* SCSI id of the adapter       */
          u_char  maxburst;       /* log base 2 of dwords burst   */
          u_char  maxwide;        /* Maximum transfer width       */
          u_char  minsync;        /* Min sync period factor (ST)  */
          u_char  maxsync;        /* Max sync period factor (ST)  */
          u_char  maxoffs;        /* Max scsi offset        (ST)  */
          u_char  minsync_dt;     /* Min sync period factor (DT)  */
          u_char  maxsync_dt;     /* Max sync period factor (DT)  */
          u_char  maxoffs_dt;     /* Max scsi offset        (DT)  */
          u_char  multiplier;     /* Clock multiplier (1,2,4)     */
          u_char  clock_divn;     /* Number of clock divisors     */
          u32     clock_khz;      /* SCSI clock frequency in KHz  */
          u32     pciclk_khz;     /* Estimated PCI clock  in KHz  */
          /*
           *  Start queue management.
           *  It is filled up by the host processor and accessed by the
           *  SCRIPTS processor in order to start SCSI commands.
           */
          volatile                /* Prevent code optimizations   */
          u32     *squeue;        /* Start queue virtual address  */
          u32     squeue_ba;      /* Start queue BUS address      */
          u_short squeueput;      /* Next free slot of the queue  */
          u_short actccbs;        /* Number of allocated CCBs     */
  
          /*
           *  Command completion queue.
           *  It is the same size as the start queue to avoid overflow.
           */
          u_short dqueueget;      /* Next position to scan        */
          volatile                /* Prevent code optimizations   */
          u32     *dqueue;        /* Completion (done) queue      */
          u32     dqueue_ba;      /* Done queue BUS address       */
  
          /*
           *  Miscellaneous buffers accessed by the scripts-processor.
           *  They shall be DWORD aligned, because they may be read or
           *  written with a script command.
           */
          u_char          msgout[8];      /* Buffer for MESSAGE OUT       */
          u_char          msgin [8];      /* Buffer for MESSAGE IN        */
          u32             lastmsg;        /* Last SCSI message sent       */
          u_char          scratch;        /* Scratch for SCSI receive     */
  
          /*
           *  Miscellaneous configuration and status parameters.
           */
          u_char          usrflags;       /* Miscellaneous user flags     */
          u_char          scsi_mode;      /* Current SCSI BUS mode        */
          u_char          verbose;        /* Verbosity for this controller*/
          u32             cache;          /* Used for cache test at init. */
  
          /*
           *  CCB lists and queue.
           */
          ccb_p ccbh[CCB_HASH_SIZE];      /* CCB hashed by DSA value      */
          SYM_QUEHEAD     free_ccbq;      /* Queue of available CCBs      */
          SYM_QUEHEAD     busy_ccbq;      /* Queue of busy CCBs           */
  
          /*
           *  During error handling and/or recovery,
           *  active CCBs that are to be completed with
           *  error or requeued are moved from the busy_ccbq
           *  to the comp_ccbq prior to completion.
           */
          SYM_QUEHEAD     comp_ccbq;
  
          /*
           *  CAM CCB pending queue.
           */
          SYM_QUEHEAD     cam_ccbq;
  
          /*
           *  IMMEDIATE ARBITRATION (IARB) control.
           *
           *  We keep track in 'last_cp' of the last CCB that has been
           *  queued to the SCRIPTS processor and clear 'last_cp' when
           *  this CCB completes. If last_cp is not zero at the moment
           *  we queue a new CCB, we set a flag in 'last_cp' that is
           *  used by the SCRIPTS as a hint for setting IARB.
           *  We donnot set more than 'iarb_max' consecutive hints for
           *  IARB in order to leave devices a chance to reselect.
           *  By the way, any non zero value of 'iarb_max' is unfair. :)
           */
  #ifdef SYM_CONF_IARB_SUPPORT
          u_short         iarb_max;       /* Max. # consecutive IARB hints*/
          u_short         iarb_count;     /* Actual # of these hints      */
          ccb_p           last_cp;
  #endif
  
          /*
           *  Command abort handling.
           *  We need to synchronize tightly with the SCRIPTS
           *  processor in order to handle things correctly.
           */
          u_char          abrt_msg[4];    /* Message to send buffer       */
          struct sym_tblmove abrt_tbl;    /* Table for the MOV of it      */
          struct sym_tblsel  abrt_sel;    /* Sync params for selection    */
          u_char          istat_sem;      /* Tells the chip to stop (SEM) */
  };
  
  #define HCB_BA(np, lbl)     (np->hcb_ba      + offsetof(struct sym_hcb, lbl))
  
  /*
   *  Return the name of the controller.
   */
  static __inline const char *sym_name(hcb_p np)
  {
          return device_get_nameunit(np->device);
  }
  
  /*--------------------------------------------------------------------------*/
  /*------------------------------ FIRMWARES ---------------------------------*/
  /*--------------------------------------------------------------------------*/
  
  /*
   *  This stuff will be moved to a separate source file when
   *  the driver will be broken into several source modules.
   */
  
  /*
   *  Macros used for all firmwares.
   */
  #define SYM_GEN_A(s, label)     ((short) offsetof(s, label)),
  #define SYM_GEN_B(s, label)     ((short) offsetof(s, label)),
  #define PADDR_A(label)          SYM_GEN_PADDR_A(struct SYM_FWA_SCR, label)
  #define PADDR_B(label)          SYM_GEN_PADDR_B(struct SYM_FWB_SCR, label)
  
  
  #ifdef  SYM_CONF_GENERIC_SUPPORT
  /*
   *  Allocate firmware #1 script area.
   */
  #define SYM_FWA_SCR             sym_fw1a_scr
  #define SYM_FWB_SCR             sym_fw1b_scr
  #include <dev/sym/sym_fw1.h>
  static const struct sym_fwa_ofs sym_fw1a_ofs = {
          SYM_GEN_FW_A(struct SYM_FWA_SCR)
  };
  static const struct sym_fwb_ofs sym_fw1b_ofs = {
          SYM_GEN_FW_B(struct SYM_FWB_SCR)
  };
  #undef  SYM_FWA_SCR
  #undef  SYM_FWB_SCR
  #endif  /* SYM_CONF_GENERIC_SUPPORT */
  
  /*
   *  Allocate firmware #2 script area.
   */
  #define SYM_FWA_SCR             sym_fw2a_scr
  #define SYM_FWB_SCR             sym_fw2b_scr
  #include <dev/sym/sym_fw2.h>
  static const struct sym_fwa_ofs sym_fw2a_ofs = {
          SYM_GEN_FW_A(struct SYM_FWA_SCR)
  };
  static const struct sym_fwb_ofs sym_fw2b_ofs = {
          SYM_GEN_FW_B(struct SYM_FWB_SCR)
          SYM_GEN_B(struct SYM_FWB_SCR, start64)
          SYM_GEN_B(struct SYM_FWB_SCR, pm_handle)
  };
  #undef  SYM_FWA_SCR
  #undef  SYM_FWB_SCR
  
  #undef  SYM_GEN_A
  #undef  SYM_GEN_B
  #undef  PADDR_A
  #undef  PADDR_B
  
  #ifdef  SYM_CONF_GENERIC_SUPPORT
  /*
   *  Patch routine for firmware #1.
   */
  static void
  sym_fw1_patch(hcb_p np)
  {
          struct sym_fw1a_scr *scripta0;
          struct sym_fw1b_scr *scriptb0;
  
          scripta0 = (struct sym_fw1a_scr *) np->scripta0;
          scriptb0 = (struct sym_fw1b_scr *) np->scriptb0;
  
          /*
           *  Remove LED support if not needed.
           */
          if (!(np->features & FE_LED0)) {
                  scripta0->idle[0]       = cpu_to_scr(SCR_NO_OP);
                  scripta0->reselected[0] = cpu_to_scr(SCR_NO_OP);
                  scripta0->start[0]      = cpu_to_scr(SCR_NO_OP);
          }
  
  #ifdef SYM_CONF_IARB_SUPPORT
          /*
           *    If user does not want to use IMMEDIATE ARBITRATION
           *    when we are reselected while attempting to arbitrate,
           *    patch the SCRIPTS accordingly with a SCRIPT NO_OP.
           */
          if (!SYM_CONF_SET_IARB_ON_ARB_LOST)
                  scripta0->ungetjob[0] = cpu_to_scr(SCR_NO_OP);
  #endif
          /*
           *  Patch some data in SCRIPTS.
           *  - start and done queue initial bus address.
           *  - target bus address table bus address.
           */
          scriptb0->startpos[0]   = cpu_to_scr(np->squeue_ba);
          scriptb0->done_pos[0]   = cpu_to_scr(np->dqueue_ba);
          scriptb0->targtbl[0]    = cpu_to_scr(np->targtbl_ba);
  }
  #endif  /* SYM_CONF_GENERIC_SUPPORT */
  
  /*
   *  Patch routine for firmware #2.
   */
  static void
  sym_fw2_patch(hcb_p np)
  {
          struct sym_fw2a_scr *scripta0;
          struct sym_fw2b_scr *scriptb0;
  
          scripta0 = (struct sym_fw2a_scr *) np->scripta0;
          scriptb0 = (struct sym_fw2b_scr *) np->scriptb0;
  
          /*
           *  Remove LED support if not needed.
           */
          if (!(np->features & FE_LED0)) {
                  scripta0->idle[0]       = cpu_to_scr(SCR_NO_OP);
                  scripta0->reselected[0] = cpu_to_scr(SCR_NO_OP);
                  scripta0->start[0]      = cpu_to_scr(SCR_NO_OP);
          }
  
  #ifdef SYM_CONF_IARB_SUPPORT
          /*
           *    If user does not want to use IMMEDIATE ARBITRATION
           *    when we are reselected while attempting to arbitrate,
           *    patch the SCRIPTS accordingly with a SCRIPT NO_OP.
           */
          if (!SYM_CONF_SET_IARB_ON_ARB_LOST)
                  scripta0->ungetjob[0] = cpu_to_scr(SCR_NO_OP);
  #endif
          /*
           *  Patch some variable in SCRIPTS.
           *  - start and done queue initial bus address.
           *  - target bus address table bus address.
           */
          scriptb0->startpos[0]   = cpu_to_scr(np->squeue_ba);
          scriptb0->done_pos[0]   = cpu_to_scr(np->dqueue_ba);
          scriptb0->targtbl[0]    = cpu_to_scr(np->targtbl_ba);
  
          /*
           *  Remove the load of SCNTL4 on reselection if not a C10.
           */
          if (!(np->features & FE_C10)) {
                  scripta0->resel_scntl4[0] = cpu_to_scr(SCR_NO_OP);
                  scripta0->resel_scntl4[1] = cpu_to_scr(0);
          }
  
          /*
           *  Remove a couple of work-arounds specific to C1010 if
           *  they are not desirable. See `sym_fw2.h' for more details.
           */
          if (!(np->device_id == PCI_ID_LSI53C1010_2 &&
                np->revision_id < 0x1 &&
                np->pciclk_khz < 60000)) {
                  scripta0->datao_phase[0] = cpu_to_scr(SCR_NO_OP);
                  scripta0->datao_phase[1] = cpu_to_scr(0);
          }
          if (!(np->device_id == PCI_ID_LSI53C1010 &&
                /* np->revision_id < 0xff */ 1)) {
                  scripta0->sel_done[0] = cpu_to_scr(SCR_NO_OP);
                  scripta0->sel_done[1] = cpu_to_scr(0);
          }
  
          /*
           *  Patch some other variables in SCRIPTS.
           *  These ones are loaded by the SCRIPTS processor.
           */
          scriptb0->pm0_data_addr[0] =
                  cpu_to_scr(np->scripta_ba +
                             offsetof(struct sym_fw2a_scr, pm0_data));
          scriptb0->pm1_data_addr[0] =
                  cpu_to_scr(np->scripta_ba +
                             offsetof(struct sym_fw2a_scr, pm1_data));
  }
  
  /*
   *  Fill the data area in scripts.
   *  To be done for all firmwares.
   */
  static void
  sym_fw_fill_data (u32 *in, u32 *out)
  {
          int     i;
  
          for (i = 0; i < SYM_CONF_MAX_SG; i++) {
                  *in++  = SCR_CHMOV_TBL ^ SCR_DATA_IN;
                  *in++  = offsetof (struct sym_dsb, data[i]);
                  *out++ = SCR_CHMOV_TBL ^ SCR_DATA_OUT;
                  *out++ = offsetof (struct sym_dsb, data[i]);
          }
  }
  
  /*
   *  Setup useful script bus addresses.
   *  To be done for all firmwares.
   */
  static void
  sym_fw_setup_bus_addresses(hcb_p np, const struct sym_fw *fw)
  {
          u32 *pa;
          const u_short *po;
          int i;
  
          /*
           *  Build the bus address table for script A
           *  from the script A offset table.
           */
          po = (const u_short *) fw->a_ofs;
          pa = (u32 *) &np->fwa_bas;
          for (i = 0 ; i < sizeof(np->fwa_bas)/sizeof(u32) ; i++)
                  pa[i] = np->scripta_ba + po[i];
  
          /*
           *  Same for script B.
           */
          po = (const u_short *) fw->b_ofs;
          pa = (u32 *) &np->fwb_bas;
          for (i = 0 ; i < sizeof(np->fwb_bas)/sizeof(u32) ; i++)
                  pa[i] = np->scriptb_ba + po[i];
  }
  
  #ifdef  SYM_CONF_GENERIC_SUPPORT
  /*
   *  Setup routine for firmware #1.
   */
  static void
  sym_fw1_setup(hcb_p np, const struct sym_fw *fw)
  {
          struct sym_fw1a_scr *scripta0;
          struct sym_fw1b_scr *scriptb0;
  
          scripta0 = (struct sym_fw1a_scr *) np->scripta0;
          scriptb0 = (struct sym_fw1b_scr *) np->scriptb0;
  
          /*
           *  Fill variable parts in scripts.
           */
          sym_fw_fill_data(scripta0->data_in, scripta0->data_out);
  
          /*
           *  Setup bus addresses used from the C code..
           */
          sym_fw_setup_bus_addresses(np, fw);
  }
  #endif  /* SYM_CONF_GENERIC_SUPPORT */
  
  /*
   *  Setup routine for firmware #2.
   */
  static void
  sym_fw2_setup(hcb_p np, const struct sym_fw *fw)
  {
          struct sym_fw2a_scr *scripta0;
          struct sym_fw2b_scr *scriptb0;
  
          scripta0 = (struct sym_fw2a_scr *) np->scripta0;
          scriptb0 = (struct sym_fw2b_scr *) np->scriptb0;
  
          /*
           *  Fill variable parts in scripts.
           */
          sym_fw_fill_data(scripta0->data_in, scripta0->data_out);
  
          /*
           *  Setup bus addresses used from the C code..
           */
          sym_fw_setup_bus_addresses(np, fw);
  }
  
  /*
   *  Allocate firmware descriptors.
   */
  #ifdef  SYM_CONF_GENERIC_SUPPORT
  static const struct sym_fw sym_fw1 = SYM_FW_ENTRY(sym_fw1, "NCR-generic");
  #endif  /* SYM_CONF_GENERIC_SUPPORT */
  static const struct sym_fw sym_fw2 = SYM_FW_ENTRY(sym_fw2, "LOAD/STORE-based");
  
  /*
   *  Find the most appropriate firmware for a chip.
   */
  static const struct sym_fw *
  sym_find_firmware(const struct sym_pci_chip *chip)
  {
          if (chip->features & FE_LDSTR)
                  return &sym_fw2;
  #ifdef  SYM_CONF_GENERIC_SUPPORT
          else if (!(chip->features & (FE_PFEN|FE_NOPM|FE_DAC)))
                  return &sym_fw1;
  #endif
          else
                  return NULL;
  }
  
  /*
   *  Bind a script to physical addresses.
   */
  static void sym_fw_bind_script (hcb_p np, u32 *start, int len)
  {
          u32 opcode, new, old, tmp1, tmp2;
          u32 *end, *cur;
          int relocs;
  
          cur = start;
          end = start + len/4;
  
          while (cur < end) {
  
                  opcode = *cur;
  
                  /*
                   *  If we forget to change the length
                   *  in scripts, a field will be
                   *  padded with 0. This is an illegal
                   *  command.
                   */
                  if (opcode == 0) {
                          printf ("%s: ERROR0 IN SCRIPT at %d.\n",
                                  sym_name(np), (int) (cur-start));
                          MDELAY (10000);
                          ++cur;
                          continue;
                  };
  
                  /*
                   *  We use the bogus value 0xf00ff00f ;-)
                   *  to reserve data area in SCRIPTS.
                   */
                  if (opcode == SCR_DATA_ZERO) {
                          *cur++ = 0;
                          continue;
                  }
  
                  if (DEBUG_FLAGS & DEBUG_SCRIPT)
                          printf ("%d:  <%x>\n", (int) (cur-start),
                                  (unsigned)opcode);
  
                  /*
                   *  We don't have to decode ALL commands
                   */
                  switch (opcode >> 28) {
                  case 0xf:
                          /*
                           *  LOAD / STORE DSA relative, don't relocate.
                           */
                          relocs = 0;
                          break;
                  case 0xe:
                          /*
                           *  LOAD / STORE absolute.
                           */
                          relocs = 1;
                          break;
                  case 0xc:
                          /*
                           *  COPY has TWO arguments.
                           */
                          relocs = 2;
                          tmp1 = cur[1];
                          tmp2 = cur[2];
                          if ((tmp1 ^ tmp2) & 3) {
                                  printf ("%s: ERROR1 IN SCRIPT at %d.\n",
                                          sym_name(np), (int) (cur-start));
                                  MDELAY (10000);
                          }
                          /*
                           *  If PREFETCH feature not enabled, remove
                           *  the NO FLUSH bit if present.
                           */
                          if ((opcode & SCR_NO_FLUSH) &&
                              !(np->features & FE_PFEN)) {
                                  opcode = (opcode & ~SCR_NO_FLUSH);
                          }
                          break;
                  case 0x0:
                          /*
                           *  MOVE/CHMOV (absolute address)
                           */
                          if (!(np->features & FE_WIDE))
                                  opcode = (opcode | OPC_MOVE);
                          relocs = 1;
                          break;
                  case 0x1:
                          /*
                           *  MOVE/CHMOV (table indirect)
                           */
                          if (!(np->features & FE_WIDE))
                                  opcode = (opcode | OPC_MOVE);
                          relocs = 0;
                          break;
                  case 0x8:
                          /*
                           *  JUMP / CALL
                           *  dont't relocate if relative :-)
                           */
                          if (opcode & 0x00800000)
                                  relocs = 0;
                          else if ((opcode & 0xf8400000) == 0x80400000)/*JUMP64*/
                                  relocs = 2;
                          else
                                  relocs = 1;
                          break;
                  case 0x4:
                  case 0x5:
                  case 0x6:
                  case 0x7:
                          relocs = 1;
                          break;
                  default:
                          relocs = 0;
                          break;
                  };
  
                  /*
                   *  Scriptify:) the opcode.
                   */
                  *cur++ = cpu_to_scr(opcode);
  
                  /*
                   *  If no relocation, assume 1 argument
                   *  and just scriptize:) it.
                   */
                  if (!relocs) {
                          *cur = cpu_to_scr(*cur);
                          ++cur;
                          continue;
                  }
  
                  /*
                   *  Otherwise performs all needed relocations.
                   */
                  while (relocs--) {
                          old = *cur;
  
                          switch (old & RELOC_MASK) {
                          case RELOC_REGISTER:
                                  new = (old & ~RELOC_MASK) + np->mmio_ba;
                                  break;
                          case RELOC_LABEL_A:
                                  new = (old & ~RELOC_MASK) + np->scripta_ba;
                                  break;
                          case RELOC_LABEL_B:
                                  new = (old & ~RELOC_MASK) + np->scriptb_ba;
                                  break;
                          case RELOC_SOFTC:
                                  new = (old & ~RELOC_MASK) + np->hcb_ba;
                                  break;
                          case 0:
                                  /*
                                   *  Don't relocate a 0 address.
                                   *  They are mostly used for patched or
                                   *  script self-modified areas.
                                   */
                                  if (old == 0) {
                                          new = old;
                                          break;
                                  }
                                  /* fall through */
                          default:
                                  new = 0;
                                  panic("sym_fw_bind_script: "
                                        "weird relocation %x\n", old);
                                  break;
                          }
  
                          *cur++ = cpu_to_scr(new);
                  }
          };
  }
  
  /*---------------------------------------------------------------------------*/
  /*--------------------------- END OF FIRMWARES  -----------------------------*/
  /*---------------------------------------------------------------------------*/
  
  /*
   *  Function prototypes.
   */
  static void sym_save_initial_setting (hcb_p np);
  static int  sym_prepare_setting (hcb_p np, struct sym_nvram *nvram);
  static int  sym_prepare_nego (hcb_p np, ccb_p cp, int nego, u_char *msgptr);
  static void sym_put_start_queue (hcb_p np, ccb_p cp);
  static void sym_chip_reset (hcb_p np);
  static void sym_soft_reset (hcb_p np);
  static void sym_start_reset (hcb_p np);
  static int  sym_reset_scsi_bus (hcb_p np, int enab_int);
  static int  sym_wakeup_done (hcb_p np);
  static void sym_flush_busy_queue (hcb_p np, int cam_status);
  static void sym_flush_comp_queue (hcb_p np, int cam_status);
  static void sym_init (hcb_p np, int reason);
  static int  sym_getsync(hcb_p np, u_char dt, u_char sfac, u_char *divp,
                          u_char *fakp);
  static void sym_setsync (hcb_p np, ccb_p cp, u_char ofs, u_char per,
                           u_char div, u_char fak);
  static void sym_setwide (hcb_p np, ccb_p cp, u_char wide);
  static void sym_setpprot(hcb_p np, ccb_p cp, u_char dt, u_char ofs,
                           u_char per, u_char wide, u_char div, u_char fak);
  static void sym_settrans(hcb_p np, ccb_p cp, u_char dt, u_char ofs,
                           u_char per, u_char wide, u_char div, u_char fak);
  static void sym_log_hard_error (hcb_p np, u_short sist, u_char dstat);
  static void sym_intr (void *arg);
  static void sym_poll (struct cam_sim *sim);
  static void sym_recover_scsi_int (hcb_p np, u_char hsts);
  static void sym_int_sto (hcb_p np);
  static void sym_int_udc (hcb_p np);
  static void sym_int_sbmc (hcb_p np);
  static void sym_int_par (hcb_p np, u_short sist);
  static void sym_int_ma (hcb_p np);
  static int  sym_dequeue_from_squeue(hcb_p np, int i, int target, int lun,
                                      int task);
  static void sym_sir_bad_scsi_status (hcb_p np, int num, ccb_p cp);
  static int  sym_clear_tasks (hcb_p np, int status, int targ, int lun, int task);
  static void sym_sir_task_recovery (hcb_p np, int num);
  static int  sym_evaluate_dp (hcb_p np, ccb_p cp, u32 scr, int *ofs);
  static void sym_modify_dp (hcb_p np, tcb_p tp, ccb_p cp, int ofs);
  static int  sym_compute_residual (hcb_p np, ccb_p cp);
  static int  sym_show_msg (u_char * msg);
  static void sym_print_msg (ccb_p cp, char *label, u_char *msg);
  static void sym_sync_nego (hcb_p np, tcb_p tp, ccb_p cp);
  static void sym_ppr_nego (hcb_p np, tcb_p tp, ccb_p cp);
  static void sym_wide_nego (hcb_p np, tcb_p tp, ccb_p cp);
  static void sym_nego_default (hcb_p np, tcb_p tp, ccb_p cp);
  static void sym_nego_rejected (hcb_p np, tcb_p tp, ccb_p cp);
  static void sym_int_sir (hcb_p np);
  static void sym_free_ccb (hcb_p np, ccb_p cp);
  static ccb_p sym_get_ccb (hcb_p np, u_char tn, u_char ln, u_char tag_order);
  static ccb_p sym_alloc_ccb (hcb_p np);
  static ccb_p sym_ccb_from_dsa (hcb_p np, u32 dsa);
  static lcb_p sym_alloc_lcb (hcb_p np, u_char tn, u_char ln);
  static void sym_alloc_lcb_tags (hcb_p np, u_char tn, u_char ln);
  static int  sym_snooptest (hcb_p np);
  static void sym_selectclock(hcb_p np, u_char scntl3);
  static void sym_getclock (hcb_p np, int mult);
  static int  sym_getpciclock (hcb_p np);
  static void sym_complete_ok (hcb_p np, ccb_p cp);
  static void sym_complete_error (hcb_p np, ccb_p cp);
  static void sym_timeout (void *arg);
  static int  sym_abort_scsiio (hcb_p np, union ccb *ccb, int timed_out);
  static void sym_reset_dev (hcb_p np, union ccb *ccb);
  static void sym_action (struct cam_sim *sim, union ccb *ccb);
  static void sym_action1 (struct cam_sim *sim, union ccb *ccb);
  static int  sym_setup_cdb (hcb_p np, struct ccb_scsiio *csio, ccb_p cp);
  static void sym_setup_data_and_start (hcb_p np, struct ccb_scsiio *csio,
                                        ccb_p cp);
  static int sym_fast_scatter_sg_physical(hcb_p np, ccb_p cp,
                                          bus_dma_segment_t *psegs, int nsegs);
  static int sym_scatter_sg_physical (hcb_p np, ccb_p cp,
                                      bus_dma_segment_t *psegs, int nsegs);
  static void sym_action2 (struct cam_sim *sim, union ccb *ccb);
  static void sym_update_trans (hcb_p np, tcb_p tp, struct sym_trans *tip,
                                struct ccb_trans_settings *cts);
  static void sym_update_dflags(hcb_p np, u_char *flags,
                                struct ccb_trans_settings *cts);
  
  static const struct sym_pci_chip *sym_find_pci_chip (device_t dev);
  static int  sym_pci_probe (device_t dev);
  static int  sym_pci_attach (device_t dev);
  
  static void sym_pci_free (hcb_p np);
  static int  sym_cam_attach (hcb_p np);
  static void sym_cam_free (hcb_p np);
  
  static void sym_nvram_setup_host (hcb_p np, struct sym_nvram *nvram);
  static void sym_nvram_setup_target (hcb_p np, int targ, struct sym_nvram *nvp);
  static int sym_read_nvram (hcb_p np, struct sym_nvram *nvp);
  
  /*
   *  Print something which allows to retrieve the controler type,
   *  unit, target, lun concerned by a kernel message.
   */
  static void PRINT_TARGET (hcb_p np, int target)
  {
          printf ("%s:%d:", sym_name(np), target);
  }
  
  static void PRINT_LUN(hcb_p np, int target, int lun)
  {
          printf ("%s:%d:%d:", sym_name(np), target, lun);
  }
  
  static void PRINT_ADDR (ccb_p cp)
  {
          if (cp && cp->cam_ccb)
                  xpt_print_path(cp->cam_ccb->ccb_h.path);
  }
  
  /*
   *  Take into account this ccb in the freeze count.
   */
  static void sym_freeze_cam_ccb(union ccb *ccb)
  {
          if (!(ccb->ccb_h.flags & CAM_DEV_QFRZDIS)) {
                  if (!(ccb->ccb_h.status & CAM_DEV_QFRZN)) {
                          ccb->ccb_h.status |= CAM_DEV_QFRZN;
                          xpt_freeze_devq(ccb->ccb_h.path, 1);
                  }
          }
  }
  
  /*
   *  Set the status field of a CAM CCB.
   */
  static __inline void sym_set_cam_status(union ccb *ccb, cam_status status)
  {
          ccb->ccb_h.status &= ~CAM_STATUS_MASK;
          ccb->ccb_h.status |= status;
  }
  
  /*
   *  Get the status field of a CAM CCB.
   */
  static __inline int sym_get_cam_status(union ccb *ccb)
  {
          return ccb->ccb_h.status & CAM_STATUS_MASK;
  }
  
  /*
   *  Enqueue a CAM CCB.
   */
  static void sym_enqueue_cam_ccb(hcb_p np, union ccb *ccb)
  {
          assert(!(ccb->ccb_h.status & CAM_SIM_QUEUED));
          ccb->ccb_h.status = CAM_REQ_INPROG;
  
          ccb->ccb_h.timeout_ch = timeout(sym_timeout, (caddr_t) ccb,
                                         ccb->ccb_h.timeout*hz/1000);
          ccb->ccb_h.status |= CAM_SIM_QUEUED;
          ccb->ccb_h.sym_hcb_ptr = np;
  
          sym_insque_tail(sym_qptr(&ccb->ccb_h.sim_links), &np->cam_ccbq);
  }
  
  /*
   *  Complete a pending CAM CCB.
   */
  static void sym_xpt_done(hcb_p np, union ccb *ccb)
  {
          if (ccb->ccb_h.status & CAM_SIM_QUEUED) {
                  untimeout(sym_timeout, (caddr_t) ccb, ccb->ccb_h.timeout_ch);
                  sym_remque(sym_qptr(&ccb->ccb_h.sim_links));
                  ccb->ccb_h.status &= ~CAM_SIM_QUEUED;
                  ccb->ccb_h.sym_hcb_ptr = NULL;
          }
          if (ccb->ccb_h.flags & CAM_DEV_QFREEZE)
                  sym_freeze_cam_ccb(ccb);
          xpt_done(ccb);
  }
  
  static void sym_xpt_done2(hcb_p np, union ccb *ccb, int cam_status)
  {
          sym_set_cam_status(ccb, cam_status);
          sym_xpt_done(np, ccb);
  }
  
  /*
   *  SYMBIOS chip clock divisor table.
   *
   *  Divisors are multiplied by 10,000,000 in order to make
   *  calculations more simple.
   */
  #define _5M 5000000
  static const u32 div_10M[] =
          {2*_5M, 3*_5M, 4*_5M, 6*_5M, 8*_5M, 12*_5M, 16*_5M};
  
  /*
   *  SYMBIOS chips allow burst lengths of 2, 4, 8, 16, 32, 64,
   *  128 transfers. All chips support at least 16 transfers
   *  bursts. The 825A, 875 and 895 chips support bursts of up
   *  to 128 transfers and the 895A and 896 support bursts of up
   *  to 64 transfers. All other chips support up to 16
   *  transfers bursts.
   *
   *  For PCI 32 bit data transfers each transfer is a DWORD.
   *  It is a QUADWORD (8 bytes) for PCI 64 bit data transfers.
   *
   *  We use log base 2 (burst length) as internal code, with
   *  value 0 meaning "burst disabled".
   */
  
  /*
   *  Burst length from burst code.
   */
  #define burst_length(bc) (!(bc))? 0 : 1 << (bc)
  
  /*
   *  Burst code from io register bits.
   */
  #define burst_code(dmode, ctest4, ctest5) \
          (ctest4) & 0x80? 0 : (((dmode) & 0xc0) >> 6) + ((ctest5) & 0x04) + 1
  
  /*
   *  Set initial io register bits from burst code.
   */
  static __inline void sym_init_burst(hcb_p np, u_char bc)
  {
          np->rv_ctest4   &= ~0x80;
          np->rv_dmode    &= ~(0x3 << 6);
          np->rv_ctest5   &= ~0x4;
  
          if (!bc) {
                  np->rv_ctest4   |= 0x80;
          }
          else {
                  --bc;
                  np->rv_dmode    |= ((bc & 0x3) << 6);
                  np->rv_ctest5   |= (bc & 0x4);
          }
  }
  
  
  /*
   * Print out the list of targets that have some flag disabled by user.
   */
  static void sym_print_targets_flag(hcb_p np, int mask, char *msg)
  {
          int cnt;
          int i;
  
          for (cnt = 0, i = 0 ; i < SYM_CONF_MAX_TARGET ; i++) {
                  if (i == np->myaddr)
                          continue;
                  if (np->target[i].usrflags & mask) {
                          if (!cnt++)
                                  printf("%s: %s disabled for targets",
                                          sym_name(np), msg);
                          printf(" %d", i);
                  }
          }
          if (cnt)
                  printf(".\n");
  }
  
  /*
   *  Save initial settings of some IO registers.
   *  Assumed to have been set by BIOS.
   *  We cannot reset the chip prior to reading the
   *  IO registers, since informations will be lost.
   *  Since the SCRIPTS processor may be running, this
   *  is not safe on paper, but it seems to work quite
   *  well. :)
   */
  static void sym_save_initial_setting (hcb_p np)
  {
          np->sv_scntl0   = INB(nc_scntl0) & 0x0a;
          np->sv_scntl3   = INB(nc_scntl3) & 0x07;
          np->sv_dmode    = INB(nc_dmode)  & 0xce;
          np->sv_dcntl    = INB(nc_dcntl)  & 0xa8;
          np->sv_ctest3   = INB(nc_ctest3) & 0x01;
          np->sv_ctest4   = INB(nc_ctest4) & 0x80;
          np->sv_gpcntl   = INB(nc_gpcntl);
          np->sv_stest1   = INB(nc_stest1);
          np->sv_stest2   = INB(nc_stest2) & 0x20;
          np->sv_stest4   = INB(nc_stest4);
          if (np->features & FE_C10) {    /* Always large DMA fifo + ultra3 */
                  np->sv_scntl4   = INB(nc_scntl4);
                  np->sv_ctest5   = INB(nc_ctest5) & 0x04;
          }
          else
                  np->sv_ctest5   = INB(nc_ctest5) & 0x24;
  }
  
  /*
   *  Prepare io register values used by sym_init() according
   *  to selected and supported features.
   */
  static int sym_prepare_setting(hcb_p np, struct sym_nvram *nvram)
  {
          u_char  burst_max;
          u32     period;
          int i;
  
          /*
           *  Wide ?
           */
          np->maxwide     = (np->features & FE_WIDE)? 1 : 0;
  
          /*
           *  Get the frequency of the chip's clock.
           */
          if      (np->features & FE_QUAD)
                  np->multiplier  = 4;
          else if (np->features & FE_DBLR)
                  np->multiplier  = 2;
          else
                  np->multiplier  = 1;
  
          np->clock_khz   = (np->features & FE_CLK80)? 80000 : 40000;
          np->clock_khz   *= np->multiplier;
  
          if (np->clock_khz != 40000)
                  sym_getclock(np, np->multiplier);
  
          /*
           * Divisor to be used for async (timer pre-scaler).
           */
          i = np->clock_divn - 1;
          while (--i >= 0) {
                  if (10ul * SYM_CONF_MIN_ASYNC * np->clock_khz > div_10M[i]) {
                          ++i;
                          break;
                  }
          }
          np->rv_scntl3 = i+1;
  
          /*
           * The C1010 uses hardwired divisors for async.
           * So, we just throw away, the async. divisor.:-)
           */
          if (np->features & FE_C10)
                  np->rv_scntl3 = 0;
  
          /*
           * Minimum synchronous period factor supported by the chip.
           * Btw, 'period' is in tenths of nanoseconds.
           */
          period = (4 * div_10M[0] + np->clock_khz - 1) / np->clock_khz;
          if      (period <= 250)         np->minsync = 10;
          else if (period <= 303)         np->minsync = 11;
          else if (period <= 500)         np->minsync = 12;
          else                            np->minsync = (period + 40 - 1) / 40;
  
          /*
           * Check against chip SCSI standard support (SCSI-2,ULTRA,ULTRA2).
           */
          if      (np->minsync < 25 &&
                   !(np->features & (FE_ULTRA|FE_ULTRA2|FE_ULTRA3)))
                  np->minsync = 25;
          else if (np->minsync < 12 &&
                   !(np->features & (FE_ULTRA2|FE_ULTRA3)))
                  np->minsync = 12;
  
          /*
           * Maximum synchronous period factor supported by the chip.
           */
          period = (11 * div_10M[np->clock_divn - 1]) / (4 * np->clock_khz);
          np->maxsync = period > 2540 ? 254 : period / 10;
  
          /*
           * If chip is a C1010, guess the sync limits in DT mode.
           */
          if ((np->features & (FE_C10|FE_ULTRA3)) == (FE_C10|FE_ULTRA3)) {
                  if (np->clock_khz == 160000) {
                          np->minsync_dt = 9;
                          np->maxsync_dt = 50;
                          np->maxoffs_dt = 62;
                  }
          }
  
          /*
           *  64 bit addressing  (895A/896/1010) ?
           */
          if (np->features & FE_DAC)
  #ifdef __LP64__
                  np->rv_ccntl1   |= (XTIMOD | EXTIBMV);
  #else
                  np->rv_ccntl1   |= (DDAC);
  #endif
  
          /*
           *  Phase mismatch handled by SCRIPTS (895A/896/1010) ?
           */
          if (np->features & FE_NOPM)
                  np->rv_ccntl0   |= (ENPMJ);
  
          /*
           *  C1010 Errata.
           *  In dual channel mode, contention occurs if internal cycles
           *  are used. Disable internal cycles.
           */
          if (np->device_id == PCI_ID_LSI53C1010 &&
              np->revision_id < 0x2)
                  np->rv_ccntl0   |=  DILS;
  
          /*
           *  Select burst length (dwords)
           */
          burst_max       = SYM_SETUP_BURST_ORDER;
          if (burst_max == 255)
                  burst_max = burst_code(np->sv_dmode, np->sv_ctest4,
                                         np->sv_ctest5);
          if (burst_max > 7)
                  burst_max = 7;
          if (burst_max > np->maxburst)
                  burst_max = np->maxburst;
  
          /*
           *  DEL 352 - 53C810 Rev x11 - Part Number 609-0392140 - ITEM 2.
           *  This chip and the 860 Rev 1 may wrongly use PCI cache line
           *  based transactions on LOAD/STORE instructions. So we have
           *  to prevent these chips from using such PCI transactions in
           *  this driver. The generic ncr driver that does not use
           *  LOAD/STORE instructions does not need this work-around.
           */
          if ((np->device_id == PCI_ID_SYM53C810 &&
               np->revision_id >= 0x10 && np->revision_id <= 0x11) ||
              (np->device_id == PCI_ID_SYM53C860 &&
               np->revision_id <= 0x1))
                  np->features &= ~(FE_WRIE|FE_ERL|FE_ERMP);
  
          /*
           *  Select all supported special features.
           *  If we are using on-board RAM for scripts, prefetch (PFEN)
           *  does not help, but burst op fetch (BOF) does.
           *  Disabling PFEN makes sure BOF will be used.
           */
          if (np->features & FE_ERL)
                  np->rv_dmode    |= ERL;         /* Enable Read Line */
          if (np->features & FE_BOF)
                  np->rv_dmode    |= BOF;         /* Burst Opcode Fetch */
          if (np->features & FE_ERMP)
                  np->rv_dmode    |= ERMP;        /* Enable Read Multiple */
  #if 1
          if ((np->features & FE_PFEN) && !np->ram_ba)
  #else
          if (np->features & FE_PFEN)
  #endif
                  np->rv_dcntl    |= PFEN;        /* Prefetch Enable */
          if (np->features & FE_CLSE)
                  np->rv_dcntl    |= CLSE;        /* Cache Line Size Enable */
          if (np->features & FE_WRIE)
                  np->rv_ctest3   |= WRIE;        /* Write and Invalidate */
          if (np->features & FE_DFS)
                  np->rv_ctest5   |= DFS;         /* Dma Fifo Size */
  
          /*
           *  Select some other
           */
          if (SYM_SETUP_PCI_PARITY)
                  np->rv_ctest4   |= MPEE; /* Master parity checking */
          if (SYM_SETUP_SCSI_PARITY)
                  np->rv_scntl0   |= 0x0a; /*  full arb., ena parity, par->ATN  */
  
          /*
           *  Get parity checking, host ID and verbose mode from NVRAM
           */
          np->myaddr = 255;
          sym_nvram_setup_host (np, nvram);
  
          /*
           *  Get SCSI addr of host adapter (set by bios?).
           */
          if (np->myaddr == 255) {
                  np->myaddr = INB(nc_scid) & 0x07;
                  if (!np->myaddr)
                          np->myaddr = SYM_SETUP_HOST_ID;
          }
  
          /*
           *  Prepare initial io register bits for burst length
           */
          sym_init_burst(np, burst_max);
  
          /*
           *  Set SCSI BUS mode.
           *  - LVD capable chips (895/895A/896/1010) report the
           *    current BUS mode through the STEST4 IO register.
           *  - For previous generation chips (825/825A/875),
           *    user has to tell us how to check against HVD,
           *    since a 100% safe algorithm is not possible.
           */
          np->scsi_mode = SMODE_SE;
          if (np->features & (FE_ULTRA2|FE_ULTRA3))
                  np->scsi_mode = (np->sv_stest4 & SMODE);
          else if (np->features & FE_DIFF) {
                  if (SYM_SETUP_SCSI_DIFF == 1) {
                          if (np->sv_scntl3) {
                                  if (np->sv_stest2 & 0x20)
                                          np->scsi_mode = SMODE_HVD;
                          }
                          else if (nvram->type == SYM_SYMBIOS_NVRAM) {
                                  if (!(INB(nc_gpreg) & 0x08))
                                          np->scsi_mode = SMODE_HVD;
                          }
                  }
                  else if (SYM_SETUP_SCSI_DIFF == 2)
                          np->scsi_mode = SMODE_HVD;
          }
          if (np->scsi_mode == SMODE_HVD)
                  np->rv_stest2 |= 0x20;
  
          /*
           *  Set LED support from SCRIPTS.
           *  Ignore this feature for boards known to use a
           *  specific GPIO wiring and for the 895A, 896
           *  and 1010 that drive the LED directly.
           */
          if ((SYM_SETUP_SCSI_LED ||
               (nvram->type == SYM_SYMBIOS_NVRAM ||
                (nvram->type == SYM_TEKRAM_NVRAM &&
                 np->device_id == PCI_ID_SYM53C895))) &&
              !(np->features & FE_LEDC) && !(np->sv_gpcntl & 0x01))
                  np->features |= FE_LED0;
  
          /*
           *  Set irq mode.
           */
          switch(SYM_SETUP_IRQ_MODE & 3) {
          case 2:
                  np->rv_dcntl    |= IRQM;
                  break;
          case 1:
                  np->rv_dcntl    |= (np->sv_dcntl & IRQM);
                  break;
          default:
                  break;
          }
  
          /*
           *  Configure targets according to driver setup.
           *  If NVRAM present get targets setup from NVRAM.
           */
          for (i = 0 ; i < SYM_CONF_MAX_TARGET ; i++) {
                  tcb_p tp = &np->target[i];
  
  #ifdef  FreeBSD_New_Tran_Settings
                  tp->tinfo.user.scsi_version = tp->tinfo.current.scsi_version= 2;
                  tp->tinfo.user.spi_version  = tp->tinfo.current.spi_version = 2;
  #endif
                  tp->tinfo.user.period = np->minsync;
                  if (np->features & FE_ULTRA3)
                          tp->tinfo.user.period = np->minsync_dt;
                  tp->tinfo.user.offset = np->maxoffs;
                  tp->tinfo.user.width  = np->maxwide ? BUS_16_BIT : BUS_8_BIT;
                  tp->usrflags |= (SYM_DISC_ENABLED | SYM_TAGS_ENABLED);
                  tp->usrtags = SYM_SETUP_MAX_TAG;
  
                  sym_nvram_setup_target (np, i, nvram);
  
                  /*
                   *  For now, guess PPR/DT support from the period
                   *  and BUS width.
                   */
                  if (np->features & FE_ULTRA3) {
                          if (tp->tinfo.user.period <= 9  &&
                              tp->tinfo.user.width == BUS_16_BIT) {
                                  tp->tinfo.user.options |= PPR_OPT_DT;
                                  tp->tinfo.user.offset   = np->maxoffs_dt;
  #ifdef  FreeBSD_New_Tran_Settings
                                  tp->tinfo.user.spi_version = 3;
  #endif
                          }
                  }
  
                  if (!tp->usrtags)
                          tp->usrflags &= ~SYM_TAGS_ENABLED;
          }
  
          /*
           *  Let user know about the settings.
           */
          i = nvram->type;
          printf("%s: %s NVRAM, ID %d, Fast-%d, %s, %s\n", sym_name(np),
                  i  == SYM_SYMBIOS_NVRAM ? "Symbios" :
                  (i == SYM_TEKRAM_NVRAM  ? "Tekram" : "No"),
                  np->myaddr,
                  (np->features & FE_ULTRA3) ? 80 :
                  (np->features & FE_ULTRA2) ? 40 :
                  (np->features & FE_ULTRA)  ? 20 : 10,
                  sym_scsi_bus_mode(np->scsi_mode),
                  (np->rv_scntl0 & 0xa)   ? "parity checking" : "NO parity");
          /*
           *  Tell him more on demand.
           */
          if (sym_verbose) {
                  printf("%s: %s IRQ line driver%s\n",
                          sym_name(np),
                          np->rv_dcntl & IRQM ? "totem pole" : "open drain",
                          np->ram_ba ? ", using on-chip SRAM" : "");
                  printf("%s: using %s firmware.\n", sym_name(np), np->fw_name);
                  if (np->features & FE_NOPM)
                          printf("%s: handling phase mismatch from SCRIPTS.\n",
                                 sym_name(np));
          }
          /*
           *  And still more.
           */
          if (sym_verbose > 1) {
                  printf ("%s: initial SCNTL3/DMODE/DCNTL/CTEST3/4/5 = "
                          "(hex) %02x/%02x/%02x/%02x/%02x/%02x\n",
                          sym_name(np), np->sv_scntl3, np->sv_dmode, np->sv_dcntl,
                          np->sv_ctest3, np->sv_ctest4, np->sv_ctest5);
  
                  printf ("%s: final   SCNTL3/DMODE/DCNTL/CTEST3/4/5 = "
                          "(hex) %02x/%02x/%02x/%02x/%02x/%02x\n",
                          sym_name(np), np->rv_scntl3, np->rv_dmode, np->rv_dcntl,
                          np->rv_ctest3, np->rv_ctest4, np->rv_ctest5);
          }
          /*
           *  Let user be aware of targets that have some disable flags set.
           */
          sym_print_targets_flag(np, SYM_SCAN_BOOT_DISABLED, "SCAN AT BOOT");
          if (sym_verbose)
                  sym_print_targets_flag(np, SYM_SCAN_LUNS_DISABLED,
                                         "SCAN FOR LUNS");
  
          return 0;
  }
  
  /*
   *  Prepare the next negotiation message if needed.
   *
   *  Fill in the part of message buffer that contains the
   *  negotiation and the nego_status field of the CCB.
   *  Returns the size of the message in bytes.
   */
  
  static int sym_prepare_nego(hcb_p np, ccb_p cp, int nego, u_char *msgptr)
  {
          tcb_p tp = &np->target[cp->target];
          int msglen = 0;
  
          /*
           *  Early C1010 chips need a work-around for DT
           *  data transfer to work.
           */
          if (!(np->features & FE_U3EN))
                  tp->tinfo.goal.options = 0;
          /*
           *  negotiate using PPR ?
           */
          if (tp->tinfo.goal.options & PPR_OPT_MASK)
                  nego = NS_PPR;
          /*
           *  negotiate wide transfers ?
           */
          else if (tp->tinfo.current.width != tp->tinfo.goal.width)
                  nego = NS_WIDE;
          /*
           *  negotiate synchronous transfers?
           */
          else if (tp->tinfo.current.period != tp->tinfo.goal.period ||
                   tp->tinfo.current.offset != tp->tinfo.goal.offset)
                  nego = NS_SYNC;
  
          switch (nego) {
          case NS_SYNC:
                  msgptr[msglen++] = M_EXTENDED;
                  msgptr[msglen++] = 3;
                  msgptr[msglen++] = M_X_SYNC_REQ;
                  msgptr[msglen++] = tp->tinfo.goal.period;
                  msgptr[msglen++] = tp->tinfo.goal.offset;
                  break;
          case NS_WIDE:
                  msgptr[msglen++] = M_EXTENDED;
                  msgptr[msglen++] = 2;
                  msgptr[msglen++] = M_X_WIDE_REQ;
                  msgptr[msglen++] = tp->tinfo.goal.width;
                  break;
          case NS_PPR:
                  msgptr[msglen++] = M_EXTENDED;
                  msgptr[msglen++] = 6;
                  msgptr[msglen++] = M_X_PPR_REQ;
                  msgptr[msglen++] = tp->tinfo.goal.period;
                  msgptr[msglen++] = 0;
                  msgptr[msglen++] = tp->tinfo.goal.offset;
                  msgptr[msglen++] = tp->tinfo.goal.width;
                  msgptr[msglen++] = tp->tinfo.goal.options & PPR_OPT_DT;
                  break;
          };
  
          cp->nego_status = nego;
  
          if (nego) {
                  tp->nego_cp = cp; /* Keep track a nego will be performed */
                  if (DEBUG_FLAGS & DEBUG_NEGO) {
                          sym_print_msg(cp, nego == NS_SYNC ? "sync msgout" :
                                            nego == NS_WIDE ? "wide msgout" :
                                            "ppr msgout", msgptr);
                  };
          };
  
          return msglen;
  }
  
  /*
   *  Insert a job into the start queue.
   */
  static void sym_put_start_queue(hcb_p np, ccb_p cp)
  {
          u_short qidx;
  
  #ifdef SYM_CONF_IARB_SUPPORT
          /*
           *  If the previously queued CCB is not yet done,
           *  set the IARB hint. The SCRIPTS will go with IARB
           *  for this job when starting the previous one.
           *  We leave devices a chance to win arbitration by
           *  not using more than 'iarb_max' consecutive
           *  immediate arbitrations.
           */
          if (np->last_cp && np->iarb_count < np->iarb_max) {
                  np->last_cp->host_flags |= HF_HINT_IARB;
                  ++np->iarb_count;
          }
          else
                  np->iarb_count = 0;
          np->last_cp = cp;
  #endif
  
          /*
           *  Insert first the idle task and then our job.
           *  The MB should ensure proper ordering.
           */
          qidx = np->squeueput + 2;
          if (qidx >= MAX_QUEUE*2) qidx = 0;
  
          np->squeue [qidx]          = cpu_to_scr(np->idletask_ba);
          MEMORY_BARRIER();
          np->squeue [np->squeueput] = cpu_to_scr(cp->ccb_ba);
  
          np->squeueput = qidx;
  
          if (DEBUG_FLAGS & DEBUG_QUEUE)
                  printf ("%s: queuepos=%d.\n", sym_name (np), np->squeueput);
  
          /*
           *  Script processor may be waiting for reselect.
           *  Wake it up.
           */
          MEMORY_BARRIER();
          OUTB (nc_istat, SIGP|np->istat_sem);
  }
  
  
  /*
   *  Soft reset the chip.
   *
   *  Raising SRST when the chip is running may cause
   *  problems on dual function chips (see below).
   *  On the other hand, LVD devices need some delay
   *  to settle and report actual BUS mode in STEST4.
   */
  static void sym_chip_reset (hcb_p np)
  {
          OUTB (nc_istat, SRST);
          UDELAY (10);
          OUTB (nc_istat, 0);
          UDELAY(2000);   /* For BUS MODE to settle */
  }
  
  /*
   *  Soft reset the chip.
   *
   *  Some 896 and 876 chip revisions may hang-up if we set
   *  the SRST (soft reset) bit at the wrong time when SCRIPTS
   *  are running.
   *  So, we need to abort the current operation prior to
   *  soft resetting the chip.
   */
  static void sym_soft_reset (hcb_p np)
  {
          u_char istat;
          int i;
  
          OUTB (nc_istat, CABRT);
          for (i = 1000000 ; i ; --i) {
                  istat = INB (nc_istat);
                  if (istat & SIP) {
                          INW (nc_sist);
                          continue;
                  }
                  if (istat & DIP) {
                          OUTB (nc_istat, 0);
                          INB (nc_dstat);
                          break;
                  }
          }
          if (!i)
                  printf("%s: unable to abort current chip operation.\n",
                          sym_name(np));
          sym_chip_reset (np);
  }
  
  /*
   *  Start reset process.
   *
   *  The interrupt handler will reinitialize the chip.
   */
  static void sym_start_reset(hcb_p np)
  {
          (void) sym_reset_scsi_bus(np, 1);
  }
  
  static int sym_reset_scsi_bus(hcb_p np, int enab_int)
  {
          u32 term;
          int retv = 0;
  
          sym_soft_reset(np);     /* Soft reset the chip */
          if (enab_int)
                  OUTW (nc_sien, RST);
          /*
           *  Enable Tolerant, reset IRQD if present and
           *  properly set IRQ mode, prior to resetting the bus.
           */
          OUTB (nc_stest3, TE);
          OUTB (nc_dcntl, (np->rv_dcntl & IRQM));
          OUTB (nc_scntl1, CRST);
          UDELAY (200);
  
          if (!SYM_SETUP_SCSI_BUS_CHECK)
                  goto out;
          /*
           *  Check for no terminators or SCSI bus shorts to ground.
           *  Read SCSI data bus, data parity bits and control signals.
           *  We are expecting RESET to be TRUE and other signals to be
           *  FALSE.
           */
          term =  INB(nc_sstat0);
          term =  ((term & 2) << 7) + ((term & 1) << 17); /* rst sdp0 */
          term |= ((INB(nc_sstat2) & 0x01) << 26) |       /* sdp1     */
                  ((INW(nc_sbdl) & 0xff)   << 9)  |       /* d7-0     */
                  ((INW(nc_sbdl) & 0xff00) << 10) |       /* d15-8    */
                  INB(nc_sbcl);   /* req ack bsy sel atn msg cd io    */
  
          if (!(np->features & FE_WIDE))
                  term &= 0x3ffff;
  
          if (term != (2<<7)) {
                  printf("%s: suspicious SCSI data while resetting the BUS.\n",
                          sym_name(np));
                  printf("%s: %sdp0,d7-0,rst,req,ack,bsy,sel,atn,msg,c/d,i/o = "
                          "0x%lx, expecting 0x%lx\n",
                          sym_name(np),
                          (np->features & FE_WIDE) ? "dp1,d15-8," : "",
                          (u_long)term, (u_long)(2<<7));
                  if (SYM_SETUP_SCSI_BUS_CHECK == 1)
                          retv = 1;
          }
  out:
          OUTB (nc_scntl1, 0);
          /* MDELAY(100); */
          return retv;
  }
  
  /*
   *  The chip may have completed jobs. Look at the DONE QUEUE.
   *
   *  On architectures that may reorder LOAD/STORE operations,
   *  a memory barrier may be needed after the reading of the
   *  so-called `flag' and prior to dealing with the data.
   */
  static int sym_wakeup_done (hcb_p np)
  {
          ccb_p cp;
          int i, n;
          u32 dsa;
  
          n = 0;
          i = np->dqueueget;
          while (1) {
                  dsa = scr_to_cpu(np->dqueue[i]);
                  if (!dsa)
                          break;
                  np->dqueue[i] = 0;
                  if ((i = i+2) >= MAX_QUEUE*2)
                          i = 0;
  
                  cp = sym_ccb_from_dsa(np, dsa);
                  if (cp) {
                          MEMORY_BARRIER();
                          sym_complete_ok (np, cp);
                          ++n;
                  }
                  else
                          printf ("%s: bad DSA (%x) in done queue.\n",
                                  sym_name(np), (u_int) dsa);
          }
          np->dqueueget = i;
  
          return n;
  }
  
  /*
   *  Complete all active CCBs with error.
   *  Used on CHIP/SCSI RESET.
   */
  static void sym_flush_busy_queue (hcb_p np, int cam_status)
  {
          /*
           *  Move all active CCBs to the COMP queue
           *  and flush this queue.
           */
          sym_que_splice(&np->busy_ccbq, &np->comp_ccbq);
          sym_que_init(&np->busy_ccbq);
          sym_flush_comp_queue(np, cam_status);
  }
  
  /*
   *  Start chip.
   *
   *  'reason' means:
   *     0: initialisation.
   *     1: SCSI BUS RESET delivered or received.
   *     2: SCSI BUS MODE changed.
   */
  static void sym_init (hcb_p np, int reason)
  {
          int     i;
          u32     phys;
  
          /*
           *  Reset chip if asked, otherwise just clear fifos.
           */
          if (reason == 1)
                  sym_soft_reset(np);
          else {
                  OUTB (nc_stest3, TE|CSF);
                  OUTONB (nc_ctest3, CLF);
          }
  
          /*
           *  Clear Start Queue
           */
          phys = np->squeue_ba;
          for (i = 0; i < MAX_QUEUE*2; i += 2) {
                  np->squeue[i]   = cpu_to_scr(np->idletask_ba);
                  np->squeue[i+1] = cpu_to_scr(phys + (i+2)*4);
          }
          np->squeue[MAX_QUEUE*2-1] = cpu_to_scr(phys);
  
          /*
           *  Start at first entry.
           */
          np->squeueput = 0;
  
          /*
           *  Clear Done Queue
           */
          phys = np->dqueue_ba;
          for (i = 0; i < MAX_QUEUE*2; i += 2) {
                  np->dqueue[i]   = 0;
                  np->dqueue[i+1] = cpu_to_scr(phys + (i+2)*4);
          }
          np->dqueue[MAX_QUEUE*2-1] = cpu_to_scr(phys);
  
          /*
           *  Start at first entry.
           */
          np->dqueueget = 0;
  
          /*
           *  Install patches in scripts.
           *  This also let point to first position the start
           *  and done queue pointers used from SCRIPTS.
           */
          np->fw_patch(np);
  
          /*
           *  Wakeup all pending jobs.
           */
          sym_flush_busy_queue(np, CAM_SCSI_BUS_RESET);
  
          /*
           *  Init chip.
           */
          OUTB (nc_istat,  0x00   );      /*  Remove Reset, abort */
          UDELAY (2000);  /* The 895 needs time for the bus mode to settle */
  
          OUTB (nc_scntl0, np->rv_scntl0 | 0xc0);
                                          /*  full arb., ena parity, par->ATN  */
          OUTB (nc_scntl1, 0x00);         /*  odd parity, and remove CRST!! */
  
          sym_selectclock(np, np->rv_scntl3);     /* Select SCSI clock */
  
          OUTB (nc_scid  , RRE|np->myaddr);       /* Adapter SCSI address */
          OUTW (nc_respid, 1ul<<np->myaddr);      /* Id to respond to */
          OUTB (nc_istat , SIGP   );              /*  Signal Process */
          OUTB (nc_dmode , np->rv_dmode);         /* Burst length, dma mode */
          OUTB (nc_ctest5, np->rv_ctest5);        /* Large fifo + large burst */
  
          OUTB (nc_dcntl , NOCOM|np->rv_dcntl);   /* Protect SFBR */
          OUTB (nc_ctest3, np->rv_ctest3);        /* Write and invalidate */
          OUTB (nc_ctest4, np->rv_ctest4);        /* Master parity checking */
  
          /* Extended Sreq/Sack filtering not supported on the C10 */
          if (np->features & FE_C10)
                  OUTB (nc_stest2, np->rv_stest2);
          else
                  OUTB (nc_stest2, EXT|np->rv_stest2);
  
          OUTB (nc_stest3, TE);                   /* TolerANT enable */
          OUTB (nc_stime0, 0x0c);                 /* HTH disabled  STO 0.25 sec */
  
          /*
           *  For now, disable AIP generation on C1010-66.
           */
          if (np->device_id == PCI_ID_LSI53C1010_2)
                  OUTB (nc_aipcntl1, DISAIP);
  
          /*
           *  C10101 Errata.
           *  Errant SGE's when in narrow. Write bits 4 & 5 of
           *  STEST1 register to disable SGE. We probably should do
           *  that from SCRIPTS for each selection/reselection, but
           *  I just don't want. :)
           */
          if (np->device_id == PCI_ID_LSI53C1010 &&
              /* np->revision_id < 0xff */ 1)
                  OUTB (nc_stest1, INB(nc_stest1) | 0x30);
  
          /*
           *  DEL 441 - 53C876 Rev 5 - Part Number 609-0392787/2788 - ITEM 2.
           *  Disable overlapped arbitration for some dual function devices,
           *  regardless revision id (kind of post-chip-design feature. ;-))
           */
          if (np->device_id == PCI_ID_SYM53C875)
                  OUTB (nc_ctest0, (1<<5));
          else if (np->device_id == PCI_ID_SYM53C896)
                  np->rv_ccntl0 |= DPR;
  
          /*
           *  Write CCNTL0/CCNTL1 for chips capable of 64 bit addressing
           *  and/or hardware phase mismatch, since only such chips
           *  seem to support those IO registers.
           */
          if (np->features & (FE_DAC|FE_NOPM)) {
                  OUTB (nc_ccntl0, np->rv_ccntl0);
                  OUTB (nc_ccntl1, np->rv_ccntl1);
          }
  
          /*
           *  If phase mismatch handled by scripts (895A/896/1010),
           *  set PM jump addresses.
           */
          if (np->features & FE_NOPM) {
                  OUTL (nc_pmjad1, SCRIPTB_BA (np, pm_handle));
                  OUTL (nc_pmjad2, SCRIPTB_BA (np, pm_handle));
          }
  
          /*
           *    Enable GPIO0 pin for writing if LED support from SCRIPTS.
           *    Also set GPIO5 and clear GPIO6 if hardware LED control.
           */
          if (np->features & FE_LED0)
                  OUTB(nc_gpcntl, INB(nc_gpcntl) & ~0x01);
          else if (np->features & FE_LEDC)
                  OUTB(nc_gpcntl, (INB(nc_gpcntl) & ~0x41) | 0x20);
  
          /*
           *      enable ints
           */
          OUTW (nc_sien , STO|HTH|MA|SGE|UDC|RST|PAR);
          OUTB (nc_dien , MDPE|BF|SSI|SIR|IID);
  
          /*
           *  For 895/6 enable SBMC interrupt and save current SCSI bus mode.
           *  Try to eat the spurious SBMC interrupt that may occur when
           *  we reset the chip but not the SCSI BUS (at initialization).
           */
          if (np->features & (FE_ULTRA2|FE_ULTRA3)) {
                  OUTONW (nc_sien, SBMC);
                  if (reason == 0) {
                          MDELAY(100);
                          INW (nc_sist);
                  }
                  np->scsi_mode = INB (nc_stest4) & SMODE;
          }
  
          /*
           *  Fill in target structure.
           *  Reinitialize usrsync.
           *  Reinitialize usrwide.
           *  Prepare sync negotiation according to actual SCSI bus mode.
           */
          for (i=0;i<SYM_CONF_MAX_TARGET;i++) {
                  tcb_p tp = &np->target[i];
  
                  tp->to_reset  = 0;
                  tp->head.sval = 0;
                  tp->head.wval = np->rv_scntl3;
                  tp->head.uval = 0;
  
                  tp->tinfo.current.period = 0;
                  tp->tinfo.current.offset = 0;
                  tp->tinfo.current.width  = BUS_8_BIT;
                  tp->tinfo.current.options = 0;
          }
  
          /*
           *  Download SCSI SCRIPTS to on-chip RAM if present,
           *  and start script processor.
           */
          if (np->ram_ba) {
                  if (sym_verbose > 1)
                          printf ("%s: Downloading SCSI SCRIPTS.\n",
                                  sym_name(np));
                  if (np->ram_ws == 8192) {
                          OUTRAM_OFF(4096, np->scriptb0, np->scriptb_sz);
                          OUTL (nc_mmws, np->scr_ram_seg);
                          OUTL (nc_mmrs, np->scr_ram_seg);
                          OUTL (nc_sfs,  np->scr_ram_seg);
                          phys = SCRIPTB_BA (np, start64);
                  }
                  else
                          phys = SCRIPTA_BA (np, init);
                  OUTRAM_OFF(0, np->scripta0, np->scripta_sz);
          }
          else
                  phys = SCRIPTA_BA (np, init);
  
          np->istat_sem = 0;
  
          OUTL (nc_dsa, np->hcb_ba);
          OUTL_DSP (phys);
  
          /*
           *  Notify the XPT about the RESET condition.
           */
          if (reason != 0)
                  xpt_async(AC_BUS_RESET, np->path, NULL);
  }
  
  /*
   *  Get clock factor and sync divisor for a given
   *  synchronous factor period.
   */
  static int
  sym_getsync(hcb_p np, u_char dt, u_char sfac, u_char *divp, u_char *fakp)
  {
          u32     clk = np->clock_khz;    /* SCSI clock frequency in kHz  */
          int     div = np->clock_divn;   /* Number of divisors supported */
          u32     fak;                    /* Sync factor in sxfer         */
          u32     per;                    /* Period in tenths of ns       */
          u32     kpc;                    /* (per * clk)                  */
          int     ret;
  
          /*
           *  Compute the synchronous period in tenths of nano-seconds
           */
          if (dt && sfac <= 9)    per = 125;
          else if (sfac <= 10)    per = 250;
          else if (sfac == 11)    per = 303;
          else if (sfac == 12)    per = 500;
          else                    per = 40 * sfac;
          ret = per;
  
          kpc = per * clk;
          if (dt)
                  kpc <<= 1;
  
          /*
           *  For earliest C10 revision 0, we cannot use extra
           *  clocks for the setting of the SCSI clocking.
           *  Note that this limits the lowest sync data transfer
           *  to 5 Mega-transfers per second and may result in
           *  using higher clock divisors.
           */
  #if 1
          if ((np->features & (FE_C10|FE_U3EN)) == FE_C10) {
                  /*
                   *  Look for the lowest clock divisor that allows an
                   *  output speed not faster than the period.
                   */
                  while (div > 0) {
                          --div;
                          if (kpc > (div_10M[div] << 2)) {
                                  ++div;
                                  break;
                          }
                  }
                  fak = 0;                        /* No extra clocks */
                  if (div == np->clock_divn) {    /* Are we too fast ? */
                          ret = -1;
                  }
                  *divp = div;
                  *fakp = fak;
                  return ret;
          }
  #endif
  
          /*
           *  Look for the greatest clock divisor that allows an
           *  input speed faster than the period.
           */
          while (div-- > 0)
                  if (kpc >= (div_10M[div] << 2)) break;
  
          /*
           *  Calculate the lowest clock factor that allows an output
           *  speed not faster than the period, and the max output speed.
           *  If fak >= 1 we will set both XCLKH_ST and XCLKH_DT.
           *  If fak >= 2 we will also set XCLKS_ST and XCLKS_DT.
           */
          if (dt) {
                  fak = (kpc - 1) / (div_10M[div] << 1) + 1 - 2;
                  /* ret = ((2+fak)*div_10M[div])/np->clock_khz; */
          }
          else {
                  fak = (kpc - 1) / div_10M[div] + 1 - 4;
                  /* ret = ((4+fak)*div_10M[div])/np->clock_khz; */
          }
  
          /*
           *  Check against our hardware limits, or bugs :).
           */
          if (fak < 0)    {fak = 0; ret = -1;}
          if (fak > 2)    {fak = 2; ret = -1;}
  
          /*
           *  Compute and return sync parameters.
           */
          *divp = div;
          *fakp = fak;
  
          return ret;
  }
  
  /*
   *  Tell the SCSI layer about the new transfer parameters.
   */
  static void
  sym_xpt_async_transfer_neg(hcb_p np, int target, u_int spi_valid)
  {
          struct ccb_trans_settings cts;
          struct cam_path *path;
          int sts;
          tcb_p tp = &np->target[target];
  
          sts = xpt_create_path(&path, NULL, cam_sim_path(np->sim), target,
                                CAM_LUN_WILDCARD);
          if (sts != CAM_REQ_CMP)
                  return;
  
          bzero(&cts, sizeof(cts));
  
  #ifdef  FreeBSD_New_Tran_Settings
  #define cts__scsi (cts.proto_specific.scsi)
  #define cts__spi  (cts.xport_specific.spi)
  
          cts.type      = CTS_TYPE_CURRENT_SETTINGS;
          cts.protocol  = PROTO_SCSI;
          cts.transport = XPORT_SPI;
          cts.protocol_version  = tp->tinfo.current.scsi_version;
          cts.transport_version = tp->tinfo.current.spi_version;
  
          cts__spi.valid = spi_valid;
          if (spi_valid & CTS_SPI_VALID_SYNC_RATE)
                  cts__spi.sync_period = tp->tinfo.current.period;
          if (spi_valid & CTS_SPI_VALID_SYNC_OFFSET)
                  cts__spi.sync_offset = tp->tinfo.current.offset;
          if (spi_valid & CTS_SPI_VALID_BUS_WIDTH)
                  cts__spi.bus_width   = tp->tinfo.current.width;
          if (spi_valid & CTS_SPI_VALID_PPR_OPTIONS)
                  cts__spi.ppr_options = tp->tinfo.current.options;
  #undef cts__spi
  #undef cts__scsi
  #else
          cts.valid = spi_valid;
          if (spi_valid & CCB_TRANS_SYNC_RATE_VALID)
                  cts.sync_period = tp->tinfo.current.period;
          if (spi_valid & CCB_TRANS_SYNC_OFFSET_VALID)
                  cts.sync_offset = tp->tinfo.current.offset;
          if (spi_valid & CCB_TRANS_BUS_WIDTH_VALID)
                  cts.bus_width   = tp->tinfo.current.width;
  #endif
          xpt_setup_ccb(&cts.ccb_h, path, /*priority*/1);
          xpt_async(AC_TRANSFER_NEG, path, &cts);
          xpt_free_path(path);
  }
  
  #ifdef  FreeBSD_New_Tran_Settings
  #define SYM_SPI_VALID_WDTR              \
          CTS_SPI_VALID_BUS_WIDTH |       \
          CTS_SPI_VALID_SYNC_RATE |       \
          CTS_SPI_VALID_SYNC_OFFSET
  #define SYM_SPI_VALID_SDTR              \
          CTS_SPI_VALID_SYNC_RATE |       \
          CTS_SPI_VALID_SYNC_OFFSET
  #define SYM_SPI_VALID_PPR               \
          CTS_SPI_VALID_PPR_OPTIONS |     \
          CTS_SPI_VALID_BUS_WIDTH |       \
          CTS_SPI_VALID_SYNC_RATE |       \
          CTS_SPI_VALID_SYNC_OFFSET
  #else
  #define SYM_SPI_VALID_WDTR              \
          CCB_TRANS_BUS_WIDTH_VALID |     \
          CCB_TRANS_SYNC_RATE_VALID |     \
          CCB_TRANS_SYNC_OFFSET_VALID
  #define SYM_SPI_VALID_SDTR              \
          CCB_TRANS_SYNC_RATE_VALID |     \
          CCB_TRANS_SYNC_OFFSET_VALID
  #define SYM_SPI_VALID_PPR               \
          CCB_TRANS_BUS_WIDTH_VALID |     \
          CCB_TRANS_SYNC_RATE_VALID |     \
          CCB_TRANS_SYNC_OFFSET_VALID
  #endif
  
  /*
   *  We received a WDTR.
   *  Let everything be aware of the changes.
   */
  static void sym_setwide(hcb_p np, ccb_p cp, u_char wide)
  {
          tcb_p tp = &np->target[cp->target];
  
          sym_settrans(np, cp, 0, 0, 0, wide, 0, 0);
  
          /*
           *  Tell the SCSI layer about the new transfer parameters.
           */
          tp->tinfo.goal.width = tp->tinfo.current.width = wide;
          tp->tinfo.current.offset = 0;
          tp->tinfo.current.period = 0;
          tp->tinfo.current.options = 0;
  
          sym_xpt_async_transfer_neg(np, cp->target, SYM_SPI_VALID_WDTR);
  }
  
  /*
   *  We received a SDTR.
   *  Let everything be aware of the changes.
   */
  static void
  sym_setsync(hcb_p np, ccb_p cp, u_char ofs, u_char per, u_char div, u_char fak)
  {
          tcb_p tp = &np->target[cp->target];
          u_char wide = (cp->phys.select.sel_scntl3 & EWS) ? 1 : 0;
  
          sym_settrans(np, cp, 0, ofs, per, wide, div, fak);
  
          /*
           *  Tell the SCSI layer about the new transfer parameters.
           */
          tp->tinfo.goal.period   = tp->tinfo.current.period  = per;
          tp->tinfo.goal.offset   = tp->tinfo.current.offset  = ofs;
          tp->tinfo.goal.options  = tp->tinfo.current.options = 0;
  
          sym_xpt_async_transfer_neg(np, cp->target, SYM_SPI_VALID_SDTR);
  }
  
  /*
   *  We received a PPR.
   *  Let everything be aware of the changes.
   */
  static void sym_setpprot(hcb_p np, ccb_p cp, u_char dt, u_char ofs,
                           u_char per, u_char wide, u_char div, u_char fak)
  {
          tcb_p tp = &np->target[cp->target];
  
          sym_settrans(np, cp, dt, ofs, per, wide, div, fak);
  
          /*
           *  Tell the SCSI layer about the new transfer parameters.
           */
          tp->tinfo.goal.width    = tp->tinfo.current.width  = wide;
          tp->tinfo.goal.period   = tp->tinfo.current.period = per;
          tp->tinfo.goal.offset   = tp->tinfo.current.offset = ofs;
          tp->tinfo.goal.options  = tp->tinfo.current.options = dt;
  
          sym_xpt_async_transfer_neg(np, cp->target, SYM_SPI_VALID_PPR);
  }
  
  /*
   *  Switch trans mode for current job and it's target.
   */
  static void sym_settrans(hcb_p np, ccb_p cp, u_char dt, u_char ofs,
                           u_char per, u_char wide, u_char div, u_char fak)
  {
          SYM_QUEHEAD *qp;
          union   ccb *ccb;
          tcb_p tp;
          u_char target = INB (nc_sdid) & 0x0f;
          u_char sval, wval, uval;
  
          assert (cp);
          if (!cp) return;
          ccb = cp->cam_ccb;
          assert (ccb);
          if (!ccb) return;
          assert (target == (cp->target & 0xf));
          tp = &np->target[target];
  
          sval = tp->head.sval;
          wval = tp->head.wval;
          uval = tp->head.uval;
  
  #if 0
          printf("XXXX sval=%x wval=%x uval=%x (%x)\n",
                  sval, wval, uval, np->rv_scntl3);
  #endif
          /*
           *  Set the offset.
           */
          if (!(np->features & FE_C10))
                  sval = (sval & ~0x1f) | ofs;
          else
                  sval = (sval & ~0x3f) | ofs;
  
          /*
           *  Set the sync divisor and extra clock factor.
           */
          if (ofs != 0) {
                  wval = (wval & ~0x70) | ((div+1) << 4);
                  if (!(np->features & FE_C10))
                          sval = (sval & ~0xe0) | (fak << 5);
                  else {
                          uval = uval & ~(XCLKH_ST|XCLKH_DT|XCLKS_ST|XCLKS_DT);
                          if (fak >= 1) uval |= (XCLKH_ST|XCLKH_DT);
                          if (fak >= 2) uval |= (XCLKS_ST|XCLKS_DT);
                  }
          }
  
          /*
           *  Set the bus width.
           */
          wval = wval & ~EWS;
          if (wide != 0)
                  wval |= EWS;
  
          /*
           *  Set misc. ultra enable bits.
           */
          if (np->features & FE_C10) {
                  uval = uval & ~(U3EN|AIPCKEN);
                  if (dt) {
                          assert(np->features & FE_U3EN);
                          uval |= U3EN;
                  }
          }
          else {
                  wval = wval & ~ULTRA;
                  if (per <= 12)  wval |= ULTRA;
          }
  
          /*
           *   Stop there if sync parameters are unchanged.
           */
          if (tp->head.sval == sval &&
              tp->head.wval == wval &&
              tp->head.uval == uval)
                  return;
          tp->head.sval = sval;
          tp->head.wval = wval;
          tp->head.uval = uval;
  
          /*
           *  Disable extended Sreq/Sack filtering if per < 50.
           *  Not supported on the C1010.
           */
          if (per < 50 && !(np->features & FE_C10))
                  OUTOFFB (nc_stest2, EXT);
  
          /*
           *  set actual value and sync_status
           */
          OUTB (nc_sxfer,  tp->head.sval);
          OUTB (nc_scntl3, tp->head.wval);
  
          if (np->features & FE_C10) {
                  OUTB (nc_scntl4, tp->head.uval);
          }
  
          /*
           *  patch ALL busy ccbs of this target.
           */
          FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
                  cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
                  if (cp->target != target)
                          continue;
                  cp->phys.select.sel_scntl3 = tp->head.wval;
                  cp->phys.select.sel_sxfer  = tp->head.sval;
                  if (np->features & FE_C10) {
                          cp->phys.select.sel_scntl4 = tp->head.uval;
                  }
          }
  }
  
  /*
   *  log message for real hard errors
   *
   *  sym0 targ 0?: ERROR (ds:si) (so-si-sd) (sxfer/scntl3) @ name (dsp:dbc).
   *            reg: r0 r1 r2 r3 r4 r5 r6 ..... rf.
   *
   *  exception register:
   *      ds:     dstat
   *      si:     sist
   *
   *  SCSI bus lines:
   *      so:     control lines as driven by chip.
   *      si:     control lines as seen by chip.
   *      sd:     scsi data lines as seen by chip.
   *
   *  wide/fastmode:
   *      sxfer:  (see the manual)
   *      scntl3: (see the manual)
   *
   *  current script command:
   *      dsp:    script address (relative to start of script).
   *      dbc:    first word of script command.
   *
   *  First 24 register of the chip:
   *      r0..rf
   */
  static void sym_log_hard_error(hcb_p np, u_short sist, u_char dstat)
  {
          u32     dsp;
          int     script_ofs;
          int     script_size;
          char    *script_name;
          u_char  *script_base;
          int     i;
  
          dsp     = INL (nc_dsp);
  
          if      (dsp > np->scripta_ba &&
                   dsp <= np->scripta_ba + np->scripta_sz) {
                  script_ofs      = dsp - np->scripta_ba;
                  script_size     = np->scripta_sz;
                  script_base     = (u_char *) np->scripta0;
                  script_name     = "scripta";
          }
          else if (np->scriptb_ba < dsp &&
                   dsp <= np->scriptb_ba + np->scriptb_sz) {
                  script_ofs      = dsp - np->scriptb_ba;
                  script_size     = np->scriptb_sz;
                  script_base     = (u_char *) np->scriptb0;
                  script_name     = "scriptb";
          } else {
                  script_ofs      = dsp;
                  script_size     = 0;
                  script_base     = 0;
                  script_name     = "mem";
          }
  
          printf ("%s:%d: ERROR (%x:%x) (%x-%x-%x) (%x/%x) @ (%s %x:%08x).\n",
                  sym_name (np), (unsigned)INB (nc_sdid)&0x0f, dstat, sist,
                  (unsigned)INB (nc_socl), (unsigned)INB (nc_sbcl),
                  (unsigned)INB (nc_sbdl), (unsigned)INB (nc_sxfer),
                  (unsigned)INB (nc_scntl3), script_name, script_ofs,
                  (unsigned)INL (nc_dbc));
  
          if (((script_ofs & 3) == 0) &&
              (unsigned)script_ofs < script_size) {
                  printf ("%s: script cmd = %08x\n", sym_name(np),
                          scr_to_cpu((int) *(u32 *)(script_base + script_ofs)));
          }
  
          printf ("%s: regdump:", sym_name(np));
          for (i=0; i<24;i++)
              printf (" %02x", (unsigned)INB_OFF(i));
          printf (".\n");
  
          /*
           *  PCI BUS error, read the PCI ststus register.
           */
          if (dstat & (MDPE|BF)) {
                  u_short pci_sts;
                  pci_sts = pci_read_config(np->device, PCIR_STATUS, 2);
                  if (pci_sts & 0xf900) {
                          pci_write_config(np->device, PCIR_STATUS, pci_sts, 2);
                          printf("%s: PCI STATUS = 0x%04x\n",
                                  sym_name(np), pci_sts & 0xf900);
                  }
          }
  }
  
  /*
   *  chip interrupt handler
   *
   *  In normal situations, interrupt conditions occur one at
   *  a time. But when something bad happens on the SCSI BUS,
   *  the chip may raise several interrupt flags before
   *  stopping and interrupting the CPU. The additionnal
   *  interrupt flags are stacked in some extra registers
   *  after the SIP and/or DIP flag has been raised in the
   *  ISTAT. After the CPU has read the interrupt condition
   *  flag from SIST or DSTAT, the chip unstacks the other
   *  interrupt flags and sets the corresponding bits in
   *  SIST or DSTAT. Since the chip starts stacking once the
   *  SIP or DIP flag is set, there is a small window of time
   *  where the stacking does not occur.
   *
   *  Typically, multiple interrupt conditions may happen in
   *  the following situations:
   *
   *  - SCSI parity error + Phase mismatch  (PAR|MA)
   *    When a parity error is detected in input phase
   *    and the device switches to msg-in phase inside a
   *    block MOV.
   *  - SCSI parity error + Unexpected disconnect (PAR|UDC)
   *    When a stupid device does not want to handle the
   *    recovery of an SCSI parity error.
   *  - Some combinations of STO, PAR, UDC, ...
   *    When using non compliant SCSI stuff, when user is
   *    doing non compliant hot tampering on the BUS, when
   *    something really bad happens to a device, etc ...
   *
   *  The heuristic suggested by SYMBIOS to handle
   *  multiple interrupts is to try unstacking all
   *  interrupts conditions and to handle them on some
   *  priority based on error severity.
   *  This will work when the unstacking has been
   *  successful, but we cannot be 100 % sure of that,
   *  since the CPU may have been faster to unstack than
   *  the chip is able to stack. Hmmm ... But it seems that
   *  such a situation is very unlikely to happen.
   *
   *  If this happen, for example STO caught by the CPU
   *  then UDC happenning before the CPU have restarted
   *  the SCRIPTS, the driver may wrongly complete the
   *  same command on UDC, since the SCRIPTS didn't restart
   *  and the DSA still points to the same command.
   *  We avoid this situation by setting the DSA to an
   *  invalid value when the CCB is completed and before
   *  restarting the SCRIPTS.
   *
   *  Another issue is that we need some section of our
   *  recovery procedures to be somehow uninterruptible but
   *  the SCRIPTS processor does not provides such a
   *  feature. For this reason, we handle recovery preferently
   *  from the C code and check against some SCRIPTS critical
   *  sections from the C code.
   *
   *  Hopefully, the interrupt handling of the driver is now
   *  able to resist to weird BUS error conditions, but donnot
   *  ask me for any guarantee that it will never fail. :-)
   *  Use at your own decision and risk.
   */
  
  static void sym_intr1 (hcb_p np)
  {
          u_char  istat, istatc;
          u_char  dstat;
          u_short sist;
  
          /*
           *  interrupt on the fly ?
           *
           *  A `dummy read' is needed to ensure that the
           *  clear of the INTF flag reaches the device
           *  before the scanning of the DONE queue.
           */
          istat = INB (nc_istat);
          if (istat & INTF) {
                  OUTB (nc_istat, (istat & SIGP) | INTF | np->istat_sem);
                  istat = INB (nc_istat);         /* DUMMY READ */
                  if (DEBUG_FLAGS & DEBUG_TINY) printf ("F ");
                  (void)sym_wakeup_done (np);
          };
  
          if (!(istat & (SIP|DIP)))
                  return;
  
  #if 0   /* We should never get this one */
          if (istat & CABRT)
                  OUTB (nc_istat, CABRT);
  #endif
  
          /*
           *  PAR and MA interrupts may occur at the same time,
           *  and we need to know of both in order to handle
           *  this situation properly. We try to unstack SCSI
           *  interrupts for that reason. BTW, I dislike a LOT
           *  such a loop inside the interrupt routine.
           *  Even if DMA interrupt stacking is very unlikely to
           *  happen, we also try unstacking these ones, since
           *  this has no performance impact.
           */
          sist    = 0;
          dstat   = 0;
          istatc  = istat;
          do {
                  if (istatc & SIP)
                          sist  |= INW (nc_sist);
                  if (istatc & DIP)
                          dstat |= INB (nc_dstat);
                  istatc = INB (nc_istat);
                  istat |= istatc;
          } while (istatc & (SIP|DIP));
  
          if (DEBUG_FLAGS & DEBUG_TINY)
                  printf ("<%d|%x:%x|%x:%x>",
                          (int)INB(nc_scr0),
                          dstat,sist,
                          (unsigned)INL(nc_dsp),
                          (unsigned)INL(nc_dbc));
          /*
           *  On paper, a memory barrier may be needed here.
           *  And since we are paranoid ... :)
           */
          MEMORY_BARRIER();
  
          /*
           *  First, interrupts we want to service cleanly.
           *
           *  Phase mismatch (MA) is the most frequent interrupt
           *  for chip earlier than the 896 and so we have to service
           *  it as quickly as possible.
           *  A SCSI parity error (PAR) may be combined with a phase
           *  mismatch condition (MA).
           *  Programmed interrupts (SIR) are used to call the C code
           *  from SCRIPTS.
           *  The single step interrupt (SSI) is not used in this
           *  driver.
           */
          if (!(sist  & (STO|GEN|HTH|SGE|UDC|SBMC|RST)) &&
              !(dstat & (MDPE|BF|ABRT|IID))) {
                  if      (sist & PAR)    sym_int_par (np, sist);
                  else if (sist & MA)     sym_int_ma (np);
                  else if (dstat & SIR)   sym_int_sir (np);
                  else if (dstat & SSI)   OUTONB_STD ();
                  else                    goto unknown_int;
                  return;
          };
  
          /*
           *  Now, interrupts that donnot happen in normal
           *  situations and that we may need to recover from.
           *
           *  On SCSI RESET (RST), we reset everything.
           *  On SCSI BUS MODE CHANGE (SBMC), we complete all
           *  active CCBs with RESET status, prepare all devices
           *  for negotiating again and restart the SCRIPTS.
           *  On STO and UDC, we complete the CCB with the corres-
           *  ponding status and restart the SCRIPTS.
           */
          if (sist & RST) {
                  xpt_print_path(np->path);
                  printf("SCSI BUS reset detected.\n");
                  sym_init (np, 1);
                  return;
          };
  
          OUTB (nc_ctest3, np->rv_ctest3 | CLF);  /* clear dma fifo  */
          OUTB (nc_stest3, TE|CSF);               /* clear scsi fifo */
  
          if (!(sist  & (GEN|HTH|SGE)) &&
              !(dstat & (MDPE|BF|ABRT|IID))) {
                  if      (sist & SBMC)   sym_int_sbmc (np);
                  else if (sist & STO)    sym_int_sto (np);
                  else if (sist & UDC)    sym_int_udc (np);
                  else                    goto unknown_int;
                  return;
          };
  
          /*
           *  Now, interrupts we are not able to recover cleanly.
           *
           *  Log message for hard errors.
           *  Reset everything.
           */
  
          sym_log_hard_error(np, sist, dstat);
  
          if ((sist & (GEN|HTH|SGE)) ||
                  (dstat & (MDPE|BF|ABRT|IID))) {
                  sym_start_reset(np);
                  return;
          };
  
  unknown_int:
          /*
           *  We just miss the cause of the interrupt. :(
           *  Print a message. The timeout will do the real work.
           */
          printf( "%s: unknown interrupt(s) ignored, "
                  "ISTAT=0x%x DSTAT=0x%x SIST=0x%x\n",
                  sym_name(np), istat, dstat, sist);
  }
  
  static void sym_intr(void *arg)
  {
          if (DEBUG_FLAGS & DEBUG_TINY) printf ("[");
          sym_intr1((hcb_p) arg);
          if (DEBUG_FLAGS & DEBUG_TINY) printf ("]");
  }
  
  static void sym_poll(struct cam_sim *sim)
  {
          int s = splcam();
          sym_intr(cam_sim_softc(sim));
          splx(s);
  }
  
  
  /*
   *  generic recovery from scsi interrupt
   *
   *  The doc says that when the chip gets an SCSI interrupt,
   *  it tries to stop in an orderly fashion, by completing
   *  an instruction fetch that had started or by flushing
   *  the DMA fifo for a write to memory that was executing.
   *  Such a fashion is not enough to know if the instruction
   *  that was just before the current DSP value has been
   *  executed or not.
   *
   *  There are some small SCRIPTS sections that deal with
   *  the start queue and the done queue that may break any
   *  assomption from the C code if we are interrupted
   *  inside, so we reset if this happens. Btw, since these
   *  SCRIPTS sections are executed while the SCRIPTS hasn't
   *  started SCSI operations, it is very unlikely to happen.
   *
   *  All the driver data structures are supposed to be
   *  allocated from the same 4 GB memory window, so there
   *  is a 1 to 1 relationship between DSA and driver data
   *  structures. Since we are careful :) to invalidate the
   *  DSA when we complete a command or when the SCRIPTS
   *  pushes a DSA into a queue, we can trust it when it
   *  points to a CCB.
   */
  static void sym_recover_scsi_int (hcb_p np, u_char hsts)
  {
          u32     dsp     = INL (nc_dsp);
          u32     dsa     = INL (nc_dsa);
          ccb_p cp        = sym_ccb_from_dsa(np, dsa);
  
          /*
           *  If we haven't been interrupted inside the SCRIPTS
           *  critical pathes, we can safely restart the SCRIPTS
           *  and trust the DSA value if it matches a CCB.
           */
          if ((!(dsp > SCRIPTA_BA (np, getjob_begin) &&
                 dsp < SCRIPTA_BA (np, getjob_end) + 1)) &&
              (!(dsp > SCRIPTA_BA (np, ungetjob) &&
                 dsp < SCRIPTA_BA (np, reselect) + 1)) &&
              (!(dsp > SCRIPTB_BA (np, sel_for_abort) &&
                 dsp < SCRIPTB_BA (np, sel_for_abort_1) + 1)) &&
              (!(dsp > SCRIPTA_BA (np, done) &&
                 dsp < SCRIPTA_BA (np, done_end) + 1))) {
                  OUTB (nc_ctest3, np->rv_ctest3 | CLF);  /* clear dma fifo  */
                  OUTB (nc_stest3, TE|CSF);               /* clear scsi fifo */
                  /*
                   *  If we have a CCB, let the SCRIPTS call us back for
                   *  the handling of the error with SCRATCHA filled with
                   *  STARTPOS. This way, we will be able to freeze the
                   *  device queue and requeue awaiting IOs.
                   */
                  if (cp) {
                          cp->host_status = hsts;
                          OUTL_DSP (SCRIPTA_BA (np, complete_error));
                  }
                  /*
                   *  Otherwise just restart the SCRIPTS.
                   */
                  else {
                          OUTL (nc_dsa, 0xffffff);
                          OUTL_DSP (SCRIPTA_BA (np, start));
                  }
          }
          else
                  goto reset_all;
  
          return;
  
  reset_all:
          sym_start_reset(np);
  }
  
  /*
   *  chip exception handler for selection timeout
   */
  static void sym_int_sto (hcb_p np)
  {
          u32 dsp = INL (nc_dsp);
  
          if (DEBUG_FLAGS & DEBUG_TINY) printf ("T");
  
          if (dsp == SCRIPTA_BA (np, wf_sel_done) + 8)
                  sym_recover_scsi_int(np, HS_SEL_TIMEOUT);
          else
                  sym_start_reset(np);
  }
  
  /*
   *  chip exception handler for unexpected disconnect
   */
  static void sym_int_udc (hcb_p np)
  {
          printf ("%s: unexpected disconnect\n", sym_name(np));
          sym_recover_scsi_int(np, HS_UNEXPECTED);
  }
  
  /*
   *  chip exception handler for SCSI bus mode change
   *
   *  spi2-r12 11.2.3 says a transceiver mode change must
   *  generate a reset event and a device that detects a reset
   *  event shall initiate a hard reset. It says also that a
   *  device that detects a mode change shall set data transfer
   *  mode to eight bit asynchronous, etc...
   *  So, just reinitializing all except chip should be enough.
   */
  static void sym_int_sbmc (hcb_p np)
  {
          u_char scsi_mode = INB (nc_stest4) & SMODE;
  
          /*
           *  Notify user.
           */
          xpt_print_path(np->path);
          printf("SCSI BUS mode change from %s to %s.\n",
                  sym_scsi_bus_mode(np->scsi_mode), sym_scsi_bus_mode(scsi_mode));
  
          /*
           *  Should suspend command processing for a few seconds and
           *  reinitialize all except the chip.
           */
          sym_init (np, 2);
  }
  
  /*
   *  chip exception handler for SCSI parity error.
   *
   *  When the chip detects a SCSI parity error and is
   *  currently executing a (CH)MOV instruction, it does
   *  not interrupt immediately, but tries to finish the
   *  transfer of the current scatter entry before
   *  interrupting. The following situations may occur:
   *
   *  - The complete scatter entry has been transferred
   *    without the device having changed phase.
   *    The chip will then interrupt with the DSP pointing
   *    to the instruction that follows the MOV.
   *
   *  - A phase mismatch occurs before the MOV finished
   *    and phase errors are to be handled by the C code.
   *    The chip will then interrupt with both PAR and MA
   *    conditions set.
   *
   *  - A phase mismatch occurs before the MOV finished and
   *    phase errors are to be handled by SCRIPTS.
   *    The chip will load the DSP with the phase mismatch
   *    JUMP address and interrupt the host processor.
   */
  static void sym_int_par (hcb_p np, u_short sist)
  {
          u_char  hsts    = INB (HS_PRT);
          u32     dsp     = INL (nc_dsp);
          u32     dbc     = INL (nc_dbc);
          u32     dsa     = INL (nc_dsa);
          u_char  sbcl    = INB (nc_sbcl);
          u_char  cmd     = dbc >> 24;
          int phase       = cmd & 7;
          ccb_p   cp      = sym_ccb_from_dsa(np, dsa);
  
          printf("%s: SCSI parity error detected: SCR1=%d DBC=%x SBCL=%x\n",
                  sym_name(np), hsts, dbc, sbcl);
  
          /*
           *  Check that the chip is connected to the SCSI BUS.
           */
          if (!(INB (nc_scntl1) & ISCON)) {
                  sym_recover_scsi_int(np, HS_UNEXPECTED);
                  return;
          }
  
          /*
           *  If the nexus is not clearly identified, reset the bus.
           *  We will try to do better later.
           */
          if (!cp)
                  goto reset_all;
  
          /*
           *  Check instruction was a MOV, direction was INPUT and
           *  ATN is asserted.
           */
          if ((cmd & 0xc0) || !(phase & 1) || !(sbcl & 0x8))
                  goto reset_all;
  
          /*
           *  Keep track of the parity error.
           */
          OUTONB (HF_PRT, HF_EXT_ERR);
          cp->xerr_status |= XE_PARITY_ERR;
  
          /*
           *  Prepare the message to send to the device.
           */
          np->msgout[0] = (phase == 7) ? M_PARITY : M_ID_ERROR;
  
          /*
           *  If the old phase was DATA IN phase, we have to deal with
           *  the 3 situations described above.
           *  For other input phases (MSG IN and STATUS), the device
           *  must resend the whole thing that failed parity checking
           *  or signal error. So, jumping to dispatcher should be OK.
           */
          if (phase == 1 || phase == 5) {
                  /* Phase mismatch handled by SCRIPTS */
                  if (dsp == SCRIPTB_BA (np, pm_handle))
                          OUTL_DSP (dsp);
                  /* Phase mismatch handled by the C code */
                  else if (sist & MA)
                          sym_int_ma (np);
                  /* No phase mismatch occurred */
                  else {
                          OUTL (nc_temp, dsp);
                          OUTL_DSP (SCRIPTA_BA (np, dispatch));
                  }
          }
          else
                  OUTL_DSP (SCRIPTA_BA (np, clrack));
          return;
  
  reset_all:
          sym_start_reset(np);
  }
  
  /*
   *  chip exception handler for phase errors.
   *
   *  We have to construct a new transfer descriptor,
   *  to transfer the rest of the current block.
   */
  static void sym_int_ma (hcb_p np)
  {
          u32     dbc;
          u32     rest;
          u32     dsp;
          u32     dsa;
          u32     nxtdsp;
          u32     *vdsp;
          u32     oadr, olen;
          u32     *tblp;
          u32     newcmd;
          u_int   delta;
          u_char  cmd;
          u_char  hflags, hflags0;
          struct  sym_pmc *pm;
          ccb_p   cp;
  
          dsp     = INL (nc_dsp);
          dbc     = INL (nc_dbc);
          dsa     = INL (nc_dsa);
  
          cmd     = dbc >> 24;
          rest    = dbc & 0xffffff;
          delta   = 0;
  
          /*
           *  locate matching cp if any.
           */
          cp = sym_ccb_from_dsa(np, dsa);
  
          /*
           *  Donnot take into account dma fifo and various buffers in
           *  INPUT phase since the chip flushes everything before
           *  raising the MA interrupt for interrupted INPUT phases.
           *  For DATA IN phase, we will check for the SWIDE later.
           */
          if ((cmd & 7) != 1 && (cmd & 7) != 5) {
                  u_char ss0, ss2;
  
                  if (np->features & FE_DFBC)
                          delta = INW (nc_dfbc);
                  else {
                          u32 dfifo;
  
                          /*
                           * Read DFIFO, CTEST[4-6] using 1 PCI bus ownership.
                           */
                          dfifo = INL(nc_dfifo);
  
                          /*
                           *  Calculate remaining bytes in DMA fifo.
                           *  (CTEST5 = dfifo >> 16)
                           */
                          if (dfifo & (DFS << 16))
                                  delta = ((((dfifo >> 8) & 0x300) |
                                            (dfifo & 0xff)) - rest) & 0x3ff;
                          else
                                  delta = ((dfifo & 0xff) - rest) & 0x7f;
                  }
  
                  /*
                   *  The data in the dma fifo has not been transfered to
                   *  the target -> add the amount to the rest
                   *  and clear the data.
                   *  Check the sstat2 register in case of wide transfer.
                   */
                  rest += delta;
                  ss0  = INB (nc_sstat0);
                  if (ss0 & OLF) rest++;
                  if (!(np->features & FE_C10))
                          if (ss0 & ORF) rest++;
                  if (cp && (cp->phys.select.sel_scntl3 & EWS)) {
                          ss2 = INB (nc_sstat2);
                          if (ss2 & OLF1) rest++;
                          if (!(np->features & FE_C10))
                                  if (ss2 & ORF1) rest++;
                  };
  
                  /*
                   *  Clear fifos.
                   */
                  OUTB (nc_ctest3, np->rv_ctest3 | CLF);  /* dma fifo  */
                  OUTB (nc_stest3, TE|CSF);               /* scsi fifo */
          }
  
          /*
           *  log the information
           */
          if (DEBUG_FLAGS & (DEBUG_TINY|DEBUG_PHASE))
                  printf ("P%x%x RL=%d D=%d ", cmd&7, INB(nc_sbcl)&7,
                          (unsigned) rest, (unsigned) delta);
  
          /*
           *  try to find the interrupted script command,
           *  and the address at which to continue.
           */
          vdsp    = 0;
          nxtdsp  = 0;
          if      (dsp >  np->scripta_ba &&
                   dsp <= np->scripta_ba + np->scripta_sz) {
                  vdsp = (u32 *)((char*)np->scripta0 + (dsp-np->scripta_ba-8));
                  nxtdsp = dsp;
          }
          else if (dsp >  np->scriptb_ba &&
                   dsp <= np->scriptb_ba + np->scriptb_sz) {
                  vdsp = (u32 *)((char*)np->scriptb0 + (dsp-np->scriptb_ba-8));
                  nxtdsp = dsp;
          }
  
          /*
           *  log the information
           */
          if (DEBUG_FLAGS & DEBUG_PHASE) {
                  printf ("\nCP=%p DSP=%x NXT=%x VDSP=%p CMD=%x ",
                          cp, (unsigned)dsp, (unsigned)nxtdsp, vdsp, cmd);
          };
  
          if (!vdsp) {
                  printf ("%s: interrupted SCRIPT address not found.\n",
                          sym_name (np));
                  goto reset_all;
          }
  
          if (!cp) {
                  printf ("%s: SCSI phase error fixup: CCB already dequeued.\n",
                          sym_name (np));
                  goto reset_all;
          }
  
          /*
           *  get old startaddress and old length.
           */
          oadr = scr_to_cpu(vdsp[1]);
  
          if (cmd & 0x10) {       /* Table indirect */
                  tblp = (u32 *) ((char*) &cp->phys + oadr);
                  olen = scr_to_cpu(tblp[0]);
                  oadr = scr_to_cpu(tblp[1]);
          } else {
                  tblp = (u32 *) 0;
                  olen = scr_to_cpu(vdsp[0]) & 0xffffff;
          };
  
          if (DEBUG_FLAGS & DEBUG_PHASE) {
                  printf ("OCMD=%x\nTBLP=%p OLEN=%x OADR=%x\n",
                          (unsigned) (scr_to_cpu(vdsp[0]) >> 24),
                          tblp,
                          (unsigned) olen,
                          (unsigned) oadr);
          };
  
          /*
           *  check cmd against assumed interrupted script command.
           *  If dt data phase, the MOVE instruction hasn't bit 4 of
           *  the phase.
           */
          if (((cmd & 2) ? cmd : (cmd & ~4)) != (scr_to_cpu(vdsp[0]) >> 24)) {
                  PRINT_ADDR(cp);
                  printf ("internal error: cmd=%02x != %02x=(vdsp[0] >> 24)\n",
                          (unsigned)cmd, (unsigned)scr_to_cpu(vdsp[0]) >> 24);
  
                  goto reset_all;
          };
  
          /*
           *  if old phase not dataphase, leave here.
           */
          if (cmd & 2) {
                  PRINT_ADDR(cp);
                  printf ("phase change %x-%x %d@%08x resid=%d.\n",
                          cmd&7, INB(nc_sbcl)&7, (unsigned)olen,
                          (unsigned)oadr, (unsigned)rest);
                  goto unexpected_phase;
          };
  
          /*
           *  Choose the correct PM save area.
           *
           *  Look at the PM_SAVE SCRIPT if you want to understand
           *  this stuff. The equivalent code is implemented in
           *  SCRIPTS for the 895A, 896 and 1010 that are able to
           *  handle PM from the SCRIPTS processor.
           */
          hflags0 = INB (HF_PRT);
          hflags = hflags0;
  
          if (hflags & (HF_IN_PM0 | HF_IN_PM1 | HF_DP_SAVED)) {
                  if (hflags & HF_IN_PM0)
                          nxtdsp = scr_to_cpu(cp->phys.pm0.ret);
                  else if (hflags & HF_IN_PM1)
                          nxtdsp = scr_to_cpu(cp->phys.pm1.ret);
  
                  if (hflags & HF_DP_SAVED)
                          hflags ^= HF_ACT_PM;
          }
  
          if (!(hflags & HF_ACT_PM)) {
                  pm = &cp->phys.pm0;
                  newcmd = SCRIPTA_BA (np, pm0_data);
          }
          else {
                  pm = &cp->phys.pm1;
                  newcmd = SCRIPTA_BA (np, pm1_data);
          }
  
          hflags &= ~(HF_IN_PM0 | HF_IN_PM1 | HF_DP_SAVED);
          if (hflags != hflags0)
                  OUTB (HF_PRT, hflags);
  
          /*
           *  fillin the phase mismatch context
           */
          pm->sg.addr = cpu_to_scr(oadr + olen - rest);
          pm->sg.size = cpu_to_scr(rest);
          pm->ret     = cpu_to_scr(nxtdsp);
  
          /*
           *  If we have a SWIDE,
           *  - prepare the address to write the SWIDE from SCRIPTS,
           *  - compute the SCRIPTS address to restart from,
           *  - move current data pointer context by one byte.
           */
          nxtdsp = SCRIPTA_BA (np, dispatch);
          if ((cmd & 7) == 1 && cp && (cp->phys.select.sel_scntl3 & EWS) &&
              (INB (nc_scntl2) & WSR)) {
                  u32 tmp;
  
                  /*
                   *  Set up the table indirect for the MOVE
                   *  of the residual byte and adjust the data
                   *  pointer context.
                   */
                  tmp = scr_to_cpu(pm->sg.addr);
                  cp->phys.wresid.addr = cpu_to_scr(tmp);
                  pm->sg.addr = cpu_to_scr(tmp + 1);
                  tmp = scr_to_cpu(pm->sg.size);
                  cp->phys.wresid.size = cpu_to_scr((tmp&0xff000000) | 1);
                  pm->sg.size = cpu_to_scr(tmp - 1);
  
                  /*
                   *  If only the residual byte is to be moved,
                   *  no PM context is needed.
                   */
                  if ((tmp&0xffffff) == 1)
                          newcmd = pm->ret;
  
                  /*
                   *  Prepare the address of SCRIPTS that will
                   *  move the residual byte to memory.
                   */
                  nxtdsp = SCRIPTB_BA (np, wsr_ma_helper);
          }
  
          if (DEBUG_FLAGS & DEBUG_PHASE) {
                  PRINT_ADDR(cp);
                  printf ("PM %x %x %x / %x %x %x.\n",
                          hflags0, hflags, newcmd,
                          (unsigned)scr_to_cpu(pm->sg.addr),
                          (unsigned)scr_to_cpu(pm->sg.size),
                          (unsigned)scr_to_cpu(pm->ret));
          }
  
          /*
           *  Restart the SCRIPTS processor.
           */
          OUTL (nc_temp, newcmd);
          OUTL_DSP (nxtdsp);
          return;
  
          /*
           *  Unexpected phase changes that occurs when the current phase
           *  is not a DATA IN or DATA OUT phase are due to error conditions.
           *  Such event may only happen when the SCRIPTS is using a
           *  multibyte SCSI MOVE.
           *
           *  Phase change                Some possible cause
           *
           *  COMMAND  --> MSG IN SCSI parity error detected by target.
           *  COMMAND  --> STATUS Bad command or refused by target.
           *  MSG OUT  --> MSG IN     Message rejected by target.
           *  MSG OUT  --> COMMAND    Bogus target that discards extended
           *                      negotiation messages.
           *
           *  The code below does not care of the new phase and so
           *  trusts the target. Why to annoy it ?
           *  If the interrupted phase is COMMAND phase, we restart at
           *  dispatcher.
           *  If a target does not get all the messages after selection,
           *  the code assumes blindly that the target discards extended
           *  messages and clears the negotiation status.
           *  If the target does not want all our response to negotiation,
           *  we force a SIR_NEGO_PROTO interrupt (it is a hack that avoids
           *  bloat for such a should_not_happen situation).
           *  In all other situation, we reset the BUS.
           *  Are these assumptions reasonnable ? (Wait and see ...)
           */
  unexpected_phase:
          dsp -= 8;
          nxtdsp = 0;
  
          switch (cmd & 7) {
          case 2: /* COMMAND phase */
                  nxtdsp = SCRIPTA_BA (np, dispatch);
                  break;
  #if 0
          case 3: /* STATUS  phase */
                  nxtdsp = SCRIPTA_BA (np, dispatch);
                  break;
  #endif
          case 6: /* MSG OUT phase */
                  /*
                   *  If the device may want to use untagged when we want
                   *  tagged, we prepare an IDENTIFY without disc. granted,
                   *  since we will not be able to handle reselect.
                   *  Otherwise, we just don't care.
                   */
                  if      (dsp == SCRIPTA_BA (np, send_ident)) {
                          if (cp->tag != NO_TAG && olen - rest <= 3) {
                                  cp->host_status = HS_BUSY;
                                  np->msgout[0] = M_IDENTIFY | cp->lun;
                                  nxtdsp = SCRIPTB_BA (np, ident_break_atn);
                          }
                          else
                                  nxtdsp = SCRIPTB_BA (np, ident_break);
                  }
                  else if (dsp == SCRIPTB_BA (np, send_wdtr) ||
                           dsp == SCRIPTB_BA (np, send_sdtr) ||
                           dsp == SCRIPTB_BA (np, send_ppr)) {
                          nxtdsp = SCRIPTB_BA (np, nego_bad_phase);
                  }
                  break;
  #if 0
          case 7: /* MSG IN  phase */
                  nxtdsp = SCRIPTA_BA (np, clrack);
                  break;
  #endif
          }
  
          if (nxtdsp) {
                  OUTL_DSP (nxtdsp);
                  return;
          }
  
  reset_all:
          sym_start_reset(np);
  }
  
  /*
   *  Dequeue from the START queue all CCBs that match
   *  a given target/lun/task condition (-1 means all),
   *  and move them from the BUSY queue to the COMP queue
   *  with CAM_REQUEUE_REQ status condition.
   *  This function is used during error handling/recovery.
   *  It is called with SCRIPTS not running.
   */
  static int
  sym_dequeue_from_squeue(hcb_p np, int i, int target, int lun, int task)
  {
          int j;
          ccb_p cp;
  
          /*
           *  Make sure the starting index is within range.
           */
          assert((i >= 0) && (i < 2*MAX_QUEUE));
  
          /*
           *  Walk until end of START queue and dequeue every job
           *  that matches the target/lun/task condition.
           */
          j = i;
          while (i != np->squeueput) {
                  cp = sym_ccb_from_dsa(np, scr_to_cpu(np->squeue[i]));
                  assert(cp);
  #ifdef SYM_CONF_IARB_SUPPORT
                  /* Forget hints for IARB, they may be no longer relevant */
                  cp->host_flags &= ~HF_HINT_IARB;
  #endif
                  if ((target == -1 || cp->target == target) &&
                      (lun    == -1 || cp->lun    == lun)    &&
                      (task   == -1 || cp->tag    == task)) {
                          sym_set_cam_status(cp->cam_ccb, CAM_REQUEUE_REQ);
                          sym_remque(&cp->link_ccbq);
                          sym_insque_tail(&cp->link_ccbq, &np->comp_ccbq);
                  }
                  else {
                          if (i != j)
                                  np->squeue[j] = np->squeue[i];
                          if ((j += 2) >= MAX_QUEUE*2) j = 0;
                  }
                  if ((i += 2) >= MAX_QUEUE*2) i = 0;
          }
          if (i != j)             /* Copy back the idle task if needed */
                  np->squeue[j] = np->squeue[i];
          np->squeueput = j;      /* Update our current start queue pointer */
  
          return (i - j) / 2;
  }
  
  /*
   *  Complete all CCBs queued to the COMP queue.
   *
   *  These CCBs are assumed:
   *  - Not to be referenced either by devices or
   *    SCRIPTS-related queues and datas.
   *  - To have to be completed with an error condition
   *    or requeued.
   *
   *  The device queue freeze count is incremented
   *  for each CCB that does not prevent this.
   *  This function is called when all CCBs involved
   *  in error handling/recovery have been reaped.
   */
  static void
  sym_flush_comp_queue(hcb_p np, int cam_status)
  {
          SYM_QUEHEAD *qp;
          ccb_p cp;
  
          while ((qp = sym_remque_head(&np->comp_ccbq)) != 0) {
                  union ccb *ccb;
                  cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
                  sym_insque_tail(&cp->link_ccbq, &np->busy_ccbq);
                  /* Leave quiet CCBs waiting for resources */
                  if (cp->host_status == HS_WAIT)
                          continue;
                  ccb = cp->cam_ccb;
                  if (cam_status)
                          sym_set_cam_status(ccb, cam_status);
                  sym_free_ccb(np, cp);
                  sym_freeze_cam_ccb(ccb);
                  sym_xpt_done(np, ccb);
          }
  }
  
  /*
   *  chip handler for bad SCSI status condition
   *
   *  In case of bad SCSI status, we unqueue all the tasks
   *  currently queued to the controller but not yet started
   *  and then restart the SCRIPTS processor immediately.
   *
   *  QUEUE FULL and BUSY conditions are handled the same way.
   *  Basically all the not yet started tasks are requeued in
   *  device queue and the queue is frozen until a completion.
   *
   *  For CHECK CONDITION and COMMAND TERMINATED status, we use
   *  the CCB of the failed command to prepare a REQUEST SENSE
   *  SCSI command and queue it to the controller queue.
   *
   *  SCRATCHA is assumed to have been loaded with STARTPOS
   *  before the SCRIPTS called the C code.
   */
  static void sym_sir_bad_scsi_status(hcb_p np, int num, ccb_p cp)
  {
          tcb_p tp        = &np->target[cp->target];
          u32             startp;
          u_char          s_status = cp->ssss_status;
          u_char          h_flags  = cp->host_flags;
          int             msglen;
          int             nego;
          int             i;
  
          /*
           *  Compute the index of the next job to start from SCRIPTS.
           */
          i = (INL (nc_scratcha) - np->squeue_ba) / 4;
  
          /*
           *  The last CCB queued used for IARB hint may be
           *  no longer relevant. Forget it.
           */
  #ifdef SYM_CONF_IARB_SUPPORT
          if (np->last_cp)
                  np->last_cp = NULL;
  #endif
  
          /*
           *  Now deal with the SCSI status.
           */
          switch(s_status) {
          case S_BUSY:
          case S_QUEUE_FULL:
                  if (sym_verbose >= 2) {
                          PRINT_ADDR(cp);
                          printf (s_status == S_BUSY ? "BUSY" : "QUEUE FULL\n");
                  }
          default:        /* S_INT, S_INT_COND_MET, S_CONFLICT */
                  sym_complete_error (np, cp);
                  break;
          case S_TERMINATED:
          case S_CHECK_COND:
                  /*
                   *  If we get an SCSI error when requesting sense, give up.
                   */
                  if (h_flags & HF_SENSE) {
                          sym_complete_error (np, cp);
                          break;
                  }
  
                  /*
                   *  Dequeue all queued CCBs for that device not yet started,
                   *  and restart the SCRIPTS processor immediately.
                   */
                  (void) sym_dequeue_from_squeue(np, i, cp->target, cp->lun, -1);
                  OUTL_DSP (SCRIPTA_BA (np, start));
  
                  /*
                   *  Save some info of the actual IO.
                   *  Compute the data residual.
                   */
                  cp->sv_scsi_status = cp->ssss_status;
                  cp->sv_xerr_status = cp->xerr_status;
                  cp->sv_resid = sym_compute_residual(np, cp);
  
                  /*
                   *  Prepare all needed data structures for
                   *  requesting sense data.
                   */
  
                  /*
                   *  identify message
                   */
                  cp->scsi_smsg2[0] = M_IDENTIFY | cp->lun;
                  msglen = 1;
  
                  /*
                   *  If we are currently using anything different from
                   *  async. 8 bit data transfers with that target,
                   *  start a negotiation, since the device may want
                   *  to report us a UNIT ATTENTION condition due to
                   *  a cause we currently ignore, and we donnot want
                   *  to be stuck with WIDE and/or SYNC data transfer.
                   *
                   *  cp->nego_status is filled by sym_prepare_nego().
                   */
                  cp->nego_status = 0;
                  nego = 0;
                  if      (tp->tinfo.current.options & PPR_OPT_MASK)
                          nego = NS_PPR;
                  else if (tp->tinfo.current.width != BUS_8_BIT)
                          nego = NS_WIDE;
                  else if (tp->tinfo.current.offset != 0)
                          nego = NS_SYNC;
                  if (nego)
                          msglen +=
                          sym_prepare_nego (np,cp, nego, &cp->scsi_smsg2[msglen]);
                  /*
                   *  Message table indirect structure.
                   */
                  cp->phys.smsg.addr      = cpu_to_scr(CCB_BA (cp, scsi_smsg2));
                  cp->phys.smsg.size      = cpu_to_scr(msglen);
  
                  /*
                   *  sense command
                   */
                  cp->phys.cmd.addr       = cpu_to_scr(CCB_BA (cp, sensecmd));
                  cp->phys.cmd.size       = cpu_to_scr(6);
  
                  /*
                   *  patch requested size into sense command
                   */
                  cp->sensecmd[0]         = 0x03;
                  cp->sensecmd[1]         = cp->lun << 5;
  #ifdef  FreeBSD_New_Tran_Settings
                  if (tp->tinfo.current.scsi_version > 2 || cp->lun > 7)
                          cp->sensecmd[1] = 0;
  #endif
                  cp->sensecmd[4]         = SYM_SNS_BBUF_LEN;
                  cp->data_len            = SYM_SNS_BBUF_LEN;
  
                  /*
                   *  sense data
                   */
                  bzero(cp->sns_bbuf, SYM_SNS_BBUF_LEN);
                  cp->phys.sense.addr     = cpu_to_scr(vtobus(cp->sns_bbuf));
                  cp->phys.sense.size     = cpu_to_scr(SYM_SNS_BBUF_LEN);
  
                  /*
                   *  requeue the command.
                   */
                  startp = SCRIPTB_BA (np, sdata_in);
  
                  cp->phys.head.savep     = cpu_to_scr(startp);
                  cp->phys.head.goalp     = cpu_to_scr(startp + 16);
                  cp->phys.head.lastp     = cpu_to_scr(startp);
                  cp->startp      = cpu_to_scr(startp);
  
                  cp->actualquirks = SYM_QUIRK_AUTOSAVE;
                  cp->host_status = cp->nego_status ? HS_NEGOTIATE : HS_BUSY;
                  cp->ssss_status = S_ILLEGAL;
                  cp->host_flags  = (HF_SENSE|HF_DATA_IN);
                  cp->xerr_status = 0;
                  cp->extra_bytes = 0;
  
                  cp->phys.head.go.start = cpu_to_scr(SCRIPTA_BA (np, select));
  
                  /*
                   *  Requeue the command.
                   */
                  sym_put_start_queue(np, cp);
  
                  /*
                   *  Give back to upper layer everything we have dequeued.
                   */
                  sym_flush_comp_queue(np, 0);
                  break;
          }
  }
  
  /*
   *  After a device has accepted some management message
   *  as BUS DEVICE RESET, ABORT TASK, etc ..., or when
   *  a device signals a UNIT ATTENTION condition, some
   *  tasks are thrown away by the device. We are required
   *  to reflect that on our tasks list since the device
   *  will never complete these tasks.
   *
   *  This function move from the BUSY queue to the COMP
   *  queue all disconnected CCBs for a given target that
   *  match the following criteria:
   *  - lun=-1  means any logical UNIT otherwise a given one.
   *  - task=-1 means any task, otherwise a given one.
   */
  static int
  sym_clear_tasks(hcb_p np, int cam_status, int target, int lun, int task)
  {
          SYM_QUEHEAD qtmp, *qp;
          int i = 0;
          ccb_p cp;
  
          /*
           *  Move the entire BUSY queue to our temporary queue.
           */
          sym_que_init(&qtmp);
          sym_que_splice(&np->busy_ccbq, &qtmp);
          sym_que_init(&np->busy_ccbq);
  
          /*
           *  Put all CCBs that matches our criteria into
           *  the COMP queue and put back other ones into
           *  the BUSY queue.
           */
          while ((qp = sym_remque_head(&qtmp)) != 0) {
                  union ccb *ccb;
                  cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
                  ccb = cp->cam_ccb;
                  if (cp->host_status != HS_DISCONNECT ||
                      cp->target != target             ||
                      (lun  != -1 && cp->lun != lun)   ||
                      (task != -1 &&
                          (cp->tag != NO_TAG && cp->scsi_smsg[2] != task))) {
                          sym_insque_tail(&cp->link_ccbq, &np->busy_ccbq);
                          continue;
                  }
                  sym_insque_tail(&cp->link_ccbq, &np->comp_ccbq);
  
                  /* Preserve the software timeout condition */
                  if (sym_get_cam_status(ccb) != CAM_CMD_TIMEOUT)
                          sym_set_cam_status(ccb, cam_status);
                  ++i;
  #if 0
  printf("XXXX TASK @%p CLEARED\n", cp);
  #endif
          }
          return i;
  }
  
  /*
   *  chip handler for TASKS recovery
   *
   *  We cannot safely abort a command, while the SCRIPTS
   *  processor is running, since we just would be in race
   *  with it.
   *
   *  As long as we have tasks to abort, we keep the SEM
   *  bit set in the ISTAT. When this bit is set, the
   *  SCRIPTS processor interrupts (SIR_SCRIPT_STOPPED)
   *  each time it enters the scheduler.
   *
   *  If we have to reset a target, clear tasks of a unit,
   *  or to perform the abort of a disconnected job, we
   *  restart the SCRIPTS for selecting the target. Once
   *  selected, the SCRIPTS interrupts (SIR_TARGET_SELECTED).
   *  If it loses arbitration, the SCRIPTS will interrupt again
   *  the next time it will enter its scheduler, and so on ...
   *
   *  On SIR_TARGET_SELECTED, we scan for the more
   *  appropriate thing to do:
   *
   *  - If nothing, we just sent a M_ABORT message to the
   *    target to get rid of the useless SCSI bus ownership.
   *    According to the specs, no tasks shall be affected.
   *  - If the target is to be reset, we send it a M_RESET
   *    message.
   *  - If a logical UNIT is to be cleared , we send the
   *    IDENTIFY(lun) + M_ABORT.
   *  - If an untagged task is to be aborted, we send the
   *    IDENTIFY(lun) + M_ABORT.
   *  - If a tagged task is to be aborted, we send the
   *    IDENTIFY(lun) + task attributes + M_ABORT_TAG.
   *
   *  Once our 'kiss of death' :) message has been accepted
   *  by the target, the SCRIPTS interrupts again
   *  (SIR_ABORT_SENT). On this interrupt, we complete
   *  all the CCBs that should have been aborted by the
   *  target according to our message.
   */
  static void sym_sir_task_recovery(hcb_p np, int num)
  {
          SYM_QUEHEAD *qp;
          ccb_p cp;
          tcb_p tp;
          int target=-1, lun=-1, task;
          int i, k;
  
          switch(num) {
          /*
           *  The SCRIPTS processor stopped before starting
           *  the next command in order to allow us to perform
           *  some task recovery.
           */
          case SIR_SCRIPT_STOPPED:
                  /*
                   *  Do we have any target to reset or unit to clear ?
                   */
                  for (i = 0 ; i < SYM_CONF_MAX_TARGET ; i++) {
                          tp = &np->target[i];
                          if (tp->to_reset ||
                              (tp->lun0p && tp->lun0p->to_clear)) {
                                  target = i;
                                  break;
                          }
                          if (!tp->lunmp)
                                  continue;
                          for (k = 1 ; k < SYM_CONF_MAX_LUN ; k++) {
                                  if (tp->lunmp[k] && tp->lunmp[k]->to_clear) {
                                          target  = i;
                                          break;
                                  }
                          }
                          if (target != -1)
                                  break;
                  }
  
                  /*
                   *  If not, walk the busy queue for any
                   *  disconnected CCB to be aborted.
                   */
                  if (target == -1) {
                          FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
                                  cp = sym_que_entry(qp,struct sym_ccb,link_ccbq);
                                  if (cp->host_status != HS_DISCONNECT)
                                          continue;
                                  if (cp->to_abort) {
                                          target = cp->target;
                                          break;
                                  }
                          }
                  }
  
                  /*
                   *  If some target is to be selected,
                   *  prepare and start the selection.
                   */
                  if (target != -1) {
                          tp = &np->target[target];
                          np->abrt_sel.sel_id     = target;
                          np->abrt_sel.sel_scntl3 = tp->head.wval;
                          np->abrt_sel.sel_sxfer  = tp->head.sval;
                          OUTL(nc_dsa, np->hcb_ba);
                          OUTL_DSP (SCRIPTB_BA (np, sel_for_abort));
                          return;
                  }
  
                  /*
                   *  Now look for a CCB to abort that haven't started yet.
                   *  Btw, the SCRIPTS processor is still stopped, so
                   *  we are not in race.
                   */
                  i = 0;
                  cp = NULL;
                  FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
                          cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
                          if (cp->host_status != HS_BUSY &&
                              cp->host_status != HS_NEGOTIATE)
                                  continue;
                          if (!cp->to_abort)
                                  continue;
  #ifdef SYM_CONF_IARB_SUPPORT
                          /*
                           *    If we are using IMMEDIATE ARBITRATION, we donnot
                           *    want to cancel the last queued CCB, since the
                           *    SCRIPTS may have anticipated the selection.
                           */
                          if (cp == np->last_cp) {
                                  cp->to_abort = 0;
                                  continue;
                          }
  #endif
                          i = 1;  /* Means we have found some */
                          break;
                  }
                  if (!i) {
                          /*
                           *  We are done, so we donnot need
                           *  to synchronize with the SCRIPTS anylonger.
                           *  Remove the SEM flag from the ISTAT.
                           */
                          np->istat_sem = 0;
                          OUTB (nc_istat, SIGP);
                          break;
                  }
                  /*
                   *  Compute index of next position in the start
                   *  queue the SCRIPTS intends to start and dequeue
                   *  all CCBs for that device that haven't been started.
                   */
                  i = (INL (nc_scratcha) - np->squeue_ba) / 4;
                  i = sym_dequeue_from_squeue(np, i, cp->target, cp->lun, -1);
  
                  /*
                   *  Make sure at least our IO to abort has been dequeued.
                   */
                  assert(i && sym_get_cam_status(cp->cam_ccb) == CAM_REQUEUE_REQ);
  
                  /*
                   *  Keep track in cam status of the reason of the abort.
                   */
                  if (cp->to_abort == 2)
                          sym_set_cam_status(cp->cam_ccb, CAM_CMD_TIMEOUT);
                  else
                          sym_set_cam_status(cp->cam_ccb, CAM_REQ_ABORTED);
  
                  /*
                   *  Complete with error everything that we have dequeued.
                   */
                  sym_flush_comp_queue(np, 0);
                  break;
          /*
           *  The SCRIPTS processor has selected a target
           *  we may have some manual recovery to perform for.
           */
          case SIR_TARGET_SELECTED:
                  target = (INB (nc_sdid) & 0xf);
                  tp = &np->target[target];
  
                  np->abrt_tbl.addr = cpu_to_scr(vtobus(np->abrt_msg));
  
                  /*
                   *  If the target is to be reset, prepare a
                   *  M_RESET message and clear the to_reset flag
                   *  since we donnot expect this operation to fail.
                   */
                  if (tp->to_reset) {
                          np->abrt_msg[0] = M_RESET;
                          np->abrt_tbl.size = 1;
                          tp->to_reset = 0;
                          break;
                  }
  
                  /*
                   *  Otherwise, look for some logical unit to be cleared.
                   */
                  if (tp->lun0p && tp->lun0p->to_clear)
                          lun = 0;
                  else if (tp->lunmp) {
                          for (k = 1 ; k < SYM_CONF_MAX_LUN ; k++) {
                                  if (tp->lunmp[k] && tp->lunmp[k]->to_clear) {
                                          lun = k;
                                          break;
                                  }
                          }
                  }
  
                  /*
                   *  If a logical unit is to be cleared, prepare
                   *  an IDENTIFY(lun) + ABORT MESSAGE.
                   */
                  if (lun != -1) {
                          lcb_p lp = sym_lp(np, tp, lun);
                          lp->to_clear = 0; /* We donnot expect to fail here */
                          np->abrt_msg[0] = M_IDENTIFY | lun;
                          np->abrt_msg[1] = M_ABORT;
                          np->abrt_tbl.size = 2;
                          break;
                  }
  
                  /*
                   *  Otherwise, look for some disconnected job to
                   *  abort for this target.
                   */
                  i = 0;
                  cp = NULL;
                  FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
                          cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
                          if (cp->host_status != HS_DISCONNECT)
                                  continue;
                          if (cp->target != target)
                                  continue;
                          if (!cp->to_abort)
                                  continue;
                          i = 1;  /* Means we have some */
                          break;
                  }
  
                  /*
                   *  If we have none, probably since the device has
                   *  completed the command before we won abitration,
                   *  send a M_ABORT message without IDENTIFY.
                   *  According to the specs, the device must just
                   *  disconnect the BUS and not abort any task.
                   */
                  if (!i) {
                          np->abrt_msg[0] = M_ABORT;
                          np->abrt_tbl.size = 1;
                          break;
                  }
  
                  /*
                   *  We have some task to abort.
                   *  Set the IDENTIFY(lun)
                   */
                  np->abrt_msg[0] = M_IDENTIFY | cp->lun;
  
                  /*
                   *  If we want to abort an untagged command, we
                   *  will send an IDENTIFY + M_ABORT.
                   *  Otherwise (tagged command), we will send
                   *  an IDENTIFY + task attributes + ABORT TAG.
                   */
                  if (cp->tag == NO_TAG) {
                          np->abrt_msg[1] = M_ABORT;
                          np->abrt_tbl.size = 2;
                  }
                  else {
                          np->abrt_msg[1] = cp->scsi_smsg[1];
                          np->abrt_msg[2] = cp->scsi_smsg[2];
                          np->abrt_msg[3] = M_ABORT_TAG;
                          np->abrt_tbl.size = 4;
                  }
                  /*
                   *  Keep track of software timeout condition, since the
                   *  peripheral driver may not count retries on abort
                   *  conditions not due to timeout.
                   */
                  if (cp->to_abort == 2)
                          sym_set_cam_status(cp->cam_ccb, CAM_CMD_TIMEOUT);
                  cp->to_abort = 0; /* We donnot expect to fail here */
                  break;
  
          /*
           *  The target has accepted our message and switched
           *  to BUS FREE phase as we expected.
           */
          case SIR_ABORT_SENT:
                  target = (INB (nc_sdid) & 0xf);
                  tp = &np->target[target];
  
                  /*
                  **  If we didn't abort anything, leave here.
                  */
                  if (np->abrt_msg[0] == M_ABORT)
                          break;
  
                  /*
                   *  If we sent a M_RESET, then a hardware reset has
                   *  been performed by the target.
                   *  - Reset everything to async 8 bit
                   *  - Tell ourself to negotiate next time :-)
                   *  - Prepare to clear all disconnected CCBs for
                   *    this target from our task list (lun=task=-1)
                   */
                  lun = -1;
                  task = -1;
                  if (np->abrt_msg[0] == M_RESET) {
                          tp->head.sval = 0;
                          tp->head.wval = np->rv_scntl3;
                          tp->head.uval = 0;
                          tp->tinfo.current.period = 0;
                          tp->tinfo.current.offset = 0;
                          tp->tinfo.current.width  = BUS_8_BIT;
                          tp->tinfo.current.options = 0;
                  }
  
                  /*
                   *  Otherwise, check for the LUN and TASK(s)
                   *  concerned by the cancelation.
                   *  If it is not ABORT_TAG then it is CLEAR_QUEUE
                   *  or an ABORT message :-)
                   */
                  else {
                          lun = np->abrt_msg[0] & 0x3f;
                          if (np->abrt_msg[1] == M_ABORT_TAG)
                                  task = np->abrt_msg[2];
                  }
  
                  /*
                   *  Complete all the CCBs the device should have
                   *  aborted due to our 'kiss of death' message.
                   */
                  i = (INL (nc_scratcha) - np->squeue_ba) / 4;
                  (void) sym_dequeue_from_squeue(np, i, target, lun, -1);
                  (void) sym_clear_tasks(np, CAM_REQ_ABORTED, target, lun, task);
                  sym_flush_comp_queue(np, 0);
  
                  /*
                   *  If we sent a BDR, make uper layer aware of that.
                   */
                  if (np->abrt_msg[0] == M_RESET)
                          xpt_async(AC_SENT_BDR, np->path, NULL);
                  break;
          }
  
          /*
           *  Print to the log the message we intend to send.
           */
          if (num == SIR_TARGET_SELECTED) {
                  PRINT_TARGET(np, target);
                  sym_printl_hex("control msgout:", np->abrt_msg,
                                np->abrt_tbl.size);
                  np->abrt_tbl.size = cpu_to_scr(np->abrt_tbl.size);
          }
  
          /*
           *  Let the SCRIPTS processor continue.
           */
          OUTONB_STD ();
  }
  
  /*
   *  Gerard's alchemy:) that deals with with the data
   *  pointer for both MDP and the residual calculation.
   *
   *  I didn't want to bloat the code by more than 200
   *  lignes for the handling of both MDP and the residual.
   *  This has been achieved by using a data pointer
   *  representation consisting in an index in the data
   *  array (dp_sg) and a negative offset (dp_ofs) that
   *  have the following meaning:
   *
   *  - dp_sg = SYM_CONF_MAX_SG
   *    we are at the end of the data script.
   *  - dp_sg < SYM_CONF_MAX_SG
   *    dp_sg points to the next entry of the scatter array
   *    we want to transfer.
   *  - dp_ofs < 0
   *    dp_ofs represents the residual of bytes of the
   *    previous entry scatter entry we will send first.
   *  - dp_ofs = 0
   *    no residual to send first.
   *
   *  The function sym_evaluate_dp() accepts an arbitray
   *  offset (basically from the MDP message) and returns
   *  the corresponding values of dp_sg and dp_ofs.
   */
  
  static int sym_evaluate_dp(hcb_p np, ccb_p cp, u32 scr, int *ofs)
  {
          u32     dp_scr;
          int     dp_ofs, dp_sg, dp_sgmin;
          int     tmp;
          struct sym_pmc *pm;
  
          /*
           *  Compute the resulted data pointer in term of a script
           *  address within some DATA script and a signed byte offset.
           */
          dp_scr = scr;
          dp_ofs = *ofs;
          if      (dp_scr == SCRIPTA_BA (np, pm0_data))
                  pm = &cp->phys.pm0;
          else if (dp_scr == SCRIPTA_BA (np, pm1_data))
                  pm = &cp->phys.pm1;
          else
                  pm = NULL;
  
          if (pm) {
                  dp_scr  = scr_to_cpu(pm->ret);
                  dp_ofs -= scr_to_cpu(pm->sg.size);
          }
  
          /*
           *  If we are auto-sensing, then we are done.
           */
          if (cp->host_flags & HF_SENSE) {
                  *ofs = dp_ofs;
                  return 0;
          }
  
          /*
           *  Deduce the index of the sg entry.
           *  Keep track of the index of the first valid entry.
           *  If result is dp_sg = SYM_CONF_MAX_SG, then we are at the
           *  end of the data.
           */
          tmp = scr_to_cpu(cp->phys.head.goalp);
          dp_sg = SYM_CONF_MAX_SG;
          if (dp_scr != tmp)
                  dp_sg -= (tmp - 8 - (int)dp_scr) / (2*4);
          dp_sgmin = SYM_CONF_MAX_SG - cp->segments;
  
          /*
           *  Move to the sg entry the data pointer belongs to.
           *
           *  If we are inside the data area, we expect result to be:
           *
           *  Either,
           *      dp_ofs = 0 and dp_sg is the index of the sg entry
           *      the data pointer belongs to (or the end of the data)
           *  Or,
           *      dp_ofs < 0 and dp_sg is the index of the sg entry
           *      the data pointer belongs to + 1.
           */
          if (dp_ofs < 0) {
                  int n;
                  while (dp_sg > dp_sgmin) {
                          --dp_sg;
                          tmp = scr_to_cpu(cp->phys.data[dp_sg].size);
                          n = dp_ofs + (tmp & 0xffffff);
                          if (n > 0) {
                                  ++dp_sg;
                                  break;
                          }
                          dp_ofs = n;
                  }
          }
          else if (dp_ofs > 0) {
                  while (dp_sg < SYM_CONF_MAX_SG) {
                          tmp = scr_to_cpu(cp->phys.data[dp_sg].size);
                          dp_ofs -= (tmp & 0xffffff);
                          ++dp_sg;
                          if (dp_ofs <= 0)
                                  break;
                  }
          }
  
          /*
           *  Make sure the data pointer is inside the data area.
           *  If not, return some error.
           */
          if      (dp_sg < dp_sgmin || (dp_sg == dp_sgmin && dp_ofs < 0))
                  goto out_err;
          else if (dp_sg > SYM_CONF_MAX_SG ||
                   (dp_sg == SYM_CONF_MAX_SG && dp_ofs > 0))
                  goto out_err;
  
          /*
           *  Save the extreme pointer if needed.
           */
          if (dp_sg > cp->ext_sg ||
              (dp_sg == cp->ext_sg && dp_ofs > cp->ext_ofs)) {
                  cp->ext_sg  = dp_sg;
                  cp->ext_ofs = dp_ofs;
          }
  
          /*
           *  Return data.
           */
          *ofs = dp_ofs;
          return dp_sg;
  
  out_err:
          return -1;
  }
  
  /*
   *  chip handler for MODIFY DATA POINTER MESSAGE
   *
   *  We also call this function on IGNORE WIDE RESIDUE
   *  messages that do not match a SWIDE full condition.
   *  Btw, we assume in that situation that such a message
   *  is equivalent to a MODIFY DATA POINTER (offset=-1).
   */
  
  static void sym_modify_dp(hcb_p np, tcb_p tp, ccb_p cp, int ofs)
  {
          int dp_ofs      = ofs;
          u32     dp_scr  = INL (nc_temp);
          u32     dp_ret;
          u32     tmp;
          u_char  hflags;
          int     dp_sg;
          struct  sym_pmc *pm;
  
          /*
           *  Not supported for auto-sense.
           */
          if (cp->host_flags & HF_SENSE)
                  goto out_reject;
  
          /*
           *  Apply our alchemy:) (see comments in sym_evaluate_dp()),
           *  to the resulted data pointer.
           */
          dp_sg = sym_evaluate_dp(np, cp, dp_scr, &dp_ofs);
          if (dp_sg < 0)
                  goto out_reject;
  
          /*
           *  And our alchemy:) allows to easily calculate the data
           *  script address we want to return for the next data phase.
           */
          dp_ret = cpu_to_scr(cp->phys.head.goalp);
          dp_ret = dp_ret - 8 - (SYM_CONF_MAX_SG - dp_sg) * (2*4);
  
          /*
           *  If offset / scatter entry is zero we donnot need
           *  a context for the new current data pointer.
           */
          if (dp_ofs == 0) {
                  dp_scr = dp_ret;
                  goto out_ok;
          }
  
          /*
           *  Get a context for the new current data pointer.
           */
          hflags = INB (HF_PRT);
  
          if (hflags & HF_DP_SAVED)
                  hflags ^= HF_ACT_PM;
  
          if (!(hflags & HF_ACT_PM)) {
                  pm  = &cp->phys.pm0;
                  dp_scr = SCRIPTA_BA (np, pm0_data);
          }
          else {
                  pm = &cp->phys.pm1;
                  dp_scr = SCRIPTA_BA (np, pm1_data);
          }
  
          hflags &= ~(HF_DP_SAVED);
  
          OUTB (HF_PRT, hflags);
  
          /*
           *  Set up the new current data pointer.
           *  ofs < 0 there, and for the next data phase, we
           *  want to transfer part of the data of the sg entry
           *  corresponding to index dp_sg-1 prior to returning
           *  to the main data script.
           */
          pm->ret = cpu_to_scr(dp_ret);
          tmp  = scr_to_cpu(cp->phys.data[dp_sg-1].addr);
          tmp += scr_to_cpu(cp->phys.data[dp_sg-1].size) + dp_ofs;
          pm->sg.addr = cpu_to_scr(tmp);
          pm->sg.size = cpu_to_scr(-dp_ofs);
  
  out_ok:
          OUTL (nc_temp, dp_scr);
          OUTL_DSP (SCRIPTA_BA (np, clrack));
          return;
  
  out_reject:
          OUTL_DSP (SCRIPTB_BA (np, msg_bad));
  }
  
  
  /*
   *  chip calculation of the data residual.
   *
   *  As I used to say, the requirement of data residual
   *  in SCSI is broken, useless and cannot be achieved
   *  without huge complexity.
   *  But most OSes and even the official CAM require it.
   *  When stupidity happens to be so widely spread inside
   *  a community, it gets hard to convince.
   *
   *  Anyway, I don't care, since I am not going to use
   *  any software that considers this data residual as
   *  a relevant information. :)
   */
  
  static int sym_compute_residual(hcb_p np, ccb_p cp)
  {
          int dp_sg, dp_sgmin, resid = 0;
          int dp_ofs = 0;
  
          /*
           *  Check for some data lost or just thrown away.
           *  We are not required to be quite accurate in this
           *  situation. Btw, if we are odd for output and the
           *  device claims some more data, it may well happen
           *  than our residual be zero. :-)
           */
          if (cp->xerr_status & (XE_EXTRA_DATA|XE_SODL_UNRUN|XE_SWIDE_OVRUN)) {
                  if (cp->xerr_status & XE_EXTRA_DATA)
                          resid -= cp->extra_bytes;
                  if (cp->xerr_status & XE_SODL_UNRUN)
                          ++resid;
                  if (cp->xerr_status & XE_SWIDE_OVRUN)
                          --resid;
          }
  
          /*
           *  If all data has been transferred,
           *  there is no residual.
           */
          if (cp->phys.head.lastp == cp->phys.head.goalp)
                  return resid;
  
          /*
           *  If no data transfer occurs, or if the data
           *  pointer is weird, return full residual.
           */
          if (cp->startp == cp->phys.head.lastp ||
              sym_evaluate_dp(np, cp, scr_to_cpu(cp->phys.head.lastp),
                              &dp_ofs) < 0) {
                  return cp->data_len;
          }
  
          /*
           *  If we were auto-sensing, then we are done.
           */
          if (cp->host_flags & HF_SENSE) {
                  return -dp_ofs;
          }
  
          /*
           *  We are now full comfortable in the computation
           *  of the data residual (2's complement).
           */
          dp_sgmin = SYM_CONF_MAX_SG - cp->segments;
          resid = -cp->ext_ofs;
          for (dp_sg = cp->ext_sg; dp_sg < SYM_CONF_MAX_SG; ++dp_sg) {
                  u_int tmp = scr_to_cpu(cp->phys.data[dp_sg].size);
                  resid += (tmp & 0xffffff);
          }
  
          /*
           *  Hopefully, the result is not too wrong.
           */
          return resid;
  }
  
  /*
   *  Print out the content of a SCSI message.
   */
  
  static int sym_show_msg (u_char * msg)
  {
          u_char i;
          printf ("%x",*msg);
          if (*msg==M_EXTENDED) {
                  for (i=1;i<8;i++) {
                          if (i-1>msg[1]) break;
                          printf ("-%x",msg[i]);
                  };
                  return (i+1);
          } else if ((*msg & 0xf0) == 0x20) {
                  printf ("-%x",msg[1]);
                  return (2);
          };
          return (1);
  }
  
  static void sym_print_msg (ccb_p cp, char *label, u_char *msg)
  {
          PRINT_ADDR(cp);
          if (label)
                  printf ("%s: ", label);
  
          (void) sym_show_msg (msg);
          printf (".\n");
  }
  
  /*
   *  Negotiation for WIDE and SYNCHRONOUS DATA TRANSFER.
   *
   *  When we try to negotiate, we append the negotiation message
   *  to the identify and (maybe) simple tag message.
   *  The host status field is set to HS_NEGOTIATE to mark this
   *  situation.
   *
   *  If the target doesn't answer this message immediately
   *  (as required by the standard), the SIR_NEGO_FAILED interrupt
   *  will be raised eventually.
   *  The handler removes the HS_NEGOTIATE status, and sets the
   *  negotiated value to the default (async / nowide).
   *
   *  If we receive a matching answer immediately, we check it
   *  for validity, and set the values.
   *
   *  If we receive a Reject message immediately, we assume the
   *  negotiation has failed, and fall back to standard values.
   *
   *  If we receive a negotiation message while not in HS_NEGOTIATE
   *  state, it's a target initiated negotiation. We prepare a
   *  (hopefully) valid answer, set our parameters, and send back
   *  this answer to the target.
   *
   *  If the target doesn't fetch the answer (no message out phase),
   *  we assume the negotiation has failed, and fall back to default
   *  settings (SIR_NEGO_PROTO interrupt).
   *
   *  When we set the values, we adjust them in all ccbs belonging
   *  to this target, in the controller's register, and in the "phys"
   *  field of the controller's struct sym_hcb.
   */
  
  /*
   *  chip handler for SYNCHRONOUS DATA TRANSFER REQUEST (SDTR) message.
   */
  static void sym_sync_nego(hcb_p np, tcb_p tp, ccb_p cp)
  {
          u_char  chg, ofs, per, fak, div;
          int     req = 1;
  
          /*
           *  Synchronous request message received.
           */
          if (DEBUG_FLAGS & DEBUG_NEGO) {
                  sym_print_msg(cp, "sync msgin", np->msgin);
          };
  
          /*
           * request or answer ?
           */
          if (INB (HS_PRT) == HS_NEGOTIATE) {
                  OUTB (HS_PRT, HS_BUSY);
                  if (cp->nego_status && cp->nego_status != NS_SYNC)
                          goto reject_it;
                  req = 0;
          }
  
          /*
           *  get requested values.
           */
          chg = 0;
          per = np->msgin[3];
          ofs = np->msgin[4];
  
          /*
           *  check values against our limits.
           */
          if (ofs) {
                  if (ofs > np->maxoffs)
                          {chg = 1; ofs = np->maxoffs;}
                  if (req) {
                          if (ofs > tp->tinfo.user.offset)
                                  {chg = 1; ofs = tp->tinfo.user.offset;}
                  }
          }
  
          if (ofs) {
                  if (per < np->minsync)
                          {chg = 1; per = np->minsync;}
                  if (req) {
                          if (per < tp->tinfo.user.period)
                                  {chg = 1; per = tp->tinfo.user.period;}
                  }
          }
  
          div = fak = 0;
          if (ofs && sym_getsync(np, 0, per, &div, &fak) < 0)
                  goto reject_it;
  
          if (DEBUG_FLAGS & DEBUG_NEGO) {
                  PRINT_ADDR(cp);
                  printf ("sdtr: ofs=%d per=%d div=%d fak=%d chg=%d.\n",
                          ofs, per, div, fak, chg);
          }
  
          /*
           *  This was an answer message
           */
          if (req == 0) {
                  if (chg)        /* Answer wasn't acceptable. */
                          goto reject_it;
                  sym_setsync (np, cp, ofs, per, div, fak);
                  OUTL_DSP (SCRIPTA_BA (np, clrack));
                  return;
          }
  
          /*
           *  It was a request. Set value and
           *  prepare an answer message
           */
          sym_setsync (np, cp, ofs, per, div, fak);
  
          np->msgout[0] = M_EXTENDED;
          np->msgout[1] = 3;
          np->msgout[2] = M_X_SYNC_REQ;
          np->msgout[3] = per;
          np->msgout[4] = ofs;
  
          cp->nego_status = NS_SYNC;
  
          if (DEBUG_FLAGS & DEBUG_NEGO) {
                  sym_print_msg(cp, "sync msgout", np->msgout);
          }
  
          np->msgin [0] = M_NOOP;
  
          OUTL_DSP (SCRIPTB_BA (np, sdtr_resp));
          return;
  reject_it:
          sym_setsync (np, cp, 0, 0, 0, 0);
          OUTL_DSP (SCRIPTB_BA (np, msg_bad));
  }
  
  /*
   *  chip handler for PARALLEL PROTOCOL REQUEST (PPR) message.
   */
  static void sym_ppr_nego(hcb_p np, tcb_p tp, ccb_p cp)
  {
          u_char  chg, ofs, per, fak, dt, div, wide;
          int     req = 1;
  
          /*
           * Synchronous request message received.
           */
          if (DEBUG_FLAGS & DEBUG_NEGO) {
                  sym_print_msg(cp, "ppr msgin", np->msgin);
          };
  
          /*
           *  get requested values.
           */
          chg  = 0;
          per  = np->msgin[3];
          ofs  = np->msgin[5];
          wide = np->msgin[6];
          dt   = np->msgin[7] & PPR_OPT_DT;
  
          /*
           * request or answer ?
           */
          if (INB (HS_PRT) == HS_NEGOTIATE) {
                  OUTB (HS_PRT, HS_BUSY);
                  if (cp->nego_status && cp->nego_status != NS_PPR)
                          goto reject_it;
                  req = 0;
          }
  
          /*
           *  check values against our limits.
           */
          if (wide > np->maxwide)
                  {chg = 1; wide = np->maxwide;}
          if (!wide || !(np->features & FE_ULTRA3))
                  dt &= ~PPR_OPT_DT;
          if (req) {
                  if (wide > tp->tinfo.user.width)
                          {chg = 1; wide = tp->tinfo.user.width;}
          }
  
          if (!(np->features & FE_U3EN))  /* Broken U3EN bit not supported */
                  dt &= ~PPR_OPT_DT;
  
          if (dt != (np->msgin[7] & PPR_OPT_MASK)) chg = 1;
  
          if (ofs) {
                  if (dt) {
                          if (ofs > np->maxoffs_dt)
                                  {chg = 1; ofs = np->maxoffs_dt;}
                  }
                  else if (ofs > np->maxoffs)
                          {chg = 1; ofs = np->maxoffs;}
                  if (req) {
                          if (ofs > tp->tinfo.user.offset)
                                  {chg = 1; ofs = tp->tinfo.user.offset;}
                  }
          }
  
          if (ofs) {
                  if (dt) {
                          if (per < np->minsync_dt)
                                  {chg = 1; per = np->minsync_dt;}
                  }
                  else if (per < np->minsync)
                          {chg = 1; per = np->minsync;}
                  if (req) {
                          if (per < tp->tinfo.user.period)
                                  {chg = 1; per = tp->tinfo.user.period;}
                  }
          }
  
          div = fak = 0;
          if (ofs && sym_getsync(np, dt, per, &div, &fak) < 0)
                  goto reject_it;
  
          if (DEBUG_FLAGS & DEBUG_NEGO) {
                  PRINT_ADDR(cp);
                  printf ("ppr: "
                          "dt=%x ofs=%d per=%d wide=%d div=%d fak=%d chg=%d.\n",
                          dt, ofs, per, wide, div, fak, chg);
          }
  
          /*
           *  It was an answer.
           */
          if (req == 0) {
                  if (chg)        /* Answer wasn't acceptable */
                          goto reject_it;
                  sym_setpprot (np, cp, dt, ofs, per, wide, div, fak);
                  OUTL_DSP (SCRIPTA_BA (np, clrack));
                  return;
          }
  
          /*
           *  It was a request. Set value and
           *  prepare an answer message
           */
          sym_setpprot (np, cp, dt, ofs, per, wide, div, fak);
  
          np->msgout[0] = M_EXTENDED;
          np->msgout[1] = 6;
          np->msgout[2] = M_X_PPR_REQ;
          np->msgout[3] = per;
          np->msgout[4] = 0;
          np->msgout[5] = ofs;
          np->msgout[6] = wide;
          np->msgout[7] = dt;
  
          cp->nego_status = NS_PPR;
  
          if (DEBUG_FLAGS & DEBUG_NEGO) {
                  sym_print_msg(cp, "ppr msgout", np->msgout);
          }
  
          np->msgin [0] = M_NOOP;
  
          OUTL_DSP (SCRIPTB_BA (np, ppr_resp));
          return;
  reject_it:
          sym_setpprot (np, cp, 0, 0, 0, 0, 0, 0);
          OUTL_DSP (SCRIPTB_BA (np, msg_bad));
          /*
           *  If it was a device response that should result in
           *  ST, we may want to try a legacy negotiation later.
           */
          if (!req && !dt) {
                  tp->tinfo.goal.options = 0;
                  tp->tinfo.goal.width   = wide;
                  tp->tinfo.goal.period  = per;
                  tp->tinfo.goal.offset  = ofs;
          }
  }
  
  /*
   *  chip handler for WIDE DATA TRANSFER REQUEST (WDTR) message.
   */
  static void sym_wide_nego(hcb_p np, tcb_p tp, ccb_p cp)
  {
          u_char  chg, wide;
          int     req = 1;
  
          /*
           *  Wide request message received.
           */
          if (DEBUG_FLAGS & DEBUG_NEGO) {
                  sym_print_msg(cp, "wide msgin", np->msgin);
          };
  
          /*
           * Is it a request from the device?
           */
          if (INB (HS_PRT) == HS_NEGOTIATE) {
                  OUTB (HS_PRT, HS_BUSY);
                  if (cp->nego_status && cp->nego_status != NS_WIDE)
                          goto reject_it;
                  req = 0;
          }
  
          /*
           *  get requested values.
           */
          chg  = 0;
          wide = np->msgin[3];
  
          /*
           *  check values against driver limits.
           */
          if (wide > np->maxwide)
                  {chg = 1; wide = np->maxwide;}
          if (req) {
                  if (wide > tp->tinfo.user.width)
                          {chg = 1; wide = tp->tinfo.user.width;}
          }
  
          if (DEBUG_FLAGS & DEBUG_NEGO) {
                  PRINT_ADDR(cp);
                  printf ("wdtr: wide=%d chg=%d.\n", wide, chg);
          }
  
          /*
           * This was an answer message
           */
          if (req == 0) {
                  if (chg)        /*  Answer wasn't acceptable. */
                          goto reject_it;
                  sym_setwide (np, cp, wide);
  
                  /*
                   * Negotiate for SYNC immediately after WIDE response.
                   * This allows to negotiate for both WIDE and SYNC on
                   * a single SCSI command (Suggested by Justin Gibbs).
                   */
                  if (tp->tinfo.goal.offset) {
                          np->msgout[0] = M_EXTENDED;
                          np->msgout[1] = 3;
                          np->msgout[2] = M_X_SYNC_REQ;
                          np->msgout[3] = tp->tinfo.goal.period;
                          np->msgout[4] = tp->tinfo.goal.offset;
  
                          if (DEBUG_FLAGS & DEBUG_NEGO) {
                                  sym_print_msg(cp, "sync msgout", np->msgout);
                          }
  
                          cp->nego_status = NS_SYNC;
                          OUTB (HS_PRT, HS_NEGOTIATE);
                          OUTL_DSP (SCRIPTB_BA (np, sdtr_resp));
                          return;
                  }
  
                  OUTL_DSP (SCRIPTA_BA (np, clrack));
                  return;
          };
  
          /*
           *  It was a request, set value and
           *  prepare an answer message
           */
          sym_setwide (np, cp, wide);
  
          np->msgout[0] = M_EXTENDED;
          np->msgout[1] = 2;
          np->msgout[2] = M_X_WIDE_REQ;
          np->msgout[3] = wide;
  
          np->msgin [0] = M_NOOP;
  
          cp->nego_status = NS_WIDE;
  
          if (DEBUG_FLAGS & DEBUG_NEGO) {
                  sym_print_msg(cp, "wide msgout", np->msgout);
          }
  
          OUTL_DSP (SCRIPTB_BA (np, wdtr_resp));
          return;
  reject_it:
          OUTL_DSP (SCRIPTB_BA (np, msg_bad));
  }
  
  /*
   *  Reset SYNC or WIDE to default settings.
   *
   *  Called when a negotiation does not succeed either
   *  on rejection or on protocol error.
   *
   *  If it was a PPR that made problems, we may want to
   *  try a legacy negotiation later.
   */
  static void sym_nego_default(hcb_p np, tcb_p tp, ccb_p cp)
  {
          /*
           *  any error in negotiation:
           *  fall back to default mode.
           */
          switch (cp->nego_status) {
          case NS_PPR:
  #if 0
                  sym_setpprot (np, cp, 0, 0, 0, 0, 0, 0);
  #else
                  tp->tinfo.goal.options = 0;
                  if (tp->tinfo.goal.period < np->minsync)
                          tp->tinfo.goal.period = np->minsync;
                  if (tp->tinfo.goal.offset > np->maxoffs)
                          tp->tinfo.goal.offset = np->maxoffs;
  #endif
                  break;
          case NS_SYNC:
                  sym_setsync (np, cp, 0, 0, 0, 0);
                  break;
          case NS_WIDE:
                  sym_setwide (np, cp, 0);
                  break;
          };
          np->msgin [0] = M_NOOP;
          np->msgout[0] = M_NOOP;
          cp->nego_status = 0;
  }
  
  /*
   *  chip handler for MESSAGE REJECT received in response to
   *  a WIDE or SYNCHRONOUS negotiation.
   */
  static void sym_nego_rejected(hcb_p np, tcb_p tp, ccb_p cp)
  {
          sym_nego_default(np, tp, cp);
          OUTB (HS_PRT, HS_BUSY);
  }
  
  /*
   *  chip exception handler for programmed interrupts.
   */
  static void sym_int_sir (hcb_p np)
  {
          u_char  num     = INB (nc_dsps);
          u32     dsa     = INL (nc_dsa);
          ccb_p   cp      = sym_ccb_from_dsa(np, dsa);
          u_char  target  = INB (nc_sdid) & 0x0f;
          tcb_p   tp      = &np->target[target];
          int     tmp;
  
          if (DEBUG_FLAGS & DEBUG_TINY) printf ("I#%d", num);
  
          switch (num) {
          /*
           *  Command has been completed with error condition
           *  or has been auto-sensed.
           */
          case SIR_COMPLETE_ERROR:
                  sym_complete_error(np, cp);
                  return;
          /*
           *  The C code is currently trying to recover from something.
           *  Typically, user want to abort some command.
           */
          case SIR_SCRIPT_STOPPED:
          case SIR_TARGET_SELECTED:
          case SIR_ABORT_SENT:
                  sym_sir_task_recovery(np, num);
                  return;
          /*
           *  The device didn't go to MSG OUT phase after having
           *  been selected with ATN. We donnot want to handle
           *  that.
           */
          case SIR_SEL_ATN_NO_MSG_OUT:
                  printf ("%s:%d: No MSG OUT phase after selection with ATN.\n",
                          sym_name (np), target);
                  goto out_stuck;
          /*
           *  The device didn't switch to MSG IN phase after
           *  having reseleted the initiator.
           */
          case SIR_RESEL_NO_MSG_IN:
                  printf ("%s:%d: No MSG IN phase after reselection.\n",
                          sym_name (np), target);
                  goto out_stuck;
          /*
           *  After reselection, the device sent a message that wasn't
           *  an IDENTIFY.
           */
          case SIR_RESEL_NO_IDENTIFY:
                  printf ("%s:%d: No IDENTIFY after reselection.\n",
                          sym_name (np), target);
                  goto out_stuck;
          /*
           *  The device reselected a LUN we donnot know about.
           */
          case SIR_RESEL_BAD_LUN:
                  np->msgout[0] = M_RESET;
                  goto out;
          /*
           *  The device reselected for an untagged nexus and we
           *  haven't any.
           */
          case SIR_RESEL_BAD_I_T_L:
                  np->msgout[0] = M_ABORT;
                  goto out;
          /*
           *  The device reselected for a tagged nexus that we donnot
           *  have.
           */
          case SIR_RESEL_BAD_I_T_L_Q:
                  np->msgout[0] = M_ABORT_TAG;
                  goto out;
          /*
           *  The SCRIPTS let us know that the device has grabbed
           *  our message and will abort the job.
           */
          case SIR_RESEL_ABORTED:
                  np->lastmsg = np->msgout[0];
                  np->msgout[0] = M_NOOP;
                  printf ("%s:%d: message %x sent on bad reselection.\n",
                          sym_name (np), target, np->lastmsg);
                  goto out;
          /*
           *  The SCRIPTS let us know that a message has been
           *  successfully sent to the device.
           */
          case SIR_MSG_OUT_DONE:
                  np->lastmsg = np->msgout[0];
                  np->msgout[0] = M_NOOP;
                  /* Should we really care of that */
                  if (np->lastmsg == M_PARITY || np->lastmsg == M_ID_ERROR) {
                          if (cp) {
                                  cp->xerr_status &= ~XE_PARITY_ERR;
                                  if (!cp->xerr_status)
                                          OUTOFFB (HF_PRT, HF_EXT_ERR);
                          }
                  }
                  goto out;
          /*
           *  The device didn't send a GOOD SCSI status.
           *  We may have some work to do prior to allow
           *  the SCRIPTS processor to continue.
           */
          case SIR_BAD_SCSI_STATUS:
                  if (!cp)
                          goto out;
                  sym_sir_bad_scsi_status(np, num, cp);
                  return;
          /*
           *  We are asked by the SCRIPTS to prepare a
           *  REJECT message.
           */
          case SIR_REJECT_TO_SEND:
                  sym_print_msg(cp, "M_REJECT to send for ", np->msgin);
                  np->msgout[0] = M_REJECT;
                  goto out;
          /*
           *  We have been ODD at the end of a DATA IN
           *  transfer and the device didn't send a
           *  IGNORE WIDE RESIDUE message.
           *  It is a data overrun condition.
           */
          case SIR_SWIDE_OVERRUN:
                  if (cp) {
                          OUTONB (HF_PRT, HF_EXT_ERR);
                          cp->xerr_status |= XE_SWIDE_OVRUN;
                  }
                  goto out;
          /*
           *  We have been ODD at the end of a DATA OUT
           *  transfer.
           *  It is a data underrun condition.
           */
          case SIR_SODL_UNDERRUN:
                  if (cp) {
                          OUTONB (HF_PRT, HF_EXT_ERR);
                          cp->xerr_status |= XE_SODL_UNRUN;
                  }
                  goto out;
          /*
           *  The device wants us to tranfer more data than
           *  expected or in the wrong direction.
           *  The number of extra bytes is in scratcha.
           *  It is a data overrun condition.
           */
          case SIR_DATA_OVERRUN:
                  if (cp) {
                          OUTONB (HF_PRT, HF_EXT_ERR);
                          cp->xerr_status |= XE_EXTRA_DATA;
                          cp->extra_bytes += INL (nc_scratcha);
                  }
                  goto out;
          /*
           *  The device switched to an illegal phase (4/5).
           */
          case SIR_BAD_PHASE:
                  if (cp) {
                          OUTONB (HF_PRT, HF_EXT_ERR);
                          cp->xerr_status |= XE_BAD_PHASE;
                  }
                  goto out;
          /*
           *  We received a message.
           */
          case SIR_MSG_RECEIVED:
                  if (!cp)
                          goto out_stuck;
                  switch (np->msgin [0]) {
                  /*
                   *  We received an extended message.
                   *  We handle MODIFY DATA POINTER, SDTR, WDTR
                   *  and reject all other extended messages.
                   */
                  case M_EXTENDED:
                          switch (np->msgin [2]) {
                          case M_X_MODIFY_DP:
                                  if (DEBUG_FLAGS & DEBUG_POINTER)
                                          sym_print_msg(cp,"modify DP",np->msgin);
                                  tmp = (np->msgin[3]<<24) + (np->msgin[4]<<16) +
                                        (np->msgin[5]<<8)  + (np->msgin[6]);
                                  sym_modify_dp(np, tp, cp, tmp);
                                  return;
                          case M_X_SYNC_REQ:
                                  sym_sync_nego(np, tp, cp);
                                  return;
                          case M_X_PPR_REQ:
                                  sym_ppr_nego(np, tp, cp);
                                  return;
                          case M_X_WIDE_REQ:
                                  sym_wide_nego(np, tp, cp);
                                  return;
                          default:
                                  goto out_reject;
                          }
                          break;
                  /*
                   *  We received a 1/2 byte message not handled from SCRIPTS.
                   *  We are only expecting MESSAGE REJECT and IGNORE WIDE
                   *  RESIDUE messages that haven't been anticipated by
                   *  SCRIPTS on SWIDE full condition. Unanticipated IGNORE
                   *  WIDE RESIDUE messages are aliased as MODIFY DP (-1).
                   */
                  case M_IGN_RESIDUE:
                          if (DEBUG_FLAGS & DEBUG_POINTER)
                                  sym_print_msg(cp,"ign wide residue", np->msgin);
                          sym_modify_dp(np, tp, cp, -1);
                          return;
                  case M_REJECT:
                          if (INB (HS_PRT) == HS_NEGOTIATE)
                                  sym_nego_rejected(np, tp, cp);
                          else {
                                  PRINT_ADDR(cp);
                                  printf ("M_REJECT received (%x:%x).\n",
                                          scr_to_cpu(np->lastmsg), np->msgout[0]);
                          }
                          goto out_clrack;
                          break;
                  default:
                          goto out_reject;
                  }
                  break;
          /*
           *  We received an unknown message.
           *  Ignore all MSG IN phases and reject it.
           */
          case SIR_MSG_WEIRD:
                  sym_print_msg(cp, "WEIRD message received", np->msgin);
                  OUTL_DSP (SCRIPTB_BA (np, msg_weird));
                  return;
          /*
           *  Negotiation failed.
           *  Target does not send us the reply.
           *  Remove the HS_NEGOTIATE status.
           */
          case SIR_NEGO_FAILED:
                  OUTB (HS_PRT, HS_BUSY);
          /*
           *  Negotiation failed.
           *  Target does not want answer message.
           */
          case SIR_NEGO_PROTO:
                  sym_nego_default(np, tp, cp);
                  goto out;
          };
  
  out:
          OUTONB_STD ();
          return;
  out_reject:
          OUTL_DSP (SCRIPTB_BA (np, msg_bad));
          return;
  out_clrack:
          OUTL_DSP (SCRIPTA_BA (np, clrack));
          return;
  out_stuck:
          return;
  }
  
  /*
   *  Acquire a control block
   */
  static  ccb_p sym_get_ccb (hcb_p np, u_char tn, u_char ln, u_char tag_order)
  {
          tcb_p tp = &np->target[tn];
          lcb_p lp = sym_lp(np, tp, ln);
          u_short tag = NO_TAG;
          SYM_QUEHEAD *qp;
          ccb_p cp = (ccb_p) NULL;
  
          /*
           *  Look for a free CCB
           */
          if (sym_que_empty(&np->free_ccbq))
                  (void) sym_alloc_ccb(np);
          qp = sym_remque_head(&np->free_ccbq);
          if (!qp)
                  goto out;
          cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
  
          /*
           *  If the LCB is not yet available and the LUN
           *  has been probed ok, try to allocate the LCB.
           */
          if (!lp && sym_is_bit(tp->lun_map, ln)) {
                  lp = sym_alloc_lcb(np, tn, ln);
                  if (!lp)
                          goto out_free;
          }
  
          /*
           *  If the LCB is not available here, then the
           *  logical unit is not yet discovered. For those
           *  ones only accept 1 SCSI IO per logical unit,
           *  since we cannot allow disconnections.
           */
          if (!lp) {
                  if (!sym_is_bit(tp->busy0_map, ln))
                          sym_set_bit(tp->busy0_map, ln);
                  else
                          goto out_free;
          } else {
                  /*
                   *  If we have been asked for a tagged command.
                   */
                  if (tag_order) {
                          /*
                           *  Debugging purpose.
                           */
                          assert(lp->busy_itl == 0);
                          /*
                           *  Allocate resources for tags if not yet.
                           */
                          if (!lp->cb_tags) {
                                  sym_alloc_lcb_tags(np, tn, ln);
                                  if (!lp->cb_tags)
                                          goto out_free;
                          }
                          /*
                           *  Get a tag for this SCSI IO and set up
                           *  the CCB bus address for reselection,
                           *  and count it for this LUN.
                           *  Toggle reselect path to tagged.
                           */
                          if (lp->busy_itlq < SYM_CONF_MAX_TASK) {
                                  tag = lp->cb_tags[lp->ia_tag];
                                  if (++lp->ia_tag == SYM_CONF_MAX_TASK)
                                          lp->ia_tag = 0;
                                  lp->itlq_tbl[tag] = cpu_to_scr(cp->ccb_ba);
                                  ++lp->busy_itlq;
                                  lp->head.resel_sa =
                                          cpu_to_scr(SCRIPTA_BA (np, resel_tag));
                          }
                          else
                                  goto out_free;
                  }
                  /*
                   *  This command will not be tagged.
                   *  If we already have either a tagged or untagged
                   *  one, refuse to overlap this untagged one.
                   */
                  else {
                          /*
                           *  Debugging purpose.
                           */
                          assert(lp->busy_itl == 0 && lp->busy_itlq == 0);
                          /*
                           *  Count this nexus for this LUN.
                           *  Set up the CCB bus address for reselection.
                           *  Toggle reselect path to untagged.
                           */
                          if (++lp->busy_itl == 1) {
                                  lp->head.itl_task_sa = cpu_to_scr(cp->ccb_ba);
                                  lp->head.resel_sa =
                                        cpu_to_scr(SCRIPTA_BA (np, resel_no_tag));
                          }
                          else
                                  goto out_free;
                  }
          }
          /*
           *  Put the CCB into the busy queue.
           */
          sym_insque_tail(&cp->link_ccbq, &np->busy_ccbq);
  
          /*
           *  Remember all informations needed to free this CCB.
           */
          cp->to_abort = 0;
          cp->tag    = tag;
          cp->target = tn;
          cp->lun    = ln;
  
          if (DEBUG_FLAGS & DEBUG_TAGS) {
                  PRINT_LUN(np, tn, ln);
                  printf ("ccb @%p using tag %d.\n", cp, tag);
          }
  
  out:
          return cp;
  out_free:
          sym_insque_head(&cp->link_ccbq, &np->free_ccbq);
          return NULL;
  }
  
  /*
   *  Release one control block
   */
  static void sym_free_ccb (hcb_p np, ccb_p cp)
  {
          tcb_p tp = &np->target[cp->target];
          lcb_p lp = sym_lp(np, tp, cp->lun);
  
          if (DEBUG_FLAGS & DEBUG_TAGS) {
                  PRINT_LUN(np, cp->target, cp->lun);
                  printf ("ccb @%p freeing tag %d.\n", cp, cp->tag);
          }
  
          /*
           *  If LCB available,
           */
          if (lp) {
                  /*
                   *  If tagged, release the tag, set the relect path
                   */
                  if (cp->tag != NO_TAG) {
                          /*
                           *  Free the tag value.
                           */
                          lp->cb_tags[lp->if_tag] = cp->tag;
                          if (++lp->if_tag == SYM_CONF_MAX_TASK)
                                  lp->if_tag = 0;
                          /*
                           *  Make the reselect path invalid,
                           *  and uncount this CCB.
                           */
                          lp->itlq_tbl[cp->tag] = cpu_to_scr(np->bad_itlq_ba);
                          --lp->busy_itlq;
                  } else {        /* Untagged */
                          /*
                           *  Make the reselect path invalid,
                           *  and uncount this CCB.
                           */
                          lp->head.itl_task_sa = cpu_to_scr(np->bad_itl_ba);
                          --lp->busy_itl;
                  }
                  /*
                   *  If no JOB active, make the LUN reselect path invalid.
                   */
                  if (lp->busy_itlq == 0 && lp->busy_itl == 0)
                          lp->head.resel_sa =
                                  cpu_to_scr(SCRIPTB_BA (np, resel_bad_lun));
          }
          /*
           *  Otherwise, we only accept 1 IO per LUN.
           *  Clear the bit that keeps track of this IO.
           */
          else
                  sym_clr_bit(tp->busy0_map, cp->lun);
  
          /*
           *  We donnot queue more than 1 ccb per target
           *  with negotiation at any time. If this ccb was
           *  used for negotiation, clear this info in the tcb.
           */
          if (cp == tp->nego_cp)
                  tp->nego_cp = NULL;
  
  #ifdef SYM_CONF_IARB_SUPPORT
          /*
           *  If we just complete the last queued CCB,
           *  clear this info that is no longer relevant.
           */
          if (cp == np->last_cp)
                  np->last_cp = NULL;
  #endif
  
          /*
           *  Unmap user data from DMA map if needed.
           */
          if (cp->dmamapped) {
                  bus_dmamap_unload(np->data_dmat, cp->dmamap);
                  cp->dmamapped = 0;
          }
  
          /*
           *  Make this CCB available.
           */
          cp->cam_ccb = NULL;
          cp->host_status = HS_IDLE;
          sym_remque(&cp->link_ccbq);
          sym_insque_head(&cp->link_ccbq, &np->free_ccbq);
  }
  
  /*
   *  Allocate a CCB from memory and initialize its fixed part.
   */
  static ccb_p sym_alloc_ccb(hcb_p np)
  {
          ccb_p cp = NULL;
          int hcode;
  
          /*
           *  Prevent from allocating more CCBs than we can
           *  queue to the controller.
           */
          if (np->actccbs >= SYM_CONF_MAX_START)
                  return NULL;
  
          /*
           *  Allocate memory for this CCB.
           */
          cp = sym_calloc_dma(sizeof(struct sym_ccb), "CCB");
          if (!cp)
                  goto out_free;
  
          /*
           *  Allocate a bounce buffer for sense data.
           */
          cp->sns_bbuf = sym_calloc_dma(SYM_SNS_BBUF_LEN, "SNS_BBUF");
          if (!cp->sns_bbuf)
                  goto out_free;
  
          /*
           *  Allocate a map for the DMA of user data.
           */
          if (bus_dmamap_create(np->data_dmat, 0, &cp->dmamap))
                  goto out_free;
          /*
           *  Count it.
           */
          np->actccbs++;
  
          /*
           *  Compute the bus address of this ccb.
           */
          cp->ccb_ba = vtobus(cp);
  
          /*
           *  Insert this ccb into the hashed list.
           */
          hcode = CCB_HASH_CODE(cp->ccb_ba);
          cp->link_ccbh = np->ccbh[hcode];
          np->ccbh[hcode] = cp;
  
          /*
           *  Initialize the start and restart actions.
           */
          cp->phys.head.go.start   = cpu_to_scr(SCRIPTA_BA (np, idle));
          cp->phys.head.go.restart = cpu_to_scr(SCRIPTB_BA (np, bad_i_t_l));
  
          /*
           *  Initilialyze some other fields.
           */
          cp->phys.smsg_ext.addr = cpu_to_scr(HCB_BA(np, msgin[2]));
  
          /*
           *  Chain into free ccb queue.
           */
          sym_insque_head(&cp->link_ccbq, &np->free_ccbq);
  
          return cp;
  out_free:
          if (cp) {
                  if (cp->sns_bbuf)
                          sym_mfree_dma(cp->sns_bbuf,SYM_SNS_BBUF_LEN,"SNS_BBUF");
                  sym_mfree_dma(cp, sizeof(*cp), "CCB");
          }
          return NULL;
  }
  
  /*
   *  Look up a CCB from a DSA value.
   */
  static ccb_p sym_ccb_from_dsa(hcb_p np, u32 dsa)
  {
          int hcode;
          ccb_p cp;
  
          hcode = CCB_HASH_CODE(dsa);
          cp = np->ccbh[hcode];
          while (cp) {
                  if (cp->ccb_ba == dsa)
                          break;
                  cp = cp->link_ccbh;
          }
  
          return cp;
  }
  
  /*
   *  Target control block initialisation.
   *  Nothing important to do at the moment.
   */
  static void sym_init_tcb (hcb_p np, u_char tn)
  {
          /*
           *  Check some alignments required by the chip.
           */
          assert (((offsetof(struct sym_reg, nc_sxfer) ^
                  offsetof(struct sym_tcb, head.sval)) &3) == 0);
          assert (((offsetof(struct sym_reg, nc_scntl3) ^
                  offsetof(struct sym_tcb, head.wval)) &3) == 0);
  }
  
  /*
   *  Lun control block allocation and initialization.
   */
  static lcb_p sym_alloc_lcb (hcb_p np, u_char tn, u_char ln)
  {
          tcb_p tp = &np->target[tn];
          lcb_p lp = sym_lp(np, tp, ln);
  
          /*
           *  Already done, just return.
           */
          if (lp)
                  return lp;
          /*
           *  Check against some race.
           */
          assert(!sym_is_bit(tp->busy0_map, ln));
  
          /*
           *  Initialize the target control block if not yet.
           */
          sym_init_tcb (np, tn);
  
          /*
           *  Allocate the LCB bus address array.
           *  Compute the bus address of this table.
           */
          if (ln && !tp->luntbl) {
                  int i;
  
                  tp->luntbl = sym_calloc_dma(256, "LUNTBL");
                  if (!tp->luntbl)
                          goto fail;
                  for (i = 0 ; i < 64 ; i++)
                          tp->luntbl[i] = cpu_to_scr(vtobus(&np->badlun_sa));
                  tp->head.luntbl_sa = cpu_to_scr(vtobus(tp->luntbl));
          }
  
          /*
           *  Allocate the table of pointers for LUN(s) > 0, if needed.
           */
          if (ln && !tp->lunmp) {
                  tp->lunmp = sym_calloc(SYM_CONF_MAX_LUN * sizeof(lcb_p),
                                     "LUNMP");
                  if (!tp->lunmp)
                          goto fail;
          }
  
          /*
           *  Allocate the lcb.
           *  Make it available to the chip.
           */
          lp = sym_calloc_dma(sizeof(struct sym_lcb), "LCB");
          if (!lp)
                  goto fail;
          if (ln) {
                  tp->lunmp[ln] = lp;
                  tp->luntbl[ln] = cpu_to_scr(vtobus(lp));
          }
          else {
                  tp->lun0p = lp;
                  tp->head.lun0_sa = cpu_to_scr(vtobus(lp));
          }
  
          /*
           *  Let the itl task point to error handling.
           */
          lp->head.itl_task_sa = cpu_to_scr(np->bad_itl_ba);
  
          /*
           *  Set the reselect pattern to our default. :)
           */
          lp->head.resel_sa = cpu_to_scr(SCRIPTB_BA (np, resel_bad_lun));
  
          /*
           *  Set user capabilities.
           */
          lp->user_flags = tp->usrflags & (SYM_DISC_ENABLED | SYM_TAGS_ENABLED);
  
  fail:
          return lp;
  }
  
  /*
   *  Allocate LCB resources for tagged command queuing.
   */
  static void sym_alloc_lcb_tags (hcb_p np, u_char tn, u_char ln)
  {
          tcb_p tp = &np->target[tn];
          lcb_p lp = sym_lp(np, tp, ln);
          int i;
  
          /*
           *  If LCB not available, try to allocate it.
           */
          if (!lp && !(lp = sym_alloc_lcb(np, tn, ln)))
                  return;
  
          /*
           *  Allocate the task table and and the tag allocation
           *  circular buffer. We want both or none.
           */
          lp->itlq_tbl = sym_calloc_dma(SYM_CONF_MAX_TASK*4, "ITLQ_TBL");
          if (!lp->itlq_tbl)
                  return;
          lp->cb_tags = sym_calloc(SYM_CONF_MAX_TASK, "CB_TAGS");
          if (!lp->cb_tags) {
                  sym_mfree_dma(lp->itlq_tbl, SYM_CONF_MAX_TASK*4, "ITLQ_TBL");
                  lp->itlq_tbl = 0;
                  return;
          }
  
          /*
           *  Initialize the task table with invalid entries.
           */
          for (i = 0 ; i < SYM_CONF_MAX_TASK ; i++)
                  lp->itlq_tbl[i] = cpu_to_scr(np->notask_ba);
  
          /*
           *  Fill up the tag buffer with tag numbers.
           */
          for (i = 0 ; i < SYM_CONF_MAX_TASK ; i++)
                  lp->cb_tags[i] = i;
  
          /*
           *  Make the task table available to SCRIPTS,
           *  And accept tagged commands now.
           */
          lp->head.itlq_tbl_sa = cpu_to_scr(vtobus(lp->itlq_tbl));
  }
  
  /*
   *  Test the pci bus snoop logic :-(
   *
   *  Has to be called with interrupts disabled.
   */
  #ifndef SYM_CONF_IOMAPPED
  static int sym_regtest (hcb_p np)
  {
          register volatile u32 data;
          /*
           *  chip registers may NOT be cached.
           *  write 0xffffffff to a read only register area,
           *  and try to read it back.
           */
          data = 0xffffffff;
          OUTL_OFF(offsetof(struct sym_reg, nc_dstat), data);
          data = INL_OFF(offsetof(struct sym_reg, nc_dstat));
  #if 1
          if (data == 0xffffffff) {
  #else
          if ((data & 0xe2f0fffd) != 0x02000080) {
  #endif
                  printf ("CACHE TEST FAILED: reg dstat-sstat2 readback %x.\n",
                          (unsigned) data);
                  return (0x10);
          };
          return (0);
  }
  #endif
  
  static int sym_snooptest (hcb_p np)
  {
          u32     sym_rd, sym_wr, sym_bk, host_rd, host_wr, pc, dstat;
          int     i, err=0;
  #ifndef SYM_CONF_IOMAPPED
          err |= sym_regtest (np);
          if (err) return (err);
  #endif
  restart_test:
          /*
           *  Enable Master Parity Checking as we intend
           *  to enable it for normal operations.
           */
          OUTB (nc_ctest4, (np->rv_ctest4 & MPEE));
          /*
           *  init
           */
          pc  = SCRIPTB0_BA (np, snooptest);
          host_wr = 1;
          sym_wr  = 2;
          /*
           *  Set memory and register.
           */
          np->cache = cpu_to_scr(host_wr);
          OUTL (nc_temp, sym_wr);
          /*
           *  Start script (exchange values)
           */
          OUTL (nc_dsa, np->hcb_ba);
          OUTL_DSP (pc);
          /*
           *  Wait 'til done (with timeout)
           */
          for (i=0; i<SYM_SNOOP_TIMEOUT; i++)
                  if (INB(nc_istat) & (INTF|SIP|DIP))
                          break;
          if (i>=SYM_SNOOP_TIMEOUT) {
                  printf ("CACHE TEST FAILED: timeout.\n");
                  return (0x20);
          };
          /*
           *  Check for fatal DMA errors.
           */
          dstat = INB (nc_dstat);
  #if 1   /* Band aiding for broken hardwares that fail PCI parity */
          if ((dstat & MDPE) && (np->rv_ctest4 & MPEE)) {
                  printf ("%s: PCI DATA PARITY ERROR DETECTED - "
                          "DISABLING MASTER DATA PARITY CHECKING.\n",
                          sym_name(np));
                  np->rv_ctest4 &= ~MPEE;
                  goto restart_test;
          }
  #endif
          if (dstat & (MDPE|BF|IID)) {
                  printf ("CACHE TEST FAILED: DMA error (dstat=0x%02x).", dstat);
                  return (0x80);
          }
          /*
           *  Save termination position.
           */
          pc = INL (nc_dsp);
          /*
           *  Read memory and register.
           */
          host_rd = scr_to_cpu(np->cache);
          sym_rd  = INL (nc_scratcha);
          sym_bk  = INL (nc_temp);
  
          /*
           *  Check termination position.
           */
          if (pc != SCRIPTB0_BA (np, snoopend)+8) {
                  printf ("CACHE TEST FAILED: script execution failed.\n");
                  printf ("start=%08lx, pc=%08lx, end=%08lx\n",
                          (u_long) SCRIPTB0_BA (np, snooptest), (u_long) pc,
                          (u_long) SCRIPTB0_BA (np, snoopend) +8);
                  return (0x40);
          };
          /*
           *  Show results.
           */
          if (host_wr != sym_rd) {
                  printf ("CACHE TEST FAILED: host wrote %d, chip read %d.\n",
                          (int) host_wr, (int) sym_rd);
                  err |= 1;
          };
          if (host_rd != sym_wr) {
                  printf ("CACHE TEST FAILED: chip wrote %d, host read %d.\n",
                          (int) sym_wr, (int) host_rd);
                  err |= 2;
          };
          if (sym_bk != sym_wr) {
                  printf ("CACHE TEST FAILED: chip wrote %d, read back %d.\n",
                          (int) sym_wr, (int) sym_bk);
                  err |= 4;
          };
  
          return (err);
  }
  
  /*
   *  Determine the chip's clock frequency.
   *
   *  This is essential for the negotiation of the synchronous
   *  transfer rate.
   *
   *  Note: we have to return the correct value.
   *  THERE IS NO SAFE DEFAULT VALUE.
   *
   *  Most NCR/SYMBIOS boards are delivered with a 40 Mhz clock.
   *  53C860 and 53C875 rev. 1 support fast20 transfers but
   *  do not have a clock doubler and so are provided with a
   *  80 MHz clock. All other fast20 boards incorporate a doubler
   *  and so should be delivered with a 40 MHz clock.
   *  The recent fast40 chips (895/896/895A/1010) use a 40 Mhz base
   *  clock and provide a clock quadrupler (160 Mhz).
   */
  
  /*
   *  Select SCSI clock frequency
   */
  static void sym_selectclock(hcb_p np, u_char scntl3)
  {
          /*
           *  If multiplier not present or not selected, leave here.
           */
          if (np->multiplier <= 1) {
                  OUTB(nc_scntl3, scntl3);
                  return;
          }
  
          if (sym_verbose >= 2)
                  printf ("%s: enabling clock multiplier\n", sym_name(np));
  
          OUTB(nc_stest1, DBLEN);    /* Enable clock multiplier             */
          /*
           *  Wait for the LCKFRQ bit to be set if supported by the chip.
           *  Otherwise wait 20 micro-seconds.
           */
          if (np->features & FE_LCKFRQ) {
                  int i = 20;
                  while (!(INB(nc_stest4) & LCKFRQ) && --i > 0)
                          UDELAY (20);
                  if (!i)
                          printf("%s: the chip cannot lock the frequency\n",
                                  sym_name(np));
          } else
                  UDELAY (20);
          OUTB(nc_stest3, HSC);           /* Halt the scsi clock          */
          OUTB(nc_scntl3, scntl3);
          OUTB(nc_stest1, (DBLEN|DBLSEL));/* Select clock multiplier      */
          OUTB(nc_stest3, 0x00);          /* Restart scsi clock           */
  }
  
  /*
   *  calculate SCSI clock frequency (in KHz)
   */
  static unsigned getfreq (hcb_p np, int gen)
  {
          unsigned int ms = 0;
          unsigned int f;
  
          /*
           * Measure GEN timer delay in order
           * to calculate SCSI clock frequency
           *
           * This code will never execute too
           * many loop iterations (if DELAY is
           * reasonably correct). It could get
           * too low a delay (too high a freq.)
           * if the CPU is slow executing the
           * loop for some reason (an NMI, for
           * example). For this reason we will
           * if multiple measurements are to be
           * performed trust the higher delay
           * (lower frequency returned).
           */
          OUTW (nc_sien , 0);     /* mask all scsi interrupts */
          (void) INW (nc_sist);   /* clear pending scsi interrupt */
          OUTB (nc_dien , 0);     /* mask all dma interrupts */
          (void) INW (nc_sist);   /* another one, just to be sure :) */
          OUTB (nc_scntl3, 4);    /* set pre-scaler to divide by 3 */
          OUTB (nc_stime1, 0);    /* disable general purpose timer */
          OUTB (nc_stime1, gen);  /* set to nominal delay of 1<<gen * 125us */
          while (!(INW(nc_sist) & GEN) && ms++ < 100000)
                  UDELAY (1000);  /* count ms */
          OUTB (nc_stime1, 0);    /* disable general purpose timer */
          /*
           * set prescaler to divide by whatever 0 means
           * 0 ought to choose divide by 2, but appears
           * to set divide by 3.5 mode in my 53c810 ...
           */
          OUTB (nc_scntl3, 0);
  
          /*
           * adjust for prescaler, and convert into KHz
           */
          f = ms ? ((1 << gen) * 4340) / ms : 0;
  
          if (sym_verbose >= 2)
                  printf ("%s: Delay (GEN=%d): %u msec, %u KHz\n",
                          sym_name(np), gen, ms, f);
  
          return f;
  }
  
  static unsigned sym_getfreq (hcb_p np)
  {
          u_int f1, f2;
          int gen = 11;
  
          (void) getfreq (np, gen);       /* throw away first result */
          f1 = getfreq (np, gen);
          f2 = getfreq (np, gen);
          if (f1 > f2) f1 = f2;           /* trust lower result   */
          return f1;
  }
  
  /*
   *  Get/probe chip SCSI clock frequency
   */
  static void sym_getclock (hcb_p np, int mult)
  {
          unsigned char scntl3 = np->sv_scntl3;
          unsigned char stest1 = np->sv_stest1;
          unsigned f1;
  
          /*
           *  For the C10 core, assume 40 MHz.
           */
          if (np->features & FE_C10) {
                  np->multiplier = mult;
                  np->clock_khz = 40000 * mult;
                  return;
          }
  
          np->multiplier = 1;
          f1 = 40000;
          /*
           *  True with 875/895/896/895A with clock multiplier selected
           */
          if (mult > 1 && (stest1 & (DBLEN+DBLSEL)) == DBLEN+DBLSEL) {
                  if (sym_verbose >= 2)
                          printf ("%s: clock multiplier found\n", sym_name(np));
                  np->multiplier = mult;
          }
  
          /*
           *  If multiplier not found or scntl3 not 7,5,3,
           *  reset chip and get frequency from general purpose timer.
           *  Otherwise trust scntl3 BIOS setting.
           */
          if (np->multiplier != mult || (scntl3 & 7) < 3 || !(scntl3 & 1)) {
                  OUTB (nc_stest1, 0);            /* make sure doubler is OFF */
                  f1 = sym_getfreq (np);
  
                  if (sym_verbose)
                          printf ("%s: chip clock is %uKHz\n", sym_name(np), f1);
  
                  if      (f1 <   45000)          f1 =  40000;
                  else if (f1 <   55000)          f1 =  50000;
                  else                            f1 =  80000;
  
                  if (f1 < 80000 && mult > 1) {
                          if (sym_verbose >= 2)
                                  printf ("%s: clock multiplier assumed\n",
                                          sym_name(np));
                          np->multiplier  = mult;
                  }
          } else {
                  if      ((scntl3 & 7) == 3)     f1 =  40000;
                  else if ((scntl3 & 7) == 5)     f1 =  80000;
                  else                            f1 = 160000;
  
                  f1 /= np->multiplier;
          }
  
          /*
           *  Compute controller synchronous parameters.
           */
          f1              *= np->multiplier;
          np->clock_khz   = f1;
  }
  
  /*
   *  Get/probe PCI clock frequency
   */
  static int sym_getpciclock (hcb_p np)
  {
          int f = 0;
  
          /*
           *  For the C1010-33, this doesn't work.
           *  For the C1010-66, this will be tested when I'll have
           *  such a beast to play with.
           */
          if (!(np->features & FE_C10)) {
                  OUTB (nc_stest1, SCLK); /* Use the PCI clock as SCSI clock */
                  f = (int) sym_getfreq (np);
                  OUTB (nc_stest1, 0);
          }
          np->pciclk_khz = f;
  
          return f;
  }
  
  /*============= DRIVER ACTION/COMPLETION ====================*/
  
  /*
   *  Print something that tells about extended errors.
   */
  static void sym_print_xerr(ccb_p cp, int x_status)
  {
          if (x_status & XE_PARITY_ERR) {
                  PRINT_ADDR(cp);
                  printf ("unrecovered SCSI parity error.\n");
          }
          if (x_status & XE_EXTRA_DATA) {
                  PRINT_ADDR(cp);
                  printf ("extraneous data discarded.\n");
          }
          if (x_status & XE_BAD_PHASE) {
                  PRINT_ADDR(cp);
                  printf ("illegal scsi phase (4/5).\n");
          }
          if (x_status & XE_SODL_UNRUN) {
                  PRINT_ADDR(cp);
                  printf ("ODD transfer in DATA OUT phase.\n");
          }
          if (x_status & XE_SWIDE_OVRUN) {
                  PRINT_ADDR(cp);
                  printf ("ODD transfer in DATA IN phase.\n");
          }
  }
  
  /*
   *  Choose the more appropriate CAM status if
   *  the IO encountered an extended error.
   */
  static int sym_xerr_cam_status(int cam_status, int x_status)
  {
          if (x_status) {
                  if      (x_status & XE_PARITY_ERR)
                          cam_status = CAM_UNCOR_PARITY;
                  else if (x_status &(XE_EXTRA_DATA|XE_SODL_UNRUN|XE_SWIDE_OVRUN))
                          cam_status = CAM_DATA_RUN_ERR;
                  else if (x_status & XE_BAD_PHASE)
                          cam_status = CAM_REQ_CMP_ERR;
                  else
                          cam_status = CAM_REQ_CMP_ERR;
          }
          return cam_status;
  }
  
  /*
   *  Complete execution of a SCSI command with extented
   *  error, SCSI status error, or having been auto-sensed.
   *
   *  The SCRIPTS processor is not running there, so we
   *  can safely access IO registers and remove JOBs from
   *  the START queue.
   *  SCRATCHA is assumed to have been loaded with STARTPOS
   *  before the SCRIPTS called the C code.
   */
  static void sym_complete_error (hcb_p np, ccb_p cp)
  {
          struct ccb_scsiio *csio;
          u_int cam_status;
          int i;
  
          /*
           *  Paranoid check. :)
           */
          if (!cp || !cp->cam_ccb)
                  return;
  
          if (DEBUG_FLAGS & (DEBUG_TINY|DEBUG_RESULT)) {
                  printf ("CCB=%lx STAT=%x/%x/%x DEV=%d/%d\n", (unsigned long)cp,
                          cp->host_status, cp->ssss_status, cp->host_flags,
                          cp->target, cp->lun);
                  MDELAY(100);
          }
  
          /*
           *  Get CAM command pointer.
           */
          csio = &cp->cam_ccb->csio;
  
          /*
           *  Check for extended errors.
           */
          if (cp->xerr_status) {
                  if (sym_verbose)
                          sym_print_xerr(cp, cp->xerr_status);
                  if (cp->host_status == HS_COMPLETE)
                          cp->host_status = HS_COMP_ERR;
          }
  
          /*
           *  Calculate the residual.
           */
          csio->sense_resid = 0;
          csio->resid = sym_compute_residual(np, cp);
  
          if (!SYM_CONF_RESIDUAL_SUPPORT) {/* If user does not want residuals */
                  csio->resid  = 0;       /* throw them away. :)             */
                  cp->sv_resid = 0;
          }
  
          if (cp->host_flags & HF_SENSE) {                /* Auto sense     */
                  csio->scsi_status = cp->sv_scsi_status; /* Restore status */
                  csio->sense_resid = csio->resid;        /* Swap residuals */
                  csio->resid       = cp->sv_resid;
                  cp->sv_resid      = 0;
                  if (sym_verbose && cp->sv_xerr_status)
                          sym_print_xerr(cp, cp->sv_xerr_status);
                  if (cp->host_status == HS_COMPLETE &&
                      cp->ssss_status == S_GOOD &&
                      cp->xerr_status == 0) {
                          cam_status = sym_xerr_cam_status(CAM_SCSI_STATUS_ERROR,
                                                           cp->sv_xerr_status);
                          cam_status |= CAM_AUTOSNS_VALID;
                          /*
                           *  Bounce back the sense data to user and
                           *  fix the residual.
                           */
                          bzero(&csio->sense_data, csio->sense_len);
                          bcopy(cp->sns_bbuf, &csio->sense_data,
                                MIN(csio->sense_len, SYM_SNS_BBUF_LEN));
                          csio->sense_resid += csio->sense_len;
                          csio->sense_resid -= SYM_SNS_BBUF_LEN;
  #if 0
                          /*
                           *  If the device reports a UNIT ATTENTION condition
                           *  due to a RESET condition, we should consider all
                           *  disconnect CCBs for this unit as aborted.
                           */
                          if (1) {
                                  u_char *p;
                                  p  = (u_char *) csio->sense_data;
                                  if (p[0]==0x70 && p[2]==0x6 && p[12]==0x29)
                                          sym_clear_tasks(np, CAM_REQ_ABORTED,
                                                          cp->target,cp->lun, -1);
                          }
  #endif
                  }
                  else
                          cam_status = CAM_AUTOSENSE_FAIL;
          }
          else if (cp->host_status == HS_COMPLETE) {      /* Bad SCSI status */
                  csio->scsi_status = cp->ssss_status;
                  cam_status = CAM_SCSI_STATUS_ERROR;
          }
          else if (cp->host_status == HS_SEL_TIMEOUT)     /* Selection timeout */
                  cam_status = CAM_SEL_TIMEOUT;
          else if (cp->host_status == HS_UNEXPECTED)      /* Unexpected BUS FREE*/
                  cam_status = CAM_UNEXP_BUSFREE;
          else {                                          /* Extended error */
                  if (sym_verbose) {
                          PRINT_ADDR(cp);
                          printf ("COMMAND FAILED (%x %x %x).\n",
                                  cp->host_status, cp->ssss_status,
                                  cp->xerr_status);
                  }
                  csio->scsi_status = cp->ssss_status;
                  /*
                   *  Set the most appropriate value for CAM status.
                   */
                  cam_status = sym_xerr_cam_status(CAM_REQ_CMP_ERR,
                                                   cp->xerr_status);
          }
  
          /*
           *  Dequeue all queued CCBs for that device
           *  not yet started by SCRIPTS.
           */
          i = (INL (nc_scratcha) - np->squeue_ba) / 4;
          (void) sym_dequeue_from_squeue(np, i, cp->target, cp->lun, -1);
  
          /*
           *  Restart the SCRIPTS processor.
           */
          OUTL_DSP (SCRIPTA_BA (np, start));
  
          /*
           *  Synchronize DMA map if needed.
           */
          if (cp->dmamapped) {
                  bus_dmamap_sync(np->data_dmat, cp->dmamap,
                          (cp->dmamapped == SYM_DMA_READ ?
                                  BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE));
          }
          /*
           *  Add this one to the COMP queue.
           *  Complete all those commands with either error
           *  or requeue condition.
           */
          sym_set_cam_status((union ccb *) csio, cam_status);
          sym_remque(&cp->link_ccbq);
          sym_insque_head(&cp->link_ccbq, &np->comp_ccbq);
          sym_flush_comp_queue(np, 0);
  }
  
  /*
   *  Complete execution of a successful SCSI command.
   *
   *  Only successful commands go to the DONE queue,
   *  since we need to have the SCRIPTS processor
   *  stopped on any error condition.
   *  The SCRIPTS processor is running while we are
   *  completing successful commands.
   */
  static void sym_complete_ok (hcb_p np, ccb_p cp)
  {
          struct ccb_scsiio *csio;
          tcb_p tp;
          lcb_p lp;
  
          /*
           *  Paranoid check. :)
           */
          if (!cp || !cp->cam_ccb)
                  return;
          assert (cp->host_status == HS_COMPLETE);
  
          /*
           *  Get command, target and lun pointers.
           */
          csio = &cp->cam_ccb->csio;
          tp = &np->target[cp->target];
          lp = sym_lp(np, tp, cp->lun);
  
          /*
           *  Assume device discovered on first success.
           */
          if (!lp)
                  sym_set_bit(tp->lun_map, cp->lun);
  
          /*
           *  If all data have been transferred, given than no
           *  extended error did occur, there is no residual.
           */
          csio->resid = 0;
          if (cp->phys.head.lastp != cp->phys.head.goalp)
                  csio->resid = sym_compute_residual(np, cp);
  
          /*
           *  Wrong transfer residuals may be worse than just always
           *  returning zero. User can disable this feature from
           *  sym_conf.h. Residual support is enabled by default.
           */
          if (!SYM_CONF_RESIDUAL_SUPPORT)
                  csio->resid  = 0;
  
          /*
           *  Synchronize DMA map if needed.
           */
          if (cp->dmamapped) {
                  bus_dmamap_sync(np->data_dmat, cp->dmamap,
                          (cp->dmamapped == SYM_DMA_READ ?
                                  BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE));
          }
          /*
           *  Set status and complete the command.
           */
          csio->scsi_status = cp->ssss_status;
          sym_set_cam_status((union ccb *) csio, CAM_REQ_CMP);
          sym_free_ccb (np, cp);
          sym_xpt_done(np, (union ccb *) csio);
  }
  
  /*
   *  Our timeout handler.
   */
  static void sym_timeout1(void *arg)
  {
          union ccb *ccb = (union ccb *) arg;
          hcb_p np = ccb->ccb_h.sym_hcb_ptr;
  
          /*
           *  Check that the CAM CCB is still queued.
           */
          if (!np)
                  return;
  
          switch(ccb->ccb_h.func_code) {
          case XPT_SCSI_IO:
                  (void) sym_abort_scsiio(np, ccb, 1);
                  break;
          default:
                  break;
          }
  }
  
  static void sym_timeout(void *arg)
  {
          int s = splcam();
          sym_timeout1(arg);
          splx(s);
  }
  
  /*
   *  Abort an SCSI IO.
   */
  static int sym_abort_scsiio(hcb_p np, union ccb *ccb, int timed_out)
  {
          ccb_p cp;
          SYM_QUEHEAD *qp;
  
          /*
           *  Look up our CCB control block.
           */
          cp = NULL;
          FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
                  ccb_p cp2 = sym_que_entry(qp, struct sym_ccb, link_ccbq);
                  if (cp2->cam_ccb == ccb) {
                          cp = cp2;
                          break;
                  }
          }
          if (!cp || cp->host_status == HS_WAIT)
                  return -1;
  
          /*
           *  If a previous abort didn't succeed in time,
           *  perform a BUS reset.
           */
          if (cp->to_abort) {
                  sym_reset_scsi_bus(np, 1);
                  return 0;
          }
  
          /*
           *  Mark the CCB for abort and allow time for.
           */
          cp->to_abort = timed_out ? 2 : 1;
          ccb->ccb_h.timeout_ch = timeout(sym_timeout, (caddr_t) ccb, 10*hz);
  
          /*
           *  Tell the SCRIPTS processor to stop and synchronize with us.
           */
          np->istat_sem = SEM;
          OUTB (nc_istat, SIGP|SEM);
          return 0;
  }
  
  /*
   *  Reset a SCSI device (all LUNs of a target).
   */
  static void sym_reset_dev(hcb_p np, union ccb *ccb)
  {
          tcb_p tp;
          struct ccb_hdr *ccb_h = &ccb->ccb_h;
  
          if (ccb_h->target_id   == np->myaddr ||
              ccb_h->target_id   >= SYM_CONF_MAX_TARGET ||
              ccb_h->target_lun  >= SYM_CONF_MAX_LUN) {
                  sym_xpt_done2(np, ccb, CAM_DEV_NOT_THERE);
                  return;
          }
  
          tp = &np->target[ccb_h->target_id];
  
          tp->to_reset = 1;
          sym_xpt_done2(np, ccb, CAM_REQ_CMP);
  
          np->istat_sem = SEM;
          OUTB (nc_istat, SIGP|SEM);
  }
  
  /*
   *  SIM action entry point.
   */
  static void sym_action(struct cam_sim *sim, union ccb *ccb)
  {
          int s = splcam();
          sym_action1(sim, ccb);
          splx(s);
  }
  
  static void sym_action1(struct cam_sim *sim, union ccb *ccb)
  {
          hcb_p   np;
          tcb_p   tp;
          lcb_p   lp;
          ccb_p   cp;
          int     tmp;
          u_char  idmsg, *msgptr;
          u_int   msglen;
          struct  ccb_scsiio *csio;
          struct  ccb_hdr  *ccb_h;
  
          CAM_DEBUG(ccb->ccb_h.path, CAM_DEBUG_TRACE, ("sym_action\n"));
  
          /*
           *  Retrieve our controller data structure.
           */
          np = (hcb_p) cam_sim_softc(sim);
  
          /*
           *  The common case is SCSI IO.
           *  We deal with other ones elsewhere.
           */
          if (ccb->ccb_h.func_code != XPT_SCSI_IO) {
                  sym_action2(sim, ccb);
                  return;
          }
          csio  = &ccb->csio;
          ccb_h = &csio->ccb_h;
  
          /*
           *  Work around races.
           */
          if ((ccb_h->status & CAM_STATUS_MASK) != CAM_REQ_INPROG) {
                  xpt_done(ccb);
                  return;
          }
  
          /*
           *  Minimal checkings, so that we will not
           *  go outside our tables.
           */
          if (ccb_h->target_id   == np->myaddr ||
              ccb_h->target_id   >= SYM_CONF_MAX_TARGET ||
              ccb_h->target_lun  >= SYM_CONF_MAX_LUN) {
                  sym_xpt_done2(np, ccb, CAM_DEV_NOT_THERE);
                  return;
          }
  
          /*
           *  Retreive the target and lun descriptors.
           */
          tp = &np->target[ccb_h->target_id];
          lp = sym_lp(np, tp, ccb_h->target_lun);
  
          /*
           *  Complete the 1st INQUIRY command with error
           *  condition if the device is flagged NOSCAN
           *  at BOOT in the NVRAM. This may speed up
           *  the boot and maintain coherency with BIOS
           *  device numbering. Clearing the flag allows
           *  user to rescan skipped devices later.
           *  We also return error for devices not flagged
           *  for SCAN LUNS in the NVRAM since some mono-lun
           *  devices behave badly when asked for some non
           *  zero LUN. Btw, this is an absolute hack.:-)
           */
          if (!(ccb_h->flags & CAM_CDB_PHYS) &&
              (0x12 == ((ccb_h->flags & CAM_CDB_POINTER) ?
                    csio->cdb_io.cdb_ptr[0] : csio->cdb_io.cdb_bytes[0]))) {
                  if ((tp->usrflags & SYM_SCAN_BOOT_DISABLED) ||
                      ((tp->usrflags & SYM_SCAN_LUNS_DISABLED) &&
                       ccb_h->target_lun != 0)) {
                          tp->usrflags &= ~SYM_SCAN_BOOT_DISABLED;
                          sym_xpt_done2(np, ccb, CAM_DEV_NOT_THERE);
                          return;
                  }
          }
  
          /*
           *  Get a control block for this IO.
           */
          tmp = ((ccb_h->flags & CAM_TAG_ACTION_VALID) != 0);
          cp = sym_get_ccb(np, ccb_h->target_id, ccb_h->target_lun, tmp);
          if (!cp) {
                  sym_xpt_done2(np, ccb, CAM_RESRC_UNAVAIL);
                  return;
          }
  
          /*
           *  Keep track of the IO in our CCB.
           */
          cp->cam_ccb = ccb;
  
          /*
           *  Build the IDENTIFY message.
           */
          idmsg = M_IDENTIFY | cp->lun;
          if (cp->tag != NO_TAG || (lp && (lp->current_flags & SYM_DISC_ENABLED)))
                  idmsg |= 0x40;
  
          msgptr = cp->scsi_smsg;
          msglen = 0;
          msgptr[msglen++] = idmsg;
  
          /*
           *  Build the tag message if present.
           */
          if (cp->tag != NO_TAG) {
                  u_char order = csio->tag_action;
  
                  switch(order) {
                  case M_ORDERED_TAG:
                          break;
                  case M_HEAD_TAG:
                          break;
                  default:
                          order = M_SIMPLE_TAG;
                  }
                  msgptr[msglen++] = order;
  
                  /*
                   *  For less than 128 tags, actual tags are numbered
                   *  1,3,5,..2*MAXTAGS+1,since we may have to deal
                   *  with devices that have problems with #TAG 0 or too
                   *  great #TAG numbers. For more tags (up to 256),
                   *  we use directly our tag number.
                   */
  #if SYM_CONF_MAX_TASK > (512/4)
                  msgptr[msglen++] = cp->tag;
  #else
                  msgptr[msglen++] = (cp->tag << 1) + 1;
  #endif
          }
  
          /*
           *  Build a negotiation message if needed.
           *  (nego_status is filled by sym_prepare_nego())
           */
          cp->nego_status = 0;
          if (tp->tinfo.current.width   != tp->tinfo.goal.width  ||
              tp->tinfo.current.period  != tp->tinfo.goal.period ||
              tp->tinfo.current.offset  != tp->tinfo.goal.offset ||
              tp->tinfo.current.options != tp->tinfo.goal.options) {
                  if (!tp->nego_cp && lp)
                          msglen += sym_prepare_nego(np, cp, 0, msgptr + msglen);
          }
  
          /*
           *  Fill in our ccb
           */
  
          /*
           *  Startqueue
           */
          cp->phys.head.go.start   = cpu_to_scr(SCRIPTA_BA (np, select));
          cp->phys.head.go.restart = cpu_to_scr(SCRIPTA_BA (np, resel_dsa));
  
          /*
           *  select
           */
          cp->phys.select.sel_id          = cp->target;
          cp->phys.select.sel_scntl3      = tp->head.wval;
          cp->phys.select.sel_sxfer       = tp->head.sval;
          cp->phys.select.sel_scntl4      = tp->head.uval;
  
          /*
           *  message
           */
          cp->phys.smsg.addr      = cpu_to_scr(CCB_BA (cp, scsi_smsg));
          cp->phys.smsg.size      = cpu_to_scr(msglen);
  
          /*
           *  command
           */
          if (sym_setup_cdb(np, csio, cp) < 0) {
                  sym_free_ccb(np, cp);
                  sym_xpt_done(np, ccb);
                  return;
          }
  
          /*
           *  status
           */
  #if     0       /* Provision */
          cp->actualquirks        = tp->quirks;
  #endif
          cp->actualquirks        = SYM_QUIRK_AUTOSAVE;
          cp->host_status         = cp->nego_status ? HS_NEGOTIATE : HS_BUSY;
          cp->ssss_status         = S_ILLEGAL;
          cp->xerr_status         = 0;
          cp->host_flags          = 0;
          cp->extra_bytes         = 0;
  
          /*
           *  extreme data pointer.
           *  shall be positive, so -1 is lower than lowest.:)
           */
          cp->ext_sg  = -1;
          cp->ext_ofs = 0;
  
          /*
           *  Build the data descriptor block
           *  and start the IO.
           */
          sym_setup_data_and_start(np, csio, cp);
  }
  
  /*
   *  Setup buffers and pointers that address the CDB.
   *  I bet, physical CDBs will never be used on the planet,
   *  since they can be bounced without significant overhead.
   */
  static int sym_setup_cdb(hcb_p np, struct ccb_scsiio *csio, ccb_p cp)
  {
          struct ccb_hdr *ccb_h;
          u32     cmd_ba;
          int     cmd_len;
  
          ccb_h = &csio->ccb_h;
  
          /*
           *  CDB is 16 bytes max.
           */
          if (csio->cdb_len > sizeof(cp->cdb_buf)) {
                  sym_set_cam_status(cp->cam_ccb, CAM_REQ_INVALID);
                  return -1;
          }
          cmd_len = csio->cdb_len;
  
          if (ccb_h->flags & CAM_CDB_POINTER) {
                  /* CDB is a pointer */
                  if (!(ccb_h->flags & CAM_CDB_PHYS)) {
                          /* CDB pointer is virtual */
                          bcopy(csio->cdb_io.cdb_ptr, cp->cdb_buf, cmd_len);
                          cmd_ba = CCB_BA (cp, cdb_buf[0]);
                  } else {
                          /* CDB pointer is physical */
  #if 0
                          cmd_ba = ((u32)csio->cdb_io.cdb_ptr) & 0xffffffff;
  #else
                          sym_set_cam_status(cp->cam_ccb, CAM_REQ_INVALID);
                          return -1;
  #endif
                  }
          } else {
                  /* CDB is in the CAM ccb (buffer) */
                  bcopy(csio->cdb_io.cdb_bytes, cp->cdb_buf, cmd_len);
                  cmd_ba = CCB_BA (cp, cdb_buf[0]);
          }
  
          cp->phys.cmd.addr       = cpu_to_scr(cmd_ba);
          cp->phys.cmd.size       = cpu_to_scr(cmd_len);
  
          return 0;
  }
  
  /*
   *  Set up data pointers used by SCRIPTS.
   */
  static void __inline
  sym_setup_data_pointers(hcb_p np, ccb_p cp, int dir)
  {
          u32 lastp, goalp;
  
          /*
           *  No segments means no data.
           */
          if (!cp->segments)
                  dir = CAM_DIR_NONE;
  
          /*
           *  Set the data pointer.
           */
          switch(dir) {
          case CAM_DIR_OUT:
                  goalp = SCRIPTA_BA (np, data_out2) + 8;
                  lastp = goalp - 8 - (cp->segments * (2*4));
                  break;
          case CAM_DIR_IN:
                  cp->host_flags |= HF_DATA_IN;
                  goalp = SCRIPTA_BA (np, data_in2) + 8;
                  lastp = goalp - 8 - (cp->segments * (2*4));
                  break;
          case CAM_DIR_NONE:
          default:
                  lastp = goalp = SCRIPTB_BA (np, no_data);
                  break;
          }
  
          cp->phys.head.lastp = cpu_to_scr(lastp);
          cp->phys.head.goalp = cpu_to_scr(goalp);
          cp->phys.head.savep = cpu_to_scr(lastp);
          cp->startp          = cp->phys.head.savep;
  }
  
  
  /*
   *  Call back routine for the DMA map service.
   *  If bounce buffers are used (why ?), we may sleep and then
   *  be called there in another context.
   */
  static void
  sym_execute_ccb(void *arg, bus_dma_segment_t *psegs, int nsegs, int error)
  {
          ccb_p   cp;
          hcb_p   np;
          union   ccb *ccb;
          int     s;
  
          s = splcam();
  
          cp  = (ccb_p) arg;
          ccb = cp->cam_ccb;
          np  = (hcb_p) cp->arg;
  
          /*
           *  Deal with weird races.
           */
          if (sym_get_cam_status(ccb) != CAM_REQ_INPROG)
                  goto out_abort;
  
          /*
           *  Deal with weird errors.
           */
          if (error) {
                  cp->dmamapped = 0;
                  sym_set_cam_status(cp->cam_ccb, CAM_REQ_ABORTED);
                  goto out_abort;
          }
  
          /*
           *  Build the data descriptor for the chip.
           */
          if (nsegs) {
                  int retv;
                  /* 896 rev 1 requires to be careful about boundaries */
                  if (np->device_id == PCI_ID_SYM53C896 && np->revision_id <= 1)
                          retv = sym_scatter_sg_physical(np, cp, psegs, nsegs);
                  else
                          retv = sym_fast_scatter_sg_physical(np,cp, psegs,nsegs);
                  if (retv < 0) {
                          sym_set_cam_status(cp->cam_ccb, CAM_REQ_TOO_BIG);
                          goto out_abort;
                  }
          }
  
          /*
           *  Synchronize the DMA map only if we have
           *  actually mapped the data.
           */
          if (cp->dmamapped) {
                  bus_dmamap_sync(np->data_dmat, cp->dmamap,
                          (cp->dmamapped == SYM_DMA_READ ?
                                  BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE));
          }
  
          /*
           *  Set host status to busy state.
           *  May have been set back to HS_WAIT to avoid a race.
           */
          cp->host_status = cp->nego_status ? HS_NEGOTIATE : HS_BUSY;
  
          /*
           *  Set data pointers.
           */
          sym_setup_data_pointers(np, cp,  (ccb->ccb_h.flags & CAM_DIR_MASK));
  
          /*
           *  Enqueue this IO in our pending queue.
           */
          sym_enqueue_cam_ccb(np, ccb);
  
          /*
           *  When `#ifed 1', the code below makes the driver
           *  panic on the first attempt to write to a SCSI device.
           *  It is the first test we want to do after a driver
           *  change that does not seem obviously safe. :)
           */
  #if 0
          switch (cp->cdb_buf[0]) {
          case 0x0A: case 0x2A: case 0xAA:
                  panic("XXXXXXXXXXXXX WRITE NOT YET ALLOWED XXXXXXXXXXXXXX\n");
                  MDELAY(10000);
                  break;
          default:
                  break;
          }
  #endif
          /*
           *  Activate this job.
           */
          sym_put_start_queue(np, cp);
  out:
          splx(s);
          return;
  out_abort:
          sym_free_ccb(np, cp);
          sym_xpt_done(np, ccb);
          goto out;
  }
  
  /*
   *  How complex it gets to deal with the data in CAM.
   *  The Bus Dma stuff makes things still more complex.
   */
  static void
  sym_setup_data_and_start(hcb_p np, struct ccb_scsiio *csio, ccb_p cp)
  {
          struct ccb_hdr *ccb_h;
          int dir, retv;
  
          ccb_h = &csio->ccb_h;
  
          /*
           *  Now deal with the data.
           */
          cp->data_len = csio->dxfer_len;
          cp->arg      = np;
  
          /*
           *  No direction means no data.
           */
          dir = (ccb_h->flags & CAM_DIR_MASK);
          if (dir == CAM_DIR_NONE) {
                  sym_execute_ccb(cp, NULL, 0, 0);
                  return;
          }
  
          if (!(ccb_h->flags & CAM_SCATTER_VALID)) {
                  /* Single buffer */
                  if (!(ccb_h->flags & CAM_DATA_PHYS)) {
                          /* Buffer is virtual */
                          int s;
  
                          cp->dmamapped = (dir == CAM_DIR_IN) ?
                                                  SYM_DMA_READ : SYM_DMA_WRITE;
                          s = splsoftvm();
                          retv = bus_dmamap_load(np->data_dmat, cp->dmamap,
                                                 csio->data_ptr, csio->dxfer_len,
                                                 sym_execute_ccb, cp, 0);
                          if (retv == EINPROGRESS) {
                                  cp->host_status = HS_WAIT;
                                  xpt_freeze_simq(np->sim, 1);
                                  csio->ccb_h.status |= CAM_RELEASE_SIMQ;
                          }
                          splx(s);
                  } else {
                          /* Buffer is physical */
                          struct bus_dma_segment seg;
  
                          seg.ds_addr = (bus_addr_t) csio->data_ptr;
                          sym_execute_ccb(cp, &seg, 1, 0);
                  }
          } else {
                  /* Scatter/gather list */
                  struct bus_dma_segment *segs;
  
                  if ((ccb_h->flags & CAM_SG_LIST_PHYS) != 0) {
                          /* The SG list pointer is physical */
                          sym_set_cam_status(cp->cam_ccb, CAM_REQ_INVALID);
                          goto out_abort;
                  }
  
                  if (!(ccb_h->flags & CAM_DATA_PHYS)) {
                          /* SG buffer pointers are virtual */
                          sym_set_cam_status(cp->cam_ccb, CAM_REQ_INVALID);
                          goto out_abort;
                  }
  
                  /* SG buffer pointers are physical */
                  segs  = (struct bus_dma_segment *)csio->data_ptr;
                  sym_execute_ccb(cp, segs, csio->sglist_cnt, 0);
          }
          return;
  out_abort:
          sym_free_ccb(np, cp);
          sym_xpt_done(np, (union ccb *) csio);
  }
  
  /*
   *  Move the scatter list to our data block.
   */
  static int
  sym_fast_scatter_sg_physical(hcb_p np, ccb_p cp,
                               bus_dma_segment_t *psegs, int nsegs)
  {
          struct sym_tblmove *data;
          bus_dma_segment_t *psegs2;
  
          if (nsegs > SYM_CONF_MAX_SG)
                  return -1;
  
          data   = &cp->phys.data[SYM_CONF_MAX_SG-1];
          psegs2 = &psegs[nsegs-1];
          cp->segments = nsegs;
  
          while (1) {
                  data->addr = cpu_to_scr(psegs2->ds_addr);
                  data->size = cpu_to_scr(psegs2->ds_len);
                  if (DEBUG_FLAGS & DEBUG_SCATTER) {
                          printf ("%s scatter: paddr=%lx len=%ld\n",
                                  sym_name(np), (long) psegs2->ds_addr,
                                  (long) psegs2->ds_len);
                  }
                  if (psegs2 != psegs) {
                          --data;
                          --psegs2;
                          continue;
                  }
                  break;
          }
          return 0;
  }
  
  
  /*
   *  Scatter a SG list with physical addresses into bus addressable chunks.
   *  We need to ensure 16MB boundaries not to be crossed during DMA of
   *  each segment, due to some chips being flawed.
   */
  #define BOUND_MASK ((1UL<<24)-1)
  static int
  sym_scatter_sg_physical(hcb_p np, ccb_p cp, bus_dma_segment_t *psegs, int nsegs)
  {
          u_long  ps, pe, pn;
          u_long  k;
          int s, t;
  
          s  = SYM_CONF_MAX_SG - 1;
          t  = nsegs - 1;
          ps = psegs[t].ds_addr;
          pe = ps + psegs[t].ds_len;
  
          while (s >= 0) {
                  pn = (pe - 1) & ~BOUND_MASK;
                  if (pn <= ps)
                          pn = ps;
                  k = pe - pn;
                  if (DEBUG_FLAGS & DEBUG_SCATTER) {
                          printf ("%s scatter: paddr=%lx len=%ld\n",
                                  sym_name(np), pn, k);
                  }
                  cp->phys.data[s].addr = cpu_to_scr(pn);
                  cp->phys.data[s].size = cpu_to_scr(k);
                  --s;
                  if (pn == ps) {
                          if (--t < 0)
                                  break;
                          ps = psegs[t].ds_addr;
                          pe = ps + psegs[t].ds_len;
                  }
                  else
                          pe = pn;
          }
  
          cp->segments = SYM_CONF_MAX_SG - 1 - s;
  
          return t >= 0 ? -1 : 0;
  }
  #undef BOUND_MASK
  
  /*
   *  SIM action for non performance critical stuff.
   */
  static void sym_action2(struct cam_sim *sim, union ccb *ccb)
  {
          hcb_p   np;
          tcb_p   tp;
          lcb_p   lp;
          struct  ccb_hdr  *ccb_h;
  
          /*
           *  Retrieve our controller data structure.
           */
          np = (hcb_p) cam_sim_softc(sim);
  
          ccb_h = &ccb->ccb_h;
  
          switch (ccb_h->func_code) {
          case XPT_SET_TRAN_SETTINGS:
          {
                  struct ccb_trans_settings *cts;
  
                  cts  = &ccb->cts;
                  tp = &np->target[ccb_h->target_id];
  
                  /*
                   *  Update SPI transport settings in TARGET control block.
                   *  Update SCSI device settings in LUN control block.
                   */
                  lp = sym_lp(np, tp, ccb_h->target_lun);
  #ifdef  FreeBSD_New_Tran_Settings
                  if (cts->type == CTS_TYPE_CURRENT_SETTINGS) {
  #else
                  if ((cts->flags & CCB_TRANS_CURRENT_SETTINGS) != 0) {
  #endif
                          sym_update_trans(np, tp, &tp->tinfo.goal, cts);
                          if (lp)
                                  sym_update_dflags(np, &lp->current_flags, cts);
                  }
  #ifdef  FreeBSD_New_Tran_Settings
                  if (cts->type == CTS_TYPE_USER_SETTINGS) {
  #else
                  if ((cts->flags & CCB_TRANS_USER_SETTINGS) != 0) {
  #endif
                          sym_update_trans(np, tp, &tp->tinfo.user, cts);
                          if (lp)
                                  sym_update_dflags(np, &lp->user_flags, cts);
                  }
  
                  sym_xpt_done2(np, ccb, CAM_REQ_CMP);
                  break;
          }
          case XPT_GET_TRAN_SETTINGS:
          {
                  struct ccb_trans_settings *cts;
                  struct sym_trans *tip;
                  u_char dflags;
  
                  cts = &ccb->cts;
                  tp = &np->target[ccb_h->target_id];
                  lp = sym_lp(np, tp, ccb_h->target_lun);
  
  #ifdef  FreeBSD_New_Tran_Settings
  #define cts__scsi (&cts->proto_specific.scsi)
  #define cts__spi  (&cts->xport_specific.spi)
                  if (cts->type == CTS_TYPE_CURRENT_SETTINGS) {
                          tip = &tp->tinfo.current;
                          dflags = lp ? lp->current_flags : 0;
                  }
                  else {
                          tip = &tp->tinfo.user;
                          dflags = lp ? lp->user_flags : tp->usrflags;
                  }
  
                  cts->protocol  = PROTO_SCSI;
                  cts->transport = XPORT_SPI;
                  cts->protocol_version  = tip->scsi_version;
                  cts->transport_version = tip->spi_version;
  
                  cts__spi->sync_period = tip->period;
                  cts__spi->sync_offset = tip->offset;
                  cts__spi->bus_width   = tip->width;
                  cts__spi->ppr_options = tip->options;
  
                  cts__spi->valid = CTS_SPI_VALID_SYNC_RATE
                                  | CTS_SPI_VALID_SYNC_OFFSET
                                  | CTS_SPI_VALID_BUS_WIDTH
                                  | CTS_SPI_VALID_PPR_OPTIONS;
  
                  cts__spi->flags &= ~CTS_SPI_FLAGS_DISC_ENB;
                  if (dflags & SYM_DISC_ENABLED)
                          cts__spi->flags |= CTS_SPI_FLAGS_DISC_ENB;
                  cts__spi->valid |= CTS_SPI_VALID_DISC;
  
                  cts__scsi->flags &= ~CTS_SCSI_FLAGS_TAG_ENB;
                  if (dflags & SYM_TAGS_ENABLED)
                          cts__scsi->flags |= CTS_SCSI_FLAGS_TAG_ENB;
                  cts__scsi->valid |= CTS_SCSI_VALID_TQ;
  #undef  cts__spi
  #undef  cts__scsi
  #else
                  if ((cts->flags & CCB_TRANS_CURRENT_SETTINGS) != 0) {
                          tip = &tp->tinfo.current;
                          dflags = lp ? lp->current_flags : 0;
                  }
                  else {
                          tip = &tp->tinfo.user;
                          dflags = lp ? lp->user_flags : tp->usrflags;
                  }
                  
                  cts->sync_period = tip->period;
                  cts->sync_offset = tip->offset;
                  cts->bus_width   = tip->width;
  
                  cts->valid = CCB_TRANS_SYNC_RATE_VALID
                             | CCB_TRANS_SYNC_OFFSET_VALID
                             | CCB_TRANS_BUS_WIDTH_VALID;
  
                  cts->flags &= ~(CCB_TRANS_DISC_ENB|CCB_TRANS_TAG_ENB);
  
                  if (dflags & SYM_DISC_ENABLED)
                          cts->flags |= CCB_TRANS_DISC_ENB;
  
                  if (dflags & SYM_TAGS_ENABLED)
                          cts->flags |= CCB_TRANS_TAG_ENB;
  
                  cts->valid |= CCB_TRANS_DISC_VALID;
                  cts->valid |= CCB_TRANS_TQ_VALID;
  #endif
                  sym_xpt_done2(np, ccb, CAM_REQ_CMP);
                  break;
          }
          case XPT_CALC_GEOMETRY:
          {
                  cam_calc_geometry(&ccb->ccg, /*extended*/1);
                  sym_xpt_done2(np, ccb, CAM_REQ_CMP);
                  break;
          }
          case XPT_PATH_INQ:
          {
                  struct ccb_pathinq *cpi = &ccb->cpi;
                  cpi->version_num = 1;
                  cpi->hba_inquiry = PI_MDP_ABLE|PI_SDTR_ABLE|PI_TAG_ABLE;
                  if ((np->features & FE_WIDE) != 0)
                          cpi->hba_inquiry |= PI_WIDE_16;
                  cpi->target_sprt = 0;
                  cpi->hba_misc = 0;
                  if (np->usrflags & SYM_SCAN_TARGETS_HILO)
                          cpi->hba_misc |= PIM_SCANHILO;
                  if (np->usrflags & SYM_AVOID_BUS_RESET)
                          cpi->hba_misc |= PIM_NOBUSRESET;
                  cpi->hba_eng_cnt = 0;
                  cpi->max_target = (np->features & FE_WIDE) ? 15 : 7;
                  /* Semantic problem:)LUN number max = max number of LUNs - 1 */
                  cpi->max_lun = SYM_CONF_MAX_LUN-1;
                  if (SYM_SETUP_MAX_LUN < SYM_CONF_MAX_LUN)
                          cpi->max_lun = SYM_SETUP_MAX_LUN-1;
                  cpi->bus_id = cam_sim_bus(sim);
                  cpi->initiator_id = np->myaddr;
                  cpi->base_transfer_speed = 3300;
                  strncpy(cpi->sim_vid, "FreeBSD", SIM_IDLEN);
                  strncpy(cpi->hba_vid, "Symbios", HBA_IDLEN);
                  strncpy(cpi->dev_name, cam_sim_name(sim), DEV_IDLEN);
                  cpi->unit_number = cam_sim_unit(sim);
  
  #ifdef  FreeBSD_New_Tran_Settings
                  cpi->protocol = PROTO_SCSI;
                  cpi->protocol_version = SCSI_REV_2;
                  cpi->transport = XPORT_SPI;
                  cpi->transport_version = 2;
                  cpi->xport_specific.spi.ppr_options = SID_SPI_CLOCK_ST;
                  if (np->features & FE_ULTRA3) {
                          cpi->transport_version = 3;
                          cpi->xport_specific.spi.ppr_options =
                              SID_SPI_CLOCK_DT_ST;
                  }
  #endif
                  sym_xpt_done2(np, ccb, CAM_REQ_CMP);
                  break;
          }
          case XPT_ABORT:
          {
                  union ccb *abort_ccb = ccb->cab.abort_ccb;
                  switch(abort_ccb->ccb_h.func_code) {
                  case XPT_SCSI_IO:
                          if (sym_abort_scsiio(np, abort_ccb, 0) == 0) {
                                  sym_xpt_done2(np, ccb, CAM_REQ_CMP);
                                  break;
                          }
                  default:
                          sym_xpt_done2(np, ccb, CAM_UA_ABORT);
                          break;
                  }
                  break;
          }
          case XPT_RESET_DEV:
          {
                  sym_reset_dev(np, ccb);
                  break;
          }
          case XPT_RESET_BUS:
          {
                  sym_reset_scsi_bus(np, 0);
                  if (sym_verbose) {
                          xpt_print_path(np->path);
                          printf("SCSI BUS reset delivered.\n");
                  }
                  sym_init (np, 1);
                  sym_xpt_done2(np, ccb, CAM_REQ_CMP);
                  break;
          }
          case XPT_ACCEPT_TARGET_IO:
          case XPT_CONT_TARGET_IO:
          case XPT_EN_LUN:
          case XPT_NOTIFY_ACK:
          case XPT_IMMED_NOTIFY:
          case XPT_TERM_IO:
          default:
                  sym_xpt_done2(np, ccb, CAM_REQ_INVALID);
                  break;
          }
  }
  
  /*
   *  Asynchronous notification handler.
   */
  static void
  sym_async(void *cb_arg, u32 code, struct cam_path *path, void *arg)
  {
          hcb_p np;
          struct cam_sim *sim;
          u_int tn;
          tcb_p tp;
          int s;
  
          s = splcam();
  
          sim = (struct cam_sim *) cb_arg;
          np  = (hcb_p) cam_sim_softc(sim);
  
          switch (code) {
          case AC_LOST_DEVICE:
                  tn = xpt_path_target_id(path);
                  if (tn >= SYM_CONF_MAX_TARGET)
                          break;
  
                  tp = &np->target[tn];
  
                  tp->to_reset  = 0;
                  tp->head.sval = 0;
                  tp->head.wval = np->rv_scntl3;
                  tp->head.uval = 0;
  
                  tp->tinfo.current.period  = tp->tinfo.goal.period = 0;
                  tp->tinfo.current.offset  = tp->tinfo.goal.offset = 0;
                  tp->tinfo.current.width   = tp->tinfo.goal.width  = BUS_8_BIT;
                  tp->tinfo.current.options = tp->tinfo.goal.options = 0;
  
                  break;
          default:
                  break;
          }
  
          splx(s);
  }
  
  /*
   *  Update transfer settings of a target.
   */
  static void sym_update_trans(hcb_p np, tcb_p tp, struct sym_trans *tip,
                              struct ccb_trans_settings *cts)
  {
          /*
           *  Update the infos.
           */
  #ifdef  FreeBSD_New_Tran_Settings
  #define cts__spi (&cts->xport_specific.spi)
          if ((cts__spi->valid & CTS_SPI_VALID_BUS_WIDTH) != 0)
                  tip->width = cts__spi->bus_width;
          if ((cts__spi->valid & CTS_SPI_VALID_SYNC_OFFSET) != 0)
                  tip->offset = cts__spi->sync_offset;
          if ((cts__spi->valid & CTS_SPI_VALID_SYNC_RATE) != 0)
                  tip->period = cts__spi->sync_period;
          if ((cts__spi->valid & CTS_SPI_VALID_PPR_OPTIONS) != 0)
                  tip->options = (cts__spi->ppr_options & PPR_OPT_DT);
          if (cts->protocol_version != PROTO_VERSION_UNSPECIFIED &&
              cts->protocol_version != PROTO_VERSION_UNKNOWN)
                  tip->scsi_version = cts->protocol_version;
          if (cts->transport_version != XPORT_VERSION_UNSPECIFIED &&
              cts->transport_version != XPORT_VERSION_UNKNOWN)
                  tip->spi_version = cts->transport_version;
  #undef cts__spi
  #else
          if ((cts->valid & CCB_TRANS_BUS_WIDTH_VALID) != 0)
                  tip->width = cts->bus_width;
          if ((cts->valid & CCB_TRANS_SYNC_OFFSET_VALID) != 0)
                  tip->offset = cts->sync_offset;
          if ((cts->valid & CCB_TRANS_SYNC_RATE_VALID) != 0)
                  tip->period = cts->sync_period;
  #endif
          /*
           *  Scale against driver configuration limits.
           */
          if (tip->width  > SYM_SETUP_MAX_WIDE) tip->width  = SYM_SETUP_MAX_WIDE;
          if (tip->offset > SYM_SETUP_MAX_OFFS) tip->offset = SYM_SETUP_MAX_OFFS;
          if (tip->period < SYM_SETUP_MIN_SYNC) tip->period = SYM_SETUP_MIN_SYNC;
  
          /*
           *  Scale against actual controller BUS width.
           */
          if (tip->width > np->maxwide)
                  tip->width  = np->maxwide;
  
  #ifdef  FreeBSD_New_Tran_Settings
          /*
           *  Only accept DT if controller supports and SYNC/WIDE asked.
           */
          if (!((np->features & (FE_C10|FE_ULTRA3)) == (FE_C10|FE_ULTRA3)) ||
              !(tip->width == BUS_16_BIT && tip->offset)) {
                  tip->options &= ~PPR_OPT_DT;
          }
  #else
          /*
           *  For now, only assume DT if period <= 9, BUS 16 and offset != 0.
           */
          tip->options = 0;
          if ((np->features & (FE_C10|FE_ULTRA3)) == (FE_C10|FE_ULTRA3) &&
              tip->period <= 9 && tip->width == BUS_16_BIT && tip->offset) {
                  tip->options |= PPR_OPT_DT;
          }
  #endif
  
          /*
           *  Scale period factor and offset against controller limits.
           */
          if (tip->options & PPR_OPT_DT) {
                  if (tip->period < np->minsync_dt)
                          tip->period = np->minsync_dt;
                  if (tip->period > np->maxsync_dt)
                          tip->period = np->maxsync_dt;
                  if (tip->offset > np->maxoffs_dt)
                          tip->offset = np->maxoffs_dt;
          }
          else {
                  if (tip->period < np->minsync)
                          tip->period = np->minsync;
                  if (tip->period > np->maxsync)
                          tip->period = np->maxsync;
                  if (tip->offset > np->maxoffs)
                          tip->offset = np->maxoffs;
          }
  }
  
  /*
   *  Update flags for a device (logical unit).
   */
  static void
  sym_update_dflags(hcb_p np, u_char *flags, struct ccb_trans_settings *cts)
  {
  #ifdef  FreeBSD_New_Tran_Settings
  #define cts__scsi (&cts->proto_specific.scsi)
  #define cts__spi  (&cts->xport_specific.spi)
          if ((cts__spi->valid & CTS_SPI_VALID_DISC) != 0) {
                  if ((cts__spi->flags & CTS_SPI_FLAGS_DISC_ENB) != 0)
                          *flags |= SYM_DISC_ENABLED;
                  else
                          *flags &= ~SYM_DISC_ENABLED;
          }
  
          if ((cts__scsi->valid & CTS_SCSI_VALID_TQ) != 0) {
                  if ((cts__scsi->flags & CTS_SCSI_FLAGS_TAG_ENB) != 0)
                          *flags |= SYM_TAGS_ENABLED;
                  else
                          *flags &= ~SYM_TAGS_ENABLED;
          }
  #undef  cts__spi
  #undef  cts__scsi
  #else
          if ((cts->valid & CCB_TRANS_DISC_VALID) != 0) {
                  if ((cts->flags & CCB_TRANS_DISC_ENB) != 0)
                          *flags |= SYM_DISC_ENABLED;
                  else
                          *flags &= ~SYM_DISC_ENABLED;
          }
  
          if ((cts->valid & CCB_TRANS_TQ_VALID) != 0) {
                  if ((cts->flags & CCB_TRANS_TAG_ENB) != 0)
                          *flags |= SYM_TAGS_ENABLED;
                  else
                          *flags &= ~SYM_TAGS_ENABLED;
          }
  #endif
  }
  
  
  /*============= DRIVER INITIALISATION ==================*/
  
  
  static device_method_t sym_pci_methods[] = {
          DEVMETHOD(device_probe,  sym_pci_probe),
          DEVMETHOD(device_attach, sym_pci_attach),
          { 0, 0 }
  };
  
  static driver_t sym_pci_driver = {
          "sym",
          sym_pci_methods,
          1       /* no softc */
  };
  
  static devclass_t sym_devclass;
  
  DRIVER_MODULE(sym, pci, sym_pci_driver, sym_devclass, 0, 0);
  MODULE_DEPEND(sym, cam, 1, 1, 1);
  MODULE_DEPEND(sym, pci, 1, 1, 1);
  
  
  static const struct sym_pci_chip sym_pci_dev_table[] = {
   {PCI_ID_SYM53C810, 0x0f, "810", 4, 8, 4, 64,
   FE_ERL}
   ,
  #ifdef SYM_DEBUG_GENERIC_SUPPORT
   {PCI_ID_SYM53C810, 0xff, "810a", 4,  8, 4, 1,
   FE_BOF}
   ,
  #else
   {PCI_ID_SYM53C810, 0xff, "810a", 4,  8, 4, 1,
   FE_CACHE_SET|FE_LDSTR|FE_PFEN|FE_BOF}
   ,
  #endif
   {PCI_ID_SYM53C815, 0xff, "815", 4,  8, 4, 64,
   FE_BOF|FE_ERL}
   ,
   {PCI_ID_SYM53C825, 0x0f, "825", 6,  8, 4, 64,
   FE_WIDE|FE_BOF|FE_ERL|FE_DIFF}
   ,
   {PCI_ID_SYM53C825, 0xff, "825a", 6,  8, 4, 2,
   FE_WIDE|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM|FE_DIFF}
   ,
   {PCI_ID_SYM53C860, 0xff, "860", 4,  8, 5, 1,
   FE_ULTRA|FE_CLK80|FE_CACHE_SET|FE_BOF|FE_LDSTR|FE_PFEN}
   ,
   {PCI_ID_SYM53C875, 0x01, "875", 6, 16, 5, 2,
   FE_WIDE|FE_ULTRA|FE_CLK80|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
   FE_RAM|FE_DIFF}
   ,
   {PCI_ID_SYM53C875, 0xff, "875", 6, 16, 5, 2,
   FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
   FE_RAM|FE_DIFF}
   ,
   {PCI_ID_SYM53C875_2, 0xff, "875", 6, 16, 5, 2,
   FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
   FE_RAM|FE_DIFF}
   ,
   {PCI_ID_SYM53C885, 0xff, "885", 6, 16, 5, 2,
   FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE0_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
   FE_RAM|FE_DIFF}
   ,
  #ifdef SYM_DEBUG_GENERIC_SUPPORT
   {PCI_ID_SYM53C895, 0xff, "895", 6, 31, 7, 2,
   FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|
   FE_RAM|FE_LCKFRQ}
   ,
  #else
   {PCI_ID_SYM53C895, 0xff, "895", 6, 31, 7, 2,
   FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
   FE_RAM|FE_LCKFRQ}
   ,
  #endif
   {PCI_ID_SYM53C896, 0xff, "896", 6, 31, 7, 4,
   FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
   FE_RAM|FE_RAM8K|FE_64BIT|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_LCKFRQ}
   ,
   {PCI_ID_SYM53C895A, 0xff, "895a", 6, 31, 7, 4,
   FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
   FE_RAM|FE_RAM8K|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_LCKFRQ}
   ,
   {PCI_ID_LSI53C1010, 0x00, "1010-33", 6, 31, 7, 8,
   FE_WIDE|FE_ULTRA3|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFBC|FE_LDSTR|FE_PFEN|
   FE_RAM|FE_RAM8K|FE_64BIT|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_CRC|
   FE_C10}
   ,
   {PCI_ID_LSI53C1010, 0xff, "1010-33", 6, 31, 7, 8,
   FE_WIDE|FE_ULTRA3|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFBC|FE_LDSTR|FE_PFEN|
   FE_RAM|FE_RAM8K|FE_64BIT|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_CRC|
   FE_C10|FE_U3EN}
   ,
   {PCI_ID_LSI53C1010_2, 0xff, "1010-66", 6, 31, 7, 8,
   FE_WIDE|FE_ULTRA3|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFBC|FE_LDSTR|FE_PFEN|
   FE_RAM|FE_RAM8K|FE_64BIT|FE_DAC|FE_IO256|FE_NOPM|FE_LEDC|FE_66MHZ|FE_CRC|
   FE_C10|FE_U3EN}
   ,
   {PCI_ID_LSI53C1510D, 0xff, "1510d", 6, 31, 7, 4,
   FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_BOF|FE_DFS|FE_LDSTR|FE_PFEN|
   FE_RAM|FE_IO256|FE_LEDC}
  };
  
  #define sym_pci_num_devs \
          (sizeof(sym_pci_dev_table) / sizeof(sym_pci_dev_table[0]))
  
  /*
   *  Look up the chip table.
   *
   *  Return a pointer to the chip entry if found,
   *  zero otherwise.
   */
  static const struct sym_pci_chip *
  sym_find_pci_chip(device_t dev)
  {
          const struct    sym_pci_chip *chip;
          int     i;
          u_short device_id;
          u_char  revision;
  
          if (pci_get_vendor(dev) != PCI_VENDOR_NCR)
                  return NULL;
  
          device_id = pci_get_device(dev);
          revision  = pci_get_revid(dev);
  
          for (i = 0; i < sym_pci_num_devs; i++) {
                  chip = &sym_pci_dev_table[i];
                  if (device_id != chip->device_id)
                          continue;
                  if (revision > chip->revision_id)
                          continue;
                  return chip;
          }
  
          return NULL;
  }
  
  /*
   *  Tell upper layer if the chip is supported.
   */
  static int
  sym_pci_probe(device_t dev)
  {
          const struct    sym_pci_chip *chip;
  
          chip = sym_find_pci_chip(dev);
          if (chip && sym_find_firmware(chip)) {
                  device_set_desc(dev, chip->name);
                  return (chip->lp_probe_bit & SYM_SETUP_LP_PROBE_MAP)?
                    BUS_PROBE_LOW_PRIORITY : BUS_PROBE_DEFAULT;
          }
          return ENXIO;
  }
  
  /*
   *  Attach a sym53c8xx device.
   */
  static int
  sym_pci_attach(device_t dev)
  {
          const struct    sym_pci_chip *chip;
          u_short command;
          u_char  cachelnsz;
          struct  sym_hcb *np = NULL;
          struct  sym_nvram nvram;
          const struct    sym_fw *fw = NULL;
          int     i;
          bus_dma_tag_t   bus_dmat;
  
          /*
           *  I expected to be told about a parent 
           *  DMA tag, but didn't find any.
           */
          bus_dmat = NULL;
  
          /*
           *  Only probed devices should be attached.
           *  We just enjoy being paranoid. :)
           */
          chip = sym_find_pci_chip(dev);
          if (chip == NULL || (fw = sym_find_firmware(chip)) == NULL)
                  return (ENXIO);
          device_set_softc(dev, np);
  
          /*
           *  Allocate immediately the host control block,
           *  since we are only expecting to succeed. :)
           *  We keep track in the HCB of all the resources that
           *  are to be released on error.
           */
          np = __sym_calloc_dma(bus_dmat, sizeof(*np), "HCB");
          if (np)
                  np->bus_dmat = bus_dmat;
          else
                  goto attach_failed;
  
          /*
           *  Copy some useful infos to the HCB.
           */
          np->hcb_ba       = vtobus(np);
          np->verbose      = bootverbose;
          np->device       = dev;
          np->device_id    = pci_get_device(dev);
          np->revision_id  = pci_get_revid(dev);
          np->features     = chip->features;
          np->clock_divn   = chip->nr_divisor;
          np->maxoffs      = chip->offset_max;
          np->maxburst     = chip->burst_max;
          np->scripta_sz   = fw->a_size;
          np->scriptb_sz   = fw->b_size;
          np->fw_setup     = fw->setup;
          np->fw_patch     = fw->patch;
          np->fw_name      = fw->name;
  
  #ifdef __amd64__
          np->target = sym_calloc_dma(SYM_CONF_MAX_TARGET * sizeof(*(np->target)),
                          "TARGET");
          if (!np->target)
                  goto attach_failed;
  #endif
  
          /*
           *  Initialize the CCB free and busy queues.
           */
          sym_que_init(&np->free_ccbq);
          sym_que_init(&np->busy_ccbq);
          sym_que_init(&np->comp_ccbq);
          sym_que_init(&np->cam_ccbq);
  
          /*
           *  Allocate a tag for the DMA of user data.
           */
          if (bus_dma_tag_create(np->bus_dmat, 1, (1<<24),
                                  BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR,
                                  NULL, NULL,
                                  BUS_SPACE_MAXSIZE, SYM_CONF_MAX_SG,
                                  (1<<24), 0, busdma_lock_mutex, &Giant,
                                  &np->data_dmat)) {
                  device_printf(dev, "failed to create DMA tag.\n");
                  goto attach_failed;
          }
          /*
           *  Read and apply some fix-ups to the PCI COMMAND
           *  register. We want the chip to be enabled for:
           *  - BUS mastering
           *  - PCI parity checking (reporting would also be fine)
           *  - Write And Invalidate.
           */
          command = pci_read_config(dev, PCIR_COMMAND, 2);
          command |= PCIM_CMD_BUSMASTEREN;
          command |= PCIM_CMD_PERRESPEN;
          command |= /* PCIM_CMD_MWIEN */ 0x0010;
          pci_write_config(dev, PCIR_COMMAND, command, 2);
  
          /*
           *  Let the device know about the cache line size,
           *  if it doesn't yet.
           */
          cachelnsz = pci_read_config(dev, PCIR_CACHELNSZ, 1);
          if (!cachelnsz) {
                  cachelnsz = 8;
                  pci_write_config(dev, PCIR_CACHELNSZ, cachelnsz, 1);
          }
  
          /*
           *  Alloc/get/map/retrieve everything that deals with MMIO.
           */
          if ((command & PCIM_CMD_MEMEN) != 0) {
                  int regs_id = SYM_PCI_MMIO;
                  np->mmio_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
                                                        &regs_id, RF_ACTIVE);
          }
          if (!np->mmio_res) {
                  device_printf(dev, "failed to allocate MMIO resources\n");
                  goto attach_failed;
          }
          np->mmio_bsh = rman_get_bushandle(np->mmio_res);
          np->mmio_tag = rman_get_bustag(np->mmio_res);
          np->mmio_ba  = rman_get_start(np->mmio_res);
  
          /*
           *  Allocate the IRQ.
           */
          i = 0;
          np->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &i,
                                               RF_ACTIVE | RF_SHAREABLE);
          if (!np->irq_res) {
                  device_printf(dev, "failed to allocate IRQ resource\n");
                  goto attach_failed;
          }
  
  #ifdef  SYM_CONF_IOMAPPED
          /*
           *  User want us to use normal IO with PCI.
           *  Alloc/get/map/retrieve everything that deals with IO.
           */
          if ((command & PCI_COMMAND_IO_ENABLE) != 0) {
                  int regs_id = SYM_PCI_IO;
                  np->io_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT,
                                                      &regs_id, RF_ACTIVE);
          }
          if (!np->io_res) {
                  device_printf(dev, "failed to allocate IO resources\n");
                  goto attach_failed;
          }
          np->io_bsh  = rman_get_bushandle(np->io_res);
          np->io_tag  = rman_get_bustag(np->io_res);
          np->io_port = rman_get_start(np->io_res);
  
  #endif /* SYM_CONF_IOMAPPED */
  
          /*
           *  If the chip has RAM.
           *  Alloc/get/map/retrieve the corresponding resources.
           */
          if ((np->features & (FE_RAM|FE_RAM8K)) &&
              (command & PCIM_CMD_MEMEN) != 0) {
                  int regs_id = SYM_PCI_RAM;
                  if (np->features & FE_64BIT)
                          regs_id = SYM_PCI_RAM64;
                  np->ram_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
                                                       &regs_id, RF_ACTIVE);
                  if (!np->ram_res) {
                          device_printf(dev,"failed to allocate RAM resources\n");
                          goto attach_failed;
                  }
                  np->ram_id  = regs_id;
                  np->ram_bsh = rman_get_bushandle(np->ram_res);
                  np->ram_tag = rman_get_bustag(np->ram_res);
                  np->ram_ba  = rman_get_start(np->ram_res);
          }
  
          /*
           *  Save setting of some IO registers, so we will
           *  be able to probe specific implementations.
           */
          sym_save_initial_setting (np);
  
          /*
           *  Reset the chip now, since it has been reported
           *  that SCSI clock calibration may not work properly
           *  if the chip is currently active.
           */
          sym_chip_reset (np);
  
          /*
           *  Try to read the user set-up.
           */
          (void) sym_read_nvram(np, &nvram);
  
          /*
           *  Prepare controller and devices settings, according
           *  to chip features, user set-up and driver set-up.
           */
          (void) sym_prepare_setting(np, &nvram);
  
          /*
           *  Check the PCI clock frequency.
           *  Must be performed after prepare_setting since it destroys
           *  STEST1 that is used to probe for the clock doubler.
           */
          i = sym_getpciclock(np);
          if (i > 37000)
                  device_printf(dev, "PCI BUS clock seems too high: %u KHz.\n",i);
  
          /*
           *  Allocate the start queue.
           */
          np->squeue = (u32 *) sym_calloc_dma(sizeof(u32)*(MAX_QUEUE*2),"SQUEUE");
          if (!np->squeue)
                  goto attach_failed;
          np->squeue_ba = vtobus(np->squeue);
  
          /*
           *  Allocate the done queue.
           */
          np->dqueue = (u32 *) sym_calloc_dma(sizeof(u32)*(MAX_QUEUE*2),"DQUEUE");
          if (!np->dqueue)
                  goto attach_failed;
          np->dqueue_ba = vtobus(np->dqueue);
  
          /*
           *  Allocate the target bus address array.
           */
          np->targtbl = (u32 *) sym_calloc_dma(256, "TARGTBL");
          if (!np->targtbl)
                  goto attach_failed;
          np->targtbl_ba = vtobus(np->targtbl);
  
          /*
           *  Allocate SCRIPTS areas.
           */
          np->scripta0 = sym_calloc_dma(np->scripta_sz, "SCRIPTA0");
          np->scriptb0 = sym_calloc_dma(np->scriptb_sz, "SCRIPTB0");
          if (!np->scripta0 || !np->scriptb0)
                  goto attach_failed;
  
          /*
           *  Allocate some CCB. We need at least ONE.
           */
          if (!sym_alloc_ccb(np))
                  goto attach_failed;
  
          /*
           *  Calculate BUS addresses where we are going
           *  to load the SCRIPTS.
           */
          np->scripta_ba  = vtobus(np->scripta0);
          np->scriptb_ba  = vtobus(np->scriptb0);
          np->scriptb0_ba = np->scriptb_ba;
  
          if (np->ram_ba) {
                  np->scripta_ba  = np->ram_ba;
                  if (np->features & FE_RAM8K) {
                          np->ram_ws = 8192;
                          np->scriptb_ba = np->scripta_ba + 4096;
  #ifdef __LP64__
                          np->scr_ram_seg = cpu_to_scr(np->scripta_ba >> 32);
  #endif
                  }
                  else
                          np->ram_ws = 4096;
          }
  
          /*
           *  Copy scripts to controller instance.
           */
          bcopy(fw->a_base, np->scripta0, np->scripta_sz);
          bcopy(fw->b_base, np->scriptb0, np->scriptb_sz);
  
          /*
           *  Setup variable parts in scripts and compute
           *  scripts bus addresses used from the C code.
           */
          np->fw_setup(np, fw);
  
          /*
           *  Bind SCRIPTS with physical addresses usable by the
           *  SCRIPTS processor (as seen from the BUS = BUS addresses).
           */
          sym_fw_bind_script(np, (u32 *) np->scripta0, np->scripta_sz);
          sym_fw_bind_script(np, (u32 *) np->scriptb0, np->scriptb_sz);
  
  #ifdef SYM_CONF_IARB_SUPPORT
          /*
           *    If user wants IARB to be set when we win arbitration
           *    and have other jobs, compute the max number of consecutive
           *    settings of IARB hints before we leave devices a chance to
           *    arbitrate for reselection.
           */
  #ifdef  SYM_SETUP_IARB_MAX
          np->iarb_max = SYM_SETUP_IARB_MAX;
  #else
          np->iarb_max = 4;
  #endif
  #endif
  
          /*
           *  Prepare the idle and invalid task actions.
           */
          np->idletask.start      = cpu_to_scr(SCRIPTA_BA (np, idle));
          np->idletask.restart    = cpu_to_scr(SCRIPTB_BA (np, bad_i_t_l));
          np->idletask_ba         = vtobus(&np->idletask);
  
          np->notask.start        = cpu_to_scr(SCRIPTA_BA (np, idle));
          np->notask.restart      = cpu_to_scr(SCRIPTB_BA (np, bad_i_t_l));
          np->notask_ba           = vtobus(&np->notask);
  
          np->bad_itl.start       = cpu_to_scr(SCRIPTA_BA (np, idle));
          np->bad_itl.restart     = cpu_to_scr(SCRIPTB_BA (np, bad_i_t_l));
          np->bad_itl_ba          = vtobus(&np->bad_itl);
  
          np->bad_itlq.start      = cpu_to_scr(SCRIPTA_BA (np, idle));
          np->bad_itlq.restart    = cpu_to_scr(SCRIPTB_BA (np,bad_i_t_l_q));
          np->bad_itlq_ba         = vtobus(&np->bad_itlq);
  
          /*
           *  Allocate and prepare the lun JUMP table that is used
           *  for a target prior the probing of devices (bad lun table).
           *  A private table will be allocated for the target on the
           *  first INQUIRY response received.
           */
          np->badluntbl = sym_calloc_dma(256, "BADLUNTBL");
          if (!np->badluntbl)
                  goto attach_failed;
  
          np->badlun_sa = cpu_to_scr(SCRIPTB_BA (np, resel_bad_lun));
          for (i = 0 ; i < 64 ; i++)      /* 64 luns/target, no less */
                  np->badluntbl[i] = cpu_to_scr(vtobus(&np->badlun_sa));
  
          /*
           *  Prepare the bus address array that contains the bus
           *  address of each target control block.
           *  For now, assume all logical units are wrong. :)
           */
          for (i = 0 ; i < SYM_CONF_MAX_TARGET ; i++) {
                  np->targtbl[i] = cpu_to_scr(vtobus(&np->target[i]));
                  np->target[i].head.luntbl_sa =
                                  cpu_to_scr(vtobus(np->badluntbl));
                  np->target[i].head.lun0_sa =
                                  cpu_to_scr(vtobus(&np->badlun_sa));
          }
  
          /*
           *  Now check the cache handling of the pci chipset.
           */
          if (sym_snooptest (np)) {
                  device_printf(dev, "CACHE INCORRECTLY CONFIGURED.\n");
                  goto attach_failed;
          };
  
          /*
           *  Now deal with CAM.
           *  Hopefully, we will succeed with that one.:)
           */
          if (!sym_cam_attach(np))
                  goto attach_failed;
  
          /*
           *  Sigh! we are done.
           */
          return 0;
  
          /*
           *  We have failed.
           *  We will try to free all the resources we have
           *  allocated, but if we are a boot device, this
           *  will not help that much.;)
           */
  attach_failed:
          if (np)
                  sym_pci_free(np);
          return ENXIO;
  }
  
  /*
   *  Free everything that have been allocated for this device.
   */
  static void sym_pci_free(hcb_p np)
  {
          SYM_QUEHEAD *qp;
          ccb_p cp;
          tcb_p tp;
          lcb_p lp;
          int target, lun;
          int s;
  
          /*
           *  First free CAM resources.
           */
          s = splcam();
          sym_cam_free(np);
          splx(s);
  
          /*
           *  Now every should be quiet for us to
           *  free other resources.
           */
          if (np->ram_res)
                  bus_release_resource(np->device, SYS_RES_MEMORY,
                                       np->ram_id, np->ram_res);
          if (np->mmio_res)
                  bus_release_resource(np->device, SYS_RES_MEMORY,
                                       SYM_PCI_MMIO, np->mmio_res);
          if (np->io_res)
                  bus_release_resource(np->device, SYS_RES_IOPORT,
                                       SYM_PCI_IO, np->io_res);
          if (np->irq_res)
                  bus_release_resource(np->device, SYS_RES_IRQ,
                                       0, np->irq_res);
  
          if (np->scriptb0)
                  sym_mfree_dma(np->scriptb0, np->scriptb_sz, "SCRIPTB0");
          if (np->scripta0)
                  sym_mfree_dma(np->scripta0, np->scripta_sz, "SCRIPTA0");
          if (np->squeue)
                  sym_mfree_dma(np->squeue, sizeof(u32)*(MAX_QUEUE*2), "SQUEUE");
          if (np->dqueue)
                  sym_mfree_dma(np->dqueue, sizeof(u32)*(MAX_QUEUE*2), "DQUEUE");
  
          while ((qp = sym_remque_head(&np->free_ccbq)) != 0) {
                  cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
                  bus_dmamap_destroy(np->data_dmat, cp->dmamap);
                  sym_mfree_dma(cp->sns_bbuf, SYM_SNS_BBUF_LEN, "SNS_BBUF");
                  sym_mfree_dma(cp, sizeof(*cp), "CCB");
          }
  
          if (np->badluntbl)
                  sym_mfree_dma(np->badluntbl, 256,"BADLUNTBL");
  
          for (target = 0; target < SYM_CONF_MAX_TARGET ; target++) {
                  tp = &np->target[target];
                  for (lun = 0 ; lun < SYM_CONF_MAX_LUN ; lun++) {
                          lp = sym_lp(np, tp, lun);
                          if (!lp)
                                  continue;
                          if (lp->itlq_tbl)
                                  sym_mfree_dma(lp->itlq_tbl, SYM_CONF_MAX_TASK*4,
                                         "ITLQ_TBL");
                          if (lp->cb_tags)
                                  sym_mfree(lp->cb_tags, SYM_CONF_MAX_TASK,
                                         "CB_TAGS");
                          sym_mfree_dma(lp, sizeof(*lp), "LCB");
                  }
  #if SYM_CONF_MAX_LUN > 1
                  if (tp->lunmp)
                          sym_mfree(tp->lunmp, SYM_CONF_MAX_LUN*sizeof(lcb_p),
                                 "LUNMP");
  #endif
          }
  #ifdef __amd64__
          if (np->target)
                  sym_mfree_dma(np->target,
                          SYM_CONF_MAX_TARGET * sizeof(*(np->target)), "TARGET");
  #endif
          if (np->targtbl)
                  sym_mfree_dma(np->targtbl, 256, "TARGTBL");
          if (np->data_dmat)
                  bus_dma_tag_destroy(np->data_dmat);
          device_set_softc(np->device, NULL);
          sym_mfree_dma(np, sizeof(*np), "HCB");
  }
  
  /*
   *  Allocate CAM resources and register a bus to CAM.
   */
  static int sym_cam_attach(hcb_p np)
  {
          struct cam_devq *devq = NULL;
          struct cam_sim *sim = NULL;
          struct cam_path *path = NULL;
          struct ccb_setasync csa;
          int err, s;
  
          s = splcam();
  
          /*
           *  Establish our interrupt handler.
           */
          err = bus_setup_intr(np->device, np->irq_res,
                               INTR_TYPE_CAM | INTR_ENTROPY, sym_intr, np,
                               &np->intr);
          if (err) {
                  device_printf(np->device, "bus_setup_intr() failed: %d\n",
                                err);
                  goto fail;
          }
  
          /*
           *  Create the device queue for our sym SIM.
           */
          devq = cam_simq_alloc(SYM_CONF_MAX_START);
          if (!devq)
                  goto fail;
  
          /*
           *  Construct our SIM entry.
           */
          sim = cam_sim_alloc(sym_action, sym_poll, "sym", np,
                              device_get_unit(np->device),
                              1, SYM_SETUP_MAX_TAG, devq);
          if (!sim)
                  goto fail;
          devq = 0;
  
          if (xpt_bus_register(sim, 0) != CAM_SUCCESS)
                  goto fail;
          np->sim = sim;
          sim = 0;
  
          if (xpt_create_path(&path, 0,
                              cam_sim_path(np->sim), CAM_TARGET_WILDCARD,
                              CAM_LUN_WILDCARD) != CAM_REQ_CMP) {
                  goto fail;
          }
          np->path = path;
  
          /*
           *  Establish our async notification handler.
           */
          xpt_setup_ccb(&csa.ccb_h, np->path, 5);
          csa.ccb_h.func_code = XPT_SASYNC_CB;
          csa.event_enable    = AC_LOST_DEVICE;
          csa.callback        = sym_async;
          csa.callback_arg    = np->sim;
          xpt_action((union ccb *)&csa);
  
          /*
           *  Start the chip now, without resetting the BUS, since
           *  it seems that this must stay under control of CAM.
           *  With LVD/SE capable chips and BUS in SE mode, we may
           *  get a spurious SMBC interrupt.
           */
          sym_init (np, 0);
  
          splx(s);
          return 1;
  fail:
          if (sim)
                  cam_sim_free(sim, FALSE);
          if (devq)
                  cam_simq_free(devq);
  
          sym_cam_free(np);
  
          splx(s);
          return 0;
  }
  
  /*
   *  Free everything that deals with CAM.
   */
  static void sym_cam_free(hcb_p np)
  {
          if (np->intr) {
                  bus_teardown_intr(np->device, np->irq_res, np->intr);
                  np->intr = NULL;
          }
  
          if (np->sim) {
                  xpt_bus_deregister(cam_sim_path(np->sim));
                  cam_sim_free(np->sim, /*free_devq*/ TRUE);
                  np->sim = NULL;
          }
          if (np->path) {
                  xpt_free_path(np->path);
                  np->path = NULL;
          }
  }
  
  /*============ OPTIONNAL NVRAM SUPPORT =================*/
  
  /*
   *  Get host setup from NVRAM.
   */
  static void sym_nvram_setup_host (hcb_p np, struct sym_nvram *nvram)
  {
  #ifdef SYM_CONF_NVRAM_SUPPORT
          /*
           *  Get parity checking, host ID, verbose mode
           *  and miscellaneous host flags from NVRAM.
           */
          switch(nvram->type) {
          case SYM_SYMBIOS_NVRAM:
                  if (!(nvram->data.Symbios.flags & SYMBIOS_PARITY_ENABLE))
                          np->rv_scntl0  &= ~0x0a;
                  np->myaddr = nvram->data.Symbios.host_id & 0x0f;
                  if (nvram->data.Symbios.flags & SYMBIOS_VERBOSE_MSGS)
                          np->verbose += 1;
                  if (nvram->data.Symbios.flags1 & SYMBIOS_SCAN_HI_LO)
                          np->usrflags |= SYM_SCAN_TARGETS_HILO;
                  if (nvram->data.Symbios.flags2 & SYMBIOS_AVOID_BUS_RESET)
                          np->usrflags |= SYM_AVOID_BUS_RESET;
                  break;
          case SYM_TEKRAM_NVRAM:
                  np->myaddr = nvram->data.Tekram.host_id & 0x0f;
                  break;
          default:
                  break;
          }
  #endif
  }
  
  /*
   *  Get target setup from NVRAM.
   */
  #ifdef SYM_CONF_NVRAM_SUPPORT
  static void sym_Symbios_setup_target(hcb_p np,int target, Symbios_nvram *nvram);
  static void sym_Tekram_setup_target(hcb_p np,int target, Tekram_nvram *nvram);
  #endif
  
  static void
  sym_nvram_setup_target (hcb_p np, int target, struct sym_nvram *nvp)
  {
  #ifdef SYM_CONF_NVRAM_SUPPORT
          switch(nvp->type) {
          case SYM_SYMBIOS_NVRAM:
                  sym_Symbios_setup_target (np, target, &nvp->data.Symbios);
                  break;
          case SYM_TEKRAM_NVRAM:
                  sym_Tekram_setup_target (np, target, &nvp->data.Tekram);
                  break;
          default:
                  break;
          }
  #endif
  }
  
  #ifdef SYM_CONF_NVRAM_SUPPORT
  /*
   *  Get target set-up from Symbios format NVRAM.
   */
  static void
  sym_Symbios_setup_target(hcb_p np, int target, Symbios_nvram *nvram)
  {
          tcb_p tp = &np->target[target];
          Symbios_target *tn = &nvram->target[target];
  
          tp->tinfo.user.period = tn->sync_period ? (tn->sync_period + 3) / 4 : 0;
          tp->tinfo.user.width  = tn->bus_width == 0x10 ? BUS_16_BIT : BUS_8_BIT;
          tp->usrtags =
                  (tn->flags & SYMBIOS_QUEUE_TAGS_ENABLED)? SYM_SETUP_MAX_TAG : 0;
  
          if (!(tn->flags & SYMBIOS_DISCONNECT_ENABLE))
                  tp->usrflags &= ~SYM_DISC_ENABLED;
          if (!(tn->flags & SYMBIOS_SCAN_AT_BOOT_TIME))
                  tp->usrflags |= SYM_SCAN_BOOT_DISABLED;
          if (!(tn->flags & SYMBIOS_SCAN_LUNS))
                  tp->usrflags |= SYM_SCAN_LUNS_DISABLED;
  }
  
  /*
   *  Get target set-up from Tekram format NVRAM.
   */
  static void
  sym_Tekram_setup_target(hcb_p np, int target, Tekram_nvram *nvram)
  {
          tcb_p tp = &np->target[target];
          struct Tekram_target *tn = &nvram->target[target];
          int i;
  
          if (tn->flags & TEKRAM_SYNC_NEGO) {
                  i = tn->sync_index & 0xf;
                  tp->tinfo.user.period = Tekram_sync[i];
          }
  
          tp->tinfo.user.width =
                  (tn->flags & TEKRAM_WIDE_NEGO) ? BUS_16_BIT : BUS_8_BIT;
  
          if (tn->flags & TEKRAM_TAGGED_COMMANDS) {
                  tp->usrtags = 2 << nvram->max_tags_index;
          }
  
          if (tn->flags & TEKRAM_DISCONNECT_ENABLE)
                  tp->usrflags |= SYM_DISC_ENABLED;
  
          /* If any device does not support parity, we will not use this option */
          if (!(tn->flags & TEKRAM_PARITY_CHECK))
                  np->rv_scntl0  &= ~0x0a; /* SCSI parity checking disabled */
  }
  
  #ifdef  SYM_CONF_DEBUG_NVRAM
  /*
   *  Dump Symbios format NVRAM for debugging purpose.
   */
  static void sym_display_Symbios_nvram(hcb_p np, Symbios_nvram *nvram)
  {
          int i;
  
          /* display Symbios nvram host data */
          printf("%s: HOST ID=%d%s%s%s%s%s%s\n",
                  sym_name(np), nvram->host_id & 0x0f,
                  (nvram->flags  & SYMBIOS_SCAM_ENABLE)   ? " SCAM"       :"",
                  (nvram->flags  & SYMBIOS_PARITY_ENABLE) ? " PARITY"     :"",
                  (nvram->flags  & SYMBIOS_VERBOSE_MSGS)  ? " VERBOSE"    :"",
                  (nvram->flags  & SYMBIOS_CHS_MAPPING)   ? " CHS_ALT"    :"",
                  (nvram->flags2 & SYMBIOS_AVOID_BUS_RESET)?" NO_RESET"   :"",
                  (nvram->flags1 & SYMBIOS_SCAN_HI_LO)    ? " HI_LO"      :"");
  
          /* display Symbios nvram drive data */
          for (i = 0 ; i < 15 ; i++) {
                  struct Symbios_target *tn = &nvram->target[i];
                  printf("%s-%d:%s%s%s%s WIDTH=%d SYNC=%d TMO=%d\n",
                  sym_name(np), i,
                  (tn->flags & SYMBIOS_DISCONNECT_ENABLE) ? " DISC"       : "",
                  (tn->flags & SYMBIOS_SCAN_AT_BOOT_TIME) ? " SCAN_BOOT"  : "",
                  (tn->flags & SYMBIOS_SCAN_LUNS)         ? " SCAN_LUNS"  : "",
                  (tn->flags & SYMBIOS_QUEUE_TAGS_ENABLED)? " TCQ"        : "",
                  tn->bus_width,
                  tn->sync_period / 4,
                  tn->timeout);
          }
  }
  
  /*
   *  Dump TEKRAM format NVRAM for debugging purpose.
   */
  static const u_char Tekram_boot_delay[7] = {3, 5, 10, 20, 30, 60, 120};
  static void sym_display_Tekram_nvram(hcb_p np, Tekram_nvram *nvram)
  {
          int i, tags, boot_delay;
          char *rem;
  
          /* display Tekram nvram host data */
          tags = 2 << nvram->max_tags_index;
          boot_delay = 0;
          if (nvram->boot_delay_index < 6)
                  boot_delay = Tekram_boot_delay[nvram->boot_delay_index];
          switch((nvram->flags & TEKRAM_REMOVABLE_FLAGS) >> 6) {
          default:
          case 0: rem = "";                       break;
          case 1: rem = " REMOVABLE=boot device"; break;
          case 2: rem = " REMOVABLE=all";         break;
          }
  
          printf("%s: HOST ID=%d%s%s%s%s%s%s%s%s%s BOOT DELAY=%d tags=%d\n",
                  sym_name(np), nvram->host_id & 0x0f,
                  (nvram->flags1 & SYMBIOS_SCAM_ENABLE)   ? " SCAM"       :"",
                  (nvram->flags & TEKRAM_MORE_THAN_2_DRIVES) ? " >2DRIVES"        :"",
                  (nvram->flags & TEKRAM_DRIVES_SUP_1GB)  ? " >1GB"       :"",
                  (nvram->flags & TEKRAM_RESET_ON_POWER_ON) ? " RESET"    :"",
                  (nvram->flags & TEKRAM_ACTIVE_NEGATION) ? " ACT_NEG"    :"",
                  (nvram->flags & TEKRAM_IMMEDIATE_SEEK)  ? " IMM_SEEK"   :"",
                  (nvram->flags & TEKRAM_SCAN_LUNS)       ? " SCAN_LUNS"  :"",
                  (nvram->flags1 & TEKRAM_F2_F6_ENABLED)  ? " F2_F6"      :"",
                  rem, boot_delay, tags);
  
          /* display Tekram nvram drive data */
          for (i = 0; i <= 15; i++) {
                  int sync, j;
                  struct Tekram_target *tn = &nvram->target[i];
                  j = tn->sync_index & 0xf;
                  sync = Tekram_sync[j];
                  printf("%s-%d:%s%s%s%s%s%s PERIOD=%d\n",
                  sym_name(np), i,
                  (tn->flags & TEKRAM_PARITY_CHECK)       ? " PARITY"     : "",
                  (tn->flags & TEKRAM_SYNC_NEGO)          ? " SYNC"       : "",
                  (tn->flags & TEKRAM_DISCONNECT_ENABLE)  ? " DISC"       : "",
                  (tn->flags & TEKRAM_START_CMD)          ? " START"      : "",
                  (tn->flags & TEKRAM_TAGGED_COMMANDS)    ? " TCQ"        : "",
                  (tn->flags & TEKRAM_WIDE_NEGO)          ? " WIDE"       : "",
                  sync);
          }
  }
  #endif  /* SYM_CONF_DEBUG_NVRAM */
  #endif  /* SYM_CONF_NVRAM_SUPPORT */
  
  
  /*
   *  Try reading Symbios or Tekram NVRAM
   */
  #ifdef SYM_CONF_NVRAM_SUPPORT
  static int sym_read_Symbios_nvram (hcb_p np, Symbios_nvram *nvram);
  static int sym_read_Tekram_nvram  (hcb_p np, Tekram_nvram *nvram);
  #endif
  
  static int sym_read_nvram(hcb_p np, struct sym_nvram *nvp)
  {
  #ifdef SYM_CONF_NVRAM_SUPPORT
          /*
           *  Try to read SYMBIOS nvram.
           *  Try to read TEKRAM nvram if Symbios nvram not found.
           */
          if      (SYM_SETUP_SYMBIOS_NVRAM &&
                   !sym_read_Symbios_nvram (np, &nvp->data.Symbios)) {
                  nvp->type = SYM_SYMBIOS_NVRAM;
  #ifdef SYM_CONF_DEBUG_NVRAM
                  sym_display_Symbios_nvram(np, &nvp->data.Symbios);
  #endif
          }
          else if (SYM_SETUP_TEKRAM_NVRAM &&
                   !sym_read_Tekram_nvram (np, &nvp->data.Tekram)) {
                  nvp->type = SYM_TEKRAM_NVRAM;
  #ifdef SYM_CONF_DEBUG_NVRAM
                  sym_display_Tekram_nvram(np, &nvp->data.Tekram);
  #endif
          }
          else
                  nvp->type = 0;
  #else
          nvp->type = 0;
  #endif
          return nvp->type;
  }
  
  
  #ifdef SYM_CONF_NVRAM_SUPPORT
  /*
   *  24C16 EEPROM reading.
   *
   *  GPOI0 - data in/data out
   *  GPIO1 - clock
   *  Symbios NVRAM wiring now also used by Tekram.
   */
  
  #define SET_BIT 0
  #define CLR_BIT 1
  #define SET_CLK 2
  #define CLR_CLK 3
  
  /*
   *  Set/clear data/clock bit in GPIO0
   */
  static void S24C16_set_bit(hcb_p np, u_char write_bit, u_char *gpreg,
                            int bit_mode)
  {
          UDELAY (5);
          switch (bit_mode){
          case SET_BIT:
                  *gpreg |= write_bit;
                  break;
          case CLR_BIT:
                  *gpreg &= 0xfe;
                  break;
          case SET_CLK:
                  *gpreg |= 0x02;
                  break;
          case CLR_CLK:
                  *gpreg &= 0xfd;
                  break;
  
          }
          OUTB (nc_gpreg, *gpreg);
          UDELAY (5);
  }
  
  /*
   *  Send START condition to NVRAM to wake it up.
   */
  static void S24C16_start(hcb_p np, u_char *gpreg)
  {
          S24C16_set_bit(np, 1, gpreg, SET_BIT);
          S24C16_set_bit(np, 0, gpreg, SET_CLK);
          S24C16_set_bit(np, 0, gpreg, CLR_BIT);
          S24C16_set_bit(np, 0, gpreg, CLR_CLK);
  }
  
  /*
   *  Send STOP condition to NVRAM - puts NVRAM to sleep... ZZzzzz!!
   */
  static void S24C16_stop(hcb_p np, u_char *gpreg)
  {
          S24C16_set_bit(np, 0, gpreg, SET_CLK);
          S24C16_set_bit(np, 1, gpreg, SET_BIT);
  }
  
  /*
   *  Read or write a bit to the NVRAM,
   *  read if GPIO0 input else write if GPIO0 output
   */
  static void S24C16_do_bit(hcb_p np, u_char *read_bit, u_char write_bit,
                           u_char *gpreg)
  {
          S24C16_set_bit(np, write_bit, gpreg, SET_BIT);
          S24C16_set_bit(np, 0, gpreg, SET_CLK);
          if (read_bit)
                  *read_bit = INB (nc_gpreg);
          S24C16_set_bit(np, 0, gpreg, CLR_CLK);
          S24C16_set_bit(np, 0, gpreg, CLR_BIT);
  }
  
  /*
   *  Output an ACK to the NVRAM after reading,
   *  change GPIO0 to output and when done back to an input
   */
  static void S24C16_write_ack(hcb_p np, u_char write_bit, u_char *gpreg,
                              u_char *gpcntl)
  {
          OUTB (nc_gpcntl, *gpcntl & 0xfe);
          S24C16_do_bit(np, 0, write_bit, gpreg);
          OUTB (nc_gpcntl, *gpcntl);
  }
  
  /*
   *  Input an ACK from NVRAM after writing,
   *  change GPIO0 to input and when done back to an output
   */
  static void S24C16_read_ack(hcb_p np, u_char *read_bit, u_char *gpreg,
                             u_char *gpcntl)
  {
          OUTB (nc_gpcntl, *gpcntl | 0x01);
          S24C16_do_bit(np, read_bit, 1, gpreg);
          OUTB (nc_gpcntl, *gpcntl);
  }
  
  /*
   *  WRITE a byte to the NVRAM and then get an ACK to see it was accepted OK,
   *  GPIO0 must already be set as an output
   */
  static void S24C16_write_byte(hcb_p np, u_char *ack_data, u_char write_data,
                               u_char *gpreg, u_char *gpcntl)
  {
          int x;
  
          for (x = 0; x < 8; x++)
                  S24C16_do_bit(np, 0, (write_data >> (7 - x)) & 0x01, gpreg);
  
          S24C16_read_ack(np, ack_data, gpreg, gpcntl);
  }
  
  /*
   *  READ a byte from the NVRAM and then send an ACK to say we have got it,
   *  GPIO0 must already be set as an input
   */
  static void S24C16_read_byte(hcb_p np, u_char *read_data, u_char ack_data,
                              u_char *gpreg, u_char *gpcntl)
  {
          int x;
          u_char read_bit;
  
          *read_data = 0;
          for (x = 0; x < 8; x++) {
                  S24C16_do_bit(np, &read_bit, 1, gpreg);
                  *read_data |= ((read_bit & 0x01) << (7 - x));
          }
  
          S24C16_write_ack(np, ack_data, gpreg, gpcntl);
  }
  
  /*
   *  Read 'len' bytes starting at 'offset'.
   */
  static int sym_read_S24C16_nvram (hcb_p np, int offset, u_char *data, int len)
  {
          u_char  gpcntl, gpreg;
          u_char  old_gpcntl, old_gpreg;
          u_char  ack_data;
          int     retv = 1;
          int     x;
  
          /* save current state of GPCNTL and GPREG */
          old_gpreg       = INB (nc_gpreg);
          old_gpcntl      = INB (nc_gpcntl);
          gpcntl          = old_gpcntl & 0x1c;
  
          /* set up GPREG & GPCNTL to set GPIO0 and GPIO1 in to known state */
          OUTB (nc_gpreg,  old_gpreg);
          OUTB (nc_gpcntl, gpcntl);
  
          /* this is to set NVRAM into a known state with GPIO0/1 both low */
          gpreg = old_gpreg;
          S24C16_set_bit(np, 0, &gpreg, CLR_CLK);
          S24C16_set_bit(np, 0, &gpreg, CLR_BIT);
  
          /* now set NVRAM inactive with GPIO0/1 both high */
          S24C16_stop(np, &gpreg);
  
          /* activate NVRAM */
          S24C16_start(np, &gpreg);
  
          /* write device code and random address MSB */
          S24C16_write_byte(np, &ack_data,
                  0xa0 | ((offset >> 7) & 0x0e), &gpreg, &gpcntl);
          if (ack_data & 0x01)
                  goto out;
  
          /* write random address LSB */
          S24C16_write_byte(np, &ack_data,
                  offset & 0xff, &gpreg, &gpcntl);
          if (ack_data & 0x01)
                  goto out;
  
          /* regenerate START state to set up for reading */
          S24C16_start(np, &gpreg);
  
          /* rewrite device code and address MSB with read bit set (lsb = 0x01) */
          S24C16_write_byte(np, &ack_data,
                  0xa1 | ((offset >> 7) & 0x0e), &gpreg, &gpcntl);
          if (ack_data & 0x01)
                  goto out;
  
          /* now set up GPIO0 for inputting data */
          gpcntl |= 0x01;
          OUTB (nc_gpcntl, gpcntl);
  
          /* input all requested data - only part of total NVRAM */
          for (x = 0; x < len; x++)
                  S24C16_read_byte(np, &data[x], (x == (len-1)), &gpreg, &gpcntl);
  
          /* finally put NVRAM back in inactive mode */
          gpcntl &= 0xfe;
          OUTB (nc_gpcntl, gpcntl);
          S24C16_stop(np, &gpreg);
          retv = 0;
  out:
          /* return GPIO0/1 to original states after having accessed NVRAM */
          OUTB (nc_gpcntl, old_gpcntl);
          OUTB (nc_gpreg,  old_gpreg);
  
          return retv;
  }
  
  #undef SET_BIT /* 0 */
  #undef CLR_BIT /* 1 */
  #undef SET_CLK /* 2 */
  #undef CLR_CLK /* 3 */
  
  /*
   *  Try reading Symbios NVRAM.
   *  Return 0 if OK.
   */
  static int sym_read_Symbios_nvram (hcb_p np, Symbios_nvram *nvram)
  {
          static u_char Symbios_trailer[6] = {0xfe, 0xfe, 0, 0, 0, 0};
          u_char *data = (u_char *) nvram;
          int len  = sizeof(*nvram);
          u_short csum;
          int x;
  
          /* probe the 24c16 and read the SYMBIOS 24c16 area */
          if (sym_read_S24C16_nvram (np, SYMBIOS_NVRAM_ADDRESS, data, len))
                  return 1;
  
          /* check valid NVRAM signature, verify byte count and checksum */
          if (nvram->type != 0 ||
              bcmp(nvram->trailer, Symbios_trailer, 6) ||
              nvram->byte_count != len - 12)
                  return 1;
  
          /* verify checksum */
          for (x = 6, csum = 0; x < len - 6; x++)
                  csum += data[x];
          if (csum != nvram->checksum)
                  return 1;
  
          return 0;
  }
  
  /*
   *  93C46 EEPROM reading.
   *
   *  GPOI0 - data in
   *  GPIO1 - data out
   *  GPIO2 - clock
   *  GPIO4 - chip select
   *
   *  Used by Tekram.
   */
  
  /*
   *  Pulse clock bit in GPIO0
   */
  static void T93C46_Clk(hcb_p np, u_char *gpreg)
  {
          OUTB (nc_gpreg, *gpreg | 0x04);
          UDELAY (2);
          OUTB (nc_gpreg, *gpreg);
  }
  
  /*
   *  Read bit from NVRAM
   */
  static void T93C46_Read_Bit(hcb_p np, u_char *read_bit, u_char *gpreg)
  {
          UDELAY (2);
          T93C46_Clk(np, gpreg);
          *read_bit = INB (nc_gpreg);
  }
  
  /*
   *  Write bit to GPIO0
   */
  static void T93C46_Write_Bit(hcb_p np, u_char write_bit, u_char *gpreg)
  {
          if (write_bit & 0x01)
                  *gpreg |= 0x02;
          else
                  *gpreg &= 0xfd;
  
          *gpreg |= 0x10;
  
          OUTB (nc_gpreg, *gpreg);
          UDELAY (2);
  
          T93C46_Clk(np, gpreg);
  }
  
  /*
   *  Send STOP condition to NVRAM - puts NVRAM to sleep... ZZZzzz!!
   */
  static void T93C46_Stop(hcb_p np, u_char *gpreg)
  {
          *gpreg &= 0xef;
          OUTB (nc_gpreg, *gpreg);
          UDELAY (2);
  
          T93C46_Clk(np, gpreg);
  }
  
  /*
   *  Send read command and address to NVRAM
   */
  static void T93C46_Send_Command(hcb_p np, u_short write_data,
                                  u_char *read_bit, u_char *gpreg)
  {
          int x;
  
          /* send 9 bits, start bit (1), command (2), address (6)  */
          for (x = 0; x < 9; x++)
                  T93C46_Write_Bit(np, (u_char) (write_data >> (8 - x)), gpreg);
  
          *read_bit = INB (nc_gpreg);
  }
  
  /*
   *  READ 2 bytes from the NVRAM
   */
  static void T93C46_Read_Word(hcb_p np, u_short *nvram_data, u_char *gpreg)
  {
          int x;
          u_char read_bit;
  
          *nvram_data = 0;
          for (x = 0; x < 16; x++) {
                  T93C46_Read_Bit(np, &read_bit, gpreg);
  
                  if (read_bit & 0x01)
                          *nvram_data |=  (0x01 << (15 - x));
                  else
                          *nvram_data &= ~(0x01 << (15 - x));
          }
  }
  
  /*
   *  Read Tekram NvRAM data.
   */
  static int T93C46_Read_Data(hcb_p np, u_short *data,int len,u_char *gpreg)
  {
          u_char  read_bit;
          int     x;
  
          for (x = 0; x < len; x++)  {
  
                  /* output read command and address */
                  T93C46_Send_Command(np, 0x180 | x, &read_bit, gpreg);
                  if (read_bit & 0x01)
                          return 1; /* Bad */
                  T93C46_Read_Word(np, &data[x], gpreg);
                  T93C46_Stop(np, gpreg);
          }
  
          return 0;
  }
  
  /*
   *  Try reading 93C46 Tekram NVRAM.
   */
  static int sym_read_T93C46_nvram (hcb_p np, Tekram_nvram *nvram)
  {
          u_char gpcntl, gpreg;
          u_char old_gpcntl, old_gpreg;
          int retv = 1;
  
          /* save current state of GPCNTL and GPREG */
          old_gpreg       = INB (nc_gpreg);
          old_gpcntl      = INB (nc_gpcntl);
  
          /* set up GPREG & GPCNTL to set GPIO0/1/2/4 in to known state, 0 in,
             1/2/4 out */
          gpreg = old_gpreg & 0xe9;
          OUTB (nc_gpreg, gpreg);
          gpcntl = (old_gpcntl & 0xe9) | 0x09;
          OUTB (nc_gpcntl, gpcntl);
  
          /* input all of NVRAM, 64 words */
          retv = T93C46_Read_Data(np, (u_short *) nvram,
                                  sizeof(*nvram) / sizeof(short), &gpreg);
  
          /* return GPIO0/1/2/4 to original states after having accessed NVRAM */
          OUTB (nc_gpcntl, old_gpcntl);
          OUTB (nc_gpreg,  old_gpreg);
  
          return retv;
  }
  
  /*
   *  Try reading Tekram NVRAM.
   *  Return 0 if OK.
   */
  static int sym_read_Tekram_nvram (hcb_p np, Tekram_nvram *nvram)
  {
          u_char *data = (u_char *) nvram;
          int len = sizeof(*nvram);
          u_short csum;
          int x;
  
          switch (np->device_id) {
          case PCI_ID_SYM53C885:
          case PCI_ID_SYM53C895:
          case PCI_ID_SYM53C896:
                  x = sym_read_S24C16_nvram(np, TEKRAM_24C16_NVRAM_ADDRESS,
                                            data, len);
                  break;
          case PCI_ID_SYM53C875:
                  x = sym_read_S24C16_nvram(np, TEKRAM_24C16_NVRAM_ADDRESS,
                                            data, len);
                  if (!x)
                          break;
          default:
                  x = sym_read_T93C46_nvram(np, nvram);
                  break;
          }
          if (x)
                  return 1;
  
          /* verify checksum */
          for (x = 0, csum = 0; x < len - 1; x += 2)
                  csum += data[x] + (data[x+1] << 8);
          if (csum != 0x1234)
                  return 1;
  
          return 0;
  }
  
  #endif  /* SYM_CONF_NVRAM_SUPPORT */