FreeBSD/Linux Kernel Cross Reference
sys/pci/ncr.c

     /**************************************************************************
     **
     ** $FreeBSD$
     **
     **  Device driver for the   NCR 53C8XX   PCI-SCSI-Controller Family.
     **
     **-------------------------------------------------------------------------
     **
     **  Written for 386bsd and FreeBSD by
    **      Wolfgang Stanglmeier    <wolf@cologne.de>
    **      Stefan Esser            <se@mi.Uni-Koeln.de>
    **
    **-------------------------------------------------------------------------
    **
    ** Copyright (c) 1994 Wolfgang Stanglmeier.  All rights reserved.
    **
    ** 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 AUTHOR ``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 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.
    **
    ***************************************************************************
    */
    
    #define NCR_DATE "pl30 98/1/1"
    
    #define NCR_VERSION     (2)
    #define MAX_UNITS       (16)
    
    #define NCR_GETCC_WITHMSG
    
    #if defined (__FreeBSD__) && defined(_KERNEL)
    #include "opt_ncr.h"
    #endif
    
    /*==========================================================
    **
    **      Configuration and Debugging
    **
    **      May be overwritten in <arch/conf/xxxx>
    **
    **==========================================================
    */
    
    /*
    **    SCSI address of this device.
    **    The boot routines should have set it.
    **    If not, use this.
    */
    
    #ifndef SCSI_NCR_MYADDR
    #define SCSI_NCR_MYADDR      (7)
    #endif /* SCSI_NCR_MYADDR */
    
    /*
    **    The default synchronous period factor
    **    (0=asynchronous)
    **    If maximum synchronous frequency is defined, use it instead.
    */
    
    #ifndef SCSI_NCR_MAX_SYNC
    
    #ifndef SCSI_NCR_DFLT_SYNC
    #define SCSI_NCR_DFLT_SYNC   (12)
    #endif /* SCSI_NCR_DFLT_SYNC */
    
    #else
    
    #if     SCSI_NCR_MAX_SYNC == 0
    #define SCSI_NCR_DFLT_SYNC 0
    #else
    #define SCSI_NCR_DFLT_SYNC (250000 / SCSI_NCR_MAX_SYNC)
    #endif
    
    #endif
    
    /*
    **    The minimal asynchronous pre-scaler period (ns)
    **    Shall be 40.
    */
    
    #ifndef SCSI_NCR_MIN_ASYNC
   #define SCSI_NCR_MIN_ASYNC   (40)
   #endif /* SCSI_NCR_MIN_ASYNC */
   
   /*
   **    The maximal bus with (in log2 byte)
   **    (0=8 bit, 1=16 bit)
   */
   
   #ifndef SCSI_NCR_MAX_WIDE
   #define SCSI_NCR_MAX_WIDE   (1)
   #endif /* SCSI_NCR_MAX_WIDE */
   
   /*==========================================================
   **
   **      Configuration and Debugging
   **
   **==========================================================
   */
   
   /*
   **    Number of targets supported by the driver.
   **    n permits target numbers 0..n-1.
   **    Default is 7, meaning targets #0..#6.
   **    #7 .. is myself.
   */
   
   #define MAX_TARGET  (16)
   
   /*
   **    Number of logic units supported by the driver.
   **    n enables logic unit numbers 0..n-1.
   **    The common SCSI devices require only
   **    one lun, so take 1 as the default.
   */
   
   #ifndef MAX_LUN
   #define MAX_LUN     (8)
   #endif  /* MAX_LUN */
   
   /*
   **    The maximum number of jobs scheduled for starting.
   **    There should be one slot per target, and one slot
   **    for each tag of each target in use.
   */
   
   #define MAX_START   (256)
   
   /*
   **    The maximum number of segments a transfer is split into.
   */
   
   #define MAX_SCATTER (33)
   
   /*
   **    The maximum transfer length (should be >= 64k).
   **    MUST NOT be greater than (MAX_SCATTER-1) * PAGE_SIZE.
   */
   
   #define MAX_SIZE  ((MAX_SCATTER-1) * (long) PAGE_SIZE)
   
   /*
   **      other
   */
   
   #define NCR_SNOOP_TIMEOUT (1000000)
   
   /*==========================================================
   **
   **      Include files
   **
   **==========================================================
   */
   
   #include <sys/param.h>
   #include <sys/time.h>
   
   #ifdef _KERNEL
   #include <sys/systm.h>
   #include <sys/malloc.h>
   #include <sys/buf.h>
   #include <sys/kernel.h>
   #include <sys/sysctl.h>
   #include <sys/bus.h>
   #include <machine/clock.h>
   #include <machine/md_var.h>
   #include <machine/bus.h>
   #include <machine/resource.h>
   #include <sys/rman.h>
   #include <vm/vm.h>
   #include <vm/pmap.h>
   #include <vm/vm_extern.h>
   #endif
   
   #include <pci/pcivar.h>
   #include <pci/pcireg.h>
   #include <pci/ncrreg.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>
   
   /*==========================================================
   **
   **      Debugging tags
   **
   **==========================================================
   */
   
   #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_FREEZE   (0x0800)
   #define DEBUG_RESTART  (0x1000)
   
   /*
   **    Enable/Disable debug messages.
   **    Can be changed at runtime too.
   */
   #ifdef SCSI_NCR_DEBUG
           #define DEBUG_FLAGS ncr_debug
   #else /* SCSI_NCR_DEBUG */
           #define SCSI_NCR_DEBUG  0
           #define DEBUG_FLAGS     0
   #endif /* SCSI_NCR_DEBUG */
   
   
   
   /*==========================================================
   **
   **      assert ()
   **
   **==========================================================
   **
   **      modified copy from 386bsd:/usr/include/sys/assert.h
   **
   **----------------------------------------------------------
   */
   
   #ifdef DIAGNOSTIC
   #define assert(expression) {                                    \
           if (!(expression)) {                                    \
                   (void)printf("assertion \"%s\" failed: "        \
                                "file \"%s\", line %d\n",          \
                                #expression, __FILE__, __LINE__);  \
                Debugger("");                                      \
           }                                                       \
   }
   #else
   #define assert(expression) {                                    \
           if (!(expression)) {                                    \
                   (void)printf("assertion \"%s\" failed: "        \
                                "file \"%s\", line %d\n",          \
                                #expression, __FILE__, __LINE__);  \
           }                                                       \
   }
   #endif
   
   /*==========================================================
   **
   **      Access to the controller chip.
   **
   **==========================================================
   */
   
   #ifdef __alpha__
   /* XXX */
   #undef vtophys
   #define vtophys(va)     alpha_XXX_dmamap((vm_offset_t)va)
   #endif
   
   #define INB(r) bus_space_read_1(np->bst, np->bsh, offsetof(struct ncr_reg, r))
   #define INW(r) bus_space_read_2(np->bst, np->bsh, offsetof(struct ncr_reg, r))
   #define INL(r) bus_space_read_4(np->bst, np->bsh, offsetof(struct ncr_reg, r))
   
   #define OUTB(r, val) bus_space_write_1(np->bst, np->bsh, \
                                          offsetof(struct ncr_reg, r), val)
   #define OUTW(r, val) bus_space_write_2(np->bst, np->bsh, \
                                          offsetof(struct ncr_reg, r), val)
   #define OUTL(r, val) bus_space_write_4(np->bst, np->bsh, \
                                          offsetof(struct ncr_reg, r), val)
   #define OUTL_OFF(o, val) bus_space_write_4(np->bst, np->bsh, o, val)
   
   #define INB_OFF(o) bus_space_read_1(np->bst, np->bsh, o)
   #define INW_OFF(o) bus_space_read_2(np->bst, np->bsh, o)
   #define INL_OFF(o) bus_space_read_4(np->bst, np->bsh, o)
   
   #define READSCRIPT_OFF(base, off)                                       \
       (base ? *((volatile u_int32_t *)((volatile char *)base + (off))) :  \
       bus_space_read_4(np->bst2, np->bsh2, off))
   
   #define WRITESCRIPT_OFF(base, off, val)                                 \
       do {                                                                \
           if (base)                                                       \
                   *((volatile u_int32_t *)                                \
                           ((volatile char *)base + (off))) = (val);       \
           else                                                            \
                   bus_space_write_4(np->bst2, np->bsh2, off, val);        \
       } while (0)
   
   #define READSCRIPT(r) \
       READSCRIPT_OFF(np->script, offsetof(struct script, r))
   
   #define WRITESCRIPT(r, val) \
       WRITESCRIPT_OFF(np->script, offsetof(struct script, r), val)
   
   /*
   **      Set bit field ON, OFF 
   */
   
   #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))
   
   /*==========================================================
   **
   **      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_COMPLETE     (4)
   #define HS_SEL_TIMEOUT  (5)     /* Selection timeout      */
   #define HS_RESET        (6)     /* SCSI reset        */
   #define HS_ABORTED      (7)     /* Transfer aborted       */
   #define HS_TIMEOUT      (8)     /* Software timeout       */
   #define HS_FAIL         (9)     /* SCSI or PCI bus errors */
   #define HS_UNEXPECTED   (10)    /* Unexpected disconnect  */
   #define HS_STALL        (11)    /* QUEUE FULL or BUSY     */
   
   #define HS_DONEMASK     (0xfc)
   
   /*==========================================================
   **
   **      Software Interrupt Codes
   **
   **==========================================================
   */
   
   #define SIR_SENSE_RESTART       (1)
   #define SIR_SENSE_FAILED        (2)
   #define SIR_STALL_RESTART       (3)
   #define SIR_STALL_QUEUE         (4)
   #define SIR_NEGO_SYNC           (5)
   #define SIR_NEGO_WIDE           (6)
   #define SIR_NEGO_FAILED         (7)
   #define SIR_NEGO_PROTO          (8)
   #define SIR_REJECT_RECEIVED     (9)
   #define SIR_REJECT_SENT         (10)
   #define SIR_IGN_RESIDUE         (11)
   #define SIR_MISSING_SAVE        (12)
   #define SIR_MAX                 (12)
   
   /*==========================================================
   **
   **      Extended error codes.
   **      xerr_status field of struct nccb.
   **
   **==========================================================
   */
   
   #define XE_OK           (0)
   #define XE_EXTRA_DATA   (1)     /* unexpected data phase */
   #define XE_BAD_PHASE    (2)     /* illegal phase (4/5)   */
   
   /*==========================================================
   **
   **      Negotiation status.
   **      nego_status field       of struct nccb.
   **
   **==========================================================
   */
   
   #define NS_SYNC         (1)
   #define NS_WIDE         (2)
   
   /*==========================================================
   **
   **      XXX These are no longer used.  Remove once the
   **          script is updated.
   **      "Special features" of targets.
   **      quirks field of struct tcb.
   **      actualquirks field of struct nccb.
   **
   **==========================================================
   */
   
   #define QUIRK_AUTOSAVE  (0x01)
   #define QUIRK_NOMSG     (0x02)
   #define QUIRK_NOSYNC    (0x10)
   #define QUIRK_NOWIDE16  (0x20)
   #define QUIRK_NOTAGS    (0x40)
   #define QUIRK_UPDATE    (0x80)
   
   /*==========================================================
   **
   **      Misc.
   **
   **==========================================================
   */
   
   #define CCB_MAGIC       (0xf2691ad2)
   #define MAX_TAGS        (32)            /* hard limit */
   
   /*==========================================================
   **
   **      OS dependencies.
   **
   **==========================================================
   */
   
   #define PRINT_ADDR(ccb) xpt_print_path((ccb)->ccb_h.path)
   
   /*==========================================================
   **
   **      Declaration of structs.
   **
   **==========================================================
   */
   
   struct tcb;
   struct lcb;
   struct nccb;
   struct ncb;
   struct script;
   
   typedef struct ncb * ncb_p;
   typedef struct tcb * tcb_p;
   typedef struct lcb * lcb_p;
   typedef struct nccb * nccb_p;
   
   struct link {
           ncrcmd  l_cmd;
           ncrcmd  l_paddr;
   };
   
   struct  usrcmd {
           u_long  target;
           u_long  lun;
           u_long  data;
           u_long  cmd;
   };
   
   #define UC_SETSYNC      10
   #define UC_SETTAGS      11
   #define UC_SETDEBUG     12
   #define UC_SETORDER     13
   #define UC_SETWIDE      14
   #define UC_SETFLAG      15
   
   #define UF_TRACE        (0x01)
   
   /*---------------------------------------
   **
   **      Timestamps for profiling
   **
   **---------------------------------------
   */
   
   /* Type of the kernel variable `ticks'.  XXX should be declared with the var. */
   typedef int ticks_t;
   
   struct tstamp {
           ticks_t start;
           ticks_t end;
           ticks_t select;
           ticks_t command;
           ticks_t data;
           ticks_t status;
           ticks_t disconnect;
   };
   
   /*
   **      profiling data (per device)
   */
   
   struct profile {
           u_long  num_trans;
           u_long  num_bytes;
           u_long  num_disc;
           u_long  num_break;
           u_long  num_int;
           u_long  num_fly;
           u_long  ms_setup;
           u_long  ms_data;
           u_long  ms_disc;
           u_long  ms_post;
   };
   
   /*==========================================================
   **
   **      Declaration of structs:         target control block
   **
   **==========================================================
   */
   
   #define NCR_TRANS_CUR           0x01    /* Modify current neogtiation status */
   #define NCR_TRANS_ACTIVE        0x03    /* Assume this is the active target */
   #define NCR_TRANS_GOAL          0x04    /* Modify negotiation goal */
   #define NCR_TRANS_USER          0x08    /* Modify user negotiation settings */
   
   struct ncr_transinfo {
           u_int8_t width;
           u_int8_t period;
           u_int8_t offset;
   };
   
   struct ncr_target_tinfo {
           /* Hardware version of our sync settings */
           u_int8_t disc_tag;
   #define         NCR_CUR_DISCENB 0x01
   #define         NCR_CUR_TAGENB  0x02
   #define         NCR_USR_DISCENB 0x04
   #define         NCR_USR_TAGENB  0x08
           u_int8_t sval;
           struct   ncr_transinfo current;
           struct   ncr_transinfo goal;
           struct   ncr_transinfo user;
           /* Hardware version of our wide settings */
           u_int8_t wval;
   };
   
   struct tcb {
           /*
           **      during reselection the ncr jumps to this point
           **      with SFBR set to the encoded target number
           **      with bit 7 set.
           **      if it's not this target, jump to the next.
           **
           **      JUMP  IF (SFBR != #target#)
           **      @(next tcb)
           */
   
           struct link   jump_tcb;
   
           /*
           **      load the actual values for the sxfer and the scntl3
           **      register (sync/wide mode).
           **
           **      SCR_COPY (1);
           **      @(sval field of this tcb)
           **      @(sxfer register)
           **      SCR_COPY (1);
           **      @(wval field of this tcb)
           **      @(scntl3 register)
           */
   
           ncrcmd  getscr[6];
   
           /*
           **      if next message is "identify"
           **      then load the message to SFBR,
           **      else load 0 to SFBR.
           **
           **      CALL
           **      <RESEL_LUN>
           */
   
           struct link   call_lun;
   
           /*
           **      now look for the right lun.
           **
           **      JUMP
           **      @(first nccb of this lun)
           */
   
           struct link   jump_lcb;
   
           /*
           **      pointer to interrupted getcc nccb
           */
   
           nccb_p   hold_cp;
   
           /*
           **      pointer to nccb used for negotiating.
           **      Avoid to start a nego for all queued commands 
           **      when tagged command queuing is enabled.
           */
   
           nccb_p   nego_cp;
   
           /*
           **      statistical data
           */
   
           u_long  transfers;
           u_long  bytes;
   
           /*
           **      user settable limits for sync transfer
           **      and tagged commands.
           */
   
           struct   ncr_target_tinfo tinfo;
   
           /*
           **      the lcb's of this tcb
           */
   
           lcb_p   lp[MAX_LUN];
   };
   
   /*==========================================================
   **
   **      Declaration of structs:         lun control block
   **
   **==========================================================
   */
   
   struct lcb {
           /*
           **      during reselection the ncr jumps to this point
           **      with SFBR set to the "Identify" message.
           **      if it's not this lun, jump to the next.
           **
           **      JUMP  IF (SFBR != #lun#)
           **      @(next lcb of this target)
           */
   
           struct link     jump_lcb;
   
           /*
           **      if next message is "simple tag",
           **      then load the tag to SFBR,
           **      else load 0 to SFBR.
           **
           **      CALL
           **      <RESEL_TAG>
           */
   
           struct link     call_tag;
   
           /*
           **      now look for the right nccb.
           **
           **      JUMP
           **      @(first nccb of this lun)
           */
   
           struct link     jump_nccb;
   
           /*
           **      start of the nccb chain
           */
   
           nccb_p  next_nccb;
   
           /*
           **      Control of tagged queueing
           */
   
           u_char          reqnccbs;
           u_char          reqlink;
           u_char          actlink;
           u_char          usetags;
           u_char          lasttag;
   };
   
   /*==========================================================
   **
   **      Declaration of structs:     COMMAND control block
   **
   **==========================================================
   **
   **      This substructure is copied from the nccb to a
   **      global address after selection (or reselection)
   **      and copied back before disconnect.
   **
   **      These fields are accessible to the script processor.
   **
   **----------------------------------------------------------
   */
   
   struct head {
           /*
           **      Execution of a nccb starts at this point.
           **      It's a jump to the "SELECT" label
           **      of the script.
           **
           **      After successful selection the script
           **      processor overwrites it with a jump to
           **      the IDLE label of the script.
           */
   
           struct link     launch;
   
           /*
           **      Saved data pointer.
           **      Points to the position in the script
           **      responsible for the actual transfer
           **      of data.
           **      It's written after reception of a
           **      "SAVE_DATA_POINTER" message.
           **      The goalpointer points after
           **      the last transfer command.
           */
   
           u_int32_t       savep;
           u_int32_t       lastp;
           u_int32_t       goalp;
   
           /*
           **      The virtual address of the nccb
           **      containing this header.
           */
   
           nccb_p  cp;
   
           /*
           **      space for some timestamps to gather
           **      profiling data about devices and this driver.
           */
   
           struct tstamp   stamp;
   
           /*
           **      status fields.
           */
   
           u_char          status[8];
   };
   
   /*
   **      The status bytes are used by the host and the script processor.
   **
   **      The first four byte are copied to the scratchb register
   **      (declared as scr0..scr3 in ncr_reg.h) just after the select/reselect,
   **      and copied back just after disconnecting.
   **      Inside the script the XX_REG are used.
   **
   **      The last four bytes are used inside the script by "COPY" commands.
   **      Because source and destination must have the same alignment
   **      in a longword, the fields HAVE to be at the choosen offsets.
   **              xerr_st (4)     0       (0x34)  scratcha
   **              sync_st (5)     1       (0x05)  sxfer
   **              wide_st (7)     3       (0x03)  scntl3
   */
   
   /*
   **      First four bytes (script)
   */
   #define  QU_REG scr0
   #define  HS_REG scr1
   #define  HS_PRT nc_scr1
   #define  SS_REG scr2
   #define  PS_REG scr3
   
   /*
   **      First four bytes (host)
   */
   #define  actualquirks  phys.header.status[0]
   #define  host_status   phys.header.status[1]
   #define  s_status      phys.header.status[2]
   #define  parity_status phys.header.status[3]
   
   /*
   **      Last four bytes (script)
   */
   #define  xerr_st       header.status[4] /* MUST be ==0 mod 4 */
   #define  sync_st       header.status[5] /* MUST be ==1 mod 4 */
   #define  nego_st       header.status[6]
   #define  wide_st       header.status[7] /* MUST be ==3 mod 4 */
   
   /*
   **      Last four bytes (host)
   */
   #define  xerr_status   phys.xerr_st
   #define  sync_status   phys.sync_st
   #define  nego_status   phys.nego_st
   #define  wide_status   phys.wide_st
   
   /*==========================================================
   **
   **      Declaration of structs:     Data structure block
   **
   **==========================================================
   **
   **      During execution of a nccb by the script processor,
   **      the DSA (data structure address) register points
   **      to this substructure of the nccb.
   **      This substructure contains the header with
   **      the script-processor-changable data and
   **      data blocks for the indirect move commands.
   **
   **----------------------------------------------------------
   */
   
   struct dsb {
   
           /*
           **      Header.
           **      Has to be the first entry,
           **      because it's jumped to by the
           **      script processor
           */
   
           struct head     header;
   
           /*
           **      Table data for Script
           */
   
           struct scr_tblsel  select;
           struct scr_tblmove smsg  ;
           struct scr_tblmove smsg2 ;
           struct scr_tblmove cmd   ;
           struct scr_tblmove scmd  ;
           struct scr_tblmove sense ;
           struct scr_tblmove data [MAX_SCATTER];
   };
   
   /*==========================================================
   **
   **      Declaration of structs:     Command control block.
   **
   **==========================================================
   **
   **      During execution of a nccb by the script processor,
   **      the DSA (data structure address) register points
   **      to this substructure of the nccb.
   **      This substructure contains the header with
   **      the script-processor-changable data and then
   **      data blocks for the indirect move commands.
   **
   **----------------------------------------------------------
   */
   
   
   struct nccb {
           /*
           **      This filler ensures that the global header is 
           **      cache line size aligned.
           */
           ncrcmd  filler[4];
   
           /*
           **      during reselection the ncr jumps to this point.
           **      If a "SIMPLE_TAG" message was received,
           **      then SFBR is set to the tag.
           **      else SFBR is set to 0
           **      If looking for another tag, jump to the next nccb.
           **
           **      JUMP  IF (SFBR != #TAG#)
           **      @(next nccb of this lun)
           */
   
           struct link             jump_nccb;
   
           /*
           **      After execution of this call, the return address
           **      (in  the TEMP register) points to the following
           **      data structure block.
           **      So copy it to the DSA register, and start
           **      processing of this data structure.
           **
           **      CALL
           **      <RESEL_TMP>
           */
   
           struct link             call_tmp;
   
           /*
           **      This is the data structure which is
           **      to be executed by the script processor.
           */
   
           struct dsb              phys;
   
           /*
           **      If a data transfer phase is terminated too early
           **      (after reception of a message (i.e. DISCONNECT)),
           **      we have to prepare a mini script to transfer
           **      the rest of the data.
           */
   
           ncrcmd                  patch[8];
   
           /*
           **      The general SCSI driver provides a
           **      pointer to a control block.
           */
   
           union   ccb *ccb;
   
           /*
           **      We prepare a message to be sent after selection,
           **      and a second one to be sent after getcc selection.
           **      Contents are IDENTIFY and SIMPLE_TAG.
           **      While negotiating sync or wide transfer,
           **      a SDTM or WDTM message is appended.
           */
   
           u_char                  scsi_smsg [8];
           u_char                  scsi_smsg2[8];
   
           /*
           **      Lock this nccb.
           **      Flag is used while looking for a free nccb.
           */
   
           u_long          magic;
   
           /*
           **      Physical address of this instance of nccb
           */
   
           u_long          p_nccb;
   
           /*
           **      Completion time out for this job.
           **      It's set to time of start + allowed number of seconds.
           */
   
           time_t          tlimit;
   
           /*
           **      All nccbs of one hostadapter are chained.
           */
   
           nccb_p          link_nccb;
   
           /*
           **      All nccbs of one target/lun are chained.
           */
   
           nccb_p          next_nccb;
   
           /*
           **      Sense command
           */
   
           u_char          sensecmd[6];
   
           /*
           **      Tag for this transfer.
           **      It's patched into jump_nccb.
           **      If it's not zero, a SIMPLE_TAG
           **      message is included in smsg.
           */
   
           u_char                  tag;
   };
   
   #define CCB_PHYS(cp,lbl)        (cp->p_nccb + offsetof(struct nccb, lbl))
   
   /*==========================================================
   **
   **      Declaration of structs:     NCR device descriptor
   **
   **==========================================================
   */
   
   struct ncb {
           /*
           **      The global header.
           **      Accessible to both the host and the
           **      script-processor.
           **      We assume it is cache line size aligned.
           */
           struct head     header;
   
           int     unit;
   
           /*-----------------------------------------------
           **      Scripts ..
           **-----------------------------------------------
           **
           **      During reselection the ncr jumps to this point.
           **      The SFBR register is loaded with the encoded target id.
           **
           **      Jump to the first target.
           **
           **      JUMP
           **      @(next tcb)
           */
           struct link     jump_tcb;
   
           /*-----------------------------------------------
          **      Configuration ..
          **-----------------------------------------------
          **
          **      virtual and physical addresses
          **      of the 53c810 chip.
          */
          int             reg_rid;
          struct resource *reg_res;
          bus_space_tag_t bst;
          bus_space_handle_t bsh;
  
          int             sram_rid;
          struct resource *sram_res;
          bus_space_tag_t bst2;
          bus_space_handle_t bsh2;
  
          struct resource *irq_res;
          void            *irq_handle;
  
          /*
          **      Scripts instance virtual address.
          */
          struct script   *script;
          struct scripth  *scripth;
  
          /*
          **      Scripts instance physical address.
          */
          u_long          p_script;
          u_long          p_scripth;
  
          /*
          **      The SCSI address of the host adapter.
          */
          u_char          myaddr;
  
          /*
          **      timing parameters
          */
          u_char          minsync;        /* Minimum sync period factor   */
          u_char          maxsync;        /* Maximum sync period factor   */
          u_char          maxoffs;        /* Max scsi offset              */
          u_char          clock_divn;     /* Number of clock divisors     */
          u_long          clock_khz;      /* SCSI clock frequency in KHz  */
          u_long          features;       /* Chip features map            */
          u_char          multiplier;     /* Clock multiplier (1,2,4)     */
  
          u_char          maxburst;       /* log base 2 of dwords burst   */
  
          /*
          **      BIOS supplied PCI bus options
          */
          u_char          rv_scntl3;
          u_char          rv_dcntl;
          u_char          rv_dmode;
          u_char          rv_ctest3;
          u_char          rv_ctest4;
          u_char          rv_ctest5;
          u_char          rv_gpcntl;
          u_char          rv_stest2;
  
          /*-----------------------------------------------
          **      CAM SIM information for this instance
          **-----------------------------------------------
          */
  
          struct          cam_sim  *sim;
          struct          cam_path *path;
  
          /*-----------------------------------------------
          **      Job control
          **-----------------------------------------------
          **
          **      Commands from user
          */
          struct usrcmd   user;
  
          /*
          **      Target data
          */
          struct tcb      target[MAX_TARGET];
  
          /*
          **      Start queue.
          */
          u_int32_t       squeue [MAX_START];
          u_short         squeueput;
  
          /*
          **      Timeout handler
          */
          time_t          heartbeat;
          u_short         ticks;
          u_short         latetime;
          time_t          lasttime;
          struct          callout_handle timeout_ch;
  
          /*-----------------------------------------------
          **      Debug and profiling
          **-----------------------------------------------
          **
          **      register dump
          */
          struct ncr_reg  regdump;
          time_t          regtime;
  
          /*
          **      Profiling data
          */
          struct profile  profile;
          u_long          disc_phys;
          u_long          disc_ref;
  
          /*
          **      Head of list of all nccbs for this controller.
          */
          nccb_p          link_nccb;
          
          /*
          **      message buffers.
          **      Should be longword aligned,
          **      because they're written with a
          **      COPY script command.
          */
          u_char          msgout[8];
          u_char          msgin [8];
          u_int32_t       lastmsg;
  
          /*
          **      Buffer for STATUS_IN phase.
          */
          u_char          scratch;
  
          /*
          **      controller chip dependent maximal transfer width.
          */
          u_char          maxwide;
  
  #ifdef NCR_IOMAPPED
          /*
          **      address of the ncr control registers in io space
          */
          pci_port_t      port;
  #endif
  };
  
  #define NCB_SCRIPT_PHYS(np,lbl) (np->p_script + offsetof (struct script, lbl))
  #define NCB_SCRIPTH_PHYS(np,lbl) (np->p_scripth + offsetof (struct scripth,lbl))
  
  /*==========================================================
  **
  **
  **      Script for NCR-Processor.
  **
  **      Use ncr_script_fill() to create the variable parts.
  **      Use ncr_script_copy_and_bind() to make a copy and
  **      bind to physical addresses.
  **
  **
  **==========================================================
  **
  **      We have to know the offsets of all labels before
  **      we reach them (for forward jumps).
  **      Therefore we declare a struct here.
  **      If you make changes inside the script,
  **      DONT FORGET TO CHANGE THE LENGTHS HERE!
  **
  **----------------------------------------------------------
  */
  
  /*
  **      Script fragments which are loaded into the on-board RAM 
  **      of 825A, 875 and 895 chips.
  */
  struct script {
          ncrcmd  start           [  7];
          ncrcmd  start0          [  2];
          ncrcmd  start1          [  3];
          ncrcmd  startpos        [  1];
          ncrcmd  trysel          [  8];
          ncrcmd  skip            [  8];
          ncrcmd  skip2           [  3];
          ncrcmd  idle            [  2];
          ncrcmd  select          [ 18];
          ncrcmd  prepare         [  4];
          ncrcmd  loadpos         [ 14];
          ncrcmd  prepare2        [ 24];
          ncrcmd  setmsg          [  5];
          ncrcmd  clrack          [  2];
          ncrcmd  dispatch        [ 33];
          ncrcmd  no_data         [ 17];
          ncrcmd  checkatn        [ 10];
          ncrcmd  command         [ 15];
          ncrcmd  status          [ 27];
          ncrcmd  msg_in          [ 26];
          ncrcmd  msg_bad         [  6];
          ncrcmd  complete        [ 13];
          ncrcmd  cleanup         [ 12];
          ncrcmd  cleanup0        [  9];
          ncrcmd  signal          [ 12];
          ncrcmd  save_dp         [  5];
          ncrcmd  restore_dp      [  5];
          ncrcmd  disconnect      [ 12];
          ncrcmd  disconnect0     [  5];
          ncrcmd  disconnect1     [ 23];
          ncrcmd  msg_out         [  9];
          ncrcmd  msg_out_done    [  7];
          ncrcmd  badgetcc        [  6];
          ncrcmd  reselect        [  8];
          ncrcmd  reselect1       [  8];
          ncrcmd  reselect2       [  8];
          ncrcmd  resel_tmp       [  5];
          ncrcmd  resel_lun       [ 18];
          ncrcmd  resel_tag       [ 24];
          ncrcmd  data_in         [MAX_SCATTER * 4 + 7];
          ncrcmd  data_out        [MAX_SCATTER * 4 + 7];
  };
  
  /*
  **      Script fragments which stay in main memory for all chips.
  */
  struct scripth {
          ncrcmd  tryloop         [MAX_START*5+2];
          ncrcmd  msg_parity      [  6];
          ncrcmd  msg_reject      [  8];
          ncrcmd  msg_ign_residue [ 32];
          ncrcmd  msg_extended    [ 18];
          ncrcmd  msg_ext_2       [ 18];
          ncrcmd  msg_wdtr        [ 27];
          ncrcmd  msg_ext_3       [ 18];
          ncrcmd  msg_sdtr        [ 27];
          ncrcmd  msg_out_abort   [ 10];
          ncrcmd  getcc           [  4];
          ncrcmd  getcc1          [  5];
  #ifdef NCR_GETCC_WITHMSG
          ncrcmd  getcc2          [ 29];
  #else
          ncrcmd  getcc2          [ 14];
  #endif
          ncrcmd  getcc3          [  6];
          ncrcmd  aborttag        [  4];
          ncrcmd  abort           [ 22];
          ncrcmd  snooptest       [  9];
          ncrcmd  snoopend        [  2];
  };
  
  /*==========================================================
  **
  **
  **      Function headers.
  **
  **
  **==========================================================
  */
  
  #ifdef _KERNEL
  static  nccb_p  ncr_alloc_nccb  (ncb_p np, u_long target, u_long lun);
  static  void    ncr_complete    (ncb_p np, nccb_p cp);
  static  int     ncr_delta       (int * from, int * to);
  static  void    ncr_exception   (ncb_p np);
  static  void    ncr_free_nccb   (ncb_p np, nccb_p cp);
  static  void    ncr_freeze_devq (ncb_p np, struct cam_path *path);
  static  void    ncr_selectclock (ncb_p np, u_char scntl3);
  static  void    ncr_getclock    (ncb_p np, u_char multiplier);
  static  nccb_p  ncr_get_nccb    (ncb_p np, u_long t,u_long l);
  #if 0
  static  u_int32_t ncr_info      (int unit);
  #endif
  static  void    ncr_init        (ncb_p np, char * msg, u_long code);
  static  void    ncr_intr        (void *vnp);
  static  void    ncr_int_ma      (ncb_p np, u_char dstat);
  static  void    ncr_int_sir     (ncb_p np);
  static  void    ncr_int_sto     (ncb_p np);
  #if 0
  static  void    ncr_min_phys    (struct buf *bp);
  #endif
  static  void    ncr_poll        (struct cam_sim *sim);
  static  void    ncb_profile     (ncb_p np, nccb_p cp);
  static  void    ncr_script_copy_and_bind
                                  (ncb_p np, ncrcmd *src, ncrcmd *dst, int len);
  static  void    ncr_script_fill (struct script * scr, struct scripth *scrh);
  static  int     ncr_scatter     (struct dsb* phys, vm_offset_t vaddr,
                                   vm_size_t datalen);
  static  void    ncr_getsync     (ncb_p np, u_char sfac, u_char *fakp,
                                   u_char *scntl3p);
  static  void    ncr_setsync     (ncb_p np, nccb_p cp,u_char scntl3,u_char sxfer,
                                   u_char period);
  static  void    ncr_setwide     (ncb_p np, nccb_p cp, u_char wide, u_char ack);
  static  int     ncr_show_msg    (u_char * msg);
  static  int     ncr_snooptest   (ncb_p np);
  static  void    ncr_action      (struct cam_sim *sim, union ccb *ccb);
  static  void    ncr_timeout     (void *arg);
  static  void    ncr_wakeup      (ncb_p np, u_long code);
  
  static  int     ncr_probe       (device_t dev);
  static  int     ncr_attach      (device_t dev);
  
  #endif /* _KERNEL */
  
  /*==========================================================
  **
  **
  **      Global static data.
  **
  **
  **==========================================================
  */
  
  
  #if !defined(lint)
  static const char ident[] =
          "\n$FreeBSD$\n";
  #endif
  
  static const u_long     ncr_version = NCR_VERSION       * 11
          + (u_long) sizeof (struct ncb)  *  7
          + (u_long) sizeof (struct nccb) *  5
          + (u_long) sizeof (struct lcb)  *  3
          + (u_long) sizeof (struct tcb)  *  2;
  
  #ifdef _KERNEL
  
  static int ncr_debug = SCSI_NCR_DEBUG;
  SYSCTL_INT(_debug, OID_AUTO, ncr_debug, CTLFLAG_RW, &ncr_debug, 0, "");
  
  static int ncr_cache; /* to be aligned _NOT_ static */
  
  /*==========================================================
  **
  **
  **      Global static data:     auto configure
  **
  **
  **==========================================================
  */
  
  #define NCR_810_ID      (0x00011000ul)
  #define NCR_815_ID      (0x00041000ul)
  #define NCR_820_ID      (0x00021000ul)
  #define NCR_825_ID      (0x00031000ul)
  #define NCR_860_ID      (0x00061000ul)
  #define NCR_875_ID      (0x000f1000ul)
  #define NCR_875_ID2     (0x008f1000ul)
  #define NCR_885_ID      (0x000d1000ul)
  #define NCR_895_ID      (0x000c1000ul)
  #define NCR_896_ID      (0x000b1000ul)
  #define NCR_895A_ID     (0x00121000ul)
  #define NCR_1510D_ID    (0x000a1000ul)
  
  
  static char *ncr_name (ncb_p np)
  {
          static char name[10];
          snprintf(name, sizeof(name), "ncr%d", np->unit);
          return (name);
  }
  
  /*==========================================================
  **
  **
  **      Scripts for NCR-Processor.
  **
  **      Use ncr_script_bind for binding to physical addresses.
  **
  **
  **==========================================================
  **
  **      NADDR generates a reference to a field of the controller data.
  **      PADDR generates a reference to another part of the script.
  **      RADDR generates a reference to a script processor register.
  **      FADDR generates a reference to a script processor register
  **              with offset.
  **
  **----------------------------------------------------------
  */
  
  #define RELOC_SOFTC     0x40000000
  #define RELOC_LABEL     0x50000000
  #define RELOC_REGISTER  0x60000000
  #define RELOC_KVAR      0x70000000
  #define RELOC_LABELH    0x80000000
  #define RELOC_MASK      0xf0000000
  
  #define NADDR(label)    (RELOC_SOFTC | offsetof(struct ncb, label))
  #define PADDR(label)    (RELOC_LABEL | offsetof(struct script, label))
  #define PADDRH(label)   (RELOC_LABELH | offsetof(struct scripth, label))
  #define RADDR(label)    (RELOC_REGISTER | REG(label))
  #define FADDR(label,ofs)(RELOC_REGISTER | ((REG(label))+(ofs)))
  #define KVAR(which)     (RELOC_KVAR | (which))
  
  #define KVAR_SECOND                     (0)
  #define KVAR_TICKS                      (1)
  #define KVAR_NCR_CACHE                  (2)
  
  #define SCRIPT_KVAR_FIRST               (0)
  #define SCRIPT_KVAR_LAST                (3)
  
  /*
   * Kernel variables referenced in the scripts.
   * THESE MUST ALL BE ALIGNED TO A 4-BYTE BOUNDARY.
   */
  static void *script_kvars[] =
          { &time_second, &ticks, &ncr_cache };
  
  static  struct script script0 = {
  /*--------------------------< START >-----------------------*/ {
          /*
          **      Claim to be still alive ...
          */
          SCR_COPY (sizeof (((struct ncb *)0)->heartbeat)),
                  KVAR (KVAR_SECOND),
                  NADDR (heartbeat),
          /*
          **      Make data structure address invalid.
          **      clear SIGP.
          */
          SCR_LOAD_REG (dsa, 0xff),
                  0,
          SCR_FROM_REG (ctest2),
                  0,
  }/*-------------------------< START0 >----------------------*/,{
          /*
          **      Hook for interrupted GetConditionCode.
          **      Will be patched to ... IFTRUE by
          **      the interrupt handler.
          */
          SCR_INT ^ IFFALSE (0),
                  SIR_SENSE_RESTART,
  
  }/*-------------------------< START1 >----------------------*/,{
          /*
          **      Hook for stalled start queue.
          **      Will be patched to IFTRUE by the interrupt handler.
          */
          SCR_INT ^ IFFALSE (0),
                  SIR_STALL_RESTART,
          /*
          **      Then jump to a certain point in tryloop.
          **      Due to the lack of indirect addressing the code
          **      is self modifying here.
          */
          SCR_JUMP,
  }/*-------------------------< STARTPOS >--------------------*/,{
                  PADDRH(tryloop),
  
  }/*-------------------------< TRYSEL >----------------------*/,{
          /*
          **      Now:
          **      DSA: Address of a Data Structure
          **      or   Address of the IDLE-Label.
          **
          **      TEMP:   Address of a script, which tries to
          **              start the NEXT entry.
          **
          **      Save the TEMP register into the SCRATCHA register.
          **      Then copy the DSA to TEMP and RETURN.
          **      This is kind of an indirect jump.
          **      (The script processor has NO stack, so the
          **      CALL is actually a jump and link, and the
          **      RETURN is an indirect jump.)
          **
          **      If the slot was empty, DSA contains the address
          **      of the IDLE part of this script. The processor
          **      jumps to IDLE and waits for a reselect.
          **      It will wake up and try the same slot again
          **      after the SIGP bit becomes set by the host.
          **
          **      If the slot was not empty, DSA contains
          **      the address of the phys-part of a nccb.
          **      The processor jumps to this address.
          **      phys starts with head,
          **      head starts with launch,
          **      so actually the processor jumps to
          **      the lauch part.
          **      If the entry is scheduled for execution,
          **      then launch contains a jump to SELECT.
          **      If it's not scheduled, it contains a jump to IDLE.
          */
          SCR_COPY (4),
                  RADDR (temp),
                  RADDR (scratcha),
          SCR_COPY (4),
                  RADDR (dsa),
                  RADDR (temp),
          SCR_RETURN,
                  0
  
  }/*-------------------------< SKIP >------------------------*/,{
          /*
          **      This entry has been canceled.
          **      Next time use the next slot.
          */
          SCR_COPY (4),
                  RADDR (scratcha),
                  PADDR (startpos),
          /*
          **      patch the launch field.
          **      should look like an idle process.
          */
          SCR_COPY_F (4),
                  RADDR (dsa),
                  PADDR (skip2),
          SCR_COPY (8),
                  PADDR (idle),
  }/*-------------------------< SKIP2 >-----------------------*/,{
                  0,
          SCR_JUMP,
                  PADDR(start),
  }/*-------------------------< IDLE >------------------------*/,{
          /*
          **      Nothing to do?
          **      Wait for reselect.
          */
          SCR_JUMP,
                  PADDR(reselect),
  
  }/*-------------------------< SELECT >----------------------*/,{
          /*
          **      DSA     contains the address of a scheduled
          **              data structure.
          **
          **      SCRATCHA contains the address of the script,
          **              which starts the next entry.
          **
          **      Set Initiator mode.
          **
          **      (Target mode is left as an exercise for the reader)
          */
  
          SCR_CLR (SCR_TRG),
                  0,
          SCR_LOAD_REG (HS_REG, 0xff),
                  0,
  
          /*
          **      And try to select this target.
          */
          SCR_SEL_TBL_ATN ^ offsetof (struct dsb, select),
                  PADDR (reselect),
  
          /*
          **      Now there are 4 possibilities:
          **
          **      (1) The ncr looses arbitration.
          **      This is ok, because it will try again,
          **      when the bus becomes idle.
          **      (But beware of the timeout function!)
          **
          **      (2) The ncr is reselected.
          **      Then the script processor takes the jump
          **      to the RESELECT label.
          **
          **      (3) The ncr completes the selection.
          **      Then it will execute the next statement.
          **
          **      (4) There is a selection timeout.
          **      Then the ncr should interrupt the host and stop.
          **      Unfortunately, it seems to continue execution
          **      of the script. But it will fail with an
          **      IID-interrupt on the next WHEN.
          */
  
          SCR_JUMPR ^ IFTRUE (WHEN (SCR_MSG_IN)),
                  0,
  
          /*
          **      Send the IDENTIFY and SIMPLE_TAG messages
          **      (and the MSG_EXT_SDTR message)
          */
          SCR_MOVE_TBL ^ SCR_MSG_OUT,
                  offsetof (struct dsb, smsg),
  #ifdef undef /* XXX better fail than try to deal with this ... */
          SCR_JUMPR ^ IFTRUE (WHEN (SCR_MSG_OUT)),
                  -16,
  #endif
          SCR_CLR (SCR_ATN),
                  0,
          SCR_COPY (1),
                  RADDR (sfbr),
                  NADDR (lastmsg),
          /*
          **      Selection complete.
          **      Next time use the next slot.
          */
          SCR_COPY (4),
                  RADDR (scratcha),
                  PADDR (startpos),
  }/*-------------------------< PREPARE >----------------------*/,{
          /*
          **      The ncr doesn't have an indirect load
          **      or store command. So we have to
          **      copy part of the control block to a
          **      fixed place, where we can access it.
          **
          **      We patch the address part of a
          **      COPY command with the DSA-register.
          */
          SCR_COPY_F (4),
                  RADDR (dsa),
                  PADDR (loadpos),
          /*
          **      then we do the actual copy.
          */
          SCR_COPY (sizeof (struct head)),
          /*
          **      continued after the next label ...
          */
  
  }/*-------------------------< LOADPOS >---------------------*/,{
                  0,
                  NADDR (header),
          /*
          **      Mark this nccb as not scheduled.
          */
          SCR_COPY (8),
                  PADDR (idle),
                  NADDR (header.launch),
          /*
          **      Set a time stamp for this selection
          */
          SCR_COPY (sizeof (ticks)),
                  KVAR (KVAR_TICKS),
                  NADDR (header.stamp.select),
          /*
          **      load the savep (saved pointer) into
          **      the TEMP register (actual pointer)
          */
          SCR_COPY (4),
                  NADDR (header.savep),
                  RADDR (temp),
          /*
          **      Initialize the status registers
          */
          SCR_COPY (4),
                  NADDR (header.status),
                  RADDR (scr0),
  
  }/*-------------------------< PREPARE2 >---------------------*/,{
          /*
          **      Load the synchronous mode register
          */
          SCR_COPY (1),
                  NADDR (sync_st),
                  RADDR (sxfer),
          /*
          **      Load the wide mode and timing register
          */
          SCR_COPY (1),
                  NADDR (wide_st),
                  RADDR (scntl3),
          /*
          **      Initialize the msgout buffer with a NOOP message.
          */
          SCR_LOAD_REG (scratcha, MSG_NOOP),
                  0,
          SCR_COPY (1),
                  RADDR (scratcha),
                  NADDR (msgout),
          SCR_COPY (1),
                  RADDR (scratcha),
                  NADDR (msgin),
          /*
          **      Message in phase ?
          */
          SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
                  PADDR (dispatch),
          /*
          **      Extended or reject message ?
          */
          SCR_FROM_REG (sbdl),
                  0,
          SCR_JUMP ^ IFTRUE (DATA (MSG_EXTENDED)),
                  PADDR (msg_in),
          SCR_JUMP ^ IFTRUE (DATA (MSG_MESSAGE_REJECT)),
                  PADDRH (msg_reject),
          /*
          **      normal processing
          */
          SCR_JUMP,
                  PADDR (dispatch),
  }/*-------------------------< SETMSG >----------------------*/,{
          SCR_COPY (1),
                  RADDR (scratcha),
                  NADDR (msgout),
          SCR_SET (SCR_ATN),
                  0,
  }/*-------------------------< CLRACK >----------------------*/,{
          /*
          **      Terminate possible pending message phase.
          */
          SCR_CLR (SCR_ACK),
                  0,
  
  }/*-----------------------< DISPATCH >----------------------*/,{
          SCR_FROM_REG (HS_REG),
                  0,
          SCR_INT ^ IFTRUE (DATA (HS_NEGOTIATE)),
                  SIR_NEGO_FAILED,
          /*
          **      remove bogus output signals
          */
          SCR_REG_REG (socl, SCR_AND, CACK|CATN),
                  0,
          SCR_RETURN ^ IFTRUE (WHEN (SCR_DATA_OUT)),
                  0,
          SCR_RETURN ^ IFTRUE (IF (SCR_DATA_IN)),
                  0,
          SCR_JUMP ^ IFTRUE (IF (SCR_MSG_OUT)),
                  PADDR (msg_out),
          SCR_JUMP ^ IFTRUE (IF (SCR_MSG_IN)),
                  PADDR (msg_in),
          SCR_JUMP ^ IFTRUE (IF (SCR_COMMAND)),
                  PADDR (command),
          SCR_JUMP ^ IFTRUE (IF (SCR_STATUS)),
                  PADDR (status),
          /*
          **      Discard one illegal phase byte, if required.
          */
          SCR_LOAD_REG (scratcha, XE_BAD_PHASE),
                  0,
          SCR_COPY (1),
                  RADDR (scratcha),
                  NADDR (xerr_st),
          SCR_JUMPR ^ IFFALSE (IF (SCR_ILG_OUT)),
                  8,
          SCR_MOVE_ABS (1) ^ SCR_ILG_OUT,
                  NADDR (scratch),
          SCR_JUMPR ^ IFFALSE (IF (SCR_ILG_IN)),
                  8,
          SCR_MOVE_ABS (1) ^ SCR_ILG_IN,
                  NADDR (scratch),
          SCR_JUMP,
                  PADDR (dispatch),
  
  }/*-------------------------< NO_DATA >--------------------*/,{
          /*
          **      The target wants to tranfer too much data
          **      or in the wrong direction.
          **      Remember that in extended error.
          */
          SCR_LOAD_REG (scratcha, XE_EXTRA_DATA),
                  0,
          SCR_COPY (1),
                  RADDR (scratcha),
                  NADDR (xerr_st),
          /*
          **      Discard one data byte, if required.
          */
          SCR_JUMPR ^ IFFALSE (WHEN (SCR_DATA_OUT)),
                  8,
          SCR_MOVE_ABS (1) ^ SCR_DATA_OUT,
                  NADDR (scratch),
          SCR_JUMPR ^ IFFALSE (IF (SCR_DATA_IN)),
                  8,
          SCR_MOVE_ABS (1) ^ SCR_DATA_IN,
                  NADDR (scratch),
          /*
          **      .. and repeat as required.
          */
          SCR_CALL,
                  PADDR (dispatch),
          SCR_JUMP,
                  PADDR (no_data),
  }/*-------------------------< CHECKATN >--------------------*/,{
          /*
          **      If AAP (bit 1 of scntl0 register) is set
          **      and a parity error is detected,
          **      the script processor asserts ATN.
          **
          **      The target should switch to a MSG_OUT phase
          **      to get the message.
          */
          SCR_FROM_REG (socl),
                  0,
          SCR_JUMP ^ IFFALSE (MASK (CATN, CATN)),
                  PADDR (dispatch),
          /*
          **      count it
          */
          SCR_REG_REG (PS_REG, SCR_ADD, 1),
                  0,
          /*
          **      Prepare a MSG_INITIATOR_DET_ERR message
          **      (initiator detected error).
          **      The target should retry the transfer.
          */
          SCR_LOAD_REG (scratcha, MSG_INITIATOR_DET_ERR),
                  0,
          SCR_JUMP,
                  PADDR (setmsg),
  
  }/*-------------------------< COMMAND >--------------------*/,{
          /*
          **      If this is not a GETCC transfer ...
          */
          SCR_FROM_REG (SS_REG),
                  0,
  /*<<<*/ SCR_JUMPR ^ IFTRUE (DATA (SCSI_STATUS_CHECK_COND)),
                  28,
          /*
          **      ... set a timestamp ...
          */
          SCR_COPY (sizeof (ticks)),
                  KVAR (KVAR_TICKS),
                  NADDR (header.stamp.command),
          /*
          **      ... and send the command
          */
          SCR_MOVE_TBL ^ SCR_COMMAND,
                  offsetof (struct dsb, cmd),
          SCR_JUMP,
                  PADDR (dispatch),
          /*
          **      Send the GETCC command
          */
  /*>>>*/ SCR_MOVE_TBL ^ SCR_COMMAND,
                  offsetof (struct dsb, scmd),
          SCR_JUMP,
                  PADDR (dispatch),
  
  }/*-------------------------< STATUS >--------------------*/,{
          /*
          **      set the timestamp.
          */
          SCR_COPY (sizeof (ticks)),
                  KVAR (KVAR_TICKS),
                  NADDR (header.stamp.status),
          /*
          **      If this is a GETCC transfer,
          */
          SCR_FROM_REG (SS_REG),
                  0,
  /*<<<*/ SCR_JUMPR ^ IFFALSE (DATA (SCSI_STATUS_CHECK_COND)),
                  40,
          /*
          **      get the status
          */
          SCR_MOVE_ABS (1) ^ SCR_STATUS,
                  NADDR (scratch),
          /*
          **      Save status to scsi_status.
          **      Mark as complete.
          **      And wait for disconnect.
          */
          SCR_TO_REG (SS_REG),
                  0,
          SCR_REG_REG (SS_REG, SCR_OR, SCSI_STATUS_SENSE),
                  0,
          SCR_LOAD_REG (HS_REG, HS_COMPLETE),
                  0,
          SCR_JUMP,
                  PADDR (checkatn),
          /*
          **      If it was no GETCC transfer,
          **      save the status to scsi_status.
          */
  /*>>>*/ SCR_MOVE_ABS (1) ^ SCR_STATUS,
                  NADDR (scratch),
          SCR_TO_REG (SS_REG),
                  0,
          /*
          **      if it was no check condition ...
          */
          SCR_JUMP ^ IFTRUE (DATA (SCSI_STATUS_CHECK_COND)),
                  PADDR (checkatn),
          /*
          **      ... mark as complete.
          */
          SCR_LOAD_REG (HS_REG, HS_COMPLETE),
                  0,
          SCR_JUMP,
                  PADDR (checkatn),
  
  }/*-------------------------< MSG_IN >--------------------*/,{
          /*
          **      Get the first byte of the message
          **      and save it to SCRATCHA.
          **
          **      The script processor doesn't negate the
          **      ACK signal after this transfer.
          */
          SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                  NADDR (msgin[0]),
          /*
          **      Check for message parity error.
          */
          SCR_TO_REG (scratcha),
                  0,
          SCR_FROM_REG (socl),
                  0,
          SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
                  PADDRH (msg_parity),
          SCR_FROM_REG (scratcha),
                  0,
          /*
          **      Parity was ok, handle this message.
          */
          SCR_JUMP ^ IFTRUE (DATA (MSG_CMDCOMPLETE)),
                  PADDR (complete),
          SCR_JUMP ^ IFTRUE (DATA (MSG_SAVEDATAPOINTER)),
                  PADDR (save_dp),
          SCR_JUMP ^ IFTRUE (DATA (MSG_RESTOREPOINTERS)),
                  PADDR (restore_dp),
          SCR_JUMP ^ IFTRUE (DATA (MSG_DISCONNECT)),
                  PADDR (disconnect),
          SCR_JUMP ^ IFTRUE (DATA (MSG_EXTENDED)),
                  PADDRH (msg_extended),
          SCR_JUMP ^ IFTRUE (DATA (MSG_NOOP)),
                  PADDR (clrack),
          SCR_JUMP ^ IFTRUE (DATA (MSG_MESSAGE_REJECT)),
                  PADDRH (msg_reject),
          SCR_JUMP ^ IFTRUE (DATA (MSG_IGN_WIDE_RESIDUE)),
                  PADDRH (msg_ign_residue),
          /*
          **      Rest of the messages left as
          **      an exercise ...
          **
          **      Unimplemented messages:
          **      fall through to MSG_BAD.
          */
  }/*-------------------------< MSG_BAD >------------------*/,{
          /*
          **      unimplemented message - reject it.
          */
          SCR_INT,
                  SIR_REJECT_SENT,
          SCR_LOAD_REG (scratcha, MSG_MESSAGE_REJECT),
                  0,
          SCR_JUMP,
                  PADDR (setmsg),
  
  }/*-------------------------< COMPLETE >-----------------*/,{
          /*
          **      Complete message.
          **
          **      If it's not the get condition code,
          **      copy TEMP register to LASTP in header.
          */
          SCR_FROM_REG (SS_REG),
                  0,
  /*<<<*/ SCR_JUMPR ^ IFTRUE (MASK (SCSI_STATUS_SENSE, SCSI_STATUS_SENSE)),
                  12,
          SCR_COPY (4),
                  RADDR (temp),
                  NADDR (header.lastp),
  /*>>>*/ /*
          **      When we terminate the cycle by clearing ACK,
          **      the target may disconnect immediately.
          **
          **      We don't want to be told of an
          **      "unexpected disconnect",
          **      so we disable this feature.
          */
          SCR_REG_REG (scntl2, SCR_AND, 0x7f),
                  0,
          /*
          **      Terminate cycle ...
          */
          SCR_CLR (SCR_ACK|SCR_ATN),
                  0,
          /*
          **      ... and wait for the disconnect.
          */
          SCR_WAIT_DISC,
                  0,
  }/*-------------------------< CLEANUP >-------------------*/,{
          /*
          **      dsa:    Pointer to nccb
          **            or xxxxxxFF (no nccb)
          **
          **      HS_REG:   Host-Status (<>0!)
          */
          SCR_FROM_REG (dsa),
                  0,
          SCR_JUMP ^ IFTRUE (DATA (0xff)),
                  PADDR (signal),
          /*
          **      dsa is valid.
          **      save the status registers
          */
          SCR_COPY (4),
                  RADDR (scr0),
                  NADDR (header.status),
          /*
          **      and copy back the header to the nccb.
          */
          SCR_COPY_F (4),
                  RADDR (dsa),
                  PADDR (cleanup0),
          SCR_COPY (sizeof (struct head)),
                  NADDR (header),
  }/*-------------------------< CLEANUP0 >--------------------*/,{
                  0,
  
          /*
          **      If command resulted in "check condition"
          **      status and is not yet completed,
          **      try to get the condition code.
          */
          SCR_FROM_REG (HS_REG),
                  0,
  /*<<<*/ SCR_JUMPR ^ IFFALSE (MASK (0, HS_DONEMASK)),
                  16,
          SCR_FROM_REG (SS_REG),
                  0,
          SCR_JUMP ^ IFTRUE (DATA (SCSI_STATUS_CHECK_COND)),
                  PADDRH(getcc2),
  }/*-------------------------< SIGNAL >----------------------*/,{
          /*
          **      if status = queue full,
          **      reinsert in startqueue and stall queue.
          */
  /*>>>*/ SCR_FROM_REG (SS_REG),
                  0,
          SCR_INT ^ IFTRUE (DATA (SCSI_STATUS_QUEUE_FULL)),
                  SIR_STALL_QUEUE,
          /*
          **      And make the DSA register invalid.
          */
          SCR_LOAD_REG (dsa, 0xff), /* invalid */
                  0,
          /*
          **      if job completed ...
          */
          SCR_FROM_REG (HS_REG),
                  0,
          /*
          **      ... signal completion to the host
          */
          SCR_INT_FLY ^ IFFALSE (MASK (0, HS_DONEMASK)),
                  0,
          /*
          **      Auf zu neuen Schandtaten!
          */
          SCR_JUMP,
                  PADDR(start),
  
  }/*-------------------------< SAVE_DP >------------------*/,{
          /*
          **      SAVE_DP message:
          **      Copy TEMP register to SAVEP in header.
          */
          SCR_COPY (4),
                  RADDR (temp),
                  NADDR (header.savep),
          SCR_JUMP,
                  PADDR (clrack),
  }/*-------------------------< RESTORE_DP >---------------*/,{
          /*
          **      RESTORE_DP message:
          **      Copy SAVEP in header to TEMP register.
          */
          SCR_COPY (4),
                  NADDR (header.savep),
                  RADDR (temp),
          SCR_JUMP,
                  PADDR (clrack),
  
  }/*-------------------------< DISCONNECT >---------------*/,{
          /*
          **      If QUIRK_AUTOSAVE is set,
          **      do an "save pointer" operation.
          */
          SCR_FROM_REG (QU_REG),
                  0,
  /*<<<*/ SCR_JUMPR ^ IFFALSE (MASK (QUIRK_AUTOSAVE, QUIRK_AUTOSAVE)),
                  12,
          /*
          **      like SAVE_DP message:
          **      Copy TEMP register to SAVEP in header.
          */
          SCR_COPY (4),
                  RADDR (temp),
                  NADDR (header.savep),
  /*>>>*/ /*
          **      Check if temp==savep or temp==goalp:
          **      if not, log a missing save pointer message.
          **      In fact, it's a comparison mod 256.
          **
          **      Hmmm, I hadn't thought that I would be urged to
          **      write this kind of ugly self modifying code.
          **
          **      It's unbelievable, but the ncr53c8xx isn't able
          **      to subtract one register from another.
          */
          SCR_FROM_REG (temp),
                  0,
          /*
          **      You are not expected to understand this ..
          **
          **      CAUTION: only little endian architectures supported! XXX
          */
          SCR_COPY_F (1),
                  NADDR (header.savep),
                  PADDR (disconnect0),
  }/*-------------------------< DISCONNECT0 >--------------*/,{
  /*<<<*/ SCR_JUMPR ^ IFTRUE (DATA (1)),
                  20,
          /*
          **      neither this
          */
          SCR_COPY_F (1),
                  NADDR (header.goalp),
                  PADDR (disconnect1),
  }/*-------------------------< DISCONNECT1 >--------------*/,{
          SCR_INT ^ IFFALSE (DATA (1)),
                  SIR_MISSING_SAVE,
  /*>>>*/
  
          /*
          **      DISCONNECTing  ...
          **
          **      disable the "unexpected disconnect" feature,
          **      and remove the ACK signal.
          */
          SCR_REG_REG (scntl2, SCR_AND, 0x7f),
                  0,
          SCR_CLR (SCR_ACK|SCR_ATN),
                  0,
          /*
          **      Wait for the disconnect.
          */
          SCR_WAIT_DISC,
                  0,
          /*
          **      Profiling:
          **      Set a time stamp,
          **      and count the disconnects.
          */
          SCR_COPY (sizeof (ticks)),
                  KVAR (KVAR_TICKS),
                  NADDR (header.stamp.disconnect),
          SCR_COPY (4),
                  NADDR (disc_phys),
                  RADDR (temp),
          SCR_REG_REG (temp, SCR_ADD, 0x01),
                  0,
          SCR_COPY (4),
                  RADDR (temp),
                  NADDR (disc_phys),
          /*
          **      Status is: DISCONNECTED.
          */
          SCR_LOAD_REG (HS_REG, HS_DISCONNECT),
                  0,
          SCR_JUMP,
                  PADDR (cleanup),
  
  }/*-------------------------< MSG_OUT >-------------------*/,{
          /*
          **      The target requests a message.
          */
          SCR_MOVE_ABS (1) ^ SCR_MSG_OUT,
                  NADDR (msgout),
          SCR_COPY (1),
                  RADDR (sfbr),
                  NADDR (lastmsg),
          /*
          **      If it was no ABORT message ...
          */
          SCR_JUMP ^ IFTRUE (DATA (MSG_ABORT)),
                  PADDRH (msg_out_abort),
          /*
          **      ... wait for the next phase
          **      if it's a message out, send it again, ...
          */
          SCR_JUMP ^ IFTRUE (WHEN (SCR_MSG_OUT)),
                  PADDR (msg_out),
  }/*-------------------------< MSG_OUT_DONE >--------------*/,{
          /*
          **      ... else clear the message ...
          */
          SCR_LOAD_REG (scratcha, MSG_NOOP),
                  0,
          SCR_COPY (4),
                  RADDR (scratcha),
                  NADDR (msgout),
          /*
          **      ... and process the next phase
          */
          SCR_JUMP,
                  PADDR (dispatch),
  
  }/*------------------------< BADGETCC >---------------------*/,{
          /*
          **      If SIGP was set, clear it and try again.
          */
          SCR_FROM_REG (ctest2),
                  0,
          SCR_JUMP ^ IFTRUE (MASK (CSIGP,CSIGP)),
                  PADDRH (getcc2),
          SCR_INT,
                  SIR_SENSE_FAILED,
  }/*-------------------------< RESELECT >--------------------*/,{
          /*
          **      This NOP will be patched with LED OFF
          **      SCR_REG_REG (gpreg, SCR_OR, 0x01)
          */
          SCR_NO_OP,
                  0,
  
          /*
          **      make the DSA invalid.
          */
          SCR_LOAD_REG (dsa, 0xff),
                  0,
          SCR_CLR (SCR_TRG),
                  0,
          /*
          **      Sleep waiting for a reselection.
          **      If SIGP is set, special treatment.
          **
          **      Zu allem bereit ..
          */
          SCR_WAIT_RESEL,
                  PADDR(reselect2),
  }/*-------------------------< RESELECT1 >--------------------*/,{
          /*
          **      This NOP will be patched with LED ON
          **      SCR_REG_REG (gpreg, SCR_AND, 0xfe)
          */
          SCR_NO_OP,
                  0,
          /*
          **      ... zu nichts zu gebrauchen ?
          **
          **      load the target id into the SFBR
          **      and jump to the control block.
          **
          **      Look at the declarations of
          **      - struct ncb
          **      - struct tcb
          **      - struct lcb
          **      - struct nccb
          **      to understand what's going on.
          */
          SCR_REG_SFBR (ssid, SCR_AND, 0x8F),
                  0,
          SCR_TO_REG (sdid),
                  0,
          SCR_JUMP,
                  NADDR (jump_tcb),
  }/*-------------------------< RESELECT2 >-------------------*/,{
          /*
          **      This NOP will be patched with LED ON
          **      SCR_REG_REG (gpreg, SCR_AND, 0xfe)
          */
          SCR_NO_OP,
                  0,
          /*
          **      If it's not connected :(
          **      -> interrupted by SIGP bit.
          **      Jump to start.
          */
          SCR_FROM_REG (ctest2),
                  0,
          SCR_JUMP ^ IFTRUE (MASK (CSIGP,CSIGP)),
                  PADDR (start),
          SCR_JUMP,
                  PADDR (reselect),
  
  }/*-------------------------< RESEL_TMP >-------------------*/,{
          /*
          **      The return address in TEMP
          **      is in fact the data structure address,
          **      so copy it to the DSA register.
          */
          SCR_COPY (4),
                  RADDR (temp),
                  RADDR (dsa),
          SCR_JUMP,
                  PADDR (prepare),
  
  }/*-------------------------< RESEL_LUN >-------------------*/,{
          /*
          **      come back to this point
          **      to get an IDENTIFY message
          **      Wait for a msg_in phase.
          */
  /*<<<*/ SCR_JUMPR ^ IFFALSE (WHEN (SCR_MSG_IN)),
                  48,
          /*
          **      message phase
          **      It's not a sony, it's a trick:
          **      read the data without acknowledging it.
          */
          SCR_FROM_REG (sbdl),
                  0,
  /*<<<*/ SCR_JUMPR ^ IFFALSE (MASK (MSG_IDENTIFYFLAG, 0x98)),
                  32,
          /*
          **      It WAS an Identify message.
          **      get it and ack it!
          */
          SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                  NADDR (msgin),
          SCR_CLR (SCR_ACK),
                  0,
          /*
          **      Mask out the lun.
          */
          SCR_REG_REG (sfbr, SCR_AND, 0x07),
                  0,
          SCR_RETURN,
                  0,
          /*
          **      No message phase or no IDENTIFY message:
          **      return 0.
          */
  /*>>>*/ SCR_LOAD_SFBR (0),
                  0,
          SCR_RETURN,
                  0,
  
  }/*-------------------------< RESEL_TAG >-------------------*/,{
          /*
          **      come back to this point
          **      to get a SIMPLE_TAG message
          **      Wait for a MSG_IN phase.
          */
  /*<<<*/ SCR_JUMPR ^ IFFALSE (WHEN (SCR_MSG_IN)),
                  64,
          /*
          **      message phase
          **      It's a trick - read the data
          **      without acknowledging it.
          */
          SCR_FROM_REG (sbdl),
                  0,
  /*<<<*/ SCR_JUMPR ^ IFFALSE (DATA (MSG_SIMPLE_Q_TAG)),
                  48,
          /*
          **      It WAS a SIMPLE_TAG message.
          **      get it and ack it!
          */
          SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                  NADDR (msgin),
          SCR_CLR (SCR_ACK),
                  0,
          /*
          **      Wait for the second byte (the tag)
          */
  /*<<<*/ SCR_JUMPR ^ IFFALSE (WHEN (SCR_MSG_IN)),
                  24,
          /*
          **      Get it and ack it!
          */
          SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                  NADDR (msgin),
          SCR_CLR (SCR_ACK|SCR_CARRY),
                  0,
          SCR_RETURN,
                  0,
          /*
          **      No message phase or no SIMPLE_TAG message
          **      or no second byte: return 0.
          */
  /*>>>*/ SCR_LOAD_SFBR (0),
                  0,
          SCR_SET (SCR_CARRY),
                  0,
          SCR_RETURN,
                  0,
  
  }/*-------------------------< DATA_IN >--------------------*/,{
  /*
  **      Because the size depends on the
  **      #define MAX_SCATTER parameter,
  **      it is filled in at runtime.
  **
  **      SCR_JUMP ^ IFFALSE (WHEN (SCR_DATA_IN)),
  **              PADDR (no_data),
  **      SCR_COPY (sizeof (ticks)),
  **              KVAR (KVAR_TICKS),
  **              NADDR (header.stamp.data),
  **      SCR_MOVE_TBL ^ SCR_DATA_IN,
  **              offsetof (struct dsb, data[ 0]),
  **
  **  ##===========< i=1; i<MAX_SCATTER >=========
  **  ||  SCR_CALL ^ IFFALSE (WHEN (SCR_DATA_IN)),
  **  ||          PADDR (checkatn),
  **  ||  SCR_MOVE_TBL ^ SCR_DATA_IN,
  **  ||          offsetof (struct dsb, data[ i]),
  **  ##==========================================
  **
  **      SCR_CALL,
  **              PADDR (checkatn),
  **      SCR_JUMP,
  **              PADDR (no_data),
  */
  
  }/*-------------------------< DATA_OUT >-------------------*/,{
  /*
  **      Because the size depends on the
  **      #define MAX_SCATTER parameter,
  **      it is filled in at runtime.
  **
  **      SCR_JUMP ^ IFFALSE (WHEN (SCR_DATA_OUT)),
  **              PADDR (no_data),
  **      SCR_COPY (sizeof (ticks)),
  **              KVAR (KVAR_TICKS),
  **              NADDR (header.stamp.data),
  **      SCR_MOVE_TBL ^ SCR_DATA_OUT,
  **              offsetof (struct dsb, data[ 0]),
  **
  **  ##===========< i=1; i<MAX_SCATTER >=========
  **  ||  SCR_CALL ^ IFFALSE (WHEN (SCR_DATA_OUT)),
  **  ||          PADDR (dispatch),
  **  ||  SCR_MOVE_TBL ^ SCR_DATA_OUT,
  **  ||          offsetof (struct dsb, data[ i]),
  **  ##==========================================
  **
  **      SCR_CALL,
  **              PADDR (dispatch),
  **      SCR_JUMP,
  **              PADDR (no_data),
  **
  **---------------------------------------------------------
  */
  (u_long)0
  
  }/*--------------------------------------------------------*/
  };
  
  
  static  struct scripth scripth0 = {
  /*-------------------------< TRYLOOP >---------------------*/{
  /*
  **      Load an entry of the start queue into dsa
  **      and try to start it by jumping to TRYSEL.
  **
  **      Because the size depends on the
  **      #define MAX_START parameter, it is filled
  **      in at runtime.
  **
  **-----------------------------------------------------------
  **
  **  ##===========< I=0; i<MAX_START >===========
  **  ||  SCR_COPY (4),
  **  ||          NADDR (squeue[i]),
  **  ||          RADDR (dsa),
  **  ||  SCR_CALL,
  **  ||          PADDR (trysel),
  **  ##==========================================
  **
  **      SCR_JUMP,
  **              PADDRH(tryloop),
  **
  **-----------------------------------------------------------
  */
  
  }/*-------------------------< MSG_PARITY >---------------*/,{
          /*
          **      count it
          */
          SCR_REG_REG (PS_REG, SCR_ADD, 0x01),
                  0,
          /*
          **      send a "message parity error" message.
          */
          SCR_LOAD_REG (scratcha, MSG_PARITY_ERROR),
                  0,
          SCR_JUMP,
                  PADDR (setmsg),
  }/*-------------------------< MSG_MESSAGE_REJECT >---------------*/,{
          /*
          **      If a negotiation was in progress,
          **      negotiation failed.
          */
          SCR_FROM_REG (HS_REG),
                  0,
          SCR_INT ^ IFTRUE (DATA (HS_NEGOTIATE)),
                  SIR_NEGO_FAILED,
          /*
          **      else make host log this message
          */
          SCR_INT ^ IFFALSE (DATA (HS_NEGOTIATE)),
                  SIR_REJECT_RECEIVED,
          SCR_JUMP,
                  PADDR (clrack),
  
  }/*-------------------------< MSG_IGN_RESIDUE >----------*/,{
          /*
          **      Terminate cycle
          */
          SCR_CLR (SCR_ACK),
                  0,
          SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
                  PADDR (dispatch),
          /*
          **      get residue size.
          */
          SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                  NADDR (msgin[1]),
          /*
          **      Check for message parity error.
          */
          SCR_TO_REG (scratcha),
                  0,
          SCR_FROM_REG (socl),
                  0,
          SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
                  PADDRH (msg_parity),
          SCR_FROM_REG (scratcha),
                  0,
          /*
          **      Size is 0 .. ignore message.
          */
          SCR_JUMP ^ IFTRUE (DATA (0)),
                  PADDR (clrack),
          /*
          **      Size is not 1 .. have to interrupt.
          */
  /*<<<*/ SCR_JUMPR ^ IFFALSE (DATA (1)),
                  40,
          /*
          **      Check for residue byte in swide register
          */
          SCR_FROM_REG (scntl2),
                  0,
  /*<<<*/ SCR_JUMPR ^ IFFALSE (MASK (WSR, WSR)),
                  16,
          /*
          **      There IS data in the swide register.
          **      Discard it.
          */
          SCR_REG_REG (scntl2, SCR_OR, WSR),
                  0,
          SCR_JUMP,
                  PADDR (clrack),
          /*
          **      Load again the size to the sfbr register.
          */
  /*>>>*/ SCR_FROM_REG (scratcha),
                  0,
  /*>>>*/ SCR_INT,
                  SIR_IGN_RESIDUE,
          SCR_JUMP,
                  PADDR (clrack),
  
  }/*-------------------------< MSG_EXTENDED >-------------*/,{
          /*
          **      Terminate cycle
          */
          SCR_CLR (SCR_ACK),
                  0,
          SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
                  PADDR (dispatch),
          /*
          **      get length.
          */
          SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                  NADDR (msgin[1]),
          /*
          **      Check for message parity error.
          */
          SCR_TO_REG (scratcha),
                  0,
          SCR_FROM_REG (socl),
                  0,
          SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
                  PADDRH (msg_parity),
          SCR_FROM_REG (scratcha),
                  0,
          /*
          */
          SCR_JUMP ^ IFTRUE (DATA (3)),
                  PADDRH (msg_ext_3),
          SCR_JUMP ^ IFFALSE (DATA (2)),
                  PADDR (msg_bad),
  }/*-------------------------< MSG_EXT_2 >----------------*/,{
          SCR_CLR (SCR_ACK),
                  0,
          SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
                  PADDR (dispatch),
          /*
          **      get extended message code.
          */
          SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                  NADDR (msgin[2]),
          /*
          **      Check for message parity error.
          */
          SCR_TO_REG (scratcha),
                  0,
          SCR_FROM_REG (socl),
                  0,
          SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
                  PADDRH (msg_parity),
          SCR_FROM_REG (scratcha),
                  0,
          SCR_JUMP ^ IFTRUE (DATA (MSG_EXT_WDTR)),
                  PADDRH (msg_wdtr),
          /*
          **      unknown extended message
          */
          SCR_JUMP,
                  PADDR (msg_bad)
  }/*-------------------------< MSG_WDTR >-----------------*/,{
          SCR_CLR (SCR_ACK),
                  0,
          SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
                  PADDR (dispatch),
          /*
          **      get data bus width
          */
          SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                  NADDR (msgin[3]),
          SCR_FROM_REG (socl),
                  0,
          SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
                  PADDRH (msg_parity),
          /*
          **      let the host do the real work.
          */
          SCR_INT,
                  SIR_NEGO_WIDE,
          /*
          **      let the target fetch our answer.
          */
          SCR_SET (SCR_ATN),
                  0,
          SCR_CLR (SCR_ACK),
                  0,
  
          SCR_INT ^ IFFALSE (WHEN (SCR_MSG_OUT)),
                  SIR_NEGO_PROTO,
          /*
          **      Send the MSG_EXT_WDTR
          */
          SCR_MOVE_ABS (4) ^ SCR_MSG_OUT,
                  NADDR (msgout),
          SCR_CLR (SCR_ATN),
                  0,
          SCR_COPY (1),
                  RADDR (sfbr),
                  NADDR (lastmsg),
          SCR_JUMP,
                  PADDR (msg_out_done),
  
  }/*-------------------------< MSG_EXT_3 >----------------*/,{
          SCR_CLR (SCR_ACK),
                  0,
          SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
                  PADDR (dispatch),
          /*
          **      get extended message code.
          */
          SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                  NADDR (msgin[2]),
          /*
          **      Check for message parity error.
          */
          SCR_TO_REG (scratcha),
                  0,
          SCR_FROM_REG (socl),
                  0,
          SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
                  PADDRH (msg_parity),
          SCR_FROM_REG (scratcha),
                  0,
          SCR_JUMP ^ IFTRUE (DATA (MSG_EXT_SDTR)),
                  PADDRH (msg_sdtr),
          /*
          **      unknown extended message
          */
          SCR_JUMP,
                  PADDR (msg_bad)
  
  }/*-------------------------< MSG_SDTR >-----------------*/,{
          SCR_CLR (SCR_ACK),
                  0,
          SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
                  PADDR (dispatch),
          /*
          **      get period and offset
          */
          SCR_MOVE_ABS (2) ^ SCR_MSG_IN,
                  NADDR (msgin[3]),
          SCR_FROM_REG (socl),
                  0,
          SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
                  PADDRH (msg_parity),
          /*
          **      let the host do the real work.
          */
          SCR_INT,
                  SIR_NEGO_SYNC,
          /*
          **      let the target fetch our answer.
          */
          SCR_SET (SCR_ATN),
                  0,
          SCR_CLR (SCR_ACK),
                  0,
  
          SCR_INT ^ IFFALSE (WHEN (SCR_MSG_OUT)),
                  SIR_NEGO_PROTO,
          /*
          **      Send the MSG_EXT_SDTR
          */
          SCR_MOVE_ABS (5) ^ SCR_MSG_OUT,
                  NADDR (msgout),
          SCR_CLR (SCR_ATN),
                  0,
          SCR_COPY (1),
                  RADDR (sfbr),
                  NADDR (lastmsg),
          SCR_JUMP,
                  PADDR (msg_out_done),
  
  }/*-------------------------< MSG_OUT_ABORT >-------------*/,{
          /*
          **      After ABORT message,
          **
          **      expect an immediate disconnect, ...
          */
          SCR_REG_REG (scntl2, SCR_AND, 0x7f),
                  0,
          SCR_CLR (SCR_ACK|SCR_ATN),
                  0,
          SCR_WAIT_DISC,
                  0,
          /*
          **      ... and set the status to "ABORTED"
          */
          SCR_LOAD_REG (HS_REG, HS_ABORTED),
                  0,
          SCR_JUMP,
                  PADDR (cleanup),
  
  }/*-------------------------< GETCC >-----------------------*/,{
          /*
          **      The ncr doesn't have an indirect load
          **      or store command. So we have to
          **      copy part of the control block to a
          **      fixed place, where we can modify it.
          **
          **      We patch the address part of a COPY command
          **      with the address of the dsa register ...
          */
          SCR_COPY_F (4),
                  RADDR (dsa),
                  PADDRH (getcc1),
          /*
          **      ... then we do the actual copy.
          */
          SCR_COPY (sizeof (struct head)),
  }/*-------------------------< GETCC1 >----------------------*/,{
                  0,
                  NADDR (header),
          /*
          **      Initialize the status registers
          */
          SCR_COPY (4),
                  NADDR (header.status),
                  RADDR (scr0),
  }/*-------------------------< GETCC2 >----------------------*/,{
          /*
          **      Get the condition code from a target.
          **
          **      DSA points to a data structure.
          **      Set TEMP to the script location
          **      that receives the condition code.
          **
          **      Because there is no script command
          **      to load a longword into a register,
          **      we use a CALL command.
          */
  /*<<<*/ SCR_CALLR,
                  24,
          /*
          **      Get the condition code.
          */
          SCR_MOVE_TBL ^ SCR_DATA_IN,
                  offsetof (struct dsb, sense),
          /*
          **      No data phase may follow!
          */
          SCR_CALL,
                  PADDR (checkatn),
          SCR_JUMP,
                  PADDR (no_data),
  /*>>>*/
  
          /*
          **      The CALL jumps to this point.
          **      Prepare for a RESTORE_POINTER message.
          **      Save the TEMP register into the saved pointer.
          */
          SCR_COPY (4),
                  RADDR (temp),
                  NADDR (header.savep),
          /*
          **      Load scratcha, because in case of a selection timeout,
          **      the host will expect a new value for startpos in
          **      the scratcha register.
          */
          SCR_COPY (4),
                  PADDR (startpos),
                  RADDR (scratcha),
  #ifdef NCR_GETCC_WITHMSG
          /*
          **      If QUIRK_NOMSG is set, select without ATN.
          **      and don't send a message.
          */
          SCR_FROM_REG (QU_REG),
                  0,
          SCR_JUMP ^ IFTRUE (MASK (QUIRK_NOMSG, QUIRK_NOMSG)),
                  PADDRH(getcc3),
          /*
          **      Then try to connect to the target.
          **      If we are reselected, special treatment
          **      of the current job is required before
          **      accepting the reselection.
          */
          SCR_SEL_TBL_ATN ^ offsetof (struct dsb, select),
                  PADDR(badgetcc),
          /*
          **      Send the IDENTIFY message.
          **      In case of short transfer, remove ATN.
          */
          SCR_MOVE_TBL ^ SCR_MSG_OUT,
                  offsetof (struct dsb, smsg2),
          SCR_CLR (SCR_ATN),
                  0,
          /*
          **      save the first byte of the message.
          */
          SCR_COPY (1),
                  RADDR (sfbr),
                  NADDR (lastmsg),
          SCR_JUMP,
                  PADDR (prepare2),
  
  #endif
  }/*-------------------------< GETCC3 >----------------------*/,{
          /*
          **      Try to connect to the target.
          **      If we are reselected, special treatment
          **      of the current job is required before
          **      accepting the reselection.
          **
          **      Silly target won't accept a message.
          **      Select without ATN.
          */
          SCR_SEL_TBL ^ offsetof (struct dsb, select),
                  PADDR(badgetcc),
          /*
          **      Force error if selection timeout
          */
          SCR_JUMPR ^ IFTRUE (WHEN (SCR_MSG_IN)),
                  0,
          /*
          **      don't negotiate.
          */
          SCR_JUMP,
                  PADDR (prepare2),
  }/*-------------------------< ABORTTAG >-------------------*/,{
          /*
          **      Abort a bad reselection.
          **      Set the message to ABORT vs. ABORT_TAG
          */
          SCR_LOAD_REG (scratcha, MSG_ABORT_TAG),
                  0,
          SCR_JUMPR ^ IFFALSE (CARRYSET),
                  8,
  }/*-------------------------< ABORT >----------------------*/,{
          SCR_LOAD_REG (scratcha, MSG_ABORT),
                  0,
          SCR_COPY (1),
                  RADDR (scratcha),
                  NADDR (msgout),
          SCR_SET (SCR_ATN),
                  0,
          SCR_CLR (SCR_ACK),
                  0,
          /*
          **      and send it.
          **      we expect an immediate disconnect
          */
          SCR_REG_REG (scntl2, SCR_AND, 0x7f),
                  0,
          SCR_MOVE_ABS (1) ^ SCR_MSG_OUT,
                  NADDR (msgout),
          SCR_COPY (1),
                  RADDR (sfbr),
                  NADDR (lastmsg),
          SCR_CLR (SCR_ACK|SCR_ATN),
                  0,
          SCR_WAIT_DISC,
                  0,
          SCR_JUMP,
                  PADDR (start),
  }/*-------------------------< SNOOPTEST >-------------------*/,{
          /*
          **      Read the variable.
          */
          SCR_COPY (4),
                  KVAR (KVAR_NCR_CACHE),
                  RADDR (scratcha),
          /*
          **      Write the variable.
          */
          SCR_COPY (4),
                  RADDR (temp),
                  KVAR (KVAR_NCR_CACHE),
          /*
          **      Read back the variable.
          */
          SCR_COPY (4),
                  KVAR (KVAR_NCR_CACHE),
                  RADDR (temp),
  }/*-------------------------< SNOOPEND >-------------------*/,{
          /*
          **      And stop.
          */
          SCR_INT,
                  99,
  }/*--------------------------------------------------------*/
  };
  
  
  /*==========================================================
  **
  **
  **      Fill in #define dependent parts of the script
  **
  **
  **==========================================================
  */
  
  void ncr_script_fill (struct script * scr, struct scripth * scrh)
  {
          int     i;
          ncrcmd  *p;
  
          p = scrh->tryloop;
          for (i=0; i<MAX_START; i++) {
                  *p++ =SCR_COPY (4);
                  *p++ =NADDR (squeue[i]);
                  *p++ =RADDR (dsa);
                  *p++ =SCR_CALL;
                  *p++ =PADDR (trysel);
          };
          *p++ =SCR_JUMP;
          *p++ =PADDRH(tryloop);
  
          assert ((char *)p == (char *)&scrh->tryloop + sizeof (scrh->tryloop));
  
          p = scr->data_in;
  
          *p++ =SCR_JUMP ^ IFFALSE (WHEN (SCR_DATA_IN));
          *p++ =PADDR (no_data);
          *p++ =SCR_COPY (sizeof (ticks));
          *p++ =(ncrcmd) KVAR (KVAR_TICKS);
          *p++ =NADDR (header.stamp.data);
          *p++ =SCR_MOVE_TBL ^ SCR_DATA_IN;
          *p++ =offsetof (struct dsb, data[ 0]);
  
          for (i=1; i<MAX_SCATTER; i++) {
                  *p++ =SCR_CALL ^ IFFALSE (WHEN (SCR_DATA_IN));
                  *p++ =PADDR (checkatn);
                  *p++ =SCR_MOVE_TBL ^ SCR_DATA_IN;
                  *p++ =offsetof (struct dsb, data[i]);
          };
  
          *p++ =SCR_CALL;
          *p++ =PADDR (checkatn);
          *p++ =SCR_JUMP;
          *p++ =PADDR (no_data);
  
          assert ((char *)p == (char *)&scr->data_in + sizeof (scr->data_in));
  
          p = scr->data_out;
  
          *p++ =SCR_JUMP ^ IFFALSE (WHEN (SCR_DATA_OUT));
          *p++ =PADDR (no_data);
          *p++ =SCR_COPY (sizeof (ticks));
          *p++ =(ncrcmd) KVAR (KVAR_TICKS);
          *p++ =NADDR (header.stamp.data);
          *p++ =SCR_MOVE_TBL ^ SCR_DATA_OUT;
          *p++ =offsetof (struct dsb, data[ 0]);
  
          for (i=1; i<MAX_SCATTER; i++) {
                  *p++ =SCR_CALL ^ IFFALSE (WHEN (SCR_DATA_OUT));
                  *p++ =PADDR (dispatch);
                  *p++ =SCR_MOVE_TBL ^ SCR_DATA_OUT;
                  *p++ =offsetof (struct dsb, data[i]);
          };
  
          *p++ =SCR_CALL;
          *p++ =PADDR (dispatch);
          *p++ =SCR_JUMP;
          *p++ =PADDR (no_data);
  
          assert ((char *)p == (char *)&scr->data_out + sizeof (scr->data_out));
  }
  
  /*==========================================================
  **
  **
  **      Copy and rebind a script.
  **
  **
  **==========================================================
  */
  
  static void ncr_script_copy_and_bind (ncb_p np, ncrcmd *src, ncrcmd *dst, int len)
  {
          ncrcmd  opcode, new, old, tmp1, tmp2;
          ncrcmd  *start, *end;
          int relocs, offset;
  
          start = src;
          end = src + len/4;
          offset = 0;
  
          while (src < end) {
  
                  opcode = *src++;
                  WRITESCRIPT_OFF(dst, offset, opcode);
                  offset += 4;
  
                  /*
                  **      If we forget to change the length
                  **      in struct script, a field will be
                  **      padded with 0. This is an illegal
                  **      command.
                  */
  
                  if (opcode == 0) {
                          printf ("%s: ERROR0 IN SCRIPT at %d.\n",
                                  ncr_name(np), (int) (src-start-1));
                          DELAY (1000000);
                  };
  
                  if (DEBUG_FLAGS & DEBUG_SCRIPT)
                          printf ("%p:  <%x>\n",
                                  (src-1), (unsigned)opcode);
  
                  /*
                  **      We don't have to decode ALL commands
                  */
                  switch (opcode >> 28) {
  
                  case 0xc:
                          /*
                          **      COPY has TWO arguments.
                          */
                          relocs = 2;
                          tmp1 = src[0];
                          if ((tmp1 & RELOC_MASK) == RELOC_KVAR)
                                  tmp1 = 0;
                          tmp2 = src[1];
                          if ((tmp2 & RELOC_MASK) == RELOC_KVAR)
                                  tmp2 = 0;
                          if ((tmp1 ^ tmp2) & 3) {
                                  printf ("%s: ERROR1 IN SCRIPT at %d.\n",
                                          ncr_name(np), (int) (src-start-1));
                                  DELAY (1000000);
                          }
                          /*
                          **      If PREFETCH feature not enabled, remove 
                          **      the NO FLUSH bit if present.
                          */
                          if ((opcode & SCR_NO_FLUSH) && !(np->features&FE_PFEN))
                                  WRITESCRIPT_OFF(dst, offset - 4,
                                      (opcode & ~SCR_NO_FLUSH));
                          break;
  
                  case 0x0:
                          /*
                          **      MOVE (absolute address)
                          */
                          relocs = 1;
                          break;
  
                  case 0x8:
                          /*
                          **      JUMP / CALL
                          **      dont't relocate if relative :-)
                          */
                          if (opcode & 0x00800000)
                                  relocs = 0;
                          else
                                  relocs = 1;
                          break;
  
                  case 0x4:
                  case 0x5:
                  case 0x6:
                  case 0x7:
                          relocs = 1;
                          break;
  
                  default:
                          relocs = 0;
                          break;
                  };
  
                  if (relocs) {
                          while (relocs--) {
                                  old = *src++;
  
                                  switch (old & RELOC_MASK) {
                                  case RELOC_REGISTER:
                                          new = (old & ~RELOC_MASK) + rman_get_start(np->reg_res);
                                          break;
                                  case RELOC_LABEL:
                                          new = (old & ~RELOC_MASK) + np->p_script;
                                          break;
                                  case RELOC_LABELH:
                                          new = (old & ~RELOC_MASK) + np->p_scripth;
                                          break;
                                  case RELOC_SOFTC:
                                          new = (old & ~RELOC_MASK) + vtophys(np);
                                          break;
                                  case RELOC_KVAR:
                                          if (((old & ~RELOC_MASK) <
                                               SCRIPT_KVAR_FIRST) ||
                                              ((old & ~RELOC_MASK) >
                                               SCRIPT_KVAR_LAST))
                                                  panic("ncr KVAR out of range");
                                          new = vtophys(script_kvars[old &
                                              ~RELOC_MASK]);
                                          break;
                                  case 0:
                                          /* Don't relocate a 0 address. */
                                          if (old == 0) {
                                                  new = old;
                                                  break;
                                          }
                                          /* fall through */
                                  default:
                                          panic("ncr_script_copy_and_bind: weird relocation %x @ %d\n", old, (int)(src - start));
                                          break;
                                  }
  
                                  WRITESCRIPT_OFF(dst, offset, new);
                                  offset += 4;
                          }
                  } else {
                          WRITESCRIPT_OFF(dst, offset, *src++);
                          offset += 4;
                  }
  
          };
  }
  
  /*==========================================================
  **
  **
  **      Auto configuration.
  **
  **
  **==========================================================
  */
  
  #if 0
  /*----------------------------------------------------------
  **
  **      Reduce the transfer length to the max value
  **      we can transfer safely.
  **
  **      Reading a block greater then MAX_SIZE from the
  **      raw (character) device exercises a memory leak
  **      in the vm subsystem. This is common to ALL devices.
  **      We have submitted a description of this bug to
  **      <FreeBSD-bugs@freefall.cdrom.com>.
  **      It should be fixed in the current release.
  **
  **----------------------------------------------------------
  */
  
  void ncr_min_phys (struct  buf *bp)
  {
          if ((unsigned long)bp->b_bcount > MAX_SIZE) bp->b_bcount = MAX_SIZE;
  }
  
  #endif
  
  #if 0
  /*----------------------------------------------------------
  **
  **      Maximal number of outstanding requests per target.
  **
  **----------------------------------------------------------
  */
  
  u_int32_t ncr_info (int unit)
  {
          return (1);   /* may be changed later */
  }
  
  #endif
  
  /*----------------------------------------------------------
  **
  **      NCR chip devices table and chip look up function.
  **      Features bit are defined in ncrreg.h. Is it the 
  **      right place?
  **
  **----------------------------------------------------------
  */
  typedef struct {
          unsigned long   device_id;
          unsigned short  minrevid;
          char           *name;
          unsigned char   maxburst;
          unsigned char   maxoffs;
          unsigned char   clock_divn;
          unsigned int    features;
  } ncr_chip;
  
  static ncr_chip ncr_chip_table[] = {
   {NCR_810_ID, 0x00,     "ncr 53c810 fast10 scsi",               4,  8, 4,
   FE_ERL}
   ,
   {NCR_810_ID, 0x10,     "ncr 53c810a fast10 scsi",              4,  8, 4,
   FE_ERL|FE_LDSTR|FE_PFEN|FE_BOF}
   ,
   {NCR_815_ID, 0x00,     "ncr 53c815 fast10 scsi",               4,  8, 4,
   FE_ERL|FE_BOF}
   ,
   {NCR_820_ID, 0x00,     "ncr 53c820 fast10 wide scsi",          4,  8, 4,
   FE_WIDE|FE_ERL}
   ,
   {NCR_825_ID, 0x00,     "ncr 53c825 fast10 wide scsi",          4,  8, 4,
   FE_WIDE|FE_ERL|FE_BOF}
   ,
   {NCR_825_ID, 0x10,     "ncr 53c825a fast10 wide scsi",         7,  8, 4,
   FE_WIDE|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
   ,
   {NCR_860_ID, 0x00,     "ncr 53c860 fast20 scsi",               4,  8, 5,
   FE_ULTRA|FE_CLK80|FE_CACHE_SET|FE_LDSTR|FE_PFEN}
   ,
   {NCR_875_ID, 0x00,     "ncr 53c875 fast20 wide scsi",          7, 16, 5,
   FE_WIDE|FE_ULTRA|FE_CLK80|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
   ,
   {NCR_875_ID, 0x02,     "ncr 53c875 fast20 wide scsi",          7, 16, 5,
   FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
   ,
   {NCR_875_ID2, 0x00,    "ncr 53c875j fast20 wide scsi",         7, 16, 5,
   FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
   ,
   {NCR_885_ID, 0x00,     "ncr 53c885 fast20 wide scsi",          7, 16, 5,
   FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
   ,
   {NCR_895_ID, 0x00,     "ncr 53c895 fast40 wide scsi",          7, 31, 7,
   FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
   ,
   {NCR_896_ID, 0x00,     "ncr 53c896 fast40 wide scsi",          7, 31, 7,
   FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
   ,
   {NCR_895A_ID, 0x00,    "ncr 53c895a fast40 wide scsi",         7, 31, 7,
   FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
   ,
   {NCR_1510D_ID, 0x00,   "ncr 53c1510d fast40 wide scsi",        7, 31, 7,
   FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
  };
  
  static int ncr_chip_lookup(u_long device_id, u_char revision_id)
  {
          int i, found;
          
          found = -1;
          for (i = 0; i < sizeof(ncr_chip_table)/sizeof(ncr_chip_table[0]); i++) {
                  if (device_id   == ncr_chip_table[i].device_id &&
                      ncr_chip_table[i].minrevid <= revision_id) {
                          if (found < 0 || 
                              ncr_chip_table[found].minrevid 
                                < ncr_chip_table[i].minrevid) {
                                  found = i;
                          }
                  }
          }
          return found;
  }
  
  /*----------------------------------------------------------
  **
  **      Probe the hostadapter.
  **
  **----------------------------------------------------------
  */
  
  
  
  static  int ncr_probe (device_t dev)
  {
          int i;
  
          i = ncr_chip_lookup(pci_get_devid(dev), pci_get_revid(dev));
          if (i >= 0) {
                  device_set_desc(dev, ncr_chip_table[i].name);
                  return (-1000); /* Allows to use both ncr and sym */
          }
  
          return (ENXIO);
  }
  
  
  
  /*==========================================================
  **
  **      NCR chip clock divisor table.
  **      Divisors are multiplied by 10,000,000 in order to make 
  **      calculations more simple.
  **
  **==========================================================
  */
  
  #define _5M 5000000
  static u_long div_10M[] =
          {2*_5M, 3*_5M, 4*_5M, 6*_5M, 8*_5M, 12*_5M, 16*_5M};
  
  /*===============================================================
  **
  **      NCR chips allow burst lengths of 2, 4, 8, 16, 32, 64, 128 
  **      transfers. 32,64,128 are only supported by 875 and 895 chips.
  **      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 void
  ncr_init_burst(ncb_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);
          }
  }
  
  /*==========================================================
  **
  **
  **      Auto configuration:  attach and init a host adapter.
  **
  **
  **==========================================================
  */
  
  
  static int
  ncr_attach (device_t dev)
  {
          ncb_p np = (struct ncb*) device_get_softc(dev);
          u_char   rev = 0;
          u_long   period;
          int      i, rid;
          u_int8_t usrsync;
          u_int8_t usrwide;
          struct cam_devq *devq;
  
          /*
          **      allocate and initialize structures.
          */
  
          np->unit = device_get_unit(dev);
  
          /*
          **      Try to map the controller chip to
          **      virtual and physical memory.
          */
  
          np->reg_rid = 0x14;
          np->reg_res = bus_alloc_resource(dev, SYS_RES_MEMORY, &np->reg_rid,
                                           0, ~0, 1, RF_ACTIVE);
          if (!np->reg_res) {
                  device_printf(dev, "could not map memory\n");
                  return ENXIO;
          }
  
          /*
          **      Make the controller's registers available.
          **      Now the INB INW INL OUTB OUTW OUTL macros
          **      can be used safely.
          */
  
          np->bst = rman_get_bustag(np->reg_res);
          np->bsh = rman_get_bushandle(np->reg_res);
  
  
  #ifdef NCR_IOMAPPED
          /*
          **      Try to map the controller chip into iospace.
          */
  
          if (!pci_map_port (config_id, 0x10, &np->port))
                  return;
  #endif
  
  
          /*
          **      Save some controller register default values
          */
  
          np->rv_scntl3   = INB(nc_scntl3) & 0x77;
          np->rv_dmode    = INB(nc_dmode)  & 0xce;
          np->rv_dcntl    = INB(nc_dcntl)  & 0xa9;
          np->rv_ctest3   = INB(nc_ctest3) & 0x01;
          np->rv_ctest4   = INB(nc_ctest4) & 0x88;
          np->rv_ctest5   = INB(nc_ctest5) & 0x24;
          np->rv_gpcntl   = INB(nc_gpcntl);
          np->rv_stest2   = INB(nc_stest2) & 0x20;
  
          if (bootverbose >= 2) {
                  printf ("\tBIOS values:  SCNTL3:%02x DMODE:%02x  DCNTL:%02x\n",
                          np->rv_scntl3, np->rv_dmode, np->rv_dcntl);
                  printf ("\t              CTEST3:%02x CTEST4:%02x CTEST5:%02x\n",
                          np->rv_ctest3, np->rv_ctest4, np->rv_ctest5);
          }
  
          np->rv_dcntl  |= NOCOM;
  
          /*
          **      Do chip dependent initialization.
          */
  
          rev = pci_get_revid(dev);
  
          /*
          **      Get chip features from chips table.
          */
          i = ncr_chip_lookup(pci_get_devid(dev), rev);
  
          if (i >= 0) {
                  np->maxburst    = ncr_chip_table[i].maxburst;
                  np->maxoffs     = ncr_chip_table[i].maxoffs;
                  np->clock_divn  = ncr_chip_table[i].clock_divn;
                  np->features    = ncr_chip_table[i].features;
          } else {        /* Should'nt happen if probe() is ok */
                  np->maxburst    = 4;
                  np->maxoffs     = 8;
                  np->clock_divn  = 4;
                  np->features    = FE_ERL;
          }
  
          np->maxwide     = np->features & FE_WIDE ? 1 : 0;
          np->clock_khz   = np->features & FE_CLK80 ? 80000 : 40000;
          if      (np->features & FE_QUAD)        np->multiplier = 4;
          else if (np->features & FE_DBLR)        np->multiplier = 2;
          else                                    np->multiplier = 1;
  
          /*
          **      Get the frequency of the chip's clock.
          **      Find the right value for scntl3.
          */
          if (np->features & (FE_ULTRA|FE_ULTRA2))
                  ncr_getclock(np, np->multiplier);
  
  #ifdef NCR_TEKRAM_EEPROM
          if (bootverbose) {
                  printf ("%s: Tekram EEPROM read %s\n",
                          ncr_name(np),
                          read_tekram_eeprom (np, NULL) ?
                          "succeeded" : "failed");
          }
  #endif /* NCR_TEKRAM_EEPROM */
  
          /*
           *      If scntl3 != 0, we assume BIOS is present.
           */
          if (np->rv_scntl3)
                  np->features |= FE_BIOS;
  
          /*
           * Divisor to be used for async (timer pre-scaler).
           */
          i = np->clock_divn - 1;
          while (i >= 0) {
                  --i;
                  if (10ul * SCSI_NCR_MIN_ASYNC * np->clock_khz > div_10M[i]) {
                          ++i;
                          break;
                  }
          }
          np->rv_scntl3 = i+1;
  
          /*
           * 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)))
                  np->minsync = 25;
          else if (np->minsync < 12 && !(np->features & FE_ULTRA2))
                  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;
  
          /*
           * Now, some features available with Symbios compatible boards.
           * LED support through GPIO0 and DIFF support.
           */
  
  #ifdef  SCSI_NCR_SYMBIOS_COMPAT
          if (!(np->rv_gpcntl & 0x01))
                  np->features |= FE_LED0;
  #if 0   /* Not safe enough without NVRAM support or user settable option */
          if (!(INB(nc_gpreg) & 0x08))
                  np->features |= FE_DIFF;
  #endif
  #endif  /* SCSI_NCR_SYMBIOS_COMPAT */
  
          /*
           * Prepare initial IO registers settings.
           * Trust BIOS only if we believe we have one and if we want to.
           */
  #ifdef  SCSI_NCR_TRUST_BIOS
          if (!(np->features & FE_BIOS)) {
  #else
          if (1) {
  #endif
                  np->rv_dmode = 0;
                  np->rv_dcntl = NOCOM;
                  np->rv_ctest3 = 0;
                  np->rv_ctest4 = MPEE;
                  np->rv_ctest5 = 0;
                  np->rv_stest2 = 0;
  
                  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 (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_PFEN)
                          np->rv_dcntl    |= PFEN;  /* Prefetch Enable */
                  if (np->features & FE_DFS)
                          np->rv_ctest5   |= DFS;   /* Dma Fifo Size */
                  if (np->features & FE_DIFF)     
                          np->rv_stest2   |= 0x20;  /* Differential mode */
                  ncr_init_burst(np, np->maxburst); /* Max dwords burst length */
          } else {
                  np->maxburst =
                          burst_code(np->rv_dmode, np->rv_ctest4, np->rv_ctest5);
          }
  
          /*
          **      Get on-chip SRAM address, if supported
          */
          if ((np->features & FE_RAM) && sizeof(struct script) <= 4096) {
                  np->sram_rid = 0x18;
                  np->sram_res = bus_alloc_resource(dev, SYS_RES_MEMORY,
                                                    &np->sram_rid,
                                                    0, ~0, 1, RF_ACTIVE);
          }
  
          /*
          **      Allocate structure for script relocation.
          */
          if (np->sram_res != NULL) {
                  np->script = NULL;
                  np->p_script = rman_get_start(np->sram_res);
                  np->bst2 = rman_get_bustag(np->sram_res);
                  np->bsh2 = rman_get_bushandle(np->sram_res);
          } else if (sizeof (struct script) > PAGE_SIZE) {
                  np->script  = (struct script*) vm_page_alloc_contig 
                          (round_page(sizeof (struct script)), 
                           0, 0xffffffff, PAGE_SIZE);
          } else {
                  np->script  = (struct script *)
                          malloc (sizeof (struct script), M_DEVBUF, M_WAITOK);
          }
  
          /* XXX JGibbs - Use contigmalloc */
          if (sizeof (struct scripth) > PAGE_SIZE) {
                  np->scripth = (struct scripth*) vm_page_alloc_contig 
                          (round_page(sizeof (struct scripth)), 
                           0, 0xffffffff, PAGE_SIZE);
          } else 
                  {
                  np->scripth = (struct scripth *)
                          malloc (sizeof (struct scripth), M_DEVBUF, M_WAITOK);
          }
  
  #ifdef SCSI_NCR_PCI_CONFIG_FIXUP
          /*
          **      If cache line size is enabled, check PCI config space and 
          **      try to fix it up if necessary.
          */
  #ifdef PCIR_CACHELNSZ   /* To be sure that new PCI stuff is present */
          {
                  u_char cachelnsz = pci_read_config(dev, PCIR_CACHELNSZ, 1);
                  u_short command  = pci_read_config(dev, PCIR_COMMAND, 2);
  
                  if (!cachelnsz) {
                          cachelnsz = 8;
                          printf("%s: setting PCI cache line size register to %d.\n",
                                  ncr_name(np), (int)cachelnsz);
                          pci_write_config(dev, PCIR_CACHELNSZ, cachelnsz, 1);
                  }
  
                  if (!(command & (1<<4))) {
                          command |= (1<<4);
                          printf("%s: setting PCI command write and invalidate.\n",
                                  ncr_name(np));
                          pci_write_config(dev, PCIR_COMMAND, command, 2);
                  }
          }
  #endif /* PCIR_CACHELNSZ */
  
  #endif /* SCSI_NCR_PCI_CONFIG_FIXUP */
  
          /* Initialize per-target user settings */
          usrsync = 0;
          if (SCSI_NCR_DFLT_SYNC) {
                  usrsync = SCSI_NCR_DFLT_SYNC;
                  if (usrsync > np->maxsync)
                          usrsync = np->maxsync;
                  if (usrsync < np->minsync)
                          usrsync = np->minsync;
          };
  
          usrwide = (SCSI_NCR_MAX_WIDE);
          if (usrwide > np->maxwide) usrwide=np->maxwide;
  
          for (i=0;i<MAX_TARGET;i++) {
                  tcb_p tp = &np->target[i];
  
                  tp->tinfo.user.period = usrsync;
                  tp->tinfo.user.offset = usrsync != 0 ? np->maxoffs : 0;
                  tp->tinfo.user.width = usrwide;
                  tp->tinfo.disc_tag = NCR_CUR_DISCENB
                                     | NCR_CUR_TAGENB
                                     | NCR_USR_DISCENB
                                     | NCR_USR_TAGENB;
          }
  
          /*
          **      Bells and whistles   ;-)
          */
          if (bootverbose)
                  printf("%s: minsync=%d, maxsync=%d, maxoffs=%d, %d dwords burst, %s dma fifo\n",
                  ncr_name(np), np->minsync, np->maxsync, np->maxoffs,
                  burst_length(np->maxburst),
                  (np->rv_ctest5 & DFS) ? "large" : "normal");
  
          /*
          **      Print some complementary information that can be helpfull.
          */
          if (bootverbose)
                  printf("%s: %s, %s IRQ driver%s\n",
                          ncr_name(np),
                          np->rv_stest2 & 0x20 ? "differential" : "single-ended",
                          np->rv_dcntl & IRQM ? "totem pole" : "open drain",
                          np->sram_res ? ", using on-chip SRAM" : "");
                          
          /*
          **      Patch scripts to physical addresses
          */
          ncr_script_fill (&script0, &scripth0);
  
          if (np->script)
                  np->p_script    = vtophys(np->script);
          np->p_scripth   = vtophys(np->scripth);
  
          ncr_script_copy_and_bind (np, (ncrcmd *) &script0,
                          (ncrcmd *) np->script, sizeof(struct script));
  
          ncr_script_copy_and_bind (np, (ncrcmd *) &scripth0,
                  (ncrcmd *) np->scripth, sizeof(struct scripth));
  
          /*
          **    Patch the script for LED support.
          */
  
          if (np->features & FE_LED0) {
                  WRITESCRIPT(reselect[0],  SCR_REG_REG(gpreg, SCR_OR,  0x01));
                  WRITESCRIPT(reselect1[0], SCR_REG_REG(gpreg, SCR_AND, 0xfe));
                  WRITESCRIPT(reselect2[0], SCR_REG_REG(gpreg, SCR_AND, 0xfe));
          }
  
          /*
          **      init data structure
          */
  
          np->jump_tcb.l_cmd      = SCR_JUMP;
          np->jump_tcb.l_paddr    = NCB_SCRIPTH_PHYS (np, abort);
  
          /*
          **  Get SCSI addr of host adapter (set by bios?).
          */
  
          np->myaddr = INB(nc_scid) & 0x07;
          if (!np->myaddr) np->myaddr = SCSI_NCR_MYADDR;
  
  #ifdef NCR_DUMP_REG
          /*
          **      Log the initial register contents
          */
          {
                  int reg;
                  for (reg=0; reg<256; reg+=4) {
                          if (reg%16==0) printf ("reg[%2x]", reg);
                          printf (" %08x", (int)pci_conf_read (config_id, reg));
                          if (reg%16==12) printf ("\n");
                  }
          }
  #endif /* NCR_DUMP_REG */
  
          /*
          **      Reset chip.
          */
  
          OUTB (nc_istat,  SRST);
          DELAY (1000);
          OUTB (nc_istat,  0   );
  
  
          /*
          **      Now check the cache handling of the pci chipset.
          */
  
          if (ncr_snooptest (np)) {
                  printf ("CACHE INCORRECTLY CONFIGURED.\n");
                  return EINVAL;
          };
  
          /*
          **      Install the interrupt handler.
          */
  
          rid = 0;
          np->irq_res = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, 0, ~0, 1,
                                           RF_SHAREABLE | RF_ACTIVE);
          if (np->irq_res == NULL) {
                  device_printf(dev,
                                "interruptless mode: reduced performance.\n");
          } else {
                  bus_setup_intr(dev, np->irq_res, INTR_TYPE_CAM,
                                 ncr_intr, np, &np->irq_handle);
          }
  
          /*
          ** Create the device queue.  We only allow MAX_START-1 concurrent
          ** transactions so we can be sure to have one element free in our
          ** start queue to reset to the idle loop.
          */
          devq = cam_simq_alloc(MAX_START - 1);
          if (devq == NULL)
                  return ENOMEM;
  
          /*
          **      Now tell the generic SCSI layer
          **      about our bus.
          */
          np->sim = cam_sim_alloc(ncr_action, ncr_poll, "ncr", np, np->unit,
                                  1, MAX_TAGS, devq);
          if (np->sim == NULL) {
                  cam_simq_free(devq);
                  return ENOMEM;
          }
  
          
          if (xpt_bus_register(np->sim, 0) != CAM_SUCCESS) {
                  cam_sim_free(np->sim, /*free_devq*/ TRUE);
                  return ENOMEM;
          }
          
          if (xpt_create_path(&np->path, /*periph*/NULL,
                              cam_sim_path(np->sim), CAM_TARGET_WILDCARD,
                              CAM_LUN_WILDCARD) != CAM_REQ_CMP) {
                  xpt_bus_deregister(cam_sim_path(np->sim));
                  cam_sim_free(np->sim, /*free_devq*/TRUE);
                  return ENOMEM;
          }
  
          /*
          **      start the timeout daemon
          */
          ncr_timeout (np);
          np->lasttime=0;
  
          return 0;
  }
  
  /*==========================================================
  **
  **
  **      Process pending device interrupts.
  **
  **
  **==========================================================
  */
  
  static void
  ncr_intr(vnp)
          void *vnp;
  {
          ncb_p np = vnp;
          int oldspl = splcam();
  
          if (DEBUG_FLAGS & DEBUG_TINY) printf ("[");
  
          if (INB(nc_istat) & (INTF|SIP|DIP)) {
                  /*
                  **      Repeat until no outstanding ints
                  */
                  do {
                          ncr_exception (np);
                  } while (INB(nc_istat) & (INTF|SIP|DIP));
  
                  np->ticks = 100;
          };
  
          if (DEBUG_FLAGS & DEBUG_TINY) printf ("]\n");
  
          splx (oldspl);
  }
  
  /*==========================================================
  **
  **
  **      Start execution of a SCSI command.
  **      This is called from the generic SCSI driver.
  **
  **
  **==========================================================
  */
  
  static void
  ncr_action (struct cam_sim *sim, union ccb *ccb)
  {
          ncb_p np;
  
          np = (ncb_p) cam_sim_softc(sim);
  
          switch (ccb->ccb_h.func_code) {
          /* Common cases first */
          case XPT_SCSI_IO:       /* Execute the requested I/O operation */
          {
                  nccb_p cp;
                  lcb_p lp;
                  tcb_p tp;
                  int oldspl;
                  struct ccb_scsiio *csio;
                  u_int8_t *msgptr;
                  u_int msglen;
                  u_int msglen2;
                  int segments;
                  u_int8_t nego;
                  u_int8_t idmsg;
                  u_int8_t qidx;
                  
                  tp = &np->target[ccb->ccb_h.target_id];
                  csio = &ccb->csio;
  
                  oldspl = splcam();
  
                  /*
                   * Last time we need to check if this CCB needs to
                   * be aborted.
                   */
                  if ((ccb->ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_INPROG) {
                          xpt_done(ccb);
                          splx(oldspl);
                          return;
                  }
                  ccb->ccb_h.status |= CAM_SIM_QUEUED;
  
                  /*---------------------------------------------------
                  **
                  **      Assign an nccb / bind ccb
                  **
                  **----------------------------------------------------
                  */
                  cp = ncr_get_nccb (np, ccb->ccb_h.target_id,
                                     ccb->ccb_h.target_lun);
                  if (cp == NULL) {
                          /* XXX JGibbs - Freeze SIMQ */
                          ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
                          xpt_done(ccb);
                          return;
                  };
                  
                  cp->ccb = ccb;
                  
                  /*---------------------------------------------------
                  **
                  **      timestamp
                  **
                  **----------------------------------------------------
                  */
                  /*
                  ** XXX JGibbs - Isn't this expensive
                  **              enough to be conditionalized??
                  */
  
                  bzero (&cp->phys.header.stamp, sizeof (struct tstamp));
                  cp->phys.header.stamp.start = ticks;
  
                  nego = 0;
                  if (tp->nego_cp == NULL) {
                          
                          if (tp->tinfo.current.width
                           != tp->tinfo.goal.width) {
                                  tp->nego_cp = cp;
                                  nego = NS_WIDE;
                          } else if ((tp->tinfo.current.period
                                      != tp->tinfo.goal.period)
                                  || (tp->tinfo.current.offset
                                      != tp->tinfo.goal.offset)) {
                                  tp->nego_cp = cp;
                                  nego = NS_SYNC;
                          };
                  };
  
                  /*---------------------------------------------------
                  **
                  **      choose a new tag ...
                  **
                  **----------------------------------------------------
                  */
                  lp = tp->lp[ccb->ccb_h.target_lun];
  
                  if ((ccb->ccb_h.flags & CAM_TAG_ACTION_VALID) != 0
                   && (ccb->csio.tag_action != CAM_TAG_ACTION_NONE)
                   && (nego == 0)) {
                          /*
                          **      assign a tag to this nccb
                          */
                          while (!cp->tag) {
                                  nccb_p cp2 = lp->next_nccb;
                                  lp->lasttag = lp->lasttag % 255 + 1;
                                  while (cp2 && cp2->tag != lp->lasttag)
                                          cp2 = cp2->next_nccb;
                                  if (cp2) continue;
                                  cp->tag=lp->lasttag;
                                  if (DEBUG_FLAGS & DEBUG_TAGS) {
                                          PRINT_ADDR(ccb);
                                          printf ("using tag #%d.\n", cp->tag);
                                  };
                          };
                  } else {
                          cp->tag=0;
                  };
  
                  /*----------------------------------------------------
                  **
                  **      Build the identify / tag / sdtr message
                  **
                  **----------------------------------------------------
                  */
                  idmsg = MSG_IDENTIFYFLAG | ccb->ccb_h.target_lun;
                  if (tp->tinfo.disc_tag & NCR_CUR_DISCENB)
                          idmsg |= MSG_IDENTIFY_DISCFLAG;
  
                  msgptr = cp->scsi_smsg;
                  msglen = 0;
                  msgptr[msglen++] = idmsg;
  
                  if (cp->tag) {
                          msgptr[msglen++] = ccb->csio.tag_action;
                          msgptr[msglen++] = cp->tag;
                  }
  
                  switch (nego) {
                  case NS_SYNC:
                          msgptr[msglen++] = MSG_EXTENDED;
                          msgptr[msglen++] = MSG_EXT_SDTR_LEN;
                          msgptr[msglen++] = MSG_EXT_SDTR;
                          msgptr[msglen++] = tp->tinfo.goal.period;
                          msgptr[msglen++] = tp->tinfo.goal.offset;;
                          if (DEBUG_FLAGS & DEBUG_NEGO) {
                                  PRINT_ADDR(ccb);
                                  printf ("sync msgout: ");
                                  ncr_show_msg (&cp->scsi_smsg [msglen-5]);
                                  printf (".\n");
                          };
                          break;
                  case NS_WIDE:
                          msgptr[msglen++] = MSG_EXTENDED;
                          msgptr[msglen++] = MSG_EXT_WDTR_LEN;
                          msgptr[msglen++] = MSG_EXT_WDTR;
                          msgptr[msglen++] = tp->tinfo.goal.width;
                          if (DEBUG_FLAGS & DEBUG_NEGO) {
                                  PRINT_ADDR(ccb);
                                  printf ("wide msgout: ");
                                  ncr_show_msg (&cp->scsi_smsg [msglen-4]);
                                  printf (".\n");
                          };
                          break;
                  };
  
                  /*----------------------------------------------------
                  **
                  **      Build the identify message for getcc.
                  **
                  **----------------------------------------------------
                  */
  
                  cp->scsi_smsg2 [0] = idmsg;
                  msglen2 = 1;
  
                  /*----------------------------------------------------
                  **
                  **      Build the data descriptors
                  **
                  **----------------------------------------------------
                  */
  
                  /* XXX JGibbs - Handle other types of I/O */
                  if ((ccb->ccb_h.flags & CAM_DIR_MASK) != CAM_DIR_NONE) {
                          segments = ncr_scatter(&cp->phys,
                                                 (vm_offset_t)csio->data_ptr,
                                                 (vm_size_t)csio->dxfer_len);
  
                          if (segments < 0) {
                                  ccb->ccb_h.status = CAM_REQ_TOO_BIG;
                                  ncr_free_nccb(np, cp);
                                  splx(oldspl);
                                  xpt_done(ccb);
                                  return;
                          }
                          if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN) {
                                  cp->phys.header.savep = NCB_SCRIPT_PHYS (np, data_in);
                                  cp->phys.header.goalp = cp->phys.header.savep +20 +segments*16;
                          } else { /* CAM_DIR_OUT */
                                  cp->phys.header.savep = NCB_SCRIPT_PHYS (np, data_out);
                                  cp->phys.header.goalp = cp->phys.header.savep +20 +segments*16;
                          }
                  } else {
                          cp->phys.header.savep = NCB_SCRIPT_PHYS (np, no_data);
                          cp->phys.header.goalp = cp->phys.header.savep;
                  }
  
                  cp->phys.header.lastp = cp->phys.header.savep;
  
  
                  /*----------------------------------------------------
                  **
                  **      fill in nccb
                  **
                  **----------------------------------------------------
                  **
                  **
                  **      physical -> virtual backlink
                  **      Generic SCSI command
                  */
                  cp->phys.header.cp              = cp;
                  /*
                  **      Startqueue
                  */
                  cp->phys.header.launch.l_paddr  = NCB_SCRIPT_PHYS (np, select);
                  cp->phys.header.launch.l_cmd    = SCR_JUMP;
                  /*
                  **      select
                  */
                  cp->phys.select.sel_id          = ccb->ccb_h.target_id;
                  cp->phys.select.sel_scntl3      = tp->tinfo.wval;
                  cp->phys.select.sel_sxfer       = tp->tinfo.sval;
                  /*
                  **      message
                  */
                  cp->phys.smsg.addr              = CCB_PHYS (cp, scsi_smsg);
                  cp->phys.smsg.size              = msglen;
          
                  cp->phys.smsg2.addr             = CCB_PHYS (cp, scsi_smsg2);
                  cp->phys.smsg2.size             = msglen2;
                  /*
                  **      command
                  */
                  /* XXX JGibbs - Support other command types */
                  cp->phys.cmd.addr               = vtophys (csio->cdb_io.cdb_bytes);
                  cp->phys.cmd.size               = csio->cdb_len;
                  /*
                  **      sense command
                  */
                  cp->phys.scmd.addr              = CCB_PHYS (cp, sensecmd);
                  cp->phys.scmd.size              = 6;
                  /*
                  **      patch requested size into sense command
                  */
                  cp->sensecmd[0]                 = 0x03;
                  cp->sensecmd[1]                 = ccb->ccb_h.target_lun << 5;
                  cp->sensecmd[4]                 = sizeof(struct scsi_sense_data);
                  cp->sensecmd[4]                 = csio->sense_len;
                  /*
                  **      sense data
                  */
                  cp->phys.sense.addr             = vtophys (&csio->sense_data);
                  cp->phys.sense.size             = csio->sense_len;
                  /*
                  **      status
                  */
                  cp->actualquirks                = QUIRK_NOMSG;
                  cp->host_status                 = nego ? HS_NEGOTIATE : HS_BUSY;
                  cp->s_status                    = SCSI_STATUS_ILLEGAL;
                  cp->parity_status               = 0;
          
                  cp->xerr_status                 = XE_OK;
                  cp->sync_status                 = tp->tinfo.sval;
                  cp->nego_status                 = nego;
                  cp->wide_status                 = tp->tinfo.wval;
  
                  /*----------------------------------------------------
                  **
                  **      Critical region: start this job.
                  **
                  **----------------------------------------------------
                  */
  
                  /*
                  **      reselect pattern and activate this job.
                  */
  
                  cp->jump_nccb.l_cmd     = (SCR_JUMP ^ IFFALSE (DATA (cp->tag)));
                  cp->tlimit              = time_second
                                          + ccb->ccb_h.timeout / 1000 + 2;
                  cp->magic               = CCB_MAGIC;
  
                  /*
                  **      insert into start queue.
                  */
  
                  qidx = np->squeueput + 1;
                  if (qidx >= MAX_START) qidx=0;
                  np->squeue [qidx         ] = NCB_SCRIPT_PHYS (np, idle);
                  np->squeue [np->squeueput] = CCB_PHYS (cp, phys);
                  np->squeueput = qidx;
  
                  if(DEBUG_FLAGS & DEBUG_QUEUE)
                          printf("%s: queuepos=%d tryoffset=%d.\n",
                                 ncr_name (np), np->squeueput,
                                 (unsigned)(READSCRIPT(startpos[0]) - 
                                 (NCB_SCRIPTH_PHYS (np, tryloop))));
  
                  /*
                  **      Script processor may be waiting for reselect.
                  **      Wake it up.
                  */
                  OUTB (nc_istat, SIGP);
  
                  /*
                  **      and reenable interrupts
                  */
                  splx (oldspl);
                  break;
          }
          case XPT_RESET_DEV:     /* Bus Device Reset the specified SCSI device */
          case XPT_EN_LUN:                /* Enable LUN as a target */
          case XPT_TARGET_IO:             /* Execute target I/O request */
          case XPT_ACCEPT_TARGET_IO:      /* Accept Host Target Mode CDB */
          case XPT_CONT_TARGET_IO:        /* Continue Host Target I/O Connection*/
          case XPT_ABORT:                 /* Abort the specified CCB */
                  /* XXX Implement */
                  ccb->ccb_h.status = CAM_REQ_INVALID;
                  xpt_done(ccb);
                  break;
          case XPT_SET_TRAN_SETTINGS:
          {
                  struct  ccb_trans_settings *cts;
                  tcb_p   tp;
                  u_int   update_type;
                  int     s;
  
                  cts = &ccb->cts;
                  update_type = 0;
                  if ((cts->flags & CCB_TRANS_CURRENT_SETTINGS) != 0)
                          update_type |= NCR_TRANS_GOAL;
                  if ((cts->flags & CCB_TRANS_USER_SETTINGS) != 0)
                          update_type |= NCR_TRANS_USER;
                  
                  s = splcam();
                  tp = &np->target[ccb->ccb_h.target_id];
                  /* Tag and disc enables */
                  if ((cts->valid & CCB_TRANS_DISC_VALID) != 0) {
                          if (update_type & NCR_TRANS_GOAL) {
                                  if ((cts->flags & CCB_TRANS_DISC_ENB) != 0)
                                          tp->tinfo.disc_tag |= NCR_CUR_DISCENB;
                                  else
                                          tp->tinfo.disc_tag &= ~NCR_CUR_DISCENB;
                          }
  
                          if (update_type & NCR_TRANS_USER) {
                                  if ((cts->flags & CCB_TRANS_DISC_ENB) != 0)
                                          tp->tinfo.disc_tag |= NCR_USR_DISCENB;
                                  else
                                          tp->tinfo.disc_tag &= ~NCR_USR_DISCENB;
                          }
  
                  }
  
                  if ((cts->valid & CCB_TRANS_TQ_VALID) != 0) {
                          if (update_type & NCR_TRANS_GOAL) {
                                  if ((cts->flags & CCB_TRANS_TAG_ENB) != 0)
                                          tp->tinfo.disc_tag |= NCR_CUR_TAGENB;
                                  else
                                          tp->tinfo.disc_tag &= ~NCR_CUR_TAGENB;
                          }
  
                          if (update_type & NCR_TRANS_USER) {
                                  if ((cts->flags & CCB_TRANS_TAG_ENB) != 0)
                                          tp->tinfo.disc_tag |= NCR_USR_TAGENB;
                                  else
                                          tp->tinfo.disc_tag &= ~NCR_USR_TAGENB;
                          }       
                  }
  
                  /* Filter bus width and sync negotiation settings */
                  if ((cts->valid & CCB_TRANS_BUS_WIDTH_VALID) != 0) {
                          if (cts->bus_width > np->maxwide)
                                  cts->bus_width = np->maxwide;
                  }
  
                  if (((cts->valid & CCB_TRANS_SYNC_RATE_VALID) != 0)
                   || ((cts->valid & CCB_TRANS_SYNC_OFFSET_VALID) != 0)) {
                          if ((cts->valid & CCB_TRANS_SYNC_RATE_VALID) != 0) {
                                  if (cts->sync_period != 0
                                   && (cts->sync_period < np->minsync))
                                          cts->sync_period = np->minsync;
                          }
                          if ((cts->valid & CCB_TRANS_SYNC_OFFSET_VALID) != 0) {
                                  if (cts->sync_offset == 0)
                                          cts->sync_period = 0;
                                  if (cts->sync_offset > np->maxoffs)
                                          cts->sync_offset = np->maxoffs;
                          }
                  }
                  if ((update_type & NCR_TRANS_USER) != 0) {
                          if ((cts->valid & CCB_TRANS_SYNC_RATE_VALID) != 0)
                                  tp->tinfo.user.period = cts->sync_period;
                          if ((cts->valid & CCB_TRANS_SYNC_OFFSET_VALID) != 0)
                                  tp->tinfo.user.offset = cts->sync_offset;
                          if ((cts->valid & CCB_TRANS_BUS_WIDTH_VALID) != 0)
                                  tp->tinfo.user.width = cts->bus_width;
                  }
                  if ((update_type & NCR_TRANS_GOAL) != 0) {
                          if ((cts->valid & CCB_TRANS_SYNC_RATE_VALID) != 0)
                                  tp->tinfo.goal.period = cts->sync_period;
  
                          if ((cts->valid & CCB_TRANS_SYNC_OFFSET_VALID) != 0)
                                  tp->tinfo.goal.offset = cts->sync_offset;
  
                          if ((cts->valid & CCB_TRANS_BUS_WIDTH_VALID) != 0)
                                  tp->tinfo.goal.width = cts->bus_width;
                  }
                  splx(s);
                  ccb->ccb_h.status = CAM_REQ_CMP;
                  xpt_done(ccb);
                  break;
          }
          case XPT_GET_TRAN_SETTINGS:
          /* Get default/user set transfer settings for the target */
          {
                  struct  ccb_trans_settings *cts;
                  struct  ncr_transinfo *tinfo;
                  tcb_p   tp;             
                  int     s;
  
                  cts = &ccb->cts;
                  tp = &np->target[ccb->ccb_h.target_id];
                  
                  s = splcam();
                  if ((cts->flags & CCB_TRANS_CURRENT_SETTINGS) != 0) {
                          tinfo = &tp->tinfo.current;
                          if (tp->tinfo.disc_tag & NCR_CUR_DISCENB)
                                  cts->flags |= CCB_TRANS_DISC_ENB;
                          else
                                  cts->flags &= ~CCB_TRANS_DISC_ENB;
  
                          if (tp->tinfo.disc_tag & NCR_CUR_TAGENB)
                                  cts->flags |= CCB_TRANS_TAG_ENB;
                          else
                                  cts->flags &= ~CCB_TRANS_TAG_ENB;
                  } else {
                          tinfo = &tp->tinfo.user;
                          if (tp->tinfo.disc_tag & NCR_USR_DISCENB)
                                  cts->flags |= CCB_TRANS_DISC_ENB;
                          else
                                  cts->flags &= ~CCB_TRANS_DISC_ENB;
  
                          if (tp->tinfo.disc_tag & NCR_USR_TAGENB)
                                  cts->flags |= CCB_TRANS_TAG_ENB;
                          else
                                  cts->flags &= ~CCB_TRANS_TAG_ENB;
                  }
  
                  cts->sync_period = tinfo->period;
                  cts->sync_offset = tinfo->offset;
                  cts->bus_width = tinfo->width;
  
                  splx(s);
  
                  cts->valid = CCB_TRANS_SYNC_RATE_VALID
                             | CCB_TRANS_SYNC_OFFSET_VALID
                             | CCB_TRANS_BUS_WIDTH_VALID
                             | CCB_TRANS_DISC_VALID
                             | CCB_TRANS_TQ_VALID;
  
                  ccb->ccb_h.status = CAM_REQ_CMP;
                  xpt_done(ccb);
                  break;
          }
          case XPT_CALC_GEOMETRY:
          {
                  struct    ccb_calc_geometry *ccg;
                  u_int32_t size_mb;
                  u_int32_t secs_per_cylinder;
                  int       extended;
  
                  /* XXX JGibbs - I'm sure the NCR uses a different strategy,
                   *              but it should be able to deal with Adaptec
                   *              geometry too.
                   */
                  extended = 1;
                  ccg = &ccb->ccg;
                  size_mb = ccg->volume_size
                          / ((1024L * 1024L) / ccg->block_size);
                  
                  if (size_mb > 1024 && extended) {
                          ccg->heads = 255;
                          ccg->secs_per_track = 63;
                  } else {
                          ccg->heads = 64;
                          ccg->secs_per_track = 32;
                  }
                  secs_per_cylinder = ccg->heads * ccg->secs_per_track;
                  ccg->cylinders = ccg->volume_size / secs_per_cylinder;
                  ccb->ccb_h.status = CAM_REQ_CMP;
                  xpt_done(ccb);
                  break;
          }
          case XPT_RESET_BUS:             /* Reset the specified SCSI bus */
          {
                  OUTB (nc_scntl1, CRST);
                  ccb->ccb_h.status = CAM_REQ_CMP;
                  DELAY(10000);   /* Wait until our interrupt handler sees it */ 
                  xpt_done(ccb);
                  break;
          }
          case XPT_TERM_IO:               /* Terminate the I/O process */
                  /* XXX Implement */
                  ccb->ccb_h.status = CAM_REQ_INVALID;
                  xpt_done(ccb);
                  break;
          case XPT_PATH_INQ:              /* Path routing inquiry */
          {
                  struct ccb_pathinq *cpi = &ccb->cpi;
                  
                  cpi->version_num = 1; /* XXX??? */
                  cpi->hba_inquiry = 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;
                  cpi->hba_eng_cnt = 0;
                  cpi->max_target = (np->features & FE_WIDE) ? 15 : 7;
                  cpi->max_lun = MAX_LUN - 1;
                  cpi->initiator_id = np->myaddr;
                  cpi->bus_id = cam_sim_bus(sim);
                  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);
                  cpi->ccb_h.status = CAM_REQ_CMP;
                  xpt_done(ccb);
                  break;
          }
          default:
                  ccb->ccb_h.status = CAM_REQ_INVALID;
                  xpt_done(ccb);
                  break;
          }
  }
  
  /*==========================================================
  **
  **
  **      Complete execution of a SCSI command.
  **      Signal completion to the generic SCSI driver.
  **
  **
  **==========================================================
  */
  
  void
  ncr_complete (ncb_p np, nccb_p cp)
  {
          union ccb *ccb;
          tcb_p tp;
          lcb_p lp;
  
          /*
          **      Sanity check
          */
  
          if (!cp || (cp->magic!=CCB_MAGIC) || !cp->ccb) return;
          cp->magic = 1;
          cp->tlimit= 0;
  
          /*
          **      No Reselect anymore.
          */
          cp->jump_nccb.l_cmd = (SCR_JUMP);
  
          /*
          **      No starting.
          */
          cp->phys.header.launch.l_paddr= NCB_SCRIPT_PHYS (np, idle);
  
          /*
          **      timestamp
          */
          ncb_profile (np, cp);
  
          if (DEBUG_FLAGS & DEBUG_TINY)
                  printf ("CCB=%x STAT=%x/%x\n", (int)(intptr_t)cp & 0xfff,
                          cp->host_status,cp->s_status);
  
          ccb = cp->ccb;
          cp->ccb = NULL;
          tp = &np->target[ccb->ccb_h.target_id];
          lp = tp->lp[ccb->ccb_h.target_lun];
  
          /*
          **      We do not queue more than 1 nccb per target 
          **      with negotiation at any time. If this nccb was 
          **      used for negotiation, clear this info in the tcb.
          */
  
          if (cp == tp->nego_cp)
                  tp->nego_cp = NULL;
  
          /*
          **      Check for parity errors.
          */
          /* XXX JGibbs - What about reporting them??? */
  
          if (cp->parity_status) {
                  PRINT_ADDR(ccb);
                  printf ("%d parity error(s), fallback.\n", cp->parity_status);
                  /*
                  **      fallback to asynch transfer.
                  */
                  tp->tinfo.goal.period = 0;
                  tp->tinfo.goal.offset = 0;
          };
  
          /*
          **      Check for extended errors.
          */
  
          if (cp->xerr_status != XE_OK) {
                  PRINT_ADDR(ccb);
                  switch (cp->xerr_status) {
                  case XE_EXTRA_DATA:
                          printf ("extraneous data discarded.\n");
                          break;
                  case XE_BAD_PHASE:
                          printf ("illegal scsi phase (4/5).\n");
                          break;
                  default:
                          printf ("extended error %d.\n", cp->xerr_status);
                          break;
                  };
                  if (cp->host_status==HS_COMPLETE)
                          cp->host_status = HS_FAIL;
          };
  
          /*
          **      Check the status.
          */
          if (cp->host_status == HS_COMPLETE) {
  
                  if (cp->s_status == SCSI_STATUS_OK) {
  
                          /*
                          **      All went well.
                          */
                          /* XXX JGibbs - Properly calculate residual */
  
                          tp->bytes     += ccb->csio.dxfer_len;
                          tp->transfers ++;
  
                          ccb->ccb_h.status = CAM_REQ_CMP;
                  } else if ((cp->s_status & SCSI_STATUS_SENSE) != 0) {
  
                          /*
                           * XXX Could be TERMIO too.  Should record
                           * original status.
                           */
                          ccb->csio.scsi_status = SCSI_STATUS_CHECK_COND;
                          cp->s_status &= ~SCSI_STATUS_SENSE;
                          if (cp->s_status == SCSI_STATUS_OK) {
                                  ccb->ccb_h.status =
                                      CAM_AUTOSNS_VALID|CAM_SCSI_STATUS_ERROR;
                          } else {
                                  ccb->ccb_h.status = CAM_AUTOSENSE_FAIL;
                          }
                  } else {
                          ccb->ccb_h.status = CAM_SCSI_STATUS_ERROR;                      
                          ccb->csio.scsi_status = cp->s_status;
                  }
                  
                  
          } else if (cp->host_status == HS_SEL_TIMEOUT) {
  
                  /*
                  **   Device failed selection
                  */
                  ccb->ccb_h.status = CAM_SEL_TIMEOUT;
  
          } else if (cp->host_status == HS_TIMEOUT) {
  
                  /*
                  **   No response
                  */
                  ccb->ccb_h.status = CAM_CMD_TIMEOUT;
          } else if (cp->host_status == HS_STALL) {
                  ccb->ccb_h.status = CAM_REQUEUE_REQ;
          } else {
  
                  /*
                  **  Other protocol messes
                  */
                  PRINT_ADDR(ccb);
                  printf ("COMMAND FAILED (%x %x) @%p.\n",
                          cp->host_status, cp->s_status, cp);
  
                  ccb->ccb_h.status = CAM_CMD_TIMEOUT;
          }
  
          if ((ccb->ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_CMP) {
                  xpt_freeze_devq(ccb->ccb_h.path, /*count*/1);
                  ccb->ccb_h.status |= CAM_DEV_QFRZN;
          }
  
          /*
          **      Free this nccb
          */
          ncr_free_nccb (np, cp);
  
          /*
          **      signal completion to generic driver.
          */
          xpt_done (ccb);
  }
  
  /*==========================================================
  **
  **
  **      Signal all (or one) control block done.
  **
  **
  **==========================================================
  */
  
  void
  ncr_wakeup (ncb_p np, u_long code)
  {
          /*
          **      Starting at the default nccb and following
          **      the links, complete all jobs with a
          **      host_status greater than "disconnect".
          **
          **      If the "code" parameter is not zero,
          **      complete all jobs that are not IDLE.
          */
  
          nccb_p cp = np->link_nccb;
          while (cp) {
                  switch (cp->host_status) {
  
                  case HS_IDLE:
                          break;
  
                  case HS_DISCONNECT:
                          if(DEBUG_FLAGS & DEBUG_TINY) printf ("D");
                          /* fall through */
  
                  case HS_BUSY:
                  case HS_NEGOTIATE:
                          if (!code) break;
                          cp->host_status = code;
  
                          /* fall through */
  
                  default:
                          ncr_complete (np, cp);
                          break;
                  };
                  cp = cp -> link_nccb;
          };
  }
  
  static void
  ncr_freeze_devq (ncb_p np, struct cam_path *path)
  {
          nccb_p  cp;
          int     i;
          int     count;
          int     firstskip;
          /*
          **      Starting at the first nccb and following
          **      the links, complete all jobs that match
          **      the passed in path and are in the start queue.
          */
  
          cp = np->link_nccb;
          count = 0;
          firstskip = 0;
          while (cp) {
                  switch (cp->host_status) {
  
                  case HS_BUSY:
                  case HS_NEGOTIATE:
                          if ((cp->phys.header.launch.l_paddr
                              == NCB_SCRIPT_PHYS (np, select))
                           && (xpt_path_comp(path, cp->ccb->ccb_h.path) >= 0)) {
  
                                  /* Mark for removal from the start queue */
                                  for (i = 1; i < MAX_START; i++) {
                                          int idx;
  
                                          idx = np->squeueput - i;
                                  
                                          if (idx < 0)
                                                  idx = MAX_START + idx;
                                          if (np->squeue[idx]
                                           == CCB_PHYS(cp, phys)) {
                                                  np->squeue[idx] =
                                                      NCB_SCRIPT_PHYS (np, skip);
                                                  if (i > firstskip)
                                                          firstskip = i;
                                                  break;
                                          }
                                  }
                                  cp->host_status=HS_STALL;
                                  ncr_complete (np, cp);
                                  count++;
                          }
                          break;
                  default:
                          break;
                  }
                  cp = cp->link_nccb;
          }
  
          if (count > 0) {
                  int j;
                  int bidx;
  
                  /* Compress the start queue */
                  j = 0;
                  bidx = np->squeueput;
                  i = np->squeueput - firstskip;
                  if (i < 0)
                          i = MAX_START + i;
                  for (;;) {
  
                          bidx = i - j;
                          if (bidx < 0)
                                  bidx = MAX_START + bidx;
                          
                          if (np->squeue[i] == NCB_SCRIPT_PHYS (np, skip)) {
                                  j++;
                          } else if (j != 0) {
                                  np->squeue[bidx] = np->squeue[i];
                                  if (np->squeue[bidx]
                                   == NCB_SCRIPT_PHYS(np, idle))
                                          break;
                          }
                          i = (i + 1) % MAX_START;
                  }
                  np->squeueput = bidx;
          }
  }
  
  /*==========================================================
  **
  **
  **      Start NCR chip.
  **
  **
  **==========================================================
  */
  
  void
  ncr_init(ncb_p np, char * msg, u_long code)
  {
          int     i;
  
          /*
          **      Reset chip.
          */
  
          OUTB (nc_istat,  SRST);
          DELAY (1000);
          OUTB (nc_istat, 0);
  
          /*
          **      Message.
          */
  
          if (msg) printf ("%s: restart (%s).\n", ncr_name (np), msg);
  
          /*
          **      Clear Start Queue
          */
  
          for (i=0;i<MAX_START;i++)
                  np -> squeue [i] = NCB_SCRIPT_PHYS (np, idle);
  
          /*
          **      Start at first entry.
          */
  
          np->squeueput = 0;
          WRITESCRIPT(startpos[0], NCB_SCRIPTH_PHYS (np, tryloop));
          WRITESCRIPT(start0  [0], SCR_INT ^ IFFALSE (0));
  
          /*
          **      Wakeup all pending jobs.
          */
  
          ncr_wakeup (np, code);
  
          /*
          **      Init chip.
          */
  
          OUTB (nc_istat,  0x00   );      /*  Remove Reset, abort ...          */
          OUTB (nc_scntl0, 0xca   );      /*  full arb., ena parity, par->ATN  */
          OUTB (nc_scntl1, 0x00   );      /*  odd parity, and remove CRST!!    */
          ncr_selectclock(np, np->rv_scntl3); /* Select SCSI clock             */
          OUTB (nc_scid  , RRE|np->myaddr);/*  host 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); /* XXX modify burstlen ??? */
          OUTB (nc_dcntl , np->rv_dcntl);
          OUTB (nc_ctest3, np->rv_ctest3);
          OUTB (nc_ctest5, np->rv_ctest5);
          OUTB (nc_ctest4, np->rv_ctest4);/*  enable master parity checking    */
          OUTB (nc_stest2, np->rv_stest2|EXT); /* Extended Sreq/Sack filtering */
          OUTB (nc_stest3, TE     );      /*  TolerANT enable                  */
          OUTB (nc_stime0, 0x0b   );      /*  HTH = disabled, STO = 0.1 sec.   */
  
          if (bootverbose >= 2) {
                  printf ("\tACTUAL values:SCNTL3:%02x DMODE:%02x  DCNTL:%02x\n",
                          np->rv_scntl3, np->rv_dmode, np->rv_dcntl);
                  printf ("\t              CTEST3:%02x CTEST4:%02x CTEST5:%02x\n",
                          np->rv_ctest3, np->rv_ctest4, np->rv_ctest5);
          }
  
          /*
          **    Enable GPIO0 pin for writing if LED support.
          */
  
          if (np->features & FE_LED0) {
                  OUTOFFB (nc_gpcntl, 0x01);
          }
  
          /*
          **      Fill in target structure.
          */
          for (i=0;i<MAX_TARGET;i++) {
                  tcb_p tp = &np->target[i];
  
                  tp->tinfo.sval    = 0;
                  tp->tinfo.wval    = np->rv_scntl3;
  
                  tp->tinfo.current.period = 0;
                  tp->tinfo.current.offset = 0;
                  tp->tinfo.current.width = MSG_EXT_WDTR_BUS_8_BIT;
          }
  
          /*
          **      enable ints
          */
  
          OUTW (nc_sien , STO|HTH|MA|SGE|UDC|RST);
          OUTB (nc_dien , MDPE|BF|ABRT|SSI|SIR|IID);
  
          /*
          **    Start script processor.
          */
  
          OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, start));
  
          /*
           * Notify the XPT of the event
           */
          if (code == HS_RESET)
                  xpt_async(AC_BUS_RESET, np->path, NULL);
  }
  
  static void
  ncr_poll(struct cam_sim *sim)
  {       
          ncr_intr(cam_sim_softc(sim));  
  }
  
  
  /*==========================================================
  **
  **      Get clock factor and sync divisor for a given 
  **      synchronous factor period.
  **      Returns the clock factor (in sxfer) and scntl3 
  **      synchronous divisor field.
  **
  **==========================================================
  */
  
  static void ncr_getsync(ncb_p np, u_char sfac, u_char *fakp, u_char *scntl3p)
  {
          u_long  clk = np->clock_khz;    /* SCSI clock frequency in kHz  */
          int     div = np->clock_divn;   /* Number of divisors supported */
          u_long  fak;                    /* Sync factor in sxfer         */
          u_long  per;                    /* Period in tenths of ns       */
          u_long  kpc;                    /* (per * clk)                  */
  
          /*
          **      Compute the synchronous period in tenths of nano-seconds
          */
          if      (sfac <= 10)    per = 250;
          else if (sfac == 11)    per = 303;
          else if (sfac == 12)    per = 500;
          else                    per = 40 * sfac;
  
          /*
          **      Look for the greatest clock divisor that allows an 
          **      input speed faster than the period.
          */
          kpc = per * clk;
          while (--div >= 0)
                  if (kpc >= (div_10M[div] * 4)) break;
  
          /*
          **      Calculate the lowest clock factor that allows an output 
          **      speed not faster than the period.
          */
          fak = (kpc - 1) / div_10M[div] + 1;
  
  #if 0   /* You can #if 1 if you think this optimization is usefull */
  
          per = (fak * div_10M[div]) / clk;
  
          /*
          **      Why not to try the immediate lower divisor and to choose 
          **      the one that allows the fastest output speed ?
          **      We dont want input speed too much greater than output speed.
          */
          if (div >= 1 && fak < 6) {
                  u_long fak2, per2;
                  fak2 = (kpc - 1) / div_10M[div-1] + 1;
                  per2 = (fak2 * div_10M[div-1]) / clk;
                  if (per2 < per && fak2 <= 6) {
                          fak = fak2;
                          per = per2;
                          --div;
                  }
          }
  #endif
  
          if (fak < 4) fak = 4;   /* Should never happen, too bad ... */
  
          /*
          **      Compute and return sync parameters for the ncr
          */
          *fakp           = fak - 4;
          *scntl3p        = ((div+1) << 4) + (sfac < 25 ? 0x80 : 0);
  }
  
  /*==========================================================
  **
  **      Switch sync mode for current job and its target
  **
  **==========================================================
  */
  
  static void
  ncr_setsync(ncb_p np, nccb_p cp, u_char scntl3, u_char sxfer, u_char period)
  {
          union   ccb *ccb;
          struct  ccb_trans_settings neg; 
          tcb_p   tp;
          int     div;
          u_int   target = INB (nc_sdid) & 0x0f;
          u_int   period_10ns;
  
          assert (cp);
          if (!cp) return;
  
          ccb = cp->ccb;
          assert (ccb);
          if (!ccb) return;
          assert (target == ccb->ccb_h.target_id);
  
          tp = &np->target[target];
  
          if (!scntl3 || !(sxfer & 0x1f))
                  scntl3 = np->rv_scntl3;
          scntl3 = (scntl3 & 0xf0) | (tp->tinfo.wval & EWS)
                 | (np->rv_scntl3 & 0x07);
  
          /*
          **      Deduce the value of controller sync period from scntl3.
          **      period is in tenths of nano-seconds.
          */
  
          div = ((scntl3 >> 4) & 0x7);
          if ((sxfer & 0x1f) && div)
                  period_10ns =
                      (((sxfer>>5)+4)*div_10M[div-1])/np->clock_khz;
          else
                  period_10ns = 0;
  
          tp->tinfo.goal.period = period;
          tp->tinfo.goal.offset = sxfer & 0x1f;
          tp->tinfo.current.period = period;
          tp->tinfo.current.offset = sxfer & 0x1f;
  
          /*
          **       Stop there if sync parameters are unchanged
          */
          if (tp->tinfo.sval == sxfer && tp->tinfo.wval == scntl3) return;
          tp->tinfo.sval = sxfer;
          tp->tinfo.wval = scntl3;
  
          if (sxfer & 0x1f) {
                  /*
                  **  Disable extended Sreq/Sack filtering
                  */
                  if (period_10ns <= 2000) OUTOFFB (nc_stest2, EXT);
          }
  
          /*
          ** Tell the SCSI layer about the
          ** new transfer parameters.
          */
          neg.sync_period = period;
          neg.sync_offset = sxfer & 0x1f;
          neg.valid = CCB_TRANS_SYNC_RATE_VALID
                  | CCB_TRANS_SYNC_OFFSET_VALID;
          xpt_setup_ccb(&neg.ccb_h, ccb->ccb_h.path,
                        /*priority*/1);
          xpt_async(AC_TRANSFER_NEG, ccb->ccb_h.path, &neg);
          
          /*
          **      set actual value and sync_status
          */
          OUTB (nc_sxfer, sxfer);
          np->sync_st = sxfer;
          OUTB (nc_scntl3, scntl3);
          np->wide_st = scntl3;
  
          /*
          **      patch ALL nccbs of this target.
          */
          for (cp = np->link_nccb; cp; cp = cp->link_nccb) {
                  if (!cp->ccb) continue;
                  if (cp->ccb->ccb_h.target_id != target) continue;
                  cp->sync_status = sxfer;
                  cp->wide_status = scntl3;
          };
  }
  
  /*==========================================================
  **
  **      Switch wide mode for current job and its target
  **      SCSI specs say: a SCSI device that accepts a WDTR 
  **      message shall reset the synchronous agreement to 
  **      asynchronous mode.
  **
  **==========================================================
  */
  
  static void ncr_setwide (ncb_p np, nccb_p cp, u_char wide, u_char ack)
  {
          union   ccb *ccb;
          struct  ccb_trans_settings neg;         
          u_int   target = INB (nc_sdid) & 0x0f;
          tcb_p   tp;
          u_char  scntl3;
          u_char  sxfer;
  
          assert (cp);
          if (!cp) return;
  
          ccb = cp->ccb;
          assert (ccb);
          if (!ccb) return;
          assert (target == ccb->ccb_h.target_id);
  
          tp = &np->target[target];
          tp->tinfo.current.width = wide;
          tp->tinfo.goal.width = wide;
          tp->tinfo.current.period = 0;
          tp->tinfo.current.offset = 0;
  
          scntl3 = (tp->tinfo.wval & (~EWS)) | (wide ? EWS : 0);
  
          sxfer = ack ? 0 : tp->tinfo.sval;
  
          /*
          **       Stop there if sync/wide parameters are unchanged
          */
          if (tp->tinfo.sval == sxfer && tp->tinfo.wval == scntl3) return;
          tp->tinfo.sval = sxfer;
          tp->tinfo.wval = scntl3;
  
          /* Tell the SCSI layer about the new transfer params */
          neg.bus_width = (scntl3 & EWS) ? MSG_EXT_WDTR_BUS_16_BIT
                                         : MSG_EXT_WDTR_BUS_8_BIT;
          neg.sync_period = 0;
          neg.sync_offset = 0;
          neg.valid = CCB_TRANS_BUS_WIDTH_VALID
                    | CCB_TRANS_SYNC_RATE_VALID
                    | CCB_TRANS_SYNC_OFFSET_VALID;
          xpt_setup_ccb(&neg.ccb_h, ccb->ccb_h.path,
                        /*priority*/1);
          xpt_async(AC_TRANSFER_NEG, ccb->ccb_h.path, &neg);      
  
          /*
          **      set actual value and sync_status
          */
          OUTB (nc_sxfer, sxfer);
          np->sync_st = sxfer;
          OUTB (nc_scntl3, scntl3);
          np->wide_st = scntl3;
  
          /*
          **      patch ALL nccbs of this target.
          */
          for (cp = np->link_nccb; cp; cp = cp->link_nccb) {
                  if (!cp->ccb) continue;
                  if (cp->ccb->ccb_h.target_id != target) continue;
                  cp->sync_status = sxfer;
                  cp->wide_status = scntl3;
          };
  }
  
  /*==========================================================
  **
  **
  **      ncr timeout handler.
  **
  **
  **==========================================================
  **
  **      Misused to keep the driver running when
  **      interrupts are not configured correctly.
  **
  **----------------------------------------------------------
  */
  
  static void
  ncr_timeout (void *arg)
  {
          ncb_p   np = arg;
          time_t  thistime = time_second;
          ticks_t step  = np->ticks;
          u_long  count = 0;
          long signed   t;
          nccb_p cp;
  
          if (np->lasttime != thistime) {
                  /*
                  **      block ncr interrupts
                  */
                  int oldspl = splcam();
                  np->lasttime = thistime;
  
                  /*----------------------------------------------------
                  **
                  **      handle ncr chip timeouts
                  **
                  **      Assumption:
                  **      We have a chance to arbitrate for the
                  **      SCSI bus at least every 10 seconds.
                  **
                  **----------------------------------------------------
                  */
  
                  t = thistime - np->heartbeat;
  
                  if (t<2) np->latetime=0; else np->latetime++;
  
                  if (np->latetime>2) {
                          /*
                          **      If there are no requests, the script
                          **      processor will sleep on SEL_WAIT_RESEL.
                          **      But we have to check whether it died.
                          **      Let's try to wake it up.
                          */
                          OUTB (nc_istat, SIGP);
                  };
  
                  /*----------------------------------------------------
                  **
                  **      handle nccb timeouts
                  **
                  **----------------------------------------------------
                  */
  
                  for (cp=np->link_nccb; cp; cp=cp->link_nccb) {
                          /*
                          **      look for timed out nccbs.
                          */
                          if (!cp->host_status) continue;
                          count++;
                          if (cp->tlimit > thistime) continue;
  
                          /*
                          **      Disable reselect.
                          **      Remove it from startqueue.
                          */
                          cp->jump_nccb.l_cmd = (SCR_JUMP);
                          if (cp->phys.header.launch.l_paddr ==
                                  NCB_SCRIPT_PHYS (np, select)) {
                                  printf ("%s: timeout nccb=%p (skip)\n",
                                          ncr_name (np), cp);
                                  cp->phys.header.launch.l_paddr
                                  = NCB_SCRIPT_PHYS (np, skip);
                          };
  
                          switch (cp->host_status) {
  
                          case HS_BUSY:
                          case HS_NEGOTIATE:
                                  /* fall through */
                          case HS_DISCONNECT:
                                  cp->host_status=HS_TIMEOUT;
                          };
                          cp->tag = 0;
  
                          /*
                          **      wakeup this nccb.
                          */
                          ncr_complete (np, cp);
                  };
                  splx (oldspl);
          }
  
          np->timeout_ch =
                  timeout (ncr_timeout, (caddr_t) np, step ? step : 1);
  
          if (INB(nc_istat) & (INTF|SIP|DIP)) {
  
                  /*
                  **      Process pending interrupts.
                  */
  
                  int     oldspl  = splcam();
                  if (DEBUG_FLAGS & DEBUG_TINY) printf ("{");
                  ncr_exception (np);
                  if (DEBUG_FLAGS & DEBUG_TINY) printf ("}");
                  splx (oldspl);
          };
  }
  
  /*==========================================================
  **
  **      log message for real hard errors
  **
  **      "ncr0 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 driver by NCR.
  **              si:     control lines as seen by NCR.
  **              sd:     scsi data lines as seen by NCR.
  **
  **      wide/fastmode:
  **              sxfer:  (see the manual)
  **              scntl3: (see the manual)
  **
  **      current script command:
  **              dsp:    script adress (relative to start of script).
  **              dbc:    first word of script command.
  **
  **      First 16 register of the chip:
  **              r0..rf
  **
  **==========================================================
  */
  
  static void ncr_log_hard_error(ncb_p np, u_short sist, u_char dstat)
  {
          u_int32_t dsp;
          int     script_ofs;
          int     script_size;
          char    *script_name;
          u_char  *script_base;
          int     i;
  
          dsp     = INL (nc_dsp);
  
          if (np->p_script < dsp && 
              dsp <= np->p_script + sizeof(struct script)) {
                  script_ofs      = dsp - np->p_script;
                  script_size     = sizeof(struct script);
                  script_base     = (u_char *) np->script;
                  script_name     = "script";
          }
          else if (np->p_scripth < dsp && 
                   dsp <= np->p_scripth + sizeof(struct scripth)) {
                  script_ofs      = dsp - np->p_scripth;
                  script_size     = sizeof(struct scripth);
                  script_base     = (u_char *) np->scripth;
                  script_name     = "scripth";
          } 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",
                  ncr_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", ncr_name(np),
                          (int)READSCRIPT_OFF(script_base, script_ofs));
          }
  
          printf ("%s: regdump:", ncr_name(np));
          for (i=0; i<16;i++)
              printf (" %02x", (unsigned)INB_OFF(i));
          printf (".\n");
  }
  
  /*==========================================================
  **
  **
  **      ncr chip exception handler.
  **
  **
  **==========================================================
  */
  
  void ncr_exception (ncb_p np)
  {
          u_char  istat, dstat;
          u_short sist;
  
          /*
          **      interrupt on the fly ?
          */
          while ((istat = INB (nc_istat)) & INTF) {
                  if (DEBUG_FLAGS & DEBUG_TINY) printf ("F ");
                  OUTB (nc_istat, INTF);
                  np->profile.num_fly++;
                  ncr_wakeup (np, 0);
          };
          if (!(istat & (SIP|DIP))) {
                  return;
          }
  
          /*
          **      Steinbach's Guideline for Systems Programming:
          **      Never test for an error condition you don't know how to handle.
          */
  
          sist  = (istat & SIP) ? INW (nc_sist)  : 0;
          dstat = (istat & DIP) ? INB (nc_dstat) : 0;
          np->profile.num_int++;
  
          if (DEBUG_FLAGS & DEBUG_TINY)
                  printf ("<%d|%x:%x|%x:%x>",
                          INB(nc_scr0),
                          dstat,sist,
                          (unsigned)INL(nc_dsp),
                          (unsigned)INL(nc_dbc));
          if ((dstat==DFE) && (sist==PAR)) return;
  
  /*==========================================================
  **
  **      First the normal cases.
  **
  **==========================================================
  */
          /*-------------------------------------------
          **      SCSI reset
          **-------------------------------------------
          */
  
          if (sist & RST) {
                  ncr_init (np, bootverbose ? "scsi reset" : NULL, HS_RESET);
                  return;
          };
  
          /*-------------------------------------------
          **      selection timeout
          **
          **      IID excluded from dstat mask!
          **      (chip bug)
          **-------------------------------------------
          */
  
          if ((sist  & STO) &&
                  !(sist  & (GEN|HTH|MA|SGE|UDC|RST|PAR)) &&
                  !(dstat & (MDPE|BF|ABRT|SIR))) {
                  ncr_int_sto (np);
                  return;
          };
  
          /*-------------------------------------------
          **      Phase mismatch.
          **-------------------------------------------
          */
  
          if ((sist  & MA) &&
                  !(sist  & (STO|GEN|HTH|SGE|UDC|RST|PAR)) &&
                  !(dstat & (MDPE|BF|ABRT|SIR|IID))) {
                  ncr_int_ma (np, dstat);
                  return;
          };
  
          /*----------------------------------------
          **      move command with length 0
          **----------------------------------------
          */
  
          if ((dstat & IID) &&
                  !(sist  & (STO|GEN|HTH|MA|SGE|UDC|RST|PAR)) &&
                  !(dstat & (MDPE|BF|ABRT|SIR)) &&
                  ((INL(nc_dbc) & 0xf8000000) == SCR_MOVE_TBL)) {
                  /*
                  **      Target wants more data than available.
                  **      The "no_data" script will do it.
                  */
                  OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, no_data));
                  return;
          };
  
          /*-------------------------------------------
          **      Programmed interrupt
          **-------------------------------------------
          */
  
          if ((dstat & SIR) &&
                  !(sist  & (STO|GEN|HTH|MA|SGE|UDC|RST|PAR)) &&
                  !(dstat & (MDPE|BF|ABRT|IID)) &&
                  (INB(nc_dsps) <= SIR_MAX)) {
                  ncr_int_sir (np);
                  return;
          };
  
          /*========================================
          **      log message for real hard errors
          **========================================
          */
  
          ncr_log_hard_error(np, sist, dstat);
  
          /*========================================
          **      do the register dump
          **========================================
          */
  
          if (time_second - np->regtime > 10) {
                  int i;
                  np->regtime = time_second;
                  for (i=0; i<sizeof(np->regdump); i++)
                          ((volatile char*)&np->regdump)[i] = INB_OFF(i);
                  np->regdump.nc_dstat = dstat;
                  np->regdump.nc_sist  = sist;
          };
  
  
          /*----------------------------------------
          **      clean up the dma fifo
          **----------------------------------------
          */
  
          if ( (INB(nc_sstat0) & (ILF|ORF|OLF)   ) ||
               (INB(nc_sstat1) & (FF3210) ) ||
               (INB(nc_sstat2) & (ILF1|ORF1|OLF1)) ||     /* wide .. */
               !(dstat & DFE)) {
                  printf ("%s: have to clear fifos.\n", ncr_name (np));
                  OUTB (nc_stest3, TE|CSF);       /* clear scsi fifo */
                  OUTB (nc_ctest3, np->rv_ctest3 | CLF);
                                                  /* clear dma fifo  */
          }
  
          /*----------------------------------------
          **      handshake timeout
          **----------------------------------------
          */
  
          if (sist & HTH) {
                  printf ("%s: handshake timeout\n", ncr_name(np));
                  OUTB (nc_scntl1, CRST);
                  DELAY (1000);
                  OUTB (nc_scntl1, 0x00);
                  OUTB (nc_scr0, HS_FAIL);
                  OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, cleanup));
                  return;
          }
  
          /*----------------------------------------
          **      unexpected disconnect
          **----------------------------------------
          */
  
          if ((sist  & UDC) &&
                  !(sist  & (STO|GEN|HTH|MA|SGE|RST|PAR)) &&
                  !(dstat & (MDPE|BF|ABRT|SIR|IID))) {
                  OUTB (nc_scr0, HS_UNEXPECTED);
                  OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, cleanup));
                  return;
          };
  
          /*----------------------------------------
          **      cannot disconnect
          **----------------------------------------
          */
  
          if ((dstat & IID) &&
                  !(sist  & (STO|GEN|HTH|MA|SGE|UDC|RST|PAR)) &&
                  !(dstat & (MDPE|BF|ABRT|SIR)) &&
                  ((INL(nc_dbc) & 0xf8000000) == SCR_WAIT_DISC)) {
                  /*
                  **      Unexpected data cycle while waiting for disconnect.
                  */
                  if (INB(nc_sstat2) & LDSC) {
                          /*
                          **      It's an early reconnect.
                          **      Let's continue ...
                          */
                          OUTB (nc_dcntl, np->rv_dcntl | STD);
                          /*
                          **      info message
                          */
                          printf ("%s: INFO: LDSC while IID.\n",
                                  ncr_name (np));
                          return;
                  };
                  printf ("%s: target %d doesn't release the bus.\n",
                          ncr_name (np), INB (nc_sdid)&0x0f);
                  /*
                  **      return without restarting the NCR.
                  **      timeout will do the real work.
                  */
                  return;
          };
  
          /*----------------------------------------
          **      single step
          **----------------------------------------
          */
  
          if ((dstat & SSI) &&
                  !(sist  & (STO|GEN|HTH|MA|SGE|UDC|RST|PAR)) &&
                  !(dstat & (MDPE|BF|ABRT|SIR|IID))) {
                  OUTB (nc_dcntl, np->rv_dcntl | STD);
                  return;
          };
  
  /*
  **      @RECOVER@ HTH, SGE, ABRT.
  **
  **      We should try to recover from these interrupts.
  **      They may occur if there are problems with synch transfers, or 
  **      if targets are switched on or off while the driver is running.
  */
  
          if (sist & SGE) {
                  /* clear scsi offsets */
                  OUTB (nc_ctest3, np->rv_ctest3 | CLF);
          }
  
          /*
          **      Freeze controller to be able to read the messages.
          */
  
          if (DEBUG_FLAGS & DEBUG_FREEZE) {
                  int i;
                  unsigned char val;
                  for (i=0; i<0x60; i++) {
                          switch (i%16) {
  
                          case 0:
                                  printf ("%s: reg[%d0]: ",
                                          ncr_name(np),i/16);
                                  break;
                          case 4:
                          case 8:
                          case 12:
                                  printf (" ");
                                  break;
                          };
                          val = bus_space_read_1(np->bst, np->bsh, i);
                          printf (" %x%x", val/16, val%16);
                          if (i%16==15) printf (".\n");
                  };
  
                  untimeout (ncr_timeout, (caddr_t) np, np->timeout_ch);
  
                  printf ("%s: halted!\n", ncr_name(np));
                  /*
                  **      don't restart controller ...
                  */
                  OUTB (nc_istat,  SRST);
                  return;
          };
  
  #ifdef NCR_FREEZE
          /*
          **      Freeze system to be able to read the messages.
          */
          printf ("ncr: fatal error: system halted - press reset to reboot ...");
          (void) splhigh();
          for (;;);
  #endif
  
          /*
          **      sorry, have to kill ALL jobs ...
          */
  
          ncr_init (np, "fatal error", HS_FAIL);
  }
  
  /*==========================================================
  **
  **      ncr chip exception handler for selection timeout
  **
  **==========================================================
  **
  **      There seems to be a bug in the 53c810.
  **      Although a STO-Interrupt is pending,
  **      it continues executing script commands.
  **      But it will fail and interrupt (IID) on
  **      the next instruction where it's looking
  **      for a valid phase.
  **
  **----------------------------------------------------------
  */
  
  void ncr_int_sto (ncb_p np)
  {
          u_long dsa, scratcha, diff;
          nccb_p cp;
          if (DEBUG_FLAGS & DEBUG_TINY) printf ("T");
  
          /*
          **      look for nccb and set the status.
          */
  
          dsa = INL (nc_dsa);
          cp = np->link_nccb;
          while (cp && (CCB_PHYS (cp, phys) != dsa))
                  cp = cp->link_nccb;
  
          if (cp) {
                  cp-> host_status = HS_SEL_TIMEOUT;
                  ncr_complete (np, cp);
          };
  
          /*
          **      repair start queue
          */
  
          scratcha = INL (nc_scratcha);
          diff = scratcha - NCB_SCRIPTH_PHYS (np, tryloop);
  
  /*      assert ((diff <= MAX_START * 20) && !(diff % 20));*/
  
          if ((diff <= MAX_START * 20) && !(diff % 20)) {
                  WRITESCRIPT(startpos[0], scratcha);
                  OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, start));
                  return;
          };
          ncr_init (np, "selection timeout", HS_FAIL);
  }
  
  /*==========================================================
  **
  **
  **      ncr chip exception handler for phase errors.
  **
  **
  **==========================================================
  **
  **      We have to construct a new transfer descriptor,
  **      to transfer the rest of the current block.
  **
  **----------------------------------------------------------
  */
  
  static void ncr_int_ma (ncb_p np, u_char dstat)
  {
          u_int32_t       dbc;
          u_int32_t       rest;
          u_int32_t       dsa;
          u_int32_t       dsp;
          u_int32_t       nxtdsp;
          volatile void   *vdsp_base;
          size_t          vdsp_off;
          u_int32_t       oadr, olen;
          u_int32_t       *tblp, *newcmd;
          u_char  cmd, sbcl, ss0, ss2, ctest5;
          u_short delta;
          nccb_p  cp;
  
          dsp = INL (nc_dsp);
          dsa = INL (nc_dsa);
          dbc = INL (nc_dbc);
          ss0 = INB (nc_sstat0);
          ss2 = INB (nc_sstat2);
          sbcl= INB (nc_sbcl);
  
          cmd = dbc >> 24;
          rest= dbc & 0xffffff;
  
          ctest5 = (np->rv_ctest5 & DFS) ? INB (nc_ctest5) : 0;
          if (ctest5 & DFS)
                  delta=(((ctest5<<8) | (INB (nc_dfifo) & 0xff)) - rest) & 0x3ff;
          else
                  delta=(INB (nc_dfifo) - 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.
          */
  
          if (!(dstat & DFE)) rest += delta;
          if (ss0 & OLF) rest++;
          if (ss0 & ORF) rest++;
          if (INB(nc_scntl3) & EWS) {
                  if (ss2 & OLF1) rest++;
                  if (ss2 & ORF1) rest++;
          };
          OUTB (nc_ctest3, np->rv_ctest3 | CLF);  /* clear dma fifo  */
          OUTB (nc_stest3, TE|CSF);               /* clear scsi fifo */
  
          /*
          **      locate matching cp
          */
          cp = np->link_nccb;
          while (cp && (CCB_PHYS (cp, phys) != dsa))
                  cp = cp->link_nccb;
  
          if (!cp) {
              printf ("%s: SCSI phase error fixup: CCB already dequeued (%p)\n", 
                      ncr_name (np), (void *) np->header.cp);
              return;
          }
          if (cp != np->header.cp) {
              printf ("%s: SCSI phase error fixup: CCB address mismatch "
                      "(%p != %p) np->nccb = %p\n", 
                      ncr_name (np), (void *)cp, (void *)np->header.cp,
                      (void *)np->link_nccb);
  /*          return;*/
          }
  
          /*
          **      find the interrupted script command,
          **      and the address at which to continue.
          */
  
          if (dsp == vtophys (&cp->patch[2])) {
                  vdsp_base = cp;
                  vdsp_off = offsetof(struct nccb, patch[0]);
                  nxtdsp = READSCRIPT_OFF(vdsp_base, vdsp_off + 3*4);
          } else if (dsp == vtophys (&cp->patch[6])) {
                  vdsp_base = cp;
                  vdsp_off = offsetof(struct nccb, patch[4]);
                  nxtdsp = READSCRIPT_OFF(vdsp_base, vdsp_off + 3*4);
          } else if (dsp > np->p_script &&
                     dsp <= np->p_script + sizeof(struct script)) {
                  vdsp_base = np->script;
                  vdsp_off = dsp - np->p_script - 8;
                  nxtdsp = dsp;
          } else {
                  vdsp_base = np->scripth;
                  vdsp_off = dsp - np->p_scripth - 8;
                  nxtdsp = dsp;
          };
  
          /*
          **      log the information
          */
          if (DEBUG_FLAGS & (DEBUG_TINY|DEBUG_PHASE)) {
                  printf ("P%x%x ",cmd&7, sbcl&7);
                  printf ("RL=%d D=%d SS0=%x ",
                          (unsigned) rest, (unsigned) delta, ss0);
          };
          if (DEBUG_FLAGS & DEBUG_PHASE) {
                  printf ("\nCP=%p CP2=%p DSP=%x NXT=%x VDSP=%p CMD=%x ",
                          cp, np->header.cp,
                          dsp,
                          nxtdsp, (volatile char*)vdsp_base+vdsp_off, cmd);
          };
  
          /*
          **      get old startaddress and old length.
          */
  
          oadr = READSCRIPT_OFF(vdsp_base, vdsp_off + 1*4);
  
          if (cmd & 0x10) {       /* Table indirect */
                  tblp = (u_int32_t *) ((char*) &cp->phys + oadr);
                  olen = tblp[0];
                  oadr = tblp[1];
          } else {
                  tblp = (u_int32_t *) 0;
                  olen = READSCRIPT_OFF(vdsp_base, vdsp_off) & 0xffffff;
          };
  
          if (DEBUG_FLAGS & DEBUG_PHASE) {
                  printf ("OCMD=%x\nTBLP=%p OLEN=%lx OADR=%lx\n",
                          (unsigned) (READSCRIPT_OFF(vdsp_base, vdsp_off) >> 24),
                          (void *) tblp,
                          (u_long) olen,
                          (u_long) oadr);
          };
  
          /*
          **      if old phase not dataphase, leave here.
          */
  
          if (cmd != (READSCRIPT_OFF(vdsp_base, vdsp_off) >> 24)) {
                  PRINT_ADDR(cp->ccb);
                  printf ("internal error: cmd=%02x != %02x=(vdsp[0] >> 24)\n",
                          (unsigned)cmd,
                          (unsigned)READSCRIPT_OFF(vdsp_base, vdsp_off) >> 24);
                  
                  return;
          }
          if (cmd & 0x06) {
                  PRINT_ADDR(cp->ccb);
                  printf ("phase change %x-%x %d@%08x resid=%d.\n",
                          cmd&7, sbcl&7, (unsigned)olen,
                          (unsigned)oadr, (unsigned)rest);
  
                  OUTB (nc_dcntl, np->rv_dcntl | STD);
                  return;
          };
  
          /*
          **      choose the correct patch area.
          **      if savep points to one, choose the other.
          */
  
          newcmd = cp->patch;
          if (cp->phys.header.savep == vtophys (newcmd)) newcmd+=4;
  
          /*
          **      fillin the commands
          */
  
          newcmd[0] = ((cmd & 0x0f) << 24) | rest;
          newcmd[1] = oadr + olen - rest;
          newcmd[2] = SCR_JUMP;
          newcmd[3] = nxtdsp;
  
          if (DEBUG_FLAGS & DEBUG_PHASE) {
                  PRINT_ADDR(cp->ccb);
                  printf ("newcmd[%d] %x %x %x %x.\n",
                          (int)(newcmd - cp->patch),
                          (unsigned)newcmd[0],
                          (unsigned)newcmd[1],
                          (unsigned)newcmd[2],
                          (unsigned)newcmd[3]);
          }
          /*
          **      fake the return address (to the patch).
          **      and restart script processor at dispatcher.
          */
          np->profile.num_break++;
          OUTL (nc_temp, vtophys (newcmd));
          if ((cmd & 7) == 0)
                  OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, dispatch));
          else
                  OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, checkatn));
  }
  
  /*==========================================================
  **
  **
  **      ncr chip exception handler for programmed interrupts.
  **
  **
  **==========================================================
  */
  
  static int ncr_show_msg (u_char * msg)
  {
          u_char i;
          printf ("%x",*msg);
          if (*msg==MSG_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);
  }
  
  void ncr_int_sir (ncb_p np)
  {
          u_char scntl3;
          u_char chg, ofs, per, fak, wide;
          u_char num = INB (nc_dsps);
          nccb_p  cp=0;
          u_long  dsa;
          u_int   target = INB (nc_sdid) & 0x0f;
          tcb_p   tp     = &np->target[target];
          int     i;
          if (DEBUG_FLAGS & DEBUG_TINY) printf ("I#%d", num);
  
          switch (num) {
          case SIR_SENSE_RESTART:
          case SIR_STALL_RESTART:
                  break;
  
          default:
                  /*
                  **      lookup the nccb
                  */
                  dsa = INL (nc_dsa);
                  cp = np->link_nccb;
                  while (cp && (CCB_PHYS (cp, phys) != dsa))
                          cp = cp->link_nccb;
  
                  assert (cp);
                  if (!cp)
                          goto out;
                  assert (cp == np->header.cp);
                  if (cp != np->header.cp)
                          goto out;
          }
  
          switch (num) {
  
  /*--------------------------------------------------------------------
  **
  **      Processing of interrupted getcc selects
  **
  **--------------------------------------------------------------------
  */
  
          case SIR_SENSE_RESTART:
                  /*------------------------------------------
                  **      Script processor is idle.
                  **      Look for interrupted "check cond"
                  **------------------------------------------
                  */
  
                  if (DEBUG_FLAGS & DEBUG_RESTART)
                          printf ("%s: int#%d",ncr_name (np),num);
                  cp = (nccb_p) 0;
                  for (i=0; i<MAX_TARGET; i++) {
                          if (DEBUG_FLAGS & DEBUG_RESTART) printf (" t%d", i);
                          tp = &np->target[i];
                          if (DEBUG_FLAGS & DEBUG_RESTART) printf ("+");
                          cp = tp->hold_cp;
                          if (!cp) continue;
                          if (DEBUG_FLAGS & DEBUG_RESTART) printf ("+");
                          if ((cp->host_status==HS_BUSY) &&
                                  (cp->s_status==SCSI_STATUS_CHECK_COND))
                                  break;
                          if (DEBUG_FLAGS & DEBUG_RESTART) printf ("- (remove)");
                          tp->hold_cp = cp = (nccb_p) 0;
                  };
  
                  if (cp) {
                          if (DEBUG_FLAGS & DEBUG_RESTART)
                                  printf ("+ restart job ..\n");
                          OUTL (nc_dsa, CCB_PHYS (cp, phys));
                          OUTL (nc_dsp, NCB_SCRIPTH_PHYS (np, getcc));
                          return;
                  };
  
                  /*
                  **      no job, resume normal processing
                  */
                  if (DEBUG_FLAGS & DEBUG_RESTART) printf (" -- remove trap\n");
                  WRITESCRIPT(start0[0], SCR_INT ^ IFFALSE (0));
                  break;
  
          case SIR_SENSE_FAILED:
                  /*-------------------------------------------
                  **      While trying to select for
                  **      getting the condition code,
                  **      a target reselected us.
                  **-------------------------------------------
                  */
                  if (DEBUG_FLAGS & DEBUG_RESTART) {
                          PRINT_ADDR(cp->ccb);
                          printf ("in getcc reselect by t%d.\n",
                                  INB(nc_ssid) & 0x0f);
                  }
  
                  /*
                  **      Mark this job
                  */
                  cp->host_status = HS_BUSY;
                  cp->s_status = SCSI_STATUS_CHECK_COND;
                  np->target[cp->ccb->ccb_h.target_id].hold_cp = cp;
  
                  /*
                  **      And patch code to restart it.
                  */
                  WRITESCRIPT(start0[0], SCR_INT);
                  break;
  
  /*-----------------------------------------------------------------------------
  **
  **      Was Sie schon immer ueber transfermode negotiation wissen wollten ...
  **
  **      We try to negotiate sync and wide transfer only after
  **      a successfull inquire command. We look at byte 7 of the
  **      inquire data to determine the capabilities if the target.
  **
  **      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 immidiately
  **      (as required by the standard), the SIR_NEGO_FAIL 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.
  **
  **      When we set the values, we adjust them in all nccbs belonging 
  **      to this target, in the controller's register, and in the "phys"
  **      field of the controller's struct ncb.
  **
  **      Possible cases:            hs  sir   msg_in value  send   goto
  **      We try try to negotiate:
  **      -> target doesnt't msgin   NEG FAIL  noop   defa.  -      dispatch
  **      -> target rejected our msg NEG FAIL  reject defa.  -      dispatch
  **      -> target answered  (ok)   NEG SYNC  sdtr   set    -      clrack
  **      -> target answered (!ok)   NEG SYNC  sdtr   defa.  REJ--->msg_bad
  **      -> target answered  (ok)   NEG WIDE  wdtr   set    -      clrack
  **      -> target answered (!ok)   NEG WIDE  wdtr   defa.  REJ--->msg_bad
  **      -> any other msgin         NEG FAIL  noop   defa.  -      dispatch
  **
  **      Target tries to negotiate:
  **      -> incoming message        --- SYNC  sdtr   set    SDTR   -
  **      -> incoming message        --- WIDE  wdtr   set    WDTR   -
  **      We sent our answer:
  **      -> target doesn't msgout   --- PROTO ?      defa.  -      dispatch
  **
  **-----------------------------------------------------------------------------
  */
  
          case SIR_NEGO_FAILED:
                  /*-------------------------------------------------------
                  **
                  **      Negotiation failed.
                  **      Target doesn't send an answer message,
                  **      or target rejected our message.
                  **
                  **      Remove negotiation request.
                  **
                  **-------------------------------------------------------
                  */
                  OUTB (HS_PRT, HS_BUSY);
  
                  /* fall through */
  
          case SIR_NEGO_PROTO:
                  /*-------------------------------------------------------
                  **
                  **      Negotiation failed.
                  **      Target doesn't fetch the answer message.
                  **
                  **-------------------------------------------------------
                  */
  
                  if (DEBUG_FLAGS & DEBUG_NEGO) {
                          PRINT_ADDR(cp->ccb);
                          printf ("negotiation failed sir=%x status=%x.\n",
                                  num, cp->nego_status);
                  };
  
                  /*
                  **      any error in negotiation:
                  **      fall back to default mode.
                  */
                  switch (cp->nego_status) {
  
                  case NS_SYNC:
                          ncr_setsync (np, cp, 0, 0xe0, 0);
                          break;
  
                  case NS_WIDE:
                          ncr_setwide (np, cp, 0, 0);
                          break;
  
                  };
                  np->msgin [0] = MSG_NOOP;
                  np->msgout[0] = MSG_NOOP;
                  cp->nego_status = 0;
                  OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, dispatch));
                  break;
  
          case SIR_NEGO_SYNC:
                  /*
                  **      Synchronous request message received.
                  */
  
                  if (DEBUG_FLAGS & DEBUG_NEGO) {
                          PRINT_ADDR(cp->ccb);
                          printf ("sync msgin: ");
                          (void) ncr_show_msg (np->msgin);
                          printf (".\n");
                  };
  
                  /*
                  **      get requested values.
                  */
  
                  chg = 0;
                  per = np->msgin[3];
                  ofs = np->msgin[4];
                  if (ofs==0) per=255;
  
                  /*
                  **      check values against driver limits.
                  */
                  if (per < np->minsync)
                          {chg = 1; per = np->minsync;}
                  if (per < tp->tinfo.user.period)
                          {chg = 1; per = tp->tinfo.user.period;}
                  if (ofs > tp->tinfo.user.offset)
                          {chg = 1; ofs = tp->tinfo.user.offset;}
  
                  /*
                  **      Check against controller limits.
                  */
  
                  fak     = 7;
                  scntl3  = 0;
                  if (ofs != 0) {
                          ncr_getsync(np, per, &fak, &scntl3);
                          if (fak > 7) {
                                  chg = 1;
                                  ofs = 0;
                          }
                  }
                  if (ofs == 0) {
                          fak     = 7;
                          per     = 0;
                          scntl3  = 0;
                  }
  
                  if (DEBUG_FLAGS & DEBUG_NEGO) {
                          PRINT_ADDR(cp->ccb);
                          printf ("sync: per=%d scntl3=0x%x ofs=%d fak=%d chg=%d.\n",
                                  per, scntl3, ofs, fak, chg);
                  }
  
                  if (INB (HS_PRT) == HS_NEGOTIATE) {
                          OUTB (HS_PRT, HS_BUSY);
                          switch (cp->nego_status) {
  
                          case NS_SYNC:
                                  /*
                                  **      This was an answer message
                                  */
                                  if (chg) {
                                          /*
                                          **      Answer wasn't acceptable.
                                          */
                                          ncr_setsync (np, cp, 0, 0xe0, 0);
                                          OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, msg_bad));
                                  } else {
                                          /*
                                          **      Answer is ok.
                                          */
                                          ncr_setsync (np,cp,scntl3,(fak<<5)|ofs, per);
                                          OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, clrack));
                                  };
                                  return;
  
                          case NS_WIDE:
                                  ncr_setwide (np, cp, 0, 0);
                                  break;
                          };
                  };
  
                  /*
                  **      It was a request. Set value and
                  **      prepare an answer message
                  */
  
                  ncr_setsync (np, cp, scntl3, (fak<<5)|ofs, per);
  
                  np->msgout[0] = MSG_EXTENDED;
                  np->msgout[1] = 3;
                  np->msgout[2] = MSG_EXT_SDTR;
                  np->msgout[3] = per;
                  np->msgout[4] = ofs;
  
                  cp->nego_status = NS_SYNC;
  
                  if (DEBUG_FLAGS & DEBUG_NEGO) {
                          PRINT_ADDR(cp->ccb);
                          printf ("sync msgout: ");
                          (void) ncr_show_msg (np->msgout);
                          printf (".\n");
                  }
  
                  if (!ofs) {
                          OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, msg_bad));
                          return;
                  }
                  np->msgin [0] = MSG_NOOP;
  
                  break;
  
          case SIR_NEGO_WIDE:
                  /*
                  **      Wide request message received.
                  */
                  if (DEBUG_FLAGS & DEBUG_NEGO) {
                          PRINT_ADDR(cp->ccb);
                          printf ("wide msgin: ");
                          (void) ncr_show_msg (np->msgin);
                          printf (".\n");
                  };
  
                  /*
                  **      get requested values.
                  */
  
                  chg  = 0;
                  wide = np->msgin[3];
  
                  /*
                  **      check values against driver limits.
                  */
  
                  if (wide > tp->tinfo.user.width)
                          {chg = 1; wide = tp->tinfo.user.width;}
  
                  if (DEBUG_FLAGS & DEBUG_NEGO) {
                          PRINT_ADDR(cp->ccb);
                          printf ("wide: wide=%d chg=%d.\n", wide, chg);
                  }
  
                  if (INB (HS_PRT) == HS_NEGOTIATE) {
                          OUTB (HS_PRT, HS_BUSY);
                          switch (cp->nego_status) {
  
                          case NS_WIDE:
                                  /*
                                  **      This was an answer message
                                  */
                                  if (chg) {
                                          /*
                                          **      Answer wasn't acceptable.
                                          */
                                          ncr_setwide (np, cp, 0, 1);
                                          OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, msg_bad));
                                  } else {
                                          /*
                                          **      Answer is ok.
                                          */
                                          ncr_setwide (np, cp, wide, 1);
                                          OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, clrack));
                                  };
                                  return;
  
                          case NS_SYNC:
                                  ncr_setsync (np, cp, 0, 0xe0, 0);
                                  break;
                          };
                  };
  
                  /*
                  **      It was a request, set value and
                  **      prepare an answer message
                  */
  
                  ncr_setwide (np, cp, wide, 1);
  
                  np->msgout[0] = MSG_EXTENDED;
                  np->msgout[1] = 2;
                  np->msgout[2] = MSG_EXT_WDTR;
                  np->msgout[3] = wide;
  
                  np->msgin [0] = MSG_NOOP;
  
                  cp->nego_status = NS_WIDE;
  
                  if (DEBUG_FLAGS & DEBUG_NEGO) {
                          PRINT_ADDR(cp->ccb);
                          printf ("wide msgout: ");
                          (void) ncr_show_msg (np->msgout);
                          printf (".\n");
                  }
                  break;
  
  /*--------------------------------------------------------------------
  **
  **      Processing of special messages
  **
  **--------------------------------------------------------------------
  */
  
          case SIR_REJECT_RECEIVED:
                  /*-----------------------------------------------
                  **
                  **      We received a MSG_MESSAGE_REJECT message.
                  **
                  **-----------------------------------------------
                  */
  
                  PRINT_ADDR(cp->ccb);
                  printf ("MSG_MESSAGE_REJECT received (%x:%x).\n",
                          (unsigned)np->lastmsg, np->msgout[0]);
                  break;
  
          case SIR_REJECT_SENT:
                  /*-----------------------------------------------
                  **
                  **      We received an unknown message
                  **
                  **-----------------------------------------------
                  */
  
                  PRINT_ADDR(cp->ccb);
                  printf ("MSG_MESSAGE_REJECT sent for ");
                  (void) ncr_show_msg (np->msgin);
                  printf (".\n");
                  break;
  
  /*--------------------------------------------------------------------
  **
  **      Processing of special messages
  **
  **--------------------------------------------------------------------
  */
  
          case SIR_IGN_RESIDUE:
                  /*-----------------------------------------------
                  **
                  **      We received an IGNORE RESIDUE message,
                  **      which couldn't be handled by the script.
                  **
                  **-----------------------------------------------
                  */
  
                  PRINT_ADDR(cp->ccb);
                  printf ("MSG_IGN_WIDE_RESIDUE received, but not yet implemented.\n");
                  break;
  
          case SIR_MISSING_SAVE:
                  /*-----------------------------------------------
                  **
                  **      We received an DISCONNECT message,
                  **      but the datapointer wasn't saved before.
                  **
                  **-----------------------------------------------
                  */
  
                  PRINT_ADDR(cp->ccb);
                  printf ("MSG_DISCONNECT received, but datapointer not saved:\n"
                          "\tdata=%x save=%x goal=%x.\n",
                          (unsigned) INL (nc_temp),
                          (unsigned) np->header.savep,
                          (unsigned) np->header.goalp);
                  break;
  
  /*--------------------------------------------------------------------
  **
  **      Processing of a "SCSI_STATUS_QUEUE_FULL" status.
  **
  **      XXX JGibbs - We should do the same thing for BUSY status.
  **
  **      The current command has been rejected,
  **      because there are too many in the command queue.
  **      We have started too many commands for that target.
  **
  **--------------------------------------------------------------------
  */
          case SIR_STALL_QUEUE:
                  cp->xerr_status = XE_OK;
                  cp->host_status = HS_COMPLETE;
                  cp->s_status = SCSI_STATUS_QUEUE_FULL;
                  ncr_freeze_devq(np, cp->ccb->ccb_h.path);
                  ncr_complete(np, cp);
  
                  /* FALL THROUGH */
  
          case SIR_STALL_RESTART:
                  /*-----------------------------------------------
                  **
                  **      Enable selecting again,
                  **      if NO disconnected jobs.
                  **
                  **-----------------------------------------------
                  */
                  /*
                  **      Look for a disconnected job.
                  */
                  cp = np->link_nccb;
                  while (cp && cp->host_status != HS_DISCONNECT)
                          cp = cp->link_nccb;
  
                  /*
                  **      if there is one, ...
                  */
                  if (cp) {
                          /*
                          **      wait for reselection
                          */
                          OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, reselect));
                          return;
                  };
  
                  /*
                  **      else remove the interrupt.
                  */
  
                  printf ("%s: queue empty.\n", ncr_name (np));
                  WRITESCRIPT(start1[0], SCR_INT ^ IFFALSE (0));
                  break;
          };
  
  out:
          OUTB (nc_dcntl, np->rv_dcntl | STD);
  }
  
  /*==========================================================
  **
  **
  **      Aquire a control block
  **
  **
  **==========================================================
  */
  
  static  nccb_p ncr_get_nccb
          (ncb_p np, u_long target, u_long lun)
  {
          lcb_p lp;
          int s;
          nccb_p cp = NULL;
  
          /* Keep our timeout handler out */
          s = splsoftclock();
          
          /*
          **      Lun structure available ?
          */
  
          lp = np->target[target].lp[lun];
          if (lp) {
                  cp = lp->next_nccb;
  
                  /*
                  **      Look for free CCB
                  */
  
                  while (cp && cp->magic) {
                          cp = cp->next_nccb;
                  }
          }
  
          /*
          **      if nothing available, create one.
          */
  
          if (cp == NULL)
                  cp = ncr_alloc_nccb(np, target, lun);
  
          if (cp != NULL) {
                  if (cp->magic) {
                          printf("%s: Bogus free cp found\n", ncr_name(np));
                          splx(s);
                          return (NULL);
                  }
                  cp->magic = 1;
          }
          splx(s);
          return (cp);
  }
  
  /*==========================================================
  **
  **
  **      Release one control block
  **
  **
  **==========================================================
  */
  
  void ncr_free_nccb (ncb_p np, nccb_p cp)
  {
          /*
          **    sanity
          */
  
          assert (cp != NULL);
  
          cp -> host_status = HS_IDLE;
          cp -> magic = 0;
  }
  
  /*==========================================================
  **
  **
  **      Allocation of resources for Targets/Luns/Tags.
  **
  **
  **==========================================================
  */
  
  static nccb_p
  ncr_alloc_nccb (ncb_p np, u_long target, u_long lun)
  {
          tcb_p tp;
          lcb_p lp;
          nccb_p cp;
  
          assert (np != NULL);
  
          if (target>=MAX_TARGET) return(NULL);
          if (lun   >=MAX_LUN   ) return(NULL);
  
          tp=&np->target[target];
  
          if (!tp->jump_tcb.l_cmd) {
  
                  /*
                  **      initialize it.
                  */
                  tp->jump_tcb.l_cmd   = (SCR_JUMP^IFFALSE (DATA (0x80 + target)));
                  tp->jump_tcb.l_paddr = np->jump_tcb.l_paddr;
  
                  tp->getscr[0] =
                          (np->features & FE_PFEN)? SCR_COPY(1) : SCR_COPY_F(1);
                  tp->getscr[1] = vtophys (&tp->tinfo.sval);
                  tp->getscr[2] = rman_get_start(np->reg_res) + offsetof (struct ncr_reg, nc_sxfer);
                  tp->getscr[3] =
                          (np->features & FE_PFEN)? SCR_COPY(1) : SCR_COPY_F(1);
                  tp->getscr[4] = vtophys (&tp->tinfo.wval);
                  tp->getscr[5] = rman_get_start(np->reg_res) + offsetof (struct ncr_reg, nc_scntl3);
  
                  assert (((offsetof(struct ncr_reg, nc_sxfer) ^
                           (offsetof(struct tcb ,tinfo)
                          + offsetof(struct ncr_target_tinfo, sval))) & 3) == 0);
                  assert (((offsetof(struct ncr_reg, nc_scntl3) ^
                           (offsetof(struct tcb, tinfo)
                          + offsetof(struct ncr_target_tinfo, wval))) &3) == 0);
  
                  tp->call_lun.l_cmd   = (SCR_CALL);
                  tp->call_lun.l_paddr = NCB_SCRIPT_PHYS (np, resel_lun);
  
                  tp->jump_lcb.l_cmd   = (SCR_JUMP);
                  tp->jump_lcb.l_paddr = NCB_SCRIPTH_PHYS (np, abort);
                  np->jump_tcb.l_paddr = vtophys (&tp->jump_tcb);
          }
  
          /*
          **      Logic unit control block
          */
          lp = tp->lp[lun];
          if (!lp) {
                  /*
                  **      Allocate a lcb
                  */
                  lp = (lcb_p) malloc (sizeof (struct lcb), M_DEVBUF, M_NOWAIT);
                  if (!lp) return(NULL);
  
                  /*
                  **      Initialize it
                  */
                  bzero (lp, sizeof (*lp));
                  lp->jump_lcb.l_cmd   = (SCR_JUMP ^ IFFALSE (DATA (lun)));
                  lp->jump_lcb.l_paddr = tp->jump_lcb.l_paddr;
  
                  lp->call_tag.l_cmd   = (SCR_CALL);
                  lp->call_tag.l_paddr = NCB_SCRIPT_PHYS (np, resel_tag);
  
                  lp->jump_nccb.l_cmd   = (SCR_JUMP);
                  lp->jump_nccb.l_paddr = NCB_SCRIPTH_PHYS (np, aborttag);
  
                  lp->actlink = 1;
  
                  /*
                  **   Chain into LUN list
                  */
                  tp->jump_lcb.l_paddr = vtophys (&lp->jump_lcb);
                  tp->lp[lun] = lp;
  
          }
  
          /*
          **      Allocate a nccb
          */
          cp = (nccb_p) malloc (sizeof (struct nccb), M_DEVBUF, M_NOWAIT);
  
          if (!cp)
                  return (NULL);
  
          if (DEBUG_FLAGS & DEBUG_ALLOC) { 
                  printf ("new nccb @%p.\n", cp);
          }
  
          /*
          **      Initialize it
          */
          bzero (cp, sizeof (*cp));
  
          /*
          **      Fill in physical addresses
          */
  
          cp->p_nccb           = vtophys (cp);
  
          /*
          **      Chain into reselect list
          */
          cp->jump_nccb.l_cmd   = SCR_JUMP;
          cp->jump_nccb.l_paddr = lp->jump_nccb.l_paddr;
          lp->jump_nccb.l_paddr = CCB_PHYS (cp, jump_nccb);
          cp->call_tmp.l_cmd   = SCR_CALL;
          cp->call_tmp.l_paddr = NCB_SCRIPT_PHYS (np, resel_tmp);
  
          /*
          **      Chain into wakeup list
          */
          cp->link_nccb      = np->link_nccb;
          np->link_nccb      = cp;
  
          /*
          **      Chain into CCB list
          */
          cp->next_nccb   = lp->next_nccb;
          lp->next_nccb   = cp;
  
          return (cp);
  }
  
  /*==========================================================
  **
  **
  **      Build Scatter Gather Block
  **
  **
  **==========================================================
  **
  **      The transfer area may be scattered among
  **      several non adjacent physical pages.
  **
  **      We may use MAX_SCATTER blocks.
  **
  **----------------------------------------------------------
  */
  
  static  int     ncr_scatter
          (struct dsb* phys, vm_offset_t vaddr, vm_size_t datalen)
  {
          u_long  paddr, pnext;
  
          u_short segment  = 0;
          u_long  segsize, segaddr;
          u_long  size, csize    = 0;
          u_long  chunk = MAX_SIZE;
          int     free;
  
          bzero (&phys->data, sizeof (phys->data));
          if (!datalen) return (0);
  
          paddr = vtophys (vaddr);
  
          /*
          **      insert extra break points at a distance of chunk.
          **      We try to reduce the number of interrupts caused
          **      by unexpected phase changes due to disconnects.
          **      A typical harddisk may disconnect before ANY block.
          **      If we wanted to avoid unexpected phase changes at all
          **      we had to use a break point every 512 bytes.
          **      Of course the number of scatter/gather blocks is
          **      limited.
          */
  
          free = MAX_SCATTER - 1;
  
          if (vaddr & PAGE_MASK) free -= datalen / PAGE_SIZE;
  
          if (free>1)
                  while ((chunk * free >= 2 * datalen) && (chunk>=1024))
                          chunk /= 2;
  
          if(DEBUG_FLAGS & DEBUG_SCATTER)
                  printf("ncr?:\tscattering virtual=%p size=%d chunk=%d.\n",
                         (void *) vaddr, (unsigned) datalen, (unsigned) chunk);
  
          /*
          **   Build data descriptors.
          */
          while (datalen && (segment < MAX_SCATTER)) {
  
                  /*
                  **      this segment is empty
                  */
                  segsize = 0;
                  segaddr = paddr;
                  pnext   = paddr;
  
                  if (!csize) csize = chunk;
  
                  while ((datalen) && (paddr == pnext) && (csize)) {
  
                          /*
                          **      continue this segment
                          */
                          pnext = (paddr & (~PAGE_MASK)) + PAGE_SIZE;
  
                          /*
                          **      Compute max size
                          */
  
                          size = pnext - paddr;           /* page size */
                          if (size > datalen) size = datalen;  /* data size */
                          if (size > csize  ) size = csize  ;  /* chunksize */
  
                          segsize += size;
                          vaddr   += size;
                          csize   -= size;
                          datalen -= size;
                          paddr    = vtophys (vaddr);
                  };
  
                  if(DEBUG_FLAGS & DEBUG_SCATTER)
                          printf ("\tseg #%d  addr=%x  size=%d  (rest=%d).\n",
                          segment,
                          (unsigned) segaddr,
                          (unsigned) segsize,
                          (unsigned) datalen);
  
                  phys->data[segment].addr = segaddr;
                  phys->data[segment].size = segsize;
                  segment++;
          }
  
          if (datalen) {
                  printf("ncr?: scatter/gather failed (residue=%d).\n",
                          (unsigned) datalen);
                  return (-1);
          };
  
          return (segment);
  }
  
  /*==========================================================
  **
  **
  **      Test the pci bus snoop logic :-(
  **
  **      Has to be called with interrupts disabled.
  **
  **
  **==========================================================
  */
  
  #ifndef NCR_IOMAPPED
  static int ncr_regtest (struct ncb* np)
  {
          register volatile u_int32_t data;
          /*
          **      ncr 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 ncr_reg, nc_dstat), data);
          data = INL_OFF(offsetof(struct ncr_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 ncr_snooptest (struct ncb* np)
  {
          u_int32_t ncr_rd, ncr_wr, ncr_bk, host_rd, host_wr, pc;
          int     i, err=0;
  #ifndef NCR_IOMAPPED
          err |= ncr_regtest (np);
          if (err) return (err);
  #endif
          /*
          **      init
          */
          pc  = NCB_SCRIPTH_PHYS (np, snooptest);
          host_wr = 1;
          ncr_wr  = 2;
          /*
          **      Set memory and register.
          */
          ncr_cache = host_wr;
          OUTL (nc_temp, ncr_wr);
          /*
          **      Start script (exchange values)
          */
          OUTL (nc_dsp, pc);
          /*
          **      Wait 'til done (with timeout)
          */
          for (i=0; i<NCR_SNOOP_TIMEOUT; i++)
                  if (INB(nc_istat) & (INTF|SIP|DIP))
                          break;
          /*
          **      Save termination position.
          */
          pc = INL (nc_dsp);
          /*
          **      Read memory and register.
          */
          host_rd = ncr_cache;
          ncr_rd  = INL (nc_scratcha);
          ncr_bk  = INL (nc_temp);
          /*
          **      Reset ncr chip
          */
          OUTB (nc_istat,  SRST);
          DELAY (1000);
          OUTB (nc_istat,  0   );
          /*
          **      check for timeout
          */
          if (i>=NCR_SNOOP_TIMEOUT) {
                  printf ("CACHE TEST FAILED: timeout.\n");
                  return (0x20);
          };
          /*
          **      Check termination position.
          */
          if (pc != NCB_SCRIPTH_PHYS (np, snoopend)+8) {
                  printf ("CACHE TEST FAILED: script execution failed.\n");
                  printf ("start=%08lx, pc=%08lx, end=%08lx\n", 
                          (u_long) NCB_SCRIPTH_PHYS (np, snooptest), (u_long) pc,
                          (u_long) NCB_SCRIPTH_PHYS (np, snoopend) +8);
                  return (0x40);
          };
          /*
          **      Show results.
          */
          if (host_wr != ncr_rd) {
                  printf ("CACHE TEST FAILED: host wrote %d, ncr read %d.\n",
                          (int) host_wr, (int) ncr_rd);
                  err |= 1;
          };
          if (host_rd != ncr_wr) {
                  printf ("CACHE TEST FAILED: ncr wrote %d, host read %d.\n",
                          (int) ncr_wr, (int) host_rd);
                  err |= 2;
          };
          if (ncr_bk != ncr_wr) {
                  printf ("CACHE TEST FAILED: ncr wrote %d, read back %d.\n",
                          (int) ncr_wr, (int) ncr_bk);
                  err |= 4;
          };
          return (err);
  }
  
  /*==========================================================
  **
  **
  **      Profiling the drivers and targets performance.
  **
  **
  **==========================================================
  */
  
  /*
  **      Compute the difference in milliseconds.
  **/
  
  static  int ncr_delta (int *from, int *to)
  {
          if (!from) return (-1);
          if (!to)   return (-2);
          return ((to - from) * 1000 / hz);
  }
  
  #define PROFILE  cp->phys.header.stamp
  static  void ncb_profile (ncb_p np, nccb_p cp)
  {
          int co, da, st, en, di, se, post,work,disc;
          u_long diff;
  
          PROFILE.end = ticks;
  
          st = ncr_delta (&PROFILE.start,&PROFILE.status);
          if (st<0) return;       /* status  not reached  */
  
          da = ncr_delta (&PROFILE.start,&PROFILE.data);
          if (da<0) return;       /* No data transfer phase */
  
          co = ncr_delta (&PROFILE.start,&PROFILE.command);
          if (co<0) return;       /* command not executed */
  
          en = ncr_delta (&PROFILE.start,&PROFILE.end),
          di = ncr_delta (&PROFILE.start,&PROFILE.disconnect),
          se = ncr_delta (&PROFILE.start,&PROFILE.select);
          post = en - st;
  
          /*
          **      @PROFILE@  Disconnect time invalid if multiple disconnects
          */
  
          if (di>=0) disc = se-di; else  disc = 0;
  
          work = (st - co) - disc;
  
          diff = (np->disc_phys - np->disc_ref) & 0xff;
          np->disc_ref += diff;
  
          np->profile.num_trans   += 1;
          if (cp->ccb)
                  np->profile.num_bytes   += cp->ccb->csio.dxfer_len;
          np->profile.num_disc    += diff;
          np->profile.ms_setup    += co;
          np->profile.ms_data     += work;
          np->profile.ms_disc     += disc;
          np->profile.ms_post     += post;
  }
  #undef PROFILE
  
  /*==========================================================
  **
  **      Determine the ncr'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 SAVE 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 future fast40 chips (895/895) use a 40 Mhz base clock 
  **      and provide a clock quadrupler (160 Mhz). The code below 
  **      tries to deal as cleverly as possible with all this stuff.
  **
  **----------------------------------------------------------
  */
  
  /*
   *      Select NCR SCSI clock frequency
   */
  static void ncr_selectclock(ncb_p np, u_char scntl3)
  {
          if (np->multiplier < 2) {
                  OUTB(nc_scntl3, scntl3);
                  return;
          }
  
          if (bootverbose >= 2)
                  printf ("%s: enabling clock multiplier\n", ncr_name(np));
  
          OUTB(nc_stest1, DBLEN);    /* Enable clock multiplier             */
          if (np->multiplier > 2) {  /* Poll bit 5 of stest4 for quadrupler */
                  int i = 20;
                  while (!(INB(nc_stest4) & LCKFRQ) && --i > 0)
                          DELAY(20);
                  if (!i)
                          printf("%s: the chip cannot lock the frequency\n", ncr_name(np));
          } else                  /* Wait 20 micro-seconds for doubler    */
                  DELAY(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 NCR SCSI clock frequency (in KHz)
   */
  static unsigned
  ncrgetfreq (ncb_p np, int gen)
  {
          int ms = 0;
          /*
           * 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).
           */
          OUTB (nc_stest1, 0);    /* make sure clock doubler is OFF           */
          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++ < 1000)
                  DELAY(1000);    /* count ms                                 */
          OUTB (nc_stime1, 0);    /* disable general purpose timer            */
          OUTB (nc_scntl3, 0);
          /*
           * Set prescaler to divide by whatever "" means.
           * "" ought to choose divide by 2, but appears
           * to set divide by 3.5 mode in my 53c810 ...
           */
          OUTB (nc_scntl3, 0);
  
          if (bootverbose >= 2)
                  printf ("\tDelay (GEN=%d): %u msec\n", gen, ms);
          /*
           * adjust for prescaler, and convert into KHz 
           */
          return ms ? ((1 << gen) * 4440) / ms : 0;
  }
  
  static void ncr_getclock (ncb_p np, u_char multiplier)
  {
          unsigned char scntl3;
          unsigned char stest1;
          scntl3 = INB(nc_scntl3);
          stest1 = INB(nc_stest1);
            
          np->multiplier = 1;
  
          if (multiplier > 1) {
                  np->multiplier  = multiplier;
                  np->clock_khz   = 40000 * multiplier;
          } else {
                  if ((scntl3 & 7) == 0) {
                          unsigned f1, f2;
                          /* throw away first result */
                          (void) ncrgetfreq (np, 11);
                          f1 = ncrgetfreq (np, 11);
                          f2 = ncrgetfreq (np, 11);
  
                          if (bootverbose >= 2)
                            printf ("\tNCR clock is %uKHz, %uKHz\n", f1, f2);
                          if (f1 > f2) f1 = f2;   /* trust lower result   */
                          if (f1 > 45000) {
                                  scntl3 = 5;     /* >45Mhz: assume 80MHz */
                          } else {
                                  scntl3 = 3;     /* <45Mhz: assume 40MHz */
                          }
                  }
                  else if ((scntl3 & 7) == 5)
                          np->clock_khz = 80000;  /* Probably a 875 rev. 1 ? */
          }
  }
  
  /*=========================================================================*/
  
  #ifdef NCR_TEKRAM_EEPROM
  
  struct tekram_eeprom_dev {
    u_char        devmode;
  #define TKR_PARCHK      0x01
  #define TKR_TRYSYNC     0x02
  #define TKR_ENDISC      0x04
  #define TKR_STARTUNIT   0x08
  #define TKR_USETAGS     0x10
  #define TKR_TRYWIDE     0x20
    u_char        syncparam;      /* max. sync transfer rate (table ?) */
    u_char        filler1;
    u_char        filler2;
  };
  
  
  struct tekram_eeprom {
    struct tekram_eeprom_dev 
                  dev[16];
    u_char        adaptid;
    u_char        adaptmode;
  #define TKR_ADPT_GT2DRV 0x01
  #define TKR_ADPT_GT1GB  0x02
  #define TKR_ADPT_RSTBUS 0x04
  #define TKR_ADPT_ACTNEG 0x08
  #define TKR_ADPT_NOSEEK 0x10
  #define TKR_ADPT_MORLUN 0x20
    u_char        delay;          /* unit ? ( table ??? ) */
    u_char        tags;           /* use 4 times as many ... */
    u_char        filler[60];
  };
  
  static void
  tekram_write_bit (ncb_p np, int bit)
  {
          u_char val = 0x10 + ((bit & 1) << 1);
  
          DELAY(10);
          OUTB (nc_gpreg, val);
          DELAY(10);
          OUTB (nc_gpreg, val | 0x04);
          DELAY(10);
          OUTB (nc_gpreg, val);
          DELAY(10);
  }
  
  static int
  tekram_read_bit (ncb_p np)
  {
          OUTB (nc_gpreg, 0x10);
          DELAY(10);
          OUTB (nc_gpreg, 0x14);
          DELAY(10);
          return INB (nc_gpreg) & 1;
  }
  
  static u_short
  read_tekram_eeprom_reg (ncb_p np, int reg)
  {
          int bit;
          u_short result = 0;
          int cmd = 0x80 | reg;
  
          OUTB (nc_gpreg, 0x10);
  
          tekram_write_bit (np, 1);
          for (bit = 7; bit >= 0; bit--)
          {
                  tekram_write_bit (np, cmd >> bit);
          }
  
          for (bit = 0; bit < 16; bit++)
          {
                  result <<= 1;
                  result |= tekram_read_bit (np);
          }
  
          OUTB (nc_gpreg, 0x00);
          return result;
  }
  
  static int 
  read_tekram_eeprom(ncb_p np, struct tekram_eeprom *buffer)
  {
          u_short *p = (u_short *) buffer;
          u_short sum = 0;
          int i;
  
          if (INB (nc_gpcntl) != 0x09)
          {
                  return 0;
          }
          for (i = 0; i < 64; i++)
          {
                  u_short val;
  if((i&0x0f) == 0) printf ("%02x:", i*2);
                  val = read_tekram_eeprom_reg (np, i);
                  if (p)
                          *p++ = val;
                  sum += val;
  if((i&0x01) == 0x00) printf (" ");
                  printf ("%02x%02x", val & 0xff, (val >> 8) & 0xff);
  if((i&0x0f) == 0x0f) printf ("\n");
          }
  printf ("Sum = %04x\n", sum);
          return sum == 0x1234;
  }
  #endif /* NCR_TEKRAM_EEPROM */
  
  static device_method_t ncr_methods[] = {
          /* Device interface */
          DEVMETHOD(device_probe,         ncr_probe),
          DEVMETHOD(device_attach,        ncr_attach),
  
          { 0, 0 }
  };
  
  static driver_t ncr_driver = {
          "ncr",
          ncr_methods,
          sizeof(struct ncb),
  };
  
  static devclass_t ncr_devclass;
  
  DRIVER_MODULE(if_ncr, pci, ncr_driver, ncr_devclass, 0, 0);
  
  /*=========================================================================*/
  #endif /* _KERNEL */