FreeBSD/Linux Kernel Cross Reference
sys/powerpc/powerpc/pmap.c

     /*
      * Copyright (c) 2001 The NetBSD Foundation, Inc.
      * All rights reserved.
      *
      * This code is derived from software contributed to The NetBSD Foundation
      * by Matt Thomas <matt@3am-software.com> of Allegro Networks, Inc.
      *
      * 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. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *        This product includes software developed by the NetBSD
     *        Foundation, Inc. and its contributors.
     * 4. Neither the name of The NetBSD Foundation nor the names of its
     *    contributors may be used to endorse or promote products derived
     *    from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     * POSSIBILITY OF SUCH DAMAGE.
     */
    /*
     * Copyright (C) 1995, 1996 Wolfgang Solfrank.
     * Copyright (C) 1995, 1996 TooLs GmbH.
     * 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. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by TooLs GmbH.
     * 4. The name of TooLs GmbH may not be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``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 TOOLS GMBH 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.
     *
     * $NetBSD: pmap.c,v 1.28 2000/03/26 20:42:36 kleink Exp $
     */
    /*
     * Copyright (C) 2001 Benno Rice.
     * 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.
     *
     * THIS SOFTWARE IS PROVIDED BY Benno Rice ``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 TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/5.2/sys/powerpc/powerpc/pmap.c 120722 2003-10-03 22:46:53Z alc $");
    
    /*
     * Manages physical address maps.
     *
     * In addition to hardware address maps, this module is called upon to
    * provide software-use-only maps which may or may not be stored in the
    * same form as hardware maps.  These pseudo-maps are used to store
    * intermediate results from copy operations to and from address spaces.
    *
    * Since the information managed by this module is also stored by the
    * logical address mapping module, this module may throw away valid virtual
    * to physical mappings at almost any time.  However, invalidations of
    * mappings must be done as requested.
    *
    * In order to cope with hardware architectures which make virtual to
    * physical map invalidates expensive, this module may delay invalidate
    * reduced protection operations until such time as they are actually
    * necessary.  This module is given full information as to which processors
    * are currently using which maps, and to when physical maps must be made
    * correct.
    */
   
   #include "opt_kstack_pages.h"
   
   #include <sys/param.h>
   #include <sys/kernel.h>
   #include <sys/ktr.h>
   #include <sys/lock.h>
   #include <sys/msgbuf.h>
   #include <sys/mutex.h>
   #include <sys/proc.h>
   #include <sys/sysctl.h>
   #include <sys/systm.h>
   #include <sys/vmmeter.h>
   
   #include <dev/ofw/openfirm.h>
   
   #include <vm/vm.h> 
   #include <vm/vm_param.h>
   #include <vm/vm_kern.h>
   #include <vm/vm_page.h>
   #include <vm/vm_map.h>
   #include <vm/vm_object.h>
   #include <vm/vm_extern.h>
   #include <vm/vm_pageout.h>
   #include <vm/vm_pager.h>
   #include <vm/uma.h>
   
   #include <machine/powerpc.h>
   #include <machine/bat.h>
   #include <machine/frame.h>
   #include <machine/md_var.h>
   #include <machine/psl.h>
   #include <machine/pte.h>
   #include <machine/sr.h>
   
   #define PMAP_DEBUG
   
   #define TODO    panic("%s: not implemented", __func__);
   
   #define PMAP_LOCK(pm)
   #define PMAP_UNLOCK(pm)
   
   #define TLBIE(va)       __asm __volatile("tlbie %0" :: "r"(va))
   #define TLBSYNC()       __asm __volatile("tlbsync");
   #define SYNC()          __asm __volatile("sync");
   #define EIEIO()         __asm __volatile("eieio");
   
   #define VSID_MAKE(sr, hash)     ((sr) | (((hash) & 0xfffff) << 4))
   #define VSID_TO_SR(vsid)        ((vsid) & 0xf)
   #define VSID_TO_HASH(vsid)      (((vsid) >> 4) & 0xfffff)
   
   #define PVO_PTEGIDX_MASK        0x0007          /* which PTEG slot */
   #define PVO_PTEGIDX_VALID       0x0008          /* slot is valid */
   #define PVO_WIRED               0x0010          /* PVO entry is wired */
   #define PVO_MANAGED             0x0020          /* PVO entry is managed */
   #define PVO_EXECUTABLE          0x0040          /* PVO entry is executable */
   #define PVO_BOOTSTRAP           0x0080          /* PVO entry allocated during
                                                      bootstrap */
   #define PVO_VADDR(pvo)          ((pvo)->pvo_vaddr & ~ADDR_POFF)
   #define PVO_ISEXECUTABLE(pvo)   ((pvo)->pvo_vaddr & PVO_EXECUTABLE)
   #define PVO_PTEGIDX_GET(pvo)    ((pvo)->pvo_vaddr & PVO_PTEGIDX_MASK)
   #define PVO_PTEGIDX_ISSET(pvo)  ((pvo)->pvo_vaddr & PVO_PTEGIDX_VALID)
   #define PVO_PTEGIDX_CLR(pvo)    \
           ((void)((pvo)->pvo_vaddr &= ~(PVO_PTEGIDX_VALID|PVO_PTEGIDX_MASK)))
   #define PVO_PTEGIDX_SET(pvo, i) \
           ((void)((pvo)->pvo_vaddr |= (i)|PVO_PTEGIDX_VALID))
   
   #define PMAP_PVO_CHECK(pvo)
   
   struct ofw_map {
           vm_offset_t     om_va;
           vm_size_t       om_len;
           vm_offset_t     om_pa;
           u_int           om_mode;
   };
   
   int     pmap_bootstrapped = 0;
   
   /*
    * Virtual and physical address of message buffer.
    */
   struct          msgbuf *msgbufp;
   vm_offset_t     msgbuf_phys;
   
   /*
    * Physical addresses of first and last available physical page.
    */
   vm_offset_t avail_start;
   vm_offset_t avail_end;
   
   int pmap_pagedaemon_waken;
   
   /*
    * Map of physical memory regions.
    */
   vm_offset_t     phys_avail[128];
   u_int           phys_avail_count;
   static struct   mem_region *regions;
   static struct   mem_region *pregions;
   int             regions_sz, pregions_sz;
   static struct   ofw_map *translations;
   
   /*
    * First and last available kernel virtual addresses.
    */
   vm_offset_t virtual_avail;
   vm_offset_t virtual_end;
   vm_offset_t kernel_vm_end;
   
   /*
    * Kernel pmap.
    */
   struct pmap kernel_pmap_store;
   extern struct pmap ofw_pmap;
   
   /*
    * PTEG data.
    */
   static struct   pteg *pmap_pteg_table;
   u_int           pmap_pteg_count;
   u_int           pmap_pteg_mask;
   
   /*
    * PVO data.
    */
   struct  pvo_head *pmap_pvo_table;               /* pvo entries by pteg index */
   struct  pvo_head pmap_pvo_kunmanaged =
       LIST_HEAD_INITIALIZER(pmap_pvo_kunmanaged); /* list of unmanaged pages */
   struct  pvo_head pmap_pvo_unmanaged =
       LIST_HEAD_INITIALIZER(pmap_pvo_unmanaged);  /* list of unmanaged pages */
   
   uma_zone_t      pmap_upvo_zone; /* zone for pvo entries for unmanaged pages */
   uma_zone_t      pmap_mpvo_zone; /* zone for pvo entries for managed pages */
   struct          vm_object pmap_upvo_zone_obj;
   struct          vm_object pmap_mpvo_zone_obj;
   
   #define BPVO_POOL_SIZE  32768
   static struct   pvo_entry *pmap_bpvo_pool;
   static int      pmap_bpvo_pool_index = 0;
   
   #define VSID_NBPW       (sizeof(u_int32_t) * 8)
   static u_int    pmap_vsid_bitmap[NPMAPS / VSID_NBPW];
   
   static boolean_t pmap_initialized = FALSE;
   
   /*
    * Statistics.
    */
   u_int   pmap_pte_valid = 0;
   u_int   pmap_pte_overflow = 0;
   u_int   pmap_pte_replacements = 0;
   u_int   pmap_pvo_entries = 0;
   u_int   pmap_pvo_enter_calls = 0;
   u_int   pmap_pvo_remove_calls = 0;
   u_int   pmap_pte_spills = 0;
   SYSCTL_INT(_machdep, OID_AUTO, pmap_pte_valid, CTLFLAG_RD, &pmap_pte_valid,
       0, "");
   SYSCTL_INT(_machdep, OID_AUTO, pmap_pte_overflow, CTLFLAG_RD,
       &pmap_pte_overflow, 0, "");
   SYSCTL_INT(_machdep, OID_AUTO, pmap_pte_replacements, CTLFLAG_RD,
       &pmap_pte_replacements, 0, "");
   SYSCTL_INT(_machdep, OID_AUTO, pmap_pvo_entries, CTLFLAG_RD, &pmap_pvo_entries,
       0, "");
   SYSCTL_INT(_machdep, OID_AUTO, pmap_pvo_enter_calls, CTLFLAG_RD,
       &pmap_pvo_enter_calls, 0, "");
   SYSCTL_INT(_machdep, OID_AUTO, pmap_pvo_remove_calls, CTLFLAG_RD,
       &pmap_pvo_remove_calls, 0, "");
   SYSCTL_INT(_machdep, OID_AUTO, pmap_pte_spills, CTLFLAG_RD,
       &pmap_pte_spills, 0, "");
   
   struct  pvo_entry *pmap_pvo_zeropage;
   
   vm_offset_t     pmap_rkva_start = VM_MIN_KERNEL_ADDRESS;
   u_int           pmap_rkva_count = 4;
   
   /*
    * Allocate physical memory for use in pmap_bootstrap.
    */
   static vm_offset_t      pmap_bootstrap_alloc(vm_size_t, u_int);
   
   /*
    * PTE calls.
    */
   static int              pmap_pte_insert(u_int, struct pte *);
   
   /*
    * PVO calls.
    */
   static int      pmap_pvo_enter(pmap_t, uma_zone_t, struct pvo_head *,
                       vm_offset_t, vm_offset_t, u_int, int);
   static void     pmap_pvo_remove(struct pvo_entry *, int);
   static struct   pvo_entry *pmap_pvo_find_va(pmap_t, vm_offset_t, int *);
   static struct   pte *pmap_pvo_to_pte(const struct pvo_entry *, int);
   
   /*
    * Utility routines.
    */
   static void *           pmap_pvo_allocf(uma_zone_t, int, u_int8_t *, int);
   static struct           pvo_entry *pmap_rkva_alloc(void);
   static void             pmap_pa_map(struct pvo_entry *, vm_offset_t,
                               struct pte *, int *);
   static void             pmap_pa_unmap(struct pvo_entry *, struct pte *, int *);
   static void             pmap_syncicache(vm_offset_t, vm_size_t);
   static boolean_t        pmap_query_bit(vm_page_t, int);
   static u_int            pmap_clear_bit(vm_page_t, int, int *);
   static void             tlbia(void);
   
   static __inline int
   va_to_sr(u_int *sr, vm_offset_t va)
   {
           return (sr[(uintptr_t)va >> ADDR_SR_SHFT]);
   }
   
   static __inline u_int
   va_to_pteg(u_int sr, vm_offset_t addr)
   {
           u_int hash;
   
           hash = (sr & SR_VSID_MASK) ^ (((u_int)addr & ADDR_PIDX) >>
               ADDR_PIDX_SHFT);
           return (hash & pmap_pteg_mask);
   }
   
   static __inline struct pvo_head *
   pa_to_pvoh(vm_offset_t pa, vm_page_t *pg_p)
   {
           struct  vm_page *pg;
   
           pg = PHYS_TO_VM_PAGE(pa);
   
           if (pg_p != NULL)
                   *pg_p = pg;
   
           if (pg == NULL)
                   return (&pmap_pvo_unmanaged);
   
           return (&pg->md.mdpg_pvoh);
   }
   
   static __inline struct pvo_head *
   vm_page_to_pvoh(vm_page_t m)
   {
   
           return (&m->md.mdpg_pvoh);
   }
   
   static __inline void
   pmap_attr_clear(vm_page_t m, int ptebit)
   {
   
           m->md.mdpg_attrs &= ~ptebit;
   }
   
   static __inline int
   pmap_attr_fetch(vm_page_t m)
   {
   
           return (m->md.mdpg_attrs);
   }
   
   static __inline void
   pmap_attr_save(vm_page_t m, int ptebit)
   {
   
           m->md.mdpg_attrs |= ptebit;
   }
   
   static __inline int
   pmap_pte_compare(const struct pte *pt, const struct pte *pvo_pt)
   {
           if (pt->pte_hi == pvo_pt->pte_hi)
                   return (1);
   
           return (0);
   }
   
   static __inline int
   pmap_pte_match(struct pte *pt, u_int sr, vm_offset_t va, int which)
   {
           return (pt->pte_hi & ~PTE_VALID) ==
               (((sr & SR_VSID_MASK) << PTE_VSID_SHFT) |
               ((va >> ADDR_API_SHFT) & PTE_API) | which);
   }
   
   static __inline void
   pmap_pte_create(struct pte *pt, u_int sr, vm_offset_t va, u_int pte_lo)
   {
           /*
            * Construct a PTE.  Default to IMB initially.  Valid bit only gets
            * set when the real pte is set in memory.
            *
            * Note: Don't set the valid bit for correct operation of tlb update.
            */
           pt->pte_hi = ((sr & SR_VSID_MASK) << PTE_VSID_SHFT) |
               (((va & ADDR_PIDX) >> ADDR_API_SHFT) & PTE_API);
           pt->pte_lo = pte_lo;
   }
   
   static __inline void
   pmap_pte_synch(struct pte *pt, struct pte *pvo_pt)
   {
   
           pvo_pt->pte_lo |= pt->pte_lo & (PTE_REF | PTE_CHG);
   }
   
   static __inline void
   pmap_pte_clear(struct pte *pt, vm_offset_t va, int ptebit)
   {
   
           /*
            * As shown in Section 7.6.3.2.3
            */
           pt->pte_lo &= ~ptebit;
           TLBIE(va);
           EIEIO();
           TLBSYNC();
           SYNC();
   }
   
   static __inline void
   pmap_pte_set(struct pte *pt, struct pte *pvo_pt)
   {
   
           pvo_pt->pte_hi |= PTE_VALID;
   
           /*
            * Update the PTE as defined in section 7.6.3.1.
            * Note that the REF/CHG bits are from pvo_pt and thus should havce
            * been saved so this routine can restore them (if desired).
            */
           pt->pte_lo = pvo_pt->pte_lo;
           EIEIO();
           pt->pte_hi = pvo_pt->pte_hi;
           SYNC();
           pmap_pte_valid++;
   }
   
   static __inline void
   pmap_pte_unset(struct pte *pt, struct pte *pvo_pt, vm_offset_t va)
   {
   
           pvo_pt->pte_hi &= ~PTE_VALID;
   
           /*
            * Force the reg & chg bits back into the PTEs.
            */
           SYNC();
   
           /*
            * Invalidate the pte.
            */
           pt->pte_hi &= ~PTE_VALID;
   
           SYNC();
           TLBIE(va);
           EIEIO();
           TLBSYNC();
           SYNC();
   
           /*
            * Save the reg & chg bits.
            */
           pmap_pte_synch(pt, pvo_pt);
           pmap_pte_valid--;
   }
   
   static __inline void
   pmap_pte_change(struct pte *pt, struct pte *pvo_pt, vm_offset_t va)
   {
   
           /*
            * Invalidate the PTE
            */
           pmap_pte_unset(pt, pvo_pt, va);
           pmap_pte_set(pt, pvo_pt);
   }
   
   /*
    * Quick sort callout for comparing memory regions.
    */
   static int      mr_cmp(const void *a, const void *b);
   static int      om_cmp(const void *a, const void *b);
   
   static int
   mr_cmp(const void *a, const void *b)
   {
           const struct    mem_region *regiona;
           const struct    mem_region *regionb;
   
           regiona = a;
           regionb = b;
           if (regiona->mr_start < regionb->mr_start)
                   return (-1);
           else if (regiona->mr_start > regionb->mr_start)
                   return (1);
           else
                   return (0);
   }
   
   static int
   om_cmp(const void *a, const void *b)
   {
           const struct    ofw_map *mapa;
           const struct    ofw_map *mapb;
   
           mapa = a;
           mapb = b;
           if (mapa->om_pa < mapb->om_pa)
                   return (-1);
           else if (mapa->om_pa > mapb->om_pa)
                   return (1);
           else
                   return (0);
   }
   
   void
   pmap_bootstrap(vm_offset_t kernelstart, vm_offset_t kernelend)
   {
           ihandle_t       mmui;
           phandle_t       chosen, mmu;
           int             sz;
           int             i, j;
           int             ofw_mappings;
           vm_size_t       size, physsz;
           vm_offset_t     pa, va, off;
           u_int           batl, batu;
   
           /*
            * Set up BAT0 to map the lowest 256 MB area
            */
           battable[0x0].batl = BATL(0x00000000, BAT_M, BAT_PP_RW);
           battable[0x0].batu = BATU(0x00000000, BAT_BL_256M, BAT_Vs);
   
           /*
            * Map PCI memory space.
            */
           battable[0x8].batl = BATL(0x80000000, BAT_I|BAT_G, BAT_PP_RW);
           battable[0x8].batu = BATU(0x80000000, BAT_BL_256M, BAT_Vs);
   
           battable[0x9].batl = BATL(0x90000000, BAT_I|BAT_G, BAT_PP_RW);
           battable[0x9].batu = BATU(0x90000000, BAT_BL_256M, BAT_Vs);
   
           battable[0xa].batl = BATL(0xa0000000, BAT_I|BAT_G, BAT_PP_RW);
           battable[0xa].batu = BATU(0xa0000000, BAT_BL_256M, BAT_Vs);
   
           battable[0xb].batl = BATL(0xb0000000, BAT_I|BAT_G, BAT_PP_RW);
           battable[0xb].batu = BATU(0xb0000000, BAT_BL_256M, BAT_Vs);
   
           /*
            * Map obio devices.
            */
           battable[0xf].batl = BATL(0xf0000000, BAT_I|BAT_G, BAT_PP_RW);
           battable[0xf].batu = BATU(0xf0000000, BAT_BL_256M, BAT_Vs);
   
           /*
            * Use an IBAT and a DBAT to map the bottom segment of memory
            * where we are.
            */
           batu = BATU(0x00000000, BAT_BL_256M, BAT_Vs);
           batl = BATL(0x00000000, BAT_M, BAT_PP_RW);
           __asm ("mtibatu 0,%0; mtibatl 0,%1; mtdbatu 0,%0; mtdbatl 0,%1"
               :: "r"(batu), "r"(batl));
   
   #if 0
           /* map frame buffer */
           batu = BATU(0x90000000, BAT_BL_256M, BAT_Vs);
           batl = BATL(0x90000000, BAT_I|BAT_G, BAT_PP_RW);
           __asm ("mtdbatu 1,%0; mtdbatl 1,%1"
               :: "r"(batu), "r"(batl));
   #endif
   
   #if 1
           /* map pci space */
           batu = BATU(0x80000000, BAT_BL_256M, BAT_Vs);
           batl = BATL(0x80000000, BAT_I|BAT_G, BAT_PP_RW);
           __asm ("mtdbatu 1,%0; mtdbatl 1,%1"
               :: "r"(batu), "r"(batl));
   #endif
   
           /*
            * Set the start and end of kva.
            */
           virtual_avail = VM_MIN_KERNEL_ADDRESS;
           virtual_end = VM_MAX_KERNEL_ADDRESS;
   
           mem_regions(&pregions, &pregions_sz, &regions, &regions_sz);
           CTR0(KTR_PMAP, "pmap_bootstrap: physical memory");
   
           qsort(pregions, pregions_sz, sizeof(*pregions), mr_cmp);
           for (i = 0; i < pregions_sz; i++) {
                   vm_offset_t pa;
                   vm_offset_t end;
   
                   CTR3(KTR_PMAP, "physregion: %#x - %#x (%#x)",
                           pregions[i].mr_start,
                           pregions[i].mr_start + pregions[i].mr_size,
                           pregions[i].mr_size);
                   /*
                    * Install entries into the BAT table to allow all
                    * of physmem to be convered by on-demand BAT entries.
                    * The loop will sometimes set the same battable element
                    * twice, but that's fine since they won't be used for
                    * a while yet.
                    */
                   pa = pregions[i].mr_start & 0xf0000000;
                   end = pregions[i].mr_start + pregions[i].mr_size;
                   do {
                           u_int n = pa >> ADDR_SR_SHFT;
                           
                           battable[n].batl = BATL(pa, BAT_M, BAT_PP_RW);
                           battable[n].batu = BATU(pa, BAT_BL_256M, BAT_Vs);
                           pa += SEGMENT_LENGTH;
                   } while (pa < end);
           }
   
           if (sizeof(phys_avail)/sizeof(phys_avail[0]) < regions_sz)
                   panic("pmap_bootstrap: phys_avail too small");
           qsort(regions, regions_sz, sizeof(*regions), mr_cmp);
           phys_avail_count = 0;
           physsz = 0;
           for (i = 0, j = 0; i < regions_sz; i++, j += 2) {
                   CTR3(KTR_PMAP, "region: %#x - %#x (%#x)", regions[i].mr_start,
                       regions[i].mr_start + regions[i].mr_size,
                       regions[i].mr_size);
                   phys_avail[j] = regions[i].mr_start;
                   phys_avail[j + 1] = regions[i].mr_start + regions[i].mr_size;
                   phys_avail_count++;
                   physsz += regions[i].mr_size;
           }
           physmem = btoc(physsz);
   
           /*
            * Allocate PTEG table.
            */
   #ifdef PTEGCOUNT
           pmap_pteg_count = PTEGCOUNT;
   #else
           pmap_pteg_count = 0x1000;
   
           while (pmap_pteg_count < physmem)
                   pmap_pteg_count <<= 1;
   
           pmap_pteg_count >>= 1;
   #endif /* PTEGCOUNT */
   
           size = pmap_pteg_count * sizeof(struct pteg);
           CTR2(KTR_PMAP, "pmap_bootstrap: %d PTEGs, %d bytes", pmap_pteg_count,
               size);
           pmap_pteg_table = (struct pteg *)pmap_bootstrap_alloc(size, size);
           CTR1(KTR_PMAP, "pmap_bootstrap: PTEG table at %p", pmap_pteg_table);
           bzero((void *)pmap_pteg_table, pmap_pteg_count * sizeof(struct pteg));
           pmap_pteg_mask = pmap_pteg_count - 1;
   
           /*
            * Allocate pv/overflow lists.
            */
           size = sizeof(struct pvo_head) * pmap_pteg_count;
           pmap_pvo_table = (struct pvo_head *)pmap_bootstrap_alloc(size,
               PAGE_SIZE);
           CTR1(KTR_PMAP, "pmap_bootstrap: PVO table at %p", pmap_pvo_table);
           for (i = 0; i < pmap_pteg_count; i++)
                   LIST_INIT(&pmap_pvo_table[i]);
   
           /*
            * Allocate the message buffer.
            */
           msgbuf_phys = pmap_bootstrap_alloc(MSGBUF_SIZE, 0);
   
           /*
            * Initialise the unmanaged pvo pool.
            */
           pmap_bpvo_pool = (struct pvo_entry *)pmap_bootstrap_alloc(
                   BPVO_POOL_SIZE*sizeof(struct pvo_entry), 0);
           pmap_bpvo_pool_index = 0;
   
           /*
            * Make sure kernel vsid is allocated as well as VSID 0.
            */
           pmap_vsid_bitmap[(KERNEL_VSIDBITS & (NPMAPS - 1)) / VSID_NBPW]
                   |= 1 << (KERNEL_VSIDBITS % VSID_NBPW);
           pmap_vsid_bitmap[0] |= 1;
   
           /*
            * Set up the OpenFirmware pmap and add it's mappings.
            */
           pmap_pinit(&ofw_pmap);
           ofw_pmap.pm_sr[KERNEL_SR] = KERNEL_SEGMENT;
           if ((chosen = OF_finddevice("/chosen")) == -1)
                   panic("pmap_bootstrap: can't find /chosen");
           OF_getprop(chosen, "mmu", &mmui, 4);
           if ((mmu = OF_instance_to_package(mmui)) == -1)
                   panic("pmap_bootstrap: can't get mmu package");
           if ((sz = OF_getproplen(mmu, "translations")) == -1)
                   panic("pmap_bootstrap: can't get ofw translation count");
           translations = NULL;
           for (i = 0; phys_avail[i + 2] != 0; i += 2) {
                   if (phys_avail[i + 1] >= sz)
                           translations = (struct ofw_map *)phys_avail[i];
           }
           if (translations == NULL)
                   panic("pmap_bootstrap: no space to copy translations");
           bzero(translations, sz);
           if (OF_getprop(mmu, "translations", translations, sz) == -1)
                   panic("pmap_bootstrap: can't get ofw translations");
           CTR0(KTR_PMAP, "pmap_bootstrap: translations");
           sz /= sizeof(*translations);
           qsort(translations, sz, sizeof (*translations), om_cmp);
           for (i = 0, ofw_mappings = 0; i < sz; i++) {
                   CTR3(KTR_PMAP, "translation: pa=%#x va=%#x len=%#x",
                       translations[i].om_pa, translations[i].om_va,
                       translations[i].om_len);
   
                   /*
                    * If the mapping is 1:1, let the RAM and device on-demand
                    * BAT tables take care of the translation.
                    */
                   if (translations[i].om_va == translations[i].om_pa)
                           continue;
   
                   /* Enter the pages */
                   for (off = 0; off < translations[i].om_len; off += PAGE_SIZE) {
                           struct  vm_page m;
   
                           m.phys_addr = translations[i].om_pa + off;
                           pmap_enter(&ofw_pmap, translations[i].om_va + off, &m,
                                      VM_PROT_ALL, 1);
                           ofw_mappings++;
                   }
           }
   #ifdef SMP
           TLBSYNC();
   #endif
   
           /*
            * Initialize the kernel pmap (which is statically allocated).
            */
           for (i = 0; i < 16; i++) {
                   kernel_pmap->pm_sr[i] = EMPTY_SEGMENT;
           }
           kernel_pmap->pm_sr[KERNEL_SR] = KERNEL_SEGMENT;
           kernel_pmap->pm_active = ~0;
   
           /*
            * Allocate a kernel stack with a guard page for thread0 and map it
            * into the kernel page map.
            */
           pa = pmap_bootstrap_alloc(KSTACK_PAGES * PAGE_SIZE, 0);
           kstack0_phys = pa;
           kstack0 = virtual_avail + (KSTACK_GUARD_PAGES * PAGE_SIZE);
           CTR2(KTR_PMAP, "pmap_bootstrap: kstack0 at %#x (%#x)", kstack0_phys,
               kstack0);
           virtual_avail += (KSTACK_PAGES + KSTACK_GUARD_PAGES) * PAGE_SIZE;
           for (i = 0; i < KSTACK_PAGES; i++) {
                   pa = kstack0_phys + i * PAGE_SIZE;
                   va = kstack0 + i * PAGE_SIZE;
                   pmap_kenter(va, pa);
                   TLBIE(va);
           }
   
           /*
            * Calculate the first and last available physical addresses.
            */
           avail_start = phys_avail[0];
           for (i = 0; phys_avail[i + 2] != 0; i += 2)
                   ;
           avail_end = phys_avail[i + 1];
           Maxmem = powerpc_btop(avail_end);
   
           /*
            * Allocate virtual address space for the message buffer.
            */
           msgbufp = (struct msgbuf *)virtual_avail;
           virtual_avail += round_page(MSGBUF_SIZE);
   
           /*
            * Initialize hardware.
            */
           for (i = 0; i < 16; i++) {
                   mtsrin(i << ADDR_SR_SHFT, EMPTY_SEGMENT);
           }
           __asm __volatile ("mtsr %0,%1"
               :: "n"(KERNEL_SR), "r"(KERNEL_SEGMENT));
           __asm __volatile ("sync; mtsdr1 %0; isync"
               :: "r"((u_int)pmap_pteg_table | (pmap_pteg_mask >> 10)));
           tlbia();
   
           pmap_bootstrapped++;
   }
   
   /*
    * Activate a user pmap.  The pmap must be activated before it's address
    * space can be accessed in any way.
    */
   void
   pmap_activate(struct thread *td)
   {
           pmap_t  pm, pmr;
   
           /*
            * Load all the data we need up front to encourage the compiler to
            * not issue any loads while we have interrupts disabled below.
            */
           pm = &td->td_proc->p_vmspace->vm_pmap;
   
           if ((pmr = (pmap_t)pmap_kextract((vm_offset_t)pm)) == NULL)
                   pmr = pm;
   
           pm->pm_active |= PCPU_GET(cpumask);
           PCPU_SET(curpmap, pmr);
   }
   
   void
   pmap_deactivate(struct thread *td)
   {
           pmap_t  pm;
   
           pm = &td->td_proc->p_vmspace->vm_pmap;
           pm->pm_active &= ~(PCPU_GET(cpumask));
           PCPU_SET(curpmap, NULL);
   }
   
   vm_offset_t
   pmap_addr_hint(vm_object_t object, vm_offset_t va, vm_size_t size)
   {
   
           return (va);
   }
   
   void
   pmap_change_wiring(pmap_t pm, vm_offset_t va, boolean_t wired)
   {
           struct  pvo_entry *pvo;
   
           pvo = pmap_pvo_find_va(pm, va & ~ADDR_POFF, NULL);
   
           if (pvo != NULL) {
                   if (wired) {
                           if ((pvo->pvo_vaddr & PVO_WIRED) == 0)
                                   pm->pm_stats.wired_count++;
                           pvo->pvo_vaddr |= PVO_WIRED;
                   } else {
                           if ((pvo->pvo_vaddr & PVO_WIRED) != 0)
                                   pm->pm_stats.wired_count--;
                           pvo->pvo_vaddr &= ~PVO_WIRED;
                   }
           }
   }
   
   void
   pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr,
             vm_size_t len, vm_offset_t src_addr)
   {
   
           /*
            * This is not needed as it's mainly an optimisation.
            * It may want to be implemented later though.
            */
   }
   
   void
   pmap_copy_page(vm_page_t msrc, vm_page_t mdst)
   {
           vm_offset_t     dst;
           vm_offset_t     src;
   
           dst = VM_PAGE_TO_PHYS(mdst);
           src = VM_PAGE_TO_PHYS(msrc);
   
           kcopy((void *)src, (void *)dst, PAGE_SIZE);
   }
   
   /*
    * Zero a page of physical memory by temporarily mapping it into the tlb.
    */
   void
   pmap_zero_page(vm_page_t m)
   {
           vm_offset_t pa = VM_PAGE_TO_PHYS(m);
           caddr_t va;
   
           if (pa < SEGMENT_LENGTH) {
                   va = (caddr_t) pa;
           } else if (pmap_initialized) {
                   if (pmap_pvo_zeropage == NULL)
                           pmap_pvo_zeropage = pmap_rkva_alloc();
                   pmap_pa_map(pmap_pvo_zeropage, pa, NULL, NULL);
                   va = (caddr_t)PVO_VADDR(pmap_pvo_zeropage);
           } else {
                   panic("pmap_zero_page: can't zero pa %#x", pa);
           }
   
           bzero(va, PAGE_SIZE);
   
           if (pa >= SEGMENT_LENGTH)
                   pmap_pa_unmap(pmap_pvo_zeropage, NULL, NULL);
   }
   
   void
   pmap_zero_page_area(vm_page_t m, int off, int size)
   {
           vm_offset_t pa = VM_PAGE_TO_PHYS(m);
           caddr_t va;
   
           if (pa < SEGMENT_LENGTH) {
                   va = (caddr_t) pa;
           } else if (pmap_initialized) {
                   if (pmap_pvo_zeropage == NULL)
                           pmap_pvo_zeropage = pmap_rkva_alloc();
                   pmap_pa_map(pmap_pvo_zeropage, pa, NULL, NULL);
                   va = (caddr_t)PVO_VADDR(pmap_pvo_zeropage);
           } else {
                   panic("pmap_zero_page: can't zero pa %#x", pa);
           }
   
           bzero(va + off, size);
   
           if (pa >= SEGMENT_LENGTH)
                   pmap_pa_unmap(pmap_pvo_zeropage, NULL, NULL);
   }
   
   void
   pmap_zero_page_idle(vm_page_t m)
   {
   
           /* XXX this is called outside of Giant, is pmap_zero_page safe? */
           /* XXX maybe have a dedicated mapping for this to avoid the problem? */
           mtx_lock(&Giant);
           pmap_zero_page(m);
           mtx_unlock(&Giant);
   }
   
   /*
    * Map the given physical page at the specified virtual address in the
    * target pmap with the protection requested.  If specified the page
    * will be wired down.
    */
   void
   pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
              boolean_t wired)
   {
           struct          pvo_head *pvo_head;
           uma_zone_t      zone;
           vm_page_t       pg;
           u_int           pte_lo, pvo_flags, was_exec, i;
           int             error;
   
           if (!pmap_initialized) {
                   pvo_head = &pmap_pvo_kunmanaged;
                   zone = pmap_upvo_zone;
                   pvo_flags = 0;
                   pg = NULL;
                   was_exec = PTE_EXEC;
           } else {
                   pvo_head = vm_page_to_pvoh(m);
                   pg = m;
                   zone = pmap_mpvo_zone;
                   pvo_flags = PVO_MANAGED;
                   was_exec = 0;
           }
   
           /*
            * If this is a managed page, and it's the first reference to the page,
            * clear the execness of the page.  Otherwise fetch the execness.
            */
           if (pg != NULL) {
                   if (LIST_EMPTY(pvo_head)) {
                           pmap_attr_clear(pg, PTE_EXEC);
                   } else {
                           was_exec = pmap_attr_fetch(pg) & PTE_EXEC;
                   }
           }
   
   
           /*
            * Assume the page is cache inhibited and access is guarded unless
            * it's in our available memory array.
            */
           pte_lo = PTE_I | PTE_G;
           for (i = 0; i < pregions_sz; i++) {
                   if ((VM_PAGE_TO_PHYS(m) >= pregions[i].mr_start) &&
                       (VM_PAGE_TO_PHYS(m) < 
                           (pregions[i].mr_start + pregions[i].mr_size))) {
                           pte_lo &= ~(PTE_I | PTE_G);
                           break;
                  }
          }
  
          if (prot & VM_PROT_WRITE)
                  pte_lo |= PTE_BW;
          else
                  pte_lo |= PTE_BR;
  
          pvo_flags |= (prot & VM_PROT_EXECUTE);
  
          if (wired)
                  pvo_flags |= PVO_WIRED;
  
          error = pmap_pvo_enter(pmap, zone, pvo_head, va, VM_PAGE_TO_PHYS(m),
              pte_lo, pvo_flags);
  
          /*
           * Flush the real page from the instruction cache if this page is
           * mapped executable and cacheable and was not previously mapped (or
           * was not mapped executable).
           */
          if (error == 0 && (pvo_flags & PVO_EXECUTABLE) &&
              (pte_lo & PTE_I) == 0 && was_exec == 0) {
                  /*
                   * Flush the real memory from the cache.
                   */
                  pmap_syncicache(VM_PAGE_TO_PHYS(m), PAGE_SIZE);
                  if (pg != NULL)
                          pmap_attr_save(pg, PTE_EXEC);
          }
  
          /* XXX syncicache always until problems are sorted */
          pmap_syncicache(VM_PAGE_TO_PHYS(m), PAGE_SIZE);
  }
  
  vm_page_t
  pmap_enter_quick(pmap_t pm, vm_offset_t va, vm_page_t m, vm_page_t mpte)
  {
  
          pmap_enter(pm, va, m, VM_PROT_READ | VM_PROT_EXECUTE, FALSE);
          return (NULL);
  }
  
  vm_offset_t
  pmap_extract(pmap_t pm, vm_offset_t va)
  {
          struct  pvo_entry *pvo;
  
          pvo = pmap_pvo_find_va(pm, va & ~ADDR_POFF, NULL);
  
          if (pvo != NULL) {
                  return ((pvo->pvo_pte.pte_lo & PTE_RPGN) | (va & ADDR_POFF));
          }
  
          return (0);
  }
  
  /*
   * Atomically extract and hold the physical page with the given
   * pmap and virtual address pair if that mapping permits the given
   * protection.
   */
  vm_page_t
  pmap_extract_and_hold(pmap_t pmap, vm_offset_t va, vm_prot_t prot)
  {
          vm_paddr_t pa;
          vm_page_t m;
          
          m = NULL;
          mtx_lock(&Giant);
          if ((pa = pmap_extract(pmap, va)) != 0) {
                  m = PHYS_TO_VM_PAGE(pa);
                  vm_page_lock_queues();
                  vm_page_hold(m);
                  vm_page_unlock_queues();
          }
          mtx_unlock(&Giant);
          return (m);
  }
  
  /*
   * Grow the number of kernel page table entries.  Unneeded.
   */
  void
  pmap_growkernel(vm_offset_t addr)
  {
  }
  
  void
  pmap_init(vm_offset_t phys_start, vm_offset_t phys_end)
  {
  
          CTR0(KTR_PMAP, "pmap_init");
  
          pmap_upvo_zone = uma_zcreate("UPVO entry", sizeof (struct pvo_entry),
              NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM | UMA_ZONE_NOFREE);
          uma_zone_set_allocf(pmap_upvo_zone, pmap_pvo_allocf);
          pmap_mpvo_zone = uma_zcreate("MPVO entry", sizeof(struct pvo_entry),
              NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM | UMA_ZONE_NOFREE);
          uma_zone_set_allocf(pmap_mpvo_zone, pmap_pvo_allocf);
          pmap_initialized = TRUE;
  }
  
  void
  pmap_init2(void)
  {
  
          CTR0(KTR_PMAP, "pmap_init2");
  }
  
  boolean_t
  pmap_is_modified(vm_page_t m)
  {
  
          if ((m->flags & (PG_FICTITIOUS |PG_UNMANAGED)) != 0)
                  return (FALSE);
  
          return (pmap_query_bit(m, PTE_CHG));
  }
  
  /*
   *      pmap_is_prefaultable:
   *
   *      Return whether or not the specified virtual address is elgible
   *      for prefault.
   */
  boolean_t
  pmap_is_prefaultable(pmap_t pmap, vm_offset_t addr)
  {
  
          return (FALSE);
  }
  
  void
  pmap_clear_reference(vm_page_t m)
  {
  
          if ((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) != 0)
                  return;
          pmap_clear_bit(m, PTE_REF, NULL);
  }
  
  void
  pmap_clear_modify(vm_page_t m)
  {
  
          if ((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) != 0)
                  return;
          pmap_clear_bit(m, PTE_CHG, NULL);
  }
  
  /*
   *      pmap_ts_referenced:
   *
   *      Return a count of reference bits for a page, clearing those bits.
   *      It is not necessary for every reference bit to be cleared, but it
   *      is necessary that 0 only be returned when there are truly no
   *      reference bits set.
   *
   *      XXX: The exact number of bits to check and clear is a matter that
   *      should be tested and standardized at some point in the future for
   *      optimal aging of shared pages.
   */
  int
  pmap_ts_referenced(vm_page_t m)
  {
          int count;
  
          if ((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) != 0)
                  return (0);
  
          count = pmap_clear_bit(m, PTE_REF, NULL);
  
          return (count);
  }
  
  /*
   * Map a wired page into kernel virtual address space.
   */
  void
  pmap_kenter(vm_offset_t va, vm_offset_t pa)
  {
          u_int           pte_lo;
          int             error;  
          int             i;
  
  #if 0
          if (va < VM_MIN_KERNEL_ADDRESS)
                  panic("pmap_kenter: attempt to enter non-kernel address %#x",
                      va);
  #endif
  
          pte_lo = PTE_I | PTE_G;
          for (i = 0; i < pregions_sz; i++) {
                  if ((pa >= pregions[i].mr_start) &&
                      (pa < (pregions[i].mr_start + pregions[i].mr_size))) {
                          pte_lo &= ~(PTE_I | PTE_G);
                          break;
                  }
          }       
  
          error = pmap_pvo_enter(kernel_pmap, pmap_upvo_zone,
              &pmap_pvo_kunmanaged, va, pa, pte_lo, PVO_WIRED);
  
          if (error != 0 && error != ENOENT)
                  panic("pmap_kenter: failed to enter va %#x pa %#x: %d", va,
                      pa, error);
  
          /*
           * Flush the real memory from the instruction cache.
           */
          if ((pte_lo & (PTE_I | PTE_G)) == 0) {
                  pmap_syncicache(pa, PAGE_SIZE);
          }
  }
  
  /*
   * Extract the physical page address associated with the given kernel virtual
   * address.
   */
  vm_offset_t
  pmap_kextract(vm_offset_t va)
  {
          struct          pvo_entry *pvo;
  
          pvo = pmap_pvo_find_va(kernel_pmap, va & ~ADDR_POFF, NULL);
          if (pvo == NULL) {
                  return (0);
          }
  
          return ((pvo->pvo_pte.pte_lo & PTE_RPGN) | (va & ADDR_POFF));
  }
  
  /*
   * Remove a wired page from kernel virtual address space.
   */
  void
  pmap_kremove(vm_offset_t va)
  {
  
          pmap_remove(kernel_pmap, va, va + PAGE_SIZE);
  }
  
  /*
   * Map a range of physical addresses into kernel virtual address space.
   *
   * The value passed in *virt is a suggested virtual address for the mapping.
   * Architectures which can support a direct-mapped physical to virtual region
   * can return the appropriate address within that region, leaving '*virt'
   * unchanged.  We cannot and therefore do not; *virt is updated with the
   * first usable address after the mapped region.
   */
  vm_offset_t
  pmap_map(vm_offset_t *virt, vm_offset_t pa_start, vm_offset_t pa_end, int prot)
  {
          vm_offset_t     sva, va;
  
          sva = *virt;
          va = sva;
          for (; pa_start < pa_end; pa_start += PAGE_SIZE, va += PAGE_SIZE)
                  pmap_kenter(va, pa_start);
          *virt = va;
          return (sva);
  }
  
  int
  pmap_mincore(pmap_t pmap, vm_offset_t addr)
  {
          TODO;
          return (0);
  }
  
  void
  pmap_object_init_pt(pmap_t pm, vm_offset_t addr, vm_object_t object,
                      vm_pindex_t pindex, vm_size_t size)
  {
  
          VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
          KASSERT(object->type == OBJT_DEVICE,
              ("pmap_object_init_pt: non-device object"));
          KASSERT(pm == &curproc->p_vmspace->vm_pmap || pm == kernel_pmap,
              ("pmap_object_init_pt: non current pmap"));
  }
  
  /*
   * Lower the permission for all mappings to a given page.
   */
  void
  pmap_page_protect(vm_page_t m, vm_prot_t prot)
  {
          struct  pvo_head *pvo_head;
          struct  pvo_entry *pvo, *next_pvo;
          struct  pte *pt;
  
          /*
           * Since the routine only downgrades protection, if the
           * maximal protection is desired, there isn't any change
           * to be made.
           */
          if ((prot & (VM_PROT_READ|VM_PROT_WRITE)) ==
              (VM_PROT_READ|VM_PROT_WRITE))
                  return;
  
          pvo_head = vm_page_to_pvoh(m);
          for (pvo = LIST_FIRST(pvo_head); pvo != NULL; pvo = next_pvo) {
                  next_pvo = LIST_NEXT(pvo, pvo_vlink);
                  PMAP_PVO_CHECK(pvo);    /* sanity check */
  
                  /*
                   * Downgrading to no mapping at all, we just remove the entry.
                   */
                  if ((prot & VM_PROT_READ) == 0) {
                          pmap_pvo_remove(pvo, -1);
                          continue;
                  }
  
                  /*
                   * If EXEC permission is being revoked, just clear the flag
                   * in the PVO.
                   */
                  if ((prot & VM_PROT_EXECUTE) == 0)
                          pvo->pvo_vaddr &= ~PVO_EXECUTABLE;
  
                  /*
                   * If this entry is already RO, don't diddle with the page
                   * table.
                   */
                  if ((pvo->pvo_pte.pte_lo & PTE_PP) == PTE_BR) {
                          PMAP_PVO_CHECK(pvo);
                          continue;
                  }
  
                  /*
                   * Grab the PTE before we diddle the bits so pvo_to_pte can
                   * verify the pte contents are as expected.
                   */
                  pt = pmap_pvo_to_pte(pvo, -1);
                  pvo->pvo_pte.pte_lo &= ~PTE_PP;
                  pvo->pvo_pte.pte_lo |= PTE_BR;
                  if (pt != NULL)
                          pmap_pte_change(pt, &pvo->pvo_pte, pvo->pvo_vaddr);
                  PMAP_PVO_CHECK(pvo);    /* sanity check */
          }
  }
  
  /*
   * Returns true if the pmap's pv is one of the first
   * 16 pvs linked to from this page.  This count may
   * be changed upwards or downwards in the future; it
   * is only necessary that true be returned for a small
   * subset of pmaps for proper page aging.
   */
  boolean_t
  pmap_page_exists_quick(pmap_t pmap, vm_page_t m)
  {
          int loops;
          struct pvo_entry *pvo;
  
          if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
                  return FALSE;
  
          loops = 0;
          LIST_FOREACH(pvo, vm_page_to_pvoh(m), pvo_vlink) {
                  if (pvo->pvo_pmap == pmap)
                          return (TRUE);
                  if (++loops >= 16)
                          break;
          }
  
          return (FALSE);
  }
  
  static u_int    pmap_vsidcontext;
  
  void
  pmap_pinit(pmap_t pmap)
  {
          int     i, mask;
          u_int   entropy;
  
          entropy = 0;
          __asm __volatile("mftb %0" : "=r"(entropy));
  
          /*
           * Allocate some segment registers for this pmap.
           */
          for (i = 0; i < NPMAPS; i += VSID_NBPW) {
                  u_int   hash, n;
  
                  /*
                   * Create a new value by mutiplying by a prime and adding in
                   * entropy from the timebase register.  This is to make the
                   * VSID more random so that the PT hash function collides
                   * less often.  (Note that the prime casues gcc to do shifts
                   * instead of a multiply.)
                   */
                  pmap_vsidcontext = (pmap_vsidcontext * 0x1105) + entropy;
                  hash = pmap_vsidcontext & (NPMAPS - 1);
                  if (hash == 0)          /* 0 is special, avoid it */
                          continue;
                  n = hash >> 5;
                  mask = 1 << (hash & (VSID_NBPW - 1));
                  hash = (pmap_vsidcontext & 0xfffff);
                  if (pmap_vsid_bitmap[n] & mask) {       /* collision? */
                          /* anything free in this bucket? */
                          if (pmap_vsid_bitmap[n] == 0xffffffff) {
                                  entropy = (pmap_vsidcontext >> 20);
                                  continue;
                          }
                          i = ffs(~pmap_vsid_bitmap[i]) - 1;
                          mask = 1 << i;
                          hash &= 0xfffff & ~(VSID_NBPW - 1);
                          hash |= i;
                  }
                  pmap_vsid_bitmap[n] |= mask;
                  for (i = 0; i < 16; i++)
                          pmap->pm_sr[i] = VSID_MAKE(i, hash);
                  return;
          }
  
          panic("pmap_pinit: out of segments");
  }
  
  /*
   * Initialize the pmap associated with process 0.
   */
  void
  pmap_pinit0(pmap_t pm)
  {
  
          pmap_pinit(pm);
          bzero(&pm->pm_stats, sizeof(pm->pm_stats));
  }
  
  void
  pmap_pinit2(pmap_t pmap)
  {
          /* XXX: Remove this stub when no longer called */
  }
  
  /*
   * Set the physical protection on the specified range of this map as requested.
   */
  void
  pmap_protect(pmap_t pm, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
  {
          struct  pvo_entry *pvo;
          struct  pte *pt;
          int     pteidx;
  
          CTR4(KTR_PMAP, "pmap_protect: pm=%p sva=%#x eva=%#x prot=%#x", pm, sva,
              eva, prot);
  
  
          KASSERT(pm == &curproc->p_vmspace->vm_pmap || pm == kernel_pmap,
              ("pmap_protect: non current pmap"));
  
          if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
                  pmap_remove(pm, sva, eva);
                  return;
          }
  
          for (; sva < eva; sva += PAGE_SIZE) {
                  pvo = pmap_pvo_find_va(pm, sva, &pteidx);
                  if (pvo == NULL)
                          continue;
  
                  if ((prot & VM_PROT_EXECUTE) == 0)
                          pvo->pvo_vaddr &= ~PVO_EXECUTABLE;
  
                  /*
                   * Grab the PTE pointer before we diddle with the cached PTE
                   * copy.
                   */
                  pt = pmap_pvo_to_pte(pvo, pteidx);
                  /*
                   * Change the protection of the page.
                   */
                  pvo->pvo_pte.pte_lo &= ~PTE_PP;
                  pvo->pvo_pte.pte_lo |= PTE_BR;
  
                  /*
                   * If the PVO is in the page table, update that pte as well.
                   */
                  if (pt != NULL)
                          pmap_pte_change(pt, &pvo->pvo_pte, pvo->pvo_vaddr);
          }
  }
  
  /*
   * Map a list of wired pages into kernel virtual address space.  This is
   * intended for temporary mappings which do not need page modification or
   * references recorded.  Existing mappings in the region are overwritten.
   */
  void
  pmap_qenter(vm_offset_t sva, vm_page_t *m, int count)
  {
          vm_offset_t va;
  
          va = sva;
          while (count-- > 0) {
                  pmap_kenter(va, VM_PAGE_TO_PHYS(*m));
                  va += PAGE_SIZE;
                  m++;
          }
  }
  
  /*
   * Remove page mappings from kernel virtual address space.  Intended for
   * temporary mappings entered by pmap_qenter.
   */
  void
  pmap_qremove(vm_offset_t sva, int count)
  {
          vm_offset_t va;
  
          va = sva;
          while (count-- > 0) {
                  pmap_kremove(va);
                  va += PAGE_SIZE;
          }
  }
  
  void
  pmap_release(pmap_t pmap)
  {
          int idx, mask;
          
          /*
           * Free segment register's VSID
           */
          if (pmap->pm_sr[0] == 0)
                  panic("pmap_release");
  
          idx = VSID_TO_HASH(pmap->pm_sr[0]) & (NPMAPS-1);
          mask = 1 << (idx % VSID_NBPW);
          idx /= VSID_NBPW;
          pmap_vsid_bitmap[idx] &= ~mask;
  }
  
  /*
   * Remove the given range of addresses from the specified map.
   */
  void
  pmap_remove(pmap_t pm, vm_offset_t sva, vm_offset_t eva)
  {
          struct  pvo_entry *pvo;
          int     pteidx;
  
          for (; sva < eva; sva += PAGE_SIZE) {
                  pvo = pmap_pvo_find_va(pm, sva, &pteidx);
                  if (pvo != NULL) {
                          pmap_pvo_remove(pvo, pteidx);
                  }
          }
  }
  
  /*
   * Remove physical page from all pmaps in which it resides. pmap_pvo_remove()
   * will reflect changes in pte's back to the vm_page.
   */
  void
  pmap_remove_all(vm_page_t m)
  {
          struct  pvo_head *pvo_head;
          struct  pvo_entry *pvo, *next_pvo;
  
          mtx_assert(&vm_page_queue_mtx, MA_OWNED);
  
          pvo_head = vm_page_to_pvoh(m);
          for (pvo = LIST_FIRST(pvo_head); pvo != NULL; pvo = next_pvo) {
                  next_pvo = LIST_NEXT(pvo, pvo_vlink);
                  
                  PMAP_PVO_CHECK(pvo);    /* sanity check */
                  pmap_pvo_remove(pvo, -1);
          }
          vm_page_flag_clear(m, PG_WRITEABLE);
  }
  
  /*
   * Remove all pages from specified address space, this aids process exit
   * speeds.  This is much faster than pmap_remove in the case of running down
   * an entire address space.  Only works for the current pmap.
   */
  void
  pmap_remove_pages(pmap_t pm, vm_offset_t sva, vm_offset_t eva)
  {
  
          KASSERT(pm == &curproc->p_vmspace->vm_pmap || pm == kernel_pmap,
              ("pmap_remove_pages: non current pmap"));
          pmap_remove(pm, sva, eva);
  }
  
  /*
   * Allocate a physical page of memory directly from the phys_avail map.
   * Can only be called from pmap_bootstrap before avail start and end are
   * calculated.
   */
  static vm_offset_t
  pmap_bootstrap_alloc(vm_size_t size, u_int align)
  {
          vm_offset_t     s, e;
          int             i, j;
  
          size = round_page(size);
          for (i = 0; phys_avail[i + 1] != 0; i += 2) {
                  if (align != 0)
                          s = (phys_avail[i] + align - 1) & ~(align - 1);
                  else
                          s = phys_avail[i];
                  e = s + size;
  
                  if (s < phys_avail[i] || e > phys_avail[i + 1])
                          continue;
  
                  if (s == phys_avail[i]) {
                          phys_avail[i] += size;
                  } else if (e == phys_avail[i + 1]) {
                          phys_avail[i + 1] -= size;
                  } else {
                          for (j = phys_avail_count * 2; j > i; j -= 2) {
                                  phys_avail[j] = phys_avail[j - 2];
                                  phys_avail[j + 1] = phys_avail[j - 1];
                          }
  
                          phys_avail[i + 3] = phys_avail[i + 1];
                          phys_avail[i + 1] = s;
                          phys_avail[i + 2] = e;
                          phys_avail_count++;
                  }
  
                  return (s);
          }
          panic("pmap_bootstrap_alloc: could not allocate memory");
  }
  
  /*
   * Return an unmapped pvo for a kernel virtual address.
   * Used by pmap functions that operate on physical pages.
   */
  static struct pvo_entry *
  pmap_rkva_alloc(void)
  {
          struct          pvo_entry *pvo;
          struct          pte *pt;
          vm_offset_t     kva;
          int             pteidx;
  
          if (pmap_rkva_count == 0)
                  panic("pmap_rkva_alloc: no more reserved KVAs");
  
          kva = pmap_rkva_start + (PAGE_SIZE * --pmap_rkva_count);
          pmap_kenter(kva, 0);
  
          pvo = pmap_pvo_find_va(kernel_pmap, kva, &pteidx);
  
          if (pvo == NULL)
                  panic("pmap_kva_alloc: pmap_pvo_find_va failed");
  
          pt = pmap_pvo_to_pte(pvo, pteidx);
  
          if (pt == NULL)
                  panic("pmap_kva_alloc: pmap_pvo_to_pte failed");
  
          pmap_pte_unset(pt, &pvo->pvo_pte, pvo->pvo_vaddr);
          PVO_PTEGIDX_CLR(pvo);
  
          pmap_pte_overflow++;
  
          return (pvo);
  }
  
  static void
  pmap_pa_map(struct pvo_entry *pvo, vm_offset_t pa, struct pte *saved_pt,
      int *depth_p)
  {
          struct  pte *pt;
  
          /*
           * If this pvo already has a valid pte, we need to save it so it can
           * be restored later.  We then just reload the new PTE over the old
           * slot.
           */
          if (saved_pt != NULL) {
                  pt = pmap_pvo_to_pte(pvo, -1);
  
                  if (pt != NULL) {
                          pmap_pte_unset(pt, &pvo->pvo_pte, pvo->pvo_vaddr);
                          PVO_PTEGIDX_CLR(pvo);
                          pmap_pte_overflow++;
                  }
  
                  *saved_pt = pvo->pvo_pte;
  
                  pvo->pvo_pte.pte_lo &= ~PTE_RPGN;
          }
  
          pvo->pvo_pte.pte_lo |= pa;
  
          if (!pmap_pte_spill(pvo->pvo_vaddr))
                  panic("pmap_pa_map: could not spill pvo %p", pvo);
  
          if (depth_p != NULL)
                  (*depth_p)++;
  }
  
  static void
  pmap_pa_unmap(struct pvo_entry *pvo, struct pte *saved_pt, int *depth_p)
  {
          struct  pte *pt;
  
          pt = pmap_pvo_to_pte(pvo, -1);
  
          if (pt != NULL) {
                  pmap_pte_unset(pt, &pvo->pvo_pte, pvo->pvo_vaddr);
                  PVO_PTEGIDX_CLR(pvo);
                  pmap_pte_overflow++;
          }
  
          pvo->pvo_pte.pte_lo &= ~PTE_RPGN;
  
          /*
           * If there is a saved PTE and it's valid, restore it and return.
           */
          if (saved_pt != NULL && (saved_pt->pte_lo & PTE_RPGN) != 0) {
                  if (depth_p != NULL && --(*depth_p) == 0)
                          panic("pmap_pa_unmap: restoring but depth == 0");
  
                  pvo->pvo_pte = *saved_pt;
  
                  if (!pmap_pte_spill(pvo->pvo_vaddr))
                          panic("pmap_pa_unmap: could not spill pvo %p", pvo);
          }
  }
  
  static void
  pmap_syncicache(vm_offset_t pa, vm_size_t len)
  {
          __syncicache((void *)pa, len);
  }
  
  static void
  tlbia(void)
  {
          caddr_t i;
  
          SYNC();
          for (i = 0; i < (caddr_t)0x00040000; i += 0x00001000) {
                  TLBIE(i);
                  EIEIO();
          }
          TLBSYNC();
          SYNC();
  }
  
  static int
  pmap_pvo_enter(pmap_t pm, uma_zone_t zone, struct pvo_head *pvo_head,
      vm_offset_t va, vm_offset_t pa, u_int pte_lo, int flags)
  {
          struct  pvo_entry *pvo;
          u_int   sr;
          int     first;
          u_int   ptegidx;
          int     i;
          int     bootstrap;
  
          pmap_pvo_enter_calls++;
          first = 0;
          
          bootstrap = 0;
  
          /*
           * Compute the PTE Group index.
           */
          va &= ~ADDR_POFF;
          sr = va_to_sr(pm->pm_sr, va);
          ptegidx = va_to_pteg(sr, va);
  
          /*
           * Remove any existing mapping for this page.  Reuse the pvo entry if
           * there is a mapping.
           */
          LIST_FOREACH(pvo, &pmap_pvo_table[ptegidx], pvo_olink) {
                  if (pvo->pvo_pmap == pm && PVO_VADDR(pvo) == va) {
                          if ((pvo->pvo_pte.pte_lo & PTE_RPGN) == pa &&
                              (pvo->pvo_pte.pte_lo & PTE_PP) ==
                              (pte_lo & PTE_PP)) {
                                  return (0);
                          }
                          pmap_pvo_remove(pvo, -1);
                          break;
                  }
          }
  
          /*
           * If we aren't overwriting a mapping, try to allocate.
           */
          if (pmap_initialized) {
                  pvo = uma_zalloc(zone, M_NOWAIT);
          } else {
                  if (pmap_bpvo_pool_index >= BPVO_POOL_SIZE) {
                          panic("pmap_enter: bpvo pool exhausted, %d, %d, %d",
                                pmap_bpvo_pool_index, BPVO_POOL_SIZE, 
                                BPVO_POOL_SIZE * sizeof(struct pvo_entry));
                  }
                  pvo = &pmap_bpvo_pool[pmap_bpvo_pool_index];
                  pmap_bpvo_pool_index++;
                  bootstrap = 1;
          }
  
          if (pvo == NULL) {
                  return (ENOMEM);
          }
  
          pmap_pvo_entries++;
          pvo->pvo_vaddr = va;
          pvo->pvo_pmap = pm;
          LIST_INSERT_HEAD(&pmap_pvo_table[ptegidx], pvo, pvo_olink);
          pvo->pvo_vaddr &= ~ADDR_POFF;
          if (flags & VM_PROT_EXECUTE)
                  pvo->pvo_vaddr |= PVO_EXECUTABLE;
          if (flags & PVO_WIRED)
                  pvo->pvo_vaddr |= PVO_WIRED;
          if (pvo_head != &pmap_pvo_kunmanaged)
                  pvo->pvo_vaddr |= PVO_MANAGED;
          if (bootstrap)
                  pvo->pvo_vaddr |= PVO_BOOTSTRAP;
          pmap_pte_create(&pvo->pvo_pte, sr, va, pa | pte_lo);
  
          /*
           * Remember if the list was empty and therefore will be the first
           * item.
           */
          if (LIST_FIRST(pvo_head) == NULL)
                  first = 1;
  
          LIST_INSERT_HEAD(pvo_head, pvo, pvo_vlink);
          if (pvo->pvo_pte.pte_lo & PVO_WIRED)
                  pvo->pvo_pmap->pm_stats.wired_count++;
          pvo->pvo_pmap->pm_stats.resident_count++;
  
          /*
           * We hope this succeeds but it isn't required.
           */
          i = pmap_pte_insert(ptegidx, &pvo->pvo_pte);
          if (i >= 0) {
                  PVO_PTEGIDX_SET(pvo, i);
          } else {
                  panic("pmap_pvo_enter: overflow");
                  pmap_pte_overflow++;
          }
  
          return (first ? ENOENT : 0);
  }
  
  static void
  pmap_pvo_remove(struct pvo_entry *pvo, int pteidx)
  {
          struct  pte *pt;
  
          /*
           * If there is an active pte entry, we need to deactivate it (and
           * save the ref & cfg bits).
           */
          pt = pmap_pvo_to_pte(pvo, pteidx);
          if (pt != NULL) {
                  pmap_pte_unset(pt, &pvo->pvo_pte, pvo->pvo_vaddr);
                  PVO_PTEGIDX_CLR(pvo);
          } else {
                  pmap_pte_overflow--;
          }       
  
          /*
           * Update our statistics.
           */
          pvo->pvo_pmap->pm_stats.resident_count--;
          if (pvo->pvo_pte.pte_lo & PVO_WIRED)
                  pvo->pvo_pmap->pm_stats.wired_count--;
  
          /*
           * Save the REF/CHG bits into their cache if the page is managed.
           */
          if (pvo->pvo_vaddr & PVO_MANAGED) {
                  struct  vm_page *pg;
  
                  pg = PHYS_TO_VM_PAGE(pvo->pvo_pte.pte_lo & PTE_RPGN);
                  if (pg != NULL) {
                          pmap_attr_save(pg, pvo->pvo_pte.pte_lo &
                              (PTE_REF | PTE_CHG));
                  }
          }
  
          /*
           * Remove this PVO from the PV list.
           */
          LIST_REMOVE(pvo, pvo_vlink);
  
          /*
           * Remove this from the overflow list and return it to the pool
           * if we aren't going to reuse it.
           */
          LIST_REMOVE(pvo, pvo_olink);
          if (!(pvo->pvo_vaddr & PVO_BOOTSTRAP))
                  uma_zfree(pvo->pvo_vaddr & PVO_MANAGED ? pmap_mpvo_zone :
                      pmap_upvo_zone, pvo);
          pmap_pvo_entries--;
          pmap_pvo_remove_calls++;
  }
  
  static __inline int
  pmap_pvo_pte_index(const struct pvo_entry *pvo, int ptegidx)
  {
          int     pteidx;
  
          /*
           * We can find the actual pte entry without searching by grabbing
           * the PTEG index from 3 unused bits in pte_lo[11:9] and by
           * noticing the HID bit.
           */
          pteidx = ptegidx * 8 + PVO_PTEGIDX_GET(pvo);
          if (pvo->pvo_pte.pte_hi & PTE_HID)
                  pteidx ^= pmap_pteg_mask * 8;
  
          return (pteidx);
  }
  
  static struct pvo_entry *
  pmap_pvo_find_va(pmap_t pm, vm_offset_t va, int *pteidx_p)
  {
          struct  pvo_entry *pvo;
          int     ptegidx;
          u_int   sr;
  
          va &= ~ADDR_POFF;
          sr = va_to_sr(pm->pm_sr, va);
          ptegidx = va_to_pteg(sr, va);
  
          LIST_FOREACH(pvo, &pmap_pvo_table[ptegidx], pvo_olink) {
                  if (pvo->pvo_pmap == pm && PVO_VADDR(pvo) == va) {
                          if (pteidx_p)
                                  *pteidx_p = pmap_pvo_pte_index(pvo, ptegidx);
                          return (pvo);
                  }
          }
  
          return (NULL);
  }
  
  static struct pte *
  pmap_pvo_to_pte(const struct pvo_entry *pvo, int pteidx)
  {
          struct  pte *pt;
  
          /*
           * If we haven't been supplied the ptegidx, calculate it.
           */
          if (pteidx == -1) {
                  int     ptegidx;
                  u_int   sr;
  
                  sr = va_to_sr(pvo->pvo_pmap->pm_sr, pvo->pvo_vaddr);
                  ptegidx = va_to_pteg(sr, pvo->pvo_vaddr);
                  pteidx = pmap_pvo_pte_index(pvo, ptegidx);
          }
  
          pt = &pmap_pteg_table[pteidx >> 3].pt[pteidx & 7];
  
          if ((pvo->pvo_pte.pte_hi & PTE_VALID) && !PVO_PTEGIDX_ISSET(pvo)) {
                  panic("pmap_pvo_to_pte: pvo %p has valid pte in pvo but no "
                      "valid pte index", pvo);
          }
  
          if ((pvo->pvo_pte.pte_hi & PTE_VALID) == 0 && PVO_PTEGIDX_ISSET(pvo)) {
                  panic("pmap_pvo_to_pte: pvo %p has valid pte index in pvo "
                      "pvo but no valid pte", pvo);
          }
  
          if ((pt->pte_hi ^ (pvo->pvo_pte.pte_hi & ~PTE_VALID)) == PTE_VALID) {
                  if ((pvo->pvo_pte.pte_hi & PTE_VALID) == 0) {
                          panic("pmap_pvo_to_pte: pvo %p has valid pte in "
                              "pmap_pteg_table %p but invalid in pvo", pvo, pt);
                  }
  
                  if (((pt->pte_lo ^ pvo->pvo_pte.pte_lo) & ~(PTE_CHG|PTE_REF))
                      != 0) {
                          panic("pmap_pvo_to_pte: pvo %p pte does not match "
                              "pte %p in pmap_pteg_table", pvo, pt);
                  }
  
                  return (pt);
          }
  
          if (pvo->pvo_pte.pte_hi & PTE_VALID) {
                  panic("pmap_pvo_to_pte: pvo %p has invalid pte %p in "
                      "pmap_pteg_table but valid in pvo", pvo, pt);
          }
  
          return (NULL);
  }
  
  static void *
  pmap_pvo_allocf(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
  {
          static vm_pindex_t color;
          vm_page_t       m;
  
          if (bytes != PAGE_SIZE)
                  panic("pmap_pvo_allocf: benno was shortsighted.  hit him.");
  
          *flags = UMA_SLAB_PRIV;
          /*
           * The color is only a hint.  Thus, a data race in the read-
           * modify-write operation below isn't a catastrophe.
           */
          m = vm_page_alloc(NULL, color++, VM_ALLOC_NOOBJ | VM_ALLOC_SYSTEM);
          if (m == NULL)
                  return (NULL);
          return ((void *)VM_PAGE_TO_PHYS(m));
  }
  
  /*
   * XXX: THIS STUFF SHOULD BE IN pte.c?
   */
  int
  pmap_pte_spill(vm_offset_t addr)
  {
          struct  pvo_entry *source_pvo, *victim_pvo;
          struct  pvo_entry *pvo;
          int     ptegidx, i, j;
          u_int   sr;
          struct  pteg *pteg;
          struct  pte *pt;
  
          pmap_pte_spills++;
  
          sr = mfsrin(addr);
          ptegidx = va_to_pteg(sr, addr);
  
          /*
           * Have to substitute some entry.  Use the primary hash for this.
           * Use low bits of timebase as random generator.
           */
          pteg = &pmap_pteg_table[ptegidx];
          __asm __volatile("mftb %0" : "=r"(i));
          i &= 7;
          pt = &pteg->pt[i];
  
          source_pvo = NULL;
          victim_pvo = NULL;
          LIST_FOREACH(pvo, &pmap_pvo_table[ptegidx], pvo_olink) {
                  /*
                   * We need to find a pvo entry for this address.
                   */
                  PMAP_PVO_CHECK(pvo);
                  if (source_pvo == NULL &&
                      pmap_pte_match(&pvo->pvo_pte, sr, addr,
                      pvo->pvo_pte.pte_hi & PTE_HID)) {
                          /*
                           * Now found an entry to be spilled into the pteg.
                           * The PTE is now valid, so we know it's active.
                           */
                          j = pmap_pte_insert(ptegidx, &pvo->pvo_pte);
  
                          if (j >= 0) {
                                  PVO_PTEGIDX_SET(pvo, j);
                                  pmap_pte_overflow--;
                                  PMAP_PVO_CHECK(pvo);
                                  return (1);
                          }
  
                          source_pvo = pvo;
  
                          if (victim_pvo != NULL)
                                  break;
                  }
  
                  /*
                   * We also need the pvo entry of the victim we are replacing
                   * so save the R & C bits of the PTE.
                   */
                  if ((pt->pte_hi & PTE_HID) == 0 && victim_pvo == NULL &&
                      pmap_pte_compare(pt, &pvo->pvo_pte)) {
                          victim_pvo = pvo;
                          if (source_pvo != NULL)
                                  break;
                  }
          }
  
          if (source_pvo == NULL)
                  return (0);
  
          if (victim_pvo == NULL) {
                  if ((pt->pte_hi & PTE_HID) == 0)
                          panic("pmap_pte_spill: victim p-pte (%p) has no pvo"
                              "entry", pt);
  
                  /*
                   * If this is a secondary PTE, we need to search it's primary
                   * pvo bucket for the matching PVO.
                   */
                  LIST_FOREACH(pvo, &pmap_pvo_table[ptegidx ^ pmap_pteg_mask],
                      pvo_olink) {
                          PMAP_PVO_CHECK(pvo);
                          /*
                           * We also need the pvo entry of the victim we are
                           * replacing so save the R & C bits of the PTE.
                           */
                          if (pmap_pte_compare(pt, &pvo->pvo_pte)) {
                                  victim_pvo = pvo;
                                  break;
                          }
                  }
  
                  if (victim_pvo == NULL)
                          panic("pmap_pte_spill: victim s-pte (%p) has no pvo"
                              "entry", pt);
          }
  
          /*
           * We are invalidating the TLB entry for the EA we are replacing even
           * though it's valid.  If we don't, we lose any ref/chg bit changes
           * contained in the TLB entry.
           */
          source_pvo->pvo_pte.pte_hi &= ~PTE_HID;
  
          pmap_pte_unset(pt, &victim_pvo->pvo_pte, victim_pvo->pvo_vaddr);
          pmap_pte_set(pt, &source_pvo->pvo_pte);
  
          PVO_PTEGIDX_CLR(victim_pvo);
          PVO_PTEGIDX_SET(source_pvo, i);
          pmap_pte_replacements++;
  
          PMAP_PVO_CHECK(victim_pvo);
          PMAP_PVO_CHECK(source_pvo);
  
          return (1);
  }
  
  static int
  pmap_pte_insert(u_int ptegidx, struct pte *pvo_pt)
  {
          struct  pte *pt;
          int     i;
  
          /*
           * First try primary hash.
           */
          for (pt = pmap_pteg_table[ptegidx].pt, i = 0; i < 8; i++, pt++) {
                  if ((pt->pte_hi & PTE_VALID) == 0) {
                          pvo_pt->pte_hi &= ~PTE_HID;
                          pmap_pte_set(pt, pvo_pt);
                          return (i);
                  }
          }
  
          /*
           * Now try secondary hash.
           */
          ptegidx ^= pmap_pteg_mask;
          ptegidx++;
          for (pt = pmap_pteg_table[ptegidx].pt, i = 0; i < 8; i++, pt++) {
                  if ((pt->pte_hi & PTE_VALID) == 0) {
                          pvo_pt->pte_hi |= PTE_HID;
                          pmap_pte_set(pt, pvo_pt);
                          return (i);
                  }
          }
  
          panic("pmap_pte_insert: overflow");
          return (-1);
  }
  
  static boolean_t
  pmap_query_bit(vm_page_t m, int ptebit)
  {
          struct  pvo_entry *pvo;
          struct  pte *pt;
  
          if (pmap_attr_fetch(m) & ptebit)
                  return (TRUE);
  
          LIST_FOREACH(pvo, vm_page_to_pvoh(m), pvo_vlink) {
                  PMAP_PVO_CHECK(pvo);    /* sanity check */
  
                  /*
                   * See if we saved the bit off.  If so, cache it and return
                   * success.
                   */
                  if (pvo->pvo_pte.pte_lo & ptebit) {
                          pmap_attr_save(m, ptebit);
                          PMAP_PVO_CHECK(pvo);    /* sanity check */
                          return (TRUE);
                  }
          }
  
          /*
           * No luck, now go through the hard part of looking at the PTEs
           * themselves.  Sync so that any pending REF/CHG bits are flushed to
           * the PTEs.
           */
          SYNC();
          LIST_FOREACH(pvo, vm_page_to_pvoh(m), pvo_vlink) {
                  PMAP_PVO_CHECK(pvo);    /* sanity check */
  
                  /*
                   * See if this pvo has a valid PTE.  if so, fetch the
                   * REF/CHG bits from the valid PTE.  If the appropriate
                   * ptebit is set, cache it and return success.
                   */
                  pt = pmap_pvo_to_pte(pvo, -1);
                  if (pt != NULL) {
                          pmap_pte_synch(pt, &pvo->pvo_pte);
                          if (pvo->pvo_pte.pte_lo & ptebit) {
                                  pmap_attr_save(m, ptebit);
                                  PMAP_PVO_CHECK(pvo);    /* sanity check */
                                  return (TRUE);
                          }
                  }
          }
  
          return (TRUE);
  }
  
  static u_int
  pmap_clear_bit(vm_page_t m, int ptebit, int *origbit)
  {
          u_int   count;
          struct  pvo_entry *pvo;
          struct  pte *pt;
          int     rv;
  
          /*
           * Clear the cached value.
           */
          rv = pmap_attr_fetch(m);
          pmap_attr_clear(m, ptebit);
  
          /*
           * Sync so that any pending REF/CHG bits are flushed to the PTEs (so
           * we can reset the right ones).  note that since the pvo entries and
           * list heads are accessed via BAT0 and are never placed in the page
           * table, we don't have to worry about further accesses setting the
           * REF/CHG bits.
           */
          SYNC();
  
          /*
           * For each pvo entry, clear the pvo's ptebit.  If this pvo has a
           * valid pte clear the ptebit from the valid pte.
           */
          count = 0;
          LIST_FOREACH(pvo, vm_page_to_pvoh(m), pvo_vlink) {
                  PMAP_PVO_CHECK(pvo);    /* sanity check */
                  pt = pmap_pvo_to_pte(pvo, -1);
                  if (pt != NULL) {
                          pmap_pte_synch(pt, &pvo->pvo_pte);
                          if (pvo->pvo_pte.pte_lo & ptebit) {
                                  count++;
                                  pmap_pte_clear(pt, PVO_VADDR(pvo), ptebit);
                          }
                  }
                  rv |= pvo->pvo_pte.pte_lo;
                  pvo->pvo_pte.pte_lo &= ~ptebit;
                  PMAP_PVO_CHECK(pvo);    /* sanity check */
          }
  
          if (origbit != NULL) {
                  *origbit = rv;
          }
  
          return (count);
  }
  
  /*
   * Return true if the physical range is encompassed by the battable[idx]
   */
  static int
  pmap_bat_mapped(int idx, vm_offset_t pa, vm_size_t size)
  {
          u_int prot;
          u_int32_t start;
          u_int32_t end;
          u_int32_t bat_ble;
  
          /*
           * Return immediately if not a valid mapping
           */
          if (!battable[idx].batu & BAT_Vs)
                  return (EINVAL);
  
          /*
           * The BAT entry must be cache-inhibited, guarded, and r/w
           * so it can function as an i/o page
           */
          prot = battable[idx].batl & (BAT_I|BAT_G|BAT_PP_RW);
          if (prot != (BAT_I|BAT_G|BAT_PP_RW))
                  return (EPERM); 
  
          /*
           * The address should be within the BAT range. Assume that the
           * start address in the BAT has the correct alignment (thus
           * not requiring masking)
           */
          start = battable[idx].batl & BAT_PBS;
          bat_ble = (battable[idx].batu & ~(BAT_EBS)) | 0x03;
          end = start | (bat_ble << 15) | 0x7fff;
  
          if ((pa < start) || ((pa + size) > end))
                  return (ERANGE);
  
          return (0);
  }
  
  
  /*
   * Map a set of physical memory pages into the kernel virtual
   * address space. Return a pointer to where it is mapped. This
   * routine is intended to be used for mapping device memory,
   * NOT real memory.
   */
  void *
  pmap_mapdev(vm_offset_t pa, vm_size_t size)
  {
          vm_offset_t va, tmpva, ppa, offset;
          int i;
  
          ppa = trunc_page(pa);
          offset = pa & PAGE_MASK;
          size = roundup(offset + size, PAGE_SIZE);
          
          GIANT_REQUIRED;
  
          /*
           * If the physical address lies within a valid BAT table entry,
           * return the 1:1 mapping. This currently doesn't work
           * for regions that overlap 256M BAT segments.
           */
          for (i = 0; i < 16; i++) {
                  if (pmap_bat_mapped(i, pa, size) == 0)
                          return ((void *) pa);
          }
  
          va = kmem_alloc_nofault(kernel_map, size);
          if (!va)
                  panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
  
          for (tmpva = va; size > 0;) {
                  pmap_kenter(tmpva, ppa);
                  TLBIE(tmpva); /* XXX or should it be invalidate-all ? */
                  size -= PAGE_SIZE;
                  tmpva += PAGE_SIZE;
                  ppa += PAGE_SIZE;
          }
  
          return ((void *)(va + offset));
  }
  
  void
  pmap_unmapdev(vm_offset_t va, vm_size_t size)
  {
          vm_offset_t base, offset;
  
          /*
           * If this is outside kernel virtual space, then it's a
           * battable entry and doesn't require unmapping
           */
          if ((va >= VM_MIN_KERNEL_ADDRESS) && (va <= VM_MAX_KERNEL_ADDRESS)) {
                  base = trunc_page(va);
                  offset = va & PAGE_MASK;
                  size = roundup(offset + size, PAGE_SIZE);
                  kmem_free(kernel_map, base, size);
          }
  }

Cache object: a5731269205c8571a0ea75701ddec8bd