FreeBSD/Linux Kernel Cross Reference
sys/sparc64/sparc64/pmap.c

     /*-
      * Copyright (c) 1991 Regents of the University of California.
      * All rights reserved.
      * Copyright (c) 1994 John S. Dyson
      * All rights reserved.
      * Copyright (c) 1994 David Greenman
      * All rights reserved.
      *
      * This code is derived from software contributed to Berkeley by
     * the Systems Programming Group of the University of Utah Computer
     * Science Department and William Jolitz of UUNET Technologies 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 University of
     *      California, Berkeley and its contributors.
     * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
     *
     *      from:   @(#)pmap.c      7.7 (Berkeley)  5/12/91
     * $FreeBSD: releng/6.0/sys/sparc64/sparc64/pmap.c 147217 2005-06-10 03:33:36Z 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 "opt_msgbuf.h"
    #include "opt_pmap.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/smp.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 <machine/cache.h>
    #include <machine/frame.h>
    #include <machine/instr.h>
    #include <machine/md_var.h>
    #include <machine/metadata.h>
    #include <machine/ofw_mem.h>
   #include <machine/smp.h>
   #include <machine/tlb.h>
   #include <machine/tte.h>
   #include <machine/tsb.h>
   
   #define PMAP_DEBUG
   
   #ifndef PMAP_SHPGPERPROC
   #define PMAP_SHPGPERPROC        200
   #endif
   
   /*
    * Virtual and physical address of message buffer.
    */
   struct msgbuf *msgbufp;
   vm_paddr_t msgbuf_phys;
   
   int pmap_pagedaemon_waken;
   
   /*
    * Map of physical memory reagions.
    */
   vm_paddr_t phys_avail[128];
   static struct ofw_mem_region mra[128];
   struct ofw_mem_region sparc64_memreg[128];
   int sparc64_nmemreg;
   static struct ofw_map translations[128];
   static int translations_size;
   
   static vm_offset_t pmap_idle_map;
   static vm_offset_t pmap_temp_map_1;
   static vm_offset_t pmap_temp_map_2;
   
   /*
    * First and last available kernel virtual addresses.
    */
   vm_offset_t virtual_avail;
   vm_offset_t virtual_end;
   vm_offset_t kernel_vm_end;
   
   vm_offset_t vm_max_kernel_address;
   
   /*
    * Kernel pmap.
    */
   struct pmap kernel_pmap_store;
   
   /*
    * Allocate physical memory for use in pmap_bootstrap.
    */
   static vm_paddr_t pmap_bootstrap_alloc(vm_size_t size);
   
   extern int tl1_immu_miss_patch_1[];
   extern int tl1_immu_miss_patch_2[];
   extern int tl1_dmmu_miss_patch_1[];
   extern int tl1_dmmu_miss_patch_2[];
   extern int tl1_dmmu_prot_patch_1[];
   extern int tl1_dmmu_prot_patch_2[];
   
   /*
    * If user pmap is processed with pmap_remove and with pmap_remove and the
    * resident count drops to 0, there are no more pages to remove, so we
    * need not continue.
    */
   #define PMAP_REMOVE_DONE(pm) \
           ((pm) != kernel_pmap && (pm)->pm_stats.resident_count == 0)
   
   /*
    * The threshold (in bytes) above which tsb_foreach() is used in pmap_remove()
    * and pmap_protect() instead of trying each virtual address.
    */
   #define PMAP_TSB_THRESH ((TSB_SIZE / 2) * PAGE_SIZE)
   
   SYSCTL_NODE(_debug, OID_AUTO, pmap_stats, CTLFLAG_RD, 0, "");
   
   PMAP_STATS_VAR(pmap_nenter);
   PMAP_STATS_VAR(pmap_nenter_update);
   PMAP_STATS_VAR(pmap_nenter_replace);
   PMAP_STATS_VAR(pmap_nenter_new);
   PMAP_STATS_VAR(pmap_nkenter);
   PMAP_STATS_VAR(pmap_nkenter_oc);
   PMAP_STATS_VAR(pmap_nkenter_stupid);
   PMAP_STATS_VAR(pmap_nkremove);
   PMAP_STATS_VAR(pmap_nqenter);
   PMAP_STATS_VAR(pmap_nqremove);
   PMAP_STATS_VAR(pmap_ncache_enter);
   PMAP_STATS_VAR(pmap_ncache_enter_c);
   PMAP_STATS_VAR(pmap_ncache_enter_oc);
   PMAP_STATS_VAR(pmap_ncache_enter_cc);
   PMAP_STATS_VAR(pmap_ncache_enter_coc);
   PMAP_STATS_VAR(pmap_ncache_enter_nc);
   PMAP_STATS_VAR(pmap_ncache_enter_cnc);
   PMAP_STATS_VAR(pmap_ncache_remove);
   PMAP_STATS_VAR(pmap_ncache_remove_c);
   PMAP_STATS_VAR(pmap_ncache_remove_oc);
   PMAP_STATS_VAR(pmap_ncache_remove_cc);
   PMAP_STATS_VAR(pmap_ncache_remove_coc);
   PMAP_STATS_VAR(pmap_ncache_remove_nc);
   PMAP_STATS_VAR(pmap_nzero_page);
   PMAP_STATS_VAR(pmap_nzero_page_c);
   PMAP_STATS_VAR(pmap_nzero_page_oc);
   PMAP_STATS_VAR(pmap_nzero_page_nc);
   PMAP_STATS_VAR(pmap_nzero_page_area);
   PMAP_STATS_VAR(pmap_nzero_page_area_c);
   PMAP_STATS_VAR(pmap_nzero_page_area_oc);
   PMAP_STATS_VAR(pmap_nzero_page_area_nc);
   PMAP_STATS_VAR(pmap_nzero_page_idle);
   PMAP_STATS_VAR(pmap_nzero_page_idle_c);
   PMAP_STATS_VAR(pmap_nzero_page_idle_oc);
   PMAP_STATS_VAR(pmap_nzero_page_idle_nc);
   PMAP_STATS_VAR(pmap_ncopy_page);
   PMAP_STATS_VAR(pmap_ncopy_page_c);
   PMAP_STATS_VAR(pmap_ncopy_page_oc);
   PMAP_STATS_VAR(pmap_ncopy_page_nc);
   PMAP_STATS_VAR(pmap_ncopy_page_dc);
   PMAP_STATS_VAR(pmap_ncopy_page_doc);
   PMAP_STATS_VAR(pmap_ncopy_page_sc);
   PMAP_STATS_VAR(pmap_ncopy_page_soc);
   
   PMAP_STATS_VAR(pmap_nnew_thread);
   PMAP_STATS_VAR(pmap_nnew_thread_oc);
   
   /*
    * 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 ofw_mem_region *mra;
           const struct ofw_mem_region *mrb;
   
           mra = a;
           mrb = b;
           if (mra->mr_start < mrb->mr_start)
                   return (-1);
           else if (mra->mr_start > mrb->mr_start)
                   return (1);
           else
                   return (0);
   }
   static int
   om_cmp(const void *a, const void *b)
   {
           const struct ofw_map *oma;
           const struct ofw_map *omb;
   
           oma = a;
           omb = b;
           if (oma->om_start < omb->om_start)
                   return (-1);
           else if (oma->om_start > omb->om_start)
                   return (1);
           else
                   return (0);
   }
   
   /*
    * Bootstrap the system enough to run with virtual memory.
    */
   void
   pmap_bootstrap(vm_offset_t ekva)
   {
           struct pmap *pm;
           struct tte *tp;
           vm_offset_t off;
           vm_offset_t va;
           vm_paddr_t pa;
           vm_size_t physsz;
           vm_size_t virtsz;
           ihandle_t pmem;
           ihandle_t vmem;
           int sz;
           int i;
           int j;
   
           /*
            * Find out what physical memory is available from the prom and
            * initialize the phys_avail array.  This must be done before
            * pmap_bootstrap_alloc is called.
            */
           if ((pmem = OF_finddevice("/memory")) == -1)
                   panic("pmap_bootstrap: finddevice /memory");
           if ((sz = OF_getproplen(pmem, "available")) == -1)
                   panic("pmap_bootstrap: getproplen /memory/available");
           if (sizeof(phys_avail) < sz)
                   panic("pmap_bootstrap: phys_avail too small");
           if (sizeof(mra) < sz)
                   panic("pmap_bootstrap: mra too small");
           bzero(mra, sz);
           if (OF_getprop(pmem, "available", mra, sz) == -1)
                   panic("pmap_bootstrap: getprop /memory/available");
           sz /= sizeof(*mra);
           CTR0(KTR_PMAP, "pmap_bootstrap: physical memory");
           qsort(mra, sz, sizeof (*mra), mr_cmp);
           physsz = 0;
           getenv_quad("hw.physmem", &physmem);
           for (i = 0, j = 0; i < sz; i++, j += 2) {
                   CTR2(KTR_PMAP, "start=%#lx size=%#lx", mra[i].mr_start,
                       mra[i].mr_size);
                   if (physmem != 0 && btoc(physsz + mra[i].mr_size) >= physmem) {
                           if (btoc(physsz) < physmem) {
                                   phys_avail[j] = mra[i].mr_start;
                                   phys_avail[j + 1] = mra[i].mr_start +
                                       (ctob(physmem) - physsz);
                                   physsz = ctob(physmem);
                           }
                           break;
                   }
                   phys_avail[j] = mra[i].mr_start;
                   phys_avail[j + 1] = mra[i].mr_start + mra[i].mr_size;
                   physsz += mra[i].mr_size;
           }
           physmem = btoc(physsz);
   
           /*
            * Calculate the size of kernel virtual memory, and the size and mask
            * for the kernel tsb.
            */
           virtsz = roundup(physsz, PAGE_SIZE_4M << (PAGE_SHIFT - TTE_SHIFT));
           vm_max_kernel_address = VM_MIN_KERNEL_ADDRESS + virtsz;
           tsb_kernel_size = virtsz >> (PAGE_SHIFT - TTE_SHIFT);
           tsb_kernel_mask = (tsb_kernel_size >> TTE_SHIFT) - 1;
   
           /*
            * Allocate the kernel tsb and lock it in the tlb.
            */
           pa = pmap_bootstrap_alloc(tsb_kernel_size);
           if (pa & PAGE_MASK_4M)
                   panic("pmap_bootstrap: tsb unaligned\n");
           tsb_kernel_phys = pa;
           tsb_kernel = (struct tte *)(VM_MIN_KERNEL_ADDRESS - tsb_kernel_size);
           pmap_map_tsb();
           bzero(tsb_kernel, tsb_kernel_size);
   
           /*
            * Allocate and map the message buffer.
            */
           msgbuf_phys = pmap_bootstrap_alloc(MSGBUF_SIZE);
           msgbufp = (struct msgbuf *)TLB_PHYS_TO_DIRECT(msgbuf_phys);
   
           /*
            * Patch the virtual address and the tsb mask into the trap table.
            */
   
   #define SETHI(rd, imm22) \
           (EIF_OP(IOP_FORM2) | EIF_F2_RD(rd) | EIF_F2_OP2(INS0_SETHI) | \
               EIF_IMM((imm22) >> 10, 22))
   #define OR_R_I_R(rd, imm13, rs1) \
           (EIF_OP(IOP_MISC) | EIF_F3_RD(rd) | EIF_F3_OP3(INS2_OR) | \
               EIF_F3_RS1(rs1) | EIF_F3_I(1) | EIF_IMM(imm13, 13))
   
   #define PATCH(addr) do { \
           if (addr[0] != SETHI(IF_F2_RD(addr[0]), 0x0) || \
               addr[1] != OR_R_I_R(IF_F3_RD(addr[1]), 0x0, IF_F3_RS1(addr[1])) || \
               addr[2] != SETHI(IF_F2_RD(addr[2]), 0x0)) \
                   panic("pmap_boostrap: patched instructions have changed"); \
           addr[0] |= EIF_IMM((tsb_kernel_mask) >> 10, 22); \
           addr[1] |= EIF_IMM(tsb_kernel_mask, 10); \
           addr[2] |= EIF_IMM(((vm_offset_t)tsb_kernel) >> 10, 22); \
           flush(addr); \
           flush(addr + 1); \
           flush(addr + 2); \
   } while (0)
   
           PATCH(tl1_immu_miss_patch_1);
           PATCH(tl1_immu_miss_patch_2);
           PATCH(tl1_dmmu_miss_patch_1);
           PATCH(tl1_dmmu_miss_patch_2);
           PATCH(tl1_dmmu_prot_patch_1);
           PATCH(tl1_dmmu_prot_patch_2);
           
           /*
            * Enter fake 8k pages for the 4MB kernel pages, so that
            * pmap_kextract() will work for them.
            */
           for (i = 0; i < kernel_tlb_slots; i++) {
                   pa = kernel_tlbs[i].te_pa;
                   va = kernel_tlbs[i].te_va;
                   for (off = 0; off < PAGE_SIZE_4M; off += PAGE_SIZE) {
                           tp = tsb_kvtotte(va + off);
                           tp->tte_vpn = TV_VPN(va + off, TS_8K);
                           tp->tte_data = TD_V | TD_8K | TD_PA(pa + off) |
                               TD_REF | TD_SW | TD_CP | TD_CV | TD_P | TD_W;
                   }
           }
   
           /*
            * Set the start and end of kva.  The kernel is loaded at the first
            * available 4 meg super page, so round up to the end of the page.
            */
           virtual_avail = roundup2(ekva, PAGE_SIZE_4M);
           virtual_end = vm_max_kernel_address;
           kernel_vm_end = vm_max_kernel_address;
   
           /*
            * Allocate kva space for temporary mappings.
            */
           pmap_idle_map = virtual_avail;
           virtual_avail += PAGE_SIZE * DCACHE_COLORS;
           pmap_temp_map_1 = virtual_avail;
           virtual_avail += PAGE_SIZE * DCACHE_COLORS;
           pmap_temp_map_2 = virtual_avail;
           virtual_avail += PAGE_SIZE * DCACHE_COLORS;
   
           /*
            * Allocate a kernel stack with guard page for thread0 and map it into
            * the kernel tsb.  We must ensure that the virtual address is coloured
            * properly, since we're allocating from phys_avail so the memory won't
            * have an associated vm_page_t.
            */
           pa = pmap_bootstrap_alloc(roundup(KSTACK_PAGES, DCACHE_COLORS) *
               PAGE_SIZE);
           kstack0_phys = pa;
           virtual_avail += roundup(KSTACK_GUARD_PAGES, DCACHE_COLORS) *
               PAGE_SIZE;
           kstack0 = virtual_avail;
           virtual_avail += roundup(KSTACK_PAGES, DCACHE_COLORS) * PAGE_SIZE;
           KASSERT(DCACHE_COLOR(kstack0) == DCACHE_COLOR(kstack0_phys),
               ("pmap_bootstrap: kstack0 miscoloured"));
           for (i = 0; i < KSTACK_PAGES; i++) {
                   pa = kstack0_phys + i * PAGE_SIZE;
                   va = kstack0 + i * PAGE_SIZE;
                   tp = tsb_kvtotte(va);
                   tp->tte_vpn = TV_VPN(va, TS_8K);
                   tp->tte_data = TD_V | TD_8K | TD_PA(pa) | TD_REF | TD_SW |
                       TD_CP | TD_CV | TD_P | TD_W;
           }
   
           /*
            * Calculate the last available physical address.
            */
           for (i = 0; phys_avail[i + 2] != 0; i += 2)
                   ;
           Maxmem = sparc64_btop(phys_avail[i + 1]);
   
           /*
            * Add the prom mappings to the kernel tsb.
            */
           if ((vmem = OF_finddevice("/virtual-memory")) == -1)
                   panic("pmap_bootstrap: finddevice /virtual-memory");
           if ((sz = OF_getproplen(vmem, "translations")) == -1)
                   panic("pmap_bootstrap: getproplen translations");
           if (sizeof(translations) < sz)
                   panic("pmap_bootstrap: translations too small");
           bzero(translations, sz);
           if (OF_getprop(vmem, "translations", translations, sz) == -1)
                   panic("pmap_bootstrap: getprop /virtual-memory/translations");
           sz /= sizeof(*translations);
           translations_size = sz;
           CTR0(KTR_PMAP, "pmap_bootstrap: translations");
           qsort(translations, sz, sizeof (*translations), om_cmp);
           for (i = 0; i < sz; i++) {
                   CTR3(KTR_PMAP,
                       "translation: start=%#lx size=%#lx tte=%#lx",
                       translations[i].om_start, translations[i].om_size,
                       translations[i].om_tte);
                   if (translations[i].om_start < VM_MIN_PROM_ADDRESS ||
                       translations[i].om_start > VM_MAX_PROM_ADDRESS)
                           continue;
                   for (off = 0; off < translations[i].om_size;
                       off += PAGE_SIZE) {
                           va = translations[i].om_start + off;
                           tp = tsb_kvtotte(va);
                           tp->tte_vpn = TV_VPN(va, TS_8K);
                           tp->tte_data =
                               ((translations[i].om_tte &
                                 ~(TD_SOFT_MASK << TD_SOFT_SHIFT)) | TD_EXEC) +
                               off;
                   }
           }
   
           /*
            * Get the available physical memory ranges from /memory/reg. These
            * are only used for kernel dumps, but it may not be wise to do prom
            * calls in that situation.
            */
           if ((sz = OF_getproplen(pmem, "reg")) == -1)
                   panic("pmap_bootstrap: getproplen /memory/reg");
           if (sizeof(sparc64_memreg) < sz)
                   panic("pmap_bootstrap: sparc64_memreg too small");
           if (OF_getprop(pmem, "reg", sparc64_memreg, sz) == -1)
                   panic("pmap_bootstrap: getprop /memory/reg");
           sparc64_nmemreg = sz / sizeof(*sparc64_memreg);
   
           /*
            * Initialize the kernel pmap (which is statically allocated).
            * NOTE: PMAP_LOCK_INIT() is needed as part of the initialization
            * but sparc64 start up is not ready to initialize mutexes yet.
            * It is called in machdep.c.
            */
           pm = kernel_pmap;
           for (i = 0; i < MAXCPU; i++)
                   pm->pm_context[i] = TLB_CTX_KERNEL;
           pm->pm_active = ~0;
   
           /* XXX flush all non-locked tlb entries */
   }
   
   void
   pmap_map_tsb(void)
   {
           vm_offset_t va;
           vm_paddr_t pa;
           u_long data;
           u_long s;
           int i;
   
           s = intr_disable();
   
           /*
            * Map the 4mb tsb pages.
            */
           for (i = 0; i < tsb_kernel_size; i += PAGE_SIZE_4M) {
                   va = (vm_offset_t)tsb_kernel + i;
                   pa = tsb_kernel_phys + i;
                   data = TD_V | TD_4M | TD_PA(pa) | TD_L | TD_CP | TD_CV |
                       TD_P | TD_W;
                   /* XXX - cheetah */
                   stxa(AA_DMMU_TAR, ASI_DMMU, TLB_TAR_VA(va) |
                       TLB_TAR_CTX(TLB_CTX_KERNEL));
                   stxa_sync(0, ASI_DTLB_DATA_IN_REG, data);
           }
   
           /*
            * Set the secondary context to be the kernel context (needed for
            * fp block operations in the kernel and the cache code).
            */
           stxa(AA_DMMU_SCXR, ASI_DMMU, TLB_CTX_KERNEL);
           membar(Sync);
   
           intr_restore(s);
   }
   
   /*
    * 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_paddr_t
   pmap_bootstrap_alloc(vm_size_t size)
   {
           vm_paddr_t pa;
           int i;
   
           size = round_page(size);
           for (i = 0; phys_avail[i + 1] != 0; i += 2) {
                   if (phys_avail[i + 1] - phys_avail[i] < size)
                           continue;
                   pa = phys_avail[i];
                   phys_avail[i] += size;
                   return (pa);
           }
           panic("pmap_bootstrap_alloc");
   }
   
   /*
    * Initialize a vm_page's machine-dependent fields.
    */
   void
   pmap_page_init(vm_page_t m)
   {
   
           TAILQ_INIT(&m->md.tte_list);
           m->md.color = DCACHE_COLOR(VM_PAGE_TO_PHYS(m));
           m->md.flags = 0;
           m->md.pmap = NULL;
   }
   
   /*
    * Initialize the pmap module.
    */
   void
   pmap_init(void)
   {
           vm_offset_t addr;
           vm_size_t size;
           int result;
           int i;
   
           for (i = 0; i < translations_size; i++) {
                   addr = translations[i].om_start;
                   size = translations[i].om_size;
                   if (addr < VM_MIN_PROM_ADDRESS || addr > VM_MAX_PROM_ADDRESS)
                           continue;
                   result = vm_map_find(kernel_map, NULL, 0, &addr, size, FALSE,
                       VM_PROT_ALL, VM_PROT_ALL, 0);
                   if (result != KERN_SUCCESS || addr != translations[i].om_start)
                           panic("pmap_init: vm_map_find");
           }
   }
   
   /*
    * Initialize the address space (zone) for the pv_entries.  Set a
    * high water mark so that the system can recover from excessive
    * numbers of pv entries.
    */
   void
   pmap_init2(void)
   {
   }
   
   /*
    * Extract the physical page address associated with the given
    * map/virtual_address pair.
    */
   vm_paddr_t
   pmap_extract(pmap_t pm, vm_offset_t va)
   {
           struct tte *tp;
           vm_paddr_t pa;
   
           if (pm == kernel_pmap)
                   return (pmap_kextract(va));
           PMAP_LOCK(pm);
           tp = tsb_tte_lookup(pm, va);
           if (tp == NULL)
                   pa = 0;
           else
                   pa = TTE_GET_PA(tp) | (va & TTE_GET_PAGE_MASK(tp));
           PMAP_UNLOCK(pm);
           return (pa);
   }
   
   /*
    * 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 pm, vm_offset_t va, vm_prot_t prot)
   {
           struct tte *tp;
           vm_page_t m;
   
           m = NULL;
           vm_page_lock_queues();
           if (pm == kernel_pmap) {
                   if (va >= VM_MIN_DIRECT_ADDRESS) {
                           tp = NULL;
                           m = PHYS_TO_VM_PAGE(TLB_DIRECT_TO_PHYS(va));
                           vm_page_hold(m);
                   } else {
                           tp = tsb_kvtotte(va);
                           if ((tp->tte_data & TD_V) == 0)
                                   tp = NULL;
                   }
           } else {
                   PMAP_LOCK(pm);
                   tp = tsb_tte_lookup(pm, va);
           }
           if (tp != NULL && ((tp->tte_data & TD_SW) ||
               (prot & VM_PROT_WRITE) == 0)) {
                   m = PHYS_TO_VM_PAGE(TTE_GET_PA(tp));
                   vm_page_hold(m);
           }
           vm_page_unlock_queues();
           if (pm != kernel_pmap)
                   PMAP_UNLOCK(pm);
           return (m);
   }
   
   /*
    * Extract the physical page address associated with the given kernel virtual
    * address.
    */
   vm_paddr_t
   pmap_kextract(vm_offset_t va)
   {
           struct tte *tp;
   
           if (va >= VM_MIN_DIRECT_ADDRESS)
                   return (TLB_DIRECT_TO_PHYS(va));
           tp = tsb_kvtotte(va);
           if ((tp->tte_data & TD_V) == 0)
                   return (0);
           return (TTE_GET_PA(tp) | (va & TTE_GET_PAGE_MASK(tp)));
   }
   
   int
   pmap_cache_enter(vm_page_t m, vm_offset_t va)
   {
           struct tte *tp;
           int color;
   
           mtx_assert(&vm_page_queue_mtx, MA_OWNED);
           KASSERT((m->flags & PG_FICTITIOUS) == 0,
               ("pmap_cache_enter: fake page"));
           PMAP_STATS_INC(pmap_ncache_enter);
   
           /*
            * Find the color for this virtual address and note the added mapping.
            */
           color = DCACHE_COLOR(va);
           m->md.colors[color]++;
   
           /*
            * If all existing mappings have the same color, the mapping is
            * cacheable.
            */
           if (m->md.color == color) {
                   KASSERT(m->md.colors[DCACHE_OTHER_COLOR(color)] == 0,
                       ("pmap_cache_enter: cacheable, mappings of other color"));
                   if (m->md.color == DCACHE_COLOR(VM_PAGE_TO_PHYS(m)))
                           PMAP_STATS_INC(pmap_ncache_enter_c);
                   else
                           PMAP_STATS_INC(pmap_ncache_enter_oc);
                   return (1);
           }
   
           /*
            * If there are no mappings of the other color, and the page still has
            * the wrong color, this must be a new mapping.  Change the color to
            * match the new mapping, which is cacheable.  We must flush the page
            * from the cache now.
            */
           if (m->md.colors[DCACHE_OTHER_COLOR(color)] == 0) {
                   KASSERT(m->md.colors[color] == 1,
                       ("pmap_cache_enter: changing color, not new mapping"));
                   dcache_page_inval(VM_PAGE_TO_PHYS(m));
                   m->md.color = color;
                   if (m->md.color == DCACHE_COLOR(VM_PAGE_TO_PHYS(m)))
                           PMAP_STATS_INC(pmap_ncache_enter_cc);
                   else
                           PMAP_STATS_INC(pmap_ncache_enter_coc);
                   return (1);
           }
   
           /*
            * If the mapping is already non-cacheable, just return.
            */     
           if (m->md.color == -1) {
                   PMAP_STATS_INC(pmap_ncache_enter_nc);
                   return (0);
           }
   
           PMAP_STATS_INC(pmap_ncache_enter_cnc);
   
           /*
            * Mark all mappings as uncacheable, flush any lines with the other
            * color out of the dcache, and set the color to none (-1).
            */
           TAILQ_FOREACH(tp, &m->md.tte_list, tte_link) {
                   atomic_clear_long(&tp->tte_data, TD_CV);
                   tlb_page_demap(TTE_GET_PMAP(tp), TTE_GET_VA(tp));
           }
           dcache_page_inval(VM_PAGE_TO_PHYS(m));
           m->md.color = -1;
           return (0);
   }
   
   void
   pmap_cache_remove(vm_page_t m, vm_offset_t va)
   {
           struct tte *tp;
           int color;
   
           mtx_assert(&vm_page_queue_mtx, MA_OWNED);
           CTR3(KTR_PMAP, "pmap_cache_remove: m=%p va=%#lx c=%d", m, va,
               m->md.colors[DCACHE_COLOR(va)]);
           KASSERT((m->flags & PG_FICTITIOUS) == 0,
               ("pmap_cache_remove: fake page"));
           KASSERT(m->md.colors[DCACHE_COLOR(va)] > 0,
               ("pmap_cache_remove: no mappings %d <= 0",
               m->md.colors[DCACHE_COLOR(va)]));
           PMAP_STATS_INC(pmap_ncache_remove);
   
           /*
            * Find the color for this virtual address and note the removal of
            * the mapping.
            */
           color = DCACHE_COLOR(va);
           m->md.colors[color]--;
   
           /*
            * If the page is cacheable, just return and keep the same color, even
            * if there are no longer any mappings.
            */
           if (m->md.color != -1) {
                   if (m->md.color == DCACHE_COLOR(VM_PAGE_TO_PHYS(m)))
                           PMAP_STATS_INC(pmap_ncache_remove_c);
                   else
                           PMAP_STATS_INC(pmap_ncache_remove_oc);
                   return;
           }
   
           KASSERT(m->md.colors[DCACHE_OTHER_COLOR(color)] != 0,
               ("pmap_cache_remove: uncacheable, no mappings of other color"));
   
           /*
            * If the page is not cacheable (color is -1), and the number of
            * mappings for this color is not zero, just return.  There are
            * mappings of the other color still, so remain non-cacheable.
            */
           if (m->md.colors[color] != 0) {
                   PMAP_STATS_INC(pmap_ncache_remove_nc);
                   return;
           }
   
           /*
            * The number of mappings for this color is now zero.  Recache the
            * other colored mappings, and change the page color to the other
            * color.  There should be no lines in the data cache for this page,
            * so flushing should not be needed.
            */
           TAILQ_FOREACH(tp, &m->md.tte_list, tte_link) {
                   atomic_set_long(&tp->tte_data, TD_CV);
                   tlb_page_demap(TTE_GET_PMAP(tp), TTE_GET_VA(tp));
           }
           m->md.color = DCACHE_OTHER_COLOR(color);
   
           if (m->md.color == DCACHE_COLOR(VM_PAGE_TO_PHYS(m)))
                   PMAP_STATS_INC(pmap_ncache_remove_cc);
           else
                   PMAP_STATS_INC(pmap_ncache_remove_coc);
   }
   
   /*
    * Map a wired page into kernel virtual address space.
    */
   void
   pmap_kenter(vm_offset_t va, vm_page_t m)
   {
           vm_offset_t ova;
           struct tte *tp;
           vm_page_t om;
           u_long data;
   
           mtx_assert(&vm_page_queue_mtx, MA_OWNED);
           PMAP_STATS_INC(pmap_nkenter);
           tp = tsb_kvtotte(va);
           CTR4(KTR_PMAP, "pmap_kenter: va=%#lx pa=%#lx tp=%p data=%#lx",
               va, VM_PAGE_TO_PHYS(m), tp, tp->tte_data);
           if (m->pc != DCACHE_COLOR(va)) {
                   CTR6(KTR_CT2,
           "pmap_kenter: off colour va=%#lx pa=%#lx o=%p oc=%#lx ot=%d pi=%#lx",
                       va, VM_PAGE_TO_PHYS(m), m->object,
                       m->object ? m->object->pg_color : -1,
                       m->object ? m->object->type : -1,
                       m->pindex);
                   PMAP_STATS_INC(pmap_nkenter_oc);
           }
           if ((tp->tte_data & TD_V) != 0) {
                   om = PHYS_TO_VM_PAGE(TTE_GET_PA(tp));
                   ova = TTE_GET_VA(tp);
                   if (m == om && va == ova) {
                           PMAP_STATS_INC(pmap_nkenter_stupid);
                           return;
                   }
                   TAILQ_REMOVE(&om->md.tte_list, tp, tte_link);
                   pmap_cache_remove(om, ova);
                   if (va != ova)
                           tlb_page_demap(kernel_pmap, ova);
           }
           data = TD_V | TD_8K | VM_PAGE_TO_PHYS(m) | TD_REF | TD_SW | TD_CP |
               TD_P | TD_W;
           if (pmap_cache_enter(m, va) != 0)
                   data |= TD_CV;
           tp->tte_vpn = TV_VPN(va, TS_8K);
           tp->tte_data = data;
           TAILQ_INSERT_TAIL(&m->md.tte_list, tp, tte_link);
   }
   
   /*
    * Map a wired page into kernel virtual address space. This additionally
    * takes a flag argument wich is or'ed to the TTE data. This is used by
    * bus_space_map().
    * NOTE: if the mapping is non-cacheable, it's the caller's responsibility
    * to flush entries that might still be in the cache, if applicable.
    */
   void
   pmap_kenter_flags(vm_offset_t va, vm_paddr_t pa, u_long flags)
   {
           struct tte *tp;
   
           tp = tsb_kvtotte(va);
           CTR4(KTR_PMAP, "pmap_kenter_flags: va=%#lx pa=%#lx tp=%p data=%#lx",
               va, pa, tp, tp->tte_data);
           tp->tte_vpn = TV_VPN(va, TS_8K);
           tp->tte_data = TD_V | TD_8K | TD_PA(pa) | TD_REF | TD_P | flags;
   }
   
   /*
    * Remove a wired page from kernel virtual address space.
    */
   void
   pmap_kremove(vm_offset_t va)
   {
           struct tte *tp;
           vm_page_t m;
   
           mtx_assert(&vm_page_queue_mtx, MA_OWNED);
           PMAP_STATS_INC(pmap_nkremove);
           tp = tsb_kvtotte(va);
           CTR3(KTR_PMAP, "pmap_kremove: va=%#lx tp=%p data=%#lx", va, tp,
               tp->tte_data);
           if ((tp->tte_data & TD_V) == 0)
                   return;
           m = PHYS_TO_VM_PAGE(TTE_GET_PA(tp));
           TAILQ_REMOVE(&m->md.tte_list, tp, tte_link);
           pmap_cache_remove(m, va);
           TTE_ZERO(tp);
   }
   
   /*
    * Inverse of pmap_kenter_flags, used by bus_space_unmap().
    */
   void
   pmap_kremove_flags(vm_offset_t va)
   {
           struct tte *tp;
   
           tp = tsb_kvtotte(va);
           CTR3(KTR_PMAP, "pmap_kremove: va=%#lx tp=%p data=%#lx", va, tp,
               tp->tte_data);
           TTE_ZERO(tp);
   }
   
   /*
    * 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.
    */
   vm_offset_t
   pmap_map(vm_offset_t *virt, vm_paddr_t start, vm_paddr_t end, int prot)
   {
   
           return (TLB_PHYS_TO_DIRECT(start));
   }
   
   /*
    * 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;
           int locked;
   
           PMAP_STATS_INC(pmap_nqenter);
           va = sva;
           if (!(locked = mtx_owned(&vm_page_queue_mtx)))
                   vm_page_lock_queues();
           while (count-- > 0) {
                   pmap_kenter(va, *m);
                   va += PAGE_SIZE;
                   m++;
           }
           if (!locked)
                   vm_page_unlock_queues();
           tlb_range_demap(kernel_pmap, sva, va);
   }
   
   /*
    * 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;
           int locked;
   
           PMAP_STATS_INC(pmap_nqremove);
           va = sva;
           if (!(locked = mtx_owned(&vm_page_queue_mtx)))
                   vm_page_lock_queues();
           while (count-- > 0) {
                   pmap_kremove(va);
                   va += PAGE_SIZE;
           }
           if (!locked)
                   vm_page_unlock_queues();
           tlb_range_demap(kernel_pmap, sva, va);
   }
   
   /*
    * Initialize the pmap associated with process 0.
    */
   void
   pmap_pinit0(pmap_t pm)
   {
           int i;
   
           PMAP_LOCK_INIT(pm);
           for (i = 0; i < MAXCPU; i++)
                   pm->pm_context[i] = 0;
           pm->pm_active = 0;
           pm->pm_tsb = NULL;
           pm->pm_tsb_obj = NULL;
           bzero(&pm->pm_stats, sizeof(pm->pm_stats));
   }
   
   /*
   * Initialize a preallocated and zeroed pmap structure, uch as one in a
   * vmspace structure.
   */
  void
  pmap_pinit(pmap_t pm)
  {
          vm_page_t ma[TSB_PAGES];
          vm_page_t m;
          int i;
  
          PMAP_LOCK_INIT(pm);
  
          /*
           * Allocate kva space for the tsb.
           */
          if (pm->pm_tsb == NULL) {
                  pm->pm_tsb = (struct tte *)kmem_alloc_nofault(kernel_map,
                      TSB_BSIZE);
          }
  
          /*
           * Allocate an object for it.
           */
          if (pm->pm_tsb_obj == NULL)
                  pm->pm_tsb_obj = vm_object_allocate(OBJT_DEFAULT, TSB_PAGES);
  
          VM_OBJECT_LOCK(pm->pm_tsb_obj);
          for (i = 0; i < TSB_PAGES; i++) {
                  m = vm_page_grab(pm->pm_tsb_obj, i, VM_ALLOC_NOBUSY |
                      VM_ALLOC_RETRY | VM_ALLOC_WIRED | VM_ALLOC_ZERO);
  
                  vm_page_lock_queues();
                  m->valid = VM_PAGE_BITS_ALL;
                  m->md.pmap = pm;
                  vm_page_unlock_queues();
  
                  ma[i] = m;
          }
          VM_OBJECT_UNLOCK(pm->pm_tsb_obj);
          pmap_qenter((vm_offset_t)pm->pm_tsb, ma, TSB_PAGES);
  
          for (i = 0; i < MAXCPU; i++)
                  pm->pm_context[i] = -1;
          pm->pm_active = 0;
          bzero(&pm->pm_stats, sizeof(pm->pm_stats));
  }
  
  /*
   * Release any resources held by the given physical map.
   * Called when a pmap initialized by pmap_pinit is being released.
   * Should only be called if the map contains no valid mappings.
   */
  void
  pmap_release(pmap_t pm)
  {
          vm_object_t obj;
          vm_page_t m;
          struct pcpu *pc;
  
          CTR2(KTR_PMAP, "pmap_release: ctx=%#x tsb=%p",
              pm->pm_context[PCPU_GET(cpuid)], pm->pm_tsb);
          KASSERT(pmap_resident_count(pm) == 0,
              ("pmap_release: resident pages %ld != 0",
              pmap_resident_count(pm)));
  
          /*
           * After the pmap was freed, it might be reallocated to a new process.
           * When switching, this might lead us to wrongly assume that we need
           * not switch contexts because old and new pmap pointer are equal.
           * Therefore, make sure that this pmap is not referenced by any PCPU
           * pointer any more. This could happen in two cases:
           * - A process that referenced the pmap is currently exiting on a CPU.
           *   However, it is guaranteed to not switch in any more after setting
           *   its state to PRS_ZOMBIE.
           * - A process that referenced this pmap ran on a CPU, but we switched
           *   to a kernel thread, leaving the pmap pointer unchanged.
           */
          mtx_lock_spin(&sched_lock);
          SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
                  if (pc->pc_pmap == pm)
                          pc->pc_pmap = NULL;
          }
          mtx_unlock_spin(&sched_lock);
  
          obj = pm->pm_tsb_obj;
          VM_OBJECT_LOCK(obj);
          KASSERT(obj->ref_count == 1, ("pmap_release: tsbobj ref count != 1"));
          while (!TAILQ_EMPTY(&obj->memq)) {
                  m = TAILQ_FIRST(&obj->memq);
                  vm_page_lock_queues();
                  if (vm_page_sleep_if_busy(m, FALSE, "pmaprl"))
                          continue;
                  KASSERT(m->hold_count == 0,
                      ("pmap_release: freeing held tsb page"));
                  m->md.pmap = NULL;
                  m->wire_count--;
                  atomic_subtract_int(&cnt.v_wire_count, 1);
                  vm_page_free_zero(m);
                  vm_page_unlock_queues();
          }
          VM_OBJECT_UNLOCK(obj);
          pmap_qremove((vm_offset_t)pm->pm_tsb, TSB_PAGES);
          PMAP_LOCK_DESTROY(pm);
  }
  
  /*
   * Grow the number of kernel page table entries.  Unneeded.
   */
  void
  pmap_growkernel(vm_offset_t addr)
  {
  
          panic("pmap_growkernel: can't grow kernel");
  }
  
  int
  pmap_remove_tte(struct pmap *pm, struct pmap *pm2, struct tte *tp,
                  vm_offset_t va)
  {
          vm_page_t m;
          u_long data;
  
          mtx_assert(&vm_page_queue_mtx, MA_OWNED);
          data = atomic_readandclear_long(&tp->tte_data);
          if ((data & TD_FAKE) == 0) {
                  m = PHYS_TO_VM_PAGE(TD_PA(data));
                  TAILQ_REMOVE(&m->md.tte_list, tp, tte_link);
                  if ((data & TD_WIRED) != 0)
                          pm->pm_stats.wired_count--;
                  if ((data & TD_PV) != 0) {
                          if ((data & TD_W) != 0 && pmap_track_modified(pm, va))
                                  vm_page_dirty(m);
                          if ((data & TD_REF) != 0)
                                  vm_page_flag_set(m, PG_REFERENCED);
                          if (TAILQ_EMPTY(&m->md.tte_list))
                                  vm_page_flag_clear(m, PG_WRITEABLE);
                          pm->pm_stats.resident_count--;
                  }
                  pmap_cache_remove(m, va);
          }
          TTE_ZERO(tp);
          if (PMAP_REMOVE_DONE(pm))
                  return (0);
          return (1);
  }
  
  /*
   * Remove the given range of addresses from the specified map.
   */
  void
  pmap_remove(pmap_t pm, vm_offset_t start, vm_offset_t end)
  {
          struct tte *tp;
          vm_offset_t va;
  
          CTR3(KTR_PMAP, "pmap_remove: ctx=%#lx start=%#lx end=%#lx",
              pm->pm_context[PCPU_GET(cpuid)], start, end);
          if (PMAP_REMOVE_DONE(pm))
                  return;
          vm_page_lock_queues();
          PMAP_LOCK(pm);
          if (end - start > PMAP_TSB_THRESH) {
                  tsb_foreach(pm, NULL, start, end, pmap_remove_tte);
                  tlb_context_demap(pm);
          } else {
                  for (va = start; va < end; va += PAGE_SIZE) {
                          if ((tp = tsb_tte_lookup(pm, va)) != NULL) {
                                  if (!pmap_remove_tte(pm, NULL, tp, va))
                                          break;
                          }
                  }
                  tlb_range_demap(pm, start, end - 1);
          }
          PMAP_UNLOCK(pm);
          vm_page_unlock_queues();
  }
  
  void
  pmap_remove_all(vm_page_t m)
  {
          struct pmap *pm;
          struct tte *tpn;
          struct tte *tp;
          vm_offset_t va;
  
          mtx_assert(&vm_page_queue_mtx, MA_OWNED);
          for (tp = TAILQ_FIRST(&m->md.tte_list); tp != NULL; tp = tpn) {
                  tpn = TAILQ_NEXT(tp, tte_link);
                  if ((tp->tte_data & TD_PV) == 0)
                          continue;
                  pm = TTE_GET_PMAP(tp);
                  va = TTE_GET_VA(tp);
                  PMAP_LOCK(pm);
                  if ((tp->tte_data & TD_WIRED) != 0)
                          pm->pm_stats.wired_count--;
                  if ((tp->tte_data & TD_REF) != 0)
                          vm_page_flag_set(m, PG_REFERENCED);
                  if ((tp->tte_data & TD_W) != 0 &&
                      pmap_track_modified(pm, va))
                          vm_page_dirty(m);
                  tp->tte_data &= ~TD_V;
                  tlb_page_demap(pm, va);
                  TAILQ_REMOVE(&m->md.tte_list, tp, tte_link);
                  pm->pm_stats.resident_count--;
                  pmap_cache_remove(m, va);
                  TTE_ZERO(tp);
                  PMAP_UNLOCK(pm);
          }
          vm_page_flag_clear(m, PG_WRITEABLE);
  }
  
  int
  pmap_protect_tte(struct pmap *pm, struct pmap *pm2, struct tte *tp,
                   vm_offset_t va)
  {
          u_long data;
          vm_page_t m;
  
          data = atomic_clear_long(&tp->tte_data, TD_REF | TD_SW | TD_W);
          if ((data & TD_PV) != 0) {
                  m = PHYS_TO_VM_PAGE(TD_PA(data));
                  if ((data & TD_REF) != 0)
                          vm_page_flag_set(m, PG_REFERENCED);
                  if ((data & TD_W) != 0 && pmap_track_modified(pm, va))
                          vm_page_dirty(m);
          }
          return (1);
  }
  
  /*
   * 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)
  {
          vm_offset_t va;
          struct tte *tp;
  
          CTR4(KTR_PMAP, "pmap_protect: ctx=%#lx sva=%#lx eva=%#lx prot=%#lx",
              pm->pm_context[PCPU_GET(cpuid)], sva, eva, prot);
  
          if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
                  pmap_remove(pm, sva, eva);
                  return;
          }
  
          if (prot & VM_PROT_WRITE)
                  return;
  
          vm_page_lock_queues();
          PMAP_LOCK(pm);
          if (eva - sva > PMAP_TSB_THRESH) {
                  tsb_foreach(pm, NULL, sva, eva, pmap_protect_tte);
                  tlb_context_demap(pm);
          } else {
                  for (va = sva; va < eva; va += PAGE_SIZE) {
                          if ((tp = tsb_tte_lookup(pm, va)) != NULL)
                                  pmap_protect_tte(pm, NULL, tp, va);
                  }
                  tlb_range_demap(pm, sva, eva - 1);
          }
          PMAP_UNLOCK(pm);
          vm_page_unlock_queues();
  }
  
  /*
   * 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 pm, vm_offset_t va, vm_page_t m, vm_prot_t prot,
             boolean_t wired)
  {
          struct tte *tp;
          vm_paddr_t pa;
          u_long data;
          int i;
  
          PMAP_STATS_INC(pmap_nenter);
          pa = VM_PAGE_TO_PHYS(m);
  
          /*
           * If this is a fake page from the device_pager, but it covers actual
           * physical memory, convert to the real backing page.
           */
          if ((m->flags & PG_FICTITIOUS) != 0) {
                  for (i = 0; phys_avail[i + 1] != 0; i += 2) {
                          if (pa >= phys_avail[i] && pa <= phys_avail[i + 1]) {
                                  m = PHYS_TO_VM_PAGE(pa);
                                  break;
                          }
                  }
          }
  
          CTR6(KTR_PMAP,
              "pmap_enter: ctx=%p m=%p va=%#lx pa=%#lx prot=%#x wired=%d",
              pm->pm_context[PCPU_GET(cpuid)], m, va, pa, prot, wired);
  
          vm_page_lock_queues();
          PMAP_LOCK(pm);
  
          /*
           * If there is an existing mapping, and the physical address has not
           * changed, must be protection or wiring change.
           */
          if ((tp = tsb_tte_lookup(pm, va)) != NULL && TTE_GET_PA(tp) == pa) {
                  CTR0(KTR_PMAP, "pmap_enter: update");
                  PMAP_STATS_INC(pmap_nenter_update);
  
                  /*
                   * Wiring change, just update stats.
                   */
                  if (wired) {
                          if ((tp->tte_data & TD_WIRED) == 0) {
                                  tp->tte_data |= TD_WIRED;
                                  pm->pm_stats.wired_count++;
                          }
                  } else {
                          if ((tp->tte_data & TD_WIRED) != 0) {
                                  tp->tte_data &= ~TD_WIRED;
                                  pm->pm_stats.wired_count--;
                          }
                  }
  
                  /*
                   * Save the old bits and clear the ones we're interested in.
                   */
                  data = tp->tte_data;
                  tp->tte_data &= ~(TD_EXEC | TD_SW | TD_W);
  
                  /*
                   * If we're turning off write permissions, sense modify status.
                   */
                  if ((prot & VM_PROT_WRITE) != 0) {
                          tp->tte_data |= TD_SW;
                          if (wired) {
                                  tp->tte_data |= TD_W;
                          }
                  } else if ((data & TD_W) != 0 &&
                      pmap_track_modified(pm, va)) {
                          vm_page_dirty(m);
                  }
  
                  /*
                   * If we're turning on execute permissions, flush the icache.
                   */
                  if ((prot & VM_PROT_EXECUTE) != 0) {
                          if ((data & TD_EXEC) == 0) {
                                  icache_page_inval(pa);
                          }
                          tp->tte_data |= TD_EXEC;
                  }
  
                  /*
                   * Delete the old mapping.
                   */
                  tlb_page_demap(pm, TTE_GET_VA(tp));
          } else {
                  /*
                   * If there is an existing mapping, but its for a different
                   * phsyical address, delete the old mapping.
                   */
                  if (tp != NULL) {
                          CTR0(KTR_PMAP, "pmap_enter: replace");
                          PMAP_STATS_INC(pmap_nenter_replace);
                          pmap_remove_tte(pm, NULL, tp, va);
                          tlb_page_demap(pm, va);
                  } else {
                          CTR0(KTR_PMAP, "pmap_enter: new");
                          PMAP_STATS_INC(pmap_nenter_new);
                  }
  
                  /*
                   * Now set up the data and install the new mapping.
                   */
                  data = TD_V | TD_8K | TD_PA(pa);
                  if (pm == kernel_pmap)
                          data |= TD_P;
                  if (prot & VM_PROT_WRITE)
                          data |= TD_SW;
                  if (prot & VM_PROT_EXECUTE) {
                          data |= TD_EXEC;
                          icache_page_inval(pa);
                  }
  
                  /*
                   * If its wired update stats.  We also don't need reference or
                   * modify tracking for wired mappings, so set the bits now.
                   */
                  if (wired) {
                          pm->pm_stats.wired_count++;
                          data |= TD_REF | TD_WIRED;
                          if ((prot & VM_PROT_WRITE) != 0)
                                  data |= TD_W;
                  }
  
                  tsb_tte_enter(pm, m, va, TS_8K, data);
          }
          vm_page_unlock_queues();
          PMAP_UNLOCK(pm);
  }
  
  vm_page_t
  pmap_enter_quick(pmap_t pm, vm_offset_t va, vm_page_t m, vm_page_t mpte)
  {
  
          vm_page_busy(m);
          vm_page_unlock_queues();
          VM_OBJECT_UNLOCK(m->object);
          pmap_enter(pm, va, m, VM_PROT_READ | VM_PROT_EXECUTE, FALSE);
          VM_OBJECT_LOCK(m->object);
          vm_page_lock_queues();
          vm_page_wakeup(m);
          return (NULL);
  }
  
  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"));
  }
  
  /*
   * Change the wiring attribute for a map/virtual-address pair.
   * The mapping must already exist in the pmap.
   */
  void
  pmap_change_wiring(pmap_t pm, vm_offset_t va, boolean_t wired)
  {
          struct tte *tp;
          u_long data;
  
          PMAP_LOCK(pm);
          if ((tp = tsb_tte_lookup(pm, va)) != NULL) {
                  if (wired) {
                          data = atomic_set_long(&tp->tte_data, TD_WIRED);
                          if ((data & TD_WIRED) == 0)
                                  pm->pm_stats.wired_count++;
                  } else {
                          data = atomic_clear_long(&tp->tte_data, TD_WIRED);
                          if ((data & TD_WIRED) != 0)
                                  pm->pm_stats.wired_count--;
                  }
          }
          PMAP_UNLOCK(pm);
  }
  
  static int
  pmap_copy_tte(pmap_t src_pmap, pmap_t dst_pmap, struct tte *tp, vm_offset_t va)
  {
          vm_page_t m;
          u_long data;
  
          if ((tp->tte_data & TD_FAKE) != 0)
                  return (1);
          if (tsb_tte_lookup(dst_pmap, va) == NULL) {
                  data = tp->tte_data &
                      ~(TD_PV | TD_REF | TD_SW | TD_CV | TD_W);
                  m = PHYS_TO_VM_PAGE(TTE_GET_PA(tp));
                  tsb_tte_enter(dst_pmap, m, va, TS_8K, data);
          }
          return (1);
  }
  
  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)
  {
          struct tte *tp;
          vm_offset_t va;
  
          if (dst_addr != src_addr)
                  return;
          vm_page_lock_queues();
          if (dst_pmap < src_pmap) {
                  PMAP_LOCK(dst_pmap);
                  PMAP_LOCK(src_pmap);
          } else {
                  PMAP_LOCK(src_pmap);
                  PMAP_LOCK(dst_pmap);
          }
          if (len > PMAP_TSB_THRESH) {
                  tsb_foreach(src_pmap, dst_pmap, src_addr, src_addr + len,
                      pmap_copy_tte);
                  tlb_context_demap(dst_pmap);
          } else {
                  for (va = src_addr; va < src_addr + len; va += PAGE_SIZE) {
                          if ((tp = tsb_tte_lookup(src_pmap, va)) != NULL)
                                  pmap_copy_tte(src_pmap, dst_pmap, tp, va);
                  }
                  tlb_range_demap(dst_pmap, src_addr, src_addr + len - 1);
          }
          vm_page_unlock_queues();
          PMAP_UNLOCK(src_pmap);
          PMAP_UNLOCK(dst_pmap);
  }
  
  void
  pmap_zero_page(vm_page_t m)
  {
          struct tte *tp;
          vm_offset_t va;
          vm_paddr_t pa;
  
          KASSERT((m->flags & PG_FICTITIOUS) == 0,
              ("pmap_zero_page: fake page"));
          PMAP_STATS_INC(pmap_nzero_page);
          pa = VM_PAGE_TO_PHYS(m);
          if (m->md.color == -1) {
                  PMAP_STATS_INC(pmap_nzero_page_nc);
                  aszero(ASI_PHYS_USE_EC, pa, PAGE_SIZE);
          } else if (m->md.color == DCACHE_COLOR(pa)) {
                  PMAP_STATS_INC(pmap_nzero_page_c);
                  va = TLB_PHYS_TO_DIRECT(pa);
                  cpu_block_zero((void *)va, PAGE_SIZE);
          } else {
                  PMAP_STATS_INC(pmap_nzero_page_oc);
                  PMAP_LOCK(kernel_pmap);
                  va = pmap_temp_map_1 + (m->md.color * PAGE_SIZE);
                  tp = tsb_kvtotte(va);
                  tp->tte_data = TD_V | TD_8K | TD_PA(pa) | TD_CP | TD_CV | TD_W;
                  tp->tte_vpn = TV_VPN(va, TS_8K);
                  cpu_block_zero((void *)va, PAGE_SIZE);
                  tlb_page_demap(kernel_pmap, va);
                  PMAP_UNLOCK(kernel_pmap);
          }
  }
  
  void
  pmap_zero_page_area(vm_page_t m, int off, int size)
  {
          struct tte *tp;
          vm_offset_t va;
          vm_paddr_t pa;
  
          KASSERT((m->flags & PG_FICTITIOUS) == 0,
              ("pmap_zero_page_area: fake page"));
          KASSERT(off + size <= PAGE_SIZE, ("pmap_zero_page_area: bad off/size"));
          PMAP_STATS_INC(pmap_nzero_page_area);
          pa = VM_PAGE_TO_PHYS(m);
          if (m->md.color == -1) {
                  PMAP_STATS_INC(pmap_nzero_page_area_nc);
                  aszero(ASI_PHYS_USE_EC, pa + off, size);
          } else if (m->md.color == DCACHE_COLOR(pa)) {
                  PMAP_STATS_INC(pmap_nzero_page_area_c);
                  va = TLB_PHYS_TO_DIRECT(pa);
                  bzero((void *)(va + off), size);
          } else {
                  PMAP_STATS_INC(pmap_nzero_page_area_oc);
                  PMAP_LOCK(kernel_pmap);
                  va = pmap_temp_map_1 + (m->md.color * PAGE_SIZE);
                  tp = tsb_kvtotte(va);
                  tp->tte_data = TD_V | TD_8K | TD_PA(pa) | TD_CP | TD_CV | TD_W;
                  tp->tte_vpn = TV_VPN(va, TS_8K);
                  bzero((void *)(va + off), size);
                  tlb_page_demap(kernel_pmap, va);
                  PMAP_UNLOCK(kernel_pmap);
          }
  }
  
  void
  pmap_zero_page_idle(vm_page_t m)
  {
          struct tte *tp;
          vm_offset_t va;
          vm_paddr_t pa;
  
          KASSERT((m->flags & PG_FICTITIOUS) == 0,
              ("pmap_zero_page_idle: fake page"));
          PMAP_STATS_INC(pmap_nzero_page_idle);
          pa = VM_PAGE_TO_PHYS(m);
          if (m->md.color == -1) {
                  PMAP_STATS_INC(pmap_nzero_page_idle_nc);
                  aszero(ASI_PHYS_USE_EC, pa, PAGE_SIZE);
          } else if (m->md.color == DCACHE_COLOR(pa)) {
                  PMAP_STATS_INC(pmap_nzero_page_idle_c);
                  va = TLB_PHYS_TO_DIRECT(pa);
                  cpu_block_zero((void *)va, PAGE_SIZE);
          } else {
                  PMAP_STATS_INC(pmap_nzero_page_idle_oc);
                  va = pmap_idle_map + (m->md.color * PAGE_SIZE);
                  tp = tsb_kvtotte(va);
                  tp->tte_data = TD_V | TD_8K | TD_PA(pa) | TD_CP | TD_CV | TD_W;
                  tp->tte_vpn = TV_VPN(va, TS_8K);
                  cpu_block_zero((void *)va, PAGE_SIZE);
                  tlb_page_demap(kernel_pmap, va);
          }
  }
  
  void
  pmap_copy_page(vm_page_t msrc, vm_page_t mdst)
  {
          vm_offset_t vdst;
          vm_offset_t vsrc;
          vm_paddr_t pdst;
          vm_paddr_t psrc;
          struct tte *tp;
  
          KASSERT((mdst->flags & PG_FICTITIOUS) == 0,
              ("pmap_copy_page: fake dst page"));
          KASSERT((msrc->flags & PG_FICTITIOUS) == 0,
              ("pmap_copy_page: fake src page"));
          PMAP_STATS_INC(pmap_ncopy_page);
          pdst = VM_PAGE_TO_PHYS(mdst);
          psrc = VM_PAGE_TO_PHYS(msrc);
          if (msrc->md.color == -1 && mdst->md.color == -1) {
                  PMAP_STATS_INC(pmap_ncopy_page_nc);
                  ascopy(ASI_PHYS_USE_EC, psrc, pdst, PAGE_SIZE);
          } else if (msrc->md.color == DCACHE_COLOR(psrc) &&
              mdst->md.color == DCACHE_COLOR(pdst)) {
                  PMAP_STATS_INC(pmap_ncopy_page_c);
                  vdst = TLB_PHYS_TO_DIRECT(pdst);
                  vsrc = TLB_PHYS_TO_DIRECT(psrc);
                  cpu_block_copy((void *)vsrc, (void *)vdst, PAGE_SIZE);
          } else if (msrc->md.color == -1) {
                  if (mdst->md.color == DCACHE_COLOR(pdst)) {
                          PMAP_STATS_INC(pmap_ncopy_page_dc);
                          vdst = TLB_PHYS_TO_DIRECT(pdst);
                          ascopyfrom(ASI_PHYS_USE_EC, psrc, (void *)vdst,
                              PAGE_SIZE);
                  } else {
                          PMAP_STATS_INC(pmap_ncopy_page_doc);
                          PMAP_LOCK(kernel_pmap);
                          vdst = pmap_temp_map_1 + (mdst->md.color * PAGE_SIZE);
                          tp = tsb_kvtotte(vdst);
                          tp->tte_data =
                              TD_V | TD_8K | TD_PA(pdst) | TD_CP | TD_CV | TD_W;
                          tp->tte_vpn = TV_VPN(vdst, TS_8K);
                          ascopyfrom(ASI_PHYS_USE_EC, psrc, (void *)vdst,
                              PAGE_SIZE);
                          tlb_page_demap(kernel_pmap, vdst);
                          PMAP_UNLOCK(kernel_pmap);
                  }
          } else if (mdst->md.color == -1) {
                  if (msrc->md.color == DCACHE_COLOR(psrc)) {
                          PMAP_STATS_INC(pmap_ncopy_page_sc);
                          vsrc = TLB_PHYS_TO_DIRECT(psrc);
                          ascopyto((void *)vsrc, ASI_PHYS_USE_EC, pdst,
                              PAGE_SIZE);
                  } else {
                          PMAP_STATS_INC(pmap_ncopy_page_soc);
                          PMAP_LOCK(kernel_pmap);
                          vsrc = pmap_temp_map_1 + (msrc->md.color * PAGE_SIZE);
                          tp = tsb_kvtotte(vsrc);
                          tp->tte_data =
                              TD_V | TD_8K | TD_PA(psrc) | TD_CP | TD_CV | TD_W;
                          tp->tte_vpn = TV_VPN(vsrc, TS_8K);
                          ascopyto((void *)vsrc, ASI_PHYS_USE_EC, pdst,
                              PAGE_SIZE);
                          tlb_page_demap(kernel_pmap, vsrc);
                          PMAP_UNLOCK(kernel_pmap);
                  }
          } else {
                  PMAP_STATS_INC(pmap_ncopy_page_oc);
                  PMAP_LOCK(kernel_pmap);
                  vdst = pmap_temp_map_1 + (mdst->md.color * PAGE_SIZE);
                  tp = tsb_kvtotte(vdst);
                  tp->tte_data =
                      TD_V | TD_8K | TD_PA(pdst) | TD_CP | TD_CV | TD_W;
                  tp->tte_vpn = TV_VPN(vdst, TS_8K);
                  vsrc = pmap_temp_map_2 + (msrc->md.color * PAGE_SIZE);
                  tp = tsb_kvtotte(vsrc);
                  tp->tte_data =
                      TD_V | TD_8K | TD_PA(psrc) | TD_CP | TD_CV | TD_W;
                  tp->tte_vpn = TV_VPN(vsrc, TS_8K);
                  cpu_block_copy((void *)vsrc, (void *)vdst, PAGE_SIZE);
                  tlb_page_demap(kernel_pmap, vdst);
                  tlb_page_demap(kernel_pmap, vsrc);
                  PMAP_UNLOCK(kernel_pmap);
          }
  }
  
  /*
   * 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 pm, vm_page_t m)
  {
          struct tte *tp;
          int loops;
  
          mtx_assert(&vm_page_queue_mtx, MA_OWNED);
          if ((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) != 0)
                  return (FALSE);
          loops = 0;
          TAILQ_FOREACH(tp, &m->md.tte_list, tte_link) {
                  if ((tp->tte_data & TD_PV) == 0)
                          continue;
                  if (TTE_GET_PMAP(tp) == pm)
                          return (TRUE);
                  if (++loops >= 16)
                          break;
          }
          return (FALSE);
  }
  
  /*
   * Remove all pages from specified address space, this aids process exit
   * speeds.  This is much faster than pmap_remove n 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)
  {
  }
  
  /*
   * Returns TRUE if the given page has a managed mapping.
   */
  boolean_t
  pmap_page_is_mapped(vm_page_t m)
  {
          struct tte *tp;
  
          mtx_assert(&vm_page_queue_mtx, MA_OWNED);
          if ((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) != 0)
                  return (FALSE);
          TAILQ_FOREACH(tp, &m->md.tte_list, tte_link) {
                  if ((tp->tte_data & TD_PV) != 0)
                          return (TRUE);
          }
          return (FALSE);
  }
  
  /*
   * Lower the permission for all mappings to a given page.
   */
  void
  pmap_page_protect(vm_page_t m, vm_prot_t prot)
  {
  
          KASSERT((m->flags & PG_FICTITIOUS) == 0,
              ("pmap_page_protect: fake page"));
          if ((prot & VM_PROT_WRITE) == 0) {
                  if (prot & (VM_PROT_READ | VM_PROT_EXECUTE))
                          pmap_clear_write(m);
                  else
                          pmap_remove_all(m);
          }
  }
  
  /*
   *      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)
  {
          struct tte *tpf;
          struct tte *tpn;
          struct tte *tp;
          u_long data;
          int count;
  
          mtx_assert(&vm_page_queue_mtx, MA_OWNED);
          if ((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) != 0)
                  return (0);
          count = 0;
          if ((tp = TAILQ_FIRST(&m->md.tte_list)) != NULL) {
                  tpf = tp;
                  do {
                          tpn = TAILQ_NEXT(tp, tte_link);
                          TAILQ_REMOVE(&m->md.tte_list, tp, tte_link);
                          TAILQ_INSERT_TAIL(&m->md.tte_list, tp, tte_link);
                          if ((tp->tte_data & TD_PV) == 0 ||
                              !pmap_track_modified(TTE_GET_PMAP(tp),
                               TTE_GET_VA(tp)))
                                  continue;
                          data = atomic_clear_long(&tp->tte_data, TD_REF);
                          if ((data & TD_REF) != 0 && ++count > 4)
                                  break;
                  } while ((tp = tpn) != NULL && tp != tpf);
          }
          return (count);
  }
  
  boolean_t
  pmap_is_modified(vm_page_t m)
  {
          struct tte *tp;
  
          mtx_assert(&vm_page_queue_mtx, MA_OWNED);
          if ((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) != 0)
                  return (FALSE);
          TAILQ_FOREACH(tp, &m->md.tte_list, tte_link) {
                  if ((tp->tte_data & TD_PV) == 0 ||
                      !pmap_track_modified(TTE_GET_PMAP(tp), TTE_GET_VA(tp)))
                          continue;
                  if ((tp->tte_data & TD_W) != 0)
                          return (TRUE);
          }
          return (FALSE);
  }
  
  /*
   *      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_modify(vm_page_t m)
  {
          struct tte *tp;
          u_long data;
  
          mtx_assert(&vm_page_queue_mtx, MA_OWNED);
          if ((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) != 0)
                  return;
          TAILQ_FOREACH(tp, &m->md.tte_list, tte_link) {
                  if ((tp->tte_data & TD_PV) == 0)
                          continue;
                  data = atomic_clear_long(&tp->tte_data, TD_W);
                  if ((data & TD_W) != 0)
                          tlb_page_demap(TTE_GET_PMAP(tp), TTE_GET_VA(tp));
          }
  }
  
  void
  pmap_clear_reference(vm_page_t m)
  {
          struct tte *tp;
          u_long data;
  
          mtx_assert(&vm_page_queue_mtx, MA_OWNED);
          if ((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) != 0)
                  return;
          TAILQ_FOREACH(tp, &m->md.tte_list, tte_link) {
                  if ((tp->tte_data & TD_PV) == 0)
                          continue;
                  data = atomic_clear_long(&tp->tte_data, TD_REF);
                  if ((data & TD_REF) != 0)
                          tlb_page_demap(TTE_GET_PMAP(tp), TTE_GET_VA(tp));
          }
  }
  
  void
  pmap_clear_write(vm_page_t m)
  {
          struct tte *tp;
          u_long data;
  
          mtx_assert(&vm_page_queue_mtx, MA_OWNED);
          if ((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) != 0 ||
              (m->flags & PG_WRITEABLE) == 0)
                  return;
          TAILQ_FOREACH(tp, &m->md.tte_list, tte_link) {
                  if ((tp->tte_data & TD_PV) == 0)
                          continue;
                  data = atomic_clear_long(&tp->tte_data, TD_SW | TD_W);
                  if ((data & TD_W) != 0) {
                          if (pmap_track_modified(TTE_GET_PMAP(tp),
                              TTE_GET_VA(tp)))
                                  vm_page_dirty(m);
                          tlb_page_demap(TTE_GET_PMAP(tp), TTE_GET_VA(tp));
                  }
          }
          vm_page_flag_clear(m, PG_WRITEABLE);
  }
  
  int
  pmap_mincore(pmap_t pm, vm_offset_t addr)
  {
          /* TODO; */
          return (0);
  }
  
  /*
   * Activate a user pmap.  The pmap must be activated before its address space
   * can be accessed in any way.
   */
  void
  pmap_activate(struct thread *td)
  {
          struct vmspace *vm;
          struct pmap *pm;
          int context;
  
          vm = td->td_proc->p_vmspace;
          pm = vmspace_pmap(vm);
  
          mtx_lock_spin(&sched_lock);
  
          context = PCPU_GET(tlb_ctx);
          if (context == PCPU_GET(tlb_ctx_max)) {
                  tlb_flush_user();
                  context = PCPU_GET(tlb_ctx_min);
          }
          PCPU_SET(tlb_ctx, context + 1);
  
          pm->pm_context[PCPU_GET(cpuid)] = context;
          pm->pm_active |= PCPU_GET(cpumask);
          PCPU_SET(pmap, pm);
  
          stxa(AA_DMMU_TSB, ASI_DMMU, pm->pm_tsb);
          stxa(AA_IMMU_TSB, ASI_IMMU, pm->pm_tsb);
          stxa(AA_DMMU_PCXR, ASI_DMMU, context);
          membar(Sync);
  
          mtx_unlock_spin(&sched_lock);
  }
  
  vm_offset_t
  pmap_addr_hint(vm_object_t object, vm_offset_t va, vm_size_t size)
  {
  
          return (va);
  }

Cache object: 65d51b044c92b719534255ef8ffed555