/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (C) 2007-2009 Semihalf, Rafal Jaworowski <raj@semihalf.com>
 * Copyright (C) 2006 Semihalf, Marian Balakowicz <m8@semihalf.com>
 * 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 THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Some hw specific parts of this pmap were derived or influenced
 * by NetBSD's ibm4xx pmap module. More generic code is shared with
 * a few other pmap modules from the FreeBSD tree.
 */

 /*
  * VM layout notes:
  *
  * Kernel and user threads run within one common virtual address space
  * defined by AS=0.
  *
  * 32-bit pmap:
  * Virtual address space layout:
  * -----------------------------
  * 0x0000_0000 - 0x7fff_ffff   : user process
  * 0x8000_0000 - 0xbfff_ffff   : pmap_mapdev()-ed area (PCI/PCIE etc.)
  * 0xc000_0000 - 0xc0ff_ffff   : kernel reserved
  *   0xc000_0000 - data_end    : kernel code+data, env, metadata etc.
  * 0xc100_0000 - 0xffff_ffff   : KVA
  *   0xc100_0000 - 0xc100_3fff : reserved for page zero/copy
  *   0xc100_4000 - 0xc200_3fff : reserved for ptbl bufs
  *   0xc200_4000 - 0xc200_8fff : guard page + kstack0
  *   0xc200_9000 - 0xfeef_ffff : actual free KVA space
  *
  * 64-bit pmap:
  * Virtual address space layout:
  * -----------------------------
  * 0x0000_0000_0000_0000 - 0xbfff_ffff_ffff_ffff      : user process
  *   0x0000_0000_0000_0000 - 0x8fff_ffff_ffff_ffff    : text, data, heap, maps, libraries
  *   0x9000_0000_0000_0000 - 0xafff_ffff_ffff_ffff    : mmio region
  *   0xb000_0000_0000_0000 - 0xbfff_ffff_ffff_ffff    : stack
  * 0xc000_0000_0000_0000 - 0xcfff_ffff_ffff_ffff      : kernel reserved
  *   0xc000_0000_0000_0000 - endkernel-1              : kernel code & data
  *               endkernel - msgbufp-1                : flat device tree
  *                 msgbufp - kernel_pdir-1            : message buffer
  *             kernel_pdir - kernel_pp2d-1            : kernel page directory
  *             kernel_pp2d - .                        : kernel pointers to page directory
  *      pmap_zero_copy_min - crashdumpmap-1           : reserved for page zero/copy
  *            crashdumpmap - ptbl_buf_pool_vabase-1   : reserved for ptbl bufs
  *    ptbl_buf_pool_vabase - virtual_avail-1          : user page directories and page tables
  *           virtual_avail - 0xcfff_ffff_ffff_ffff    : actual free KVA space
  * 0xd000_0000_0000_0000 - 0xdfff_ffff_ffff_ffff      : coprocessor region
  * 0xe000_0000_0000_0000 - 0xefff_ffff_ffff_ffff      : mmio region
  * 0xf000_0000_0000_0000 - 0xffff_ffff_ffff_ffff      : direct map
  *   0xf000_0000_0000_0000 - +Maxmem                  : physmem map
  *                         - 0xffff_ffff_ffff_ffff    : device direct map
  */

#include <sys/cdefs.h>
#include "opt_ddb.h"
#include "opt_kstack_pages.h"

#include <sys/param.h>
#include <sys/conf.h>
#include <sys/malloc.h>
#include <sys/ktr.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/kerneldump.h>
#include <sys/linker.h>
#include <sys/msgbuf.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rwlock.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/vmmeter.h>

#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_page.h>
#include <vm/vm_kern.h>
#include <vm/vm_pageout.h>
#include <vm/vm_extern.h>
#include <vm/vm_object.h>
#include <vm/vm_map.h>
#include <vm/vm_pager.h>
#include <vm/vm_phys.h>
#include <vm/vm_pagequeue.h>
#include <vm/vm_radix.h>
#include <vm/vm_dumpset.h>
#include <vm/uma.h>

#include <machine/_inttypes.h>
#include <machine/cpu.h>
#include <machine/pcb.h>
#include <machine/platform.h>

#include <machine/tlb.h>
#include <machine/spr.h>
#include <machine/md_var.h>
#include <machine/mmuvar.h>
#include <machine/pmap.h>
#include <machine/pte.h>

#include <ddb/ddb.h>

#define SPARSE_MAPDEV

/* Use power-of-two mappings in mmu_booke_mapdev(), to save entries. */
#define POW2_MAPPINGS

#ifdef  DEBUG
#define debugf(fmt, args...) printf(fmt, ##args)
#define __debug_used
#else
#define debugf(fmt, args...)
#define __debug_used    __unused
#endif

#ifdef __powerpc64__
#define PRI0ptrX        "016lx"
#else
#define PRI0ptrX        "08x"
#endif

#define TODO                    panic("%s: not implemented", __func__);

extern unsigned char _etext[];
extern unsigned char _end[];

extern uint32_t *bootinfo;

vm_paddr_t kernload;
vm_offset_t kernstart;
vm_size_t kernsize;

/* Message buffer and tables. */
static vm_offset_t data_start;
static vm_size_t data_end;

/* Phys/avail memory regions. */
static struct mem_region *availmem_regions;
static int availmem_regions_sz;
static struct mem_region *physmem_regions;
static int physmem_regions_sz;

#ifndef __powerpc64__
/* Reserved KVA space and mutex for mmu_booke_zero_page. */
static vm_offset_t zero_page_va;
static struct mtx zero_page_mutex;

/* Reserved KVA space and mutex for mmu_booke_copy_page. */
static vm_offset_t copy_page_src_va;
static vm_offset_t copy_page_dst_va;
static struct mtx copy_page_mutex;
#endif

static struct mtx tlbivax_mutex;

/**************************************************************************/
/* PMAP */
/**************************************************************************/

static int mmu_booke_enter_locked(pmap_t, vm_offset_t, vm_page_t,
    vm_prot_t, u_int flags, int8_t psind);

unsigned int kptbl_min;         /* Index of the first kernel ptbl. */
static uma_zone_t ptbl_root_zone;

/*
 * If user pmap is processed with mmu_booke_remove and the resident count
 * drops to 0, there are no more pages to remove, so we need not continue.
 */
#define PMAP_REMOVE_DONE(pmap) \
        ((pmap) != kernel_pmap && (pmap)->pm_stats.resident_count == 0)

#if defined(COMPAT_FREEBSD32) || !defined(__powerpc64__)
extern int elf32_nxstack;
#endif

/**************************************************************************/
/* TLB and TID handling */
/**************************************************************************/

/* Translation ID busy table */
static volatile pmap_t tidbusy[MAXCPU][TID_MAX + 1];

/*
 * TLB0 capabilities (entry, way numbers etc.). These can vary between e500
 * core revisions and should be read from h/w registers during early config.
 */
uint32_t tlb0_entries;
uint32_t tlb0_ways;
uint32_t tlb0_entries_per_way;
uint32_t tlb1_entries;

#define TLB0_ENTRIES            (tlb0_entries)
#define TLB0_WAYS               (tlb0_ways)
#define TLB0_ENTRIES_PER_WAY    (tlb0_entries_per_way)

#define TLB1_ENTRIES (tlb1_entries)

static tlbtid_t tid_alloc(struct pmap *);

#ifdef DDB
#ifdef __powerpc64__
static void tlb_print_entry(int, uint32_t, uint64_t, uint32_t, uint32_t);
#else
static void tlb_print_entry(int, uint32_t, uint32_t, uint32_t, uint32_t);
#endif
#endif

static void tlb1_read_entry(tlb_entry_t *, unsigned int);
static void tlb1_write_entry(tlb_entry_t *, unsigned int);
static int tlb1_iomapped(int, vm_paddr_t, vm_size_t, vm_offset_t *);
static vm_size_t tlb1_mapin_region(vm_offset_t, vm_paddr_t, vm_size_t, int);

static __inline uint32_t tlb_calc_wimg(vm_paddr_t pa, vm_memattr_t ma);

static vm_size_t tsize2size(unsigned int);
static unsigned int size2tsize(vm_size_t);

static void set_mas4_defaults(void);

static inline void tlb0_flush_entry(vm_offset_t);
static inline unsigned int tlb0_tableidx(vm_offset_t, unsigned int);

/**************************************************************************/
/* Page table management */
/**************************************************************************/

static struct rwlock_padalign pvh_global_lock;

/* Data for the pv entry allocation mechanism */
static uma_zone_t pvzone;
static int pv_entry_count = 0, pv_entry_max = 0, pv_entry_high_water = 0;

#define PV_ENTRY_ZONE_MIN       2048    /* min pv entries in uma zone */

#ifndef PMAP_SHPGPERPROC
#define PMAP_SHPGPERPROC        200
#endif

static vm_paddr_t pte_vatopa(pmap_t, vm_offset_t);
static int pte_enter(pmap_t, vm_page_t, vm_offset_t, uint32_t, bool);
static int pte_remove(pmap_t, vm_offset_t, uint8_t);
static pte_t *pte_find(pmap_t, vm_offset_t);
static void kernel_pte_alloc(vm_offset_t, vm_offset_t);

static pv_entry_t pv_alloc(void);
static void pv_free(pv_entry_t);
static void pv_insert(pmap_t, vm_offset_t, vm_page_t);
static void pv_remove(pmap_t, vm_offset_t, vm_page_t);

static void booke_pmap_init_qpages(void);

static inline void tlb_miss_lock(void);
static inline void tlb_miss_unlock(void);

#ifdef SMP
extern tlb_entry_t __boot_tlb1[];
void pmap_bootstrap_ap(volatile uint32_t *);
#endif

/*
 * Kernel MMU interface
 */
static void             mmu_booke_clear_modify(vm_page_t);
static void             mmu_booke_copy(pmap_t, pmap_t, vm_offset_t,
    vm_size_t, vm_offset_t);
static void             mmu_booke_copy_page(vm_page_t, vm_page_t);
static void             mmu_booke_copy_pages(vm_page_t *,
    vm_offset_t, vm_page_t *, vm_offset_t, int);
static int              mmu_booke_enter(pmap_t, vm_offset_t, vm_page_t,
    vm_prot_t, u_int flags, int8_t psind);
static void             mmu_booke_enter_object(pmap_t, vm_offset_t, vm_offset_t,
    vm_page_t, vm_prot_t);
static void             mmu_booke_enter_quick(pmap_t, vm_offset_t, vm_page_t,
    vm_prot_t);
static vm_paddr_t       mmu_booke_extract(pmap_t, vm_offset_t);
static vm_page_t        mmu_booke_extract_and_hold(pmap_t, vm_offset_t,
    vm_prot_t);
static void             mmu_booke_init(void);
static bool             mmu_booke_is_modified(vm_page_t);
static bool             mmu_booke_is_prefaultable(pmap_t, vm_offset_t);
static bool             mmu_booke_is_referenced(vm_page_t);
static int              mmu_booke_ts_referenced(vm_page_t);
static vm_offset_t      mmu_booke_map(vm_offset_t *, vm_paddr_t, vm_paddr_t,
    int);
static int              mmu_booke_mincore(pmap_t, vm_offset_t,
    vm_paddr_t *);
static void             mmu_booke_object_init_pt(pmap_t, vm_offset_t,
    vm_object_t, vm_pindex_t, vm_size_t);
static bool             mmu_booke_page_exists_quick(pmap_t, vm_page_t);
static void             mmu_booke_page_init(vm_page_t);
static int              mmu_booke_page_wired_mappings(vm_page_t);
static int              mmu_booke_pinit(pmap_t);
static void             mmu_booke_pinit0(pmap_t);
static void             mmu_booke_protect(pmap_t, vm_offset_t, vm_offset_t,
    vm_prot_t);
static void             mmu_booke_qenter(vm_offset_t, vm_page_t *, int);
static void             mmu_booke_qremove(vm_offset_t, int);
static void             mmu_booke_release(pmap_t);
static void             mmu_booke_remove(pmap_t, vm_offset_t, vm_offset_t);
static void             mmu_booke_remove_all(vm_page_t);
static void             mmu_booke_remove_write(vm_page_t);
static void             mmu_booke_unwire(pmap_t, vm_offset_t, vm_offset_t);
static void             mmu_booke_zero_page(vm_page_t);
static void             mmu_booke_zero_page_area(vm_page_t, int, int);
static void             mmu_booke_activate(struct thread *);
static void             mmu_booke_deactivate(struct thread *);
static void             mmu_booke_bootstrap(vm_offset_t, vm_offset_t);
static void             *mmu_booke_mapdev(vm_paddr_t, vm_size_t);
static void             *mmu_booke_mapdev_attr(vm_paddr_t, vm_size_t, vm_memattr_t);
static void             mmu_booke_unmapdev(void *, vm_size_t);
static vm_paddr_t       mmu_booke_kextract(vm_offset_t);
static void             mmu_booke_kenter(vm_offset_t, vm_paddr_t);
static void             mmu_booke_kenter_attr(vm_offset_t, vm_paddr_t, vm_memattr_t);
static void             mmu_booke_kremove(vm_offset_t);
static int              mmu_booke_dev_direct_mapped(vm_paddr_t, vm_size_t);
static void             mmu_booke_sync_icache(pmap_t, vm_offset_t,
    vm_size_t);
static void             mmu_booke_dumpsys_map(vm_paddr_t pa, size_t,
    void **);
static void             mmu_booke_dumpsys_unmap(vm_paddr_t pa, size_t,
    void *);
static void             mmu_booke_scan_init(void);
static vm_offset_t      mmu_booke_quick_enter_page(vm_page_t m);
static void             mmu_booke_quick_remove_page(vm_offset_t addr);
static int              mmu_booke_change_attr(vm_offset_t addr,
    vm_size_t sz, vm_memattr_t mode);
static int              mmu_booke_decode_kernel_ptr(vm_offset_t addr,
    int *is_user, vm_offset_t *decoded_addr);
static void             mmu_booke_page_array_startup(long);
static bool mmu_booke_page_is_mapped(vm_page_t m);
static bool mmu_booke_ps_enabled(pmap_t pmap);

static struct pmap_funcs mmu_booke_methods = {
        /* pmap dispatcher interface */
        .clear_modify = mmu_booke_clear_modify,
        .copy = mmu_booke_copy,
        .copy_page = mmu_booke_copy_page,
        .copy_pages = mmu_booke_copy_pages,
        .enter = mmu_booke_enter,
        .enter_object = mmu_booke_enter_object,
        .enter_quick = mmu_booke_enter_quick,
        .extract = mmu_booke_extract,
        .extract_and_hold = mmu_booke_extract_and_hold,
        .init = mmu_booke_init,
        .is_modified = mmu_booke_is_modified,
        .is_prefaultable = mmu_booke_is_prefaultable,
        .is_referenced = mmu_booke_is_referenced,
        .ts_referenced = mmu_booke_ts_referenced,
        .map = mmu_booke_map,
        .mincore = mmu_booke_mincore,
        .object_init_pt = mmu_booke_object_init_pt,
        .page_exists_quick = mmu_booke_page_exists_quick,
        .page_init = mmu_booke_page_init,
        .page_wired_mappings =  mmu_booke_page_wired_mappings,
        .pinit = mmu_booke_pinit,
        .pinit0 = mmu_booke_pinit0,
        .protect = mmu_booke_protect,
        .qenter = mmu_booke_qenter,
        .qremove = mmu_booke_qremove,
        .release = mmu_booke_release,
        .remove = mmu_booke_remove,
        .remove_all = mmu_booke_remove_all,
        .remove_write = mmu_booke_remove_write,
        .sync_icache = mmu_booke_sync_icache,
        .unwire = mmu_booke_unwire,
        .zero_page = mmu_booke_zero_page,
        .zero_page_area = mmu_booke_zero_page_area,
        .activate = mmu_booke_activate,
        .deactivate = mmu_booke_deactivate,
        .quick_enter_page =  mmu_booke_quick_enter_page,
        .quick_remove_page =  mmu_booke_quick_remove_page,
        .page_array_startup = mmu_booke_page_array_startup,
        .page_is_mapped = mmu_booke_page_is_mapped,
        .ps_enabled = mmu_booke_ps_enabled,

        /* Internal interfaces */
        .bootstrap = mmu_booke_bootstrap,
        .dev_direct_mapped = mmu_booke_dev_direct_mapped,
        .mapdev = mmu_booke_mapdev,
        .mapdev_attr = mmu_booke_mapdev_attr,
        .kenter = mmu_booke_kenter,
        .kenter_attr = mmu_booke_kenter_attr,
        .kextract = mmu_booke_kextract,
        .kremove = mmu_booke_kremove,
        .unmapdev = mmu_booke_unmapdev,
        .change_attr = mmu_booke_change_attr,
        .decode_kernel_ptr =  mmu_booke_decode_kernel_ptr,

        /* dumpsys() support */
        .dumpsys_map_chunk = mmu_booke_dumpsys_map,
        .dumpsys_unmap_chunk = mmu_booke_dumpsys_unmap,
        .dumpsys_pa_init = mmu_booke_scan_init,
};

MMU_DEF(booke_mmu, MMU_TYPE_BOOKE, mmu_booke_methods);

#ifdef __powerpc64__
#include "pmap_64.c"
#else
#include "pmap_32.c"
#endif

static vm_offset_t tlb1_map_base = VM_MAPDEV_BASE;

static __inline uint32_t
tlb_calc_wimg(vm_paddr_t pa, vm_memattr_t ma)
{
        uint32_t attrib;
        int i;

        if (ma != VM_MEMATTR_DEFAULT) {
                switch (ma) {
                case VM_MEMATTR_UNCACHEABLE:
                        return (MAS2_I | MAS2_G);
                case VM_MEMATTR_WRITE_COMBINING:
                case VM_MEMATTR_WRITE_BACK:
                case VM_MEMATTR_PREFETCHABLE:
                        return (MAS2_I);
                case VM_MEMATTR_WRITE_THROUGH:
                        return (MAS2_W | MAS2_M);
                case VM_MEMATTR_CACHEABLE:
                        return (MAS2_M);
                }
        }

        /*
         * Assume the page is cache inhibited and access is guarded unless
         * it's in our available memory array.
         */
        attrib = _TLB_ENTRY_IO;
        for (i = 0; i < physmem_regions_sz; i++) {
                if ((pa >= physmem_regions[i].mr_start) &&
                    (pa < (physmem_regions[i].mr_start +
                     physmem_regions[i].mr_size))) {
                        attrib = _TLB_ENTRY_MEM;
                        break;
                }
        }

        return (attrib);
}

static inline void
tlb_miss_lock(void)
{
#ifdef SMP
        struct pcpu *pc;

        if (!smp_started)
                return;

        STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
                if (pc != pcpup) {
                        CTR3(KTR_PMAP, "%s: tlb miss LOCK of CPU=%d, "
                            "tlb_lock=%p", __func__, pc->pc_cpuid, pc->pc_booke.tlb_lock);

                        KASSERT((pc->pc_cpuid != PCPU_GET(cpuid)),
                            ("tlb_miss_lock: tried to lock self"));

                        tlb_lock(pc->pc_booke.tlb_lock);

                        CTR1(KTR_PMAP, "%s: locked", __func__);
                }
        }
#endif
}

static inline void
tlb_miss_unlock(void)
{
#ifdef SMP
        struct pcpu *pc;

        if (!smp_started)
                return;

        STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
                if (pc != pcpup) {
                        CTR2(KTR_PMAP, "%s: tlb miss UNLOCK of CPU=%d",
                            __func__, pc->pc_cpuid);

                        tlb_unlock(pc->pc_booke.tlb_lock);

                        CTR1(KTR_PMAP, "%s: unlocked", __func__);
                }
        }
#endif
}

/* Return number of entries in TLB0. */
static __inline void
tlb0_get_tlbconf(void)
{
        uint32_t tlb0_cfg;

        tlb0_cfg = mfspr(SPR_TLB0CFG);
        tlb0_entries = tlb0_cfg & TLBCFG_NENTRY_MASK;
        tlb0_ways = (tlb0_cfg & TLBCFG_ASSOC_MASK) >> TLBCFG_ASSOC_SHIFT;
        tlb0_entries_per_way = tlb0_entries / tlb0_ways;
}

/* Return number of entries in TLB1. */
static __inline void
tlb1_get_tlbconf(void)
{
        uint32_t tlb1_cfg;

        tlb1_cfg = mfspr(SPR_TLB1CFG);
        tlb1_entries = tlb1_cfg & TLBCFG_NENTRY_MASK;
}

/**************************************************************************/
/* Page table related */
/**************************************************************************/

/* Allocate pv_entry structure. */
pv_entry_t
pv_alloc(void)
{
        pv_entry_t pv;

        pv_entry_count++;
        if (pv_entry_count > pv_entry_high_water)
                pagedaemon_wakeup(0); /* XXX powerpc NUMA */
        pv = uma_zalloc(pvzone, M_NOWAIT);

        return (pv);
}

/* Free pv_entry structure. */
static __inline void
pv_free(pv_entry_t pve)
{

        pv_entry_count--;
        uma_zfree(pvzone, pve);
}

/* Allocate and initialize pv_entry structure. */
static void
pv_insert(pmap_t pmap, vm_offset_t va, vm_page_t m)
{
        pv_entry_t pve;

        //int su = (pmap == kernel_pmap);
        //debugf("pv_insert: s (su = %d pmap = 0x%08x va = 0x%08x m = 0x%08x)\n", su,
        //      (u_int32_t)pmap, va, (u_int32_t)m);

        pve = pv_alloc();
        if (pve == NULL)
                panic("pv_insert: no pv entries!");

        pve->pv_pmap = pmap;
        pve->pv_va = va;

        /* add to pv_list */
        PMAP_LOCK_ASSERT(pmap, MA_OWNED);
        rw_assert(&pvh_global_lock, RA_WLOCKED);

        TAILQ_INSERT_TAIL(&m->md.pv_list, pve, pv_link);

        //debugf("pv_insert: e\n");
}

/* Destroy pv entry. */
static void
pv_remove(pmap_t pmap, vm_offset_t va, vm_page_t m)
{
        pv_entry_t pve;

        //int su = (pmap == kernel_pmap);
        //debugf("pv_remove: s (su = %d pmap = 0x%08x va = 0x%08x)\n", su, (u_int32_t)pmap, va);

        PMAP_LOCK_ASSERT(pmap, MA_OWNED);
        rw_assert(&pvh_global_lock, RA_WLOCKED);

        /* find pv entry */
        TAILQ_FOREACH(pve, &m->md.pv_list, pv_link) {
                if ((pmap == pve->pv_pmap) && (va == pve->pv_va)) {
                        /* remove from pv_list */
                        TAILQ_REMOVE(&m->md.pv_list, pve, pv_link);
                        if (TAILQ_EMPTY(&m->md.pv_list))
                                vm_page_aflag_clear(m, PGA_WRITEABLE);

                        /* free pv entry struct */
                        pv_free(pve);
                        break;
                }
        }

        //debugf("pv_remove: e\n");
}

/**************************************************************************/
/* PMAP related */
/**************************************************************************/

/*
 * This is called during booke_init, before the system is really initialized.
 */
static void
mmu_booke_bootstrap(vm_offset_t start, vm_offset_t kernelend)
{
        vm_paddr_t phys_kernelend;
        struct mem_region *mp, *mp1;
        int cnt, i, j;
        vm_paddr_t s, e, sz;
        vm_paddr_t physsz, hwphyssz;
        u_int phys_avail_count __debug_used;
        vm_size_t kstack0_sz;
        vm_paddr_t kstack0_phys;
        vm_offset_t kstack0;
        void *dpcpu;

        debugf("mmu_booke_bootstrap: entered\n");

        /* Set interesting system properties */
#ifdef __powerpc64__
        hw_direct_map = 1;
#else
        hw_direct_map = 0;
#endif
#if defined(COMPAT_FREEBSD32) || !defined(__powerpc64__)
        elf32_nxstack = 1;
#endif

        /* Initialize invalidation mutex */
        mtx_init(&tlbivax_mutex, "tlbivax", NULL, MTX_SPIN);

        /* Read TLB0 size and associativity. */
        tlb0_get_tlbconf();

        /*
         * Align kernel start and end address (kernel image).
         * Note that kernel end does not necessarily relate to kernsize.
         * kernsize is the size of the kernel that is actually mapped.
         */
        data_start = round_page(kernelend);
        data_end = data_start;

        /* Allocate the dynamic per-cpu area. */
        dpcpu = (void *)data_end;
        data_end += DPCPU_SIZE;

        /* Allocate space for the message buffer. */
        msgbufp = (struct msgbuf *)data_end;
        data_end += msgbufsize;
        debugf(" msgbufp at 0x%"PRI0ptrX" end = 0x%"PRI0ptrX"\n",
            (uintptr_t)msgbufp, data_end);

        data_end = round_page(data_end);
        data_end = round_page(mmu_booke_alloc_kernel_pgtables(data_end));

        /* Retrieve phys/avail mem regions */
        mem_regions(&physmem_regions, &physmem_regions_sz,
            &availmem_regions, &availmem_regions_sz);

        if (PHYS_AVAIL_ENTRIES < availmem_regions_sz)
                panic("mmu_booke_bootstrap: phys_avail too small");

        data_end = round_page(data_end);
        vm_page_array = (vm_page_t)data_end;
        /*
         * Get a rough idea (upper bound) on the size of the page array.  The
         * vm_page_array will not handle any more pages than we have in the
         * avail_regions array, and most likely much less.
         */
        sz = 0;
        for (mp = availmem_regions; mp->mr_size; mp++) {
                sz += mp->mr_size;
        }
        sz = (round_page(sz) / (PAGE_SIZE + sizeof(struct vm_page)));
        data_end += round_page(sz * sizeof(struct vm_page));

        /* Pre-round up to 1MB.  This wastes some space, but saves TLB entries */
        data_end = roundup2(data_end, 1 << 20);

        debugf(" data_end: 0x%"PRI0ptrX"\n", data_end);
        debugf(" kernstart: %#zx\n", kernstart);
        debugf(" kernsize: %#zx\n", kernsize);

        if (data_end - kernstart > kernsize) {
                kernsize += tlb1_mapin_region(kernstart + kernsize,
                    kernload + kernsize, (data_end - kernstart) - kernsize,
                    _TLB_ENTRY_MEM);
        }
        data_end = kernstart + kernsize;
        debugf(" updated data_end: 0x%"PRI0ptrX"\n", data_end);

        /*
         * Clear the structures - note we can only do it safely after the
         * possible additional TLB1 translations are in place (above) so that
         * all range up to the currently calculated 'data_end' is covered.
         */
        bzero((void *)data_start, data_end - data_start);
        dpcpu_init(dpcpu, 0);

        /*******************************************************/
        /* Set the start and end of kva. */
        /*******************************************************/
        virtual_avail = round_page(data_end);
        virtual_end = VM_MAX_KERNEL_ADDRESS;

#ifndef __powerpc64__
        /* Allocate KVA space for page zero/copy operations. */
        zero_page_va = virtual_avail;
        virtual_avail += PAGE_SIZE;
        copy_page_src_va = virtual_avail;
        virtual_avail += PAGE_SIZE;
        copy_page_dst_va = virtual_avail;
        virtual_avail += PAGE_SIZE;
        debugf("zero_page_va = 0x%"PRI0ptrX"\n", zero_page_va);
        debugf("copy_page_src_va = 0x%"PRI0ptrX"\n", copy_page_src_va);
        debugf("copy_page_dst_va = 0x%"PRI0ptrX"\n", copy_page_dst_va);

        /* Initialize page zero/copy mutexes. */
        mtx_init(&zero_page_mutex, "mmu_booke_zero_page", NULL, MTX_DEF);
        mtx_init(&copy_page_mutex, "mmu_booke_copy_page", NULL, MTX_DEF);

        /* Allocate KVA space for ptbl bufs. */
        ptbl_buf_pool_vabase = virtual_avail;
        virtual_avail += PTBL_BUFS * PTBL_PAGES * PAGE_SIZE;
        debugf("ptbl_buf_pool_vabase = 0x%"PRI0ptrX" end = 0x%"PRI0ptrX"\n",
            ptbl_buf_pool_vabase, virtual_avail);
#endif
#ifdef  __powerpc64__
        /* Allocate KVA space for crashdumpmap. */
        crashdumpmap = (caddr_t)virtual_avail;
        virtual_avail += MAXDUMPPGS * PAGE_SIZE;
#endif

        /* Calculate corresponding physical addresses for the kernel region. */
        phys_kernelend = kernload + kernsize;
        debugf("kernel image and allocated data:\n");
        debugf(" kernload    = 0x%09jx\n", (uintmax_t)kernload);
        debugf(" kernstart   = 0x%"PRI0ptrX"\n", kernstart);
        debugf(" kernsize    = 0x%"PRI0ptrX"\n", kernsize);

        /*
         * Remove kernel physical address range from avail regions list. Page
         * align all regions.  Non-page aligned memory isn't very interesting
         * to us.  Also, sort the entries for ascending addresses.
         */

        sz = 0;
        cnt = availmem_regions_sz;
        debugf("processing avail regions:\n");
        for (mp = availmem_regions; mp->mr_size; mp++) {
                s = mp->mr_start;
                e = mp->mr_start + mp->mr_size;
                debugf(" %09jx-%09jx -> ", (uintmax_t)s, (uintmax_t)e);
                /* Check whether this region holds all of the kernel. */
                if (s < kernload && e > phys_kernelend) {
                        availmem_regions[cnt].mr_start = phys_kernelend;
                        availmem_regions[cnt++].mr_size = e - phys_kernelend;
                        e = kernload;
                }
                /* Look whether this regions starts within the kernel. */
                if (s >= kernload && s < phys_kernelend) {
                        if (e <= phys_kernelend)
                                goto empty;
                        s = phys_kernelend;
                }
                /* Now look whether this region ends within the kernel. */
                if (e > kernload && e <= phys_kernelend) {
                        if (s >= kernload)
                                goto empty;
                        e = kernload;
                }
                /* Now page align the start and size of the region. */
                s = round_page(s);
                e = trunc_page(e);
                if (e < s)
                        e = s;
                sz = e - s;
                debugf("%09jx-%09jx = %jx\n",
                    (uintmax_t)s, (uintmax_t)e, (uintmax_t)sz);

                /* Check whether some memory is left here. */
                if (sz == 0) {
                empty:
                        memmove(mp, mp + 1,
                            (cnt - (mp - availmem_regions)) * sizeof(*mp));
                        cnt--;
                        mp--;
                        continue;
                }

                /* Do an insertion sort. */
                for (mp1 = availmem_regions; mp1 < mp; mp1++)
                        if (s < mp1->mr_start)
                                break;
                if (mp1 < mp) {
                        memmove(mp1 + 1, mp1, (char *)mp - (char *)mp1);
                        mp1->mr_start = s;
                        mp1->mr_size = sz;
                } else {
                        mp->mr_start = s;
                        mp->mr_size = sz;
                }
        }
        availmem_regions_sz = cnt;

        /*******************************************************/
        /* Steal physical memory for kernel stack from the end */
        /* of the first avail region                           */
        /*******************************************************/
        kstack0_sz = kstack_pages * PAGE_SIZE;
        kstack0_phys = availmem_regions[0].mr_start +
            availmem_regions[0].mr_size;
        kstack0_phys -= kstack0_sz;
        availmem_regions[0].mr_size -= kstack0_sz;

        /*******************************************************/
        /* Fill in phys_avail table, based on availmem_regions */
        /*******************************************************/
        phys_avail_count = 0;
        physsz = 0;
        hwphyssz = 0;
        TUNABLE_ULONG_FETCH("hw.physmem", (u_long *) &hwphyssz);

        debugf("fill in phys_avail:\n");
        for (i = 0, j = 0; i < availmem_regions_sz; i++, j += 2) {
                debugf(" region: 0x%jx - 0x%jx (0x%jx)\n",
                    (uintmax_t)availmem_regions[i].mr_start,
                    (uintmax_t)availmem_regions[i].mr_start +
                        availmem_regions[i].mr_size,
                    (uintmax_t)availmem_regions[i].mr_size);

                if (hwphyssz != 0 &&
                    (physsz + availmem_regions[i].mr_size) >= hwphyssz) {
                        debugf(" hw.physmem adjust\n");
                        if (physsz < hwphyssz) {
                                phys_avail[j] = availmem_regions[i].mr_start;
                                phys_avail[j + 1] =
                                    availmem_regions[i].mr_start +
                                    hwphyssz - physsz;
                                physsz = hwphyssz;
                                phys_avail_count++;
                                dump_avail[j] = phys_avail[j];
                                dump_avail[j + 1] = phys_avail[j + 1];
                        }
                        break;
                }

                phys_avail[j] = availmem_regions[i].mr_start;
                phys_avail[j + 1] = availmem_regions[i].mr_start +
                    availmem_regions[i].mr_size;
                phys_avail_count++;
                physsz += availmem_regions[i].mr_size;
                dump_avail[j] = phys_avail[j];
                dump_avail[j + 1] = phys_avail[j + 1];
        }
        physmem = btoc(physsz);

        /* Calculate the last available physical address. */
        for (i = 0; phys_avail[i + 2] != 0; i += 2)
                ;
        Maxmem = powerpc_btop(phys_avail[i + 1]);

        debugf("Maxmem = 0x%08lx\n", Maxmem);
        debugf("phys_avail_count = %d\n", phys_avail_count);
        debugf("physsz = 0x%09jx physmem = %jd (0x%09jx)\n",
            (uintmax_t)physsz, (uintmax_t)physmem, (uintmax_t)physmem);

#ifdef __powerpc64__
        /*
         * Map the physical memory contiguously in TLB1.
         * Round so it fits into a single mapping.
         */
        tlb1_mapin_region(DMAP_BASE_ADDRESS, 0,
            phys_avail[i + 1], _TLB_ENTRY_MEM);
#endif

        /*******************************************************/
        /* Initialize (statically allocated) kernel pmap. */
        /*******************************************************/
        mtx_init(&kernel_pmap->pm_mtx, "kernel pmap", NULL, MTX_DEF);

        debugf("kernel_pmap = 0x%"PRI0ptrX"\n", (uintptr_t)kernel_pmap);
        kernel_pte_alloc(virtual_avail, kernstart);
        for (i = 0; i < MAXCPU; i++) {
                kernel_pmap->pm_tid[i] = TID_KERNEL;
                
                /* Initialize each CPU's tidbusy entry 0 with kernel_pmap */
                tidbusy[i][TID_KERNEL] = kernel_pmap;
        }

        /* Mark kernel_pmap active on all CPUs */
        CPU_FILL(&kernel_pmap->pm_active);

        /*
         * Initialize the global pv list lock.
         */
        rw_init(&pvh_global_lock, "pmap pv global");

        /*******************************************************/
        /* Final setup */
        /*******************************************************/

        /* Enter kstack0 into kernel map, provide guard page */
        kstack0 = virtual_avail + KSTACK_GUARD_PAGES * PAGE_SIZE;
        thread0.td_kstack = kstack0;
        thread0.td_kstack_pages = kstack_pages;

        debugf("kstack_sz = 0x%08jx\n", (uintmax_t)kstack0_sz);
        debugf("kstack0_phys at 0x%09jx - 0x%09jx\n",
            (uintmax_t)kstack0_phys, (uintmax_t)kstack0_phys + kstack0_sz);
        debugf("kstack0 at 0x%"PRI0ptrX" - 0x%"PRI0ptrX"\n",
            kstack0, kstack0 + kstack0_sz);

        virtual_avail += KSTACK_GUARD_PAGES * PAGE_SIZE + kstack0_sz;
        for (i = 0; i < kstack_pages; i++) {
                mmu_booke_kenter(kstack0, kstack0_phys);
                kstack0 += PAGE_SIZE;
                kstack0_phys += PAGE_SIZE;
        }

        pmap_bootstrapped = 1;

        debugf("virtual_avail = %"PRI0ptrX"\n", virtual_avail);
        debugf("virtual_end   = %"PRI0ptrX"\n", virtual_end);

        debugf("mmu_booke_bootstrap: exit\n");
}

#ifdef SMP
void
tlb1_ap_prep(void)
{
        tlb_entry_t *e, tmp;
        unsigned int i;

        /* Prepare TLB1 image for AP processors */
        e = __boot_tlb1;
        for (i = 0; i < TLB1_ENTRIES; i++) {
                tlb1_read_entry(&tmp, i);

                if ((tmp.mas1 & MAS1_VALID) && (tmp.mas2 & _TLB_ENTRY_SHARED))
                        memcpy(e++, &tmp, sizeof(tmp));
        }
}

void
pmap_bootstrap_ap(volatile uint32_t *trcp __unused)
{
        int i;

        /*
         * Finish TLB1 configuration: the BSP already set up its TLB1 and we
         * have the snapshot of its contents in the s/w __boot_tlb1[] table
         * created by tlb1_ap_prep(), so use these values directly to
         * (re)program AP's TLB1 hardware.
         *
         * Start at index 1 because index 0 has the kernel map.
         */
        for (i = 1; i < TLB1_ENTRIES; i++) {
                if (__boot_tlb1[i].mas1 & MAS1_VALID)
                        tlb1_write_entry(&__boot_tlb1[i], i);
        }

        set_mas4_defaults();
}
#endif

static void
booke_pmap_init_qpages(void)
{
        struct pcpu *pc;
        int i;

        CPU_FOREACH(i) {
                pc = pcpu_find(i);
                pc->pc_qmap_addr = kva_alloc(PAGE_SIZE);
                if (pc->pc_qmap_addr == 0)
                        panic("pmap_init_qpages: unable to allocate KVA");
        }
}

SYSINIT(qpages_init, SI_SUB_CPU, SI_ORDER_ANY, booke_pmap_init_qpages, NULL);

/*
 * Get the physical page address for the given pmap/virtual address.
 */
static vm_paddr_t
mmu_booke_extract(pmap_t pmap, vm_offset_t va)
{
        vm_paddr_t pa;

        PMAP_LOCK(pmap);
        pa = pte_vatopa(pmap, va);
        PMAP_UNLOCK(pmap);

        return (pa);
}

/*
 * Extract the physical page address associated with the given
 * kernel virtual address.
 */
static vm_paddr_t
mmu_booke_kextract(vm_offset_t va)
{
        tlb_entry_t e;
        vm_paddr_t p = 0;
        int i;

#ifdef __powerpc64__
        if (va >= DMAP_BASE_ADDRESS && va <= DMAP_MAX_ADDRESS)
                return (DMAP_TO_PHYS(va));
#endif

        if (va >= VM_MIN_KERNEL_ADDRESS && va <= VM_MAX_KERNEL_ADDRESS)
                p = pte_vatopa(kernel_pmap, va);

        if (p == 0) {
                /* Check TLB1 mappings */
                for (i = 0; i < TLB1_ENTRIES; i++) {
                        tlb1_read_entry(&e, i);
                        if (!(e.mas1 & MAS1_VALID))
                                continue;
                        if (va >= e.virt && va < e.virt + e.size)
                                return (e.phys + (va - e.virt));
                }
        }

        return (p);
}

/*
 * Initialize the pmap module.
 *
 * Called by vm_mem_init(), to initialize any structures that the pmap system
 * needs to map virtual memory.
 */
static void
mmu_booke_init(void)
{
        int shpgperproc = PMAP_SHPGPERPROC;

        /*
         * 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.
         */
        pvzone = uma_zcreate("PV ENTRY", sizeof(struct pv_entry), NULL, NULL,
            NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM | UMA_ZONE_NOFREE);

        TUNABLE_INT_FETCH("vm.pmap.shpgperproc", &shpgperproc);
        pv_entry_max = shpgperproc * maxproc + vm_cnt.v_page_count;

        TUNABLE_INT_FETCH("vm.pmap.pv_entry_max", &pv_entry_max);
        pv_entry_high_water = 9 * (pv_entry_max / 10);

        uma_zone_reserve_kva(pvzone, pv_entry_max);

        /* Pre-fill pvzone with initial number of pv entries. */
        uma_prealloc(pvzone, PV_ENTRY_ZONE_MIN);

        /* Create a UMA zone for page table roots. */
        ptbl_root_zone = uma_zcreate("pmap root", PMAP_ROOT_SIZE,
            NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, UMA_ZONE_VM);

        /* Initialize ptbl allocation. */
        ptbl_init();
}

/*
 * 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.
 */
static void
mmu_booke_qenter(vm_offset_t sva, vm_page_t *m, int count)
{
        vm_offset_t va;

        va = sva;
        while (count-- > 0) {
                mmu_booke_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 mmu_booke_qenter.
 */
static void
mmu_booke_qremove(vm_offset_t sva, int count)
{
        vm_offset_t va;

        va = sva;
        while (count-- > 0) {
                mmu_booke_kremove(va);
                va += PAGE_SIZE;
        }
}

/*
 * Map a wired page into kernel virtual address space.
 */
static void
mmu_booke_kenter(vm_offset_t va, vm_paddr_t pa)
{

        mmu_booke_kenter_attr(va, pa, VM_MEMATTR_DEFAULT);
}

static void
mmu_booke_kenter_attr(vm_offset_t va, vm_paddr_t pa, vm_memattr_t ma)
{
        uint32_t flags;
        pte_t *pte;

        KASSERT(((va >= VM_MIN_KERNEL_ADDRESS) &&
            (va <= VM_MAX_KERNEL_ADDRESS)), ("mmu_booke_kenter: invalid va"));

        flags = PTE_SR | PTE_SW | PTE_SX | PTE_WIRED | PTE_VALID;
        flags |= tlb_calc_wimg(pa, ma) << PTE_MAS2_SHIFT;
        flags |= PTE_PS_4KB;

        pte = pte_find(kernel_pmap, va);
        KASSERT((pte != NULL), ("mmu_booke_kenter: invalid va.  NULL PTE"));

        mtx_lock_spin(&tlbivax_mutex);
        tlb_miss_lock();

        if (PTE_ISVALID(pte)) {
                CTR1(KTR_PMAP, "%s: replacing entry!", __func__);

                /* Flush entry from TLB0 */
                tlb0_flush_entry(va);
        }

        *pte = PTE_RPN_FROM_PA(pa) | flags;

        //debugf("mmu_booke_kenter: pdir_idx = %d ptbl_idx = %d va=0x%08x "
        //              "pa=0x%08x rpn=0x%08x flags=0x%08x\n",
        //              pdir_idx, ptbl_idx, va, pa, pte->rpn, pte->flags);

        /* Flush the real memory from the instruction cache. */
        if ((flags & (PTE_I | PTE_G)) == 0)
                __syncicache((void *)va, PAGE_SIZE);

        tlb_miss_unlock();
        mtx_unlock_spin(&tlbivax_mutex);
}

/*
 * Remove a page from kernel page table.
 */
static void
mmu_booke_kremove(vm_offset_t va)
{
        pte_t *pte;

        CTR2(KTR_PMAP,"%s: s (va = 0x%"PRI0ptrX")\n", __func__, va);

        KASSERT(((va >= VM_MIN_KERNEL_ADDRESS) &&
            (va <= VM_MAX_KERNEL_ADDRESS)),
            ("mmu_booke_kremove: invalid va"));

        pte = pte_find(kernel_pmap, va);

        if (!PTE_ISVALID(pte)) {
                CTR1(KTR_PMAP, "%s: invalid pte", __func__);

                return;
        }

        mtx_lock_spin(&tlbivax_mutex);
        tlb_miss_lock();

        /* Invalidate entry in TLB0, update PTE. */
        tlb0_flush_entry(va);
        *pte = 0;

        tlb_miss_unlock();
        mtx_unlock_spin(&tlbivax_mutex);
}

/*
 * Figure out where a given kernel pointer (usually in a fault) points
 * to from the VM's perspective, potentially remapping into userland's
 * address space.
 */
static int
mmu_booke_decode_kernel_ptr(vm_offset_t addr, int *is_user,
    vm_offset_t *decoded_addr)
{

        if (trunc_page(addr) <= VM_MAXUSER_ADDRESS)
                *is_user = 1;
        else
                *is_user = 0;

        *decoded_addr = addr;
        return (0);
}

static bool
mmu_booke_page_is_mapped(vm_page_t m)
{

        return (!TAILQ_EMPTY(&(m)->md.pv_list));
}

static bool
mmu_booke_ps_enabled(pmap_t pmap __unused)
{
        return (false);
}

/*
 * Initialize pmap associated with process 0.
 */
static void
mmu_booke_pinit0(pmap_t pmap)
{

        PMAP_LOCK_INIT(pmap);
        mmu_booke_pinit(pmap);
        PCPU_SET(curpmap, pmap);
}

/*
 * Insert the given physical page at the specified virtual address in the
 * target physical map with the protection requested. If specified the page
 * will be wired down.
 */
static int
mmu_booke_enter(pmap_t pmap, vm_offset_t va, vm_page_t m,
    vm_prot_t prot, u_int flags, int8_t psind)
{
        int error;

        rw_wlock(&pvh_global_lock);
        PMAP_LOCK(pmap);
        error = mmu_booke_enter_locked(pmap, va, m, prot, flags, psind);
        PMAP_UNLOCK(pmap);
        rw_wunlock(&pvh_global_lock);
        return (error);
}

static int
mmu_booke_enter_locked(pmap_t pmap, vm_offset_t va, vm_page_t m,
    vm_prot_t prot, u_int pmap_flags, int8_t psind __unused)
{
        pte_t *pte;
        vm_paddr_t pa;
        pte_t flags;
        int error, su, sync;

        pa = VM_PAGE_TO_PHYS(m);
        su = (pmap == kernel_pmap);
        sync = 0;

        //debugf("mmu_booke_enter_locked: s (pmap=0x%08x su=%d tid=%d m=0x%08x va=0x%08x "
        //              "pa=0x%08x prot=0x%08x flags=%#x)\n",
        //              (u_int32_t)pmap, su, pmap->pm_tid,
        //              (u_int32_t)m, va, pa, prot, flags);

        if (su) {
                KASSERT(((va >= virtual_avail) &&
                    (va <= VM_MAX_KERNEL_ADDRESS)),
                    ("mmu_booke_enter_locked: kernel pmap, non kernel va"));
        } else {
                KASSERT((va <= VM_MAXUSER_ADDRESS),
                    ("mmu_booke_enter_locked: user pmap, non user va"));
        }
        if ((m->oflags & VPO_UNMANAGED) == 0) {
                if ((pmap_flags & PMAP_ENTER_QUICK_LOCKED) == 0)
                        VM_PAGE_OBJECT_BUSY_ASSERT(m);
                else
                        VM_OBJECT_ASSERT_LOCKED(m->object);
        }

        PMAP_LOCK_ASSERT(pmap, MA_OWNED);

        /*
         * If there is an existing mapping, and the physical address has not
         * changed, must be protection or wiring change.
         */
        if (((pte = pte_find(pmap, va)) != NULL) &&
            (PTE_ISVALID(pte)) && (PTE_PA(pte) == pa)) {
            
                /*
                 * Before actually updating pte->flags we calculate and
                 * prepare its new value in a helper var.
                 */
                flags = *pte;
                flags &= ~(PTE_UW | PTE_UX | PTE_SW | PTE_SX | PTE_MODIFIED);

                /* Wiring change, just update stats. */
                if ((pmap_flags & PMAP_ENTER_WIRED) != 0) {
                        if (!PTE_ISWIRED(pte)) {
                                flags |= PTE_WIRED;
                                pmap->pm_stats.wired_count++;
                        }
                } else {
                        if (PTE_ISWIRED(pte)) {
                                flags &= ~PTE_WIRED;
                                pmap->pm_stats.wired_count--;
                        }
                }

                if (prot & VM_PROT_WRITE) {
                        /* Add write permissions. */
                        flags |= PTE_SW;
                        if (!su)
                                flags |= PTE_UW;

                        if ((flags & PTE_MANAGED) != 0)
                                vm_page_aflag_set(m, PGA_WRITEABLE);
                } else {
                        /* Handle modified pages, sense modify status. */

                        /*
                         * The PTE_MODIFIED flag could be set by underlying
                         * TLB misses since we last read it (above), possibly
                         * other CPUs could update it so we check in the PTE
                         * directly rather than rely on that saved local flags
                         * copy.
                         */
                        if (PTE_ISMODIFIED(pte))
                                vm_page_dirty(m);
                }

                if (prot & VM_PROT_EXECUTE) {
                        flags |= PTE_SX;
                        if (!su)
                                flags |= PTE_UX;

                        /*
                         * Check existing flags for execute permissions: if we
                         * are turning execute permissions on, icache should
                         * be flushed.
                         */
                        if ((*pte & (PTE_UX | PTE_SX)) == 0)
                                sync++;
                }

                flags &= ~PTE_REFERENCED;

                /*
                 * The new flags value is all calculated -- only now actually
                 * update the PTE.
                 */
                mtx_lock_spin(&tlbivax_mutex);
                tlb_miss_lock();

                tlb0_flush_entry(va);
                *pte &= ~PTE_FLAGS_MASK;
                *pte |= flags;

                tlb_miss_unlock();
                mtx_unlock_spin(&tlbivax_mutex);

        } else {
                /*
                 * If there is an existing mapping, but it's for a different
                 * physical address, pte_enter() will delete the old mapping.
                 */
                //if ((pte != NULL) && PTE_ISVALID(pte))
                //      debugf("mmu_booke_enter_locked: replace\n");
                //else
                //      debugf("mmu_booke_enter_locked: new\n");

                /* Now set up the flags and install the new mapping. */
                flags = (PTE_SR | PTE_VALID);
                flags |= PTE_M;

                if (!su)
                        flags |= PTE_UR;

                if (prot & VM_PROT_WRITE) {
                        flags |= PTE_SW;
                        if (!su)
                                flags |= PTE_UW;

                        if ((m->oflags & VPO_UNMANAGED) == 0)
                                vm_page_aflag_set(m, PGA_WRITEABLE);
                }

                if (prot & VM_PROT_EXECUTE) {
                        flags |= PTE_SX;
                        if (!su)
                                flags |= PTE_UX;
                }

                /* If its wired update stats. */
                if ((pmap_flags & PMAP_ENTER_WIRED) != 0)
                        flags |= PTE_WIRED;

                error = pte_enter(pmap, m, va, flags,
                    (pmap_flags & PMAP_ENTER_NOSLEEP) != 0);
                if (error != 0)
                        return (KERN_RESOURCE_SHORTAGE);

                if ((flags & PMAP_ENTER_WIRED) != 0)
                        pmap->pm_stats.wired_count++;

                /* Flush the real memory from the instruction cache. */
                if (prot & VM_PROT_EXECUTE)
                        sync++;
        }

        if (sync && (su || pmap == PCPU_GET(curpmap))) {
                __syncicache((void *)va, PAGE_SIZE);
                sync = 0;
        }

        return (KERN_SUCCESS);
}

/*
 * Maps a sequence of resident pages belonging to the same object.
 * The sequence begins with the given page m_start.  This page is
 * mapped at the given virtual address start.  Each subsequent page is
 * mapped at a virtual address that is offset from start by the same
 * amount as the page is offset from m_start within the object.  The
 * last page in the sequence is the page with the largest offset from
 * m_start that can be mapped at a virtual address less than the given
 * virtual address end.  Not every virtual page between start and end
 * is mapped; only those for which a resident page exists with the
 * corresponding offset from m_start are mapped.
 */
static void
mmu_booke_enter_object(pmap_t pmap, vm_offset_t start,
    vm_offset_t end, vm_page_t m_start, vm_prot_t prot)
{
        struct pctrie_iter pages;
        vm_offset_t va;
        vm_page_t m;

        VM_OBJECT_ASSERT_LOCKED(m_start->object);

        vm_page_iter_limit_init(&pages, m_start->object,
            m_start->pindex + atop(end - start));
        m = vm_radix_iter_lookup(&pages, m_start->pindex);
        rw_wlock(&pvh_global_lock);
        PMAP_LOCK(pmap);
        while (m != NULL) {
                va = start + ptoa(m->pindex - m_start->pindex);
                mmu_booke_enter_locked(pmap, va, m,
                    prot & (VM_PROT_READ | VM_PROT_EXECUTE),
                    PMAP_ENTER_NOSLEEP | PMAP_ENTER_QUICK_LOCKED, 0);
                m = vm_radix_iter_step(&pages);
        }
        PMAP_UNLOCK(pmap);
        rw_wunlock(&pvh_global_lock);
}

static void
mmu_booke_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m,
    vm_prot_t prot)
{

        rw_wlock(&pvh_global_lock);
        PMAP_LOCK(pmap);
        mmu_booke_enter_locked(pmap, va, m,
            prot & (VM_PROT_READ | VM_PROT_EXECUTE), PMAP_ENTER_NOSLEEP |
            PMAP_ENTER_QUICK_LOCKED, 0);
        PMAP_UNLOCK(pmap);
        rw_wunlock(&pvh_global_lock);
}

/*
 * Remove the given range of addresses from the specified map.
 *
 * It is assumed that the start and end are properly rounded to the page size.
 */
static void
mmu_booke_remove(pmap_t pmap, vm_offset_t va, vm_offset_t endva)
{
        pte_t *pte;
        uint8_t hold_flag;

        int su = (pmap == kernel_pmap);

        //debugf("mmu_booke_remove: s (su = %d pmap=0x%08x tid=%d va=0x%08x endva=0x%08x)\n",
        //              su, (u_int32_t)pmap, pmap->pm_tid, va, endva);

        if (su) {
                KASSERT(((va >= virtual_avail) &&
                    (va <= VM_MAX_KERNEL_ADDRESS)),
                    ("mmu_booke_remove: kernel pmap, non kernel va"));
        } else {
                KASSERT((va <= VM_MAXUSER_ADDRESS),
                    ("mmu_booke_remove: user pmap, non user va"));
        }

        if (PMAP_REMOVE_DONE(pmap)) {
                //debugf("mmu_booke_remove: e (empty)\n");
                return;
        }

        hold_flag = PTBL_HOLD_FLAG(pmap);
        //debugf("mmu_booke_remove: hold_flag = %d\n", hold_flag);

        rw_wlock(&pvh_global_lock);
        PMAP_LOCK(pmap);
        for (; va < endva; va += PAGE_SIZE) {
                pte = pte_find_next(pmap, &va);
                if ((pte == NULL) || !PTE_ISVALID(pte))
                        break;
                if (va >= endva)
                        break;
                pte_remove(pmap, va, hold_flag);
        }
        PMAP_UNLOCK(pmap);
        rw_wunlock(&pvh_global_lock);

        //debugf("mmu_booke_remove: e\n");
}

/*
 * Remove physical page from all pmaps in which it resides.
 */
static void
mmu_booke_remove_all(vm_page_t m)
{
        pv_entry_t pv, pvn;
        uint8_t hold_flag;

        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH_SAFE(pv, &m->md.pv_list, pv_link, pvn) {
                PMAP_LOCK(pv->pv_pmap);
                hold_flag = PTBL_HOLD_FLAG(pv->pv_pmap);
                pte_remove(pv->pv_pmap, pv->pv_va, hold_flag);
                PMAP_UNLOCK(pv->pv_pmap);
        }
        vm_page_aflag_clear(m, PGA_WRITEABLE);
        rw_wunlock(&pvh_global_lock);
}

/*
 * Map a range of physical addresses into kernel virtual address space.
 */
static vm_offset_t
mmu_booke_map(vm_offset_t *virt, vm_paddr_t pa_start,
    vm_paddr_t pa_end, int prot)
{
        vm_offset_t sva = *virt;
        vm_offset_t va = sva;

#ifdef __powerpc64__
        /* XXX: Handle memory not starting at 0x0. */
        if (pa_end < ctob(Maxmem))
                return (PHYS_TO_DMAP(pa_start));
#endif

        while (pa_start < pa_end) {
                mmu_booke_kenter(va, pa_start);
                va += PAGE_SIZE;
                pa_start += PAGE_SIZE;
        }
        *virt = va;

        return (sva);
}

/*
 * The pmap must be activated before it's address space can be accessed in any
 * way.
 */
static void
mmu_booke_activate(struct thread *td)
{
        pmap_t pmap;
        u_int cpuid;

        pmap = &td->td_proc->p_vmspace->vm_pmap;

        CTR5(KTR_PMAP, "%s: s (td = %p, proc = '%s', id = %d, pmap = 0x%"PRI0ptrX")",
            __func__, td, td->td_proc->p_comm, td->td_proc->p_pid, pmap);

        KASSERT((pmap != kernel_pmap), ("mmu_booke_activate: kernel_pmap!"));

        sched_pin();

        cpuid = PCPU_GET(cpuid);
        CPU_SET_ATOMIC(cpuid, &pmap->pm_active);
        PCPU_SET(curpmap, pmap);

        if (pmap->pm_tid[cpuid] == TID_NONE)
                tid_alloc(pmap);

        /* Load PID0 register with pmap tid value. */
        mtspr(SPR_PID0, pmap->pm_tid[cpuid]);
        __asm __volatile("isync");

        mtspr(SPR_DBCR0, td->td_pcb->pcb_cpu.booke.dbcr0);

        sched_unpin();

        CTR3(KTR_PMAP, "%s: e (tid = %d for '%s')", __func__,
            pmap->pm_tid[PCPU_GET(cpuid)], td->td_proc->p_comm);
}

/*
 * Deactivate the specified process's address space.
 */
static void
mmu_booke_deactivate(struct thread *td)
{
        pmap_t pmap;

        pmap = &td->td_proc->p_vmspace->vm_pmap;

        CTR5(KTR_PMAP, "%s: td=%p, proc = '%s', id = %d, pmap = 0x%"PRI0ptrX,
            __func__, td, td->td_proc->p_comm, td->td_proc->p_pid, pmap);

        td->td_pcb->pcb_cpu.booke.dbcr0 = mfspr(SPR_DBCR0);

        CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmap->pm_active);
        PCPU_SET(curpmap, NULL);
}

/*
 * Copy the range specified by src_addr/len
 * from the source map to the range dst_addr/len
 * in the destination map.
 *
 * This routine is only advisory and need not do anything.
 */
static void
mmu_booke_copy(pmap_t dst_pmap, pmap_t src_pmap,
    vm_offset_t dst_addr, vm_size_t len, vm_offset_t src_addr)
{

}

/*
 * Set the physical protection on the specified range of this map as requested.
 */
static void
mmu_booke_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva,
    vm_prot_t prot)
{
        vm_offset_t va;
        vm_page_t m;
        pte_t *pte;

        if ((prot & VM_PROT_READ) == VM_PROT_NONE) {
                mmu_booke_remove(pmap, sva, eva);
                return;
        }

        if (prot & VM_PROT_WRITE)
                return;

        PMAP_LOCK(pmap);
        for (va = sva; va < eva; va += PAGE_SIZE) {
                if ((pte = pte_find(pmap, va)) != NULL) {
                        if (PTE_ISVALID(pte)) {
                                m = PHYS_TO_VM_PAGE(PTE_PA(pte));

                                mtx_lock_spin(&tlbivax_mutex);
                                tlb_miss_lock();

                                /* Handle modified pages. */
                                if (PTE_ISMODIFIED(pte) && PTE_ISMANAGED(pte))
                                        vm_page_dirty(m);

                                tlb0_flush_entry(va);
                                *pte &= ~(PTE_UW | PTE_SW | PTE_MODIFIED);

                                tlb_miss_unlock();
                                mtx_unlock_spin(&tlbivax_mutex);
                        }
                }
        }
        PMAP_UNLOCK(pmap);
}

/*
 * Clear the write and modified bits in each of the given page's mappings.
 */
static void
mmu_booke_remove_write(vm_page_t m)
{
        pv_entry_t pv;
        pte_t *pte;

        KASSERT((m->oflags & VPO_UNMANAGED) == 0,
            ("mmu_booke_remove_write: page %p is not managed", m));
        vm_page_assert_busied(m);

        if (!pmap_page_is_write_mapped(m))
                return;
        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                PMAP_LOCK(pv->pv_pmap);
                if ((pte = pte_find(pv->pv_pmap, pv->pv_va)) != NULL) {
                        if (PTE_ISVALID(pte)) {
                                m = PHYS_TO_VM_PAGE(PTE_PA(pte));

                                mtx_lock_spin(&tlbivax_mutex);
                                tlb_miss_lock();

                                /* Handle modified pages. */
                                if (PTE_ISMODIFIED(pte))
                                        vm_page_dirty(m);

                                /* Flush mapping from TLB0. */
                                *pte &= ~(PTE_UW | PTE_SW | PTE_MODIFIED);

                                tlb_miss_unlock();
                                mtx_unlock_spin(&tlbivax_mutex);
                        }
                }
                PMAP_UNLOCK(pv->pv_pmap);
        }
        vm_page_aflag_clear(m, PGA_WRITEABLE);
        rw_wunlock(&pvh_global_lock);
}

/*
 * Atomically extract and hold the physical page with the given
 * pmap and virtual address pair if that mapping permits the given
 * protection.
 */
static vm_page_t
mmu_booke_extract_and_hold(pmap_t pmap, vm_offset_t va,
    vm_prot_t prot)
{
        pte_t *pte;
        vm_page_t m;
        uint32_t pte_wbit;

        m = NULL;
        PMAP_LOCK(pmap);
        pte = pte_find(pmap, va);
        if ((pte != NULL) && PTE_ISVALID(pte)) {
                if (pmap == kernel_pmap)
                        pte_wbit = PTE_SW;
                else
                        pte_wbit = PTE_UW;

                if ((*pte & pte_wbit) != 0 || (prot & VM_PROT_WRITE) == 0) {
                        m = PHYS_TO_VM_PAGE(PTE_PA(pte));
                        if (!vm_page_wire_mapped(m))
                                m = NULL;
                }
        }
        PMAP_UNLOCK(pmap);
        return (m);
}

/*
 * Initialize a vm_page's machine-dependent fields.
 */
static void
mmu_booke_page_init(vm_page_t m)
{

        m->md.pv_tracked = 0;
        TAILQ_INIT(&m->md.pv_list);
}

/*
 * Return whether or not the specified physical page was modified
 * in any of physical maps.
 */
static bool
mmu_booke_is_modified(vm_page_t m)
{
        pte_t *pte;
        pv_entry_t pv;
        bool rv;

        KASSERT((m->oflags & VPO_UNMANAGED) == 0,
            ("mmu_booke_is_modified: page %p is not managed", m));
        rv = false;

        /*
         * If the page is not busied then this check is racy.
         */
        if (!pmap_page_is_write_mapped(m))
                return (false);

        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                PMAP_LOCK(pv->pv_pmap);
                if ((pte = pte_find(pv->pv_pmap, pv->pv_va)) != NULL &&
                    PTE_ISVALID(pte)) {
                        if (PTE_ISMODIFIED(pte))
                                rv = true;
                }
                PMAP_UNLOCK(pv->pv_pmap);
                if (rv)
                        break;
        }
        rw_wunlock(&pvh_global_lock);
        return (rv);
}

/*
 * Return whether or not the specified virtual address is eligible
 * for prefault.
 */
static bool
mmu_booke_is_prefaultable(pmap_t pmap, vm_offset_t addr)
{

        return (false);
}

/*
 * Return whether or not the specified physical page was referenced
 * in any physical maps.
 */
static bool
mmu_booke_is_referenced(vm_page_t m)
{
        pte_t *pte;
        pv_entry_t pv;
        bool rv;

        KASSERT((m->oflags & VPO_UNMANAGED) == 0,
            ("mmu_booke_is_referenced: page %p is not managed", m));
        rv = false;
        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                PMAP_LOCK(pv->pv_pmap);
                if ((pte = pte_find(pv->pv_pmap, pv->pv_va)) != NULL &&
                    PTE_ISVALID(pte)) {
                        if (PTE_ISREFERENCED(pte))
                                rv = true;
                }
                PMAP_UNLOCK(pv->pv_pmap);
                if (rv)
                        break;
        }
        rw_wunlock(&pvh_global_lock);
        return (rv);
}

/*
 * Clear the modify bits on the specified physical page.
 */
static void
mmu_booke_clear_modify(vm_page_t m)
{
        pte_t *pte;
        pv_entry_t pv;

        KASSERT((m->oflags & VPO_UNMANAGED) == 0,
            ("mmu_booke_clear_modify: page %p is not managed", m));
        vm_page_assert_busied(m);

        if (!pmap_page_is_write_mapped(m))
                return;

        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                PMAP_LOCK(pv->pv_pmap);
                if ((pte = pte_find(pv->pv_pmap, pv->pv_va)) != NULL &&
                    PTE_ISVALID(pte)) {
                        mtx_lock_spin(&tlbivax_mutex);
                        tlb_miss_lock();
                        
                        if (*pte & (PTE_SW | PTE_UW | PTE_MODIFIED)) {
                                tlb0_flush_entry(pv->pv_va);
                                *pte &= ~(PTE_SW | PTE_UW | PTE_MODIFIED |
                                    PTE_REFERENCED);
                        }

                        tlb_miss_unlock();
                        mtx_unlock_spin(&tlbivax_mutex);
                }
                PMAP_UNLOCK(pv->pv_pmap);
        }
        rw_wunlock(&pvh_global_lock);
}

/*
 * 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.
 *
 * As an optimization, update the page's dirty field if a modified bit is
 * found while counting reference bits.  This opportunistic update can be
 * performed at low cost and can eliminate the need for some future calls
 * to pmap_is_modified().  However, since this function stops after
 * finding PMAP_TS_REFERENCED_MAX reference bits, it may not detect some
 * dirty pages.  Those dirty pages will only be detected by a future call
 * to pmap_is_modified().
 */
static int
mmu_booke_ts_referenced(vm_page_t m)
{
        pte_t *pte;
        pv_entry_t pv;
        int count;

        KASSERT((m->oflags & VPO_UNMANAGED) == 0,
            ("mmu_booke_ts_referenced: page %p is not managed", m));
        count = 0;
        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                PMAP_LOCK(pv->pv_pmap);
                if ((pte = pte_find(pv->pv_pmap, pv->pv_va)) != NULL &&
                    PTE_ISVALID(pte)) {
                        if (PTE_ISMODIFIED(pte))
                                vm_page_dirty(m);
                        if (PTE_ISREFERENCED(pte)) {
                                mtx_lock_spin(&tlbivax_mutex);
                                tlb_miss_lock();

                                tlb0_flush_entry(pv->pv_va);
                                *pte &= ~PTE_REFERENCED;

                                tlb_miss_unlock();
                                mtx_unlock_spin(&tlbivax_mutex);

                                if (++count >= PMAP_TS_REFERENCED_MAX) {
                                        PMAP_UNLOCK(pv->pv_pmap);
                                        break;
                                }
                        }
                }
                PMAP_UNLOCK(pv->pv_pmap);
        }
        rw_wunlock(&pvh_global_lock);
        return (count);
}

/*
 * Clear the wired attribute from the mappings for the specified range of
 * addresses in the given pmap.  Every valid mapping within that range must
 * have the wired attribute set.  In contrast, invalid mappings cannot have
 * the wired attribute set, so they are ignored.
 *
 * The wired attribute of the page table entry is not a hardware feature, so
 * there is no need to invalidate any TLB entries.
 */
static void
mmu_booke_unwire(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
{
        vm_offset_t va;
        pte_t *pte;

        PMAP_LOCK(pmap);
        for (va = sva; va < eva; va += PAGE_SIZE) {
                if ((pte = pte_find(pmap, va)) != NULL &&
                    PTE_ISVALID(pte)) {
                        if (!PTE_ISWIRED(pte))
                                panic("mmu_booke_unwire: pte %p isn't wired",
                                    pte);
                        *pte &= ~PTE_WIRED;
                        pmap->pm_stats.wired_count--;
                }
        }
        PMAP_UNLOCK(pmap);

}

/*
 * Return 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.
 */
static bool
mmu_booke_page_exists_quick(pmap_t pmap, vm_page_t m)
{
        pv_entry_t pv;
        int loops;
        bool rv;

        KASSERT((m->oflags & VPO_UNMANAGED) == 0,
            ("mmu_booke_page_exists_quick: page %p is not managed", m));
        loops = 0;
        rv = false;
        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                if (pv->pv_pmap == pmap) {
                        rv = true;
                        break;
                }
                if (++loops >= 16)
                        break;
        }
        rw_wunlock(&pvh_global_lock);
        return (rv);
}

/*
 * Return the number of managed mappings to the given physical page that are
 * wired.
 */
static int
mmu_booke_page_wired_mappings(vm_page_t m)
{
        pv_entry_t pv;
        pte_t *pte;
        int count = 0;

        if ((m->oflags & VPO_UNMANAGED) != 0)
                return (count);
        rw_wlock(&pvh_global_lock);
        TAILQ_FOREACH(pv, &m->md.pv_list, pv_link) {
                PMAP_LOCK(pv->pv_pmap);
                if ((pte = pte_find(pv->pv_pmap, pv->pv_va)) != NULL)
                        if (PTE_ISVALID(pte) && PTE_ISWIRED(pte))
                                count++;
                PMAP_UNLOCK(pv->pv_pmap);
        }
        rw_wunlock(&pvh_global_lock);
        return (count);
}

static int
mmu_booke_dev_direct_mapped(vm_paddr_t pa, vm_size_t size)
{
        int i;
        vm_offset_t va;

        /*
         * This currently does not work for entries that
         * overlap TLB1 entries.
         */
        for (i = 0; i < TLB1_ENTRIES; i ++) {
                if (tlb1_iomapped(i, pa, size, &va) == 0)
                        return (0);
        }

        return (EFAULT);
}

void
mmu_booke_dumpsys_map(vm_paddr_t pa, size_t sz, void **va)
{
        vm_paddr_t ppa;
        vm_offset_t ofs;
        vm_size_t gran;

        /* Minidumps are based on virtual memory addresses. */
        if (do_minidump) {
                *va = (void *)(vm_offset_t)pa;
                return;
        }

        /* Raw physical memory dumps don't have a virtual address. */
        /* We always map a 256MB page at 256M. */
        gran = 256 * 1024 * 1024;
        ppa = rounddown2(pa, gran);
        ofs = pa - ppa;
        *va = (void *)gran;
        tlb1_set_entry((vm_offset_t)va, ppa, gran, _TLB_ENTRY_IO);

        if (sz > (gran - ofs))
                tlb1_set_entry((vm_offset_t)(va + gran), ppa + gran, gran,
                    _TLB_ENTRY_IO);
}

void
mmu_booke_dumpsys_unmap(vm_paddr_t pa, size_t sz, void *va)
{
        vm_paddr_t ppa;
        vm_offset_t ofs;
        vm_size_t gran;
        tlb_entry_t e;
        int i;

        /* Minidumps are based on virtual memory addresses. */
        /* Nothing to do... */
        if (do_minidump)
                return;

        for (i = 0; i < TLB1_ENTRIES; i++) {
                tlb1_read_entry(&e, i);
                if (!(e.mas1 & MAS1_VALID))
                        break;
        }

        /* Raw physical memory dumps don't have a virtual address. */
        i--;
        e.mas1 = 0;
        e.mas2 = 0;
        e.mas3 = 0;
        tlb1_write_entry(&e, i);

        gran = 256 * 1024 * 1024;
        ppa = rounddown2(pa, gran);
        ofs = pa - ppa;
        if (sz > (gran - ofs)) {
                i--;
                e.mas1 = 0;
                e.mas2 = 0;
                e.mas3 = 0;
                tlb1_write_entry(&e, i);
        }
}

extern struct dump_pa dump_map[PHYS_AVAIL_SZ + 1];

void
mmu_booke_scan_init(void)
{
        vm_offset_t va;
        pte_t *pte;
        int i;

        if (!do_minidump) {
                /* Initialize phys. segments for dumpsys(). */
                memset(&dump_map, 0, sizeof(dump_map));
                mem_regions(&physmem_regions, &physmem_regions_sz, &availmem_regions,
                    &availmem_regions_sz);
                for (i = 0; i < physmem_regions_sz; i++) {
                        dump_map[i].pa_start = physmem_regions[i].mr_start;
                        dump_map[i].pa_size = physmem_regions[i].mr_size;
                }
                return;
        }

        /* Virtual segments for minidumps: */
        memset(&dump_map, 0, sizeof(dump_map));

        /* 1st: kernel .data and .bss. */
        dump_map[0].pa_start = trunc_page((uintptr_t)_etext);
        dump_map[0].pa_size =
            round_page((uintptr_t)_end) - dump_map[0].pa_start;

        /* 2nd: msgbuf and tables (see pmap_bootstrap()). */
        dump_map[1].pa_start = data_start;
        dump_map[1].pa_size = data_end - data_start;

        /* 3rd: kernel VM. */
        va = dump_map[1].pa_start + dump_map[1].pa_size;
        /* Find start of next chunk (from va). */
        while (va < virtual_end) {
                /* Don't dump the buffer cache. */
                if (va >= kmi.buffer_sva && va < kmi.buffer_eva) {
                        va = kmi.buffer_eva;
                        continue;
                }
                pte = pte_find(kernel_pmap, va);
                if (pte != NULL && PTE_ISVALID(pte))
                        break;
                va += PAGE_SIZE;
        }
        if (va < virtual_end) {
                dump_map[2].pa_start = va;
                va += PAGE_SIZE;
                /* Find last page in chunk. */
                while (va < virtual_end) {
                        /* Don't run into the buffer cache. */
                        if (va == kmi.buffer_sva)
                                break;
                        pte = pte_find(kernel_pmap, va);
                        if (pte == NULL || !PTE_ISVALID(pte))
                                break;
                        va += PAGE_SIZE;
                }
                dump_map[2].pa_size = va - dump_map[2].pa_start;
        }
}

/*
 * 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.
 */
static void *
mmu_booke_mapdev(vm_paddr_t pa, vm_size_t size)
{

        return (mmu_booke_mapdev_attr(pa, size, VM_MEMATTR_DEFAULT));
}

static int
tlb1_find_pa(vm_paddr_t pa, tlb_entry_t *e)
{
        int i;

        for (i = 0; i < TLB1_ENTRIES; i++) {
                tlb1_read_entry(e, i);
                if ((e->mas1 & MAS1_VALID) == 0)
                        continue;
                if (e->phys == pa)
                        return (i);
        }
        return (-1);
}

static void *
mmu_booke_mapdev_attr(vm_paddr_t pa, vm_size_t size, vm_memattr_t ma)
{
        tlb_entry_t e;
        vm_paddr_t tmppa;
#ifndef __powerpc64__
        uintptr_t tmpva;
#endif
        uintptr_t va, retva;
        vm_size_t sz;
        int i;
        int wimge;

        /*
         * Check if this is premapped in TLB1.
         */
        sz = size;
        tmppa = pa;
        va = ~0;
        wimge = tlb_calc_wimg(pa, ma);
        for (i = 0; i < TLB1_ENTRIES; i++) {
                tlb1_read_entry(&e, i);
                if (!(e.mas1 & MAS1_VALID))
                        continue;
                if (wimge != (e.mas2 & (MAS2_WIMGE_MASK & ~_TLB_ENTRY_SHARED)))
                        continue;
                if (tmppa >= e.phys && tmppa < e.phys + e.size) {
                        va = e.virt + (pa - e.phys);
                        tmppa = e.phys + e.size;
                        sz -= MIN(sz, e.size - (pa - e.phys));
                        while (sz > 0 && (i = tlb1_find_pa(tmppa, &e)) != -1) {
                                if (wimge != (e.mas2 & (MAS2_WIMGE_MASK & ~_TLB_ENTRY_SHARED)))
                                        break;
                                sz -= MIN(sz, e.size);
                                tmppa = e.phys + e.size;
                        }
                        if (sz != 0)
                                break;
                        return ((void *)va);
                }
        }

        size = roundup(size, PAGE_SIZE);

#ifdef __powerpc64__
        KASSERT(pa < VM_MAPDEV_PA_MAX,
            ("Unsupported physical address! %lx", pa));
        va = VM_MAPDEV_BASE + pa;
        retva = va;
#ifdef POW2_MAPPINGS
        /*
         * Align the mapping to a power of 2 size, taking into account that we
         * may need to increase the size multiple times to satisfy the size and
         * alignment requirements.
         *
         * This works in the general case because it's very rare (near never?)
         * to have different access properties (WIMG) within a single
         * power-of-two region.  If a design does call for that, POW2_MAPPINGS
         * can be undefined, and exact mappings will be used instead.
         */
        sz = size;
        size = roundup2(size, 1 << ilog2(size));
        while (rounddown2(va, size) + size < va + sz)
                size <<= 1;
        va = rounddown2(va, size);
        pa = rounddown2(pa, size);
#endif
#else
        /*
         * The device mapping area is between VM_MAXUSER_ADDRESS and
         * VM_MIN_KERNEL_ADDRESS.  This gives 1GB of device addressing.
         */
#ifdef SPARSE_MAPDEV
        /*
         * With a sparse mapdev, align to the largest starting region.  This
         * could feasibly be optimized for a 'best-fit' alignment, but that
         * calculation could be very costly.
         * Align to the smaller of:
         * - first set bit in overlap of (pa & size mask)
         * - largest size envelope
         *
         * It's possible the device mapping may start at a PA that's not larger
         * than the size mask, so we need to offset in to maximize the TLB entry
         * range and minimize the number of used TLB entries.
         */
        do {
            tmpva = tlb1_map_base;
            sz = ffsl((~((1 << flsl(size-1)) - 1)) & pa);
            sz = sz ? min(roundup(sz + 3, 4), flsl(size) - 1) : flsl(size) - 1;
            va = roundup(tlb1_map_base, 1 << sz) | (((1 << sz) - 1) & pa);
        } while (!atomic_cmpset_int(&tlb1_map_base, tmpva, va + size));
#endif
        va = atomic_fetchadd_int(&tlb1_map_base, size);
        retva = va;
#endif

        if (tlb1_mapin_region(va, pa, size, tlb_calc_wimg(pa, ma)) != size)
                return (NULL);

        return ((void *)retva);
}

/*
 * 'Unmap' a range mapped by mmu_booke_mapdev().
 */
static void
mmu_booke_unmapdev(void *p, vm_size_t size)
{
#ifdef SUPPORTS_SHRINKING_TLB1
        vm_offset_t base, offset, va;

        /*
         * Unmap only if this is inside kernel virtual space.
         */
        va = (vm_offset_t)p;
        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);
                mmu_booke_qremove(base, atop(size));
                kva_free(base, size);
        }
#endif
}

/*
 * mmu_booke_object_init_pt preloads the ptes for a given object into the
 * specified pmap. This eliminates the blast of soft faults on process startup
 * and immediately after an mmap.
 */
static void
mmu_booke_object_init_pt(pmap_t pmap, vm_offset_t addr,
    vm_object_t object, vm_pindex_t pindex, vm_size_t size)
{

        VM_OBJECT_ASSERT_WLOCKED(object);
        KASSERT(object->type == OBJT_DEVICE || object->type == OBJT_SG,
            ("mmu_booke_object_init_pt: non-device object"));
}

/*
 * Perform the pmap work for mincore.
 */
static int
mmu_booke_mincore(pmap_t pmap, vm_offset_t addr, vm_paddr_t *pap)
{

        /* XXX: this should be implemented at some point */
        return (0);
}

static int
mmu_booke_change_attr(vm_offset_t addr, vm_size_t sz, vm_memattr_t mode)
{
        vm_offset_t va;
        pte_t *pte;
        int i, j;
        tlb_entry_t e;

        addr = trunc_page(addr);

        /* Only allow changes to mapped kernel addresses.  This includes:
         * - KVA
         * - DMAP (powerpc64)
         * - Device mappings
         */
        if (addr <= VM_MAXUSER_ADDRESS ||
#ifdef __powerpc64__
            (addr >= tlb1_map_base && addr < DMAP_BASE_ADDRESS) ||
            (addr > DMAP_MAX_ADDRESS && addr < VM_MIN_KERNEL_ADDRESS) ||
#else
            (addr >= tlb1_map_base && addr < VM_MIN_KERNEL_ADDRESS) ||
#endif
            (addr > VM_MAX_KERNEL_ADDRESS))
                return (EINVAL);

        /* Check TLB1 mappings */
        for (i = 0; i < TLB1_ENTRIES; i++) {
                tlb1_read_entry(&e, i);
                if (!(e.mas1 & MAS1_VALID))
                        continue;
                if (addr >= e.virt && addr < e.virt + e.size)
                        break;
        }
        if (i < TLB1_ENTRIES) {
                /* Only allow full mappings to be modified for now. */
                /* Validate the range. */
                for (j = i, va = addr; va < addr + sz; va += e.size, j++) {
                        tlb1_read_entry(&e, j);
                        if (va != e.virt || (sz - (va - addr) < e.size))
                                return (EINVAL);
                }
                for (va = addr; va < addr + sz; va += e.size, i++) {
                        tlb1_read_entry(&e, i);
                        e.mas2 &= ~MAS2_WIMGE_MASK;
                        e.mas2 |= tlb_calc_wimg(e.phys, mode);

                        /*
                         * Write it out to the TLB.  Should really re-sync with other
                         * cores.
                         */
                        tlb1_write_entry(&e, i);
                }
                return (0);
        }

        /* Not in TLB1, try through pmap */
        /* First validate the range. */
        for (va = addr; va < addr + sz; va += PAGE_SIZE) {
                pte = pte_find(kernel_pmap, va);
                if (pte == NULL || !PTE_ISVALID(pte))
                        return (EINVAL);
        }

        mtx_lock_spin(&tlbivax_mutex);
        tlb_miss_lock();
        for (va = addr; va < addr + sz; va += PAGE_SIZE) {
                pte = pte_find(kernel_pmap, va);
                *pte &= ~(PTE_MAS2_MASK << PTE_MAS2_SHIFT);
                *pte |= tlb_calc_wimg(PTE_PA(pte), mode) << PTE_MAS2_SHIFT;
                tlb0_flush_entry(va);
        }
        tlb_miss_unlock();
        mtx_unlock_spin(&tlbivax_mutex);

        return (0);
}

static void
mmu_booke_page_array_startup(long pages)
{
        vm_page_array_size = pages;
}

/**************************************************************************/
/* TID handling */
/**************************************************************************/

/*
 * Allocate a TID. If necessary, steal one from someone else.
 * The new TID is flushed from the TLB before returning.
 */
static tlbtid_t
tid_alloc(pmap_t pmap)
{
        tlbtid_t tid;
        int thiscpu;

        KASSERT((pmap != kernel_pmap), ("tid_alloc: kernel pmap"));

        CTR2(KTR_PMAP, "%s: s (pmap = %p)", __func__, pmap);

        thiscpu = PCPU_GET(cpuid);

        tid = PCPU_GET(booke.tid_next);
        if (tid > TID_MAX)
                tid = TID_MIN;
        PCPU_SET(booke.tid_next, tid + 1);

        /* If we are stealing TID then clear the relevant pmap's field */
        if (tidbusy[thiscpu][tid] != NULL) {
                CTR2(KTR_PMAP, "%s: warning: stealing tid %d", __func__, tid);
                
                tidbusy[thiscpu][tid]->pm_tid[thiscpu] = TID_NONE;

                /* Flush all entries from TLB0 matching this TID. */
                tid_flush(tid);
        }

        tidbusy[thiscpu][tid] = pmap;
        pmap->pm_tid[thiscpu] = tid;
        __asm __volatile("msync; isync");

        CTR3(KTR_PMAP, "%s: e (%02d next = %02d)", __func__, tid,
            PCPU_GET(booke.tid_next));

        return (tid);
}

/**************************************************************************/
/* TLB0 handling */
/**************************************************************************/

/* Convert TLB0 va and way number to tlb0[] table index. */
static inline unsigned int
tlb0_tableidx(vm_offset_t va, unsigned int way)
{
        unsigned int idx;

        idx = (way * TLB0_ENTRIES_PER_WAY);
        idx += (va & MAS2_TLB0_ENTRY_IDX_MASK) >> MAS2_TLB0_ENTRY_IDX_SHIFT;
        return (idx);
}

/*
 * Invalidate TLB0 entry.
 */
static inline void
tlb0_flush_entry(vm_offset_t va)
{

        CTR2(KTR_PMAP, "%s: s va=0x%08x", __func__, va);

        mtx_assert(&tlbivax_mutex, MA_OWNED);

        __asm __volatile("tlbivax 0, %0" :: "r"(va & MAS2_EPN_MASK));
        __asm __volatile("isync; msync");
        __asm __volatile("tlbsync; msync");

        CTR1(KTR_PMAP, "%s: e", __func__);
}

/**************************************************************************/
/* TLB1 handling */
/**************************************************************************/

/*
 * TLB1 mapping notes:
 *
 * TLB1[0]      Kernel text and data.
 * TLB1[1-15]   Additional kernel text and data mappings (if required), PCI
 *              windows, other devices mappings.
 */

 /*
 * Read an entry from given TLB1 slot.
 */
void
tlb1_read_entry(tlb_entry_t *entry, unsigned int slot)
{
        register_t msr;
        uint32_t mas0;

        KASSERT((entry != NULL), ("%s(): Entry is NULL!", __func__));

        msr = mfmsr();
        __asm __volatile("wrteei 0");

        mas0 = MAS0_TLBSEL(1) | MAS0_ESEL(slot);
        mtspr(SPR_MAS0, mas0);
        __asm __volatile("isync; tlbre");

        entry->mas1 = mfspr(SPR_MAS1);
        entry->mas2 = mfspr(SPR_MAS2);
        entry->mas3 = mfspr(SPR_MAS3);

        switch ((mfpvr() >> 16) & 0xFFFF) {
        case FSL_E500v2:
        case FSL_E500mc:
        case FSL_E5500:
        case FSL_E6500:
                entry->mas7 = mfspr(SPR_MAS7);
                break;
        default:
                entry->mas7 = 0;
                break;
        }
        __asm __volatile("wrtee %0" :: "r"(msr));

        entry->virt = entry->mas2 & MAS2_EPN_MASK;
        entry->phys = ((vm_paddr_t)(entry->mas7 & MAS7_RPN) << 32) |
            (entry->mas3 & MAS3_RPN);
        entry->size =
            tsize2size((entry->mas1 & MAS1_TSIZE_MASK) >> MAS1_TSIZE_SHIFT);
}

struct tlbwrite_args {
        tlb_entry_t *e;
        unsigned int idx;
};

static uint32_t
tlb1_find_free(void)
{
        tlb_entry_t e;
        int i;

        for (i = 0; i < TLB1_ENTRIES; i++) {
                tlb1_read_entry(&e, i);
                if ((e.mas1 & MAS1_VALID) == 0)
                        return (i);
        }
        return (-1);
}

static void
tlb1_purge_va_range(vm_offset_t va, vm_size_t size)
{
        tlb_entry_t e;
        int i;

        for (i = 0; i < TLB1_ENTRIES; i++) {
                tlb1_read_entry(&e, i);
                if ((e.mas1 & MAS1_VALID) == 0)
                        continue;
                if ((e.mas2 & MAS2_EPN_MASK) >= va &&
                    (e.mas2 & MAS2_EPN_MASK) < va + size) {
                        mtspr(SPR_MAS1, e.mas1 & ~MAS1_VALID);
                        __asm __volatile("isync; tlbwe; isync; msync");
                }
        }
}

static void
tlb1_write_entry_int(void *arg)
{
        struct tlbwrite_args *args = arg;
        uint32_t idx, mas0;

        idx = args->idx;
        if (idx == -1) {
                tlb1_purge_va_range(args->e->virt, args->e->size);
                idx = tlb1_find_free();
                if (idx == -1)
                        panic("No free TLB1 entries!\n");
        }
        /* Select entry */
        mas0 = MAS0_TLBSEL(1) | MAS0_ESEL(idx);

        mtspr(SPR_MAS0, mas0);
        mtspr(SPR_MAS1, args->e->mas1);
        mtspr(SPR_MAS2, args->e->mas2);
        mtspr(SPR_MAS3, args->e->mas3);
        switch ((mfpvr() >> 16) & 0xFFFF) {
        case FSL_E500mc:
        case FSL_E5500:
        case FSL_E6500:
                mtspr(SPR_MAS8, 0);
                /* FALLTHROUGH */
        case FSL_E500v2:
                mtspr(SPR_MAS7, args->e->mas7);
                break;
        default:
                break;
        }

        __asm __volatile("isync; tlbwe; isync; msync");

}

static void
tlb1_write_entry_sync(void *arg)
{
        /* Empty synchronization point for smp_rendezvous(). */
}

/*
 * Write given entry to TLB1 hardware.
 */
static void
tlb1_write_entry(tlb_entry_t *e, unsigned int idx)
{
        struct tlbwrite_args args;

        args.e = e;
        args.idx = idx;

#ifdef SMP
        if ((e->mas2 & _TLB_ENTRY_SHARED) && smp_started) {
                mb();
                smp_rendezvous(tlb1_write_entry_sync,
                    tlb1_write_entry_int,
                    tlb1_write_entry_sync, &args);
        } else
#endif
        {
                register_t msr;

                msr = mfmsr();
                __asm __volatile("wrteei 0");
                tlb1_write_entry_int(&args);
                __asm __volatile("wrtee %0" :: "r"(msr));
        }
}

/*
 * Convert TLB TSIZE value to mapped region size.
 */
static vm_size_t
tsize2size(unsigned int tsize)
{

        /*
         * size = 4^tsize KB
         * size = 4^tsize * 2^10 = 2^(2 * tsize - 10)
         */

        return ((1 << (2 * tsize)) * 1024);
}

/*
 * Convert region size (must be power of 4) to TLB TSIZE value.
 */
static unsigned int
size2tsize(vm_size_t size)
{

        return (ilog2(size) / 2 - 5);
}

/*
 * Register permanent kernel mapping in TLB1.
 *
 * Entries are created starting from index 0 (current free entry is
 * kept in tlb1_idx) and are not supposed to be invalidated.
 */
int
tlb1_set_entry(vm_offset_t va, vm_paddr_t pa, vm_size_t size,
    uint32_t flags)
{
        tlb_entry_t e;
        uint32_t ts, tid;
        int tsize, index;

        /* First try to update an existing entry. */
        for (index = 0; index < TLB1_ENTRIES; index++) {
                tlb1_read_entry(&e, index);
                /* Check if we're just updating the flags, and update them. */
                if (e.phys == pa && e.virt == va && e.size == size) {
                        e.mas2 = (va & MAS2_EPN_MASK) | flags;
                        tlb1_write_entry(&e, index);
                        return (0);
                }
        }

        /* Convert size to TSIZE */
        tsize = size2tsize(size);

        tid = (TID_KERNEL << MAS1_TID_SHIFT) & MAS1_TID_MASK;
        /* XXX TS is hard coded to 0 for now as we only use single address space */
        ts = (0 << MAS1_TS_SHIFT) & MAS1_TS_MASK;

        e.phys = pa;
        e.virt = va;
        e.size = size;
        e.mas1 = MAS1_VALID | MAS1_IPROT | ts | tid;
        e.mas1 |= ((tsize << MAS1_TSIZE_SHIFT) & MAS1_TSIZE_MASK);
        e.mas2 = (va & MAS2_EPN_MASK) | flags;

        /* Set supervisor RWX permission bits */
        e.mas3 = (pa & MAS3_RPN) | MAS3_SR | MAS3_SW | MAS3_SX;
        e.mas7 = (pa >> 32) & MAS7_RPN;

        tlb1_write_entry(&e, -1);

        return (0);
}

/*
 * Map in contiguous RAM region into the TLB1.
 */
static vm_size_t
tlb1_mapin_region(vm_offset_t va, vm_paddr_t pa, vm_size_t size, int wimge)
{
        vm_offset_t base;
        vm_size_t mapped, sz, ssize;

        mapped = 0;
        base = va;
        ssize = size;

        while (size > 0) {
                sz = 1UL << (ilog2(size) & ~1);
                /* Align size to PA */
                if (pa % sz != 0) {
                        do {
                                sz >>= 2;
                        } while (pa % sz != 0);
                }
                /* Now align from there to VA */
                if (va % sz != 0) {
                        do {
                                sz >>= 2;
                        } while (va % sz != 0);
                }
#ifdef __powerpc64__
                /*
                 * Clamp TLB1 entries to 4G.
                 *
                 * While the e6500 supports up to 1TB mappings, the e5500
                 * only supports up to 4G mappings. (0b1011)
                 *
                 * If any e6500 machines capable of supporting a very
                 * large amount of memory appear in the future, we can
                 * revisit this.
                 *
                 * For now, though, since we have plenty of space in TLB1,
                 * always avoid creating entries larger than 4GB.
                 */
                sz = MIN(sz, 1UL << 32);
#endif
                if (bootverbose)
                        printf("Wiring VA=%p to PA=%jx (size=%lx)\n",
                            (void *)va, (uintmax_t)pa, (long)sz);
                if (tlb1_set_entry(va, pa, sz,
                    _TLB_ENTRY_SHARED | wimge) < 0)
                        return (mapped);
                size -= sz;
                pa += sz;
                va += sz;
        }

        mapped = (va - base);
        if (bootverbose)
                printf("mapped size 0x%"PRIxPTR" (wasted space 0x%"PRIxPTR")\n",
                    mapped, mapped - ssize);

        return (mapped);
}

/*
 * TLB1 initialization routine, to be called after the very first
 * assembler level setup done in locore.S.
 */
void
tlb1_init(void)
{
        vm_offset_t mas2;
        uint32_t mas0, mas1, mas3, mas7;
        uint32_t tsz;

        tlb1_get_tlbconf();

        mas0 = MAS0_TLBSEL(1) | MAS0_ESEL(0);
        mtspr(SPR_MAS0, mas0);
        __asm __volatile("isync; tlbre");

        mas1 = mfspr(SPR_MAS1);
        mas2 = mfspr(SPR_MAS2);
        mas3 = mfspr(SPR_MAS3);
        mas7 = mfspr(SPR_MAS7);

        kernload =  ((vm_paddr_t)(mas7 & MAS7_RPN) << 32) |
            (mas3 & MAS3_RPN);

        tsz = (mas1 & MAS1_TSIZE_MASK) >> MAS1_TSIZE_SHIFT;
        kernsize += (tsz > 0) ? tsize2size(tsz) : 0;
        kernstart = trunc_page(mas2);

        /* Setup TLB miss defaults */
        set_mas4_defaults();
}

/*
 * pmap_early_io_unmap() should be used in short conjunction with
 * pmap_early_io_map(), as in the following snippet:
 *
 * x = pmap_early_io_map(...);
 * <do something with x>
 * pmap_early_io_unmap(x, size);
 *
 * And avoiding more allocations between.
 */
void
pmap_early_io_unmap(vm_offset_t va, vm_size_t size)
{
        int i;
        tlb_entry_t e;
        vm_size_t isize;

        size = roundup(size, PAGE_SIZE);
        isize = size;
        for (i = 0; i < TLB1_ENTRIES && size > 0; i++) {
                tlb1_read_entry(&e, i);
                if (!(e.mas1 & MAS1_VALID))
                        continue;
                if (va <= e.virt && (va + isize) >= (e.virt + e.size)) {
                        size -= e.size;
                        e.mas1 &= ~MAS1_VALID;
                        tlb1_write_entry(&e, i);
                }
        }
        if (tlb1_map_base == va + isize)
                tlb1_map_base -= isize;
}       
                
vm_offset_t 
pmap_early_io_map(vm_paddr_t pa, vm_size_t size)
{
        vm_paddr_t pa_base;
        vm_offset_t va, sz;
        int i;
        tlb_entry_t e;

        KASSERT(!pmap_bootstrapped, ("Do not use after PMAP is up!"));

        for (i = 0; i < TLB1_ENTRIES; i++) {
                tlb1_read_entry(&e, i);
                if (!(e.mas1 & MAS1_VALID))
                        continue;
                if (pa >= e.phys && (pa + size) <=
                    (e.phys + e.size))
                        return (e.virt + (pa - e.phys));
        }

        pa_base = rounddown(pa, PAGE_SIZE);
        size = roundup(size + (pa - pa_base), PAGE_SIZE);
        tlb1_map_base = roundup2(tlb1_map_base, 1 << (ilog2(size) & ~1));
        va = tlb1_map_base + (pa - pa_base);

        do {
                sz = 1 << (ilog2(size) & ~1);
                tlb1_set_entry(tlb1_map_base, pa_base, sz,
                    _TLB_ENTRY_SHARED | _TLB_ENTRY_IO);
                size -= sz;
                pa_base += sz;
                tlb1_map_base += sz;
        } while (size > 0);

        return (va);
}

void
pmap_track_page(pmap_t pmap, vm_offset_t va)
{
        vm_paddr_t pa;
        vm_page_t page;
        struct pv_entry *pve;

        va = trunc_page(va);
        pa = pmap_kextract(va);
        page = PHYS_TO_VM_PAGE(pa);

        rw_wlock(&pvh_global_lock);
        PMAP_LOCK(pmap);

        TAILQ_FOREACH(pve, &page->md.pv_list, pv_link) {
                if ((pmap == pve->pv_pmap) && (va == pve->pv_va)) {
                        goto out;
                }
        }
        page->md.pv_tracked = true;
        pv_insert(pmap, va, page);
out:
        PMAP_UNLOCK(pmap);
        rw_wunlock(&pvh_global_lock);
}

/*
 * Setup MAS4 defaults.
 * These values are loaded to MAS0-2 on a TLB miss.
 */
static void
set_mas4_defaults(void)
{
        uint32_t mas4;

        /* Defaults: TLB0, PID0, TSIZED=4K */
        mas4 = MAS4_TLBSELD0;
        mas4 |= (TLB_SIZE_4K << MAS4_TSIZED_SHIFT) & MAS4_TSIZED_MASK;
#ifdef SMP
        mas4 |= MAS4_MD;
#endif
        mtspr(SPR_MAS4, mas4);
        __asm __volatile("isync");
}

/*
 * Return 0 if the physical IO range is encompassed by one of the
 * the TLB1 entries, otherwise return related error code.
 */
static int
tlb1_iomapped(int i, vm_paddr_t pa, vm_size_t size, vm_offset_t *va)
{
        uint32_t prot;
        vm_paddr_t pa_start;
        vm_paddr_t pa_end;
        unsigned int entry_tsize;
        vm_size_t entry_size;
        tlb_entry_t e;

        *va = (vm_offset_t)NULL;

        tlb1_read_entry(&e, i);
        /* Skip invalid entries */
        if (!(e.mas1 & MAS1_VALID))
                return (EINVAL);

        /*
         * The entry must be cache-inhibited, guarded, and r/w
         * so it can function as an i/o page
         */
        prot = e.mas2 & (MAS2_I | MAS2_G);
        if (prot != (MAS2_I | MAS2_G))
                return (EPERM);

        prot = e.mas3 & (MAS3_SR | MAS3_SW);
        if (prot != (MAS3_SR | MAS3_SW))
                return (EPERM);

        /* The address should be within the entry range. */
        entry_tsize = (e.mas1 & MAS1_TSIZE_MASK) >> MAS1_TSIZE_SHIFT;
        KASSERT((entry_tsize), ("tlb1_iomapped: invalid entry tsize"));

        entry_size = tsize2size(entry_tsize);
        pa_start = (((vm_paddr_t)e.mas7 & MAS7_RPN) << 32) | 
            (e.mas3 & MAS3_RPN);
        pa_end = pa_start + entry_size;

        if ((pa < pa_start) || ((pa + size) > pa_end))
                return (ERANGE);

        /* Return virtual address of this mapping. */
        *va = (e.mas2 & MAS2_EPN_MASK) + (pa - pa_start);
        return (0);
}

#ifdef DDB
/* Print out contents of the MAS registers for each TLB0 entry */
static void
#ifdef __powerpc64__
tlb_print_entry(int i, uint32_t mas1, uint64_t mas2, uint32_t mas3,
#else
tlb_print_entry(int i, uint32_t mas1, uint32_t mas2, uint32_t mas3,
#endif
    uint32_t mas7)
{
        int as;
        char desc[3];
        tlbtid_t tid;
        vm_size_t size;
        unsigned int tsize;

        desc[2] = '\0';
        if (mas1 & MAS1_VALID)
                desc[0] = 'V';
        else
                desc[0] = ' ';

        if (mas1 & MAS1_IPROT)
                desc[1] = 'P';
        else
                desc[1] = ' ';

        as = (mas1 & MAS1_TS_MASK) ? 1 : 0;
        tid = MAS1_GETTID(mas1);

        tsize = (mas1 & MAS1_TSIZE_MASK) >> MAS1_TSIZE_SHIFT;
        size = 0;
        if (tsize)
                size = tsize2size(tsize);

        printf("%3d: (%s) [AS=%d] "
            "sz = 0x%jx tsz = %d tid = %d mas1 = 0x%08x "
            "mas2(va) = 0x%"PRI0ptrX" mas3(pa) = 0x%08x mas7 = 0x%08x\n",
            i, desc, as, (uintmax_t)size, tsize, tid, mas1, mas2, mas3, mas7);
}

DB_SHOW_COMMAND(tlb0, tlb0_print_tlbentries)
{
        uint32_t mas0, mas1, mas3, mas7;
#ifdef __powerpc64__
        uint64_t mas2;
#else
        uint32_t mas2;
#endif
        int entryidx, way, idx;

        printf("TLB0 entries:\n");
        for (way = 0; way < TLB0_WAYS; way ++)
                for (entryidx = 0; entryidx < TLB0_ENTRIES_PER_WAY; entryidx++) {
                        mas0 = MAS0_TLBSEL(0) | MAS0_ESEL(way);
                        mtspr(SPR_MAS0, mas0);

                        mas2 = entryidx << MAS2_TLB0_ENTRY_IDX_SHIFT;
                        mtspr(SPR_MAS2, mas2);

                        __asm __volatile("isync; tlbre");

                        mas1 = mfspr(SPR_MAS1);
                        mas2 = mfspr(SPR_MAS2);
                        mas3 = mfspr(SPR_MAS3);
                        mas7 = mfspr(SPR_MAS7);

                        idx = tlb0_tableidx(mas2, way);
                        tlb_print_entry(idx, mas1, mas2, mas3, mas7);
                }
}

/*
 * Print out contents of the MAS registers for each TLB1 entry
 */
DB_SHOW_COMMAND(tlb1, tlb1_print_tlbentries)
{
        uint32_t mas0, mas1, mas3, mas7;
#ifdef __powerpc64__
        uint64_t mas2;
#else
        uint32_t mas2;
#endif
        int i;

        printf("TLB1 entries:\n");
        for (i = 0; i < TLB1_ENTRIES; i++) {
                mas0 = MAS0_TLBSEL(1) | MAS0_ESEL(i);
                mtspr(SPR_MAS0, mas0);

                __asm __volatile("isync; tlbre");

                mas1 = mfspr(SPR_MAS1);
                mas2 = mfspr(SPR_MAS2);
                mas3 = mfspr(SPR_MAS3);
                mas7 = mfspr(SPR_MAS7);

                tlb_print_entry(i, mas1, mas2, mas3, mas7);
        }
}
#endif