/*      $NetBSD: pmap.c,v 1.450 2026/06/10 21:30:05 andvar Exp $        */

/*
 * Copyright 2003 Wasabi Systems, Inc.
 * All rights reserved.
 *
 * Written by Steve C. Woodford for Wasabi Systems, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed for the NetBSD Project by
 *      Wasabi Systems, Inc.
 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
 *    or promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Copyright (c) 2002-2003 Wasabi Systems, Inc.
 * Copyright (c) 2001 Richard Earnshaw
 * Copyright (c) 2001-2002 Christopher Gilbert
 * All rights reserved.
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the company nor the name of the author may be used to
 *    endorse or promote products derived from this software without specific
 *    prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*-
 * Copyright (c) 1999, 2020 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Charles M. Hannum.
 *
 * 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Copyright (c) 1994-1998 Mark Brinicombe.
 * Copyright (c) 1994 Brini.
 * All rights reserved.
 *
 * This code is derived from software written for Brini by Mark Brinicombe
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Mark Brinicombe.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *
 * RiscBSD kernel project
 *
 * pmap.c
 *
 * Machine dependent vm stuff
 *
 * Created      : 20/09/94
 */

/*
 * armv6 and VIPT cache support by 3am Software Foundry,
 * Copyright (c) 2007 Microsoft
 */

/*
 * Performance improvements, UVM changes, overhauls and part-rewrites
 * were contributed by Neil A. Carson <neil@causality.com>.
 */

/*
 * Overhauled again to speedup the pmap, use MMU Domains so that L1 tables
 * can be shared, and re-work the KVM layout, by Steve Woodford of Wasabi
 * Systems, Inc.
 *
 * There are still a few things outstanding at this time:
 *
 *   - There are some unresolved issues for MP systems:
 *
 *     o The L1 metadata needs a lock, or more specifically, some places
 *       need to acquire an exclusive lock when modifying L1 translation
 *       table entries.
 *
 *     o When one cpu modifies an L1 entry, and that L1 table is also
 *       being used by another cpu, then the latter will need to be told
 *       that a tlb invalidation may be necessary. (But only if the old
 *       domain number in the L1 entry being over-written is currently
 *       the active domain on that cpu). I guess there are lots more tlb
 *       shootdown issues too...
 *
 *     o If the vector_page is at 0x00000000 instead of in kernel VA space,
 *       then MP systems will lose big-time because of the MMU domain hack.
 *       The only way this can be solved (apart from moving the vector
 *       page to 0xffff0000) is to reserve the first 1MB of user address
 *       space for kernel use only. This would require re-linking all
 *       applications so that the text section starts above this 1MB
 *       boundary.
 *
 *     o Tracking which VM space is resident in the cache/tlb has not yet
 *       been implemented for MP systems.
 *
 *     o Finally, there is a pathological condition where two cpus running
 *       two separate processes (not lwps) which happen to share an L1
 *       can get into a fight over one or more L1 entries. This will result
 *       in a significant slow-down if both processes are in tight loops.
 */

/* Include header files */

#include "opt_arm_debug.h"
#include "opt_cpuoptions.h"
#include "opt_ddb.h"
#include "opt_efi.h"
#include "opt_lockdebug.h"
#include "opt_multiprocessor.h"

#ifdef MULTIPROCESSOR
#define _INTR_PRIVATE
#endif

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.450 2026/06/10 21:30:05 andvar Exp $");

#include <sys/param.h>
#include <sys/types.h>

#include <sys/asan.h>
#include <sys/atomic.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/intr.h>
#include <sys/kernel.h>
#include <sys/kernhist.h>
#include <sys/kmem.h>
#include <sys/pool.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <sys/systm.h>

#include <uvm/uvm.h>
#include <uvm/pmap/pmap_pvt.h>

#include <arm/locore.h>

#ifdef DDB
#include <arm/db_machdep.h>
#endif

#ifdef VERBOSE_INIT_ARM
#define VPRINTF(...)    printf(__VA_ARGS__)
#else
#define VPRINTF(...)    __nothing
#endif

#if defined(EFI_RUNTIME)
#if !defined(ARM_MMU_EXTENDED)
#error EFI_RUNTIME is only supported with ARM_MMU_EXTENDED
#endif
#endif

/*
 * pmap_kernel() points here
 */
static struct pmap      kernel_pmap_store = {
#ifndef ARM_MMU_EXTENDED
        .pm_activated = true,
        .pm_domain = PMAP_DOMAIN_KERNEL,
        .pm_cstate.cs_all = PMAP_CACHE_STATE_ALL,
#endif
};
struct pmap * const     kernel_pmap_ptr = &kernel_pmap_store;
#undef pmap_kernel
#define pmap_kernel()   (&kernel_pmap_store)

#if defined(EFI_RUNTIME)
static struct pmap      efirt_pmap;

struct pmap *
pmap_efirt(void)
{
        return &efirt_pmap;
}
#endif

#ifdef PMAP_NEED_ALLOC_POOLPAGE
int                     arm_poolpage_vmfreelist = VM_FREELIST_DEFAULT;
#endif

/*
 * Pool and cache that pmap structures are allocated from.
 * We use a cache to avoid clearing the pm_l2[] array (1KB)
 * in pmap_create().
 */
static struct pool_cache pmap_cache;

/*
 * Pool of PV structures
 */
static struct pool pmap_pv_pool;
static void *pmap_bootstrap_pv_page_alloc(struct pool *, int);
static void pmap_bootstrap_pv_page_free(struct pool *, void *);
static struct pool_allocator pmap_bootstrap_pv_allocator = {
        pmap_bootstrap_pv_page_alloc, pmap_bootstrap_pv_page_free
};

/*
 * Pool and cache of l2_dtable structures.
 * We use a cache to avoid clearing the structures when they're
 * allocated. (196 bytes)
 */
static struct pool_cache pmap_l2dtable_cache;
static vaddr_t pmap_kernel_l2dtable_kva;

/*
 * Pool and cache of L2 page descriptors.
 * We use a cache to avoid clearing the descriptor table
 * when they're allocated. (1KB)
 */
static struct pool_cache pmap_l2ptp_cache;
static vaddr_t pmap_kernel_l2ptp_kva;
static paddr_t pmap_kernel_l2ptp_phys;

#ifdef PMAPCOUNTERS
#define PMAP_EVCNT_INITIALIZER(name) \
        EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, "pmap", name)

#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
static struct evcnt pmap_ev_vac_clean_one =
   PMAP_EVCNT_INITIALIZER("clean page (1 color)");
static struct evcnt pmap_ev_vac_flush_one =
   PMAP_EVCNT_INITIALIZER("flush page (1 color)");
static struct evcnt pmap_ev_vac_flush_lots =
   PMAP_EVCNT_INITIALIZER("flush page (2+ colors)");
static struct evcnt pmap_ev_vac_flush_lots2 =
   PMAP_EVCNT_INITIALIZER("flush page (2+ colors, kmpage)");
EVCNT_ATTACH_STATIC(pmap_ev_vac_clean_one);
EVCNT_ATTACH_STATIC(pmap_ev_vac_flush_one);
EVCNT_ATTACH_STATIC(pmap_ev_vac_flush_lots);
EVCNT_ATTACH_STATIC(pmap_ev_vac_flush_lots2);

static struct evcnt pmap_ev_vac_color_new =
   PMAP_EVCNT_INITIALIZER("new page color");
static struct evcnt pmap_ev_vac_color_reuse =
   PMAP_EVCNT_INITIALIZER("ok first page color");
static struct evcnt pmap_ev_vac_color_ok =
   PMAP_EVCNT_INITIALIZER("ok page color");
static struct evcnt pmap_ev_vac_color_blind =
   PMAP_EVCNT_INITIALIZER("blind page color");
static struct evcnt pmap_ev_vac_color_change =
   PMAP_EVCNT_INITIALIZER("change page color");
static struct evcnt pmap_ev_vac_color_erase =
   PMAP_EVCNT_INITIALIZER("erase page color");
static struct evcnt pmap_ev_vac_color_none =
   PMAP_EVCNT_INITIALIZER("no page color");
static struct evcnt pmap_ev_vac_color_restore =
   PMAP_EVCNT_INITIALIZER("restore page color");

EVCNT_ATTACH_STATIC(pmap_ev_vac_color_new);
EVCNT_ATTACH_STATIC(pmap_ev_vac_color_reuse);
EVCNT_ATTACH_STATIC(pmap_ev_vac_color_ok);
EVCNT_ATTACH_STATIC(pmap_ev_vac_color_blind);
EVCNT_ATTACH_STATIC(pmap_ev_vac_color_change);
EVCNT_ATTACH_STATIC(pmap_ev_vac_color_erase);
EVCNT_ATTACH_STATIC(pmap_ev_vac_color_none);
EVCNT_ATTACH_STATIC(pmap_ev_vac_color_restore);
#endif

static struct evcnt pmap_ev_mappings =
   PMAP_EVCNT_INITIALIZER("pages mapped");
static struct evcnt pmap_ev_unmappings =
   PMAP_EVCNT_INITIALIZER("pages unmapped");
static struct evcnt pmap_ev_remappings =
   PMAP_EVCNT_INITIALIZER("pages remapped");

EVCNT_ATTACH_STATIC(pmap_ev_mappings);
EVCNT_ATTACH_STATIC(pmap_ev_unmappings);
EVCNT_ATTACH_STATIC(pmap_ev_remappings);

static struct evcnt pmap_ev_kernel_mappings =
   PMAP_EVCNT_INITIALIZER("kernel pages mapped");
static struct evcnt pmap_ev_kernel_unmappings =
   PMAP_EVCNT_INITIALIZER("kernel pages unmapped");
static struct evcnt pmap_ev_kernel_remappings =
   PMAP_EVCNT_INITIALIZER("kernel pages remapped");

EVCNT_ATTACH_STATIC(pmap_ev_kernel_mappings);
EVCNT_ATTACH_STATIC(pmap_ev_kernel_unmappings);
EVCNT_ATTACH_STATIC(pmap_ev_kernel_remappings);

static struct evcnt pmap_ev_kenter_mappings =
   PMAP_EVCNT_INITIALIZER("kenter pages mapped");
static struct evcnt pmap_ev_kenter_unmappings =
   PMAP_EVCNT_INITIALIZER("kenter pages unmapped");
static struct evcnt pmap_ev_kenter_remappings =
   PMAP_EVCNT_INITIALIZER("kenter pages remapped");
static struct evcnt pmap_ev_pt_mappings =
   PMAP_EVCNT_INITIALIZER("page table pages mapped");

EVCNT_ATTACH_STATIC(pmap_ev_kenter_mappings);
EVCNT_ATTACH_STATIC(pmap_ev_kenter_unmappings);
EVCNT_ATTACH_STATIC(pmap_ev_kenter_remappings);
EVCNT_ATTACH_STATIC(pmap_ev_pt_mappings);

static struct evcnt pmap_ev_fixup_mod =
   PMAP_EVCNT_INITIALIZER("page modification emulations");
static struct evcnt pmap_ev_fixup_ref =
   PMAP_EVCNT_INITIALIZER("page reference emulations");
static struct evcnt pmap_ev_fixup_exec =
   PMAP_EVCNT_INITIALIZER("exec pages fixed up");
static struct evcnt pmap_ev_fixup_pdes =
   PMAP_EVCNT_INITIALIZER("pdes fixed up");
#ifndef ARM_MMU_EXTENDED
static struct evcnt pmap_ev_fixup_ptesync =
   PMAP_EVCNT_INITIALIZER("ptesync fixed");
#endif

EVCNT_ATTACH_STATIC(pmap_ev_fixup_mod);
EVCNT_ATTACH_STATIC(pmap_ev_fixup_ref);
EVCNT_ATTACH_STATIC(pmap_ev_fixup_exec);
EVCNT_ATTACH_STATIC(pmap_ev_fixup_pdes);
#ifndef ARM_MMU_EXTENDED
EVCNT_ATTACH_STATIC(pmap_ev_fixup_ptesync);
#endif

#ifdef PMAP_CACHE_VIPT
static struct evcnt pmap_ev_exec_mappings =
   PMAP_EVCNT_INITIALIZER("exec pages mapped");
static struct evcnt pmap_ev_exec_cached =
   PMAP_EVCNT_INITIALIZER("exec pages cached");

EVCNT_ATTACH_STATIC(pmap_ev_exec_mappings);
EVCNT_ATTACH_STATIC(pmap_ev_exec_cached);

static struct evcnt pmap_ev_exec_synced =
   PMAP_EVCNT_INITIALIZER("exec pages synced");
static struct evcnt pmap_ev_exec_synced_map =
   PMAP_EVCNT_INITIALIZER("exec pages synced (MP)");
static struct evcnt pmap_ev_exec_synced_unmap =
   PMAP_EVCNT_INITIALIZER("exec pages synced (UM)");
static struct evcnt pmap_ev_exec_synced_remap =
   PMAP_EVCNT_INITIALIZER("exec pages synced (RM)");
static struct evcnt pmap_ev_exec_synced_clearbit =
   PMAP_EVCNT_INITIALIZER("exec pages synced (DG)");
#ifndef ARM_MMU_EXTENDED
static struct evcnt pmap_ev_exec_synced_kremove =
   PMAP_EVCNT_INITIALIZER("exec pages synced (KU)");
#endif

EVCNT_ATTACH_STATIC(pmap_ev_exec_synced);
EVCNT_ATTACH_STATIC(pmap_ev_exec_synced_map);
#ifndef ARM_MMU_EXTENDED
EVCNT_ATTACH_STATIC(pmap_ev_exec_synced_unmap);
EVCNT_ATTACH_STATIC(pmap_ev_exec_synced_remap);
EVCNT_ATTACH_STATIC(pmap_ev_exec_synced_clearbit);
EVCNT_ATTACH_STATIC(pmap_ev_exec_synced_kremove);
#endif

static struct evcnt pmap_ev_exec_discarded_unmap =
   PMAP_EVCNT_INITIALIZER("exec pages discarded (UM)");
static struct evcnt pmap_ev_exec_discarded_zero =
   PMAP_EVCNT_INITIALIZER("exec pages discarded (ZP)");
static struct evcnt pmap_ev_exec_discarded_copy =
   PMAP_EVCNT_INITIALIZER("exec pages discarded (CP)");
static struct evcnt pmap_ev_exec_discarded_page_protect =
   PMAP_EVCNT_INITIALIZER("exec pages discarded (PP)");
static struct evcnt pmap_ev_exec_discarded_clearbit =
   PMAP_EVCNT_INITIALIZER("exec pages discarded (DG)");
static struct evcnt pmap_ev_exec_discarded_kremove =
   PMAP_EVCNT_INITIALIZER("exec pages discarded (KU)");
#ifdef ARM_MMU_EXTENDED
static struct evcnt pmap_ev_exec_discarded_modfixup =
   PMAP_EVCNT_INITIALIZER("exec pages discarded (MF)");
#endif

EVCNT_ATTACH_STATIC(pmap_ev_exec_discarded_unmap);
EVCNT_ATTACH_STATIC(pmap_ev_exec_discarded_zero);
EVCNT_ATTACH_STATIC(pmap_ev_exec_discarded_copy);
EVCNT_ATTACH_STATIC(pmap_ev_exec_discarded_page_protect);
EVCNT_ATTACH_STATIC(pmap_ev_exec_discarded_clearbit);
EVCNT_ATTACH_STATIC(pmap_ev_exec_discarded_kremove);
#ifdef ARM_MMU_EXTENDED
EVCNT_ATTACH_STATIC(pmap_ev_exec_discarded_modfixup);
#endif
#endif /* PMAP_CACHE_VIPT */

static struct evcnt pmap_ev_updates = PMAP_EVCNT_INITIALIZER("updates");
static struct evcnt pmap_ev_collects = PMAP_EVCNT_INITIALIZER("collects");
static struct evcnt pmap_ev_activations = PMAP_EVCNT_INITIALIZER("activations");

EVCNT_ATTACH_STATIC(pmap_ev_updates);
EVCNT_ATTACH_STATIC(pmap_ev_collects);
EVCNT_ATTACH_STATIC(pmap_ev_activations);

#define PMAPCOUNT(x)    ((void)(pmap_ev_##x.ev_count++))
#else
#define PMAPCOUNT(x)    ((void)0)
#endif

/*
 * pmap copy/zero page, and mem(5) hook point
 */
static pt_entry_t *csrc_pte, *cdst_pte;
static vaddr_t csrcp, cdstp;
#ifdef MULTIPROCESSOR
static size_t cnptes;
#define cpu_csrc_pte(o) (csrc_pte + cnptes * cpu_number() + ((o) >> L2_S_SHIFT))
#define cpu_cdst_pte(o) (cdst_pte + cnptes * cpu_number() + ((o) >> L2_S_SHIFT))
#define cpu_csrcp(o)    (csrcp + L2_S_SIZE * cnptes * cpu_number() + (o))
#define cpu_cdstp(o)    (cdstp + L2_S_SIZE * cnptes * cpu_number() + (o))
#else
#define cpu_csrc_pte(o) (csrc_pte + ((o) >> L2_S_SHIFT))
#define cpu_cdst_pte(o) (cdst_pte + ((o) >> L2_S_SHIFT))
#define cpu_csrcp(o)    (csrcp + (o))
#define cpu_cdstp(o)    (cdstp + (o))
#endif
vaddr_t memhook;                        /* used by mem.c & others */
kmutex_t memlock __cacheline_aligned;   /* used by mem.c & others */
kmutex_t pmap_lock __cacheline_aligned;
kmutex_t kpm_lock __cacheline_aligned;
extern void *msgbufaddr;
int pmap_kmpages;
/*
 * Flag to indicate if pmap_init() has done its thing
 */
bool pmap_initialized;

#if defined(ARM_MMU_EXTENDED) && defined(__HAVE_MM_MD_DIRECT_MAPPED_PHYS)
/*
 * Virtual end of direct-mapped memory
 */
vaddr_t pmap_directlimit;
#endif

/*
 * Misc. locking data structures
 */

static inline void
pmap_acquire_pmap_lock(pmap_t pm)
{
#if defined(MULTIPROCESSOR) && defined(DDB)
        if (__predict_false(db_onproc != NULL))
                return;
#endif

        mutex_enter(&pm->pm_lock);
}

static inline void
pmap_release_pmap_lock(pmap_t pm)
{
#if defined(MULTIPROCESSOR) && defined(DDB)
        if (__predict_false(db_onproc != NULL))
                return;
#endif
        mutex_exit(&pm->pm_lock);
}

static inline void
pmap_acquire_page_lock(struct vm_page_md *md)
{
        mutex_enter(&pmap_lock);
}

static inline void
pmap_release_page_lock(struct vm_page_md *md)
{
        mutex_exit(&pmap_lock);
}

static inline int __diagused
pmap_page_locked_p(struct vm_page_md *md)
{
        return mutex_owned(&pmap_lock);
}


/*
 * Metadata for L1 translation tables.
 */
#ifndef ARM_MMU_EXTENDED
struct l1_ttable {
        /* Entry on the L1 Table list */
        SLIST_ENTRY(l1_ttable) l1_link;

        /* Entry on the L1 Least Recently Used list */
        TAILQ_ENTRY(l1_ttable) l1_lru;

        /* Track how many domains are allocated from this L1 */
        volatile u_int l1_domain_use_count;

        /*
         * A free-list of domain numbers for this L1.
         * We avoid using ffs() and a bitmap to track domains since ffs()
         * is slow on ARM.
         */
        uint8_t l1_domain_first;
        uint8_t l1_domain_free[PMAP_DOMAINS];

        /* Physical address of this L1 page table */
        paddr_t l1_physaddr;

        /* KVA of this L1 page table */
        pd_entry_t *l1_kva;
};

/*
 * L1 Page Tables are tracked using a Least Recently Used list.
 *  - New L1s are allocated from the HEAD.
 *  - Freed L1s are added to the TAIL.
 *  - Recently accessed L1s (where an 'access' is some change to one of
 *    the userland pmaps which owns this L1) are moved to the TAIL.
 */
static TAILQ_HEAD(, l1_ttable) l1_lru_list;
static kmutex_t l1_lru_lock __cacheline_aligned;

/*
 * A list of all L1 tables
 */
static SLIST_HEAD(, l1_ttable) l1_list;
#endif /* ARM_MMU_EXTENDED */

/*
 * The l2_dtable tracks L2_BUCKET_SIZE worth of L1 slots.
 *
 * This is normally 16MB worth L2 page descriptors for any given pmap.
 * Reference counts are maintained for L2 descriptors so they can be
 * freed when empty.
 */
struct l2_bucket {
        pt_entry_t *l2b_kva;            /* KVA of L2 Descriptor Table */
        paddr_t l2b_pa;                 /* Physical address of same */
        u_short l2b_l1slot;             /* This L2 table's L1 index */
        u_short l2b_occupancy;          /* How many active descriptors */
};

struct l2_dtable {
        /* The number of L2 page descriptors allocated to this l2_dtable */
        u_int l2_occupancy;

        /* List of L2 page descriptors */
        struct l2_bucket l2_bucket[L2_BUCKET_SIZE];
};

/*
 * Given an L1 table index, calculate the corresponding l2_dtable index
 * and bucket index within the l2_dtable.
 */
#define L2_BUCKET_XSHIFT        (L2_BUCKET_XLOG2 - L1_S_SHIFT)
#define L2_BUCKET_XFRAME        (~(vaddr_t)0 << L2_BUCKET_XLOG2)
#define L2_BUCKET_IDX(l1slot)   ((l1slot) >> L2_BUCKET_XSHIFT)
#define L2_IDX(l1slot)          (L2_BUCKET_IDX(l1slot) >> L2_BUCKET_LOG2)
#define L2_BUCKET(l1slot)       (L2_BUCKET_IDX(l1slot) & (L2_BUCKET_SIZE - 1))

__CTASSERT(0x100000000ULL == ((uint64_t)L2_SIZE * L2_BUCKET_SIZE * L1_S_SIZE));
__CTASSERT(L2_BUCKET_XFRAME == ~(L2_BUCKET_XSIZE-1));

/*
 * Given a virtual address, this macro returns the
 * virtual address required to drop into the next L2 bucket.
 */
#define L2_NEXT_BUCKET_VA(va)   (((va) & L2_BUCKET_XFRAME) + L2_BUCKET_XSIZE)

/*
 * L2 allocation.
 */
#define pmap_alloc_l2_dtable()          \
            pool_cache_get(&pmap_l2dtable_cache, PR_NOWAIT)
#define pmap_free_l2_dtable(l2)         \
            pool_cache_put(&pmap_l2dtable_cache, (l2))
#define pmap_alloc_l2_ptp(pap)          \
            ((pt_entry_t *)pool_cache_get_paddr(&pmap_l2ptp_cache,\
            PR_NOWAIT, (pap)))

/*
 * We try to map the page tables write-through, if possible.  However, not
 * all CPUs have a write-through cache mode, so on those we have to sync
 * the cache when we frob page tables.
 *
 * We try to evaluate this at compile time, if possible.  However, it's
 * not always possible to do that, hence this run-time var.
 */
int     pmap_needs_pte_sync;

/*
 * Real definition of pv_entry.
 */
struct pv_entry {
        SLIST_ENTRY(pv_entry) pv_link;  /* next pv_entry */
        pmap_t          pv_pmap;        /* pmap where mapping lies */
        vaddr_t         pv_va;          /* virtual address for mapping */
        u_int           pv_flags;       /* flags */
};

/*
 * Macros to determine if a mapping might be resident in the
 * instruction/data cache and/or TLB
 */
#if ARM_MMU_V7 > 0 && !defined(ARM_MMU_EXTENDED)
/*
 * Speculative loads by Cortex cores can cause TLB entries to be filled even if
 * there are no explicit accesses, so there may be always be TLB entries to
 * flush.  If we used ASIDs then this would not be a problem.
 */
#define PV_BEEN_EXECD(f)  (((f) & PVF_EXEC) == PVF_EXEC)
#define PV_BEEN_REFD(f)   (true)
#else
#define PV_BEEN_EXECD(f)  (((f) & (PVF_REF | PVF_EXEC)) == (PVF_REF | PVF_EXEC))
#define PV_BEEN_REFD(f)   (((f) & PVF_REF) != 0)
#endif
#define PV_IS_EXEC_P(f)   (((f) & PVF_EXEC) != 0)
#define PV_IS_KENTRY_P(f) (((f) & PVF_KENTRY) != 0)
#define PV_IS_WRITE_P(f)  (((f) & PVF_WRITE) != 0)

/*
 * Local prototypes
 */
static bool             pmap_set_pt_cache_mode(pd_entry_t *, vaddr_t, size_t);
static void             pmap_alloc_specials(vaddr_t *, int, vaddr_t *,
                            pt_entry_t **);
static bool             pmap_is_current(pmap_t) __unused;
static bool             pmap_is_cached(pmap_t);
static void             pmap_enter_pv(struct vm_page_md *, paddr_t, struct pv_entry *,
                            pmap_t, vaddr_t, u_int);
static struct pv_entry *pmap_find_pv(struct vm_page_md *, pmap_t, vaddr_t);
static struct pv_entry *pmap_remove_pv(struct vm_page_md *, paddr_t, pmap_t, vaddr_t);
static u_int            pmap_modify_pv(struct vm_page_md *, paddr_t, pmap_t, vaddr_t,
                            u_int, u_int);

static void             pmap_pinit(pmap_t);
static int              pmap_pmap_ctor(void *, void *, int);

static void             pmap_alloc_l1(pmap_t);
static void             pmap_free_l1(pmap_t);
#ifndef ARM_MMU_EXTENDED
static void             pmap_use_l1(pmap_t);
#endif

static struct l2_bucket *pmap_get_l2_bucket(pmap_t, vaddr_t);
static struct l2_bucket *pmap_alloc_l2_bucket(pmap_t, vaddr_t);
static void             pmap_free_l2_bucket(pmap_t, struct l2_bucket *, u_int);
static int              pmap_l2ptp_ctor(void *, void *, int);
static int              pmap_l2dtable_ctor(void *, void *, int);

static void             pmap_vac_me_harder(struct vm_page_md *, paddr_t, pmap_t, vaddr_t);
#ifdef PMAP_CACHE_VIVT
static void             pmap_vac_me_kpmap(struct vm_page_md *, paddr_t, pmap_t, vaddr_t);
static void             pmap_vac_me_user(struct vm_page_md *, paddr_t, pmap_t, vaddr_t);
#endif

static void             pmap_clearbit(struct vm_page_md *, paddr_t, u_int);
#ifdef PMAP_CACHE_VIVT
static bool             pmap_clean_page(struct vm_page_md *, bool);
#endif
#ifdef PMAP_CACHE_VIPT
static void             pmap_syncicache_page(struct vm_page_md *, paddr_t);
enum pmap_flush_op {
        PMAP_FLUSH_PRIMARY,
        PMAP_FLUSH_SECONDARY,
        PMAP_CLEAN_PRIMARY
};
#ifndef ARM_MMU_EXTENDED
static void             pmap_flush_page(struct vm_page_md *, paddr_t, enum pmap_flush_op);
#endif
#endif
static void             pmap_page_remove(struct vm_page_md *, paddr_t);
static void             pmap_pv_remove(paddr_t);

#ifndef ARM_MMU_EXTENDED
static void             pmap_init_l1(struct l1_ttable *, pd_entry_t *);
#endif
static vaddr_t          kernel_pt_lookup(paddr_t);

#ifdef ARM_MMU_EXTENDED
static struct pool_cache pmap_l1tt_cache;

static int              pmap_l1tt_ctor(void *, void *, int);
static void *           pmap_l1tt_alloc(struct pool *, int);
static void             pmap_l1tt_free(struct pool *, void *);

static struct pool_allocator pmap_l1tt_allocator = {
        .pa_alloc = pmap_l1tt_alloc,
        .pa_free = pmap_l1tt_free,
        .pa_pagesz = L1TT_SIZE,
};
#endif

/*
 * Misc variables
 */
vaddr_t virtual_avail;
vaddr_t virtual_end;
vaddr_t pmap_curmaxkvaddr;

paddr_t avail_start;
paddr_t avail_end;

pv_addrqh_t pmap_boot_freeq = SLIST_HEAD_INITIALIZER(&pmap_boot_freeq);
pv_addr_t kernelpages;
pv_addr_t kernel_l1pt;
pv_addr_t systempage;
#if defined(EFI_RUNTIME)
pv_addr_t efirt_l1pt;
#endif

#ifdef PMAP_CACHE_VIPT
#define PMAP_VALIDATE_MD_PAGE(md)       \
        KASSERTMSG(arm_cache_prefer_mask == 0 || (((md)->pvh_attrs & PVF_WRITE) == 0) == ((md)->urw_mappings + (md)->krw_mappings == 0), \
            "(md) %p: attrs=%#x urw=%u krw=%u", (md), \
            (md)->pvh_attrs, (md)->urw_mappings, (md)->krw_mappings);
#endif /* PMAP_CACHE_VIPT */
/*
 * A bunch of routines to conditionally flush the caches/TLB depending
 * on whether the specified pmap actually needs to be flushed at any
 * given time.
 */
static inline void
pmap_tlb_flush_SE(pmap_t pm, vaddr_t va, u_int flags)
{
#ifdef ARM_MMU_EXTENDED
        pmap_tlb_invalidate_addr(pm, va);
#else
        if (pm->pm_cstate.cs_tlb_id != 0) {
                if (PV_BEEN_EXECD(flags)) {
                        cpu_tlb_flushID_SE(va);
                } else if (PV_BEEN_REFD(flags)) {
                        cpu_tlb_flushD_SE(va);
                }
        }
#endif /* ARM_MMU_EXTENDED */
}

#ifndef ARM_MMU_EXTENDED
static inline void
pmap_tlb_flushID(pmap_t pm)
{
        if (pm->pm_cstate.cs_tlb_id) {
                cpu_tlb_flushID();
#if ARM_MMU_V7 == 0
                /*
                 * Speculative loads by Cortex cores can cause TLB entries to
                 * be filled even if there are no explicit accesses, so there
                 * may be always be TLB entries to flush.  If we used ASIDs
                 * then it would not be a problem.
                 * This is not true for other CPUs.
                 */
                pm->pm_cstate.cs_tlb = 0;
#endif /* ARM_MMU_V7 */
        }
}

static inline void
pmap_tlb_flushD(pmap_t pm)
{
        if (pm->pm_cstate.cs_tlb_d) {
                cpu_tlb_flushD();
#if ARM_MMU_V7 == 0
                /*
                 * Speculative loads by Cortex cores can cause TLB entries to
                 * be filled even if there are no explicit accesses, so there
                 * may be always be TLB entries to flush.  If we used ASIDs
                 * then it would not be a problem.
                 * This is not true for other CPUs.
                 */
                pm->pm_cstate.cs_tlb_d = 0;
#endif /* ARM_MMU_V7 */
        }
}
#endif /* ARM_MMU_EXTENDED */

#ifdef PMAP_CACHE_VIVT
static inline void
pmap_cache_wbinv_page(pmap_t pm, vaddr_t va, bool do_inv, u_int flags)
{
        if (PV_BEEN_EXECD(flags) && pm->pm_cstate.cs_cache_id) {
                cpu_idcache_wbinv_range(va, PAGE_SIZE);
        } else if (PV_BEEN_REFD(flags) && pm->pm_cstate.cs_cache_d) {
                if (do_inv) {
                        if (flags & PVF_WRITE)
                                cpu_dcache_wbinv_range(va, PAGE_SIZE);
                        else
                                cpu_dcache_inv_range(va, PAGE_SIZE);
                } else if (flags & PVF_WRITE) {
                        cpu_dcache_wb_range(va, PAGE_SIZE);
                }
        }
}

static inline void
pmap_cache_wbinv_all(pmap_t pm, u_int flags)
{
        if (PV_BEEN_EXECD(flags)) {
                if (pm->pm_cstate.cs_cache_id) {
                        cpu_idcache_wbinv_all();
                        pm->pm_cstate.cs_cache = 0;
                }
        } else if (pm->pm_cstate.cs_cache_d) {
                cpu_dcache_wbinv_all();
                pm->pm_cstate.cs_cache_d = 0;
        }
}
#endif /* PMAP_CACHE_VIVT */

static inline uint8_t
pmap_domain(pmap_t pm)
{
#ifdef ARM_MMU_EXTENDED
        return pm == pmap_kernel() ? PMAP_DOMAIN_KERNEL : PMAP_DOMAIN_USER;
#else
        return pm->pm_domain;
#endif
}

static inline pd_entry_t *
pmap_l1_kva(pmap_t pm)
{
#ifdef ARM_MMU_EXTENDED
        return pm->pm_l1;
#else
        return pm->pm_l1->l1_kva;
#endif
}

static inline bool
pmap_is_current(pmap_t pm)
{
        if (pm == pmap_kernel() || curproc->p_vmspace->vm_map.pmap == pm)
                return true;

        return false;
}

static inline bool
pmap_is_cached(pmap_t pm)
{
#ifdef ARM_MMU_EXTENDED
        if (pm == pmap_kernel())
                return true;
#ifdef MULTIPROCESSOR
        // Is this pmap active on any CPU?
        if (!kcpuset_iszero(pm->pm_active))
                return true;
#else
        struct pmap_tlb_info * const ti = cpu_tlb_info(curcpu());
        // Is this pmap active?
        if (PMAP_PAI_ASIDVALID_P(PMAP_PAI(pm, ti), ti))
                return true;
#endif
#else
        struct cpu_info * const ci = curcpu();
        if (pm == pmap_kernel() || ci->ci_pmap_lastuser == NULL
            || ci->ci_pmap_lastuser == pm)
                return true;
#endif /* ARM_MMU_EXTENDED */

        return false;
}

/*
 * PTE_SYNC_CURRENT:
 *
 *     Make sure the pte is written out to RAM.
 *     We need to do this for one of two cases:
 *       - We're dealing with the kernel pmap
 *       - There is no pmap active in the cache/tlb.
 *       - The specified pmap is 'active' in the cache/tlb.
 */

#ifdef PMAP_INCLUDE_PTE_SYNC
static inline void
pmap_pte_sync_current(pmap_t pm, pt_entry_t *ptep)
{
        if (PMAP_NEEDS_PTE_SYNC && pmap_is_cached(pm))
                PTE_SYNC(ptep);
        dsb(sy);
}

# define PTE_SYNC_CURRENT(pm, ptep)     pmap_pte_sync_current(pm, ptep)
#else
# define PTE_SYNC_CURRENT(pm, ptep)     __nothing
#endif

/*
 * main pv_entry manipulation functions:
 *   pmap_enter_pv: enter a mapping onto a vm_page list
 *   pmap_remove_pv: remove a mapping from a vm_page list
 *
 * NOTE: pmap_enter_pv expects to lock the pvh itself
 *       pmap_remove_pv expects the caller to lock the pvh before calling
 */

/*
 * pmap_enter_pv: enter a mapping onto a vm_page lst
 *
 * => caller should hold the proper lock on pmap_main_lock
 * => caller should have pmap locked
 * => we will gain the lock on the vm_page and allocate the new pv_entry
 * => caller should adjust ptp's wire_count before calling
 * => caller should not adjust pmap's wire_count
 */
static void
pmap_enter_pv(struct vm_page_md *md, paddr_t pa, struct pv_entry *pv, pmap_t pm,
    vaddr_t va, u_int flags)
{
        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "md %#jx pa %#jx pm %#jx va %#jx",
            (uintptr_t)md, (uintptr_t)pa, (uintptr_t)pm, va);
        UVMHIST_LOG(maphist, "...pv %#jx flags %#jx",
            (uintptr_t)pv, flags, 0, 0);

        struct pv_entry **pvp;

        pv->pv_pmap = pm;
        pv->pv_va = va;
        pv->pv_flags = flags;

        pvp = &SLIST_FIRST(&md->pvh_list);
#ifdef PMAP_CACHE_VIPT
        /*
         * Insert unmanaged entries, writeable first, at the head of
         * the pv list.
         */
        if (__predict_true(!PV_IS_KENTRY_P(flags))) {
                while (*pvp != NULL && PV_IS_KENTRY_P((*pvp)->pv_flags))
                        pvp = &SLIST_NEXT(*pvp, pv_link);
        }
        if (!PV_IS_WRITE_P(flags)) {
                while (*pvp != NULL && PV_IS_WRITE_P((*pvp)->pv_flags))
                        pvp = &SLIST_NEXT(*pvp, pv_link);
        }
#endif
        SLIST_NEXT(pv, pv_link) = *pvp;         /* add to ... */
        *pvp = pv;                              /* ... locked list */
        md->pvh_attrs |= flags & (PVF_REF | PVF_MOD);
#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
        if ((pv->pv_flags & PVF_KWRITE) == PVF_KWRITE)
                md->pvh_attrs |= PVF_KMOD;
        if ((md->pvh_attrs & (PVF_DMOD|PVF_NC)) != PVF_NC)
                md->pvh_attrs |= PVF_DIRTY;
        KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
#endif
        if (pm == pmap_kernel()) {
                PMAPCOUNT(kernel_mappings);
                if (flags & PVF_WRITE)
                        md->krw_mappings++;
                else
                        md->kro_mappings++;
        } else {
                if (flags & PVF_WRITE)
                        md->urw_mappings++;
                else
                        md->uro_mappings++;
        }

#ifdef PMAP_CACHE_VIPT
#ifndef ARM_MMU_EXTENDED
        /*
         * Even though pmap_vac_me_harder will set PVF_WRITE for us,
         * do it here as well to keep the mappings & KVF_WRITE consistent.
         */
        if (arm_cache_prefer_mask != 0 && (flags & PVF_WRITE) != 0) {
                md->pvh_attrs |= PVF_WRITE;
        }
#endif
        /*
         * If this is an exec mapping and its the first exec mapping
         * for this page, make sure to sync the I-cache.
         */
        if (PV_IS_EXEC_P(flags)) {
                if (!PV_IS_EXEC_P(md->pvh_attrs)) {
                        pmap_syncicache_page(md, pa);
                        PMAPCOUNT(exec_synced_map);
                }
                PMAPCOUNT(exec_mappings);
        }
#endif

        PMAPCOUNT(mappings);

        if (pv->pv_flags & PVF_WIRED)
                ++pm->pm_stats.wired_count;
}

/*
 *
 * pmap_find_pv: Find a pv entry
 *
 * => caller should hold lock on vm_page
 */
static inline struct pv_entry *
pmap_find_pv(struct vm_page_md *md, pmap_t pm, vaddr_t va)
{
        struct pv_entry *pv;

        SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
                if (pm == pv->pv_pmap && va == pv->pv_va)
                        break;
        }

        return pv;
}

/*
 * pmap_remove_pv: try to remove a mapping from a pv_list
 *
 * => caller should hold proper lock on pmap_main_lock
 * => pmap should be locked
 * => caller should hold lock on vm_page [so that attrs can be adjusted]
 * => caller should adjust ptp's wire_count and free PTP if needed
 * => caller should NOT adjust pmap's wire_count
 * => we return the removed pv
 */
static struct pv_entry *
pmap_remove_pv(struct vm_page_md *md, paddr_t pa, pmap_t pm, vaddr_t va)
{
        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "md %#jx pa %#jx pm %#jx va %#jx",
            (uintptr_t)md, (uintptr_t)pa, (uintptr_t)pm, va);

        struct pv_entry *pv, **prevptr;

        prevptr = &SLIST_FIRST(&md->pvh_list); /* prev pv_entry ptr */
        pv = *prevptr;

        while (pv) {
                if (pv->pv_pmap == pm && pv->pv_va == va) {     /* match? */
                        UVMHIST_LOG(maphist, "pm %#jx md %#jx flags %#jx",
                            (uintptr_t)pm, (uintptr_t)md, pv->pv_flags, 0);
                        if (pv->pv_flags & PVF_WIRED) {
                                --pm->pm_stats.wired_count;
                        }
                        *prevptr = SLIST_NEXT(pv, pv_link);     /* remove it! */
                        if (pm == pmap_kernel()) {
                                PMAPCOUNT(kernel_unmappings);
                                if (pv->pv_flags & PVF_WRITE)
                                        md->krw_mappings--;
                                else
                                        md->kro_mappings--;
                        } else {
                                if (pv->pv_flags & PVF_WRITE)
                                        md->urw_mappings--;
                                else
                                        md->uro_mappings--;
                        }

                        PMAPCOUNT(unmappings);
#ifdef PMAP_CACHE_VIPT
                        /*
                         * If this page has had an exec mapping, then if
                         * this was the last mapping, discard the contents,
                         * otherwise sync the i-cache for this page.
                         */
                        if (PV_IS_EXEC_P(md->pvh_attrs)) {
                                if (SLIST_EMPTY(&md->pvh_list)) {
                                        md->pvh_attrs &= ~PVF_EXEC;
                                        PMAPCOUNT(exec_discarded_unmap);
                                } else if (pv->pv_flags & PVF_WRITE) {
                                        pmap_syncicache_page(md, pa);
                                        PMAPCOUNT(exec_synced_unmap);
                                }
                        }
#endif /* PMAP_CACHE_VIPT */
                        break;
                }
                prevptr = &SLIST_NEXT(pv, pv_link);     /* previous pointer */
                pv = *prevptr;                          /* advance */
        }

#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
        /*
         * If we no longer have a WRITEABLE KENTRY at the head of list,
         * clear the KMOD attribute from the page.
         */
        if (SLIST_FIRST(&md->pvh_list) == NULL
            || (SLIST_FIRST(&md->pvh_list)->pv_flags & PVF_KWRITE) != PVF_KWRITE)
                md->pvh_attrs &= ~PVF_KMOD;

        /*
         * If this was a writeable page and there are no more writeable
         * mappings (ignoring KMPAGE), clear the WRITE flag and writeback
         * the contents to memory.
         */
        if (arm_cache_prefer_mask != 0) {
                if (md->krw_mappings + md->urw_mappings == 0)
                        md->pvh_attrs &= ~PVF_WRITE;
                PMAP_VALIDATE_MD_PAGE(md);
        }
        KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
#endif /* PMAP_CACHE_VIPT && !ARM_MMU_EXTENDED */

        /* return removed pv */
        return pv;
}

/*
 *
 * pmap_modify_pv: Update pv flags
 *
 * => caller should hold lock on vm_page [so that attrs can be adjusted]
 * => caller should NOT adjust pmap's wire_count
 * => caller must call pmap_vac_me_harder() if writable status of a page
 *    may have changed.
 * => we return the old flags
 *
 * Modify a physical-virtual mapping in the pv table
 */
static u_int
pmap_modify_pv(struct vm_page_md *md, paddr_t pa, pmap_t pm, vaddr_t va,
    u_int clr_mask, u_int set_mask)
{
        struct pv_entry *npv;
        u_int flags, oflags;
        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "md %#jx pa %#jx pm %#jx va %#jx",
            (uintptr_t)md, (uintptr_t)pa, (uintptr_t)pm, va);
        UVMHIST_LOG(maphist, "... clr %#jx set %#jx", clr_mask, set_mask, 0, 0);

        KASSERT(!PV_IS_KENTRY_P(clr_mask));
        KASSERT(!PV_IS_KENTRY_P(set_mask));

        if ((npv = pmap_find_pv(md, pm, va)) == NULL) {
                UVMHIST_LOG(maphist, "<--- done (not found)", 0, 0, 0, 0);
                return 0;
        }

        /*
         * There is at least one VA mapping this page.
         */

        if (clr_mask & (PVF_REF | PVF_MOD)) {
                md->pvh_attrs |= set_mask & (PVF_REF | PVF_MOD);
#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
                if ((md->pvh_attrs & (PVF_DMOD|PVF_NC)) != PVF_NC)
                        md->pvh_attrs |= PVF_DIRTY;
                KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
#endif /* PMAP_CACHE_VIPT && !ARM_MMU_EXTENDED */
        }

        oflags = npv->pv_flags;
        npv->pv_flags = flags = (oflags & ~clr_mask) | set_mask;

        if ((flags ^ oflags) & PVF_WIRED) {
                if (flags & PVF_WIRED)
                        ++pm->pm_stats.wired_count;
                else
                        --pm->pm_stats.wired_count;
        }

        if ((flags ^ oflags) & PVF_WRITE) {
                if (pm == pmap_kernel()) {
                        if (flags & PVF_WRITE) {
                                md->krw_mappings++;
                                md->kro_mappings--;
                        } else {
                                md->kro_mappings++;
                                md->krw_mappings--;
                        }
                } else {
                        if (flags & PVF_WRITE) {
                                md->urw_mappings++;
                                md->uro_mappings--;
                        } else {
                                md->uro_mappings++;
                                md->urw_mappings--;
                        }
                }
        }
#ifdef PMAP_CACHE_VIPT
        if (arm_cache_prefer_mask != 0) {
                if (md->urw_mappings + md->krw_mappings == 0) {
                        md->pvh_attrs &= ~PVF_WRITE;
                } else {
                        md->pvh_attrs |= PVF_WRITE;
                }
        }
        /*
         * We have two cases here: the first is from enter_pv (new exec
         * page), the second is a combined pmap_remove_pv/pmap_enter_pv.
         * Since in latter, pmap_enter_pv won't do anything, we just have
         * to do what pmap_remove_pv would do.
         */
        if ((PV_IS_EXEC_P(flags) && !PV_IS_EXEC_P(md->pvh_attrs))
            || (PV_IS_EXEC_P(md->pvh_attrs)
                || (!(flags & PVF_WRITE) && (oflags & PVF_WRITE)))) {
                pmap_syncicache_page(md, pa);
                PMAPCOUNT(exec_synced_remap);
        }
#ifndef ARM_MMU_EXTENDED
        KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
#endif /* !ARM_MMU_EXTENDED */
#endif /* PMAP_CACHE_VIPT */

        PMAPCOUNT(remappings);

        UVMHIST_LOG(maphist, "<--- done", 0, 0, 0, 0);

        return oflags;
}


#if defined(ARM_MMU_EXTENDED)
int
pmap_maxproc_set(int nmaxproc)
{
        static const char pmap_l1ttpool_warnmsg[] =
            "WARNING: l1ttpool limit reached; increase kern.maxproc";

        pool_cache_prime(&pmap_l1tt_cache, nmaxproc);

        /*
         * Set the hard limit on the pmap_l1tt_cache to the number
         * of processes the kernel is to support.  Log the limit
         * reached message max once a minute.
         */
        pool_cache_sethardlimit(&pmap_l1tt_cache, nmaxproc,
            pmap_l1ttpool_warnmsg, 60);

        return 0;
}

#endif

/*
 * Allocate an L1 translation table for the specified pmap.
 * This is called at pmap creation time.
 */
static void
pmap_alloc_l1(pmap_t pm)
{
#ifdef ARM_MMU_EXTENDED
        vaddr_t va = (vaddr_t)pool_cache_get_paddr(&pmap_l1tt_cache, PR_WAITOK,
            &pm->pm_l1_pa);

        pm->pm_l1 = (pd_entry_t *)va;
        PTE_SYNC_RANGE(pm->pm_l1, L1TT_SIZE / sizeof(pt_entry_t));
#else
        struct l1_ttable *l1;
        uint8_t domain;

        /*
         * Remove the L1 at the head of the LRU list
         */
        mutex_spin_enter(&l1_lru_lock);
        l1 = TAILQ_FIRST(&l1_lru_list);
        KDASSERT(l1 != NULL);
        TAILQ_REMOVE(&l1_lru_list, l1, l1_lru);

        /*
         * Pick the first available domain number, and update
         * the link to the next number.
         */
        domain = l1->l1_domain_first;
        l1->l1_domain_first = l1->l1_domain_free[domain];

        /*
         * If there are still free domain numbers in this L1,
         * put it back on the TAIL of the LRU list.
         */
        if (++l1->l1_domain_use_count < PMAP_DOMAINS)
                TAILQ_INSERT_TAIL(&l1_lru_list, l1, l1_lru);

        mutex_spin_exit(&l1_lru_lock);

        /*
         * Fix up the relevant bits in the pmap structure
         */
        pm->pm_l1 = l1;
        pm->pm_domain = domain + 1;
#endif
}

/*
 * Free an L1 translation table.
 * This is called at pmap destruction time.
 */
static void
pmap_free_l1(pmap_t pm)
{
#ifdef ARM_MMU_EXTENDED
        pool_cache_put_paddr(&pmap_l1tt_cache, (void *)pm->pm_l1, pm->pm_l1_pa);

        pm->pm_l1 = NULL;
        pm->pm_l1_pa = 0;
#else
        struct l1_ttable *l1 = pm->pm_l1;

        mutex_spin_enter(&l1_lru_lock);

        /*
         * If this L1 is currently on the LRU list, remove it.
         */
        if (l1->l1_domain_use_count < PMAP_DOMAINS)
                TAILQ_REMOVE(&l1_lru_list, l1, l1_lru);

        /*
         * Free up the domain number which was allocated to the pmap
         */
        l1->l1_domain_free[pmap_domain(pm) - 1] = l1->l1_domain_first;
        l1->l1_domain_first = pmap_domain(pm) - 1;
        l1->l1_domain_use_count--;

        /*
         * The L1 now must have at least 1 free domain, so add
         * it back to the LRU list. If the use count is zero,
         * put it at the head of the list, otherwise it goes
         * to the tail.
         */
        if (l1->l1_domain_use_count == 0)
                TAILQ_INSERT_HEAD(&l1_lru_list, l1, l1_lru);
        else
                TAILQ_INSERT_TAIL(&l1_lru_list, l1, l1_lru);

        mutex_spin_exit(&l1_lru_lock);
#endif /* ARM_MMU_EXTENDED */
}

#ifndef ARM_MMU_EXTENDED
static inline void
pmap_use_l1(pmap_t pm)
{
        struct l1_ttable *l1;

        /*
         * Do nothing if we're in interrupt context.
         * Access to an L1 by the kernel pmap must not affect
         * the LRU list.
         */
        if (cpu_intr_p() || pm == pmap_kernel())
                return;

        l1 = pm->pm_l1;

        /*
         * If the L1 is not currently on the LRU list, just return
         */
        if (l1->l1_domain_use_count == PMAP_DOMAINS)
                return;

        mutex_spin_enter(&l1_lru_lock);

        /*
         * Check the use count again, now that we've acquired the lock
         */
        if (l1->l1_domain_use_count == PMAP_DOMAINS) {
                mutex_spin_exit(&l1_lru_lock);
                return;
        }

        /*
         * Move the L1 to the back of the LRU list
         */
        TAILQ_REMOVE(&l1_lru_list, l1, l1_lru);
        TAILQ_INSERT_TAIL(&l1_lru_list, l1, l1_lru);

        mutex_spin_exit(&l1_lru_lock);
}
#endif /* !ARM_MMU_EXTENDED */

/*
 * void pmap_free_l2_ptp(pt_entry_t *, paddr_t *)
 *
 * Free an L2 descriptor table.
 */
static inline void
#if defined(PMAP_INCLUDE_PTE_SYNC) && defined(PMAP_CACHE_VIVT)
pmap_free_l2_ptp(bool need_sync, pt_entry_t *l2, paddr_t pa)
#else
pmap_free_l2_ptp(pt_entry_t *l2, paddr_t pa)
#endif
{
#if defined(PMAP_INCLUDE_PTE_SYNC) && defined(PMAP_CACHE_VIVT)
        /*
         * Note: With a write-back cache, we may need to sync this
         * L2 table before re-using it.
         * This is because it may have belonged to a non-current
         * pmap, in which case the cache syncs would have been
         * skipped for the pages that were being unmapped. If the
         * L2 table were then to be immediately re-allocated to
         * the *current* pmap, it may well contain stale mappings
         * which have not yet been cleared by a cache write-back
         * and so would still be visible to the mmu.
         */
        if (need_sync)
                PTE_SYNC_RANGE(l2, L2_TABLE_SIZE_REAL / sizeof(pt_entry_t));
#endif /* PMAP_INCLUDE_PTE_SYNC && PMAP_CACHE_VIVT */
        pool_cache_put_paddr(&pmap_l2ptp_cache, (void *)l2, pa);
}

/*
 * Returns a pointer to the L2 bucket associated with the specified pmap
 * and VA, or NULL if no L2 bucket exists for the address.
 */
static inline struct l2_bucket *
pmap_get_l2_bucket(pmap_t pm, vaddr_t va)
{
        const size_t l1slot = l1pte_index(va);
        struct l2_dtable *l2;
        struct l2_bucket *l2b;

        if ((l2 = pm->pm_l2[L2_IDX(l1slot)]) == NULL ||
            (l2b = &l2->l2_bucket[L2_BUCKET(l1slot)])->l2b_kva == NULL)
                return NULL;

        return l2b;
}

/*
 * Returns a pointer to the L2 bucket associated with the specified pmap
 * and VA.
 *
 * If no L2 bucket exists, perform the necessary allocations to put an L2
 * bucket/page table in place.
 *
 * Note that if a new L2 bucket/page was allocated, the caller *must*
 * increment the bucket occupancy counter appropriately *before*
 * releasing the pmap's lock to ensure no other thread or cpu deallocates
 * the bucket/page in the meantime.
 */
static struct l2_bucket *
pmap_alloc_l2_bucket(pmap_t pm, vaddr_t va)
{
        const size_t l1slot = l1pte_index(va);
        struct l2_dtable *l2;

        if ((l2 = pm->pm_l2[L2_IDX(l1slot)]) == NULL) {
                /*
                 * No mapping at this address, as there is
                 * no entry in the L1 table.
                 * Need to allocate a new l2_dtable.
                 */
                if ((l2 = pmap_alloc_l2_dtable()) == NULL)
                        return NULL;

                /*
                 * Link it into the parent pmap
                 */
                pm->pm_l2[L2_IDX(l1slot)] = l2;
        }

        struct l2_bucket * const l2b = &l2->l2_bucket[L2_BUCKET(l1slot)];

        /*
         * Fetch pointer to the L2 page table associated with the address.
         */
        if (l2b->l2b_kva == NULL) {
                pt_entry_t *ptep;

                /*
                 * No L2 page table has been allocated. Chances are, this
                 * is because we just allocated the l2_dtable, above.
                 */
                if ((ptep = pmap_alloc_l2_ptp(&l2b->l2b_pa)) == NULL) {
                        /*
                         * Oops, no more L2 page tables available at this
                         * time. We may need to deallocate the l2_dtable
                         * if we allocated a new one above.
                         */
                        if (l2->l2_occupancy == 0) {
                                pm->pm_l2[L2_IDX(l1slot)] = NULL;
                                pmap_free_l2_dtable(l2);
                        }
                        return NULL;
                }

                l2->l2_occupancy++;
                l2b->l2b_kva = ptep;
                l2b->l2b_l1slot = l1slot;

#ifdef ARM_MMU_EXTENDED
                /*
                 * We know there will be a mapping here, so simply
                 * enter this PTP into the L1 now.
                 */
                pd_entry_t * const pdep = pmap_l1_kva(pm) + l1slot;
                pd_entry_t npde = L1_C_PROTO | l2b->l2b_pa
                    | L1_C_DOM(pmap_domain(pm));
                KASSERT(*pdep == 0);
                l1pte_setone(pdep, npde);
                PDE_SYNC(pdep);
#endif
        }

        return l2b;
}

/*
 * One or more mappings in the specified L2 descriptor table have just been
 * invalidated.
 *
 * Garbage collect the metadata and descriptor table itself if necessary.
 *
 * The pmap lock must be acquired when this is called (not necessary
 * for the kernel pmap).
 */
static void
pmap_free_l2_bucket(pmap_t pm, struct l2_bucket *l2b, u_int count)
{
        KDASSERT(count <= l2b->l2b_occupancy);

        /*
         * Update the bucket's reference count according to how many
         * PTEs the caller has just invalidated.
         */
        l2b->l2b_occupancy -= count;

        /*
         * Note:
         *
         * Level 2 page tables allocated to the kernel pmap are never freed
         * as that would require checking all Level 1 page tables and
         * removing any references to the Level 2 page table. See also the
         * comment elsewhere about never freeing bootstrap L2 descriptors.
         *
         * We make do with just invalidating the mapping in the L2 table.
         *
         * This isn't really a big deal in practice and, in fact, leads
         * to a performance win over time as we don't need to continually
         * alloc/free.
         */
        if (l2b->l2b_occupancy > 0 || pm == pmap_kernel())
                return;

        /*
         * There are no more valid mappings in this level 2 page table.
         * Go ahead and NULL-out the pointer in the bucket, then
         * free the page table.
         */
        const size_t l1slot = l2b->l2b_l1slot;
        pt_entry_t * const ptep = l2b->l2b_kva;
        l2b->l2b_kva = NULL;

        pd_entry_t * const pdep = pmap_l1_kva(pm) + l1slot;
        pd_entry_t pde __diagused = *pdep;

#ifdef ARM_MMU_EXTENDED
        /*
         * Invalidate the L1 slot.
         */
        KASSERT((pde & L1_TYPE_MASK) == L1_TYPE_C);
#else
        /*
         * If the L1 slot matches the pmap's domain number, then invalidate it.
         */
        if ((pde & (L1_C_DOM_MASK|L1_TYPE_MASK))
            == (L1_C_DOM(pmap_domain(pm))|L1_TYPE_C)) {
#endif
                l1pte_setone(pdep, 0);
                PDE_SYNC(pdep);
#ifndef ARM_MMU_EXTENDED
        }
#endif

        /*
         * Release the L2 descriptor table back to the pool cache.
         */
#if defined(PMAP_INCLUDE_PTE_SYNC) && defined(PMAP_CACHE_VIVT)
        pmap_free_l2_ptp(!pmap_is_cached(pm), ptep, l2b->l2b_pa);
#else
        pmap_free_l2_ptp(ptep, l2b->l2b_pa);
#endif

        /*
         * Update the reference count in the associated l2_dtable
         */
        struct l2_dtable * const l2 = pm->pm_l2[L2_IDX(l1slot)];
        if (--l2->l2_occupancy > 0)
                return;

        /*
         * There are no more valid mappings in any of the Level 1
         * slots managed by this l2_dtable. Go ahead and NULL-out
         * the pointer in the parent pmap and free the l2_dtable.
         */
        pm->pm_l2[L2_IDX(l1slot)] = NULL;
        pmap_free_l2_dtable(l2);
}

#if defined(ARM_MMU_EXTENDED)
/*
 * Pool cache constructors for L1 translation tables
 */

static int
pmap_l1tt_ctor(void *arg, void *v, int flags)
{
#ifndef PMAP_INCLUDE_PTE_SYNC
#error not supported
#endif

        memset(v, 0, L1TT_SIZE);
        PTE_SYNC_RANGE(v, L1TT_SIZE / sizeof(pt_entry_t));
        return 0;
}
#endif

/*
 * Pool cache constructors for L2 descriptor tables, metadata and pmap
 * structures.
 */
static int
pmap_l2ptp_ctor(void *arg, void *v, int flags)
{
#ifndef PMAP_INCLUDE_PTE_SYNC
        vaddr_t va = (vaddr_t)v & ~PGOFSET;

        /*
         * The mappings for these page tables were initially made using
         * pmap_kenter_pa() by the pool subsystem. Therefore, the cache-
         * mode will not be right for page table mappings. To avoid
         * polluting the pmap_kenter_pa() code with a special case for
         * page tables, we simply fix up the cache-mode here if it's not
         * correct.
         */
        if (pte_l2_s_cache_mode != pte_l2_s_cache_mode_pt) {
                const struct l2_bucket * const l2b =
                    pmap_get_l2_bucket(pmap_kernel(), va);
                KASSERTMSG(l2b != NULL, "%#lx", va);
                pt_entry_t * const ptep = &l2b->l2b_kva[l2pte_index(va)];
                const pt_entry_t opte = *ptep;

                if ((opte & L2_S_CACHE_MASK) != pte_l2_s_cache_mode_pt) {
                        /*
                         * Page tables must have the cache-mode set correctly.
                         */
                        const pt_entry_t npte = (opte & ~L2_S_CACHE_MASK)
                            | pte_l2_s_cache_mode_pt;
                        l2pte_set(ptep, npte, opte);
                        PTE_SYNC(ptep);
                        cpu_tlb_flushD_SE(va);
                        cpu_cpwait();
                }
        }
#endif

        memset(v, 0, L2_TABLE_SIZE_REAL);
        PTE_SYNC_RANGE(v, L2_TABLE_SIZE_REAL / sizeof(pt_entry_t));
        return 0;
}

static int
pmap_l2dtable_ctor(void *arg, void *v, int flags)
{

        memset(v, 0, sizeof(struct l2_dtable));
        return 0;
}

static int
pmap_pmap_ctor(void *arg, void *v, int flags)
{

        memset(v, 0, sizeof(struct pmap));
        return 0;
}

static void
pmap_pinit(pmap_t pm)
{
#ifndef ARM_HAS_VBAR
        struct l2_bucket *l2b;

        if (vector_page < KERNEL_BASE) {
                /*
                 * Map the vector page.
                 */
                pmap_enter(pm, vector_page, systempage.pv_pa,
                    VM_PROT_READ | VM_PROT_EXECUTE,
                    VM_PROT_READ | VM_PROT_EXECUTE | PMAP_WIRED);
                pmap_update(pm);

                pm->pm_pl1vec = pmap_l1_kva(pm) + l1pte_index(vector_page);
                l2b = pmap_get_l2_bucket(pm, vector_page);
                KASSERTMSG(l2b != NULL, "%#lx", vector_page);
                pm->pm_l1vec = l2b->l2b_pa | L1_C_PROTO |
                    L1_C_DOM(pmap_domain(pm));
        } else
                pm->pm_pl1vec = NULL;
#endif
}

#ifdef PMAP_CACHE_VIVT
/*
 * Since we have a virtually indexed cache, we may need to inhibit caching if
 * there is more than one mapping and at least one of them is writable.
 * Since we purge the cache on every context switch, we only need to check for
 * other mappings within the same pmap, or kernel_pmap.
 * This function is also called when a page is unmapped, to possibly reenable
 * caching on any remaining mappings.
 *
 * The code implements the following logic, where:
 *
 * KW = # of kernel read/write pages
 * KR = # of kernel read only pages
 * UW = # of user read/write pages
 * UR = # of user read only pages
 *
 * KC = kernel mapping is cacheable
 * UC = user mapping is cacheable
 *
 *               KW=0,KR=0  KW=0,KR>0  KW=1,KR=0  KW>1,KR>=0
 *             +---------------------------------------------
 * UW=0,UR=0   | ---        KC=1       KC=1       KC=0
 * UW=0,UR>0   | UC=1       KC=1,UC=1  KC=0,UC=0  KC=0,UC=0
 * UW=1,UR=0   | UC=1       KC=0,UC=0  KC=0,UC=0  KC=0,UC=0
 * UW>1,UR>=0  | UC=0       KC=0,UC=0  KC=0,UC=0  KC=0,UC=0
 */

static const int pmap_vac_flags[4][4] = {
        {-1,            0,              0,              PVF_KNC},
        {0,             0,              PVF_NC,         PVF_NC},
        {0,             PVF_NC,         PVF_NC,         PVF_NC},
        {PVF_UNC,       PVF_NC,         PVF_NC,         PVF_NC}
};

static inline int
pmap_get_vac_flags(const struct vm_page_md *md)
{
        int kidx, uidx;

        kidx = 0;
        if (md->kro_mappings || md->krw_mappings > 1)
                kidx |= 1;
        if (md->krw_mappings)
                kidx |= 2;

        uidx = 0;
        if (md->uro_mappings || md->urw_mappings > 1)
                uidx |= 1;
        if (md->urw_mappings)
                uidx |= 2;

        return pmap_vac_flags[uidx][kidx];
}

static inline void
pmap_vac_me_harder(struct vm_page_md *md, paddr_t pa, pmap_t pm, vaddr_t va)
{
        int nattr;

        nattr = pmap_get_vac_flags(md);

        if (nattr < 0) {
                md->pvh_attrs &= ~PVF_NC;
                return;
        }

        if (nattr == 0 && (md->pvh_attrs & PVF_NC) == 0)
                return;

        if (pm == pmap_kernel())
                pmap_vac_me_kpmap(md, pa, pm, va);
        else
                pmap_vac_me_user(md, pa, pm, va);

        md->pvh_attrs = (md->pvh_attrs & ~PVF_NC) | nattr;
}

static void
pmap_vac_me_kpmap(struct vm_page_md *md, paddr_t pa, pmap_t pm, vaddr_t va)
{
        u_int u_cacheable, u_entries;
        struct pv_entry *pv;
        pmap_t last_pmap = pm;

        /*
         * Pass one, see if there are both kernel and user pmaps for
         * this page.  Calculate whether there are user-writable or
         * kernel-writable pages.
         */
        u_cacheable = 0;
        SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
                if (pv->pv_pmap != pm && (pv->pv_flags & PVF_NC) == 0)
                        u_cacheable++;
        }

        u_entries = md->urw_mappings + md->uro_mappings;

        /*
         * We know we have just been updating a kernel entry, so if
         * all user pages are already cacheable, then there is nothing
         * further to do.
         */
        if (md->k_mappings == 0 && u_cacheable == u_entries)
                return;

        if (u_entries) {
                /*
                 * Scan over the list again, for each entry, if it
                 * might not be set correctly, call pmap_vac_me_user
                 * to recalculate the settings.
                 */
                SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
                        /*
                         * We know kernel mappings will get set
                         * correctly in other calls.  We also know
                         * that if the pmap is the same as last_pmap
                         * then we've just handled this entry.
                         */
                        if (pv->pv_pmap == pm || pv->pv_pmap == last_pmap)
                                continue;

                        /*
                         * If there are kernel entries and this page
                         * is writable but non-cacheable, then we can
                         * skip this entry also.
                         */
                        if (md->k_mappings &&
                            (pv->pv_flags & (PVF_NC | PVF_WRITE)) ==
                            (PVF_NC | PVF_WRITE))
                                continue;

                        /*
                         * Similarly if there are no kernel-writable
                         * entries and the page is already
                         * read-only/cacheable.
                         */
                        if (md->krw_mappings == 0 &&
                            (pv->pv_flags & (PVF_NC | PVF_WRITE)) == 0)
                                continue;

                        /*
                         * For some of the remaining cases, we know
                         * that we must recalculate, but for others we
                         * can't tell if they are correct or not, so
                         * we recalculate anyway.
                         */
                        pmap_vac_me_user(md, pa, (last_pmap = pv->pv_pmap), 0);
                }

                if (md->k_mappings == 0)
                        return;
        }

        pmap_vac_me_user(md, pa, pm, va);
}

static void
pmap_vac_me_user(struct vm_page_md *md, paddr_t pa, pmap_t pm, vaddr_t va)
{
        pmap_t kpmap = pmap_kernel();
        struct pv_entry *pv, *npv = NULL;
        u_int entries = 0;
        u_int writable = 0;
        u_int cacheable_entries = 0;
        u_int kern_cacheable = 0;
        u_int other_writable = 0;

        /*
         * Count mappings and writable mappings in this pmap.
         * Include kernel mappings as part of our own.
         * Keep a pointer to the first one.
         */
        npv = NULL;
        KASSERT(pmap_page_locked_p(md));
        SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
                /* Count mappings in the same pmap */
                if (pm == pv->pv_pmap || kpmap == pv->pv_pmap) {
                        if (entries++ == 0)
                                npv = pv;

                        /* Cacheable mappings */
                        if ((pv->pv_flags & PVF_NC) == 0) {
                                cacheable_entries++;
                                if (kpmap == pv->pv_pmap)
                                        kern_cacheable++;
                        }

                        /* Writable mappings */
                        if (pv->pv_flags & PVF_WRITE)
                                ++writable;
                } else if (pv->pv_flags & PVF_WRITE)
                        other_writable = 1;
        }

        /*
         * Enable or disable caching as necessary.
         * Note: the first entry might be part of the kernel pmap,
         * so we can't assume this is indicative of the state of the
         * other (maybe non-kpmap) entries.
         */
        if ((entries > 1 && writable) ||
            (entries > 0 && pm == kpmap && other_writable)) {
                if (cacheable_entries == 0) {
                        return;
                }

                for (pv = npv; pv; pv = SLIST_NEXT(pv, pv_link)) {
                        if ((pm != pv->pv_pmap && kpmap != pv->pv_pmap) ||
                            (pv->pv_flags & PVF_NC))
                                continue;

                        pv->pv_flags |= PVF_NC;

                        struct l2_bucket * const l2b
                            = pmap_get_l2_bucket(pv->pv_pmap, pv->pv_va);
                        KASSERTMSG(l2b != NULL, "%#lx", va);
                        pt_entry_t * const ptep
                            = &l2b->l2b_kva[l2pte_index(pv->pv_va)];
                        const pt_entry_t opte = *ptep;
                        pt_entry_t npte = opte & ~L2_S_CACHE_MASK;

                        if ((va != pv->pv_va || pm != pv->pv_pmap)
                            && l2pte_valid_p(opte)) {
                                pmap_cache_wbinv_page(pv->pv_pmap, pv->pv_va,
                                    true, pv->pv_flags);
                                pmap_tlb_flush_SE(pv->pv_pmap, pv->pv_va,
                                    pv->pv_flags);
                        }

                        l2pte_set(ptep, npte, opte);
                        PTE_SYNC_CURRENT(pv->pv_pmap, ptep);
                }
                cpu_cpwait();
        } else if (entries > cacheable_entries) {
                /*
                 * Turn cacheing back on for some pages.  If it is a kernel
                 * page, only do so if there are no other writable pages.
                 */
                for (pv = npv; pv; pv = SLIST_NEXT(pv, pv_link)) {
                        if (!(pv->pv_flags & PVF_NC) || (pm != pv->pv_pmap &&
                            (kpmap != pv->pv_pmap || other_writable)))
                                continue;

                        pv->pv_flags &= ~PVF_NC;

                        struct l2_bucket * const l2b
                            = pmap_get_l2_bucket(pv->pv_pmap, pv->pv_va);
                        KASSERTMSG(l2b != NULL, "%#lx", va);
                        pt_entry_t * const ptep
                            = &l2b->l2b_kva[l2pte_index(pv->pv_va)];
                        const pt_entry_t opte = *ptep;
                        pt_entry_t npte = (opte & ~L2_S_CACHE_MASK)
                            | pte_l2_s_cache_mode;

                        if (l2pte_valid_p(opte)) {
                                pmap_tlb_flush_SE(pv->pv_pmap, pv->pv_va,
                                    pv->pv_flags);
                        }

                        l2pte_set(ptep, npte, opte);
                        PTE_SYNC_CURRENT(pv->pv_pmap, ptep);
                }
        }
}
#endif

#ifdef PMAP_CACHE_VIPT
static void
pmap_vac_me_harder(struct vm_page_md *md, paddr_t pa, pmap_t pm, vaddr_t va)
{

#ifndef ARM_MMU_EXTENDED
        struct pv_entry *pv;
        vaddr_t tst_mask;
        bool bad_alias;
        const u_int
            rw_mappings = md->urw_mappings + md->krw_mappings,
            ro_mappings = md->uro_mappings + md->kro_mappings;

        /* do we need to do anything? */
        if (arm_cache_prefer_mask == 0)
                return;

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "md %#jx pa %#jx pm %#jx va %#jx",
            (uintptr_t)md, (uintptr_t)pa, (uintptr_t)pm, va);

        KASSERT(!va || pm);
        KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));

        /* Already a conflict? */
        if (__predict_false(md->pvh_attrs & PVF_NC)) {
                /* just an add, things are already non-cached */
                KASSERT(!(md->pvh_attrs & PVF_DIRTY));
                KASSERT(!(md->pvh_attrs & PVF_MULTCLR));
                bad_alias = false;
                if (va) {
                        PMAPCOUNT(vac_color_none);
                        bad_alias = true;
                        KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
                        goto fixup;
                }
                pv = SLIST_FIRST(&md->pvh_list);
                /* the list can't be empty because it would be cachable */
                if (md->pvh_attrs & PVF_KMPAGE) {
                        tst_mask = md->pvh_attrs;
                } else {
                        KASSERT(pv);
                        tst_mask = pv->pv_va;
                        pv = SLIST_NEXT(pv, pv_link);
                }
                /*
                 * Only check for a bad alias if we have writable mappings.
                 */
                tst_mask &= arm_cache_prefer_mask;
                if (rw_mappings > 0) {
                        for (; pv && !bad_alias; pv = SLIST_NEXT(pv, pv_link)) {
                                /* if there's a bad alias, stop checking. */
                                if (tst_mask != (pv->pv_va & arm_cache_prefer_mask))
                                        bad_alias = true;
                        }
                        md->pvh_attrs |= PVF_WRITE;
                        if (!bad_alias)
                                md->pvh_attrs |= PVF_DIRTY;
                } else {
                        /*
                         * We have only read-only mappings.  Let's see if there
                         * are multiple colors in use or if we mapped a KMPAGE.
                         * If the latter, we have a bad alias.  If the former,
                         * we need to remember that.
                         */
                        for (; pv; pv = SLIST_NEXT(pv, pv_link)) {
                                if (tst_mask != (pv->pv_va & arm_cache_prefer_mask)) {
                                        if (md->pvh_attrs & PVF_KMPAGE)
                                                bad_alias = true;
                                        break;
                                }
                        }
                        md->pvh_attrs &= ~PVF_WRITE;
                        /*
                         * No KMPAGE and we exited early, so we must have
                         * multiple color mappings.
                         */
                        if (!bad_alias && pv != NULL)
                                md->pvh_attrs |= PVF_MULTCLR;
                }

                /* If no conflicting colors, set everything back to cached */
                if (!bad_alias) {
#ifdef DEBUG
                        if ((md->pvh_attrs & PVF_WRITE)
                            || ro_mappings < 2) {
                                SLIST_FOREACH(pv, &md->pvh_list, pv_link)
                                        KDASSERT(((tst_mask ^ pv->pv_va) & arm_cache_prefer_mask) == 0);
                        }
#endif
                        md->pvh_attrs &= (PAGE_SIZE - 1) & ~PVF_NC;
                        md->pvh_attrs |= tst_mask | PVF_COLORED;
                        /*
                         * Restore DIRTY bit if page is modified
                         */
                        if (md->pvh_attrs & PVF_DMOD)
                                md->pvh_attrs |= PVF_DIRTY;
                        PMAPCOUNT(vac_color_restore);
                } else {
                        KASSERT(SLIST_FIRST(&md->pvh_list) != NULL);
                        KASSERT(SLIST_NEXT(SLIST_FIRST(&md->pvh_list), pv_link) != NULL);
                }
                KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
                KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
        } else if (!va) {
                KASSERT(pmap_is_page_colored_p(md));
                KASSERT(!(md->pvh_attrs & PVF_WRITE)
                    || (md->pvh_attrs & PVF_DIRTY));
                if (rw_mappings == 0) {
                        md->pvh_attrs &= ~PVF_WRITE;
                        if (ro_mappings == 1
                            && (md->pvh_attrs & PVF_MULTCLR)) {
                                /*
                                 * If this is the last readonly mapping
                                 * but it doesn't match the current color
                                 * for the page, change the current color
                                 * to match this last readonly mapping.
                                 */
                                pv = SLIST_FIRST(&md->pvh_list);
                                tst_mask = (md->pvh_attrs ^ pv->pv_va)
                                    & arm_cache_prefer_mask;
                                if (tst_mask) {
                                        md->pvh_attrs ^= tst_mask;
                                        PMAPCOUNT(vac_color_change);
                                }
                        }
                }
                KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
                KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
                return;
        } else if (!pmap_is_page_colored_p(md)) {
                /* not colored so we just use its color */
                KASSERT(md->pvh_attrs & (PVF_WRITE|PVF_DIRTY));
                KASSERT(!(md->pvh_attrs & PVF_MULTCLR));
                PMAPCOUNT(vac_color_new);
                md->pvh_attrs &= PAGE_SIZE - 1;
                md->pvh_attrs |= PVF_COLORED
                    | (va & arm_cache_prefer_mask)
                    | (rw_mappings > 0 ? PVF_WRITE : 0);
                KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
                KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
                return;
        } else if (((md->pvh_attrs ^ va) & arm_cache_prefer_mask) == 0) {
                bad_alias = false;
                if (rw_mappings > 0) {
                        /*
                         * We now have writeable mappings and if we have
                         * readonly mappings in more than once color, we have
                         * an aliasing problem.  Regardless mark the page as
                         * writeable.
                         */
                        if (md->pvh_attrs & PVF_MULTCLR) {
                                if (ro_mappings < 2) {
                                        /*
                                         * If we only have less than two
                                         * read-only mappings, just flush the
                                         * non-primary colors from the cache.
                                         */
                                        pmap_flush_page(md, pa,
                                            PMAP_FLUSH_SECONDARY);
                                } else {
                                        bad_alias = true;
                                }
                        }
                        md->pvh_attrs |= PVF_WRITE;
                }
                /* If no conflicting colors, set everything back to cached */
                if (!bad_alias) {
#ifdef DEBUG
                        if (rw_mappings > 0
                            || (md->pvh_attrs & PMAP_KMPAGE)) {
                                tst_mask = md->pvh_attrs & arm_cache_prefer_mask;
                                SLIST_FOREACH(pv, &md->pvh_list, pv_link)
                                        KDASSERT(((tst_mask ^ pv->pv_va) & arm_cache_prefer_mask) == 0);
                        }
#endif
                        if (SLIST_EMPTY(&md->pvh_list))
                                PMAPCOUNT(vac_color_reuse);
                        else
                                PMAPCOUNT(vac_color_ok);

                        /* matching color, just return */
                        KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
                        KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
                        return;
                }
                KASSERT(SLIST_FIRST(&md->pvh_list) != NULL);
                KASSERT(SLIST_NEXT(SLIST_FIRST(&md->pvh_list), pv_link) != NULL);

                /* color conflict.  evict from cache. */

                pmap_flush_page(md, pa, PMAP_FLUSH_PRIMARY);
                md->pvh_attrs &= ~PVF_COLORED;
                md->pvh_attrs |= PVF_NC;
                KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
                KASSERT(!(md->pvh_attrs & PVF_MULTCLR));
                PMAPCOUNT(vac_color_erase);
        } else if (rw_mappings == 0
                   && (md->pvh_attrs & PVF_KMPAGE) == 0) {
                KASSERT((md->pvh_attrs & PVF_WRITE) == 0);

                /*
                 * If the page has dirty cache lines, clean it.
                 */
                if (md->pvh_attrs & PVF_DIRTY)
                        pmap_flush_page(md, pa, PMAP_CLEAN_PRIMARY);

                /*
                 * If this is the first remapping (we know that there are no
                 * writeable mappings), then this is a simple color change.
                 * Otherwise this is a seconary r/o mapping, which means
                 * we don't have to do anything.
                 */
                if (ro_mappings == 1) {
                        KASSERT(((md->pvh_attrs ^ va) & arm_cache_prefer_mask) != 0);
                        md->pvh_attrs &= PAGE_SIZE - 1;
                        md->pvh_attrs |= (va & arm_cache_prefer_mask);
                        PMAPCOUNT(vac_color_change);
                } else {
                        PMAPCOUNT(vac_color_blind);
                }
                md->pvh_attrs |= PVF_MULTCLR;
                KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
                KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
                return;
        } else {
                if (rw_mappings > 0)
                        md->pvh_attrs |= PVF_WRITE;

                /* color conflict.  evict from cache. */
                pmap_flush_page(md, pa, PMAP_FLUSH_PRIMARY);

                /* the list can't be empty because this was a enter/modify */
                pv = SLIST_FIRST(&md->pvh_list);
                if ((md->pvh_attrs & PVF_KMPAGE) == 0) {
                        KASSERT(pv);
                        /*
                         * If there's only one mapped page, change color to the
                         * page's new color and return.  Restore the DIRTY bit
                         * that was erased by pmap_flush_page.
                         */
                        if (SLIST_NEXT(pv, pv_link) == NULL) {
                                md->pvh_attrs &= PAGE_SIZE - 1;
                                md->pvh_attrs |= (va & arm_cache_prefer_mask);
                                if (md->pvh_attrs & PVF_DMOD)
                                        md->pvh_attrs |= PVF_DIRTY;
                                PMAPCOUNT(vac_color_change);
                                KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
                                KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
                                KASSERT(!(md->pvh_attrs & PVF_MULTCLR));
                                return;
                        }
                }
                bad_alias = true;
                md->pvh_attrs &= ~PVF_COLORED;
                md->pvh_attrs |= PVF_NC;
                PMAPCOUNT(vac_color_erase);
                KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
        }

  fixup:
        KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));

        /*
         * Turn cacheing on/off for all pages.
         */
        SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
                struct l2_bucket * const l2b = pmap_get_l2_bucket(pv->pv_pmap,
                    pv->pv_va);
                KASSERTMSG(l2b != NULL, "%#lx", va);
                pt_entry_t * const ptep = &l2b->l2b_kva[l2pte_index(pv->pv_va)];
                const pt_entry_t opte = *ptep;
                pt_entry_t npte = opte & ~L2_S_CACHE_MASK;
                if (bad_alias) {
                        pv->pv_flags |= PVF_NC;
                } else {
                        pv->pv_flags &= ~PVF_NC;
                        npte |= pte_l2_s_cache_mode;
                }

                if (opte == npte)       /* only update is there's a change */
                        continue;

                if (l2pte_valid_p(opte)) {
                        pmap_tlb_flush_SE(pv->pv_pmap, pv->pv_va, pv->pv_flags);
                }

                l2pte_set(ptep, npte, opte);
                PTE_SYNC_CURRENT(pv->pv_pmap, ptep);
        }
#endif /* !ARM_MMU_EXTENDED */
}
#endif  /* PMAP_CACHE_VIPT */


/*
 * Modify pte bits for all ptes corresponding to the given physical address.
 * We use `maskbits' rather than `clearbits' because we're always passing
 * constants and the latter would require an extra inversion at run-time.
 */
static void
pmap_clearbit(struct vm_page_md *md, paddr_t pa, u_int maskbits)
{
        struct pv_entry *pv;
#ifdef PMAP_CACHE_VIPT
        const bool want_syncicache = PV_IS_EXEC_P(md->pvh_attrs);
        bool need_syncicache = false;
#ifndef ARM_MMU_EXTENDED
        bool need_vac_me_harder = false;
#endif
#endif /* PMAP_CACHE_VIPT */

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "md %#jx pa %#jx maskbits %#jx",
            (uintptr_t)md, pa, maskbits, 0);

#ifdef PMAP_CACHE_VIPT
        /*
         * If we might want to sync the I-cache and we've modified it,
         * then we know we definitely need to sync or discard it.
         */
        if (want_syncicache) {
                if (md->pvh_attrs & PVF_MOD) {
                        need_syncicache = true;
                }
        }
#endif
        KASSERT(pmap_page_locked_p(md));

        /*
         * Clear saved attributes (modify, reference)
         */
        md->pvh_attrs &= ~(maskbits & (PVF_MOD | PVF_REF));

        if (SLIST_EMPTY(&md->pvh_list)) {
#if defined(PMAP_CACHE_VIPT)
                if (need_syncicache) {
                        /*
                         * No one has it mapped, so just discard it.  The next
                         * exec remapping will cause it to be synced.
                         */
                        md->pvh_attrs &= ~PVF_EXEC;
                        PMAPCOUNT(exec_discarded_clearbit);
                }
#endif
                return;
        }

        /*
         * Loop over all current mappings setting/clearing as appropriate
         */
        for (pv = SLIST_FIRST(&md->pvh_list); pv != NULL;) {
                pmap_t pm = pv->pv_pmap;
                const vaddr_t va = pv->pv_va;
                const u_int oflags = pv->pv_flags;
#ifndef ARM_MMU_EXTENDED
                /*
                 * Kernel entries are unmanaged and as such not to be changed.
                 */
                if (PV_IS_KENTRY_P(oflags)) {
                        pv = SLIST_NEXT(pv, pv_link);
                        continue;
                }
#endif

                /*
                 * Try to get a hold on the pmap's lock.  We must do this
                 * while still holding the page locked, to know that the
                 * page is still associated with the pmap and the mapping is
                 * in place.  If a hold can't be had, unlock and wait for
                 * the pmap's lock to become available and retry.  The pmap
                 * must be ref'd over this dance to stop it disappearing
                 * behind us.
                 */
                if (!mutex_tryenter(&pm->pm_lock)) {
                        pmap_reference(pm);
                        pmap_release_page_lock(md);
                        pmap_acquire_pmap_lock(pm);
                        /* nothing, just wait for it */
                        pmap_release_pmap_lock(pm);
                        pmap_destroy(pm);
                        /* Restart from the beginning. */
                        pmap_acquire_page_lock(md);
                        pv = SLIST_FIRST(&md->pvh_list);
                        continue;
                }
                pv->pv_flags &= ~maskbits;

                struct l2_bucket * const l2b = pmap_get_l2_bucket(pm, va);
                KASSERTMSG(l2b != NULL, "%#lx", va);

                pt_entry_t * const ptep = &l2b->l2b_kva[l2pte_index(va)];
                const pt_entry_t opte = *ptep;
                pt_entry_t npte = opte;

#if defined(ARM_MMU_EXTENDED)
                if ((maskbits & PVF_EXEC) != 0 && l2pte_valid_p(opte)) {
                        KASSERT((opte & L2_TYPE_S) != 0);
                        npte |= L2_XS_XN;
                }

                KASSERT((opte & L2_XS_nG) == (pm == pmap_kernel() ? 0 : L2_XS_nG));
#endif

                UVMHIST_LOG(maphist, "pv %#jx pm %#jx va %#jx flag %#jx",
                    (uintptr_t)pv, (uintptr_t)pm, va, oflags);

                if (maskbits & (PVF_WRITE|PVF_MOD)) {
#ifdef PMAP_CACHE_VIVT
                        if ((oflags & PVF_NC)) {
                                /*
                                 * Entry is not cacheable:
                                 *
                                 * Don't turn caching on again if this is a
                                 * modified emulation. This would be
                                 * inconsistent with the settings created by
                                 * pmap_vac_me_harder(). Otherwise, it's safe
                                 * to re-enable cacheing.
                                 *
                                 * There's no need to call pmap_vac_me_harder()
                                 * here: all pages are losing their write
                                 * permission.
                                 */
                                if (maskbits & PVF_WRITE) {
                                        npte |= pte_l2_s_cache_mode;
                                        pv->pv_flags &= ~PVF_NC;
                                }
                        } else if (l2pte_writable_p(opte)) {
                                /*
                                 * Entry is writable/cacheable: check if pmap
                                 * is current if it is flush it, otherwise it
                                 * won't be in the cache
                                 */
                                pmap_cache_wbinv_page(pm, va,
                                    (maskbits & PVF_REF) != 0,
                                    oflags|PVF_WRITE);
                        }
#endif

                        /* make the pte read only */
                        npte = l2pte_set_readonly(npte);

                        if ((maskbits & oflags & PVF_WRITE)) {
                                /*
                                 * Keep alias accounting up to date
                                 */
                                if (pm == pmap_kernel()) {
                                        md->krw_mappings--;
                                        md->kro_mappings++;
                                } else {
                                        md->urw_mappings--;
                                        md->uro_mappings++;
                                }
#ifdef PMAP_CACHE_VIPT
                                if (arm_cache_prefer_mask != 0) {
                                        if (md->urw_mappings + md->krw_mappings == 0) {
                                                md->pvh_attrs &= ~PVF_WRITE;
                                        } else {
                                                PMAP_VALIDATE_MD_PAGE(md);
                                        }
                                }
                                if (want_syncicache)
                                        need_syncicache = true;
#ifndef ARM_MMU_EXTENDED
                                need_vac_me_harder = true;
#endif
#endif /* PMAP_CACHE_VIPT */
                        }
                }

                if (maskbits & PVF_REF) {
                        if (true
#ifndef ARM_MMU_EXTENDED
                            && (oflags & PVF_NC) == 0
#endif
                            && (maskbits & (PVF_WRITE|PVF_MOD)) == 0
                            && l2pte_valid_p(npte)) {
#ifdef PMAP_CACHE_VIVT
                                /*
                                 * Check npte here; we may have already
                                 * done the wbinv above, and the validity
                                 * of the PTE is the same for opte and
                                 * npte.
                                 */
                                pmap_cache_wbinv_page(pm, va, true, oflags);
#endif
                        }

                        /*
                         * Make the PTE invalid so that we will take a
                         * page fault the next time the mapping is
                         * referenced.
                         */
                        npte &= ~L2_TYPE_MASK;
                        npte |= L2_TYPE_INV;
                }

                if (npte != opte) {
                        l2pte_reset(ptep);
                        PTE_SYNC(ptep);

                        /* Flush the TLB entry if a current pmap. */
                        pmap_tlb_flush_SE(pm, va, oflags);

                        l2pte_set(ptep, npte, 0);
                        PTE_SYNC(ptep);
                }

                pmap_release_pmap_lock(pm);

                UVMHIST_LOG(maphist, "pm %#jx va %#jx opte %#jx npte %#jx",
                    (uintptr_t)pm, va, opte, npte);

                /* Move to next entry. */
                pv = SLIST_NEXT(pv, pv_link);
        }

#if defined(PMAP_CACHE_VIPT)
        /*
         * If we need to sync the I-cache and we haven't done it yet, do it.
         */
        if (need_syncicache) {
                pmap_syncicache_page(md, pa);
                PMAPCOUNT(exec_synced_clearbit);
        }
#ifndef ARM_MMU_EXTENDED
        /*
         * If we are changing this to read-only, we need to call vac_me_harder
         * so we can change all the read-only pages to cacheable.  We pretend
         * this as a page deletion.
         */
        if (need_vac_me_harder) {
                if (md->pvh_attrs & PVF_NC)
                        pmap_vac_me_harder(md, pa, NULL, 0);
        }
#endif /* !ARM_MMU_EXTENDED */
#endif /* PMAP_CACHE_VIPT */
}

/*
 * pmap_clean_page()
 *
 * This is a local function used to work out the best strategy to clean
 * a single page referenced by its entry in the PV table. It's used by
 * pmap_copy_page, pmap_zero_page and maybe some others later on.
 *
 * Its policy is effectively:
 *  o If there are no mappings, we don't bother doing anything with the cache.
 *  o If there is one mapping, we clean just that page.
 *  o If there are multiple mappings, we clean the entire cache.
 *
 * So that some functions can be further optimised, it returns 0 if it didn't
 * clean the entire cache, or 1 if it did.
 *
 * XXX One bug in this routine is that if the pv_entry has a single page
 * mapped at 0x00000000 a whole cache clean will be performed rather than
 * just the 1 page. Since this should not occur in everyday use and if it does
 * it will just result in not the most efficient clean for the page.
 */
#ifdef PMAP_CACHE_VIVT
static bool
pmap_clean_page(struct vm_page_md *md, bool is_src)
{
        struct pv_entry *pv;
        pmap_t pm_to_clean = NULL;
        bool cache_needs_cleaning = false;
        vaddr_t page_to_clean = 0;
        u_int flags = 0;

        /*
         * Since we flush the cache each time we change to a different
         * user vmspace, we only need to flush the page if it is in the
         * current pmap.
         */
        KASSERT(pmap_page_locked_p(md));
        SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
                if (pmap_is_current(pv->pv_pmap)) {
                        flags |= pv->pv_flags;
                        /*
                         * The page is mapped non-cacheable in
                         * this map.  No need to flush the cache.
                         */
                        if (pv->pv_flags & PVF_NC) {
#ifdef DIAGNOSTIC
                                KASSERT(!cache_needs_cleaning);
#endif
                                break;
                        } else if (is_src && (pv->pv_flags & PVF_WRITE) == 0)
                                continue;
                        if (cache_needs_cleaning) {
                                page_to_clean = 0;
                                break;
                        } else {
                                page_to_clean = pv->pv_va;
                                pm_to_clean = pv->pv_pmap;
                        }
                        cache_needs_cleaning = true;
                }
        }

        if (page_to_clean) {
                pmap_cache_wbinv_page(pm_to_clean, page_to_clean,
                    !is_src, flags | PVF_REF);
        } else if (cache_needs_cleaning) {
                pmap_t const pm = curproc->p_vmspace->vm_map.pmap;

                pmap_cache_wbinv_all(pm, flags);
                return true;
        }
        return false;
}
#endif

#ifdef PMAP_CACHE_VIPT
/*
 * Sync a page with the I-cache.  Since this is a VIPT, we must pick the
 * right cache alias to make sure we flush the right stuff.
 */
void
pmap_syncicache_page(struct vm_page_md *md, paddr_t pa)
{
        pmap_t kpm = pmap_kernel();
        const size_t way_size = arm_pcache.icache_type == CACHE_TYPE_PIPT
            ? PAGE_SIZE
            : arm_pcache.icache_way_size;

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "md %#jx pa %#jx (attrs=%#jx)",
            (uintptr_t)md, pa, md->pvh_attrs, 0);

        /*
         * No need to clean the page if it's non-cached.
         */
#ifndef ARM_MMU_EXTENDED
        if (md->pvh_attrs & PVF_NC)
                return;
        KASSERT(arm_cache_prefer_mask == 0 || md->pvh_attrs & PVF_COLORED);
#endif

        pt_entry_t * const ptep = cpu_cdst_pte(0);
        const vaddr_t dstp = cpu_cdstp(0);
#ifdef __HAVE_MM_MD_DIRECT_MAPPED_PHYS
        if (way_size <= PAGE_SIZE) {
                bool ok = false;
                vaddr_t vdstp = pmap_direct_mapped_phys(pa, &ok, dstp);
                if (ok) {
                        cpu_icache_sync_range(vdstp, way_size);
                        return;
                }
        }
#endif

        /*
         * We don't worry about the color of the exec page, we map the
         * same page to pages in the way and then do the icache_sync on
         * the entire way making sure we are cleaned.
         */
        const pt_entry_t npte = L2_S_PROTO | pa | pte_l2_s_cache_mode
            | L2_S_PROT(PTE_KERNEL, VM_PROT_READ|VM_PROT_WRITE);

        for (size_t i = 0, j = 0; i < way_size;
             i += PAGE_SIZE, j += PAGE_SIZE / L2_S_SIZE) {
                l2pte_reset(ptep + j);
                PTE_SYNC(ptep + j);

                pmap_tlb_flush_SE(kpm, dstp + i, PVF_REF | PVF_EXEC);
                /*
                 * Set up a PTE with to flush these cache lines.
                 */
                l2pte_set(ptep + j, npte, 0);
        }
        PTE_SYNC_RANGE(ptep, way_size / L2_S_SIZE);

        /*
         * Flush it.
         */
        cpu_icache_sync_range(dstp, way_size);

        for (size_t i = 0, j = 0; i < way_size;
             i += PAGE_SIZE, j += PAGE_SIZE / L2_S_SIZE) {
                /*
                 * Unmap the page(s).
                 */
                l2pte_reset(ptep + j);
                PTE_SYNC(ptep + j);

                pmap_tlb_flush_SE(kpm, dstp + i, PVF_REF | PVF_EXEC);
        }

        md->pvh_attrs |= PVF_EXEC;
        PMAPCOUNT(exec_synced);
}

#ifndef ARM_MMU_EXTENDED
void
pmap_flush_page(struct vm_page_md *md, paddr_t pa, enum pmap_flush_op flush)
{
        vsize_t va_offset, end_va;
        bool wbinv_p;

        if (arm_cache_prefer_mask == 0)
                return;

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "md %#jx pa %#jx op %#jx",
            (uintptr_t)md, pa, op, 0);

        switch (flush) {
        case PMAP_FLUSH_PRIMARY:
                if (md->pvh_attrs & PVF_MULTCLR) {
                        va_offset = 0;
                        end_va = arm_cache_prefer_mask;
                        md->pvh_attrs &= ~PVF_MULTCLR;
                        PMAPCOUNT(vac_flush_lots);
                } else {
                        va_offset = md->pvh_attrs & arm_cache_prefer_mask;
                        end_va = va_offset;
                        PMAPCOUNT(vac_flush_one);
                }
                /*
                 * Mark that the page is no longer dirty.
                 */
                md->pvh_attrs &= ~PVF_DIRTY;
                wbinv_p = true;
                break;
        case PMAP_FLUSH_SECONDARY:
                va_offset = 0;
                end_va = arm_cache_prefer_mask;
                wbinv_p = true;
                md->pvh_attrs &= ~PVF_MULTCLR;
                PMAPCOUNT(vac_flush_lots);
                break;
        case PMAP_CLEAN_PRIMARY:
                va_offset = md->pvh_attrs & arm_cache_prefer_mask;
                end_va = va_offset;
                wbinv_p = false;
                /*
                 * Mark that the page is no longer dirty.
                 */
                if ((md->pvh_attrs & PVF_DMOD) == 0)
                        md->pvh_attrs &= ~PVF_DIRTY;
                PMAPCOUNT(vac_clean_one);
                break;
        default:
                return;
        }

        KASSERT(!(md->pvh_attrs & PVF_NC));

        UVMHIST_LOG(maphist, "md %#jx (attrs=%#jx)", (uintptr_t)md,
            md->pvh_attrs, 0, 0);

        const size_t scache_line_size = arm_scache.dcache_line_size;

        for (; va_offset <= end_va; va_offset += PAGE_SIZE) {
                pt_entry_t * const ptep = cpu_cdst_pte(va_offset);
                const vaddr_t dstp = cpu_cdstp(va_offset);
                const pt_entry_t opte = *ptep;

                if (flush == PMAP_FLUSH_SECONDARY
                    && va_offset == (md->pvh_attrs & arm_cache_prefer_mask))
                        continue;

                pmap_tlb_flush_SE(pmap_kernel(), dstp, PVF_REF | PVF_EXEC);
                /*
                 * Set up a PTE with the right coloring to flush
                 * existing cache entries.
                 */
                const pt_entry_t npte = L2_S_PROTO
                    | pa
                    | L2_S_PROT(PTE_KERNEL, VM_PROT_READ|VM_PROT_WRITE)
                    | pte_l2_s_cache_mode;
                l2pte_set(ptep, npte, opte);
                PTE_SYNC(ptep);

                /*
                 * Flush it.  Make sure to flush secondary cache too since
                 * bus_dma will ignore uncached pages.
                 */
                if (scache_line_size != 0) {
                        cpu_dcache_wb_range(dstp, PAGE_SIZE);
                        if (wbinv_p) {
                                cpu_sdcache_wbinv_range(dstp, pa, PAGE_SIZE);
                                cpu_dcache_inv_range(dstp, PAGE_SIZE);
                        } else {
                                cpu_sdcache_wb_range(dstp, pa, PAGE_SIZE);
                        }
                } else {
                        if (wbinv_p) {
                                cpu_dcache_wbinv_range(dstp, PAGE_SIZE);
                        } else {
                                cpu_dcache_wb_range(dstp, PAGE_SIZE);
                        }
                }

                /*
                 * Restore the page table entry since we might have interrupted
                 * pmap_zero_page or pmap_copy_page which was already using
                 * this pte.
                 */
                if (opte) {
                        l2pte_set(ptep, opte, npte);
                } else {
                        l2pte_reset(ptep);
                }
                PTE_SYNC(ptep);
                pmap_tlb_flush_SE(pmap_kernel(), dstp, PVF_REF | PVF_EXEC);
        }
}
#endif /* ARM_MMU_EXTENDED */
#endif /* PMAP_CACHE_VIPT */

/*
 * Routine:     pmap_page_remove
 * Function:
 *              Removes this physical page from
 *              all physical maps in which it resides.
 *              Reflects back modify bits to the pager.
 */
static void
pmap_page_remove(struct vm_page_md *md, paddr_t pa)
{
        struct l2_bucket *l2b;
        struct pv_entry *pv;
        pt_entry_t *ptep;
#ifndef ARM_MMU_EXTENDED
        bool flush = false;
#endif
        u_int flags = 0;

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "md %#jx pa %#jx", (uintptr_t)md, pa, 0, 0);

        kpreempt_disable();
        pmap_acquire_page_lock(md);
        struct pv_entry **pvp = &SLIST_FIRST(&md->pvh_list);
        if (*pvp == NULL) {
#ifdef PMAP_CACHE_VIPT
                /*
                 * We *know* the page contents are about to be replaced.
                 * Discard the exec contents
                 */
                if (PV_IS_EXEC_P(md->pvh_attrs))
                        PMAPCOUNT(exec_discarded_page_protect);
                md->pvh_attrs &= ~PVF_EXEC;
                PMAP_VALIDATE_MD_PAGE(md);
#endif
                pmap_release_page_lock(md);
                kpreempt_enable();

                return;
        }
#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
        KASSERT(arm_cache_prefer_mask == 0 || pmap_is_page_colored_p(md));
#endif

        /*
         * Clear alias counts
         */
#ifdef PMAP_CACHE_VIVT
        md->k_mappings = 0;
#endif
        md->urw_mappings = md->uro_mappings = 0;

#ifdef PMAP_CACHE_VIVT
        pmap_clean_page(md, false);
#endif

        for (pv = *pvp; pv != NULL;) {
                pmap_t pm = pv->pv_pmap;
#ifndef ARM_MMU_EXTENDED
                if (flush == false && pmap_is_current(pm))
                        flush = true;
#endif

#ifdef PMAP_CACHE_VIPT
                if (pm == pmap_kernel() && PV_IS_KENTRY_P(pv->pv_flags)) {
                        /* If this was unmanaged mapping, it must be ignored. */
                        pvp = &SLIST_NEXT(pv, pv_link);
                        pv = *pvp;
                        continue;
                }
#endif

                /*
                 * Try to get a hold on the pmap's lock.  We must do this
                 * while still holding the page locked, to know that the
                 * page is still associated with the pmap and the mapping is
                 * in place.  If a hold can't be had, unlock and wait for
                 * the pmap's lock to become available and retry.  The pmap
                 * must be ref'd over this dance to stop it disappearing
                 * behind us.
                 */
                if (!mutex_tryenter(&pm->pm_lock)) {
                        pmap_reference(pm);
                        pmap_release_page_lock(md);
                        pmap_acquire_pmap_lock(pm);
                        /* nothing, just wait for it */
                        pmap_release_pmap_lock(pm);
                        pmap_destroy(pm);
                        /* Restart from the beginning. */
                        pmap_acquire_page_lock(md);
                        pvp = &SLIST_FIRST(&md->pvh_list);
                        pv = *pvp;
                        continue;
                }

                if (pm == pmap_kernel()) {
#ifdef PMAP_CACHE_VIPT
                        if (pv->pv_flags & PVF_WRITE)
                                md->krw_mappings--;
                        else
                                md->kro_mappings--;
#endif
                        PMAPCOUNT(kernel_unmappings);
                }
                *pvp = SLIST_NEXT(pv, pv_link); /* remove from list */
                PMAPCOUNT(unmappings);

                pmap_release_page_lock(md);

                l2b = pmap_get_l2_bucket(pm, pv->pv_va);
                KASSERTMSG(l2b != NULL, "%#lx", pv->pv_va);

                ptep = &l2b->l2b_kva[l2pte_index(pv->pv_va)];

                /*
                 * Update statistics
                 */
                --pm->pm_stats.resident_count;

                /* Wired bit */
                if (pv->pv_flags & PVF_WIRED)
                        --pm->pm_stats.wired_count;

                flags |= pv->pv_flags;

                /*
                 * Invalidate the PTEs.
                 */
                l2pte_reset(ptep);
                PTE_SYNC_CURRENT(pm, ptep);

#ifdef ARM_MMU_EXTENDED
                pmap_tlb_invalidate_addr(pm, pv->pv_va);
#endif

                pmap_free_l2_bucket(pm, l2b, PAGE_SIZE / L2_S_SIZE);

                pmap_release_pmap_lock(pm);

                pool_put(&pmap_pv_pool, pv);
                pmap_acquire_page_lock(md);

                /*
                 * Restart at the beginning of the list.
                 */
                pvp = &SLIST_FIRST(&md->pvh_list);
                pv = *pvp;
        }
        /*
         * if we reach the end of the list and there are still mappings, they
         * might be able to be cached now.  And they must be kernel mappings.
         */
        if (!SLIST_EMPTY(&md->pvh_list)) {
                pmap_vac_me_harder(md, pa, pmap_kernel(), 0);
        }

#ifdef PMAP_CACHE_VIPT
        /*
         * Its EXEC cache is now gone.
         */
        if (PV_IS_EXEC_P(md->pvh_attrs))
                PMAPCOUNT(exec_discarded_page_protect);
        md->pvh_attrs &= ~PVF_EXEC;
        KASSERT(md->urw_mappings == 0);
        KASSERT(md->uro_mappings == 0);
#ifndef ARM_MMU_EXTENDED
        if (arm_cache_prefer_mask != 0) {
                if (md->krw_mappings == 0)
                        md->pvh_attrs &= ~PVF_WRITE;
                PMAP_VALIDATE_MD_PAGE(md);
        }
#endif /* ARM_MMU_EXTENDED */
#endif /* PMAP_CACHE_VIPT */
        pmap_release_page_lock(md);

#ifndef ARM_MMU_EXTENDED
        if (flush) {
                /*
                 * Note: We can't use pmap_tlb_flush{I,D}() here since that
                 * would need a subsequent call to pmap_update() to ensure
                 * curpm->pm_cstate.cs_all is reset. Our callers are not
                 * required to do that (see pmap(9)), so we can't modify
                 * the current pmap's state.
                 */
                if (PV_BEEN_EXECD(flags))
                        cpu_tlb_flushID();
                else
                        cpu_tlb_flushD();
        }
        cpu_cpwait();
#endif /* ARM_MMU_EXTENDED */

        kpreempt_enable();
}

/*
 * pmap_t pmap_create(void)
 *
 *      Create a new pmap structure from scratch.
 */
pmap_t
pmap_create(void)
{
        pmap_t pm;

        pm = pool_cache_get(&pmap_cache, PR_WAITOK);

        mutex_init(&pm->pm_lock, MUTEX_DEFAULT, IPL_NONE);

        pm->pm_refs = 1;
        pm->pm_stats.wired_count = 0;
        pm->pm_stats.resident_count = 1;
#ifdef ARM_MMU_EXTENDED
#ifdef MULTIPROCESSOR
        kcpuset_create(&pm->pm_active, true);
        kcpuset_create(&pm->pm_onproc, true);
#endif
#else
        pm->pm_cstate.cs_all = 0;
#endif
        pmap_alloc_l1(pm);

        /*
         * Note: The pool cache ensures that the pm_l2[] array is already
         * initialised to zero.
         */

        pmap_pinit(pm);

        return pm;
}

u_int
arm32_mmap_flags(paddr_t pa)
{
        /*
         * the upper 8 bits in pmap_enter()'s flags are reserved for MD stuff
         * and we're using the upper bits in page numbers to pass flags around
         * so we might as well use the same bits
         */
        return (u_int)pa & PMAP_MD_MASK;
}
/*
 * int pmap_enter(pmap_t pm, vaddr_t va, paddr_t pa, vm_prot_t prot,
 *      u_int flags)
 *
 *      Insert the given physical page (p) at
 *      the specified virtual address (v) in the
 *      target physical map with the protection requested.
 *
 *      NB:  This is the only routine which MAY NOT lazy-evaluate
 *      or lose information.  That is, this routine must actually
 *      insert this page into the given map NOW.
 */
int
pmap_enter(pmap_t pm, vaddr_t va, paddr_t pa, vm_prot_t prot, u_int flags)
{
        struct l2_bucket *l2b;
        struct vm_page *pg, *opg;
        u_int nflags;
        u_int oflags;
        const bool kpm_p = pm == pmap_kernel();
#if defined(EFI_RUNTIME)
        const bool efirt_p = pm == pmap_efirt();
#else
        const bool efirt_p = false;
#endif
#ifdef ARM_HAS_VBAR
        const bool vector_page_p = false;
#else
        const bool vector_page_p = (va == vector_page);
#endif
        struct pmap_page *pp = pmap_pv_tracked(pa);
        struct pv_entry *new_pv = NULL;
        struct pv_entry *old_pv = NULL;
        int error = 0;

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "pm %#jx va %#jx pa %#jx prot %#jx",
            (uintptr_t)pm, va, pa, prot);
        UVMHIST_LOG(maphist, "  flag %#jx", flags, 0, 0, 0);

        KDASSERT((flags & PMAP_WIRED) == 0 || (flags & VM_PROT_ALL) != 0);
        KDASSERT(((va | pa) & PGOFSET) == 0);

        /*
         * Get a pointer to the page.  Later on in this function, we
         * test for a managed page by checking pg != NULL.
         */
        pg = pmap_initialized ? PHYS_TO_VM_PAGE(pa) : NULL;
        /*
         * if we may need a new pv entry allocate if now, as we can't do it
         * with the kernel_pmap locked
         */
        if (pg || pp)
                new_pv = pool_get(&pmap_pv_pool, PR_NOWAIT);

        nflags = 0;
        if (prot & VM_PROT_WRITE)
                nflags |= PVF_WRITE;
        if (prot & VM_PROT_EXECUTE)
                nflags |= PVF_EXEC;
        if (flags & PMAP_WIRED)
                nflags |= PVF_WIRED;

        kpreempt_disable();
        pmap_acquire_pmap_lock(pm);

        /*
         * Fetch the L2 bucket which maps this page, allocating one if
         * necessary for user pmaps.
         */
        if (kpm_p) {
                l2b = pmap_get_l2_bucket(pm, va);
        } else {
                l2b = pmap_alloc_l2_bucket(pm, va);
        }
        if (l2b == NULL) {
                if (flags & PMAP_CANFAIL) {
                        pmap_release_pmap_lock(pm);
                        kpreempt_enable();

                        error = ENOMEM;
                        goto free_pv;
                }
                panic("pmap_enter: failed to allocate L2 bucket");
        }
        pt_entry_t *ptep = &l2b->l2b_kva[l2pte_index(va)];
        const pt_entry_t opte = *ptep;
        pt_entry_t npte = pa;
        oflags = 0;

        if (opte) {
                /*
                 * There is already a mapping at this address.
                 * If the physical address is different, lookup the
                 * vm_page.
                 */
                if (l2pte_pa(opte) != pa) {
                        KASSERT(!pmap_pv_tracked(pa));
                        opg = PHYS_TO_VM_PAGE(l2pte_pa(opte));
                } else
                        opg = pg;
        } else
                opg = NULL;

        if (pg || pp) {
                KASSERT((pg != NULL) != (pp != NULL));
                struct vm_page_md *md = (pg != NULL) ? VM_PAGE_TO_MD(pg) :
                    PMAP_PAGE_TO_MD(pp);

                UVMHIST_LOG(maphist, "  pg %#jx pp %#jx pvh_attrs %#jx "
                    "nflags %#jx", (uintptr_t)pg, (uintptr_t)pp,
                    md->pvh_attrs, nflags);

                /*
                 * This is to be a managed mapping.
                 */
                pmap_acquire_page_lock(md);
                if ((flags & VM_PROT_ALL) || (md->pvh_attrs & PVF_REF)) {
                        /*
                         * - The access type indicates that we don't need
                         *   to do referenced emulation.
                         * OR
                         * - The physical page has already been referenced
                         *   so no need to re-do referenced emulation here.
                         */
                        npte |= l2pte_set_readonly(L2_S_PROTO);

                        nflags |= PVF_REF;

                        if ((prot & VM_PROT_WRITE) != 0 &&
                            ((flags & VM_PROT_WRITE) != 0 ||
                             (md->pvh_attrs & PVF_MOD) != 0)) {
                                /*
                                 * This is a writable mapping, and the
                                 * page's mod state indicates it has
                                 * already been modified. Make it
                                 * writable from the outset.
                                 */
                                npte = l2pte_set_writable(npte);
                                nflags |= PVF_MOD;
                        }

#ifdef ARM_MMU_EXTENDED
                        /*
                         * If the page has been cleaned, then the pvh_attrs
                         * will have PVF_EXEC set, so mark it execute so we
                         * don't get an access fault when trying to execute
                         * from it.
                         */
                        if (md->pvh_attrs & nflags & PVF_EXEC) {
                                npte &= ~L2_XS_XN;
                        }
#endif
                } else {
                        /*
                         * Need to do page referenced emulation.
                         */
                        npte |= L2_TYPE_INV;
                }

                if (flags & ARM32_MMAP_WRITECOMBINE) {
                        npte |= pte_l2_s_wc_mode;
                } else
                        npte |= pte_l2_s_cache_mode;

                if (pg != NULL && pg == opg) {
                        /*
                         * We're changing the attrs of an existing mapping.
                         */
                        oflags = pmap_modify_pv(md, pa, pm, va,
                            PVF_WRITE | PVF_EXEC | PVF_WIRED |
                            PVF_MOD | PVF_REF, nflags);

#ifdef PMAP_CACHE_VIVT
                        /*
                         * We may need to flush the cache if we're
                         * doing rw-ro...
                         */
                        if (pm->pm_cstate.cs_cache_d &&
                            (oflags & PVF_NC) == 0 &&
                            l2pte_writable_p(opte) &&
                            (prot & VM_PROT_WRITE) == 0)
                                cpu_dcache_wb_range(va, PAGE_SIZE);
#endif
                } else {
                        struct pv_entry *pv;
                        /*
                         * New mapping, or changing the backing page
                         * of an existing mapping.
                         */
                        if (opg) {
                                struct vm_page_md *omd = VM_PAGE_TO_MD(opg);
                                paddr_t opa = VM_PAGE_TO_PHYS(opg);

                                /*
                                 * Replacing an existing mapping with a new one.
                                 * It is part of our managed memory so we
                                 * must remove it from the PV list
                                 */
                                pv = pmap_remove_pv(omd, opa, pm, va);
                                pmap_vac_me_harder(omd, opa, pm, 0);
                                oflags = pv->pv_flags;

#ifdef PMAP_CACHE_VIVT
                                /*
                                 * If the old mapping was valid (ref/mod
                                 * emulation creates 'invalid' mappings
                                 * initially) then make sure to frob
                                 * the cache.
                                 */
                                if (!(oflags & PVF_NC) && l2pte_valid_p(opte)) {
                                        pmap_cache_wbinv_page(pm, va, true,
                                            oflags);
                                }
#endif
                        } else {
                                pv = new_pv;
                                new_pv = NULL;
                                if (pv == NULL) {
                                        pmap_release_page_lock(md);
                                        pmap_release_pmap_lock(pm);
                                        if ((flags & PMAP_CANFAIL) == 0)
                                                panic("pmap_enter: "
                                                    "no pv entries");

                                        pmap_free_l2_bucket(pm, l2b, 0);
                                        UVMHIST_LOG(maphist, "  <-- done (ENOMEM)",
                                            0, 0, 0, 0);
                                        kpreempt_enable();

                                        return ENOMEM;
                                }
                        }

                        pmap_enter_pv(md, pa, pv, pm, va, nflags);
                }
                pmap_release_page_lock(md);
        } else {
                /*
                 * We're mapping an unmanaged page.
                 * These are always readable, and possibly writable, from
                 * the get go as we don't need to track ref/mod status.
                 */
                npte |= l2pte_set_readonly(L2_S_PROTO);
                if (prot & VM_PROT_WRITE)
                        npte = l2pte_set_writable(npte);

                if (efirt_p) {
                        if (prot & VM_PROT_EXECUTE) {
                                npte &= ~L2_XS_XN;      /* and executable */
                        }
                }

                /*
                 * Make sure the vector table is mapped cacheable
                 */
                if ((vector_page_p && !kpm_p)
                    || (flags & ARM32_MMAP_CACHEABLE)) {
                        npte |= pte_l2_s_cache_mode;
#ifdef ARM_MMU_EXTENDED
                        npte &= ~L2_XS_XN;      /* and executable */
#endif
                } else if (flags & ARM32_MMAP_WRITECOMBINE) {
                        npte |= pte_l2_s_wc_mode;
                }
                if (opg) {
                        /*
                         * Looks like there's an existing 'managed' mapping
                         * at this address.
                         */
                        struct vm_page_md *omd = VM_PAGE_TO_MD(opg);
                        paddr_t opa = VM_PAGE_TO_PHYS(opg);

                        pmap_acquire_page_lock(omd);
                        old_pv = pmap_remove_pv(omd, opa, pm, va);
                        pmap_vac_me_harder(omd, opa, pm, 0);
                        oflags = old_pv->pv_flags;
                        pmap_release_page_lock(omd);

#ifdef PMAP_CACHE_VIVT
                        if (!(oflags & PVF_NC) && l2pte_valid_p(opte)) {
                                pmap_cache_wbinv_page(pm, va, true, oflags);
                        }
#endif
                }
        }

        /*
         * Make sure userland mappings get the right permissions
         */
        if (!vector_page_p && !kpm_p) {
                npte |= L2_S_PROT_U;
#ifdef ARM_MMU_EXTENDED
                npte |= L2_XS_nG;       /* user pages are not global */
#endif
        }

        /*
         * Keep the stats up to date
         */
        if (opte == 0) {
                l2b->l2b_occupancy += PAGE_SIZE / L2_S_SIZE;
                pm->pm_stats.resident_count++;
        }

        UVMHIST_LOG(maphist, " opte %#jx npte %#jx", opte, npte, 0, 0);

#if defined(ARM_MMU_EXTENDED)
        /*
         * If exec protection was requested but the page hasn't been synced,
         * sync it now and allow execution from it.
         */

        if ((nflags & PVF_EXEC) && (npte & L2_XS_XN)) {
                struct vm_page_md *md = VM_PAGE_TO_MD(pg);
                npte &= ~L2_XS_XN;
                pmap_syncicache_page(md, pa);
                PMAPCOUNT(exec_synced_map);
        }
#endif
        /*
         * If this is just a wiring change, the two PTEs will be
         * identical, so there's no need to update the page table.
         */
        if (npte != opte) {
                l2pte_reset(ptep);
                PTE_SYNC(ptep);
                if (l2pte_valid_p(opte)) {
                        pmap_tlb_flush_SE(pm, va, oflags);
                }
                l2pte_set(ptep, npte, 0);
                PTE_SYNC(ptep);
#ifndef ARM_MMU_EXTENDED
                bool is_cached = pmap_is_cached(pm);
                if (is_cached) {
                        /*
                         * We only need to frob the cache/tlb if this pmap
                         * is current
                         */
                        if (!vector_page_p && l2pte_valid_p(npte)) {
                                /*
                                 * This mapping is likely to be accessed as
                                 * soon as we return to userland. Fix up the
                                 * L1 entry to avoid taking another
                                 * page/domain fault.
                                 */
                                pd_entry_t *pdep = pmap_l1_kva(pm)
                                     + l1pte_index(va);
                                pd_entry_t pde = L1_C_PROTO | l2b->l2b_pa
                                    | L1_C_DOM(pmap_domain(pm));
                                if (*pdep != pde) {
                                        l1pte_setone(pdep, pde);
                                        PDE_SYNC(pdep);
                                }
                        }
                }

                UVMHIST_LOG(maphist, "  is_cached %jd cs 0x%08jx",
                    is_cached, pm->pm_cstate.cs_all, 0, 0);

                if (pg != NULL) {
                        struct vm_page_md *md = VM_PAGE_TO_MD(pg);

                        pmap_acquire_page_lock(md);
                        pmap_vac_me_harder(md, pa, pm, va);
                        pmap_release_page_lock(md);
                }
#endif
        }
#if defined(PMAP_CACHE_VIPT) && defined(DIAGNOSTIC)
        if (pg) {
                struct vm_page_md *md = VM_PAGE_TO_MD(pg);

                pmap_acquire_page_lock(md);
#ifndef ARM_MMU_EXTENDED
                KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
#endif
                PMAP_VALIDATE_MD_PAGE(md);
                pmap_release_page_lock(md);
        }
#endif

        pmap_release_pmap_lock(pm);
        kpreempt_enable();

        if (old_pv)
                pool_put(&pmap_pv_pool, old_pv);
free_pv:
        if (new_pv)
                pool_put(&pmap_pv_pool, new_pv);

        return error;
}

/*
 * pmap_remove()
 *
 * pmap_remove is responsible for nuking a number of mappings for a range
 * of virtual address space in the current pmap. To do this efficiently
 * is interesting, because in a number of cases a wide virtual address
 * range may be supplied that contains few actual mappings. So, the
 * optimisations are:
 *  1. Skip over hunks of address space for which no L1 or L2 entry exists.
 *  2. Build up a list of pages we've hit, up to a maximum, so we can
 *     maybe do just a partial cache clean. This path of execution is
 *     complicated by the fact that the cache must be flushed _before_
 *     the PTE is nuked, being a VAC :-)
 *  3. If we're called after UVM calls pmap_remove_all(), we can defer
 *     all invalidations until pmap_update(), since pmap_remove_all() has
 *     already flushed the cache.
 *  4. Maybe later fast-case a single page, but I don't think this is
 *     going to make _that_ much difference overall.
 */

#define PMAP_REMOVE_CLEAN_LIST_SIZE     3

void
pmap_remove(pmap_t pm, vaddr_t sva, vaddr_t eva)
{
        SLIST_HEAD(,pv_entry) opv_list;
        struct pv_entry *pv, *npv;
        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, " (pm=%#jx, sva=%#jx, eva=%#jx)",
            (uintptr_t)pm, sva, eva, 0);

#ifdef PMAP_FAULTINFO
        curpcb->pcb_faultinfo.pfi_faultaddr = 0;
        curpcb->pcb_faultinfo.pfi_repeats = 0;
        curpcb->pcb_faultinfo.pfi_faultptep = NULL;
#endif

        SLIST_INIT(&opv_list);
        /*
         * we lock in the pmap => pv_head direction
         */
        kpreempt_disable();
        pmap_acquire_pmap_lock(pm);

#ifndef ARM_MMU_EXTENDED
        u_int cleanlist_idx, total, cnt;
        struct {
                vaddr_t va;
                pt_entry_t *ptep;
        } cleanlist[PMAP_REMOVE_CLEAN_LIST_SIZE];

        if (pm->pm_remove_all || !pmap_is_cached(pm)) {
                cleanlist_idx = PMAP_REMOVE_CLEAN_LIST_SIZE + 1;
                if (pm->pm_cstate.cs_tlb == 0)
                        pm->pm_remove_all = true;
        } else
                cleanlist_idx = 0;
        total = 0;
#endif

        while (sva < eva) {
                /*
                 * Do one L2 bucket's worth at a time.
                 */
                vaddr_t next_bucket = L2_NEXT_BUCKET_VA(sva);
                if (next_bucket > eva)
                        next_bucket = eva;

                struct l2_bucket * const l2b = pmap_get_l2_bucket(pm, sva);
                if (l2b == NULL) {
                        sva = next_bucket;
                        continue;
                }

                pt_entry_t *ptep = &l2b->l2b_kva[l2pte_index(sva)];
                u_int mappings = 0;

                for (;sva < next_bucket;
                     sva += PAGE_SIZE, ptep += PAGE_SIZE / L2_S_SIZE) {
                        pt_entry_t opte = *ptep;

                        if (opte == 0) {
                                /* Nothing here, move along */
                                continue;
                        }

                        u_int flags = PVF_REF;
                        paddr_t pa = l2pte_pa(opte);
                        struct vm_page * const pg = PHYS_TO_VM_PAGE(pa);

                        /*
                         * Update flags. In a number of circumstances,
                         * we could cluster a lot of these and do a
                         * number of sequential pages in one go.
                         */
                        if (pg != NULL) {
                                struct vm_page_md *md = VM_PAGE_TO_MD(pg);

                                pmap_acquire_page_lock(md);
                                pv = pmap_remove_pv(md, pa, pm, sva);
                                pmap_vac_me_harder(md, pa, pm, 0);
                                pmap_release_page_lock(md);
                                if (pv != NULL) {
                                        if (pm->pm_remove_all == false) {
                                                flags = pv->pv_flags;
                                        }
                                        SLIST_INSERT_HEAD(&opv_list,
                                            pv, pv_link);
                                }
                        }
                        mappings += PAGE_SIZE / L2_S_SIZE;

                        if (!l2pte_valid_p(opte)) {
                                /*
                                 * Ref/Mod emulation is still active for this
                                 * mapping, therefore it is has not yet been
                                 * accessed. No need to frob the cache/tlb.
                                 */
                                l2pte_reset(ptep);
                                PTE_SYNC_CURRENT(pm, ptep);
                                continue;
                        }

#ifdef ARM_MMU_EXTENDED
                        l2pte_reset(ptep);
                        PTE_SYNC(ptep);
                        if (__predict_false(pm->pm_remove_all == false)) {
                                pmap_tlb_flush_SE(pm, sva, flags);
                        }
#else
                        if (cleanlist_idx < PMAP_REMOVE_CLEAN_LIST_SIZE) {
                                /* Add to the clean list. */
                                cleanlist[cleanlist_idx].ptep = ptep;
                                cleanlist[cleanlist_idx].va =
                                    sva | (flags & PVF_EXEC);
                                cleanlist_idx++;
                        } else if (cleanlist_idx == PMAP_REMOVE_CLEAN_LIST_SIZE) {
                                /* Nuke everything if needed. */
#ifdef PMAP_CACHE_VIVT
                                pmap_cache_wbinv_all(pm, PVF_EXEC);
#endif
                                /*
                                 * Roll back the previous PTE list,
                                 * and zero out the current PTE.
                                 */
                                for (cnt = 0;
                                     cnt < PMAP_REMOVE_CLEAN_LIST_SIZE; cnt++) {
                                        l2pte_reset(cleanlist[cnt].ptep);
                                        PTE_SYNC(cleanlist[cnt].ptep);
                                }
                                l2pte_reset(ptep);
                                PTE_SYNC(ptep);
                                cleanlist_idx++;
                                pm->pm_remove_all = true;
                        } else {
                                l2pte_reset(ptep);
                                PTE_SYNC(ptep);
                                if (pm->pm_remove_all == false) {
                                        pmap_tlb_flush_SE(pm, sva, flags);
                                }
                        }
#endif
                }

#ifndef ARM_MMU_EXTENDED
                /*
                 * Deal with any left overs
                 */
                if (cleanlist_idx <= PMAP_REMOVE_CLEAN_LIST_SIZE) {
                        total += cleanlist_idx;
                        for (cnt = 0; cnt < cleanlist_idx; cnt++) {
                                l2pte_reset(cleanlist[cnt].ptep);
                                PTE_SYNC_CURRENT(pm, cleanlist[cnt].ptep);
                                vaddr_t va = cleanlist[cnt].va;
                                if (pm->pm_cstate.cs_all != 0) {
                                        vaddr_t clva = va & ~PAGE_MASK;
                                        u_int flags = va & PVF_EXEC;
#ifdef PMAP_CACHE_VIVT
                                        pmap_cache_wbinv_page(pm, clva, true,
                                            PVF_REF | PVF_WRITE | flags);
#endif
                                        pmap_tlb_flush_SE(pm, clva,
                                            PVF_REF | flags);
                                }
                        }

                        /*
                         * If it looks like we're removing a whole bunch
                         * of mappings, it's faster to just write-back
                         * the whole cache now and defer TLB flushes until
                         * pmap_update() is called.
                         */
                        if (total <= PMAP_REMOVE_CLEAN_LIST_SIZE)
                                cleanlist_idx = 0;
                        else {
                                cleanlist_idx = PMAP_REMOVE_CLEAN_LIST_SIZE + 1;
#ifdef PMAP_CACHE_VIVT
                                pmap_cache_wbinv_all(pm, PVF_EXEC);
#endif
                                pm->pm_remove_all = true;
                        }
                }
#endif /* ARM_MMU_EXTENDED */

                pmap_free_l2_bucket(pm, l2b, mappings);
                pm->pm_stats.resident_count -= mappings / (PAGE_SIZE/L2_S_SIZE);
        }

        pmap_release_pmap_lock(pm);
        kpreempt_enable();

        SLIST_FOREACH_SAFE(pv, &opv_list, pv_link, npv) {
                pool_put(&pmap_pv_pool, pv);
        }
}

#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
static struct pv_entry *
pmap_kremove_pg(struct vm_page *pg, vaddr_t va)
{
        struct vm_page_md *md = VM_PAGE_TO_MD(pg);
        paddr_t pa = VM_PAGE_TO_PHYS(pg);
        struct pv_entry *pv;

        KASSERT(arm_cache_prefer_mask == 0 || md->pvh_attrs & (PVF_COLORED|PVF_NC));
        KASSERT((md->pvh_attrs & PVF_KMPAGE) == 0);
        KASSERT(pmap_page_locked_p(md));

        pv = pmap_remove_pv(md, pa, pmap_kernel(), va);
        KASSERTMSG(pv, "pg %p (pa #%lx) va %#lx", pg, pa, va);
        KASSERT(PV_IS_KENTRY_P(pv->pv_flags));

        /*
         * We are removing a writeable mapping to a cached exec page, if
         * it's the last mapping then clear its execness otherwise sync
         * the page to the icache.
         */
        if ((md->pvh_attrs & (PVF_NC|PVF_EXEC)) == PVF_EXEC
            && (pv->pv_flags & PVF_WRITE) != 0) {
                if (SLIST_EMPTY(&md->pvh_list)) {
                        md->pvh_attrs &= ~PVF_EXEC;
                        PMAPCOUNT(exec_discarded_kremove);
                } else {
                        pmap_syncicache_page(md, pa);
                        PMAPCOUNT(exec_synced_kremove);
                }
        }
        pmap_vac_me_harder(md, pa, pmap_kernel(), 0);

        return pv;
}
#endif /* PMAP_CACHE_VIPT && !ARM_MMU_EXTENDED */

/*
 * pmap_kenter_pa: enter an unmanaged, wired kernel mapping
 *
 * We assume there is already sufficient KVM space available
 * to do this, as we can't allocate L2 descriptor tables/metadata
 * from here.
 */
void
pmap_kenter_pa(vaddr_t va, paddr_t pa, vm_prot_t prot, u_int flags)
{
#ifdef PMAP_CACHE_VIVT
        struct vm_page *pg = (flags & PMAP_KMPAGE) ? PHYS_TO_VM_PAGE(pa) : NULL;
#endif
#ifdef PMAP_CACHE_VIPT
        struct vm_page *pg = PHYS_TO_VM_PAGE(pa);
        struct vm_page *opg;
#ifndef ARM_MMU_EXTENDED
        struct pv_entry *pv = NULL;
#endif
#endif
        struct vm_page_md *md = pg != NULL ? VM_PAGE_TO_MD(pg) : NULL;

        UVMHIST_FUNC(__func__);

        if (pmap_initialized) {
                UVMHIST_CALLARGS(maphist,
                    "va=%#jx, pa=%#jx, prot=%#jx, flags=%#jx", va, pa, prot,
                     flags);
        }

        kpreempt_disable();
        pmap_t kpm = pmap_kernel();
        pmap_acquire_pmap_lock(kpm);
        struct l2_bucket * const l2b = pmap_get_l2_bucket(kpm, va);
        const size_t l1slot __diagused = l1pte_index(va);
        KASSERTMSG(l2b != NULL,
            "va %#lx pa %#lx prot %d maxkvaddr %#lx: l2 %p l2b %p kva %p",
            va, pa, prot, pmap_curmaxkvaddr, kpm->pm_l2[L2_IDX(l1slot)],
            kpm->pm_l2[L2_IDX(l1slot)]
                ? &kpm->pm_l2[L2_IDX(l1slot)]->l2_bucket[L2_BUCKET(l1slot)]
                : NULL,
            kpm->pm_l2[L2_IDX(l1slot)]
                ? kpm->pm_l2[L2_IDX(l1slot)]->l2_bucket[L2_BUCKET(l1slot)].l2b_kva
                : NULL);
        KASSERT(l2b->l2b_kva != NULL);

        pt_entry_t * const ptep = &l2b->l2b_kva[l2pte_index(va)];
        const pt_entry_t opte = *ptep;

        if (opte == 0) {
                PMAPCOUNT(kenter_mappings);
                l2b->l2b_occupancy += PAGE_SIZE / L2_S_SIZE;
        } else {
                PMAPCOUNT(kenter_remappings);
#ifdef PMAP_CACHE_VIPT
                opg = PHYS_TO_VM_PAGE(l2pte_pa(opte));
                struct vm_page_md *omd = VM_PAGE_TO_MD(opg);
                if (opg && arm_cache_prefer_mask != 0) {
                        KASSERT(opg != pg);
                        KASSERT((omd->pvh_attrs & PVF_KMPAGE) == 0);
                        KASSERT((flags & PMAP_KMPAGE) == 0);
#ifndef ARM_MMU_EXTENDED
                        pmap_acquire_page_lock(omd);
                        pv = pmap_kremove_pg(opg, va);
                        pmap_release_page_lock(omd);
#endif
                }
#endif
                if (l2pte_valid_p(opte)) {
                        l2pte_reset(ptep);
                        PTE_SYNC(ptep);
#ifdef PMAP_CACHE_VIVT
                        cpu_dcache_wbinv_range(va, PAGE_SIZE);
#endif
                        cpu_tlb_flushD_SE(va);
                        cpu_cpwait();
                }
        }
        pmap_release_pmap_lock(kpm);
        pt_entry_t npte = L2_S_PROTO | pa | L2_S_PROT(PTE_KERNEL, prot);

        if (flags & PMAP_PTE) {
                KASSERT((flags & PMAP_CACHE_MASK) == 0);
                if (!(flags & PMAP_NOCACHE))
                        npte |= pte_l2_s_cache_mode_pt;
        } else {
                switch (flags & (PMAP_CACHE_MASK | PMAP_DEV_MASK)) {
                case PMAP_DEV ... PMAP_DEV | PMAP_CACHE_MASK:
                        break;
                case PMAP_NOCACHE:
                        npte |= pte_l2_s_nocache_mode;
                        break;
                case PMAP_WRITE_COMBINE:
                        npte |= pte_l2_s_wc_mode;
                        break;
                default:
                        npte |= pte_l2_s_cache_mode;
                        break;
                }
        }
#ifdef ARM_MMU_EXTENDED
        if (prot & VM_PROT_EXECUTE)
                npte &= ~L2_XS_XN;
#endif
        l2pte_set(ptep, npte, 0);
        PTE_SYNC(ptep);

        if (pg) {
                if (flags & PMAP_KMPAGE) {
                        KASSERT(md->urw_mappings == 0);
                        KASSERT(md->uro_mappings == 0);
                        KASSERT(md->krw_mappings == 0);
                        KASSERT(md->kro_mappings == 0);
#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
                        KASSERT(pv == NULL);
                        KASSERT(arm_cache_prefer_mask == 0 || (va & PVF_COLORED) == 0);
                        KASSERT((md->pvh_attrs & PVF_NC) == 0);
                        /* if there is a color conflict, evict from cache. */
                        if (pmap_is_page_colored_p(md)
                            && ((va ^ md->pvh_attrs) & arm_cache_prefer_mask)) {
                                PMAPCOUNT(vac_color_change);
                                pmap_flush_page(md, pa, PMAP_FLUSH_PRIMARY);
                        } else if (md->pvh_attrs & PVF_MULTCLR) {
                                /*
                                 * If this page has multiple colors, expunge
                                 * them.
                                 */
                                PMAPCOUNT(vac_flush_lots2);
                                pmap_flush_page(md, pa, PMAP_FLUSH_SECONDARY);
                        }
                        /*
                         * Since this is a KMPAGE, there can be no contention
                         * for this page so don't lock it.
                         */
                        md->pvh_attrs &= PAGE_SIZE - 1;
                        md->pvh_attrs |= PVF_KMPAGE | PVF_COLORED | PVF_DIRTY
                            | (va & arm_cache_prefer_mask);
#else /* !PMAP_CACHE_VIPT || ARM_MMU_EXTENDED */
                        md->pvh_attrs |= PVF_KMPAGE;
#endif
                        atomic_inc_32(&pmap_kmpages);
#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
                } else if (arm_cache_prefer_mask != 0) {
                        if (pv == NULL) {
                                pv = pool_get(&pmap_pv_pool, PR_NOWAIT);
                                KASSERT(pv != NULL);
                        }
                        pmap_acquire_page_lock(md);
                        pmap_enter_pv(md, pa, pv, pmap_kernel(), va,
                            PVF_WIRED | PVF_KENTRY
                            | (prot & VM_PROT_WRITE ? PVF_WRITE : 0));
                        if ((prot & VM_PROT_WRITE)
                            && !(md->pvh_attrs & PVF_NC))
                                md->pvh_attrs |= PVF_DIRTY;
                        KASSERT((prot & VM_PROT_WRITE) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
                        pmap_vac_me_harder(md, pa, pmap_kernel(), va);
                        pmap_release_page_lock(md);
#endif
                }
#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
        } else {
                if (pv != NULL)
                        pool_put(&pmap_pv_pool, pv);
#endif
        }
        kpreempt_enable();

        if (pmap_initialized) {
                UVMHIST_LOG(maphist, "  <-- done (ptep %#jx: %#jx -> %#jx)",
                    (uintptr_t)ptep, opte, npte, 0);
        }

}

void
pmap_kremove(vaddr_t va, vsize_t len)
{
#ifdef UVMHIST
        u_int total_mappings = 0;
#endif

        PMAPCOUNT(kenter_unmappings);

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, " (va=%#jx, len=%#jx)", va, len, 0, 0);

        const vaddr_t eva = va + len;
        pmap_t kpm = pmap_kernel();

        kpreempt_disable();
        pmap_acquire_pmap_lock(kpm);

        while (va < eva) {
                vaddr_t next_bucket = L2_NEXT_BUCKET_VA(va);
                if (next_bucket > eva)
                        next_bucket = eva;

                struct l2_bucket * const l2b = pmap_get_l2_bucket(kpm, va);
                KDASSERT(l2b != NULL);

                pt_entry_t * const sptep = &l2b->l2b_kva[l2pte_index(va)];
                pt_entry_t *ptep = sptep;
                u_int mappings = 0;

                while (va < next_bucket) {
                        const pt_entry_t opte = *ptep;
                        struct vm_page *opg = PHYS_TO_VM_PAGE(l2pte_pa(opte));
                        if (opg != NULL) {
                                struct vm_page_md *omd = VM_PAGE_TO_MD(opg);

                                if (omd->pvh_attrs & PVF_KMPAGE) {
                                        KASSERT(omd->urw_mappings == 0);
                                        KASSERT(omd->uro_mappings == 0);
                                        KASSERT(omd->krw_mappings == 0);
                                        KASSERT(omd->kro_mappings == 0);
                                        omd->pvh_attrs &= ~PVF_KMPAGE;
#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
                                        if (arm_cache_prefer_mask != 0) {
                                                omd->pvh_attrs &= ~PVF_WRITE;
                                        }
#endif
                                        atomic_dec_32(&pmap_kmpages);
#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
                                } else if (arm_cache_prefer_mask != 0) {
                                        pmap_acquire_page_lock(omd);
                                        pool_put(&pmap_pv_pool,
                                            pmap_kremove_pg(opg, va));
                                        pmap_release_page_lock(omd);
#endif
                                }
                        }
                        if (l2pte_valid_p(opte)) {
                                l2pte_reset(ptep);
                                PTE_SYNC(ptep);
#ifdef PMAP_CACHE_VIVT
                                cpu_dcache_wbinv_range(va, PAGE_SIZE);
#endif
                                cpu_tlb_flushD_SE(va);

                                mappings += PAGE_SIZE / L2_S_SIZE;
                        }
                        va += PAGE_SIZE;
                        ptep += PAGE_SIZE / L2_S_SIZE;
                }
                KDASSERTMSG(mappings <= l2b->l2b_occupancy, "%u %u",
                    mappings, l2b->l2b_occupancy);
                l2b->l2b_occupancy -= mappings;
                //PTE_SYNC_RANGE(sptep, (u_int)(ptep - sptep));
#ifdef UVMHIST
                total_mappings += mappings;
#endif
        }
        pmap_release_pmap_lock(kpm);
        cpu_cpwait();
        kpreempt_enable();

        UVMHIST_LOG(maphist, "  <--- done (%ju mappings removed)",
            total_mappings, 0, 0, 0);
}

bool
pmap_extract(pmap_t pm, vaddr_t va, paddr_t *pap)
{

        return pmap_extract_coherency(pm, va, pap, NULL);
}

bool
pmap_extract_coherency(pmap_t pm, vaddr_t va, paddr_t *pap, bool *coherentp)
{
        struct l2_dtable *l2;
        pd_entry_t *pdep, pde;
        pt_entry_t *ptep, pte;
        paddr_t pa;
        u_int l1slot;
        bool coherent;

        kpreempt_disable();
        pmap_acquire_pmap_lock(pm);

        l1slot = l1pte_index(va);
        pdep = pmap_l1_kva(pm) + l1slot;
        pde = *pdep;

        if (l1pte_section_p(pde)) {
                /*
                 * These should only happen for pmap_kernel()
                 */
                KDASSERT(pm == pmap_kernel());
                pmap_release_pmap_lock(pm);
                kpreempt_enable();

#if (ARM_MMU_V6 + ARM_MMU_V7) > 0
                if (l1pte_supersection_p(pde)) {
                        pa = (pde & L1_SS_FRAME) | (va & L1_SS_OFFSET);
                } else
#endif
                        pa = (pde & L1_S_FRAME) | (va & L1_S_OFFSET);
                coherent = (pde & L1_S_CACHE_MASK) == 0;
        } else {
                /*
                 * Note that we can't rely on the validity of the L1
                 * descriptor as an indication that a mapping exists.
                 * We have to look it up in the L2 dtable.
                 */
                l2 = pm->pm_l2[L2_IDX(l1slot)];

                if (l2 == NULL ||
                    (ptep = l2->l2_bucket[L2_BUCKET(l1slot)].l2b_kva) == NULL) {
                        pmap_release_pmap_lock(pm);
                        kpreempt_enable();

                        return false;
                }

                pte = ptep[l2pte_index(va)];
                pmap_release_pmap_lock(pm);
                kpreempt_enable();

                if (pte == 0)
                        return false;

                switch (pte & L2_TYPE_MASK) {
                case L2_TYPE_L:
                        pa = (pte & L2_L_FRAME) | (va & L2_L_OFFSET);
                        coherent = (pte & L2_L_CACHE_MASK) == 0;
                        break;

                default:
                        pa = (pte & ~PAGE_MASK) | (va & PAGE_MASK);
                        coherent = (pte & L2_S_CACHE_MASK) == 0;
                        break;
                }
        }

        if (pap != NULL)
                *pap = pa;

        if (coherentp != NULL)
                *coherentp = (pm == pmap_kernel() && coherent);

        return true;
}

/*
 * pmap_pv_remove: remove an unmanaged pv-tracked page from all pmaps
 *      that map it
 */

static void
pmap_pv_remove(paddr_t pa)
{
        struct pmap_page *pp;

        KASSERT(kpreempt_disabled());
        pp = pmap_pv_tracked(pa);
        if (pp == NULL)
                panic("pmap_pv_protect: page not pv-tracked: 0x%"PRIxPADDR,
                    pa);

        struct vm_page_md *md = PMAP_PAGE_TO_MD(pp);
        pmap_page_remove(md, pa);
}

void
pmap_pv_protect(paddr_t pa, vm_prot_t prot)
{

        /* the only case is remove at the moment */
        KASSERT(prot == VM_PROT_NONE);
        pmap_pv_remove(pa);
}

void
pmap_protect(pmap_t pm, vaddr_t sva, vaddr_t eva, vm_prot_t prot)
{
        struct l2_bucket *l2b;
        vaddr_t next_bucket;

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "pm %#jx va %#jx...#%jx prot %#jx",
            (uintptr_t)pm, sva, eva, prot);

        if ((prot & VM_PROT_READ) == 0) {
                pmap_remove(pm, sva, eva);
                return;
        }

        if (prot & VM_PROT_WRITE) {
                /*
                 * If this is a read->write transition, just ignore it and let
                 * uvm_fault() take care of it later.
                 */
                return;
        }

        kpreempt_disable();
        pmap_acquire_pmap_lock(pm);

#ifndef ARM_MMU_EXTENDED
        const bool flush = eva - sva >= PAGE_SIZE * 4;
        u_int flags = 0;
#endif
        u_int clr_mask = PVF_WRITE | ((prot & VM_PROT_EXECUTE) ? 0 : PVF_EXEC);

        while (sva < eva) {
                next_bucket = L2_NEXT_BUCKET_VA(sva);
                if (next_bucket > eva)
                        next_bucket = eva;

                l2b = pmap_get_l2_bucket(pm, sva);
                if (l2b == NULL) {
                        sva = next_bucket;
                        continue;
                }

                pt_entry_t *ptep = &l2b->l2b_kva[l2pte_index(sva)];

                while (sva < next_bucket) {
                        const pt_entry_t opte = *ptep;
                        if (l2pte_valid_p(opte) && l2pte_writable_p(opte)) {
                                struct vm_page *pg;
#ifndef ARM_MMU_EXTENDED
                                u_int f;
#endif

#ifdef PMAP_CACHE_VIVT
                                /*
                                 * OK, at this point, we know we're doing
                                 * write-protect operation.  If the pmap is
                                 * active, write-back the page.
                                 */
                                pmap_cache_wbinv_page(pm, sva, false,
                                    PVF_REF | PVF_WRITE);
#endif

                                pg = PHYS_TO_VM_PAGE(l2pte_pa(opte));
                                pt_entry_t npte = l2pte_set_readonly(opte);
                                l2pte_reset(ptep);
                                PTE_SYNC(ptep);
#ifdef ARM_MMU_EXTENDED
                                pmap_tlb_flush_SE(pm, sva, PVF_REF);
#endif
                                l2pte_set(ptep, npte, 0);
                                PTE_SYNC(ptep);

                                if (pg != NULL) {
                                        struct vm_page_md *md = VM_PAGE_TO_MD(pg);
                                        paddr_t pa = VM_PAGE_TO_PHYS(pg);

                                        pmap_acquire_page_lock(md);
#ifndef ARM_MMU_EXTENDED
                                        f =
#endif
                                            pmap_modify_pv(md, pa, pm, sva,
                                               clr_mask, 0);
                                        pmap_vac_me_harder(md, pa, pm, sva);
                                        pmap_release_page_lock(md);
#ifndef ARM_MMU_EXTENDED
                                } else {
                                        f = PVF_REF | PVF_EXEC;
                                }

                                if (flush) {
                                        flags |= f;
                                } else {
                                        pmap_tlb_flush_SE(pm, sva, f);
#endif
                                }
                        }

                        sva += PAGE_SIZE;
                        ptep += PAGE_SIZE / L2_S_SIZE;
                }
        }

#ifndef ARM_MMU_EXTENDED
        if (flush) {
                if (PV_BEEN_EXECD(flags)) {
                        pmap_tlb_flushID(pm);
                } else if (PV_BEEN_REFD(flags)) {
                        pmap_tlb_flushD(pm);
                }
        }
#endif

        pmap_release_pmap_lock(pm);
        kpreempt_enable();
}

void
pmap_icache_sync_range(pmap_t pm, vaddr_t sva, vaddr_t eva)
{
        struct l2_bucket *l2b;
        pt_entry_t *ptep;
        vaddr_t next_bucket;
        vsize_t page_size = trunc_page(sva) + PAGE_SIZE - sva;

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "pm %#jx va %#jx...#%jx",
            (uintptr_t)pm, sva, eva, 0);

        pmap_acquire_pmap_lock(pm);

        while (sva < eva) {
                next_bucket = L2_NEXT_BUCKET_VA(sva);
                if (next_bucket > eva)
                        next_bucket = eva;

                l2b = pmap_get_l2_bucket(pm, sva);
                if (l2b == NULL) {
                        sva = next_bucket;
                        continue;
                }

                for (ptep = &l2b->l2b_kva[l2pte_index(sva)];
                     sva < next_bucket;
                     sva += page_size,
                     ptep += PAGE_SIZE / L2_S_SIZE,
                     page_size = PAGE_SIZE) {
                        if (l2pte_valid_p(*ptep)) {
                                cpu_icache_sync_range(sva,
                                    uimin(page_size, eva - sva));
                        }
                }
        }

        pmap_release_pmap_lock(pm);
}

void
pmap_page_protect(struct vm_page *pg, vm_prot_t prot)
{
        struct vm_page_md *md = VM_PAGE_TO_MD(pg);
        paddr_t pa = VM_PAGE_TO_PHYS(pg);

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "md %#jx pa %#jx prot %#jx",
            (uintptr_t)md, pa, prot, 0);

        switch(prot) {
        case VM_PROT_READ|VM_PROT_WRITE:
#if defined(ARM_MMU_EXTENDED)
                pmap_acquire_page_lock(md);
                pmap_clearbit(md, pa, PVF_EXEC);
                pmap_release_page_lock(md);
                break;
#endif
        case VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE:
                break;

        case VM_PROT_READ:
#if defined(ARM_MMU_EXTENDED)
                pmap_acquire_page_lock(md);
                pmap_clearbit(md, pa, PVF_WRITE|PVF_EXEC);
                pmap_release_page_lock(md);
                break;
#endif
        case VM_PROT_READ|VM_PROT_EXECUTE:
                pmap_acquire_page_lock(md);
                pmap_clearbit(md, pa, PVF_WRITE);
                pmap_release_page_lock(md);
                break;

        default:
                pmap_page_remove(md, pa);
                break;
        }
}

/*
 * pmap_clear_modify:
 *
 *      Clear the "modified" attribute for a page.
 */
bool
pmap_clear_modify(struct vm_page *pg)
{
        struct vm_page_md *md = VM_PAGE_TO_MD(pg);
        paddr_t pa = VM_PAGE_TO_PHYS(pg);
        bool rv;

        pmap_acquire_page_lock(md);

        if (md->pvh_attrs & PVF_MOD) {
                rv = true;
#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
                /*
                 * If we are going to clear the modified bit and there are
                 * no other modified bits set, flush the page to memory and
                 * mark it clean.
                 */
                if ((md->pvh_attrs & (PVF_DMOD|PVF_NC)) == PVF_MOD)
                        pmap_flush_page(md, pa, PMAP_CLEAN_PRIMARY);
#endif
                pmap_clearbit(md, pa, PVF_MOD);
        } else {
                rv = false;
        }
        pmap_release_page_lock(md);

        return rv;
}

/*
 * pmap_clear_reference:
 *
 *      Clear the "referenced" attribute for a page.
 */
bool
pmap_clear_reference(struct vm_page *pg)
{
        struct vm_page_md *md = VM_PAGE_TO_MD(pg);
        paddr_t pa = VM_PAGE_TO_PHYS(pg);
        bool rv;

        pmap_acquire_page_lock(md);

        if (md->pvh_attrs & PVF_REF) {
                rv = true;
                pmap_clearbit(md, pa, PVF_REF);
        } else {
                rv = false;
        }
        pmap_release_page_lock(md);

        return rv;
}

/*
 * pmap_is_modified:
 *
 *      Test if a page has the "modified" attribute.
 */
/* See <arm/arm32/pmap.h> */

/*
 * pmap_is_referenced:
 *
 *      Test if a page has the "referenced" attribute.
 */
/* See <arm/arm32/pmap.h> */

#if defined(ARM_MMU_EXTENDED) && 0
int
pmap_prefetchabt_fixup(void *v)
{
        struct trapframe * const tf = v;
        vaddr_t va = trunc_page(tf->tf_pc);
        int rv = ABORT_FIXUP_FAILED;

        if (!TRAP_USERMODE(tf) && va < VM_MAXUSER_ADDRESS)
                return rv;

        kpreempt_disable();
        pmap_t pm = curcpu()->ci_pmap_cur;
        const size_t l1slot = l1pte_index(va);
        struct l2_dtable * const l2 = pm->pm_l2[L2_IDX(l1slot)];
        if (l2 == NULL)
                goto out;

        struct l2_bucket * const l2b = &l2->l2_bucket[L2_BUCKET(l1slot)];
        if (l2b->l2b_kva == NULL)
                goto out;

        /*
         * Check the PTE itself.
         */
        pt_entry_t * const ptep = &l2b->l2b_kva[l2pte_index(va)];
        const pt_entry_t opte = *ptep;
        if ((opte & L2_S_PROT_U) == 0 || (opte & L2_XS_XN) == 0)
                goto out;

        paddr_t pa = l2pte_pa(opte);
        struct vm_page * const pg = PHYS_TO_VM_PAGE(pa);
        KASSERT(pg != NULL);

        struct vm_page_md * const md = VM_PAGE_TO_MD(pg);

        pmap_acquire_page_lock(md);
        struct pv_entry * const pv = pmap_find_pv(md, pm, va);
        KASSERT(pv != NULL);

        if (PV_IS_EXEC_P(pv->pv_flags)) {
                l2pte_reset(ptep);
                PTE_SYNC(ptep);
                pmap_tlb_flush_SE(pm, va, PVF_EXEC | PVF_REF);
                if (!PV_IS_EXEC_P(md->pvh_attrs)) {
                        pmap_syncicache_page(md, pa);
                }
                rv = ABORT_FIXUP_RETURN;
                l2pte_set(ptep, opte & ~L2_XS_XN, 0);
                PTE_SYNC(ptep);
        }
        pmap_release_page_lock(md);

  out:
        kpreempt_enable();

        return rv;
}
#endif

int
pmap_fault_fixup(pmap_t pm, vaddr_t va, vm_prot_t ftype, int user)
{
        struct l2_dtable *l2;
        struct l2_bucket *l2b;
        paddr_t pa;
        const size_t l1slot = l1pte_index(va);
        int rv = 0;

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "pm=%#jx, va=%#jx, ftype=%#jx, user=%jd",
            (uintptr_t)pm, va, ftype, user);

        va = trunc_page(va);

        KASSERT(!user || (pm != pmap_kernel()));

#ifdef ARM_MMU_EXTENDED
        UVMHIST_LOG(maphist, " ti=%#jx pai=%#jx asid=%#jx",
            (uintptr_t)cpu_tlb_info(curcpu()),
            (uintptr_t)PMAP_PAI(pm, cpu_tlb_info(curcpu())),
            (uintptr_t)PMAP_PAI(pm, cpu_tlb_info(curcpu()))->pai_asid, 0);
#endif

        kpreempt_disable();
        pmap_acquire_pmap_lock(pm);

        /*
         * If there is no l2_dtable for this address, then the process
         * has no business accessing it.
         *
         * Note: This will catch userland processes trying to access
         * kernel addresses.
         */
        l2 = pm->pm_l2[L2_IDX(l1slot)];
        if (l2 == NULL) {
                UVMHIST_LOG(maphist, " no l2 for l1slot %#jx", l1slot, 0, 0, 0);
                goto out;
        }

        /*
         * Likewise if there is no L2 descriptor table
         */
        l2b = &l2->l2_bucket[L2_BUCKET(l1slot)];
        if (l2b->l2b_kva == NULL) {
                UVMHIST_LOG(maphist, " <-- done (no ptep for l1slot %#jx)",
                    l1slot, 0, 0, 0);
                goto out;
        }

        /*
         * Check the PTE itself.
         */
        pt_entry_t * const ptep = &l2b->l2b_kva[l2pte_index(va)];
        pt_entry_t const opte = *ptep;
        if (opte == 0 || (opte & L2_TYPE_MASK) == L2_TYPE_L) {
                UVMHIST_LOG(maphist, " <-- done (empty pte)",
                    0, 0, 0, 0);
                goto out;
        }

#ifndef ARM_HAS_VBAR
        /*
         * Catch a userland access to the vector page mapped at 0x0
         */
        if (user && (opte & L2_S_PROT_U) == 0) {
                UVMHIST_LOG(maphist, " <-- done (vector_page)", 0, 0, 0, 0);
                goto out;
        }
#endif

        pa = l2pte_pa(opte);
        UVMHIST_LOG(maphist, " pa %#jx opte %#jx ", pa, opte, 0, 0);

        if ((ftype & VM_PROT_WRITE) && !l2pte_writable_p(opte)) {
                /*
                 * This looks like a good candidate for "page modified"
                 * emulation...
                 */
                struct pv_entry *pv;
                struct vm_page *pg;

                /* Extract the physical address of the page */
                if ((pg = PHYS_TO_VM_PAGE(pa)) == NULL) {
                        UVMHIST_LOG(maphist, " <-- done (mod/ref unmanaged page)", 0, 0, 0, 0);
                        goto out;
                }

                struct vm_page_md *md = VM_PAGE_TO_MD(pg);

                /* Get the current flags for this page. */
                pmap_acquire_page_lock(md);
                pv = pmap_find_pv(md, pm, va);
                if (pv == NULL || PV_IS_KENTRY_P(pv->pv_flags)) {
                        pmap_release_page_lock(md);
                        UVMHIST_LOG(maphist, " <-- done (mod/ref emul: no PV)", 0, 0, 0, 0);
                        goto out;
                }

                /*
                 * Do the flags say this page is writable? If not then it
                 * is a genuine write fault. If yes then the write fault is
                 * our fault as we did not reflect the write access in the
                 * PTE. Now we know a write has occurred we can correct this
                 * and also set the modified bit
                 */
                if ((pv->pv_flags & PVF_WRITE) == 0) {
                        pmap_release_page_lock(md);
                        UVMHIST_LOG(maphist, " <-- done (write fault)", 0, 0, 0, 0);
                        goto out;
                }

                md->pvh_attrs |= PVF_REF | PVF_MOD;
                pv->pv_flags |= PVF_REF | PVF_MOD;
#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
                /*
                 * If there are cacheable mappings for this page, mark it dirty.
                 */
                if ((md->pvh_attrs & PVF_NC) == 0)
                        md->pvh_attrs |= PVF_DIRTY;
#endif
#ifdef ARM_MMU_EXTENDED
                if (md->pvh_attrs & PVF_EXEC) {
                        md->pvh_attrs &= ~PVF_EXEC;
                        PMAPCOUNT(exec_discarded_modfixup);
                }
#endif
                pmap_release_page_lock(md);

                /*
                 * Re-enable write permissions for the page.  No need to call
                 * pmap_vac_me_harder(), since this is just a
                 * modified-emulation fault, and the PVF_WRITE bit isn't
                 * changing. We've already set the cacheable bits based on
                 * the assumption that we can write to this page.
                 */
                const pt_entry_t npte =
                    l2pte_set_writable((opte & ~L2_TYPE_MASK) | L2_S_PROTO)
#ifdef ARM_MMU_EXTENDED
                    | (pm != pmap_kernel() ? L2_XS_nG : 0)
#endif
                    | 0;
                l2pte_reset(ptep);
                PTE_SYNC(ptep);
                pmap_tlb_flush_SE(pm, va,
                    (ftype & VM_PROT_EXECUTE) ? PVF_EXEC | PVF_REF : PVF_REF);
                l2pte_set(ptep, npte, 0);
                PTE_SYNC(ptep);
                PMAPCOUNT(fixup_mod);
                rv = 1;
                UVMHIST_LOG(maphist, " <-- done (mod/ref emul: changed pte "
                    "from %#jx to %#jx)", opte, npte, 0, 0);
        } else if ((opte & L2_TYPE_MASK) == L2_TYPE_INV) {
                /*
                 * This looks like a good candidate for "page referenced"
                 * emulation.
                 */
                struct vm_page *pg;

                /* Extract the physical address of the page */
                if ((pg = PHYS_TO_VM_PAGE(pa)) == NULL) {
                        UVMHIST_LOG(maphist, " <-- done (ref emul: unmanaged page)", 0, 0, 0, 0);
                        goto out;
                }

                struct vm_page_md *md = VM_PAGE_TO_MD(pg);

                /* Get the current flags for this page. */
                pmap_acquire_page_lock(md);
                struct pv_entry *pv = pmap_find_pv(md, pm, va);
                if (pv == NULL || PV_IS_KENTRY_P(pv->pv_flags)) {
                        pmap_release_page_lock(md);
                        UVMHIST_LOG(maphist, " <-- done (ref emul no PV)", 0, 0, 0, 0);
                        goto out;
                }

                md->pvh_attrs |= PVF_REF;
                pv->pv_flags |= PVF_REF;

                pt_entry_t npte =
                    l2pte_set_readonly((opte & ~L2_TYPE_MASK) | L2_S_PROTO);
#ifdef ARM_MMU_EXTENDED
                if (pm != pmap_kernel()) {
                        npte |= L2_XS_nG;
                }
                /*
                 * If we got called from prefetch abort, then ftype will have
                 * VM_PROT_EXECUTE set.  Now see if we have no-execute set in
                 * the PTE.
                 */
                if (user && (ftype & VM_PROT_EXECUTE) && (npte & L2_XS_XN)) {
                        /*
                         * Is this a mapping of an executable page?
                         */
                        if ((pv->pv_flags & PVF_EXEC) == 0) {
                                pmap_release_page_lock(md);
                                UVMHIST_LOG(maphist, " <-- done (ref emul: no exec)",
                                    0, 0, 0, 0);
                                goto out;
                        }
                        /*
                         * If we haven't synced the page, do so now.
                         */
                        if ((md->pvh_attrs & PVF_EXEC) == 0) {
                                UVMHIST_LOG(maphist, " ref emul: syncicache "
                                    "page #%#jx", pa, 0, 0, 0);
                                pmap_syncicache_page(md, pa);
                                PMAPCOUNT(fixup_exec);
                        }
                        npte &= ~L2_XS_XN;
                }
#endif /* ARM_MMU_EXTENDED */
                pmap_release_page_lock(md);
                l2pte_reset(ptep);
                PTE_SYNC(ptep);
                pmap_tlb_flush_SE(pm, va,
                    (ftype & VM_PROT_EXECUTE) ? PVF_EXEC | PVF_REF : PVF_REF);
                l2pte_set(ptep, npte, 0);
                PTE_SYNC(ptep);
                PMAPCOUNT(fixup_ref);
                rv = 1;
                UVMHIST_LOG(maphist, " <-- done (ref emul: changed pte from "
                    "%#jx to %#jx)", opte, npte, 0, 0);
#ifdef ARM_MMU_EXTENDED
        } else if (user && (ftype & VM_PROT_EXECUTE) && (opte & L2_XS_XN)) {
                struct vm_page * const pg = PHYS_TO_VM_PAGE(pa);
                if (pg == NULL) {
                        UVMHIST_LOG(maphist, " <-- done (unmanaged page)", 0, 0, 0, 0);
                        goto out;
                }

                struct vm_page_md * const md = VM_PAGE_TO_MD(pg);

                /* Get the current flags for this page. */
                pmap_acquire_page_lock(md);
                struct pv_entry * const pv = pmap_find_pv(md, pm, va);
                if (pv == NULL || (pv->pv_flags & PVF_EXEC) == 0) {
                        pmap_release_page_lock(md);
                        UVMHIST_LOG(maphist, " <-- done (no PV or not EXEC)", 0, 0, 0, 0);
                        goto out;
                }

                /*
                 * If we haven't synced the page, do so now.
                 */
                if ((md->pvh_attrs & PVF_EXEC) == 0) {
                        UVMHIST_LOG(maphist, "syncicache page #%#jx",
                            pa, 0, 0, 0);
                        pmap_syncicache_page(md, pa);
                }
                pmap_release_page_lock(md);
                /*
                 * Turn off no-execute.
                 */
                KASSERT(opte & L2_XS_nG);
                l2pte_reset(ptep);
                PTE_SYNC(ptep);
                pmap_tlb_flush_SE(pm, va, PVF_EXEC | PVF_REF);
                l2pte_set(ptep, opte & ~L2_XS_XN, 0);
                PTE_SYNC(ptep);
                rv = 1;
                PMAPCOUNT(fixup_exec);
                UVMHIST_LOG(maphist, "exec: changed pte from %#jx to %#jx",
                    opte, opte & ~L2_XS_XN, 0, 0);
#endif
        }

#ifndef ARM_MMU_EXTENDED
        /*
         * We know there is a valid mapping here, so simply
         * fix up the L1 if necessary.
         */
        pd_entry_t * const pdep = pmap_l1_kva(pm) + l1slot;
        pd_entry_t pde = L1_C_PROTO | l2b->l2b_pa | L1_C_DOM(pmap_domain(pm));
        if (*pdep != pde) {
                l1pte_setone(pdep, pde);
                PDE_SYNC(pdep);
                rv = 1;
                PMAPCOUNT(fixup_pdes);
        }
#endif

#ifdef CPU_SA110
        /*
         * There are bugs in the rev K SA110.  This is a check for one
         * of them.
         */
        if (rv == 0 && curcpu()->ci_arm_cputype == CPU_ID_SA110 &&
            curcpu()->ci_arm_cpurev < 3) {
                /* Always current pmap */
                if (l2pte_valid_p(opte)) {
                        extern int kernel_debug;
                        if (kernel_debug & 1) {
                                struct proc *p = curlwp->l_proc;
                                printf("prefetch_abort: page is already "
                                    "mapped - pte=%p *pte=%08x\n", ptep, opte);
                                printf("prefetch_abort: pc=%08lx proc=%p "
                                    "process=%s\n", va, p, p->p_comm);
                                printf("prefetch_abort: far=%08x fs=%x\n",
                                    cpu_faultaddress(), cpu_faultstatus());
                        }
#ifdef DDB
                        if (kernel_debug & 2)
                                Debugger();
#endif
                        rv = 1;
                }
        }
#endif /* CPU_SA110 */

#ifndef ARM_MMU_EXTENDED
        /*
         * If 'rv == 0' at this point, it generally indicates that there is a
         * stale TLB entry for the faulting address.  That might be due to a
         * wrong setting of pmap_needs_pte_sync.  So set it and retry.
         */
        if (rv == 0
            && pm->pm_l1->l1_domain_use_count == 1
            && pmap_needs_pte_sync == 0) {
                pmap_needs_pte_sync = 1;
                PTE_SYNC(ptep);
                PMAPCOUNT(fixup_ptesync);
                rv = 1;
        }
#endif

#ifndef MULTIPROCESSOR
#if defined(DEBUG) || 1
        /*
         * If 'rv == 0' at this point, it generally indicates that there is a
         * stale TLB entry for the faulting address. This happens when two or
         * more processes are sharing an L1. Since we don't flush the TLB on
         * a context switch between such processes, we can take domain faults
         * for mappings which exist at the same VA in both processes. EVEN IF
         * WE'VE RECENTLY FIXED UP THE CORRESPONDING L1 in pmap_enter(), for
         * example.
         *
         * This is extremely likely to happen if pmap_enter() updated the L1
         * entry for a recently entered mapping. In this case, the TLB is
         * flushed for the new mapping, but there may still be TLB entries for
         * other mappings belonging to other processes in the 1MB range
         * covered by the L1 entry.
         *
         * Since 'rv == 0', we know that the L1 already contains the correct
         * value, so the fault must be due to a stale TLB entry.
         *
         * Since we always need to flush the TLB anyway in the case where we
         * fixed up the L1, or frobbed the L2 PTE, we effectively deal with
         * stale TLB entries dynamically.
         *
         * However, the above condition can ONLY happen if the current L1 is
         * being shared. If it happens when the L1 is unshared, it indicates
         * that other parts of the pmap are not doing their job WRT managing
         * the TLB.
         */
        if (rv == 0
#ifndef ARM_MMU_EXTENDED
            && pm->pm_l1->l1_domain_use_count == 1
#endif
            && true) {
#ifdef DEBUG
                extern int last_fault_code;
#else
                int last_fault_code = ftype & VM_PROT_EXECUTE
                    ? armreg_ifsr_read()
                    : armreg_dfsr_read();
#endif
                printf("fixup: pm %p, va 0x%lx, ftype %d - nothing to do!\n",
                    pm, va, ftype);
                printf("fixup: l2 %p, l2b %p, ptep %p, pte %#x\n",
                    l2, l2b, ptep, opte);

#ifndef ARM_MMU_EXTENDED
                printf("fixup: pdep %p, pde %#x, fsr %#x\n",
                    pdep, pde, last_fault_code);
#else
                printf("fixup: pdep %p, pde %#x, ttbcr %#x\n",
                    &pmap_l1_kva(pm)[l1slot], pmap_l1_kva(pm)[l1slot],
                   armreg_ttbcr_read());
                printf("fixup: fsr %#x cpm %p casid %#x contextidr %#x dacr %#x\n",
                    last_fault_code, curcpu()->ci_pmap_cur,
                    curcpu()->ci_pmap_asid_cur,
                    armreg_contextidr_read(), armreg_dacr_read());
#ifdef _ARM_ARCH_7
                if (ftype & VM_PROT_WRITE)
                        armreg_ats1cuw_write(va);
                else
                        armreg_ats1cur_write(va);
                isb();
                printf("fixup: par %#x\n", armreg_par_read());
#endif
#endif
#ifdef DDB
                extern int kernel_debug;

                if (kernel_debug & 2) {
                        pmap_release_pmap_lock(pm);
#ifdef UVMHIST
                        KERNHIST_DUMP(maphist);
#endif
                        cpu_Debugger();
                        pmap_acquire_pmap_lock(pm);
                }
#endif
        }
#endif
#endif

#ifndef ARM_MMU_EXTENDED
        /* Flush the TLB in the shared L1 case - see comment above */
        pmap_tlb_flush_SE(pm, va,
            (ftype & VM_PROT_EXECUTE) ? PVF_EXEC | PVF_REF : PVF_REF);
#endif

        rv = 1;

out:
        pmap_release_pmap_lock(pm);
        kpreempt_enable();

        return rv;
}

/*
 * Routine:     pmap_procwr
 *
 * Function:
 *      Synchronize caches corresponding to [addr, addr+len) in p.
 *
 */
void
pmap_procwr(struct proc *p, vaddr_t va, int len)
{
#ifndef ARM_MMU_EXTENDED

        /* We only need to do anything if it is the current process. */
        if (p == curproc)
                cpu_icache_sync_range(va, len);
#endif
}

/*
 * Routine:     pmap_unwire
 * Function:    Clear the wired attribute for a map/virtual-address pair.
 *
 * In/out conditions:
 *              The mapping must already exist in the pmap.
 */
void
pmap_unwire(pmap_t pm, vaddr_t va)
{
        struct l2_bucket *l2b;
        pt_entry_t *ptep, pte;
        struct vm_page *pg;
        paddr_t pa;

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "pm %#jx va %#jx", (uintptr_t)pm, va, 0, 0);

        kpreempt_disable();
        pmap_acquire_pmap_lock(pm);

        l2b = pmap_get_l2_bucket(pm, va);
        KDASSERT(l2b != NULL);

        ptep = &l2b->l2b_kva[l2pte_index(va)];
        pte = *ptep;

        /* Extract the physical address of the page */
        pa = l2pte_pa(pte);

        if ((pg = PHYS_TO_VM_PAGE(pa)) != NULL) {
                /* Update the wired bit in the pv entry for this page. */
                struct vm_page_md *md = VM_PAGE_TO_MD(pg);

                pmap_acquire_page_lock(md);
                (void) pmap_modify_pv(md, pa, pm, va, PVF_WIRED, 0);
                pmap_release_page_lock(md);
        }

        pmap_release_pmap_lock(pm);
        kpreempt_enable();

        UVMHIST_LOG(maphist, " <-- done", 0, 0, 0, 0);
}

#if defined(EFI_RUNTIME)
void
pmap_activate_efirt(void)
{
        struct pmap * const pm = &efirt_pmap;

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, " (pm=%#jx)", (uintptr_t)pm, 0, 0, 0);

        KASSERT(kpreempt_disabled());

        struct cpu_info * const ci = curcpu();
        struct pmap_asid_info * const pai = PMAP_PAI(pm, cpu_tlb_info(ci));

        PMAPCOUNT(activations);

        KASSERT(
            (armreg_pfr1_read() & ARM_PFR1_SEC_MASK) == 0 ||
            (armreg_ttbcr_read() & TTBCR_S_PD0) != 0
        );

        armreg_contextidr_write(pai->pai_asid);
        armreg_ttbr_write(pm->pm_l1_pa |
            (ci->ci_mpidr ? TTBR_MPATTR : TTBR_UPATTR));
        /*
         * Now we can reenable tablewalks since the CONTEXTIDR and TTRB0
         * have been updated.
         */
        isb();

        const uint32_t old_ttbcr = armreg_ttbcr_read();
        armreg_ttbcr_write(old_ttbcr & ~TTBCR_S_PD0);

        ci->ci_pmap_asid_cur = pai->pai_asid;
        ci->ci_pmap_cur = pm;

        KASSERT(
            (armreg_pfr1_read() & ARM_PFR1_SEC_MASK) == 0 ||
            (armreg_ttbcr_read() & TTBCR_S_PD0) == 0
        );

        UVMHIST_LOG(maphist, " <-- done", 0, 0, 0, 0);
}

#endif

static inline void
pmap_blockuserspace(bool flag)
{
#if \
    defined(CPU_SA110) || defined(CPU_SA1100) || \
    defined(CPU_SA1110) || defined(CPU_IXP12X0) || \
    defined(CPU_XSCALE)

        extern int block_userspace_access;

        block_userspace_access = flag ? 1 : 0;
#endif
}

void
pmap_activate(struct lwp *l)
{
        pmap_t npm = l->l_proc->p_vmspace->vm_map.pmap;

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "l=%#jx pm=%#jx", (uintptr_t)l,
            (uintptr_t)npm, 0, 0);

#ifdef ARM_MMU_EXTENDED
        KASSERT(kpreempt_disabled());
#endif

        struct cpu_info * const ci = curcpu();

        /*
         * If activating a non-current lwp or the current lwp is
         * already active, just return.
         */
        if (false
            || l != curlwp
#ifdef ARM_MMU_EXTENDED
            || (ci->ci_pmap_cur == npm &&
                (npm == pmap_kernel()
                 /* || PMAP_PAI_ASIDVALID_P(pai, cpu_tlb_info(ci)) */))
#else
            || npm->pm_activated == true
#endif
            || false) {
                UVMHIST_LOG(maphist, " <-- (same pmap)", (uintptr_t)curlwp,
                    (uintptr_t)l, 0, 0);
                return;
        }

#ifndef ARM_MMU_EXTENDED
        const uint32_t ndacr = (DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL * 2))
            | (DOMAIN_CLIENT << (pmap_domain(npm) * 2));

        /*
         * If TTB and DACR are unchanged, short-circuit all the
         * TLB/cache management stuff.
         */
        pmap_t opm = ci->ci_lastlwp
            ? ci->ci_lastlwp->l_proc->p_vmspace->vm_map.pmap
            : NULL;
        if (opm != NULL) {
                uint32_t odacr = (DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL * 2))
                    | (DOMAIN_CLIENT << (pmap_domain(opm) * 2));

                if (opm->pm_l1 == npm->pm_l1 && odacr == ndacr)
                        goto all_done;
        }
#endif /* !ARM_MMU_EXTENDED */

        PMAPCOUNT(activations);

        pmap_blockuserspace(true);

#ifndef ARM_MMU_EXTENDED
        /*
         * If switching to a user vmspace which is different to the
         * most recent one, and the most recent one is potentially
         * live in the cache, we must write-back and invalidate the
         * entire cache.
         */
        pmap_t rpm = ci->ci_pmap_lastuser;

        /*
         * XXXSCW: There's a corner case here which can leave turds in the
         * cache as reported in kern/41058. They're probably left over during
         * tear-down and switching away from an exiting process. Until the root
         * cause is identified and fixed, zap the cache when switching pmaps.
         * This will result in a few unnecessary cache flushes, but that's
         * better than silently corrupting data.
         */
#if 0
        if (npm != pmap_kernel() && rpm && npm != rpm &&
            rpm->pm_cstate.cs_cache) {
                rpm->pm_cstate.cs_cache = 0;
#ifdef PMAP_CACHE_VIVT
                cpu_idcache_wbinv_all();
#endif
        }
#else
        if (rpm) {
                rpm->pm_cstate.cs_cache = 0;
                if (npm == pmap_kernel())
                        ci->ci_pmap_lastuser = NULL;
#ifdef PMAP_CACHE_VIVT
                cpu_idcache_wbinv_all();
#endif
        }
#endif

        /* No interrupts while we frob the TTB/DACR */
        uint32_t oldirqstate = disable_interrupts(IF32_bits);
#endif /* !ARM_MMU_EXTENDED */

#ifndef ARM_HAS_VBAR
        /*
         * For ARM_VECTORS_LOW, we MUST, I repeat, MUST fix up the L1
         * entry corresponding to 'vector_page' in the incoming L1 table
         * before switching to it otherwise subsequent interrupts/exceptions
         * (including domain faults!) will jump into hyperspace.
         */
        if (npm->pm_pl1vec != NULL) {
                cpu_tlb_flushID_SE((u_int)vector_page);
                cpu_cpwait();
                *npm->pm_pl1vec = npm->pm_l1vec;
                PTE_SYNC(npm->pm_pl1vec);
        }
#endif

#ifdef ARM_MMU_EXTENDED
        /*
         * While a vmspace is being recycled in uvmspace_exec and the pmap
         * is marked pm_remove_all = true amap_wipeout may voluntarily
         * preempt allowing other LWPs to be activate. When returning to
         * the recylcing process we can skip acquiring an ASID and activating it
         * as it'll happen in pmap_update.
         */
        if (__predict_true(!npm->pm_remove_all)) {
                /* this calls pmap_md_asid_activate */
                pmap_tlb_asid_acquire(npm, l);
        }
#else
        cpu_domains(ndacr);
        if (npm == pmap_kernel() || npm == rpm) {
                /*
                 * Switching to a kernel thread, or back to the
                 * same user vmspace as before... Simply update
                 * the TTB (no TLB flush required)
                 */
                cpu_setttb(npm->pm_l1->l1_physaddr, false);
                cpu_cpwait();
        } else {
                /*
                 * Otherwise, update TTB and flush TLB
                 */
                cpu_context_switch(npm->pm_l1->l1_physaddr);
                if (rpm != NULL)
                        rpm->pm_cstate.cs_tlb = 0;
        }

        restore_interrupts(oldirqstate);
#endif /* ARM_MMU_EXTENDED */

        pmap_blockuserspace(false);

#ifndef ARM_MMU_EXTENDED
 all_done:
        /*
         * The new pmap is resident. Make sure it's marked
         * as resident in the cache/TLB.
         */
        npm->pm_cstate.cs_all = PMAP_CACHE_STATE_ALL;
        if (npm != pmap_kernel())
                ci->ci_pmap_lastuser = npm;

        /* The old pmap is not longer active */
        if (opm != npm) {
                if (opm != NULL)
                        opm->pm_activated = false;

                /* But the new one is */
                npm->pm_activated = true;
        }
        ci->ci_pmap_cur = npm;
#endif
        UVMHIST_LOG(maphist, " <-- done", 0, 0, 0, 0);
}


void
pmap_deactivate(struct lwp *l)
{
        pmap_t pm = l->l_proc->p_vmspace->vm_map.pmap;

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "l=%#jx (pm=%#jx)", (uintptr_t)l,
                (uintptr_t)pm, 0, 0);

#ifdef ARM_MMU_EXTENDED
        KASSERT(kpreempt_disabled());
        pmap_tlb_asid_deactivate(pm);

        KASSERT(
            (armreg_pfr1_read() & ARM_PFR1_SEC_MASK) == 0 ||
            (armreg_ttbcr_read() & TTBCR_S_PD0) != 0
        );
#else
        /*
         * If the process is exiting, make sure pmap_activate() does
         * a full MMU context-switch and cache flush, which we might
         * otherwise skip. See PR port-arm/38950.
         */
        if (l->l_proc->p_sflag & PS_WEXIT)
                curcpu()->ci_lastlwp = NULL;

        pm->pm_activated = false;
#endif
        UVMHIST_LOG(maphist, "  <-- done", 0, 0, 0, 0);
}


#if defined(EFI_RUNTIME)
void
pmap_deactivate_efirt(void)
{
        UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);

        KASSERT(kpreempt_disabled());
        struct cpu_info * const ci = curcpu();

        /*
         * Disable translation table walks from TTBR0 while no pmap has been
         * activated.
         */
        const uint32_t old_ttbcr = armreg_ttbcr_read();
        armreg_ttbcr_write(old_ttbcr | TTBCR_S_PD0);
        isb();

        armreg_contextidr_write(KERNEL_PID);
        isb();

        KASSERTMSG(ci->ci_pmap_asid_cur == KERNEL_PID, "ci_pmap_asid_cur %u",
            ci->ci_pmap_asid_cur);

        KASSERT(
            (armreg_pfr1_read() & ARM_PFR1_SEC_MASK) == 0 ||
            (armreg_ttbcr_read() & TTBCR_S_PD0) != 0
        );

        UVMHIST_LOG(maphist, " <-- done", 0, 0, 0, 0);
}
#endif


void
pmap_update(pmap_t pm)
{

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "pm=%#jx remove_all %jd", (uintptr_t)pm,
            pm->pm_remove_all, 0, 0);

#ifndef ARM_MMU_EXTENDED
        if (pm->pm_remove_all) {
                /*
                 * Finish up the pmap_remove_all() optimisation by flushing
                 * the TLB.
                 */
                pmap_tlb_flushID(pm);
                pm->pm_remove_all = false;
        }

        if (pmap_is_current(pm)) {
                /*
                 * If we're dealing with a current userland pmap, move its L1
                 * to the end of the LRU.
                 */
                if (pm != pmap_kernel())
                        pmap_use_l1(pm);

                /*
                 * We can assume we're done with frobbing the cache/tlb for
                 * now. Make sure any future pmap ops don't skip cache/tlb
                 * flushes.
                 */
                pm->pm_cstate.cs_all = PMAP_CACHE_STATE_ALL;
        }
#else

        kpreempt_disable();
#if defined(MULTIPROCESSOR) && PMAP_TLB_MAX > 1
        u_int pending = atomic_swap_uint(&pmap->pm_shootdown_pending, 0);
        if (pending && pmap_tlb_shootdown_bystanders(pmap)) {
                PMAP_COUNT(shootdown_ipis);
        }
#endif

        /*
         * If pmap_remove_all was called, we deactivated ourselves and released
         * our ASID.  Now we have to reactivate ourselves.
         */
        if (__predict_false(pm->pm_remove_all)) {
                pm->pm_remove_all = false;

                KASSERT(
                    (armreg_pfr1_read() & ARM_PFR1_SEC_MASK) == 0 ||
                    (armreg_ttbcr_read() & TTBCR_S_PD0) != 0
                );

                KASSERT(pm != pmap_kernel());
                /* this calls pmap_md_asid_activate */
                pmap_tlb_asid_acquire(pm, curlwp);
        }

        if (arm_has_mpext_p)
                armreg_bpiallis_write(0);
        else
                armreg_bpiall_write(0);

        kpreempt_enable();

        KASSERTMSG(pm == pmap_kernel()
            || curcpu()->ci_pmap_cur != pm
            || pm->pm_pai[0].pai_asid == curcpu()->ci_pmap_asid_cur,
            "pmap/asid %p/%#x != %s cur pmap/asid %p/%#x", pm,
            pm->pm_pai[0].pai_asid, curcpu()->ci_data.cpu_name,
            curcpu()->ci_pmap_cur, curcpu()->ci_pmap_asid_cur);
#endif

        PMAPCOUNT(updates);

        /*
         * make sure TLB/cache operations have completed.
         */
        cpu_cpwait();
        UVMHIST_LOG(maphist, "  <-- done", 0, 0, 0, 0);
}

bool
pmap_remove_all(pmap_t pm)
{

        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "(pm=%#jx)", (uintptr_t)pm, 0, 0, 0);

        KASSERT(pm != pmap_kernel());

        kpreempt_disable();
        /*
         * The vmspace described by this pmap is about to be torn down.
         * Until pmap_update() is called, UVM will only make calls
         * to pmap_remove(). We can make life much simpler by flushing
         * the cache now, and deferring TLB invalidation to pmap_update().
         */
#ifdef PMAP_CACHE_VIVT
        pmap_cache_wbinv_all(pm, PVF_EXEC);
#endif

#ifdef ARM_MMU_EXTENDED
#ifdef MULTIPROCESSOR
        struct cpu_info * const ci = curcpu();
        // This should be the last CPU with this pmap onproc
        KASSERT(!kcpuset_isotherset(pm->pm_onproc, cpu_index(ci)));
        if (kcpuset_isset(pm->pm_onproc, cpu_index(ci)))
#endif
                pmap_tlb_asid_deactivate(pm);
#ifdef MULTIPROCESSOR
        KASSERT(kcpuset_iszero(pm->pm_onproc));
#endif

        pmap_tlb_asid_release_all(pm);
#endif
        pm->pm_remove_all = true;
        kpreempt_enable();

        UVMHIST_LOG(maphist, " <-- done", 0, 0, 0, 0);
        return false;
}

/*
 * Retire the given physical map from service.
 * Should only be called if the map contains no valid mappings.
 */
void
pmap_destroy(pmap_t pm)
{
        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "pm=%#jx remove_all %jd", (uintptr_t)pm,
            pm ? pm->pm_remove_all : 0, 0, 0);

        if (pm == NULL)
                return;

        if (pm->pm_remove_all) {
#ifdef ARM_MMU_EXTENDED
                pmap_tlb_asid_release_all(pm);
#else
                pmap_tlb_flushID(pm);
#endif
                pm->pm_remove_all = false;
        }

        /*
         * Drop reference count
         */
        membar_release();
        if (atomic_dec_uint_nv(&pm->pm_refs) > 0) {
#ifndef ARM_MMU_EXTENDED
                if (pmap_is_current(pm)) {
                        if (pm != pmap_kernel())
                                pmap_use_l1(pm);
                        pm->pm_cstate.cs_all = PMAP_CACHE_STATE_ALL;
                }
#endif
                return;
        }
        membar_acquire();

        /*
         * reference count is zero, free pmap resources and then free pmap.
         */

#ifndef ARM_HAS_VBAR
        if (vector_page < KERNEL_BASE) {
                KDASSERT(!pmap_is_current(pm));

                /* Remove the vector page mapping */
                pmap_remove(pm, vector_page, vector_page + PAGE_SIZE);
                pmap_update(pm);
        }
#endif

        pmap_free_l1(pm);

#ifdef ARM_MMU_EXTENDED
#ifdef MULTIPROCESSOR
        kcpuset_destroy(pm->pm_active);
        kcpuset_destroy(pm->pm_onproc);
#endif
#else
        struct cpu_info * const ci = curcpu();
        if (ci->ci_pmap_lastuser == pm)
                ci->ci_pmap_lastuser = NULL;
#endif

        mutex_destroy(&pm->pm_lock);
        pool_cache_put(&pmap_cache, pm);
        UVMHIST_LOG(maphist, "  <-- done", 0, 0, 0, 0);
}


/*
 * void pmap_reference(pmap_t pm)
 *
 * Add a reference to the specified pmap.
 */
void
pmap_reference(pmap_t pm)
{

        if (pm == NULL)
                return;

#ifndef ARM_MMU_EXTENDED
        pmap_use_l1(pm);
#endif

        atomic_inc_uint(&pm->pm_refs);
}

#if (ARM_MMU_V6 + ARM_MMU_V7) > 0

static struct evcnt pmap_prefer_nochange_ev =
    EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, "pmap prefer", "nochange");
static struct evcnt pmap_prefer_change_ev =
    EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, "pmap prefer", "change");

EVCNT_ATTACH_STATIC(pmap_prefer_change_ev);
EVCNT_ATTACH_STATIC(pmap_prefer_nochange_ev);

void
pmap_prefer(vaddr_t hint, vaddr_t *vap, int td)
{
        vsize_t mask = arm_cache_prefer_mask | (PAGE_SIZE - 1);
        vaddr_t va = *vap;
        vaddr_t diff = (hint - va) & mask;
        if (diff == 0) {
                pmap_prefer_nochange_ev.ev_count++;
        } else {
                pmap_prefer_change_ev.ev_count++;
                if (__predict_false(td))
                        va -= mask + 1;
                *vap = va + diff;
        }
}
#endif /* ARM_MMU_V6 | ARM_MMU_V7 */

/*
 * pmap_zero_page()
 *
 * Zero a given physical page by mapping it at a page hook point.
 * In doing the zero page op, the page we zero is mapped cachable, as with
 * StrongARM accesses to non-cached pages are non-burst making writing
 * _any_ bulk data very slow.
 */
#if (ARM_MMU_GENERIC + ARM_MMU_SA1 + ARM_MMU_V6 + ARM_MMU_V7) != 0
void
pmap_zero_page_generic(paddr_t pa)
{
#if defined(PMAP_CACHE_VIPT) || defined(DEBUG)
        struct vm_page *pg = PHYS_TO_VM_PAGE(pa);
        struct vm_page_md *md = VM_PAGE_TO_MD(pg);
#endif
#if defined(PMAP_CACHE_VIPT)
        /* Choose the last page color it had, if any */
        const vsize_t va_offset = md->pvh_attrs & arm_cache_prefer_mask;
#else
        const vsize_t va_offset = 0;
#endif
#if defined(__HAVE_MM_MD_DIRECT_MAPPED_PHYS)
        /*
         * Is this page mapped at its natural color?
         * If we have all of memory mapped, then just convert PA to VA.
         */
        bool okcolor = arm_pcache.dcache_type == CACHE_TYPE_PIPT
           || va_offset == (pa & arm_cache_prefer_mask);
        const vaddr_t vdstp = okcolor
            ? pmap_direct_mapped_phys(pa, &okcolor, cpu_cdstp(va_offset))
            : cpu_cdstp(va_offset);
#else
        const bool okcolor = false;
        const vaddr_t vdstp = cpu_cdstp(va_offset);
#endif
        pt_entry_t * const ptep = cpu_cdst_pte(va_offset);


#ifdef DEBUG
        if (!SLIST_EMPTY(&md->pvh_list))
                panic("pmap_zero_page: page has mappings");
#endif

        KDASSERT((pa & PGOFSET) == 0);

        if (!okcolor) {
                /*
                 * Hook in the page, zero it, and purge the cache for that
                 * zeroed page. Invalidate the TLB as needed.
                 */
                const pt_entry_t npte = L2_S_PROTO | pa | pte_l2_s_cache_mode
                    | L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE);
                l2pte_set(ptep, npte, 0);
                PTE_SYNC(ptep);
                cpu_tlb_flushD_SE(vdstp);
                cpu_cpwait();
#if defined(__HAVE_MM_MD_DIRECT_MAPPED_PHYS) && defined(PMAP_CACHE_VIPT) \
    && !defined(ARM_MMU_EXTENDED)
                /*
                 * If we are direct-mapped and our color isn't ok, then before
                 * we bzero the page invalidate its contents from the cache and
                 * reset the color to its natural color.
                 */
                cpu_dcache_inv_range(vdstp, PAGE_SIZE);
                md->pvh_attrs &= ~arm_cache_prefer_mask;
                md->pvh_attrs |= (pa & arm_cache_prefer_mask);
#endif
        }
        bzero_page(vdstp);
        if (!okcolor) {
                /*
                 * Unmap the page.
                 */
                l2pte_reset(ptep);
                PTE_SYNC(ptep);
                cpu_tlb_flushD_SE(vdstp);
#ifdef PMAP_CACHE_VIVT
                cpu_dcache_wbinv_range(vdstp, PAGE_SIZE);
#endif
        }
#ifdef PMAP_CACHE_VIPT
        /*
         * This page is now cache resident so it now has a page color.
         * Any contents have been obliterated so clear the EXEC flag.
         */
#ifndef ARM_MMU_EXTENDED
        if (!pmap_is_page_colored_p(md)) {
                PMAPCOUNT(vac_color_new);
                md->pvh_attrs |= PVF_COLORED;
        }
        md->pvh_attrs |= PVF_DIRTY;
#endif
        if (PV_IS_EXEC_P(md->pvh_attrs)) {
                md->pvh_attrs &= ~PVF_EXEC;
                PMAPCOUNT(exec_discarded_zero);
        }
#endif
}
#endif /* (ARM_MMU_GENERIC + ARM_MMU_SA1 + ARM_MMU_V6) != 0 */

#if ARM_MMU_XSCALE == 1
void
pmap_zero_page_xscale(paddr_t pa)
{
#ifdef DEBUG
        struct vm_page *pg = PHYS_TO_VM_PAGE(pa);
        struct vm_page_md *md = VM_PAGE_TO_MD(pg);

        if (!SLIST_EMPTY(&md->pvh_list))
                panic("pmap_zero_page: page has mappings");
#endif

        KDASSERT((pa & PGOFSET) == 0);

        /*
         * Hook in the page, zero it, and purge the cache for that
         * zeroed page. Invalidate the TLB as needed.
         */

        pt_entry_t npte = L2_S_PROTO | pa |
            L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE) |
            L2_C | L2_XS_T_TEX(TEX_XSCALE_X);   /* mini-data */
        l2pte_set(cdst_pte, npte, 0);
        PTE_SYNC(cdst_pte);
        cpu_tlb_flushD_SE(cdstp);
        cpu_cpwait();
        bzero_page(cdstp);
        xscale_cache_clean_minidata();
        l2pte_reset(cdst_pte);
        PTE_SYNC(cdst_pte);
}
#endif /* ARM_MMU_XSCALE == 1 */

/* pmap_pageidlezero()
 *
 * The same as above, except that we assume that the page is not
 * mapped.  This means we never have to flush the cache first.  Called
 * from the idle loop.
 */
bool
pmap_pageidlezero(paddr_t pa)
{
        bool rv = true;
#if defined(PMAP_CACHE_VIPT) || defined(DEBUG)
        struct vm_page * const pg = PHYS_TO_VM_PAGE(pa);
        struct vm_page_md *md = VM_PAGE_TO_MD(pg);
#endif
#ifdef PMAP_CACHE_VIPT
        /* Choose the last page color it had, if any */
        const vsize_t va_offset = md->pvh_attrs & arm_cache_prefer_mask;
#else
        const vsize_t va_offset = 0;
#endif
#ifdef __HAVE_MM_MD_DIRECT_MAPPED_PHYS
        bool okcolor = arm_pcache.dcache_type == CACHE_TYPE_PIPT
           || va_offset == (pa & arm_cache_prefer_mask);
        const vaddr_t vdstp = okcolor
            ? pmap_direct_mapped_phys(pa, &okcolor, cpu_cdstp(va_offset))
            : cpu_cdstp(va_offset);
#else
        const bool okcolor = false;
        const vaddr_t vdstp = cpu_cdstp(va_offset);
#endif
        pt_entry_t * const ptep = cpu_cdst_pte(va_offset);


#ifdef DEBUG
        if (!SLIST_EMPTY(&md->pvh_list))
                panic("pmap_pageidlezero: page has mappings");
#endif

        KDASSERT((pa & PGOFSET) == 0);

        if (!okcolor) {
                /*
                 * Hook in the page, zero it, and purge the cache for that
                 * zeroed page. Invalidate the TLB as needed.
                 */
                const pt_entry_t npte = L2_S_PROTO | pa |
                    L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE) | pte_l2_s_cache_mode;
                l2pte_set(ptep, npte, 0);
                PTE_SYNC(ptep);
                cpu_tlb_flushD_SE(vdstp);
                cpu_cpwait();
        }

        uint64_t *ptr = (uint64_t *)vdstp;
        for (size_t i = 0; i < PAGE_SIZE / sizeof(*ptr); i++) {
                if (sched_curcpu_runnable_p() != 0) {
                        /*
                         * A process has become ready.  Abort now,
                         * so we don't keep it waiting while we
                         * do slow memory access to finish this
                         * page.
                         */
                        rv = false;
                        break;
                }
                *ptr++ = 0;
        }

#ifdef PMAP_CACHE_VIVT
        if (rv)
                /*
                 * if we aborted we'll rezero this page again later so don't
                 * purge it unless we finished it
                 */
                cpu_dcache_wbinv_range(vdstp, PAGE_SIZE);
#elif defined(PMAP_CACHE_VIPT)
        /*
         * This page is now cache resident so it now has a page color.
         * Any contents have been obliterated so clear the EXEC flag.
         */
#ifndef ARM_MMU_EXTENDED
        if (!pmap_is_page_colored_p(md)) {
                PMAPCOUNT(vac_color_new);
                md->pvh_attrs |= PVF_COLORED;
        }
#endif
        if (PV_IS_EXEC_P(md->pvh_attrs)) {
                md->pvh_attrs &= ~PVF_EXEC;
                PMAPCOUNT(exec_discarded_zero);
        }
#endif
        /*
         * Unmap the page.
         */
        if (!okcolor) {
                l2pte_reset(ptep);
                PTE_SYNC(ptep);
                cpu_tlb_flushD_SE(vdstp);
        }

        return rv;
}

/*
 * pmap_copy_page()
 *
 * Copy one physical page into another, by mapping the pages into
 * hook points. The same comment regarding cachability as in
 * pmap_zero_page also applies here.
 */
#if (ARM_MMU_GENERIC + ARM_MMU_SA1 + ARM_MMU_V6 + ARM_MMU_V7) != 0
void
pmap_copy_page_generic(paddr_t src, paddr_t dst)
{
        struct vm_page * const src_pg = PHYS_TO_VM_PAGE(src);
        struct vm_page_md *src_md = VM_PAGE_TO_MD(src_pg);
#if defined(PMAP_CACHE_VIPT) || defined(DEBUG)
        struct vm_page * const dst_pg = PHYS_TO_VM_PAGE(dst);
        struct vm_page_md *dst_md = VM_PAGE_TO_MD(dst_pg);
#endif
#ifdef PMAP_CACHE_VIPT
        const vsize_t src_va_offset = src_md->pvh_attrs & arm_cache_prefer_mask;
        const vsize_t dst_va_offset = dst_md->pvh_attrs & arm_cache_prefer_mask;
#else
        const vsize_t src_va_offset = 0;
        const vsize_t dst_va_offset = 0;
#endif
#if defined(__HAVE_MM_MD_DIRECT_MAPPED_PHYS)
        /*
         * Is this page mapped at its natural color?
         * If we have all of memory mapped, then just convert PA to VA.
         */
        bool src_okcolor = arm_pcache.dcache_type == CACHE_TYPE_PIPT
            || src_va_offset == (src & arm_cache_prefer_mask);
        bool dst_okcolor = arm_pcache.dcache_type == CACHE_TYPE_PIPT
            || dst_va_offset == (dst & arm_cache_prefer_mask);
        const vaddr_t vsrcp = src_okcolor
            ? pmap_direct_mapped_phys(src, &src_okcolor,
                cpu_csrcp(src_va_offset))
            : cpu_csrcp(src_va_offset);
        const vaddr_t vdstp = pmap_direct_mapped_phys(dst, &dst_okcolor,
            cpu_cdstp(dst_va_offset));
#else
        const bool src_okcolor = false;
        const bool dst_okcolor = false;
        const vaddr_t vsrcp = cpu_csrcp(src_va_offset);
        const vaddr_t vdstp = cpu_cdstp(dst_va_offset);
#endif
        pt_entry_t * const src_ptep = cpu_csrc_pte(src_va_offset);
        pt_entry_t * const dst_ptep = cpu_cdst_pte(dst_va_offset);

#ifdef DEBUG
        if (!SLIST_EMPTY(&dst_md->pvh_list))
                panic("pmap_copy_page: dst page has mappings");
#endif

#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
        KASSERT(arm_cache_prefer_mask == 0 || src_md->pvh_attrs & (PVF_COLORED|PVF_NC));
#endif
        KDASSERT((src & PGOFSET) == 0);
        KDASSERT((dst & PGOFSET) == 0);

        /*
         * Clean the source page.  Hold the source page's lock for
         * the duration of the copy so that no other mappings can
         * be created while we have a potentially aliased mapping.
         */
#ifdef PMAP_CACHE_VIVT
        pmap_acquire_page_lock(src_md);
        (void) pmap_clean_page(src_md, true);
        pmap_release_page_lock(src_md);
#endif

        /*
         * Map the pages into the page hook points, copy them, and purge
         * the cache for the appropriate page. Invalidate the TLB
         * as required.
         */
        if (!src_okcolor) {
                const pt_entry_t nsrc_pte = L2_S_PROTO
                    | src
#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
                    | ((src_md->pvh_attrs & PVF_NC) ? 0 : pte_l2_s_cache_mode)
#else // defined(PMAP_CACHE_VIVT) || defined(ARM_MMU_EXTENDED)
                    | pte_l2_s_cache_mode
#endif
                    | L2_S_PROT(PTE_KERNEL, VM_PROT_READ);
                l2pte_set(src_ptep, nsrc_pte, 0);
                PTE_SYNC(src_ptep);
                cpu_tlb_flushD_SE(vsrcp);
                cpu_cpwait();
        }
        if (!dst_okcolor) {
                const pt_entry_t ndst_pte = L2_S_PROTO | dst |
                    L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE) | pte_l2_s_cache_mode;
                l2pte_set(dst_ptep, ndst_pte, 0);
                PTE_SYNC(dst_ptep);
                cpu_tlb_flushD_SE(vdstp);
                cpu_cpwait();
#if defined(__HAVE_MM_MD_DIRECT_MAPPED_PHYS) && defined(PMAP_CACHE_VIPT)
                /*
                 * If we are direct-mapped and our color isn't ok, then before
                 * we bcopy to the new page invalidate its contents from the
                 * cache and reset its color to its natural color.
                 */
                cpu_dcache_inv_range(vdstp, PAGE_SIZE);
                dst_md->pvh_attrs &= ~arm_cache_prefer_mask;
                dst_md->pvh_attrs |= (dst & arm_cache_prefer_mask);
#endif
        }
        bcopy_page(vsrcp, vdstp);
#ifdef PMAP_CACHE_VIVT
        cpu_dcache_inv_range(vsrcp, PAGE_SIZE);
        cpu_dcache_wbinv_range(vdstp, PAGE_SIZE);
#endif
        /*
         * Unmap the pages.
         */
        if (!src_okcolor) {
                l2pte_reset(src_ptep);
                PTE_SYNC(src_ptep);
                cpu_tlb_flushD_SE(vsrcp);
                cpu_cpwait();
        }
        if (!dst_okcolor) {
                l2pte_reset(dst_ptep);
                PTE_SYNC(dst_ptep);
                cpu_tlb_flushD_SE(vdstp);
                cpu_cpwait();
        }
#ifdef PMAP_CACHE_VIPT
        /*
         * Now that the destination page is in the cache, mark it as colored.
         * If this was an exec page, discard it.
         */
        pmap_acquire_page_lock(dst_md);
#ifndef ARM_MMU_EXTENDED
        if (arm_pcache.cache_type == CACHE_TYPE_PIPT) {
                dst_md->pvh_attrs &= ~arm_cache_prefer_mask;
                dst_md->pvh_attrs |= (dst & arm_cache_prefer_mask);
        }
        if (!pmap_is_page_colored_p(dst_md)) {
                PMAPCOUNT(vac_color_new);
                dst_md->pvh_attrs |= PVF_COLORED;
        }
        dst_md->pvh_attrs |= PVF_DIRTY;
#endif
        if (PV_IS_EXEC_P(dst_md->pvh_attrs)) {
                dst_md->pvh_attrs &= ~PVF_EXEC;
                PMAPCOUNT(exec_discarded_copy);
        }
        pmap_release_page_lock(dst_md);
#endif
}
#endif /* (ARM_MMU_GENERIC + ARM_MMU_SA1 + ARM_MMU_V6) != 0 */

#if ARM_MMU_XSCALE == 1
void
pmap_copy_page_xscale(paddr_t src, paddr_t dst)
{
        struct vm_page *src_pg = PHYS_TO_VM_PAGE(src);
        struct vm_page_md *src_md = VM_PAGE_TO_MD(src_pg);
#ifdef DEBUG
        struct vm_page_md *dst_md = VM_PAGE_TO_MD(PHYS_TO_VM_PAGE(dst));

        if (!SLIST_EMPTY(&dst_md->pvh_list))
                panic("pmap_copy_page: dst page has mappings");
#endif

        KDASSERT((src & PGOFSET) == 0);
        KDASSERT((dst & PGOFSET) == 0);

        /*
         * Clean the source page.  Hold the source page's lock for
         * the duration of the copy so that no other mappings can
         * be created while we have a potentially aliased mapping.
         */
#ifdef PMAP_CACHE_VIVT
        pmap_acquire_page_lock(src_md);
        (void) pmap_clean_page(src_md, true);
        pmap_release_page_lock(src_md);
#endif

        /*
         * Map the pages into the page hook points, copy them, and purge
         * the cache for the appropriate page. Invalidate the TLB
         * as required.
         */
        const pt_entry_t nsrc_pte = L2_S_PROTO | src
            | L2_S_PROT(PTE_KERNEL, VM_PROT_READ)
            | L2_C | L2_XS_T_TEX(TEX_XSCALE_X); /* mini-data */
        l2pte_set(csrc_pte, nsrc_pte, 0);
        PTE_SYNC(csrc_pte);

        const pt_entry_t ndst_pte = L2_S_PROTO | dst
            | L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE)
            | L2_C | L2_XS_T_TEX(TEX_XSCALE_X); /* mini-data */
        l2pte_set(cdst_pte, ndst_pte, 0);
        PTE_SYNC(cdst_pte);

        cpu_tlb_flushD_SE(csrcp);
        cpu_tlb_flushD_SE(cdstp);
        cpu_cpwait();
        bcopy_page(csrcp, cdstp);
        xscale_cache_clean_minidata();
        l2pte_reset(csrc_pte);
        l2pte_reset(cdst_pte);
        PTE_SYNC(csrc_pte);
        PTE_SYNC(cdst_pte);
}
#endif /* ARM_MMU_XSCALE == 1 */

/*
 * void pmap_virtual_space(vaddr_t *start, vaddr_t *end)
 *
 * Return the start and end addresses of the kernel's virtual space.
 * These values are setup in pmap_bootstrap and are updated as pages
 * are allocated.
 */
void
pmap_virtual_space(vaddr_t *start, vaddr_t *end)
{
        *start = virtual_avail;
        *end = virtual_end;
}

/*
 * Helper function for pmap_grow_l2_bucket()
 */
static inline int
pmap_grow_map(vaddr_t va, paddr_t *pap)
{
        paddr_t pa;

        KASSERT((va & PGOFSET) == 0);

        if (uvm.page_init_done == false) {
#ifdef PMAP_STEAL_MEMORY
                pv_addr_t pv;
                pmap_boot_pagealloc(PAGE_SIZE,
#ifdef PMAP_CACHE_VIPT
                    arm_cache_prefer_mask,
                    va & arm_cache_prefer_mask,
#else
                    0, 0,
#endif
                    &pv);
                pa = pv.pv_pa;
#else
                if (uvm_page_physget(&pa) == false)
                        return 1;
#endif  /* PMAP_STEAL_MEMORY */
        } else {
                struct vm_page *pg;
                pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_USERESERVE);
                if (pg == NULL)
                        return 1;
                pa = VM_PAGE_TO_PHYS(pg);
                /*
                 * This new page must not have any mappings.
                 */
                struct vm_page_md *md __diagused = VM_PAGE_TO_MD(pg);
                KASSERT(SLIST_EMPTY(&md->pvh_list));
        }

        /*
         * Enter it via pmap_kenter_pa and let that routine do the hard work.
         */
        pmap_kenter_pa(va, pa, VM_PROT_READ | VM_PROT_WRITE,
            PMAP_KMPAGE | PMAP_PTE);

        if (pap)
                *pap = pa;

        PMAPCOUNT(pt_mappings);

        const pmap_t kpm __diagused = pmap_kernel();
        struct l2_bucket * const l2b __diagused = pmap_get_l2_bucket(kpm, va);
        KASSERT(l2b != NULL);

        pt_entry_t * const ptep __diagused = &l2b->l2b_kva[l2pte_index(va)];
        const pt_entry_t pte __diagused = *ptep;
        KASSERT(l2pte_valid_p(pte));
        KASSERT((pte & L2_S_CACHE_MASK) == pte_l2_s_cache_mode_pt);

        memset((void *)va, 0, PAGE_SIZE);

        return 0;
}

/*
 * This is the same as pmap_alloc_l2_bucket(), except that it is only
 * used by pmap_growkernel().
 */
static inline struct l2_bucket *
pmap_grow_l2_bucket(pmap_t pm, vaddr_t va)
{
        const size_t l1slot = l1pte_index(va);
        struct l2_dtable *l2;
        vaddr_t nva;

        CTASSERT((PAGE_SIZE % L2_TABLE_SIZE_REAL) == 0);
        if ((l2 = pm->pm_l2[L2_IDX(l1slot)]) == NULL) {
                /*
                 * No mapping at this address, as there is
                 * no entry in the L1 table.
                 * Need to allocate a new l2_dtable.
                 */
                nva = pmap_kernel_l2dtable_kva;
                if ((nva & PGOFSET) == 0) {
                        /*
                         * Need to allocate a backing page
                         */
                        if (pmap_grow_map(nva, NULL))
                                return NULL;
                }

                l2 = (struct l2_dtable *)nva;
                nva += sizeof(struct l2_dtable);

                if ((nva & PGOFSET) < (pmap_kernel_l2dtable_kva & PGOFSET)) {
                        /*
                         * The new l2_dtable straddles a page boundary.
                         * Map in another page to cover it.
                         */
                        if (pmap_grow_map(nva & ~PGOFSET, NULL))
                                return NULL;
                }

                pmap_kernel_l2dtable_kva = nva;

                /*
                 * Link it into the parent pmap
                 */
                pm->pm_l2[L2_IDX(l1slot)] = l2;
        }

        struct l2_bucket * const l2b = &l2->l2_bucket[L2_BUCKET(l1slot)];

        /*
         * Fetch pointer to the L2 page table associated with the address.
         */
        if (l2b->l2b_kva == NULL) {
                pt_entry_t *ptep;

                /*
                 * No L2 page table has been allocated. Chances are, this
                 * is because we just allocated the l2_dtable, above.
                 */
                nva = pmap_kernel_l2ptp_kva;
                ptep = (pt_entry_t *)nva;
                if ((nva & PGOFSET) == 0) {
                        /*
                         * Need to allocate a backing page
                         */
                        if (pmap_grow_map(nva, &pmap_kernel_l2ptp_phys))
                                return NULL;
                        PTE_SYNC_RANGE(ptep, PAGE_SIZE / sizeof(pt_entry_t));
                }

                l2->l2_occupancy++;
                l2b->l2b_kva = ptep;
                l2b->l2b_l1slot = l1slot;
                l2b->l2b_pa = pmap_kernel_l2ptp_phys;

                pmap_kernel_l2ptp_kva += L2_TABLE_SIZE_REAL;
                pmap_kernel_l2ptp_phys += L2_TABLE_SIZE_REAL;
        }

        return l2b;
}

vaddr_t
pmap_growkernel(vaddr_t maxkvaddr)
{
        UVMHIST_FUNC(__func__);
        UVMHIST_CALLARGS(maphist, "growing kernel from %#jx to %#jx",
            pmap_curmaxkvaddr, maxkvaddr, 0, 0);

        pmap_t kpm = pmap_kernel();
#ifndef ARM_MMU_EXTENDED
        struct l1_ttable *l1;
#endif
        int s;

        if (maxkvaddr <= pmap_curmaxkvaddr)
                goto out;               /* we are OK */

        KDASSERT(maxkvaddr <= virtual_end);

        /*
         * whoops!   we need to add kernel PTPs
         */

        vaddr_t pmap_maxkvaddr = pmap_curmaxkvaddr;

        s = splvm();    /* to be safe */
        mutex_enter(&kpm_lock);

        /* Map 1MB at a time */
        size_t l1slot = l1pte_index(pmap_maxkvaddr);
#ifdef ARM_MMU_EXTENDED
        pd_entry_t * const spdep = &kpm->pm_l1[l1slot];
        pd_entry_t *pdep = spdep;
#endif
        for (;pmap_curmaxkvaddr < maxkvaddr; pmap_curmaxkvaddr += L1_S_SIZE,
#ifdef ARM_MMU_EXTENDED
             pdep++,
#endif
             l1slot++) {
                struct l2_bucket *l2b =
                    pmap_grow_l2_bucket(kpm, pmap_curmaxkvaddr);
                KASSERT(l2b != NULL);

                const pd_entry_t npde = L1_C_PROTO | l2b->l2b_pa
                    | L1_C_DOM(PMAP_DOMAIN_KERNEL);
#ifdef ARM_MMU_EXTENDED
                KASSERT(*pdep == 0);
                l1pte_setone(pdep, npde);
#else
                /* Distribute new L1 entry to all L1s */
                SLIST_FOREACH(l1, &l1_list, l1_link) {
                        pd_entry_t * const pdep = &l1->l1_kva[l1slot];
                        l1pte_setone(pdep, npde);
                        PDE_SYNC(pdep);
                }
#endif
        }
#ifdef ARM_MMU_EXTENDED
        PDE_SYNC_RANGE(spdep, pdep - spdep);
#endif

#ifdef PMAP_CACHE_VIVT
        /*
         * flush out the cache, expensive but growkernel will happen so
         * rarely
         */
        cpu_dcache_wbinv_all();
        cpu_tlb_flushD();
        cpu_cpwait();
#endif

        mutex_exit(&kpm_lock);
        splx(s);

        kasan_shadow_map((void *)pmap_maxkvaddr,
            (size_t)(pmap_curmaxkvaddr - pmap_maxkvaddr));

out:
        return pmap_curmaxkvaddr;
}

/************************ Utility routines ****************************/

#ifndef ARM_HAS_VBAR
/*
 * vector_page_setprot:
 *
 *      Manipulate the protection of the vector page.
 */
void
vector_page_setprot(int prot)
{
        struct l2_bucket *l2b;
        pt_entry_t *ptep;

#if defined(CPU_ARMV7) || defined(CPU_ARM11)
        /*
         * If we are using VBAR to use the vectors in the kernel, then it's
         * already mapped in the kernel text so no need to anything here.
         */
        if (vector_page != ARM_VECTORS_LOW && vector_page != ARM_VECTORS_HIGH) {
                KASSERT((armreg_pfr1_read() & ARM_PFR1_SEC_MASK) != 0);
                return;
        }
#endif

        l2b = pmap_get_l2_bucket(pmap_kernel(), vector_page);
        KASSERT(l2b != NULL);

        ptep = &l2b->l2b_kva[l2pte_index(vector_page)];

        const pt_entry_t opte = *ptep;
#ifdef ARM_MMU_EXTENDED
        const pt_entry_t npte = (opte & ~(L2_S_PROT_MASK|L2_XS_XN))
            | L2_S_PROT(PTE_KERNEL, prot);
#else
        const pt_entry_t npte = (opte & ~L2_S_PROT_MASK)
            | L2_S_PROT(PTE_KERNEL, prot);
#endif
        l2pte_set(ptep, npte, opte);
        PTE_SYNC(ptep);
        cpu_tlb_flushD_SE(vector_page);
        cpu_cpwait();
}
#endif

/*
 * Fetch pointers to the PDE/PTE for the given pmap/VA pair.
 * Returns true if the mapping exists, else false.
 *
 * NOTE: This function is only used by a couple of arm-specific modules.
 * It is not safe to take any pmap locks here, since we could be right
 * in the middle of debugging the pmap anyway...
 *
 * It is possible for this routine to return false even though a valid
 * mapping does exist. This is because we don't lock, so the metadata
 * state may be inconsistent.
 *
 * NOTE: We can return a NULL *ptp in the case where the L1 pde is
 * a "section" mapping.
 */
bool
pmap_get_pde_pte(pmap_t pm, vaddr_t va, pd_entry_t **pdp, pt_entry_t **ptp)
{
        struct l2_dtable *l2;
        pd_entry_t *pdep, pde;
        pt_entry_t *ptep;
        u_short l1slot;

        if (pm->pm_l1 == NULL)
                return false;

        l1slot = l1pte_index(va);
        *pdp = pdep = pmap_l1_kva(pm) + l1slot;
        pde = *pdep;

        if (l1pte_section_p(pde)) {
                *ptp = NULL;
                return true;
        }

        l2 = pm->pm_l2[L2_IDX(l1slot)];
        if (l2 == NULL ||
            (ptep = l2->l2_bucket[L2_BUCKET(l1slot)].l2b_kva) == NULL) {
                return false;
        }

        *ptp = &ptep[l2pte_index(va)];
        return true;
}

bool
pmap_get_pde(pmap_t pm, vaddr_t va, pd_entry_t **pdp)
{

        if (pm->pm_l1 == NULL)
                return false;

        *pdp = pmap_l1_kva(pm) + l1pte_index(va);

        return true;
}

/************************ Bootstrapping routines ****************************/

#ifndef ARM_MMU_EXTENDED
static void
pmap_init_l1(struct l1_ttable *l1, pd_entry_t *l1pt)
{
        int i;

        l1->l1_kva = l1pt;
        l1->l1_domain_use_count = 0;
        l1->l1_domain_first = 0;

        for (i = 0; i < PMAP_DOMAINS; i++)
                l1->l1_domain_free[i] = i + 1;

        /*
         * Copy the kernel's L1 entries to each new L1.
         */
        if (pmap_initialized)
                memcpy(l1pt, pmap_l1_kva(pmap_kernel()), L1_TABLE_SIZE);

        if (pmap_extract(pmap_kernel(), (vaddr_t)l1pt,
            &l1->l1_physaddr) == false)
                panic("pmap_init_l1: can't get PA of L1 at %p", l1pt);

        SLIST_INSERT_HEAD(&l1_list, l1, l1_link);
        TAILQ_INSERT_TAIL(&l1_lru_list, l1, l1_lru);
}
#endif /* !ARM_MMU_EXTENDED */

/*
 * pmap_bootstrap() is called from the board-specific initarm() routine
 * once the kernel L1/L2 descriptors tables have been set up.
 *
 * This is a somewhat convoluted process since pmap bootstrap is, effectively,
 * spread over a number of disparate files/functions.
 *
 * We are passed the following parameters
 *  - vstart
 *    1MB-aligned start of managed kernel virtual memory.
 *  - vend
 *    1MB-aligned end of managed kernel virtual memory.
 *
 * We use 'kernel_l1pt' to build the metadata (struct l1_ttable and
 * struct l2_dtable) necessary to track kernel mappings.
 */
#define PMAP_STATIC_L2_SIZE 16
void
pmap_bootstrap(vaddr_t vstart, vaddr_t vend)
{
        static struct l2_dtable static_l2[PMAP_STATIC_L2_SIZE];
#ifndef ARM_MMU_EXTENDED
        static struct l1_ttable static_l1;
        struct l1_ttable *l1 = &static_l1;
#endif
        struct l2_dtable *l2;
        struct l2_bucket *l2b;
        pd_entry_t *l1pt = (pd_entry_t *) kernel_l1pt.pv_va;
        pmap_t pm = pmap_kernel();
        pt_entry_t *ptep;
        paddr_t pa;
        vsize_t size;
        int nptes, l2idx, l2next = 0;

#ifdef ARM_MMU_EXTENDED
        KASSERT(pte_l1_s_cache_mode == pte_l1_s_cache_mode_pt);
        KASSERT(pte_l2_s_cache_mode == pte_l2_s_cache_mode_pt);
#endif

        VPRINTF("kpm ");
        /*
         * Initialise the kernel pmap object
         */
        curcpu()->ci_pmap_cur = pm;
        pm->pm_refs = 1;
#ifdef ARM_MMU_EXTENDED
        pm->pm_l1 = l1pt;
        pm->pm_l1_pa = kernel_l1pt.pv_pa;
        VPRINTF("tlb0 ");
        pmap_tlb_info_init(&pmap_tlb0_info);
#ifdef MULTIPROCESSOR
        VPRINTF("kcpusets ");
        pm->pm_onproc = kcpuset_running;
        pm->pm_active = kcpuset_running;
#endif
#else
        pm->pm_l1 = l1;
#endif
        mutex_init(&pm->pm_lock, MUTEX_DEFAULT, IPL_VM);


#if defined(EFI_RUNTIME)
        VPRINTF("efirt ");
        memset(&efirt_pmap, 0, sizeof(efirt_pmap));
        struct pmap * const efipm = &efirt_pmap;
        struct pmap_asid_info * const efipai = PMAP_PAI(efipm, cpu_tlb_info(curcpu()));

        efipai->pai_asid = KERNEL_PID;
        efipm->pm_refs = 1;
        efipm->pm_stats.wired_count = 0;
        efipm->pm_stats.resident_count = 1;
        efipm->pm_l1 = (pd_entry_t *)efirt_l1pt.pv_va;
        efipm->pm_l1_pa = efirt_l1pt.pv_pa;
        // Needed?
#ifdef MULTIPROCESSOR
        kcpuset_create(&efipm->pm_active, true);
        kcpuset_create(&efipm->pm_onproc, true);
#endif
        mutex_init(&efipm->pm_lock, MUTEX_DEFAULT, IPL_NONE);
#endif

        VPRINTF("locks ");
        /*
         * pmap_kenter_pa() and pmap_kremove() may be called from interrupt
         * context, so its locks have to be at IPL_VM
         */
        mutex_init(&pmap_lock, MUTEX_DEFAULT, IPL_VM);
        mutex_init(&kpm_lock, MUTEX_DEFAULT, IPL_NONE);

        VPRINTF("l1pt ");
        /*
         * Scan the L1 translation table created by initarm() and create
         * the required metadata for all valid mappings found in it.
         */
        for (size_t l1slot = 0;
             l1slot < L1_TABLE_SIZE / sizeof(pd_entry_t);
             l1slot++) {
                pd_entry_t pde = l1pt[l1slot];

                /*
                 * We're only interested in Coarse mappings.
                 * pmap_extract() can deal with section mappings without
                 * recourse to checking L2 metadata.
                 */
                if ((pde & L1_TYPE_MASK) != L1_TYPE_C)
                        continue;

                /*
                 * Lookup the KVA of this L2 descriptor table
                 */
                pa = l1pte_pa(pde);
                ptep = (pt_entry_t *)kernel_pt_lookup(pa);
                if (ptep == NULL) {
                        panic("pmap_bootstrap: No L2 for va 0x%x, pa 0x%lx",
                            (u_int)l1slot << L1_S_SHIFT, pa);
                }

                /*
                 * Fetch the associated L2 metadata structure.
                 * Allocate a new one if necessary.
                 */
                if ((l2 = pm->pm_l2[L2_IDX(l1slot)]) == NULL) {
                        if (l2next == PMAP_STATIC_L2_SIZE)
                                panic("pmap_bootstrap: out of static L2s");
                        pm->pm_l2[L2_IDX(l1slot)] = l2 = &static_l2[l2next++];
                }

                /*
                 * One more L1 slot tracked...
                 */
                l2->l2_occupancy++;

                /*
                 * Fill in the details of the L2 descriptor in the
                 * appropriate bucket.
                 */
                l2b = &l2->l2_bucket[L2_BUCKET(l1slot)];
                l2b->l2b_kva = ptep;
                l2b->l2b_pa = pa;
                l2b->l2b_l1slot = l1slot;

                /*
                 * Establish an initial occupancy count for this descriptor
                 */
                for (l2idx = 0;
                    l2idx < (L2_TABLE_SIZE_REAL / sizeof(pt_entry_t));
                    l2idx++) {
                        if ((ptep[l2idx] & L2_TYPE_MASK) != L2_TYPE_INV) {
                                l2b->l2b_occupancy++;
                        }
                }

                /*
                 * Make sure the descriptor itself has the correct cache mode.
                 * If not, fix it, but whine about the problem. Port-meisters
                 * should consider this a clue to fix up their initarm()
                 * function. :)
                 */
                if (pmap_set_pt_cache_mode(l1pt, (vaddr_t)ptep, 1)) {
                        printf("pmap_bootstrap: WARNING! wrong cache mode for "
                            "L2 pte @ %p\n", ptep);
                }
        }

        VPRINTF("cache(l1pt) ");
        /*
         * Ensure the primary (kernel) L1 has the correct cache mode for
         * a page table. Bitch if it is not correctly set.
         */
        if (pmap_set_pt_cache_mode(l1pt, kernel_l1pt.pv_va,
                    L1_TABLE_SIZE / L2_S_SIZE)) {
                printf("pmap_bootstrap: WARNING! wrong cache mode for "
                    "primary L1 @ 0x%lx\n", kernel_l1pt.pv_va);
        }
#if defined(EFI_RUNTIME)
        if (pmap_set_pt_cache_mode(l1pt, efirt_l1pt.pv_va,
                    L1_TABLE_SIZE / L2_S_SIZE)) {
                printf("pmap_bootstrap: WARNING! wrong cache mode for "
                    "EFI RT L1 @ 0x%lx\n", efirt_l1pt.pv_va);
        }
#endif

#ifdef PMAP_CACHE_VIVT
        cpu_dcache_wbinv_all();
        cpu_tlb_flushID();
        cpu_cpwait();
#endif

        /*
         * now we allocate the "special" VAs which are used for tmp mappings
         * by the pmap (and other modules).  we allocate the VAs by advancing
         * virtual_avail (note that there are no pages mapped at these VAs).
         *
         * Managed KVM space start from wherever initarm() tells us.
         */
        virtual_avail = vstart;
        virtual_end = vend;

        VPRINTF("specials ");

        pmap_alloc_specials(&virtual_avail, 1, &memhook, NULL);

#ifdef PMAP_CACHE_VIPT
        /*
         * If we have a VIPT cache, we need one page/pte per possible alias
         * page so we won't violate cache aliasing rules.
         */
        virtual_avail = (virtual_avail + arm_cache_prefer_mask) & ~arm_cache_prefer_mask;
        nptes = (arm_cache_prefer_mask >> L2_S_SHIFT) + 1;
        nptes = roundup(nptes, PAGE_SIZE / L2_S_SIZE);
        if (arm_pcache.icache_type != CACHE_TYPE_PIPT
            && arm_pcache.icache_way_size > nptes * L2_S_SIZE) {
                nptes = arm_pcache.icache_way_size >> L2_S_SHIFT;
                nptes = roundup(nptes, PAGE_SIZE / L2_S_SIZE);
        }
#else
        nptes = PAGE_SIZE / L2_S_SIZE;
#endif
#ifdef MULTIPROCESSOR
        cnptes = nptes;
        nptes *= arm_cpu_max;
#endif
        pmap_alloc_specials(&virtual_avail, nptes, &csrcp, &csrc_pte);
        pmap_set_pt_cache_mode(l1pt, (vaddr_t)csrc_pte, nptes);
        pmap_alloc_specials(&virtual_avail, nptes, &cdstp, &cdst_pte);
        pmap_set_pt_cache_mode(l1pt, (vaddr_t)cdst_pte, nptes);
        if (msgbufaddr == NULL) {
                pmap_alloc_specials(&virtual_avail,
                    round_page(MSGBUFSIZE) / PAGE_SIZE,
                    (void *)&msgbufaddr, NULL);
        }

        /*
         * Allocate a range of kernel virtual address space to be used
         * for L2 descriptor tables and metadata allocation in
         * pmap_growkernel().
         */
        size = howmany(virtual_end - pmap_curmaxkvaddr, L1_S_SIZE);
        pmap_alloc_specials(&virtual_avail,
            round_page(size * L2_TABLE_SIZE_REAL) / PAGE_SIZE,
            &pmap_kernel_l2ptp_kva, NULL);

        size = howmany(size, L2_BUCKET_SIZE);
        pmap_alloc_specials(&virtual_avail,
            round_page(size * sizeof(struct l2_dtable)) / PAGE_SIZE,
            &pmap_kernel_l2dtable_kva, NULL);

#ifndef ARM_MMU_EXTENDED
        /*
         * init the static-global locks and global pmap list.
         */
        mutex_init(&l1_lru_lock, MUTEX_DEFAULT, IPL_VM);

        /*
         * We can now initialise the first L1's metadata.
         */
        SLIST_INIT(&l1_list);
        TAILQ_INIT(&l1_lru_list);
        pmap_init_l1(l1, l1pt);
#endif /* ARM_MMU_EXTENDED */

#ifndef ARM_HAS_VBAR
        /* Set up vector page L1 details, if necessary */
        if (vector_page < KERNEL_BASE) {
                pm->pm_pl1vec = pmap_l1_kva(pm) + l1pte_index(vector_page);
                l2b = pmap_get_l2_bucket(pm, vector_page);
                KDASSERT(l2b != NULL);
                pm->pm_l1vec = l2b->l2b_pa | L1_C_PROTO |
                    L1_C_DOM(pmap_domain(pm));
        } else
                pm->pm_pl1vec = NULL;
#endif

        VPRINTF("pools ");
        /*
         * Initialize the pmap cache
         */
        pool_cache_bootstrap(&pmap_cache, sizeof(struct pmap), 0, 0, 0,
            "pmappl", NULL, IPL_NONE, pmap_pmap_ctor, NULL, NULL);

        /*
         * Initialize the pv pool.
         */
        pool_init(&pmap_pv_pool, sizeof(struct pv_entry), 0, 0, 0, "pvepl",
            &pmap_bootstrap_pv_allocator, IPL_NONE);

        /*
         * Initialize the L2 dtable pool and cache.
         */
        pool_cache_bootstrap(&pmap_l2dtable_cache, sizeof(struct l2_dtable), 0,
            0, 0, "l2dtblpl", NULL, IPL_NONE, pmap_l2dtable_ctor, NULL, NULL);

        /*
         * Initialise the L2 descriptor table pool and cache
         */
        pool_cache_bootstrap(&pmap_l2ptp_cache, L2_TABLE_SIZE_REAL,
            L2_TABLE_SIZE_REAL, 0, 0, "l2ptppl", NULL, IPL_NONE,
            pmap_l2ptp_ctor, NULL, NULL);

        mutex_init(&memlock, MUTEX_DEFAULT, IPL_NONE);

        cpu_dcache_wbinv_all();
}

static bool
pmap_set_pt_cache_mode(pd_entry_t *kl1, vaddr_t va, size_t nptes)
{
#ifdef ARM_MMU_EXTENDED
        return false;
#else
        if (pte_l1_s_cache_mode == pte_l1_s_cache_mode_pt
            && pte_l2_s_cache_mode == pte_l2_s_cache_mode_pt)
                return false;

        const vaddr_t eva = va + nptes * PAGE_SIZE;
        int rv = 0;

        while (va < eva) {
                /*
                 * Make sure the descriptor itself has the correct cache mode
                 */
                pd_entry_t * const pdep = &kl1[l1pte_index(va)];
                pd_entry_t pde = *pdep;

                if (l1pte_section_p(pde)) {
                        KASSERT((L1_S_CACHE_MASK & L1_S_V6_SUPER) == 0);
                        if ((pde & L1_S_CACHE_MASK) != pte_l1_s_cache_mode_pt) {
                                *pdep = (pde & ~L1_S_CACHE_MASK) |
                                    pte_l1_s_cache_mode_pt;
                                PDE_SYNC(pdep);
                                cpu_dcache_wbinv_range((vaddr_t)pdep,
                                    sizeof(*pdep));
                                rv = 1;
                        }
                        return rv;
                }
                vaddr_t pa = l1pte_pa(pde);
                pt_entry_t *ptep = (pt_entry_t *)kernel_pt_lookup(pa);
                if (ptep == NULL)
                        panic("pmap_bootstrap: No PTP for va %#lx\n", va);

                ptep += l2pte_index(va);
                const pt_entry_t opte = *ptep;
                if ((opte & L2_S_CACHE_MASK) != pte_l2_s_cache_mode_pt) {
                        const pt_entry_t npte = (opte & ~L2_S_CACHE_MASK)
                            | pte_l2_s_cache_mode_pt;
                        l2pte_set(ptep, npte, opte);
                        PTE_SYNC(ptep);
                        cpu_dcache_wbinv_range((vaddr_t)ptep, sizeof(*ptep));
                        rv = 1;
                }
                va += PAGE_SIZE;
        }

        return rv;
#endif
}

static void
pmap_alloc_specials(vaddr_t *availp, int pages, vaddr_t *vap, pt_entry_t **ptep)
{
        vaddr_t va = *availp;
        struct l2_bucket *l2b;

        if (ptep) {
                l2b = pmap_get_l2_bucket(pmap_kernel(), va);
                if (l2b == NULL)
                        panic("pmap_alloc_specials: no l2b for 0x%lx", va);

                *ptep = &l2b->l2b_kva[l2pte_index(va)];
        }

        *vap = va;
        *availp = va + (PAGE_SIZE * pages);
}

void
pmap_init(void)
{

        /*
         * Set the available memory vars - These do not map to real memory
         * addresses and cannot as the physical memory is fragmented.
         * They are used by ps for %mem calculations.
         * One could argue whether this should be the entire memory or just
         * the memory that is useable in a user process.
         */
        avail_start = ptoa(uvm_physseg_get_avail_start(uvm_physseg_get_first()));
        avail_end = ptoa(uvm_physseg_get_avail_end(uvm_physseg_get_last()));

        /*
         * Now we need to free enough pv_entry structures to allow us to get
         * the kmem_map/kmem_object allocated and inited (done after this
         * function is finished).  to do this we allocate one bootstrap page out
         * of kernel_map and use it to provide an initial pool of pv_entry
         * structures.   we never free this page.
         */
        pool_setlowat(&pmap_pv_pool, (PAGE_SIZE / sizeof(struct pv_entry)) * 2);

#ifdef ARM_MMU_EXTENDED
        /*
         * Initialise the L1 pool and cache.
         */

        pool_cache_bootstrap(&pmap_l1tt_cache, L1TT_SIZE, L1TT_SIZE,
            0, 0, "l1ttpl", &pmap_l1tt_allocator, IPL_NONE, pmap_l1tt_ctor,
             NULL, NULL);

        int error __diagused = pmap_maxproc_set(maxproc);
        KASSERT(error == 0);

        pmap_tlb_info_evcnt_attach(&pmap_tlb0_info);
#endif

        pmap_initialized = true;
}

static vaddr_t last_bootstrap_page = 0;
static void *free_bootstrap_pages = NULL;

static void *
pmap_bootstrap_pv_page_alloc(struct pool *pp, int flags)
{
        extern void *pool_page_alloc(struct pool *, int);
        vaddr_t new_page;
        void *rv;

        if (pmap_initialized)
                return pool_page_alloc(pp, flags);

        if (free_bootstrap_pages) {
                rv = free_bootstrap_pages;
                free_bootstrap_pages = *((void **)rv);
                return rv;
        }

        KASSERT(kernel_map != NULL);
        new_page = uvm_km_alloc(kernel_map, PAGE_SIZE, 0,
            UVM_KMF_WIRED | ((flags & PR_WAITOK) ? 0 : UVM_KMF_NOWAIT));

        KASSERT(new_page > last_bootstrap_page);
        last_bootstrap_page = new_page;
        return (void *)new_page;
}

static void
pmap_bootstrap_pv_page_free(struct pool *pp, void *v)
{
        extern void pool_page_free(struct pool *, void *);

        if ((vaddr_t)v <= last_bootstrap_page) {
                *((void **)v) = free_bootstrap_pages;
                free_bootstrap_pages = v;
                return;
        }

        if (pmap_initialized) {
                pool_page_free(pp, v);
                return;
        }
}


#if defined(ARM_MMU_EXTENDED)
static void *
pmap_l1tt_alloc(struct pool *pp, int flags)
{
        struct pglist plist;
        vaddr_t va;

        const int waitok = flags & PR_WAITOK;

        int error = uvm_pglistalloc(L1TT_SIZE, 0, -1, L1TT_SIZE, 0, &plist, 1,
            waitok);
        if (error)
                panic("Cannot allocate L1TT physical pages, %d", error);

        struct vm_page *pg = TAILQ_FIRST(&plist);
#if !defined( __HAVE_MM_MD_DIRECT_MAPPED_PHYS)

        /* Allocate a L1 translation table VA */
        va = uvm_km_alloc(kernel_map, L1TT_SIZE, L1TT_SIZE, UVM_KMF_VAONLY);
        if (va == 0)
                panic("Cannot allocate L1TT KVA");

        const vaddr_t eva = va + L1TT_SIZE;
        vaddr_t mva = va;
        while (pg && mva < eva) {
                paddr_t pa = VM_PAGE_TO_PHYS(pg);

                pmap_kenter_pa(mva, pa,
                    VM_PROT_READ|VM_PROT_WRITE, PMAP_KMPAGE|PMAP_PTE);

                mva += PAGE_SIZE;
                pg = TAILQ_NEXT(pg, pageq.queue);
        }
        KASSERTMSG(pg == NULL && mva == eva, "pg %p mva %" PRIxVADDR
            " eva %" PRIxVADDR, pg, mva, eva);
#else
        bool ok;
        paddr_t pa = VM_PAGE_TO_PHYS(pg);
        va = pmap_direct_mapped_phys(pa, &ok, 0);
        KASSERT(ok);
        KASSERT(va >= KERNEL_BASE);
#endif

        return (void *)va;
}

static void
pmap_l1tt_free(struct pool *pp, void *v)
{
        vaddr_t va = (vaddr_t)v;

#if !defined( __HAVE_MM_MD_DIRECT_MAPPED_PHYS)
        uvm_km_free(kernel_map, va, L1TT_SIZE, UVM_KMF_WIRED);
#else
#if defined(KERNEL_BASE_VOFFSET)
        paddr_t pa = va - KERNEL_BASE_VOFFSET;
#else
        paddr_t pa = va - KERNEL_BASE + physical_start;
#endif
        const paddr_t epa = pa + L1TT_SIZE;

        for (; pa < epa; pa += PAGE_SIZE) {
                struct vm_page *pg = PHYS_TO_VM_PAGE(pa);
                uvm_pagefree(pg);
        }
#endif
}
#endif

/*
 * pmap_postinit()
 *
 * This routine is called after the vm and kmem subsystems have been
 * initialised. This allows the pmap code to perform any initialisation
 * that can only be done once the memory allocation is in place.
 */
void
pmap_postinit(void)
{
#ifndef ARM_MMU_EXTENDED
        extern paddr_t physical_start, physical_end;
        struct l1_ttable *l1;
        struct pglist plist;
        struct vm_page *m;
        pd_entry_t *pdep;
        vaddr_t va, eva;
        u_int loop, needed;
        int error;
#endif

        pool_cache_setlowat(&pmap_l2ptp_cache, (PAGE_SIZE / L2_TABLE_SIZE_REAL) * 4);
        pool_cache_setlowat(&pmap_l2dtable_cache,
            (PAGE_SIZE / sizeof(struct l2_dtable)) * 2);

#ifndef ARM_MMU_EXTENDED
        needed = (maxproc / PMAP_DOMAINS) + ((maxproc % PMAP_DOMAINS) ? 1 : 0);
        needed -= 1;

        l1 = kmem_alloc(sizeof(*l1) * needed, KM_SLEEP);

        for (loop = 0; loop < needed; loop++, l1++) {
                /* Allocate a L1 page table */
                va = uvm_km_alloc(kernel_map, L1_TABLE_SIZE, 0, UVM_KMF_VAONLY);
                if (va == 0)
                        panic("Cannot allocate L1 KVM");

                error = uvm_pglistalloc(L1_TABLE_SIZE, physical_start,
                    physical_end, L1_TABLE_SIZE, 0, &plist, 1, 1);
                if (error)
                        panic("Cannot allocate L1 physical pages");

                m = TAILQ_FIRST(&plist);
                eva = va + L1_TABLE_SIZE;
                pdep = (pd_entry_t *)va;

                while (m && va < eva) {
                        paddr_t pa = VM_PAGE_TO_PHYS(m);

                        pmap_kenter_pa(va, pa,
                            VM_PROT_READ|VM_PROT_WRITE, PMAP_KMPAGE|PMAP_PTE);

                        va += PAGE_SIZE;
                        m = TAILQ_NEXT(m, pageq.queue);
                }

#ifdef DIAGNOSTIC
                if (m)
                        panic("pmap_alloc_l1pt: pglist not empty");
#endif  /* DIAGNOSTIC */

                pmap_init_l1(l1, pdep);
        }

#ifdef DEBUG
        printf("pmap_postinit: Allocated %d static L1 descriptor tables\n",
            needed);
#endif
#endif /* !ARM_MMU_EXTENDED */
}

/*
 * Note that the following routines are used by board-specific initialisation
 * code to configure the initial kernel page tables.
 *
 */

/*
 * This list exists for the benefit of pmap_map_chunk().  It keeps track
 * of the kernel L2 tables during bootstrap, so that pmap_map_chunk() can
 * find them as necessary.
 *
 * Note that the data on this list MUST remain valid after initarm() returns,
 * as pmap_bootstrap() uses it to construct L2 table metadata.
 */
SLIST_HEAD(, pv_addr) kernel_pt_list = SLIST_HEAD_INITIALIZER(kernel_pt_list);

static vaddr_t
kernel_pt_lookup(paddr_t pa)
{
        pv_addr_t *pv;

        SLIST_FOREACH(pv, &kernel_pt_list, pv_list) {
                if (pv->pv_pa == (pa & ~PGOFSET))
                        return pv->pv_va | (pa & PGOFSET);
        }
        return 0;
}

/*
 * pmap_map_section:
 *
 *      Create a single section mapping.
 */
void
pmap_map_section(vaddr_t l1pt, vaddr_t va, paddr_t pa, int prot, int cache)
{
        pd_entry_t * const pdep = (pd_entry_t *) l1pt;
        const size_t l1slot = l1pte_index(va);
        pd_entry_t fl;

        KASSERT(((va | pa) & L1_S_OFFSET) == 0);

        switch (cache) {
        case PTE_NOCACHE:
                fl = pte_l1_s_nocache_mode;
                break;

        case PTE_CACHE:
                fl = pte_l1_s_cache_mode;
                break;

        case PTE_PAGETABLE:
                fl = pte_l1_s_cache_mode_pt;
                break;

        case PTE_DEV:
        default:
                fl = 0;
                break;
        }

        const pd_entry_t npde = L1_S_PROTO | pa |
            L1_S_PROT(PTE_KERNEL, prot) | fl | L1_S_DOM(PMAP_DOMAIN_KERNEL);
        l1pte_setone(pdep + l1slot, npde);
        PDE_SYNC(pdep + l1slot);
}

/*
 * pmap_map_entry:
 *
 *      Create a single page mapping.
 */
void
pmap_map_entry(vaddr_t l1pt, vaddr_t va, paddr_t pa, int prot, int cache)
{
        pd_entry_t * const pdep = (pd_entry_t *) l1pt;
        const size_t l1slot = l1pte_index(va);
        pt_entry_t npte;
        pt_entry_t *ptep;

        KASSERT(((va | pa) & PGOFSET) == 0);

        switch (cache) {
        case PTE_NOCACHE:
                npte = pte_l2_s_nocache_mode;
                break;

        case PTE_CACHE:
                npte = pte_l2_s_cache_mode;
                break;

        case PTE_PAGETABLE:
                npte = pte_l2_s_cache_mode_pt;
                break;

        default:
                npte = 0;
                break;
        }

        if ((pdep[l1slot] & L1_TYPE_MASK) != L1_TYPE_C)
                panic("pmap_map_entry: no L2 table for VA 0x%08lx", va);

        ptep = (pt_entry_t *) kernel_pt_lookup(l1pte_pa(pdep[l1slot]));
        if (ptep == NULL)
                panic("pmap_map_entry: can't find L2 table for VA 0x%08lx", va);

        npte |= L2_S_PROTO | pa | L2_S_PROT(PTE_KERNEL, prot);
#ifdef ARM_MMU_EXTENDED
        if (prot & VM_PROT_EXECUTE) {
                npte &= ~L2_XS_XN;
        }
#endif
        ptep += l2pte_index(va);
        l2pte_set(ptep, npte, 0);
        PTE_SYNC(ptep);
}

/*
 * pmap_link_l2pt:
 *
 *      Link the L2 page table specified by "l2pv" into the L1
 *      page table at the slot for "va".
 */
void
pmap_link_l2pt(vaddr_t l1pt, vaddr_t va, pv_addr_t *l2pv)
{
        pd_entry_t * const pdep = (pd_entry_t *) l1pt + l1pte_index(va);

        KASSERT((va & ((L1_S_SIZE * (PAGE_SIZE / L2_T_SIZE)) - 1)) == 0);
        KASSERT((l2pv->pv_pa & PGOFSET) == 0);

        const pd_entry_t npde = L1_C_DOM(PMAP_DOMAIN_KERNEL) | L1_C_PROTO
            | l2pv->pv_pa;

        l1pte_set(pdep, npde);
        PDE_SYNC_RANGE(pdep, PAGE_SIZE / L2_T_SIZE);

        SLIST_INSERT_HEAD(&kernel_pt_list, l2pv, pv_list);
}

/*
 * pmap_map_chunk:
 *
 *      Map a chunk of memory using the most efficient mappings
 *      possible (section, large page, small page) into the
 *      provided L1 and L2 tables at the specified virtual address.
 */
vsize_t
pmap_map_chunk(vaddr_t l1pt, vaddr_t va, paddr_t pa, vsize_t size,
    int prot, int cache)
{
        pd_entry_t * const pdep = (pd_entry_t *) l1pt;
        pt_entry_t f1, f2s, f2l;
        vsize_t resid;

        resid = (size + (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);

        if (l1pt == 0)
                panic("pmap_map_chunk: no L1 table provided");

//      VPRINTF("pmap_map_chunk: pa=0x%lx va=0x%lx size=0x%lx resid=0x%lx "
//          "prot=0x%x cache=%d\n", pa, va, size, resid, prot, cache);

        switch (cache) {
        case PTE_NOCACHE:
                f1 = pte_l1_s_nocache_mode;
                f2l = pte_l2_l_nocache_mode;
                f2s = pte_l2_s_nocache_mode;
                break;

        case PTE_CACHE:
                f1 = pte_l1_s_cache_mode;
                f2l = pte_l2_l_cache_mode;
                f2s = pte_l2_s_cache_mode;
                break;

        case PTE_PAGETABLE:
                f1 = pte_l1_s_cache_mode_pt;
                f2l = pte_l2_l_cache_mode_pt;
                f2s = pte_l2_s_cache_mode_pt;
                break;

        case PTE_DEV:
        default:
                f1 = 0;
                f2l = 0;
                f2s = 0;
                break;
        }

        size = resid;

        while (resid > 0) {
                const size_t l1slot = l1pte_index(va);
#ifdef ARM_MMU_EXTENDED
                /* See if we can use a supersection mapping. */
                if (L1_SS_PROTO && L1_SS_MAPPABLE_P(va, pa, resid)) {
                        /* Supersection are always domain 0 */
                        const pd_entry_t npde = L1_SS_PROTO | pa
                            | ((prot & VM_PROT_EXECUTE) ? 0 : L1_S_V6_XN)
                            | (va & 0x80000000 ? 0 : L1_S_V6_nG)
                            | L1_S_PROT(PTE_KERNEL, prot) | f1;
                        VPRINTF("sS");
                        l1pte_set(&pdep[l1slot], npde);
                        PDE_SYNC_RANGE(&pdep[l1slot], L1_SS_SIZE / L1_S_SIZE);
//                      VPRINTF("\npmap_map_chunk: pa=0x%lx va=0x%lx resid=0x%08lx "
//                          "npdep=%p pde=0x%x\n", pa, va, resid, &pdep[l1slot], npde);
                        va += L1_SS_SIZE;
                        pa += L1_SS_SIZE;
                        resid -= L1_SS_SIZE;
                        continue;
                }
#endif
                /* See if we can use a section mapping. */
                if (L1_S_MAPPABLE_P(va, pa, resid)) {
                        const pd_entry_t npde = L1_S_PROTO | pa
#ifdef ARM_MMU_EXTENDED
                            | ((prot & VM_PROT_EXECUTE) ? 0 : L1_S_V6_XN)
                            | (va & 0x80000000 ? 0 : L1_S_V6_nG)
#endif
                            | L1_S_PROT(PTE_KERNEL, prot) | f1
                            | L1_S_DOM(PMAP_DOMAIN_KERNEL);
                        VPRINTF("S");
                        l1pte_set(&pdep[l1slot], npde);
                        PDE_SYNC(&pdep[l1slot]);
//                      VPRINTF("\npmap_map_chunk: pa=0x%lx va=0x%lx resid=0x%08lx "
//                          "npdep=%p pde=0x%x\n", pa, va, resid, &pdep[l1slot], npde);
                        va += L1_S_SIZE;
                        pa += L1_S_SIZE;
                        resid -= L1_S_SIZE;
                        continue;
                }

                /*
                 * Ok, we're going to use an L2 table.  Make sure
                 * one is actually in the corresponding L1 slot
                 * for the current VA.
                 */
                if ((pdep[l1slot] & L1_TYPE_MASK) != L1_TYPE_C)
                        panic("%s: no L2 table for VA %#lx", __func__, va);

                pt_entry_t *ptep = (pt_entry_t *) kernel_pt_lookup(l1pte_pa(pdep[l1slot]));
                if (ptep == NULL)
                        panic("%s: can't find L2 table for VA %#lx", __func__,
                            va);

                ptep += l2pte_index(va);

                /* See if we can use a L2 large page mapping. */
                if (L2_L_MAPPABLE_P(va, pa, resid)) {
                        const pt_entry_t npte = L2_L_PROTO | pa
#ifdef ARM_MMU_EXTENDED
                            | ((prot & VM_PROT_EXECUTE) ? 0 : L2_XS_L_XN)
                            | (va & 0x80000000 ? 0 : L2_XS_nG)
#endif
                            | L2_L_PROT(PTE_KERNEL, prot) | f2l;
                        VPRINTF("L");
                        l2pte_set(ptep, npte, 0);
                        PTE_SYNC_RANGE(ptep, L2_L_SIZE / L2_S_SIZE);
                        va += L2_L_SIZE;
                        pa += L2_L_SIZE;
                        resid -= L2_L_SIZE;
                        continue;
                }

                VPRINTF("P");
                /* Use a small page mapping. */
                pt_entry_t npte = L2_S_PROTO | pa
#ifdef ARM_MMU_EXTENDED
                    | ((prot & VM_PROT_EXECUTE) ? 0 : L2_XS_XN)
                    | (va & 0x80000000 ? 0 : L2_XS_nG)
#endif
                    | L2_S_PROT(PTE_KERNEL, prot) | f2s;
#ifdef ARM_MMU_EXTENDED
                npte &= ((prot & VM_PROT_EXECUTE) ? ~L2_XS_XN : ~0);
#endif
                l2pte_set(ptep, npte, 0);
                PTE_SYNC(ptep);
                va += PAGE_SIZE;
                pa += PAGE_SIZE;
                resid -= PAGE_SIZE;
        }
        VPRINTF("\n");
        return size;
}

/*
 * pmap_unmap_chunk:
 *
 *      Unmap a chunk of memory that was previously pmap_map_chunk
 */
void
pmap_unmap_chunk(vaddr_t l1pt, vaddr_t va, vsize_t size)
{
        pd_entry_t * const pdep = (pd_entry_t *) l1pt;
        const size_t l1slot = l1pte_index(va);

        KASSERT(size == L1_SS_SIZE || size == L1_S_SIZE);

        l1pte_set(&pdep[l1slot], 0);
        PDE_SYNC_RANGE(&pdep[l1slot], size / L1_S_SIZE);

        pmap_tlb_flush_SE(pmap_kernel(), va, PVF_REF);
}


vsize_t
pmap_kenter_range(vaddr_t va, paddr_t pa, vsize_t size, vm_prot_t prot,
    u_int flags)
{
        const vaddr_t root = pmap_devmap_root();

        int cache;
        switch (flags) {
        case PMAP_DEV:
                cache = PTE_DEV;
                break;
        case PMAP_NOCACHE:
                cache = PTE_NOCACHE;
                break;
        default:
                cache = PTE_CACHE;
                break;
        }

        return pmap_map_chunk(root, va, pa, size, prot, cache);
}


/********************** PTE initialization routines **************************/

/*
 * These routines are called when the CPU type is identified to set up
 * the PTE prototypes, cache modes, etc.
 *
 * The variables are always here, just in case modules need to reference
 * them (though, they shouldn't).
 */

pt_entry_t      pte_l1_s_nocache_mode;
pt_entry_t      pte_l1_s_cache_mode;
pt_entry_t      pte_l1_s_wc_mode;
pt_entry_t      pte_l1_s_cache_mode_pt;
pt_entry_t      pte_l1_s_cache_mask;

pt_entry_t      pte_l2_l_nocache_mode;
pt_entry_t      pte_l2_l_cache_mode;
pt_entry_t      pte_l2_l_wc_mode;
pt_entry_t      pte_l2_l_cache_mode_pt;
pt_entry_t      pte_l2_l_cache_mask;

pt_entry_t      pte_l2_s_nocache_mode;
pt_entry_t      pte_l2_s_cache_mode;
pt_entry_t      pte_l2_s_wc_mode;
pt_entry_t      pte_l2_s_cache_mode_pt;
pt_entry_t      pte_l2_s_cache_mask;

pt_entry_t      pte_l1_s_prot_u;
pt_entry_t      pte_l1_s_prot_w;
pt_entry_t      pte_l1_s_prot_ro;
pt_entry_t      pte_l1_s_prot_mask;

pt_entry_t      pte_l2_s_prot_u;
pt_entry_t      pte_l2_s_prot_w;
pt_entry_t      pte_l2_s_prot_ro;
pt_entry_t      pte_l2_s_prot_mask;

pt_entry_t      pte_l2_l_prot_u;
pt_entry_t      pte_l2_l_prot_w;
pt_entry_t      pte_l2_l_prot_ro;
pt_entry_t      pte_l2_l_prot_mask;

pt_entry_t      pte_l1_ss_proto;
pt_entry_t      pte_l1_s_proto;
pt_entry_t      pte_l1_c_proto;
pt_entry_t      pte_l2_s_proto;

void            (*pmap_copy_page_func)(paddr_t, paddr_t);
void            (*pmap_zero_page_func)(paddr_t);

#if (ARM_MMU_GENERIC + ARM_MMU_SA1 + ARM_MMU_V6 + ARM_MMU_V7) != 0
void
pmap_pte_init_generic(void)
{

        pte_l1_s_nocache_mode = 0;
        pte_l1_s_cache_mode = L1_S_B|L1_S_C;
        pte_l1_s_wc_mode = L1_S_B;
        pte_l1_s_cache_mask = L1_S_CACHE_MASK_generic;

        pte_l2_l_nocache_mode = 0;
        pte_l2_l_cache_mode = L2_B|L2_C;
        pte_l2_l_wc_mode = L2_B;
        pte_l2_l_cache_mask = L2_L_CACHE_MASK_generic;

        pte_l2_s_nocache_mode = 0;
        pte_l2_s_cache_mode = L2_B|L2_C;
        pte_l2_s_wc_mode = L2_B;
        pte_l2_s_cache_mask = L2_S_CACHE_MASK_generic;

        /*
         * If we have a write-through cache, set B and C.  If
         * we have a write-back cache, then we assume setting
         * only C will make those pages write-through (except for those
         * Cortex CPUs which can read the L1 caches).
         */
        if (cpufuncs.cf_dcache_wb_range == (void *) cpufunc_nullop
#if ARM_MMU_V7 > 0
            || CPU_ID_CORTEX_P(curcpu()->ci_arm_cpuid)
#endif
#if ARM_MMU_V6 > 0
            || CPU_ID_ARM11_P(curcpu()->ci_arm_cpuid) /* arm116 errata 399234 */
#endif
            || false) {
                pte_l1_s_cache_mode_pt = L1_S_B|L1_S_C;
                pte_l2_l_cache_mode_pt = L2_B|L2_C;
                pte_l2_s_cache_mode_pt = L2_B|L2_C;
        } else {
                pte_l1_s_cache_mode_pt = L1_S_C;        /* write through */
                pte_l2_l_cache_mode_pt = L2_C;          /* write through */
                pte_l2_s_cache_mode_pt = L2_C;          /* write through */
        }

        pte_l1_s_prot_u = L1_S_PROT_U_generic;
        pte_l1_s_prot_w = L1_S_PROT_W_generic;
        pte_l1_s_prot_ro = L1_S_PROT_RO_generic;
        pte_l1_s_prot_mask = L1_S_PROT_MASK_generic;

        pte_l2_s_prot_u = L2_S_PROT_U_generic;
        pte_l2_s_prot_w = L2_S_PROT_W_generic;
        pte_l2_s_prot_ro = L2_S_PROT_RO_generic;
        pte_l2_s_prot_mask = L2_S_PROT_MASK_generic;

        pte_l2_l_prot_u = L2_L_PROT_U_generic;
        pte_l2_l_prot_w = L2_L_PROT_W_generic;
        pte_l2_l_prot_ro = L2_L_PROT_RO_generic;
        pte_l2_l_prot_mask = L2_L_PROT_MASK_generic;

        pte_l1_ss_proto = L1_SS_PROTO_generic;
        pte_l1_s_proto = L1_S_PROTO_generic;
        pte_l1_c_proto = L1_C_PROTO_generic;
        pte_l2_s_proto = L2_S_PROTO_generic;

        pmap_copy_page_func = pmap_copy_page_generic;
        pmap_zero_page_func = pmap_zero_page_generic;
}

#if defined(CPU_ARM8)
void
pmap_pte_init_arm8(void)
{

        /*
         * ARM8 is compatible with generic, but we need to use
         * the page tables uncached.
         */
        pmap_pte_init_generic();

        pte_l1_s_cache_mode_pt = 0;
        pte_l2_l_cache_mode_pt = 0;
        pte_l2_s_cache_mode_pt = 0;
}
#endif /* CPU_ARM8 */

#if defined(CPU_ARM9) && defined(ARM9_CACHE_WRITE_THROUGH)
void
pmap_pte_init_arm9(void)
{

        /*
         * ARM9 is compatible with generic, but we want to use
         * write-through caching for now.
         */
        pmap_pte_init_generic();

        pte_l1_s_cache_mode = L1_S_C;
        pte_l2_l_cache_mode = L2_C;
        pte_l2_s_cache_mode = L2_C;

        pte_l1_s_wc_mode = L1_S_B;
        pte_l2_l_wc_mode = L2_B;
        pte_l2_s_wc_mode = L2_B;

        pte_l1_s_cache_mode_pt = L1_S_C;
        pte_l2_l_cache_mode_pt = L2_C;
        pte_l2_s_cache_mode_pt = L2_C;
}
#endif /* CPU_ARM9 && ARM9_CACHE_WRITE_THROUGH */
#endif /* (ARM_MMU_GENERIC + ARM_MMU_SA1 + ARM_MMU_V6) != 0 */

#if defined(CPU_ARM10)
void
pmap_pte_init_arm10(void)
{

        /*
         * ARM10 is compatible with generic, but we want to use
         * write-through caching for now.
         */
        pmap_pte_init_generic();

        pte_l1_s_cache_mode = L1_S_B | L1_S_C;
        pte_l2_l_cache_mode = L2_B | L2_C;
        pte_l2_s_cache_mode = L2_B | L2_C;

        pte_l1_s_cache_mode = L1_S_B;
        pte_l2_l_cache_mode = L2_B;
        pte_l2_s_cache_mode = L2_B;

        pte_l1_s_cache_mode_pt = L1_S_C;
        pte_l2_l_cache_mode_pt = L2_C;
        pte_l2_s_cache_mode_pt = L2_C;

}
#endif /* CPU_ARM10 */

#if defined(CPU_ARM11) && defined(ARM11_CACHE_WRITE_THROUGH)
void
pmap_pte_init_arm11(void)
{

        /*
         * ARM11 is compatible with generic, but we want to use
         * write-through caching for now.
         */
        pmap_pte_init_generic();

        pte_l1_s_cache_mode = L1_S_C;
        pte_l2_l_cache_mode = L2_C;
        pte_l2_s_cache_mode = L2_C;

        pte_l1_s_wc_mode = L1_S_B;
        pte_l2_l_wc_mode = L2_B;
        pte_l2_s_wc_mode = L2_B;

        pte_l1_s_cache_mode_pt = L1_S_C;
        pte_l2_l_cache_mode_pt = L2_C;
        pte_l2_s_cache_mode_pt = L2_C;
}
#endif /* CPU_ARM11 && ARM11_CACHE_WRITE_THROUGH */

#if ARM_MMU_SA1 == 1
void
pmap_pte_init_sa1(void)
{

        /*
         * The StrongARM SA-1 cache does not have a write-through
         * mode.  So, do the generic initialization, then reset
         * the page table cache mode to B=1,C=1, and note that
         * the PTEs need to be sync'd.
         */
        pmap_pte_init_generic();

        pte_l1_s_cache_mode_pt = L1_S_B|L1_S_C;
        pte_l2_l_cache_mode_pt = L2_B|L2_C;
        pte_l2_s_cache_mode_pt = L2_B|L2_C;

        pmap_needs_pte_sync = 1;
}
#endif /* ARM_MMU_SA1 == 1*/

#if ARM_MMU_XSCALE == 1
#if (ARM_NMMUS > 1)
static u_int xscale_use_minidata;
#endif

void
pmap_pte_init_xscale(void)
{
        uint32_t auxctl;
        int write_through = 0;

        pte_l1_s_cache_mode = L1_S_B|L1_S_C;
        pte_l1_s_wc_mode = L1_S_B;
        pte_l1_s_cache_mask = L1_S_CACHE_MASK_xscale;

        pte_l2_l_cache_mode = L2_B|L2_C;
        pte_l2_l_wc_mode = L2_B;
        pte_l2_l_cache_mask = L2_L_CACHE_MASK_xscale;

        pte_l2_s_cache_mode = L2_B|L2_C;
        pte_l2_s_wc_mode = L2_B;
        pte_l2_s_cache_mask = L2_S_CACHE_MASK_xscale;

        pte_l1_s_cache_mode_pt = L1_S_C;
        pte_l2_l_cache_mode_pt = L2_C;
        pte_l2_s_cache_mode_pt = L2_C;

#ifdef XSCALE_CACHE_READ_WRITE_ALLOCATE
        /*
         * The XScale core has an enhanced mode where writes that
         * miss the cache cause a cache line to be allocated.  This
         * is significantly faster than the traditional, write-through
         * behavior of this case.
         */
        pte_l1_s_cache_mode |= L1_S_XS_TEX(TEX_XSCALE_X);
        pte_l2_l_cache_mode |= L2_XS_L_TEX(TEX_XSCALE_X);
        pte_l2_s_cache_mode |= L2_XS_T_TEX(TEX_XSCALE_X);
#endif /* XSCALE_CACHE_READ_WRITE_ALLOCATE */

#ifdef XSCALE_CACHE_WRITE_THROUGH
        /*
         * Some versions of the XScale core have various bugs in
         * their cache units, the work-around for which is to run
         * the cache in write-through mode.  Unfortunately, this
         * has a major (negative) impact on performance.  So, we
         * go ahead and run fast-and-loose, in the hopes that we
         * don't line up the planets in a way that will trip the
         * bugs.
         *
         * However, we give you the option to be slow-but-correct.
         */
        write_through = 1;
#elif defined(XSCALE_CACHE_WRITE_BACK)
        /* force write back cache mode */
        write_through = 0;
#elif defined(CPU_XSCALE_PXA250) || defined(CPU_XSCALE_PXA270)
        /*
         * Intel PXA2[15]0 processors are known to have a bug in
         * write-back cache on revision 4 and earlier (stepping
         * A[01] and B[012]).  Fixed for C0 and later.
         */
        {
                uint32_t id, type;

                id = cpufunc_id();
                type = id & ~(CPU_ID_XSCALE_COREREV_MASK|CPU_ID_REVISION_MASK);

                if (type == CPU_ID_PXA250 || type == CPU_ID_PXA210) {
                        if ((id & CPU_ID_REVISION_MASK) < 5) {
                                /* write through for stepping A0-1 and B0-2 */
                                write_through = 1;
                        }
                }
        }
#endif /* XSCALE_CACHE_WRITE_THROUGH */

        if (write_through) {
                pte_l1_s_cache_mode = L1_S_C;
                pte_l2_l_cache_mode = L2_C;
                pte_l2_s_cache_mode = L2_C;
        }

#if (ARM_NMMUS > 1)
        xscale_use_minidata = 1;
#endif

        pte_l1_s_prot_u = L1_S_PROT_U_xscale;
        pte_l1_s_prot_w = L1_S_PROT_W_xscale;
        pte_l1_s_prot_ro = L1_S_PROT_RO_xscale;
        pte_l1_s_prot_mask = L1_S_PROT_MASK_xscale;

        pte_l2_s_prot_u = L2_S_PROT_U_xscale;
        pte_l2_s_prot_w = L2_S_PROT_W_xscale;
        pte_l2_s_prot_ro = L2_S_PROT_RO_xscale;
        pte_l2_s_prot_mask = L2_S_PROT_MASK_xscale;

        pte_l2_l_prot_u = L2_L_PROT_U_xscale;
        pte_l2_l_prot_w = L2_L_PROT_W_xscale;
        pte_l2_l_prot_ro = L2_L_PROT_RO_xscale;
        pte_l2_l_prot_mask = L2_L_PROT_MASK_xscale;

        pte_l1_ss_proto = L1_SS_PROTO_xscale;
        pte_l1_s_proto = L1_S_PROTO_xscale;
        pte_l1_c_proto = L1_C_PROTO_xscale;
        pte_l2_s_proto = L2_S_PROTO_xscale;

        pmap_copy_page_func = pmap_copy_page_xscale;
        pmap_zero_page_func = pmap_zero_page_xscale;

        /*
         * Disable ECC protection of page table access, for now.
         */
        auxctl = armreg_auxctl_read();
        auxctl &= ~XSCALE_AUXCTL_P;
        armreg_auxctl_write(auxctl);
}

/*
 * xscale_setup_minidata:
 *
 *      Set up the mini-data cache clean area.  We require the
 *      caller to allocate the right amount of physically and
 *      virtually contiguous space.
 */
void
xscale_setup_minidata(vaddr_t l1pt, vaddr_t va, paddr_t pa)
{
        pd_entry_t *pde = (pd_entry_t *) l1pt;
        vsize_t size;
        uint32_t auxctl;

        xscale_minidata_clean_addr = va;

        /* Round it to page size. */
        size = (xscale_minidata_clean_size + L2_S_OFFSET) & L2_S_FRAME;

        for (; size != 0;
             va += L2_S_SIZE, pa += L2_S_SIZE, size -= L2_S_SIZE) {
                const size_t l1slot = l1pte_index(va);
                pt_entry_t *ptep = (pt_entry_t *) kernel_pt_lookup(l1pte_pa(pde[l1slot]));
                if (ptep == NULL)
                        panic("xscale_setup_minidata: can't find L2 table for "
                            "VA 0x%08lx", va);

                ptep += l2pte_index(va);
                pt_entry_t opte = *ptep;
                l2pte_set(ptep,
                    L2_S_PROTO | pa | L2_S_PROT(PTE_KERNEL, VM_PROT_READ)
                    | L2_C | L2_XS_T_TEX(TEX_XSCALE_X), opte);
        }

        /*
         * Configure the mini-data cache for write-back with
         * read/write-allocate.
         *
         * NOTE: In order to reconfigure the mini-data cache, we must
         * make sure it contains no valid data!  In order to do that,
         * we must issue a global data cache invalidate command!
         *
         * WE ASSUME WE ARE RUNNING UN-CACHED WHEN THIS ROUTINE IS CALLED!
         * THIS IS VERY IMPORTANT!
         */

        /* Invalidate data and mini-data. */
        __asm volatile("mcr p15, 0, %0, c7, c6, 0" : : "r" (0));
        auxctl = armreg_auxctl_read();
        auxctl = (auxctl & ~XSCALE_AUXCTL_MD_MASK) | XSCALE_AUXCTL_MD_WB_RWA;
        armreg_auxctl_write(auxctl);
}

/*
 * Change the PTEs for the specified kernel mappings such that they
 * will use the mini data cache instead of the main data cache.
 */
void
pmap_uarea(vaddr_t va)
{
        vaddr_t next_bucket, eva;

#if (ARM_NMMUS > 1)
        if (xscale_use_minidata == 0)
                return;
#endif

        eva = va + USPACE;

        while (va < eva) {
                next_bucket = L2_NEXT_BUCKET_VA(va);
                if (next_bucket > eva)
                        next_bucket = eva;

                struct l2_bucket *l2b = pmap_get_l2_bucket(pmap_kernel(), va);
                KDASSERT(l2b != NULL);

                pt_entry_t * const sptep = &l2b->l2b_kva[l2pte_index(va)];
                pt_entry_t *ptep = sptep;

                while (va < next_bucket) {
                        const pt_entry_t opte = *ptep;
                        if (!l2pte_minidata_p(opte)) {
                                cpu_dcache_wbinv_range(va, PAGE_SIZE);
                                cpu_tlb_flushD_SE(va);
                                l2pte_set(ptep, opte & ~L2_B, opte);
                        }
                        ptep += PAGE_SIZE / L2_S_SIZE;
                        va += PAGE_SIZE;
                }
                PTE_SYNC_RANGE(sptep, (u_int)(ptep - sptep));
        }
        cpu_cpwait();
}
#endif /* ARM_MMU_XSCALE == 1 */


#if defined(CPU_ARM11MPCORE)
void
pmap_pte_init_arm11mpcore(void)
{

        /* cache mode is controlled by 5 bits (B, C, TEX[2:0]) */
        pte_l1_s_cache_mask = L1_S_CACHE_MASK_armv6;
        pte_l2_l_cache_mask = L2_L_CACHE_MASK_armv6;
#if defined(ARM11MPCORE_COMPAT_MMU) || defined(ARMV6_EXTENDED_SMALL_PAGE)
        /* use extended small page (without APn, with TEX) */
        pte_l2_s_cache_mask = L2_XS_CACHE_MASK_armv6;
#else
        pte_l2_s_cache_mask = L2_S_CACHE_MASK_armv6c;
#endif

        /* write-back, write-allocate */
        pte_l1_s_cache_mode = L1_S_C | L1_S_B | L1_S_V6_TEX(0x01);
        pte_l2_l_cache_mode = L2_C | L2_B | L2_V6_L_TEX(0x01);
#if defined(ARM11MPCORE_COMPAT_MMU) || defined(ARMV6_EXTENDED_SMALL_PAGE)
        pte_l2_s_cache_mode = L2_C | L2_B | L2_V6_XS_TEX(0x01);
#else
        /* no TEX. read-allocate */
        pte_l2_s_cache_mode = L2_C | L2_B;
#endif
        /*
         * write-back, write-allocate for page tables.
         */
        pte_l1_s_cache_mode_pt = L1_S_C | L1_S_B | L1_S_V6_TEX(0x01);
        pte_l2_l_cache_mode_pt = L2_C | L2_B | L2_V6_L_TEX(0x01);
#if defined(ARM11MPCORE_COMPAT_MMU) || defined(ARMV6_EXTENDED_SMALL_PAGE)
        pte_l2_s_cache_mode_pt = L2_C | L2_B | L2_V6_XS_TEX(0x01);
#else
        pte_l2_s_cache_mode_pt = L2_C | L2_B;
#endif

        pte_l1_s_prot_u = L1_S_PROT_U_armv6;
        pte_l1_s_prot_w = L1_S_PROT_W_armv6;
        pte_l1_s_prot_ro = L1_S_PROT_RO_armv6;
        pte_l1_s_prot_mask = L1_S_PROT_MASK_armv6;

#if defined(ARM11MPCORE_COMPAT_MMU) || defined(ARMV6_EXTENDED_SMALL_PAGE)
        pte_l2_s_prot_u = L2_S_PROT_U_armv6n;
        pte_l2_s_prot_w = L2_S_PROT_W_armv6n;
        pte_l2_s_prot_ro = L2_S_PROT_RO_armv6n;
        pte_l2_s_prot_mask = L2_S_PROT_MASK_armv6n;

#else
        /* with AP[0..3] */
        pte_l2_s_prot_u = L2_S_PROT_U_generic;
        pte_l2_s_prot_w = L2_S_PROT_W_generic;
        pte_l2_s_prot_ro = L2_S_PROT_RO_generic;
        pte_l2_s_prot_mask = L2_S_PROT_MASK_generic;
#endif

#ifdef  ARM11MPCORE_COMPAT_MMU
        /* with AP[0..3] */
        pte_l2_l_prot_u = L2_L_PROT_U_generic;
        pte_l2_l_prot_w = L2_L_PROT_W_generic;
        pte_l2_l_prot_ro = L2_L_PROT_RO_generic;
        pte_l2_l_prot_mask = L2_L_PROT_MASK_generic;

        pte_l1_ss_proto = L1_SS_PROTO_armv6;
        pte_l1_s_proto = L1_S_PROTO_armv6;
        pte_l1_c_proto = L1_C_PROTO_armv6;
        pte_l2_s_proto = L2_S_PROTO_armv6c;
#else
        pte_l2_l_prot_u = L2_L_PROT_U_armv6n;
        pte_l2_l_prot_w = L2_L_PROT_W_armv6n;
        pte_l2_l_prot_ro = L2_L_PROT_RO_armv6n;
        pte_l2_l_prot_mask = L2_L_PROT_MASK_armv6n;

        pte_l1_ss_proto = L1_SS_PROTO_armv6;
        pte_l1_s_proto = L1_S_PROTO_armv6;
        pte_l1_c_proto = L1_C_PROTO_armv6;
        pte_l2_s_proto = L2_S_PROTO_armv6n;
#endif

        pmap_copy_page_func = pmap_copy_page_generic;
        pmap_zero_page_func = pmap_zero_page_generic;
        pmap_needs_pte_sync = 1;
}
#endif  /* CPU_ARM11MPCORE */


#if ARM_MMU_V6 == 1
void
pmap_pte_init_armv6(void)
{
        /*
         * The ARMv6-A MMU is mostly compatible with generic. If the
         * AP field is zero, that now means "no access" rather than
         * read-only. The prototypes are a little different because of
         * the XN bit.
         */
        pmap_pte_init_generic();

        pte_l1_s_nocache_mode = L1_S_XS_TEX(1);
        pte_l2_l_nocache_mode = L2_XS_L_TEX(1);
        pte_l2_s_nocache_mode = L2_XS_T_TEX(1);

#ifdef ARM11_COMPAT_MMU
        /* with AP[0..3] */
        pte_l1_ss_proto = L1_SS_PROTO_armv6;
#else
        pte_l1_s_cache_mask = L1_S_CACHE_MASK_armv6n;
        pte_l2_l_cache_mask = L2_L_CACHE_MASK_armv6n;
        pte_l2_s_cache_mask = L2_S_CACHE_MASK_armv6n;

        pte_l1_ss_proto = L1_SS_PROTO_armv6;
        pte_l1_s_proto = L1_S_PROTO_armv6;
        pte_l1_c_proto = L1_C_PROTO_armv6;
        pte_l2_s_proto = L2_S_PROTO_armv6n;

        pte_l1_s_prot_u = L1_S_PROT_U_armv6;
        pte_l1_s_prot_w = L1_S_PROT_W_armv6;
        pte_l1_s_prot_ro = L1_S_PROT_RO_armv6;
        pte_l1_s_prot_mask = L1_S_PROT_MASK_armv6;

        pte_l2_l_prot_u = L2_L_PROT_U_armv6n;
        pte_l2_l_prot_w = L2_L_PROT_W_armv6n;
        pte_l2_l_prot_ro = L2_L_PROT_RO_armv6n;
        pte_l2_l_prot_mask = L2_L_PROT_MASK_armv6n;

        pte_l2_s_prot_u = L2_S_PROT_U_armv6n;
        pte_l2_s_prot_w = L2_S_PROT_W_armv6n;
        pte_l2_s_prot_ro = L2_S_PROT_RO_armv6n;
        pte_l2_s_prot_mask = L2_S_PROT_MASK_armv6n;

#endif
}
#endif /* ARM_MMU_V6 */

#if ARM_MMU_V7 == 1
void
pmap_pte_init_armv7(void)
{
        /*
         * The ARMv7-A MMU is mostly compatible with generic. If the
         * AP field is zero, that now means "no access" rather than
         * read-only. The prototypes are a little different because of
         * the XN bit.
         */
        pmap_pte_init_generic();

        pmap_needs_pte_sync = 1;

        pte_l1_s_nocache_mode = L1_S_XS_TEX(1);
        pte_l2_l_nocache_mode = L2_XS_L_TEX(1);
        pte_l2_s_nocache_mode = L2_XS_T_TEX(1);

        pte_l1_s_cache_mask = L1_S_CACHE_MASK_armv7;
        pte_l2_l_cache_mask = L2_L_CACHE_MASK_armv7;
        pte_l2_s_cache_mask = L2_S_CACHE_MASK_armv7;

        /*
         * If the core support coherent walk then updates to translation tables
         * do not require a clean to the point of unification to ensure
         * visibility by subsequent translation table walks.  That means we can
         * map everything shareable and cached and the right thing will happen.
         */
        if (__SHIFTOUT(armreg_mmfr3_read(), __BITS(23,20))) {
                pmap_needs_pte_sync = 0;

                /*
                 * write-back, no write-allocate, shareable for normal pages.
                 */
                pte_l1_s_cache_mode |= L1_S_V6_S;
                pte_l2_l_cache_mode |= L2_XS_S;
                pte_l2_s_cache_mode |= L2_XS_S;
        }

        /*
         * Page tables are just all other memory.  We can use write-back since
         * pmap_needs_pte_sync is 1 (or the MMU can read out of cache).
         */
        pte_l1_s_cache_mode_pt = pte_l1_s_cache_mode;
        pte_l2_l_cache_mode_pt = pte_l2_l_cache_mode;
        pte_l2_s_cache_mode_pt = pte_l2_s_cache_mode;

        /*
         * Check the Memory Model Features to see if this CPU supports
         * the TLBIASID coproc op.
         */
        if (__SHIFTOUT(armreg_mmfr2_read(), __BITS(16,19)) >= 2) {
                arm_has_tlbiasid_p = true;
        } else if (__SHIFTOUT(armreg_mmfr2_read(), __BITS(12,15)) >= 2) {
                arm_has_tlbiasid_p = true;
        }

        /*
         * Check the MPIDR to see if this CPU supports MP extensions.
         */
#ifdef MULTIPROCESSOR
        arm_has_mpext_p = (armreg_mpidr_read() & (MPIDR_MP|MPIDR_U)) == MPIDR_MP;
#else
        arm_has_mpext_p = false;
#endif

        pte_l1_s_prot_u = L1_S_PROT_U_armv7;
        pte_l1_s_prot_w = L1_S_PROT_W_armv7;
        pte_l1_s_prot_ro = L1_S_PROT_RO_armv7;
        pte_l1_s_prot_mask = L1_S_PROT_MASK_armv7;

        pte_l2_s_prot_u = L2_S_PROT_U_armv7;
        pte_l2_s_prot_w = L2_S_PROT_W_armv7;
        pte_l2_s_prot_ro = L2_S_PROT_RO_armv7;
        pte_l2_s_prot_mask = L2_S_PROT_MASK_armv7;

        pte_l2_l_prot_u = L2_L_PROT_U_armv7;
        pte_l2_l_prot_w = L2_L_PROT_W_armv7;
        pte_l2_l_prot_ro = L2_L_PROT_RO_armv7;
        pte_l2_l_prot_mask = L2_L_PROT_MASK_armv7;

        pte_l1_ss_proto = L1_SS_PROTO_armv7;
        pte_l1_s_proto = L1_S_PROTO_armv7;
        pte_l1_c_proto = L1_C_PROTO_armv7;
        pte_l2_s_proto = L2_S_PROTO_armv7;

}
#endif /* ARM_MMU_V7 */

/*
 * return the PA of the current L1 table, for use when handling a crash dump
 */
uint32_t
pmap_kernel_L1_addr(void)
{
#ifdef ARM_MMU_EXTENDED
        return pmap_kernel()->pm_l1_pa;
#else
        return pmap_kernel()->pm_l1->l1_physaddr;
#endif
}

#if defined(DDB)
/*
 * A couple of ddb-callable functions for dumping pmaps
 */
void pmap_dump(pmap_t);

static pt_entry_t ncptes[64];
static void pmap_dump_ncpg(pmap_t);

void
pmap_dump(pmap_t pm)
{
        struct l2_dtable *l2;
        struct l2_bucket *l2b;
        pt_entry_t *ptep, pte;
        vaddr_t l2_va, l2b_va, va;
        int i, j, k, occ, rows = 0;

        if (pm == pmap_kernel())
                printf("pmap_kernel (%p): ", pm);
        else
                printf("user pmap (%p): ", pm);

#ifdef ARM_MMU_EXTENDED
        printf("l1 at %p\n", pmap_l1_kva(pm));
#else
        printf("domain %d, l1 at %p\n", pmap_domain(pm), pmap_l1_kva(pm));
#endif

        l2_va = 0;
        for (i = 0; i < L2_SIZE; i++, l2_va += 0x01000000) {
                l2 = pm->pm_l2[i];

                if (l2 == NULL || l2->l2_occupancy == 0)
                        continue;

                l2b_va = l2_va;
                for (j = 0; j < L2_BUCKET_SIZE; j++, l2b_va += 0x00100000) {
                        l2b = &l2->l2_bucket[j];

                        if (l2b->l2b_occupancy == 0 || l2b->l2b_kva == NULL)
                                continue;

                        ptep = l2b->l2b_kva;

                        for (k = 0; k < 256 && ptep[k] == 0; k++)
                                ;

                        k &= ~63;
                        occ = l2b->l2b_occupancy;
                        va = l2b_va + (k * 4096);
                        for (; k < 256; k++, va += 0x1000) {
                                char ch = ' ';
                                if ((k % 64) == 0) {
                                        if ((rows % 8) == 0) {
                                                printf(
"          |0000   |8000   |10000  |18000  |20000  |28000  |30000  |38000\n");
                                        }
                                        printf("%08lx: ", va);
                                }

                                ncptes[k & 63] = 0;
                                pte = ptep[k];
                                if (pte == 0) {
                                        ch = '.';
                                } else {
                                        occ--;
                                        switch (pte & 0x4c) {
                                        case 0x00:
                                                ch = 'N'; /* No cache No buff */
                                                break;
                                        case 0x04:
                                                ch = 'B'; /* No cache buff */
                                                break;
                                        case 0x08:
                                                ch = 'C'; /* Cache No buff */
                                                break;
                                        case 0x0c:
                                                ch = 'F'; /* Cache Buff */
                                                break;
                                        case 0x40:
                                                ch = 'D';
                                                break;
                                        case 0x48:
                                                ch = 'm'; /* Xscale mini-data */
                                                break;
                                        default:
                                                ch = '?';
                                                break;
                                        }

                                        if ((pte & L2_S_PROT_U) == L2_S_PROT_U)
                                                ch += 0x20;

                                        if ((pte & 0xc) == 0)
                                                ncptes[k & 63] = pte;
                                }

                                if ((k % 64) == 63) {
                                        rows++;
                                        printf("%c\n", ch);
                                        pmap_dump_ncpg(pm);
                                        if (occ == 0)
                                                break;
                                } else
                                        printf("%c", ch);
                        }
                }
        }
}

static void
pmap_dump_ncpg(pmap_t pm)
{
        struct vm_page *pg;
        struct vm_page_md *md;
        struct pv_entry *pv;
        int i;

        for (i = 0; i < 63; i++) {
                if (ncptes[i] == 0)
                        continue;

                pg = PHYS_TO_VM_PAGE(l2pte_pa(ncptes[i]));
                if (pg == NULL)
                        continue;
                md = VM_PAGE_TO_MD(pg);

                printf(" pa 0x%08lx: krw %d kro %d urw %d uro %d\n",
                    VM_PAGE_TO_PHYS(pg),
                    md->krw_mappings, md->kro_mappings,
                    md->urw_mappings, md->uro_mappings);

                SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
                        printf("   %c va 0x%08lx, flags 0x%x\n",
                            (pm == pv->pv_pmap) ? '*' : ' ',
                            pv->pv_va, pv->pv_flags);
                }
        }
}
#endif

#ifdef PMAP_STEAL_MEMORY
void
pmap_boot_pageadd(pv_addr_t *newpv)
{
        pv_addr_t *pv, *npv;

        if ((pv = SLIST_FIRST(&pmap_boot_freeq)) != NULL) {
                if (newpv->pv_pa < pv->pv_va) {
                        KASSERT(newpv->pv_pa + newpv->pv_size <= pv->pv_pa);
                        if (newpv->pv_pa + newpv->pv_size == pv->pv_pa) {
                                newpv->pv_size += pv->pv_size;
                                SLIST_REMOVE_HEAD(&pmap_boot_freeq, pv_list);
                        }
                        pv = NULL;
                } else {
                        for (; (npv = SLIST_NEXT(pv, pv_list)) != NULL;
                             pv = npv) {
                                KASSERT(pv->pv_pa + pv->pv_size < npv->pv_pa);
                                KASSERT(pv->pv_pa < newpv->pv_pa);
                                if (newpv->pv_pa > npv->pv_pa)
                                        continue;
                                if (pv->pv_pa + pv->pv_size == newpv->pv_pa) {
                                        pv->pv_size += newpv->pv_size;
                                        return;
                                }
                                if (newpv->pv_pa + newpv->pv_size < npv->pv_pa)
                                        break;
                                newpv->pv_size += npv->pv_size;
                                SLIST_INSERT_AFTER(pv, newpv, pv_list);
                                SLIST_REMOVE_AFTER(newpv, pv_list);
                                return;
                        }
                }
        }

        if (pv) {
                SLIST_INSERT_AFTER(pv, newpv, pv_list);
        } else {
                SLIST_INSERT_HEAD(&pmap_boot_freeq, newpv, pv_list);
        }
}

void
pmap_boot_pagealloc(psize_t amount, psize_t mask, psize_t match,
        pv_addr_t *rpv)
{
        pv_addr_t *pv, **pvp;

        KASSERT(amount & PGOFSET);
        KASSERT((mask & PGOFSET) == 0);
        KASSERT((match & PGOFSET) == 0);
        KASSERT(amount != 0);

        for (pvp = &SLIST_FIRST(&pmap_boot_freeq);
             (pv = *pvp) != NULL;
             pvp = &SLIST_NEXT(pv, pv_list)) {
                pv_addr_t *newpv;
                psize_t off;
                /*
                 * If this entry is too small to satisfy the request...
                 */
                KASSERT(pv->pv_size > 0);
                if (pv->pv_size < amount)
                        continue;

                for (off = 0; off <= mask; off += PAGE_SIZE) {
                        if (((pv->pv_pa + off) & mask) == match
                            && off + amount <= pv->pv_size)
                                break;
                }
                if (off > mask)
                        continue;

                rpv->pv_va = pv->pv_va + off;
                rpv->pv_pa = pv->pv_pa + off;
                rpv->pv_size = amount;
                pv->pv_size -= amount;
                if (pv->pv_size == 0) {
                        KASSERT(off == 0);
                        KASSERT((vaddr_t) pv == rpv->pv_va);
                        *pvp = SLIST_NEXT(pv, pv_list);
                } else if (off == 0) {
                        KASSERT((vaddr_t) pv == rpv->pv_va);
                        newpv = (pv_addr_t *) (rpv->pv_va + amount);
                        *newpv = *pv;
                        newpv->pv_pa += amount;
                        newpv->pv_va += amount;
                        *pvp = newpv;
                } else if (off < pv->pv_size) {
                        newpv = (pv_addr_t *) (rpv->pv_va + amount);
                        *newpv = *pv;
                        newpv->pv_size -= off;
                        newpv->pv_pa += off + amount;
                        newpv->pv_va += off + amount;

                        SLIST_NEXT(pv, pv_list) = newpv;
                        pv->pv_size = off;
                } else {
                        KASSERT((vaddr_t) pv != rpv->pv_va);
                }
                memset((void *)rpv->pv_va, 0, amount);
                return;
        }

        if (!uvm_physseg_valid_p(uvm_physseg_get_first()))
                panic("pmap_boot_pagealloc: couldn't allocate memory");

        for (pvp = &SLIST_FIRST(&pmap_boot_freeq);
             (pv = *pvp) != NULL;
             pvp = &SLIST_NEXT(pv, pv_list)) {
                if (SLIST_NEXT(pv, pv_list) == NULL)
                        break;
        }
        KASSERT(mask == 0);

        for (uvm_physseg_t ups = uvm_physseg_get_first();
            uvm_physseg_valid_p(ups);
            ups = uvm_physseg_get_next(ups)) {

                paddr_t spn = uvm_physseg_get_start(ups);
                paddr_t epn = uvm_physseg_get_end(ups);
                if (spn == atop(pv->pv_pa + pv->pv_size)
                    && pv->pv_va + pv->pv_size <= ptoa(epn)) {
                        rpv->pv_va = pv->pv_va;
                        rpv->pv_pa = pv->pv_pa;
                        rpv->pv_size = amount;
                        *pvp = NULL;
                        pmap_map_chunk(kernel_l1pt.pv_va,
                             ptoa(spn) + (pv->pv_va - pv->pv_pa),
                             ptoa(spn),
                             amount - pv->pv_size,
                             VM_PROT_READ|VM_PROT_WRITE,
                             PTE_CACHE);

                        uvm_physseg_unplug(spn, atop(amount - pv->pv_size));
                        memset((void *)rpv->pv_va, 0, rpv->pv_size);
                        return;
                }
        }

        panic("pmap_boot_pagealloc: couldn't allocate memory");
}

vaddr_t
pmap_steal_memory(vsize_t size, vaddr_t *vstartp, vaddr_t *vendp)
{
        pv_addr_t pv;

        pmap_boot_pagealloc(size, 0, 0, &pv);

        return pv.pv_va;
}
#endif /* PMAP_STEAL_MEMORY */

SYSCTL_SETUP(sysctl_machdep_pmap_setup, "sysctl machdep.kmpages setup")
{
        sysctl_createv(clog, 0, NULL, NULL,
                        CTLFLAG_PERMANENT,
                        CTLTYPE_NODE, "machdep", NULL,
                        NULL, 0, NULL, 0,
                        CTL_MACHDEP, CTL_EOL);

        sysctl_createv(clog, 0, NULL, NULL,
                        CTLFLAG_PERMANENT,
                        CTLTYPE_INT, "kmpages",
                        SYSCTL_DESCR("count of pages allocated to kernel memory allocators"),
                        NULL, 0, &pmap_kmpages, 0,
                        CTL_MACHDEP, CTL_CREATE, CTL_EOL);
}

#ifdef PMAP_NEED_ALLOC_POOLPAGE
struct vm_page *
arm_pmap_alloc_poolpage(int flags)
{
        /*
         * On some systems, only some pages may be "coherent" for dma and we
         * want to prefer those for pool pages (think mbufs) but fallback to
         * any page if none is available.
         */
        if (arm_poolpage_vmfreelist != VM_FREELIST_DEFAULT) {
                return uvm_pagealloc_strat(NULL, 0, NULL, flags,
                    UVM_PGA_STRAT_FALLBACK, arm_poolpage_vmfreelist);
        }

        return uvm_pagealloc(NULL, 0, NULL, flags);
}
#endif

#if defined(ARM_MMU_EXTENDED) && defined(MULTIPROCESSOR)
void
pmap_md_tlb_info_attach(struct pmap_tlb_info *ti, struct cpu_info *ci)
{
        /* nothing */
}

int
pic_ipi_shootdown(void *arg)
{
#if PMAP_TLB_NEED_SHOOTDOWN
        pmap_tlb_shootdown_process();
#endif
        return 1;
}
#endif /* ARM_MMU_EXTENDED && MULTIPROCESSOR */


#ifdef __HAVE_MM_MD_DIRECT_MAPPED_PHYS
vaddr_t
pmap_direct_mapped_phys(paddr_t pa, bool *ok_p, vaddr_t va)
{
        bool ok = false;
        if (physical_start <= pa && pa < physical_end) {
#ifdef KERNEL_BASE_VOFFSET
                const vaddr_t newva = pa + KERNEL_BASE_VOFFSET;
#else
                const vaddr_t newva = KERNEL_BASE + pa - physical_start;
#endif
#ifdef ARM_MMU_EXTENDED
                if (newva >= KERNEL_BASE && newva < pmap_directlimit) {
#endif
                        va = newva;
                        ok = true;
#ifdef ARM_MMU_EXTENDED
                }
#endif
        }
        KASSERT(ok_p);
        *ok_p = ok;
        return va;
}

vaddr_t
pmap_map_poolpage(paddr_t pa)
{
        bool ok __diagused;
        vaddr_t va = pmap_direct_mapped_phys(pa, &ok, 0);
        KASSERTMSG(ok, "pa %#lx not direct mappable", pa);
#if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
        if (arm_cache_prefer_mask != 0) {
                struct vm_page * const pg = PHYS_TO_VM_PAGE(pa);
                struct vm_page_md * const md = VM_PAGE_TO_MD(pg);
                pmap_acquire_page_lock(md);
                pmap_vac_me_harder(md, pa, pmap_kernel(), va);
                pmap_release_page_lock(md);
        }
#endif
        return va;
}

paddr_t
pmap_unmap_poolpage(vaddr_t va)
{
        KASSERT(va >= KERNEL_BASE);
#ifdef PMAP_CACHE_VIVT
        cpu_idcache_wbinv_range(va, PAGE_SIZE);
#endif
#if defined(KERNEL_BASE_VOFFSET)
        return va - KERNEL_BASE_VOFFSET;
#else
        return va - KERNEL_BASE + physical_start;
#endif
}
#endif /* __HAVE_MM_MD_DIRECT_MAPPED_PHYS */