cxgbe/t4_tom: Read the chip's DDP page sizes and save them in a

[freebsd-src.git] / sys / vm / vm_phys.c

/*-
 * Copyright (c) 2002-2006 Rice University
 * Copyright (c) 2007 Alan L. Cox <alc@cs.rice.edu>
 * All rights reserved.
 *
 * This software was developed for the FreeBSD Project by Alan L. Cox,
 * Olivier Crameri, Peter Druschel, Sitaram Iyer, and Juan Navarro.
 *
 * 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 COPYRIGHT HOLDERS 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 COPYRIGHT
 * HOLDERS 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.
 */

/*
 *      Physical memory system implementation
 *
 * Any external functions defined by this module are only to be used by the
 * virtual memory system.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "opt_ddb.h"
#include "opt_vm.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/rwlock.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/tree.h>
#include <sys/vmmeter.h>
#include <sys/seq.h>

#include <ddb/ddb.h>

#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_phys.h>

#include <vm/vm_domain.h>

_Static_assert(sizeof(long) * NBBY >= VM_PHYSSEG_MAX,
    "Too many physsegs.");

#ifdef VM_NUMA_ALLOC
struct mem_affinity *mem_affinity;
int *mem_locality;
#endif

int vm_ndomains = 1;

struct vm_phys_seg vm_phys_segs[VM_PHYSSEG_MAX];
int vm_phys_nsegs;

struct vm_phys_fictitious_seg;
static int vm_phys_fictitious_cmp(struct vm_phys_fictitious_seg *,
    struct vm_phys_fictitious_seg *);

RB_HEAD(fict_tree, vm_phys_fictitious_seg) vm_phys_fictitious_tree =
    RB_INITIALIZER(_vm_phys_fictitious_tree);

struct vm_phys_fictitious_seg {
        RB_ENTRY(vm_phys_fictitious_seg) node;
        /* Memory region data */
        vm_paddr_t      start;
        vm_paddr_t      end;
        vm_page_t       first_page;
};

RB_GENERATE_STATIC(fict_tree, vm_phys_fictitious_seg, node,
    vm_phys_fictitious_cmp);

static struct rwlock vm_phys_fictitious_reg_lock;
MALLOC_DEFINE(M_FICT_PAGES, "vm_fictitious", "Fictitious VM pages");

static struct vm_freelist
    vm_phys_free_queues[MAXMEMDOM][VM_NFREELIST][VM_NFREEPOOL][VM_NFREEORDER];

static int vm_nfreelists;

/*
 * Provides the mapping from VM_FREELIST_* to free list indices (flind).
 */
static int vm_freelist_to_flind[VM_NFREELIST];

CTASSERT(VM_FREELIST_DEFAULT == 0);

#ifdef VM_FREELIST_ISADMA
#define VM_ISADMA_BOUNDARY      16777216
#endif
#ifdef VM_FREELIST_DMA32
#define VM_DMA32_BOUNDARY       ((vm_paddr_t)1 << 32)
#endif

/*
 * Enforce the assumptions made by vm_phys_add_seg() and vm_phys_init() about
 * the ordering of the free list boundaries.
 */
#if defined(VM_ISADMA_BOUNDARY) && defined(VM_LOWMEM_BOUNDARY)
CTASSERT(VM_ISADMA_BOUNDARY < VM_LOWMEM_BOUNDARY);
#endif
#if defined(VM_LOWMEM_BOUNDARY) && defined(VM_DMA32_BOUNDARY)
CTASSERT(VM_LOWMEM_BOUNDARY < VM_DMA32_BOUNDARY);
#endif

static int cnt_prezero;
SYSCTL_INT(_vm_stats_misc, OID_AUTO, cnt_prezero, CTLFLAG_RD,
    &cnt_prezero, 0, "The number of physical pages prezeroed at idle time");

static int sysctl_vm_phys_free(SYSCTL_HANDLER_ARGS);
SYSCTL_OID(_vm, OID_AUTO, phys_free, CTLTYPE_STRING | CTLFLAG_RD,
    NULL, 0, sysctl_vm_phys_free, "A", "Phys Free Info");

static int sysctl_vm_phys_segs(SYSCTL_HANDLER_ARGS);
SYSCTL_OID(_vm, OID_AUTO, phys_segs, CTLTYPE_STRING | CTLFLAG_RD,
    NULL, 0, sysctl_vm_phys_segs, "A", "Phys Seg Info");

#ifdef VM_NUMA_ALLOC
static int sysctl_vm_phys_locality(SYSCTL_HANDLER_ARGS);
SYSCTL_OID(_vm, OID_AUTO, phys_locality, CTLTYPE_STRING | CTLFLAG_RD,
    NULL, 0, sysctl_vm_phys_locality, "A", "Phys Locality Info");
#endif

SYSCTL_INT(_vm, OID_AUTO, ndomains, CTLFLAG_RD,
    &vm_ndomains, 0, "Number of physical memory domains available.");

/*
 * Default to first-touch + round-robin.
 */
static struct mtx vm_default_policy_mtx;
MTX_SYSINIT(vm_default_policy, &vm_default_policy_mtx, "default policy mutex",
    MTX_DEF);
#ifdef VM_NUMA_ALLOC
static struct vm_domain_policy vm_default_policy =
    VM_DOMAIN_POLICY_STATIC_INITIALISER(VM_POLICY_FIRST_TOUCH_ROUND_ROBIN, 0);
#else
/* Use round-robin so the domain policy code will only try once per allocation */
static struct vm_domain_policy vm_default_policy =
    VM_DOMAIN_POLICY_STATIC_INITIALISER(VM_POLICY_ROUND_ROBIN, 0);
#endif

static vm_page_t vm_phys_alloc_domain_pages(int domain, int flind, int pool,
    int order);
static vm_page_t vm_phys_alloc_seg_contig(struct vm_phys_seg *seg,
    u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
    vm_paddr_t boundary);
static void _vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int domain);
static void vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end);
static int vm_phys_paddr_to_segind(vm_paddr_t pa);
static void vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl,
    int order);

static int
sysctl_vm_default_policy(SYSCTL_HANDLER_ARGS)
{
        char policy_name[32];
        int error;

        mtx_lock(&vm_default_policy_mtx);

        /* Map policy to output string */
        switch (vm_default_policy.p.policy) {
        case VM_POLICY_FIRST_TOUCH:
                strcpy(policy_name, "first-touch");
                break;
        case VM_POLICY_FIRST_TOUCH_ROUND_ROBIN:
                strcpy(policy_name, "first-touch-rr");
                break;
        case VM_POLICY_ROUND_ROBIN:
        default:
                strcpy(policy_name, "rr");
                break;
        }
        mtx_unlock(&vm_default_policy_mtx);

        error = sysctl_handle_string(oidp, &policy_name[0],
            sizeof(policy_name), req);
        if (error != 0 || req->newptr == NULL)
                return (error);

        mtx_lock(&vm_default_policy_mtx);
        /* Set: match on the subset of policies that make sense as a default */
        if (strcmp("first-touch-rr", policy_name) == 0) {
                vm_domain_policy_set(&vm_default_policy,
                    VM_POLICY_FIRST_TOUCH_ROUND_ROBIN, 0);
        } else if (strcmp("first-touch", policy_name) == 0) {
                vm_domain_policy_set(&vm_default_policy,
                    VM_POLICY_FIRST_TOUCH, 0);
        } else if (strcmp("rr", policy_name) == 0) {
                vm_domain_policy_set(&vm_default_policy,
                    VM_POLICY_ROUND_ROBIN, 0);
        } else {
                error = EINVAL;
                goto finish;
        }

        error = 0;
finish:
        mtx_unlock(&vm_default_policy_mtx);
        return (error);
}

SYSCTL_PROC(_vm, OID_AUTO, default_policy, CTLTYPE_STRING | CTLFLAG_RW,
    0, 0, sysctl_vm_default_policy, "A",
    "Default policy (rr, first-touch, first-touch-rr");

/*
 * Red-black tree helpers for vm fictitious range management.
 */
static inline int
vm_phys_fictitious_in_range(struct vm_phys_fictitious_seg *p,
    struct vm_phys_fictitious_seg *range)
{

        KASSERT(range->start != 0 && range->end != 0,
            ("Invalid range passed on search for vm_fictitious page"));
        if (p->start >= range->end)
                return (1);
        if (p->start < range->start)
                return (-1);

        return (0);
}

static int
vm_phys_fictitious_cmp(struct vm_phys_fictitious_seg *p1,
    struct vm_phys_fictitious_seg *p2)
{

        /* Check if this is a search for a page */
        if (p1->end == 0)
                return (vm_phys_fictitious_in_range(p1, p2));

        KASSERT(p2->end != 0,
    ("Invalid range passed as second parameter to vm fictitious comparison"));

        /* Searching to add a new range */
        if (p1->end <= p2->start)
                return (-1);
        if (p1->start >= p2->end)
                return (1);

        panic("Trying to add overlapping vm fictitious ranges:\n"
            "[%#jx:%#jx] and [%#jx:%#jx]", (uintmax_t)p1->start,
            (uintmax_t)p1->end, (uintmax_t)p2->start, (uintmax_t)p2->end);
}

static __inline int
vm_rr_selectdomain(void)
{
#ifdef VM_NUMA_ALLOC
        struct thread *td;

        td = curthread;

        td->td_dom_rr_idx++;
        td->td_dom_rr_idx %= vm_ndomains;
        return (td->td_dom_rr_idx);
#else
        return (0);
#endif
}

/*
 * Initialise a VM domain iterator.
 *
 * Check the thread policy, then the proc policy,
 * then default to the system policy.
 *
 * Later on the various layers will have this logic
 * plumbed into them and the phys code will be explicitly
 * handed a VM domain policy to use.
 */
static void
vm_policy_iterator_init(struct vm_domain_iterator *vi)
{
#ifdef VM_NUMA_ALLOC
        struct vm_domain_policy lcl;
#endif

        vm_domain_iterator_init(vi);

#ifdef VM_NUMA_ALLOC
        /* Copy out the thread policy */
        vm_domain_policy_localcopy(&lcl, &curthread->td_vm_dom_policy);
        if (lcl.p.policy != VM_POLICY_NONE) {
                /* Thread policy is present; use it */
                vm_domain_iterator_set_policy(vi, &lcl);
                return;
        }

        vm_domain_policy_localcopy(&lcl,
            &curthread->td_proc->p_vm_dom_policy);
        if (lcl.p.policy != VM_POLICY_NONE) {
                /* Process policy is present; use it */
                vm_domain_iterator_set_policy(vi, &lcl);
                return;
        }
#endif
        /* Use system default policy */
        vm_domain_iterator_set_policy(vi, &vm_default_policy);
}

static void
vm_policy_iterator_finish(struct vm_domain_iterator *vi)
{

        vm_domain_iterator_cleanup(vi);
}

boolean_t
vm_phys_domain_intersects(long mask, vm_paddr_t low, vm_paddr_t high)
{
        struct vm_phys_seg *s;
        int idx;

        while ((idx = ffsl(mask)) != 0) {
                idx--;  /* ffsl counts from 1 */
                mask &= ~(1UL << idx);
                s = &vm_phys_segs[idx];
                if (low < s->end && high > s->start)
                        return (TRUE);
        }
        return (FALSE);
}

/*
 * Outputs the state of the physical memory allocator, specifically,
 * the amount of physical memory in each free list.
 */
static int
sysctl_vm_phys_free(SYSCTL_HANDLER_ARGS)
{
        struct sbuf sbuf;
        struct vm_freelist *fl;
        int dom, error, flind, oind, pind;

        error = sysctl_wire_old_buffer(req, 0);
        if (error != 0)
                return (error);
        sbuf_new_for_sysctl(&sbuf, NULL, 128 * vm_ndomains, req);
        for (dom = 0; dom < vm_ndomains; dom++) {
                sbuf_printf(&sbuf,"\nDOMAIN %d:\n", dom);
                for (flind = 0; flind < vm_nfreelists; flind++) {
                        sbuf_printf(&sbuf, "\nFREE LIST %d:\n"
                            "\n  ORDER (SIZE)  |  NUMBER"
                            "\n              ", flind);
                        for (pind = 0; pind < VM_NFREEPOOL; pind++)
                                sbuf_printf(&sbuf, "  |  POOL %d", pind);
                        sbuf_printf(&sbuf, "\n--            ");
                        for (pind = 0; pind < VM_NFREEPOOL; pind++)
                                sbuf_printf(&sbuf, "-- --      ");
                        sbuf_printf(&sbuf, "--\n");
                        for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
                                sbuf_printf(&sbuf, "  %2d (%6dK)", oind,
                                    1 << (PAGE_SHIFT - 10 + oind));
                                for (pind = 0; pind < VM_NFREEPOOL; pind++) {
                                fl = vm_phys_free_queues[dom][flind][pind];
                                        sbuf_printf(&sbuf, "  |  %6d",
                                            fl[oind].lcnt);
                                }
                                sbuf_printf(&sbuf, "\n");
                        }
                }
        }
        error = sbuf_finish(&sbuf);
        sbuf_delete(&sbuf);
        return (error);
}

/*
 * Outputs the set of physical memory segments.
 */
static int
sysctl_vm_phys_segs(SYSCTL_HANDLER_ARGS)
{
        struct sbuf sbuf;
        struct vm_phys_seg *seg;
        int error, segind;

        error = sysctl_wire_old_buffer(req, 0);
        if (error != 0)
                return (error);
        sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
        for (segind = 0; segind < vm_phys_nsegs; segind++) {
                sbuf_printf(&sbuf, "\nSEGMENT %d:\n\n", segind);
                seg = &vm_phys_segs[segind];
                sbuf_printf(&sbuf, "start:     %#jx\n",
                    (uintmax_t)seg->start);
                sbuf_printf(&sbuf, "end:       %#jx\n",
                    (uintmax_t)seg->end);
                sbuf_printf(&sbuf, "domain:    %d\n", seg->domain);
                sbuf_printf(&sbuf, "free list: %p\n", seg->free_queues);
        }
        error = sbuf_finish(&sbuf);
        sbuf_delete(&sbuf);
        return (error);
}

/*
 * Return affinity, or -1 if there's no affinity information.
 */
int
vm_phys_mem_affinity(int f, int t)
{

#ifdef VM_NUMA_ALLOC
        if (mem_locality == NULL)
                return (-1);
        if (f >= vm_ndomains || t >= vm_ndomains)
                return (-1);
        return (mem_locality[f * vm_ndomains + t]);
#else
        return (-1);
#endif
}

#ifdef VM_NUMA_ALLOC
/*
 * Outputs the VM locality table.
 */
static int
sysctl_vm_phys_locality(SYSCTL_HANDLER_ARGS)
{
        struct sbuf sbuf;
        int error, i, j;

        error = sysctl_wire_old_buffer(req, 0);
        if (error != 0)
                return (error);
        sbuf_new_for_sysctl(&sbuf, NULL, 128, req);

        sbuf_printf(&sbuf, "\n");

        for (i = 0; i < vm_ndomains; i++) {
                sbuf_printf(&sbuf, "%d: ", i);
                for (j = 0; j < vm_ndomains; j++) {
                        sbuf_printf(&sbuf, "%d ", vm_phys_mem_affinity(i, j));
                }
                sbuf_printf(&sbuf, "\n");
        }
        error = sbuf_finish(&sbuf);
        sbuf_delete(&sbuf);
        return (error);
}
#endif

static void
vm_freelist_add(struct vm_freelist *fl, vm_page_t m, int order, int tail)
{

        m->order = order;
        if (tail)
                TAILQ_INSERT_TAIL(&fl[order].pl, m, plinks.q);
        else
                TAILQ_INSERT_HEAD(&fl[order].pl, m, plinks.q);
        fl[order].lcnt++;
}

static void
vm_freelist_rem(struct vm_freelist *fl, vm_page_t m, int order)
{

        TAILQ_REMOVE(&fl[order].pl, m, plinks.q);
        fl[order].lcnt--;
        m->order = VM_NFREEORDER;
}

/*
 * Create a physical memory segment.
 */
static void
_vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int domain)
{
        struct vm_phys_seg *seg;

        KASSERT(vm_phys_nsegs < VM_PHYSSEG_MAX,
            ("vm_phys_create_seg: increase VM_PHYSSEG_MAX"));
        KASSERT(domain < vm_ndomains,
            ("vm_phys_create_seg: invalid domain provided"));
        seg = &vm_phys_segs[vm_phys_nsegs++];
        while (seg > vm_phys_segs && (seg - 1)->start >= end) {
                *seg = *(seg - 1);
                seg--;
        }
        seg->start = start;
        seg->end = end;
        seg->domain = domain;
}

static void
vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end)
{
#ifdef VM_NUMA_ALLOC
        int i;

        if (mem_affinity == NULL) {
                _vm_phys_create_seg(start, end, 0);
                return;
        }

        for (i = 0;; i++) {
                if (mem_affinity[i].end == 0)
                        panic("Reached end of affinity info");
                if (mem_affinity[i].end <= start)
                        continue;
                if (mem_affinity[i].start > start)
                        panic("No affinity info for start %jx",
                            (uintmax_t)start);
                if (mem_affinity[i].end >= end) {
                        _vm_phys_create_seg(start, end,
                            mem_affinity[i].domain);
                        break;
                }
                _vm_phys_create_seg(start, mem_affinity[i].end,
                    mem_affinity[i].domain);
                start = mem_affinity[i].end;
        }
#else
        _vm_phys_create_seg(start, end, 0);
#endif
}

/*
 * Add a physical memory segment.
 */
void
vm_phys_add_seg(vm_paddr_t start, vm_paddr_t end)
{
        vm_paddr_t paddr;

        KASSERT((start & PAGE_MASK) == 0,
            ("vm_phys_define_seg: start is not page aligned"));
        KASSERT((end & PAGE_MASK) == 0,
            ("vm_phys_define_seg: end is not page aligned"));

        /*
         * Split the physical memory segment if it spans two or more free
         * list boundaries.
         */
        paddr = start;
#ifdef  VM_FREELIST_ISADMA
        if (paddr < VM_ISADMA_BOUNDARY && end > VM_ISADMA_BOUNDARY) {
                vm_phys_create_seg(paddr, VM_ISADMA_BOUNDARY);
                paddr = VM_ISADMA_BOUNDARY;
        }
#endif
#ifdef  VM_FREELIST_LOWMEM
        if (paddr < VM_LOWMEM_BOUNDARY && end > VM_LOWMEM_BOUNDARY) {
                vm_phys_create_seg(paddr, VM_LOWMEM_BOUNDARY);
                paddr = VM_LOWMEM_BOUNDARY;
        }
#endif
#ifdef  VM_FREELIST_DMA32
        if (paddr < VM_DMA32_BOUNDARY && end > VM_DMA32_BOUNDARY) {
                vm_phys_create_seg(paddr, VM_DMA32_BOUNDARY);
                paddr = VM_DMA32_BOUNDARY;
        }
#endif
        vm_phys_create_seg(paddr, end);
}

/*
 * Initialize the physical memory allocator.
 *
 * Requires that vm_page_array is initialized!
 */
void
vm_phys_init(void)
{
        struct vm_freelist *fl;
        struct vm_phys_seg *seg;
        u_long npages;
        int dom, flind, freelist, oind, pind, segind;

        /*
         * Compute the number of free lists, and generate the mapping from the
         * manifest constants VM_FREELIST_* to the free list indices.
         *
         * Initially, the entries of vm_freelist_to_flind[] are set to either
         * 0 or 1 to indicate which free lists should be created.
         */
        npages = 0;
        for (segind = vm_phys_nsegs - 1; segind >= 0; segind--) {
                seg = &vm_phys_segs[segind];
#ifdef  VM_FREELIST_ISADMA
                if (seg->end <= VM_ISADMA_BOUNDARY)
                        vm_freelist_to_flind[VM_FREELIST_ISADMA] = 1;
                else
#endif
#ifdef  VM_FREELIST_LOWMEM
                if (seg->end <= VM_LOWMEM_BOUNDARY)
                        vm_freelist_to_flind[VM_FREELIST_LOWMEM] = 1;
                else
#endif
#ifdef  VM_FREELIST_DMA32
                if (
#ifdef  VM_DMA32_NPAGES_THRESHOLD
                    /*
                     * Create the DMA32 free list only if the amount of
                     * physical memory above physical address 4G exceeds the
                     * given threshold.
                     */
                    npages > VM_DMA32_NPAGES_THRESHOLD &&
#endif
                    seg->end <= VM_DMA32_BOUNDARY)
                        vm_freelist_to_flind[VM_FREELIST_DMA32] = 1;
                else
#endif
                {
                        npages += atop(seg->end - seg->start);
                        vm_freelist_to_flind[VM_FREELIST_DEFAULT] = 1;
                }
        }
        /* Change each entry into a running total of the free lists. */
        for (freelist = 1; freelist < VM_NFREELIST; freelist++) {
                vm_freelist_to_flind[freelist] +=
                    vm_freelist_to_flind[freelist - 1];
        }
        vm_nfreelists = vm_freelist_to_flind[VM_NFREELIST - 1];
        KASSERT(vm_nfreelists > 0, ("vm_phys_init: no free lists"));
        /* Change each entry into a free list index. */
        for (freelist = 0; freelist < VM_NFREELIST; freelist++)
                vm_freelist_to_flind[freelist]--;

        /*
         * Initialize the first_page and free_queues fields of each physical
         * memory segment.
         */
#ifdef VM_PHYSSEG_SPARSE
        npages = 0;
#endif
        for (segind = 0; segind < vm_phys_nsegs; segind++) {
                seg = &vm_phys_segs[segind];
#ifdef VM_PHYSSEG_SPARSE
                seg->first_page = &vm_page_array[npages];
                npages += atop(seg->end - seg->start);
#else
                seg->first_page = PHYS_TO_VM_PAGE(seg->start);
#endif
#ifdef  VM_FREELIST_ISADMA
                if (seg->end <= VM_ISADMA_BOUNDARY) {
                        flind = vm_freelist_to_flind[VM_FREELIST_ISADMA];
                        KASSERT(flind >= 0,
                            ("vm_phys_init: ISADMA flind < 0"));
                } else
#endif
#ifdef  VM_FREELIST_LOWMEM
                if (seg->end <= VM_LOWMEM_BOUNDARY) {
                        flind = vm_freelist_to_flind[VM_FREELIST_LOWMEM];
                        KASSERT(flind >= 0,
                            ("vm_phys_init: LOWMEM flind < 0"));
                } else
#endif
#ifdef  VM_FREELIST_DMA32
                if (seg->end <= VM_DMA32_BOUNDARY) {
                        flind = vm_freelist_to_flind[VM_FREELIST_DMA32];
                        KASSERT(flind >= 0,
                            ("vm_phys_init: DMA32 flind < 0"));
                } else
#endif
                {
                        flind = vm_freelist_to_flind[VM_FREELIST_DEFAULT];
                        KASSERT(flind >= 0,
                            ("vm_phys_init: DEFAULT flind < 0"));
                }
                seg->free_queues = &vm_phys_free_queues[seg->domain][flind];
        }

        /*
         * Initialize the free queues.
         */
        for (dom = 0; dom < vm_ndomains; dom++) {
                for (flind = 0; flind < vm_nfreelists; flind++) {
                        for (pind = 0; pind < VM_NFREEPOOL; pind++) {
                                fl = vm_phys_free_queues[dom][flind][pind];
                                for (oind = 0; oind < VM_NFREEORDER; oind++)
                                        TAILQ_INIT(&fl[oind].pl);
                        }
                }
        }

        rw_init(&vm_phys_fictitious_reg_lock, "vmfctr");
}

/*
 * Split a contiguous, power of two-sized set of physical pages.
 */
static __inline void
vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl, int order)
{
        vm_page_t m_buddy;

        while (oind > order) {
                oind--;
                m_buddy = &m[1 << oind];
                KASSERT(m_buddy->order == VM_NFREEORDER,
                    ("vm_phys_split_pages: page %p has unexpected order %d",
                    m_buddy, m_buddy->order));
                vm_freelist_add(fl, m_buddy, oind, 0);
        }
}

/*
 * Initialize a physical page and add it to the free lists.
 */
void
vm_phys_add_page(vm_paddr_t pa)
{
        vm_page_t m;
        struct vm_domain *vmd;

        vm_cnt.v_page_count++;
        m = vm_phys_paddr_to_vm_page(pa);
        m->phys_addr = pa;
        m->queue = PQ_NONE;
        m->segind = vm_phys_paddr_to_segind(pa);
        vmd = vm_phys_domain(m);
        vmd->vmd_page_count++;
        vmd->vmd_segs |= 1UL << m->segind;
        KASSERT(m->order == VM_NFREEORDER,
            ("vm_phys_add_page: page %p has unexpected order %d",
            m, m->order));
        m->pool = VM_FREEPOOL_DEFAULT;
        pmap_page_init(m);
        mtx_lock(&vm_page_queue_free_mtx);
        vm_phys_freecnt_adj(m, 1);
        vm_phys_free_pages(m, 0);
        mtx_unlock(&vm_page_queue_free_mtx);
}

/*
 * Allocate a contiguous, power of two-sized set of physical pages
 * from the free lists.
 *
 * The free page queues must be locked.
 */
vm_page_t
vm_phys_alloc_pages(int pool, int order)
{
        vm_page_t m;
        int domain, flind;
        struct vm_domain_iterator vi;

        KASSERT(pool < VM_NFREEPOOL,
            ("vm_phys_alloc_pages: pool %d is out of range", pool));
        KASSERT(order < VM_NFREEORDER,
            ("vm_phys_alloc_pages: order %d is out of range", order));

        vm_policy_iterator_init(&vi);

        while ((vm_domain_iterator_run(&vi, &domain)) == 0) {
                for (flind = 0; flind < vm_nfreelists; flind++) {
                        m = vm_phys_alloc_domain_pages(domain, flind, pool,
                            order);
                        if (m != NULL)
                                return (m);
                }
        }

        vm_policy_iterator_finish(&vi);
        return (NULL);
}

/*
 * Allocate a contiguous, power of two-sized set of physical pages from the
 * specified free list.  The free list must be specified using one of the
 * manifest constants VM_FREELIST_*.
 *
 * The free page queues must be locked.
 */
vm_page_t
vm_phys_alloc_freelist_pages(int freelist, int pool, int order)
{
        vm_page_t m;
        struct vm_domain_iterator vi;
        int domain;

        KASSERT(freelist < VM_NFREELIST,
            ("vm_phys_alloc_freelist_pages: freelist %d is out of range",
            freelist));
        KASSERT(pool < VM_NFREEPOOL,
            ("vm_phys_alloc_freelist_pages: pool %d is out of range", pool));
        KASSERT(order < VM_NFREEORDER,
            ("vm_phys_alloc_freelist_pages: order %d is out of range", order));

        vm_policy_iterator_init(&vi);

        while ((vm_domain_iterator_run(&vi, &domain)) == 0) {
                m = vm_phys_alloc_domain_pages(domain,
                    vm_freelist_to_flind[freelist], pool, order);
                if (m != NULL)
                        return (m);
        }

        vm_policy_iterator_finish(&vi);
        return (NULL);
}

static vm_page_t
vm_phys_alloc_domain_pages(int domain, int flind, int pool, int order)
{       
        struct vm_freelist *fl;
        struct vm_freelist *alt;
        int oind, pind;
        vm_page_t m;

        mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
        fl = &vm_phys_free_queues[domain][flind][pool][0];
        for (oind = order; oind < VM_NFREEORDER; oind++) {
                m = TAILQ_FIRST(&fl[oind].pl);
                if (m != NULL) {
                        vm_freelist_rem(fl, m, oind);
                        vm_phys_split_pages(m, oind, fl, order);
                        return (m);
                }
        }

        /*
         * The given pool was empty.  Find the largest
         * contiguous, power-of-two-sized set of pages in any
         * pool.  Transfer these pages to the given pool, and
         * use them to satisfy the allocation.
         */
        for (oind = VM_NFREEORDER - 1; oind >= order; oind--) {
                for (pind = 0; pind < VM_NFREEPOOL; pind++) {
                        alt = &vm_phys_free_queues[domain][flind][pind][0];
                        m = TAILQ_FIRST(&alt[oind].pl);
                        if (m != NULL) {
                                vm_freelist_rem(alt, m, oind);
                                vm_phys_set_pool(pool, m, oind);
                                vm_phys_split_pages(m, oind, fl, order);
                                return (m);
                        }
                }
        }
        return (NULL);
}

/*
 * Find the vm_page corresponding to the given physical address.
 */
vm_page_t
vm_phys_paddr_to_vm_page(vm_paddr_t pa)
{
        struct vm_phys_seg *seg;
        int segind;

        for (segind = 0; segind < vm_phys_nsegs; segind++) {
                seg = &vm_phys_segs[segind];
                if (pa >= seg->start && pa < seg->end)
                        return (&seg->first_page[atop(pa - seg->start)]);
        }
        return (NULL);
}

vm_page_t
vm_phys_fictitious_to_vm_page(vm_paddr_t pa)
{
        struct vm_phys_fictitious_seg tmp, *seg;
        vm_page_t m;

        m = NULL;
        tmp.start = pa;
        tmp.end = 0;

        rw_rlock(&vm_phys_fictitious_reg_lock);
        seg = RB_FIND(fict_tree, &vm_phys_fictitious_tree, &tmp);
        rw_runlock(&vm_phys_fictitious_reg_lock);
        if (seg == NULL)
                return (NULL);

        m = &seg->first_page[atop(pa - seg->start)];
        KASSERT((m->flags & PG_FICTITIOUS) != 0, ("%p not fictitious", m));

        return (m);
}

static inline void
vm_phys_fictitious_init_range(vm_page_t range, vm_paddr_t start,
    long page_count, vm_memattr_t memattr)
{
        long i;

        for (i = 0; i < page_count; i++) {
                vm_page_initfake(&range[i], start + PAGE_SIZE * i, memattr);
                range[i].oflags &= ~VPO_UNMANAGED;
                range[i].busy_lock = VPB_UNBUSIED;
        }
}

int
vm_phys_fictitious_reg_range(vm_paddr_t start, vm_paddr_t end,
    vm_memattr_t memattr)
{
        struct vm_phys_fictitious_seg *seg;
        vm_page_t fp;
        long page_count;
#ifdef VM_PHYSSEG_DENSE
        long pi, pe;
        long dpage_count;
#endif

        KASSERT(start < end,
            ("Start of segment isn't less than end (start: %jx end: %jx)",
            (uintmax_t)start, (uintmax_t)end));

        page_count = (end - start) / PAGE_SIZE;

#ifdef VM_PHYSSEG_DENSE
        pi = atop(start);
        pe = atop(end);
        if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
                fp = &vm_page_array[pi - first_page];
                if ((pe - first_page) > vm_page_array_size) {
                        /*
                         * We have a segment that starts inside
                         * of vm_page_array, but ends outside of it.
                         *
                         * Use vm_page_array pages for those that are
                         * inside of the vm_page_array range, and
                         * allocate the remaining ones.
                         */
                        dpage_count = vm_page_array_size - (pi - first_page);
                        vm_phys_fictitious_init_range(fp, start, dpage_count,
                            memattr);
                        page_count -= dpage_count;
                        start += ptoa(dpage_count);
                        goto alloc;
                }
                /*
                 * We can allocate the full range from vm_page_array,
                 * so there's no need to register the range in the tree.
                 */
                vm_phys_fictitious_init_range(fp, start, page_count, memattr);
                return (0);
        } else if (pe > first_page && (pe - first_page) < vm_page_array_size) {
                /*
                 * We have a segment that ends inside of vm_page_array,
                 * but starts outside of it.
                 */
                fp = &vm_page_array[0];
                dpage_count = pe - first_page;
                vm_phys_fictitious_init_range(fp, ptoa(first_page), dpage_count,
                    memattr);
                end -= ptoa(dpage_count);
                page_count -= dpage_count;
                goto alloc;
        } else if (pi < first_page && pe > (first_page + vm_page_array_size)) {
                /*
                 * Trying to register a fictitious range that expands before
                 * and after vm_page_array.
                 */
                return (EINVAL);
        } else {
alloc:
#endif
                fp = malloc(page_count * sizeof(struct vm_page), M_FICT_PAGES,
                    M_WAITOK | M_ZERO);
#ifdef VM_PHYSSEG_DENSE
        }
#endif
        vm_phys_fictitious_init_range(fp, start, page_count, memattr);

        seg = malloc(sizeof(*seg), M_FICT_PAGES, M_WAITOK | M_ZERO);
        seg->start = start;
        seg->end = end;
        seg->first_page = fp;

        rw_wlock(&vm_phys_fictitious_reg_lock);
        RB_INSERT(fict_tree, &vm_phys_fictitious_tree, seg);
        rw_wunlock(&vm_phys_fictitious_reg_lock);

        return (0);
}

void
vm_phys_fictitious_unreg_range(vm_paddr_t start, vm_paddr_t end)
{
        struct vm_phys_fictitious_seg *seg, tmp;
#ifdef VM_PHYSSEG_DENSE
        long pi, pe;
#endif

        KASSERT(start < end,
            ("Start of segment isn't less than end (start: %jx end: %jx)",
            (uintmax_t)start, (uintmax_t)end));

#ifdef VM_PHYSSEG_DENSE
        pi = atop(start);
        pe = atop(end);
        if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
                if ((pe - first_page) <= vm_page_array_size) {
                        /*
                         * This segment was allocated using vm_page_array
                         * only, there's nothing to do since those pages
                         * were never added to the tree.
                         */
                        return;
                }
                /*
                 * We have a segment that starts inside
                 * of vm_page_array, but ends outside of it.
                 *
                 * Calculate how many pages were added to the
                 * tree and free them.
                 */
                start = ptoa(first_page + vm_page_array_size);
        } else if (pe > first_page && (pe - first_page) < vm_page_array_size) {
                /*
                 * We have a segment that ends inside of vm_page_array,
                 * but starts outside of it.
                 */
                end = ptoa(first_page);
        } else if (pi < first_page && pe > (first_page + vm_page_array_size)) {
                /* Since it's not possible to register such a range, panic. */
                panic(
                    "Unregistering not registered fictitious range [%#jx:%#jx]",
                    (uintmax_t)start, (uintmax_t)end);
        }
#endif
        tmp.start = start;
        tmp.end = 0;

        rw_wlock(&vm_phys_fictitious_reg_lock);
        seg = RB_FIND(fict_tree, &vm_phys_fictitious_tree, &tmp);
        if (seg->start != start || seg->end != end) {
                rw_wunlock(&vm_phys_fictitious_reg_lock);
                panic(
                    "Unregistering not registered fictitious range [%#jx:%#jx]",
                    (uintmax_t)start, (uintmax_t)end);
        }
        RB_REMOVE(fict_tree, &vm_phys_fictitious_tree, seg);
        rw_wunlock(&vm_phys_fictitious_reg_lock);
        free(seg->first_page, M_FICT_PAGES);
        free(seg, M_FICT_PAGES);
}

/*
 * Find the segment containing the given physical address.
 */
static int
vm_phys_paddr_to_segind(vm_paddr_t pa)
{
        struct vm_phys_seg *seg;
        int segind;

        for (segind = 0; segind < vm_phys_nsegs; segind++) {
                seg = &vm_phys_segs[segind];
                if (pa >= seg->start && pa < seg->end)
                        return (segind);
        }
        panic("vm_phys_paddr_to_segind: paddr %#jx is not in any segment" ,
            (uintmax_t)pa);
}

/*
 * Free a contiguous, power of two-sized set of physical pages.
 *
 * The free page queues must be locked.
 */
void
vm_phys_free_pages(vm_page_t m, int order)
{
        struct vm_freelist *fl;
        struct vm_phys_seg *seg;
        vm_paddr_t pa;
        vm_page_t m_buddy;

        KASSERT(m->order == VM_NFREEORDER,
            ("vm_phys_free_pages: page %p has unexpected order %d",
            m, m->order));
        KASSERT(m->pool < VM_NFREEPOOL,
            ("vm_phys_free_pages: page %p has unexpected pool %d",
            m, m->pool));
        KASSERT(order < VM_NFREEORDER,
            ("vm_phys_free_pages: order %d is out of range", order));
        mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
        seg = &vm_phys_segs[m->segind];
        if (order < VM_NFREEORDER - 1) {
                pa = VM_PAGE_TO_PHYS(m);
                do {
                        pa ^= ((vm_paddr_t)1 << (PAGE_SHIFT + order));
                        if (pa < seg->start || pa >= seg->end)
                                break;
                        m_buddy = &seg->first_page[atop(pa - seg->start)];
                        if (m_buddy->order != order)
                                break;
                        fl = (*seg->free_queues)[m_buddy->pool];
                        vm_freelist_rem(fl, m_buddy, order);
                        if (m_buddy->pool != m->pool)
                                vm_phys_set_pool(m->pool, m_buddy, order);
                        order++;
                        pa &= ~(((vm_paddr_t)1 << (PAGE_SHIFT + order)) - 1);
                        m = &seg->first_page[atop(pa - seg->start)];
                } while (order < VM_NFREEORDER - 1);
        }
        fl = (*seg->free_queues)[m->pool];
        vm_freelist_add(fl, m, order, 1);
}

/*
 * Free a contiguous, arbitrarily sized set of physical pages.
 *
 * The free page queues must be locked.
 */
void
vm_phys_free_contig(vm_page_t m, u_long npages)
{
        u_int n;
        int order;

        /*
         * Avoid unnecessary coalescing by freeing the pages in the largest
         * possible power-of-two-sized subsets.
         */
        mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
        for (;; npages -= n) {
                /*
                 * Unsigned "min" is used here so that "order" is assigned
                 * "VM_NFREEORDER - 1" when "m"'s physical address is zero
                 * or the low-order bits of its physical address are zero
                 * because the size of a physical address exceeds the size of
                 * a long.
                 */
                order = min(ffsl(VM_PAGE_TO_PHYS(m) >> PAGE_SHIFT) - 1,
                    VM_NFREEORDER - 1);
                n = 1 << order;
                if (npages < n)
                        break;
                vm_phys_free_pages(m, order);
                m += n;
        }
        /* The residual "npages" is less than "1 << (VM_NFREEORDER - 1)". */
        for (; npages > 0; npages -= n) {
                order = flsl(npages) - 1;
                n = 1 << order;
                vm_phys_free_pages(m, order);
                m += n;
        }
}

/*
 * Scan physical memory between the specified addresses "low" and "high" for a
 * run of contiguous physical pages that satisfy the specified conditions, and
 * return the lowest page in the run.  The specified "alignment" determines
 * the alignment of the lowest physical page in the run.  If the specified
 * "boundary" is non-zero, then the run of physical pages cannot span a
 * physical address that is a multiple of "boundary".
 *
 * "npages" must be greater than zero.  Both "alignment" and "boundary" must
 * be a power of two.
 */
vm_page_t
vm_phys_scan_contig(u_long npages, vm_paddr_t low, vm_paddr_t high,
    u_long alignment, vm_paddr_t boundary, int options)
{
        vm_paddr_t pa_end;
        vm_page_t m_end, m_run, m_start;
        struct vm_phys_seg *seg;
        int segind;

        KASSERT(npages > 0, ("npages is 0"));
        KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
        KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
        if (low >= high)
                return (NULL);
        for (segind = 0; segind < vm_phys_nsegs; segind++) {
                seg = &vm_phys_segs[segind];
                if (seg->start >= high)
                        break;
                if (low >= seg->end)
                        continue;
                if (low <= seg->start)
                        m_start = seg->first_page;
                else
                        m_start = &seg->first_page[atop(low - seg->start)];
                if (high < seg->end)
                        pa_end = high;
                else
                        pa_end = seg->end;
                if (pa_end - VM_PAGE_TO_PHYS(m_start) < ptoa(npages))
                        continue;
                m_end = &seg->first_page[atop(pa_end - seg->start)];
                m_run = vm_page_scan_contig(npages, m_start, m_end,
                    alignment, boundary, options);
                if (m_run != NULL)
                        return (m_run);
        }
        return (NULL);
}

/*
 * Set the pool for a contiguous, power of two-sized set of physical pages. 
 */
void
vm_phys_set_pool(int pool, vm_page_t m, int order)
{
        vm_page_t m_tmp;

        for (m_tmp = m; m_tmp < &m[1 << order]; m_tmp++)
                m_tmp->pool = pool;
}

/*
 * Search for the given physical page "m" in the free lists.  If the search
 * succeeds, remove "m" from the free lists and return TRUE.  Otherwise, return
 * FALSE, indicating that "m" is not in the free lists.
 *
 * The free page queues must be locked.
 */
boolean_t
vm_phys_unfree_page(vm_page_t m)
{
        struct vm_freelist *fl;
        struct vm_phys_seg *seg;
        vm_paddr_t pa, pa_half;
        vm_page_t m_set, m_tmp;
        int order;

        mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);

        /*
         * First, find the contiguous, power of two-sized set of free
         * physical pages containing the given physical page "m" and
         * assign it to "m_set".
         */
        seg = &vm_phys_segs[m->segind];
        for (m_set = m, order = 0; m_set->order == VM_NFREEORDER &&
            order < VM_NFREEORDER - 1; ) {
                order++;
                pa = m->phys_addr & (~(vm_paddr_t)0 << (PAGE_SHIFT + order));
                if (pa >= seg->start)
                        m_set = &seg->first_page[atop(pa - seg->start)];
                else
                        return (FALSE);
        }
        if (m_set->order < order)
                return (FALSE);
        if (m_set->order == VM_NFREEORDER)
                return (FALSE);
        KASSERT(m_set->order < VM_NFREEORDER,
            ("vm_phys_unfree_page: page %p has unexpected order %d",
            m_set, m_set->order));

        /*
         * Next, remove "m_set" from the free lists.  Finally, extract
         * "m" from "m_set" using an iterative algorithm: While "m_set"
         * is larger than a page, shrink "m_set" by returning the half
         * of "m_set" that does not contain "m" to the free lists.
         */
        fl = (*seg->free_queues)[m_set->pool];
        order = m_set->order;
        vm_freelist_rem(fl, m_set, order);
        while (order > 0) {
                order--;
                pa_half = m_set->phys_addr ^ (1 << (PAGE_SHIFT + order));
                if (m->phys_addr < pa_half)
                        m_tmp = &seg->first_page[atop(pa_half - seg->start)];
                else {
                        m_tmp = m_set;
                        m_set = &seg->first_page[atop(pa_half - seg->start)];
                }
                vm_freelist_add(fl, m_tmp, order, 0);
        }
        KASSERT(m_set == m, ("vm_phys_unfree_page: fatal inconsistency"));
        return (TRUE);
}

/*
 * Try to zero one physical page.  Used by an idle priority thread.
 */
boolean_t
vm_phys_zero_pages_idle(void)
{
        static struct vm_freelist *fl;
        static int flind, oind, pind;
        vm_page_t m, m_tmp;
        int domain;

        domain = vm_rr_selectdomain();
        fl = vm_phys_free_queues[domain][0][0];
        mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
        for (;;) {
                TAILQ_FOREACH_REVERSE(m, &fl[oind].pl, pglist, plinks.q) {
                        for (m_tmp = m; m_tmp < &m[1 << oind]; m_tmp++) {
                                if ((m_tmp->flags & (PG_CACHED | PG_ZERO)) == 0) {
                                        vm_phys_unfree_page(m_tmp);
                                        vm_phys_freecnt_adj(m, -1);
                                        mtx_unlock(&vm_page_queue_free_mtx);
                                        pmap_zero_page_idle(m_tmp);
                                        m_tmp->flags |= PG_ZERO;
                                        mtx_lock(&vm_page_queue_free_mtx);
                                        vm_phys_freecnt_adj(m, 1);
                                        vm_phys_free_pages(m_tmp, 0);
                                        vm_page_zero_count++;
                                        cnt_prezero++;
                                        return (TRUE);
                                }
                        }
                }
                oind++;
                if (oind == VM_NFREEORDER) {
                        oind = 0;
                        pind++;
                        if (pind == VM_NFREEPOOL) {
                                pind = 0;
                                flind++;
                                if (flind == vm_nfreelists)
                                        flind = 0;
                        }
                        fl = vm_phys_free_queues[domain][flind][pind];
                }
        }
}

/*
 * Allocate a contiguous set of physical pages of the given size
 * "npages" from the free lists.  All of the physical pages must be at
 * or above the given physical address "low" and below the given
 * physical address "high".  The given value "alignment" determines the
 * alignment of the first physical page in the set.  If the given value
 * "boundary" is non-zero, then the set of physical pages cannot cross
 * any physical address boundary that is a multiple of that value.  Both
 * "alignment" and "boundary" must be a power of two.
 */
vm_page_t
vm_phys_alloc_contig(u_long npages, vm_paddr_t low, vm_paddr_t high,
    u_long alignment, vm_paddr_t boundary)
{
        vm_paddr_t pa_end, pa_start;
        vm_page_t m_run;
        struct vm_domain_iterator vi;
        struct vm_phys_seg *seg;
        int domain, segind;

        KASSERT(npages > 0, ("npages is 0"));
        KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
        KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
        mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
        if (low >= high)
                return (NULL);
        vm_policy_iterator_init(&vi);
restartdom:
        if (vm_domain_iterator_run(&vi, &domain) != 0) {
                vm_policy_iterator_finish(&vi);
                return (NULL);
        }
        m_run = NULL;
        for (segind = vm_phys_nsegs - 1; segind >= 0; segind--) {
                seg = &vm_phys_segs[segind];
                if (seg->start >= high || seg->domain != domain)
                        continue;
                if (low >= seg->end)
                        break;
                if (low <= seg->start)
                        pa_start = seg->start;
                else
                        pa_start = low;
                if (high < seg->end)
                        pa_end = high;
                else
                        pa_end = seg->end;
                if (pa_end - pa_start < ptoa(npages))
                        continue;
                m_run = vm_phys_alloc_seg_contig(seg, npages, low, high,
                    alignment, boundary);
                if (m_run != NULL)
                        break;
        }
        if (m_run == NULL && !vm_domain_iterator_isdone(&vi))
                goto restartdom;
        vm_policy_iterator_finish(&vi);
        return (m_run);
}

/*
 * Allocate a run of contiguous physical pages from the free list for the
 * specified segment.
 */
static vm_page_t
vm_phys_alloc_seg_contig(struct vm_phys_seg *seg, u_long npages,
    vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
{
        struct vm_freelist *fl;
        vm_paddr_t pa, pa_end, size;
        vm_page_t m, m_ret;
        u_long npages_end;
        int oind, order, pind;

        KASSERT(npages > 0, ("npages is 0"));
        KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
        KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
        mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
        /* Compute the queue that is the best fit for npages. */
        for (order = 0; (1 << order) < npages; order++);
        /* Search for a run satisfying the specified conditions. */
        size = npages << PAGE_SHIFT;
        for (oind = min(order, VM_NFREEORDER - 1); oind < VM_NFREEORDER;
            oind++) {
                for (pind = 0; pind < VM_NFREEPOOL; pind++) {
                        fl = (*seg->free_queues)[pind];
                        TAILQ_FOREACH(m_ret, &fl[oind].pl, plinks.q) {
                                /*
                                 * Is the size of this allocation request
                                 * larger than the largest block size?
                                 */
                                if (order >= VM_NFREEORDER) {
                                        /*
                                         * Determine if a sufficient number of
                                         * subsequent blocks to satisfy the
                                         * allocation request are free.
                                         */
                                        pa = VM_PAGE_TO_PHYS(m_ret);
                                        pa_end = pa + size;
                                        for (;;) {
                                                pa += 1 << (PAGE_SHIFT +
                                                    VM_NFREEORDER - 1);
                                                if (pa >= pa_end ||
                                                    pa < seg->start ||
                                                    pa >= seg->end)
                                                        break;
                                                m = &seg->first_page[atop(pa -
                                                    seg->start)];
                                                if (m->order != VM_NFREEORDER -
                                                    1)
                                                        break;
                                        }
                                        /* If not, go to the next block. */
                                        if (pa < pa_end)
                                                continue;
                                }

                                /*
                                 * Determine if the blocks are within the
                                 * given range, satisfy the given alignment,
                                 * and do not cross the given boundary.
                                 */
                                pa = VM_PAGE_TO_PHYS(m_ret);
                                pa_end = pa + size;
                                if (pa >= low && pa_end <= high &&
                                    (pa & (alignment - 1)) == 0 &&
                                    rounddown2(pa ^ (pa_end - 1), boundary) == 0)
                                        goto done;
                        }
                }
        }
        return (NULL);
done:
        for (m = m_ret; m < &m_ret[npages]; m = &m[1 << oind]) {
                fl = (*seg->free_queues)[m->pool];
                vm_freelist_rem(fl, m, m->order);
        }
        if (m_ret->pool != VM_FREEPOOL_DEFAULT)
                vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m_ret, oind);
        fl = (*seg->free_queues)[m_ret->pool];
        vm_phys_split_pages(m_ret, oind, fl, order);
        /* Return excess pages to the free lists. */
        npages_end = roundup2(npages, 1 << imin(oind, order));
        if (npages < npages_end)
                vm_phys_free_contig(&m_ret[npages], npages_end - npages);
        return (m_ret);
}

#ifdef DDB
/*
 * Show the number of physical pages in each of the free lists.
 */
DB_SHOW_COMMAND(freepages, db_show_freepages)
{
        struct vm_freelist *fl;
        int flind, oind, pind, dom;

        for (dom = 0; dom < vm_ndomains; dom++) {
                db_printf("DOMAIN: %d\n", dom);
                for (flind = 0; flind < vm_nfreelists; flind++) {
                        db_printf("FREE LIST %d:\n"
                            "\n  ORDER (SIZE)  |  NUMBER"
                            "\n              ", flind);
                        for (pind = 0; pind < VM_NFREEPOOL; pind++)
                                db_printf("  |  POOL %d", pind);
                        db_printf("\n--            ");
                        for (pind = 0; pind < VM_NFREEPOOL; pind++)
                                db_printf("-- --      ");
                        db_printf("--\n");
                        for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
                                db_printf("  %2.2d (%6.6dK)", oind,
                                    1 << (PAGE_SHIFT - 10 + oind));
                                for (pind = 0; pind < VM_NFREEPOOL; pind++) {
                                fl = vm_phys_free_queues[dom][flind][pind];
                                        db_printf("  |  %6.6d", fl[oind].lcnt);
                                }
                                db_printf("\n");
                        }
                        db_printf("\n");
                }
                db_printf("\n");
        }
}
#endif