/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2000 Peter Wemm
*
* 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 AUTHORS 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 AUTHORS 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/proc.h>
#include <sys/mutex.h>
#include <sys/mman.h>
#include <sys/rwlock.h>
#include <sys/sysctl.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_pager.h>
/* list of phys pager objects */
static struct pagerlst phys_pager_object_list;
/* protect access to phys_pager_object_list */
static struct mtx phys_pager_mtx;
static int default_phys_pager_getpages(vm_object_t object, vm_page_t *m,
int count, int *rbehind, int *rahead);
static int default_phys_pager_populate(vm_object_t object, vm_pindex_t pidx,
int fault_type, vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last);
static boolean_t default_phys_pager_haspage(vm_object_t object,
vm_pindex_t pindex, int *before, int *after);
struct phys_pager_ops default_phys_pg_ops = {
.phys_pg_getpages = default_phys_pager_getpages,
.phys_pg_populate = default_phys_pager_populate,
.phys_pg_haspage = default_phys_pager_haspage,
.phys_pg_ctor = NULL,
.phys_pg_dtor = NULL,
};
static void
phys_pager_init(void)
{
TAILQ_INIT(&phys_pager_object_list);
mtx_init(&phys_pager_mtx, "phys_pager list", NULL, MTX_DEF);
}
vm_object_t
phys_pager_allocate(void *handle, struct phys_pager_ops *ops, void *data,
vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff, struct ucred *cred)
{
vm_object_t object, object1;
vm_pindex_t pindex;
bool init;
/*
* Offset should be page aligned.
*/
if (foff & PAGE_MASK)
return (NULL);
pindex = OFF_TO_IDX(foff + PAGE_MASK + size);
init = true;
if (handle != NULL) {
mtx_lock(&phys_pager_mtx);
/*
* Look up pager, creating as necessary.
*/
object1 = NULL;
object = vm_pager_object_lookup(&phys_pager_object_list, handle);
if (object == NULL) {
/*
* Allocate object and associate it with the pager.
*/
mtx_unlock(&phys_pager_mtx);
object1 = vm_object_allocate(OBJT_PHYS, pindex);
mtx_lock(&phys_pager_mtx);
object = vm_pager_object_lookup(&phys_pager_object_list,
handle);
if (object != NULL) {
/*
* We raced with other thread while
* allocating object.
*/
if (pindex > object->size)
object->size = pindex;
init = false;
} else {
object = object1;
object1 = NULL;
object->handle = handle;
object->un_pager.phys.ops = ops;
object->un_pager.phys.data_ptr = data;
if (ops->phys_pg_populate != NULL)
vm_object_set_flag(object, OBJ_POPULATE);
TAILQ_INSERT_TAIL(&phys_pager_object_list,
object, pager_object_list);
}
} else {
if (pindex > object->size)
object->size = pindex;
}
mtx_unlock(&phys_pager_mtx);
vm_object_deallocate(object1);
} else {
object = vm_object_allocate(OBJT_PHYS, pindex);
object->un_pager.phys.ops = ops;
object->un_pager.phys.data_ptr = data;
if (ops->phys_pg_populate != NULL)
vm_object_set_flag(object, OBJ_POPULATE);
}
if (init && ops->phys_pg_ctor != NULL)
ops->phys_pg_ctor(object, prot, foff, cred);
return (object);
}
static vm_object_t
phys_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
vm_ooffset_t foff, struct ucred *ucred)
{
return (phys_pager_allocate(handle, &default_phys_pg_ops, NULL,
size, prot, foff, ucred));
}
static void
phys_pager_dealloc(vm_object_t object)
{
if (object->handle != NULL) {
VM_OBJECT_WUNLOCK(object);
mtx_lock(&phys_pager_mtx);
TAILQ_REMOVE(&phys_pager_object_list, object, pager_object_list);
mtx_unlock(&phys_pager_mtx);
VM_OBJECT_WLOCK(object);
}
object->type = OBJT_DEAD;
if (object->un_pager.phys.ops->phys_pg_dtor != NULL)
object->un_pager.phys.ops->phys_pg_dtor(object);
object->handle = NULL;
}
/*
* Fill as many pages as vm_fault has allocated for us.
*/
static int
default_phys_pager_getpages(vm_object_t object, vm_page_t *m, int count,
int *rbehind, int *rahead)
{
int i;
for (i = 0; i < count; i++) {
if (vm_page_none_valid(m[i])) {
if ((m[i]->flags & PG_ZERO) == 0)
pmap_zero_page(m[i]);
vm_page_valid(m[i]);
}
KASSERT(vm_page_all_valid(m[i]),
("phys_pager_getpages: partially valid page %p", m[i]));
KASSERT(m[i]->dirty == 0,
("phys_pager_getpages: dirty page %p", m[i]));
}
if (rbehind)
*rbehind = 0;
if (rahead)
*rahead = 0;
return (VM_PAGER_OK);
}
static int
phys_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind,
int *rahead)
{
return (object->un_pager.phys.ops->phys_pg_getpages(object, m,
count, rbehind, rahead));
}
/*
* Implement a pretty aggressive clustered getpages strategy. Hint that
* everything in an entire 4MB window should be prefaulted at once.
*
* 4MB (1024 slots per page table page) is convenient for x86,
* but may not be for other arches.
*/
#ifndef PHYSCLUSTER
#define PHYSCLUSTER 1024
#endif
static int phys_pager_cluster = PHYSCLUSTER;
SYSCTL_INT(_vm, OID_AUTO, phys_pager_cluster, CTLFLAG_RWTUN,
&phys_pager_cluster, 0,
"prefault window size for phys pager");
/*
* Max hint to vm_page_alloc() about the further allocation needs
* inside the phys_pager_populate() loop. The number of bits used to
* implement VM_ALLOC_COUNT() determines the hard limit on this value.
* That limit is currently 65535.
*/
#define PHYSALLOC 16
static int
default_phys_pager_populate(vm_object_t object, vm_pindex_t pidx,
int fault_type __unused, vm_prot_t max_prot __unused, vm_pindex_t *first,
vm_pindex_t *last)
{
vm_page_t m;
vm_pindex_t base, end, i;
int ahead;
base = rounddown(pidx, phys_pager_cluster);
end = base + phys_pager_cluster - 1;
if (end >= object->size)
end = object->size - 1;
if (*first > base)
base = *first;
if (end > *last)
end = *last;
*first = base;
*last = end;
for (i = base; i <= end; i++) {
ahead = MIN(end - i, PHYSALLOC);
m = vm_page_grab(object, i,
VM_ALLOC_NORMAL | VM_ALLOC_COUNT(ahead));
if (!vm_page_all_valid(m))
vm_page_zero_invalid(m, TRUE);
KASSERT(m->dirty == 0,
("phys_pager_populate: dirty page %p", m));
}
return (VM_PAGER_OK);
}
static int
phys_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type,
vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last)
{
return (object->un_pager.phys.ops->phys_pg_populate(object, pidx,
fault_type, max_prot, first, last));
}
static void
phys_pager_putpages(vm_object_t object, vm_page_t *m, int count, boolean_t sync,
int *rtvals)
{
panic("phys_pager_putpage called");
}
static boolean_t
default_phys_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
int *after)
{
vm_pindex_t base, end;
base = rounddown(pindex, phys_pager_cluster);
end = base + phys_pager_cluster - 1;
if (before != NULL)
*before = pindex - base;
if (after != NULL)
*after = end - pindex;
return (TRUE);
}
static boolean_t
phys_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
int *after)
{
return (object->un_pager.phys.ops->phys_pg_haspage(object, pindex,
before, after));
}
struct pagerops physpagerops = {
.pgo_init = phys_pager_init,
.pgo_alloc = phys_pager_alloc,
.pgo_dealloc = phys_pager_dealloc,
.pgo_getpages = phys_pager_getpages,
.pgo_putpages = phys_pager_putpages,
.pgo_haspage = phys_pager_haspage,
.pgo_populate = phys_pager_populate,
};
