/*-
* SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
*
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)vm_kern.c 8.3 (Berkeley) 1/12/94
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Authors: Avadis Tevanian, Jr., Michael Wayne Young
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*
* Kernel memory management.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_vm.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h> /* for ticks and hz */
#include <sys/domainset.h>
#include <sys/eventhandler.h>
#include <sys/lock.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/rwlock.h>
#include <sys/sysctl.h>
#include <sys/vmem.h>
#include <sys/vmmeter.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_domainset.h>
#include <vm/vm_kern.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_phys.h>
#include <vm/vm_pagequeue.h>
#include <vm/vm_radix.h>
#include <vm/vm_extern.h>
#include <vm/uma.h>
vm_map_t kernel_map;
vm_map_t exec_map;
vm_map_t pipe_map;
const void *zero_region;
CTASSERT((ZERO_REGION_SIZE & PAGE_MASK) == 0);
/* NB: Used by kernel debuggers. */
const u_long vm_maxuser_address = VM_MAXUSER_ADDRESS;
u_int exec_map_entry_size;
u_int exec_map_entries;
SYSCTL_ULONG(_vm, OID_AUTO, min_kernel_address, CTLFLAG_RD,
SYSCTL_NULL_ULONG_PTR, VM_MIN_KERNEL_ADDRESS, "Min kernel address");
SYSCTL_ULONG(_vm, OID_AUTO, max_kernel_address, CTLFLAG_RD,
#if defined(__arm__)
&vm_max_kernel_address, 0,
#else
SYSCTL_NULL_ULONG_PTR, VM_MAX_KERNEL_ADDRESS,
#endif
"Max kernel address");
#if VM_NRESERVLEVEL > 0
#define KVA_QUANTUM_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT)
#else
/* On non-superpage architectures we want large import sizes. */
#define KVA_QUANTUM_SHIFT (8 + PAGE_SHIFT)
#endif
#define KVA_QUANTUM (1 << KVA_QUANTUM_SHIFT)
extern void uma_startup2(void);
/*
* kva_alloc:
*
* Allocate a virtual address range with no underlying object and
* no initial mapping to physical memory. Any mapping from this
* range to physical memory must be explicitly created prior to
* its use, typically with pmap_qenter(). Any attempt to create
* a mapping on demand through vm_fault() will result in a panic.
*/
vm_offset_t
kva_alloc(vm_size_t size)
{
vm_offset_t addr;
size = round_page(size);
if (vmem_alloc(kernel_arena, size, M_BESTFIT | M_NOWAIT, &addr))
return (0);
return (addr);
}
/*
* kva_free:
*
* Release a region of kernel virtual memory allocated
* with kva_alloc, and return the physical pages
* associated with that region.
*
* This routine may not block on kernel maps.
*/
void
kva_free(vm_offset_t addr, vm_size_t size)
{
size = round_page(size);
vmem_free(kernel_arena, addr, size);
}
/*
* Allocates a region from the kernel address map and physical pages
* within the specified address range to the kernel object. Creates a
* wired mapping from this region to these pages, and returns the
* region's starting virtual address. The allocated pages are not
* necessarily physically contiguous. If M_ZERO is specified through the
* given flags, then the pages are zeroed before they are mapped.
*/
static vm_offset_t
kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low,
vm_paddr_t high, vm_memattr_t memattr)
{
vmem_t *vmem;
vm_object_t object = kernel_object;
vm_offset_t addr, i, offset;
vm_page_t m;
int pflags, tries;
vm_prot_t prot;
size = round_page(size);
vmem = vm_dom[domain].vmd_kernel_arena;
if (vmem_alloc(vmem, size, M_BESTFIT | flags, &addr))
return (0);
offset = addr - VM_MIN_KERNEL_ADDRESS;
pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
pflags |= VM_ALLOC_NOWAIT;
prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW;
VM_OBJECT_WLOCK(object);
for (i = 0; i < size; i += PAGE_SIZE) {
tries = 0;
retry:
m = vm_page_alloc_contig_domain(object, atop(offset + i),
domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr);
if (m == NULL) {
VM_OBJECT_WUNLOCK(object);
if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) {
if (!vm_page_reclaim_contig_domain(domain,
pflags, 1, low, high, PAGE_SIZE, 0) &&
(flags & M_WAITOK) != 0)
vm_wait_domain(domain);
VM_OBJECT_WLOCK(object);
tries++;
goto retry;
}
kmem_unback(object, addr, i);
vmem_free(vmem, addr, size);
return (0);
}
KASSERT(vm_phys_domain(m) == domain,
("kmem_alloc_attr_domain: Domain mismatch %d != %d",
vm_phys_domain(m), domain));
if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
pmap_zero_page(m);
vm_page_valid(m);
vm_page_xunbusy(m);
pmap_enter(kernel_pmap, addr + i, m, prot,
prot | PMAP_ENTER_WIRED, 0);
}
VM_OBJECT_WUNLOCK(object);
return (addr);
}
vm_offset_t
kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high,
vm_memattr_t memattr)
{
return (kmem_alloc_attr_domainset(DOMAINSET_RR(), size, flags, low,
high, memattr));
}
vm_offset_t
kmem_alloc_attr_domainset(struct domainset *ds, vm_size_t size, int flags,
vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr)
{
struct vm_domainset_iter di;
vm_offset_t addr;
int domain;
vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
do {
addr = kmem_alloc_attr_domain(domain, size, flags, low, high,
memattr);
if (addr != 0)
break;
} while (vm_domainset_iter_policy(&di, &domain) == 0);
return (addr);
}
/*
* Allocates a region from the kernel address map and physically
* contiguous pages within the specified address range to the kernel
* object. Creates a wired mapping from this region to these pages, and
* returns the region's starting virtual address. If M_ZERO is specified
* through the given flags, then the pages are zeroed before they are
* mapped.
*/
static vm_offset_t
kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low,
vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
vm_memattr_t memattr)
{
vmem_t *vmem;
vm_object_t object = kernel_object;
vm_offset_t addr, offset, tmp;
vm_page_t end_m, m;
u_long npages;
int pflags, tries;
size = round_page(size);
vmem = vm_dom[domain].vmd_kernel_arena;
if (vmem_alloc(vmem, size, flags | M_BESTFIT, &addr))
return (0);
offset = addr - VM_MIN_KERNEL_ADDRESS;
pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
pflags |= VM_ALLOC_NOWAIT;
npages = atop(size);
VM_OBJECT_WLOCK(object);
tries = 0;
retry:
m = vm_page_alloc_contig_domain(object, atop(offset), domain, pflags,
npages, low, high, alignment, boundary, memattr);
if (m == NULL) {
VM_OBJECT_WUNLOCK(object);
if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) {
if (!vm_page_reclaim_contig_domain(domain, pflags,
npages, low, high, alignment, boundary) &&
(flags & M_WAITOK) != 0)
vm_wait_domain(domain);
VM_OBJECT_WLOCK(object);
tries++;
goto retry;
}
vmem_free(vmem, addr, size);
return (0);
}
KASSERT(vm_phys_domain(m) == domain,
("kmem_alloc_contig_domain: Domain mismatch %d != %d",
vm_phys_domain(m), domain));
end_m = m + npages;
tmp = addr;
for (; m < end_m; m++) {
if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
pmap_zero_page(m);
vm_page_valid(m);
vm_page_xunbusy(m);
pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW,
VM_PROT_RW | PMAP_ENTER_WIRED, 0);
tmp += PAGE_SIZE;
}
VM_OBJECT_WUNLOCK(object);
return (addr);
}
vm_offset_t
kmem_alloc_contig(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high,
u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr)
{
return (kmem_alloc_contig_domainset(DOMAINSET_RR(), size, flags, low,
high, alignment, boundary, memattr));
}
vm_offset_t
kmem_alloc_contig_domainset(struct domainset *ds, vm_size_t size, int flags,
vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
vm_memattr_t memattr)
{
struct vm_domainset_iter di;
vm_offset_t addr;
int domain;
vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
do {
addr = kmem_alloc_contig_domain(domain, size, flags, low, high,
alignment, boundary, memattr);
if (addr != 0)
break;
} while (vm_domainset_iter_policy(&di, &domain) == 0);
return (addr);
}
/*
* kmem_suballoc:
*
* Allocates a map to manage a subrange
* of the kernel virtual address space.
*
* Arguments are as follows:
*
* parent Map to take range from
* min, max Returned endpoints of map
* size Size of range to find
* superpage_align Request that min is superpage aligned
*/
vm_map_t
kmem_suballoc(vm_map_t parent, vm_offset_t *min, vm_offset_t *max,
vm_size_t size, boolean_t superpage_align)
{
int ret;
vm_map_t result;
size = round_page(size);
*min = vm_map_min(parent);
ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ?
VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL,
MAP_ACC_NO_CHARGE);
if (ret != KERN_SUCCESS)
panic("kmem_suballoc: bad status return of %d", ret);
*max = *min + size;
result = vm_map_create(vm_map_pmap(parent), *min, *max);
if (result == NULL)
panic("kmem_suballoc: cannot create submap");
if (vm_map_submap(parent, *min, *max, result) != KERN_SUCCESS)
panic("kmem_suballoc: unable to change range to submap");
return (result);
}
/*
* kmem_malloc_domain:
*
* Allocate wired-down pages in the kernel's address space.
*/
static vm_offset_t
kmem_malloc_domain(int domain, vm_size_t size, int flags)
{
vmem_t *arena;
vm_offset_t addr;
int rv;
#if VM_NRESERVLEVEL > 0
if (__predict_true((flags & M_EXEC) == 0))
arena = vm_dom[domain].vmd_kernel_arena;
else
arena = vm_dom[domain].vmd_kernel_rwx_arena;
#else
arena = vm_dom[domain].vmd_kernel_arena;
#endif
size = round_page(size);
if (vmem_alloc(arena, size, flags | M_BESTFIT, &addr))
return (0);
rv = kmem_back_domain(domain, kernel_object, addr, size, flags);
if (rv != KERN_SUCCESS) {
vmem_free(arena, addr, size);
return (0);
}
return (addr);
}
vm_offset_t
kmem_malloc(vm_size_t size, int flags)
{
return (kmem_malloc_domainset(DOMAINSET_RR(), size, flags));
}
vm_offset_t
kmem_malloc_domainset(struct domainset *ds, vm_size_t size, int flags)
{
struct vm_domainset_iter di;
vm_offset_t addr;
int domain;
vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
do {
addr = kmem_malloc_domain(domain, size, flags);
if (addr != 0)
break;
} while (vm_domainset_iter_policy(&di, &domain) == 0);
return (addr);
}
/*
* kmem_back_domain:
*
* Allocate physical pages from the specified domain for the specified
* virtual address range.
*/
int
kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr,
vm_size_t size, int flags)
{
vm_offset_t offset, i;
vm_page_t m, mpred;
vm_prot_t prot;
int pflags;
KASSERT(object == kernel_object,
("kmem_back_domain: only supports kernel object."));
offset = addr - VM_MIN_KERNEL_ADDRESS;
pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
if (flags & M_WAITOK)
pflags |= VM_ALLOC_WAITFAIL;
prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW;
i = 0;
VM_OBJECT_WLOCK(object);
retry:
mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i));
for (; i < size; i += PAGE_SIZE, mpred = m) {
m = vm_page_alloc_domain_after(object, atop(offset + i),
domain, pflags, mpred);
/*
* Ran out of space, free everything up and return. Don't need
* to lock page queues here as we know that the pages we got
* aren't on any queues.
*/
if (m == NULL) {
if ((flags & M_NOWAIT) == 0)
goto retry;
VM_OBJECT_WUNLOCK(object);
kmem_unback(object, addr, i);
return (KERN_NO_SPACE);
}
KASSERT(vm_phys_domain(m) == domain,
("kmem_back_domain: Domain mismatch %d != %d",
vm_phys_domain(m), domain));
if (flags & M_ZERO && (m->flags & PG_ZERO) == 0)
pmap_zero_page(m);
KASSERT((m->oflags & VPO_UNMANAGED) != 0,
("kmem_malloc: page %p is managed", m));
vm_page_valid(m);
vm_page_xunbusy(m);
pmap_enter(kernel_pmap, addr + i, m, prot,
prot | PMAP_ENTER_WIRED, 0);
#if VM_NRESERVLEVEL > 0
if (__predict_false((prot & VM_PROT_EXECUTE) != 0))
m->oflags |= VPO_KMEM_EXEC;
#endif
}
VM_OBJECT_WUNLOCK(object);
return (KERN_SUCCESS);
}
/*
* kmem_back:
*
* Allocate physical pages for the specified virtual address range.
*/
int
kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags)
{
vm_offset_t end, next, start;
int domain, rv;
KASSERT(object == kernel_object,
("kmem_back: only supports kernel object."));
for (start = addr, end = addr + size; addr < end; addr = next) {
/*
* We must ensure that pages backing a given large virtual page
* all come from the same physical domain.
*/
if (vm_ndomains > 1) {
domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains;
while (VM_DOMAIN_EMPTY(domain))
domain++;
next = roundup2(addr + 1, KVA_QUANTUM);
if (next > end || next < start)
next = end;
} else {
domain = 0;
next = end;
}
rv = kmem_back_domain(domain, object, addr, next - addr, flags);
if (rv != KERN_SUCCESS) {
kmem_unback(object, start, addr - start);
break;
}
}
return (rv);
}
/*
* kmem_unback:
*
* Unmap and free the physical pages underlying the specified virtual
* address range.
*
* A physical page must exist within the specified object at each index
* that is being unmapped.
*/
static struct vmem *
_kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
{
struct vmem *arena;
vm_page_t m, next;
vm_offset_t end, offset;
int domain;
KASSERT(object == kernel_object,
("kmem_unback: only supports kernel object."));
if (size == 0)
return (NULL);
pmap_remove(kernel_pmap, addr, addr + size);
offset = addr - VM_MIN_KERNEL_ADDRESS;
end = offset + size;
VM_OBJECT_WLOCK(object);
m = vm_page_lookup(object, atop(offset));
domain = vm_phys_domain(m);
#if VM_NRESERVLEVEL > 0
if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0))
arena = vm_dom[domain].vmd_kernel_arena;
else
arena = vm_dom[domain].vmd_kernel_rwx_arena;
#else
arena = vm_dom[domain].vmd_kernel_arena;
#endif
for (; offset < end; offset += PAGE_SIZE, m = next) {
next = vm_page_next(m);
vm_page_busy_acquire(m, 0);
vm_page_unwire_noq(m);
vm_page_free(m);
}
VM_OBJECT_WUNLOCK(object);
return (arena);
}
void
kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
{
(void)_kmem_unback(object, addr, size);
}
/*
* kmem_free:
*
* Free memory allocated with kmem_malloc. The size must match the
* original allocation.
*/
void
kmem_free(vm_offset_t addr, vm_size_t size)
{
struct vmem *arena;
size = round_page(size);
arena = _kmem_unback(kernel_object, addr, size);
if (arena != NULL)
vmem_free(arena, addr, size);
}
/*
* kmap_alloc_wait:
*
* Allocates pageable memory from a sub-map of the kernel. If the submap
* has no room, the caller sleeps waiting for more memory in the submap.
*
* This routine may block.
*/
vm_offset_t
kmap_alloc_wait(vm_map_t map, vm_size_t size)
{
vm_offset_t addr;
size = round_page(size);
if (!swap_reserve(size))
return (0);
for (;;) {
/*
* To make this work for more than one map, use the map's lock
* to lock out sleepers/wakers.
*/
vm_map_lock(map);
addr = vm_map_findspace(map, vm_map_min(map), size);
if (addr + size <= vm_map_max(map))
break;
/* no space now; see if we can ever get space */
if (vm_map_max(map) - vm_map_min(map) < size) {
vm_map_unlock(map);
swap_release(size);
return (0);
}
map->needs_wakeup = TRUE;
vm_map_unlock_and_wait(map, 0);
}
vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_RW, VM_PROT_RW,
MAP_ACC_CHARGED);
vm_map_unlock(map);
return (addr);
}
/*
* kmap_free_wakeup:
*
* Returns memory to a submap of the kernel, and wakes up any processes
* waiting for memory in that map.
*/
void
kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size)
{
vm_map_lock(map);
(void) vm_map_delete(map, trunc_page(addr), round_page(addr + size));
if (map->needs_wakeup) {
map->needs_wakeup = FALSE;
vm_map_wakeup(map);
}
vm_map_unlock(map);
}
void
kmem_init_zero_region(void)
{
vm_offset_t addr, i;
vm_page_t m;
/*
* Map a single physical page of zeros to a larger virtual range.
* This requires less looping in places that want large amounts of
* zeros, while not using much more physical resources.
*/
addr = kva_alloc(ZERO_REGION_SIZE);
m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL |
VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO);
if ((m->flags & PG_ZERO) == 0)
pmap_zero_page(m);
for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE)
pmap_qenter(addr + i, &m, 1);
pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ);
zero_region = (const void *)addr;
}
/*
* Import KVA from the kernel map into the kernel arena.
*/
static int
kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp)
{
vm_offset_t addr;
int result;
KASSERT((size % KVA_QUANTUM) == 0,
("kva_import: Size %jd is not a multiple of %d",
(intmax_t)size, (int)KVA_QUANTUM));
addr = vm_map_min(kernel_map);
result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0,
VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
if (result != KERN_SUCCESS)
return (ENOMEM);
*addrp = addr;
return (0);
}
/*
* Import KVA from a parent arena into a per-domain arena. Imports must be
* KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size.
*/
static int
kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp)
{
KASSERT((size % KVA_QUANTUM) == 0,
("kva_import_domain: Size %jd is not a multiple of %d",
(intmax_t)size, (int)KVA_QUANTUM));
return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN,
VMEM_ADDR_MAX, flags, addrp));
}
/*
* kmem_init:
*
* Create the kernel map; insert a mapping covering kernel text,
* data, bss, and all space allocated thus far (`boostrap' data). The
* new map will thus map the range between VM_MIN_KERNEL_ADDRESS and
* `start' as allocated, and the range between `start' and `end' as free.
* Create the kernel vmem arena and its per-domain children.
*/
void
kmem_init(vm_offset_t start, vm_offset_t end)
{
vm_map_t m;
int domain;
m = vm_map_create(kernel_pmap, VM_MIN_KERNEL_ADDRESS, end);
m->system_map = 1;
vm_map_lock(m);
/* N.B.: cannot use kgdb to debug, starting with this assignment ... */
kernel_map = m;
(void)vm_map_insert(m, NULL, 0,
#ifdef __amd64__
KERNBASE,
#else
VM_MIN_KERNEL_ADDRESS,
#endif
start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
/* ... and ending with the completion of the above `insert' */
#ifdef __amd64__
/*
* Mark KVA used for the page array as allocated. Other platforms
* that handle vm_page_array allocation can simply adjust virtual_avail
* instead.
*/
(void)vm_map_insert(m, NULL, 0, (vm_offset_t)vm_page_array,
(vm_offset_t)vm_page_array + round_2mpage(vm_page_array_size *
sizeof(struct vm_page)),
VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
#endif
vm_map_unlock(m);
/*
* Initialize the kernel_arena. This can grow on demand.
*/
vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0);
vmem_set_import(kernel_arena, kva_import, NULL, NULL, KVA_QUANTUM);
for (domain = 0; domain < vm_ndomains; domain++) {
/*
* Initialize the per-domain arenas. These are used to color
* the KVA space in a way that ensures that virtual large pages
* are backed by memory from the same physical domain,
* maximizing the potential for superpage promotion.
*/
vm_dom[domain].vmd_kernel_arena = vmem_create(
"kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK);
vmem_set_import(vm_dom[domain].vmd_kernel_arena,
kva_import_domain, NULL, kernel_arena, KVA_QUANTUM);
/*
* In architectures with superpages, maintain separate arenas
* for allocations with permissions that differ from the
* "standard" read/write permissions used for kernel memory,
* so as not to inhibit superpage promotion.
*/
#if VM_NRESERVLEVEL > 0
vm_dom[domain].vmd_kernel_rwx_arena = vmem_create(
"kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK);
vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena,
kva_import_domain, (vmem_release_t *)vmem_xfree,
kernel_arena, KVA_QUANTUM);
#endif
}
/*
* This must be the very first call so that the virtual address
* space used for early allocations is properly marked used in
* the map.
*/
uma_startup2();
}
/*
* kmem_bootstrap_free:
*
* Free pages backing preloaded data (e.g., kernel modules) to the
* system. Currently only supported on platforms that create a
* vm_phys segment for preloaded data.
*/
void
kmem_bootstrap_free(vm_offset_t start, vm_size_t size)
{
#if defined(__i386__) || defined(__amd64__)
struct vm_domain *vmd;
vm_offset_t end, va;
vm_paddr_t pa;
vm_page_t m;
end = trunc_page(start + size);
start = round_page(start);
#ifdef __amd64__
/*
* Preloaded files do not have execute permissions by default on amd64.
* Restore the default permissions to ensure that the direct map alias
* is updated.
*/
pmap_change_prot(start, end - start, VM_PROT_RW);
#endif
for (va = start; va < end; va += PAGE_SIZE) {
pa = pmap_kextract(va);
m = PHYS_TO_VM_PAGE(pa);
vmd = vm_pagequeue_domain(m);
vm_domain_free_lock(vmd);
vm_phys_free_pages(m, 0);
vm_domain_free_unlock(vmd);
vm_domain_freecnt_inc(vmd, 1);
vm_cnt.v_page_count++;
}
pmap_remove(kernel_pmap, start, end);
(void)vmem_add(kernel_arena, start, end - start, M_WAITOK);
#endif
}
/*
* Allow userspace to directly trigger the VM drain routine for testing
* purposes.
*/
static int
debug_vm_lowmem(SYSCTL_HANDLER_ARGS)
{
int error, i;
i = 0;
error = sysctl_handle_int(oidp, &i, 0, req);
if (error)
return (error);
if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0)
return (EINVAL);
if (i != 0)
EVENTHANDLER_INVOKE(vm_lowmem, i);
return (0);
}
SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0,
debug_vm_lowmem, "I", "set to trigger vm_lowmem event with given flags");
