/* $NetBSD: uvm_km.c,v 1.166 2024/12/07 23:19:07 chs Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
* 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.
*
* @(#)vm_kern.c 8.3 (Berkeley) 1/12/94
* from: Id: uvm_km.c,v 1.1.2.14 1998/02/06 05:19:27 chs Exp
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* 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.
*/
/*
* uvm_km.c: handle kernel memory allocation and management
*/
/*
* overview of kernel memory management:
*
* the kernel virtual address space is mapped by "kernel_map." kernel_map
* starts at VM_MIN_KERNEL_ADDRESS and goes to VM_MAX_KERNEL_ADDRESS.
* note that VM_MIN_KERNEL_ADDRESS is equal to vm_map_min(kernel_map).
*
* the kernel_map has several "submaps." submaps can only appear in
* the kernel_map (user processes can't use them). submaps "take over"
* the management of a sub-range of the kernel's address space. submaps
* are typically allocated at boot time and are never released. kernel
* virtual address space that is mapped by a submap is locked by the
* submap's lock -- not the kernel_map's lock.
*
* thus, the useful feature of submaps is that they allow us to break
* up the locking and protection of the kernel address space into smaller
* chunks.
*
* the vm system has several standard kernel submaps/arenas, including:
* kmem_arena => used for kmem/pool (memoryallocators(9))
* pager_map => used to map "buf" structures into kernel space
* exec_map => used during exec to handle exec args
* etc...
*
* The kmem_arena is a "special submap", as it lives in a fixed map entry
* within the kernel_map and is controlled by vmem(9).
*
* the kernel allocates its private memory out of special uvm_objects whose
* reference count is set to UVM_OBJ_KERN (thus indicating that the objects
* are "special" and never die). all kernel objects should be thought of
* as large, fixed-sized, sparsely populated uvm_objects. each kernel
* object is equal to the size of kernel virtual address space (i.e. the
* value "VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS").
*
* note that just because a kernel object spans the entire kernel virtual
* address space doesn't mean that it has to be mapped into the entire space.
* large chunks of a kernel object's space go unused either because
* that area of kernel VM is unmapped, or there is some other type of
* object mapped into that range (e.g. a vnode). for submap's kernel
* objects, the only part of the object that can ever be populated is the
* offsets that are managed by the submap.
*
* note that the "offset" in a kernel object is always the kernel virtual
* address minus the VM_MIN_KERNEL_ADDRESS (aka vm_map_min(kernel_map)).
* example:
* suppose VM_MIN_KERNEL_ADDRESS is 0xf8000000 and the kernel does a
* uvm_km_alloc(kernel_map, PAGE_SIZE) [allocate 1 wired down page in the
* kernel map]. if uvm_km_alloc returns virtual address 0xf8235000,
* then that means that the page at offset 0x235000 in kernel_object is
* mapped at 0xf8235000.
*
* kernel object have one other special property: when the kernel virtual
* memory mapping them is unmapped, the backing memory in the object is
* freed right away. this is done with the uvm_km_pgremove() function.
* this has to be done because there is no backing store for kernel pages
* and no need to save them after they are no longer referenced.
*
* Generic arenas:
*
* kmem_arena:
* Main arena controlling the kernel KVA used by other arenas.
*
* kmem_va_arena:
* Implements quantum caching in order to speedup allocations and
* reduce fragmentation. The pool(9), unless created with a custom
* meta-data allocator, and kmem(9) subsystems use this arena.
*
* Arenas for meta-data allocations are used by vmem(9) and pool(9).
* These arenas cannot use quantum cache. However, kmem_va_meta_arena
* compensates this by importing larger chunks from kmem_arena.
*
* kmem_va_meta_arena:
* Space for meta-data.
*
* kmem_meta_arena:
* Imports from kmem_va_meta_arena. Allocations from this arena are
* backed with the pages.
*
* Arena stacking:
*
* kmem_arena
* kmem_va_arena
* kmem_va_meta_arena
* kmem_meta_arena
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: uvm_km.c,v 1.166 2024/12/07 23:19:07 chs Exp $");
#include "opt_uvmhist.h"
#include "opt_kmempages.h"
#ifndef NKMEMPAGES
#define NKMEMPAGES 0
#endif
/*
* Defaults for lower and upper-bounds for the kmem_arena page count.
* Can be overridden by kernel config options.
*/
#ifndef NKMEMPAGES_MIN
#define NKMEMPAGES_MIN NKMEMPAGES_MIN_DEFAULT
#endif
#ifndef NKMEMPAGES_MAX
#define NKMEMPAGES_MAX NKMEMPAGES_MAX_DEFAULT
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/atomic.h>
#include <sys/proc.h>
#include <sys/pool.h>
#include <sys/vmem.h>
#include <sys/vmem_impl.h>
#include <sys/kmem.h>
#include <sys/msan.h>
#include <uvm/uvm.h>
/*
* global data structures
*/
struct vm_map *kernel_map = NULL;
/*
* local data structures
*/
static struct vm_map kernel_map_store;
static struct vm_map_entry kernel_image_mapent_store;
static struct vm_map_entry kernel_kmem_mapent_store;
size_t nkmempages = 0;
vaddr_t kmembase;
vsize_t kmemsize;
static struct vmem kmem_arena_store;
vmem_t *kmem_arena = NULL;
static struct vmem kmem_va_arena_store;
vmem_t *kmem_va_arena;
/*
* kmeminit_nkmempages: calculate the size of kmem_arena.
*/
void
kmeminit_nkmempages(void)
{
size_t npages;
if (nkmempages != 0) {
/*
* It's already been set (by us being here before)
* bail out now;
*/
return;
}
#if defined(NKMEMPAGES_MAX_UNLIMITED) && !defined(KMSAN)
/*
* The extra 1/9 here is to account for uvm_km_va_starved_p()
* wanting to keep 10% of kmem virtual space free.
* The intent is that on "unlimited" platforms we should be able
* to allocate all of physical memory as kmem without behaving
* as though we running short of kmem virtual space.
*/
npages = (physmem * 10) / 9;
#else
#if defined(KMSAN)
npages = (physmem / 4);
#elif defined(PMAP_MAP_POOLPAGE)
npages = (physmem / 4);
#else
npages = (physmem / 3) * 2;
#endif /* defined(PMAP_MAP_POOLPAGE) */
#if !defined(NKMEMPAGES_MAX_UNLIMITED)
if (npages > NKMEMPAGES_MAX)
npages = NKMEMPAGES_MAX;
#endif
#endif
if (npages < NKMEMPAGES_MIN)
npages = NKMEMPAGES_MIN;
nkmempages = npages;
}
/*
* uvm_km_bootstrap: init kernel maps and objects to reflect reality (i.e.
* KVM already allocated for text, data, bss, and static data structures).
*
* => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS.
* we assume that [vmin -> start] has already been allocated and that
* "end" is the end.
*/
void
uvm_km_bootstrap(vaddr_t start, vaddr_t end)
{
bool kmem_arena_small;
vaddr_t base = VM_MIN_KERNEL_ADDRESS;
struct uvm_map_args args;
int error;
UVMHIST_FUNC(__func__);
UVMHIST_CALLARGS(maphist, "start=%#jx end=%#jx", start, end, 0,0);
kmeminit_nkmempages();
kmemsize = (vsize_t)nkmempages * PAGE_SIZE;
kmem_arena_small = kmemsize < 64 * 1024 * 1024;
UVMHIST_LOG(maphist, "kmemsize=%#jx", kmemsize, 0,0,0);
/*
* next, init kernel memory objects.
*/
/* kernel_object: for pageable anonymous kernel memory */
uvm_kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS -
VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ);
/*
* init the map and reserve any space that might already
* have been allocated kernel space before installing.
*/
uvm_map_setup(&kernel_map_store, base, end, VM_MAP_PAGEABLE);
kernel_map_store.pmap = pmap_kernel();
if (start != base) {
error = uvm_map_prepare(&kernel_map_store,
base, start - base,
NULL, UVM_UNKNOWN_OFFSET, 0,
UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args);
if (!error) {
kernel_image_mapent_store.flags =
UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE;
error = uvm_map_enter(&kernel_map_store, &args,
&kernel_image_mapent_store);
}
if (error)
panic(
"uvm_km_bootstrap: could not reserve space for kernel");
kmembase = args.uma_start + args.uma_size;
} else {
kmembase = base;
}
error = uvm_map_prepare(&kernel_map_store,
kmembase, kmemsize,
NULL, UVM_UNKNOWN_OFFSET, 0,
UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args);
if (!error) {
kernel_kmem_mapent_store.flags =
UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE;
error = uvm_map_enter(&kernel_map_store, &args,
&kernel_kmem_mapent_store);
}
if (error)
panic("uvm_km_bootstrap: could not reserve kernel kmem");
/*
* install!
*/
kernel_map = &kernel_map_store;
pool_subsystem_init();
kmem_arena = vmem_init(&kmem_arena_store, "kmem",
kmembase, kmemsize, PAGE_SIZE, NULL, NULL, NULL,
0, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM);
#ifdef PMAP_GROWKERNEL
/*
* kmem_arena VA allocations happen independently of uvm_map.
* grow kernel to accommodate the kmem_arena.
*/
if (uvm_maxkaddr < kmembase + kmemsize) {
uvm_maxkaddr = pmap_growkernel(kmembase + kmemsize);
KASSERTMSG(uvm_maxkaddr >= kmembase + kmemsize,
"%#"PRIxVADDR" %#"PRIxVADDR" %#"PRIxVSIZE,
uvm_maxkaddr, kmembase, kmemsize);
}
#endif
vmem_subsystem_init(kmem_arena);
UVMHIST_LOG(maphist, "kmem vmem created (base=%#jx, size=%#jx",
kmembase, kmemsize, 0,0);
kmem_va_arena = vmem_init(&kmem_va_arena_store, "kva",
0, 0, PAGE_SIZE, vmem_alloc, vmem_free, kmem_arena,
(kmem_arena_small ? 4 : VMEM_QCACHE_IDX_MAX) * PAGE_SIZE,
VM_NOSLEEP, IPL_VM);
UVMHIST_LOG(maphist, "<- done", 0,0,0,0);
}
/*
* uvm_km_init: init the kernel maps virtual memory caches
* and start the pool/kmem allocator.
*/
void
uvm_km_init(void)
{
kmem_init();
}
/*
* uvm_km_suballoc: allocate a submap in the kernel map. once a submap
* is allocated all references to that area of VM must go through it. this
* allows the locking of VAs in kernel_map to be broken up into regions.
*
* => if `fixed' is true, *vmin specifies where the region described
* pager_map => used to map "buf" structures into kernel space
* by the submap must start
* => if submap is non NULL we use that as the submap, otherwise we
* alloc a new map
*/
struct vm_map *
uvm_km_suballoc(struct vm_map *map, vaddr_t *vmin /* IN/OUT */,
vaddr_t *vmax /* OUT */, vsize_t size, int flags, bool fixed,
struct vm_map *submap)
{
int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0);
UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
KASSERT(vm_map_pmap(map) == pmap_kernel());
size = round_page(size); /* round up to pagesize */
/*
* first allocate a blank spot in the parent map
*/
if (uvm_map(map, vmin, size, NULL, UVM_UNKNOWN_OFFSET, 0,
UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
UVM_ADV_RANDOM, mapflags)) != 0) {
panic("%s: unable to allocate space in parent map", __func__);
}
/*
* set VM bounds (vmin is filled in by uvm_map)
*/
*vmax = *vmin + size;
/*
* add references to pmap and create or init the submap
*/
pmap_reference(vm_map_pmap(map));
if (submap == NULL) {
submap = kmem_alloc(sizeof(*submap), KM_SLEEP);
}
uvm_map_setup(submap, *vmin, *vmax, flags);
submap->pmap = vm_map_pmap(map);
/*
* now let uvm_map_submap plug in it...
*/
if (uvm_map_submap(map, *vmin, *vmax, submap) != 0)
panic("uvm_km_suballoc: submap allocation failed");
return(submap);
}
/*
* uvm_km_pgremove: remove pages from a kernel uvm_object and KVA.
*/
void
uvm_km_pgremove(vaddr_t startva, vaddr_t endva)
{
struct uvm_object * const uobj = uvm_kernel_object;
const voff_t start = startva - vm_map_min(kernel_map);
const voff_t end = endva - vm_map_min(kernel_map);
struct vm_page *pg;
voff_t curoff, nextoff;
int swpgonlydelta = 0;
UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
KASSERT(VM_MIN_KERNEL_ADDRESS <= startva);
KASSERT(startva < endva);
KASSERT(endva <= VM_MAX_KERNEL_ADDRESS);
rw_enter(uobj->vmobjlock, RW_WRITER);
pmap_remove(pmap_kernel(), startva, endva);
for (curoff = start; curoff < end; curoff = nextoff) {
nextoff = curoff + PAGE_SIZE;
pg = uvm_pagelookup(uobj, curoff);
if (pg != NULL && pg->flags & PG_BUSY) {
uvm_pagewait(pg, uobj->vmobjlock, "km_pgrm");
rw_enter(uobj->vmobjlock, RW_WRITER);
nextoff = curoff;
continue;
}
/*
* free the swap slot, then the page.
*/
if (pg == NULL &&
uao_find_swslot(uobj, curoff >> PAGE_SHIFT) > 0) {
swpgonlydelta++;
}
uao_dropswap(uobj, curoff >> PAGE_SHIFT);
if (pg != NULL) {
uvm_pagefree(pg);
}
}
rw_exit(uobj->vmobjlock);
if (swpgonlydelta > 0) {
KASSERT(uvmexp.swpgonly >= swpgonlydelta);
atomic_add_int(&uvmexp.swpgonly, -swpgonlydelta);
}
}
/*
* uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for non object backed
* regions.
*
* => when you unmap a part of anonymous kernel memory you want to toss
* the pages right away. (this is called from uvm_unmap_...).
* => none of the pages will ever be busy, and none of them will ever
* be on the active or inactive queues (because they have no object).
*/
void
uvm_km_pgremove_intrsafe(struct vm_map *map, vaddr_t start, vaddr_t end)
{
#define __PGRM_BATCH 16
struct vm_page *pg;
paddr_t pa[__PGRM_BATCH];
int npgrm, i;
vaddr_t va, batch_vastart;
UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
KASSERT(VM_MAP_IS_KERNEL(map));
KASSERTMSG(vm_map_min(map) <= start,
"vm_map_min(map) [%#"PRIxVADDR"] <= start [%#"PRIxVADDR"]"
" (size=%#"PRIxVSIZE")",
vm_map_min(map), start, end - start);
KASSERT(start < end);
KASSERT(end <= vm_map_max(map));
for (va = start; va < end;) {
batch_vastart = va;
/* create a batch of at most __PGRM_BATCH pages to free */
for (i = 0;
i < __PGRM_BATCH && va < end;
va += PAGE_SIZE) {
if (!pmap_extract(pmap_kernel(), va, &pa[i])) {
continue;
}
i++;
}
npgrm = i;
/* now remove the mappings */
pmap_kremove(batch_vastart, va - batch_vastart);
/* and free the pages */
for (i = 0; i < npgrm; i++) {
pg = PHYS_TO_VM_PAGE(pa[i]);
KASSERT(pg);
KASSERT(pg->uobject == NULL);
KASSERT(pg->uanon == NULL);
KASSERT((pg->flags & PG_BUSY) == 0);
uvm_pagefree(pg);
}
}
#undef __PGRM_BATCH
}
#if defined(DEBUG)
void
uvm_km_check_empty(struct vm_map *map, vaddr_t start, vaddr_t end)
{
vaddr_t va;
UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
KDASSERT(VM_MAP_IS_KERNEL(map));
KDASSERT(vm_map_min(map) <= start);
KDASSERT(start < end);
KDASSERT(end <= vm_map_max(map));
for (va = start; va < end; va += PAGE_SIZE) {
paddr_t pa;
if (pmap_extract(pmap_kernel(), va, &pa)) {
panic("uvm_km_check_empty: va %p has pa %#llx",
(void *)va, (long long)pa);
}
/*
* kernel_object should not have pages for the corresponding
* region. check it.
*
* why trylock? because:
* - caller might not want to block.
* - we can recurse when allocating radix_node for
* kernel_object.
*/
if (rw_tryenter(uvm_kernel_object->vmobjlock, RW_READER)) {
struct vm_page *pg;
pg = uvm_pagelookup(uvm_kernel_object,
va - vm_map_min(kernel_map));
rw_exit(uvm_kernel_object->vmobjlock);
if (pg) {
panic("uvm_km_check_empty: "
"has page hashed at %p",
(const void *)va);
}
}
}
}
#endif /* defined(DEBUG) */
/*
* uvm_km_alloc: allocate an area of kernel memory.
*
* => NOTE: we can return 0 even if we can wait if there is not enough
* free VM space in the map... caller should be prepared to handle
* this case.
* => we return KVA of memory allocated
*/
vaddr_t
uvm_km_alloc(struct vm_map *map, vsize_t size, vsize_t align, uvm_flag_t flags)
{
vaddr_t kva, loopva;
vaddr_t offset;
vsize_t loopsize;
struct vm_page *pg;
struct uvm_object *obj;
int pgaflags;
vm_prot_t prot, vaprot;
UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
KASSERT(vm_map_pmap(map) == pmap_kernel());
KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED ||
(flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE ||
(flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY);
KASSERT((flags & UVM_KMF_VAONLY) != 0 || (flags & UVM_KMF_COLORMATCH) == 0);
KASSERT((flags & UVM_KMF_COLORMATCH) == 0 || (flags & UVM_KMF_VAONLY) != 0);
/*
* setup for call
*/
kva = vm_map_min(map); /* hint */
size = round_page(size);
obj = (flags & UVM_KMF_PAGEABLE) ? uvm_kernel_object : NULL;
UVMHIST_LOG(maphist," (map=%#jx, obj=%#jx, size=%#jx, flags=%#jx)",
(uintptr_t)map, (uintptr_t)obj, size, flags);
/*
* allocate some virtual space
*/
vaprot = (flags & UVM_KMF_EXEC) ? UVM_PROT_ALL : UVM_PROT_RW;
if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET,
align, UVM_MAPFLAG(vaprot, UVM_PROT_ALL, UVM_INH_NONE,
UVM_ADV_RANDOM,
(flags & (UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT | UVM_KMF_WAITVA
| UVM_KMF_COLORMATCH)))) != 0)) {
UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0);
return(0);
}
/*
* if all we wanted was VA, return now
*/
if (flags & (UVM_KMF_VAONLY | UVM_KMF_PAGEABLE)) {
UVMHIST_LOG(maphist,"<- done valloc (kva=%#jx)", kva,0,0,0);
return(kva);
}
/*
* recover object offset from virtual address
*/
offset = kva - vm_map_min(kernel_map);
UVMHIST_LOG(maphist, " kva=%#jx, offset=%#jx", kva, offset,0,0);
/*
* now allocate and map in the memory... note that we are the only ones
* whom should ever get a handle on this area of VM.
*/
loopva = kva;
loopsize = size;
pgaflags = UVM_FLAG_COLORMATCH;
if (flags & UVM_KMF_NOWAIT)
pgaflags |= UVM_PGA_USERESERVE;
if (flags & UVM_KMF_ZERO)
pgaflags |= UVM_PGA_ZERO;
prot = VM_PROT_READ | VM_PROT_WRITE;
if (flags & UVM_KMF_EXEC)
prot |= VM_PROT_EXECUTE;
while (loopsize) {
KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, NULL),
"loopva=%#"PRIxVADDR, loopva);
pg = uvm_pagealloc_strat(NULL, offset, NULL, pgaflags,
#ifdef UVM_KM_VMFREELIST
UVM_PGA_STRAT_ONLY, UVM_KM_VMFREELIST
#else
UVM_PGA_STRAT_NORMAL, 0
#endif
);
/*
* out of memory?
*/
if (__predict_false(pg == NULL)) {
if ((flags & UVM_KMF_NOWAIT) ||
((flags & UVM_KMF_CANFAIL) && !uvm_reclaimable())) {
/* free everything! */
uvm_km_free(map, kva, size,
flags & UVM_KMF_TYPEMASK);
return (0);
} else {
uvm_wait("km_getwait2"); /* sleep here */
continue;
}
}
pg->flags &= ~PG_BUSY; /* new page */
UVM_PAGE_OWN(pg, NULL);
/*
* map it in
*/
pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg),
prot, PMAP_KMPAGE);
loopva += PAGE_SIZE;
offset += PAGE_SIZE;
loopsize -= PAGE_SIZE;
}
pmap_update(pmap_kernel());
if ((flags & UVM_KMF_ZERO) == 0) {
kmsan_orig((void *)kva, size, KMSAN_TYPE_UVM, __RET_ADDR);
kmsan_mark((void *)kva, size, KMSAN_STATE_UNINIT);
}
UVMHIST_LOG(maphist,"<- done (kva=%#jx)", kva,0,0,0);
return(kva);
}
/*
* uvm_km_protect: change the protection of an allocated area
*/
int
uvm_km_protect(struct vm_map *map, vaddr_t addr, vsize_t size, vm_prot_t prot)
{
return uvm_map_protect(map, addr, addr + round_page(size), prot, false);
}
/*
* uvm_km_free: free an area of kernel memory
*/
void
uvm_km_free(struct vm_map *map, vaddr_t addr, vsize_t size, uvm_flag_t flags)
{
UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED ||
(flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE ||
(flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY);
KASSERT((addr & PAGE_MASK) == 0);
KASSERT(vm_map_pmap(map) == pmap_kernel());
size = round_page(size);
if (flags & UVM_KMF_PAGEABLE) {
uvm_km_pgremove(addr, addr + size);
} else if (flags & UVM_KMF_WIRED) {
/*
* Note: uvm_km_pgremove_intrsafe() extracts mapping, thus
* remove it after. See comment below about KVA visibility.
*/
uvm_km_pgremove_intrsafe(map, addr, addr + size);
}
/*
* Note: uvm_unmap_remove() calls pmap_update() for us, before
* KVA becomes globally available.
*/
uvm_unmap1(map, addr, addr + size, UVM_FLAG_VAONLY);
}
/* Sanity; must specify both or none. */
#if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \
(!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE))
#error Must specify MAP and UNMAP together.
#endif
#if defined(PMAP_ALLOC_POOLPAGE) && \
!defined(PMAP_MAP_POOLPAGE) && !defined(PMAP_UNMAP_POOLPAGE)
#error Must specify ALLOC with MAP and UNMAP
#endif
int
uvm_km_kmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags,
vmem_addr_t *addr)
{
struct vm_page *pg;
vmem_addr_t va;
int rc;
vaddr_t loopva;
vsize_t loopsize;
size = round_page(size);
#if defined(PMAP_MAP_POOLPAGE)
if (size == PAGE_SIZE) {
again:
#ifdef PMAP_ALLOC_POOLPAGE
pg = PMAP_ALLOC_POOLPAGE((flags & VM_SLEEP) ?
0 : UVM_PGA_USERESERVE);
#else
pg = uvm_pagealloc(NULL, 0, NULL,
(flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE);
#endif /* PMAP_ALLOC_POOLPAGE */
if (__predict_false(pg == NULL)) {
if (flags & VM_SLEEP) {
uvm_wait("plpg");
goto again;
}
return ENOMEM;
}
va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg));
KASSERT(va != 0);
*addr = va;
return 0;
}
#endif /* PMAP_MAP_POOLPAGE */
rc = vmem_alloc(vm, size, flags, &va);
if (rc != 0)
return rc;
#ifdef PMAP_GROWKERNEL
/*
* These VA allocations happen independently of uvm_map
* so this allocation must not extend beyond the current limit.
*/
KASSERTMSG(uvm_maxkaddr >= va + size,
"%#"PRIxVADDR" %#"PRIxPTR" %#zx",
uvm_maxkaddr, va, size);
#endif
loopva = va;
loopsize = size;
while (loopsize) {
paddr_t pa __diagused;
KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, &pa),
"loopva=%#"PRIxVADDR" loopsize=%#"PRIxVSIZE
" pa=%#"PRIxPADDR" vmem=%p",
loopva, loopsize, pa, vm);
pg = uvm_pagealloc(NULL, loopva, NULL,
UVM_FLAG_COLORMATCH
| ((flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE));
if (__predict_false(pg == NULL)) {
if (flags & VM_SLEEP) {
uvm_wait("plpg");
continue;
} else {
uvm_km_pgremove_intrsafe(kernel_map, va,
va + size);
vmem_free(vm, va, size);
return ENOMEM;
}
}
pg->flags &= ~PG_BUSY; /* new page */
UVM_PAGE_OWN(pg, NULL);
pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg),
VM_PROT_READ|VM_PROT_WRITE, PMAP_KMPAGE);
loopva += PAGE_SIZE;
loopsize -= PAGE_SIZE;
}
pmap_update(pmap_kernel());
*addr = va;
return 0;
}
void
uvm_km_kmem_free(vmem_t *vm, vmem_addr_t addr, size_t size)
{
size = round_page(size);
#if defined(PMAP_UNMAP_POOLPAGE)
if (size == PAGE_SIZE) {
paddr_t pa;
pa = PMAP_UNMAP_POOLPAGE(addr);
uvm_pagefree(PHYS_TO_VM_PAGE(pa));
return;
}
#endif /* PMAP_UNMAP_POOLPAGE */
uvm_km_pgremove_intrsafe(kernel_map, addr, addr + size);
pmap_update(pmap_kernel());
vmem_free(vm, addr, size);
}
bool
uvm_km_va_starved_p(void)
{
vmem_size_t total;
vmem_size_t free;
if (kmem_arena == NULL)
return false;
total = vmem_size(kmem_arena, VMEM_ALLOC|VMEM_FREE);
free = vmem_size(kmem_arena, VMEM_FREE);
return (free < (total / 10));
}