NetBSD/sys/uvm/uvm_km.c
bouyer d986226518 Change uvm_km_kmemalloc() to accept flag UVM_KMF_NOWAIT and pass it to
uvm_map(). Change uvm_map() to honnor UVM_KMF_NOWAIT. For this, change
amap_extend() to take a flags parameter instead of just boolean for
direction, and introduce AMAP_EXTEND_FORWARDS and AMAP_EXTEND_NOWAIT flags
(AMAP_EXTEND_BACKWARDS is still defined as 0x0, to keep the code easier to
read).
Add a flag parameter to uvm_mapent_alloc().
This solves a problem a pool_get(PR_NOWAIT) could trigger a pool_get(PR_WAITOK)
in uvm_mapent_alloc().
Thanks to Chuck Silvers, enami tsugutomo, Andrew Brown and Jason R Thorpe
for feedback.
2002-11-30 18:28:04 +00:00

791 lines
21 KiB
C

/* $NetBSD: uvm_km.c,v 1.60 2002/11/30 18:28:05 bouyer 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Charles D. Cranor,
* Washington University, the University of California, Berkeley and
* its contributors.
* 4. 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, including:
* kmem_map => contains only wired kernel memory for the kernel
* malloc. *** access to kmem_map must be protected
* by splvm() because we are allowed to call malloc()
* at interrupt time ***
* mb_map => memory for large mbufs, *** protected by splvm ***
* pager_map => used to map "buf" structures into kernel space
* exec_map => used during exec to handle exec args
* etc...
*
* 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").
*
* most kernel private memory lives in kernel_object. the only exception
* to this is for memory that belongs to submaps that must be protected
* by splvm(). pages in these submaps are not assigned to an object.
*
* note that just because a kernel object spans the entire kernel virutal
* 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: uvm_km.c,v 1.60 2002/11/30 18:28:05 bouyer Exp $");
#include "opt_uvmhist.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <uvm/uvm.h>
/*
* global data structures
*/
struct vm_map *kernel_map = NULL;
/*
* local data structues
*/
static struct vm_map kernel_map_store;
/*
* uvm_km_init: 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 [min -> start] has already been allocated and that
* "end" is the end.
*/
void
uvm_km_init(start, end)
vaddr_t start, end;
{
vaddr_t base = VM_MIN_KERNEL_ADDRESS;
/*
* next, init kernel memory objects.
*/
/* kernel_object: for pageable anonymous kernel memory */
uao_init();
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 &&
uvm_map(&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)) != 0)
panic("uvm_km_init: could not reserve space for kernel");
/*
* install!
*/
kernel_map = &kernel_map_store;
}
/*
* 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, *min specifies where the region described
* 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(map, min, max, size, flags, fixed, submap)
struct vm_map *map;
vaddr_t *min, *max; /* IN/OUT, OUT */
vsize_t size;
int flags;
boolean_t fixed;
struct vm_map *submap;
{
int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0);
size = round_page(size); /* round up to pagesize */
/*
* first allocate a blank spot in the parent map
*/
if (uvm_map(map, min, size, NULL, UVM_UNKNOWN_OFFSET, 0,
UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
UVM_ADV_RANDOM, mapflags)) != 0) {
panic("uvm_km_suballoc: unable to allocate space in parent map");
}
/*
* set VM bounds (min is filled in by uvm_map)
*/
*max = *min + size;
/*
* add references to pmap and create or init the submap
*/
pmap_reference(vm_map_pmap(map));
if (submap == NULL) {
submap = uvm_map_create(vm_map_pmap(map), *min, *max, flags);
if (submap == NULL)
panic("uvm_km_suballoc: unable to create submap");
} else {
uvm_map_setup(submap, *min, *max, flags);
submap->pmap = vm_map_pmap(map);
}
/*
* now let uvm_map_submap plug in it...
*/
if (uvm_map_submap(map, *min, *max, submap) != 0)
panic("uvm_km_suballoc: submap allocation failed");
return(submap);
}
/*
* uvm_km_pgremove: remove pages from a kernel uvm_object.
*
* => when you unmap a part of anonymous kernel memory you want to toss
* the pages right away. (this gets called from uvm_unmap_...).
*/
void
uvm_km_pgremove(uobj, start, end)
struct uvm_object *uobj;
vaddr_t start, end;
{
struct vm_page *pg;
voff_t curoff, nextoff;
int swpgonlydelta = 0;
UVMHIST_FUNC("uvm_km_pgremove"); UVMHIST_CALLED(maphist);
KASSERT(uobj->pgops == &aobj_pager);
simple_lock(&uobj->vmobjlock);
for (curoff = start; curoff < end; curoff = nextoff) {
nextoff = curoff + PAGE_SIZE;
pg = uvm_pagelookup(uobj, curoff);
if (pg != NULL && pg->flags & PG_BUSY) {
pg->flags |= PG_WANTED;
UVM_UNLOCK_AND_WAIT(pg, &uobj->vmobjlock, 0,
"km_pgrm", 0);
simple_lock(&uobj->vmobjlock);
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_lock_pageq();
uvm_pagefree(pg);
uvm_unlock_pageq();
}
}
simple_unlock(&uobj->vmobjlock);
if (swpgonlydelta > 0) {
simple_lock(&uvm.swap_data_lock);
KASSERT(uvmexp.swpgonly >= swpgonlydelta);
uvmexp.swpgonly -= swpgonlydelta;
simple_unlock(&uvm.swap_data_lock);
}
}
/*
* uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for "intrsafe"
* maps
*
* => 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(start, end)
vaddr_t start, end;
{
struct vm_page *pg;
paddr_t pa;
UVMHIST_FUNC("uvm_km_pgremove_intrsafe"); UVMHIST_CALLED(maphist);
for (; start < end; start += PAGE_SIZE) {
if (!pmap_extract(pmap_kernel(), start, &pa)) {
continue;
}
pg = PHYS_TO_VM_PAGE(pa);
KASSERT(pg);
KASSERT(pg->uobject == NULL && pg->uanon == NULL);
uvm_pagefree(pg);
}
}
/*
* uvm_km_kmemalloc: lower level kernel memory allocator for malloc()
*
* => we map wired memory into the specified map using the obj passed in
* => NOTE: we can return NULL 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
* => flags: NOWAIT, VALLOC - just allocate VA, TRYLOCK - fail if we can't
* lock the map
*/
vaddr_t
uvm_km_kmemalloc(map, obj, size, flags)
struct vm_map *map;
struct uvm_object *obj;
vsize_t size;
int flags;
{
vaddr_t kva, loopva;
vaddr_t offset;
vsize_t loopsize;
struct vm_page *pg;
UVMHIST_FUNC("uvm_km_kmemalloc"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist," (map=0x%x, obj=0x%x, size=0x%x, flags=%d)",
map, obj, size, flags);
KASSERT(vm_map_pmap(map) == pmap_kernel());
/*
* setup for call
*/
size = round_page(size);
kva = vm_map_min(map); /* hint */
/*
* allocate some virtual space
*/
if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET,
0, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
UVM_ADV_RANDOM,
(flags & (UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT))))
!= 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_VALLOC) {
UVMHIST_LOG(maphist,"<- done valloc (kva=0x%x)", kva,0,0,0);
return(kva);
}
/*
* recover object offset from virtual address
*/
offset = kva - vm_map_min(kernel_map);
UVMHIST_LOG(maphist, " kva=0x%x, offset=0x%x", 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;
while (loopsize) {
if (obj) {
simple_lock(&obj->vmobjlock);
}
pg = uvm_pagealloc(obj, offset, NULL, UVM_PGA_USERESERVE);
if (__predict_true(pg != NULL)) {
pg->flags &= ~PG_BUSY; /* new page */
UVM_PAGE_OWN(pg, NULL);
}
if (obj) {
simple_unlock(&obj->vmobjlock);
}
/*
* out of memory?
*/
if (__predict_false(pg == NULL)) {
if ((flags & UVM_KMF_NOWAIT) ||
((flags & UVM_KMF_CANFAIL) &&
uvmexp.swpgonly == uvmexp.swpages)) {
/* free everything! */
uvm_unmap(map, kva, kva + size);
return (0);
} else {
uvm_wait("km_getwait2"); /* sleep here */
continue;
}
}
/*
* map it in
*/
if (obj == NULL) {
pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg),
VM_PROT_READ | VM_PROT_WRITE);
} else {
pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg),
UVM_PROT_ALL,
PMAP_WIRED | VM_PROT_READ | VM_PROT_WRITE);
}
loopva += PAGE_SIZE;
offset += PAGE_SIZE;
loopsize -= PAGE_SIZE;
}
pmap_update(pmap_kernel());
UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0);
return(kva);
}
/*
* uvm_km_free: free an area of kernel memory
*/
void
uvm_km_free(map, addr, size)
struct vm_map *map;
vaddr_t addr;
vsize_t size;
{
uvm_unmap(map, trunc_page(addr), round_page(addr+size));
}
/*
* uvm_km_free_wakeup: free an area of kernel memory and wake up
* anyone waiting for vm space.
*
* => XXX: "wanted" bit + unlock&wait on other end?
*/
void
uvm_km_free_wakeup(map, addr, size)
struct vm_map *map;
vaddr_t addr;
vsize_t size;
{
struct vm_map_entry *dead_entries;
vm_map_lock(map);
uvm_unmap_remove(map, trunc_page(addr), round_page(addr + size),
&dead_entries);
wakeup(map);
vm_map_unlock(map);
if (dead_entries != NULL)
uvm_unmap_detach(dead_entries, 0);
}
/*
* uvm_km_alloc1: allocate wired down memory in the kernel map.
*
* => we can sleep if needed
*/
vaddr_t
uvm_km_alloc1(map, size, zeroit)
struct vm_map *map;
vsize_t size;
boolean_t zeroit;
{
vaddr_t kva, loopva, offset;
struct vm_page *pg;
UVMHIST_FUNC("uvm_km_alloc1"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x, size=0x%x)", map, size,0,0);
KASSERT(vm_map_pmap(map) == pmap_kernel());
size = round_page(size);
kva = vm_map_min(map); /* hint */
/*
* allocate some virtual space
*/
if (__predict_false(uvm_map(map, &kva, size, uvm.kernel_object,
UVM_UNKNOWN_OFFSET, 0, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL,
UVM_INH_NONE, UVM_ADV_RANDOM,
0)) != 0)) {
UVMHIST_LOG(maphist,"<- done (no VM)",0,0,0,0);
return(0);
}
/*
* recover object offset from virtual address
*/
offset = kva - vm_map_min(kernel_map);
UVMHIST_LOG(maphist," kva=0x%x, offset=0x%x", kva, offset,0,0);
/*
* now allocate the memory.
*/
loopva = kva;
while (size) {
simple_lock(&uvm.kernel_object->vmobjlock);
KASSERT(uvm_pagelookup(uvm.kernel_object, offset) == NULL);
pg = uvm_pagealloc(uvm.kernel_object, offset, NULL, 0);
if (pg) {
pg->flags &= ~PG_BUSY;
UVM_PAGE_OWN(pg, NULL);
}
simple_unlock(&uvm.kernel_object->vmobjlock);
if (pg == NULL) {
uvm_wait("km_alloc1w");
continue;
}
pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg),
UVM_PROT_ALL, PMAP_WIRED | VM_PROT_READ | VM_PROT_WRITE);
loopva += PAGE_SIZE;
offset += PAGE_SIZE;
size -= PAGE_SIZE;
}
pmap_update(map->pmap);
/*
* zero on request (note that "size" is now zero due to the above loop
* so we need to subtract kva from loopva to reconstruct the size).
*/
if (zeroit)
memset((caddr_t)kva, 0, loopva - kva);
UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0);
return(kva);
}
/*
* uvm_km_valloc: allocate zero-fill memory in the kernel's address space
*
* => memory is not allocated until fault time
*/
vaddr_t
uvm_km_valloc(map, size)
struct vm_map *map;
vsize_t size;
{
return(uvm_km_valloc_align(map, size, 0));
}
vaddr_t
uvm_km_valloc_align(map, size, align)
struct vm_map *map;
vsize_t size;
vsize_t align;
{
vaddr_t kva;
UVMHIST_FUNC("uvm_km_valloc"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0);
KASSERT(vm_map_pmap(map) == pmap_kernel());
size = round_page(size);
kva = vm_map_min(map); /* hint */
/*
* allocate some virtual space. will be demand filled by kernel_object.
*/
if (__predict_false(uvm_map(map, &kva, size, uvm.kernel_object,
UVM_UNKNOWN_OFFSET, align, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL,
UVM_INH_NONE, UVM_ADV_RANDOM,
0)) != 0)) {
UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0);
return(0);
}
UVMHIST_LOG(maphist, "<- done (kva=0x%x)", kva,0,0,0);
return(kva);
}
/*
* uvm_km_valloc_wait: allocate zero-fill memory in the kernel's address space
*
* => memory is not allocated until fault time
* => if no room in map, wait for space to free, unless requested size
* is larger than map (in which case we return 0)
*/
vaddr_t
uvm_km_valloc_prefer_wait(map, size, prefer)
struct vm_map *map;
vsize_t size;
voff_t prefer;
{
vaddr_t kva;
UVMHIST_FUNC("uvm_km_valloc_prefer_wait"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0);
KASSERT(vm_map_pmap(map) == pmap_kernel());
size = round_page(size);
if (size > vm_map_max(map) - vm_map_min(map))
return(0);
for (;;) {
kva = vm_map_min(map); /* hint */
/*
* allocate some virtual space. will be demand filled
* by kernel_object.
*/
if (__predict_true(uvm_map(map, &kva, size, uvm.kernel_object,
prefer, 0, UVM_MAPFLAG(UVM_PROT_ALL,
UVM_PROT_ALL, UVM_INH_NONE, UVM_ADV_RANDOM, 0))
== 0)) {
UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0);
return(kva);
}
/*
* failed. sleep for a while (on map)
*/
UVMHIST_LOG(maphist,"<<<sleeping>>>",0,0,0,0);
tsleep((caddr_t)map, PVM, "vallocwait", 0);
}
/*NOTREACHED*/
}
vaddr_t
uvm_km_valloc_wait(map, size)
struct vm_map *map;
vsize_t size;
{
return uvm_km_valloc_prefer_wait(map, size, UVM_UNKNOWN_OFFSET);
}
/* 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
/*
* uvm_km_alloc_poolpage: allocate a page for the pool allocator
*
* => if the pmap specifies an alternate mapping method, we use it.
*/
/* ARGSUSED */
vaddr_t
uvm_km_alloc_poolpage1(map, obj, waitok)
struct vm_map *map;
struct uvm_object *obj;
boolean_t waitok;
{
#if defined(PMAP_MAP_POOLPAGE)
struct vm_page *pg;
vaddr_t va;
again:
pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_USERESERVE);
if (__predict_false(pg == NULL)) {
if (waitok) {
uvm_wait("plpg");
goto again;
} else
return (0);
}
va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg));
if (__predict_false(va == 0))
uvm_pagefree(pg);
return (va);
#else
vaddr_t va;
int s;
/*
* NOTE: We may be called with a map that doens't require splvm
* protection (e.g. kernel_map). However, it does not hurt to
* go to splvm in this case (since unprocted maps will never be
* accessed in interrupt context).
*
* XXX We may want to consider changing the interface to this
* XXX function.
*/
s = splvm();
va = uvm_km_kmemalloc(map, obj, PAGE_SIZE,
waitok ? 0 : UVM_KMF_NOWAIT | UVM_KMF_TRYLOCK);
splx(s);
return (va);
#endif /* PMAP_MAP_POOLPAGE */
}
/*
* uvm_km_free_poolpage: free a previously allocated pool page
*
* => if the pmap specifies an alternate unmapping method, we use it.
*/
/* ARGSUSED */
void
uvm_km_free_poolpage1(map, addr)
struct vm_map *map;
vaddr_t addr;
{
#if defined(PMAP_UNMAP_POOLPAGE)
paddr_t pa;
pa = PMAP_UNMAP_POOLPAGE(addr);
uvm_pagefree(PHYS_TO_VM_PAGE(pa));
#else
int s;
/*
* NOTE: We may be called with a map that doens't require splvm
* protection (e.g. kernel_map). However, it does not hurt to
* go to splvm in this case (since unprocted maps will never be
* accessed in interrupt context).
*
* XXX We may want to consider changing the interface to this
* XXX function.
*/
s = splvm();
uvm_km_free(map, addr, PAGE_SIZE);
splx(s);
#endif /* PMAP_UNMAP_POOLPAGE */
}