File: [local] / sys / uvm / uvm_km.c (download)
Revision 1.1.1.1 (vendor branch), Tue Mar 4 16:15:22 2008 UTC (16 years, 3 months ago) by nbrk
Branch: OPENBSD_4_2_BASE, MAIN
CVS Tags: jornada-partial-support-wip, HEAD Changes since 1.1: +0 -0 lines
Import of OpenBSD 4.2 release kernel tree with initial code to support
Jornada 720/728, StrongARM 1110-based handheld PC.
At this point kernel roots on NFS and boots into vfs_mountroot() and traps.
What is supported:
- glass console, Jornada framebuffer (jfb) works in 16bpp direct color mode
(needs some palette tweaks for non black/white/blue colors, i think)
- saic, SA11x0 interrupt controller (needs cleanup)
- sacom, SA11x0 UART (supported only as boot console for now)
- SA11x0 GPIO controller fully supported (but can't handle multiple interrupt
handlers on one gpio pin)
- sassp, SSP port on SA11x0 that attaches spibus
- Jornada microcontroller (jmcu) to control kbd, battery, etc throught
the SPI bus (wskbd attaches on jmcu, but not tested)
- tod functions seem work
- initial code for SA-1111 (chip companion) : this is TODO
Next important steps, i think:
- gpio and intc on sa1111
- pcmcia support for sa11x0 (and sa1111 help logic)
- REAL root on nfs when we have PCMCIA support (we may use any of supported pccard NICs)
- root on wd0! (using already supported PCMCIA-ATA)
|
/* $OpenBSD: uvm_km.c,v 1.64 2007/08/03 22:49:07 art Exp $ */
/* $NetBSD: uvm_km.c,v 1.42 2001/01/14 02:10:01 thorpej 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 ***
* 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(). each of these submaps manages their own pages.
*
* 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 objects 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/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/kthread.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(vaddr_t start, vaddr_t 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 already allocated kernel space
* before installing.
*/
uvm_map_setup(&kernel_map_store, base, end, VM_MAP_PAGEABLE);
kernel_map_store.pmap = pmap_kernel();
if (base != start && 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(struct vm_map *map, vaddr_t *min, vaddr_t *max, 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(struct uvm_object *uobj, vaddr_t start, vaddr_t end)
{
struct vm_page *pp;
voff_t curoff;
UVMHIST_FUNC("uvm_km_pgremove"); UVMHIST_CALLED(maphist);
KASSERT(uobj->pgops == &aobj_pager);
for (curoff = start ; curoff < end ; curoff += PAGE_SIZE) {
pp = uvm_pagelookup(uobj, curoff);
if (pp == NULL)
continue;
UVMHIST_LOG(maphist," page %p, busy=%ld", pp,
pp->pg_flags & PG_BUSY, 0, 0);
if (pp->pg_flags & PG_BUSY) {
/* owner must check for this when done */
atomic_setbits_int(&pp->pg_flags, PG_RELEASED);
} else {
/* free the swap slot... */
uao_dropswap(uobj, curoff >> PAGE_SHIFT);
/*
* ...and free the page; note it may be on the
* active or inactive queues.
*/
uvm_lock_pageq();
uvm_pagefree(pp);
uvm_unlock_pageq();
}
}
}
/*
* uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for "intrsafe"
* objects
*
* => when you unmap a part of anonymous kernel memory you want to toss
* the pages right away. (this gets 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 these objects are
* never allowed to "page").
*/
void
uvm_km_pgremove_intrsafe(vaddr_t start, vaddr_t end)
{
struct vm_page *pg;
vaddr_t va;
paddr_t pa;
for (va = start; va < end; va += PAGE_SIZE) {
if (!pmap_extract(pmap_kernel(), va, &pa))
continue;
pg = PHYS_TO_VM_PAGE(pa);
if (pg == NULL)
panic("uvm_km_pgremove_intrsafe: no page");
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(struct vm_map *map, struct uvm_object *obj, vsize_t size,
int flags)
{
vaddr_t kva, loopva;
voff_t offset;
struct vm_page *pg;
UVMHIST_FUNC("uvm_km_kmemalloc"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist," (map=%p, obj=%p, size=0x%lx, 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_RW, UVM_PROT_RW, UVM_INH_NONE,
UVM_ADV_RANDOM, (flags & UVM_KMF_TRYLOCK))) != 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%lx)", kva,0,0,0);
return(kva);
}
/*
* recover object offset from virtual address
*/
if (obj != NULL)
offset = kva - vm_map_min(kernel_map);
else
offset = 0;
UVMHIST_LOG(maphist, " kva=0x%lx, offset=0x%lx", 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;
while (loopva != kva + size) {
pg = uvm_pagealloc(obj, offset, NULL, 0);
if (pg) {
atomic_clearbits_int(&pg->pg_flags, PG_BUSY);
UVM_PAGE_OWN(pg, NULL);
}
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: note that we call pmap_enter with the map and
* object unlocked in case we are kmem_map.
*/
if (obj == NULL) {
pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg),
UVM_PROT_RW);
} else {
pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg),
UVM_PROT_RW,
PMAP_WIRED | VM_PROT_READ | VM_PROT_WRITE);
}
loopva += PAGE_SIZE;
offset += PAGE_SIZE;
}
pmap_update(pmap_kernel());
UVMHIST_LOG(maphist,"<- done (kva=0x%lx)", kva,0,0,0);
return(kva);
}
/*
* uvm_km_free: free an area of kernel memory
*/
void
uvm_km_free(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(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, NULL);
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(struct vm_map *map, vsize_t size, vsize_t align, boolean_t zeroit)
{
vaddr_t kva, loopva;
voff_t offset;
struct vm_page *pg;
UVMHIST_FUNC("uvm_km_alloc1"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=%p, size=0x%lx)", 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, 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);
}
/*
* recover object offset from virtual address
*/
offset = kva - vm_map_min(kernel_map);
UVMHIST_LOG(maphist," kva=0x%lx, offset=0x%lx", kva, offset,0,0);
/*
* now allocate the memory. we must be careful about released pages.
*/
loopva = kva;
while (size) {
simple_lock(&uvm.kernel_object->vmobjlock);
pg = uvm_pagelookup(uvm.kernel_object, offset);
/*
* if we found a page in an unallocated region, it must be
* released
*/
if (pg) {
if ((pg->pg_flags & PG_RELEASED) == 0)
panic("uvm_km_alloc1: non-released page");
atomic_setbits_int(&pg->pg_flags, PG_WANTED);
UVM_UNLOCK_AND_WAIT(pg, &uvm.kernel_object->vmobjlock,
FALSE, "km_alloc", 0);
continue; /* retry */
}
/* allocate ram */
pg = uvm_pagealloc(uvm.kernel_object, offset, NULL, 0);
if (pg) {
atomic_clearbits_int(&pg->pg_flags, PG_BUSY);
UVM_PAGE_OWN(pg, NULL);
}
simple_unlock(&uvm.kernel_object->vmobjlock);
if (__predict_false(pg == NULL)) {
if (curproc == uvm.pagedaemon_proc) {
/*
* It is unfeasible for the page daemon to
* sleep for memory, so free what we have
* allocated and fail.
*/
uvm_unmap(map, kva, loopva - kva);
return (NULL);
} else {
uvm_wait("km_alloc1w"); /* wait for memory */
continue;
}
}
/*
* map it in; note we're never called with an intrsafe
* object, so we always use regular old pmap_enter().
*/
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%lx)", 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(struct vm_map *map, vsize_t size)
{
return(uvm_km_valloc_align(map, size, 0));
}
vaddr_t
uvm_km_valloc_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=%p, size=0x%lx)", 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%lx)", 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(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=%p, size=0x%lx)", 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);
while (1) {
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%lx)", 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(struct vm_map *map, vsize_t size)
{
return uvm_km_valloc_prefer_wait(map, size, UVM_UNKNOWN_OFFSET);
}
/*
* 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(struct vm_map *map, struct uvm_object *obj,
boolean_t waitok)
{
#if defined(__HAVE_PMAP_DIRECT)
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_direct(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 doesn't require splvm
* protection (e.g. kernel_map). However, it does not hurt to
* go to splvm in this case (since unprotected 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);
splx(s);
return (va);
#endif /* __HAVE_PMAP_DIRECT */
}
/*
* 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(struct vm_map *map, vaddr_t addr)
{
#if defined(__HAVE_PMAP_DIRECT)
uvm_pagefree(pmap_unmap_direct(addr));
#else
int s;
/*
* NOTE: We may be called with a map that doesn'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 /* __HAVE_PMAP_DIRECT */
}
#if defined(__HAVE_PMAP_DIRECT)
/*
* uvm_km_page allocator, __HAVE_PMAP_DIRECT arch
* On architectures with machine memory direct mapped into a portion
* of KVM, we have very little work to do. Just get a physical page,
* and find and return its VA. We use the poolpage functions for this.
*/
void
uvm_km_page_init(void)
{
/* nothing */
}
void *
uvm_km_getpage(boolean_t waitok)
{
return ((void *)uvm_km_alloc_poolpage1(NULL, NULL, waitok));
}
void
uvm_km_putpage(void *v)
{
uvm_km_free_poolpage1(NULL, (vaddr_t)v);
}
#else
/*
* uvm_km_page allocator, non __HAVE_PMAP_DIRECT archs
* This is a special allocator that uses a reserve of free pages
* to fulfill requests. It is fast and interrupt safe, but can only
* return page sized regions. Its primary use is as a backend for pool.
*
* The memory returned is allocated from the larger kernel_map, sparing
* pressure on the small interrupt-safe kmem_map. It is wired, but
* not zero filled.
*/
int uvm_km_pages_lowat; /* allocate more when reserve drops below this */
int uvm_km_pages_free; /* number of pages currently on free list */
struct km_page {
struct km_page *next;
} *uvm_km_pages_head;
void uvm_km_createthread(void *);
void uvm_km_thread(void *);
/*
* Allocate the initial reserve, and create the thread which will
* keep the reserve full. For bootstrapping, we allocate more than
* the lowat amount, because it may be a while before the thread is
* running.
*/
void
uvm_km_page_init(void)
{
struct km_page *page;
int i;
if (!uvm_km_pages_lowat) {
/* based on physmem, calculate a good value here */
uvm_km_pages_lowat = physmem / 256;
if (uvm_km_pages_lowat > 2048)
uvm_km_pages_lowat = 2048;
if (uvm_km_pages_lowat < 128)
uvm_km_pages_lowat = 128;
}
for (i = 0; i < uvm_km_pages_lowat * 4; i++) {
page = (void *)uvm_km_alloc(kernel_map, PAGE_SIZE);
page->next = uvm_km_pages_head;
uvm_km_pages_head = page;
}
uvm_km_pages_free = i;
/* tone down if really high */
if (uvm_km_pages_lowat > 512)
uvm_km_pages_lowat = 512;
kthread_create_deferred(uvm_km_createthread, NULL);
}
void
uvm_km_createthread(void *arg)
{
kthread_create(uvm_km_thread, NULL, NULL, "kmthread");
}
/*
* Endless loop. We grab pages in increments of 16 pages, then
* quickly swap them into the list. At some point we can consider
* returning memory to the system if we have too many free pages,
* but that's not implemented yet.
*/
void
uvm_km_thread(void *arg)
{
struct km_page *head, *tail, *page;
int i, s, want;
for (i = want = 16; ; ) {
if (i < want || uvm_km_pages_free >= uvm_km_pages_lowat)
tsleep(&uvm_km_pages_head, PVM, "kmalloc", 0);
for (i = 0; i < want; i++) {
page = (void *)uvm_km_alloc(kernel_map, PAGE_SIZE);
if (i == 0)
head = tail = page;
if (page == NULL)
break;
page->next = head;
head = page;
}
if (head != NULL) {
s = splvm();
tail->next = uvm_km_pages_head;
uvm_km_pages_head = head;
uvm_km_pages_free += i;
splx(s);
}
if (uvm_km_pages_free)
wakeup(&uvm_km_pages_free);
}
}
/*
* Allocate one page. We can sleep for more if the caller
* permits it. Wake up the thread if we've dropped below lowat.
*/
void *
uvm_km_getpage(boolean_t waitok)
{
struct km_page *page = NULL;
int s;
s = splvm();
for (;;) {
page = uvm_km_pages_head;
if (page) {
uvm_km_pages_head = page->next;
uvm_km_pages_free--;
break;
}
if (!waitok)
break;
tsleep(&uvm_km_pages_free, PVM, "getpage", 0);
}
splx(s);
if (uvm_km_pages_free < uvm_km_pages_lowat)
wakeup(&uvm_km_pages_head);
return (page);
}
void
uvm_km_putpage(void *v)
{
struct km_page *page = v;
int s;
s = splvm();
page->next = uvm_km_pages_head;
uvm_km_pages_head = page;
uvm_km_pages_free++;
splx(s);
}
#endif