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NetBSD/sys/uvm/uvm_km.c

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/* $NetBSD: uvm_km.c,v 1.3 1998/02/07 02:29:21 chs Exp $ */
/*
* XXXCDC: "ROUGH DRAFT" QUALITY UVM PRE-RELEASE FILE!
* >>>USE AT YOUR OWN RISK, WORK IS NOT FINISHED<<<
*/
/*
* 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
*
*
* 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
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_kern.h>
#include <uvm/uvm.h>
/*
* global data structures
*/
vm_map_t kernel_map = NULL;
/*
* local functions
*/
static int uvm_km_get __P((struct uvm_object *, vm_offset_t,
vm_page_t *, int *, int, vm_prot_t, int, int));
/*
* local data structues
*/
static struct vm_map kernel_map_store;
static struct uvm_object kmem_object_store;
static struct uvm_object mb_object_store;
static struct uvm_pagerops km_pager = {
NULL, /* init */
NULL, /* attach */
NULL, /* reference */
NULL, /* detach */
NULL, /* fault */
NULL, /* flush */
uvm_km_get, /* get */
/* ... rest are NULL */
};
/*
* uvm_km_get: pager get function for kernel objects
*
* => currently we do not support pageout to the swap area, so this
* pager is very simple. eventually we may want an anonymous
* object pager which will do paging.
*/
static int uvm_km_get(uobj, offset, pps, npagesp, centeridx, access_type,
advice, flags)
struct uvm_object *uobj;
vm_offset_t offset;
struct vm_page **pps;
int *npagesp;
int centeridx, advice, flags;
vm_prot_t access_type;
{
vm_offset_t current_offset;
vm_page_t ptmp;
int lcv, gotpages, maxpages;
boolean_t done;
UVMHIST_FUNC("uvm_km_get"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist, "flags=%d", flags,0,0,0);
/*
* get number of pages
*/
maxpages = *npagesp;
/*
* step 1: handled the case where fault data structures are locked.
*/
if (flags & PGO_LOCKED) {
/*
* step 1a: get pages that are already resident. only do this
* if the data structures are locked (i.e. the first time through).
*/
done = TRUE; /* be optimistic */
gotpages = 0; /* # of pages we got so far */
for (lcv = 0, current_offset = offset ;
lcv < maxpages ; lcv++, current_offset += PAGE_SIZE) {
/* do we care about this page? if not, skip it */
if (pps[lcv] == PGO_DONTCARE)
continue;
/* lookup page */
ptmp = uvm_pagelookup(uobj, current_offset);
/* null? attempt to allocate the page */
if (ptmp == NULL) {
ptmp = uvm_pagealloc(uobj, current_offset, NULL);
if (ptmp) {
ptmp->flags &= ~(PG_BUSY|PG_FAKE); /* new page */
UVM_PAGE_OWN(ptmp, NULL);
ptmp->wire_count = 1; /* XXX: prevents pageout attempts */
uvm_pagezero(ptmp);
}
}
/* to be useful must get a non-busy, non-released page */
if (ptmp == NULL || (ptmp->flags & (PG_BUSY|PG_RELEASED)) != 0) {
if (lcv == centeridx || (flags & PGO_ALLPAGES) != 0)
done = FALSE; /* need to do a wait or I/O! */
continue;
}
/* useful page: busy/lock it and plug it in our result array */
ptmp->flags |= PG_BUSY; /* caller must un-busy this page */
UVM_PAGE_OWN(ptmp, "uvm_km_get1");
pps[lcv] = ptmp;
gotpages++;
} /* "for" lcv loop */
/*
* step 1b: now we've either done everything needed or we to unlock
* and do some waiting or I/O.
*/
UVMHIST_LOG(maphist, "<- done (done=%d)", done, 0,0,0);
*npagesp = gotpages;
if (done)
return(VM_PAGER_OK); /* bingo! */
else
return(VM_PAGER_UNLOCK); /* EEK! Need to unlock and I/O */
}
/*
* step 2: get non-resident or busy pages.
* object is locked. data structures are unlocked.
*/
for (lcv = 0, current_offset = offset ;
lcv < maxpages ; lcv++, current_offset += PAGE_SIZE) {
/* skip over pages we've already gotten or don't want */
/* skip over pages we don't _have_ to get */
if (pps[lcv] != NULL ||
(lcv != centeridx && (flags & PGO_ALLPAGES) == 0))
continue;
/*
* we have yet to locate the current page (pps[lcv]). we first
* look for a page that is already at the current offset. if we
* find a page, we check to see if it is busy or released. if that
* is the case, then we sleep on the page until it is no longer busy
* or released and repeat the lookup. if the page we found is
* neither busy nor released, then we busy it (so we own it) and
* plug it into pps[lcv]. this 'break's the following while loop
* and indicates we are ready to move on to the next page in the
* "lcv" loop above.
*
* if we exit the while loop with pps[lcv] still set to NULL, then
* it means that we allocated a new busy/fake/clean page ptmp in the
* object and we need to do I/O to fill in the data.
*/
while (pps[lcv] == NULL) { /* top of "pps" while loop */
/* look for a current page */
ptmp = uvm_pagelookup(uobj, current_offset);
/* nope? allocate one now (if we can) */
if (ptmp == NULL) {
ptmp = uvm_pagealloc(uobj, current_offset, NULL); /* alloc */
/* out of RAM? */
if (ptmp == NULL) {
simple_unlock(&uobj->vmobjlock);
uvm_wait("kmgetwait1");
simple_lock(&uobj->vmobjlock);
continue; /* goto top of pps while loop */
}
/*
* got new page ready for I/O. break pps while loop. pps[lcv] is
* still NULL.
*/
break;
}
/* page is there, see if we need to wait on it */
if ((ptmp->flags & (PG_BUSY|PG_RELEASED)) != 0) {
ptmp->flags |= PG_WANTED;
UVM_UNLOCK_AND_WAIT(ptmp,&uobj->vmobjlock,0,"uvn_get",0);
simple_lock(&uobj->vmobjlock);
continue; /* goto top of pps while loop */
}
/*
* if we get here then the page has become resident and unbusy
* between steps 1 and 2. we busy it now (so we own it) and set
* pps[lcv] (so that we exit the while loop).
*/
ptmp->flags |= PG_BUSY; /* we own it, caller must un-busy */
UVM_PAGE_OWN(ptmp, "uvm_km_get2");
pps[lcv] = ptmp;
}
/*
* if we own the a valid page at the correct offset, pps[lcv] will
* point to it. nothing more to do except go to the next page.
*/
if (pps[lcv])
continue; /* next lcv */
/*
* we have a "fake/busy/clean" page that we just allocated.
* do the needed "i/o" (in this case that means zero it).
*/
uvm_pagezero(ptmp);
ptmp->flags &= ~(PG_FAKE);
ptmp->wire_count = 1; /* XXX: prevents pageout attempts */
pps[lcv] = ptmp;
} /* lcv loop */
/*
* finally, unlock object and return.
*/
simple_unlock(&uobj->vmobjlock);
UVMHIST_LOG(maphist, "<- done (OK)",0,0,0,0);
return(VM_PAGER_OK);
}
/*
* 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)
vm_offset_t start, end;
{
vm_offset_t base = VM_MIN_KERNEL_ADDRESS;
/*
* first, 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);
/* kmem_object: for malloc'd memory (always wired) */
simple_lock_init(&kmem_object_store.vmobjlock);
kmem_object_store.pgops = &km_pager;
TAILQ_INIT(&kmem_object_store.memq);
kmem_object_store.uo_npages = 0;
kmem_object_store.uo_refs = UVM_OBJ_KERN;
/* we are special. we never die */
uvmexp.kmem_object = &kmem_object_store;
/* mb_object: for mbuf memory (always wired) */
simple_lock_init(&mb_object_store.vmobjlock);
mb_object_store.pgops = &km_pager;
TAILQ_INIT(&mb_object_store.memq);
mb_object_store.uo_npages = 0;
mb_object_store.uo_refs = UVM_OBJ_KERN;
/* we are special. we never die */
uvmexp.mb_object = &mb_object_store;
/*
* init the map and reserve kernel space before installing.
*/
uvm_map_setup(&kernel_map_store, base, end, FALSE);
kernel_map_store.pmap = pmap_kernel();
if (uvm_map(&kernel_map_store, &base, start - base, NULL, UVM_UNKNOWN_OFFSET,
UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
UVM_ADV_RANDOM,UVM_FLAG_FIXED)) != KERN_SUCCESS)
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 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, pageable, submap)
struct vm_map *map;
vm_offset_t *min, *max; /* OUT, OUT */
vm_size_t size;
boolean_t pageable;
struct vm_map *submap;
{
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,
UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
UVM_ADV_RANDOM, UVM_FLAG_NOMERGE)) != KERN_SUCCESS) {
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, pageable);
if (submap == NULL)
panic("uvm_km_suballoc: unable to create submap");
} else {
uvm_map_setup(submap, *min, *max, pageable);
submap->pmap = vm_map_pmap(map);
}
/*
* now let uvm_map_submap plug in it...
*/
if (uvm_map_submap(map, *min, *max, submap) != KERN_SUCCESS)
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_...).
*/
#define UKM_HASH_PENALTY 4 /* a guess */
void uvm_km_pgremove(uobj, start, end)
struct uvm_object *uobj;
vm_offset_t start, end;
{
boolean_t by_list, is_aobj;
struct vm_page *pp, *ppnext;
vm_offset_t curoff;
UVMHIST_FUNC("uvm_km_pgremove"); UVMHIST_CALLED(maphist);
simple_lock(&uobj->vmobjlock); /* lock object */
/* is uobj an aobj? */
is_aobj = uobj->pgops == &aobj_pager;
/* choose cheapest traversal */
by_list = (uobj->uo_npages <=
((end - start) / PAGE_SIZE) * UKM_HASH_PENALTY);
if (by_list)
goto loop_by_list;
/* by hash */
for (curoff = start ; curoff < end ; curoff += PAGE_SIZE) {
pp = uvm_pagelookup(uobj, curoff);
if (pp == NULL)
continue;
UVMHIST_LOG(maphist," page 0x%x, busy=%d", pp,pp->flags & PG_BUSY,0,0);
/* now do the actual work */
if (pp->flags & PG_BUSY)
pp->flags |= PG_RELEASED; /* owner must check for this when done */
else {
pmap_page_protect(PMAP_PGARG(pp), VM_PROT_NONE);
/*
* if this kernel object is an aobj, free the swap slot.
*/
if (is_aobj) {
int slot = uao_set_swslot(uobj, curoff / PAGE_SIZE, 0);
if (slot)
uvm_swap_free(slot, 1);
}
uvm_lock_pageq();
uvm_pagefree(pp);
uvm_unlock_pageq();
}
/* done */
}
simple_unlock(&uobj->vmobjlock);
return;
loop_by_list:
for (pp = uobj->memq.tqh_first ; pp != NULL ; pp = ppnext) {
ppnext = pp->listq.tqe_next;
if (pp->offset < start || pp->offset >= end) {
continue;
}
UVMHIST_LOG(maphist," page 0x%x, busy=%d", pp,pp->flags & PG_BUSY,0,0);
/* now do the actual work */
if (pp->flags & PG_BUSY)
pp->flags |= PG_RELEASED; /* owner must check for this when done */
else {
pmap_page_protect(PMAP_PGARG(pp), VM_PROT_NONE);
/*
* if this kernel object is an aobj, free the swap slot.
*/
if (is_aobj) {
int slot = uao_set_swslot(uobj, pp->offset / PAGE_SIZE, 0);
if (slot)
uvm_swap_free(slot, 1);
}
uvm_lock_pageq();
uvm_pagefree(pp);
uvm_unlock_pageq();
}
/* done */
}
simple_unlock(&uobj->vmobjlock);
return;
}
/*
* 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
*/
vm_offset_t uvm_km_kmemalloc(map, obj, size, flags)
vm_map_t map;
struct uvm_object *obj;
vm_size_t size;
int flags;
{
vm_offset_t kva, loopva;
vm_offset_t offset;
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);
#ifdef DIAGNOSTIC
/* sanity check */
if (vm_map_pmap(map) != pmap_kernel())
panic("uvm_km_kmemalloc: invalid map");
#endif
/*
* setup for call
*/
size = round_page(size);
kva = vm_map_min(map); /* hint */
/*
* allocate some virtual space
*/
if (uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET,
UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
UVM_ADV_RANDOM, (flags & UVM_KMF_TRYLOCK)))
!= KERN_SUCCESS) {
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(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;
while (size) {
simple_lock(&obj->vmobjlock);
pg = uvm_pagealloc(obj, offset, NULL);
if (pg) {
pg->flags &= ~PG_BUSY; /* new page */
UVM_PAGE_OWN(pg, NULL);
pg->wire_count = 1;
uvmexp.wired++;
}
simple_unlock(&obj->vmobjlock);
/*
* out of memory?
*/
if (pg == NULL) {
if (flags & UVM_KMF_NOWAIT) {
uvm_unmap(map, kva, kva + size, 0); /* free everything! */
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/kmem_object (because if pmap_enter
* wants to allocate out of kmem_object it will need to lock it itself!)
*/
#if defined(PMAP_NEW)
pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), VM_PROT_ALL);
#else
pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg), UVM_PROT_ALL, TRUE);
#endif
loopva += PAGE_SIZE;
offset += PAGE_SIZE;
size -= PAGE_SIZE;
}
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)
vm_map_t map;
vm_offset_t addr;
vm_size_t size;
{
uvm_unmap(map, trunc_page(addr), round_page(addr+size), 1);
}
/*
* 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)
vm_map_t map;
vm_offset_t addr;
vm_size_t size;
{
vm_map_entry_t dead_entries;
vm_map_lock(map);
(void)uvm_unmap_remove(map, trunc_page(addr), round_page(addr+size), 1,
&dead_entries);
thread_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
*/
vm_offset_t uvm_km_alloc1(map, size, zeroit)
vm_map_t map;
vm_size_t size;
boolean_t zeroit;
{
vm_offset_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);
#ifdef DIAGNOSTIC
if (vm_map_pmap(map) != pmap_kernel())
panic("uvm_km_alloc1");
#endif
size = round_page(size);
kva = vm_map_min(map); /* hint */
/*
* allocate some virtual space
*/
if (uvm_map(map, &kva, size, uvm.kernel_object, UVM_UNKNOWN_OFFSET,
UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
UVM_ADV_RANDOM, 0)) != KERN_SUCCESS) {
UVMHIST_LOG(maphist,"<- done (no VM)",0,0,0,0);
return(0);
}
/*
* recover object offset from virtual address
*/
offset = kva - vm_map_min(map);
UVMHIST_LOG(maphist," kva=0x%x, offset=0x%x", 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->flags & PG_RELEASED) == 0)
panic("uvm_km_alloc1: non-released page");
pg->flags |= PG_WANTED;
UVM_UNLOCK_AND_WAIT(pg, &uvm.kernel_object->vmobjlock,0,"km_alloc",0);
continue; /* retry */
}
/* allocate ram */
pg = uvm_pagealloc(uvm.kernel_object, offset, NULL);
if (pg) {
pg->flags &= ~PG_BUSY; /* new page */
UVM_PAGE_OWN(pg, NULL);
}
simple_unlock(&uvm.kernel_object->vmobjlock);
if (pg == NULL) {
uvm_wait("km_alloc1w"); /* wait for memory */
continue;
}
/* map it in */
#if defined(PMAP_NEW)
pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), UVM_PROT_ALL);
#else
pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg), UVM_PROT_ALL, TRUE);
#endif
loopva += PAGE_SIZE;
offset += PAGE_SIZE;
size -= PAGE_SIZE;
}
/*
* 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)
bzero((caddr_t)kva, 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
*/
vm_offset_t uvm_km_valloc(map, size)
vm_map_t map;
vm_size_t size;
{
vm_offset_t kva;
UVMHIST_FUNC("uvm_km_valloc"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0);
#ifdef DIAGNOSTIC
if (vm_map_pmap(map) != pmap_kernel())
panic("uvm_km_valloc");
#endif
size = round_page(size);
kva = vm_map_min(map); /* hint */
/*
* allocate some virtual space. will be demand filled by kernel_object.
*/
if (uvm_map(map, &kva, size, uvm.kernel_object, UVM_UNKNOWN_OFFSET,
UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
UVM_ADV_RANDOM, 0)) != KERN_SUCCESS) {
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)
*/
vm_offset_t uvm_km_valloc_wait(map, size)
vm_map_t map;
vm_size_t size;
{
vm_offset_t kva;
UVMHIST_FUNC("uvm_km_valloc_wait"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0);
#ifdef DIAGNOSTIC
if (vm_map_pmap(map) != pmap_kernel())
panic("uvm_km_valloc_wait");
#endif
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 (uvm_map(map, &kva, size, uvm.kernel_object, UVM_UNKNOWN_OFFSET,
UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE,
UVM_ADV_RANDOM, 0)) == KERN_SUCCESS){
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*/
}
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