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mirror of https://git.FreeBSD.org/src.git synced 2024-12-15 10:17:20 +00:00
freebsd/sys/vm/vm_pager.c
1994-10-09 01:52:19 +00:00

425 lines
9.8 KiB
C

/*
* 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 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.
*
* from: @(#)vm_pager.c 8.6 (Berkeley) 1/12/94
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Authors: Avadis Tevanian, Jr., Michael Wayne Young
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*
* $Id: vm_pager.c,v 1.7 1994/08/18 22:36:09 wollman Exp $
*/
/*
* Paging space routine stubs. Emulates a matchmaker-like interface
* for builtin pagers.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/buf.h>
#include <sys/ucred.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_kern.h>
extern struct pagerops swappagerops;
extern struct pagerops vnodepagerops;
extern struct pagerops devicepagerops;
struct pagerops *pagertab[] = {
&swappagerops, /* PG_SWAP */
&vnodepagerops, /* PG_VNODE */
&devicepagerops, /* PG_DEV */
};
int npagers = sizeof (pagertab) / sizeof (pagertab[0]);
struct pagerops *dfltpagerops = NULL; /* default pager */
/*
* Kernel address space for mapping pages.
* Used by pagers where KVAs are needed for IO.
*
* XXX needs to be large enough to support the number of pending async
* cleaning requests (NPENDINGIO == 64) * the maximum swap cluster size
* (MAXPHYS == 64k) if you want to get the most efficiency.
*/
#define PAGER_MAP_SIZE (8 * 1024 * 1024)
int pager_map_size = PAGER_MAP_SIZE;
vm_map_t pager_map;
boolean_t pager_map_wanted;
vm_offset_t pager_sva, pager_eva;
int bswneeded;
vm_offset_t swapbkva; /* swap buffers kva */
void
vm_pager_init()
{
struct pagerops **pgops;
/*
* Initialize known pagers
*/
for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++)
if (pgops)
(*(*pgops)->pgo_init)();
if (dfltpagerops == NULL)
panic("no default pager");
}
void
vm_pager_bufferinit()
{
struct buf *bp;
int i;
bp = swbuf;
/*
* Now set up swap and physical I/O buffer headers.
*/
for (i = 0; i < nswbuf - 1; i++, bp++) {
TAILQ_INSERT_HEAD(&bswlist, bp, b_freelist);
bp->b_rcred = bp->b_wcred = NOCRED;
bp->b_vnbufs.le_next = NOLIST;
}
bp->b_rcred = bp->b_wcred = NOCRED;
bp->b_vnbufs.le_next = NOLIST;
bp->b_actf = NULL;
swapbkva = kmem_alloc_pageable( pager_map, nswbuf * MAXPHYS);
if( !swapbkva)
panic("Not enough pager_map VM space for physical buffers");
}
/*
* Allocate an instance of a pager of the given type.
* Size, protection and offset parameters are passed in for pagers that
* need to perform page-level validation (e.g. the device pager).
*/
vm_pager_t
vm_pager_allocate(type, handle, size, prot, off)
int type;
caddr_t handle;
vm_size_t size;
vm_prot_t prot;
vm_offset_t off;
{
struct pagerops *ops;
ops = (type == PG_DFLT) ? dfltpagerops : pagertab[type];
if (ops)
return ((*ops->pgo_alloc)(handle, size, prot, off));
return (NULL);
}
void
vm_pager_deallocate(pager)
vm_pager_t pager;
{
if (pager == NULL)
panic("vm_pager_deallocate: null pager");
(*pager->pg_ops->pgo_dealloc)(pager);
}
int
vm_pager_get_pages(pager, m, count, reqpage, sync)
vm_pager_t pager;
vm_page_t *m;
int count;
int reqpage;
boolean_t sync;
{
int i;
if (pager == NULL) {
for (i=0;i<count;i++) {
if( i != reqpage) {
PAGE_WAKEUP(m[i]);
vm_page_free(m[i]);
}
}
vm_page_zero_fill(m[reqpage]);
return VM_PAGER_OK;
}
if( pager->pg_ops->pgo_getpages == 0) {
for(i=0;i<count;i++) {
if( i != reqpage) {
PAGE_WAKEUP(m[i]);
vm_page_free(m[i]);
}
}
return(VM_PAGER_GET(pager, m[reqpage], sync));
} else {
return(VM_PAGER_GET_MULTI(pager, m, count, reqpage, sync));
}
}
int
vm_pager_put_pages(pager, m, count, sync, rtvals)
vm_pager_t pager;
vm_page_t *m;
int count;
boolean_t sync;
int *rtvals;
{
int i;
if( pager->pg_ops->pgo_putpages)
return(VM_PAGER_PUT_MULTI(pager, m, count, sync, rtvals));
else {
for(i=0;i<count;i++) {
rtvals[i] = VM_PAGER_PUT( pager, m[i], sync);
}
return rtvals[0];
}
}
boolean_t
vm_pager_has_page(pager, offset)
vm_pager_t pager;
vm_offset_t offset;
{
if (pager == NULL)
panic("vm_pager_has_page: null pager");
return ((*pager->pg_ops->pgo_haspage)(pager, offset));
}
/*
* Called by pageout daemon before going back to sleep.
* Gives pagers a chance to clean up any completed async pageing operations.
*/
void
vm_pager_sync()
{
struct pagerops **pgops;
for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++)
if (pgops)
(*(*pgops)->pgo_putpage)(NULL, NULL, 0);
}
#if 0
void
vm_pager_cluster(pager, offset, loff, hoff)
vm_pager_t pager;
vm_offset_t offset;
vm_offset_t *loff;
vm_offset_t *hoff;
{
if (pager == NULL)
panic("vm_pager_cluster: null pager");
return ((*pager->pg_ops->pgo_cluster)(pager, offset, loff, hoff));
}
#endif
vm_offset_t
vm_pager_map_page(m)
vm_page_t m;
{
vm_offset_t kva;
kva = kmem_alloc_wait(pager_map, PAGE_SIZE);
pmap_kenter(kva, VM_PAGE_TO_PHYS(m));
return(kva);
}
void
vm_pager_unmap_page(kva)
vm_offset_t kva;
{
pmap_kremove(kva);
kmem_free_wakeup(pager_map, kva, PAGE_SIZE);
}
vm_page_t
vm_pager_atop(kva)
vm_offset_t kva;
{
vm_offset_t pa;
pa = pmap_kextract( kva);
if (pa == 0)
panic("vm_pager_atop");
return (PHYS_TO_VM_PAGE(pa));
}
vm_pager_t
vm_pager_lookup(pglist, handle)
register struct pagerlst *pglist;
caddr_t handle;
{
register vm_pager_t pager;
for (pager = pglist->tqh_first; pager; pager = pager->pg_list.tqe_next)
if (pager->pg_handle == handle)
return (pager);
return (NULL);
}
/*
* This routine gains a reference to the object.
* Explicit deallocation is necessary.
*/
int
pager_cache(object, should_cache)
vm_object_t object;
boolean_t should_cache;
{
if (object == NULL)
return (KERN_INVALID_ARGUMENT);
vm_object_cache_lock();
vm_object_lock(object);
if (should_cache)
object->flags |= OBJ_CANPERSIST;
else
object->flags &= ~OBJ_CANPERSIST;
vm_object_unlock(object);
vm_object_cache_unlock();
vm_object_deallocate(object);
return (KERN_SUCCESS);
}
/*
* allocate a physical buffer
*/
struct buf *
getpbuf() {
int s;
struct buf *bp;
s = splbio();
/* get a bp from the swap buffer header pool */
while ((bp = bswlist.tqh_first) == NULL) {
bswneeded = 1;
tsleep((caddr_t)&bswneeded, PVM, "wswbuf", 0);
}
TAILQ_REMOVE(&bswlist, bp, b_freelist);
splx(s);
bzero(bp, sizeof *bp);
bp->b_rcred = NOCRED;
bp->b_wcred = NOCRED;
bp->b_data = (caddr_t) (MAXPHYS * (bp-swbuf)) + swapbkva;
return bp;
}
/*
* allocate a physical buffer, if one is available
*/
struct buf *
trypbuf() {
int s;
struct buf *bp;
s = splbio();
if ((bp = bswlist.tqh_first) == NULL) {
splx(s);
return NULL;
}
TAILQ_REMOVE(&bswlist, bp, b_freelist);
splx(s);
bzero(bp, sizeof *bp);
bp->b_rcred = NOCRED;
bp->b_wcred = NOCRED;
bp->b_data = (caddr_t) (MAXPHYS * (bp-swbuf)) + swapbkva;
return bp;
}
/*
* release a physical buffer
*/
void
relpbuf(bp)
struct buf *bp;
{
int s;
s = splbio();
if (bp->b_rcred != NOCRED) {
crfree(bp->b_rcred);
bp->b_rcred = NOCRED;
}
if (bp->b_wcred != NOCRED) {
crfree(bp->b_wcred);
bp->b_wcred = NOCRED;
}
if (bp->b_vp)
brelvp(bp);
TAILQ_INSERT_HEAD(&bswlist, bp, b_freelist);
if (bswneeded) {
bswneeded = 0;
wakeup((caddr_t)&bswlist);
}
splx(s);
}