/*
* 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 1.36 1998/03/07 21:37:21 dyson Exp $
*/
/*
* Paging space routine stubs. Emulates a matchmaker-like interface
* for builtin pagers.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/ucred.h>
#include <sys/malloc.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_prot.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <vm/vm_extern.h>
MALLOC_DEFINE(M_VMPGDATA, "VM pgdata", "XXX: VM pager private data");
extern struct pagerops defaultpagerops;
extern struct pagerops swappagerops;
extern struct pagerops vnodepagerops;
extern struct pagerops devicepagerops;
static int dead_pager_getpages __P((vm_object_t, vm_page_t *, int, int));
static vm_object_t dead_pager_alloc __P((void *, vm_size_t, vm_prot_t,
vm_ooffset_t));
static int dead_pager_putpages __P((vm_object_t, vm_page_t *, int, int, int *));
static boolean_t dead_pager_haspage __P((vm_object_t, vm_pindex_t, int *, int *));
static void dead_pager_dealloc __P((vm_object_t));
int
dead_pager_getpages(obj, ma, count, req)
vm_object_t obj;
vm_page_t *ma;
int count;
int req;
{
return VM_PAGER_FAIL;
}
vm_object_t
dead_pager_alloc(handle, size, prot, off)
void *handle;
vm_size_t size;
vm_prot_t prot;
vm_ooffset_t off;
{
return NULL;
}
int
dead_pager_putpages(object, m, count, flags, rtvals)
vm_object_t object;
vm_page_t *m;
int count;
int flags;
int *rtvals;
{
int i;
for (i = 0; i < count; i++) {
rtvals[i] = VM_PAGER_AGAIN;
}
return VM_PAGER_AGAIN;
}
int
dead_pager_haspage(object, pindex, prev, next)
vm_object_t object;
vm_pindex_t pindex;
int *prev;
int *next;
{
if (prev)
*prev = 0;
if (next)
*next = 0;
return FALSE;
}
void
dead_pager_dealloc(object)
vm_object_t object;
{
return;
}
struct pagerops deadpagerops = {
NULL,
dead_pager_alloc,
dead_pager_dealloc,
dead_pager_getpages,
dead_pager_putpages,
dead_pager_haspage,
NULL
};
static struct pagerops *pagertab[] = {
&defaultpagerops, /* OBJT_DEFAULT */
&swappagerops, /* OBJT_SWAP */
&vnodepagerops, /* OBJT_VNODE */
&devicepagerops, /* OBJT_DEVICE */
&deadpagerops /* OBJT_DEAD */
};
static int npagers = sizeof(pagertab) / sizeof(pagertab[0]);
/*
* 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;
static int bswneeded;
static 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 != NULL))
(*(*pgops)->pgo_init) ();
}
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; i++, bp++) {
TAILQ_INSERT_HEAD(&bswlist, bp, b_freelist);
bp->b_rcred = bp->b_wcred = NOCRED;
bp->b_vnbufs.le_next = NOLIST;
}
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_object_t
vm_pager_allocate(objtype_t type, void *handle, vm_size_t size, vm_prot_t prot,
vm_ooffset_t off)
{
struct pagerops *ops;
ops = pagertab[type];
if (ops)
return ((*ops->pgo_alloc) (handle, size, prot, off));
return (NULL);
}
void
vm_pager_deallocate(object)
vm_object_t object;
{
(*pagertab[object->type]->pgo_dealloc) (object);
}
int
vm_pager_get_pages(object, m, count, reqpage)
vm_object_t object;
vm_page_t *m;
int count;
int reqpage;
{
return ((*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage));
}
int
vm_pager_put_pages(object, m, count, flags, rtvals)
vm_object_t object;
vm_page_t *m;
int count;
int flags;
int *rtvals;
{
return ((*pagertab[object->type]->pgo_putpages)(object, m, count, flags, rtvals));
}
boolean_t
vm_pager_has_page(object, offset, before, after)
vm_object_t object;
vm_pindex_t offset;
int *before;
int *after;
{
return ((*pagertab[object->type]->pgo_haspage) (object, offset, before, after));
}
/*
* 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_sync != NULL))
(*(*pgops)->pgo_sync) ();
}
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_object_t
vm_pager_object_lookup(pg_list, handle)
register struct pagerlst *pg_list;
void *handle;
{
register vm_object_t object;
for (object = TAILQ_FIRST(pg_list); object != NULL; object = TAILQ_NEXT(object,pager_object_list))
if (object->handle == handle)
return (object);
return (NULL);
}
/*
* initialize a physical buffer
*/
static void
initpbuf(struct buf *bp) {
bzero(bp, sizeof *bp);
bp->b_rcred = NOCRED;
bp->b_wcred = NOCRED;
bp->b_qindex = QUEUE_NONE;
bp->b_data = (caddr_t) (MAXPHYS * (bp - swbuf)) + swapbkva;
bp->b_kvabase = bp->b_data;
bp->b_kvasize = MAXPHYS;
bp->b_vnbufs.le_next = NOLIST;
}
/*
* allocate a physical buffer
*/
struct buf *
getpbuf()
{
int s;
struct buf *bp;
s = splvm();
/* get a bp from the swap buffer header pool */
while ((bp = TAILQ_FIRST(&bswlist)) == NULL) {
bswneeded = 1;
tsleep(&bswneeded, PVM, "wswbuf", 0);
}
TAILQ_REMOVE(&bswlist, bp, b_freelist);
splx(s);
initpbuf(bp);
return bp;
}
/*
* allocate a physical buffer, if one is available
*/
struct buf *
trypbuf()
{
int s;
struct buf *bp;
s = splvm();
if ((bp = TAILQ_FIRST(&bswlist)) == NULL) {
splx(s);
return NULL;
}
TAILQ_REMOVE(&bswlist, bp, b_freelist);
splx(s);
initpbuf(bp);
return bp;
}
/*
* release a physical buffer
*/
void
relpbuf(bp)
struct buf *bp;
{
int s;
s = splvm();
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)
pbrelvp(bp);
if (bp->b_flags & B_WANTED)
wakeup(bp);
TAILQ_INSERT_HEAD(&bswlist, bp, b_freelist);
if (bswneeded) {
bswneeded = 0;
wakeup(&bswneeded);
}
splx(s);
}
