freebsd-dev/sys/vm/vm_pager.h
alfred 217f9af8c7 Introduce a global lock for the vm subsystem (vm_mtx).
vm_mtx does not recurse and is required for most low level
vm operations.

faults can not be taken without holding Giant.

Memory subsystems can now call the base page allocators safely.

Almost all atomic ops were removed as they are covered under the
vm mutex.

Alpha and ia64 now need to catch up to i386's trap handlers.

FFS and NFS have been tested, other filesystems will need minor
changes (grabbing the vm lock when twiddling page properties).

Reviewed (partially) by: jake, jhb
2001-05-19 01:28:09 +00:00

199 lines
6.2 KiB
C

/*
* Copyright (c) 1990 University of Utah.
* 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 Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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.
*
* @(#)vm_pager.h 8.4 (Berkeley) 1/12/94
* $FreeBSD$
*/
/*
* Pager routine interface definition.
*/
#ifndef _VM_PAGER_
#define _VM_PAGER_
#include <sys/queue.h>
TAILQ_HEAD(pagerlst, vm_object);
struct bio;
struct pagerops {
void (*pgo_init) __P((void)); /* Initialize pager. */
vm_object_t (*pgo_alloc) __P((void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t)); /* Allocate pager. */
void (*pgo_dealloc) __P((vm_object_t)); /* Disassociate. */
int (*pgo_getpages) __P((vm_object_t, vm_page_t *, int, int)); /* Get (read) page. */
void (*pgo_putpages) __P((vm_object_t, vm_page_t *, int, int, int *)); /* Put (write) page. */
boolean_t (*pgo_haspage) __P((vm_object_t, vm_pindex_t, int *, int *)); /* Does pager have page? */
void (*pgo_pageunswapped) __P((vm_page_t));
void (*pgo_strategy) __P((vm_object_t, struct bio *));
};
/*
* get/put return values
* OK operation was successful
* BAD specified data was out of the accepted range
* FAIL specified data was in range, but doesn't exist
* PEND operations was initiated but not completed
* ERROR error while accessing data that is in range and exists
* AGAIN temporary resource shortage prevented operation from happening
*/
#define VM_PAGER_OK 0
#define VM_PAGER_BAD 1
#define VM_PAGER_FAIL 2
#define VM_PAGER_PEND 3
#define VM_PAGER_ERROR 4
#define VM_PAGER_AGAIN 5
#define VM_PAGER_PUT_SYNC 0x1
#define VM_PAGER_PUT_INVAL 0x2
#ifdef _KERNEL
#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_VMPGDATA);
#endif
extern vm_map_t pager_map;
extern int pager_map_size;
extern struct pagerops *pagertab[];
extern struct mtx pbuf_mtx;
vm_object_t vm_pager_allocate __P((objtype_t, void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t));
void vm_pager_bufferinit __P((void));
void vm_pager_deallocate __P((vm_object_t));
static __inline int vm_pager_get_pages __P((vm_object_t, vm_page_t *, int, int));
static __inline boolean_t vm_pager_has_page __P((vm_object_t, vm_pindex_t, int *, int *));
void vm_pager_init __P((void));
vm_object_t vm_pager_object_lookup __P((struct pagerlst *, void *));
vm_offset_t vm_pager_map_pages __P((vm_page_t *, int, boolean_t));
vm_offset_t vm_pager_map_page __P((vm_page_t));
void vm_pager_sync __P((void));
void vm_pager_unmap_pages __P((vm_offset_t, int));
void vm_pager_unmap_page __P((vm_offset_t));
void vm_pager_strategy __P((vm_object_t object, struct bio *bp));
/*
* vm_page_get_pages:
*
* Retrieve pages from the VM system in order to map them into an object
* ( or into VM space somewhere ). If the pagein was successful, we
* must fully validate it.
*/
static __inline int
vm_pager_get_pages(
vm_object_t object,
vm_page_t *m,
int count,
int reqpage
) {
int r;
mtx_assert(&vm_mtx, MA_OWNED);
r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage);
if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) {
vm_page_zero_invalid(m[reqpage], TRUE);
}
mtx_assert(&vm_mtx, MA_OWNED);
return(r);
}
static __inline void
vm_pager_put_pages(
vm_object_t object,
vm_page_t *m,
int count,
int flags,
int *rtvals
) {
mtx_assert(&vm_mtx, MA_OWNED);
(*pagertab[object->type]->pgo_putpages)
(object, m, count, flags, rtvals);
mtx_assert(&vm_mtx, MA_OWNED);
}
/*
* vm_pager_haspage
*
* Check to see if an object's pager has the requested page. The
* object's pager will also set before and after to give the caller
* some idea of the number of pages before and after the requested
* page can be I/O'd efficiently.
*
* This routine does not have to be called at any particular spl.
*/
static __inline boolean_t
vm_pager_has_page(
vm_object_t object,
vm_pindex_t offset,
int *before,
int *after
) {
boolean_t ret;
mtx_assert(&vm_mtx, MA_OWNED);
ret = (*pagertab[object->type]->pgo_haspage)
(object, offset, before, after);
mtx_assert(&vm_mtx, MA_OWNED);
return (ret);
}
/*
* vm_pager_page_unswapped
*
* called at splvm() to destroy swap associated with the page.
*
* This function may not block.
*/
static __inline void
vm_pager_page_unswapped(vm_page_t m)
{
mtx_assert(&vm_mtx, MA_OWNED);
if (pagertab[m->object->type]->pgo_pageunswapped)
(*pagertab[m->object->type]->pgo_pageunswapped)(m);
mtx_assert(&vm_mtx, MA_OWNED);
}
#endif
#endif /* _VM_PAGER_ */