freebsd-dev/sys/vm/swap_pager.h
David Greenman ee3a64c992 Changed "handle" from type caddr_t to void *; "handle" is several different
types of pointers, and "char *" is a bad choice for the type.
1995-05-10 18:56:09 +00:00

103 lines
4.1 KiB
C

/*
* Copyright (c) 1990 University of Utah.
* Copyright (c) 1991 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.
*
* from: @(#)swap_pager.h 7.1 (Berkeley) 12/5/90
* $Id: swap_pager.h,v 1.5 1995/02/02 09:08:09 davidg Exp $
*/
/*
* Modifications to the block allocation data structure by John S. Dyson
* 18 Dec 93.
*/
#ifndef _SWAP_PAGER_
#define _SWAP_PAGER_ 1
/*
* SWB_NPAGES can be set to any value from 1 to 16 pages per allocation,
* however, due to the allocation spilling into non-swap pager backed memory,
* suggest keeping SWB_NPAGES small (1-4). If high performance is manditory
* perhaps up to 8 pages might be in order????
* Above problem has been fixed, now we support 16 pages per block. Unused
* space is recovered by the swap pager now...
*/
#define SWB_NPAGES 8
struct swblock {
unsigned short swb_valid; /* bitmask for valid pages */
unsigned short swb_locked; /* block locked */
int swb_block[SWB_NPAGES]; /* unfortunately int instead of daddr_t */
};
typedef struct swblock *sw_blk_t;
/*
* Swap pager private data.
*/
struct swpager {
vm_size_t sw_osize; /* size of object we are backing (bytes) */
int sw_nblocks; /* number of blocks in list (sw_blk_t units) */
int sw_allocsize; /* amount of space actually allocated */
sw_blk_t sw_blocks; /* pointer to list of swap blocks */
short sw_flags; /* flags */
short sw_poip; /* pageouts in progress */
short sw_piip; /* pageins in progress */
};
typedef struct swpager *sw_pager_t;
#define SW_WANTED 0x01
#define SW_NAMED 0x02
#ifdef KERNEL
void swap_pager_init(void);
vm_pager_t swap_pager_alloc(void *, vm_size_t, vm_prot_t, vm_offset_t);
void swap_pager_dealloc(vm_pager_t);
boolean_t swap_pager_getpage(vm_pager_t, vm_page_t, boolean_t);
boolean_t swap_pager_putpage(vm_pager_t, vm_page_t, boolean_t);
boolean_t swap_pager_getmulti(vm_pager_t, vm_page_t *, int, int, boolean_t);
boolean_t swap_pager_haspage(vm_pager_t, vm_offset_t);
int swap_pager_io(sw_pager_t, vm_page_t *, int, int, int);
void swap_pager_iodone(struct buf *);
boolean_t swap_pager_clean();
void swap_pager_copy __P((vm_pager_t, vm_offset_t, vm_pager_t, vm_offset_t, vm_offset_t));
void swap_pager_freespace __P((vm_pager_t, vm_offset_t, vm_offset_t));
extern struct pagerops swappagerops;
#endif
#endif /* _SWAP_PAGER_ */