1 /* 2 * Copyright (c) 1990 University of Utah. 3 * Copyright (c) 1991 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * from: @(#)swap_pager.h 7.1 (Berkeley) 12/5/90 39 * $Id: swap_pager.h,v 1.4 1995/01/09 16:05:37 davidg Exp $ 40 */ 41 42 /* 43 * Modifications to the block allocation data structure by John S. Dyson 44 * 18 Dec 93. 45 */ 46 47 #ifndef _SWAP_PAGER_ 48 #define _SWAP_PAGER_ 1 49 50 /* 51 * SWB_NPAGES can be set to any value from 1 to 16 pages per allocation, 52 * however, due to the allocation spilling into non-swap pager backed memory, 53 * suggest keeping SWB_NPAGES small (1-4). If high performance is manditory 54 * perhaps up to 8 pages might be in order???? 55 * Above problem has been fixed, now we support 16 pages per block. Unused 56 * space is recovered by the swap pager now... 57 */ 58 #define SWB_NPAGES 8 59 struct swblock { 60 unsigned short swb_valid; /* bitmask for valid pages */ 61 unsigned short swb_locked; /* block locked */ 62 int swb_block[SWB_NPAGES]; /* unfortunately int instead of daddr_t */ 63 }; 64 typedef struct swblock *sw_blk_t; 65 66 /* 67 * Swap pager private data. 68 */ 69 struct swpager { 70 vm_size_t sw_osize; /* size of object we are backing (bytes) */ 71 int sw_nblocks; /* number of blocks in list (sw_blk_t units) */ 72 int sw_allocsize; /* amount of space actually allocated */ 73 sw_blk_t sw_blocks; /* pointer to list of swap blocks */ 74 short sw_flags; /* flags */ 75 short sw_poip; /* pageouts in progress */ 76 short sw_piip; /* pageins in progress */ 77 }; 78 typedef struct swpager *sw_pager_t; 79 80 #define SW_WANTED 0x01 81 #define SW_NAMED 0x02 82 83 #ifdef KERNEL 84 85 void swap_pager_init(void); 86 vm_pager_t swap_pager_alloc(caddr_t, vm_size_t, vm_prot_t, vm_offset_t); 87 void swap_pager_dealloc(vm_pager_t); 88 boolean_t swap_pager_getpage(vm_pager_t, vm_page_t, boolean_t); 89 boolean_t swap_pager_putpage(vm_pager_t, vm_page_t, boolean_t); 90 boolean_t swap_pager_getmulti(vm_pager_t, vm_page_t *, int, int, boolean_t); 91 boolean_t swap_pager_haspage(vm_pager_t, vm_offset_t); 92 int swap_pager_io(sw_pager_t, vm_page_t *, int, int, int); 93 void swap_pager_iodone(struct buf *); 94 boolean_t swap_pager_clean(); 95 void swap_pager_copy __P((vm_pager_t, vm_offset_t, vm_pager_t, vm_offset_t, vm_offset_t)); 96 void swap_pager_freespace __P((vm_pager_t, vm_offset_t, vm_offset_t)); 97 98 extern struct pagerops swappagerops; 99 100 #endif 101 102 #endif /* _SWAP_PAGER_ */ 103