vm_pager.h revision 194766
1/*- 2 * Copyright (c) 1990 University of Utah. 3 * Copyright (c) 1991, 1993 4 * The Regents of the University of California. 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 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)vm_pager.h 8.4 (Berkeley) 1/12/94 35 * $FreeBSD: head/sys/vm/vm_pager.h 194766 2009-06-23 20:45:22Z kib $ 36 */ 37 38/* 39 * Pager routine interface definition. 40 */ 41 42#ifndef _VM_PAGER_ 43#define _VM_PAGER_ 44 45#include <sys/queue.h> 46 47TAILQ_HEAD(pagerlst, vm_object); 48 49typedef void pgo_init_t(void); 50typedef vm_object_t pgo_alloc_t(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t, 51 struct ucred *); 52typedef void pgo_dealloc_t(vm_object_t); 53typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int); 54typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *); 55typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *); 56typedef void pgo_pageunswapped_t(vm_page_t); 57 58struct pagerops { 59 pgo_init_t *pgo_init; /* Initialize pager. */ 60 pgo_alloc_t *pgo_alloc; /* Allocate pager. */ 61 pgo_dealloc_t *pgo_dealloc; /* Disassociate. */ 62 pgo_getpages_t *pgo_getpages; /* Get (read) page. */ 63 pgo_putpages_t *pgo_putpages; /* Put (write) page. */ 64 pgo_haspage_t *pgo_haspage; /* Does pager have page? */ 65 pgo_pageunswapped_t *pgo_pageunswapped; 66}; 67 68extern struct pagerops defaultpagerops; 69extern struct pagerops swappagerops; 70extern struct pagerops vnodepagerops; 71extern struct pagerops devicepagerops; 72extern struct pagerops physpagerops; 73 74/* 75 * get/put return values 76 * OK operation was successful 77 * BAD specified data was out of the accepted range 78 * FAIL specified data was in range, but doesn't exist 79 * PEND operations was initiated but not completed 80 * ERROR error while accessing data that is in range and exists 81 * AGAIN temporary resource shortage prevented operation from happening 82 */ 83#define VM_PAGER_OK 0 84#define VM_PAGER_BAD 1 85#define VM_PAGER_FAIL 2 86#define VM_PAGER_PEND 3 87#define VM_PAGER_ERROR 4 88#define VM_PAGER_AGAIN 5 89 90#define VM_PAGER_PUT_SYNC 0x0001 91#define VM_PAGER_PUT_INVAL 0x0002 92#define VM_PAGER_IGNORE_CLEANCHK 0x0004 93#define VM_PAGER_CLUSTER_OK 0x0008 94 95#ifdef _KERNEL 96#ifdef MALLOC_DECLARE 97MALLOC_DECLARE(M_VMPGDATA); 98#endif 99 100extern vm_map_t pager_map; 101extern struct pagerops *pagertab[]; 102extern struct mtx pbuf_mtx; 103 104vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, 105 vm_ooffset_t, struct ucred *); 106void vm_pager_bufferinit(void); 107void vm_pager_deallocate(vm_object_t); 108static __inline int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int); 109static __inline boolean_t vm_pager_has_page(vm_object_t, vm_pindex_t, int *, int *); 110void vm_pager_init(void); 111vm_object_t vm_pager_object_lookup(struct pagerlst *, void *); 112 113/* 114 * vm_page_get_pages: 115 * 116 * Retrieve pages from the VM system in order to map them into an object 117 * ( or into VM space somewhere ). If the pagein was successful, we 118 * must fully validate it. 119 */ 120static __inline int 121vm_pager_get_pages( 122 vm_object_t object, 123 vm_page_t *m, 124 int count, 125 int reqpage 126) { 127 int r; 128 129 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 130 r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage); 131 if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) { 132 vm_page_zero_invalid(m[reqpage], TRUE); 133 } 134 return (r); 135} 136 137static __inline void 138vm_pager_put_pages( 139 vm_object_t object, 140 vm_page_t *m, 141 int count, 142 int flags, 143 int *rtvals 144) { 145 146 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 147 (*pagertab[object->type]->pgo_putpages) 148 (object, m, count, flags, rtvals); 149} 150 151/* 152 * vm_pager_haspage 153 * 154 * Check to see if an object's pager has the requested page. The 155 * object's pager will also set before and after to give the caller 156 * some idea of the number of pages before and after the requested 157 * page can be I/O'd efficiently. 158 * 159 * The object must be locked. 160 */ 161static __inline boolean_t 162vm_pager_has_page( 163 vm_object_t object, 164 vm_pindex_t offset, 165 int *before, 166 int *after 167) { 168 boolean_t ret; 169 170 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 171 ret = (*pagertab[object->type]->pgo_haspage) 172 (object, offset, before, after); 173 return (ret); 174} 175 176/* 177 * vm_pager_page_unswapped 178 * 179 * Destroy swap associated with the page. 180 * 181 * The object containing the page must be locked. 182 * This function may not block. 183 * 184 * XXX: A much better name would be "vm_pager_page_dirtied()" 185 * XXX: It is not obvious if this could be profitably used by any 186 * XXX: pagers besides the swap_pager or if it should even be a 187 * XXX: generic pager_op in the first place. 188 */ 189static __inline void 190vm_pager_page_unswapped(vm_page_t m) 191{ 192 193 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 194 if (pagertab[m->object->type]->pgo_pageunswapped) 195 (*pagertab[m->object->type]->pgo_pageunswapped)(m); 196} 197 198#endif /* _KERNEL */ 199#endif /* _VM_PAGER_ */ 200