vm_pager.h revision 193594
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 193594 2009-06-06 21:23:29Z alc $ 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); 51typedef void pgo_dealloc_t(vm_object_t); 52typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int); 53typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *); 54typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *); 55typedef void pgo_pageunswapped_t(vm_page_t); 56 57struct pagerops { 58 pgo_init_t *pgo_init; /* Initialize pager. */ 59 pgo_alloc_t *pgo_alloc; /* Allocate pager. */ 60 pgo_dealloc_t *pgo_dealloc; /* Disassociate. */ 61 pgo_getpages_t *pgo_getpages; /* Get (read) page. */ 62 pgo_putpages_t *pgo_putpages; /* Put (write) page. */ 63 pgo_haspage_t *pgo_haspage; /* Does pager have page? */ 64 pgo_pageunswapped_t *pgo_pageunswapped; 65}; 66 67extern struct pagerops defaultpagerops; 68extern struct pagerops swappagerops; 69extern struct pagerops vnodepagerops; 70extern struct pagerops devicepagerops; 71extern struct pagerops physpagerops; 72 73/* 74 * get/put return values 75 * OK operation was successful 76 * BAD specified data was out of the accepted range 77 * FAIL specified data was in range, but doesn't exist 78 * PEND operations was initiated but not completed 79 * ERROR error while accessing data that is in range and exists 80 * AGAIN temporary resource shortage prevented operation from happening 81 */ 82#define VM_PAGER_OK 0 83#define VM_PAGER_BAD 1 84#define VM_PAGER_FAIL 2 85#define VM_PAGER_PEND 3 86#define VM_PAGER_ERROR 4 87#define VM_PAGER_AGAIN 5 88 89#define VM_PAGER_PUT_SYNC 0x0001 90#define VM_PAGER_PUT_INVAL 0x0002 91#define VM_PAGER_IGNORE_CLEANCHK 0x0004 92#define VM_PAGER_CLUSTER_OK 0x0008 93 94#ifdef _KERNEL 95#ifdef MALLOC_DECLARE 96MALLOC_DECLARE(M_VMPGDATA); 97#endif 98 99extern vm_map_t pager_map; 100extern struct pagerops *pagertab[]; 101extern struct mtx pbuf_mtx; 102 103vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t); 104void vm_pager_bufferinit(void); 105void vm_pager_deallocate(vm_object_t); 106static __inline int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int); 107static __inline boolean_t vm_pager_has_page(vm_object_t, vm_pindex_t, int *, int *); 108void vm_pager_init(void); 109vm_object_t vm_pager_object_lookup(struct pagerlst *, void *); 110 111/* 112 * vm_page_get_pages: 113 * 114 * Retrieve pages from the VM system in order to map them into an object 115 * ( or into VM space somewhere ). If the pagein was successful, we 116 * must fully validate it. 117 */ 118static __inline int 119vm_pager_get_pages( 120 vm_object_t object, 121 vm_page_t *m, 122 int count, 123 int reqpage 124) { 125 int r; 126 127 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 128 r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage); 129 if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) { 130 vm_page_zero_invalid(m[reqpage], TRUE); 131 } 132 return (r); 133} 134 135static __inline void 136vm_pager_put_pages( 137 vm_object_t object, 138 vm_page_t *m, 139 int count, 140 int flags, 141 int *rtvals 142) { 143 144 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 145 (*pagertab[object->type]->pgo_putpages) 146 (object, m, count, flags, rtvals); 147} 148 149/* 150 * vm_pager_haspage 151 * 152 * Check to see if an object's pager has the requested page. The 153 * object's pager will also set before and after to give the caller 154 * some idea of the number of pages before and after the requested 155 * page can be I/O'd efficiently. 156 * 157 * The object must be locked. 158 */ 159static __inline boolean_t 160vm_pager_has_page( 161 vm_object_t object, 162 vm_pindex_t offset, 163 int *before, 164 int *after 165) { 166 boolean_t ret; 167 168 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 169 ret = (*pagertab[object->type]->pgo_haspage) 170 (object, offset, before, after); 171 return (ret); 172} 173 174/* 175 * vm_pager_page_unswapped 176 * 177 * Destroy swap associated with the page. 178 * 179 * The object containing the page must be locked. 180 * This function may not block. 181 * 182 * XXX: A much better name would be "vm_pager_page_dirtied()" 183 * XXX: It is not obvious if this could be profitably used by any 184 * XXX: pagers besides the swap_pager or if it should even be a 185 * XXX: generic pager_op in the first place. 186 */ 187static __inline void 188vm_pager_page_unswapped(vm_page_t m) 189{ 190 191 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 192 if (pagertab[m->object->type]->pgo_pageunswapped) 193 (*pagertab[m->object->type]->pgo_pageunswapped)(m); 194} 195 196#endif /* _KERNEL */ 197#endif /* _VM_PAGER_ */ 198