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 * $FreeBSD$ 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 47 TAILQ_HEAD(pagerlst, vm_object); 48 49 struct bio; 50 51 struct pagerops { 52 void (*pgo_init)(void); /* Initialize pager. */ 53 vm_object_t (*pgo_alloc)(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t); /* Allocate pager. */ 54 void (*pgo_dealloc)(vm_object_t); /* Disassociate. */ 55 int (*pgo_getpages)(vm_object_t, vm_page_t *, int, int); /* Get (read) page. */ 56 void (*pgo_putpages)(vm_object_t, vm_page_t *, int, int, int *); /* Put (write) page. */ 57 boolean_t (*pgo_haspage)(vm_object_t, vm_pindex_t, int *, int *); /* Does pager have page? */ 58 void (*pgo_pageunswapped)(vm_page_t); 59 }; 60 61 extern struct pagerops defaultpagerops; 62 extern struct pagerops swappagerops; 63 extern struct pagerops vnodepagerops; 64 extern struct pagerops devicepagerops; 65 extern struct pagerops physpagerops; 66 67 /* 68 * get/put return values 69 * OK operation was successful 70 * BAD specified data was out of the accepted range 71 * FAIL specified data was in range, but doesn't exist 72 * PEND operations was initiated but not completed 73 * ERROR error while accessing data that is in range and exists 74 * AGAIN temporary resource shortage prevented operation from happening 75 */ 76 #define VM_PAGER_OK 0 77 #define VM_PAGER_BAD 1 78 #define VM_PAGER_FAIL 2 79 #define VM_PAGER_PEND 3 80 #define VM_PAGER_ERROR 4 81 #define VM_PAGER_AGAIN 5 82 83 #define VM_PAGER_PUT_SYNC 0x0001 84 #define VM_PAGER_PUT_INVAL 0x0002 85 #define VM_PAGER_IGNORE_CLEANCHK 0x0004 86 #define VM_PAGER_CLUSTER_OK 0x0008 87 88 #ifdef _KERNEL 89 #ifdef MALLOC_DECLARE 90 MALLOC_DECLARE(M_VMPGDATA); 91 #endif 92 93 extern vm_map_t pager_map; 94 extern struct pagerops *pagertab[]; 95 extern struct mtx pbuf_mtx; 96 97 vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t); 98 void vm_pager_bufferinit(void); 99 void vm_pager_deallocate(vm_object_t); 100 static __inline int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int); 101 static __inline boolean_t vm_pager_has_page(vm_object_t, vm_pindex_t, int *, int *); 102 void vm_pager_init(void); 103 vm_object_t vm_pager_object_lookup(struct pagerlst *, void *); 104 105 /* 106 * vm_page_get_pages: 107 * 108 * Retrieve pages from the VM system in order to map them into an object 109 * ( or into VM space somewhere ). If the pagein was successful, we 110 * must fully validate it. 111 */ 112 static __inline int 113 vm_pager_get_pages( 114 vm_object_t object, 115 vm_page_t *m, 116 int count, 117 int reqpage 118 ) { 119 int r; 120 121 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 122 r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage); 123 if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) { 124 vm_page_zero_invalid(m[reqpage], TRUE); 125 } 126 return (r); 127 } 128 129 static __inline void 130 vm_pager_put_pages( 131 vm_object_t object, 132 vm_page_t *m, 133 int count, 134 int flags, 135 int *rtvals 136 ) { 137 138 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 139 (*pagertab[object->type]->pgo_putpages) 140 (object, m, count, flags, rtvals); 141 } 142 143 /* 144 * vm_pager_haspage 145 * 146 * Check to see if an object's pager has the requested page. The 147 * object's pager will also set before and after to give the caller 148 * some idea of the number of pages before and after the requested 149 * page can be I/O'd efficiently. 150 * 151 * This routine does not have to be called at any particular spl. 152 */ 153 static __inline boolean_t 154 vm_pager_has_page( 155 vm_object_t object, 156 vm_pindex_t offset, 157 int *before, 158 int *after 159 ) { 160 boolean_t ret; 161 162 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 163 ret = (*pagertab[object->type]->pgo_haspage) 164 (object, offset, before, after); 165 return (ret); 166 } 167 168 /* 169 * vm_pager_page_unswapped 170 * 171 * called at splvm() to destroy swap associated with the page. 172 * 173 * This function may not block. 174 * 175 * XXX: A much better name would be "vm_pager_page_dirtied()" 176 * XXX: It is not obvious if this could be profitably used by any 177 * XXX: pagers besides the swap_pager or if it should even be a 178 * XXX: generic pager_op in the first place. 179 */ 180 static __inline void 181 vm_pager_page_unswapped(vm_page_t m) 182 { 183 184 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); 185 if (pagertab[m->object->type]->pgo_pageunswapped) 186 (*pagertab[m->object->type]->pgo_pageunswapped)(m); 187 } 188 189 #endif /* _KERNEL */ 190 #endif /* _VM_PAGER_ */ 191