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 typedef void pgo_init_t(void); 50 typedef vm_object_t pgo_alloc_t(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t, 51 struct ucred *); 52 typedef void pgo_dealloc_t(vm_object_t); 53 typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int); 54 typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *); 55 typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *); 56 typedef void pgo_pageunswapped_t(vm_page_t); 57 58 struct 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 68 extern struct pagerops defaultpagerops; 69 extern struct pagerops swappagerops; 70 extern struct pagerops vnodepagerops; 71 extern struct pagerops devicepagerops; 72 extern struct pagerops physpagerops; 73 extern struct pagerops sgpagerops; 74 extern struct pagerops mgtdevicepagerops; 75 76 /* 77 * get/put return values 78 * OK operation was successful 79 * BAD specified data was out of the accepted range 80 * FAIL specified data was in range, but doesn't exist 81 * PEND operations was initiated but not completed 82 * ERROR error while accessing data that is in range and exists 83 * AGAIN temporary resource shortage prevented operation from happening 84 */ 85 #define VM_PAGER_OK 0 86 #define VM_PAGER_BAD 1 87 #define VM_PAGER_FAIL 2 88 #define VM_PAGER_PEND 3 89 #define VM_PAGER_ERROR 4 90 #define VM_PAGER_AGAIN 5 91 92 #define VM_PAGER_PUT_SYNC 0x0001 93 #define VM_PAGER_PUT_INVAL 0x0002 94 #define VM_PAGER_CLUSTER_OK 0x0008 95 96 #ifdef _KERNEL 97 98 extern struct pagerops *pagertab[]; 99 extern struct mtx_padalign pbuf_mtx; 100 101 vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t, 102 vm_ooffset_t, struct ucred *); 103 void vm_pager_bufferinit(void); 104 void vm_pager_deallocate(vm_object_t); 105 static __inline int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int); 106 static __inline boolean_t vm_pager_has_page(vm_object_t, vm_pindex_t, int *, int *); 107 void vm_pager_init(void); 108 vm_object_t vm_pager_object_lookup(struct pagerlst *, void *); 109 110 /* 111 * vm_page_get_pages: 112 * 113 * Retrieve pages from the VM system in order to map them into an object 114 * ( or into VM space somewhere ). If the pagein was successful, we 115 * must fully validate it. 116 */ 117 static __inline int 118 vm_pager_get_pages( 119 vm_object_t object, 120 vm_page_t *m, 121 int count, 122 int reqpage 123 ) { 124 int r; 125 126 VM_OBJECT_ASSERT_WLOCKED(object); 127 r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage); 128 if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) { 129 vm_page_zero_invalid(m[reqpage], TRUE); 130 } 131 return (r); 132 } 133 134 static __inline void 135 vm_pager_put_pages( 136 vm_object_t object, 137 vm_page_t *m, 138 int count, 139 int flags, 140 int *rtvals 141 ) { 142 143 VM_OBJECT_ASSERT_WLOCKED(object); 144 (*pagertab[object->type]->pgo_putpages) 145 (object, m, count, flags, rtvals); 146 } 147 148 /* 149 * vm_pager_haspage 150 * 151 * Check to see if an object's pager has the requested page. The 152 * object's pager will also set before and after to give the caller 153 * some idea of the number of pages before and after the requested 154 * page can be I/O'd efficiently. 155 * 156 * The object must be locked. 157 */ 158 static __inline boolean_t 159 vm_pager_has_page( 160 vm_object_t object, 161 vm_pindex_t offset, 162 int *before, 163 int *after 164 ) { 165 boolean_t ret; 166 167 VM_OBJECT_ASSERT_WLOCKED(object); 168 ret = (*pagertab[object->type]->pgo_haspage) 169 (object, offset, before, after); 170 return (ret); 171 } 172 173 /* 174 * vm_pager_page_unswapped 175 * 176 * Destroy swap associated with the page. 177 * 178 * The object containing the page must be locked. 179 * This function may not block. 180 * 181 * XXX: A much better name would be "vm_pager_page_dirtied()" 182 * XXX: It is not obvious if this could be profitably used by any 183 * XXX: pagers besides the swap_pager or if it should even be a 184 * XXX: generic pager_op in the first place. 185 */ 186 static __inline void 187 vm_pager_page_unswapped(vm_page_t m) 188 { 189 190 VM_OBJECT_ASSERT_WLOCKED(m->object); 191 if (pagertab[m->object->type]->pgo_pageunswapped) 192 (*pagertab[m->object->type]->pgo_pageunswapped)(m); 193 } 194 195 struct cdev_pager_ops { 196 int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset, 197 int prot, vm_page_t *mres); 198 int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot, 199 vm_ooffset_t foff, struct ucred *cred, u_short *color); 200 void (*cdev_pg_dtor)(void *handle); 201 }; 202 203 vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp, 204 struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot, 205 vm_ooffset_t foff, struct ucred *cred); 206 vm_object_t cdev_pager_lookup(void *handle); 207 void cdev_pager_free_page(vm_object_t object, vm_page_t m); 208 209 #endif /* _KERNEL */ 210 #endif /* _VM_PAGER_ */ 211