| 1 | /* |
| 2 | * Copyright (c) 1991 Regents of the University of California. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * This code is derived from software contributed to Berkeley by |
| 6 | * The Mach Operating System project at Carnegie-Mellon University. |
| 7 | * |
| 8 | * Redistribution and use in source and binary forms, with or without |
| 9 | * modification, are permitted provided that the following conditions |
| 10 | * are met: |
| 11 | * 1. Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in the |
| 15 | * documentation and/or other materials provided with the distribution. |
| 16 | * 3. All advertising materials mentioning features or use of this software |
| 17 | * must display the following acknowledgement: |
| 18 | * This product includes software developed by the University of |
| 19 | * California, Berkeley and its contributors. |
| 20 | * 4. Neither the name of the University nor the names of its contributors |
| 21 | * may be used to endorse or promote products derived from this software |
| 22 | * without specific prior written permission. |
| 23 | * |
| 24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 34 | * SUCH DAMAGE. |
| 35 | * |
| 36 | * @(#)vm_pager.c 7.4 (Berkeley) 5/7/91 |
| 37 | * |
| 38 | * |
| 39 | * Copyright (c) 1987, 1990 Carnegie-Mellon University. |
| 40 | * All rights reserved. |
| 41 | * |
| 42 | * Authors: Avadis Tevanian, Jr., Michael Wayne Young |
| 43 | * |
| 44 | * Permission to use, copy, modify and distribute this software and |
| 45 | * its documentation is hereby granted, provided that both the copyright |
| 46 | * notice and this permission notice appear in all copies of the |
| 47 | * software, derivative works or modified versions, and any portions |
| 48 | * thereof, and that both notices appear in supporting documentation. |
| 49 | * |
| 50 | * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" |
| 51 | * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND |
| 52 | * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. |
| 53 | * |
| 54 | * Carnegie Mellon requests users of this software to return to |
| 55 | * |
| 56 | * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU |
| 57 | * School of Computer Science |
| 58 | * Carnegie Mellon University |
| 59 | * Pittsburgh PA 15213-3890 |
| 60 | * |
| 61 | * any improvements or extensions that they make and grant Carnegie the |
| 62 | * rights to redistribute these changes. |
| 63 | */ |
| 64 | |
| 65 | /* |
| 66 | * Paging space routine stubs. Emulates a matchmaker-like interface |
| 67 | * for builtin pagers. |
| 68 | */ |
| 69 | |
| 70 | #include "param.h" |
| 71 | #include "malloc.h" |
| 72 | |
| 73 | #include "vm.h" |
| 74 | #include "vm_page.h" |
| 75 | #include "vm_kern.h" |
| 76 | |
| 77 | #include "swappager.h" |
| 78 | |
| 79 | #if NSWAPPAGER > 0 |
| 80 | extern struct pagerops swappagerops; |
| 81 | #else |
| 82 | #define swappagerops NULL |
| 83 | #endif |
| 84 | #include "vnodepager.h" |
| 85 | #if NVNODEPAGER > 0 |
| 86 | extern struct pagerops vnodepagerops; |
| 87 | #else |
| 88 | #define vnodepagerops NULL |
| 89 | #endif |
| 90 | #include "devpager.h" |
| 91 | #if NDEVPAGER > 0 |
| 92 | extern struct pagerops devicepagerops; |
| 93 | #else |
| 94 | #define devicepagerops NULL |
| 95 | #endif |
| 96 | |
| 97 | struct pagerops *pagertab[] = { |
| 98 | &swappagerops, /* PG_SWAP */ |
| 99 | &vnodepagerops, /* PG_VNODE */ |
| 100 | &devicepagerops, /* PG_DEV */ |
| 101 | }; |
| 102 | int npagers = sizeof (pagertab) / sizeof (pagertab[0]); |
| 103 | |
| 104 | struct pagerops *dfltpagerops = NULL; /* default pager */ |
| 105 | |
| 106 | /* |
| 107 | * Kernel address space for mapping pages. |
| 108 | * Used by pagers where KVAs are needed for IO. |
| 109 | */ |
| 110 | #define PAGER_MAP_SIZE (256 * PAGE_SIZE) |
| 111 | vm_map_t pager_map; |
| 112 | vm_offset_t pager_sva, pager_eva; |
| 113 | |
| 114 | void |
| 115 | vm_pager_init() |
| 116 | { |
| 117 | struct pagerops **pgops; |
| 118 | |
| 119 | /* |
| 120 | * Allocate a kernel submap for tracking get/put page mappings |
| 121 | */ |
| 122 | pager_map = kmem_suballoc(kernel_map, &pager_sva, &pager_eva, |
| 123 | PAGER_MAP_SIZE, FALSE); |
| 124 | /* |
| 125 | * Initialize known pagers |
| 126 | */ |
| 127 | for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++) |
| 128 | (*(*pgops)->pgo_init)(); |
| 129 | if (dfltpagerops == NULL) |
| 130 | panic("no default pager"); |
| 131 | } |
| 132 | |
| 133 | /* |
| 134 | * Allocate an instance of a pager of the given type. |
| 135 | */ |
| 136 | vm_pager_t |
| 137 | vm_pager_allocate(type, handle, size, prot) |
| 138 | int type; |
| 139 | caddr_t handle; |
| 140 | vm_size_t size; |
| 141 | vm_prot_t prot; |
| 142 | { |
| 143 | vm_pager_t pager; |
| 144 | struct pagerops *ops; |
| 145 | |
| 146 | ops = (type == PG_DFLT) ? dfltpagerops : pagertab[type]; |
| 147 | return((*ops->pgo_alloc)(handle, size, prot)); |
| 148 | } |
| 149 | |
| 150 | void |
| 151 | vm_pager_deallocate(pager) |
| 152 | vm_pager_t pager; |
| 153 | { |
| 154 | if (pager == NULL) |
| 155 | panic("vm_pager_deallocate: null pager"); |
| 156 | |
| 157 | VM_PAGER_DEALLOC(pager); |
| 158 | } |
| 159 | |
| 160 | vm_pager_get(pager, m, sync) |
| 161 | vm_pager_t pager; |
| 162 | vm_page_t m; |
| 163 | boolean_t sync; |
| 164 | { |
| 165 | extern boolean_t vm_page_zero_fill(); |
| 166 | |
| 167 | if (pager == NULL) |
| 168 | return(vm_page_zero_fill(m) ? VM_PAGER_OK : VM_PAGER_FAIL); |
| 169 | return(VM_PAGER_GET(pager, m, sync)); |
| 170 | } |
| 171 | |
| 172 | vm_pager_put(pager, m, sync) |
| 173 | vm_pager_t pager; |
| 174 | vm_page_t m; |
| 175 | boolean_t sync; |
| 176 | { |
| 177 | if (pager == NULL) |
| 178 | panic("vm_pager_put: null pager"); |
| 179 | return(VM_PAGER_PUT(pager, m, sync)); |
| 180 | } |
| 181 | |
| 182 | boolean_t |
| 183 | vm_pager_has_page(pager, offset) |
| 184 | vm_pager_t pager; |
| 185 | vm_offset_t offset; |
| 186 | { |
| 187 | if (pager == NULL) |
| 188 | panic("vm_pager_has_page"); |
| 189 | return(VM_PAGER_HASPAGE(pager, offset)); |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * Called by pageout daemon before going back to sleep. |
| 194 | * Gives pagers a chance to clean up any completed async pageing operations. |
| 195 | */ |
| 196 | void |
| 197 | vm_pager_sync() |
| 198 | { |
| 199 | struct pagerops **pgops; |
| 200 | |
| 201 | for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++) |
| 202 | (*(*pgops)->pgo_putpage)(NULL, NULL, FALSE); |
| 203 | } |
| 204 | |
| 205 | vm_offset_t |
| 206 | vm_pager_map_page(m) |
| 207 | vm_page_t m; |
| 208 | { |
| 209 | vm_offset_t kva; |
| 210 | |
| 211 | #ifdef DEBUG |
| 212 | if (!m->busy || m->active) |
| 213 | panic("vm_pager_map_page: page active or not busy"); |
| 214 | if (m->pagerowned) |
| 215 | printf("vm_pager_map_page: page %x already in pager\n", m); |
| 216 | #endif |
| 217 | kva = kmem_alloc_wait(pager_map, PAGE_SIZE); |
| 218 | #ifdef DEBUG |
| 219 | m->pagerowned = 1; |
| 220 | #endif |
| 221 | pmap_enter(vm_map_pmap(pager_map), kva, VM_PAGE_TO_PHYS(m), |
| 222 | VM_PROT_DEFAULT, TRUE); |
| 223 | return(kva); |
| 224 | } |
| 225 | |
| 226 | void |
| 227 | vm_pager_unmap_page(kva) |
| 228 | vm_offset_t kva; |
| 229 | { |
| 230 | #ifdef DEBUG |
| 231 | vm_page_t m; |
| 232 | |
| 233 | m = PHYS_TO_VM_PAGE(pmap_extract(vm_map_pmap(pager_map), kva)); |
| 234 | #endif |
| 235 | pmap_remove(vm_map_pmap(pager_map), kva, kva + PAGE_SIZE); |
| 236 | kmem_free_wakeup(pager_map, kva, PAGE_SIZE); |
| 237 | #ifdef DEBUG |
| 238 | if (m->pagerowned) |
| 239 | m->pagerowned = 0; |
| 240 | else |
| 241 | printf("vm_pager_unmap_page: page %x(%x/%x) not owned\n", |
| 242 | m, kva, VM_PAGE_TO_PHYS(m)); |
| 243 | #endif |
| 244 | } |
| 245 | |
| 246 | vm_pager_t |
| 247 | vm_pager_lookup(list, handle) |
| 248 | register queue_head_t *list; |
| 249 | caddr_t handle; |
| 250 | { |
| 251 | register vm_pager_t pager; |
| 252 | |
| 253 | pager = (vm_pager_t) queue_first(list); |
| 254 | while (!queue_end(list, (queue_entry_t)pager)) { |
| 255 | if (pager->pg_handle == handle) |
| 256 | return(pager); |
| 257 | pager = (vm_pager_t) queue_next(&pager->pg_list); |
| 258 | } |
| 259 | return(NULL); |
| 260 | } |
| 261 | |
| 262 | /* |
| 263 | * This routine gains a reference to the object. |
| 264 | * Explicit deallocation is necessary. |
| 265 | */ |
| 266 | pager_cache(object, should_cache) |
| 267 | vm_object_t object; |
| 268 | boolean_t should_cache; |
| 269 | { |
| 270 | if (object == NULL) |
| 271 | return(KERN_INVALID_ARGUMENT); |
| 272 | |
| 273 | vm_object_cache_lock(); |
| 274 | vm_object_lock(object); |
| 275 | object->can_persist = should_cache; |
| 276 | vm_object_unlock(object); |
| 277 | vm_object_cache_unlock(); |
| 278 | |
| 279 | vm_object_deallocate(object); |
| 280 | |
| 281 | return(KERN_SUCCESS); |
| 282 | } |