1 /* 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. 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 * %sccs.include.redist.c% 9 * 10 * @(#)vm_pager.c 8.6 (Berkeley) 01/12/94 11 * 12 * 13 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 14 * All rights reserved. 15 * 16 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 17 * 18 * Permission to use, copy, modify and distribute this software and 19 * its documentation is hereby granted, provided that both the copyright 20 * notice and this permission notice appear in all copies of the 21 * software, derivative works or modified versions, and any portions 22 * thereof, and that both notices appear in supporting documentation. 23 * 24 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 25 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 26 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 27 * 28 * Carnegie Mellon requests users of this software to return to 29 * 30 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 31 * School of Computer Science 32 * Carnegie Mellon University 33 * Pittsburgh PA 15213-3890 34 * 35 * any improvements or extensions that they make and grant Carnegie the 36 * rights to redistribute these changes. 37 */ 38 39 /* 40 * Paging space routine stubs. Emulates a matchmaker-like interface 41 * for builtin pagers. 42 */ 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/malloc.h> 47 48 #include <vm/vm.h> 49 #include <vm/vm_page.h> 50 #include <vm/vm_kern.h> 51 52 #ifdef SWAPPAGER 53 extern struct pagerops swappagerops; 54 #endif 55 56 #ifdef VNODEPAGER 57 extern struct pagerops vnodepagerops; 58 #endif 59 60 #ifdef DEVPAGER 61 extern struct pagerops devicepagerops; 62 #endif 63 64 struct pagerops *pagertab[] = { 65 #ifdef SWAPPAGER 66 &swappagerops, /* PG_SWAP */ 67 #else 68 NULL, 69 #endif 70 #ifdef VNODEPAGER 71 &vnodepagerops, /* PG_VNODE */ 72 #else 73 NULL, 74 #endif 75 #ifdef DEVPAGER 76 &devicepagerops, /* PG_DEV */ 77 #else 78 NULL, 79 #endif 80 }; 81 int npagers = sizeof (pagertab) / sizeof (pagertab[0]); 82 83 struct pagerops *dfltpagerops = NULL; /* default pager */ 84 85 /* 86 * Kernel address space for mapping pages. 87 * Used by pagers where KVAs are needed for IO. 88 * 89 * XXX needs to be large enough to support the number of pending async 90 * cleaning requests (NPENDINGIO == 64) * the maximum swap cluster size 91 * (MAXPHYS == 64k) if you want to get the most efficiency. 92 */ 93 #define PAGER_MAP_SIZE (4 * 1024 * 1024) 94 95 vm_map_t pager_map; 96 boolean_t pager_map_wanted; 97 vm_offset_t pager_sva, pager_eva; 98 99 void 100 vm_pager_init() 101 { 102 struct pagerops **pgops; 103 104 /* 105 * Allocate a kernel submap for tracking get/put page mappings 106 */ 107 pager_map = kmem_suballoc(kernel_map, &pager_sva, &pager_eva, 108 PAGER_MAP_SIZE, FALSE); 109 /* 110 * Initialize known pagers 111 */ 112 for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++) 113 if (pgops) 114 (*(*pgops)->pgo_init)(); 115 if (dfltpagerops == NULL) 116 panic("no default pager"); 117 } 118 119 /* 120 * Allocate an instance of a pager of the given type. 121 * Size, protection and offset parameters are passed in for pagers that 122 * need to perform page-level validation (e.g. the device pager). 123 */ 124 vm_pager_t 125 vm_pager_allocate(type, handle, size, prot, off) 126 int type; 127 caddr_t handle; 128 vm_size_t size; 129 vm_prot_t prot; 130 vm_offset_t off; 131 { 132 struct pagerops *ops; 133 134 ops = (type == PG_DFLT) ? dfltpagerops : pagertab[type]; 135 if (ops) 136 return ((*ops->pgo_alloc)(handle, size, prot, off)); 137 return (NULL); 138 } 139 140 void 141 vm_pager_deallocate(pager) 142 vm_pager_t pager; 143 { 144 if (pager == NULL) 145 panic("vm_pager_deallocate: null pager"); 146 147 (*pager->pg_ops->pgo_dealloc)(pager); 148 } 149 150 int 151 vm_pager_get_pages(pager, mlist, npages, sync) 152 vm_pager_t pager; 153 vm_page_t *mlist; 154 int npages; 155 boolean_t sync; 156 { 157 int rv; 158 159 if (pager == NULL) { 160 rv = VM_PAGER_OK; 161 while (npages--) 162 if (!vm_page_zero_fill(*mlist)) { 163 rv = VM_PAGER_FAIL; 164 break; 165 } else 166 mlist++; 167 return (rv); 168 } 169 return ((*pager->pg_ops->pgo_getpages)(pager, mlist, npages, sync)); 170 } 171 172 int 173 vm_pager_put_pages(pager, mlist, npages, sync) 174 vm_pager_t pager; 175 vm_page_t *mlist; 176 int npages; 177 boolean_t sync; 178 { 179 if (pager == NULL) 180 panic("vm_pager_put_pages: null pager"); 181 return ((*pager->pg_ops->pgo_putpages)(pager, mlist, npages, sync)); 182 } 183 184 boolean_t 185 vm_pager_has_page(pager, offset) 186 vm_pager_t pager; 187 vm_offset_t offset; 188 { 189 if (pager == NULL) 190 panic("vm_pager_has_page: null pager"); 191 return ((*pager->pg_ops->pgo_haspage)(pager, offset)); 192 } 193 194 /* 195 * Called by pageout daemon before going back to sleep. 196 * Gives pagers a chance to clean up any completed async pageing operations. 197 */ 198 void 199 vm_pager_sync() 200 { 201 struct pagerops **pgops; 202 203 for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++) 204 if (pgops) 205 (*(*pgops)->pgo_putpages)(NULL, NULL, 0, FALSE); 206 } 207 208 void 209 vm_pager_cluster(pager, offset, loff, hoff) 210 vm_pager_t pager; 211 vm_offset_t offset; 212 vm_offset_t *loff; 213 vm_offset_t *hoff; 214 { 215 if (pager == NULL) 216 panic("vm_pager_cluster: null pager"); 217 return ((*pager->pg_ops->pgo_cluster)(pager, offset, loff, hoff)); 218 } 219 220 void 221 vm_pager_clusternull(pager, offset, loff, hoff) 222 vm_pager_t pager; 223 vm_offset_t offset; 224 vm_offset_t *loff; 225 vm_offset_t *hoff; 226 { 227 panic("vm_pager_nullcluster called"); 228 } 229 230 vm_offset_t 231 vm_pager_map_pages(mlist, npages, canwait) 232 vm_page_t *mlist; 233 int npages; 234 boolean_t canwait; 235 { 236 vm_offset_t kva, va; 237 vm_size_t size; 238 vm_page_t m; 239 240 /* 241 * Allocate space in the pager map, if none available return 0. 242 * This is basically an expansion of kmem_alloc_wait with optional 243 * blocking on no space. 244 */ 245 size = npages * PAGE_SIZE; 246 vm_map_lock(pager_map); 247 while (vm_map_findspace(pager_map, 0, size, &kva)) { 248 if (!canwait) { 249 vm_map_unlock(pager_map); 250 return (0); 251 } 252 pager_map_wanted = TRUE; 253 vm_map_unlock(pager_map); 254 (void) tsleep(pager_map, PVM, "pager_map", 0); 255 vm_map_lock(pager_map); 256 } 257 vm_map_insert(pager_map, NULL, 0, kva, kva + size); 258 vm_map_unlock(pager_map); 259 260 for (va = kva; npages--; va += PAGE_SIZE) { 261 m = *mlist++; 262 #ifdef DEBUG 263 if ((m->flags & PG_BUSY) == 0) 264 panic("vm_pager_map_pages: page not busy"); 265 if (m->flags & PG_PAGEROWNED) 266 panic("vm_pager_map_pages: page already in pager"); 267 #endif 268 #ifdef DEBUG 269 m->flags |= PG_PAGEROWNED; 270 #endif 271 pmap_enter(vm_map_pmap(pager_map), va, VM_PAGE_TO_PHYS(m), 272 VM_PROT_DEFAULT, TRUE); 273 } 274 return (kva); 275 } 276 277 void 278 vm_pager_unmap_pages(kva, npages) 279 vm_offset_t kva; 280 int npages; 281 { 282 vm_size_t size = npages * PAGE_SIZE; 283 284 #ifdef DEBUG 285 vm_offset_t va; 286 vm_page_t m; 287 int np = npages; 288 289 for (va = kva; np--; va += PAGE_SIZE) { 290 m = vm_pager_atop(va); 291 if (m->flags & PG_PAGEROWNED) 292 m->flags &= ~PG_PAGEROWNED; 293 else 294 printf("vm_pager_unmap_pages: %x(%x/%x) not owned\n", 295 m, va, VM_PAGE_TO_PHYS(m)); 296 } 297 #endif 298 pmap_remove(vm_map_pmap(pager_map), kva, kva + size); 299 vm_map_lock(pager_map); 300 (void) vm_map_delete(pager_map, kva, kva + size); 301 if (pager_map_wanted) 302 wakeup(pager_map); 303 vm_map_unlock(pager_map); 304 } 305 306 vm_page_t 307 vm_pager_atop(kva) 308 vm_offset_t kva; 309 { 310 vm_offset_t pa; 311 312 pa = pmap_extract(vm_map_pmap(pager_map), kva); 313 if (pa == 0) 314 panic("vm_pager_atop"); 315 return (PHYS_TO_VM_PAGE(pa)); 316 } 317 318 vm_pager_t 319 vm_pager_lookup(pglist, handle) 320 register struct pagerlst *pglist; 321 caddr_t handle; 322 { 323 register vm_pager_t pager; 324 325 for (pager = pglist->tqh_first; pager; pager = pager->pg_list.tqe_next) 326 if (pager->pg_handle == handle) 327 return (pager); 328 return (NULL); 329 } 330 331 /* 332 * This routine gains a reference to the object. 333 * Explicit deallocation is necessary. 334 */ 335 int 336 pager_cache(object, should_cache) 337 vm_object_t object; 338 boolean_t should_cache; 339 { 340 if (object == NULL) 341 return (KERN_INVALID_ARGUMENT); 342 343 vm_object_cache_lock(); 344 vm_object_lock(object); 345 if (should_cache) 346 object->flags |= OBJ_CANPERSIST; 347 else 348 object->flags &= ~OBJ_CANPERSIST; 349 vm_object_unlock(object); 350 vm_object_cache_unlock(); 351 352 vm_object_deallocate(object); 353 354 return (KERN_SUCCESS); 355 } 356