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 * 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 * from: @(#)vm_pager.c 8.6 (Berkeley) 1/12/94 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 * $Id: vm_pager.c,v 1.16 1995/07/13 08:48:42 davidg Exp $ 65 */ 66 67 /* 68 * Paging space routine stubs. Emulates a matchmaker-like interface 69 * for builtin pagers. 70 */ 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/proc.h> 75 #include <sys/malloc.h> 76 #include <sys/buf.h> 77 #include <sys/ucred.h> 78 79 #include <vm/vm.h> 80 #include <vm/vm_page.h> 81 #include <vm/vm_kern.h> 82 #include <vm/vm_pager.h> 83 84 extern struct pagerops defaultpagerops; 85 extern struct pagerops swappagerops; 86 extern struct pagerops vnodepagerops; 87 extern struct pagerops devicepagerops; 88 89 struct pagerops *pagertab[] = { 90 &defaultpagerops, /* OBJT_DEFAULT */ 91 &swappagerops, /* OBJT_SWAP */ 92 &vnodepagerops, /* OBJT_VNODE */ 93 &devicepagerops, /* OBJT_DEVICE */ 94 }; 95 int npagers = sizeof(pagertab) / sizeof(pagertab[0]); 96 97 /* 98 * Kernel address space for mapping pages. 99 * Used by pagers where KVAs are needed for IO. 100 * 101 * XXX needs to be large enough to support the number of pending async 102 * cleaning requests (NPENDINGIO == 64) * the maximum swap cluster size 103 * (MAXPHYS == 64k) if you want to get the most efficiency. 104 */ 105 #define PAGER_MAP_SIZE (8 * 1024 * 1024) 106 107 int pager_map_size = PAGER_MAP_SIZE; 108 vm_map_t pager_map; 109 boolean_t pager_map_wanted; 110 int bswneeded; 111 vm_offset_t swapbkva; /* swap buffers kva */ 112 113 void 114 vm_pager_init() 115 { 116 struct pagerops **pgops; 117 118 /* 119 * Initialize known pagers 120 */ 121 for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++) 122 if (pgops && ((*pgops)->pgo_init != NULL)) 123 (*(*pgops)->pgo_init) (); 124 } 125 126 void 127 vm_pager_bufferinit() 128 { 129 struct buf *bp; 130 int i; 131 132 bp = swbuf; 133 /* 134 * Now set up swap and physical I/O buffer headers. 135 */ 136 for (i = 0; i < nswbuf - 1; i++, bp++) { 137 TAILQ_INSERT_HEAD(&bswlist, bp, b_freelist); 138 bp->b_rcred = bp->b_wcred = NOCRED; 139 bp->b_vnbufs.le_next = NOLIST; 140 } 141 bp->b_rcred = bp->b_wcred = NOCRED; 142 bp->b_vnbufs.le_next = NOLIST; 143 bp->b_actf = NULL; 144 145 swapbkva = kmem_alloc_pageable(pager_map, nswbuf * MAXPHYS); 146 if (!swapbkva) 147 panic("Not enough pager_map VM space for physical buffers"); 148 } 149 150 /* 151 * Allocate an instance of a pager of the given type. 152 * Size, protection and offset parameters are passed in for pagers that 153 * need to perform page-level validation (e.g. the device pager). 154 */ 155 vm_object_t 156 vm_pager_allocate(type, handle, size, prot, off) 157 objtype_t type; 158 void *handle; 159 vm_size_t size; 160 vm_prot_t prot; 161 vm_offset_t off; 162 { 163 struct pagerops *ops; 164 165 ops = pagertab[type]; 166 if (ops) 167 return ((*ops->pgo_alloc) (handle, size, prot, off)); 168 return (NULL); 169 } 170 171 void 172 vm_pager_deallocate(object) 173 vm_object_t object; 174 { 175 (*pagertab[object->type]->pgo_dealloc) (object); 176 } 177 178 179 int 180 vm_pager_get_pages(object, m, count, reqpage) 181 vm_object_t object; 182 vm_page_t *m; 183 int count; 184 int reqpage; 185 { 186 return ((*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage)); 187 } 188 189 int 190 vm_pager_put_pages(object, m, count, sync, rtvals) 191 vm_object_t object; 192 vm_page_t *m; 193 int count; 194 boolean_t sync; 195 int *rtvals; 196 { 197 return ((*pagertab[object->type]->pgo_putpages)(object, m, count, sync, rtvals)); 198 } 199 200 boolean_t 201 vm_pager_has_page(object, offset, before, after) 202 vm_object_t object; 203 vm_offset_t offset; 204 int *before; 205 int *after; 206 { 207 return ((*pagertab[object->type]->pgo_haspage) (object, offset, before, after)); 208 } 209 210 /* 211 * Called by pageout daemon before going back to sleep. 212 * Gives pagers a chance to clean up any completed async pageing operations. 213 */ 214 void 215 vm_pager_sync() 216 { 217 struct pagerops **pgops; 218 219 for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++) 220 if (pgops && ((*pgops)->pgo_sync != NULL)) 221 (*(*pgops)->pgo_sync) (); 222 } 223 224 vm_offset_t 225 vm_pager_map_page(m) 226 vm_page_t m; 227 { 228 vm_offset_t kva; 229 230 kva = kmem_alloc_wait(pager_map, PAGE_SIZE); 231 pmap_kenter(kva, VM_PAGE_TO_PHYS(m)); 232 return (kva); 233 } 234 235 void 236 vm_pager_unmap_page(kva) 237 vm_offset_t kva; 238 { 239 pmap_kremove(kva); 240 kmem_free_wakeup(pager_map, kva, PAGE_SIZE); 241 } 242 243 vm_page_t 244 vm_pager_atop(kva) 245 vm_offset_t kva; 246 { 247 vm_offset_t pa; 248 249 pa = pmap_kextract(kva); 250 if (pa == 0) 251 panic("vm_pager_atop"); 252 return (PHYS_TO_VM_PAGE(pa)); 253 } 254 255 vm_object_t 256 vm_pager_object_lookup(pg_list, handle) 257 register struct pagerlst *pg_list; 258 void *handle; 259 { 260 register vm_object_t object; 261 262 for (object = pg_list->tqh_first; object != NULL; object = object->pager_object_list.tqe_next) 263 if (object->handle == handle) 264 return (object); 265 return (NULL); 266 } 267 268 /* 269 * This routine loses a reference to the object - 270 * thus a reference must be gained before calling. 271 */ 272 int 273 pager_cache(object, should_cache) 274 vm_object_t object; 275 boolean_t should_cache; 276 { 277 if (object == NULL) 278 return (KERN_INVALID_ARGUMENT); 279 280 if (should_cache) 281 object->flags |= OBJ_CANPERSIST; 282 else 283 object->flags &= ~OBJ_CANPERSIST; 284 285 vm_object_deallocate(object); 286 287 return (KERN_SUCCESS); 288 } 289 290 /* 291 * allocate a physical buffer 292 */ 293 struct buf * 294 getpbuf() 295 { 296 int s; 297 struct buf *bp; 298 299 s = splbio(); 300 /* get a bp from the swap buffer header pool */ 301 while ((bp = bswlist.tqh_first) == NULL) { 302 bswneeded = 1; 303 tsleep(&bswneeded, PVM, "wswbuf", 0); 304 } 305 TAILQ_REMOVE(&bswlist, bp, b_freelist); 306 splx(s); 307 308 bzero(bp, sizeof *bp); 309 bp->b_rcred = NOCRED; 310 bp->b_wcred = NOCRED; 311 bp->b_data = (caddr_t) (MAXPHYS * (bp - swbuf)) + swapbkva; 312 bp->b_vnbufs.le_next = NOLIST; 313 return bp; 314 } 315 316 /* 317 * allocate a physical buffer, if one is available 318 */ 319 struct buf * 320 trypbuf() 321 { 322 int s; 323 struct buf *bp; 324 325 s = splbio(); 326 if ((bp = bswlist.tqh_first) == NULL) { 327 splx(s); 328 return NULL; 329 } 330 TAILQ_REMOVE(&bswlist, bp, b_freelist); 331 splx(s); 332 333 bzero(bp, sizeof *bp); 334 bp->b_rcred = NOCRED; 335 bp->b_wcred = NOCRED; 336 bp->b_data = (caddr_t) (MAXPHYS * (bp - swbuf)) + swapbkva; 337 bp->b_vnbufs.le_next = NOLIST; 338 return bp; 339 } 340 341 /* 342 * release a physical buffer 343 */ 344 void 345 relpbuf(bp) 346 struct buf *bp; 347 { 348 int s; 349 350 s = splbio(); 351 352 if (bp->b_rcred != NOCRED) { 353 crfree(bp->b_rcred); 354 bp->b_rcred = NOCRED; 355 } 356 if (bp->b_wcred != NOCRED) { 357 crfree(bp->b_wcred); 358 bp->b_wcred = NOCRED; 359 } 360 if (bp->b_vp) 361 pbrelvp(bp); 362 363 if (bp->b_flags & B_WANTED) 364 wakeup(bp); 365 366 TAILQ_INSERT_HEAD(&bswlist, bp, b_freelist); 367 368 if (bswneeded) { 369 bswneeded = 0; 370 wakeup(&bswneeded); 371 } 372 splx(s); 373 } 374