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_kern.c 8.3 (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_kern.c,v 1.33 1997/02/22 09:48:21 peter Exp $ 65 */ 66 67 /* 68 * Kernel memory management. 69 */ 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/kernel.h> 74 #include <sys/proc.h> 75 #include <sys/malloc.h> 76 #include <sys/syslog.h> 77 #include <sys/queue.h> 78 #include <sys/vmmeter.h> 79 80 #include <vm/vm.h> 81 #include <vm/vm_param.h> 82 #include <vm/vm_prot.h> 83 #include <sys/lock.h> 84 #include <vm/pmap.h> 85 #include <vm/vm_map.h> 86 #include <vm/vm_object.h> 87 #include <vm/vm_page.h> 88 #include <vm/vm_pageout.h> 89 #include <vm/vm_kern.h> 90 #include <vm/vm_extern.h> 91 92 vm_map_t kernel_map=0; 93 vm_map_t kmem_map=0; 94 vm_map_t exec_map=0; 95 vm_map_t clean_map=0; 96 vm_map_t u_map=0; 97 vm_map_t buffer_map=0; 98 vm_map_t mb_map=0; 99 int mb_map_full=0; 100 vm_map_t io_map=0; 101 vm_map_t phys_map=0; 102 103 /* 104 * kmem_alloc_pageable: 105 * 106 * Allocate pageable memory to the kernel's address map. 107 * "map" must be kernel_map or a submap of kernel_map. 108 */ 109 110 vm_offset_t 111 kmem_alloc_pageable(map, size) 112 vm_map_t map; 113 register vm_size_t size; 114 { 115 vm_offset_t addr; 116 register int result; 117 118 size = round_page(size); 119 addr = vm_map_min(map); 120 result = vm_map_find(map, NULL, (vm_offset_t) 0, 121 &addr, size, TRUE, VM_PROT_ALL, VM_PROT_ALL, 0); 122 if (result != KERN_SUCCESS) { 123 return (0); 124 } 125 return (addr); 126 } 127 128 /* 129 * Allocate wired-down memory in the kernel's address map 130 * or a submap. 131 */ 132 vm_offset_t 133 kmem_alloc(map, size) 134 register vm_map_t map; 135 register vm_size_t size; 136 { 137 vm_offset_t addr; 138 register vm_offset_t offset; 139 vm_offset_t i; 140 141 size = round_page(size); 142 143 /* 144 * Use the kernel object for wired-down kernel pages. Assume that no 145 * region of the kernel object is referenced more than once. 146 */ 147 148 /* 149 * Locate sufficient space in the map. This will give us the final 150 * virtual address for the new memory, and thus will tell us the 151 * offset within the kernel map. 152 */ 153 vm_map_lock(map); 154 if (vm_map_findspace(map, 0, size, &addr)) { 155 vm_map_unlock(map); 156 return (0); 157 } 158 offset = addr - VM_MIN_KERNEL_ADDRESS; 159 vm_object_reference(kernel_object); 160 vm_map_insert(map, kernel_object, offset, addr, addr + size, 161 VM_PROT_ALL, VM_PROT_ALL, 0); 162 vm_map_unlock(map); 163 164 /* 165 * Guarantee that there are pages already in this object before 166 * calling vm_map_pageable. This is to prevent the following 167 * scenario: 168 * 169 * 1) Threads have swapped out, so that there is a pager for the 170 * kernel_object. 2) The kmsg zone is empty, and so we are 171 * kmem_allocing a new page for it. 3) vm_map_pageable calls vm_fault; 172 * there is no page, but there is a pager, so we call 173 * pager_data_request. But the kmsg zone is empty, so we must 174 * kmem_alloc. 4) goto 1 5) Even if the kmsg zone is not empty: when 175 * we get the data back from the pager, it will be (very stale) 176 * non-zero data. kmem_alloc is defined to return zero-filled memory. 177 * 178 * We're intentionally not activating the pages we allocate to prevent a 179 * race with page-out. vm_map_pageable will wire the pages. 180 */ 181 182 for (i = 0; i < size; i += PAGE_SIZE) { 183 vm_page_t mem; 184 185 while ((mem = vm_page_alloc(kernel_object, 186 OFF_TO_IDX(offset + i), VM_ALLOC_ZERO)) == NULL) { 187 VM_WAIT; 188 } 189 if ((mem->flags & PG_ZERO) == 0) 190 vm_page_zero_fill(mem); 191 mem->flags &= ~(PG_BUSY|PG_ZERO); 192 mem->valid = VM_PAGE_BITS_ALL; 193 } 194 195 /* 196 * And finally, mark the data as non-pageable. 197 */ 198 199 (void) vm_map_pageable(map, (vm_offset_t) addr, addr + size, FALSE); 200 201 return (addr); 202 } 203 204 /* 205 * kmem_free: 206 * 207 * Release a region of kernel virtual memory allocated 208 * with kmem_alloc, and return the physical pages 209 * associated with that region. 210 */ 211 void 212 kmem_free(map, addr, size) 213 vm_map_t map; 214 register vm_offset_t addr; 215 vm_size_t size; 216 { 217 (void) vm_map_remove(map, trunc_page(addr), round_page(addr + size)); 218 } 219 220 /* 221 * kmem_suballoc: 222 * 223 * Allocates a map to manage a subrange 224 * of the kernel virtual address space. 225 * 226 * Arguments are as follows: 227 * 228 * parent Map to take range from 229 * size Size of range to find 230 * min, max Returned endpoints of map 231 * pageable Can the region be paged 232 */ 233 vm_map_t 234 kmem_suballoc(parent, min, max, size, pageable) 235 register vm_map_t parent; 236 vm_offset_t *min, *max; 237 register vm_size_t size; 238 boolean_t pageable; 239 { 240 register int ret; 241 vm_map_t result; 242 243 size = round_page(size); 244 245 *min = (vm_offset_t) vm_map_min(parent); 246 ret = vm_map_find(parent, NULL, (vm_offset_t) 0, 247 min, size, TRUE, VM_PROT_ALL, VM_PROT_ALL, 0); 248 if (ret != KERN_SUCCESS) { 249 printf("kmem_suballoc: bad status return of %d.\n", ret); 250 panic("kmem_suballoc"); 251 } 252 *max = *min + size; 253 pmap_reference(vm_map_pmap(parent)); 254 result = vm_map_create(vm_map_pmap(parent), *min, *max, pageable); 255 if (result == NULL) 256 panic("kmem_suballoc: cannot create submap"); 257 if ((ret = vm_map_submap(parent, *min, *max, result)) != KERN_SUCCESS) 258 panic("kmem_suballoc: unable to change range to submap"); 259 return (result); 260 } 261 262 /* 263 * Allocate wired-down memory in the kernel's address map for the higher 264 * level kernel memory allocator (kern/kern_malloc.c). We cannot use 265 * kmem_alloc() because we may need to allocate memory at interrupt 266 * level where we cannot block (canwait == FALSE). 267 * 268 * This routine has its own private kernel submap (kmem_map) and object 269 * (kmem_object). This, combined with the fact that only malloc uses 270 * this routine, ensures that we will never block in map or object waits. 271 * 272 * Note that this still only works in a uni-processor environment and 273 * when called at splhigh(). 274 * 275 * We don't worry about expanding the map (adding entries) since entries 276 * for wired maps are statically allocated. 277 */ 278 vm_offset_t 279 kmem_malloc(map, size, waitflag) 280 register vm_map_t map; 281 register vm_size_t size; 282 boolean_t waitflag; 283 { 284 register vm_offset_t offset, i; 285 vm_map_entry_t entry; 286 vm_offset_t addr; 287 vm_page_t m; 288 289 if (map != kmem_map && map != mb_map) 290 panic("kmem_malloc: map != {kmem,mb}_map"); 291 292 size = round_page(size); 293 addr = vm_map_min(map); 294 295 /* 296 * Locate sufficient space in the map. This will give us the final 297 * virtual address for the new memory, and thus will tell us the 298 * offset within the kernel map. 299 */ 300 vm_map_lock(map); 301 if (vm_map_findspace(map, 0, size, &addr)) { 302 vm_map_unlock(map); 303 if (map == mb_map) { 304 mb_map_full = TRUE; 305 log(LOG_ERR, "Out of mbuf clusters - increase maxusers!\n"); 306 return (0); 307 } 308 if (waitflag == M_WAITOK) 309 panic("kmem_malloc: kmem_map too small"); 310 return (0); 311 } 312 offset = addr - VM_MIN_KERNEL_ADDRESS; 313 vm_object_reference(kmem_object); 314 vm_map_insert(map, kmem_object, offset, addr, addr + size, 315 VM_PROT_ALL, VM_PROT_ALL, 0); 316 317 for (i = 0; i < size; i += PAGE_SIZE) { 318 retry: 319 m = vm_page_alloc(kmem_object, OFF_TO_IDX(offset + i), 320 (waitflag == M_NOWAIT) ? VM_ALLOC_INTERRUPT : VM_ALLOC_SYSTEM); 321 322 /* 323 * Ran out of space, free everything up and return. Don't need 324 * to lock page queues here as we know that the pages we got 325 * aren't on any queues. 326 */ 327 if (m == NULL) { 328 if (waitflag == M_WAITOK) { 329 VM_WAIT; 330 goto retry; 331 } 332 while (i != 0) { 333 i -= PAGE_SIZE; 334 m = vm_page_lookup(kmem_object, 335 OFF_TO_IDX(offset + i)); 336 PAGE_WAKEUP(m); 337 vm_page_free(m); 338 } 339 vm_map_delete(map, addr, addr + size); 340 vm_map_unlock(map); 341 return (0); 342 } 343 m->flags &= ~PG_ZERO; 344 m->valid = VM_PAGE_BITS_ALL; 345 } 346 347 /* 348 * Mark map entry as non-pageable. Assert: vm_map_insert() will never 349 * be able to extend the previous entry so there will be a new entry 350 * exactly corresponding to this address range and it will have 351 * wired_count == 0. 352 */ 353 if (!vm_map_lookup_entry(map, addr, &entry) || 354 entry->start != addr || entry->end != addr + size || 355 entry->wired_count) 356 panic("kmem_malloc: entry not found or misaligned"); 357 entry->wired_count++; 358 359 vm_map_simplify_entry(map, entry); 360 361 /* 362 * Loop thru pages, entering them in the pmap. (We cannot add them to 363 * the wired count without wrapping the vm_page_queue_lock in 364 * splimp...) 365 */ 366 for (i = 0; i < size; i += PAGE_SIZE) { 367 m = vm_page_lookup(kmem_object, OFF_TO_IDX(offset + i)); 368 vm_page_wire(m); 369 PAGE_WAKEUP(m); 370 pmap_enter(kernel_pmap, addr + i, VM_PAGE_TO_PHYS(m), 371 VM_PROT_ALL, 1); 372 m->flags |= PG_MAPPED|PG_WRITEABLE; 373 } 374 vm_map_unlock(map); 375 376 return (addr); 377 } 378 379 /* 380 * kmem_alloc_wait 381 * 382 * Allocates pageable memory from a sub-map of the kernel. If the submap 383 * has no room, the caller sleeps waiting for more memory in the submap. 384 * 385 */ 386 vm_offset_t 387 kmem_alloc_wait(map, size) 388 vm_map_t map; 389 vm_size_t size; 390 { 391 vm_offset_t addr; 392 393 size = round_page(size); 394 395 for (;;) { 396 /* 397 * To make this work for more than one map, use the map's lock 398 * to lock out sleepers/wakers. 399 */ 400 vm_map_lock(map); 401 if (vm_map_findspace(map, 0, size, &addr) == 0) 402 break; 403 /* no space now; see if we can ever get space */ 404 if (vm_map_max(map) - vm_map_min(map) < size) { 405 vm_map_unlock(map); 406 return (0); 407 } 408 vm_map_unlock(map); 409 tsleep(map, PVM, "kmaw", 0); 410 } 411 vm_map_insert(map, NULL, (vm_offset_t) 0, addr, addr + size, VM_PROT_ALL, VM_PROT_ALL, 0); 412 vm_map_unlock(map); 413 return (addr); 414 } 415 416 /* 417 * kmem_free_wakeup 418 * 419 * Returns memory to a submap of the kernel, and wakes up any processes 420 * waiting for memory in that map. 421 */ 422 void 423 kmem_free_wakeup(map, addr, size) 424 vm_map_t map; 425 vm_offset_t addr; 426 vm_size_t size; 427 { 428 vm_map_lock(map); 429 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size)); 430 wakeup(map); 431 vm_map_unlock(map); 432 } 433 434 /* 435 * Create the kernel map; insert a mapping covering kernel text, data, bss, 436 * and all space allocated thus far (`boostrap' data). The new map will thus 437 * map the range between VM_MIN_KERNEL_ADDRESS and `start' as allocated, and 438 * the range between `start' and `end' as free. 439 */ 440 void 441 kmem_init(start, end) 442 vm_offset_t start, end; 443 { 444 register vm_map_t m; 445 446 m = vm_map_create(kernel_pmap, VM_MIN_KERNEL_ADDRESS, end, FALSE); 447 vm_map_lock(m); 448 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */ 449 kernel_map = m; 450 (void) vm_map_insert(m, NULL, (vm_offset_t) 0, 451 VM_MIN_KERNEL_ADDRESS, start, VM_PROT_ALL, VM_PROT_ALL, 0); 452 /* ... and ending with the completion of the above `insert' */ 453 vm_map_unlock(m); 454 } 455