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 1.49 1998/08/24 08:39:37 dfr Exp $ 65 */ 66 67 /* 68 * Kernel memory management. 69 */ 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/proc.h> 74 #include <sys/malloc.h> 75 76 #include <vm/vm.h> 77 #include <vm/vm_param.h> 78 #include <vm/vm_prot.h> 79 #include <sys/lock.h> 80 #include <vm/pmap.h> 81 #include <vm/vm_map.h> 82 #include <vm/vm_object.h> 83 #include <vm/vm_page.h> 84 #include <vm/vm_pageout.h> 85 #include <vm/vm_extern.h> 86 87 vm_map_t kernel_map=0; 88 vm_map_t kmem_map=0; 89 vm_map_t exec_map=0; 90 vm_map_t clean_map=0; 91 vm_map_t u_map=0; 92 vm_map_t buffer_map=0; 93 vm_map_t mb_map=0; 94 int mb_map_full=0; 95 vm_map_t io_map=0; 96 vm_map_t phys_map=0; 97 98 /* 99 * kmem_alloc_pageable: 100 * 101 * Allocate pageable memory to the kernel's address map. 102 * "map" must be kernel_map or a submap of kernel_map. 103 */ 104 105 vm_offset_t 106 kmem_alloc_pageable(map, size) 107 vm_map_t map; 108 register vm_size_t size; 109 { 110 vm_offset_t addr; 111 register int result; 112 113 size = round_page(size); 114 addr = vm_map_min(map); 115 result = vm_map_find(map, NULL, (vm_offset_t) 0, 116 &addr, size, TRUE, VM_PROT_ALL, VM_PROT_ALL, 0); 117 if (result != KERN_SUCCESS) { 118 return (0); 119 } 120 return (addr); 121 } 122 123 /* 124 * Allocate wired-down memory in the kernel's address map 125 * or a submap. 126 */ 127 vm_offset_t 128 kmem_alloc(map, size) 129 register vm_map_t map; 130 register vm_size_t size; 131 { 132 vm_offset_t addr; 133 register vm_offset_t offset; 134 vm_offset_t i; 135 136 size = round_page(size); 137 138 /* 139 * Use the kernel object for wired-down kernel pages. Assume that no 140 * region of the kernel object is referenced more than once. 141 */ 142 143 /* 144 * Locate sufficient space in the map. This will give us the final 145 * virtual address for the new memory, and thus will tell us the 146 * offset within the kernel map. 147 */ 148 vm_map_lock(map); 149 if (vm_map_findspace(map, vm_map_min(map), size, &addr)) { 150 vm_map_unlock(map); 151 return (0); 152 } 153 offset = addr - VM_MIN_KERNEL_ADDRESS; 154 vm_object_reference(kernel_object); 155 vm_map_insert(map, kernel_object, offset, addr, addr + size, 156 VM_PROT_ALL, VM_PROT_ALL, 0); 157 vm_map_unlock(map); 158 159 /* 160 * Guarantee that there are pages already in this object before 161 * calling vm_map_pageable. This is to prevent the following 162 * scenario: 163 * 164 * 1) Threads have swapped out, so that there is a pager for the 165 * kernel_object. 2) The kmsg zone is empty, and so we are 166 * kmem_allocing a new page for it. 3) vm_map_pageable calls vm_fault; 167 * there is no page, but there is a pager, so we call 168 * pager_data_request. But the kmsg zone is empty, so we must 169 * kmem_alloc. 4) goto 1 5) Even if the kmsg zone is not empty: when 170 * we get the data back from the pager, it will be (very stale) 171 * non-zero data. kmem_alloc is defined to return zero-filled memory. 172 * 173 * We're intentionally not activating the pages we allocate to prevent a 174 * race with page-out. vm_map_pageable will wire the pages. 175 */ 176 177 for (i = 0; i < size; i += PAGE_SIZE) { 178 vm_page_t mem; 179 180 mem = vm_page_grab(kernel_object, OFF_TO_IDX(offset + i), 181 VM_ALLOC_ZERO | VM_ALLOC_RETRY); 182 if ((mem->flags & PG_ZERO) == 0) 183 vm_page_zero_fill(mem); 184 vm_page_flag_clear(mem, (PG_BUSY | PG_ZERO)); 185 mem->valid = VM_PAGE_BITS_ALL; 186 } 187 188 /* 189 * And finally, mark the data as non-pageable. 190 */ 191 192 (void) vm_map_pageable(map, (vm_offset_t) addr, addr + size, FALSE); 193 194 return (addr); 195 } 196 197 /* 198 * kmem_free: 199 * 200 * Release a region of kernel virtual memory allocated 201 * with kmem_alloc, and return the physical pages 202 * associated with that region. 203 */ 204 void 205 kmem_free(map, addr, size) 206 vm_map_t map; 207 register vm_offset_t addr; 208 vm_size_t size; 209 { 210 (void) vm_map_remove(map, trunc_page(addr), round_page(addr + size)); 211 } 212 213 /* 214 * kmem_suballoc: 215 * 216 * Allocates a map to manage a subrange 217 * of the kernel virtual address space. 218 * 219 * Arguments are as follows: 220 * 221 * parent Map to take range from 222 * size Size of range to find 223 * min, max Returned endpoints of map 224 * pageable Can the region be paged 225 */ 226 vm_map_t 227 kmem_suballoc(parent, min, max, size) 228 register vm_map_t parent; 229 vm_offset_t *min, *max; 230 register vm_size_t size; 231 { 232 register int ret; 233 vm_map_t result; 234 235 size = round_page(size); 236 237 *min = (vm_offset_t) vm_map_min(parent); 238 ret = vm_map_find(parent, NULL, (vm_offset_t) 0, 239 min, size, TRUE, VM_PROT_ALL, VM_PROT_ALL, 0); 240 if (ret != KERN_SUCCESS) { 241 printf("kmem_suballoc: bad status return of %d.\n", ret); 242 panic("kmem_suballoc"); 243 } 244 *max = *min + size; 245 pmap_reference(vm_map_pmap(parent)); 246 result = vm_map_create(vm_map_pmap(parent), *min, *max); 247 if (result == NULL) 248 panic("kmem_suballoc: cannot create submap"); 249 if ((ret = vm_map_submap(parent, *min, *max, result)) != KERN_SUCCESS) 250 panic("kmem_suballoc: unable to change range to submap"); 251 return (result); 252 } 253 254 /* 255 * Allocate wired-down memory in the kernel's address map for the higher 256 * level kernel memory allocator (kern/kern_malloc.c). We cannot use 257 * kmem_alloc() because we may need to allocate memory at interrupt 258 * level where we cannot block (canwait == FALSE). 259 * 260 * This routine has its own private kernel submap (kmem_map) and object 261 * (kmem_object). This, combined with the fact that only malloc uses 262 * this routine, ensures that we will never block in map or object waits. 263 * 264 * Note that this still only works in a uni-processor environment and 265 * when called at splhigh(). 266 * 267 * We don't worry about expanding the map (adding entries) since entries 268 * for wired maps are statically allocated. 269 */ 270 vm_offset_t 271 kmem_malloc(map, size, waitflag) 272 register vm_map_t map; 273 register vm_size_t size; 274 boolean_t waitflag; 275 { 276 register vm_offset_t offset, i; 277 vm_map_entry_t entry; 278 vm_offset_t addr; 279 vm_page_t m; 280 281 if (map != kmem_map && map != mb_map) 282 panic("kmem_malloc: map != {kmem,mb}_map"); 283 284 size = round_page(size); 285 addr = vm_map_min(map); 286 287 /* 288 * Locate sufficient space in the map. This will give us the final 289 * virtual address for the new memory, and thus will tell us the 290 * offset within the kernel map. 291 */ 292 vm_map_lock(map); 293 if (vm_map_findspace(map, vm_map_min(map), size, &addr)) { 294 vm_map_unlock(map); 295 if (map == mb_map) { 296 mb_map_full = TRUE; 297 printf("Out of mbuf clusters - adjust NMBCLUSTERS or increase maxusers!\n"); 298 return (0); 299 } 300 if (waitflag == M_WAITOK) 301 panic("kmem_malloc(%d): kmem_map too small: %d total allocated", 302 size, map->size); 303 return (0); 304 } 305 offset = addr - VM_MIN_KERNEL_ADDRESS; 306 vm_object_reference(kmem_object); 307 vm_map_insert(map, kmem_object, offset, addr, addr + size, 308 VM_PROT_ALL, VM_PROT_ALL, 0); 309 310 for (i = 0; i < size; i += PAGE_SIZE) { 311 retry: 312 m = vm_page_alloc(kmem_object, OFF_TO_IDX(offset + i), 313 (waitflag == M_NOWAIT) ? VM_ALLOC_INTERRUPT : VM_ALLOC_SYSTEM); 314 315 /* 316 * Ran out of space, free everything up and return. Don't need 317 * to lock page queues here as we know that the pages we got 318 * aren't on any queues. 319 */ 320 if (m == NULL) { 321 if (waitflag == M_WAITOK) { 322 VM_WAIT; 323 goto retry; 324 } 325 while (i != 0) { 326 i -= PAGE_SIZE; 327 m = vm_page_lookup(kmem_object, 328 OFF_TO_IDX(offset + i)); 329 vm_page_free(m); 330 } 331 vm_map_delete(map, addr, addr + size); 332 vm_map_unlock(map); 333 return (0); 334 } 335 vm_page_flag_clear(m, PG_ZERO); 336 m->valid = VM_PAGE_BITS_ALL; 337 } 338 339 /* 340 * Mark map entry as non-pageable. Assert: vm_map_insert() will never 341 * be able to extend the previous entry so there will be a new entry 342 * exactly corresponding to this address range and it will have 343 * wired_count == 0. 344 */ 345 if (!vm_map_lookup_entry(map, addr, &entry) || 346 entry->start != addr || entry->end != addr + size || 347 entry->wired_count) 348 panic("kmem_malloc: entry not found or misaligned"); 349 entry->wired_count++; 350 351 vm_map_simplify_entry(map, entry); 352 353 /* 354 * Loop thru pages, entering them in the pmap. (We cannot add them to 355 * the wired count without wrapping the vm_page_queue_lock in 356 * splimp...) 357 */ 358 for (i = 0; i < size; i += PAGE_SIZE) { 359 m = vm_page_lookup(kmem_object, OFF_TO_IDX(offset + i)); 360 vm_page_wire(m); 361 vm_page_wakeup(m); 362 pmap_enter(kernel_pmap, addr + i, VM_PAGE_TO_PHYS(m), 363 VM_PROT_ALL, 1); 364 vm_page_flag_set(m, PG_MAPPED | PG_WRITEABLE | PG_REFERENCED); 365 } 366 vm_map_unlock(map); 367 368 return (addr); 369 } 370 371 /* 372 * kmem_alloc_wait 373 * 374 * Allocates pageable memory from a sub-map of the kernel. If the submap 375 * has no room, the caller sleeps waiting for more memory in the submap. 376 * 377 */ 378 vm_offset_t 379 kmem_alloc_wait(map, size) 380 vm_map_t map; 381 vm_size_t size; 382 { 383 vm_offset_t addr; 384 385 size = round_page(size); 386 387 for (;;) { 388 /* 389 * To make this work for more than one map, use the map's lock 390 * to lock out sleepers/wakers. 391 */ 392 vm_map_lock(map); 393 if (vm_map_findspace(map, vm_map_min(map), size, &addr) == 0) 394 break; 395 /* no space now; see if we can ever get space */ 396 if (vm_map_max(map) - vm_map_min(map) < size) { 397 vm_map_unlock(map); 398 return (0); 399 } 400 vm_map_unlock(map); 401 tsleep(map, PVM, "kmaw", 0); 402 } 403 vm_map_insert(map, NULL, (vm_offset_t) 0, addr, addr + size, VM_PROT_ALL, VM_PROT_ALL, 0); 404 vm_map_unlock(map); 405 return (addr); 406 } 407 408 /* 409 * kmem_free_wakeup 410 * 411 * Returns memory to a submap of the kernel, and wakes up any processes 412 * waiting for memory in that map. 413 */ 414 void 415 kmem_free_wakeup(map, addr, size) 416 vm_map_t map; 417 vm_offset_t addr; 418 vm_size_t size; 419 { 420 vm_map_lock(map); 421 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size)); 422 wakeup(map); 423 vm_map_unlock(map); 424 } 425 426 /* 427 * Create the kernel map; insert a mapping covering kernel text, data, bss, 428 * and all space allocated thus far (`boostrap' data). The new map will thus 429 * map the range between VM_MIN_KERNEL_ADDRESS and `start' as allocated, and 430 * the range between `start' and `end' as free. 431 */ 432 void 433 kmem_init(start, end) 434 vm_offset_t start, end; 435 { 436 register vm_map_t m; 437 438 m = vm_map_create(kernel_pmap, VM_MIN_KERNEL_ADDRESS, end); 439 vm_map_lock(m); 440 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */ 441 kernel_map = m; 442 kernel_map->system_map = 1; 443 (void) vm_map_insert(m, NULL, (vm_offset_t) 0, 444 VM_MIN_KERNEL_ADDRESS, start, VM_PROT_ALL, VM_PROT_ALL, 0); 445 /* ... and ending with the completion of the above `insert' */ 446 vm_map_unlock(m); 447 } 448