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 * $FreeBSD$ 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 exech_map=0; 96 vm_map_t clean_map=0; 97 vm_map_t u_map=0; 98 vm_map_t buffer_map=0; 99 vm_map_t mb_map=0; 100 int mb_map_full=0; 101 vm_map_t io_map=0; 102 vm_map_t phys_map=0; 103 104 /* 105 * kmem_alloc_pageable: 106 * 107 * Allocate pageable memory to the kernel's address map. 108 * "map" must be kernel_map or a submap of kernel_map. 109 */ 110 111 vm_offset_t 112 kmem_alloc_pageable(map, size) 113 vm_map_t map; 114 register vm_size_t size; 115 { 116 vm_offset_t addr; 117 register int result; 118 119 size = round_page(size); 120 addr = vm_map_min(map); 121 result = vm_map_find(map, NULL, (vm_offset_t) 0, 122 &addr, size, TRUE, VM_PROT_ALL, VM_PROT_ALL, 0); 123 if (result != KERN_SUCCESS) { 124 return (0); 125 } 126 return (addr); 127 } 128 129 /* 130 * Allocate wired-down memory in the kernel's address map 131 * or a submap. 132 */ 133 vm_offset_t 134 kmem_alloc(map, size) 135 register vm_map_t map; 136 register vm_size_t size; 137 { 138 vm_offset_t addr; 139 register vm_offset_t offset; 140 vm_offset_t i; 141 142 size = round_page(size); 143 144 /* 145 * Use the kernel object for wired-down kernel pages. Assume that no 146 * region of the kernel object is referenced more than once. 147 */ 148 149 /* 150 * Locate sufficient space in the map. This will give us the final 151 * virtual address for the new memory, and thus will tell us the 152 * offset within the kernel map. 153 */ 154 vm_map_lock(map); 155 if (vm_map_findspace(map, 0, size, &addr)) { 156 vm_map_unlock(map); 157 return (0); 158 } 159 offset = addr - VM_MIN_KERNEL_ADDRESS; 160 vm_object_reference(kernel_object); 161 vm_map_insert(map, kernel_object, offset, addr, addr + size, 162 VM_PROT_ALL, VM_PROT_ALL, 0); 163 vm_map_unlock(map); 164 165 /* 166 * Guarantee that there are pages already in this object before 167 * calling vm_map_pageable. This is to prevent the following 168 * scenario: 169 * 170 * 1) Threads have swapped out, so that there is a pager for the 171 * kernel_object. 2) The kmsg zone is empty, and so we are 172 * kmem_allocing a new page for it. 3) vm_map_pageable calls vm_fault; 173 * there is no page, but there is a pager, so we call 174 * pager_data_request. But the kmsg zone is empty, so we must 175 * kmem_alloc. 4) goto 1 5) Even if the kmsg zone is not empty: when 176 * we get the data back from the pager, it will be (very stale) 177 * non-zero data. kmem_alloc is defined to return zero-filled memory. 178 * 179 * We're intentionally not activating the pages we allocate to prevent a 180 * race with page-out. vm_map_pageable will wire the pages. 181 */ 182 183 for (i = 0; i < size; i += PAGE_SIZE) { 184 vm_page_t mem; 185 186 while ((mem = vm_page_alloc(kernel_object, 187 OFF_TO_IDX(offset + i), VM_ALLOC_ZERO)) == NULL) { 188 VM_WAIT; 189 } 190 if ((mem->flags & PG_ZERO) == 0) 191 vm_page_zero_fill(mem); 192 mem->flags &= ~(PG_BUSY|PG_ZERO); 193 mem->valid = VM_PAGE_BITS_ALL; 194 } 195 196 /* 197 * And finally, mark the data as non-pageable. 198 */ 199 200 (void) vm_map_pageable(map, (vm_offset_t) addr, addr + size, FALSE); 201 202 return (addr); 203 } 204 205 /* 206 * kmem_free: 207 * 208 * Release a region of kernel virtual memory allocated 209 * with kmem_alloc, and return the physical pages 210 * associated with that region. 211 */ 212 void 213 kmem_free(map, addr, size) 214 vm_map_t map; 215 register vm_offset_t addr; 216 vm_size_t size; 217 { 218 (void) vm_map_remove(map, trunc_page(addr), round_page(addr + size)); 219 } 220 221 /* 222 * kmem_suballoc: 223 * 224 * Allocates a map to manage a subrange 225 * of the kernel virtual address space. 226 * 227 * Arguments are as follows: 228 * 229 * parent Map to take range from 230 * size Size of range to find 231 * min, max Returned endpoints of map 232 * pageable Can the region be paged 233 */ 234 vm_map_t 235 kmem_suballoc(parent, min, max, size, pageable) 236 register vm_map_t parent; 237 vm_offset_t *min, *max; 238 register vm_size_t size; 239 boolean_t pageable; 240 { 241 register int ret; 242 vm_map_t result; 243 244 size = round_page(size); 245 246 *min = (vm_offset_t) vm_map_min(parent); 247 ret = vm_map_find(parent, NULL, (vm_offset_t) 0, 248 min, size, TRUE, VM_PROT_ALL, VM_PROT_ALL, 0); 249 if (ret != KERN_SUCCESS) { 250 printf("kmem_suballoc: bad status return of %d.\n", ret); 251 panic("kmem_suballoc"); 252 } 253 *max = *min + size; 254 pmap_reference(vm_map_pmap(parent)); 255 result = vm_map_create(vm_map_pmap(parent), *min, *max, pageable); 256 if (result == NULL) 257 panic("kmem_suballoc: cannot create submap"); 258 if ((ret = vm_map_submap(parent, *min, *max, result)) != KERN_SUCCESS) 259 panic("kmem_suballoc: unable to change range to submap"); 260 return (result); 261 } 262 263 /* 264 * Allocate wired-down memory in the kernel's address map for the higher 265 * level kernel memory allocator (kern/kern_malloc.c). We cannot use 266 * kmem_alloc() because we may need to allocate memory at interrupt 267 * level where we cannot block (canwait == FALSE). 268 * 269 * This routine has its own private kernel submap (kmem_map) and object 270 * (kmem_object). This, combined with the fact that only malloc uses 271 * this routine, ensures that we will never block in map or object waits. 272 * 273 * Note that this still only works in a uni-processor environment and 274 * when called at splhigh(). 275 * 276 * We don't worry about expanding the map (adding entries) since entries 277 * for wired maps are statically allocated. 278 */ 279 vm_offset_t 280 kmem_malloc(map, size, waitflag) 281 register vm_map_t map; 282 register vm_size_t size; 283 boolean_t waitflag; 284 { 285 register vm_offset_t offset, i; 286 vm_map_entry_t entry; 287 vm_offset_t addr; 288 vm_page_t m; 289 290 if (map != kmem_map && map != mb_map) 291 panic("kmem_malloc: map != {kmem,mb}_map"); 292 293 size = round_page(size); 294 addr = vm_map_min(map); 295 296 /* 297 * Locate sufficient space in the map. This will give us the final 298 * virtual address for the new memory, and thus will tell us the 299 * offset within the kernel map. 300 */ 301 vm_map_lock(map); 302 if (vm_map_findspace(map, 0, size, &addr)) { 303 vm_map_unlock(map); 304 if (map == mb_map) { 305 mb_map_full = TRUE; 306 log(LOG_ERR, "Out of mbuf clusters - increase maxusers!\n"); 307 return (0); 308 } 309 if (waitflag == M_WAITOK) 310 panic("kmem_malloc: kmem_map too small"); 311 return (0); 312 } 313 offset = addr - VM_MIN_KERNEL_ADDRESS; 314 vm_object_reference(kmem_object); 315 vm_map_insert(map, kmem_object, offset, addr, addr + size, 316 VM_PROT_ALL, VM_PROT_ALL, 0); 317 318 for (i = 0; i < size; i += PAGE_SIZE) { 319 retry: 320 m = vm_page_alloc(kmem_object, OFF_TO_IDX(offset + i), 321 (waitflag == M_NOWAIT) ? VM_ALLOC_INTERRUPT : VM_ALLOC_SYSTEM); 322 323 /* 324 * Ran out of space, free everything up and return. Don't need 325 * to lock page queues here as we know that the pages we got 326 * aren't on any queues. 327 */ 328 if (m == NULL) { 329 if (waitflag == M_WAITOK) { 330 VM_WAIT; 331 goto retry; 332 } 333 while (i != 0) { 334 i -= PAGE_SIZE; 335 m = vm_page_lookup(kmem_object, 336 OFF_TO_IDX(offset + i)); 337 PAGE_WAKEUP(m); 338 vm_page_free(m); 339 } 340 vm_map_delete(map, addr, addr + size); 341 vm_map_unlock(map); 342 return (0); 343 } 344 m->flags &= ~PG_ZERO; 345 m->valid = VM_PAGE_BITS_ALL; 346 } 347 348 /* 349 * Mark map entry as non-pageable. Assert: vm_map_insert() will never 350 * be able to extend the previous entry so there will be a new entry 351 * exactly corresponding to this address range and it will have 352 * wired_count == 0. 353 */ 354 if (!vm_map_lookup_entry(map, addr, &entry) || 355 entry->start != addr || entry->end != addr + size || 356 entry->wired_count) 357 panic("kmem_malloc: entry not found or misaligned"); 358 entry->wired_count++; 359 360 vm_map_simplify_entry(map, entry); 361 362 /* 363 * Loop thru pages, entering them in the pmap. (We cannot add them to 364 * the wired count without wrapping the vm_page_queue_lock in 365 * splimp...) 366 */ 367 for (i = 0; i < size; i += PAGE_SIZE) { 368 m = vm_page_lookup(kmem_object, OFF_TO_IDX(offset + i)); 369 vm_page_wire(m); 370 PAGE_WAKEUP(m); 371 pmap_enter(kernel_pmap, addr + i, VM_PAGE_TO_PHYS(m), 372 VM_PROT_ALL, 1); 373 m->flags |= PG_MAPPED|PG_WRITEABLE; 374 } 375 vm_map_unlock(map); 376 377 return (addr); 378 } 379 380 /* 381 * kmem_alloc_wait 382 * 383 * Allocates pageable memory from a sub-map of the kernel. If the submap 384 * has no room, the caller sleeps waiting for more memory in the submap. 385 * 386 */ 387 vm_offset_t 388 kmem_alloc_wait(map, size) 389 vm_map_t map; 390 vm_size_t size; 391 { 392 vm_offset_t addr; 393 394 size = round_page(size); 395 396 for (;;) { 397 /* 398 * To make this work for more than one map, use the map's lock 399 * to lock out sleepers/wakers. 400 */ 401 vm_map_lock(map); 402 if (vm_map_findspace(map, 0, size, &addr) == 0) 403 break; 404 /* no space now; see if we can ever get space */ 405 if (vm_map_max(map) - vm_map_min(map) < size) { 406 vm_map_unlock(map); 407 return (0); 408 } 409 vm_map_unlock(map); 410 tsleep(map, PVM, "kmaw", 0); 411 } 412 vm_map_insert(map, NULL, (vm_offset_t) 0, addr, addr + size, VM_PROT_ALL, VM_PROT_ALL, 0); 413 vm_map_unlock(map); 414 return (addr); 415 } 416 417 /* 418 * kmem_free_wakeup 419 * 420 * Returns memory to a submap of the kernel, and wakes up any processes 421 * waiting for memory in that map. 422 */ 423 void 424 kmem_free_wakeup(map, addr, size) 425 vm_map_t map; 426 vm_offset_t addr; 427 vm_size_t size; 428 { 429 vm_map_lock(map); 430 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size)); 431 wakeup(map); 432 vm_map_unlock(map); 433 } 434 435 /* 436 * Create the kernel map; insert a mapping covering kernel text, data, bss, 437 * and all space allocated thus far (`boostrap' data). The new map will thus 438 * map the range between VM_MIN_KERNEL_ADDRESS and `start' as allocated, and 439 * the range between `start' and `end' as free. 440 */ 441 void 442 kmem_init(start, end) 443 vm_offset_t start, end; 444 { 445 register vm_map_t m; 446 447 m = vm_map_create(kernel_pmap, VM_MIN_KERNEL_ADDRESS, end, FALSE); 448 vm_map_lock(m); 449 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */ 450 kernel_map = m; 451 (void) vm_map_insert(m, NULL, (vm_offset_t) 0, 452 VM_MIN_KERNEL_ADDRESS, start, VM_PROT_ALL, VM_PROT_ALL, 0); 453 /* ... and ending with the completion of the above `insert' */ 454 vm_map_unlock(m); 455 } 456