1 /*- 2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU) 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * The Mach Operating System project at Carnegie-Mellon University. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: @(#)vm_kern.c 8.3 (Berkeley) 1/12/94 35 * 36 * 37 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 38 * All rights reserved. 39 * 40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 41 * 42 * Permission to use, copy, modify and distribute this software and 43 * its documentation is hereby granted, provided that both the copyright 44 * notice and this permission notice appear in all copies of the 45 * software, derivative works or modified versions, and any portions 46 * thereof, and that both notices appear in supporting documentation. 47 * 48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 51 * 52 * Carnegie Mellon requests users of this software to return to 53 * 54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 55 * School of Computer Science 56 * Carnegie Mellon University 57 * Pittsburgh PA 15213-3890 58 * 59 * any improvements or extensions that they make and grant Carnegie the 60 * rights to redistribute these changes. 61 */ 62 63 /* 64 * Kernel memory management. 65 */ 66 67 #include <sys/cdefs.h> 68 __FBSDID("$FreeBSD$"); 69 70 #include "opt_vm.h" 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/kernel.h> /* for ticks and hz */ 75 #include <sys/domainset.h> 76 #include <sys/eventhandler.h> 77 #include <sys/lock.h> 78 #include <sys/proc.h> 79 #include <sys/malloc.h> 80 #include <sys/rwlock.h> 81 #include <sys/sysctl.h> 82 #include <sys/vmem.h> 83 #include <sys/vmmeter.h> 84 85 #include <vm/vm.h> 86 #include <vm/vm_param.h> 87 #include <vm/vm_domainset.h> 88 #include <vm/vm_kern.h> 89 #include <vm/pmap.h> 90 #include <vm/vm_map.h> 91 #include <vm/vm_object.h> 92 #include <vm/vm_page.h> 93 #include <vm/vm_pageout.h> 94 #include <vm/vm_phys.h> 95 #include <vm/vm_pagequeue.h> 96 #include <vm/vm_radix.h> 97 #include <vm/vm_extern.h> 98 #include <vm/uma.h> 99 100 vm_map_t kernel_map; 101 vm_map_t exec_map; 102 vm_map_t pipe_map; 103 104 const void *zero_region; 105 CTASSERT((ZERO_REGION_SIZE & PAGE_MASK) == 0); 106 107 /* NB: Used by kernel debuggers. */ 108 const u_long vm_maxuser_address = VM_MAXUSER_ADDRESS; 109 110 u_int exec_map_entry_size; 111 u_int exec_map_entries; 112 113 SYSCTL_ULONG(_vm, OID_AUTO, min_kernel_address, CTLFLAG_RD, 114 SYSCTL_NULL_ULONG_PTR, VM_MIN_KERNEL_ADDRESS, "Min kernel address"); 115 116 SYSCTL_ULONG(_vm, OID_AUTO, max_kernel_address, CTLFLAG_RD, 117 #if defined(__arm__) || defined(__sparc64__) 118 &vm_max_kernel_address, 0, 119 #else 120 SYSCTL_NULL_ULONG_PTR, VM_MAX_KERNEL_ADDRESS, 121 #endif 122 "Max kernel address"); 123 124 /* 125 * kva_alloc: 126 * 127 * Allocate a virtual address range with no underlying object and 128 * no initial mapping to physical memory. Any mapping from this 129 * range to physical memory must be explicitly created prior to 130 * its use, typically with pmap_qenter(). Any attempt to create 131 * a mapping on demand through vm_fault() will result in a panic. 132 */ 133 vm_offset_t 134 kva_alloc(vm_size_t size) 135 { 136 vm_offset_t addr; 137 138 size = round_page(size); 139 if (vmem_alloc(kernel_arena, size, M_BESTFIT | M_NOWAIT, &addr)) 140 return (0); 141 142 return (addr); 143 } 144 145 /* 146 * kva_free: 147 * 148 * Release a region of kernel virtual memory allocated 149 * with kva_alloc, and return the physical pages 150 * associated with that region. 151 * 152 * This routine may not block on kernel maps. 153 */ 154 void 155 kva_free(vm_offset_t addr, vm_size_t size) 156 { 157 158 size = round_page(size); 159 vmem_free(kernel_arena, addr, size); 160 } 161 162 /* 163 * Allocates a region from the kernel address map and physical pages 164 * within the specified address range to the kernel object. Creates a 165 * wired mapping from this region to these pages, and returns the 166 * region's starting virtual address. The allocated pages are not 167 * necessarily physically contiguous. If M_ZERO is specified through the 168 * given flags, then the pages are zeroed before they are mapped. 169 */ 170 vm_offset_t 171 kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 172 vm_paddr_t high, vm_memattr_t memattr) 173 { 174 vmem_t *vmem; 175 vm_object_t object = kernel_object; 176 vm_offset_t addr, i, offset; 177 vm_page_t m; 178 int pflags, tries; 179 180 size = round_page(size); 181 vmem = vm_dom[domain].vmd_kernel_arena; 182 if (vmem_alloc(vmem, size, M_BESTFIT | flags, &addr)) 183 return (0); 184 offset = addr - VM_MIN_KERNEL_ADDRESS; 185 pflags = malloc2vm_flags(flags) | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED; 186 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 187 pflags |= VM_ALLOC_NOWAIT; 188 VM_OBJECT_WLOCK(object); 189 for (i = 0; i < size; i += PAGE_SIZE) { 190 tries = 0; 191 retry: 192 m = vm_page_alloc_contig_domain(object, atop(offset + i), 193 domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr); 194 if (m == NULL) { 195 VM_OBJECT_WUNLOCK(object); 196 if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) { 197 if (!vm_page_reclaim_contig_domain(domain, 198 pflags, 1, low, high, PAGE_SIZE, 0) && 199 (flags & M_WAITOK) != 0) 200 vm_wait_domain(domain); 201 VM_OBJECT_WLOCK(object); 202 tries++; 203 goto retry; 204 } 205 kmem_unback(object, addr, i); 206 vmem_free(vmem, addr, size); 207 return (0); 208 } 209 KASSERT(vm_phys_domain(m) == domain, 210 ("kmem_alloc_attr_domain: Domain mismatch %d != %d", 211 vm_phys_domain(m), domain)); 212 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 213 pmap_zero_page(m); 214 m->valid = VM_PAGE_BITS_ALL; 215 pmap_enter(kernel_pmap, addr + i, m, VM_PROT_RW, 216 VM_PROT_RW | PMAP_ENTER_WIRED, 0); 217 } 218 VM_OBJECT_WUNLOCK(object); 219 return (addr); 220 } 221 222 vm_offset_t 223 kmem_alloc_attr(vmem_t *vmem, vm_size_t size, int flags, vm_paddr_t low, 224 vm_paddr_t high, vm_memattr_t memattr) 225 { 226 struct vm_domainset_iter di; 227 vm_offset_t addr; 228 int domain; 229 230 KASSERT(vmem == kernel_arena, 231 ("kmem_alloc_attr: Only kernel_arena is supported.")); 232 233 vm_domainset_iter_malloc_init(&di, kernel_object, &domain, &flags); 234 do { 235 addr = kmem_alloc_attr_domain(domain, size, flags, low, high, 236 memattr); 237 if (addr != 0) 238 break; 239 } while (vm_domainset_iter_malloc(&di, &domain, &flags) == 0); 240 241 return (addr); 242 } 243 244 /* 245 * Allocates a region from the kernel address map and physically 246 * contiguous pages within the specified address range to the kernel 247 * object. Creates a wired mapping from this region to these pages, and 248 * returns the region's starting virtual address. If M_ZERO is specified 249 * through the given flags, then the pages are zeroed before they are 250 * mapped. 251 */ 252 vm_offset_t 253 kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 254 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 255 vm_memattr_t memattr) 256 { 257 vmem_t *vmem; 258 vm_object_t object = kernel_object; 259 vm_offset_t addr, offset, tmp; 260 vm_page_t end_m, m; 261 u_long npages; 262 int pflags, tries; 263 264 size = round_page(size); 265 vmem = vm_dom[domain].vmd_kernel_arena; 266 if (vmem_alloc(vmem, size, flags | M_BESTFIT, &addr)) 267 return (0); 268 offset = addr - VM_MIN_KERNEL_ADDRESS; 269 pflags = malloc2vm_flags(flags) | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED; 270 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 271 pflags |= VM_ALLOC_NOWAIT; 272 npages = atop(size); 273 VM_OBJECT_WLOCK(object); 274 tries = 0; 275 retry: 276 m = vm_page_alloc_contig_domain(object, atop(offset), domain, pflags, 277 npages, low, high, alignment, boundary, memattr); 278 if (m == NULL) { 279 VM_OBJECT_WUNLOCK(object); 280 if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) { 281 if (!vm_page_reclaim_contig_domain(domain, pflags, 282 npages, low, high, alignment, boundary) && 283 (flags & M_WAITOK) != 0) 284 vm_wait_domain(domain); 285 VM_OBJECT_WLOCK(object); 286 tries++; 287 goto retry; 288 } 289 vmem_free(vmem, addr, size); 290 return (0); 291 } 292 KASSERT(vm_phys_domain(m) == domain, 293 ("kmem_alloc_contig_domain: Domain mismatch %d != %d", 294 vm_phys_domain(m), domain)); 295 end_m = m + npages; 296 tmp = addr; 297 for (; m < end_m; m++) { 298 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 299 pmap_zero_page(m); 300 m->valid = VM_PAGE_BITS_ALL; 301 pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW, 302 VM_PROT_RW | PMAP_ENTER_WIRED, 0); 303 tmp += PAGE_SIZE; 304 } 305 VM_OBJECT_WUNLOCK(object); 306 return (addr); 307 } 308 309 vm_offset_t 310 kmem_alloc_contig(struct vmem *vmem, vm_size_t size, int flags, vm_paddr_t low, 311 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 312 vm_memattr_t memattr) 313 { 314 struct vm_domainset_iter di; 315 vm_offset_t addr; 316 int domain; 317 318 KASSERT(vmem == kernel_arena, 319 ("kmem_alloc_contig: Only kernel_arena is supported.")); 320 321 vm_domainset_iter_malloc_init(&di, kernel_object, &domain, &flags); 322 do { 323 addr = kmem_alloc_contig_domain(domain, size, flags, low, high, 324 alignment, boundary, memattr); 325 if (addr != 0) 326 break; 327 } while (vm_domainset_iter_malloc(&di, &domain, &flags) == 0); 328 329 return (addr); 330 } 331 332 /* 333 * kmem_suballoc: 334 * 335 * Allocates a map to manage a subrange 336 * of the kernel virtual address space. 337 * 338 * Arguments are as follows: 339 * 340 * parent Map to take range from 341 * min, max Returned endpoints of map 342 * size Size of range to find 343 * superpage_align Request that min is superpage aligned 344 */ 345 vm_map_t 346 kmem_suballoc(vm_map_t parent, vm_offset_t *min, vm_offset_t *max, 347 vm_size_t size, boolean_t superpage_align) 348 { 349 int ret; 350 vm_map_t result; 351 352 size = round_page(size); 353 354 *min = vm_map_min(parent); 355 ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ? 356 VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL, 357 MAP_ACC_NO_CHARGE); 358 if (ret != KERN_SUCCESS) 359 panic("kmem_suballoc: bad status return of %d", ret); 360 *max = *min + size; 361 result = vm_map_create(vm_map_pmap(parent), *min, *max); 362 if (result == NULL) 363 panic("kmem_suballoc: cannot create submap"); 364 if (vm_map_submap(parent, *min, *max, result) != KERN_SUCCESS) 365 panic("kmem_suballoc: unable to change range to submap"); 366 return (result); 367 } 368 369 /* 370 * kmem_malloc: 371 * 372 * Allocate wired-down pages in the kernel's address space. 373 */ 374 vm_offset_t 375 kmem_malloc_domain(struct vmem *vmem, int domain, vm_size_t size, int flags) 376 { 377 vmem_t *arena; 378 vm_offset_t addr; 379 int rv; 380 381 #if VM_NRESERVLEVEL > 0 382 KASSERT(vmem == kernel_arena || vmem == kernel_rwx_arena, 383 ("kmem_malloc_domain: Only kernel_arena or kernel_rwx_arena " 384 "are supported.")); 385 if (__predict_true(vmem == kernel_arena)) 386 arena = vm_dom[domain].vmd_kernel_arena; 387 else 388 arena = vm_dom[domain].vmd_kernel_rwx_arena; 389 #else 390 KASSERT(vmem == kernel_arena, 391 ("kmem_malloc_domain: Only kernel_arena is supported.")); 392 arena = vm_dom[domain].vmd_kernel_arena; 393 #endif 394 size = round_page(size); 395 if (vmem_alloc(arena, size, flags | M_BESTFIT, &addr)) 396 return (0); 397 398 rv = kmem_back_domain(domain, kernel_object, addr, size, flags); 399 if (rv != KERN_SUCCESS) { 400 vmem_free(arena, addr, size); 401 return (0); 402 } 403 return (addr); 404 } 405 406 vm_offset_t 407 kmem_malloc(struct vmem *vmem, vm_size_t size, int flags) 408 { 409 struct vm_domainset_iter di; 410 vm_offset_t addr; 411 int domain; 412 413 vm_domainset_iter_malloc_init(&di, kernel_object, &domain, &flags); 414 do { 415 addr = kmem_malloc_domain(vmem, domain, size, flags); 416 if (addr != 0) 417 break; 418 } while (vm_domainset_iter_malloc(&di, &domain, &flags) == 0); 419 420 return (addr); 421 } 422 423 /* 424 * kmem_back: 425 * 426 * Allocate physical pages for the specified virtual address range. 427 */ 428 int 429 kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr, 430 vm_size_t size, int flags) 431 { 432 vm_offset_t offset, i; 433 vm_page_t m, mpred; 434 vm_prot_t prot; 435 int pflags; 436 437 KASSERT(object == kernel_object, 438 ("kmem_back_domain: only supports kernel object.")); 439 440 offset = addr - VM_MIN_KERNEL_ADDRESS; 441 pflags = malloc2vm_flags(flags) | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED; 442 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 443 if (flags & M_WAITOK) 444 pflags |= VM_ALLOC_WAITFAIL; 445 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 446 447 i = 0; 448 VM_OBJECT_WLOCK(object); 449 retry: 450 mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i)); 451 for (; i < size; i += PAGE_SIZE, mpred = m) { 452 m = vm_page_alloc_domain_after(object, atop(offset + i), 453 domain, pflags, mpred); 454 455 /* 456 * Ran out of space, free everything up and return. Don't need 457 * to lock page queues here as we know that the pages we got 458 * aren't on any queues. 459 */ 460 if (m == NULL) { 461 if ((flags & M_NOWAIT) == 0) 462 goto retry; 463 VM_OBJECT_WUNLOCK(object); 464 kmem_unback(object, addr, i); 465 return (KERN_NO_SPACE); 466 } 467 KASSERT(vm_phys_domain(m) == domain, 468 ("kmem_back_domain: Domain mismatch %d != %d", 469 vm_phys_domain(m), domain)); 470 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0) 471 pmap_zero_page(m); 472 KASSERT((m->oflags & VPO_UNMANAGED) != 0, 473 ("kmem_malloc: page %p is managed", m)); 474 m->valid = VM_PAGE_BITS_ALL; 475 pmap_enter(kernel_pmap, addr + i, m, prot, 476 prot | PMAP_ENTER_WIRED, 0); 477 } 478 VM_OBJECT_WUNLOCK(object); 479 480 return (KERN_SUCCESS); 481 } 482 483 int 484 kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags) 485 { 486 struct vm_domainset_iter di; 487 int domain; 488 int ret; 489 490 KASSERT(object == kernel_object, 491 ("kmem_back: only supports kernel object.")); 492 493 vm_domainset_iter_malloc_init(&di, kernel_object, &domain, &flags); 494 do { 495 ret = kmem_back_domain(domain, object, addr, size, flags); 496 if (ret == KERN_SUCCESS) 497 break; 498 } while (vm_domainset_iter_malloc(&di, &domain, &flags) == 0); 499 500 return (ret); 501 } 502 503 /* 504 * kmem_unback: 505 * 506 * Unmap and free the physical pages underlying the specified virtual 507 * address range. 508 * 509 * A physical page must exist within the specified object at each index 510 * that is being unmapped. 511 */ 512 static int 513 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 514 { 515 vm_page_t m, next; 516 vm_offset_t end, offset; 517 int domain; 518 519 KASSERT(object == kernel_object, 520 ("kmem_unback: only supports kernel object.")); 521 522 if (size == 0) 523 return (0); 524 pmap_remove(kernel_pmap, addr, addr + size); 525 offset = addr - VM_MIN_KERNEL_ADDRESS; 526 end = offset + size; 527 VM_OBJECT_WLOCK(object); 528 m = vm_page_lookup(object, atop(offset)); 529 domain = vm_phys_domain(m); 530 for (; offset < end; offset += PAGE_SIZE, m = next) { 531 next = vm_page_next(m); 532 vm_page_unwire(m, PQ_NONE); 533 vm_page_free(m); 534 } 535 VM_OBJECT_WUNLOCK(object); 536 537 return (domain); 538 } 539 540 void 541 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 542 { 543 544 _kmem_unback(object, addr, size); 545 } 546 547 /* 548 * kmem_free: 549 * 550 * Free memory allocated with kmem_malloc. The size must match the 551 * original allocation. 552 */ 553 void 554 kmem_free(struct vmem *vmem, vm_offset_t addr, vm_size_t size) 555 { 556 struct vmem *arena; 557 int domain; 558 559 #if VM_NRESERVLEVEL > 0 560 KASSERT(vmem == kernel_arena || vmem == kernel_rwx_arena, 561 ("kmem_free: Only kernel_arena or kernel_rwx_arena are supported.")); 562 #else 563 KASSERT(vmem == kernel_arena, 564 ("kmem_free: Only kernel_arena is supported.")); 565 #endif 566 567 size = round_page(size); 568 domain = _kmem_unback(kernel_object, addr, size); 569 #if VM_NRESERVLEVEL > 0 570 if (__predict_true(vmem == kernel_arena)) 571 arena = vm_dom[domain].vmd_kernel_arena; 572 else 573 arena = vm_dom[domain].vmd_kernel_rwx_arena; 574 #else 575 arena = vm_dom[domain].vmd_kernel_arena; 576 #endif 577 vmem_free(arena, addr, size); 578 } 579 580 /* 581 * kmap_alloc_wait: 582 * 583 * Allocates pageable memory from a sub-map of the kernel. If the submap 584 * has no room, the caller sleeps waiting for more memory in the submap. 585 * 586 * This routine may block. 587 */ 588 vm_offset_t 589 kmap_alloc_wait(vm_map_t map, vm_size_t size) 590 { 591 vm_offset_t addr; 592 593 size = round_page(size); 594 if (!swap_reserve(size)) 595 return (0); 596 597 for (;;) { 598 /* 599 * To make this work for more than one map, use the map's lock 600 * to lock out sleepers/wakers. 601 */ 602 vm_map_lock(map); 603 if (vm_map_findspace(map, vm_map_min(map), size, &addr) == 0) 604 break; 605 /* no space now; see if we can ever get space */ 606 if (vm_map_max(map) - vm_map_min(map) < size) { 607 vm_map_unlock(map); 608 swap_release(size); 609 return (0); 610 } 611 map->needs_wakeup = TRUE; 612 vm_map_unlock_and_wait(map, 0); 613 } 614 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_ALL, 615 VM_PROT_ALL, MAP_ACC_CHARGED); 616 vm_map_unlock(map); 617 return (addr); 618 } 619 620 /* 621 * kmap_free_wakeup: 622 * 623 * Returns memory to a submap of the kernel, and wakes up any processes 624 * waiting for memory in that map. 625 */ 626 void 627 kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size) 628 { 629 630 vm_map_lock(map); 631 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size)); 632 if (map->needs_wakeup) { 633 map->needs_wakeup = FALSE; 634 vm_map_wakeup(map); 635 } 636 vm_map_unlock(map); 637 } 638 639 void 640 kmem_init_zero_region(void) 641 { 642 vm_offset_t addr, i; 643 vm_page_t m; 644 645 /* 646 * Map a single physical page of zeros to a larger virtual range. 647 * This requires less looping in places that want large amounts of 648 * zeros, while not using much more physical resources. 649 */ 650 addr = kva_alloc(ZERO_REGION_SIZE); 651 m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL | 652 VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO); 653 if ((m->flags & PG_ZERO) == 0) 654 pmap_zero_page(m); 655 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE) 656 pmap_qenter(addr + i, &m, 1); 657 pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ); 658 659 zero_region = (const void *)addr; 660 } 661 662 /* 663 * kmem_init: 664 * 665 * Create the kernel map; insert a mapping covering kernel text, 666 * data, bss, and all space allocated thus far (`boostrap' data). The 667 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and 668 * `start' as allocated, and the range between `start' and `end' as free. 669 */ 670 void 671 kmem_init(vm_offset_t start, vm_offset_t end) 672 { 673 vm_map_t m; 674 675 m = vm_map_create(kernel_pmap, VM_MIN_KERNEL_ADDRESS, end); 676 m->system_map = 1; 677 vm_map_lock(m); 678 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */ 679 kernel_map = m; 680 (void) vm_map_insert(m, NULL, (vm_ooffset_t) 0, 681 #ifdef __amd64__ 682 KERNBASE, 683 #else 684 VM_MIN_KERNEL_ADDRESS, 685 #endif 686 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 687 /* ... and ending with the completion of the above `insert' */ 688 vm_map_unlock(m); 689 } 690 691 /* 692 * kmem_bootstrap_free: 693 * 694 * Free pages backing preloaded data (e.g., kernel modules) to the 695 * system. Currently only supported on platforms that create a 696 * vm_phys segment for preloaded data. 697 */ 698 void 699 kmem_bootstrap_free(vm_offset_t start, vm_size_t size) 700 { 701 #if defined(__i386__) || defined(__amd64__) 702 struct vm_domain *vmd; 703 vm_offset_t end, va; 704 vm_paddr_t pa; 705 vm_page_t m; 706 707 end = trunc_page(start + size); 708 start = round_page(start); 709 710 for (va = start; va < end; va += PAGE_SIZE) { 711 pa = pmap_kextract(va); 712 m = PHYS_TO_VM_PAGE(pa); 713 714 vmd = vm_pagequeue_domain(m); 715 vm_domain_free_lock(vmd); 716 vm_phys_free_pages(m, 0); 717 vm_domain_free_unlock(vmd); 718 } 719 pmap_remove(kernel_pmap, start, end); 720 (void)vmem_add(kernel_arena, start, end - start, M_WAITOK); 721 #endif 722 } 723 724 #ifdef DIAGNOSTIC 725 /* 726 * Allow userspace to directly trigger the VM drain routine for testing 727 * purposes. 728 */ 729 static int 730 debug_vm_lowmem(SYSCTL_HANDLER_ARGS) 731 { 732 int error, i; 733 734 i = 0; 735 error = sysctl_handle_int(oidp, &i, 0, req); 736 if (error) 737 return (error); 738 if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0) 739 return (EINVAL); 740 if (i != 0) 741 EVENTHANDLER_INVOKE(vm_lowmem, i); 742 return (0); 743 } 744 745 SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, CTLTYPE_INT | CTLFLAG_RW, 0, 0, 746 debug_vm_lowmem, "I", "set to trigger vm_lowmem event with given flags"); 747 #endif 748