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 #if VM_NRESERVLEVEL > 0 125 #define KVA_QUANTUM_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT) 126 #else 127 /* On non-superpage architectures want large import sizes. */ 128 #define KVA_QUANTUM_SHIFT (10 + PAGE_SHIFT) 129 #endif 130 #define KVA_QUANTUM (1 << KVA_QUANTUM_SHIFT) 131 132 /* 133 * kva_alloc: 134 * 135 * Allocate a virtual address range with no underlying object and 136 * no initial mapping to physical memory. Any mapping from this 137 * range to physical memory must be explicitly created prior to 138 * its use, typically with pmap_qenter(). Any attempt to create 139 * a mapping on demand through vm_fault() will result in a panic. 140 */ 141 vm_offset_t 142 kva_alloc(vm_size_t size) 143 { 144 vm_offset_t addr; 145 146 size = round_page(size); 147 if (vmem_alloc(kernel_arena, size, M_BESTFIT | M_NOWAIT, &addr)) 148 return (0); 149 150 return (addr); 151 } 152 153 /* 154 * kva_free: 155 * 156 * Release a region of kernel virtual memory allocated 157 * with kva_alloc, and return the physical pages 158 * associated with that region. 159 * 160 * This routine may not block on kernel maps. 161 */ 162 void 163 kva_free(vm_offset_t addr, vm_size_t size) 164 { 165 166 size = round_page(size); 167 vmem_free(kernel_arena, addr, size); 168 } 169 170 /* 171 * Allocates a region from the kernel address map and physical pages 172 * within the specified address range to the kernel object. Creates a 173 * wired mapping from this region to these pages, and returns the 174 * region's starting virtual address. The allocated pages are not 175 * necessarily physically contiguous. If M_ZERO is specified through the 176 * given flags, then the pages are zeroed before they are mapped. 177 */ 178 vm_offset_t 179 kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 180 vm_paddr_t high, vm_memattr_t memattr) 181 { 182 vmem_t *vmem; 183 vm_object_t object = kernel_object; 184 vm_offset_t addr, i, offset; 185 vm_page_t m; 186 int pflags, tries; 187 188 size = round_page(size); 189 vmem = vm_dom[domain].vmd_kernel_arena; 190 if (vmem_alloc(vmem, size, M_BESTFIT | flags, &addr)) 191 return (0); 192 offset = addr - VM_MIN_KERNEL_ADDRESS; 193 pflags = malloc2vm_flags(flags) | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED; 194 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 195 pflags |= VM_ALLOC_NOWAIT; 196 VM_OBJECT_WLOCK(object); 197 for (i = 0; i < size; i += PAGE_SIZE) { 198 tries = 0; 199 retry: 200 m = vm_page_alloc_contig_domain(object, atop(offset + i), 201 domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr); 202 if (m == NULL) { 203 VM_OBJECT_WUNLOCK(object); 204 if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) { 205 if (!vm_page_reclaim_contig_domain(domain, 206 pflags, 1, low, high, PAGE_SIZE, 0) && 207 (flags & M_WAITOK) != 0) 208 vm_wait_domain(domain); 209 VM_OBJECT_WLOCK(object); 210 tries++; 211 goto retry; 212 } 213 kmem_unback(object, addr, i); 214 vmem_free(vmem, addr, size); 215 return (0); 216 } 217 KASSERT(vm_phys_domain(m) == domain, 218 ("kmem_alloc_attr_domain: Domain mismatch %d != %d", 219 vm_phys_domain(m), domain)); 220 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 221 pmap_zero_page(m); 222 m->valid = VM_PAGE_BITS_ALL; 223 pmap_enter(kernel_pmap, addr + i, m, VM_PROT_RW, 224 VM_PROT_RW | PMAP_ENTER_WIRED, 0); 225 } 226 VM_OBJECT_WUNLOCK(object); 227 return (addr); 228 } 229 230 vm_offset_t 231 kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 232 vm_memattr_t memattr) 233 { 234 struct vm_domainset_iter di; 235 vm_offset_t addr; 236 int domain; 237 238 vm_domainset_iter_malloc_init(&di, kernel_object, &domain, &flags); 239 do { 240 addr = kmem_alloc_attr_domain(domain, size, flags, low, high, 241 memattr); 242 if (addr != 0) 243 break; 244 } while (vm_domainset_iter_malloc(&di, &domain, &flags) == 0); 245 246 return (addr); 247 } 248 249 /* 250 * Allocates a region from the kernel address map and physically 251 * contiguous pages within the specified address range to the kernel 252 * object. Creates a wired mapping from this region to these pages, and 253 * returns the region's starting virtual address. If M_ZERO is specified 254 * through the given flags, then the pages are zeroed before they are 255 * mapped. 256 */ 257 vm_offset_t 258 kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 259 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 260 vm_memattr_t memattr) 261 { 262 vmem_t *vmem; 263 vm_object_t object = kernel_object; 264 vm_offset_t addr, offset, tmp; 265 vm_page_t end_m, m; 266 u_long npages; 267 int pflags, tries; 268 269 size = round_page(size); 270 vmem = vm_dom[domain].vmd_kernel_arena; 271 if (vmem_alloc(vmem, size, flags | M_BESTFIT, &addr)) 272 return (0); 273 offset = addr - VM_MIN_KERNEL_ADDRESS; 274 pflags = malloc2vm_flags(flags) | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED; 275 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 276 pflags |= VM_ALLOC_NOWAIT; 277 npages = atop(size); 278 VM_OBJECT_WLOCK(object); 279 tries = 0; 280 retry: 281 m = vm_page_alloc_contig_domain(object, atop(offset), domain, pflags, 282 npages, low, high, alignment, boundary, memattr); 283 if (m == NULL) { 284 VM_OBJECT_WUNLOCK(object); 285 if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) { 286 if (!vm_page_reclaim_contig_domain(domain, pflags, 287 npages, low, high, alignment, boundary) && 288 (flags & M_WAITOK) != 0) 289 vm_wait_domain(domain); 290 VM_OBJECT_WLOCK(object); 291 tries++; 292 goto retry; 293 } 294 vmem_free(vmem, addr, size); 295 return (0); 296 } 297 KASSERT(vm_phys_domain(m) == domain, 298 ("kmem_alloc_contig_domain: Domain mismatch %d != %d", 299 vm_phys_domain(m), domain)); 300 end_m = m + npages; 301 tmp = addr; 302 for (; m < end_m; m++) { 303 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 304 pmap_zero_page(m); 305 m->valid = VM_PAGE_BITS_ALL; 306 pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW, 307 VM_PROT_RW | PMAP_ENTER_WIRED, 0); 308 tmp += PAGE_SIZE; 309 } 310 VM_OBJECT_WUNLOCK(object); 311 return (addr); 312 } 313 314 vm_offset_t 315 kmem_alloc_contig(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 316 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) 317 { 318 struct vm_domainset_iter di; 319 vm_offset_t addr; 320 int domain; 321 322 vm_domainset_iter_malloc_init(&di, kernel_object, &domain, &flags); 323 do { 324 addr = kmem_alloc_contig_domain(domain, size, flags, low, high, 325 alignment, boundary, memattr); 326 if (addr != 0) 327 break; 328 } while (vm_domainset_iter_malloc(&di, &domain, &flags) == 0); 329 330 return (addr); 331 } 332 333 /* 334 * kmem_suballoc: 335 * 336 * Allocates a map to manage a subrange 337 * of the kernel virtual address space. 338 * 339 * Arguments are as follows: 340 * 341 * parent Map to take range from 342 * min, max Returned endpoints of map 343 * size Size of range to find 344 * superpage_align Request that min is superpage aligned 345 */ 346 vm_map_t 347 kmem_suballoc(vm_map_t parent, vm_offset_t *min, vm_offset_t *max, 348 vm_size_t size, boolean_t superpage_align) 349 { 350 int ret; 351 vm_map_t result; 352 353 size = round_page(size); 354 355 *min = vm_map_min(parent); 356 ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ? 357 VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL, 358 MAP_ACC_NO_CHARGE); 359 if (ret != KERN_SUCCESS) 360 panic("kmem_suballoc: bad status return of %d", ret); 361 *max = *min + size; 362 result = vm_map_create(vm_map_pmap(parent), *min, *max); 363 if (result == NULL) 364 panic("kmem_suballoc: cannot create submap"); 365 if (vm_map_submap(parent, *min, *max, result) != KERN_SUCCESS) 366 panic("kmem_suballoc: unable to change range to submap"); 367 return (result); 368 } 369 370 /* 371 * kmem_malloc: 372 * 373 * Allocate wired-down pages in the kernel's address space. 374 */ 375 vm_offset_t 376 kmem_malloc_domain(int domain, vm_size_t size, int flags) 377 { 378 vmem_t *arena; 379 vm_offset_t addr; 380 int rv; 381 382 #if VM_NRESERVLEVEL > 0 383 if (__predict_true((flags & M_EXEC) == 0)) 384 arena = vm_dom[domain].vmd_kernel_arena; 385 else 386 arena = vm_dom[domain].vmd_kernel_rwx_arena; 387 #else 388 arena = vm_dom[domain].vmd_kernel_arena; 389 #endif 390 size = round_page(size); 391 if (vmem_alloc(arena, size, flags | M_BESTFIT, &addr)) 392 return (0); 393 394 rv = kmem_back_domain(domain, kernel_object, addr, size, flags); 395 if (rv != KERN_SUCCESS) { 396 vmem_free(arena, addr, size); 397 return (0); 398 } 399 return (addr); 400 } 401 402 vm_offset_t 403 kmem_malloc(vm_size_t size, int flags) 404 { 405 struct vm_domainset_iter di; 406 vm_offset_t addr; 407 int domain; 408 409 vm_domainset_iter_malloc_init(&di, kernel_object, &domain, &flags); 410 do { 411 addr = kmem_malloc_domain(domain, size, flags); 412 if (addr != 0) 413 break; 414 } while (vm_domainset_iter_malloc(&di, &domain, &flags) == 0); 415 416 return (addr); 417 } 418 419 /* 420 * kmem_back_domain: 421 * 422 * Allocate physical pages from the specified domain for the specified 423 * virtual address range. 424 */ 425 int 426 kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr, 427 vm_size_t size, int flags) 428 { 429 vm_offset_t offset, i; 430 vm_page_t m, mpred; 431 vm_prot_t prot; 432 int pflags; 433 434 KASSERT(object == kernel_object, 435 ("kmem_back_domain: only supports kernel object.")); 436 437 offset = addr - VM_MIN_KERNEL_ADDRESS; 438 pflags = malloc2vm_flags(flags) | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED; 439 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 440 if (flags & M_WAITOK) 441 pflags |= VM_ALLOC_WAITFAIL; 442 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 443 444 i = 0; 445 VM_OBJECT_WLOCK(object); 446 retry: 447 mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i)); 448 for (; i < size; i += PAGE_SIZE, mpred = m) { 449 m = vm_page_alloc_domain_after(object, atop(offset + i), 450 domain, pflags, mpred); 451 452 /* 453 * Ran out of space, free everything up and return. Don't need 454 * to lock page queues here as we know that the pages we got 455 * aren't on any queues. 456 */ 457 if (m == NULL) { 458 if ((flags & M_NOWAIT) == 0) 459 goto retry; 460 VM_OBJECT_WUNLOCK(object); 461 kmem_unback(object, addr, i); 462 return (KERN_NO_SPACE); 463 } 464 KASSERT(vm_phys_domain(m) == domain, 465 ("kmem_back_domain: Domain mismatch %d != %d", 466 vm_phys_domain(m), domain)); 467 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0) 468 pmap_zero_page(m); 469 KASSERT((m->oflags & VPO_UNMANAGED) != 0, 470 ("kmem_malloc: page %p is managed", m)); 471 m->valid = VM_PAGE_BITS_ALL; 472 pmap_enter(kernel_pmap, addr + i, m, prot, 473 prot | PMAP_ENTER_WIRED, 0); 474 #if VM_NRESERVLEVEL > 0 475 if (__predict_false((prot & VM_PROT_EXECUTE) != 0)) 476 m->oflags |= VPO_KMEM_EXEC; 477 #endif 478 } 479 VM_OBJECT_WUNLOCK(object); 480 481 return (KERN_SUCCESS); 482 } 483 484 /* 485 * kmem_back: 486 * 487 * Allocate physical pages for the specified virtual address range. 488 */ 489 int 490 kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags) 491 { 492 vm_offset_t end, next, start; 493 int domain, rv; 494 495 KASSERT(object == kernel_object, 496 ("kmem_back: only supports kernel object.")); 497 498 for (start = addr, end = addr + size; addr < end; addr = next) { 499 /* 500 * We must ensure that pages backing a given large virtual page 501 * all come from the same physical domain. 502 */ 503 if (vm_ndomains > 1) { 504 domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains; 505 while (VM_DOMAIN_EMPTY(domain)) 506 domain++; 507 next = roundup2(addr + 1, KVA_QUANTUM); 508 if (next > end || next < start) 509 next = end; 510 } else { 511 domain = 0; 512 next = end; 513 } 514 rv = kmem_back_domain(domain, object, addr, next - addr, flags); 515 if (rv != KERN_SUCCESS) { 516 kmem_unback(object, start, addr - start); 517 break; 518 } 519 } 520 return (rv); 521 } 522 523 /* 524 * kmem_unback: 525 * 526 * Unmap and free the physical pages underlying the specified virtual 527 * address range. 528 * 529 * A physical page must exist within the specified object at each index 530 * that is being unmapped. 531 */ 532 static struct vmem * 533 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 534 { 535 struct vmem *arena; 536 vm_page_t m, next; 537 vm_offset_t end, offset; 538 int domain; 539 540 KASSERT(object == kernel_object, 541 ("kmem_unback: only supports kernel object.")); 542 543 if (size == 0) 544 return (NULL); 545 pmap_remove(kernel_pmap, addr, addr + size); 546 offset = addr - VM_MIN_KERNEL_ADDRESS; 547 end = offset + size; 548 VM_OBJECT_WLOCK(object); 549 m = vm_page_lookup(object, atop(offset)); 550 domain = vm_phys_domain(m); 551 #if VM_NRESERVLEVEL > 0 552 if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0)) 553 arena = vm_dom[domain].vmd_kernel_arena; 554 else 555 arena = vm_dom[domain].vmd_kernel_rwx_arena; 556 #else 557 arena = vm_dom[domain].vmd_kernel_arena; 558 #endif 559 for (; offset < end; offset += PAGE_SIZE, m = next) { 560 next = vm_page_next(m); 561 vm_page_unwire(m, PQ_NONE); 562 vm_page_free(m); 563 } 564 VM_OBJECT_WUNLOCK(object); 565 566 return (arena); 567 } 568 569 void 570 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 571 { 572 573 (void)_kmem_unback(object, addr, size); 574 } 575 576 /* 577 * kmem_free: 578 * 579 * Free memory allocated with kmem_malloc. The size must match the 580 * original allocation. 581 */ 582 void 583 kmem_free(vm_offset_t addr, vm_size_t size) 584 { 585 struct vmem *arena; 586 587 size = round_page(size); 588 arena = _kmem_unback(kernel_object, addr, size); 589 if (arena != NULL) 590 vmem_free(arena, addr, size); 591 } 592 593 /* 594 * kmap_alloc_wait: 595 * 596 * Allocates pageable memory from a sub-map of the kernel. If the submap 597 * has no room, the caller sleeps waiting for more memory in the submap. 598 * 599 * This routine may block. 600 */ 601 vm_offset_t 602 kmap_alloc_wait(vm_map_t map, vm_size_t size) 603 { 604 vm_offset_t addr; 605 606 size = round_page(size); 607 if (!swap_reserve(size)) 608 return (0); 609 610 for (;;) { 611 /* 612 * To make this work for more than one map, use the map's lock 613 * to lock out sleepers/wakers. 614 */ 615 vm_map_lock(map); 616 if (vm_map_findspace(map, vm_map_min(map), size, &addr) == 0) 617 break; 618 /* no space now; see if we can ever get space */ 619 if (vm_map_max(map) - vm_map_min(map) < size) { 620 vm_map_unlock(map); 621 swap_release(size); 622 return (0); 623 } 624 map->needs_wakeup = TRUE; 625 vm_map_unlock_and_wait(map, 0); 626 } 627 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_ALL, 628 VM_PROT_ALL, MAP_ACC_CHARGED); 629 vm_map_unlock(map); 630 return (addr); 631 } 632 633 /* 634 * kmap_free_wakeup: 635 * 636 * Returns memory to a submap of the kernel, and wakes up any processes 637 * waiting for memory in that map. 638 */ 639 void 640 kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size) 641 { 642 643 vm_map_lock(map); 644 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size)); 645 if (map->needs_wakeup) { 646 map->needs_wakeup = FALSE; 647 vm_map_wakeup(map); 648 } 649 vm_map_unlock(map); 650 } 651 652 void 653 kmem_init_zero_region(void) 654 { 655 vm_offset_t addr, i; 656 vm_page_t m; 657 658 /* 659 * Map a single physical page of zeros to a larger virtual range. 660 * This requires less looping in places that want large amounts of 661 * zeros, while not using much more physical resources. 662 */ 663 addr = kva_alloc(ZERO_REGION_SIZE); 664 m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL | 665 VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO); 666 if ((m->flags & PG_ZERO) == 0) 667 pmap_zero_page(m); 668 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE) 669 pmap_qenter(addr + i, &m, 1); 670 pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ); 671 672 zero_region = (const void *)addr; 673 } 674 675 /* 676 * Import KVA from the kernel map into the kernel arena. 677 */ 678 static int 679 kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp) 680 { 681 vm_offset_t addr; 682 int result; 683 684 KASSERT((size % KVA_QUANTUM) == 0, 685 ("kva_import: Size %jd is not a multiple of %d", 686 (intmax_t)size, (int)KVA_QUANTUM)); 687 addr = vm_map_min(kernel_map); 688 result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0, 689 VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 690 if (result != KERN_SUCCESS) 691 return (ENOMEM); 692 693 *addrp = addr; 694 695 return (0); 696 } 697 698 /* 699 * Import KVA from a parent arena into a per-domain arena. Imports must be 700 * KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size. 701 */ 702 static int 703 kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp) 704 { 705 706 KASSERT((size % KVA_QUANTUM) == 0, 707 ("kva_import_domain: Size %jd is not a multiple of %d", 708 (intmax_t)size, (int)KVA_QUANTUM)); 709 return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN, 710 VMEM_ADDR_MAX, flags, addrp)); 711 } 712 713 /* 714 * kmem_init: 715 * 716 * Create the kernel map; insert a mapping covering kernel text, 717 * data, bss, and all space allocated thus far (`boostrap' data). The 718 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and 719 * `start' as allocated, and the range between `start' and `end' as free. 720 * Create the kernel vmem arena and its per-domain children. 721 */ 722 void 723 kmem_init(vm_offset_t start, vm_offset_t end) 724 { 725 vm_map_t m; 726 int domain; 727 728 m = vm_map_create(kernel_pmap, VM_MIN_KERNEL_ADDRESS, end); 729 m->system_map = 1; 730 vm_map_lock(m); 731 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */ 732 kernel_map = m; 733 (void) vm_map_insert(m, NULL, (vm_ooffset_t) 0, 734 #ifdef __amd64__ 735 KERNBASE, 736 #else 737 VM_MIN_KERNEL_ADDRESS, 738 #endif 739 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 740 /* ... and ending with the completion of the above `insert' */ 741 vm_map_unlock(m); 742 743 /* 744 * Initialize the kernel_arena. This can grow on demand. 745 */ 746 vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0); 747 vmem_set_import(kernel_arena, kva_import, NULL, NULL, KVA_QUANTUM); 748 749 for (domain = 0; domain < vm_ndomains; domain++) { 750 /* 751 * Initialize the per-domain arenas. These are used to color 752 * the KVA space in a way that ensures that virtual large pages 753 * are backed by memory from the same physical domain, 754 * maximizing the potential for superpage promotion. 755 */ 756 vm_dom[domain].vmd_kernel_arena = vmem_create( 757 "kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 758 vmem_set_import(vm_dom[domain].vmd_kernel_arena, 759 kva_import_domain, NULL, kernel_arena, KVA_QUANTUM); 760 761 /* 762 * In architectures with superpages, maintain separate arenas 763 * for allocations with permissions that differ from the 764 * "standard" read/write permissions used for kernel memory, 765 * so as not to inhibit superpage promotion. 766 */ 767 #if VM_NRESERVLEVEL > 0 768 vm_dom[domain].vmd_kernel_rwx_arena = vmem_create( 769 "kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 770 vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena, 771 kva_import_domain, (vmem_release_t *)vmem_xfree, 772 kernel_arena, KVA_QUANTUM); 773 #endif 774 } 775 } 776 777 /* 778 * kmem_bootstrap_free: 779 * 780 * Free pages backing preloaded data (e.g., kernel modules) to the 781 * system. Currently only supported on platforms that create a 782 * vm_phys segment for preloaded data. 783 */ 784 void 785 kmem_bootstrap_free(vm_offset_t start, vm_size_t size) 786 { 787 #if defined(__i386__) || defined(__amd64__) 788 struct vm_domain *vmd; 789 vm_offset_t end, va; 790 vm_paddr_t pa; 791 vm_page_t m; 792 793 end = trunc_page(start + size); 794 start = round_page(start); 795 796 for (va = start; va < end; va += PAGE_SIZE) { 797 pa = pmap_kextract(va); 798 m = PHYS_TO_VM_PAGE(pa); 799 800 vmd = vm_pagequeue_domain(m); 801 vm_domain_free_lock(vmd); 802 vm_phys_free_pages(m, 0); 803 vmd->vmd_page_count++; 804 vm_domain_free_unlock(vmd); 805 806 vm_domain_freecnt_inc(vmd, 1); 807 vm_cnt.v_page_count++; 808 } 809 pmap_remove(kernel_pmap, start, end); 810 (void)vmem_add(kernel_arena, start, end - start, M_WAITOK); 811 #endif 812 } 813 814 #ifdef DIAGNOSTIC 815 /* 816 * Allow userspace to directly trigger the VM drain routine for testing 817 * purposes. 818 */ 819 static int 820 debug_vm_lowmem(SYSCTL_HANDLER_ARGS) 821 { 822 int error, i; 823 824 i = 0; 825 error = sysctl_handle_int(oidp, &i, 0, req); 826 if (error) 827 return (error); 828 if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0) 829 return (EINVAL); 830 if (i != 0) 831 EVENTHANDLER_INVOKE(vm_lowmem, i); 832 return (0); 833 } 834 835 SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, CTLTYPE_INT | CTLFLAG_RW, 0, 0, 836 debug_vm_lowmem, "I", "set to trigger vm_lowmem event with given flags"); 837 #endif 838