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 we want large import sizes. */ 128 #define KVA_QUANTUM_SHIFT (8 + PAGE_SHIFT) 129 #endif 130 #define KVA_QUANTUM (1 << KVA_QUANTUM_SHIFT) 131 132 extern void uma_startup2(void); 133 134 /* 135 * kva_alloc: 136 * 137 * Allocate a virtual address range with no underlying object and 138 * no initial mapping to physical memory. Any mapping from this 139 * range to physical memory must be explicitly created prior to 140 * its use, typically with pmap_qenter(). Any attempt to create 141 * a mapping on demand through vm_fault() will result in a panic. 142 */ 143 vm_offset_t 144 kva_alloc(vm_size_t size) 145 { 146 vm_offset_t addr; 147 148 size = round_page(size); 149 if (vmem_alloc(kernel_arena, size, M_BESTFIT | M_NOWAIT, &addr)) 150 return (0); 151 152 return (addr); 153 } 154 155 /* 156 * kva_free: 157 * 158 * Release a region of kernel virtual memory allocated 159 * with kva_alloc, and return the physical pages 160 * associated with that region. 161 * 162 * This routine may not block on kernel maps. 163 */ 164 void 165 kva_free(vm_offset_t addr, vm_size_t size) 166 { 167 168 size = round_page(size); 169 vmem_free(kernel_arena, addr, size); 170 } 171 172 /* 173 * Allocates a region from the kernel address map and physical pages 174 * within the specified address range to the kernel object. Creates a 175 * wired mapping from this region to these pages, and returns the 176 * region's starting virtual address. The allocated pages are not 177 * necessarily physically contiguous. If M_ZERO is specified through the 178 * given flags, then the pages are zeroed before they are mapped. 179 */ 180 static vm_offset_t 181 kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 182 vm_paddr_t high, vm_memattr_t memattr) 183 { 184 vmem_t *vmem; 185 vm_object_t object = kernel_object; 186 vm_offset_t addr, i, offset; 187 vm_page_t m; 188 int pflags, tries; 189 vm_prot_t prot; 190 191 size = round_page(size); 192 vmem = vm_dom[domain].vmd_kernel_arena; 193 if (vmem_alloc(vmem, size, M_BESTFIT | flags, &addr)) 194 return (0); 195 offset = addr - VM_MIN_KERNEL_ADDRESS; 196 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 197 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 198 pflags |= VM_ALLOC_NOWAIT; 199 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 200 VM_OBJECT_WLOCK(object); 201 for (i = 0; i < size; i += PAGE_SIZE) { 202 tries = 0; 203 retry: 204 m = vm_page_alloc_contig_domain(object, atop(offset + i), 205 domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr); 206 if (m == NULL) { 207 VM_OBJECT_WUNLOCK(object); 208 if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) { 209 if (!vm_page_reclaim_contig_domain(domain, 210 pflags, 1, low, high, PAGE_SIZE, 0) && 211 (flags & M_WAITOK) != 0) 212 vm_wait_domain(domain); 213 VM_OBJECT_WLOCK(object); 214 tries++; 215 goto retry; 216 } 217 kmem_unback(object, addr, i); 218 vmem_free(vmem, addr, size); 219 return (0); 220 } 221 KASSERT(vm_phys_domain(m) == domain, 222 ("kmem_alloc_attr_domain: Domain mismatch %d != %d", 223 vm_phys_domain(m), domain)); 224 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 225 pmap_zero_page(m); 226 vm_page_valid(m); 227 vm_page_xunbusy(m); 228 pmap_enter(kernel_pmap, addr + i, m, prot, 229 prot | PMAP_ENTER_WIRED, 0); 230 } 231 VM_OBJECT_WUNLOCK(object); 232 return (addr); 233 } 234 235 vm_offset_t 236 kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 237 vm_memattr_t memattr) 238 { 239 240 return (kmem_alloc_attr_domainset(DOMAINSET_RR(), size, flags, low, 241 high, memattr)); 242 } 243 244 vm_offset_t 245 kmem_alloc_attr_domainset(struct domainset *ds, vm_size_t size, int flags, 246 vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr) 247 { 248 struct vm_domainset_iter di; 249 vm_offset_t addr; 250 int domain; 251 252 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 253 do { 254 addr = kmem_alloc_attr_domain(domain, size, flags, low, high, 255 memattr); 256 if (addr != 0) 257 break; 258 } while (vm_domainset_iter_policy(&di, &domain) == 0); 259 260 return (addr); 261 } 262 263 /* 264 * Allocates a region from the kernel address map and physically 265 * contiguous pages within the specified address range to the kernel 266 * object. Creates a wired mapping from this region to these pages, and 267 * returns the region's starting virtual address. If M_ZERO is specified 268 * through the given flags, then the pages are zeroed before they are 269 * mapped. 270 */ 271 static vm_offset_t 272 kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 273 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 274 vm_memattr_t memattr) 275 { 276 vmem_t *vmem; 277 vm_object_t object = kernel_object; 278 vm_offset_t addr, offset, tmp; 279 vm_page_t end_m, m; 280 u_long npages; 281 int pflags, tries; 282 283 size = round_page(size); 284 vmem = vm_dom[domain].vmd_kernel_arena; 285 if (vmem_alloc(vmem, size, flags | M_BESTFIT, &addr)) 286 return (0); 287 offset = addr - VM_MIN_KERNEL_ADDRESS; 288 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 289 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 290 pflags |= VM_ALLOC_NOWAIT; 291 npages = atop(size); 292 VM_OBJECT_WLOCK(object); 293 tries = 0; 294 retry: 295 m = vm_page_alloc_contig_domain(object, atop(offset), domain, pflags, 296 npages, low, high, alignment, boundary, memattr); 297 if (m == NULL) { 298 VM_OBJECT_WUNLOCK(object); 299 if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) { 300 if (!vm_page_reclaim_contig_domain(domain, pflags, 301 npages, low, high, alignment, boundary) && 302 (flags & M_WAITOK) != 0) 303 vm_wait_domain(domain); 304 VM_OBJECT_WLOCK(object); 305 tries++; 306 goto retry; 307 } 308 vmem_free(vmem, addr, size); 309 return (0); 310 } 311 KASSERT(vm_phys_domain(m) == domain, 312 ("kmem_alloc_contig_domain: Domain mismatch %d != %d", 313 vm_phys_domain(m), domain)); 314 end_m = m + npages; 315 tmp = addr; 316 for (; m < end_m; m++) { 317 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 318 pmap_zero_page(m); 319 vm_page_valid(m); 320 vm_page_xunbusy(m); 321 pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW, 322 VM_PROT_RW | PMAP_ENTER_WIRED, 0); 323 tmp += PAGE_SIZE; 324 } 325 VM_OBJECT_WUNLOCK(object); 326 return (addr); 327 } 328 329 vm_offset_t 330 kmem_alloc_contig(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 331 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) 332 { 333 334 return (kmem_alloc_contig_domainset(DOMAINSET_RR(), size, flags, low, 335 high, alignment, boundary, memattr)); 336 } 337 338 vm_offset_t 339 kmem_alloc_contig_domainset(struct domainset *ds, vm_size_t size, int flags, 340 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 341 vm_memattr_t memattr) 342 { 343 struct vm_domainset_iter di; 344 vm_offset_t addr; 345 int domain; 346 347 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 348 do { 349 addr = kmem_alloc_contig_domain(domain, size, flags, low, high, 350 alignment, boundary, memattr); 351 if (addr != 0) 352 break; 353 } while (vm_domainset_iter_policy(&di, &domain) == 0); 354 355 return (addr); 356 } 357 358 /* 359 * kmem_suballoc: 360 * 361 * Allocates a map to manage a subrange 362 * of the kernel virtual address space. 363 * 364 * Arguments are as follows: 365 * 366 * parent Map to take range from 367 * min, max Returned endpoints of map 368 * size Size of range to find 369 * superpage_align Request that min is superpage aligned 370 */ 371 vm_map_t 372 kmem_suballoc(vm_map_t parent, vm_offset_t *min, vm_offset_t *max, 373 vm_size_t size, boolean_t superpage_align) 374 { 375 int ret; 376 vm_map_t result; 377 378 size = round_page(size); 379 380 *min = vm_map_min(parent); 381 ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ? 382 VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL, 383 MAP_ACC_NO_CHARGE); 384 if (ret != KERN_SUCCESS) 385 panic("kmem_suballoc: bad status return of %d", ret); 386 *max = *min + size; 387 result = vm_map_create(vm_map_pmap(parent), *min, *max); 388 if (result == NULL) 389 panic("kmem_suballoc: cannot create submap"); 390 if (vm_map_submap(parent, *min, *max, result) != KERN_SUCCESS) 391 panic("kmem_suballoc: unable to change range to submap"); 392 return (result); 393 } 394 395 /* 396 * kmem_malloc_domain: 397 * 398 * Allocate wired-down pages in the kernel's address space. 399 */ 400 static vm_offset_t 401 kmem_malloc_domain(int domain, vm_size_t size, int flags) 402 { 403 vmem_t *arena; 404 vm_offset_t addr; 405 int rv; 406 407 #if VM_NRESERVLEVEL > 0 408 if (__predict_true((flags & M_EXEC) == 0)) 409 arena = vm_dom[domain].vmd_kernel_arena; 410 else 411 arena = vm_dom[domain].vmd_kernel_rwx_arena; 412 #else 413 arena = vm_dom[domain].vmd_kernel_arena; 414 #endif 415 size = round_page(size); 416 if (vmem_alloc(arena, size, flags | M_BESTFIT, &addr)) 417 return (0); 418 419 rv = kmem_back_domain(domain, kernel_object, addr, size, flags); 420 if (rv != KERN_SUCCESS) { 421 vmem_free(arena, addr, size); 422 return (0); 423 } 424 return (addr); 425 } 426 427 vm_offset_t 428 kmem_malloc(vm_size_t size, int flags) 429 { 430 431 return (kmem_malloc_domainset(DOMAINSET_RR(), size, flags)); 432 } 433 434 vm_offset_t 435 kmem_malloc_domainset(struct domainset *ds, vm_size_t size, int flags) 436 { 437 struct vm_domainset_iter di; 438 vm_offset_t addr; 439 int domain; 440 441 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 442 do { 443 addr = kmem_malloc_domain(domain, size, flags); 444 if (addr != 0) 445 break; 446 } while (vm_domainset_iter_policy(&di, &domain) == 0); 447 448 return (addr); 449 } 450 451 /* 452 * kmem_back_domain: 453 * 454 * Allocate physical pages from the specified domain for the specified 455 * virtual address range. 456 */ 457 int 458 kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr, 459 vm_size_t size, int flags) 460 { 461 vm_offset_t offset, i; 462 vm_page_t m, mpred; 463 vm_prot_t prot; 464 int pflags; 465 466 KASSERT(object == kernel_object, 467 ("kmem_back_domain: only supports kernel object.")); 468 469 offset = addr - VM_MIN_KERNEL_ADDRESS; 470 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 471 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 472 if (flags & M_WAITOK) 473 pflags |= VM_ALLOC_WAITFAIL; 474 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 475 476 i = 0; 477 VM_OBJECT_WLOCK(object); 478 retry: 479 mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i)); 480 for (; i < size; i += PAGE_SIZE, mpred = m) { 481 m = vm_page_alloc_domain_after(object, atop(offset + i), 482 domain, pflags, mpred); 483 484 /* 485 * Ran out of space, free everything up and return. Don't need 486 * to lock page queues here as we know that the pages we got 487 * aren't on any queues. 488 */ 489 if (m == NULL) { 490 if ((flags & M_NOWAIT) == 0) 491 goto retry; 492 VM_OBJECT_WUNLOCK(object); 493 kmem_unback(object, addr, i); 494 return (KERN_NO_SPACE); 495 } 496 KASSERT(vm_phys_domain(m) == domain, 497 ("kmem_back_domain: Domain mismatch %d != %d", 498 vm_phys_domain(m), domain)); 499 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0) 500 pmap_zero_page(m); 501 KASSERT((m->oflags & VPO_UNMANAGED) != 0, 502 ("kmem_malloc: page %p is managed", m)); 503 vm_page_valid(m); 504 vm_page_xunbusy(m); 505 pmap_enter(kernel_pmap, addr + i, m, prot, 506 prot | PMAP_ENTER_WIRED, 0); 507 #if VM_NRESERVLEVEL > 0 508 if (__predict_false((prot & VM_PROT_EXECUTE) != 0)) 509 m->oflags |= VPO_KMEM_EXEC; 510 #endif 511 } 512 VM_OBJECT_WUNLOCK(object); 513 514 return (KERN_SUCCESS); 515 } 516 517 /* 518 * kmem_back: 519 * 520 * Allocate physical pages for the specified virtual address range. 521 */ 522 int 523 kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags) 524 { 525 vm_offset_t end, next, start; 526 int domain, rv; 527 528 KASSERT(object == kernel_object, 529 ("kmem_back: only supports kernel object.")); 530 531 for (start = addr, end = addr + size; addr < end; addr = next) { 532 /* 533 * We must ensure that pages backing a given large virtual page 534 * all come from the same physical domain. 535 */ 536 if (vm_ndomains > 1) { 537 domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains; 538 while (VM_DOMAIN_EMPTY(domain)) 539 domain++; 540 next = roundup2(addr + 1, KVA_QUANTUM); 541 if (next > end || next < start) 542 next = end; 543 } else { 544 domain = 0; 545 next = end; 546 } 547 rv = kmem_back_domain(domain, object, addr, next - addr, flags); 548 if (rv != KERN_SUCCESS) { 549 kmem_unback(object, start, addr - start); 550 break; 551 } 552 } 553 return (rv); 554 } 555 556 /* 557 * kmem_unback: 558 * 559 * Unmap and free the physical pages underlying the specified virtual 560 * address range. 561 * 562 * A physical page must exist within the specified object at each index 563 * that is being unmapped. 564 */ 565 static struct vmem * 566 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 567 { 568 struct vmem *arena; 569 vm_page_t m, next; 570 vm_offset_t end, offset; 571 int domain; 572 573 KASSERT(object == kernel_object, 574 ("kmem_unback: only supports kernel object.")); 575 576 if (size == 0) 577 return (NULL); 578 pmap_remove(kernel_pmap, addr, addr + size); 579 offset = addr - VM_MIN_KERNEL_ADDRESS; 580 end = offset + size; 581 VM_OBJECT_WLOCK(object); 582 m = vm_page_lookup(object, atop(offset)); 583 domain = vm_phys_domain(m); 584 #if VM_NRESERVLEVEL > 0 585 if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0)) 586 arena = vm_dom[domain].vmd_kernel_arena; 587 else 588 arena = vm_dom[domain].vmd_kernel_rwx_arena; 589 #else 590 arena = vm_dom[domain].vmd_kernel_arena; 591 #endif 592 for (; offset < end; offset += PAGE_SIZE, m = next) { 593 next = vm_page_next(m); 594 vm_page_busy_acquire(m, 0); 595 vm_page_unwire_noq(m); 596 vm_page_free(m); 597 } 598 VM_OBJECT_WUNLOCK(object); 599 600 return (arena); 601 } 602 603 void 604 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 605 { 606 607 (void)_kmem_unback(object, addr, size); 608 } 609 610 /* 611 * kmem_free: 612 * 613 * Free memory allocated with kmem_malloc. The size must match the 614 * original allocation. 615 */ 616 void 617 kmem_free(vm_offset_t addr, vm_size_t size) 618 { 619 struct vmem *arena; 620 621 size = round_page(size); 622 arena = _kmem_unback(kernel_object, addr, size); 623 if (arena != NULL) 624 vmem_free(arena, addr, size); 625 } 626 627 /* 628 * kmap_alloc_wait: 629 * 630 * Allocates pageable memory from a sub-map of the kernel. If the submap 631 * has no room, the caller sleeps waiting for more memory in the submap. 632 * 633 * This routine may block. 634 */ 635 vm_offset_t 636 kmap_alloc_wait(vm_map_t map, vm_size_t size) 637 { 638 vm_offset_t addr; 639 640 size = round_page(size); 641 if (!swap_reserve(size)) 642 return (0); 643 644 for (;;) { 645 /* 646 * To make this work for more than one map, use the map's lock 647 * to lock out sleepers/wakers. 648 */ 649 vm_map_lock(map); 650 addr = vm_map_findspace(map, vm_map_min(map), size); 651 if (addr + size <= vm_map_max(map)) 652 break; 653 /* no space now; see if we can ever get space */ 654 if (vm_map_max(map) - vm_map_min(map) < size) { 655 vm_map_unlock(map); 656 swap_release(size); 657 return (0); 658 } 659 map->needs_wakeup = TRUE; 660 vm_map_unlock_and_wait(map, 0); 661 } 662 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_RW, VM_PROT_RW, 663 MAP_ACC_CHARGED); 664 vm_map_unlock(map); 665 return (addr); 666 } 667 668 /* 669 * kmap_free_wakeup: 670 * 671 * Returns memory to a submap of the kernel, and wakes up any processes 672 * waiting for memory in that map. 673 */ 674 void 675 kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size) 676 { 677 678 vm_map_lock(map); 679 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size)); 680 if (map->needs_wakeup) { 681 map->needs_wakeup = FALSE; 682 vm_map_wakeup(map); 683 } 684 vm_map_unlock(map); 685 } 686 687 void 688 kmem_init_zero_region(void) 689 { 690 vm_offset_t addr, i; 691 vm_page_t m; 692 693 /* 694 * Map a single physical page of zeros to a larger virtual range. 695 * This requires less looping in places that want large amounts of 696 * zeros, while not using much more physical resources. 697 */ 698 addr = kva_alloc(ZERO_REGION_SIZE); 699 m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL | 700 VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO); 701 if ((m->flags & PG_ZERO) == 0) 702 pmap_zero_page(m); 703 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE) 704 pmap_qenter(addr + i, &m, 1); 705 pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ); 706 707 zero_region = (const void *)addr; 708 } 709 710 /* 711 * Import KVA from the kernel map into the kernel arena. 712 */ 713 static int 714 kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp) 715 { 716 vm_offset_t addr; 717 int result; 718 719 KASSERT((size % KVA_QUANTUM) == 0, 720 ("kva_import: Size %jd is not a multiple of %d", 721 (intmax_t)size, (int)KVA_QUANTUM)); 722 addr = vm_map_min(kernel_map); 723 result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0, 724 VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 725 if (result != KERN_SUCCESS) 726 return (ENOMEM); 727 728 *addrp = addr; 729 730 return (0); 731 } 732 733 /* 734 * Import KVA from a parent arena into a per-domain arena. Imports must be 735 * KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size. 736 */ 737 static int 738 kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp) 739 { 740 741 KASSERT((size % KVA_QUANTUM) == 0, 742 ("kva_import_domain: Size %jd is not a multiple of %d", 743 (intmax_t)size, (int)KVA_QUANTUM)); 744 return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN, 745 VMEM_ADDR_MAX, flags, addrp)); 746 } 747 748 /* 749 * kmem_init: 750 * 751 * Create the kernel map; insert a mapping covering kernel text, 752 * data, bss, and all space allocated thus far (`boostrap' data). The 753 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and 754 * `start' as allocated, and the range between `start' and `end' as free. 755 * Create the kernel vmem arena and its per-domain children. 756 */ 757 void 758 kmem_init(vm_offset_t start, vm_offset_t end) 759 { 760 vm_map_t m; 761 int domain; 762 763 m = vm_map_create(kernel_pmap, VM_MIN_KERNEL_ADDRESS, end); 764 m->system_map = 1; 765 vm_map_lock(m); 766 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */ 767 kernel_map = m; 768 (void)vm_map_insert(m, NULL, 0, 769 #ifdef __amd64__ 770 KERNBASE, 771 #else 772 VM_MIN_KERNEL_ADDRESS, 773 #endif 774 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 775 /* ... and ending with the completion of the above `insert' */ 776 777 #ifdef __amd64__ 778 /* 779 * Mark KVA used for the page array as allocated. Other platforms 780 * that handle vm_page_array allocation can simply adjust virtual_avail 781 * instead. 782 */ 783 (void)vm_map_insert(m, NULL, 0, (vm_offset_t)vm_page_array, 784 (vm_offset_t)vm_page_array + round_2mpage(vm_page_array_size * 785 sizeof(struct vm_page)), 786 VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT); 787 #endif 788 vm_map_unlock(m); 789 790 /* 791 * Initialize the kernel_arena. This can grow on demand. 792 */ 793 vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0); 794 vmem_set_import(kernel_arena, kva_import, NULL, NULL, KVA_QUANTUM); 795 796 for (domain = 0; domain < vm_ndomains; domain++) { 797 /* 798 * Initialize the per-domain arenas. These are used to color 799 * the KVA space in a way that ensures that virtual large pages 800 * are backed by memory from the same physical domain, 801 * maximizing the potential for superpage promotion. 802 */ 803 vm_dom[domain].vmd_kernel_arena = vmem_create( 804 "kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 805 vmem_set_import(vm_dom[domain].vmd_kernel_arena, 806 kva_import_domain, NULL, kernel_arena, KVA_QUANTUM); 807 808 /* 809 * In architectures with superpages, maintain separate arenas 810 * for allocations with permissions that differ from the 811 * "standard" read/write permissions used for kernel memory, 812 * so as not to inhibit superpage promotion. 813 */ 814 #if VM_NRESERVLEVEL > 0 815 vm_dom[domain].vmd_kernel_rwx_arena = vmem_create( 816 "kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 817 vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena, 818 kva_import_domain, (vmem_release_t *)vmem_xfree, 819 kernel_arena, KVA_QUANTUM); 820 #endif 821 } 822 823 /* 824 * This must be the very first call so that the virtual address 825 * space used for early allocations is properly marked used in 826 * the map. 827 */ 828 uma_startup2(); 829 } 830 831 /* 832 * kmem_bootstrap_free: 833 * 834 * Free pages backing preloaded data (e.g., kernel modules) to the 835 * system. Currently only supported on platforms that create a 836 * vm_phys segment for preloaded data. 837 */ 838 void 839 kmem_bootstrap_free(vm_offset_t start, vm_size_t size) 840 { 841 #if defined(__i386__) || defined(__amd64__) 842 struct vm_domain *vmd; 843 vm_offset_t end, va; 844 vm_paddr_t pa; 845 vm_page_t m; 846 847 end = trunc_page(start + size); 848 start = round_page(start); 849 850 #ifdef __amd64__ 851 /* 852 * Preloaded files do not have execute permissions by default on amd64. 853 * Restore the default permissions to ensure that the direct map alias 854 * is updated. 855 */ 856 pmap_change_prot(start, end - start, VM_PROT_RW); 857 #endif 858 for (va = start; va < end; va += PAGE_SIZE) { 859 pa = pmap_kextract(va); 860 m = PHYS_TO_VM_PAGE(pa); 861 862 vmd = vm_pagequeue_domain(m); 863 vm_domain_free_lock(vmd); 864 vm_phys_free_pages(m, 0); 865 vm_domain_free_unlock(vmd); 866 867 vm_domain_freecnt_inc(vmd, 1); 868 vm_cnt.v_page_count++; 869 } 870 pmap_remove(kernel_pmap, start, end); 871 (void)vmem_add(kernel_arena, start, end - start, M_WAITOK); 872 #endif 873 } 874 875 /* 876 * Allow userspace to directly trigger the VM drain routine for testing 877 * purposes. 878 */ 879 static int 880 debug_vm_lowmem(SYSCTL_HANDLER_ARGS) 881 { 882 int error, i; 883 884 i = 0; 885 error = sysctl_handle_int(oidp, &i, 0, req); 886 if (error) 887 return (error); 888 if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0) 889 return (EINVAL); 890 if (i != 0) 891 EVENTHANDLER_INVOKE(vm_lowmem, i); 892 return (0); 893 } 894 895 SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, 896 debug_vm_lowmem, "I", "set to trigger vm_lowmem event with given flags"); 897