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/asan.h> 75 #include <sys/domainset.h> 76 #include <sys/eventhandler.h> 77 #include <sys/kernel.h> 78 #include <sys/lock.h> 79 #include <sys/malloc.h> 80 #include <sys/proc.h> 81 #include <sys/rwlock.h> 82 #include <sys/sysctl.h> 83 #include <sys/vmem.h> 84 #include <sys/vmmeter.h> 85 86 #include <vm/vm.h> 87 #include <vm/vm_param.h> 88 #include <vm/vm_domainset.h> 89 #include <vm/vm_kern.h> 90 #include <vm/pmap.h> 91 #include <vm/vm_map.h> 92 #include <vm/vm_object.h> 93 #include <vm/vm_page.h> 94 #include <vm/vm_pageout.h> 95 #include <vm/vm_pagequeue.h> 96 #include <vm/vm_phys.h> 97 #include <vm/vm_radix.h> 98 #include <vm/vm_extern.h> 99 #include <vm/uma.h> 100 101 struct vm_map kernel_map_store; 102 struct vm_map exec_map_store; 103 struct vm_map pipe_map_store; 104 105 const void *zero_region; 106 CTASSERT((ZERO_REGION_SIZE & PAGE_MASK) == 0); 107 108 /* NB: Used by kernel debuggers. */ 109 const u_long vm_maxuser_address = VM_MAXUSER_ADDRESS; 110 111 u_int exec_map_entry_size; 112 u_int exec_map_entries; 113 114 SYSCTL_ULONG(_vm, OID_AUTO, min_kernel_address, CTLFLAG_RD, 115 SYSCTL_NULL_ULONG_PTR, VM_MIN_KERNEL_ADDRESS, "Min kernel address"); 116 117 SYSCTL_ULONG(_vm, OID_AUTO, max_kernel_address, CTLFLAG_RD, 118 #if defined(__arm__) 119 &vm_max_kernel_address, 0, 120 #else 121 SYSCTL_NULL_ULONG_PTR, VM_MAX_KERNEL_ADDRESS, 122 #endif 123 "Max kernel address"); 124 125 #if VM_NRESERVLEVEL > 0 126 #define KVA_QUANTUM_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT) 127 #else 128 /* On non-superpage architectures we want large import sizes. */ 129 #define KVA_QUANTUM_SHIFT (8 + PAGE_SHIFT) 130 #endif 131 #define KVA_QUANTUM (1ul << KVA_QUANTUM_SHIFT) 132 #define KVA_NUMA_IMPORT_QUANTUM (KVA_QUANTUM * 128) 133 134 extern void uma_startup2(void); 135 136 /* 137 * kva_alloc: 138 * 139 * Allocate a virtual address range with no underlying object and 140 * no initial mapping to physical memory. Any mapping from this 141 * range to physical memory must be explicitly created prior to 142 * its use, typically with pmap_qenter(). Any attempt to create 143 * a mapping on demand through vm_fault() will result in a panic. 144 */ 145 vm_offset_t 146 kva_alloc(vm_size_t size) 147 { 148 vm_offset_t addr; 149 150 size = round_page(size); 151 if (vmem_alloc(kernel_arena, size, M_BESTFIT | M_NOWAIT, &addr)) 152 return (0); 153 154 return (addr); 155 } 156 157 /* 158 * kva_free: 159 * 160 * Release a region of kernel virtual memory allocated 161 * with kva_alloc, and return the physical pages 162 * associated with that region. 163 * 164 * This routine may not block on kernel maps. 165 */ 166 void 167 kva_free(vm_offset_t addr, vm_size_t size) 168 { 169 170 size = round_page(size); 171 vmem_free(kernel_arena, addr, size); 172 } 173 174 static vm_page_t 175 kmem_alloc_contig_pages(vm_object_t object, vm_pindex_t pindex, int domain, 176 int pflags, u_long npages, vm_paddr_t low, vm_paddr_t high, 177 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) 178 { 179 vm_page_t m; 180 int tries; 181 bool wait, reclaim; 182 183 VM_OBJECT_ASSERT_WLOCKED(object); 184 185 wait = (pflags & VM_ALLOC_WAITOK) != 0; 186 reclaim = (pflags & VM_ALLOC_NORECLAIM) == 0; 187 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 188 pflags |= VM_ALLOC_NOWAIT; 189 for (tries = wait ? 3 : 1;; tries--) { 190 m = vm_page_alloc_contig_domain(object, pindex, domain, pflags, 191 npages, low, high, alignment, boundary, memattr); 192 if (m != NULL || tries == 0 || !reclaim) 193 break; 194 195 VM_OBJECT_WUNLOCK(object); 196 if (!vm_page_reclaim_contig_domain(domain, pflags, npages, 197 low, high, alignment, boundary) && wait) 198 vm_wait_domain(domain); 199 VM_OBJECT_WLOCK(object); 200 } 201 return (m); 202 } 203 204 /* 205 * Allocates a region from the kernel address map and physical pages 206 * within the specified address range to the kernel object. Creates a 207 * wired mapping from this region to these pages, and returns the 208 * region's starting virtual address. The allocated pages are not 209 * necessarily physically contiguous. If M_ZERO is specified through the 210 * given flags, then the pages are zeroed before they are mapped. 211 */ 212 static vm_offset_t 213 kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 214 vm_paddr_t high, vm_memattr_t memattr) 215 { 216 vmem_t *vmem; 217 vm_object_t object; 218 vm_offset_t addr, i, offset; 219 vm_page_t m; 220 vm_size_t asize; 221 int pflags; 222 vm_prot_t prot; 223 224 object = kernel_object; 225 asize = round_page(size); 226 vmem = vm_dom[domain].vmd_kernel_arena; 227 if (vmem_alloc(vmem, asize, M_BESTFIT | flags, &addr)) 228 return (0); 229 offset = addr - VM_MIN_KERNEL_ADDRESS; 230 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 231 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 232 VM_OBJECT_WLOCK(object); 233 for (i = 0; i < asize; i += PAGE_SIZE) { 234 m = kmem_alloc_contig_pages(object, atop(offset + i), 235 domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr); 236 if (m == NULL) { 237 VM_OBJECT_WUNLOCK(object); 238 kmem_unback(object, addr, i); 239 vmem_free(vmem, addr, asize); 240 return (0); 241 } 242 KASSERT(vm_page_domain(m) == domain, 243 ("kmem_alloc_attr_domain: Domain mismatch %d != %d", 244 vm_page_domain(m), domain)); 245 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 246 pmap_zero_page(m); 247 vm_page_valid(m); 248 pmap_enter(kernel_pmap, addr + i, m, prot, 249 prot | PMAP_ENTER_WIRED, 0); 250 } 251 VM_OBJECT_WUNLOCK(object); 252 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE); 253 return (addr); 254 } 255 256 vm_offset_t 257 kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 258 vm_memattr_t memattr) 259 { 260 261 return (kmem_alloc_attr_domainset(DOMAINSET_RR(), size, flags, low, 262 high, memattr)); 263 } 264 265 vm_offset_t 266 kmem_alloc_attr_domainset(struct domainset *ds, vm_size_t size, int flags, 267 vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr) 268 { 269 struct vm_domainset_iter di; 270 vm_offset_t addr; 271 int domain; 272 273 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 274 do { 275 addr = kmem_alloc_attr_domain(domain, size, flags, low, high, 276 memattr); 277 if (addr != 0) 278 break; 279 } while (vm_domainset_iter_policy(&di, &domain) == 0); 280 281 return (addr); 282 } 283 284 /* 285 * Allocates a region from the kernel address map and physically 286 * contiguous pages within the specified address range to the kernel 287 * object. Creates a wired mapping from this region to these pages, and 288 * returns the region's starting virtual address. If M_ZERO is specified 289 * through the given flags, then the pages are zeroed before they are 290 * mapped. 291 */ 292 static vm_offset_t 293 kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 294 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 295 vm_memattr_t memattr) 296 { 297 vmem_t *vmem; 298 vm_object_t object; 299 vm_offset_t addr, offset, tmp; 300 vm_page_t end_m, m; 301 vm_size_t asize; 302 u_long npages; 303 int pflags; 304 305 object = kernel_object; 306 asize = round_page(size); 307 vmem = vm_dom[domain].vmd_kernel_arena; 308 if (vmem_alloc(vmem, asize, flags | M_BESTFIT, &addr)) 309 return (0); 310 offset = addr - VM_MIN_KERNEL_ADDRESS; 311 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 312 npages = atop(asize); 313 VM_OBJECT_WLOCK(object); 314 m = kmem_alloc_contig_pages(object, atop(offset), domain, 315 pflags, npages, low, high, alignment, boundary, memattr); 316 if (m == NULL) { 317 VM_OBJECT_WUNLOCK(object); 318 vmem_free(vmem, addr, asize); 319 return (0); 320 } 321 KASSERT(vm_page_domain(m) == domain, 322 ("kmem_alloc_contig_domain: Domain mismatch %d != %d", 323 vm_page_domain(m), domain)); 324 end_m = m + npages; 325 tmp = addr; 326 for (; m < end_m; m++) { 327 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 328 pmap_zero_page(m); 329 vm_page_valid(m); 330 pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW, 331 VM_PROT_RW | PMAP_ENTER_WIRED, 0); 332 tmp += PAGE_SIZE; 333 } 334 VM_OBJECT_WUNLOCK(object); 335 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE); 336 return (addr); 337 } 338 339 vm_offset_t 340 kmem_alloc_contig(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 341 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) 342 { 343 344 return (kmem_alloc_contig_domainset(DOMAINSET_RR(), size, flags, low, 345 high, alignment, boundary, memattr)); 346 } 347 348 vm_offset_t 349 kmem_alloc_contig_domainset(struct domainset *ds, vm_size_t size, int flags, 350 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 351 vm_memattr_t memattr) 352 { 353 struct vm_domainset_iter di; 354 vm_offset_t addr; 355 int domain; 356 357 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 358 do { 359 addr = kmem_alloc_contig_domain(domain, size, flags, low, high, 360 alignment, boundary, memattr); 361 if (addr != 0) 362 break; 363 } while (vm_domainset_iter_policy(&di, &domain) == 0); 364 365 return (addr); 366 } 367 368 /* 369 * kmem_subinit: 370 * 371 * Initializes a map to manage a subrange 372 * of the kernel virtual address space. 373 * 374 * Arguments are as follows: 375 * 376 * parent Map to take range from 377 * min, max Returned endpoints of map 378 * size Size of range to find 379 * superpage_align Request that min is superpage aligned 380 */ 381 void 382 kmem_subinit(vm_map_t map, vm_map_t parent, vm_offset_t *min, vm_offset_t *max, 383 vm_size_t size, bool superpage_align) 384 { 385 int ret; 386 387 size = round_page(size); 388 389 *min = vm_map_min(parent); 390 ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ? 391 VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL, 392 MAP_ACC_NO_CHARGE); 393 if (ret != KERN_SUCCESS) 394 panic("kmem_subinit: bad status return of %d", ret); 395 *max = *min + size; 396 vm_map_init(map, vm_map_pmap(parent), *min, *max); 397 if (vm_map_submap(parent, *min, *max, map) != KERN_SUCCESS) 398 panic("kmem_subinit: unable to change range to submap"); 399 } 400 401 /* 402 * kmem_malloc_domain: 403 * 404 * Allocate wired-down pages in the kernel's address space. 405 */ 406 static vm_offset_t 407 kmem_malloc_domain(int domain, vm_size_t size, int flags) 408 { 409 vmem_t *arena; 410 vm_offset_t addr; 411 vm_size_t asize; 412 int rv; 413 414 if (__predict_true((flags & M_EXEC) == 0)) 415 arena = vm_dom[domain].vmd_kernel_arena; 416 else 417 arena = vm_dom[domain].vmd_kernel_rwx_arena; 418 asize = round_page(size); 419 if (vmem_alloc(arena, asize, flags | M_BESTFIT, &addr)) 420 return (0); 421 422 rv = kmem_back_domain(domain, kernel_object, addr, asize, flags); 423 if (rv != KERN_SUCCESS) { 424 vmem_free(arena, addr, asize); 425 return (0); 426 } 427 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE); 428 return (addr); 429 } 430 431 vm_offset_t 432 kmem_malloc(vm_size_t size, int flags) 433 { 434 435 return (kmem_malloc_domainset(DOMAINSET_RR(), size, flags)); 436 } 437 438 vm_offset_t 439 kmem_malloc_domainset(struct domainset *ds, vm_size_t size, int flags) 440 { 441 struct vm_domainset_iter di; 442 vm_offset_t addr; 443 int domain; 444 445 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 446 do { 447 addr = kmem_malloc_domain(domain, size, flags); 448 if (addr != 0) 449 break; 450 } while (vm_domainset_iter_policy(&di, &domain) == 0); 451 452 return (addr); 453 } 454 455 /* 456 * kmem_back_domain: 457 * 458 * Allocate physical pages from the specified domain for the specified 459 * virtual address range. 460 */ 461 int 462 kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr, 463 vm_size_t size, int flags) 464 { 465 vm_offset_t offset, i; 466 vm_page_t m, mpred; 467 vm_prot_t prot; 468 int pflags; 469 470 KASSERT(object == kernel_object, 471 ("kmem_back_domain: only supports kernel object.")); 472 473 offset = addr - VM_MIN_KERNEL_ADDRESS; 474 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 475 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 476 if (flags & M_WAITOK) 477 pflags |= VM_ALLOC_WAITFAIL; 478 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 479 480 i = 0; 481 VM_OBJECT_WLOCK(object); 482 retry: 483 mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i)); 484 for (; i < size; i += PAGE_SIZE, mpred = m) { 485 m = vm_page_alloc_domain_after(object, atop(offset + i), 486 domain, pflags, mpred); 487 488 /* 489 * Ran out of space, free everything up and return. Don't need 490 * to lock page queues here as we know that the pages we got 491 * aren't on any queues. 492 */ 493 if (m == NULL) { 494 if ((flags & M_NOWAIT) == 0) 495 goto retry; 496 VM_OBJECT_WUNLOCK(object); 497 kmem_unback(object, addr, i); 498 return (KERN_NO_SPACE); 499 } 500 KASSERT(vm_page_domain(m) == domain, 501 ("kmem_back_domain: Domain mismatch %d != %d", 502 vm_page_domain(m), domain)); 503 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0) 504 pmap_zero_page(m); 505 KASSERT((m->oflags & VPO_UNMANAGED) != 0, 506 ("kmem_malloc: page %p is managed", m)); 507 vm_page_valid(m); 508 pmap_enter(kernel_pmap, addr + i, m, prot, 509 prot | PMAP_ENTER_WIRED, 0); 510 if (__predict_false((prot & VM_PROT_EXECUTE) != 0)) 511 m->oflags |= VPO_KMEM_EXEC; 512 } 513 VM_OBJECT_WUNLOCK(object); 514 515 return (KERN_SUCCESS); 516 } 517 518 /* 519 * kmem_back: 520 * 521 * Allocate physical pages for the specified virtual address range. 522 */ 523 int 524 kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags) 525 { 526 vm_offset_t end, next, start; 527 int domain, rv; 528 529 KASSERT(object == kernel_object, 530 ("kmem_back: only supports kernel object.")); 531 532 for (start = addr, end = addr + size; addr < end; addr = next) { 533 /* 534 * We must ensure that pages backing a given large virtual page 535 * all come from the same physical domain. 536 */ 537 if (vm_ndomains > 1) { 538 domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains; 539 while (VM_DOMAIN_EMPTY(domain)) 540 domain++; 541 next = roundup2(addr + 1, KVA_QUANTUM); 542 if (next > end || next < start) 543 next = end; 544 } else { 545 domain = 0; 546 next = end; 547 } 548 rv = kmem_back_domain(domain, object, addr, next - addr, flags); 549 if (rv != KERN_SUCCESS) { 550 kmem_unback(object, start, addr - start); 551 break; 552 } 553 } 554 return (rv); 555 } 556 557 /* 558 * kmem_unback: 559 * 560 * Unmap and free the physical pages underlying the specified virtual 561 * address range. 562 * 563 * A physical page must exist within the specified object at each index 564 * that is being unmapped. 565 */ 566 static struct vmem * 567 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 568 { 569 struct vmem *arena; 570 vm_page_t m, next; 571 vm_offset_t end, offset; 572 int domain; 573 574 KASSERT(object == kernel_object, 575 ("kmem_unback: only supports kernel object.")); 576 577 if (size == 0) 578 return (NULL); 579 pmap_remove(kernel_pmap, addr, addr + size); 580 offset = addr - VM_MIN_KERNEL_ADDRESS; 581 end = offset + size; 582 VM_OBJECT_WLOCK(object); 583 m = vm_page_lookup(object, atop(offset)); 584 domain = vm_page_domain(m); 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 for (; offset < end; offset += PAGE_SIZE, m = next) { 590 next = vm_page_next(m); 591 vm_page_xbusy_claim(m); 592 vm_page_unwire_noq(m); 593 vm_page_free(m); 594 } 595 VM_OBJECT_WUNLOCK(object); 596 597 return (arena); 598 } 599 600 void 601 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 602 { 603 604 (void)_kmem_unback(object, addr, size); 605 } 606 607 /* 608 * kmem_free: 609 * 610 * Free memory allocated with kmem_malloc. The size must match the 611 * original allocation. 612 */ 613 void 614 kmem_free(vm_offset_t addr, vm_size_t size) 615 { 616 struct vmem *arena; 617 618 size = round_page(size); 619 kasan_mark((void *)addr, size, size, 0); 620 arena = _kmem_unback(kernel_object, addr, size); 621 if (arena != NULL) 622 vmem_free(arena, addr, size); 623 } 624 625 /* 626 * kmap_alloc_wait: 627 * 628 * Allocates pageable memory from a sub-map of the kernel. If the submap 629 * has no room, the caller sleeps waiting for more memory in the submap. 630 * 631 * This routine may block. 632 */ 633 vm_offset_t 634 kmap_alloc_wait(vm_map_t map, vm_size_t size) 635 { 636 vm_offset_t addr; 637 638 size = round_page(size); 639 if (!swap_reserve(size)) 640 return (0); 641 642 for (;;) { 643 /* 644 * To make this work for more than one map, use the map's lock 645 * to lock out sleepers/wakers. 646 */ 647 vm_map_lock(map); 648 addr = vm_map_findspace(map, vm_map_min(map), size); 649 if (addr + size <= vm_map_max(map)) 650 break; 651 /* no space now; see if we can ever get space */ 652 if (vm_map_max(map) - vm_map_min(map) < size) { 653 vm_map_unlock(map); 654 swap_release(size); 655 return (0); 656 } 657 map->needs_wakeup = TRUE; 658 vm_map_unlock_and_wait(map, 0); 659 } 660 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_RW, VM_PROT_RW, 661 MAP_ACC_CHARGED); 662 vm_map_unlock(map); 663 return (addr); 664 } 665 666 /* 667 * kmap_free_wakeup: 668 * 669 * Returns memory to a submap of the kernel, and wakes up any processes 670 * waiting for memory in that map. 671 */ 672 void 673 kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size) 674 { 675 676 vm_map_lock(map); 677 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size)); 678 if (map->needs_wakeup) { 679 map->needs_wakeup = FALSE; 680 vm_map_wakeup(map); 681 } 682 vm_map_unlock(map); 683 } 684 685 void 686 kmem_init_zero_region(void) 687 { 688 vm_offset_t addr, i; 689 vm_page_t m; 690 691 /* 692 * Map a single physical page of zeros to a larger virtual range. 693 * This requires less looping in places that want large amounts of 694 * zeros, while not using much more physical resources. 695 */ 696 addr = kva_alloc(ZERO_REGION_SIZE); 697 m = vm_page_alloc_noobj(VM_ALLOC_WIRED | VM_ALLOC_ZERO); 698 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE) 699 pmap_qenter(addr + i, &m, 1); 700 pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ); 701 702 zero_region = (const void *)addr; 703 } 704 705 /* 706 * Import KVA from the kernel map into the kernel arena. 707 */ 708 static int 709 kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp) 710 { 711 vm_offset_t addr; 712 int result; 713 714 KASSERT((size % KVA_QUANTUM) == 0, 715 ("kva_import: Size %jd is not a multiple of %d", 716 (intmax_t)size, (int)KVA_QUANTUM)); 717 addr = vm_map_min(kernel_map); 718 result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0, 719 VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 720 if (result != KERN_SUCCESS) 721 return (ENOMEM); 722 723 *addrp = addr; 724 725 return (0); 726 } 727 728 /* 729 * Import KVA from a parent arena into a per-domain arena. Imports must be 730 * KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size. 731 */ 732 static int 733 kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp) 734 { 735 736 KASSERT((size % KVA_QUANTUM) == 0, 737 ("kva_import_domain: Size %jd is not a multiple of %d", 738 (intmax_t)size, (int)KVA_QUANTUM)); 739 return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN, 740 VMEM_ADDR_MAX, flags, addrp)); 741 } 742 743 /* 744 * kmem_init: 745 * 746 * Create the kernel map; insert a mapping covering kernel text, 747 * data, bss, and all space allocated thus far (`boostrap' data). The 748 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and 749 * `start' as allocated, and the range between `start' and `end' as free. 750 * Create the kernel vmem arena and its per-domain children. 751 */ 752 void 753 kmem_init(vm_offset_t start, vm_offset_t end) 754 { 755 vm_size_t quantum; 756 int domain; 757 758 vm_map_init(kernel_map, kernel_pmap, VM_MIN_KERNEL_ADDRESS, end); 759 kernel_map->system_map = 1; 760 vm_map_lock(kernel_map); 761 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */ 762 (void)vm_map_insert(kernel_map, NULL, 0, 763 #ifdef __amd64__ 764 KERNBASE, 765 #else 766 VM_MIN_KERNEL_ADDRESS, 767 #endif 768 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 769 /* ... and ending with the completion of the above `insert' */ 770 771 #ifdef __amd64__ 772 /* 773 * Mark KVA used for the page array as allocated. Other platforms 774 * that handle vm_page_array allocation can simply adjust virtual_avail 775 * instead. 776 */ 777 (void)vm_map_insert(kernel_map, NULL, 0, (vm_offset_t)vm_page_array, 778 (vm_offset_t)vm_page_array + round_2mpage(vm_page_array_size * 779 sizeof(struct vm_page)), 780 VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT); 781 #endif 782 vm_map_unlock(kernel_map); 783 784 /* 785 * Use a large import quantum on NUMA systems. This helps minimize 786 * interleaving of superpages, reducing internal fragmentation within 787 * the per-domain arenas. 788 */ 789 if (vm_ndomains > 1 && PMAP_HAS_DMAP) 790 quantum = KVA_NUMA_IMPORT_QUANTUM; 791 else 792 quantum = KVA_QUANTUM; 793 794 /* 795 * Initialize the kernel_arena. This can grow on demand. 796 */ 797 vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0); 798 vmem_set_import(kernel_arena, kva_import, NULL, NULL, quantum); 799 800 for (domain = 0; domain < vm_ndomains; domain++) { 801 /* 802 * Initialize the per-domain arenas. These are used to color 803 * the KVA space in a way that ensures that virtual large pages 804 * are backed by memory from the same physical domain, 805 * maximizing the potential for superpage promotion. 806 */ 807 vm_dom[domain].vmd_kernel_arena = vmem_create( 808 "kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 809 vmem_set_import(vm_dom[domain].vmd_kernel_arena, 810 kva_import_domain, NULL, kernel_arena, quantum); 811 812 /* 813 * In architectures with superpages, maintain separate arenas 814 * for allocations with permissions that differ from the 815 * "standard" read/write permissions used for kernel memory, 816 * so as not to inhibit superpage promotion. 817 * 818 * Use the base import quantum since this arena is rarely used. 819 */ 820 #if VM_NRESERVLEVEL > 0 821 vm_dom[domain].vmd_kernel_rwx_arena = vmem_create( 822 "kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 823 vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena, 824 kva_import_domain, (vmem_release_t *)vmem_xfree, 825 kernel_arena, KVA_QUANTUM); 826 #else 827 vm_dom[domain].vmd_kernel_rwx_arena = 828 vm_dom[domain].vmd_kernel_arena; 829 #endif 830 } 831 832 /* 833 * This must be the very first call so that the virtual address 834 * space used for early allocations is properly marked used in 835 * the map. 836 */ 837 uma_startup2(); 838 } 839 840 /* 841 * kmem_bootstrap_free: 842 * 843 * Free pages backing preloaded data (e.g., kernel modules) to the 844 * system. Currently only supported on platforms that create a 845 * vm_phys segment for preloaded data. 846 */ 847 void 848 kmem_bootstrap_free(vm_offset_t start, vm_size_t size) 849 { 850 #if defined(__i386__) || defined(__amd64__) 851 struct vm_domain *vmd; 852 vm_offset_t end, va; 853 vm_paddr_t pa; 854 vm_page_t m; 855 856 end = trunc_page(start + size); 857 start = round_page(start); 858 859 #ifdef __amd64__ 860 /* 861 * Preloaded files do not have execute permissions by default on amd64. 862 * Restore the default permissions to ensure that the direct map alias 863 * is updated. 864 */ 865 pmap_change_prot(start, end - start, VM_PROT_RW); 866 #endif 867 for (va = start; va < end; va += PAGE_SIZE) { 868 pa = pmap_kextract(va); 869 m = PHYS_TO_VM_PAGE(pa); 870 871 vmd = vm_pagequeue_domain(m); 872 vm_domain_free_lock(vmd); 873 vm_phys_free_pages(m, 0); 874 vm_domain_free_unlock(vmd); 875 876 vm_domain_freecnt_inc(vmd, 1); 877 vm_cnt.v_page_count++; 878 } 879 pmap_remove(kernel_pmap, start, end); 880 (void)vmem_add(kernel_arena, start, end - start, M_WAITOK); 881 #endif 882 } 883 884 /* 885 * Allow userspace to directly trigger the VM drain routine for testing 886 * purposes. 887 */ 888 static int 889 debug_vm_lowmem(SYSCTL_HANDLER_ARGS) 890 { 891 int error, i; 892 893 i = 0; 894 error = sysctl_handle_int(oidp, &i, 0, req); 895 if (error != 0) 896 return (error); 897 if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0) 898 return (EINVAL); 899 if (i != 0) 900 EVENTHANDLER_INVOKE(vm_lowmem, i); 901 return (0); 902 } 903 SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, 904 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, debug_vm_lowmem, "I", 905 "set to trigger vm_lowmem event with given flags"); 906 907 static int 908 debug_uma_reclaim(SYSCTL_HANDLER_ARGS) 909 { 910 int error, i; 911 912 i = 0; 913 error = sysctl_handle_int(oidp, &i, 0, req); 914 if (error != 0 || req->newptr == NULL) 915 return (error); 916 if (i != UMA_RECLAIM_TRIM && i != UMA_RECLAIM_DRAIN && 917 i != UMA_RECLAIM_DRAIN_CPU) 918 return (EINVAL); 919 uma_reclaim(i); 920 return (0); 921 } 922 SYSCTL_PROC(_debug, OID_AUTO, uma_reclaim, 923 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, debug_uma_reclaim, "I", 924 "set to generate request to reclaim uma caches"); 925 926 static int 927 debug_uma_reclaim_domain(SYSCTL_HANDLER_ARGS) 928 { 929 int domain, error, request; 930 931 request = 0; 932 error = sysctl_handle_int(oidp, &request, 0, req); 933 if (error != 0 || req->newptr == NULL) 934 return (error); 935 936 domain = request >> 4; 937 request &= 0xf; 938 if (request != UMA_RECLAIM_TRIM && request != UMA_RECLAIM_DRAIN && 939 request != UMA_RECLAIM_DRAIN_CPU) 940 return (EINVAL); 941 if (domain < 0 || domain >= vm_ndomains) 942 return (EINVAL); 943 uma_reclaim_domain(request, domain); 944 return (0); 945 } 946 SYSCTL_PROC(_debug, OID_AUTO, uma_reclaim_domain, 947 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, 948 debug_uma_reclaim_domain, "I", 949 ""); 950