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/msan.h> 81 #include <sys/proc.h> 82 #include <sys/rwlock.h> 83 #include <sys/sysctl.h> 84 #include <sys/vmem.h> 85 #include <sys/vmmeter.h> 86 87 #include <vm/vm.h> 88 #include <vm/vm_param.h> 89 #include <vm/vm_domainset.h> 90 #include <vm/vm_kern.h> 91 #include <vm/pmap.h> 92 #include <vm/vm_map.h> 93 #include <vm/vm_object.h> 94 #include <vm/vm_page.h> 95 #include <vm/vm_pageout.h> 96 #include <vm/vm_pagequeue.h> 97 #include <vm/vm_phys.h> 98 #include <vm/vm_radix.h> 99 #include <vm/vm_extern.h> 100 #include <vm/uma.h> 101 102 struct vm_map kernel_map_store; 103 struct vm_map exec_map_store; 104 struct vm_map pipe_map_store; 105 106 const void *zero_region; 107 CTASSERT((ZERO_REGION_SIZE & PAGE_MASK) == 0); 108 109 /* NB: Used by kernel debuggers. */ 110 const u_long vm_maxuser_address = VM_MAXUSER_ADDRESS; 111 112 u_int exec_map_entry_size; 113 u_int exec_map_entries; 114 115 SYSCTL_ULONG(_vm, OID_AUTO, min_kernel_address, CTLFLAG_RD, 116 SYSCTL_NULL_ULONG_PTR, VM_MIN_KERNEL_ADDRESS, "Min kernel address"); 117 118 SYSCTL_ULONG(_vm, OID_AUTO, max_kernel_address, CTLFLAG_RD, 119 #if defined(__arm__) 120 &vm_max_kernel_address, 0, 121 #else 122 SYSCTL_NULL_ULONG_PTR, VM_MAX_KERNEL_ADDRESS, 123 #endif 124 "Max kernel address"); 125 126 #if VM_NRESERVLEVEL > 0 127 #define KVA_QUANTUM_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT) 128 #else 129 /* On non-superpage architectures we want large import sizes. */ 130 #define KVA_QUANTUM_SHIFT (8 + PAGE_SHIFT) 131 #endif 132 #define KVA_QUANTUM (1ul << KVA_QUANTUM_SHIFT) 133 #define KVA_NUMA_IMPORT_QUANTUM (KVA_QUANTUM * 128) 134 135 extern void uma_startup2(void); 136 137 /* 138 * kva_alloc: 139 * 140 * Allocate a virtual address range with no underlying object and 141 * no initial mapping to physical memory. Any mapping from this 142 * range to physical memory must be explicitly created prior to 143 * its use, typically with pmap_qenter(). Any attempt to create 144 * a mapping on demand through vm_fault() will result in a panic. 145 */ 146 vm_offset_t 147 kva_alloc(vm_size_t size) 148 { 149 vm_offset_t addr; 150 151 size = round_page(size); 152 if (vmem_alloc(kernel_arena, size, M_BESTFIT | M_NOWAIT, &addr)) 153 return (0); 154 155 return (addr); 156 } 157 158 /* 159 * kva_free: 160 * 161 * Release a region of kernel virtual memory allocated 162 * with kva_alloc, and return the physical pages 163 * associated with that region. 164 * 165 * This routine may not block on kernel maps. 166 */ 167 void 168 kva_free(vm_offset_t addr, vm_size_t size) 169 { 170 171 size = round_page(size); 172 vmem_free(kernel_arena, addr, size); 173 } 174 175 /* 176 * Update sanitizer shadow state to reflect a new allocation. Force inlining to 177 * help make KMSAN origin tracking more precise. 178 */ 179 static __always_inline void 180 kmem_alloc_san(vm_offset_t addr, vm_size_t size, vm_size_t asize, int flags) 181 { 182 if ((flags & M_ZERO) == 0) { 183 kmsan_mark((void *)addr, asize, KMSAN_STATE_UNINIT); 184 kmsan_orig((void *)addr, asize, KMSAN_TYPE_KMEM, 185 KMSAN_RET_ADDR); 186 } else { 187 kmsan_mark((void *)addr, asize, KMSAN_STATE_INITED); 188 } 189 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE); 190 } 191 192 static vm_page_t 193 kmem_alloc_contig_pages(vm_object_t object, vm_pindex_t pindex, int domain, 194 int pflags, u_long npages, vm_paddr_t low, vm_paddr_t high, 195 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) 196 { 197 vm_page_t m; 198 int tries; 199 bool wait, reclaim; 200 201 VM_OBJECT_ASSERT_WLOCKED(object); 202 203 wait = (pflags & VM_ALLOC_WAITOK) != 0; 204 reclaim = (pflags & VM_ALLOC_NORECLAIM) == 0; 205 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 206 pflags |= VM_ALLOC_NOWAIT; 207 for (tries = wait ? 3 : 1;; tries--) { 208 m = vm_page_alloc_contig_domain(object, pindex, domain, pflags, 209 npages, low, high, alignment, boundary, memattr); 210 if (m != NULL || tries == 0 || !reclaim) 211 break; 212 213 VM_OBJECT_WUNLOCK(object); 214 if (!vm_page_reclaim_contig_domain(domain, pflags, npages, 215 low, high, alignment, boundary) && wait) 216 vm_wait_domain(domain); 217 VM_OBJECT_WLOCK(object); 218 } 219 return (m); 220 } 221 222 /* 223 * Allocates a region from the kernel address map and physical pages 224 * within the specified address range to the kernel object. Creates a 225 * wired mapping from this region to these pages, and returns the 226 * region's starting virtual address. The allocated pages are not 227 * necessarily physically contiguous. If M_ZERO is specified through the 228 * given flags, then the pages are zeroed before they are mapped. 229 */ 230 static vm_offset_t 231 kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 232 vm_paddr_t high, vm_memattr_t memattr) 233 { 234 vmem_t *vmem; 235 vm_object_t object; 236 vm_offset_t addr, i, offset; 237 vm_page_t m; 238 vm_size_t asize; 239 int pflags; 240 vm_prot_t prot; 241 242 object = kernel_object; 243 asize = round_page(size); 244 vmem = vm_dom[domain].vmd_kernel_arena; 245 if (vmem_alloc(vmem, asize, M_BESTFIT | flags, &addr)) 246 return (0); 247 offset = addr - VM_MIN_KERNEL_ADDRESS; 248 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 249 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 250 VM_OBJECT_WLOCK(object); 251 for (i = 0; i < asize; i += PAGE_SIZE) { 252 m = kmem_alloc_contig_pages(object, atop(offset + i), 253 domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr); 254 if (m == NULL) { 255 VM_OBJECT_WUNLOCK(object); 256 kmem_unback(object, addr, i); 257 vmem_free(vmem, addr, asize); 258 return (0); 259 } 260 KASSERT(vm_page_domain(m) == domain, 261 ("kmem_alloc_attr_domain: Domain mismatch %d != %d", 262 vm_page_domain(m), domain)); 263 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 264 pmap_zero_page(m); 265 vm_page_valid(m); 266 pmap_enter(kernel_pmap, addr + i, m, prot, 267 prot | PMAP_ENTER_WIRED, 0); 268 } 269 VM_OBJECT_WUNLOCK(object); 270 kmem_alloc_san(addr, size, asize, flags); 271 return (addr); 272 } 273 274 vm_offset_t 275 kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 276 vm_memattr_t memattr) 277 { 278 279 return (kmem_alloc_attr_domainset(DOMAINSET_RR(), size, flags, low, 280 high, memattr)); 281 } 282 283 vm_offset_t 284 kmem_alloc_attr_domainset(struct domainset *ds, vm_size_t size, int flags, 285 vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr) 286 { 287 struct vm_domainset_iter di; 288 vm_offset_t addr; 289 int domain; 290 291 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 292 do { 293 addr = kmem_alloc_attr_domain(domain, size, flags, low, high, 294 memattr); 295 if (addr != 0) 296 break; 297 } while (vm_domainset_iter_policy(&di, &domain) == 0); 298 299 return (addr); 300 } 301 302 /* 303 * Allocates a region from the kernel address map and physically 304 * contiguous pages within the specified address range to the kernel 305 * object. Creates a wired mapping from this region to these pages, and 306 * returns the region's starting virtual address. If M_ZERO is specified 307 * through the given flags, then the pages are zeroed before they are 308 * mapped. 309 */ 310 static vm_offset_t 311 kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 312 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 313 vm_memattr_t memattr) 314 { 315 vmem_t *vmem; 316 vm_object_t object; 317 vm_offset_t addr, offset, tmp; 318 vm_page_t end_m, m; 319 vm_size_t asize; 320 u_long npages; 321 int pflags; 322 323 object = kernel_object; 324 asize = round_page(size); 325 vmem = vm_dom[domain].vmd_kernel_arena; 326 if (vmem_alloc(vmem, asize, flags | M_BESTFIT, &addr)) 327 return (0); 328 offset = addr - VM_MIN_KERNEL_ADDRESS; 329 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 330 npages = atop(asize); 331 VM_OBJECT_WLOCK(object); 332 m = kmem_alloc_contig_pages(object, atop(offset), domain, 333 pflags, npages, low, high, alignment, boundary, memattr); 334 if (m == NULL) { 335 VM_OBJECT_WUNLOCK(object); 336 vmem_free(vmem, addr, asize); 337 return (0); 338 } 339 KASSERT(vm_page_domain(m) == domain, 340 ("kmem_alloc_contig_domain: Domain mismatch %d != %d", 341 vm_page_domain(m), domain)); 342 end_m = m + npages; 343 tmp = addr; 344 for (; m < end_m; m++) { 345 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 346 pmap_zero_page(m); 347 vm_page_valid(m); 348 pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW, 349 VM_PROT_RW | PMAP_ENTER_WIRED, 0); 350 tmp += PAGE_SIZE; 351 } 352 VM_OBJECT_WUNLOCK(object); 353 kmem_alloc_san(addr, size, asize, flags); 354 return (addr); 355 } 356 357 vm_offset_t 358 kmem_alloc_contig(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 359 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) 360 { 361 362 return (kmem_alloc_contig_domainset(DOMAINSET_RR(), size, flags, low, 363 high, alignment, boundary, memattr)); 364 } 365 366 vm_offset_t 367 kmem_alloc_contig_domainset(struct domainset *ds, vm_size_t size, int flags, 368 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 369 vm_memattr_t memattr) 370 { 371 struct vm_domainset_iter di; 372 vm_offset_t addr; 373 int domain; 374 375 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 376 do { 377 addr = kmem_alloc_contig_domain(domain, size, flags, low, high, 378 alignment, boundary, memattr); 379 if (addr != 0) 380 break; 381 } while (vm_domainset_iter_policy(&di, &domain) == 0); 382 383 return (addr); 384 } 385 386 /* 387 * kmem_subinit: 388 * 389 * Initializes a map to manage a subrange 390 * of the kernel virtual address space. 391 * 392 * Arguments are as follows: 393 * 394 * parent Map to take range from 395 * min, max Returned endpoints of map 396 * size Size of range to find 397 * superpage_align Request that min is superpage aligned 398 */ 399 void 400 kmem_subinit(vm_map_t map, vm_map_t parent, vm_offset_t *min, vm_offset_t *max, 401 vm_size_t size, bool superpage_align) 402 { 403 int ret; 404 405 size = round_page(size); 406 407 *min = vm_map_min(parent); 408 ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ? 409 VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL, 410 MAP_ACC_NO_CHARGE); 411 if (ret != KERN_SUCCESS) 412 panic("kmem_subinit: bad status return of %d", ret); 413 *max = *min + size; 414 vm_map_init(map, vm_map_pmap(parent), *min, *max); 415 if (vm_map_submap(parent, *min, *max, map) != KERN_SUCCESS) 416 panic("kmem_subinit: unable to change range to submap"); 417 } 418 419 /* 420 * kmem_malloc_domain: 421 * 422 * Allocate wired-down pages in the kernel's address space. 423 */ 424 static vm_offset_t 425 kmem_malloc_domain(int domain, vm_size_t size, int flags) 426 { 427 vmem_t *arena; 428 vm_offset_t addr; 429 vm_size_t asize; 430 int rv; 431 432 if (__predict_true((flags & M_EXEC) == 0)) 433 arena = vm_dom[domain].vmd_kernel_arena; 434 else 435 arena = vm_dom[domain].vmd_kernel_rwx_arena; 436 asize = round_page(size); 437 if (vmem_alloc(arena, asize, flags | M_BESTFIT, &addr)) 438 return (0); 439 440 rv = kmem_back_domain(domain, kernel_object, addr, asize, flags); 441 if (rv != KERN_SUCCESS) { 442 vmem_free(arena, addr, asize); 443 return (0); 444 } 445 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE); 446 return (addr); 447 } 448 449 vm_offset_t 450 kmem_malloc(vm_size_t size, int flags) 451 { 452 453 return (kmem_malloc_domainset(DOMAINSET_RR(), size, flags)); 454 } 455 456 vm_offset_t 457 kmem_malloc_domainset(struct domainset *ds, vm_size_t size, int flags) 458 { 459 struct vm_domainset_iter di; 460 vm_offset_t addr; 461 int domain; 462 463 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 464 do { 465 addr = kmem_malloc_domain(domain, size, flags); 466 if (addr != 0) 467 break; 468 } while (vm_domainset_iter_policy(&di, &domain) == 0); 469 470 return (addr); 471 } 472 473 /* 474 * kmem_back_domain: 475 * 476 * Allocate physical pages from the specified domain for the specified 477 * virtual address range. 478 */ 479 int 480 kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr, 481 vm_size_t size, int flags) 482 { 483 vm_offset_t offset, i; 484 vm_page_t m, mpred; 485 vm_prot_t prot; 486 int pflags; 487 488 KASSERT(object == kernel_object, 489 ("kmem_back_domain: only supports kernel object.")); 490 491 offset = addr - VM_MIN_KERNEL_ADDRESS; 492 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 493 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 494 if (flags & M_WAITOK) 495 pflags |= VM_ALLOC_WAITFAIL; 496 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 497 498 i = 0; 499 VM_OBJECT_WLOCK(object); 500 retry: 501 mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i)); 502 for (; i < size; i += PAGE_SIZE, mpred = m) { 503 m = vm_page_alloc_domain_after(object, atop(offset + i), 504 domain, pflags, mpred); 505 506 /* 507 * Ran out of space, free everything up and return. Don't need 508 * to lock page queues here as we know that the pages we got 509 * aren't on any queues. 510 */ 511 if (m == NULL) { 512 if ((flags & M_NOWAIT) == 0) 513 goto retry; 514 VM_OBJECT_WUNLOCK(object); 515 kmem_unback(object, addr, i); 516 return (KERN_NO_SPACE); 517 } 518 KASSERT(vm_page_domain(m) == domain, 519 ("kmem_back_domain: Domain mismatch %d != %d", 520 vm_page_domain(m), domain)); 521 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0) 522 pmap_zero_page(m); 523 KASSERT((m->oflags & VPO_UNMANAGED) != 0, 524 ("kmem_malloc: page %p is managed", m)); 525 vm_page_valid(m); 526 pmap_enter(kernel_pmap, addr + i, m, prot, 527 prot | PMAP_ENTER_WIRED, 0); 528 if (__predict_false((prot & VM_PROT_EXECUTE) != 0)) 529 m->oflags |= VPO_KMEM_EXEC; 530 } 531 VM_OBJECT_WUNLOCK(object); 532 kmem_alloc_san(addr, size, size, flags); 533 return (KERN_SUCCESS); 534 } 535 536 /* 537 * kmem_back: 538 * 539 * Allocate physical pages for the specified virtual address range. 540 */ 541 int 542 kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags) 543 { 544 vm_offset_t end, next, start; 545 int domain, rv; 546 547 KASSERT(object == kernel_object, 548 ("kmem_back: only supports kernel object.")); 549 550 for (start = addr, end = addr + size; addr < end; addr = next) { 551 /* 552 * We must ensure that pages backing a given large virtual page 553 * all come from the same physical domain. 554 */ 555 if (vm_ndomains > 1) { 556 domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains; 557 while (VM_DOMAIN_EMPTY(domain)) 558 domain++; 559 next = roundup2(addr + 1, KVA_QUANTUM); 560 if (next > end || next < start) 561 next = end; 562 } else { 563 domain = 0; 564 next = end; 565 } 566 rv = kmem_back_domain(domain, object, addr, next - addr, flags); 567 if (rv != KERN_SUCCESS) { 568 kmem_unback(object, start, addr - start); 569 break; 570 } 571 } 572 return (rv); 573 } 574 575 /* 576 * kmem_unback: 577 * 578 * Unmap and free the physical pages underlying the specified virtual 579 * address range. 580 * 581 * A physical page must exist within the specified object at each index 582 * that is being unmapped. 583 */ 584 static struct vmem * 585 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 586 { 587 struct vmem *arena; 588 vm_page_t m, next; 589 vm_offset_t end, offset; 590 int domain; 591 592 KASSERT(object == kernel_object, 593 ("kmem_unback: only supports kernel object.")); 594 595 if (size == 0) 596 return (NULL); 597 pmap_remove(kernel_pmap, addr, addr + size); 598 offset = addr - VM_MIN_KERNEL_ADDRESS; 599 end = offset + size; 600 VM_OBJECT_WLOCK(object); 601 m = vm_page_lookup(object, atop(offset)); 602 domain = vm_page_domain(m); 603 if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0)) 604 arena = vm_dom[domain].vmd_kernel_arena; 605 else 606 arena = vm_dom[domain].vmd_kernel_rwx_arena; 607 for (; offset < end; offset += PAGE_SIZE, m = next) { 608 next = vm_page_next(m); 609 vm_page_xbusy_claim(m); 610 vm_page_unwire_noq(m); 611 vm_page_free(m); 612 } 613 VM_OBJECT_WUNLOCK(object); 614 615 return (arena); 616 } 617 618 void 619 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 620 { 621 622 (void)_kmem_unback(object, addr, size); 623 } 624 625 /* 626 * kmem_free: 627 * 628 * Free memory allocated with kmem_malloc. The size must match the 629 * original allocation. 630 */ 631 void 632 kmem_free(vm_offset_t addr, vm_size_t size) 633 { 634 struct vmem *arena; 635 636 size = round_page(size); 637 kasan_mark((void *)addr, size, size, 0); 638 arena = _kmem_unback(kernel_object, addr, size); 639 if (arena != NULL) 640 vmem_free(arena, addr, size); 641 } 642 643 /* 644 * kmap_alloc_wait: 645 * 646 * Allocates pageable memory from a sub-map of the kernel. If the submap 647 * has no room, the caller sleeps waiting for more memory in the submap. 648 * 649 * This routine may block. 650 */ 651 vm_offset_t 652 kmap_alloc_wait(vm_map_t map, vm_size_t size) 653 { 654 vm_offset_t addr; 655 656 size = round_page(size); 657 if (!swap_reserve(size)) 658 return (0); 659 660 for (;;) { 661 /* 662 * To make this work for more than one map, use the map's lock 663 * to lock out sleepers/wakers. 664 */ 665 vm_map_lock(map); 666 addr = vm_map_findspace(map, vm_map_min(map), size); 667 if (addr + size <= vm_map_max(map)) 668 break; 669 /* no space now; see if we can ever get space */ 670 if (vm_map_max(map) - vm_map_min(map) < size) { 671 vm_map_unlock(map); 672 swap_release(size); 673 return (0); 674 } 675 map->needs_wakeup = TRUE; 676 vm_map_unlock_and_wait(map, 0); 677 } 678 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_RW, VM_PROT_RW, 679 MAP_ACC_CHARGED); 680 vm_map_unlock(map); 681 return (addr); 682 } 683 684 /* 685 * kmap_free_wakeup: 686 * 687 * Returns memory to a submap of the kernel, and wakes up any processes 688 * waiting for memory in that map. 689 */ 690 void 691 kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size) 692 { 693 694 vm_map_lock(map); 695 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size)); 696 if (map->needs_wakeup) { 697 map->needs_wakeup = FALSE; 698 vm_map_wakeup(map); 699 } 700 vm_map_unlock(map); 701 } 702 703 void 704 kmem_init_zero_region(void) 705 { 706 vm_offset_t addr, i; 707 vm_page_t m; 708 709 /* 710 * Map a single physical page of zeros to a larger virtual range. 711 * This requires less looping in places that want large amounts of 712 * zeros, while not using much more physical resources. 713 */ 714 addr = kva_alloc(ZERO_REGION_SIZE); 715 m = vm_page_alloc_noobj(VM_ALLOC_WIRED | VM_ALLOC_ZERO); 716 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE) 717 pmap_qenter(addr + i, &m, 1); 718 pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ); 719 720 zero_region = (const void *)addr; 721 } 722 723 /* 724 * Import KVA from the kernel map into the kernel arena. 725 */ 726 static int 727 kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp) 728 { 729 vm_offset_t addr; 730 int result; 731 732 KASSERT((size % KVA_QUANTUM) == 0, 733 ("kva_import: Size %jd is not a multiple of %d", 734 (intmax_t)size, (int)KVA_QUANTUM)); 735 addr = vm_map_min(kernel_map); 736 result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0, 737 VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 738 if (result != KERN_SUCCESS) 739 return (ENOMEM); 740 741 *addrp = addr; 742 743 return (0); 744 } 745 746 /* 747 * Import KVA from a parent arena into a per-domain arena. Imports must be 748 * KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size. 749 */ 750 static int 751 kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp) 752 { 753 754 KASSERT((size % KVA_QUANTUM) == 0, 755 ("kva_import_domain: Size %jd is not a multiple of %d", 756 (intmax_t)size, (int)KVA_QUANTUM)); 757 return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN, 758 VMEM_ADDR_MAX, flags, addrp)); 759 } 760 761 /* 762 * kmem_init: 763 * 764 * Create the kernel map; insert a mapping covering kernel text, 765 * data, bss, and all space allocated thus far (`boostrap' data). The 766 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and 767 * `start' as allocated, and the range between `start' and `end' as free. 768 * Create the kernel vmem arena and its per-domain children. 769 */ 770 void 771 kmem_init(vm_offset_t start, vm_offset_t end) 772 { 773 vm_size_t quantum; 774 int domain; 775 776 vm_map_init(kernel_map, kernel_pmap, VM_MIN_KERNEL_ADDRESS, end); 777 kernel_map->system_map = 1; 778 vm_map_lock(kernel_map); 779 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */ 780 (void)vm_map_insert(kernel_map, NULL, 0, 781 #ifdef __amd64__ 782 KERNBASE, 783 #else 784 VM_MIN_KERNEL_ADDRESS, 785 #endif 786 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 787 /* ... and ending with the completion of the above `insert' */ 788 789 #ifdef __amd64__ 790 /* 791 * Mark KVA used for the page array as allocated. Other platforms 792 * that handle vm_page_array allocation can simply adjust virtual_avail 793 * instead. 794 */ 795 (void)vm_map_insert(kernel_map, NULL, 0, (vm_offset_t)vm_page_array, 796 (vm_offset_t)vm_page_array + round_2mpage(vm_page_array_size * 797 sizeof(struct vm_page)), 798 VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT); 799 #endif 800 vm_map_unlock(kernel_map); 801 802 /* 803 * Use a large import quantum on NUMA systems. This helps minimize 804 * interleaving of superpages, reducing internal fragmentation within 805 * the per-domain arenas. 806 */ 807 if (vm_ndomains > 1 && PMAP_HAS_DMAP) 808 quantum = KVA_NUMA_IMPORT_QUANTUM; 809 else 810 quantum = KVA_QUANTUM; 811 812 /* 813 * Initialize the kernel_arena. This can grow on demand. 814 */ 815 vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0); 816 vmem_set_import(kernel_arena, kva_import, NULL, NULL, quantum); 817 818 for (domain = 0; domain < vm_ndomains; domain++) { 819 /* 820 * Initialize the per-domain arenas. These are used to color 821 * the KVA space in a way that ensures that virtual large pages 822 * are backed by memory from the same physical domain, 823 * maximizing the potential for superpage promotion. 824 */ 825 vm_dom[domain].vmd_kernel_arena = vmem_create( 826 "kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 827 vmem_set_import(vm_dom[domain].vmd_kernel_arena, 828 kva_import_domain, NULL, kernel_arena, quantum); 829 830 /* 831 * In architectures with superpages, maintain separate arenas 832 * for allocations with permissions that differ from the 833 * "standard" read/write permissions used for kernel memory, 834 * so as not to inhibit superpage promotion. 835 * 836 * Use the base import quantum since this arena is rarely used. 837 */ 838 #if VM_NRESERVLEVEL > 0 839 vm_dom[domain].vmd_kernel_rwx_arena = vmem_create( 840 "kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 841 vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena, 842 kva_import_domain, (vmem_release_t *)vmem_xfree, 843 kernel_arena, KVA_QUANTUM); 844 #else 845 vm_dom[domain].vmd_kernel_rwx_arena = 846 vm_dom[domain].vmd_kernel_arena; 847 #endif 848 } 849 850 /* 851 * This must be the very first call so that the virtual address 852 * space used for early allocations is properly marked used in 853 * the map. 854 */ 855 uma_startup2(); 856 } 857 858 /* 859 * kmem_bootstrap_free: 860 * 861 * Free pages backing preloaded data (e.g., kernel modules) to the 862 * system. Currently only supported on platforms that create a 863 * vm_phys segment for preloaded data. 864 */ 865 void 866 kmem_bootstrap_free(vm_offset_t start, vm_size_t size) 867 { 868 #if defined(__i386__) || defined(__amd64__) 869 struct vm_domain *vmd; 870 vm_offset_t end, va; 871 vm_paddr_t pa; 872 vm_page_t m; 873 874 end = trunc_page(start + size); 875 start = round_page(start); 876 877 #ifdef __amd64__ 878 /* 879 * Preloaded files do not have execute permissions by default on amd64. 880 * Restore the default permissions to ensure that the direct map alias 881 * is updated. 882 */ 883 pmap_change_prot(start, end - start, VM_PROT_RW); 884 #endif 885 for (va = start; va < end; va += PAGE_SIZE) { 886 pa = pmap_kextract(va); 887 m = PHYS_TO_VM_PAGE(pa); 888 889 vmd = vm_pagequeue_domain(m); 890 vm_domain_free_lock(vmd); 891 vm_phys_free_pages(m, 0); 892 vm_domain_free_unlock(vmd); 893 894 vm_domain_freecnt_inc(vmd, 1); 895 vm_cnt.v_page_count++; 896 } 897 pmap_remove(kernel_pmap, start, end); 898 (void)vmem_add(kernel_arena, start, end - start, M_WAITOK); 899 #endif 900 } 901 902 /* 903 * Allow userspace to directly trigger the VM drain routine for testing 904 * purposes. 905 */ 906 static int 907 debug_vm_lowmem(SYSCTL_HANDLER_ARGS) 908 { 909 int error, i; 910 911 i = 0; 912 error = sysctl_handle_int(oidp, &i, 0, req); 913 if (error != 0) 914 return (error); 915 if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0) 916 return (EINVAL); 917 if (i != 0) 918 EVENTHANDLER_INVOKE(vm_lowmem, i); 919 return (0); 920 } 921 SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, 922 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, debug_vm_lowmem, "I", 923 "set to trigger vm_lowmem event with given flags"); 924 925 static int 926 debug_uma_reclaim(SYSCTL_HANDLER_ARGS) 927 { 928 int error, i; 929 930 i = 0; 931 error = sysctl_handle_int(oidp, &i, 0, req); 932 if (error != 0 || req->newptr == NULL) 933 return (error); 934 if (i != UMA_RECLAIM_TRIM && i != UMA_RECLAIM_DRAIN && 935 i != UMA_RECLAIM_DRAIN_CPU) 936 return (EINVAL); 937 uma_reclaim(i); 938 return (0); 939 } 940 SYSCTL_PROC(_debug, OID_AUTO, uma_reclaim, 941 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, debug_uma_reclaim, "I", 942 "set to generate request to reclaim uma caches"); 943 944 static int 945 debug_uma_reclaim_domain(SYSCTL_HANDLER_ARGS) 946 { 947 int domain, error, request; 948 949 request = 0; 950 error = sysctl_handle_int(oidp, &request, 0, req); 951 if (error != 0 || req->newptr == NULL) 952 return (error); 953 954 domain = request >> 4; 955 request &= 0xf; 956 if (request != UMA_RECLAIM_TRIM && request != UMA_RECLAIM_DRAIN && 957 request != UMA_RECLAIM_DRAIN_CPU) 958 return (EINVAL); 959 if (domain < 0 || domain >= vm_ndomains) 960 return (EINVAL); 961 uma_reclaim_domain(request, domain); 962 return (0); 963 } 964 SYSCTL_PROC(_debug, OID_AUTO, uma_reclaim_domain, 965 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, 966 debug_uma_reclaim_domain, "I", 967 ""); 968