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 TSENTER(); 152 size = round_page(size); 153 if (vmem_alloc(kernel_arena, size, M_BESTFIT | M_NOWAIT, &addr)) 154 return (0); 155 TSEXIT(); 156 157 return (addr); 158 } 159 160 /* 161 * kva_free: 162 * 163 * Release a region of kernel virtual memory allocated 164 * with kva_alloc, and return the physical pages 165 * associated with that region. 166 * 167 * This routine may not block on kernel maps. 168 */ 169 void 170 kva_free(vm_offset_t addr, vm_size_t size) 171 { 172 173 size = round_page(size); 174 vmem_free(kernel_arena, addr, size); 175 } 176 177 /* 178 * Update sanitizer shadow state to reflect a new allocation. Force inlining to 179 * help make KMSAN origin tracking more precise. 180 */ 181 static __always_inline void 182 kmem_alloc_san(vm_offset_t addr, vm_size_t size, vm_size_t asize, int flags) 183 { 184 if ((flags & M_ZERO) == 0) { 185 kmsan_mark((void *)addr, asize, KMSAN_STATE_UNINIT); 186 kmsan_orig((void *)addr, asize, KMSAN_TYPE_KMEM, 187 KMSAN_RET_ADDR); 188 } else { 189 kmsan_mark((void *)addr, asize, KMSAN_STATE_INITED); 190 } 191 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE); 192 } 193 194 static vm_page_t 195 kmem_alloc_contig_pages(vm_object_t object, vm_pindex_t pindex, int domain, 196 int pflags, u_long npages, vm_paddr_t low, vm_paddr_t high, 197 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) 198 { 199 vm_page_t m; 200 int tries; 201 bool wait, reclaim; 202 203 VM_OBJECT_ASSERT_WLOCKED(object); 204 205 wait = (pflags & VM_ALLOC_WAITOK) != 0; 206 reclaim = (pflags & VM_ALLOC_NORECLAIM) == 0; 207 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 208 pflags |= VM_ALLOC_NOWAIT; 209 for (tries = wait ? 3 : 1;; tries--) { 210 m = vm_page_alloc_contig_domain(object, pindex, domain, pflags, 211 npages, low, high, alignment, boundary, memattr); 212 if (m != NULL || tries == 0 || !reclaim) 213 break; 214 215 VM_OBJECT_WUNLOCK(object); 216 if (!vm_page_reclaim_contig_domain(domain, pflags, npages, 217 low, high, alignment, boundary) && wait) 218 vm_wait_domain(domain); 219 VM_OBJECT_WLOCK(object); 220 } 221 return (m); 222 } 223 224 /* 225 * Allocates a region from the kernel address map and physical pages 226 * within the specified address range to the kernel object. Creates a 227 * wired mapping from this region to these pages, and returns the 228 * region's starting virtual address. The allocated pages are not 229 * necessarily physically contiguous. If M_ZERO is specified through the 230 * given flags, then the pages are zeroed before they are mapped. 231 */ 232 static void * 233 kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 234 vm_paddr_t high, vm_memattr_t memattr) 235 { 236 vmem_t *vmem; 237 vm_object_t object; 238 vm_offset_t addr, i, offset; 239 vm_page_t m; 240 vm_size_t asize; 241 int pflags; 242 vm_prot_t prot; 243 244 object = kernel_object; 245 asize = round_page(size); 246 vmem = vm_dom[domain].vmd_kernel_arena; 247 if (vmem_alloc(vmem, asize, M_BESTFIT | flags, &addr)) 248 return (0); 249 offset = addr - VM_MIN_KERNEL_ADDRESS; 250 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 251 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 252 VM_OBJECT_WLOCK(object); 253 for (i = 0; i < asize; i += PAGE_SIZE) { 254 m = kmem_alloc_contig_pages(object, atop(offset + i), 255 domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr); 256 if (m == NULL) { 257 VM_OBJECT_WUNLOCK(object); 258 kmem_unback(object, addr, i); 259 vmem_free(vmem, addr, asize); 260 return (0); 261 } 262 KASSERT(vm_page_domain(m) == domain, 263 ("kmem_alloc_attr_domain: Domain mismatch %d != %d", 264 vm_page_domain(m), domain)); 265 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 266 pmap_zero_page(m); 267 vm_page_valid(m); 268 pmap_enter(kernel_pmap, addr + i, m, prot, 269 prot | PMAP_ENTER_WIRED, 0); 270 } 271 VM_OBJECT_WUNLOCK(object); 272 kmem_alloc_san(addr, size, asize, flags); 273 return ((void *)addr); 274 } 275 276 void * 277 kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 278 vm_memattr_t memattr) 279 { 280 281 return (kmem_alloc_attr_domainset(DOMAINSET_RR(), size, flags, low, 282 high, memattr)); 283 } 284 285 void * 286 kmem_alloc_attr_domainset(struct domainset *ds, vm_size_t size, int flags, 287 vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr) 288 { 289 struct vm_domainset_iter di; 290 void *addr; 291 int domain; 292 293 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 294 do { 295 addr = kmem_alloc_attr_domain(domain, size, flags, low, high, 296 memattr); 297 if (addr != NULL) 298 break; 299 } while (vm_domainset_iter_policy(&di, &domain) == 0); 300 301 return (addr); 302 } 303 304 /* 305 * Allocates a region from the kernel address map and physically 306 * contiguous pages within the specified address range to the kernel 307 * object. Creates a wired mapping from this region to these pages, and 308 * returns the region's starting virtual address. If M_ZERO is specified 309 * through the given flags, then the pages are zeroed before they are 310 * mapped. 311 */ 312 static void * 313 kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 314 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 315 vm_memattr_t memattr) 316 { 317 vmem_t *vmem; 318 vm_object_t object; 319 vm_offset_t addr, offset, tmp; 320 vm_page_t end_m, m; 321 vm_size_t asize; 322 u_long npages; 323 int pflags; 324 325 object = kernel_object; 326 asize = round_page(size); 327 vmem = vm_dom[domain].vmd_kernel_arena; 328 if (vmem_alloc(vmem, asize, flags | M_BESTFIT, &addr)) 329 return (NULL); 330 offset = addr - VM_MIN_KERNEL_ADDRESS; 331 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 332 npages = atop(asize); 333 VM_OBJECT_WLOCK(object); 334 m = kmem_alloc_contig_pages(object, atop(offset), domain, 335 pflags, npages, low, high, alignment, boundary, memattr); 336 if (m == NULL) { 337 VM_OBJECT_WUNLOCK(object); 338 vmem_free(vmem, addr, asize); 339 return (NULL); 340 } 341 KASSERT(vm_page_domain(m) == domain, 342 ("kmem_alloc_contig_domain: Domain mismatch %d != %d", 343 vm_page_domain(m), domain)); 344 end_m = m + npages; 345 tmp = addr; 346 for (; m < end_m; m++) { 347 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 348 pmap_zero_page(m); 349 vm_page_valid(m); 350 pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW, 351 VM_PROT_RW | PMAP_ENTER_WIRED, 0); 352 tmp += PAGE_SIZE; 353 } 354 VM_OBJECT_WUNLOCK(object); 355 kmem_alloc_san(addr, size, asize, flags); 356 return ((void *)addr); 357 } 358 359 void * 360 kmem_alloc_contig(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 361 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) 362 { 363 364 return (kmem_alloc_contig_domainset(DOMAINSET_RR(), size, flags, low, 365 high, alignment, boundary, memattr)); 366 } 367 368 void * 369 kmem_alloc_contig_domainset(struct domainset *ds, vm_size_t size, int flags, 370 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 371 vm_memattr_t memattr) 372 { 373 struct vm_domainset_iter di; 374 void *addr; 375 int domain; 376 377 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 378 do { 379 addr = kmem_alloc_contig_domain(domain, size, flags, low, high, 380 alignment, boundary, memattr); 381 if (addr != NULL) 382 break; 383 } while (vm_domainset_iter_policy(&di, &domain) == 0); 384 385 return (addr); 386 } 387 388 /* 389 * kmem_subinit: 390 * 391 * Initializes a map to manage a subrange 392 * of the kernel virtual address space. 393 * 394 * Arguments are as follows: 395 * 396 * parent Map to take range from 397 * min, max Returned endpoints of map 398 * size Size of range to find 399 * superpage_align Request that min is superpage aligned 400 */ 401 void 402 kmem_subinit(vm_map_t map, vm_map_t parent, vm_offset_t *min, vm_offset_t *max, 403 vm_size_t size, bool superpage_align) 404 { 405 int ret; 406 407 size = round_page(size); 408 409 *min = vm_map_min(parent); 410 ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ? 411 VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL, 412 MAP_ACC_NO_CHARGE); 413 if (ret != KERN_SUCCESS) 414 panic("kmem_subinit: bad status return of %d", ret); 415 *max = *min + size; 416 vm_map_init(map, vm_map_pmap(parent), *min, *max); 417 if (vm_map_submap(parent, *min, *max, map) != KERN_SUCCESS) 418 panic("kmem_subinit: unable to change range to submap"); 419 } 420 421 /* 422 * kmem_malloc_domain: 423 * 424 * Allocate wired-down pages in the kernel's address space. 425 */ 426 static void * 427 kmem_malloc_domain(int domain, vm_size_t size, int flags) 428 { 429 vmem_t *arena; 430 vm_offset_t addr; 431 vm_size_t asize; 432 int rv; 433 434 if (__predict_true((flags & M_EXEC) == 0)) 435 arena = vm_dom[domain].vmd_kernel_arena; 436 else 437 arena = vm_dom[domain].vmd_kernel_rwx_arena; 438 asize = round_page(size); 439 if (vmem_alloc(arena, asize, flags | M_BESTFIT, &addr)) 440 return (0); 441 442 rv = kmem_back_domain(domain, kernel_object, addr, asize, flags); 443 if (rv != KERN_SUCCESS) { 444 vmem_free(arena, addr, asize); 445 return (0); 446 } 447 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE); 448 return ((void *)addr); 449 } 450 451 void * 452 kmem_malloc(vm_size_t size, int flags) 453 { 454 void * p; 455 456 TSENTER(); 457 p = kmem_malloc_domainset(DOMAINSET_RR(), size, flags); 458 TSEXIT(); 459 return (p); 460 } 461 462 void * 463 kmem_malloc_domainset(struct domainset *ds, vm_size_t size, int flags) 464 { 465 struct vm_domainset_iter di; 466 void *addr; 467 int domain; 468 469 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 470 do { 471 addr = kmem_malloc_domain(domain, size, flags); 472 if (addr != NULL) 473 break; 474 } while (vm_domainset_iter_policy(&di, &domain) == 0); 475 476 return (addr); 477 } 478 479 /* 480 * kmem_back_domain: 481 * 482 * Allocate physical pages from the specified domain for the specified 483 * virtual address range. 484 */ 485 int 486 kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr, 487 vm_size_t size, int flags) 488 { 489 vm_offset_t offset, i; 490 vm_page_t m, mpred; 491 vm_prot_t prot; 492 int pflags; 493 494 KASSERT(object == kernel_object, 495 ("kmem_back_domain: only supports kernel object.")); 496 497 offset = addr - VM_MIN_KERNEL_ADDRESS; 498 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 499 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 500 if (flags & M_WAITOK) 501 pflags |= VM_ALLOC_WAITFAIL; 502 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 503 504 i = 0; 505 VM_OBJECT_WLOCK(object); 506 retry: 507 mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i)); 508 for (; i < size; i += PAGE_SIZE, mpred = m) { 509 m = vm_page_alloc_domain_after(object, atop(offset + i), 510 domain, pflags, mpred); 511 512 /* 513 * Ran out of space, free everything up and return. Don't need 514 * to lock page queues here as we know that the pages we got 515 * aren't on any queues. 516 */ 517 if (m == NULL) { 518 if ((flags & M_NOWAIT) == 0) 519 goto retry; 520 VM_OBJECT_WUNLOCK(object); 521 kmem_unback(object, addr, i); 522 return (KERN_NO_SPACE); 523 } 524 KASSERT(vm_page_domain(m) == domain, 525 ("kmem_back_domain: Domain mismatch %d != %d", 526 vm_page_domain(m), domain)); 527 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0) 528 pmap_zero_page(m); 529 KASSERT((m->oflags & VPO_UNMANAGED) != 0, 530 ("kmem_malloc: page %p is managed", m)); 531 vm_page_valid(m); 532 pmap_enter(kernel_pmap, addr + i, m, prot, 533 prot | PMAP_ENTER_WIRED, 0); 534 if (__predict_false((prot & VM_PROT_EXECUTE) != 0)) 535 m->oflags |= VPO_KMEM_EXEC; 536 } 537 VM_OBJECT_WUNLOCK(object); 538 kmem_alloc_san(addr, size, size, flags); 539 return (KERN_SUCCESS); 540 } 541 542 /* 543 * kmem_back: 544 * 545 * Allocate physical pages for the specified virtual address range. 546 */ 547 int 548 kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags) 549 { 550 vm_offset_t end, next, start; 551 int domain, rv; 552 553 KASSERT(object == kernel_object, 554 ("kmem_back: only supports kernel object.")); 555 556 for (start = addr, end = addr + size; addr < end; addr = next) { 557 /* 558 * We must ensure that pages backing a given large virtual page 559 * all come from the same physical domain. 560 */ 561 if (vm_ndomains > 1) { 562 domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains; 563 while (VM_DOMAIN_EMPTY(domain)) 564 domain++; 565 next = roundup2(addr + 1, KVA_QUANTUM); 566 if (next > end || next < start) 567 next = end; 568 } else { 569 domain = 0; 570 next = end; 571 } 572 rv = kmem_back_domain(domain, object, addr, next - addr, flags); 573 if (rv != KERN_SUCCESS) { 574 kmem_unback(object, start, addr - start); 575 break; 576 } 577 } 578 return (rv); 579 } 580 581 /* 582 * kmem_unback: 583 * 584 * Unmap and free the physical pages underlying the specified virtual 585 * address range. 586 * 587 * A physical page must exist within the specified object at each index 588 * that is being unmapped. 589 */ 590 static struct vmem * 591 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 592 { 593 struct vmem *arena; 594 vm_page_t m, next; 595 vm_offset_t end, offset; 596 int domain; 597 598 KASSERT(object == kernel_object, 599 ("kmem_unback: only supports kernel object.")); 600 601 if (size == 0) 602 return (NULL); 603 pmap_remove(kernel_pmap, addr, addr + size); 604 offset = addr - VM_MIN_KERNEL_ADDRESS; 605 end = offset + size; 606 VM_OBJECT_WLOCK(object); 607 m = vm_page_lookup(object, atop(offset)); 608 domain = vm_page_domain(m); 609 if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0)) 610 arena = vm_dom[domain].vmd_kernel_arena; 611 else 612 arena = vm_dom[domain].vmd_kernel_rwx_arena; 613 for (; offset < end; offset += PAGE_SIZE, m = next) { 614 next = vm_page_next(m); 615 vm_page_xbusy_claim(m); 616 vm_page_unwire_noq(m); 617 vm_page_free(m); 618 } 619 VM_OBJECT_WUNLOCK(object); 620 621 return (arena); 622 } 623 624 void 625 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 626 { 627 628 (void)_kmem_unback(object, addr, size); 629 } 630 631 /* 632 * kmem_free: 633 * 634 * Free memory allocated with kmem_malloc. The size must match the 635 * original allocation. 636 */ 637 void 638 kmem_free(void *addr, vm_size_t size) 639 { 640 struct vmem *arena; 641 642 size = round_page(size); 643 kasan_mark(addr, size, size, 0); 644 arena = _kmem_unback(kernel_object, (uintptr_t)addr, size); 645 if (arena != NULL) 646 vmem_free(arena, (uintptr_t)addr, size); 647 } 648 649 /* 650 * kmap_alloc_wait: 651 * 652 * Allocates pageable memory from a sub-map of the kernel. If the submap 653 * has no room, the caller sleeps waiting for more memory in the submap. 654 * 655 * This routine may block. 656 */ 657 vm_offset_t 658 kmap_alloc_wait(vm_map_t map, vm_size_t size) 659 { 660 vm_offset_t addr; 661 662 size = round_page(size); 663 if (!swap_reserve(size)) 664 return (0); 665 666 for (;;) { 667 /* 668 * To make this work for more than one map, use the map's lock 669 * to lock out sleepers/wakers. 670 */ 671 vm_map_lock(map); 672 addr = vm_map_findspace(map, vm_map_min(map), size); 673 if (addr + size <= vm_map_max(map)) 674 break; 675 /* no space now; see if we can ever get space */ 676 if (vm_map_max(map) - vm_map_min(map) < size) { 677 vm_map_unlock(map); 678 swap_release(size); 679 return (0); 680 } 681 map->needs_wakeup = TRUE; 682 vm_map_unlock_and_wait(map, 0); 683 } 684 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_RW, VM_PROT_RW, 685 MAP_ACC_CHARGED); 686 vm_map_unlock(map); 687 return (addr); 688 } 689 690 /* 691 * kmap_free_wakeup: 692 * 693 * Returns memory to a submap of the kernel, and wakes up any processes 694 * waiting for memory in that map. 695 */ 696 void 697 kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size) 698 { 699 700 vm_map_lock(map); 701 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size)); 702 if (map->needs_wakeup) { 703 map->needs_wakeup = FALSE; 704 vm_map_wakeup(map); 705 } 706 vm_map_unlock(map); 707 } 708 709 void 710 kmem_init_zero_region(void) 711 { 712 vm_offset_t addr, i; 713 vm_page_t m; 714 715 /* 716 * Map a single physical page of zeros to a larger virtual range. 717 * This requires less looping in places that want large amounts of 718 * zeros, while not using much more physical resources. 719 */ 720 addr = kva_alloc(ZERO_REGION_SIZE); 721 m = vm_page_alloc_noobj(VM_ALLOC_WIRED | VM_ALLOC_ZERO); 722 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE) 723 pmap_qenter(addr + i, &m, 1); 724 pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ); 725 726 zero_region = (const void *)addr; 727 } 728 729 /* 730 * Import KVA from the kernel map into the kernel arena. 731 */ 732 static int 733 kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp) 734 { 735 vm_offset_t addr; 736 int result; 737 738 TSENTER(); 739 KASSERT((size % KVA_QUANTUM) == 0, 740 ("kva_import: Size %jd is not a multiple of %d", 741 (intmax_t)size, (int)KVA_QUANTUM)); 742 addr = vm_map_min(kernel_map); 743 result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0, 744 VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 745 if (result != KERN_SUCCESS) { 746 TSEXIT(); 747 return (ENOMEM); 748 } 749 750 *addrp = addr; 751 752 TSEXIT(); 753 return (0); 754 } 755 756 /* 757 * Import KVA from a parent arena into a per-domain arena. Imports must be 758 * KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size. 759 */ 760 static int 761 kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp) 762 { 763 764 KASSERT((size % KVA_QUANTUM) == 0, 765 ("kva_import_domain: Size %jd is not a multiple of %d", 766 (intmax_t)size, (int)KVA_QUANTUM)); 767 return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN, 768 VMEM_ADDR_MAX, flags, addrp)); 769 } 770 771 /* 772 * kmem_init: 773 * 774 * Create the kernel map; insert a mapping covering kernel text, 775 * data, bss, and all space allocated thus far (`boostrap' data). The 776 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and 777 * `start' as allocated, and the range between `start' and `end' as free. 778 * Create the kernel vmem arena and its per-domain children. 779 */ 780 void 781 kmem_init(vm_offset_t start, vm_offset_t end) 782 { 783 vm_size_t quantum; 784 int domain; 785 786 vm_map_init(kernel_map, kernel_pmap, VM_MIN_KERNEL_ADDRESS, end); 787 kernel_map->system_map = 1; 788 vm_map_lock(kernel_map); 789 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */ 790 (void)vm_map_insert(kernel_map, NULL, 0, 791 #ifdef __amd64__ 792 KERNBASE, 793 #else 794 VM_MIN_KERNEL_ADDRESS, 795 #endif 796 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 797 /* ... and ending with the completion of the above `insert' */ 798 799 #ifdef __amd64__ 800 /* 801 * Mark KVA used for the page array as allocated. Other platforms 802 * that handle vm_page_array allocation can simply adjust virtual_avail 803 * instead. 804 */ 805 (void)vm_map_insert(kernel_map, NULL, 0, (vm_offset_t)vm_page_array, 806 (vm_offset_t)vm_page_array + round_2mpage(vm_page_array_size * 807 sizeof(struct vm_page)), 808 VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT); 809 #endif 810 vm_map_unlock(kernel_map); 811 812 /* 813 * Use a large import quantum on NUMA systems. This helps minimize 814 * interleaving of superpages, reducing internal fragmentation within 815 * the per-domain arenas. 816 */ 817 if (vm_ndomains > 1 && PMAP_HAS_DMAP) 818 quantum = KVA_NUMA_IMPORT_QUANTUM; 819 else 820 quantum = KVA_QUANTUM; 821 822 /* 823 * Initialize the kernel_arena. This can grow on demand. 824 */ 825 vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0); 826 vmem_set_import(kernel_arena, kva_import, NULL, NULL, quantum); 827 828 for (domain = 0; domain < vm_ndomains; domain++) { 829 /* 830 * Initialize the per-domain arenas. These are used to color 831 * the KVA space in a way that ensures that virtual large pages 832 * are backed by memory from the same physical domain, 833 * maximizing the potential for superpage promotion. 834 */ 835 vm_dom[domain].vmd_kernel_arena = vmem_create( 836 "kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 837 vmem_set_import(vm_dom[domain].vmd_kernel_arena, 838 kva_import_domain, NULL, kernel_arena, quantum); 839 840 /* 841 * In architectures with superpages, maintain separate arenas 842 * for allocations with permissions that differ from the 843 * "standard" read/write permissions used for kernel memory, 844 * so as not to inhibit superpage promotion. 845 * 846 * Use the base import quantum since this arena is rarely used. 847 */ 848 #if VM_NRESERVLEVEL > 0 849 vm_dom[domain].vmd_kernel_rwx_arena = vmem_create( 850 "kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 851 vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena, 852 kva_import_domain, (vmem_release_t *)vmem_xfree, 853 kernel_arena, KVA_QUANTUM); 854 #else 855 vm_dom[domain].vmd_kernel_rwx_arena = 856 vm_dom[domain].vmd_kernel_arena; 857 #endif 858 } 859 860 /* 861 * This must be the very first call so that the virtual address 862 * space used for early allocations is properly marked used in 863 * the map. 864 */ 865 uma_startup2(); 866 } 867 868 /* 869 * kmem_bootstrap_free: 870 * 871 * Free pages backing preloaded data (e.g., kernel modules) to the 872 * system. Currently only supported on platforms that create a 873 * vm_phys segment for preloaded data. 874 */ 875 void 876 kmem_bootstrap_free(vm_offset_t start, vm_size_t size) 877 { 878 #if defined(__i386__) || defined(__amd64__) 879 struct vm_domain *vmd; 880 vm_offset_t end, va; 881 vm_paddr_t pa; 882 vm_page_t m; 883 884 end = trunc_page(start + size); 885 start = round_page(start); 886 887 #ifdef __amd64__ 888 /* 889 * Preloaded files do not have execute permissions by default on amd64. 890 * Restore the default permissions to ensure that the direct map alias 891 * is updated. 892 */ 893 pmap_change_prot(start, end - start, VM_PROT_RW); 894 #endif 895 for (va = start; va < end; va += PAGE_SIZE) { 896 pa = pmap_kextract(va); 897 m = PHYS_TO_VM_PAGE(pa); 898 899 vmd = vm_pagequeue_domain(m); 900 vm_domain_free_lock(vmd); 901 vm_phys_free_pages(m, 0); 902 vm_domain_free_unlock(vmd); 903 904 vm_domain_freecnt_inc(vmd, 1); 905 vm_cnt.v_page_count++; 906 } 907 pmap_remove(kernel_pmap, start, end); 908 (void)vmem_add(kernel_arena, start, end - start, M_WAITOK); 909 #endif 910 } 911 912 /* 913 * Allow userspace to directly trigger the VM drain routine for testing 914 * purposes. 915 */ 916 static int 917 debug_vm_lowmem(SYSCTL_HANDLER_ARGS) 918 { 919 int error, i; 920 921 i = 0; 922 error = sysctl_handle_int(oidp, &i, 0, req); 923 if (error != 0) 924 return (error); 925 if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0) 926 return (EINVAL); 927 if (i != 0) 928 EVENTHANDLER_INVOKE(vm_lowmem, i); 929 return (0); 930 } 931 SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, 932 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, debug_vm_lowmem, "I", 933 "set to trigger vm_lowmem event with given flags"); 934 935 static int 936 debug_uma_reclaim(SYSCTL_HANDLER_ARGS) 937 { 938 int error, i; 939 940 i = 0; 941 error = sysctl_handle_int(oidp, &i, 0, req); 942 if (error != 0 || req->newptr == NULL) 943 return (error); 944 if (i != UMA_RECLAIM_TRIM && i != UMA_RECLAIM_DRAIN && 945 i != UMA_RECLAIM_DRAIN_CPU) 946 return (EINVAL); 947 uma_reclaim(i); 948 return (0); 949 } 950 SYSCTL_PROC(_debug, OID_AUTO, uma_reclaim, 951 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, debug_uma_reclaim, "I", 952 "set to generate request to reclaim uma caches"); 953 954 static int 955 debug_uma_reclaim_domain(SYSCTL_HANDLER_ARGS) 956 { 957 int domain, error, request; 958 959 request = 0; 960 error = sysctl_handle_int(oidp, &request, 0, req); 961 if (error != 0 || req->newptr == NULL) 962 return (error); 963 964 domain = request >> 4; 965 request &= 0xf; 966 if (request != UMA_RECLAIM_TRIM && request != UMA_RECLAIM_DRAIN && 967 request != UMA_RECLAIM_DRAIN_CPU) 968 return (EINVAL); 969 if (domain < 0 || domain >= vm_ndomains) 970 return (EINVAL); 971 uma_reclaim_domain(request, domain); 972 return (0); 973 } 974 SYSCTL_PROC(_debug, OID_AUTO, uma_reclaim_domain, 975 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, 976 debug_uma_reclaim_domain, "I", 977 ""); 978