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 #include "opt_vm.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/asan.h> 73 #include <sys/domainset.h> 74 #include <sys/eventhandler.h> 75 #include <sys/kernel.h> 76 #include <sys/lock.h> 77 #include <sys/malloc.h> 78 #include <sys/msan.h> 79 #include <sys/proc.h> 80 #include <sys/rwlock.h> 81 #include <sys/smp.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 TSENTER(); 151 size = round_page(size); 152 if (vmem_alloc(kernel_arena, size, M_BESTFIT | M_NOWAIT, &addr)) 153 return (0); 154 TSEXIT(); 155 156 return (addr); 157 } 158 159 /* 160 * kva_free: 161 * 162 * Release a region of kernel virtual memory allocated 163 * with kva_alloc, and return the physical pages 164 * associated with that region. 165 * 166 * This routine may not block on kernel maps. 167 */ 168 void 169 kva_free(vm_offset_t addr, vm_size_t size) 170 { 171 172 size = round_page(size); 173 vmem_free(kernel_arena, addr, size); 174 } 175 176 /* 177 * Update sanitizer shadow state to reflect a new allocation. Force inlining to 178 * help make KMSAN origin tracking more precise. 179 */ 180 static __always_inline void 181 kmem_alloc_san(vm_offset_t addr, vm_size_t size, vm_size_t asize, int flags) 182 { 183 if ((flags & M_ZERO) == 0) { 184 kmsan_mark((void *)addr, asize, KMSAN_STATE_UNINIT); 185 kmsan_orig((void *)addr, asize, KMSAN_TYPE_KMEM, 186 KMSAN_RET_ADDR); 187 } else { 188 kmsan_mark((void *)addr, asize, KMSAN_STATE_INITED); 189 } 190 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE); 191 } 192 193 static vm_page_t 194 kmem_alloc_contig_pages(vm_object_t object, vm_pindex_t pindex, int domain, 195 int pflags, u_long npages, vm_paddr_t low, vm_paddr_t high, 196 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) 197 { 198 vm_page_t m; 199 int tries; 200 bool wait, reclaim; 201 202 VM_OBJECT_ASSERT_WLOCKED(object); 203 204 wait = (pflags & VM_ALLOC_WAITOK) != 0; 205 reclaim = (pflags & VM_ALLOC_NORECLAIM) == 0; 206 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 207 pflags |= VM_ALLOC_NOWAIT; 208 for (tries = wait ? 3 : 1;; tries--) { 209 m = vm_page_alloc_contig_domain(object, pindex, domain, pflags, 210 npages, low, high, alignment, boundary, memattr); 211 if (m != NULL || tries == 0 || !reclaim) 212 break; 213 214 VM_OBJECT_WUNLOCK(object); 215 if (!vm_page_reclaim_contig_domain(domain, pflags, npages, 216 low, high, alignment, boundary) && wait) 217 vm_wait_domain(domain); 218 VM_OBJECT_WLOCK(object); 219 } 220 return (m); 221 } 222 223 /* 224 * Allocates a region from the kernel address map and physical pages 225 * within the specified address range to the kernel object. Creates a 226 * wired mapping from this region to these pages, and returns the 227 * region's starting virtual address. The allocated pages are not 228 * necessarily physically contiguous. If M_ZERO is specified through the 229 * given flags, then the pages are zeroed before they are mapped. 230 */ 231 static void * 232 kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 233 vm_paddr_t high, vm_memattr_t memattr) 234 { 235 vmem_t *vmem; 236 vm_object_t object; 237 vm_offset_t addr, i, offset; 238 vm_page_t m; 239 vm_size_t asize; 240 int pflags; 241 vm_prot_t prot; 242 243 object = kernel_object; 244 asize = round_page(size); 245 vmem = vm_dom[domain].vmd_kernel_arena; 246 if (vmem_alloc(vmem, asize, M_BESTFIT | flags, &addr)) 247 return (0); 248 offset = addr - VM_MIN_KERNEL_ADDRESS; 249 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 250 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 251 VM_OBJECT_WLOCK(object); 252 for (i = 0; i < asize; i += PAGE_SIZE) { 253 m = kmem_alloc_contig_pages(object, atop(offset + i), 254 domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr); 255 if (m == NULL) { 256 VM_OBJECT_WUNLOCK(object); 257 kmem_unback(object, addr, i); 258 vmem_free(vmem, addr, asize); 259 return (0); 260 } 261 KASSERT(vm_page_domain(m) == domain, 262 ("kmem_alloc_attr_domain: Domain mismatch %d != %d", 263 vm_page_domain(m), domain)); 264 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 265 pmap_zero_page(m); 266 vm_page_valid(m); 267 pmap_enter(kernel_pmap, addr + i, m, prot, 268 prot | PMAP_ENTER_WIRED, 0); 269 } 270 VM_OBJECT_WUNLOCK(object); 271 kmem_alloc_san(addr, size, asize, flags); 272 return ((void *)addr); 273 } 274 275 void * 276 kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 277 vm_memattr_t memattr) 278 { 279 280 return (kmem_alloc_attr_domainset(DOMAINSET_RR(), size, flags, low, 281 high, memattr)); 282 } 283 284 void * 285 kmem_alloc_attr_domainset(struct domainset *ds, vm_size_t size, int flags, 286 vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr) 287 { 288 struct vm_domainset_iter di; 289 void *addr; 290 int domain; 291 292 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 293 do { 294 addr = kmem_alloc_attr_domain(domain, size, flags, low, high, 295 memattr); 296 if (addr != NULL) 297 break; 298 } while (vm_domainset_iter_policy(&di, &domain) == 0); 299 300 return (addr); 301 } 302 303 /* 304 * Allocates a region from the kernel address map and physically 305 * contiguous pages within the specified address range to the kernel 306 * object. Creates a wired mapping from this region to these pages, and 307 * returns the region's starting virtual address. If M_ZERO is specified 308 * through the given flags, then the pages are zeroed before they are 309 * mapped. 310 */ 311 static void * 312 kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 313 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 314 vm_memattr_t memattr) 315 { 316 vmem_t *vmem; 317 vm_object_t object; 318 vm_offset_t addr, offset, tmp; 319 vm_page_t end_m, m; 320 vm_size_t asize; 321 u_long npages; 322 int pflags; 323 324 object = kernel_object; 325 asize = round_page(size); 326 vmem = vm_dom[domain].vmd_kernel_arena; 327 if (vmem_alloc(vmem, asize, flags | M_BESTFIT, &addr)) 328 return (NULL); 329 offset = addr - VM_MIN_KERNEL_ADDRESS; 330 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 331 npages = atop(asize); 332 VM_OBJECT_WLOCK(object); 333 m = kmem_alloc_contig_pages(object, atop(offset), domain, 334 pflags, npages, low, high, alignment, boundary, memattr); 335 if (m == NULL) { 336 VM_OBJECT_WUNLOCK(object); 337 vmem_free(vmem, addr, asize); 338 return (NULL); 339 } 340 KASSERT(vm_page_domain(m) == domain, 341 ("kmem_alloc_contig_domain: Domain mismatch %d != %d", 342 vm_page_domain(m), domain)); 343 end_m = m + npages; 344 tmp = addr; 345 for (; m < end_m; m++) { 346 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 347 pmap_zero_page(m); 348 vm_page_valid(m); 349 pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW, 350 VM_PROT_RW | PMAP_ENTER_WIRED, 0); 351 tmp += PAGE_SIZE; 352 } 353 VM_OBJECT_WUNLOCK(object); 354 kmem_alloc_san(addr, size, asize, flags); 355 return ((void *)addr); 356 } 357 358 void * 359 kmem_alloc_contig(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 360 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) 361 { 362 363 return (kmem_alloc_contig_domainset(DOMAINSET_RR(), size, flags, low, 364 high, alignment, boundary, memattr)); 365 } 366 367 void * 368 kmem_alloc_contig_domainset(struct domainset *ds, vm_size_t size, int flags, 369 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 370 vm_memattr_t memattr) 371 { 372 struct vm_domainset_iter di; 373 void *addr; 374 int domain; 375 376 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 377 do { 378 addr = kmem_alloc_contig_domain(domain, size, flags, low, high, 379 alignment, boundary, memattr); 380 if (addr != NULL) 381 break; 382 } while (vm_domainset_iter_policy(&di, &domain) == 0); 383 384 return (addr); 385 } 386 387 /* 388 * kmem_subinit: 389 * 390 * Initializes a map to manage a subrange 391 * of the kernel virtual address space. 392 * 393 * Arguments are as follows: 394 * 395 * parent Map to take range from 396 * min, max Returned endpoints of map 397 * size Size of range to find 398 * superpage_align Request that min is superpage aligned 399 */ 400 void 401 kmem_subinit(vm_map_t map, vm_map_t parent, vm_offset_t *min, vm_offset_t *max, 402 vm_size_t size, bool superpage_align) 403 { 404 int ret; 405 406 size = round_page(size); 407 408 *min = vm_map_min(parent); 409 ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ? 410 VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL, 411 MAP_ACC_NO_CHARGE); 412 if (ret != KERN_SUCCESS) 413 panic("kmem_subinit: bad status return of %d", ret); 414 *max = *min + size; 415 vm_map_init(map, vm_map_pmap(parent), *min, *max); 416 if (vm_map_submap(parent, *min, *max, map) != KERN_SUCCESS) 417 panic("kmem_subinit: unable to change range to submap"); 418 } 419 420 /* 421 * kmem_malloc_domain: 422 * 423 * Allocate wired-down pages in the kernel's address space. 424 */ 425 static void * 426 kmem_malloc_domain(int domain, vm_size_t size, int flags) 427 { 428 vmem_t *arena; 429 vm_offset_t addr; 430 vm_size_t asize; 431 int rv; 432 433 if (__predict_true((flags & M_EXEC) == 0)) 434 arena = vm_dom[domain].vmd_kernel_arena; 435 else 436 arena = vm_dom[domain].vmd_kernel_rwx_arena; 437 asize = round_page(size); 438 if (vmem_alloc(arena, asize, flags | M_BESTFIT, &addr)) 439 return (0); 440 441 rv = kmem_back_domain(domain, kernel_object, addr, asize, flags); 442 if (rv != KERN_SUCCESS) { 443 vmem_free(arena, addr, asize); 444 return (0); 445 } 446 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE); 447 return ((void *)addr); 448 } 449 450 void * 451 kmem_malloc(vm_size_t size, int flags) 452 { 453 void * p; 454 455 TSENTER(); 456 p = kmem_malloc_domainset(DOMAINSET_RR(), size, flags); 457 TSEXIT(); 458 return (p); 459 } 460 461 void * 462 kmem_malloc_domainset(struct domainset *ds, vm_size_t size, int flags) 463 { 464 struct vm_domainset_iter di; 465 void *addr; 466 int domain; 467 468 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 469 do { 470 addr = kmem_malloc_domain(domain, size, flags); 471 if (addr != NULL) 472 break; 473 } while (vm_domainset_iter_policy(&di, &domain) == 0); 474 475 return (addr); 476 } 477 478 /* 479 * kmem_back_domain: 480 * 481 * Allocate physical pages from the specified domain for the specified 482 * virtual address range. 483 */ 484 int 485 kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr, 486 vm_size_t size, int flags) 487 { 488 vm_offset_t offset, i; 489 vm_page_t m, mpred; 490 vm_prot_t prot; 491 int pflags; 492 493 KASSERT(object == kernel_object, 494 ("kmem_back_domain: only supports kernel object.")); 495 496 offset = addr - VM_MIN_KERNEL_ADDRESS; 497 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 498 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 499 if (flags & M_WAITOK) 500 pflags |= VM_ALLOC_WAITFAIL; 501 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 502 503 i = 0; 504 VM_OBJECT_WLOCK(object); 505 retry: 506 mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i)); 507 for (; i < size; i += PAGE_SIZE, mpred = m) { 508 m = vm_page_alloc_domain_after(object, atop(offset + i), 509 domain, pflags, mpred); 510 511 /* 512 * Ran out of space, free everything up and return. Don't need 513 * to lock page queues here as we know that the pages we got 514 * aren't on any queues. 515 */ 516 if (m == NULL) { 517 if ((flags & M_NOWAIT) == 0) 518 goto retry; 519 VM_OBJECT_WUNLOCK(object); 520 kmem_unback(object, addr, i); 521 return (KERN_NO_SPACE); 522 } 523 KASSERT(vm_page_domain(m) == domain, 524 ("kmem_back_domain: Domain mismatch %d != %d", 525 vm_page_domain(m), domain)); 526 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0) 527 pmap_zero_page(m); 528 KASSERT((m->oflags & VPO_UNMANAGED) != 0, 529 ("kmem_malloc: page %p is managed", m)); 530 vm_page_valid(m); 531 pmap_enter(kernel_pmap, addr + i, m, prot, 532 prot | PMAP_ENTER_WIRED, 0); 533 if (__predict_false((prot & VM_PROT_EXECUTE) != 0)) 534 m->oflags |= VPO_KMEM_EXEC; 535 } 536 VM_OBJECT_WUNLOCK(object); 537 kmem_alloc_san(addr, size, size, flags); 538 return (KERN_SUCCESS); 539 } 540 541 /* 542 * kmem_back: 543 * 544 * Allocate physical pages for the specified virtual address range. 545 */ 546 int 547 kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags) 548 { 549 vm_offset_t end, next, start; 550 int domain, rv; 551 552 KASSERT(object == kernel_object, 553 ("kmem_back: only supports kernel object.")); 554 555 for (start = addr, end = addr + size; addr < end; addr = next) { 556 /* 557 * We must ensure that pages backing a given large virtual page 558 * all come from the same physical domain. 559 */ 560 if (vm_ndomains > 1) { 561 domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains; 562 while (VM_DOMAIN_EMPTY(domain)) 563 domain++; 564 next = roundup2(addr + 1, KVA_QUANTUM); 565 if (next > end || next < start) 566 next = end; 567 } else { 568 domain = 0; 569 next = end; 570 } 571 rv = kmem_back_domain(domain, object, addr, next - addr, flags); 572 if (rv != KERN_SUCCESS) { 573 kmem_unback(object, start, addr - start); 574 break; 575 } 576 } 577 return (rv); 578 } 579 580 /* 581 * kmem_unback: 582 * 583 * Unmap and free the physical pages underlying the specified virtual 584 * address range. 585 * 586 * A physical page must exist within the specified object at each index 587 * that is being unmapped. 588 */ 589 static struct vmem * 590 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 591 { 592 struct vmem *arena; 593 vm_page_t m, next; 594 vm_offset_t end, offset; 595 int domain; 596 597 KASSERT(object == kernel_object, 598 ("kmem_unback: only supports kernel object.")); 599 600 if (size == 0) 601 return (NULL); 602 pmap_remove(kernel_pmap, addr, addr + size); 603 offset = addr - VM_MIN_KERNEL_ADDRESS; 604 end = offset + size; 605 VM_OBJECT_WLOCK(object); 606 m = vm_page_lookup(object, atop(offset)); 607 domain = vm_page_domain(m); 608 if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0)) 609 arena = vm_dom[domain].vmd_kernel_arena; 610 else 611 arena = vm_dom[domain].vmd_kernel_rwx_arena; 612 for (; offset < end; offset += PAGE_SIZE, m = next) { 613 next = vm_page_next(m); 614 vm_page_xbusy_claim(m); 615 vm_page_unwire_noq(m); 616 vm_page_free(m); 617 } 618 VM_OBJECT_WUNLOCK(object); 619 620 return (arena); 621 } 622 623 void 624 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 625 { 626 627 (void)_kmem_unback(object, addr, size); 628 } 629 630 /* 631 * kmem_free: 632 * 633 * Free memory allocated with kmem_malloc. The size must match the 634 * original allocation. 635 */ 636 void 637 kmem_free(void *addr, vm_size_t size) 638 { 639 struct vmem *arena; 640 641 size = round_page(size); 642 kasan_mark(addr, size, size, 0); 643 arena = _kmem_unback(kernel_object, (uintptr_t)addr, size); 644 if (arena != NULL) 645 vmem_free(arena, (uintptr_t)addr, size); 646 } 647 648 /* 649 * kmap_alloc_wait: 650 * 651 * Allocates pageable memory from a sub-map of the kernel. If the submap 652 * has no room, the caller sleeps waiting for more memory in the submap. 653 * 654 * This routine may block. 655 */ 656 vm_offset_t 657 kmap_alloc_wait(vm_map_t map, vm_size_t size) 658 { 659 vm_offset_t addr; 660 661 size = round_page(size); 662 if (!swap_reserve(size)) 663 return (0); 664 665 for (;;) { 666 /* 667 * To make this work for more than one map, use the map's lock 668 * to lock out sleepers/wakers. 669 */ 670 vm_map_lock(map); 671 addr = vm_map_findspace(map, vm_map_min(map), size); 672 if (addr + size <= vm_map_max(map)) 673 break; 674 /* no space now; see if we can ever get space */ 675 if (vm_map_max(map) - vm_map_min(map) < size) { 676 vm_map_unlock(map); 677 swap_release(size); 678 return (0); 679 } 680 map->needs_wakeup = TRUE; 681 vm_map_unlock_and_wait(map, 0); 682 } 683 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_RW, VM_PROT_RW, 684 MAP_ACC_CHARGED); 685 vm_map_unlock(map); 686 return (addr); 687 } 688 689 /* 690 * kmap_free_wakeup: 691 * 692 * Returns memory to a submap of the kernel, and wakes up any processes 693 * waiting for memory in that map. 694 */ 695 void 696 kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size) 697 { 698 699 vm_map_lock(map); 700 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size)); 701 if (map->needs_wakeup) { 702 map->needs_wakeup = FALSE; 703 vm_map_wakeup(map); 704 } 705 vm_map_unlock(map); 706 } 707 708 void 709 kmem_init_zero_region(void) 710 { 711 vm_offset_t addr, i; 712 vm_page_t m; 713 714 /* 715 * Map a single physical page of zeros to a larger virtual range. 716 * This requires less looping in places that want large amounts of 717 * zeros, while not using much more physical resources. 718 */ 719 addr = kva_alloc(ZERO_REGION_SIZE); 720 m = vm_page_alloc_noobj(VM_ALLOC_WIRED | VM_ALLOC_ZERO); 721 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE) 722 pmap_qenter(addr + i, &m, 1); 723 pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ); 724 725 zero_region = (const void *)addr; 726 } 727 728 /* 729 * Import KVA from the kernel map into the kernel arena. 730 */ 731 static int 732 kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp) 733 { 734 vm_offset_t addr; 735 int result; 736 737 TSENTER(); 738 KASSERT((size % KVA_QUANTUM) == 0, 739 ("kva_import: Size %jd is not a multiple of %d", 740 (intmax_t)size, (int)KVA_QUANTUM)); 741 addr = vm_map_min(kernel_map); 742 result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0, 743 VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 744 if (result != KERN_SUCCESS) { 745 TSEXIT(); 746 return (ENOMEM); 747 } 748 749 *addrp = addr; 750 751 TSEXIT(); 752 return (0); 753 } 754 755 /* 756 * Import KVA from a parent arena into a per-domain arena. Imports must be 757 * KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size. 758 */ 759 static int 760 kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp) 761 { 762 763 KASSERT((size % KVA_QUANTUM) == 0, 764 ("kva_import_domain: Size %jd is not a multiple of %d", 765 (intmax_t)size, (int)KVA_QUANTUM)); 766 return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN, 767 VMEM_ADDR_MAX, flags, addrp)); 768 } 769 770 /* 771 * kmem_init: 772 * 773 * Create the kernel map; insert a mapping covering kernel text, 774 * data, bss, and all space allocated thus far (`boostrap' data). The 775 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and 776 * `start' as allocated, and the range between `start' and `end' as free. 777 * Create the kernel vmem arena and its per-domain children. 778 */ 779 void 780 kmem_init(vm_offset_t start, vm_offset_t end) 781 { 782 vm_size_t quantum; 783 int domain; 784 785 vm_map_init(kernel_map, kernel_pmap, VM_MIN_KERNEL_ADDRESS, end); 786 kernel_map->system_map = 1; 787 vm_map_lock(kernel_map); 788 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */ 789 (void)vm_map_insert(kernel_map, NULL, 0, 790 #ifdef __amd64__ 791 KERNBASE, 792 #else 793 VM_MIN_KERNEL_ADDRESS, 794 #endif 795 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 796 /* ... and ending with the completion of the above `insert' */ 797 798 #ifdef __amd64__ 799 /* 800 * Mark KVA used for the page array as allocated. Other platforms 801 * that handle vm_page_array allocation can simply adjust virtual_avail 802 * instead. 803 */ 804 (void)vm_map_insert(kernel_map, NULL, 0, (vm_offset_t)vm_page_array, 805 (vm_offset_t)vm_page_array + round_2mpage(vm_page_array_size * 806 sizeof(struct vm_page)), 807 VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT); 808 #endif 809 vm_map_unlock(kernel_map); 810 811 /* 812 * Use a large import quantum on NUMA systems. This helps minimize 813 * interleaving of superpages, reducing internal fragmentation within 814 * the per-domain arenas. 815 */ 816 if (vm_ndomains > 1 && PMAP_HAS_DMAP) 817 quantum = KVA_NUMA_IMPORT_QUANTUM; 818 else 819 quantum = KVA_QUANTUM; 820 821 /* 822 * Initialize the kernel_arena. This can grow on demand. 823 */ 824 vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0); 825 vmem_set_import(kernel_arena, kva_import, NULL, NULL, quantum); 826 827 for (domain = 0; domain < vm_ndomains; domain++) { 828 /* 829 * Initialize the per-domain arenas. These are used to color 830 * the KVA space in a way that ensures that virtual large pages 831 * are backed by memory from the same physical domain, 832 * maximizing the potential for superpage promotion. 833 */ 834 vm_dom[domain].vmd_kernel_arena = vmem_create( 835 "kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 836 vmem_set_import(vm_dom[domain].vmd_kernel_arena, 837 kva_import_domain, NULL, kernel_arena, quantum); 838 839 /* 840 * In architectures with superpages, maintain separate arenas 841 * for allocations with permissions that differ from the 842 * "standard" read/write permissions used for kernel memory, 843 * so as not to inhibit superpage promotion. 844 * 845 * Use the base import quantum since this arena is rarely used. 846 */ 847 #if VM_NRESERVLEVEL > 0 848 vm_dom[domain].vmd_kernel_rwx_arena = vmem_create( 849 "kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 850 vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena, 851 kva_import_domain, (vmem_release_t *)vmem_xfree, 852 kernel_arena, KVA_QUANTUM); 853 #else 854 vm_dom[domain].vmd_kernel_rwx_arena = 855 vm_dom[domain].vmd_kernel_arena; 856 #endif 857 } 858 859 /* 860 * This must be the very first call so that the virtual address 861 * space used for early allocations is properly marked used in 862 * the map. 863 */ 864 uma_startup2(); 865 } 866 867 /* 868 * kmem_bootstrap_free: 869 * 870 * Free pages backing preloaded data (e.g., kernel modules) to the 871 * system. Currently only supported on platforms that create a 872 * vm_phys segment for preloaded data. 873 */ 874 void 875 kmem_bootstrap_free(vm_offset_t start, vm_size_t size) 876 { 877 #if defined(__i386__) || defined(__amd64__) 878 struct vm_domain *vmd; 879 vm_offset_t end, va; 880 vm_paddr_t pa; 881 vm_page_t m; 882 883 end = trunc_page(start + size); 884 start = round_page(start); 885 886 #ifdef __amd64__ 887 /* 888 * Preloaded files do not have execute permissions by default on amd64. 889 * Restore the default permissions to ensure that the direct map alias 890 * is updated. 891 */ 892 pmap_change_prot(start, end - start, VM_PROT_RW); 893 #endif 894 for (va = start; va < end; va += PAGE_SIZE) { 895 pa = pmap_kextract(va); 896 m = PHYS_TO_VM_PAGE(pa); 897 898 vmd = vm_pagequeue_domain(m); 899 vm_domain_free_lock(vmd); 900 vm_phys_free_pages(m, 0); 901 vm_domain_free_unlock(vmd); 902 903 vm_domain_freecnt_inc(vmd, 1); 904 vm_cnt.v_page_count++; 905 } 906 pmap_remove(kernel_pmap, start, end); 907 (void)vmem_add(kernel_arena, start, end - start, M_WAITOK); 908 #endif 909 } 910 911 #ifdef PMAP_WANT_ACTIVE_CPUS_NAIVE 912 void 913 pmap_active_cpus(pmap_t pmap, cpuset_t *res) 914 { 915 struct thread *td; 916 struct proc *p; 917 struct vmspace *vm; 918 int c; 919 920 CPU_ZERO(res); 921 CPU_FOREACH(c) { 922 td = cpuid_to_pcpu[c]->pc_curthread; 923 p = td->td_proc; 924 if (p == NULL) 925 continue; 926 vm = vmspace_acquire_ref(p); 927 if (vm == NULL) 928 continue; 929 if (pmap == vmspace_pmap(vm)) 930 CPU_SET(c, res); 931 vmspace_free(vm); 932 } 933 } 934 #endif 935 936 /* 937 * Allow userspace to directly trigger the VM drain routine for testing 938 * purposes. 939 */ 940 static int 941 debug_vm_lowmem(SYSCTL_HANDLER_ARGS) 942 { 943 int error, i; 944 945 i = 0; 946 error = sysctl_handle_int(oidp, &i, 0, req); 947 if (error != 0) 948 return (error); 949 if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0) 950 return (EINVAL); 951 if (i != 0) 952 EVENTHANDLER_INVOKE(vm_lowmem, i); 953 return (0); 954 } 955 SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, 956 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, debug_vm_lowmem, "I", 957 "set to trigger vm_lowmem event with given flags"); 958 959 static int 960 debug_uma_reclaim(SYSCTL_HANDLER_ARGS) 961 { 962 int error, i; 963 964 i = 0; 965 error = sysctl_handle_int(oidp, &i, 0, req); 966 if (error != 0 || req->newptr == NULL) 967 return (error); 968 if (i != UMA_RECLAIM_TRIM && i != UMA_RECLAIM_DRAIN && 969 i != UMA_RECLAIM_DRAIN_CPU) 970 return (EINVAL); 971 uma_reclaim(i); 972 return (0); 973 } 974 SYSCTL_PROC(_debug, OID_AUTO, uma_reclaim, 975 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, debug_uma_reclaim, "I", 976 "set to generate request to reclaim uma caches"); 977 978 static int 979 debug_uma_reclaim_domain(SYSCTL_HANDLER_ARGS) 980 { 981 int domain, error, request; 982 983 request = 0; 984 error = sysctl_handle_int(oidp, &request, 0, req); 985 if (error != 0 || req->newptr == NULL) 986 return (error); 987 988 domain = request >> 4; 989 request &= 0xf; 990 if (request != UMA_RECLAIM_TRIM && request != UMA_RECLAIM_DRAIN && 991 request != UMA_RECLAIM_DRAIN_CPU) 992 return (EINVAL); 993 if (domain < 0 || domain >= vm_ndomains) 994 return (EINVAL); 995 uma_reclaim_domain(request, domain); 996 return (0); 997 } 998 SYSCTL_PROC(_debug, OID_AUTO, uma_reclaim_domain, 999 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, 1000 debug_uma_reclaim_domain, "I", 1001 ""); 1002