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 * 35 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 36 * All rights reserved. 37 * 38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 39 * 40 * Permission to use, copy, modify and distribute this software and 41 * its documentation is hereby granted, provided that both the copyright 42 * notice and this permission notice appear in all copies of the 43 * software, derivative works or modified versions, and any portions 44 * thereof, and that both notices appear in supporting documentation. 45 * 46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 49 * 50 * Carnegie Mellon requests users of this software to return to 51 * 52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 53 * School of Computer Science 54 * Carnegie Mellon University 55 * Pittsburgh PA 15213-3890 56 * 57 * any improvements or extensions that they make and grant Carnegie the 58 * rights to redistribute these changes. 59 */ 60 61 /* 62 * Kernel memory management. 63 */ 64 65 #include <sys/cdefs.h> 66 #include "opt_vm.h" 67 68 #include <sys/param.h> 69 #include <sys/systm.h> 70 #include <sys/asan.h> 71 #include <sys/domainset.h> 72 #include <sys/eventhandler.h> 73 #include <sys/kernel.h> 74 #include <sys/lock.h> 75 #include <sys/malloc.h> 76 #include <sys/msan.h> 77 #include <sys/proc.h> 78 #include <sys/rwlock.h> 79 #include <sys/smp.h> 80 #include <sys/sysctl.h> 81 #include <sys/vmem.h> 82 #include <sys/vmmeter.h> 83 84 #include <vm/vm.h> 85 #include <vm/vm_param.h> 86 #include <vm/vm_domainset.h> 87 #include <vm/vm_kern.h> 88 #include <vm/pmap.h> 89 #include <vm/vm_map.h> 90 #include <vm/vm_object.h> 91 #include <vm/vm_page.h> 92 #include <vm/vm_pageout.h> 93 #include <vm/vm_pagequeue.h> 94 #include <vm/vm_phys.h> 95 #include <vm/vm_radix.h> 96 #include <vm/vm_extern.h> 97 #include <vm/uma.h> 98 99 struct vm_map kernel_map_store; 100 struct vm_map exec_map_store; 101 struct vm_map pipe_map_store; 102 103 const void *zero_region; 104 CTASSERT((ZERO_REGION_SIZE & PAGE_MASK) == 0); 105 106 /* NB: Used by kernel debuggers. */ 107 const u_long vm_maxuser_address = VM_MAXUSER_ADDRESS; 108 109 u_int exec_map_entry_size; 110 u_int exec_map_entries; 111 112 SYSCTL_ULONG(_vm, OID_AUTO, min_kernel_address, CTLFLAG_RD, 113 SYSCTL_NULL_ULONG_PTR, VM_MIN_KERNEL_ADDRESS, "Min kernel address"); 114 115 SYSCTL_ULONG(_vm, OID_AUTO, max_kernel_address, CTLFLAG_RD, 116 #if defined(__arm__) 117 &vm_max_kernel_address, 0, 118 #else 119 SYSCTL_NULL_ULONG_PTR, VM_MAX_KERNEL_ADDRESS, 120 #endif 121 "Max kernel address"); 122 123 #if VM_NRESERVLEVEL > 1 124 #define KVA_QUANTUM_SHIFT (VM_LEVEL_1_ORDER + VM_LEVEL_0_ORDER + \ 125 PAGE_SHIFT) 126 #elif 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_xalloc(kernel_arena, size, 0, 0, 0, VMEM_ADDR_MIN, 154 VMEM_ADDR_MAX, M_BESTFIT | M_NOWAIT, &addr)) 155 return (0); 156 TSEXIT(); 157 158 return (addr); 159 } 160 161 /* 162 * kva_alloc_aligned: 163 * 164 * Allocate a virtual address range as in kva_alloc where the base 165 * address is aligned to align. 166 */ 167 vm_offset_t 168 kva_alloc_aligned(vm_size_t size, vm_size_t align) 169 { 170 vm_offset_t addr; 171 172 TSENTER(); 173 size = round_page(size); 174 if (vmem_xalloc(kernel_arena, size, align, 0, 0, VMEM_ADDR_MIN, 175 VMEM_ADDR_MAX, M_BESTFIT | M_NOWAIT, &addr)) 176 return (0); 177 TSEXIT(); 178 179 return (addr); 180 } 181 182 /* 183 * kva_free: 184 * 185 * Release a region of kernel virtual memory allocated 186 * with kva_alloc, and return the physical pages 187 * associated with that region. 188 * 189 * This routine may not block on kernel maps. 190 */ 191 void 192 kva_free(vm_offset_t addr, vm_size_t size) 193 { 194 195 size = round_page(size); 196 vmem_xfree(kernel_arena, addr, size); 197 } 198 199 /* 200 * Update sanitizer shadow state to reflect a new allocation. Force inlining to 201 * help make KMSAN origin tracking more precise. 202 */ 203 static __always_inline void 204 kmem_alloc_san(vm_offset_t addr, vm_size_t size, vm_size_t asize, int flags) 205 { 206 if ((flags & M_ZERO) == 0) { 207 kmsan_mark((void *)addr, asize, KMSAN_STATE_UNINIT); 208 kmsan_orig((void *)addr, asize, KMSAN_TYPE_KMEM, 209 KMSAN_RET_ADDR); 210 } else { 211 kmsan_mark((void *)addr, asize, KMSAN_STATE_INITED); 212 } 213 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE); 214 } 215 216 static vm_page_t 217 kmem_alloc_contig_pages(vm_object_t object, vm_pindex_t pindex, int domain, 218 int pflags, u_long npages, vm_paddr_t low, vm_paddr_t high, 219 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) 220 { 221 vm_page_t m; 222 int tries; 223 bool wait, reclaim; 224 225 VM_OBJECT_ASSERT_WLOCKED(object); 226 227 wait = (pflags & VM_ALLOC_WAITOK) != 0; 228 reclaim = (pflags & VM_ALLOC_NORECLAIM) == 0; 229 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 230 pflags |= VM_ALLOC_NOWAIT; 231 for (tries = wait ? 3 : 1;; tries--) { 232 m = vm_page_alloc_contig_domain(object, pindex, domain, pflags, 233 npages, low, high, alignment, boundary, memattr); 234 if (m != NULL || tries == 0 || !reclaim) 235 break; 236 237 VM_OBJECT_WUNLOCK(object); 238 if (vm_page_reclaim_contig_domain(domain, pflags, npages, 239 low, high, alignment, boundary) == ENOMEM && wait) 240 vm_wait_domain(domain); 241 VM_OBJECT_WLOCK(object); 242 } 243 return (m); 244 } 245 246 /* 247 * Allocates a region from the kernel address map and physical pages 248 * within the specified address range to the kernel object. Creates a 249 * wired mapping from this region to these pages, and returns the 250 * region's starting virtual address. The allocated pages are not 251 * necessarily physically contiguous. If M_ZERO is specified through the 252 * given flags, then the pages are zeroed before they are mapped. 253 */ 254 static void * 255 kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 256 vm_paddr_t high, vm_memattr_t memattr) 257 { 258 vmem_t *vmem; 259 vm_object_t object; 260 vm_offset_t addr, i, offset; 261 vm_page_t m; 262 vm_size_t asize; 263 int pflags; 264 vm_prot_t prot; 265 266 object = kernel_object; 267 asize = round_page(size); 268 vmem = vm_dom[domain].vmd_kernel_arena; 269 if (vmem_alloc(vmem, asize, M_BESTFIT | flags, &addr)) 270 return (0); 271 offset = addr - VM_MIN_KERNEL_ADDRESS; 272 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 273 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 274 VM_OBJECT_WLOCK(object); 275 for (i = 0; i < asize; i += PAGE_SIZE) { 276 m = kmem_alloc_contig_pages(object, atop(offset + i), 277 domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr); 278 if (m == NULL) { 279 VM_OBJECT_WUNLOCK(object); 280 kmem_unback(object, addr, i); 281 vmem_free(vmem, addr, asize); 282 return (0); 283 } 284 KASSERT(vm_page_domain(m) == domain, 285 ("kmem_alloc_attr_domain: Domain mismatch %d != %d", 286 vm_page_domain(m), domain)); 287 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 288 pmap_zero_page(m); 289 vm_page_valid(m); 290 pmap_enter(kernel_pmap, addr + i, m, prot, 291 prot | PMAP_ENTER_WIRED, 0); 292 } 293 VM_OBJECT_WUNLOCK(object); 294 kmem_alloc_san(addr, size, asize, flags); 295 return ((void *)addr); 296 } 297 298 void * 299 kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 300 vm_memattr_t memattr) 301 { 302 303 return (kmem_alloc_attr_domainset(DOMAINSET_RR(), size, flags, low, 304 high, memattr)); 305 } 306 307 void * 308 kmem_alloc_attr_domainset(struct domainset *ds, vm_size_t size, int flags, 309 vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr) 310 { 311 struct vm_domainset_iter di; 312 vm_page_t bounds[2]; 313 void *addr; 314 int domain; 315 int start_segind; 316 317 start_segind = -1; 318 319 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 320 do { 321 addr = kmem_alloc_attr_domain(domain, size, flags, low, high, 322 memattr); 323 if (addr != NULL) 324 break; 325 if (start_segind == -1) 326 start_segind = vm_phys_lookup_segind(low); 327 if (vm_phys_find_range(bounds, start_segind, domain, 328 atop(round_page(size)), low, high) == -1) { 329 vm_domainset_iter_ignore(&di, domain); 330 } 331 } while (vm_domainset_iter_policy(&di, &domain) == 0); 332 333 return (addr); 334 } 335 336 /* 337 * Allocates a region from the kernel address map and physically 338 * contiguous pages within the specified address range to the kernel 339 * object. Creates a wired mapping from this region to these pages, and 340 * returns the region's starting virtual address. If M_ZERO is specified 341 * through the given flags, then the pages are zeroed before they are 342 * mapped. 343 */ 344 static void * 345 kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 346 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 347 vm_memattr_t memattr) 348 { 349 vmem_t *vmem; 350 vm_object_t object; 351 vm_offset_t addr, offset, tmp; 352 vm_page_t end_m, m; 353 vm_size_t asize; 354 u_long npages; 355 int pflags; 356 357 object = kernel_object; 358 asize = round_page(size); 359 vmem = vm_dom[domain].vmd_kernel_arena; 360 if (vmem_alloc(vmem, asize, flags | M_BESTFIT, &addr)) 361 return (NULL); 362 offset = addr - VM_MIN_KERNEL_ADDRESS; 363 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 364 npages = atop(asize); 365 VM_OBJECT_WLOCK(object); 366 m = kmem_alloc_contig_pages(object, atop(offset), domain, 367 pflags, npages, low, high, alignment, boundary, memattr); 368 if (m == NULL) { 369 VM_OBJECT_WUNLOCK(object); 370 vmem_free(vmem, addr, asize); 371 return (NULL); 372 } 373 KASSERT(vm_page_domain(m) == domain, 374 ("kmem_alloc_contig_domain: Domain mismatch %d != %d", 375 vm_page_domain(m), domain)); 376 end_m = m + npages; 377 tmp = addr; 378 for (; m < end_m; m++) { 379 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 380 pmap_zero_page(m); 381 vm_page_valid(m); 382 pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW, 383 VM_PROT_RW | PMAP_ENTER_WIRED, 0); 384 tmp += PAGE_SIZE; 385 } 386 VM_OBJECT_WUNLOCK(object); 387 kmem_alloc_san(addr, size, asize, flags); 388 return ((void *)addr); 389 } 390 391 void * 392 kmem_alloc_contig(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 393 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) 394 { 395 396 return (kmem_alloc_contig_domainset(DOMAINSET_RR(), size, flags, low, 397 high, alignment, boundary, memattr)); 398 } 399 400 void * 401 kmem_alloc_contig_domainset(struct domainset *ds, vm_size_t size, int flags, 402 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 403 vm_memattr_t memattr) 404 { 405 struct vm_domainset_iter di; 406 vm_page_t bounds[2]; 407 void *addr; 408 int domain; 409 int start_segind; 410 411 start_segind = -1; 412 413 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 414 do { 415 addr = kmem_alloc_contig_domain(domain, size, flags, low, high, 416 alignment, boundary, memattr); 417 if (addr != NULL) 418 break; 419 if (start_segind == -1) 420 start_segind = vm_phys_lookup_segind(low); 421 if (vm_phys_find_range(bounds, start_segind, domain, 422 atop(round_page(size)), low, high) == -1) { 423 vm_domainset_iter_ignore(&di, domain); 424 } 425 } while (vm_domainset_iter_policy(&di, &domain) == 0); 426 427 return (addr); 428 } 429 430 /* 431 * kmem_subinit: 432 * 433 * Initializes a map to manage a subrange 434 * of the kernel virtual address space. 435 * 436 * Arguments are as follows: 437 * 438 * parent Map to take range from 439 * min, max Returned endpoints of map 440 * size Size of range to find 441 * superpage_align Request that min is superpage aligned 442 */ 443 void 444 kmem_subinit(vm_map_t map, vm_map_t parent, vm_offset_t *min, vm_offset_t *max, 445 vm_size_t size, bool superpage_align) 446 { 447 int ret; 448 449 size = round_page(size); 450 451 *min = vm_map_min(parent); 452 ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ? 453 VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL, 454 MAP_ACC_NO_CHARGE); 455 if (ret != KERN_SUCCESS) 456 panic("kmem_subinit: bad status return of %d", ret); 457 *max = *min + size; 458 vm_map_init(map, vm_map_pmap(parent), *min, *max); 459 if (vm_map_submap(parent, *min, *max, map) != KERN_SUCCESS) 460 panic("kmem_subinit: unable to change range to submap"); 461 } 462 463 /* 464 * kmem_malloc_domain: 465 * 466 * Allocate wired-down pages in the kernel's address space. 467 */ 468 static void * 469 kmem_malloc_domain(int domain, vm_size_t size, int flags) 470 { 471 vmem_t *arena; 472 vm_offset_t addr; 473 vm_size_t asize; 474 int rv; 475 476 if (__predict_true((flags & M_EXEC) == 0)) 477 arena = vm_dom[domain].vmd_kernel_arena; 478 else 479 arena = vm_dom[domain].vmd_kernel_rwx_arena; 480 asize = round_page(size); 481 if (vmem_alloc(arena, asize, flags | M_BESTFIT, &addr)) 482 return (0); 483 484 rv = kmem_back_domain(domain, kernel_object, addr, asize, flags); 485 if (rv != KERN_SUCCESS) { 486 vmem_free(arena, addr, asize); 487 return (0); 488 } 489 kasan_mark((void *)addr, size, asize, KASAN_KMEM_REDZONE); 490 return ((void *)addr); 491 } 492 493 void * 494 kmem_malloc(vm_size_t size, int flags) 495 { 496 void * p; 497 498 TSENTER(); 499 p = kmem_malloc_domainset(DOMAINSET_RR(), size, flags); 500 TSEXIT(); 501 return (p); 502 } 503 504 void * 505 kmem_malloc_domainset(struct domainset *ds, vm_size_t size, int flags) 506 { 507 struct vm_domainset_iter di; 508 void *addr; 509 int domain; 510 511 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 512 do { 513 addr = kmem_malloc_domain(domain, size, flags); 514 if (addr != NULL) 515 break; 516 } while (vm_domainset_iter_policy(&di, &domain) == 0); 517 518 return (addr); 519 } 520 521 /* 522 * kmem_back_domain: 523 * 524 * Allocate physical pages from the specified domain for the specified 525 * virtual address range. 526 */ 527 int 528 kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr, 529 vm_size_t size, int flags) 530 { 531 vm_offset_t offset, i; 532 vm_page_t m, mpred; 533 vm_prot_t prot; 534 int pflags; 535 536 KASSERT(object == kernel_object, 537 ("kmem_back_domain: only supports kernel object.")); 538 539 offset = addr - VM_MIN_KERNEL_ADDRESS; 540 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 541 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 542 if (flags & M_WAITOK) 543 pflags |= VM_ALLOC_WAITFAIL; 544 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 545 546 i = 0; 547 VM_OBJECT_WLOCK(object); 548 retry: 549 mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i)); 550 for (; i < size; i += PAGE_SIZE, mpred = m) { 551 m = vm_page_alloc_domain_after(object, atop(offset + i), 552 domain, pflags, mpred); 553 554 /* 555 * Ran out of space, free everything up and return. Don't need 556 * to lock page queues here as we know that the pages we got 557 * aren't on any queues. 558 */ 559 if (m == NULL) { 560 if ((flags & M_NOWAIT) == 0) 561 goto retry; 562 VM_OBJECT_WUNLOCK(object); 563 kmem_unback(object, addr, i); 564 return (KERN_NO_SPACE); 565 } 566 KASSERT(vm_page_domain(m) == domain, 567 ("kmem_back_domain: Domain mismatch %d != %d", 568 vm_page_domain(m), domain)); 569 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0) 570 pmap_zero_page(m); 571 KASSERT((m->oflags & VPO_UNMANAGED) != 0, 572 ("kmem_malloc: page %p is managed", m)); 573 vm_page_valid(m); 574 pmap_enter(kernel_pmap, addr + i, m, prot, 575 prot | PMAP_ENTER_WIRED, 0); 576 if (__predict_false((prot & VM_PROT_EXECUTE) != 0)) 577 m->oflags |= VPO_KMEM_EXEC; 578 } 579 VM_OBJECT_WUNLOCK(object); 580 kmem_alloc_san(addr, size, size, flags); 581 return (KERN_SUCCESS); 582 } 583 584 /* 585 * kmem_back: 586 * 587 * Allocate physical pages for the specified virtual address range. 588 */ 589 int 590 kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags) 591 { 592 vm_offset_t end, next, start; 593 int domain, rv; 594 595 KASSERT(object == kernel_object, 596 ("kmem_back: only supports kernel object.")); 597 598 for (start = addr, end = addr + size; addr < end; addr = next) { 599 /* 600 * We must ensure that pages backing a given large virtual page 601 * all come from the same physical domain. 602 */ 603 if (vm_ndomains > 1) { 604 domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains; 605 while (VM_DOMAIN_EMPTY(domain)) 606 domain++; 607 next = roundup2(addr + 1, KVA_QUANTUM); 608 if (next > end || next < start) 609 next = end; 610 } else { 611 domain = 0; 612 next = end; 613 } 614 rv = kmem_back_domain(domain, object, addr, next - addr, flags); 615 if (rv != KERN_SUCCESS) { 616 kmem_unback(object, start, addr - start); 617 break; 618 } 619 } 620 return (rv); 621 } 622 623 /* 624 * kmem_unback: 625 * 626 * Unmap and free the physical pages underlying the specified virtual 627 * address range. 628 * 629 * A physical page must exist within the specified object at each index 630 * that is being unmapped. 631 */ 632 static struct vmem * 633 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 634 { 635 struct vmem *arena; 636 vm_page_t m, next; 637 vm_offset_t end, offset; 638 int domain; 639 640 KASSERT(object == kernel_object, 641 ("kmem_unback: only supports kernel object.")); 642 643 if (size == 0) 644 return (NULL); 645 pmap_remove(kernel_pmap, addr, addr + size); 646 offset = addr - VM_MIN_KERNEL_ADDRESS; 647 end = offset + size; 648 VM_OBJECT_WLOCK(object); 649 m = vm_page_lookup(object, atop(offset)); 650 domain = vm_page_domain(m); 651 if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0)) 652 arena = vm_dom[domain].vmd_kernel_arena; 653 else 654 arena = vm_dom[domain].vmd_kernel_rwx_arena; 655 for (; offset < end; offset += PAGE_SIZE, m = next) { 656 next = vm_page_next(m); 657 vm_page_xbusy_claim(m); 658 vm_page_unwire_noq(m); 659 vm_page_free(m); 660 } 661 VM_OBJECT_WUNLOCK(object); 662 663 return (arena); 664 } 665 666 void 667 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 668 { 669 670 (void)_kmem_unback(object, addr, size); 671 } 672 673 /* 674 * kmem_free: 675 * 676 * Free memory allocated with kmem_malloc. The size must match the 677 * original allocation. 678 */ 679 void 680 kmem_free(void *addr, vm_size_t size) 681 { 682 struct vmem *arena; 683 684 size = round_page(size); 685 kasan_mark(addr, size, size, 0); 686 arena = _kmem_unback(kernel_object, (uintptr_t)addr, size); 687 if (arena != NULL) 688 vmem_free(arena, (uintptr_t)addr, size); 689 } 690 691 /* 692 * kmap_alloc_wait: 693 * 694 * Allocates pageable memory from a sub-map of the kernel. If the submap 695 * has no room, the caller sleeps waiting for more memory in the submap. 696 * 697 * This routine may block. 698 */ 699 vm_offset_t 700 kmap_alloc_wait(vm_map_t map, vm_size_t size) 701 { 702 vm_offset_t addr; 703 704 size = round_page(size); 705 if (!swap_reserve(size)) 706 return (0); 707 708 for (;;) { 709 /* 710 * To make this work for more than one map, use the map's lock 711 * to lock out sleepers/wakers. 712 */ 713 vm_map_lock(map); 714 addr = vm_map_findspace(map, vm_map_min(map), size); 715 if (addr + size <= vm_map_max(map)) 716 break; 717 /* no space now; see if we can ever get space */ 718 if (vm_map_max(map) - vm_map_min(map) < size) { 719 vm_map_unlock(map); 720 swap_release(size); 721 return (0); 722 } 723 map->needs_wakeup = TRUE; 724 vm_map_unlock_and_wait(map, 0); 725 } 726 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_RW, VM_PROT_RW, 727 MAP_ACC_CHARGED); 728 vm_map_unlock(map); 729 return (addr); 730 } 731 732 /* 733 * kmap_free_wakeup: 734 * 735 * Returns memory to a submap of the kernel, and wakes up any processes 736 * waiting for memory in that map. 737 */ 738 void 739 kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size) 740 { 741 742 vm_map_lock(map); 743 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size)); 744 if (map->needs_wakeup) { 745 map->needs_wakeup = FALSE; 746 vm_map_wakeup(map); 747 } 748 vm_map_unlock(map); 749 } 750 751 void 752 kmem_init_zero_region(void) 753 { 754 vm_offset_t addr, i; 755 vm_page_t m; 756 757 /* 758 * Map a single physical page of zeros to a larger virtual range. 759 * This requires less looping in places that want large amounts of 760 * zeros, while not using much more physical resources. 761 */ 762 addr = kva_alloc(ZERO_REGION_SIZE); 763 m = vm_page_alloc_noobj(VM_ALLOC_WIRED | VM_ALLOC_ZERO); 764 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE) 765 pmap_qenter(addr + i, &m, 1); 766 pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ); 767 768 zero_region = (const void *)addr; 769 } 770 771 /* 772 * Import KVA from the kernel map into the kernel arena. 773 */ 774 static int 775 kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp) 776 { 777 vm_offset_t addr; 778 int result; 779 780 TSENTER(); 781 KASSERT((size % KVA_QUANTUM) == 0, 782 ("kva_import: Size %jd is not a multiple of %d", 783 (intmax_t)size, (int)KVA_QUANTUM)); 784 addr = vm_map_min(kernel_map); 785 result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0, 786 VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 787 if (result != KERN_SUCCESS) { 788 TSEXIT(); 789 return (ENOMEM); 790 } 791 792 *addrp = addr; 793 794 TSEXIT(); 795 return (0); 796 } 797 798 /* 799 * Import KVA from a parent arena into a per-domain arena. Imports must be 800 * KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size. 801 */ 802 static int 803 kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp) 804 { 805 806 KASSERT((size % KVA_QUANTUM) == 0, 807 ("kva_import_domain: Size %jd is not a multiple of %d", 808 (intmax_t)size, (int)KVA_QUANTUM)); 809 return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN, 810 VMEM_ADDR_MAX, flags, addrp)); 811 } 812 813 /* 814 * kmem_init: 815 * 816 * Create the kernel map; insert a mapping covering kernel text, 817 * data, bss, and all space allocated thus far (`boostrap' data). The 818 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and 819 * `start' as allocated, and the range between `start' and `end' as free. 820 * Create the kernel vmem arena and its per-domain children. 821 */ 822 void 823 kmem_init(vm_offset_t start, vm_offset_t end) 824 { 825 vm_size_t quantum; 826 int domain; 827 828 vm_map_init(kernel_map, kernel_pmap, VM_MIN_KERNEL_ADDRESS, end); 829 kernel_map->system_map = 1; 830 vm_map_lock(kernel_map); 831 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */ 832 (void)vm_map_insert(kernel_map, NULL, 0, 833 #ifdef __amd64__ 834 KERNBASE, 835 #else 836 VM_MIN_KERNEL_ADDRESS, 837 #endif 838 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 839 /* ... and ending with the completion of the above `insert' */ 840 841 #ifdef __amd64__ 842 /* 843 * Mark KVA used for the page array as allocated. Other platforms 844 * that handle vm_page_array allocation can simply adjust virtual_avail 845 * instead. 846 */ 847 (void)vm_map_insert(kernel_map, NULL, 0, (vm_offset_t)vm_page_array, 848 (vm_offset_t)vm_page_array + round_2mpage(vm_page_array_size * 849 sizeof(struct vm_page)), 850 VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT); 851 #endif 852 vm_map_unlock(kernel_map); 853 854 /* 855 * Use a large import quantum on NUMA systems. This helps minimize 856 * interleaving of superpages, reducing internal fragmentation within 857 * the per-domain arenas. 858 */ 859 if (vm_ndomains > 1 && PMAP_HAS_DMAP) 860 quantum = KVA_NUMA_IMPORT_QUANTUM; 861 else 862 quantum = KVA_QUANTUM; 863 864 /* 865 * Initialize the kernel_arena. This can grow on demand. 866 */ 867 vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0); 868 vmem_set_import(kernel_arena, kva_import, NULL, NULL, quantum); 869 870 for (domain = 0; domain < vm_ndomains; domain++) { 871 /* 872 * Initialize the per-domain arenas. These are used to color 873 * the KVA space in a way that ensures that virtual large pages 874 * are backed by memory from the same physical domain, 875 * maximizing the potential for superpage promotion. 876 */ 877 vm_dom[domain].vmd_kernel_arena = vmem_create( 878 "kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 879 vmem_set_import(vm_dom[domain].vmd_kernel_arena, 880 kva_import_domain, NULL, kernel_arena, quantum); 881 882 /* 883 * In architectures with superpages, maintain separate arenas 884 * for allocations with permissions that differ from the 885 * "standard" read/write permissions used for kernel memory, 886 * so as not to inhibit superpage promotion. 887 * 888 * Use the base import quantum since this arena is rarely used. 889 */ 890 #if VM_NRESERVLEVEL > 0 891 vm_dom[domain].vmd_kernel_rwx_arena = vmem_create( 892 "kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 893 vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena, 894 kva_import_domain, (vmem_release_t *)vmem_xfree, 895 kernel_arena, KVA_QUANTUM); 896 #else 897 vm_dom[domain].vmd_kernel_rwx_arena = 898 vm_dom[domain].vmd_kernel_arena; 899 #endif 900 } 901 902 /* 903 * This must be the very first call so that the virtual address 904 * space used for early allocations is properly marked used in 905 * the map. 906 */ 907 uma_startup2(); 908 } 909 910 /* 911 * kmem_bootstrap_free: 912 * 913 * Free pages backing preloaded data (e.g., kernel modules) to the 914 * system. Currently only supported on platforms that create a 915 * vm_phys segment for preloaded data. 916 */ 917 void 918 kmem_bootstrap_free(vm_offset_t start, vm_size_t size) 919 { 920 #if defined(__i386__) || defined(__amd64__) 921 struct vm_domain *vmd; 922 vm_offset_t end, va; 923 vm_paddr_t pa; 924 vm_page_t m; 925 926 end = trunc_page(start + size); 927 start = round_page(start); 928 929 #ifdef __amd64__ 930 /* 931 * Preloaded files do not have execute permissions by default on amd64. 932 * Restore the default permissions to ensure that the direct map alias 933 * is updated. 934 */ 935 pmap_change_prot(start, end - start, VM_PROT_RW); 936 #endif 937 for (va = start; va < end; va += PAGE_SIZE) { 938 pa = pmap_kextract(va); 939 m = PHYS_TO_VM_PAGE(pa); 940 941 vmd = vm_pagequeue_domain(m); 942 vm_domain_free_lock(vmd); 943 vm_phys_free_pages(m, 0); 944 vm_domain_free_unlock(vmd); 945 946 vm_domain_freecnt_inc(vmd, 1); 947 vm_cnt.v_page_count++; 948 } 949 pmap_remove(kernel_pmap, start, end); 950 (void)vmem_add(kernel_arena, start, end - start, M_WAITOK); 951 #endif 952 } 953 954 #ifdef PMAP_WANT_ACTIVE_CPUS_NAIVE 955 void 956 pmap_active_cpus(pmap_t pmap, cpuset_t *res) 957 { 958 struct thread *td; 959 struct proc *p; 960 struct vmspace *vm; 961 int c; 962 963 CPU_ZERO(res); 964 CPU_FOREACH(c) { 965 td = cpuid_to_pcpu[c]->pc_curthread; 966 p = td->td_proc; 967 if (p == NULL) 968 continue; 969 vm = vmspace_acquire_ref(p); 970 if (vm == NULL) 971 continue; 972 if (pmap == vmspace_pmap(vm)) 973 CPU_SET(c, res); 974 vmspace_free(vm); 975 } 976 } 977 #endif 978 979 /* 980 * Allow userspace to directly trigger the VM drain routine for testing 981 * purposes. 982 */ 983 static int 984 debug_vm_lowmem(SYSCTL_HANDLER_ARGS) 985 { 986 int error, i; 987 988 i = 0; 989 error = sysctl_handle_int(oidp, &i, 0, req); 990 if (error != 0) 991 return (error); 992 if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0) 993 return (EINVAL); 994 if (i != 0) 995 EVENTHANDLER_INVOKE(vm_lowmem, i); 996 return (0); 997 } 998 SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, 999 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, debug_vm_lowmem, "I", 1000 "set to trigger vm_lowmem event with given flags"); 1001 1002 static int 1003 debug_uma_reclaim(SYSCTL_HANDLER_ARGS) 1004 { 1005 int error, i; 1006 1007 i = 0; 1008 error = sysctl_handle_int(oidp, &i, 0, req); 1009 if (error != 0 || req->newptr == NULL) 1010 return (error); 1011 if (i != UMA_RECLAIM_TRIM && i != UMA_RECLAIM_DRAIN && 1012 i != UMA_RECLAIM_DRAIN_CPU) 1013 return (EINVAL); 1014 uma_reclaim(i); 1015 return (0); 1016 } 1017 SYSCTL_PROC(_debug, OID_AUTO, uma_reclaim, 1018 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, debug_uma_reclaim, "I", 1019 "set to generate request to reclaim uma caches"); 1020 1021 static int 1022 debug_uma_reclaim_domain(SYSCTL_HANDLER_ARGS) 1023 { 1024 int domain, error, request; 1025 1026 request = 0; 1027 error = sysctl_handle_int(oidp, &request, 0, req); 1028 if (error != 0 || req->newptr == NULL) 1029 return (error); 1030 1031 domain = request >> 4; 1032 request &= 0xf; 1033 if (request != UMA_RECLAIM_TRIM && request != UMA_RECLAIM_DRAIN && 1034 request != UMA_RECLAIM_DRAIN_CPU) 1035 return (EINVAL); 1036 if (domain < 0 || domain >= vm_ndomains) 1037 return (EINVAL); 1038 uma_reclaim_domain(request, domain); 1039 return (0); 1040 } 1041 SYSCTL_PROC(_debug, OID_AUTO, uma_reclaim_domain, 1042 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, 1043 debug_uma_reclaim_domain, "I", 1044 ""); 1045