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/kernel.h> /* for ticks and hz */ 75 #include <sys/domainset.h> 76 #include <sys/eventhandler.h> 77 #include <sys/lock.h> 78 #include <sys/proc.h> 79 #include <sys/malloc.h> 80 #include <sys/rwlock.h> 81 #include <sys/sysctl.h> 82 #include <sys/vmem.h> 83 #include <sys/vmmeter.h> 84 85 #include <vm/vm.h> 86 #include <vm/vm_param.h> 87 #include <vm/vm_domainset.h> 88 #include <vm/vm_kern.h> 89 #include <vm/pmap.h> 90 #include <vm/vm_map.h> 91 #include <vm/vm_object.h> 92 #include <vm/vm_page.h> 93 #include <vm/vm_pageout.h> 94 #include <vm/vm_pagequeue.h> 95 #include <vm/vm_phys.h> 96 #include <vm/vm_radix.h> 97 #include <vm/vm_extern.h> 98 #include <vm/uma.h> 99 100 struct vm_map kernel_map_store; 101 struct vm_map exec_map_store; 102 struct vm_map pipe_map_store; 103 104 const void *zero_region; 105 CTASSERT((ZERO_REGION_SIZE & PAGE_MASK) == 0); 106 107 /* NB: Used by kernel debuggers. */ 108 const u_long vm_maxuser_address = VM_MAXUSER_ADDRESS; 109 110 u_int exec_map_entry_size; 111 u_int exec_map_entries; 112 113 SYSCTL_ULONG(_vm, OID_AUTO, min_kernel_address, CTLFLAG_RD, 114 SYSCTL_NULL_ULONG_PTR, VM_MIN_KERNEL_ADDRESS, "Min kernel address"); 115 116 SYSCTL_ULONG(_vm, OID_AUTO, max_kernel_address, CTLFLAG_RD, 117 #if defined(__arm__) 118 &vm_max_kernel_address, 0, 119 #else 120 SYSCTL_NULL_ULONG_PTR, VM_MAX_KERNEL_ADDRESS, 121 #endif 122 "Max kernel address"); 123 124 #if VM_NRESERVLEVEL > 0 125 #define KVA_QUANTUM_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT) 126 #else 127 /* On non-superpage architectures we want large import sizes. */ 128 #define KVA_QUANTUM_SHIFT (8 + PAGE_SHIFT) 129 #endif 130 #define KVA_QUANTUM (1 << KVA_QUANTUM_SHIFT) 131 #define KVA_NUMA_IMPORT_QUANTUM (KVA_QUANTUM * 128) 132 133 extern void uma_startup2(void); 134 135 /* 136 * kva_alloc: 137 * 138 * Allocate a virtual address range with no underlying object and 139 * no initial mapping to physical memory. Any mapping from this 140 * range to physical memory must be explicitly created prior to 141 * its use, typically with pmap_qenter(). Any attempt to create 142 * a mapping on demand through vm_fault() will result in a panic. 143 */ 144 vm_offset_t 145 kva_alloc(vm_size_t size) 146 { 147 vm_offset_t addr; 148 149 size = round_page(size); 150 if (vmem_alloc(kernel_arena, size, M_BESTFIT | M_NOWAIT, &addr)) 151 return (0); 152 153 return (addr); 154 } 155 156 /* 157 * kva_free: 158 * 159 * Release a region of kernel virtual memory allocated 160 * with kva_alloc, and return the physical pages 161 * associated with that region. 162 * 163 * This routine may not block on kernel maps. 164 */ 165 void 166 kva_free(vm_offset_t addr, vm_size_t size) 167 { 168 169 size = round_page(size); 170 vmem_free(kernel_arena, addr, size); 171 } 172 173 static vm_page_t 174 kmem_alloc_contig_pages(vm_object_t object, vm_pindex_t pindex, int domain, 175 int pflags, u_long npages, vm_paddr_t low, vm_paddr_t high, 176 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) 177 { 178 vm_page_t m; 179 int tries; 180 bool wait; 181 182 VM_OBJECT_ASSERT_WLOCKED(object); 183 184 wait = (pflags & VM_ALLOC_WAITOK) != 0; 185 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 186 pflags |= VM_ALLOC_NOWAIT; 187 for (tries = wait ? 3 : 1;; tries--) { 188 m = vm_page_alloc_contig_domain(object, pindex, domain, pflags, 189 npages, low, high, alignment, boundary, memattr); 190 if (m != NULL || tries == 0) 191 break; 192 193 VM_OBJECT_WUNLOCK(object); 194 if (!vm_page_reclaim_contig_domain(domain, pflags, npages, 195 low, high, alignment, boundary) && wait) 196 vm_wait_domain(domain); 197 VM_OBJECT_WLOCK(object); 198 } 199 return (m); 200 } 201 202 /* 203 * Allocates a region from the kernel address map and physical pages 204 * within the specified address range to the kernel object. Creates a 205 * wired mapping from this region to these pages, and returns the 206 * region's starting virtual address. The allocated pages are not 207 * necessarily physically contiguous. If M_ZERO is specified through the 208 * given flags, then the pages are zeroed before they are mapped. 209 */ 210 static vm_offset_t 211 kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 212 vm_paddr_t high, vm_memattr_t memattr) 213 { 214 vmem_t *vmem; 215 vm_object_t object; 216 vm_offset_t addr, i, offset; 217 vm_page_t m; 218 int pflags; 219 vm_prot_t prot; 220 221 object = kernel_object; 222 size = round_page(size); 223 vmem = vm_dom[domain].vmd_kernel_arena; 224 if (vmem_alloc(vmem, size, M_BESTFIT | flags, &addr)) 225 return (0); 226 offset = addr - VM_MIN_KERNEL_ADDRESS; 227 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 228 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 229 VM_OBJECT_WLOCK(object); 230 for (i = 0; i < size; i += PAGE_SIZE) { 231 m = kmem_alloc_contig_pages(object, atop(offset + i), 232 domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr); 233 if (m == NULL) { 234 VM_OBJECT_WUNLOCK(object); 235 kmem_unback(object, addr, i); 236 vmem_free(vmem, addr, size); 237 return (0); 238 } 239 KASSERT(vm_page_domain(m) == domain, 240 ("kmem_alloc_attr_domain: Domain mismatch %d != %d", 241 vm_page_domain(m), domain)); 242 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 243 pmap_zero_page(m); 244 vm_page_valid(m); 245 pmap_enter(kernel_pmap, addr + i, m, prot, 246 prot | PMAP_ENTER_WIRED, 0); 247 } 248 VM_OBJECT_WUNLOCK(object); 249 return (addr); 250 } 251 252 vm_offset_t 253 kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 254 vm_memattr_t memattr) 255 { 256 257 return (kmem_alloc_attr_domainset(DOMAINSET_RR(), size, flags, low, 258 high, memattr)); 259 } 260 261 vm_offset_t 262 kmem_alloc_attr_domainset(struct domainset *ds, vm_size_t size, int flags, 263 vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr) 264 { 265 struct vm_domainset_iter di; 266 vm_offset_t addr; 267 int domain, iflags; 268 269 /* 270 * Do not allow the domainset iterator to override wait flags. The 271 * contiguous memory allocator defines special semantics for M_WAITOK 272 * that do not match the iterator's implementation. 273 */ 274 iflags = (flags & ~M_WAITOK) | M_NOWAIT; 275 vm_domainset_iter_policy_init(&di, ds, &domain, &iflags); 276 do { 277 addr = kmem_alloc_attr_domain(domain, size, flags, low, high, 278 memattr); 279 if (addr != 0) 280 break; 281 } while (vm_domainset_iter_policy(&di, &domain) == 0); 282 283 return (addr); 284 } 285 286 /* 287 * Allocates a region from the kernel address map and physically 288 * contiguous pages within the specified address range to the kernel 289 * object. Creates a wired mapping from this region to these pages, and 290 * returns the region's starting virtual address. If M_ZERO is specified 291 * through the given flags, then the pages are zeroed before they are 292 * mapped. 293 */ 294 static vm_offset_t 295 kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, 296 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 297 vm_memattr_t memattr) 298 { 299 vmem_t *vmem; 300 vm_object_t object; 301 vm_offset_t addr, offset, tmp; 302 vm_page_t end_m, m; 303 u_long npages; 304 int pflags; 305 306 object = kernel_object; 307 size = round_page(size); 308 vmem = vm_dom[domain].vmd_kernel_arena; 309 if (vmem_alloc(vmem, size, flags | M_BESTFIT, &addr)) 310 return (0); 311 offset = addr - VM_MIN_KERNEL_ADDRESS; 312 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 313 npages = atop(size); 314 VM_OBJECT_WLOCK(object); 315 m = kmem_alloc_contig_pages(object, atop(offset), domain, 316 pflags, npages, low, high, alignment, boundary, memattr); 317 if (m == NULL) { 318 VM_OBJECT_WUNLOCK(object); 319 vmem_free(vmem, addr, size); 320 return (0); 321 } 322 KASSERT(vm_page_domain(m) == domain, 323 ("kmem_alloc_contig_domain: Domain mismatch %d != %d", 324 vm_page_domain(m), domain)); 325 end_m = m + npages; 326 tmp = addr; 327 for (; m < end_m; m++) { 328 if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) 329 pmap_zero_page(m); 330 vm_page_valid(m); 331 pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW, 332 VM_PROT_RW | PMAP_ENTER_WIRED, 0); 333 tmp += PAGE_SIZE; 334 } 335 VM_OBJECT_WUNLOCK(object); 336 return (addr); 337 } 338 339 vm_offset_t 340 kmem_alloc_contig(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high, 341 u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr) 342 { 343 344 return (kmem_alloc_contig_domainset(DOMAINSET_RR(), size, flags, low, 345 high, alignment, boundary, memattr)); 346 } 347 348 vm_offset_t 349 kmem_alloc_contig_domainset(struct domainset *ds, vm_size_t size, int flags, 350 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 351 vm_memattr_t memattr) 352 { 353 struct vm_domainset_iter di; 354 vm_offset_t addr; 355 int domain, iflags; 356 357 /* 358 * Do not allow the domainset iterator to override wait flags. The 359 * contiguous memory allocator defines special semantics for M_WAITOK 360 * that do not match the iterator's implementation. 361 */ 362 iflags = (flags & ~M_WAITOK) | M_NOWAIT; 363 vm_domainset_iter_policy_init(&di, ds, &domain, &iflags); 364 do { 365 addr = kmem_alloc_contig_domain(domain, size, flags, low, high, 366 alignment, boundary, memattr); 367 if (addr != 0) 368 break; 369 } while (vm_domainset_iter_policy(&di, &domain) == 0); 370 371 return (addr); 372 } 373 374 /* 375 * kmem_subinit: 376 * 377 * Initializes a map to manage a subrange 378 * of the kernel virtual address space. 379 * 380 * Arguments are as follows: 381 * 382 * parent Map to take range from 383 * min, max Returned endpoints of map 384 * size Size of range to find 385 * superpage_align Request that min is superpage aligned 386 */ 387 void 388 kmem_subinit(vm_map_t map, vm_map_t parent, vm_offset_t *min, vm_offset_t *max, 389 vm_size_t size, bool superpage_align) 390 { 391 int ret; 392 393 size = round_page(size); 394 395 *min = vm_map_min(parent); 396 ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ? 397 VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL, 398 MAP_ACC_NO_CHARGE); 399 if (ret != KERN_SUCCESS) 400 panic("kmem_subinit: bad status return of %d", ret); 401 *max = *min + size; 402 vm_map_init(map, vm_map_pmap(parent), *min, *max); 403 if (vm_map_submap(parent, *min, *max, map) != KERN_SUCCESS) 404 panic("kmem_subinit: unable to change range to submap"); 405 } 406 407 /* 408 * kmem_malloc_domain: 409 * 410 * Allocate wired-down pages in the kernel's address space. 411 */ 412 static vm_offset_t 413 kmem_malloc_domain(int domain, vm_size_t size, int flags) 414 { 415 vmem_t *arena; 416 vm_offset_t addr; 417 int rv; 418 419 if (__predict_true((flags & M_EXEC) == 0)) 420 arena = vm_dom[domain].vmd_kernel_arena; 421 else 422 arena = vm_dom[domain].vmd_kernel_rwx_arena; 423 size = round_page(size); 424 if (vmem_alloc(arena, size, flags | M_BESTFIT, &addr)) 425 return (0); 426 427 rv = kmem_back_domain(domain, kernel_object, addr, size, flags); 428 if (rv != KERN_SUCCESS) { 429 vmem_free(arena, addr, size); 430 return (0); 431 } 432 return (addr); 433 } 434 435 vm_offset_t 436 kmem_malloc(vm_size_t size, int flags) 437 { 438 439 return (kmem_malloc_domainset(DOMAINSET_RR(), size, flags)); 440 } 441 442 vm_offset_t 443 kmem_malloc_domainset(struct domainset *ds, vm_size_t size, int flags) 444 { 445 struct vm_domainset_iter di; 446 vm_offset_t addr; 447 int domain; 448 449 vm_domainset_iter_policy_init(&di, ds, &domain, &flags); 450 do { 451 addr = kmem_malloc_domain(domain, size, flags); 452 if (addr != 0) 453 break; 454 } while (vm_domainset_iter_policy(&di, &domain) == 0); 455 456 return (addr); 457 } 458 459 /* 460 * kmem_back_domain: 461 * 462 * Allocate physical pages from the specified domain for the specified 463 * virtual address range. 464 */ 465 int 466 kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr, 467 vm_size_t size, int flags) 468 { 469 vm_offset_t offset, i; 470 vm_page_t m, mpred; 471 vm_prot_t prot; 472 int pflags; 473 474 KASSERT(object == kernel_object, 475 ("kmem_back_domain: only supports kernel object.")); 476 477 offset = addr - VM_MIN_KERNEL_ADDRESS; 478 pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; 479 pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL); 480 if (flags & M_WAITOK) 481 pflags |= VM_ALLOC_WAITFAIL; 482 prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; 483 484 i = 0; 485 VM_OBJECT_WLOCK(object); 486 retry: 487 mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i)); 488 for (; i < size; i += PAGE_SIZE, mpred = m) { 489 m = vm_page_alloc_domain_after(object, atop(offset + i), 490 domain, pflags, mpred); 491 492 /* 493 * Ran out of space, free everything up and return. Don't need 494 * to lock page queues here as we know that the pages we got 495 * aren't on any queues. 496 */ 497 if (m == NULL) { 498 if ((flags & M_NOWAIT) == 0) 499 goto retry; 500 VM_OBJECT_WUNLOCK(object); 501 kmem_unback(object, addr, i); 502 return (KERN_NO_SPACE); 503 } 504 KASSERT(vm_page_domain(m) == domain, 505 ("kmem_back_domain: Domain mismatch %d != %d", 506 vm_page_domain(m), domain)); 507 if (flags & M_ZERO && (m->flags & PG_ZERO) == 0) 508 pmap_zero_page(m); 509 KASSERT((m->oflags & VPO_UNMANAGED) != 0, 510 ("kmem_malloc: page %p is managed", m)); 511 vm_page_valid(m); 512 pmap_enter(kernel_pmap, addr + i, m, prot, 513 prot | PMAP_ENTER_WIRED, 0); 514 if (__predict_false((prot & VM_PROT_EXECUTE) != 0)) 515 m->oflags |= VPO_KMEM_EXEC; 516 } 517 VM_OBJECT_WUNLOCK(object); 518 519 return (KERN_SUCCESS); 520 } 521 522 /* 523 * kmem_back: 524 * 525 * Allocate physical pages for the specified virtual address range. 526 */ 527 int 528 kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags) 529 { 530 vm_offset_t end, next, start; 531 int domain, rv; 532 533 KASSERT(object == kernel_object, 534 ("kmem_back: only supports kernel object.")); 535 536 for (start = addr, end = addr + size; addr < end; addr = next) { 537 /* 538 * We must ensure that pages backing a given large virtual page 539 * all come from the same physical domain. 540 */ 541 if (vm_ndomains > 1) { 542 domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains; 543 while (VM_DOMAIN_EMPTY(domain)) 544 domain++; 545 next = roundup2(addr + 1, KVA_QUANTUM); 546 if (next > end || next < start) 547 next = end; 548 } else { 549 domain = 0; 550 next = end; 551 } 552 rv = kmem_back_domain(domain, object, addr, next - addr, flags); 553 if (rv != KERN_SUCCESS) { 554 kmem_unback(object, start, addr - start); 555 break; 556 } 557 } 558 return (rv); 559 } 560 561 /* 562 * kmem_unback: 563 * 564 * Unmap and free the physical pages underlying the specified virtual 565 * address range. 566 * 567 * A physical page must exist within the specified object at each index 568 * that is being unmapped. 569 */ 570 static struct vmem * 571 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 572 { 573 struct vmem *arena; 574 vm_page_t m, next; 575 vm_offset_t end, offset; 576 int domain; 577 578 KASSERT(object == kernel_object, 579 ("kmem_unback: only supports kernel object.")); 580 581 if (size == 0) 582 return (NULL); 583 pmap_remove(kernel_pmap, addr, addr + size); 584 offset = addr - VM_MIN_KERNEL_ADDRESS; 585 end = offset + size; 586 VM_OBJECT_WLOCK(object); 587 m = vm_page_lookup(object, atop(offset)); 588 domain = vm_page_domain(m); 589 if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0)) 590 arena = vm_dom[domain].vmd_kernel_arena; 591 else 592 arena = vm_dom[domain].vmd_kernel_rwx_arena; 593 for (; offset < end; offset += PAGE_SIZE, m = next) { 594 next = vm_page_next(m); 595 vm_page_xbusy_claim(m); 596 vm_page_unwire_noq(m); 597 vm_page_free(m); 598 } 599 VM_OBJECT_WUNLOCK(object); 600 601 return (arena); 602 } 603 604 void 605 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size) 606 { 607 608 (void)_kmem_unback(object, addr, size); 609 } 610 611 /* 612 * kmem_free: 613 * 614 * Free memory allocated with kmem_malloc. The size must match the 615 * original allocation. 616 */ 617 void 618 kmem_free(vm_offset_t addr, vm_size_t size) 619 { 620 struct vmem *arena; 621 622 size = round_page(size); 623 arena = _kmem_unback(kernel_object, addr, size); 624 if (arena != NULL) 625 vmem_free(arena, addr, size); 626 } 627 628 /* 629 * kmap_alloc_wait: 630 * 631 * Allocates pageable memory from a sub-map of the kernel. If the submap 632 * has no room, the caller sleeps waiting for more memory in the submap. 633 * 634 * This routine may block. 635 */ 636 vm_offset_t 637 kmap_alloc_wait(vm_map_t map, vm_size_t size) 638 { 639 vm_offset_t addr; 640 641 size = round_page(size); 642 if (!swap_reserve(size)) 643 return (0); 644 645 for (;;) { 646 /* 647 * To make this work for more than one map, use the map's lock 648 * to lock out sleepers/wakers. 649 */ 650 vm_map_lock(map); 651 addr = vm_map_findspace(map, vm_map_min(map), size); 652 if (addr + size <= vm_map_max(map)) 653 break; 654 /* no space now; see if we can ever get space */ 655 if (vm_map_max(map) - vm_map_min(map) < size) { 656 vm_map_unlock(map); 657 swap_release(size); 658 return (0); 659 } 660 map->needs_wakeup = TRUE; 661 vm_map_unlock_and_wait(map, 0); 662 } 663 vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_RW, VM_PROT_RW, 664 MAP_ACC_CHARGED); 665 vm_map_unlock(map); 666 return (addr); 667 } 668 669 /* 670 * kmap_free_wakeup: 671 * 672 * Returns memory to a submap of the kernel, and wakes up any processes 673 * waiting for memory in that map. 674 */ 675 void 676 kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size) 677 { 678 679 vm_map_lock(map); 680 (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size)); 681 if (map->needs_wakeup) { 682 map->needs_wakeup = FALSE; 683 vm_map_wakeup(map); 684 } 685 vm_map_unlock(map); 686 } 687 688 void 689 kmem_init_zero_region(void) 690 { 691 vm_offset_t addr, i; 692 vm_page_t m; 693 694 /* 695 * Map a single physical page of zeros to a larger virtual range. 696 * This requires less looping in places that want large amounts of 697 * zeros, while not using much more physical resources. 698 */ 699 addr = kva_alloc(ZERO_REGION_SIZE); 700 m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL | 701 VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO); 702 if ((m->flags & PG_ZERO) == 0) 703 pmap_zero_page(m); 704 for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE) 705 pmap_qenter(addr + i, &m, 1); 706 pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ); 707 708 zero_region = (const void *)addr; 709 } 710 711 /* 712 * Import KVA from the kernel map into the kernel arena. 713 */ 714 static int 715 kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp) 716 { 717 vm_offset_t addr; 718 int result; 719 720 KASSERT((size % KVA_QUANTUM) == 0, 721 ("kva_import: Size %jd is not a multiple of %d", 722 (intmax_t)size, (int)KVA_QUANTUM)); 723 addr = vm_map_min(kernel_map); 724 result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0, 725 VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 726 if (result != KERN_SUCCESS) 727 return (ENOMEM); 728 729 *addrp = addr; 730 731 return (0); 732 } 733 734 /* 735 * Import KVA from a parent arena into a per-domain arena. Imports must be 736 * KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size. 737 */ 738 static int 739 kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp) 740 { 741 742 KASSERT((size % KVA_QUANTUM) == 0, 743 ("kva_import_domain: Size %jd is not a multiple of %d", 744 (intmax_t)size, (int)KVA_QUANTUM)); 745 return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN, 746 VMEM_ADDR_MAX, flags, addrp)); 747 } 748 749 /* 750 * kmem_init: 751 * 752 * Create the kernel map; insert a mapping covering kernel text, 753 * data, bss, and all space allocated thus far (`boostrap' data). The 754 * new map will thus map the range between VM_MIN_KERNEL_ADDRESS and 755 * `start' as allocated, and the range between `start' and `end' as free. 756 * Create the kernel vmem arena and its per-domain children. 757 */ 758 void 759 kmem_init(vm_offset_t start, vm_offset_t end) 760 { 761 vm_size_t quantum; 762 int domain; 763 764 vm_map_init(kernel_map, kernel_pmap, VM_MIN_KERNEL_ADDRESS, end); 765 kernel_map->system_map = 1; 766 vm_map_lock(kernel_map); 767 /* N.B.: cannot use kgdb to debug, starting with this assignment ... */ 768 (void)vm_map_insert(kernel_map, NULL, 0, 769 #ifdef __amd64__ 770 KERNBASE, 771 #else 772 VM_MIN_KERNEL_ADDRESS, 773 #endif 774 start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); 775 /* ... and ending with the completion of the above `insert' */ 776 777 #ifdef __amd64__ 778 /* 779 * Mark KVA used for the page array as allocated. Other platforms 780 * that handle vm_page_array allocation can simply adjust virtual_avail 781 * instead. 782 */ 783 (void)vm_map_insert(kernel_map, NULL, 0, (vm_offset_t)vm_page_array, 784 (vm_offset_t)vm_page_array + round_2mpage(vm_page_array_size * 785 sizeof(struct vm_page)), 786 VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT); 787 #endif 788 vm_map_unlock(kernel_map); 789 790 /* 791 * Use a large import quantum on NUMA systems. This helps minimize 792 * interleaving of superpages, reducing internal fragmentation within 793 * the per-domain arenas. 794 */ 795 if (vm_ndomains > 1 && PMAP_HAS_DMAP) 796 quantum = KVA_NUMA_IMPORT_QUANTUM; 797 else 798 quantum = KVA_QUANTUM; 799 800 /* 801 * Initialize the kernel_arena. This can grow on demand. 802 */ 803 vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0); 804 vmem_set_import(kernel_arena, kva_import, NULL, NULL, quantum); 805 806 for (domain = 0; domain < vm_ndomains; domain++) { 807 /* 808 * Initialize the per-domain arenas. These are used to color 809 * the KVA space in a way that ensures that virtual large pages 810 * are backed by memory from the same physical domain, 811 * maximizing the potential for superpage promotion. 812 */ 813 vm_dom[domain].vmd_kernel_arena = vmem_create( 814 "kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 815 vmem_set_import(vm_dom[domain].vmd_kernel_arena, 816 kva_import_domain, NULL, kernel_arena, quantum); 817 818 /* 819 * In architectures with superpages, maintain separate arenas 820 * for allocations with permissions that differ from the 821 * "standard" read/write permissions used for kernel memory, 822 * so as not to inhibit superpage promotion. 823 * 824 * Use the base import quantum since this arena is rarely used. 825 */ 826 #if VM_NRESERVLEVEL > 0 827 vm_dom[domain].vmd_kernel_rwx_arena = vmem_create( 828 "kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK); 829 vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena, 830 kva_import_domain, (vmem_release_t *)vmem_xfree, 831 kernel_arena, KVA_QUANTUM); 832 #else 833 vm_dom[domain].vmd_kernel_rwx_arena = 834 vm_dom[domain].vmd_kernel_arena; 835 #endif 836 } 837 838 /* 839 * This must be the very first call so that the virtual address 840 * space used for early allocations is properly marked used in 841 * the map. 842 */ 843 uma_startup2(); 844 } 845 846 /* 847 * kmem_bootstrap_free: 848 * 849 * Free pages backing preloaded data (e.g., kernel modules) to the 850 * system. Currently only supported on platforms that create a 851 * vm_phys segment for preloaded data. 852 */ 853 void 854 kmem_bootstrap_free(vm_offset_t start, vm_size_t size) 855 { 856 #if defined(__i386__) || defined(__amd64__) 857 struct vm_domain *vmd; 858 vm_offset_t end, va; 859 vm_paddr_t pa; 860 vm_page_t m; 861 862 end = trunc_page(start + size); 863 start = round_page(start); 864 865 #ifdef __amd64__ 866 /* 867 * Preloaded files do not have execute permissions by default on amd64. 868 * Restore the default permissions to ensure that the direct map alias 869 * is updated. 870 */ 871 pmap_change_prot(start, end - start, VM_PROT_RW); 872 #endif 873 for (va = start; va < end; va += PAGE_SIZE) { 874 pa = pmap_kextract(va); 875 m = PHYS_TO_VM_PAGE(pa); 876 877 vmd = vm_pagequeue_domain(m); 878 vm_domain_free_lock(vmd); 879 vm_phys_free_pages(m, 0); 880 vm_domain_free_unlock(vmd); 881 882 vm_domain_freecnt_inc(vmd, 1); 883 vm_cnt.v_page_count++; 884 } 885 pmap_remove(kernel_pmap, start, end); 886 (void)vmem_add(kernel_arena, start, end - start, M_WAITOK); 887 #endif 888 } 889 890 /* 891 * Allow userspace to directly trigger the VM drain routine for testing 892 * purposes. 893 */ 894 static int 895 debug_vm_lowmem(SYSCTL_HANDLER_ARGS) 896 { 897 int error, i; 898 899 i = 0; 900 error = sysctl_handle_int(oidp, &i, 0, req); 901 if (error) 902 return (error); 903 if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0) 904 return (EINVAL); 905 if (i != 0) 906 EVENTHANDLER_INVOKE(vm_lowmem, i); 907 return (0); 908 } 909 910 SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0, 911 debug_vm_lowmem, "I", "set to trigger vm_lowmem event with given flags"); 912