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