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