1 /* $NetBSD: uvm_km.c,v 1.169 2026/08/23 22:08:41 riastradh Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Charles D. Cranor and Washington University. 5 * Copyright (c) 1991, 1993, The Regents of the University of California. 6 * 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * The Mach Operating System project at Carnegie-Mellon University. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vm_kern.c 8.3 (Berkeley) 1/12/94 37 * from: Id: uvm_km.c,v 1.1.2.14 1998/02/06 05:19:27 chs Exp 38 * 39 * 40 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 41 * All rights reserved. 42 * 43 * Permission to use, copy, modify and distribute this software and 44 * its documentation is hereby granted, provided that both the copyright 45 * notice and this permission notice appear in all copies of the 46 * software, derivative works or modified versions, and any portions 47 * thereof, and that both notices appear in supporting documentation. 48 * 49 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 50 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 51 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 52 * 53 * Carnegie Mellon requests users of this software to return to 54 * 55 * Software Distribution Coordinator or Software.Distribution (at) CS.CMU.EDU 56 * School of Computer Science 57 * Carnegie Mellon University 58 * Pittsburgh PA 15213-3890 59 * 60 * any improvements or extensions that they make and grant Carnegie the 61 * rights to redistribute these changes. 62 */ 63 64 /* 65 * uvm_km.c: handle kernel memory allocation and management 66 */ 67 68 /* 69 * overview of kernel memory management: 70 * 71 * the kernel virtual address space is mapped by "kernel_map." kernel_map 72 * starts at VM_MIN_KERNEL_ADDRESS and goes to VM_MAX_KERNEL_ADDRESS. 73 * note that VM_MIN_KERNEL_ADDRESS is equal to vm_map_min(kernel_map). 74 * 75 * the kernel_map has several "submaps." submaps can only appear in 76 * the kernel_map (user processes can't use them). submaps "take over" 77 * the management of a sub-range of the kernel's address space. submaps 78 * are typically allocated at boot time and are never released. kernel 79 * virtual address space that is mapped by a submap is locked by the 80 * submap's lock -- not the kernel_map's lock. 81 * 82 * thus, the useful feature of submaps is that they allow us to break 83 * up the locking and protection of the kernel address space into smaller 84 * chunks. 85 * 86 * the vm system has several standard kernel submaps/arenas, including: 87 * kmem_arena => used for kmem/pool (memoryallocators(9)) 88 * pager_map => used to map "buf" structures into kernel space 89 * exec_map => used during exec to handle exec args 90 * etc... 91 * 92 * The kmem_arena is a "special submap", as it lives in a fixed map entry 93 * within the kernel_map and is controlled by vmem(9). 94 * 95 * the kernel allocates its private memory out of special uvm_objects whose 96 * reference count is set to UVM_OBJ_KERN (thus indicating that the objects 97 * are "special" and never die). all kernel objects should be thought of 98 * as large, fixed-sized, sparsely populated uvm_objects. each kernel 99 * object is equal to the size of kernel virtual address space (i.e. the 100 * value "VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS"). 101 * 102 * note that just because a kernel object spans the entire kernel virtual 103 * address space doesn't mean that it has to be mapped into the entire space. 104 * large chunks of a kernel object's space go unused either because 105 * that area of kernel VM is unmapped, or there is some other type of 106 * object mapped into that range (e.g. a vnode). for submap's kernel 107 * objects, the only part of the object that can ever be populated is the 108 * offsets that are managed by the submap. 109 * 110 * note that the "offset" in a kernel object is always the kernel virtual 111 * address minus the VM_MIN_KERNEL_ADDRESS (aka vm_map_min(kernel_map)). 112 * example: 113 * suppose VM_MIN_KERNEL_ADDRESS is 0xf8000000 and the kernel does a 114 * uvm_km_alloc(kernel_map, PAGE_SIZE) [allocate 1 wired down page in the 115 * kernel map]. if uvm_km_alloc returns virtual address 0xf8235000, 116 * then that means that the page at offset 0x235000 in kernel_object is 117 * mapped at 0xf8235000. 118 * 119 * kernel object have one other special property: when the kernel virtual 120 * memory mapping them is unmapped, the backing memory in the object is 121 * freed right away. this is done with the uvm_km_pgremove() function. 122 * this has to be done because there is no backing store for kernel pages 123 * and no need to save them after they are no longer referenced. 124 * 125 * Generic arenas: 126 * 127 * kmem_arena: 128 * Main arena controlling the kernel KVA used by other arenas. 129 * 130 * kmem_va_arena: 131 * Implements quantum caching in order to speedup allocations and 132 * reduce fragmentation. The pool(9), unless created with a custom 133 * meta-data allocator, and kmem(9) subsystems use this arena. 134 * 135 * Arenas for meta-data allocations are used by vmem(9) and pool(9). 136 * These arenas cannot use quantum cache. However, kmem_va_meta_arena 137 * compensates this by importing larger chunks from kmem_arena. 138 * 139 * kmem_va_meta_arena: 140 * Space for meta-data. 141 * 142 * kmem_meta_arena: 143 * Imports from kmem_va_meta_arena. Allocations from this arena are 144 * backed with the pages. 145 * 146 * Arena stacking: 147 * 148 * kmem_arena 149 * kmem_va_arena 150 * kmem_va_meta_arena 151 * kmem_meta_arena 152 */ 153 154 #include <sys/cdefs.h> 155 __KERNEL_RCSID(0, "$NetBSD: uvm_km.c,v 1.169 2026/08/23 22:08:41 riastradh Exp $"); 156 157 #include "opt_uvmhist.h" 158 159 #include "opt_kmempages.h" 160 161 #ifndef NKMEMPAGES 162 #define NKMEMPAGES 0 163 #endif 164 165 /* 166 * Defaults for lower and upper-bounds for the kmem_arena page count. 167 * Can be overridden by kernel config options. 168 */ 169 #ifndef NKMEMPAGES_MIN 170 #define NKMEMPAGES_MIN NKMEMPAGES_MIN_DEFAULT 171 #endif 172 173 #ifndef NKMEMPAGES_MAX 174 #define NKMEMPAGES_MAX NKMEMPAGES_MAX_DEFAULT 175 #endif 176 177 178 #include <sys/param.h> 179 #include <sys/systm.h> 180 #include <sys/atomic.h> 181 #include <sys/proc.h> 182 #include <sys/pool.h> 183 #include <sys/vmem.h> 184 #include <sys/vmem_impl.h> 185 #include <sys/kmem.h> 186 #include <sys/msan.h> 187 188 #include <uvm/uvm.h> 189 190 /* 191 * global data structures 192 */ 193 194 struct vm_map *kernel_map = NULL; 195 196 /* 197 * local data structures 198 */ 199 200 static struct vm_map kernel_map_store; 201 static struct vm_map_entry kernel_image_mapent_store; 202 static struct vm_map_entry kernel_kmem_mapent_store; 203 204 size_t nkmempages = 0; 205 vaddr_t kmembase; 206 vsize_t kmemsize; 207 208 static struct vmem kmem_arena_store; 209 vmem_t *kmem_arena = NULL; 210 static struct vmem kmem_va_arena_store; 211 vmem_t *kmem_va_arena; 212 213 /* 214 * kmeminit_nkmempages: calculate the size of kmem_arena. 215 */ 216 void 217 kmeminit_nkmempages(void) 218 { 219 size_t npages; 220 221 if (nkmempages != 0) { 222 /* 223 * It's already been set (by us being here before) 224 * bail out now; 225 */ 226 return; 227 } 228 229 #if defined(NKMEMPAGES_MAX_UNLIMITED) && !defined(KMSAN) 230 /* 231 * The extra 1/9 here is to account for uvm_km_va_starved_p() 232 * wanting to keep 10% of kmem virtual space free. 233 * The intent is that on "unlimited" platforms we should be able 234 * to allocate all of physical memory as kmem without behaving 235 * as though we running short of kmem virtual space. 236 */ 237 npages = (physmem * 10) / 9; 238 #else 239 240 #if defined(KMSAN) 241 npages = (physmem / 4); 242 #elif defined(PMAP_MAP_POOLPAGE) 243 npages = (physmem / 4); 244 #else 245 npages = (physmem / 3) * 2; 246 #endif /* defined(PMAP_MAP_POOLPAGE) */ 247 248 #if !defined(NKMEMPAGES_MAX_UNLIMITED) 249 if (npages > NKMEMPAGES_MAX) 250 npages = NKMEMPAGES_MAX; 251 #endif 252 253 #endif 254 255 if (npages < NKMEMPAGES_MIN) 256 npages = NKMEMPAGES_MIN; 257 258 nkmempages = npages; 259 } 260 261 /* 262 * uvm_km_bootstrap: init kernel maps and objects to reflect reality (i.e. 263 * KVM already allocated for text, data, bss, and static data structures). 264 * 265 * => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS. 266 * we assume that [vmin -> start] has already been allocated and that 267 * "end" is the end. 268 */ 269 270 void 271 uvm_km_bootstrap(vaddr_t start, vaddr_t end) 272 { 273 bool kmem_arena_small; 274 vaddr_t base = VM_MIN_KERNEL_ADDRESS; 275 struct uvm_map_args args; 276 int error; 277 278 UVMHIST_FUNC(__func__); 279 UVMHIST_CALLARGS(maphist, "start=%#jx end=%#jx", start, end, 0,0); 280 281 kmeminit_nkmempages(); 282 kmemsize = (vsize_t)nkmempages * PAGE_SIZE; 283 kmem_arena_small = kmemsize < 64 * 1024 * 1024; 284 285 UVMHIST_LOG(maphist, "kmemsize=%#jx", kmemsize, 0,0,0); 286 287 /* 288 * next, init kernel memory objects. 289 */ 290 291 /* kernel_object: for pageable anonymous kernel memory */ 292 uvm_kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS - 293 VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ); 294 295 /* 296 * init the map and reserve any space that might already 297 * have been allocated kernel space before installing. 298 */ 299 300 uvm_map_setup(&kernel_map_store, base, end, VM_MAP_PAGEABLE); 301 kernel_map_store.pmap = pmap_kernel(); 302 if (start != base) { 303 error = uvm_map_prepare(&kernel_map_store, 304 base, start - base, 305 NULL, UVM_UNKNOWN_OFFSET, 0, 306 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 307 UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args); 308 if (!error) { 309 kernel_image_mapent_store.flags = 310 UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE; 311 error = uvm_map_enter(&kernel_map_store, &args, 312 &kernel_image_mapent_store); 313 } 314 315 if (error) 316 panic( 317 "uvm_km_bootstrap: could not reserve space for kernel"); 318 319 kmembase = args.uma_start + args.uma_size; 320 } else { 321 kmembase = base; 322 } 323 324 error = uvm_map_prepare(&kernel_map_store, 325 kmembase, kmemsize, 326 NULL, UVM_UNKNOWN_OFFSET, 0, 327 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 328 UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args); 329 if (!error) { 330 kernel_kmem_mapent_store.flags = 331 UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE; 332 error = uvm_map_enter(&kernel_map_store, &args, 333 &kernel_kmem_mapent_store); 334 } 335 336 if (error) 337 panic("uvm_km_bootstrap: could not reserve kernel kmem"); 338 339 /* 340 * install! 341 */ 342 343 kernel_map = &kernel_map_store; 344 345 pool_subsystem_init(); 346 347 kmem_arena = vmem_init(&kmem_arena_store, "kmem", 348 kmembase, kmemsize, PAGE_SIZE, NULL, NULL, NULL, 349 0, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM); 350 #ifdef PMAP_GROWKERNEL 351 /* 352 * kmem_arena VA allocations happen independently of uvm_map. 353 * grow kernel to accommodate the kmem_arena. 354 */ 355 if (uvm_maxkaddr < kmembase + kmemsize) { 356 uvm_maxkaddr = pmap_growkernel(kmembase + kmemsize); 357 KASSERTMSG(uvm_maxkaddr >= kmembase + kmemsize, 358 "%#"PRIxVADDR" %#"PRIxVADDR" %#"PRIxVSIZE, 359 uvm_maxkaddr, kmembase, kmemsize); 360 } 361 #endif 362 363 vmem_subsystem_init(kmem_arena); 364 365 UVMHIST_LOG(maphist, "kmem vmem created (base=%#jx, size=%#jx", 366 kmembase, kmemsize, 0,0); 367 368 kmem_va_arena = vmem_init(&kmem_va_arena_store, "kva", 369 0, 0, PAGE_SIZE, vmem_alloc, vmem_free, kmem_arena, 370 (kmem_arena_small ? 4 : VMEM_QCACHE_IDX_MAX) * PAGE_SIZE, 371 VM_NOSLEEP, IPL_VM); 372 373 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 374 } 375 376 /* 377 * uvm_km_init: init the kernel maps virtual memory caches 378 * and start the pool/kmem allocator. 379 */ 380 void 381 uvm_km_init(void) 382 { 383 kmem_init(); 384 } 385 386 /* 387 * uvm_km_suballoc: allocate a submap in the kernel map. once a submap 388 * is allocated all references to that area of VM must go through it. this 389 * allows the locking of VAs in kernel_map to be broken up into regions. 390 * 391 * => if `fixed' is true, *vmin specifies where the region described 392 * pager_map => used to map "buf" structures into kernel space 393 * by the submap must start 394 * => if submap is non NULL we use that as the submap, otherwise we 395 * alloc a new map 396 */ 397 398 struct vm_map * 399 uvm_km_suballoc(struct vm_map *map, vaddr_t *vmin /* IN/OUT */, 400 vaddr_t *vmax /* OUT */, vsize_t size, int flags, bool fixed, 401 struct vm_map *submap) 402 { 403 int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0); 404 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 405 406 KASSERT(vm_map_pmap(map) == pmap_kernel()); 407 408 size = round_page(size); /* round up to pagesize */ 409 410 /* 411 * first allocate a blank spot in the parent map 412 */ 413 414 if (uvm_map(map, vmin, size, NULL, UVM_UNKNOWN_OFFSET, 0, 415 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 416 UVM_ADV_RANDOM, mapflags)) != 0) { 417 panic("%s: unable to allocate space in parent map", __func__); 418 } 419 420 /* 421 * set VM bounds (vmin is filled in by uvm_map) 422 */ 423 424 *vmax = *vmin + size; 425 426 /* 427 * add references to pmap and create or init the submap 428 */ 429 430 pmap_reference(vm_map_pmap(map)); 431 if (submap == NULL) { 432 submap = kmem_alloc(sizeof(*submap), KM_SLEEP); 433 } 434 uvm_map_setup(submap, *vmin, *vmax, flags); 435 submap->pmap = vm_map_pmap(map); 436 437 /* 438 * now let uvm_map_submap plug in it... 439 */ 440 441 if (uvm_map_submap(map, *vmin, *vmax, submap) != 0) 442 panic("uvm_km_suballoc: submap allocation failed"); 443 444 return(submap); 445 } 446 447 /* 448 * uvm_km_pgremove: remove pages from a kernel uvm_object and KVA. 449 */ 450 451 void 452 uvm_km_pgremove(vaddr_t startva, vaddr_t endva) 453 { 454 struct uvm_object * const uobj = uvm_kernel_object; 455 const voff_t start = startva - vm_map_min(kernel_map); 456 const voff_t end = endva - vm_map_min(kernel_map); 457 struct vm_page *pg; 458 voff_t curoff, nextoff; 459 int swpgonlydelta = 0; 460 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 461 462 KASSERT(VM_MIN_KERNEL_ADDRESS <= startva); 463 KASSERT(startva < endva); 464 KASSERT(endva <= VM_MAX_KERNEL_ADDRESS); 465 466 rw_enter(uobj->vmobjlock, RW_WRITER); 467 pmap_remove(pmap_kernel(), startva, endva); 468 pmap_update(pmap_kernel()); 469 for (curoff = start; curoff < end; curoff = nextoff) { 470 nextoff = curoff + PAGE_SIZE; 471 pg = uvm_pagelookup(uobj, curoff); 472 if (pg != NULL && pg->flags & PG_BUSY) { 473 uvm_pagewait(pg, uobj->vmobjlock, "km_pgrm"); 474 rw_enter(uobj->vmobjlock, RW_WRITER); 475 nextoff = curoff; 476 continue; 477 } 478 479 /* 480 * free the swap slot, then the page. 481 */ 482 483 if (pg == NULL && 484 uao_find_swslot(uobj, curoff >> PAGE_SHIFT) > 0) { 485 swpgonlydelta++; 486 } 487 uao_dropswap(uobj, curoff >> PAGE_SHIFT); 488 if (pg != NULL) { 489 uvm_pagefree(pg); 490 } 491 } 492 rw_exit(uobj->vmobjlock); 493 494 if (swpgonlydelta > 0) { 495 KASSERT(uvmexp.swpgonly >= swpgonlydelta); 496 atomic_add_int(&uvmexp.swpgonly, -swpgonlydelta); 497 } 498 } 499 500 501 /* 502 * uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for non object backed 503 * regions. 504 * 505 * => when you unmap a part of anonymous kernel memory you want to toss 506 * the pages right away. (this is called from uvm_unmap_...). 507 * => none of the pages will ever be busy, and none of them will ever 508 * be on the active or inactive queues (because they have no object). 509 */ 510 511 void 512 uvm_km_pgremove_intrsafe(struct vm_map *map, vaddr_t start, vaddr_t end) 513 { 514 #define __PGRM_BATCH 16 515 struct vm_page *pg; 516 paddr_t pa[__PGRM_BATCH]; 517 int npgrm, i; 518 vaddr_t va, batch_vastart; 519 520 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 521 522 KASSERT(VM_MAP_IS_KERNEL(map)); 523 KASSERTMSG(vm_map_min(map) <= start, 524 "vm_map_min(map) [%#"PRIxVADDR"] <= start [%#"PRIxVADDR"]" 525 " (size=%#"PRIxVSIZE")", 526 vm_map_min(map), start, end - start); 527 KASSERT(start < end); 528 KASSERT(end <= vm_map_max(map)); 529 530 for (va = start; va < end;) { 531 batch_vastart = va; 532 /* create a batch of at most __PGRM_BATCH pages to free */ 533 for (i = 0; 534 i < __PGRM_BATCH && va < end; 535 va += PAGE_SIZE) { 536 if (!pmap_extract(pmap_kernel(), va, &pa[i])) { 537 continue; 538 } 539 i++; 540 } 541 npgrm = i; 542 /* now remove the mappings */ 543 pmap_kremove(batch_vastart, va - batch_vastart); 544 pmap_update(pmap_kernel()); 545 /* and free the pages */ 546 for (i = 0; i < npgrm; i++) { 547 pg = PHYS_TO_VM_PAGE(pa[i]); 548 KASSERT(pg); 549 KASSERT(pg->uobject == NULL); 550 KASSERT(pg->uanon == NULL); 551 KASSERT((pg->flags & PG_BUSY) == 0); 552 uvm_pagefree(pg); 553 } 554 } 555 #undef __PGRM_BATCH 556 } 557 558 #if defined(DEBUG) 559 void 560 uvm_km_check_empty(struct vm_map *map, vaddr_t start, vaddr_t end) 561 { 562 vaddr_t va; 563 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 564 565 KDASSERT(VM_MAP_IS_KERNEL(map)); 566 KDASSERT(vm_map_min(map) <= start); 567 KDASSERT(start < end); 568 KDASSERT(end <= vm_map_max(map)); 569 570 for (va = start; va < end; va += PAGE_SIZE) { 571 paddr_t pa; 572 573 if (pmap_extract(pmap_kernel(), va, &pa)) { 574 panic("uvm_km_check_empty: va %p has pa %#llx", 575 (void *)va, (long long)pa); 576 } 577 /* 578 * kernel_object should not have pages for the corresponding 579 * region. check it. 580 * 581 * why trylock? because: 582 * - caller might not want to block. 583 * - we can recurse when allocating radix_node for 584 * kernel_object. 585 */ 586 if (rw_tryenter(uvm_kernel_object->vmobjlock, RW_READER)) { 587 struct vm_page *pg; 588 589 pg = uvm_pagelookup(uvm_kernel_object, 590 va - vm_map_min(kernel_map)); 591 rw_exit(uvm_kernel_object->vmobjlock); 592 if (pg) { 593 panic("uvm_km_check_empty: " 594 "has page hashed at %p", 595 (const void *)va); 596 } 597 } 598 } 599 } 600 #endif /* defined(DEBUG) */ 601 602 /* 603 * uvm_km_alloc: allocate an area of kernel memory. 604 * 605 * => NOTE: we can return 0 even if we can wait if there is not enough 606 * free VM space in the map... caller should be prepared to handle 607 * this case. 608 * => we return KVA of memory allocated 609 */ 610 611 vaddr_t 612 uvm_km_alloc(struct vm_map *map, vsize_t size, vsize_t align, uvm_flag_t flags) 613 { 614 vaddr_t kva, loopva; 615 vaddr_t offset; 616 vsize_t loopsize; 617 uint64_t ticket; 618 struct vm_page *pg; 619 struct uvm_object *obj; 620 int pgaflags; 621 vm_prot_t prot, vaprot; 622 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 623 624 KASSERT(vm_map_pmap(map) == pmap_kernel()); 625 KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED || 626 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE || 627 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY); 628 KASSERT((flags & UVM_KMF_VAONLY) != 0 || (flags & UVM_KMF_COLORMATCH) == 0); 629 KASSERT((flags & UVM_KMF_COLORMATCH) == 0 || (flags & UVM_KMF_VAONLY) != 0); 630 631 /* 632 * setup for call 633 */ 634 635 kva = vm_map_min(map); /* hint */ 636 size = round_page(size); 637 obj = (flags & UVM_KMF_PAGEABLE) ? uvm_kernel_object : NULL; 638 UVMHIST_LOG(maphist," (map=%#jx, obj=%#jx, size=%#jx, flags=%#jx)", 639 (uintptr_t)map, (uintptr_t)obj, size, flags); 640 641 /* 642 * allocate some virtual space 643 */ 644 645 vaprot = (flags & UVM_KMF_EXEC) ? UVM_PROT_ALL : UVM_PROT_RW; 646 if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET, 647 align, UVM_MAPFLAG(vaprot, UVM_PROT_ALL, UVM_INH_NONE, 648 UVM_ADV_RANDOM, 649 (flags & (UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT | UVM_KMF_WAITVA 650 | UVM_KMF_COLORMATCH)))) != 0)) { 651 UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0); 652 return(0); 653 } 654 655 /* 656 * if all we wanted was VA, return now 657 */ 658 659 if (flags & (UVM_KMF_VAONLY | UVM_KMF_PAGEABLE)) { 660 UVMHIST_LOG(maphist,"<- done valloc (kva=%#jx)", kva,0,0,0); 661 return(kva); 662 } 663 664 /* 665 * recover object offset from virtual address 666 */ 667 668 offset = kva - vm_map_min(kernel_map); 669 UVMHIST_LOG(maphist, " kva=%#jx, offset=%#jx", kva, offset,0,0); 670 671 /* 672 * now allocate and map in the memory... note that we are the only ones 673 * whom should ever get a handle on this area of VM. 674 */ 675 676 loopva = kva; 677 loopsize = size; 678 679 pgaflags = UVM_FLAG_COLORMATCH; 680 if (flags & UVM_KMF_NOWAIT) 681 pgaflags |= UVM_PGA_USERESERVE; 682 if (flags & UVM_KMF_ZERO) 683 pgaflags |= UVM_PGA_ZERO; 684 prot = VM_PROT_READ | VM_PROT_WRITE; 685 if (flags & UVM_KMF_EXEC) 686 prot |= VM_PROT_EXECUTE; 687 while (loopsize) { 688 KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, NULL), 689 "loopva=%#"PRIxVADDR, loopva); 690 691 ticket = uvm_wait_prepare(); 692 pg = uvm_pagealloc_strat(NULL, offset, NULL, pgaflags, 693 #ifdef UVM_KM_VMFREELIST 694 UVM_PGA_STRAT_ONLY, UVM_KM_VMFREELIST 695 #else 696 UVM_PGA_STRAT_NORMAL, 0 697 #endif 698 ); 699 700 /* 701 * out of memory? 702 */ 703 704 if (__predict_false(pg == NULL)) { 705 if ((flags & UVM_KMF_NOWAIT) || 706 ((flags & UVM_KMF_CANFAIL) && !uvm_reclaimable())) { 707 /* free everything! */ 708 uvm_km_free(map, kva, size, 709 flags & UVM_KMF_TYPEMASK); 710 return (0); 711 } else { 712 /* sleep here */ 713 uvm_wait("km_getwait2", ticket); 714 continue; 715 } 716 } 717 718 pg->flags &= ~PG_BUSY; /* new page */ 719 UVM_PAGE_OWN(pg, NULL); 720 721 /* 722 * map it in 723 */ 724 725 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), 726 prot, PMAP_KMPAGE); 727 loopva += PAGE_SIZE; 728 offset += PAGE_SIZE; 729 loopsize -= PAGE_SIZE; 730 } 731 732 pmap_update(pmap_kernel()); 733 734 if ((flags & UVM_KMF_ZERO) == 0) { 735 kmsan_orig((void *)kva, size, KMSAN_TYPE_UVM, __RET_ADDR); 736 kmsan_mark((void *)kva, size, KMSAN_STATE_UNINIT); 737 } 738 739 UVMHIST_LOG(maphist,"<- done (kva=%#jx)", kva,0,0,0); 740 return(kva); 741 } 742 743 /* 744 * uvm_km_protect: change the protection of an allocated area 745 */ 746 747 int 748 uvm_km_protect(struct vm_map *map, vaddr_t addr, vsize_t size, vm_prot_t prot) 749 { 750 return uvm_map_protect(map, addr, addr + round_page(size), prot, false); 751 } 752 753 /* 754 * uvm_km_free: free an area of kernel memory 755 */ 756 757 void 758 uvm_km_free(struct vm_map *map, vaddr_t addr, vsize_t size, uvm_flag_t flags) 759 { 760 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 761 762 KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED || 763 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE || 764 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY); 765 KASSERT((addr & PAGE_MASK) == 0); 766 KASSERT(vm_map_pmap(map) == pmap_kernel()); 767 768 size = round_page(size); 769 770 if (flags & UVM_KMF_PAGEABLE) { 771 uvm_km_pgremove(addr, addr + size); 772 } else if (flags & UVM_KMF_WIRED) { 773 /* 774 * Note: uvm_km_pgremove_intrsafe() extracts mapping, thus 775 * remove it after. See comment below about KVA visibility. 776 */ 777 uvm_km_pgremove_intrsafe(map, addr, addr + size); 778 } 779 780 /* 781 * Note: pmap_update() for the mappings was done inside 782 * uvm_km_pgremove*() above (before any page frees). 783 * VAONLY below tells uvm_unmap_remove() to skip pmap work. 784 */ 785 786 uvm_unmap1(map, addr, addr + size, UVM_FLAG_VAONLY); 787 } 788 789 /* Sanity; must specify both or none. */ 790 #if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \ 791 (!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE)) 792 #error Must specify MAP and UNMAP together. 793 #endif 794 795 #if defined(PMAP_ALLOC_POOLPAGE) && \ 796 !defined(PMAP_MAP_POOLPAGE) && !defined(PMAP_UNMAP_POOLPAGE) 797 #error Must specify ALLOC with MAP and UNMAP 798 #endif 799 800 int 801 uvm_km_kmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags, 802 vmem_addr_t *addr) 803 { 804 uint64_t ticket; 805 struct vm_page *pg; 806 vmem_addr_t va; 807 int rc; 808 vaddr_t loopva; 809 vsize_t loopsize; 810 811 size = round_page(size); 812 813 #if defined(PMAP_MAP_POOLPAGE) 814 if (size == PAGE_SIZE) { 815 again: 816 ticket = uvm_wait_prepare(); 817 #ifdef PMAP_ALLOC_POOLPAGE 818 pg = PMAP_ALLOC_POOLPAGE((flags & VM_SLEEP) ? 819 0 : UVM_PGA_USERESERVE); 820 #else 821 pg = uvm_pagealloc(NULL, 0, NULL, 822 (flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE); 823 #endif /* PMAP_ALLOC_POOLPAGE */ 824 if (__predict_false(pg == NULL)) { 825 if (flags & VM_SLEEP) { 826 uvm_wait("plpg", ticket); 827 goto again; 828 } 829 return ENOMEM; 830 } 831 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 832 KASSERT(va != 0); 833 *addr = va; 834 return 0; 835 } 836 #endif /* PMAP_MAP_POOLPAGE */ 837 838 rc = vmem_alloc(vm, size, flags, &va); 839 if (rc != 0) 840 return rc; 841 842 #ifdef PMAP_GROWKERNEL 843 /* 844 * These VA allocations happen independently of uvm_map 845 * so this allocation must not extend beyond the current limit. 846 */ 847 KASSERTMSG(uvm_maxkaddr >= va + size, 848 "%#"PRIxVADDR" %#"PRIxPTR" %#zx", 849 uvm_maxkaddr, va, size); 850 #endif 851 852 loopva = va; 853 loopsize = size; 854 855 while (loopsize) { 856 paddr_t pa __diagused; 857 KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, &pa), 858 "loopva=%#"PRIxVADDR" loopsize=%#"PRIxVSIZE 859 " pa=%#"PRIxPADDR" vmem=%p", 860 loopva, loopsize, pa, vm); 861 862 ticket = uvm_wait_prepare(); 863 pg = uvm_pagealloc(NULL, loopva, NULL, 864 UVM_FLAG_COLORMATCH 865 | ((flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE)); 866 if (__predict_false(pg == NULL)) { 867 if (flags & VM_SLEEP) { 868 uvm_wait("plpg", ticket); 869 continue; 870 } else { 871 uvm_km_pgremove_intrsafe(kernel_map, va, 872 va + size); 873 vmem_free(vm, va, size); 874 return ENOMEM; 875 } 876 } 877 878 pg->flags &= ~PG_BUSY; /* new page */ 879 UVM_PAGE_OWN(pg, NULL); 880 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), 881 VM_PROT_READ|VM_PROT_WRITE, PMAP_KMPAGE); 882 883 loopva += PAGE_SIZE; 884 loopsize -= PAGE_SIZE; 885 } 886 pmap_update(pmap_kernel()); 887 888 *addr = va; 889 890 return 0; 891 } 892 893 void 894 uvm_km_kmem_free(vmem_t *vm, vmem_addr_t addr, size_t size) 895 { 896 897 size = round_page(size); 898 #if defined(PMAP_UNMAP_POOLPAGE) 899 if (size == PAGE_SIZE) { 900 paddr_t pa; 901 902 pa = PMAP_UNMAP_POOLPAGE(addr); 903 uvm_pagefree(PHYS_TO_VM_PAGE(pa)); 904 return; 905 } 906 #endif /* PMAP_UNMAP_POOLPAGE */ 907 uvm_km_pgremove_intrsafe(kernel_map, addr, addr + size); 908 pmap_update(pmap_kernel()); 909 910 vmem_free(vm, addr, size); 911 } 912 913 bool 914 uvm_km_va_starved_p(void) 915 { 916 vmem_size_t total; 917 vmem_size_t free; 918 919 if (kmem_arena == NULL) 920 return false; 921 922 total = vmem_size(kmem_arena, VMEM_ALLOC|VMEM_FREE); 923 free = vmem_size(kmem_arena, VMEM_FREE); 924 925 return (free < (total / 10)); 926 } 927
Indexes created Fri Sep 25 00:27:33 UTC 2026