uvm_km.c revision 1.163
1/* $NetBSD: uvm_km.c,v 1.163 2023/02/12 16:28:32 andvar 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@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 1.163 2023/02/12 16:28:32 andvar 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 194struct vm_map *kernel_map = NULL; 195 196/* 197 * local data structures 198 */ 199 200static struct vm_map kernel_map_store; 201static struct vm_map_entry kernel_image_mapent_store; 202static struct vm_map_entry kernel_kmem_mapent_store; 203 204int nkmempages = 0; 205vaddr_t kmembase; 206vsize_t kmemsize; 207 208static struct vmem kmem_arena_store; 209vmem_t *kmem_arena = NULL; 210static struct vmem kmem_va_arena_store; 211vmem_t *kmem_va_arena; 212 213/* 214 * kmeminit_nkmempages: calculate the size of kmem_arena. 215 */ 216void 217kmeminit_nkmempages(void) 218{ 219 int 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 npages = physmem; 231#else 232 233#if defined(KMSAN) 234 npages = (physmem / 4); 235#elif defined(PMAP_MAP_POOLPAGE) 236 npages = (physmem / 4); 237#else 238 npages = (physmem / 3) * 2; 239#endif /* defined(PMAP_MAP_POOLPAGE) */ 240 241#if !defined(NKMEMPAGES_MAX_UNLIMITED) 242 if (npages > NKMEMPAGES_MAX) 243 npages = NKMEMPAGES_MAX; 244#endif 245 246#endif 247 248 if (npages < NKMEMPAGES_MIN) 249 npages = NKMEMPAGES_MIN; 250 251 nkmempages = npages; 252} 253 254/* 255 * uvm_km_bootstrap: init kernel maps and objects to reflect reality (i.e. 256 * KVM already allocated for text, data, bss, and static data structures). 257 * 258 * => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS. 259 * we assume that [vmin -> start] has already been allocated and that 260 * "end" is the end. 261 */ 262 263void 264uvm_km_bootstrap(vaddr_t start, vaddr_t end) 265{ 266 bool kmem_arena_small; 267 vaddr_t base = VM_MIN_KERNEL_ADDRESS; 268 struct uvm_map_args args; 269 int error; 270 271 UVMHIST_FUNC(__func__); 272 UVMHIST_CALLARGS(maphist, "start=%#jx end=%#jx", start, end, 0,0); 273 274 kmeminit_nkmempages(); 275 kmemsize = (vsize_t)nkmempages * PAGE_SIZE; 276 kmem_arena_small = kmemsize < 64 * 1024 * 1024; 277 278 UVMHIST_LOG(maphist, "kmemsize=%#jx", kmemsize, 0,0,0); 279 280 /* 281 * next, init kernel memory objects. 282 */ 283 284 /* kernel_object: for pageable anonymous kernel memory */ 285 uvm_kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS - 286 VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ); 287 288 /* 289 * init the map and reserve any space that might already 290 * have been allocated kernel space before installing. 291 */ 292 293 uvm_map_setup(&kernel_map_store, base, end, VM_MAP_PAGEABLE); 294 kernel_map_store.pmap = pmap_kernel(); 295 if (start != base) { 296 error = uvm_map_prepare(&kernel_map_store, 297 base, start - base, 298 NULL, UVM_UNKNOWN_OFFSET, 0, 299 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 300 UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args); 301 if (!error) { 302 kernel_image_mapent_store.flags = 303 UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE; 304 error = uvm_map_enter(&kernel_map_store, &args, 305 &kernel_image_mapent_store); 306 } 307 308 if (error) 309 panic( 310 "uvm_km_bootstrap: could not reserve space for kernel"); 311 312 kmembase = args.uma_start + args.uma_size; 313 } else { 314 kmembase = base; 315 } 316 317 error = uvm_map_prepare(&kernel_map_store, 318 kmembase, kmemsize, 319 NULL, UVM_UNKNOWN_OFFSET, 0, 320 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 321 UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args); 322 if (!error) { 323 kernel_kmem_mapent_store.flags = 324 UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE; 325 error = uvm_map_enter(&kernel_map_store, &args, 326 &kernel_kmem_mapent_store); 327 } 328 329 if (error) 330 panic("uvm_km_bootstrap: could not reserve kernel kmem"); 331 332 /* 333 * install! 334 */ 335 336 kernel_map = &kernel_map_store; 337 338 pool_subsystem_init(); 339 340 kmem_arena = vmem_init(&kmem_arena_store, "kmem", 341 kmembase, kmemsize, PAGE_SIZE, NULL, NULL, NULL, 342 0, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM); 343#ifdef PMAP_GROWKERNEL 344 /* 345 * kmem_arena VA allocations happen independently of uvm_map. 346 * grow kernel to accommodate the kmem_arena. 347 */ 348 if (uvm_maxkaddr < kmembase + kmemsize) { 349 uvm_maxkaddr = pmap_growkernel(kmembase + kmemsize); 350 KASSERTMSG(uvm_maxkaddr >= kmembase + kmemsize, 351 "%#"PRIxVADDR" %#"PRIxVADDR" %#"PRIxVSIZE, 352 uvm_maxkaddr, kmembase, kmemsize); 353 } 354#endif 355 356 vmem_subsystem_init(kmem_arena); 357 358 UVMHIST_LOG(maphist, "kmem vmem created (base=%#jx, size=%#jx", 359 kmembase, kmemsize, 0,0); 360 361 kmem_va_arena = vmem_init(&kmem_va_arena_store, "kva", 362 0, 0, PAGE_SIZE, vmem_alloc, vmem_free, kmem_arena, 363 (kmem_arena_small ? 4 : VMEM_QCACHE_IDX_MAX) * PAGE_SIZE, 364 VM_NOSLEEP, IPL_VM); 365 366 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 367} 368 369/* 370 * uvm_km_init: init the kernel maps virtual memory caches 371 * and start the pool/kmem allocator. 372 */ 373void 374uvm_km_init(void) 375{ 376 kmem_init(); 377} 378 379/* 380 * uvm_km_suballoc: allocate a submap in the kernel map. once a submap 381 * is allocated all references to that area of VM must go through it. this 382 * allows the locking of VAs in kernel_map to be broken up into regions. 383 * 384 * => if `fixed' is true, *vmin specifies where the region described 385 * pager_map => used to map "buf" structures into kernel space 386 * by the submap must start 387 * => if submap is non NULL we use that as the submap, otherwise we 388 * alloc a new map 389 */ 390 391struct vm_map * 392uvm_km_suballoc(struct vm_map *map, vaddr_t *vmin /* IN/OUT */, 393 vaddr_t *vmax /* OUT */, vsize_t size, int flags, bool fixed, 394 struct vm_map *submap) 395{ 396 int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0); 397 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 398 399 KASSERT(vm_map_pmap(map) == pmap_kernel()); 400 401 size = round_page(size); /* round up to pagesize */ 402 403 /* 404 * first allocate a blank spot in the parent map 405 */ 406 407 if (uvm_map(map, vmin, size, NULL, UVM_UNKNOWN_OFFSET, 0, 408 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 409 UVM_ADV_RANDOM, mapflags)) != 0) { 410 panic("%s: unable to allocate space in parent map", __func__); 411 } 412 413 /* 414 * set VM bounds (vmin is filled in by uvm_map) 415 */ 416 417 *vmax = *vmin + size; 418 419 /* 420 * add references to pmap and create or init the submap 421 */ 422 423 pmap_reference(vm_map_pmap(map)); 424 if (submap == NULL) { 425 submap = kmem_alloc(sizeof(*submap), KM_SLEEP); 426 } 427 uvm_map_setup(submap, *vmin, *vmax, flags); 428 submap->pmap = vm_map_pmap(map); 429 430 /* 431 * now let uvm_map_submap plug in it... 432 */ 433 434 if (uvm_map_submap(map, *vmin, *vmax, submap) != 0) 435 panic("uvm_km_suballoc: submap allocation failed"); 436 437 return(submap); 438} 439 440/* 441 * uvm_km_pgremove: remove pages from a kernel uvm_object and KVA. 442 */ 443 444void 445uvm_km_pgremove(vaddr_t startva, vaddr_t endva) 446{ 447 struct uvm_object * const uobj = uvm_kernel_object; 448 const voff_t start = startva - vm_map_min(kernel_map); 449 const voff_t end = endva - vm_map_min(kernel_map); 450 struct vm_page *pg; 451 voff_t curoff, nextoff; 452 int swpgonlydelta = 0; 453 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 454 455 KASSERT(VM_MIN_KERNEL_ADDRESS <= startva); 456 KASSERT(startva < endva); 457 KASSERT(endva <= VM_MAX_KERNEL_ADDRESS); 458 459 rw_enter(uobj->vmobjlock, RW_WRITER); 460 pmap_remove(pmap_kernel(), startva, endva); 461 for (curoff = start; curoff < end; curoff = nextoff) { 462 nextoff = curoff + PAGE_SIZE; 463 pg = uvm_pagelookup(uobj, curoff); 464 if (pg != NULL && pg->flags & PG_BUSY) { 465 uvm_pagewait(pg, uobj->vmobjlock, "km_pgrm"); 466 rw_enter(uobj->vmobjlock, RW_WRITER); 467 nextoff = curoff; 468 continue; 469 } 470 471 /* 472 * free the swap slot, then the page. 473 */ 474 475 if (pg == NULL && 476 uao_find_swslot(uobj, curoff >> PAGE_SHIFT) > 0) { 477 swpgonlydelta++; 478 } 479 uao_dropswap(uobj, curoff >> PAGE_SHIFT); 480 if (pg != NULL) { 481 uvm_pagefree(pg); 482 } 483 } 484 rw_exit(uobj->vmobjlock); 485 486 if (swpgonlydelta > 0) { 487 KASSERT(uvmexp.swpgonly >= swpgonlydelta); 488 atomic_add_int(&uvmexp.swpgonly, -swpgonlydelta); 489 } 490} 491 492 493/* 494 * uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for non object backed 495 * regions. 496 * 497 * => when you unmap a part of anonymous kernel memory you want to toss 498 * the pages right away. (this is called from uvm_unmap_...). 499 * => none of the pages will ever be busy, and none of them will ever 500 * be on the active or inactive queues (because they have no object). 501 */ 502 503void 504uvm_km_pgremove_intrsafe(struct vm_map *map, vaddr_t start, vaddr_t end) 505{ 506#define __PGRM_BATCH 16 507 struct vm_page *pg; 508 paddr_t pa[__PGRM_BATCH]; 509 int npgrm, i; 510 vaddr_t va, batch_vastart; 511 512 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 513 514 KASSERT(VM_MAP_IS_KERNEL(map)); 515 KASSERTMSG(vm_map_min(map) <= start, 516 "vm_map_min(map) [%#"PRIxVADDR"] <= start [%#"PRIxVADDR"]" 517 " (size=%#"PRIxVSIZE")", 518 vm_map_min(map), start, end - start); 519 KASSERT(start < end); 520 KASSERT(end <= vm_map_max(map)); 521 522 for (va = start; va < end;) { 523 batch_vastart = va; 524 /* create a batch of at most __PGRM_BATCH pages to free */ 525 for (i = 0; 526 i < __PGRM_BATCH && va < end; 527 va += PAGE_SIZE) { 528 if (!pmap_extract(pmap_kernel(), va, &pa[i])) { 529 continue; 530 } 531 i++; 532 } 533 npgrm = i; 534 /* now remove the mappings */ 535 pmap_kremove(batch_vastart, va - batch_vastart); 536 /* and free the pages */ 537 for (i = 0; i < npgrm; i++) { 538 pg = PHYS_TO_VM_PAGE(pa[i]); 539 KASSERT(pg); 540 KASSERT(pg->uobject == NULL && pg->uanon == NULL); 541 KASSERT((pg->flags & PG_BUSY) == 0); 542 uvm_pagefree(pg); 543 } 544 } 545#undef __PGRM_BATCH 546} 547 548#if defined(DEBUG) 549void 550uvm_km_check_empty(struct vm_map *map, vaddr_t start, vaddr_t end) 551{ 552 vaddr_t va; 553 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 554 555 KDASSERT(VM_MAP_IS_KERNEL(map)); 556 KDASSERT(vm_map_min(map) <= start); 557 KDASSERT(start < end); 558 KDASSERT(end <= vm_map_max(map)); 559 560 for (va = start; va < end; va += PAGE_SIZE) { 561 paddr_t pa; 562 563 if (pmap_extract(pmap_kernel(), va, &pa)) { 564 panic("uvm_km_check_empty: va %p has pa %#llx", 565 (void *)va, (long long)pa); 566 } 567 /* 568 * kernel_object should not have pages for the corresponding 569 * region. check it. 570 * 571 * why trylock? because: 572 * - caller might not want to block. 573 * - we can recurse when allocating radix_node for 574 * kernel_object. 575 */ 576 if (rw_tryenter(uvm_kernel_object->vmobjlock, RW_READER)) { 577 struct vm_page *pg; 578 579 pg = uvm_pagelookup(uvm_kernel_object, 580 va - vm_map_min(kernel_map)); 581 rw_exit(uvm_kernel_object->vmobjlock); 582 if (pg) { 583 panic("uvm_km_check_empty: " 584 "has page hashed at %p", 585 (const void *)va); 586 } 587 } 588 } 589} 590#endif /* defined(DEBUG) */ 591 592/* 593 * uvm_km_alloc: allocate an area of kernel memory. 594 * 595 * => NOTE: we can return 0 even if we can wait if there is not enough 596 * free VM space in the map... caller should be prepared to handle 597 * this case. 598 * => we return KVA of memory allocated 599 */ 600 601vaddr_t 602uvm_km_alloc(struct vm_map *map, vsize_t size, vsize_t align, uvm_flag_t flags) 603{ 604 vaddr_t kva, loopva; 605 vaddr_t offset; 606 vsize_t loopsize; 607 struct vm_page *pg; 608 struct uvm_object *obj; 609 int pgaflags; 610 vm_prot_t prot, vaprot; 611 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 612 613 KASSERT(vm_map_pmap(map) == pmap_kernel()); 614 KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED || 615 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE || 616 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY); 617 KASSERT((flags & UVM_KMF_VAONLY) != 0 || (flags & UVM_KMF_COLORMATCH) == 0); 618 KASSERT((flags & UVM_KMF_COLORMATCH) == 0 || (flags & UVM_KMF_VAONLY) != 0); 619 620 /* 621 * setup for call 622 */ 623 624 kva = vm_map_min(map); /* hint */ 625 size = round_page(size); 626 obj = (flags & UVM_KMF_PAGEABLE) ? uvm_kernel_object : NULL; 627 UVMHIST_LOG(maphist," (map=%#jx, obj=%#jx, size=%#jx, flags=%#jx)", 628 (uintptr_t)map, (uintptr_t)obj, size, flags); 629 630 /* 631 * allocate some virtual space 632 */ 633 634 vaprot = (flags & UVM_KMF_EXEC) ? UVM_PROT_ALL : UVM_PROT_RW; 635 if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET, 636 align, UVM_MAPFLAG(vaprot, UVM_PROT_ALL, UVM_INH_NONE, 637 UVM_ADV_RANDOM, 638 (flags & (UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT | UVM_KMF_WAITVA 639 | UVM_KMF_COLORMATCH)))) != 0)) { 640 UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0); 641 return(0); 642 } 643 644 /* 645 * if all we wanted was VA, return now 646 */ 647 648 if (flags & (UVM_KMF_VAONLY | UVM_KMF_PAGEABLE)) { 649 UVMHIST_LOG(maphist,"<- done valloc (kva=%#jx)", kva,0,0,0); 650 return(kva); 651 } 652 653 /* 654 * recover object offset from virtual address 655 */ 656 657 offset = kva - vm_map_min(kernel_map); 658 UVMHIST_LOG(maphist, " kva=%#jx, offset=%#jx", kva, offset,0,0); 659 660 /* 661 * now allocate and map in the memory... note that we are the only ones 662 * whom should ever get a handle on this area of VM. 663 */ 664 665 loopva = kva; 666 loopsize = size; 667 668 pgaflags = UVM_FLAG_COLORMATCH; 669 if (flags & UVM_KMF_NOWAIT) 670 pgaflags |= UVM_PGA_USERESERVE; 671 if (flags & UVM_KMF_ZERO) 672 pgaflags |= UVM_PGA_ZERO; 673 prot = VM_PROT_READ | VM_PROT_WRITE; 674 if (flags & UVM_KMF_EXEC) 675 prot |= VM_PROT_EXECUTE; 676 while (loopsize) { 677 KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, NULL), 678 "loopva=%#"PRIxVADDR, loopva); 679 680 pg = uvm_pagealloc_strat(NULL, offset, NULL, pgaflags, 681#ifdef UVM_KM_VMFREELIST 682 UVM_PGA_STRAT_ONLY, UVM_KM_VMFREELIST 683#else 684 UVM_PGA_STRAT_NORMAL, 0 685#endif 686 ); 687 688 /* 689 * out of memory? 690 */ 691 692 if (__predict_false(pg == NULL)) { 693 if ((flags & UVM_KMF_NOWAIT) || 694 ((flags & UVM_KMF_CANFAIL) && !uvm_reclaimable())) { 695 /* free everything! */ 696 uvm_km_free(map, kva, size, 697 flags & UVM_KMF_TYPEMASK); 698 return (0); 699 } else { 700 uvm_wait("km_getwait2"); /* sleep here */ 701 continue; 702 } 703 } 704 705 pg->flags &= ~PG_BUSY; /* new page */ 706 UVM_PAGE_OWN(pg, NULL); 707 708 /* 709 * map it in 710 */ 711 712 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), 713 prot, PMAP_KMPAGE); 714 loopva += PAGE_SIZE; 715 offset += PAGE_SIZE; 716 loopsize -= PAGE_SIZE; 717 } 718 719 pmap_update(pmap_kernel()); 720 721 if ((flags & UVM_KMF_ZERO) == 0) { 722 kmsan_orig((void *)kva, size, KMSAN_TYPE_UVM, __RET_ADDR); 723 kmsan_mark((void *)kva, size, KMSAN_STATE_UNINIT); 724 } 725 726 UVMHIST_LOG(maphist,"<- done (kva=%#jx)", kva,0,0,0); 727 return(kva); 728} 729 730/* 731 * uvm_km_protect: change the protection of an allocated area 732 */ 733 734int 735uvm_km_protect(struct vm_map *map, vaddr_t addr, vsize_t size, vm_prot_t prot) 736{ 737 return uvm_map_protect(map, addr, addr + round_page(size), prot, false); 738} 739 740/* 741 * uvm_km_free: free an area of kernel memory 742 */ 743 744void 745uvm_km_free(struct vm_map *map, vaddr_t addr, vsize_t size, uvm_flag_t flags) 746{ 747 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 748 749 KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED || 750 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE || 751 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY); 752 KASSERT((addr & PAGE_MASK) == 0); 753 KASSERT(vm_map_pmap(map) == pmap_kernel()); 754 755 size = round_page(size); 756 757 if (flags & UVM_KMF_PAGEABLE) { 758 uvm_km_pgremove(addr, addr + size); 759 } else if (flags & UVM_KMF_WIRED) { 760 /* 761 * Note: uvm_km_pgremove_intrsafe() extracts mapping, thus 762 * remove it after. See comment below about KVA visibility. 763 */ 764 uvm_km_pgremove_intrsafe(map, addr, addr + size); 765 } 766 767 /* 768 * Note: uvm_unmap_remove() calls pmap_update() for us, before 769 * KVA becomes globally available. 770 */ 771 772 uvm_unmap1(map, addr, addr + size, UVM_FLAG_VAONLY); 773} 774 775/* Sanity; must specify both or none. */ 776#if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \ 777 (!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE)) 778#error Must specify MAP and UNMAP together. 779#endif 780 781#if defined(PMAP_ALLOC_POOLPAGE) && \ 782 !defined(PMAP_MAP_POOLPAGE) && !defined(PMAP_UNMAP_POOLPAGE) 783#error Must specify ALLOC with MAP and UNMAP 784#endif 785 786int 787uvm_km_kmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags, 788 vmem_addr_t *addr) 789{ 790 struct vm_page *pg; 791 vmem_addr_t va; 792 int rc; 793 vaddr_t loopva; 794 vsize_t loopsize; 795 796 size = round_page(size); 797 798#if defined(PMAP_MAP_POOLPAGE) 799 if (size == PAGE_SIZE) { 800again: 801#ifdef PMAP_ALLOC_POOLPAGE 802 pg = PMAP_ALLOC_POOLPAGE((flags & VM_SLEEP) ? 803 0 : UVM_PGA_USERESERVE); 804#else 805 pg = uvm_pagealloc(NULL, 0, NULL, 806 (flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE); 807#endif /* PMAP_ALLOC_POOLPAGE */ 808 if (__predict_false(pg == NULL)) { 809 if (flags & VM_SLEEP) { 810 uvm_wait("plpg"); 811 goto again; 812 } 813 return ENOMEM; 814 } 815 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 816 KASSERT(va != 0); 817 *addr = va; 818 return 0; 819 } 820#endif /* PMAP_MAP_POOLPAGE */ 821 822 rc = vmem_alloc(vm, size, flags, &va); 823 if (rc != 0) 824 return rc; 825 826#ifdef PMAP_GROWKERNEL 827 /* 828 * These VA allocations happen independently of uvm_map 829 * so this allocation must not extend beyond the current limit. 830 */ 831 KASSERTMSG(uvm_maxkaddr >= va + size, 832 "%#"PRIxVADDR" %#"PRIxPTR" %#zx", 833 uvm_maxkaddr, va, size); 834#endif 835 836 loopva = va; 837 loopsize = size; 838 839 while (loopsize) { 840 paddr_t pa __diagused; 841 KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, &pa), 842 "loopva=%#"PRIxVADDR" loopsize=%#"PRIxVSIZE 843 " pa=%#"PRIxPADDR" vmem=%p", 844 loopva, loopsize, pa, vm); 845 846 pg = uvm_pagealloc(NULL, loopva, NULL, 847 UVM_FLAG_COLORMATCH 848 | ((flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE)); 849 if (__predict_false(pg == NULL)) { 850 if (flags & VM_SLEEP) { 851 uvm_wait("plpg"); 852 continue; 853 } else { 854 uvm_km_pgremove_intrsafe(kernel_map, va, 855 va + size); 856 vmem_free(vm, va, size); 857 return ENOMEM; 858 } 859 } 860 861 pg->flags &= ~PG_BUSY; /* new page */ 862 UVM_PAGE_OWN(pg, NULL); 863 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), 864 VM_PROT_READ|VM_PROT_WRITE, PMAP_KMPAGE); 865 866 loopva += PAGE_SIZE; 867 loopsize -= PAGE_SIZE; 868 } 869 pmap_update(pmap_kernel()); 870 871 *addr = va; 872 873 return 0; 874} 875 876void 877uvm_km_kmem_free(vmem_t *vm, vmem_addr_t addr, size_t size) 878{ 879 880 size = round_page(size); 881#if defined(PMAP_UNMAP_POOLPAGE) 882 if (size == PAGE_SIZE) { 883 paddr_t pa; 884 885 pa = PMAP_UNMAP_POOLPAGE(addr); 886 uvm_pagefree(PHYS_TO_VM_PAGE(pa)); 887 return; 888 } 889#endif /* PMAP_UNMAP_POOLPAGE */ 890 uvm_km_pgremove_intrsafe(kernel_map, addr, addr + size); 891 pmap_update(pmap_kernel()); 892 893 vmem_free(vm, addr, size); 894} 895 896bool 897uvm_km_va_starved_p(void) 898{ 899 vmem_size_t total; 900 vmem_size_t free; 901 902 if (kmem_arena == NULL) 903 return false; 904 905 total = vmem_size(kmem_arena, VMEM_ALLOC|VMEM_FREE); 906 free = vmem_size(kmem_arena, VMEM_FREE); 907 908 return (free < (total / 10)); 909} 910