uvm_km.c revision 1.138.12.1
1 /* $NetBSD: uvm_km.c,v 1.138.12.1 2015/03/25 16:54:37 snj 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 1.138.12.1 2015/03/25 16:54:37 snj 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/proc.h> 181 #include <sys/pool.h> 182 #include <sys/vmem.h> 183 #include <sys/vmem_impl.h> 184 #include <sys/kmem.h> 185 186 #include <uvm/uvm.h> 187 188 /* 189 * global data structures 190 */ 191 192 struct vm_map *kernel_map = NULL; 193 194 /* 195 * local data structues 196 */ 197 198 static struct vm_map kernel_map_store; 199 static struct vm_map_entry kernel_image_mapent_store; 200 static struct vm_map_entry kernel_kmem_mapent_store; 201 202 int nkmempages = 0; 203 vaddr_t kmembase; 204 vsize_t kmemsize; 205 206 static struct vmem kmem_arena_store; 207 vmem_t *kmem_arena = NULL; 208 static struct vmem kmem_va_arena_store; 209 vmem_t *kmem_va_arena; 210 211 /* 212 * kmeminit_nkmempages: calculate the size of kmem_arena. 213 */ 214 void 215 kmeminit_nkmempages(void) 216 { 217 int npages; 218 219 if (nkmempages != 0) { 220 /* 221 * It's already been set (by us being here before) 222 * bail out now; 223 */ 224 return; 225 } 226 227 #if defined(PMAP_MAP_POOLPAGE) 228 npages = (physmem / 4); 229 #else 230 npages = (physmem / 3) * 2; 231 #endif /* defined(PMAP_MAP_POOLPAGE) */ 232 233 #ifndef NKMEMPAGES_MAX_UNLIMITED 234 if (npages > NKMEMPAGES_MAX) 235 npages = NKMEMPAGES_MAX; 236 #endif 237 238 if (npages < NKMEMPAGES_MIN) 239 npages = NKMEMPAGES_MIN; 240 241 nkmempages = npages; 242 } 243 244 /* 245 * uvm_km_bootstrap: init kernel maps and objects to reflect reality (i.e. 246 * KVM already allocated for text, data, bss, and static data structures). 247 * 248 * => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS. 249 * we assume that [vmin -> start] has already been allocated and that 250 * "end" is the end. 251 */ 252 253 void 254 uvm_km_bootstrap(vaddr_t start, vaddr_t end) 255 { 256 bool kmem_arena_small; 257 vaddr_t base = VM_MIN_KERNEL_ADDRESS; 258 struct uvm_map_args args; 259 int error; 260 261 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 262 UVMHIST_LOG(maphist, "start=%"PRIxVADDR" end=%#"PRIxVADDR, 263 start, end, 0,0); 264 265 kmeminit_nkmempages(); 266 kmemsize = (vsize_t)nkmempages * PAGE_SIZE; 267 kmem_arena_small = kmemsize < 64 * 1024 * 1024; 268 269 UVMHIST_LOG(maphist, "kmemsize=%#"PRIxVSIZE, kmemsize, 0,0,0); 270 271 /* 272 * next, init kernel memory objects. 273 */ 274 275 /* kernel_object: for pageable anonymous kernel memory */ 276 uvm_kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS - 277 VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ); 278 279 /* 280 * init the map and reserve any space that might already 281 * have been allocated kernel space before installing. 282 */ 283 284 uvm_map_setup(&kernel_map_store, base, end, VM_MAP_PAGEABLE); 285 kernel_map_store.pmap = pmap_kernel(); 286 if (start != base) { 287 error = uvm_map_prepare(&kernel_map_store, 288 base, start - base, 289 NULL, UVM_UNKNOWN_OFFSET, 0, 290 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 291 UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args); 292 if (!error) { 293 kernel_image_mapent_store.flags = 294 UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE; 295 error = uvm_map_enter(&kernel_map_store, &args, 296 &kernel_image_mapent_store); 297 } 298 299 if (error) 300 panic( 301 "uvm_km_bootstrap: could not reserve space for kernel"); 302 303 kmembase = args.uma_start + args.uma_size; 304 } else { 305 kmembase = base; 306 } 307 308 error = uvm_map_prepare(&kernel_map_store, 309 kmembase, kmemsize, 310 NULL, UVM_UNKNOWN_OFFSET, 0, 311 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 312 UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args); 313 if (!error) { 314 kernel_kmem_mapent_store.flags = 315 UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE; 316 error = uvm_map_enter(&kernel_map_store, &args, 317 &kernel_kmem_mapent_store); 318 } 319 320 if (error) 321 panic("uvm_km_bootstrap: could not reserve kernel kmem"); 322 323 /* 324 * install! 325 */ 326 327 kernel_map = &kernel_map_store; 328 329 pool_subsystem_init(); 330 331 kmem_arena = vmem_init(&kmem_arena_store, "kmem", 332 kmembase, kmemsize, PAGE_SIZE, NULL, NULL, NULL, 333 0, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM); 334 #ifdef PMAP_GROWKERNEL 335 /* 336 * kmem_arena VA allocations happen independently of uvm_map. 337 * grow kernel to accommodate the kmem_arena. 338 */ 339 if (uvm_maxkaddr < kmembase + kmemsize) { 340 uvm_maxkaddr = pmap_growkernel(kmembase + kmemsize); 341 KASSERTMSG(uvm_maxkaddr >= kmembase + kmemsize, 342 "%#"PRIxVADDR" %#"PRIxVADDR" %#"PRIxVSIZE, 343 uvm_maxkaddr, kmembase, kmemsize); 344 } 345 #endif 346 347 vmem_subsystem_init(kmem_arena); 348 349 UVMHIST_LOG(maphist, "kmem vmem created (base=%#"PRIxVADDR 350 ", size=%#"PRIxVSIZE, kmembase, kmemsize, 0,0); 351 352 kmem_va_arena = vmem_init(&kmem_va_arena_store, "kva", 353 0, 0, PAGE_SIZE, vmem_alloc, vmem_free, kmem_arena, 354 (kmem_arena_small ? 4 : VMEM_QCACHE_IDX_MAX) * PAGE_SIZE, 355 VM_NOSLEEP, IPL_VM); 356 357 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 358 } 359 360 /* 361 * uvm_km_init: init the kernel maps virtual memory caches 362 * and start the pool/kmem allocator. 363 */ 364 void 365 uvm_km_init(void) 366 { 367 kmem_init(); 368 } 369 370 /* 371 * uvm_km_suballoc: allocate a submap in the kernel map. once a submap 372 * is allocated all references to that area of VM must go through it. this 373 * allows the locking of VAs in kernel_map to be broken up into regions. 374 * 375 * => if `fixed' is true, *vmin specifies where the region described 376 * pager_map => used to map "buf" structures into kernel space 377 * by the submap must start 378 * => if submap is non NULL we use that as the submap, otherwise we 379 * alloc a new map 380 */ 381 382 struct vm_map * 383 uvm_km_suballoc(struct vm_map *map, vaddr_t *vmin /* IN/OUT */, 384 vaddr_t *vmax /* OUT */, vsize_t size, int flags, bool fixed, 385 struct vm_map *submap) 386 { 387 int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0); 388 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 389 390 KASSERT(vm_map_pmap(map) == pmap_kernel()); 391 392 size = round_page(size); /* round up to pagesize */ 393 394 /* 395 * first allocate a blank spot in the parent map 396 */ 397 398 if (uvm_map(map, vmin, size, NULL, UVM_UNKNOWN_OFFSET, 0, 399 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 400 UVM_ADV_RANDOM, mapflags)) != 0) { 401 panic("%s: unable to allocate space in parent map", __func__); 402 } 403 404 /* 405 * set VM bounds (vmin is filled in by uvm_map) 406 */ 407 408 *vmax = *vmin + size; 409 410 /* 411 * add references to pmap and create or init the submap 412 */ 413 414 pmap_reference(vm_map_pmap(map)); 415 if (submap == NULL) { 416 submap = kmem_alloc(sizeof(*submap), KM_SLEEP); 417 if (submap == NULL) 418 panic("uvm_km_suballoc: unable to create submap"); 419 } 420 uvm_map_setup(submap, *vmin, *vmax, flags); 421 submap->pmap = vm_map_pmap(map); 422 423 /* 424 * now let uvm_map_submap plug in it... 425 */ 426 427 if (uvm_map_submap(map, *vmin, *vmax, submap) != 0) 428 panic("uvm_km_suballoc: submap allocation failed"); 429 430 return(submap); 431 } 432 433 /* 434 * uvm_km_pgremove: remove pages from a kernel uvm_object and KVA. 435 */ 436 437 void 438 uvm_km_pgremove(vaddr_t startva, vaddr_t endva) 439 { 440 struct uvm_object * const uobj = uvm_kernel_object; 441 const voff_t start = startva - vm_map_min(kernel_map); 442 const voff_t end = endva - vm_map_min(kernel_map); 443 struct vm_page *pg; 444 voff_t curoff, nextoff; 445 int swpgonlydelta = 0; 446 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 447 448 KASSERT(VM_MIN_KERNEL_ADDRESS <= startva); 449 KASSERT(startva < endva); 450 KASSERT(endva <= VM_MAX_KERNEL_ADDRESS); 451 452 mutex_enter(uobj->vmobjlock); 453 pmap_remove(pmap_kernel(), startva, endva); 454 for (curoff = start; curoff < end; curoff = nextoff) { 455 nextoff = curoff + PAGE_SIZE; 456 pg = uvm_pagelookup(uobj, curoff); 457 if (pg != NULL && pg->flags & PG_BUSY) { 458 pg->flags |= PG_WANTED; 459 UVM_UNLOCK_AND_WAIT(pg, uobj->vmobjlock, 0, 460 "km_pgrm", 0); 461 mutex_enter(uobj->vmobjlock); 462 nextoff = curoff; 463 continue; 464 } 465 466 /* 467 * free the swap slot, then the page. 468 */ 469 470 if (pg == NULL && 471 uao_find_swslot(uobj, curoff >> PAGE_SHIFT) > 0) { 472 swpgonlydelta++; 473 } 474 uao_dropswap(uobj, curoff >> PAGE_SHIFT); 475 if (pg != NULL) { 476 mutex_enter(&uvm_pageqlock); 477 uvm_pagefree(pg); 478 mutex_exit(&uvm_pageqlock); 479 } 480 } 481 mutex_exit(uobj->vmobjlock); 482 483 if (swpgonlydelta > 0) { 484 mutex_enter(&uvm_swap_data_lock); 485 KASSERT(uvmexp.swpgonly >= swpgonlydelta); 486 uvmexp.swpgonly -= swpgonlydelta; 487 mutex_exit(&uvm_swap_data_lock); 488 } 489 } 490 491 492 /* 493 * uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for non object backed 494 * regions. 495 * 496 * => when you unmap a part of anonymous kernel memory you want to toss 497 * the pages right away. (this is called from uvm_unmap_...). 498 * => none of the pages will ever be busy, and none of them will ever 499 * be on the active or inactive queues (because they have no object). 500 */ 501 502 void 503 uvm_km_pgremove_intrsafe(struct vm_map *map, vaddr_t start, vaddr_t end) 504 { 505 #define __PGRM_BATCH 16 506 struct vm_page *pg; 507 paddr_t pa[__PGRM_BATCH]; 508 int npgrm, i; 509 vaddr_t va, batch_vastart; 510 511 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 512 513 KASSERT(VM_MAP_IS_KERNEL(map)); 514 KASSERTMSG(vm_map_min(map) <= start, 515 "vm_map_min(map) [%#"PRIxVADDR"] <= start [%#"PRIxVADDR"]" 516 " (size=%#"PRIxVSIZE")", 517 vm_map_min(map), start, end - start); 518 KASSERT(start < end); 519 KASSERT(end <= vm_map_max(map)); 520 521 for (va = start; va < end;) { 522 batch_vastart = va; 523 /* create a batch of at most __PGRM_BATCH pages to free */ 524 for (i = 0; 525 i < __PGRM_BATCH && va < end; 526 va += PAGE_SIZE) { 527 if (!pmap_extract(pmap_kernel(), va, &pa[i])) { 528 continue; 529 } 530 i++; 531 } 532 npgrm = i; 533 /* now remove the mappings */ 534 pmap_kremove(batch_vastart, va - batch_vastart); 535 /* and free the pages */ 536 for (i = 0; i < npgrm; i++) { 537 pg = PHYS_TO_VM_PAGE(pa[i]); 538 KASSERT(pg); 539 KASSERT(pg->uobject == NULL && pg->uanon == NULL); 540 KASSERT((pg->flags & PG_BUSY) == 0); 541 uvm_pagefree(pg); 542 } 543 } 544 #undef __PGRM_BATCH 545 } 546 547 #if defined(DEBUG) 548 void 549 uvm_km_check_empty(struct vm_map *map, vaddr_t start, vaddr_t end) 550 { 551 struct vm_page *pg; 552 vaddr_t va; 553 paddr_t pa; 554 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 555 556 KDASSERT(VM_MAP_IS_KERNEL(map)); 557 KDASSERT(vm_map_min(map) <= start); 558 KDASSERT(start < end); 559 KDASSERT(end <= vm_map_max(map)); 560 561 for (va = start; va < end; va += PAGE_SIZE) { 562 if (pmap_extract(pmap_kernel(), va, &pa)) { 563 panic("uvm_km_check_empty: va %p has pa 0x%llx", 564 (void *)va, (long long)pa); 565 } 566 mutex_enter(uvm_kernel_object->vmobjlock); 567 pg = uvm_pagelookup(uvm_kernel_object, 568 va - vm_map_min(kernel_map)); 569 mutex_exit(uvm_kernel_object->vmobjlock); 570 if (pg) { 571 panic("uvm_km_check_empty: " 572 "has page hashed at %p", (const void *)va); 573 } 574 } 575 } 576 #endif /* defined(DEBUG) */ 577 578 /* 579 * uvm_km_alloc: allocate an area of kernel memory. 580 * 581 * => NOTE: we can return 0 even if we can wait if there is not enough 582 * free VM space in the map... caller should be prepared to handle 583 * this case. 584 * => we return KVA of memory allocated 585 */ 586 587 vaddr_t 588 uvm_km_alloc(struct vm_map *map, vsize_t size, vsize_t align, uvm_flag_t flags) 589 { 590 vaddr_t kva, loopva; 591 vaddr_t offset; 592 vsize_t loopsize; 593 struct vm_page *pg; 594 struct uvm_object *obj; 595 int pgaflags; 596 vm_prot_t prot; 597 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 598 599 KASSERT(vm_map_pmap(map) == pmap_kernel()); 600 KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED || 601 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE || 602 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY); 603 KASSERT((flags & UVM_KMF_VAONLY) != 0 || (flags & UVM_KMF_COLORMATCH) == 0); 604 KASSERT((flags & UVM_KMF_COLORMATCH) == 0 || (flags & UVM_KMF_VAONLY) != 0); 605 606 /* 607 * setup for call 608 */ 609 610 kva = vm_map_min(map); /* hint */ 611 size = round_page(size); 612 obj = (flags & UVM_KMF_PAGEABLE) ? uvm_kernel_object : NULL; 613 UVMHIST_LOG(maphist," (map=0x%x, obj=0x%x, size=0x%x, flags=%d)", 614 map, obj, size, flags); 615 616 /* 617 * allocate some virtual space 618 */ 619 620 if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET, 621 align, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 622 UVM_ADV_RANDOM, 623 (flags & (UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT | UVM_KMF_WAITVA 624 | UVM_KMF_COLORMATCH)))) != 0)) { 625 UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0); 626 return(0); 627 } 628 629 /* 630 * if all we wanted was VA, return now 631 */ 632 633 if (flags & (UVM_KMF_VAONLY | UVM_KMF_PAGEABLE)) { 634 UVMHIST_LOG(maphist,"<- done valloc (kva=0x%x)", kva,0,0,0); 635 return(kva); 636 } 637 638 /* 639 * recover object offset from virtual address 640 */ 641 642 offset = kva - vm_map_min(kernel_map); 643 UVMHIST_LOG(maphist, " kva=0x%x, offset=0x%x", kva, offset,0,0); 644 645 /* 646 * now allocate and map in the memory... note that we are the only ones 647 * whom should ever get a handle on this area of VM. 648 */ 649 650 loopva = kva; 651 loopsize = size; 652 653 pgaflags = UVM_FLAG_COLORMATCH; 654 if (flags & UVM_KMF_NOWAIT) 655 pgaflags |= UVM_PGA_USERESERVE; 656 if (flags & UVM_KMF_ZERO) 657 pgaflags |= UVM_PGA_ZERO; 658 prot = VM_PROT_READ | VM_PROT_WRITE; 659 if (flags & UVM_KMF_EXEC) 660 prot |= VM_PROT_EXECUTE; 661 while (loopsize) { 662 KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, NULL), 663 "loopva=%#"PRIxVADDR, loopva); 664 665 pg = uvm_pagealloc_strat(NULL, offset, NULL, pgaflags, 666 #ifdef UVM_KM_VMFREELIST 667 UVM_PGA_STRAT_ONLY, UVM_KM_VMFREELIST 668 #else 669 UVM_PGA_STRAT_NORMAL, 0 670 #endif 671 ); 672 673 /* 674 * out of memory? 675 */ 676 677 if (__predict_false(pg == NULL)) { 678 if ((flags & UVM_KMF_NOWAIT) || 679 ((flags & UVM_KMF_CANFAIL) && !uvm_reclaimable())) { 680 /* free everything! */ 681 uvm_km_free(map, kva, size, 682 flags & UVM_KMF_TYPEMASK); 683 return (0); 684 } else { 685 uvm_wait("km_getwait2"); /* sleep here */ 686 continue; 687 } 688 } 689 690 pg->flags &= ~PG_BUSY; /* new page */ 691 UVM_PAGE_OWN(pg, NULL); 692 693 /* 694 * map it in 695 */ 696 697 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), 698 prot, PMAP_KMPAGE); 699 loopva += PAGE_SIZE; 700 offset += PAGE_SIZE; 701 loopsize -= PAGE_SIZE; 702 } 703 704 pmap_update(pmap_kernel()); 705 706 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 707 return(kva); 708 } 709 710 /* 711 * uvm_km_free: free an area of kernel memory 712 */ 713 714 void 715 uvm_km_free(struct vm_map *map, vaddr_t addr, vsize_t size, uvm_flag_t flags) 716 { 717 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 718 719 KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED || 720 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE || 721 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY); 722 KASSERT((addr & PAGE_MASK) == 0); 723 KASSERT(vm_map_pmap(map) == pmap_kernel()); 724 725 size = round_page(size); 726 727 if (flags & UVM_KMF_PAGEABLE) { 728 uvm_km_pgremove(addr, addr + size); 729 } else if (flags & UVM_KMF_WIRED) { 730 /* 731 * Note: uvm_km_pgremove_intrsafe() extracts mapping, thus 732 * remove it after. See comment below about KVA visibility. 733 */ 734 uvm_km_pgremove_intrsafe(map, addr, addr + size); 735 } 736 737 /* 738 * Note: uvm_unmap_remove() calls pmap_update() for us, before 739 * KVA becomes globally available. 740 */ 741 742 uvm_unmap1(map, addr, addr + size, UVM_FLAG_VAONLY); 743 } 744 745 /* Sanity; must specify both or none. */ 746 #if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \ 747 (!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE)) 748 #error Must specify MAP and UNMAP together. 749 #endif 750 751 int 752 uvm_km_kmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags, 753 vmem_addr_t *addr) 754 { 755 struct vm_page *pg; 756 vmem_addr_t va; 757 int rc; 758 vaddr_t loopva; 759 vsize_t loopsize; 760 761 size = round_page(size); 762 763 #if defined(PMAP_MAP_POOLPAGE) 764 if (size == PAGE_SIZE) { 765 again: 766 #ifdef PMAP_ALLOC_POOLPAGE 767 pg = PMAP_ALLOC_POOLPAGE((flags & VM_SLEEP) ? 768 0 : UVM_PGA_USERESERVE); 769 #else 770 pg = uvm_pagealloc(NULL, 0, NULL, 771 (flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE); 772 #endif /* PMAP_ALLOC_POOLPAGE */ 773 if (__predict_false(pg == NULL)) { 774 if (flags & VM_SLEEP) { 775 uvm_wait("plpg"); 776 goto again; 777 } 778 return ENOMEM; 779 } 780 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 781 if (__predict_false(va == 0)) { 782 uvm_pagefree(pg); 783 return ENOMEM; 784 } 785 *addr = va; 786 return 0; 787 } 788 #endif /* PMAP_MAP_POOLPAGE */ 789 790 rc = vmem_alloc(vm, size, flags, &va); 791 if (rc != 0) 792 return rc; 793 794 #ifdef PMAP_GROWKERNEL 795 /* 796 * These VA allocations happen independently of uvm_map 797 * so this allocation must not extend beyond the current limit. 798 */ 799 KASSERTMSG(uvm_maxkaddr >= va + size, 800 "%#"PRIxVADDR" %#"PRIxPTR" %#zx", 801 uvm_maxkaddr, va, size); 802 #endif 803 804 loopva = va; 805 loopsize = size; 806 807 while (loopsize) { 808 #ifdef DIAGNOSTIC 809 paddr_t pa; 810 #endif 811 KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, &pa), 812 "loopva=%#"PRIxVADDR" loopsize=%#"PRIxVSIZE 813 " pa=%#"PRIxPADDR" vmem=%p", 814 loopva, loopsize, pa, vm); 815 816 pg = uvm_pagealloc(NULL, loopva, NULL, 817 UVM_FLAG_COLORMATCH 818 | ((flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE)); 819 if (__predict_false(pg == NULL)) { 820 if (flags & VM_SLEEP) { 821 uvm_wait("plpg"); 822 continue; 823 } else { 824 uvm_km_pgremove_intrsafe(kernel_map, va, 825 va + size); 826 vmem_free(vm, va, size); 827 return ENOMEM; 828 } 829 } 830 831 pg->flags &= ~PG_BUSY; /* new page */ 832 UVM_PAGE_OWN(pg, NULL); 833 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), 834 VM_PROT_READ|VM_PROT_WRITE, PMAP_KMPAGE); 835 836 loopva += PAGE_SIZE; 837 loopsize -= PAGE_SIZE; 838 } 839 pmap_update(pmap_kernel()); 840 841 *addr = va; 842 843 return 0; 844 } 845 846 void 847 uvm_km_kmem_free(vmem_t *vm, vmem_addr_t addr, size_t size) 848 { 849 850 size = round_page(size); 851 #if defined(PMAP_UNMAP_POOLPAGE) 852 if (size == PAGE_SIZE) { 853 paddr_t pa; 854 855 pa = PMAP_UNMAP_POOLPAGE(addr); 856 uvm_pagefree(PHYS_TO_VM_PAGE(pa)); 857 return; 858 } 859 #endif /* PMAP_UNMAP_POOLPAGE */ 860 uvm_km_pgremove_intrsafe(kernel_map, addr, addr + size); 861 pmap_update(pmap_kernel()); 862 863 vmem_free(vm, addr, size); 864 } 865 866 bool 867 uvm_km_va_starved_p(void) 868 { 869 vmem_size_t total; 870 vmem_size_t free; 871 872 if (kmem_arena == NULL) 873 return false; 874 875 total = vmem_size(kmem_arena, VMEM_ALLOC|VMEM_FREE); 876 free = vmem_size(kmem_arena, VMEM_FREE); 877 878 return (free < (total / 10)); 879 } 880
Indexes created Thu Oct 23 22:10:10 GMT 2025