uvm_km.c revision 1.114
1/* $NetBSD: uvm_km.c,v 1.114 2012/01/31 00:30:52 matt 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, including: 87 * pager_map => used to map "buf" structures into kernel space 88 * exec_map => used during exec to handle exec args 89 * etc... 90 * 91 * the kernel allocates its private memory out of special uvm_objects whose 92 * reference count is set to UVM_OBJ_KERN (thus indicating that the objects 93 * are "special" and never die). all kernel objects should be thought of 94 * as large, fixed-sized, sparsely populated uvm_objects. each kernel 95 * object is equal to the size of kernel virtual address space (i.e. the 96 * value "VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS"). 97 * 98 * note that just because a kernel object spans the entire kernel virtual 99 * address space doesn't mean that it has to be mapped into the entire space. 100 * large chunks of a kernel object's space go unused either because 101 * that area of kernel VM is unmapped, or there is some other type of 102 * object mapped into that range (e.g. a vnode). for submap's kernel 103 * objects, the only part of the object that can ever be populated is the 104 * offsets that are managed by the submap. 105 * 106 * note that the "offset" in a kernel object is always the kernel virtual 107 * address minus the VM_MIN_KERNEL_ADDRESS (aka vm_map_min(kernel_map)). 108 * example: 109 * suppose VM_MIN_KERNEL_ADDRESS is 0xf8000000 and the kernel does a 110 * uvm_km_alloc(kernel_map, PAGE_SIZE) [allocate 1 wired down page in the 111 * kernel map]. if uvm_km_alloc returns virtual address 0xf8235000, 112 * then that means that the page at offset 0x235000 in kernel_object is 113 * mapped at 0xf8235000. 114 * 115 * kernel object have one other special property: when the kernel virtual 116 * memory mapping them is unmapped, the backing memory in the object is 117 * freed right away. this is done with the uvm_km_pgremove() function. 118 * this has to be done because there is no backing store for kernel pages 119 * and no need to save them after they are no longer referenced. 120 */ 121 122#include <sys/cdefs.h> 123__KERNEL_RCSID(0, "$NetBSD: uvm_km.c,v 1.114 2012/01/31 00:30:52 matt Exp $"); 124 125#include "opt_uvmhist.h" 126 127#include <sys/param.h> 128#include <sys/systm.h> 129#include <sys/proc.h> 130#include <sys/pool.h> 131#include <sys/vmem.h> 132#include <sys/kmem.h> 133 134#include <uvm/uvm.h> 135 136/* 137 * global data structures 138 */ 139 140struct vm_map *kernel_map = NULL; 141 142/* 143 * local data structues 144 */ 145 146static struct vm_map kernel_map_store; 147static struct vm_map_entry kernel_image_mapent_store; 148static struct vm_map_entry kernel_kmem_mapent_store; 149 150vaddr_t kmembase; 151vsize_t kmemsize; 152 153vmem_t *kmem_arena; 154vmem_t *kmem_va_arena; 155 156/* 157 * uvm_km_bootstrap: init kernel maps and objects to reflect reality (i.e. 158 * KVM already allocated for text, data, bss, and static data structures). 159 * 160 * => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS. 161 * we assume that [vmin -> start] has already been allocated and that 162 * "end" is the end. 163 */ 164 165void 166uvm_km_bootstrap(vaddr_t start, vaddr_t end) 167{ 168 vaddr_t base = VM_MIN_KERNEL_ADDRESS; 169 170 kmemsize = MIN(((((vsize_t)(end - start)) / 3) * 2), 171 ((((vsize_t)uvmexp.npages) * PAGE_SIZE))); 172 kmemsize = round_page(kmemsize); 173 174 /* 175 * next, init kernel memory objects. 176 */ 177 178 /* kernel_object: for pageable anonymous kernel memory */ 179 uvm_kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS - 180 VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ); 181 182 /* 183 * init the map and reserve any space that might already 184 * have been allocated kernel space before installing. 185 */ 186 187 uvm_map_setup(&kernel_map_store, base, end, VM_MAP_PAGEABLE); 188 kernel_map_store.pmap = pmap_kernel(); 189 if (start != base) { 190 int error; 191 struct uvm_map_args args; 192 193 error = uvm_map_prepare(&kernel_map_store, 194 base, start - base, 195 NULL, UVM_UNKNOWN_OFFSET, 0, 196 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 197 UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args); 198 if (!error) { 199 kernel_image_mapent_store.flags = 200 UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE; 201 error = uvm_map_enter(&kernel_map_store, &args, 202 &kernel_image_mapent_store); 203 } 204 205 if (error) 206 panic( 207 "uvm_km_bootstrap: could not reserve space for kernel"); 208 209 kmembase = args.uma_start + args.uma_size; 210 error = uvm_map_prepare(&kernel_map_store, 211 kmembase, kmemsize, 212 NULL, UVM_UNKNOWN_OFFSET, 0, 213 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 214 UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args); 215 if (!error) { 216 kernel_kmem_mapent_store.flags = 217 UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE; 218 error = uvm_map_enter(&kernel_map_store, &args, 219 &kernel_kmem_mapent_store); 220 } 221 222 if (error) 223 panic( 224 "uvm_km_bootstrap: could not reserve kernel kmem"); 225 } else { 226 kmembase = base; 227 } 228 229 /* 230 * install! 231 */ 232 233 kernel_map = &kernel_map_store; 234 235 pool_subsystem_init(); 236 vmem_bootstrap(); 237 238 kmem_arena = vmem_create("kmem", kmembase, kmemsize, PAGE_SIZE, 239 NULL, NULL, NULL, 240 0, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM); 241 242 vmem_init(kmem_arena); 243 244 kmem_va_arena = vmem_create("kva", 0, 0, PAGE_SIZE, 245 vmem_alloc, vmem_free, kmem_arena, 246 16 * PAGE_SIZE, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM); 247} 248 249/* 250 * uvm_km_init: init the kernel maps virtual memory caches 251 * and start the pool/kmem allocator. 252 */ 253void 254uvm_km_init(void) 255{ 256 257 kmem_init(); 258 259 kmeminit(); // killme 260} 261 262/* 263 * uvm_km_suballoc: allocate a submap in the kernel map. once a submap 264 * is allocated all references to that area of VM must go through it. this 265 * allows the locking of VAs in kernel_map to be broken up into regions. 266 * 267 * => if `fixed' is true, *vmin specifies where the region described 268 * pager_map => used to map "buf" structures into kernel space 269 * by the submap must start 270 * => if submap is non NULL we use that as the submap, otherwise we 271 * alloc a new map 272 */ 273 274struct vm_map * 275uvm_km_suballoc(struct vm_map *map, vaddr_t *vmin /* IN/OUT */, 276 vaddr_t *vmax /* OUT */, vsize_t size, int flags, bool fixed, 277 struct vm_map *submap) 278{ 279 int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0); 280 281 KASSERT(vm_map_pmap(map) == pmap_kernel()); 282 283 size = round_page(size); /* round up to pagesize */ 284 285 /* 286 * first allocate a blank spot in the parent map 287 */ 288 289 if (uvm_map(map, vmin, size, NULL, UVM_UNKNOWN_OFFSET, 0, 290 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 291 UVM_ADV_RANDOM, mapflags)) != 0) { 292 panic("uvm_km_suballoc: unable to allocate space in parent map"); 293 } 294 295 /* 296 * set VM bounds (vmin is filled in by uvm_map) 297 */ 298 299 *vmax = *vmin + size; 300 301 /* 302 * add references to pmap and create or init the submap 303 */ 304 305 pmap_reference(vm_map_pmap(map)); 306 if (submap == NULL) { 307 submap = kmem_alloc(sizeof(*submap), KM_SLEEP); 308 if (submap == NULL) 309 panic("uvm_km_suballoc: unable to create submap"); 310 } 311 uvm_map_setup(submap, *vmin, *vmax, flags); 312 submap->pmap = vm_map_pmap(map); 313 314 /* 315 * now let uvm_map_submap plug in it... 316 */ 317 318 if (uvm_map_submap(map, *vmin, *vmax, submap) != 0) 319 panic("uvm_km_suballoc: submap allocation failed"); 320 321 return(submap); 322} 323 324/* 325 * uvm_km_pgremove: remove pages from a kernel uvm_object and KVA. 326 */ 327 328void 329uvm_km_pgremove(vaddr_t startva, vaddr_t endva) 330{ 331 struct uvm_object * const uobj = uvm_kernel_object; 332 const voff_t start = startva - vm_map_min(kernel_map); 333 const voff_t end = endva - vm_map_min(kernel_map); 334 struct vm_page *pg; 335 voff_t curoff, nextoff; 336 int swpgonlydelta = 0; 337 UVMHIST_FUNC("uvm_km_pgremove"); UVMHIST_CALLED(maphist); 338 339 KASSERT(VM_MIN_KERNEL_ADDRESS <= startva); 340 KASSERT(startva < endva); 341 KASSERT(endva <= VM_MAX_KERNEL_ADDRESS); 342 343 mutex_enter(uobj->vmobjlock); 344 pmap_remove(pmap_kernel(), startva, endva); 345 for (curoff = start; curoff < end; curoff = nextoff) { 346 nextoff = curoff + PAGE_SIZE; 347 pg = uvm_pagelookup(uobj, curoff); 348 if (pg != NULL && pg->flags & PG_BUSY) { 349 pg->flags |= PG_WANTED; 350 UVM_UNLOCK_AND_WAIT(pg, uobj->vmobjlock, 0, 351 "km_pgrm", 0); 352 mutex_enter(uobj->vmobjlock); 353 nextoff = curoff; 354 continue; 355 } 356 357 /* 358 * free the swap slot, then the page. 359 */ 360 361 if (pg == NULL && 362 uao_find_swslot(uobj, curoff >> PAGE_SHIFT) > 0) { 363 swpgonlydelta++; 364 } 365 uao_dropswap(uobj, curoff >> PAGE_SHIFT); 366 if (pg != NULL) { 367 mutex_enter(&uvm_pageqlock); 368 uvm_pagefree(pg); 369 mutex_exit(&uvm_pageqlock); 370 } 371 } 372 mutex_exit(uobj->vmobjlock); 373 374 if (swpgonlydelta > 0) { 375 mutex_enter(&uvm_swap_data_lock); 376 KASSERT(uvmexp.swpgonly >= swpgonlydelta); 377 uvmexp.swpgonly -= swpgonlydelta; 378 mutex_exit(&uvm_swap_data_lock); 379 } 380} 381 382 383/* 384 * uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for non object backed 385 * regions. 386 * 387 * => when you unmap a part of anonymous kernel memory you want to toss 388 * the pages right away. (this is called from uvm_unmap_...). 389 * => none of the pages will ever be busy, and none of them will ever 390 * be on the active or inactive queues (because they have no object). 391 */ 392 393void 394uvm_km_pgremove_intrsafe(struct vm_map *map, vaddr_t start, vaddr_t end) 395{ 396 struct vm_page *pg; 397 paddr_t pa; 398 UVMHIST_FUNC("uvm_km_pgremove_intrsafe"); UVMHIST_CALLED(maphist); 399 400 KASSERT(VM_MAP_IS_KERNEL(map)); 401 KASSERT(vm_map_min(map) <= start); 402 KASSERT(start < end); 403 KASSERT(end <= vm_map_max(map)); 404 405 for (; start < end; start += PAGE_SIZE) { 406 if (!pmap_extract(pmap_kernel(), start, &pa)) { 407 continue; 408 } 409 pg = PHYS_TO_VM_PAGE(pa); 410 KASSERT(pg); 411 KASSERT(pg->uobject == NULL && pg->uanon == NULL); 412 KASSERT((pg->flags & PG_BUSY) == 0); 413 uvm_pagefree(pg); 414 } 415} 416 417#if defined(DEBUG) 418void 419uvm_km_check_empty(struct vm_map *map, vaddr_t start, vaddr_t end) 420{ 421 struct vm_page *pg; 422 vaddr_t va; 423 paddr_t pa; 424 425 KDASSERT(VM_MAP_IS_KERNEL(map)); 426 KDASSERT(vm_map_min(map) <= start); 427 KDASSERT(start < end); 428 KDASSERT(end <= vm_map_max(map)); 429 430 for (va = start; va < end; va += PAGE_SIZE) { 431 if (pmap_extract(pmap_kernel(), va, &pa)) { 432 panic("uvm_km_check_empty: va %p has pa 0x%llx", 433 (void *)va, (long long)pa); 434 } 435 if ((map->flags & VM_MAP_INTRSAFE) == 0) { 436 mutex_enter(uvm_kernel_object->vmobjlock); 437 pg = uvm_pagelookup(uvm_kernel_object, 438 va - vm_map_min(kernel_map)); 439 mutex_exit(uvm_kernel_object->vmobjlock); 440 if (pg) { 441 panic("uvm_km_check_empty: " 442 "has page hashed at %p", (const void *)va); 443 } 444 } 445 } 446} 447#endif /* defined(DEBUG) */ 448 449/* 450 * uvm_km_alloc: allocate an area of kernel memory. 451 * 452 * => NOTE: we can return 0 even if we can wait if there is not enough 453 * free VM space in the map... caller should be prepared to handle 454 * this case. 455 * => we return KVA of memory allocated 456 */ 457 458vaddr_t 459uvm_km_alloc(struct vm_map *map, vsize_t size, vsize_t align, uvm_flag_t flags) 460{ 461 vaddr_t kva, loopva; 462 vaddr_t offset; 463 vsize_t loopsize; 464 struct vm_page *pg; 465 struct uvm_object *obj; 466 int pgaflags; 467 vm_prot_t prot; 468 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 469 470 KASSERT(vm_map_pmap(map) == pmap_kernel()); 471 KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED || 472 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE || 473 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY); 474 KASSERT((flags & UVM_KMF_VAONLY) != 0 || (flags & UVM_KMF_COLORMATCH) == 0); 475 KASSERT((flags & UVM_KMF_COLORMATCH) == 0 || (flags & UVM_KMF_VAONLY) != 0); 476 477 /* 478 * setup for call 479 */ 480 481 kva = vm_map_min(map); /* hint */ 482 size = round_page(size); 483 obj = (flags & UVM_KMF_PAGEABLE) ? uvm_kernel_object : NULL; 484 UVMHIST_LOG(maphist," (map=0x%x, obj=0x%x, size=0x%x, flags=%d)", 485 map, obj, size, flags); 486 487 /* 488 * allocate some virtual space 489 */ 490 491 if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET, 492 align, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 493 UVM_ADV_RANDOM, 494 (flags & (UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT | UVM_KMF_WAITVA 495 | UVM_KMF_COLORMATCH)))) != 0)) { 496 UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0); 497 return(0); 498 } 499 500 /* 501 * if all we wanted was VA, return now 502 */ 503 504 if (flags & (UVM_KMF_VAONLY | UVM_KMF_PAGEABLE)) { 505 UVMHIST_LOG(maphist,"<- done valloc (kva=0x%x)", kva,0,0,0); 506 return(kva); 507 } 508 509 /* 510 * recover object offset from virtual address 511 */ 512 513 offset = kva - vm_map_min(kernel_map); 514 UVMHIST_LOG(maphist, " kva=0x%x, offset=0x%x", kva, offset,0,0); 515 516 /* 517 * now allocate and map in the memory... note that we are the only ones 518 * whom should ever get a handle on this area of VM. 519 */ 520 521 loopva = kva; 522 loopsize = size; 523 524 pgaflags = UVM_FLAG_COLORMATCH; 525 if (flags & UVM_KMF_NOWAIT) 526 pgaflags |= UVM_PGA_USERESERVE; 527 if (flags & UVM_KMF_ZERO) 528 pgaflags |= UVM_PGA_ZERO; 529 prot = VM_PROT_READ | VM_PROT_WRITE; 530 if (flags & UVM_KMF_EXEC) 531 prot |= VM_PROT_EXECUTE; 532 while (loopsize) { 533 KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, NULL), 534 "loopva=%#"PRIxVADDR, loopva); 535 536 pg = uvm_pagealloc_strat(NULL, offset, NULL, pgaflags, 537#ifdef UVM_KM_VMFREELIST 538 UVM_PGA_STRAT_ONLY, UVM_KM_VMFREELIST 539#else 540 UVM_PGA_STRAT_NORMAL, 0 541#endif 542 ); 543 544 /* 545 * out of memory? 546 */ 547 548 if (__predict_false(pg == NULL)) { 549 if ((flags & UVM_KMF_NOWAIT) || 550 ((flags & UVM_KMF_CANFAIL) && !uvm_reclaimable())) { 551 /* free everything! */ 552 uvm_km_free(map, kva, size, 553 flags & UVM_KMF_TYPEMASK); 554 return (0); 555 } else { 556 uvm_wait("km_getwait2"); /* sleep here */ 557 continue; 558 } 559 } 560 561 pg->flags &= ~PG_BUSY; /* new page */ 562 UVM_PAGE_OWN(pg, NULL); 563 564 /* 565 * map it in 566 */ 567 568 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), 569 prot, PMAP_KMPAGE); 570 loopva += PAGE_SIZE; 571 offset += PAGE_SIZE; 572 loopsize -= PAGE_SIZE; 573 } 574 575 pmap_update(pmap_kernel()); 576 577 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 578 return(kva); 579} 580 581/* 582 * uvm_km_free: free an area of kernel memory 583 */ 584 585void 586uvm_km_free(struct vm_map *map, vaddr_t addr, vsize_t size, uvm_flag_t flags) 587{ 588 589 KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED || 590 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE || 591 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY); 592 KASSERT((addr & PAGE_MASK) == 0); 593 KASSERT(vm_map_pmap(map) == pmap_kernel()); 594 595 size = round_page(size); 596 597 if (flags & UVM_KMF_PAGEABLE) { 598 uvm_km_pgremove(addr, addr + size); 599 } else if (flags & UVM_KMF_WIRED) { 600 /* 601 * Note: uvm_km_pgremove_intrsafe() extracts mapping, thus 602 * remove it after. See comment below about KVA visibility. 603 */ 604 uvm_km_pgremove_intrsafe(map, addr, addr + size); 605 pmap_kremove(addr, size); 606 } 607 608 /* 609 * Note: uvm_unmap_remove() calls pmap_update() for us, before 610 * KVA becomes globally available. 611 */ 612 613 uvm_unmap1(map, addr, addr + size, UVM_FLAG_VAONLY); 614} 615 616/* Sanity; must specify both or none. */ 617#if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \ 618 (!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE)) 619#error Must specify MAP and UNMAP together. 620#endif 621 622int 623uvm_km_kmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags, 624 vmem_addr_t *addr) 625{ 626 struct vm_page *pg; 627 vmem_addr_t va; 628 int rc; 629 vaddr_t loopva; 630 vsize_t loopsize; 631 632 size = round_page(size); 633 634#if defined(PMAP_MAP_POOLPAGE) 635 if (size == PAGE_SIZE) { 636again: 637#ifdef PMAP_ALLOC_POOLPAGE 638 pg = PMAP_ALLOC_POOLPAGE((flags & VM_SLEEP) ? 639 0 : UVM_PGA_USERESERVE); 640#else 641 pg = uvm_pagealloc(NULL, 0, NULL, 642 (flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE); 643#endif /* PMAP_ALLOC_POOLPAGE */ 644 if (__predict_false(pg == NULL)) { 645 if (flags & VM_SLEEP) { 646 uvm_wait("plpg"); 647 goto again; 648 } 649 } 650 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 651 if (__predict_false(va == 0)) { 652 uvm_pagefree(pg); 653 return ENOMEM; 654 } 655 *addr = va; 656 return 0; 657 } 658#endif /* PMAP_MAP_POOLPAGE */ 659 660 rc = vmem_alloc(vm, size, flags, &va); 661 if (rc != 0) 662 return rc; 663 664 loopva = va; 665 loopsize = size; 666 667 while (loopsize) { 668 KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, NULL), 669 "loopva=%#"PRIxVADDR" loopsize=%#"PRIxVSIZE" vmem=%p", 670 loopva, loopsize, vm); 671 672 pg = uvm_pagealloc(NULL, loopva, NULL, 673 UVM_KMF_COLORMATCH 674 | ((flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE)); 675 if (__predict_false(pg == NULL)) { 676 if (flags & VM_SLEEP) { 677 uvm_wait("plpg"); 678 continue; 679 } else { 680 uvm_km_pgremove_intrsafe(kernel_map, va, 681 va + size); 682 pmap_kremove(va, size); 683 vmem_free(kmem_va_arena, va, size); 684 return ENOMEM; 685 } 686 } 687 688 pg->flags &= ~PG_BUSY; /* new page */ 689 UVM_PAGE_OWN(pg, NULL); 690 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), 691 VM_PROT_READ|VM_PROT_WRITE, PMAP_KMPAGE); 692 693 loopva += PAGE_SIZE; 694 loopsize -= PAGE_SIZE; 695 } 696 pmap_update(pmap_kernel()); 697 698 *addr = va; 699 700 return 0; 701} 702 703void 704uvm_km_kmem_free(vmem_t *vm, vmem_addr_t addr, size_t size) 705{ 706 707 size = round_page(size); 708#if defined(PMAP_UNMAP_POOLPAGE) 709 if (size == PAGE_SIZE) { 710 paddr_t pa; 711 712 pa = PMAP_UNMAP_POOLPAGE(addr); 713 uvm_pagefree(PHYS_TO_VM_PAGE(pa)); 714 return; 715 } 716#endif /* PMAP_UNMAP_POOLPAGE */ 717 uvm_km_pgremove_intrsafe(kernel_map, addr, addr + size); 718 pmap_kremove(addr, size); 719 pmap_update(pmap_kernel()); 720 721 vmem_free(vm, addr, size); 722} 723 724bool 725uvm_km_va_starved_p(void) 726{ 727 vmem_size_t total; 728 vmem_size_t free; 729 730 total = vmem_size(kmem_arena, VMEM_ALLOC|VMEM_FREE); 731 free = vmem_size(kmem_arena, VMEM_FREE); 732 733 return (free < (total / 10)); 734} 735 736