uvm_km.c revision 1.118
1 /* $NetBSD: uvm_km.c,v 1.118 2012/02/03 19:25:07 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 (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, 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 1.118 2012/02/03 19:25:07 matt Exp $"); 124 125 #include "opt_uvmhist.h" 126 127 #include "opt_kmempages.h" 128 129 #ifndef NKMEMPAGES 130 #define NKMEMPAGES 0 131 #endif 132 133 /* 134 * Defaults for lower and upper-bounds for the kmem_arena page count. 135 * Can be overridden by kernel config options. 136 */ 137 #ifndef NKMEMPAGES_MIN 138 #define NKMEMPAGES_MIN NKMEMPAGES_MIN_DEFAULT 139 #endif 140 141 #ifndef NKMEMPAGES_MAX 142 #define NKMEMPAGES_MAX NKMEMPAGES_MAX_DEFAULT 143 #endif 144 145 146 #include <sys/param.h> 147 #include <sys/systm.h> 148 #include <sys/proc.h> 149 #include <sys/pool.h> 150 #include <sys/vmem.h> 151 #include <sys/kmem.h> 152 153 #include <uvm/uvm.h> 154 155 /* 156 * global data structures 157 */ 158 159 struct vm_map *kernel_map = NULL; 160 161 /* 162 * local data structues 163 */ 164 165 static struct vm_map kernel_map_store; 166 static struct vm_map_entry kernel_image_mapent_store; 167 static struct vm_map_entry kernel_kmem_mapent_store; 168 169 int nkmempages = 0; 170 vaddr_t kmembase; 171 vsize_t kmemsize; 172 173 vmem_t *kmem_arena; 174 vmem_t *kmem_va_arena; 175 176 /* 177 * kmeminit_nkmempages: calculate the size of kmem_arena. 178 */ 179 void 180 kmeminit_nkmempages(void) 181 { 182 int npages; 183 184 if (nkmempages != 0) { 185 /* 186 * It's already been set (by us being here before) 187 * bail out now; 188 */ 189 return; 190 } 191 192 npages = physmem; 193 194 if (npages > NKMEMPAGES_MAX) 195 npages = NKMEMPAGES_MAX; 196 197 if (npages < NKMEMPAGES_MIN) 198 npages = NKMEMPAGES_MIN; 199 200 nkmempages = npages; 201 } 202 203 /* 204 * uvm_km_bootstrap: init kernel maps and objects to reflect reality (i.e. 205 * KVM already allocated for text, data, bss, and static data structures). 206 * 207 * => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS. 208 * we assume that [vmin -> start] has already been allocated and that 209 * "end" is the end. 210 */ 211 212 void 213 uvm_km_bootstrap(vaddr_t start, vaddr_t end) 214 { 215 vaddr_t base = VM_MIN_KERNEL_ADDRESS; 216 struct uvm_map_args args; 217 int error; 218 219 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 220 UVMHIST_LOG(maphist, "start=%"PRIxVADDR" end=%#"PRIxVADDR, 221 start, end, 0,0); 222 223 kmeminit_nkmempages(); 224 kmemsize = nkmempages * PAGE_SIZE; 225 226 /* kmemsize = MIN((((vsize_t)(end - start)) / 3), 227 ((((vsize_t)uvmexp.npages) * PAGE_SIZE) / 2)); 228 kmemsize = round_page(kmemsize); */ 229 230 UVMHIST_LOG(maphist, "kmemsize=%#"PRIxVSIZE, kmemsize, 0,0,0); 231 232 /* 233 * next, init kernel memory objects. 234 */ 235 236 /* kernel_object: for pageable anonymous kernel memory */ 237 uvm_kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS - 238 VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ); 239 240 /* 241 * init the map and reserve any space that might already 242 * have been allocated kernel space before installing. 243 */ 244 245 uvm_map_setup(&kernel_map_store, base, end, VM_MAP_PAGEABLE); 246 kernel_map_store.pmap = pmap_kernel(); 247 if (start != base) { 248 error = uvm_map_prepare(&kernel_map_store, 249 base, start - base, 250 NULL, UVM_UNKNOWN_OFFSET, 0, 251 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 252 UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args); 253 if (!error) { 254 kernel_image_mapent_store.flags = 255 UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE; 256 error = uvm_map_enter(&kernel_map_store, &args, 257 &kernel_image_mapent_store); 258 } 259 260 if (error) 261 panic( 262 "uvm_km_bootstrap: could not reserve space for kernel"); 263 264 kmembase = args.uma_start + args.uma_size; 265 } else { 266 kmembase = base; 267 } 268 269 error = uvm_map_prepare(&kernel_map_store, 270 kmembase, kmemsize, 271 NULL, UVM_UNKNOWN_OFFSET, 0, 272 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 273 UVM_ADV_RANDOM, UVM_FLAG_FIXED), &args); 274 if (!error) { 275 kernel_kmem_mapent_store.flags = 276 UVM_MAP_KERNEL | UVM_MAP_STATIC | UVM_MAP_NOMERGE; 277 error = uvm_map_enter(&kernel_map_store, &args, 278 &kernel_kmem_mapent_store); 279 } 280 281 if (error) 282 panic("uvm_km_bootstrap: could not reserve kernel kmem"); 283 284 /* 285 * install! 286 */ 287 288 kernel_map = &kernel_map_store; 289 290 pool_subsystem_init(); 291 vmem_bootstrap(); 292 293 kmem_arena = vmem_create("kmem", kmembase, kmemsize, PAGE_SIZE, 294 NULL, NULL, NULL, 295 0, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM); 296 297 vmem_init(kmem_arena); 298 299 UVMHIST_LOG(maphist, "kmem vmem created (base=%#"PRIxVADDR 300 ", size=%#"PRIxVSIZE, kmembase, kmemsize, 0,0); 301 302 kmem_va_arena = vmem_create("kva", 0, 0, PAGE_SIZE, 303 vmem_alloc, vmem_free, kmem_arena, 304 16 * PAGE_SIZE, VM_NOSLEEP | VM_BOOTSTRAP, IPL_VM); 305 306 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 307 } 308 309 /* 310 * uvm_km_init: init the kernel maps virtual memory caches 311 * and start the pool/kmem allocator. 312 */ 313 void 314 uvm_km_init(void) 315 { 316 317 kmem_init(); 318 319 kmeminit(); // killme 320 } 321 322 /* 323 * uvm_km_suballoc: allocate a submap in the kernel map. once a submap 324 * is allocated all references to that area of VM must go through it. this 325 * allows the locking of VAs in kernel_map to be broken up into regions. 326 * 327 * => if `fixed' is true, *vmin specifies where the region described 328 * pager_map => used to map "buf" structures into kernel space 329 * by the submap must start 330 * => if submap is non NULL we use that as the submap, otherwise we 331 * alloc a new map 332 */ 333 334 struct vm_map * 335 uvm_km_suballoc(struct vm_map *map, vaddr_t *vmin /* IN/OUT */, 336 vaddr_t *vmax /* OUT */, vsize_t size, int flags, bool fixed, 337 struct vm_map *submap) 338 { 339 int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0); 340 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 341 342 KASSERT(vm_map_pmap(map) == pmap_kernel()); 343 344 size = round_page(size); /* round up to pagesize */ 345 346 /* 347 * first allocate a blank spot in the parent map 348 */ 349 350 if (uvm_map(map, vmin, size, NULL, UVM_UNKNOWN_OFFSET, 0, 351 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 352 UVM_ADV_RANDOM, mapflags)) != 0) { 353 panic("%s: unable to allocate space in parent map", __func__); 354 } 355 356 /* 357 * set VM bounds (vmin is filled in by uvm_map) 358 */ 359 360 *vmax = *vmin + size; 361 362 /* 363 * add references to pmap and create or init the submap 364 */ 365 366 pmap_reference(vm_map_pmap(map)); 367 if (submap == NULL) { 368 submap = kmem_alloc(sizeof(*submap), KM_SLEEP); 369 if (submap == NULL) 370 panic("uvm_km_suballoc: unable to create submap"); 371 } 372 uvm_map_setup(submap, *vmin, *vmax, flags); 373 submap->pmap = vm_map_pmap(map); 374 375 /* 376 * now let uvm_map_submap plug in it... 377 */ 378 379 if (uvm_map_submap(map, *vmin, *vmax, submap) != 0) 380 panic("uvm_km_suballoc: submap allocation failed"); 381 382 return(submap); 383 } 384 385 /* 386 * uvm_km_pgremove: remove pages from a kernel uvm_object and KVA. 387 */ 388 389 void 390 uvm_km_pgremove(vaddr_t startva, vaddr_t endva) 391 { 392 struct uvm_object * const uobj = uvm_kernel_object; 393 const voff_t start = startva - vm_map_min(kernel_map); 394 const voff_t end = endva - vm_map_min(kernel_map); 395 struct vm_page *pg; 396 voff_t curoff, nextoff; 397 int swpgonlydelta = 0; 398 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 399 400 KASSERT(VM_MIN_KERNEL_ADDRESS <= startva); 401 KASSERT(startva < endva); 402 KASSERT(endva <= VM_MAX_KERNEL_ADDRESS); 403 404 mutex_enter(uobj->vmobjlock); 405 pmap_remove(pmap_kernel(), startva, endva); 406 for (curoff = start; curoff < end; curoff = nextoff) { 407 nextoff = curoff + PAGE_SIZE; 408 pg = uvm_pagelookup(uobj, curoff); 409 if (pg != NULL && pg->flags & PG_BUSY) { 410 pg->flags |= PG_WANTED; 411 UVM_UNLOCK_AND_WAIT(pg, uobj->vmobjlock, 0, 412 "km_pgrm", 0); 413 mutex_enter(uobj->vmobjlock); 414 nextoff = curoff; 415 continue; 416 } 417 418 /* 419 * free the swap slot, then the page. 420 */ 421 422 if (pg == NULL && 423 uao_find_swslot(uobj, curoff >> PAGE_SHIFT) > 0) { 424 swpgonlydelta++; 425 } 426 uao_dropswap(uobj, curoff >> PAGE_SHIFT); 427 if (pg != NULL) { 428 mutex_enter(&uvm_pageqlock); 429 uvm_pagefree(pg); 430 mutex_exit(&uvm_pageqlock); 431 } 432 } 433 mutex_exit(uobj->vmobjlock); 434 435 if (swpgonlydelta > 0) { 436 mutex_enter(&uvm_swap_data_lock); 437 KASSERT(uvmexp.swpgonly >= swpgonlydelta); 438 uvmexp.swpgonly -= swpgonlydelta; 439 mutex_exit(&uvm_swap_data_lock); 440 } 441 } 442 443 444 /* 445 * uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for non object backed 446 * regions. 447 * 448 * => when you unmap a part of anonymous kernel memory you want to toss 449 * the pages right away. (this is called from uvm_unmap_...). 450 * => none of the pages will ever be busy, and none of them will ever 451 * be on the active or inactive queues (because they have no object). 452 */ 453 454 void 455 uvm_km_pgremove_intrsafe(struct vm_map *map, vaddr_t start, vaddr_t end) 456 { 457 struct vm_page *pg; 458 paddr_t pa; 459 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 460 461 KASSERT(VM_MAP_IS_KERNEL(map)); 462 KASSERT(vm_map_min(map) <= start); 463 KASSERT(start < end); 464 KASSERT(end <= vm_map_max(map)); 465 466 for (; start < end; start += PAGE_SIZE) { 467 if (!pmap_extract(pmap_kernel(), start, &pa)) { 468 continue; 469 } 470 pg = PHYS_TO_VM_PAGE(pa); 471 KASSERT(pg); 472 KASSERT(pg->uobject == NULL && pg->uanon == NULL); 473 KASSERT((pg->flags & PG_BUSY) == 0); 474 uvm_pagefree(pg); 475 } 476 } 477 478 #if defined(DEBUG) 479 void 480 uvm_km_check_empty(struct vm_map *map, vaddr_t start, vaddr_t end) 481 { 482 struct vm_page *pg; 483 vaddr_t va; 484 paddr_t pa; 485 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 486 487 KDASSERT(VM_MAP_IS_KERNEL(map)); 488 KDASSERT(vm_map_min(map) <= start); 489 KDASSERT(start < end); 490 KDASSERT(end <= vm_map_max(map)); 491 492 for (va = start; va < end; va += PAGE_SIZE) { 493 if (pmap_extract(pmap_kernel(), va, &pa)) { 494 panic("uvm_km_check_empty: va %p has pa 0x%llx", 495 (void *)va, (long long)pa); 496 } 497 if ((map->flags & VM_MAP_INTRSAFE) == 0) { 498 mutex_enter(uvm_kernel_object->vmobjlock); 499 pg = uvm_pagelookup(uvm_kernel_object, 500 va - vm_map_min(kernel_map)); 501 mutex_exit(uvm_kernel_object->vmobjlock); 502 if (pg) { 503 panic("uvm_km_check_empty: " 504 "has page hashed at %p", (const void *)va); 505 } 506 } 507 } 508 } 509 #endif /* defined(DEBUG) */ 510 511 /* 512 * uvm_km_alloc: allocate an area of kernel memory. 513 * 514 * => NOTE: we can return 0 even if we can wait if there is not enough 515 * free VM space in the map... caller should be prepared to handle 516 * this case. 517 * => we return KVA of memory allocated 518 */ 519 520 vaddr_t 521 uvm_km_alloc(struct vm_map *map, vsize_t size, vsize_t align, uvm_flag_t flags) 522 { 523 vaddr_t kva, loopva; 524 vaddr_t offset; 525 vsize_t loopsize; 526 struct vm_page *pg; 527 struct uvm_object *obj; 528 int pgaflags; 529 vm_prot_t prot; 530 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 531 532 KASSERT(vm_map_pmap(map) == pmap_kernel()); 533 KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED || 534 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE || 535 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY); 536 KASSERT((flags & UVM_KMF_VAONLY) != 0 || (flags & UVM_KMF_COLORMATCH) == 0); 537 KASSERT((flags & UVM_KMF_COLORMATCH) == 0 || (flags & UVM_KMF_VAONLY) != 0); 538 539 /* 540 * setup for call 541 */ 542 543 kva = vm_map_min(map); /* hint */ 544 size = round_page(size); 545 obj = (flags & UVM_KMF_PAGEABLE) ? uvm_kernel_object : NULL; 546 UVMHIST_LOG(maphist," (map=0x%x, obj=0x%x, size=0x%x, flags=%d)", 547 map, obj, size, flags); 548 549 /* 550 * allocate some virtual space 551 */ 552 553 if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET, 554 align, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 555 UVM_ADV_RANDOM, 556 (flags & (UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT | UVM_KMF_WAITVA 557 | UVM_KMF_COLORMATCH)))) != 0)) { 558 UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0); 559 return(0); 560 } 561 562 /* 563 * if all we wanted was VA, return now 564 */ 565 566 if (flags & (UVM_KMF_VAONLY | UVM_KMF_PAGEABLE)) { 567 UVMHIST_LOG(maphist,"<- done valloc (kva=0x%x)", kva,0,0,0); 568 return(kva); 569 } 570 571 /* 572 * recover object offset from virtual address 573 */ 574 575 offset = kva - vm_map_min(kernel_map); 576 UVMHIST_LOG(maphist, " kva=0x%x, offset=0x%x", kva, offset,0,0); 577 578 /* 579 * now allocate and map in the memory... note that we are the only ones 580 * whom should ever get a handle on this area of VM. 581 */ 582 583 loopva = kva; 584 loopsize = size; 585 586 pgaflags = UVM_FLAG_COLORMATCH; 587 if (flags & UVM_KMF_NOWAIT) 588 pgaflags |= UVM_PGA_USERESERVE; 589 if (flags & UVM_KMF_ZERO) 590 pgaflags |= UVM_PGA_ZERO; 591 prot = VM_PROT_READ | VM_PROT_WRITE; 592 if (flags & UVM_KMF_EXEC) 593 prot |= VM_PROT_EXECUTE; 594 while (loopsize) { 595 KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, NULL), 596 "loopva=%#"PRIxVADDR, loopva); 597 598 pg = uvm_pagealloc_strat(NULL, offset, NULL, pgaflags, 599 #ifdef UVM_KM_VMFREELIST 600 UVM_PGA_STRAT_ONLY, UVM_KM_VMFREELIST 601 #else 602 UVM_PGA_STRAT_NORMAL, 0 603 #endif 604 ); 605 606 /* 607 * out of memory? 608 */ 609 610 if (__predict_false(pg == NULL)) { 611 if ((flags & UVM_KMF_NOWAIT) || 612 ((flags & UVM_KMF_CANFAIL) && !uvm_reclaimable())) { 613 /* free everything! */ 614 uvm_km_free(map, kva, size, 615 flags & UVM_KMF_TYPEMASK); 616 return (0); 617 } else { 618 uvm_wait("km_getwait2"); /* sleep here */ 619 continue; 620 } 621 } 622 623 pg->flags &= ~PG_BUSY; /* new page */ 624 UVM_PAGE_OWN(pg, NULL); 625 626 /* 627 * map it in 628 */ 629 630 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), 631 prot, PMAP_KMPAGE); 632 loopva += PAGE_SIZE; 633 offset += PAGE_SIZE; 634 loopsize -= PAGE_SIZE; 635 } 636 637 pmap_update(pmap_kernel()); 638 639 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 640 return(kva); 641 } 642 643 /* 644 * uvm_km_free: free an area of kernel memory 645 */ 646 647 void 648 uvm_km_free(struct vm_map *map, vaddr_t addr, vsize_t size, uvm_flag_t flags) 649 { 650 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 651 652 KASSERT((flags & UVM_KMF_TYPEMASK) == UVM_KMF_WIRED || 653 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_PAGEABLE || 654 (flags & UVM_KMF_TYPEMASK) == UVM_KMF_VAONLY); 655 KASSERT((addr & PAGE_MASK) == 0); 656 KASSERT(vm_map_pmap(map) == pmap_kernel()); 657 658 size = round_page(size); 659 660 if (flags & UVM_KMF_PAGEABLE) { 661 uvm_km_pgremove(addr, addr + size); 662 } else if (flags & UVM_KMF_WIRED) { 663 /* 664 * Note: uvm_km_pgremove_intrsafe() extracts mapping, thus 665 * remove it after. See comment below about KVA visibility. 666 */ 667 uvm_km_pgremove_intrsafe(map, addr, addr + size); 668 pmap_kremove(addr, size); 669 } 670 671 /* 672 * Note: uvm_unmap_remove() calls pmap_update() for us, before 673 * KVA becomes globally available. 674 */ 675 676 uvm_unmap1(map, addr, addr + size, UVM_FLAG_VAONLY); 677 } 678 679 /* Sanity; must specify both or none. */ 680 #if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \ 681 (!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE)) 682 #error Must specify MAP and UNMAP together. 683 #endif 684 685 int 686 uvm_km_kmem_alloc(vmem_t *vm, vmem_size_t size, vm_flag_t flags, 687 vmem_addr_t *addr) 688 { 689 struct vm_page *pg; 690 vmem_addr_t va; 691 int rc; 692 vaddr_t loopva; 693 vsize_t loopsize; 694 695 size = round_page(size); 696 697 #if defined(PMAP_MAP_POOLPAGE) 698 if (size == PAGE_SIZE) { 699 again: 700 #ifdef PMAP_ALLOC_POOLPAGE 701 pg = PMAP_ALLOC_POOLPAGE((flags & VM_SLEEP) ? 702 0 : UVM_PGA_USERESERVE); 703 #else 704 pg = uvm_pagealloc(NULL, 0, NULL, 705 (flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE); 706 #endif /* PMAP_ALLOC_POOLPAGE */ 707 if (__predict_false(pg == NULL)) { 708 if (flags & VM_SLEEP) { 709 uvm_wait("plpg"); 710 goto again; 711 } 712 } 713 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 714 if (__predict_false(va == 0)) { 715 uvm_pagefree(pg); 716 return ENOMEM; 717 } 718 *addr = va; 719 return 0; 720 } 721 #endif /* PMAP_MAP_POOLPAGE */ 722 723 rc = vmem_alloc(vm, size, flags, &va); 724 if (rc != 0) 725 return rc; 726 727 loopva = va; 728 loopsize = size; 729 730 while (loopsize) { 731 KASSERTMSG(!pmap_extract(pmap_kernel(), loopva, NULL), 732 "loopva=%#"PRIxVADDR" loopsize=%#"PRIxVSIZE" vmem=%p", 733 loopva, loopsize, vm); 734 735 pg = uvm_pagealloc(NULL, loopva, NULL, 736 UVM_FLAG_COLORMATCH 737 | ((flags & VM_SLEEP) ? 0 : UVM_PGA_USERESERVE)); 738 if (__predict_false(pg == NULL)) { 739 if (flags & VM_SLEEP) { 740 uvm_wait("plpg"); 741 continue; 742 } else { 743 uvm_km_pgremove_intrsafe(kernel_map, va, 744 va + size); 745 pmap_kremove(va, size); 746 vmem_free(kmem_va_arena, va, size); 747 return ENOMEM; 748 } 749 } 750 751 pg->flags &= ~PG_BUSY; /* new page */ 752 UVM_PAGE_OWN(pg, NULL); 753 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), 754 VM_PROT_READ|VM_PROT_WRITE, PMAP_KMPAGE); 755 756 loopva += PAGE_SIZE; 757 loopsize -= PAGE_SIZE; 758 } 759 pmap_update(pmap_kernel()); 760 761 *addr = va; 762 763 return 0; 764 } 765 766 void 767 uvm_km_kmem_free(vmem_t *vm, vmem_addr_t addr, size_t size) 768 { 769 770 size = round_page(size); 771 #if defined(PMAP_UNMAP_POOLPAGE) 772 if (size == PAGE_SIZE) { 773 paddr_t pa; 774 775 pa = PMAP_UNMAP_POOLPAGE(addr); 776 uvm_pagefree(PHYS_TO_VM_PAGE(pa)); 777 return; 778 } 779 #endif /* PMAP_UNMAP_POOLPAGE */ 780 uvm_km_pgremove_intrsafe(kernel_map, addr, addr + size); 781 pmap_kremove(addr, size); 782 pmap_update(pmap_kernel()); 783 784 vmem_free(vm, addr, size); 785 } 786 787 bool 788 uvm_km_va_starved_p(void) 789 { 790 vmem_size_t total; 791 vmem_size_t free; 792 793 total = vmem_size(kmem_arena, VMEM_ALLOC|VMEM_FREE); 794 free = vmem_size(kmem_arena, VMEM_FREE); 795 796 return (free < (total / 10)); 797 } 798 799
Indexes created Wed Oct 22 13:09:56 GMT 2025