uvm_km.c revision 1.54
1/* $NetBSD: uvm_km.c,v 1.54 2001/11/07 08:43:32 chs 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. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by Charles D. Cranor, 23 * Washington University, the University of California, Berkeley and 24 * its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * @(#)vm_kern.c 8.3 (Berkeley) 1/12/94 42 * from: Id: uvm_km.c,v 1.1.2.14 1998/02/06 05:19:27 chs Exp 43 * 44 * 45 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 46 * All rights reserved. 47 * 48 * Permission to use, copy, modify and distribute this software and 49 * its documentation is hereby granted, provided that both the copyright 50 * notice and this permission notice appear in all copies of the 51 * software, derivative works or modified versions, and any portions 52 * thereof, and that both notices appear in supporting documentation. 53 * 54 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 55 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 56 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 57 * 58 * Carnegie Mellon requests users of this software to return to 59 * 60 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 61 * School of Computer Science 62 * Carnegie Mellon University 63 * Pittsburgh PA 15213-3890 64 * 65 * any improvements or extensions that they make and grant Carnegie the 66 * rights to redistribute these changes. 67 */ 68 69#include "opt_uvmhist.h" 70 71/* 72 * uvm_km.c: handle kernel memory allocation and management 73 */ 74 75/* 76 * overview of kernel memory management: 77 * 78 * the kernel virtual address space is mapped by "kernel_map." kernel_map 79 * starts at VM_MIN_KERNEL_ADDRESS and goes to VM_MAX_KERNEL_ADDRESS. 80 * note that VM_MIN_KERNEL_ADDRESS is equal to vm_map_min(kernel_map). 81 * 82 * the kernel_map has several "submaps." submaps can only appear in 83 * the kernel_map (user processes can't use them). submaps "take over" 84 * the management of a sub-range of the kernel's address space. submaps 85 * are typically allocated at boot time and are never released. kernel 86 * virtual address space that is mapped by a submap is locked by the 87 * submap's lock -- not the kernel_map's lock. 88 * 89 * thus, the useful feature of submaps is that they allow us to break 90 * up the locking and protection of the kernel address space into smaller 91 * chunks. 92 * 93 * the vm system has several standard kernel submaps, including: 94 * kmem_map => contains only wired kernel memory for the kernel 95 * malloc. *** access to kmem_map must be protected 96 * by splvm() because we are allowed to call malloc() 97 * at interrupt time *** 98 * mb_map => memory for large mbufs, *** protected by splvm *** 99 * pager_map => used to map "buf" structures into kernel space 100 * exec_map => used during exec to handle exec args 101 * etc... 102 * 103 * the kernel allocates its private memory out of special uvm_objects whose 104 * reference count is set to UVM_OBJ_KERN (thus indicating that the objects 105 * are "special" and never die). all kernel objects should be thought of 106 * as large, fixed-sized, sparsely populated uvm_objects. each kernel 107 * object is equal to the size of kernel virtual address space (i.e. the 108 * value "VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS"). 109 * 110 * most kernel private memory lives in kernel_object. the only exception 111 * to this is for memory that belongs to submaps that must be protected 112 * by splvm(). pages in these submaps are not assigned to an object. 113 * 114 * note that just because a kernel object spans the entire kernel virutal 115 * address space doesn't mean that it has to be mapped into the entire space. 116 * large chunks of a kernel object's space go unused either because 117 * that area of kernel VM is unmapped, or there is some other type of 118 * object mapped into that range (e.g. a vnode). for submap's kernel 119 * objects, the only part of the object that can ever be populated is the 120 * offsets that are managed by the submap. 121 * 122 * note that the "offset" in a kernel object is always the kernel virtual 123 * address minus the VM_MIN_KERNEL_ADDRESS (aka vm_map_min(kernel_map)). 124 * example: 125 * suppose VM_MIN_KERNEL_ADDRESS is 0xf8000000 and the kernel does a 126 * uvm_km_alloc(kernel_map, PAGE_SIZE) [allocate 1 wired down page in the 127 * kernel map]. if uvm_km_alloc returns virtual address 0xf8235000, 128 * then that means that the page at offset 0x235000 in kernel_object is 129 * mapped at 0xf8235000. 130 * 131 * kernel object have one other special property: when the kernel virtual 132 * memory mapping them is unmapped, the backing memory in the object is 133 * freed right away. this is done with the uvm_km_pgremove() function. 134 * this has to be done because there is no backing store for kernel pages 135 * and no need to save them after they are no longer referenced. 136 */ 137 138#include <sys/param.h> 139#include <sys/systm.h> 140#include <sys/proc.h> 141 142#include <uvm/uvm.h> 143 144/* 145 * global data structures 146 */ 147 148struct vm_map *kernel_map = NULL; 149 150/* 151 * local data structues 152 */ 153 154static struct vm_map kernel_map_store; 155 156/* 157 * uvm_km_init: 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 [min -> start] has already been allocated and that 162 * "end" is the end. 163 */ 164 165void 166uvm_km_init(start, end) 167 vaddr_t start, end; 168{ 169 vaddr_t base = VM_MIN_KERNEL_ADDRESS; 170 171 /* 172 * next, init kernel memory objects. 173 */ 174 175 /* kernel_object: for pageable anonymous kernel memory */ 176 uao_init(); 177 uvm.kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS - 178 VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ); 179 180 /* 181 * init the map and reserve already allocated kernel space 182 * before installing. 183 */ 184 185 uvm_map_setup(&kernel_map_store, base, end, VM_MAP_PAGEABLE); 186 kernel_map_store.pmap = pmap_kernel(); 187 if (uvm_map(&kernel_map_store, &base, start - base, NULL, 188 UVM_UNKNOWN_OFFSET, 0, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 189 UVM_INH_NONE, UVM_ADV_RANDOM,UVM_FLAG_FIXED)) != 0) 190 panic("uvm_km_init: could not reserve space for kernel"); 191 192 /* 193 * install! 194 */ 195 196 kernel_map = &kernel_map_store; 197} 198 199/* 200 * uvm_km_suballoc: allocate a submap in the kernel map. once a submap 201 * is allocated all references to that area of VM must go through it. this 202 * allows the locking of VAs in kernel_map to be broken up into regions. 203 * 204 * => if `fixed' is true, *min specifies where the region described 205 * by the submap must start 206 * => if submap is non NULL we use that as the submap, otherwise we 207 * alloc a new map 208 */ 209struct vm_map * 210uvm_km_suballoc(map, min, max, size, flags, fixed, submap) 211 struct vm_map *map; 212 vaddr_t *min, *max; /* IN/OUT, OUT */ 213 vsize_t size; 214 int flags; 215 boolean_t fixed; 216 struct vm_map *submap; 217{ 218 int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0); 219 220 size = round_page(size); /* round up to pagesize */ 221 222 /* 223 * first allocate a blank spot in the parent map 224 */ 225 226 if (uvm_map(map, min, size, NULL, UVM_UNKNOWN_OFFSET, 0, 227 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 228 UVM_ADV_RANDOM, mapflags)) != 0) { 229 panic("uvm_km_suballoc: unable to allocate space in parent map"); 230 } 231 232 /* 233 * set VM bounds (min is filled in by uvm_map) 234 */ 235 236 *max = *min + size; 237 238 /* 239 * add references to pmap and create or init the submap 240 */ 241 242 pmap_reference(vm_map_pmap(map)); 243 if (submap == NULL) { 244 submap = uvm_map_create(vm_map_pmap(map), *min, *max, flags); 245 if (submap == NULL) 246 panic("uvm_km_suballoc: unable to create submap"); 247 } else { 248 uvm_map_setup(submap, *min, *max, flags); 249 submap->pmap = vm_map_pmap(map); 250 } 251 252 /* 253 * now let uvm_map_submap plug in it... 254 */ 255 256 if (uvm_map_submap(map, *min, *max, submap) != 0) 257 panic("uvm_km_suballoc: submap allocation failed"); 258 259 return(submap); 260} 261 262/* 263 * uvm_km_pgremove: remove pages from a kernel uvm_object. 264 * 265 * => when you unmap a part of anonymous kernel memory you want to toss 266 * the pages right away. (this gets called from uvm_unmap_...). 267 */ 268 269void 270uvm_km_pgremove(uobj, start, end) 271 struct uvm_object *uobj; 272 vaddr_t start, end; 273{ 274 struct vm_page *pg; 275 voff_t curoff, nextoff; 276 int swpgonlydelta = 0; 277 UVMHIST_FUNC("uvm_km_pgremove"); UVMHIST_CALLED(maphist); 278 279 KASSERT(uobj->pgops == &aobj_pager); 280 simple_lock(&uobj->vmobjlock); 281 282 for (curoff = start; curoff < end; curoff = nextoff) { 283 nextoff = curoff + PAGE_SIZE; 284 pg = uvm_pagelookup(uobj, curoff); 285 if (pg != NULL && pg->flags & PG_BUSY) { 286 pg->flags |= PG_WANTED; 287 UVM_UNLOCK_AND_WAIT(pg, &uobj->vmobjlock, 0, 288 "km_pgrm", 0); 289 simple_lock(&uobj->vmobjlock); 290 nextoff = curoff; 291 continue; 292 } 293 294 /* 295 * free the swap slot, then the page. 296 */ 297 298 if (pg == NULL && 299 uao_find_swslot(uobj, curoff >> PAGE_SHIFT) != 0) { 300 swpgonlydelta++; 301 } 302 uao_dropswap(uobj, curoff >> PAGE_SHIFT); 303 if (pg != NULL) { 304 uvm_lock_pageq(); 305 uvm_pagefree(pg); 306 uvm_unlock_pageq(); 307 } 308 } 309 simple_unlock(&uobj->vmobjlock); 310 311 if (swpgonlydelta > 0) { 312 simple_lock(&uvm.swap_data_lock); 313 KASSERT(uvmexp.swpgonly >= swpgonlydelta); 314 uvmexp.swpgonly -= swpgonlydelta; 315 simple_unlock(&uvm.swap_data_lock); 316 } 317} 318 319 320/* 321 * uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for "intrsafe" 322 * maps 323 * 324 * => when you unmap a part of anonymous kernel memory you want to toss 325 * the pages right away. (this is called from uvm_unmap_...). 326 * => none of the pages will ever be busy, and none of them will ever 327 * be on the active or inactive queues (because they have no object). 328 */ 329 330void 331uvm_km_pgremove_intrsafe(start, end) 332 vaddr_t start, end; 333{ 334 struct vm_page *pg; 335 paddr_t pa; 336 UVMHIST_FUNC("uvm_km_pgremove_intrsafe"); UVMHIST_CALLED(maphist); 337 338 for (; start < end; start += PAGE_SIZE) { 339 if (!pmap_extract(pmap_kernel(), start, &pa)) { 340 continue; 341 } 342 pg = PHYS_TO_VM_PAGE(pa); 343 KASSERT(pg); 344 KASSERT(pg->uobject == NULL && pg->uanon == NULL); 345 uvm_pagefree(pg); 346 } 347} 348 349 350/* 351 * uvm_km_kmemalloc: lower level kernel memory allocator for malloc() 352 * 353 * => we map wired memory into the specified map using the obj passed in 354 * => NOTE: we can return NULL even if we can wait if there is not enough 355 * free VM space in the map... caller should be prepared to handle 356 * this case. 357 * => we return KVA of memory allocated 358 * => flags: NOWAIT, VALLOC - just allocate VA, TRYLOCK - fail if we can't 359 * lock the map 360 */ 361 362vaddr_t 363uvm_km_kmemalloc(map, obj, size, flags) 364 struct vm_map *map; 365 struct uvm_object *obj; 366 vsize_t size; 367 int flags; 368{ 369 vaddr_t kva, loopva; 370 vaddr_t offset; 371 vsize_t loopsize; 372 struct vm_page *pg; 373 UVMHIST_FUNC("uvm_km_kmemalloc"); UVMHIST_CALLED(maphist); 374 375 UVMHIST_LOG(maphist," (map=0x%x, obj=0x%x, size=0x%x, flags=%d)", 376 map, obj, size, flags); 377 KASSERT(vm_map_pmap(map) == pmap_kernel()); 378 379 /* 380 * setup for call 381 */ 382 383 size = round_page(size); 384 kva = vm_map_min(map); /* hint */ 385 386 /* 387 * allocate some virtual space 388 */ 389 390 if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET, 391 0, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 392 UVM_ADV_RANDOM, (flags & UVM_KMF_TRYLOCK))) 393 != 0)) { 394 UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0); 395 return(0); 396 } 397 398 /* 399 * if all we wanted was VA, return now 400 */ 401 402 if (flags & UVM_KMF_VALLOC) { 403 UVMHIST_LOG(maphist,"<- done valloc (kva=0x%x)", kva,0,0,0); 404 return(kva); 405 } 406 407 /* 408 * recover object offset from virtual address 409 */ 410 411 offset = kva - vm_map_min(kernel_map); 412 UVMHIST_LOG(maphist, " kva=0x%x, offset=0x%x", kva, offset,0,0); 413 414 /* 415 * now allocate and map in the memory... note that we are the only ones 416 * whom should ever get a handle on this area of VM. 417 */ 418 419 loopva = kva; 420 loopsize = size; 421 while (loopsize) { 422 if (obj) { 423 simple_lock(&obj->vmobjlock); 424 } 425 pg = uvm_pagealloc(obj, offset, NULL, UVM_PGA_USERESERVE); 426 if (__predict_true(pg != NULL)) { 427 pg->flags &= ~PG_BUSY; /* new page */ 428 UVM_PAGE_OWN(pg, NULL); 429 } 430 if (obj) { 431 simple_unlock(&obj->vmobjlock); 432 } 433 434 /* 435 * out of memory? 436 */ 437 438 if (__predict_false(pg == NULL)) { 439 if (flags & UVM_KMF_NOWAIT) { 440 /* free everything! */ 441 uvm_unmap(map, kva, kva + size); 442 return(0); 443 } else { 444 uvm_wait("km_getwait2"); /* sleep here */ 445 continue; 446 } 447 } 448 449 /* 450 * map it in 451 */ 452 453 if (obj == NULL) { 454 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), 455 VM_PROT_ALL); 456 } else { 457 pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg), 458 UVM_PROT_ALL, 459 PMAP_WIRED | VM_PROT_READ | VM_PROT_WRITE); 460 } 461 loopva += PAGE_SIZE; 462 offset += PAGE_SIZE; 463 loopsize -= PAGE_SIZE; 464 } 465 466 pmap_update(pmap_kernel()); 467 468 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 469 return(kva); 470} 471 472/* 473 * uvm_km_free: free an area of kernel memory 474 */ 475 476void 477uvm_km_free(map, addr, size) 478 struct vm_map *map; 479 vaddr_t addr; 480 vsize_t size; 481{ 482 uvm_unmap(map, trunc_page(addr), round_page(addr+size)); 483} 484 485/* 486 * uvm_km_free_wakeup: free an area of kernel memory and wake up 487 * anyone waiting for vm space. 488 * 489 * => XXX: "wanted" bit + unlock&wait on other end? 490 */ 491 492void 493uvm_km_free_wakeup(map, addr, size) 494 struct vm_map *map; 495 vaddr_t addr; 496 vsize_t size; 497{ 498 struct vm_map_entry *dead_entries; 499 500 vm_map_lock(map); 501 uvm_unmap_remove(map, trunc_page(addr), round_page(addr + size), 502 &dead_entries); 503 wakeup(map); 504 vm_map_unlock(map); 505 if (dead_entries != NULL) 506 uvm_unmap_detach(dead_entries, 0); 507} 508 509/* 510 * uvm_km_alloc1: allocate wired down memory in the kernel map. 511 * 512 * => we can sleep if needed 513 */ 514 515vaddr_t 516uvm_km_alloc1(map, size, zeroit) 517 struct vm_map *map; 518 vsize_t size; 519 boolean_t zeroit; 520{ 521 vaddr_t kva, loopva, offset; 522 struct vm_page *pg; 523 UVMHIST_FUNC("uvm_km_alloc1"); UVMHIST_CALLED(maphist); 524 525 UVMHIST_LOG(maphist,"(map=0x%x, size=0x%x)", map, size,0,0); 526 KASSERT(vm_map_pmap(map) == pmap_kernel()); 527 528 size = round_page(size); 529 kva = vm_map_min(map); /* hint */ 530 531 /* 532 * allocate some virtual space 533 */ 534 535 if (__predict_false(uvm_map(map, &kva, size, uvm.kernel_object, 536 UVM_UNKNOWN_OFFSET, 0, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 537 UVM_INH_NONE, UVM_ADV_RANDOM, 538 0)) != 0)) { 539 UVMHIST_LOG(maphist,"<- done (no VM)",0,0,0,0); 540 return(0); 541 } 542 543 /* 544 * recover object offset from virtual address 545 */ 546 547 offset = kva - vm_map_min(kernel_map); 548 UVMHIST_LOG(maphist," kva=0x%x, offset=0x%x", kva, offset,0,0); 549 550 /* 551 * now allocate the memory. 552 */ 553 554 loopva = kva; 555 while (size) { 556 simple_lock(&uvm.kernel_object->vmobjlock); 557 KASSERT(uvm_pagelookup(uvm.kernel_object, offset) == NULL); 558 pg = uvm_pagealloc(uvm.kernel_object, offset, NULL, 0); 559 if (pg) { 560 pg->flags &= ~PG_BUSY; 561 UVM_PAGE_OWN(pg, NULL); 562 } 563 simple_unlock(&uvm.kernel_object->vmobjlock); 564 if (pg == NULL) { 565 uvm_wait("km_alloc1w"); 566 continue; 567 } 568 pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg), 569 UVM_PROT_ALL, PMAP_WIRED | VM_PROT_READ | VM_PROT_WRITE); 570 loopva += PAGE_SIZE; 571 offset += PAGE_SIZE; 572 size -= PAGE_SIZE; 573 } 574 pmap_update(map->pmap); 575 576 /* 577 * zero on request (note that "size" is now zero due to the above loop 578 * so we need to subtract kva from loopva to reconstruct the size). 579 */ 580 581 if (zeroit) 582 memset((caddr_t)kva, 0, loopva - kva); 583 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 584 return(kva); 585} 586 587/* 588 * uvm_km_valloc: allocate zero-fill memory in the kernel's address space 589 * 590 * => memory is not allocated until fault time 591 */ 592 593vaddr_t 594uvm_km_valloc(map, size) 595 struct vm_map *map; 596 vsize_t size; 597{ 598 return(uvm_km_valloc_align(map, size, 0)); 599} 600 601vaddr_t 602uvm_km_valloc_align(map, size, align) 603 struct vm_map *map; 604 vsize_t size; 605 vsize_t align; 606{ 607 vaddr_t kva; 608 UVMHIST_FUNC("uvm_km_valloc"); UVMHIST_CALLED(maphist); 609 610 UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0); 611 KASSERT(vm_map_pmap(map) == pmap_kernel()); 612 613 size = round_page(size); 614 kva = vm_map_min(map); /* hint */ 615 616 /* 617 * allocate some virtual space. will be demand filled by kernel_object. 618 */ 619 620 if (__predict_false(uvm_map(map, &kva, size, uvm.kernel_object, 621 UVM_UNKNOWN_OFFSET, align, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 622 UVM_INH_NONE, UVM_ADV_RANDOM, 623 0)) != 0)) { 624 UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0); 625 return(0); 626 } 627 628 UVMHIST_LOG(maphist, "<- done (kva=0x%x)", kva,0,0,0); 629 return(kva); 630} 631 632/* 633 * uvm_km_valloc_wait: allocate zero-fill memory in the kernel's address space 634 * 635 * => memory is not allocated until fault time 636 * => if no room in map, wait for space to free, unless requested size 637 * is larger than map (in which case we return 0) 638 */ 639 640vaddr_t 641uvm_km_valloc_prefer_wait(map, size, prefer) 642 struct vm_map *map; 643 vsize_t size; 644 voff_t prefer; 645{ 646 vaddr_t kva; 647 UVMHIST_FUNC("uvm_km_valloc_prefer_wait"); UVMHIST_CALLED(maphist); 648 649 UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0); 650 KASSERT(vm_map_pmap(map) == pmap_kernel()); 651 652 size = round_page(size); 653 if (size > vm_map_max(map) - vm_map_min(map)) 654 return(0); 655 656 for (;;) { 657 kva = vm_map_min(map); /* hint */ 658 659 /* 660 * allocate some virtual space. will be demand filled 661 * by kernel_object. 662 */ 663 664 if (__predict_true(uvm_map(map, &kva, size, uvm.kernel_object, 665 prefer, 0, UVM_MAPFLAG(UVM_PROT_ALL, 666 UVM_PROT_ALL, UVM_INH_NONE, UVM_ADV_RANDOM, 0)) 667 == 0)) { 668 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 669 return(kva); 670 } 671 672 /* 673 * failed. sleep for a while (on map) 674 */ 675 676 UVMHIST_LOG(maphist,"<<<sleeping>>>",0,0,0,0); 677 tsleep((caddr_t)map, PVM, "vallocwait", 0); 678 } 679 /*NOTREACHED*/ 680} 681 682vaddr_t 683uvm_km_valloc_wait(map, size) 684 struct vm_map *map; 685 vsize_t size; 686{ 687 return uvm_km_valloc_prefer_wait(map, size, UVM_UNKNOWN_OFFSET); 688} 689 690/* Sanity; must specify both or none. */ 691#if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \ 692 (!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE)) 693#error Must specify MAP and UNMAP together. 694#endif 695 696/* 697 * uvm_km_alloc_poolpage: allocate a page for the pool allocator 698 * 699 * => if the pmap specifies an alternate mapping method, we use it. 700 */ 701 702/* ARGSUSED */ 703vaddr_t 704uvm_km_alloc_poolpage1(map, obj, waitok) 705 struct vm_map *map; 706 struct uvm_object *obj; 707 boolean_t waitok; 708{ 709#if defined(PMAP_MAP_POOLPAGE) 710 struct vm_page *pg; 711 vaddr_t va; 712 713 again: 714 pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_USERESERVE); 715 if (__predict_false(pg == NULL)) { 716 if (waitok) { 717 uvm_wait("plpg"); 718 goto again; 719 } else 720 return (0); 721 } 722 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 723 if (__predict_false(va == 0)) 724 uvm_pagefree(pg); 725 return (va); 726#else 727 vaddr_t va; 728 int s; 729 730 /* 731 * NOTE: We may be called with a map that doens't require splvm 732 * protection (e.g. kernel_map). However, it does not hurt to 733 * go to splvm in this case (since unprocted maps will never be 734 * accessed in interrupt context). 735 * 736 * XXX We may want to consider changing the interface to this 737 * XXX function. 738 */ 739 740 s = splvm(); 741 va = uvm_km_kmemalloc(map, obj, PAGE_SIZE, waitok ? 0 : UVM_KMF_NOWAIT); 742 splx(s); 743 return (va); 744#endif /* PMAP_MAP_POOLPAGE */ 745} 746 747/* 748 * uvm_km_free_poolpage: free a previously allocated pool page 749 * 750 * => if the pmap specifies an alternate unmapping method, we use it. 751 */ 752 753/* ARGSUSED */ 754void 755uvm_km_free_poolpage1(map, addr) 756 struct vm_map *map; 757 vaddr_t addr; 758{ 759#if defined(PMAP_UNMAP_POOLPAGE) 760 paddr_t pa; 761 762 pa = PMAP_UNMAP_POOLPAGE(addr); 763 uvm_pagefree(PHYS_TO_VM_PAGE(pa)); 764#else 765 int s; 766 767 /* 768 * NOTE: We may be called with a map that doens't require splvm 769 * protection (e.g. kernel_map). However, it does not hurt to 770 * go to splvm in this case (since unprocted maps will never be 771 * accessed in interrupt context). 772 * 773 * XXX We may want to consider changing the interface to this 774 * XXX function. 775 */ 776 777 s = splvm(); 778 uvm_km_free(map, addr, PAGE_SIZE); 779 splx(s); 780#endif /* PMAP_UNMAP_POOLPAGE */ 781} 782