uvm_km.c revision 1.51
1/* $NetBSD: uvm_km.c,v 1.51 2001/09/10 21:19:42 chris 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(). each of these submaps has their own private kernel 113 * object (e.g. kmem_object, mb_object). 114 * 115 * note that just because a kernel object spans the entire kernel virutal 116 * address space doesn't mean that it has to be mapped into the entire space. 117 * large chunks of a kernel object's space go unused either because 118 * that area of kernel VM is unmapped, or there is some other type of 119 * object mapped into that range (e.g. a vnode). for submap's kernel 120 * objects, the only part of the object that can ever be populated is the 121 * offsets that are managed by the submap. 122 * 123 * note that the "offset" in a kernel object is always the kernel virtual 124 * address minus the VM_MIN_KERNEL_ADDRESS (aka vm_map_min(kernel_map)). 125 * example: 126 * suppose VM_MIN_KERNEL_ADDRESS is 0xf8000000 and the kernel does a 127 * uvm_km_alloc(kernel_map, PAGE_SIZE) [allocate 1 wired down page in the 128 * kernel map]. if uvm_km_alloc returns virtual address 0xf8235000, 129 * then that means that the page at offset 0x235000 in kernel_object is 130 * mapped at 0xf8235000. 131 * 132 * note that the offsets in kmem_object and mb_object also follow this 133 * rule. this means that the offsets for kmem_object must fall in the 134 * range of [vm_map_min(kmem_object) - vm_map_min(kernel_map)] to 135 * [vm_map_max(kmem_object) - vm_map_min(kernel_map)], so the offsets 136 * in those objects will typically not start at zero. 137 * 138 * kernel object have one other special property: when the kernel virtual 139 * memory mapping them is unmapped, the backing memory in the object is 140 * freed right away. this is done with the uvm_km_pgremove() function. 141 * this has to be done because there is no backing store for kernel pages 142 * and no need to save them after they are no longer referenced. 143 */ 144 145#include <sys/param.h> 146#include <sys/systm.h> 147#include <sys/proc.h> 148 149#include <uvm/uvm.h> 150 151/* 152 * global data structures 153 */ 154 155struct vm_map *kernel_map = NULL; 156 157/* 158 * local data structues 159 */ 160 161static struct vm_map kernel_map_store; 162static struct uvm_object kmem_object_store; 163static struct uvm_object mb_object_store; 164 165/* 166 * All pager operations here are NULL, but the object must have 167 * a pager ops vector associated with it; various places assume 168 * it to be so. 169 */ 170static struct uvm_pagerops km_pager; 171 172/* 173 * uvm_km_init: init kernel maps and objects to reflect reality (i.e. 174 * KVM already allocated for text, data, bss, and static data structures). 175 * 176 * => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS. 177 * we assume that [min -> start] has already been allocated and that 178 * "end" is the end. 179 */ 180 181void 182uvm_km_init(start, end) 183 vaddr_t start, end; 184{ 185 vaddr_t base = VM_MIN_KERNEL_ADDRESS; 186 187 /* 188 * next, init kernel memory objects. 189 */ 190 191 /* kernel_object: for pageable anonymous kernel memory */ 192 uao_init(); 193 uvm.kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS - 194 VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ); 195 196 /* 197 * kmem_object: for use by the kernel malloc(). Memory is always 198 * wired, and this object (and the kmem_map) can be accessed at 199 * interrupt time. 200 */ 201 simple_lock_init(&kmem_object_store.vmobjlock); 202 kmem_object_store.pgops = &km_pager; 203 TAILQ_INIT(&kmem_object_store.memq); 204 kmem_object_store.uo_npages = 0; 205 /* we are special. we never die */ 206 kmem_object_store.uo_refs = UVM_OBJ_KERN_INTRSAFE; 207 uvmexp.kmem_object = &kmem_object_store; 208 209 /* 210 * mb_object: for mbuf cluster pages on platforms which use the 211 * mb_map. Memory is always wired, and this object (and the mb_map) 212 * can be accessed at interrupt time. 213 */ 214 simple_lock_init(&mb_object_store.vmobjlock); 215 mb_object_store.pgops = &km_pager; 216 TAILQ_INIT(&mb_object_store.memq); 217 mb_object_store.uo_npages = 0; 218 /* we are special. we never die */ 219 mb_object_store.uo_refs = UVM_OBJ_KERN_INTRSAFE; 220 uvmexp.mb_object = &mb_object_store; 221 222 /* 223 * init the map and reserve allready allocated kernel space 224 * before installing. 225 */ 226 227 uvm_map_setup(&kernel_map_store, base, end, VM_MAP_PAGEABLE); 228 kernel_map_store.pmap = pmap_kernel(); 229 if (uvm_map(&kernel_map_store, &base, start - base, NULL, 230 UVM_UNKNOWN_OFFSET, 0, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 231 UVM_INH_NONE, UVM_ADV_RANDOM,UVM_FLAG_FIXED)) != 0) 232 panic("uvm_km_init: could not reserve space for kernel"); 233 234 /* 235 * install! 236 */ 237 238 kernel_map = &kernel_map_store; 239} 240 241/* 242 * uvm_km_suballoc: allocate a submap in the kernel map. once a submap 243 * is allocated all references to that area of VM must go through it. this 244 * allows the locking of VAs in kernel_map to be broken up into regions. 245 * 246 * => if `fixed' is true, *min specifies where the region described 247 * by the submap must start 248 * => if submap is non NULL we use that as the submap, otherwise we 249 * alloc a new map 250 */ 251struct vm_map * 252uvm_km_suballoc(map, min, max, size, flags, fixed, submap) 253 struct vm_map *map; 254 vaddr_t *min, *max; /* OUT, OUT */ 255 vsize_t size; 256 int flags; 257 boolean_t fixed; 258 struct vm_map *submap; 259{ 260 int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0); 261 262 size = round_page(size); /* round up to pagesize */ 263 264 /* 265 * first allocate a blank spot in the parent map 266 */ 267 268 if (uvm_map(map, min, size, NULL, UVM_UNKNOWN_OFFSET, 0, 269 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 270 UVM_ADV_RANDOM, mapflags)) != 0) { 271 panic("uvm_km_suballoc: unable to allocate space in parent map"); 272 } 273 274 /* 275 * set VM bounds (min is filled in by uvm_map) 276 */ 277 278 *max = *min + size; 279 280 /* 281 * add references to pmap and create or init the submap 282 */ 283 284 pmap_reference(vm_map_pmap(map)); 285 if (submap == NULL) { 286 submap = uvm_map_create(vm_map_pmap(map), *min, *max, flags); 287 if (submap == NULL) 288 panic("uvm_km_suballoc: unable to create submap"); 289 } else { 290 uvm_map_setup(submap, *min, *max, flags); 291 submap->pmap = vm_map_pmap(map); 292 } 293 294 /* 295 * now let uvm_map_submap plug in it... 296 */ 297 298 if (uvm_map_submap(map, *min, *max, submap) != 0) 299 panic("uvm_km_suballoc: submap allocation failed"); 300 301 return(submap); 302} 303 304/* 305 * uvm_km_pgremove: remove pages from a kernel uvm_object. 306 * 307 * => when you unmap a part of anonymous kernel memory you want to toss 308 * the pages right away. (this gets called from uvm_unmap_...). 309 */ 310 311#define UKM_HASH_PENALTY 4 /* a guess */ 312 313void 314uvm_km_pgremove(uobj, start, end) 315 struct uvm_object *uobj; 316 vaddr_t start, end; 317{ 318 boolean_t by_list; 319 struct vm_page *pp, *ppnext; 320 vaddr_t curoff; 321 UVMHIST_FUNC("uvm_km_pgremove"); UVMHIST_CALLED(maphist); 322 323 KASSERT(uobj->pgops == &aobj_pager); 324 simple_lock(&uobj->vmobjlock); 325 326 /* choose cheapest traversal */ 327 by_list = (uobj->uo_npages <= 328 ((end - start) >> PAGE_SHIFT) * UKM_HASH_PENALTY); 329 330 if (by_list) 331 goto loop_by_list; 332 333 /* by hash */ 334 335 for (curoff = start ; curoff < end ; curoff += PAGE_SIZE) { 336 pp = uvm_pagelookup(uobj, curoff); 337 if (pp == NULL) 338 continue; 339 340 UVMHIST_LOG(maphist," page 0x%x, busy=%d", pp, 341 pp->flags & PG_BUSY, 0, 0); 342 343 /* now do the actual work */ 344 if (pp->flags & PG_BUSY) { 345 /* owner must check for this when done */ 346 pp->flags |= PG_RELEASED; 347 } else { 348 /* free the swap slot... */ 349 uao_dropswap(uobj, curoff >> PAGE_SHIFT); 350 351 /* 352 * ...and free the page; note it may be on the 353 * active or inactive queues. 354 */ 355 uvm_lock_pageq(); 356 uvm_pagefree(pp); 357 uvm_unlock_pageq(); 358 } 359 } 360 simple_unlock(&uobj->vmobjlock); 361 return; 362 363loop_by_list: 364 365 for (pp = TAILQ_FIRST(&uobj->memq); pp != NULL; pp = ppnext) { 366 ppnext = TAILQ_NEXT(pp, listq); 367 if (pp->offset < start || pp->offset >= end) { 368 continue; 369 } 370 371 UVMHIST_LOG(maphist," page 0x%x, busy=%d", pp, 372 pp->flags & PG_BUSY, 0, 0); 373 374 if (pp->flags & PG_BUSY) { 375 /* owner must check for this when done */ 376 pp->flags |= PG_RELEASED; 377 } else { 378 /* free the swap slot... */ 379 uao_dropswap(uobj, pp->offset >> PAGE_SHIFT); 380 381 /* 382 * ...and free the page; note it may be on the 383 * active or inactive queues. 384 */ 385 uvm_lock_pageq(); 386 uvm_pagefree(pp); 387 uvm_unlock_pageq(); 388 } 389 } 390 simple_unlock(&uobj->vmobjlock); 391} 392 393 394/* 395 * uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for "intrsafe" 396 * objects 397 * 398 * => when you unmap a part of anonymous kernel memory you want to toss 399 * the pages right away. (this gets called from uvm_unmap_...). 400 * => none of the pages will ever be busy, and none of them will ever 401 * be on the active or inactive queues (because these objects are 402 * never allowed to "page"). 403 */ 404 405void 406uvm_km_pgremove_intrsafe(uobj, start, end) 407 struct uvm_object *uobj; 408 vaddr_t start, end; 409{ 410 boolean_t by_list; 411 struct vm_page *pp, *ppnext; 412 vaddr_t curoff; 413 UVMHIST_FUNC("uvm_km_pgremove_intrsafe"); UVMHIST_CALLED(maphist); 414 415 KASSERT(UVM_OBJ_IS_INTRSAFE_OBJECT(uobj)); 416 simple_lock(&uobj->vmobjlock); /* lock object */ 417 418 /* choose cheapest traversal */ 419 by_list = (uobj->uo_npages <= 420 ((end - start) >> PAGE_SHIFT) * UKM_HASH_PENALTY); 421 422 if (by_list) 423 goto loop_by_list; 424 425 /* by hash */ 426 427 for (curoff = start ; curoff < end ; curoff += PAGE_SIZE) { 428 pp = uvm_pagelookup(uobj, curoff); 429 if (pp == NULL) { 430 continue; 431 } 432 433 UVMHIST_LOG(maphist," page 0x%x, busy=%d", pp, 434 pp->flags & PG_BUSY, 0, 0); 435 KASSERT((pp->flags & PG_BUSY) == 0); 436 KASSERT((pp->pqflags & PQ_ACTIVE) == 0); 437 KASSERT((pp->pqflags & PQ_INACTIVE) == 0); 438 uvm_pagefree(pp); 439 } 440 simple_unlock(&uobj->vmobjlock); 441 return; 442 443loop_by_list: 444 445 for (pp = TAILQ_FIRST(&uobj->memq); pp != NULL; pp = ppnext) { 446 ppnext = TAILQ_NEXT(pp, listq); 447 if (pp->offset < start || pp->offset >= end) { 448 continue; 449 } 450 451 UVMHIST_LOG(maphist," page 0x%x, busy=%d", pp, 452 pp->flags & PG_BUSY, 0, 0); 453 KASSERT((pp->flags & PG_BUSY) == 0); 454 KASSERT((pp->pqflags & PQ_ACTIVE) == 0); 455 KASSERT((pp->pqflags & PQ_INACTIVE) == 0); 456 uvm_pagefree(pp); 457 } 458 simple_unlock(&uobj->vmobjlock); 459} 460 461 462/* 463 * uvm_km_kmemalloc: lower level kernel memory allocator for malloc() 464 * 465 * => we map wired memory into the specified map using the obj passed in 466 * => NOTE: we can return NULL even if we can wait if there is not enough 467 * free VM space in the map... caller should be prepared to handle 468 * this case. 469 * => we return KVA of memory allocated 470 * => flags: NOWAIT, VALLOC - just allocate VA, TRYLOCK - fail if we can't 471 * lock the map 472 */ 473 474vaddr_t 475uvm_km_kmemalloc(map, obj, size, flags) 476 struct vm_map *map; 477 struct uvm_object *obj; 478 vsize_t size; 479 int flags; 480{ 481 vaddr_t kva, loopva; 482 vaddr_t offset; 483 vsize_t loopsize; 484 struct vm_page *pg; 485 UVMHIST_FUNC("uvm_km_kmemalloc"); UVMHIST_CALLED(maphist); 486 487 UVMHIST_LOG(maphist," (map=0x%x, obj=0x%x, size=0x%x, flags=%d)", 488 map, obj, size, flags); 489 KASSERT(vm_map_pmap(map) == pmap_kernel()); 490 491 /* 492 * setup for call 493 */ 494 495 size = round_page(size); 496 kva = vm_map_min(map); /* hint */ 497 498 /* 499 * allocate some virtual space 500 */ 501 502 if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET, 503 0, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 504 UVM_ADV_RANDOM, (flags & UVM_KMF_TRYLOCK))) 505 != 0)) { 506 UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0); 507 return(0); 508 } 509 510 /* 511 * if all we wanted was VA, return now 512 */ 513 514 if (flags & UVM_KMF_VALLOC) { 515 UVMHIST_LOG(maphist,"<- done valloc (kva=0x%x)", kva,0,0,0); 516 return(kva); 517 } 518 519 /* 520 * recover object offset from virtual address 521 */ 522 523 offset = kva - vm_map_min(kernel_map); 524 UVMHIST_LOG(maphist, " kva=0x%x, offset=0x%x", kva, offset,0,0); 525 526 /* 527 * now allocate and map in the memory... note that we are the only ones 528 * whom should ever get a handle on this area of VM. 529 */ 530 531 loopva = kva; 532 loopsize = size; 533 while (loopsize) { 534 simple_lock(&obj->vmobjlock); 535 pg = uvm_pagealloc(obj, offset, NULL, 0); 536 if (__predict_true(pg != NULL)) { 537 pg->flags &= ~PG_BUSY; /* new page */ 538 UVM_PAGE_OWN(pg, NULL); 539 } 540 simple_unlock(&obj->vmobjlock); 541 542 /* 543 * out of memory? 544 */ 545 546 if (__predict_false(pg == NULL)) { 547 if (flags & UVM_KMF_NOWAIT) { 548 /* free everything! */ 549 uvm_unmap(map, kva, kva + size); 550 return(0); 551 } else { 552 uvm_wait("km_getwait2"); /* sleep here */ 553 continue; 554 } 555 } 556 557 /* 558 * map it in: note that we call pmap_enter with the map and 559 * object unlocked in case we are kmem_map/kmem_object 560 * (because if pmap_enter wants to allocate out of kmem_object 561 * it will need to lock it itself!) 562 */ 563 564 if (UVM_OBJ_IS_INTRSAFE_OBJECT(obj)) { 565 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), 566 VM_PROT_ALL); 567 } else { 568 pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg), 569 UVM_PROT_ALL, 570 PMAP_WIRED | VM_PROT_READ | VM_PROT_WRITE); 571 } 572 loopva += PAGE_SIZE; 573 offset += PAGE_SIZE; 574 loopsize -= PAGE_SIZE; 575 } 576 577 pmap_update(pmap_kernel()); 578 579 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 580 return(kva); 581} 582 583/* 584 * uvm_km_free: free an area of kernel memory 585 */ 586 587void 588uvm_km_free(map, addr, size) 589 struct vm_map *map; 590 vaddr_t addr; 591 vsize_t size; 592{ 593 uvm_unmap(map, trunc_page(addr), round_page(addr+size)); 594} 595 596/* 597 * uvm_km_free_wakeup: free an area of kernel memory and wake up 598 * anyone waiting for vm space. 599 * 600 * => XXX: "wanted" bit + unlock&wait on other end? 601 */ 602 603void 604uvm_km_free_wakeup(map, addr, size) 605 struct vm_map *map; 606 vaddr_t addr; 607 vsize_t size; 608{ 609 struct vm_map_entry *dead_entries; 610 611 vm_map_lock(map); 612 uvm_unmap_remove(map, trunc_page(addr), round_page(addr + size), 613 &dead_entries); 614 wakeup(map); 615 vm_map_unlock(map); 616 if (dead_entries != NULL) 617 uvm_unmap_detach(dead_entries, 0); 618} 619 620/* 621 * uvm_km_alloc1: allocate wired down memory in the kernel map. 622 * 623 * => we can sleep if needed 624 */ 625 626vaddr_t 627uvm_km_alloc1(map, size, zeroit) 628 struct vm_map *map; 629 vsize_t size; 630 boolean_t zeroit; 631{ 632 vaddr_t kva, loopva, offset; 633 struct vm_page *pg; 634 UVMHIST_FUNC("uvm_km_alloc1"); UVMHIST_CALLED(maphist); 635 636 UVMHIST_LOG(maphist,"(map=0x%x, size=0x%x)", map, size,0,0); 637 KASSERT(vm_map_pmap(map) == pmap_kernel()); 638 639 size = round_page(size); 640 kva = vm_map_min(map); /* hint */ 641 642 /* 643 * allocate some virtual space 644 */ 645 646 if (__predict_false(uvm_map(map, &kva, size, uvm.kernel_object, 647 UVM_UNKNOWN_OFFSET, 0, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 648 UVM_INH_NONE, UVM_ADV_RANDOM, 649 0)) != 0)) { 650 UVMHIST_LOG(maphist,"<- done (no VM)",0,0,0,0); 651 return(0); 652 } 653 654 /* 655 * recover object offset from virtual address 656 */ 657 658 offset = kva - vm_map_min(kernel_map); 659 UVMHIST_LOG(maphist," kva=0x%x, offset=0x%x", kva, offset,0,0); 660 661 /* 662 * now allocate the memory. we must be careful about released pages. 663 */ 664 665 loopva = kva; 666 while (size) { 667 simple_lock(&uvm.kernel_object->vmobjlock); 668 pg = uvm_pagelookup(uvm.kernel_object, offset); 669 670 /* 671 * if we found a page in an unallocated region, it must be 672 * released 673 */ 674 if (pg) { 675 if ((pg->flags & PG_RELEASED) == 0) 676 panic("uvm_km_alloc1: non-released page"); 677 pg->flags |= PG_WANTED; 678 UVM_UNLOCK_AND_WAIT(pg, &uvm.kernel_object->vmobjlock, 679 FALSE, "km_alloc", 0); 680 continue; /* retry */ 681 } 682 683 /* allocate ram */ 684 pg = uvm_pagealloc(uvm.kernel_object, offset, NULL, 0); 685 if (pg) { 686 pg->flags &= ~PG_BUSY; /* new page */ 687 UVM_PAGE_OWN(pg, NULL); 688 } 689 simple_unlock(&uvm.kernel_object->vmobjlock); 690 if (__predict_false(pg == NULL)) { 691 uvm_wait("km_alloc1w"); /* wait for memory */ 692 continue; 693 } 694 695 /* 696 * map it in; note we're never called with an intrsafe 697 * object, so we always use regular old pmap_enter(). 698 */ 699 pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg), 700 UVM_PROT_ALL, PMAP_WIRED | VM_PROT_READ | VM_PROT_WRITE); 701 702 loopva += PAGE_SIZE; 703 offset += PAGE_SIZE; 704 size -= PAGE_SIZE; 705 } 706 707 pmap_update(map->pmap); 708 709 /* 710 * zero on request (note that "size" is now zero due to the above loop 711 * so we need to subtract kva from loopva to reconstruct the size). 712 */ 713 714 if (zeroit) 715 memset((caddr_t)kva, 0, loopva - kva); 716 717 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 718 return(kva); 719} 720 721/* 722 * uvm_km_valloc: allocate zero-fill memory in the kernel's address space 723 * 724 * => memory is not allocated until fault time 725 */ 726 727vaddr_t 728uvm_km_valloc(map, size) 729 struct vm_map *map; 730 vsize_t size; 731{ 732 return(uvm_km_valloc_align(map, size, 0)); 733} 734 735vaddr_t 736uvm_km_valloc_align(map, size, align) 737 struct vm_map *map; 738 vsize_t size; 739 vsize_t align; 740{ 741 vaddr_t kva; 742 UVMHIST_FUNC("uvm_km_valloc"); UVMHIST_CALLED(maphist); 743 744 UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0); 745 KASSERT(vm_map_pmap(map) == pmap_kernel()); 746 747 size = round_page(size); 748 kva = vm_map_min(map); /* hint */ 749 750 /* 751 * allocate some virtual space. will be demand filled by kernel_object. 752 */ 753 754 if (__predict_false(uvm_map(map, &kva, size, uvm.kernel_object, 755 UVM_UNKNOWN_OFFSET, align, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 756 UVM_INH_NONE, UVM_ADV_RANDOM, 757 0)) != 0)) { 758 UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0); 759 return(0); 760 } 761 762 UVMHIST_LOG(maphist, "<- done (kva=0x%x)", kva,0,0,0); 763 return(kva); 764} 765 766/* 767 * uvm_km_valloc_wait: allocate zero-fill memory in the kernel's address space 768 * 769 * => memory is not allocated until fault time 770 * => if no room in map, wait for space to free, unless requested size 771 * is larger than map (in which case we return 0) 772 */ 773 774vaddr_t 775uvm_km_valloc_prefer_wait(map, size, prefer) 776 struct vm_map *map; 777 vsize_t size; 778 voff_t prefer; 779{ 780 vaddr_t kva; 781 UVMHIST_FUNC("uvm_km_valloc_prefer_wait"); UVMHIST_CALLED(maphist); 782 783 UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0); 784 KASSERT(vm_map_pmap(map) == pmap_kernel()); 785 786 size = round_page(size); 787 if (size > vm_map_max(map) - vm_map_min(map)) 788 return(0); 789 790 while (1) { 791 kva = vm_map_min(map); /* hint */ 792 793 /* 794 * allocate some virtual space. will be demand filled 795 * by kernel_object. 796 */ 797 798 if (__predict_true(uvm_map(map, &kva, size, uvm.kernel_object, 799 prefer, 0, UVM_MAPFLAG(UVM_PROT_ALL, 800 UVM_PROT_ALL, UVM_INH_NONE, UVM_ADV_RANDOM, 0)) 801 == 0)) { 802 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 803 return(kva); 804 } 805 806 /* 807 * failed. sleep for a while (on map) 808 */ 809 810 UVMHIST_LOG(maphist,"<<<sleeping>>>",0,0,0,0); 811 tsleep((caddr_t)map, PVM, "vallocwait", 0); 812 } 813 /*NOTREACHED*/ 814} 815 816vaddr_t 817uvm_km_valloc_wait(map, size) 818 struct vm_map *map; 819 vsize_t size; 820{ 821 return uvm_km_valloc_prefer_wait(map, size, UVM_UNKNOWN_OFFSET); 822} 823 824/* Sanity; must specify both or none. */ 825#if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \ 826 (!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE)) 827#error Must specify MAP and UNMAP together. 828#endif 829 830/* 831 * uvm_km_alloc_poolpage: allocate a page for the pool allocator 832 * 833 * => if the pmap specifies an alternate mapping method, we use it. 834 */ 835 836/* ARGSUSED */ 837vaddr_t 838uvm_km_alloc_poolpage1(map, obj, waitok) 839 struct vm_map *map; 840 struct uvm_object *obj; 841 boolean_t waitok; 842{ 843#if defined(PMAP_MAP_POOLPAGE) 844 struct vm_page *pg; 845 vaddr_t va; 846 847 again: 848 pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_USERESERVE); 849 if (__predict_false(pg == NULL)) { 850 if (waitok) { 851 uvm_wait("plpg"); 852 goto again; 853 } else 854 return (0); 855 } 856 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 857 if (__predict_false(va == 0)) 858 uvm_pagefree(pg); 859 return (va); 860#else 861 vaddr_t va; 862 int s; 863 864 /* 865 * NOTE: We may be called with a map that doens't require splvm 866 * protection (e.g. kernel_map). However, it does not hurt to 867 * go to splvm in this case (since unprocted maps will never be 868 * accessed in interrupt context). 869 * 870 * XXX We may want to consider changing the interface to this 871 * XXX function. 872 */ 873 874 s = splvm(); 875 va = uvm_km_kmemalloc(map, obj, PAGE_SIZE, waitok ? 0 : UVM_KMF_NOWAIT); 876 splx(s); 877 return (va); 878#endif /* PMAP_MAP_POOLPAGE */ 879} 880 881/* 882 * uvm_km_free_poolpage: free a previously allocated pool page 883 * 884 * => if the pmap specifies an alternate unmapping method, we use it. 885 */ 886 887/* ARGSUSED */ 888void 889uvm_km_free_poolpage1(map, addr) 890 struct vm_map *map; 891 vaddr_t addr; 892{ 893#if defined(PMAP_UNMAP_POOLPAGE) 894 paddr_t pa; 895 896 pa = PMAP_UNMAP_POOLPAGE(addr); 897 uvm_pagefree(PHYS_TO_VM_PAGE(pa)); 898#else 899 int s; 900 901 /* 902 * NOTE: We may be called with a map that doens't require splvm 903 * protection (e.g. kernel_map). However, it does not hurt to 904 * go to splvm in this case (since unprocted maps will never be 905 * accessed in interrupt context). 906 * 907 * XXX We may want to consider changing the interface to this 908 * XXX function. 909 */ 910 911 s = splvm(); 912 uvm_km_free(map, addr, PAGE_SIZE); 913 splx(s); 914#endif /* PMAP_UNMAP_POOLPAGE */ 915} 916