1 /* $NetBSD: uvm_km.c,v 1.55 2001/11/10 07:37:00 lukem 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 /* 70 * uvm_km.c: handle kernel memory allocation and management 71 */ 72 73 /* 74 * overview of kernel memory management: 75 * 76 * the kernel virtual address space is mapped by "kernel_map." kernel_map 77 * starts at VM_MIN_KERNEL_ADDRESS and goes to VM_MAX_KERNEL_ADDRESS. 78 * note that VM_MIN_KERNEL_ADDRESS is equal to vm_map_min(kernel_map). 79 * 80 * the kernel_map has several "submaps." submaps can only appear in 81 * the kernel_map (user processes can't use them). submaps "take over" 82 * the management of a sub-range of the kernel's address space. submaps 83 * are typically allocated at boot time and are never released. kernel 84 * virtual address space that is mapped by a submap is locked by the 85 * submap's lock -- not the kernel_map's lock. 86 * 87 * thus, the useful feature of submaps is that they allow us to break 88 * up the locking and protection of the kernel address space into smaller 89 * chunks. 90 * 91 * the vm system has several standard kernel submaps, including: 92 * kmem_map => contains only wired kernel memory for the kernel 93 * malloc. *** access to kmem_map must be protected 94 * by splvm() because we are allowed to call malloc() 95 * at interrupt time *** 96 * mb_map => memory for large mbufs, *** protected by splvm *** 97 * pager_map => used to map "buf" structures into kernel space 98 * exec_map => used during exec to handle exec args 99 * etc... 100 * 101 * the kernel allocates its private memory out of special uvm_objects whose 102 * reference count is set to UVM_OBJ_KERN (thus indicating that the objects 103 * are "special" and never die). all kernel objects should be thought of 104 * as large, fixed-sized, sparsely populated uvm_objects. each kernel 105 * object is equal to the size of kernel virtual address space (i.e. the 106 * value "VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS"). 107 * 108 * most kernel private memory lives in kernel_object. the only exception 109 * to this is for memory that belongs to submaps that must be protected 110 * by splvm(). pages in these submaps are not assigned to an object. 111 * 112 * note that just because a kernel object spans the entire kernel virutal 113 * address space doesn't mean that it has to be mapped into the entire space. 114 * large chunks of a kernel object's space go unused either because 115 * that area of kernel VM is unmapped, or there is some other type of 116 * object mapped into that range (e.g. a vnode). for submap's kernel 117 * objects, the only part of the object that can ever be populated is the 118 * offsets that are managed by the submap. 119 * 120 * note that the "offset" in a kernel object is always the kernel virtual 121 * address minus the VM_MIN_KERNEL_ADDRESS (aka vm_map_min(kernel_map)). 122 * example: 123 * suppose VM_MIN_KERNEL_ADDRESS is 0xf8000000 and the kernel does a 124 * uvm_km_alloc(kernel_map, PAGE_SIZE) [allocate 1 wired down page in the 125 * kernel map]. if uvm_km_alloc returns virtual address 0xf8235000, 126 * then that means that the page at offset 0x235000 in kernel_object is 127 * mapped at 0xf8235000. 128 * 129 * kernel object have one other special property: when the kernel virtual 130 * memory mapping them is unmapped, the backing memory in the object is 131 * freed right away. this is done with the uvm_km_pgremove() function. 132 * this has to be done because there is no backing store for kernel pages 133 * and no need to save them after they are no longer referenced. 134 */ 135 136 #include <sys/cdefs.h> 137 __KERNEL_RCSID(0, "$NetBSD: uvm_km.c,v 1.55 2001/11/10 07:37:00 lukem Exp $"); 138 139 #include "opt_uvmhist.h" 140 141 #include <sys/param.h> 142 #include <sys/systm.h> 143 #include <sys/proc.h> 144 145 #include <uvm/uvm.h> 146 147 /* 148 * global data structures 149 */ 150 151 struct vm_map *kernel_map = NULL; 152 153 /* 154 * local data structues 155 */ 156 157 static struct vm_map kernel_map_store; 158 159 /* 160 * uvm_km_init: init kernel maps and objects to reflect reality (i.e. 161 * KVM already allocated for text, data, bss, and static data structures). 162 * 163 * => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS. 164 * we assume that [min -> start] has already been allocated and that 165 * "end" is the end. 166 */ 167 168 void 169 uvm_km_init(start, end) 170 vaddr_t start, end; 171 { 172 vaddr_t base = VM_MIN_KERNEL_ADDRESS; 173 174 /* 175 * next, init kernel memory objects. 176 */ 177 178 /* kernel_object: for pageable anonymous kernel memory */ 179 uao_init(); 180 uvm.kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS - 181 VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ); 182 183 /* 184 * init the map and reserve already allocated kernel space 185 * before installing. 186 */ 187 188 uvm_map_setup(&kernel_map_store, base, end, VM_MAP_PAGEABLE); 189 kernel_map_store.pmap = pmap_kernel(); 190 if (uvm_map(&kernel_map_store, &base, start - base, NULL, 191 UVM_UNKNOWN_OFFSET, 0, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 192 UVM_INH_NONE, UVM_ADV_RANDOM,UVM_FLAG_FIXED)) != 0) 193 panic("uvm_km_init: could not reserve space for kernel"); 194 195 /* 196 * install! 197 */ 198 199 kernel_map = &kernel_map_store; 200 } 201 202 /* 203 * uvm_km_suballoc: allocate a submap in the kernel map. once a submap 204 * is allocated all references to that area of VM must go through it. this 205 * allows the locking of VAs in kernel_map to be broken up into regions. 206 * 207 * => if `fixed' is true, *min specifies where the region described 208 * by the submap must start 209 * => if submap is non NULL we use that as the submap, otherwise we 210 * alloc a new map 211 */ 212 struct vm_map * 213 uvm_km_suballoc(map, min, max, size, flags, fixed, submap) 214 struct vm_map *map; 215 vaddr_t *min, *max; /* IN/OUT, OUT */ 216 vsize_t size; 217 int flags; 218 boolean_t fixed; 219 struct vm_map *submap; 220 { 221 int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0); 222 223 size = round_page(size); /* round up to pagesize */ 224 225 /* 226 * first allocate a blank spot in the parent map 227 */ 228 229 if (uvm_map(map, min, size, NULL, UVM_UNKNOWN_OFFSET, 0, 230 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 231 UVM_ADV_RANDOM, mapflags)) != 0) { 232 panic("uvm_km_suballoc: unable to allocate space in parent map"); 233 } 234 235 /* 236 * set VM bounds (min is filled in by uvm_map) 237 */ 238 239 *max = *min + size; 240 241 /* 242 * add references to pmap and create or init the submap 243 */ 244 245 pmap_reference(vm_map_pmap(map)); 246 if (submap == NULL) { 247 submap = uvm_map_create(vm_map_pmap(map), *min, *max, flags); 248 if (submap == NULL) 249 panic("uvm_km_suballoc: unable to create submap"); 250 } else { 251 uvm_map_setup(submap, *min, *max, flags); 252 submap->pmap = vm_map_pmap(map); 253 } 254 255 /* 256 * now let uvm_map_submap plug in it... 257 */ 258 259 if (uvm_map_submap(map, *min, *max, submap) != 0) 260 panic("uvm_km_suballoc: submap allocation failed"); 261 262 return(submap); 263 } 264 265 /* 266 * uvm_km_pgremove: remove pages from a kernel uvm_object. 267 * 268 * => when you unmap a part of anonymous kernel memory you want to toss 269 * the pages right away. (this gets called from uvm_unmap_...). 270 */ 271 272 void 273 uvm_km_pgremove(uobj, start, end) 274 struct uvm_object *uobj; 275 vaddr_t start, end; 276 { 277 struct vm_page *pg; 278 voff_t curoff, nextoff; 279 int swpgonlydelta = 0; 280 UVMHIST_FUNC("uvm_km_pgremove"); UVMHIST_CALLED(maphist); 281 282 KASSERT(uobj->pgops == &aobj_pager); 283 simple_lock(&uobj->vmobjlock); 284 285 for (curoff = start; curoff < end; curoff = nextoff) { 286 nextoff = curoff + PAGE_SIZE; 287 pg = uvm_pagelookup(uobj, curoff); 288 if (pg != NULL && pg->flags & PG_BUSY) { 289 pg->flags |= PG_WANTED; 290 UVM_UNLOCK_AND_WAIT(pg, &uobj->vmobjlock, 0, 291 "km_pgrm", 0); 292 simple_lock(&uobj->vmobjlock); 293 nextoff = curoff; 294 continue; 295 } 296 297 /* 298 * free the swap slot, then the page. 299 */ 300 301 if (pg == NULL && 302 uao_find_swslot(uobj, curoff >> PAGE_SHIFT) != 0) { 303 swpgonlydelta++; 304 } 305 uao_dropswap(uobj, curoff >> PAGE_SHIFT); 306 if (pg != NULL) { 307 uvm_lock_pageq(); 308 uvm_pagefree(pg); 309 uvm_unlock_pageq(); 310 } 311 } 312 simple_unlock(&uobj->vmobjlock); 313 314 if (swpgonlydelta > 0) { 315 simple_lock(&uvm.swap_data_lock); 316 KASSERT(uvmexp.swpgonly >= swpgonlydelta); 317 uvmexp.swpgonly -= swpgonlydelta; 318 simple_unlock(&uvm.swap_data_lock); 319 } 320 } 321 322 323 /* 324 * uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for "intrsafe" 325 * maps 326 * 327 * => when you unmap a part of anonymous kernel memory you want to toss 328 * the pages right away. (this is called from uvm_unmap_...). 329 * => none of the pages will ever be busy, and none of them will ever 330 * be on the active or inactive queues (because they have no object). 331 */ 332 333 void 334 uvm_km_pgremove_intrsafe(start, end) 335 vaddr_t start, end; 336 { 337 struct vm_page *pg; 338 paddr_t pa; 339 UVMHIST_FUNC("uvm_km_pgremove_intrsafe"); UVMHIST_CALLED(maphist); 340 341 for (; start < end; start += PAGE_SIZE) { 342 if (!pmap_extract(pmap_kernel(), start, &pa)) { 343 continue; 344 } 345 pg = PHYS_TO_VM_PAGE(pa); 346 KASSERT(pg); 347 KASSERT(pg->uobject == NULL && pg->uanon == NULL); 348 uvm_pagefree(pg); 349 } 350 } 351 352 353 /* 354 * uvm_km_kmemalloc: lower level kernel memory allocator for malloc() 355 * 356 * => we map wired memory into the specified map using the obj passed in 357 * => NOTE: we can return NULL even if we can wait if there is not enough 358 * free VM space in the map... caller should be prepared to handle 359 * this case. 360 * => we return KVA of memory allocated 361 * => flags: NOWAIT, VALLOC - just allocate VA, TRYLOCK - fail if we can't 362 * lock the map 363 */ 364 365 vaddr_t 366 uvm_km_kmemalloc(map, obj, size, flags) 367 struct vm_map *map; 368 struct uvm_object *obj; 369 vsize_t size; 370 int flags; 371 { 372 vaddr_t kva, loopva; 373 vaddr_t offset; 374 vsize_t loopsize; 375 struct vm_page *pg; 376 UVMHIST_FUNC("uvm_km_kmemalloc"); UVMHIST_CALLED(maphist); 377 378 UVMHIST_LOG(maphist," (map=0x%x, obj=0x%x, size=0x%x, flags=%d)", 379 map, obj, size, flags); 380 KASSERT(vm_map_pmap(map) == pmap_kernel()); 381 382 /* 383 * setup for call 384 */ 385 386 size = round_page(size); 387 kva = vm_map_min(map); /* hint */ 388 389 /* 390 * allocate some virtual space 391 */ 392 393 if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET, 394 0, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 395 UVM_ADV_RANDOM, (flags & UVM_KMF_TRYLOCK))) 396 != 0)) { 397 UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0); 398 return(0); 399 } 400 401 /* 402 * if all we wanted was VA, return now 403 */ 404 405 if (flags & UVM_KMF_VALLOC) { 406 UVMHIST_LOG(maphist,"<- done valloc (kva=0x%x)", kva,0,0,0); 407 return(kva); 408 } 409 410 /* 411 * recover object offset from virtual address 412 */ 413 414 offset = kva - vm_map_min(kernel_map); 415 UVMHIST_LOG(maphist, " kva=0x%x, offset=0x%x", kva, offset,0,0); 416 417 /* 418 * now allocate and map in the memory... note that we are the only ones 419 * whom should ever get a handle on this area of VM. 420 */ 421 422 loopva = kva; 423 loopsize = size; 424 while (loopsize) { 425 if (obj) { 426 simple_lock(&obj->vmobjlock); 427 } 428 pg = uvm_pagealloc(obj, offset, NULL, UVM_PGA_USERESERVE); 429 if (__predict_true(pg != NULL)) { 430 pg->flags &= ~PG_BUSY; /* new page */ 431 UVM_PAGE_OWN(pg, NULL); 432 } 433 if (obj) { 434 simple_unlock(&obj->vmobjlock); 435 } 436 437 /* 438 * out of memory? 439 */ 440 441 if (__predict_false(pg == NULL)) { 442 if (flags & UVM_KMF_NOWAIT) { 443 /* free everything! */ 444 uvm_unmap(map, kva, kva + size); 445 return(0); 446 } else { 447 uvm_wait("km_getwait2"); /* sleep here */ 448 continue; 449 } 450 } 451 452 /* 453 * map it in 454 */ 455 456 if (obj == NULL) { 457 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), 458 VM_PROT_ALL); 459 } else { 460 pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg), 461 UVM_PROT_ALL, 462 PMAP_WIRED | VM_PROT_READ | VM_PROT_WRITE); 463 } 464 loopva += PAGE_SIZE; 465 offset += PAGE_SIZE; 466 loopsize -= PAGE_SIZE; 467 } 468 469 pmap_update(pmap_kernel()); 470 471 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 472 return(kva); 473 } 474 475 /* 476 * uvm_km_free: free an area of kernel memory 477 */ 478 479 void 480 uvm_km_free(map, addr, size) 481 struct vm_map *map; 482 vaddr_t addr; 483 vsize_t size; 484 { 485 uvm_unmap(map, trunc_page(addr), round_page(addr+size)); 486 } 487 488 /* 489 * uvm_km_free_wakeup: free an area of kernel memory and wake up 490 * anyone waiting for vm space. 491 * 492 * => XXX: "wanted" bit + unlock&wait on other end? 493 */ 494 495 void 496 uvm_km_free_wakeup(map, addr, size) 497 struct vm_map *map; 498 vaddr_t addr; 499 vsize_t size; 500 { 501 struct vm_map_entry *dead_entries; 502 503 vm_map_lock(map); 504 uvm_unmap_remove(map, trunc_page(addr), round_page(addr + size), 505 &dead_entries); 506 wakeup(map); 507 vm_map_unlock(map); 508 if (dead_entries != NULL) 509 uvm_unmap_detach(dead_entries, 0); 510 } 511 512 /* 513 * uvm_km_alloc1: allocate wired down memory in the kernel map. 514 * 515 * => we can sleep if needed 516 */ 517 518 vaddr_t 519 uvm_km_alloc1(map, size, zeroit) 520 struct vm_map *map; 521 vsize_t size; 522 boolean_t zeroit; 523 { 524 vaddr_t kva, loopva, offset; 525 struct vm_page *pg; 526 UVMHIST_FUNC("uvm_km_alloc1"); UVMHIST_CALLED(maphist); 527 528 UVMHIST_LOG(maphist,"(map=0x%x, size=0x%x)", map, size,0,0); 529 KASSERT(vm_map_pmap(map) == pmap_kernel()); 530 531 size = round_page(size); 532 kva = vm_map_min(map); /* hint */ 533 534 /* 535 * allocate some virtual space 536 */ 537 538 if (__predict_false(uvm_map(map, &kva, size, uvm.kernel_object, 539 UVM_UNKNOWN_OFFSET, 0, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 540 UVM_INH_NONE, UVM_ADV_RANDOM, 541 0)) != 0)) { 542 UVMHIST_LOG(maphist,"<- done (no VM)",0,0,0,0); 543 return(0); 544 } 545 546 /* 547 * recover object offset from virtual address 548 */ 549 550 offset = kva - vm_map_min(kernel_map); 551 UVMHIST_LOG(maphist," kva=0x%x, offset=0x%x", kva, offset,0,0); 552 553 /* 554 * now allocate the memory. 555 */ 556 557 loopva = kva; 558 while (size) { 559 simple_lock(&uvm.kernel_object->vmobjlock); 560 KASSERT(uvm_pagelookup(uvm.kernel_object, offset) == NULL); 561 pg = uvm_pagealloc(uvm.kernel_object, offset, NULL, 0); 562 if (pg) { 563 pg->flags &= ~PG_BUSY; 564 UVM_PAGE_OWN(pg, NULL); 565 } 566 simple_unlock(&uvm.kernel_object->vmobjlock); 567 if (pg == NULL) { 568 uvm_wait("km_alloc1w"); 569 continue; 570 } 571 pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg), 572 UVM_PROT_ALL, PMAP_WIRED | VM_PROT_READ | VM_PROT_WRITE); 573 loopva += PAGE_SIZE; 574 offset += PAGE_SIZE; 575 size -= PAGE_SIZE; 576 } 577 pmap_update(map->pmap); 578 579 /* 580 * zero on request (note that "size" is now zero due to the above loop 581 * so we need to subtract kva from loopva to reconstruct the size). 582 */ 583 584 if (zeroit) 585 memset((caddr_t)kva, 0, loopva - kva); 586 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 587 return(kva); 588 } 589 590 /* 591 * uvm_km_valloc: allocate zero-fill memory in the kernel's address space 592 * 593 * => memory is not allocated until fault time 594 */ 595 596 vaddr_t 597 uvm_km_valloc(map, size) 598 struct vm_map *map; 599 vsize_t size; 600 { 601 return(uvm_km_valloc_align(map, size, 0)); 602 } 603 604 vaddr_t 605 uvm_km_valloc_align(map, size, align) 606 struct vm_map *map; 607 vsize_t size; 608 vsize_t align; 609 { 610 vaddr_t kva; 611 UVMHIST_FUNC("uvm_km_valloc"); UVMHIST_CALLED(maphist); 612 613 UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0); 614 KASSERT(vm_map_pmap(map) == pmap_kernel()); 615 616 size = round_page(size); 617 kva = vm_map_min(map); /* hint */ 618 619 /* 620 * allocate some virtual space. will be demand filled by kernel_object. 621 */ 622 623 if (__predict_false(uvm_map(map, &kva, size, uvm.kernel_object, 624 UVM_UNKNOWN_OFFSET, align, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 625 UVM_INH_NONE, UVM_ADV_RANDOM, 626 0)) != 0)) { 627 UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0); 628 return(0); 629 } 630 631 UVMHIST_LOG(maphist, "<- done (kva=0x%x)", kva,0,0,0); 632 return(kva); 633 } 634 635 /* 636 * uvm_km_valloc_wait: allocate zero-fill memory in the kernel's address space 637 * 638 * => memory is not allocated until fault time 639 * => if no room in map, wait for space to free, unless requested size 640 * is larger than map (in which case we return 0) 641 */ 642 643 vaddr_t 644 uvm_km_valloc_prefer_wait(map, size, prefer) 645 struct vm_map *map; 646 vsize_t size; 647 voff_t prefer; 648 { 649 vaddr_t kva; 650 UVMHIST_FUNC("uvm_km_valloc_prefer_wait"); UVMHIST_CALLED(maphist); 651 652 UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0); 653 KASSERT(vm_map_pmap(map) == pmap_kernel()); 654 655 size = round_page(size); 656 if (size > vm_map_max(map) - vm_map_min(map)) 657 return(0); 658 659 for (;;) { 660 kva = vm_map_min(map); /* hint */ 661 662 /* 663 * allocate some virtual space. will be demand filled 664 * by kernel_object. 665 */ 666 667 if (__predict_true(uvm_map(map, &kva, size, uvm.kernel_object, 668 prefer, 0, UVM_MAPFLAG(UVM_PROT_ALL, 669 UVM_PROT_ALL, UVM_INH_NONE, UVM_ADV_RANDOM, 0)) 670 == 0)) { 671 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 672 return(kva); 673 } 674 675 /* 676 * failed. sleep for a while (on map) 677 */ 678 679 UVMHIST_LOG(maphist,"<<<sleeping>>>",0,0,0,0); 680 tsleep((caddr_t)map, PVM, "vallocwait", 0); 681 } 682 /*NOTREACHED*/ 683 } 684 685 vaddr_t 686 uvm_km_valloc_wait(map, size) 687 struct vm_map *map; 688 vsize_t size; 689 { 690 return uvm_km_valloc_prefer_wait(map, size, UVM_UNKNOWN_OFFSET); 691 } 692 693 /* Sanity; must specify both or none. */ 694 #if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \ 695 (!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE)) 696 #error Must specify MAP and UNMAP together. 697 #endif 698 699 /* 700 * uvm_km_alloc_poolpage: allocate a page for the pool allocator 701 * 702 * => if the pmap specifies an alternate mapping method, we use it. 703 */ 704 705 /* ARGSUSED */ 706 vaddr_t 707 uvm_km_alloc_poolpage1(map, obj, waitok) 708 struct vm_map *map; 709 struct uvm_object *obj; 710 boolean_t waitok; 711 { 712 #if defined(PMAP_MAP_POOLPAGE) 713 struct vm_page *pg; 714 vaddr_t va; 715 716 again: 717 pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_USERESERVE); 718 if (__predict_false(pg == NULL)) { 719 if (waitok) { 720 uvm_wait("plpg"); 721 goto again; 722 } else 723 return (0); 724 } 725 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 726 if (__predict_false(va == 0)) 727 uvm_pagefree(pg); 728 return (va); 729 #else 730 vaddr_t va; 731 int s; 732 733 /* 734 * NOTE: We may be called with a map that doens't require splvm 735 * protection (e.g. kernel_map). However, it does not hurt to 736 * go to splvm in this case (since unprocted maps will never be 737 * accessed in interrupt context). 738 * 739 * XXX We may want to consider changing the interface to this 740 * XXX function. 741 */ 742 743 s = splvm(); 744 va = uvm_km_kmemalloc(map, obj, PAGE_SIZE, waitok ? 0 : UVM_KMF_NOWAIT); 745 splx(s); 746 return (va); 747 #endif /* PMAP_MAP_POOLPAGE */ 748 } 749 750 /* 751 * uvm_km_free_poolpage: free a previously allocated pool page 752 * 753 * => if the pmap specifies an alternate unmapping method, we use it. 754 */ 755 756 /* ARGSUSED */ 757 void 758 uvm_km_free_poolpage1(map, addr) 759 struct vm_map *map; 760 vaddr_t addr; 761 { 762 #if defined(PMAP_UNMAP_POOLPAGE) 763 paddr_t pa; 764 765 pa = PMAP_UNMAP_POOLPAGE(addr); 766 uvm_pagefree(PHYS_TO_VM_PAGE(pa)); 767 #else 768 int s; 769 770 /* 771 * NOTE: We may be called with a map that doens't require splvm 772 * protection (e.g. kernel_map). However, it does not hurt to 773 * go to splvm in this case (since unprocted maps will never be 774 * accessed in interrupt context). 775 * 776 * XXX We may want to consider changing the interface to this 777 * XXX function. 778 */ 779 780 s = splvm(); 781 uvm_km_free(map, addr, PAGE_SIZE); 782 splx(s); 783 #endif /* PMAP_UNMAP_POOLPAGE */ 784 } 785