1 /* $OpenBSD: uvm_km.c,v 1.14 2001/08/11 10:57:22 art Exp $ */ 2 /* $NetBSD: uvm_km.c,v 1.35 2000/05/08 23:10:20 thorpej Exp $ */ 3 4 /* 5 * Copyright (c) 1997 Charles D. Cranor and Washington University. 6 * Copyright (c) 1991, 1993, The Regents of the University of California. 7 * 8 * All rights reserved. 9 * 10 * This code is derived from software contributed to Berkeley by 11 * The Mach Operating System project at Carnegie-Mellon University. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by Charles D. Cranor, 24 * Washington University, the University of California, Berkeley and 25 * its contributors. 26 * 4. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * @(#)vm_kern.c 8.3 (Berkeley) 1/12/94 43 * from: Id: uvm_km.c,v 1.1.2.14 1998/02/06 05:19:27 chs Exp 44 * 45 * 46 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 47 * All rights reserved. 48 * 49 * Permission to use, copy, modify and distribute this software and 50 * its documentation is hereby granted, provided that both the copyright 51 * notice and this permission notice appear in all copies of the 52 * software, derivative works or modified versions, and any portions 53 * thereof, and that both notices appear in supporting documentation. 54 * 55 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 56 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 57 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 58 * 59 * Carnegie Mellon requests users of this software to return to 60 * 61 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 62 * School of Computer Science 63 * Carnegie Mellon University 64 * Pittsburgh PA 15213-3890 65 * 66 * any improvements or extensions that they make and grant Carnegie the 67 * rights to redistribute these changes. 68 */ 69 70 /* 71 * uvm_km.c: handle kernel memory allocation and management 72 */ 73 74 /* 75 * overview of kernel memory management: 76 * 77 * the kernel virtual address space is mapped by "kernel_map." kernel_map 78 * starts at VM_MIN_KERNEL_ADDRESS and goes to VM_MAX_KERNEL_ADDRESS. 79 * note that VM_MIN_KERNEL_ADDRESS is equal to vm_map_min(kernel_map). 80 * 81 * the kernel_map has several "submaps." submaps can only appear in 82 * the kernel_map (user processes can't use them). submaps "take over" 83 * the management of a sub-range of the kernel's address space. submaps 84 * are typically allocated at boot time and are never released. kernel 85 * virtual address space that is mapped by a submap is locked by the 86 * submap's lock -- not the kernel_map's lock. 87 * 88 * thus, the useful feature of submaps is that they allow us to break 89 * up the locking and protection of the kernel address space into smaller 90 * chunks. 91 * 92 * the vm system has several standard kernel submaps, including: 93 * kmem_map => contains only wired kernel memory for the kernel 94 * malloc. *** access to kmem_map must be protected 95 * by splimp() because we are allowed to call malloc() 96 * at interrupt time *** 97 * mb_map => memory for large mbufs, *** protected by splimp *** 98 * pager_map => used to map "buf" structures into kernel space 99 * exec_map => used during exec to handle exec args 100 * etc... 101 * 102 * the kernel allocates its private memory out of special uvm_objects whose 103 * reference count is set to UVM_OBJ_KERN (thus indicating that the objects 104 * are "special" and never die). all kernel objects should be thought of 105 * as large, fixed-sized, sparsely populated uvm_objects. each kernel 106 * object is equal to the size of kernel virtual address space (i.e. the 107 * value "VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS"). 108 * 109 * most kernel private memory lives in kernel_object. the only exception 110 * to this is for memory that belongs to submaps that must be protected 111 * by splimp(). each of these submaps has their own private kernel 112 * object (e.g. kmem_object, mb_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 * note that the offsets in kmem_object and mb_object also follow this 132 * rule. this means that the offsets for kmem_object must fall in the 133 * range of [vm_map_min(kmem_object) - vm_map_min(kernel_map)] to 134 * [vm_map_max(kmem_object) - vm_map_min(kernel_map)], so the offsets 135 * in those objects will typically not start at zero. 136 * 137 * kernel object have one other special property: when the kernel virtual 138 * memory mapping them is unmapped, the backing memory in the object is 139 * freed right away. this is done with the uvm_km_pgremove() function. 140 * this has to be done because there is no backing store for kernel pages 141 * and no need to save them after they are no longer referenced. 142 */ 143 144 #include <sys/param.h> 145 #include <sys/systm.h> 146 #include <sys/proc.h> 147 148 #include <vm/vm.h> 149 #include <vm/vm_page.h> 150 #include <vm/vm_kern.h> 151 152 #include <uvm/uvm.h> 153 154 /* 155 * global data structures 156 */ 157 158 vm_map_t kernel_map = NULL; 159 160 struct vmi_list vmi_list; 161 simple_lock_data_t vmi_list_slock; 162 163 /* 164 * local data structues 165 */ 166 167 static struct vm_map kernel_map_store; 168 static struct uvm_object kmem_object_store; 169 static struct uvm_object mb_object_store; 170 171 /* 172 * All pager operations here are NULL, but the object must have 173 * a pager ops vector associated with it; various places assume 174 * it to be so. 175 */ 176 static struct uvm_pagerops km_pager; 177 178 /* 179 * uvm_km_init: init kernel maps and objects to reflect reality (i.e. 180 * KVM already allocated for text, data, bss, and static data structures). 181 * 182 * => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS. 183 * we assume that [min -> start] has already been allocated and that 184 * "end" is the end. 185 */ 186 187 void 188 uvm_km_init(start, end) 189 vaddr_t start, end; 190 { 191 vaddr_t base = VM_MIN_KERNEL_ADDRESS; 192 193 /* 194 * first, initialize the interrupt-safe map list. 195 */ 196 LIST_INIT(&vmi_list); 197 simple_lock_init(&vmi_list_slock); 198 199 /* 200 * next, init kernel memory objects. 201 */ 202 203 /* kernel_object: for pageable anonymous kernel memory */ 204 uao_init(); 205 uvm.kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS - 206 VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ); 207 208 /* 209 * kmem_object: for use by the kernel malloc(). Memory is always 210 * wired, and this object (and the kmem_map) can be accessed at 211 * interrupt time. 212 */ 213 simple_lock_init(&kmem_object_store.vmobjlock); 214 kmem_object_store.pgops = &km_pager; 215 TAILQ_INIT(&kmem_object_store.memq); 216 kmem_object_store.uo_npages = 0; 217 /* we are special. we never die */ 218 kmem_object_store.uo_refs = UVM_OBJ_KERN_INTRSAFE; 219 uvmexp.kmem_object = &kmem_object_store; 220 221 /* 222 * mb_object: for mbuf cluster pages on platforms which use the 223 * mb_map. Memory is always wired, and this object (and the mb_map) 224 * can be accessed at interrupt time. 225 */ 226 simple_lock_init(&mb_object_store.vmobjlock); 227 mb_object_store.pgops = &km_pager; 228 TAILQ_INIT(&mb_object_store.memq); 229 mb_object_store.uo_npages = 0; 230 /* we are special. we never die */ 231 mb_object_store.uo_refs = UVM_OBJ_KERN_INTRSAFE; 232 uvmexp.mb_object = &mb_object_store; 233 234 /* 235 * init the map and reserve allready allocated kernel space 236 * before installing. 237 */ 238 239 uvm_map_setup(&kernel_map_store, base, end, VM_MAP_PAGEABLE); 240 kernel_map_store.pmap = pmap_kernel(); 241 if (uvm_map(&kernel_map_store, &base, start - base, NULL, 242 UVM_UNKNOWN_OFFSET, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 243 UVM_INH_NONE, UVM_ADV_RANDOM,UVM_FLAG_FIXED)) != KERN_SUCCESS) 244 panic("uvm_km_init: could not reserve space for kernel"); 245 246 /* 247 * install! 248 */ 249 250 kernel_map = &kernel_map_store; 251 } 252 253 /* 254 * uvm_km_suballoc: allocate a submap in the kernel map. once a submap 255 * is allocated all references to that area of VM must go through it. this 256 * allows the locking of VAs in kernel_map to be broken up into regions. 257 * 258 * => if `fixed' is true, *min specifies where the region described 259 * by the submap must start 260 * => if submap is non NULL we use that as the submap, otherwise we 261 * alloc a new map 262 */ 263 struct vm_map * 264 uvm_km_suballoc(map, min, max, size, flags, fixed, submap) 265 struct vm_map *map; 266 vaddr_t *min, *max; /* OUT, OUT */ 267 vsize_t size; 268 int flags; 269 boolean_t fixed; 270 struct vm_map *submap; 271 { 272 int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0); 273 274 size = round_page(size); /* round up to pagesize */ 275 276 /* 277 * first allocate a blank spot in the parent map 278 */ 279 280 if (uvm_map(map, min, size, NULL, UVM_UNKNOWN_OFFSET, 281 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 282 UVM_ADV_RANDOM, mapflags)) != KERN_SUCCESS) { 283 panic("uvm_km_suballoc: unable to allocate space in parent map"); 284 } 285 286 /* 287 * set VM bounds (min is filled in by uvm_map) 288 */ 289 290 *max = *min + size; 291 292 /* 293 * add references to pmap and create or init the submap 294 */ 295 296 pmap_reference(vm_map_pmap(map)); 297 if (submap == NULL) { 298 submap = uvm_map_create(vm_map_pmap(map), *min, *max, flags); 299 if (submap == NULL) 300 panic("uvm_km_suballoc: unable to create submap"); 301 } else { 302 uvm_map_setup(submap, *min, *max, flags); 303 submap->pmap = vm_map_pmap(map); 304 } 305 306 /* 307 * now let uvm_map_submap plug in it... 308 */ 309 310 if (uvm_map_submap(map, *min, *max, submap) != KERN_SUCCESS) 311 panic("uvm_km_suballoc: submap allocation failed"); 312 313 return(submap); 314 } 315 316 /* 317 * uvm_km_pgremove: remove pages from a kernel uvm_object. 318 * 319 * => when you unmap a part of anonymous kernel memory you want to toss 320 * the pages right away. (this gets called from uvm_unmap_...). 321 */ 322 323 #define UKM_HASH_PENALTY 4 /* a guess */ 324 325 void 326 uvm_km_pgremove(uobj, start, end) 327 struct uvm_object *uobj; 328 vaddr_t start, end; 329 { 330 boolean_t by_list; 331 struct vm_page *pp, *ppnext; 332 vaddr_t curoff; 333 UVMHIST_FUNC("uvm_km_pgremove"); UVMHIST_CALLED(maphist); 334 335 simple_lock(&uobj->vmobjlock); /* lock object */ 336 337 #ifdef DIAGNOSTIC 338 if (__predict_false(uobj->pgops != &aobj_pager)) 339 panic("uvm_km_pgremove: object %p not an aobj", uobj); 340 #endif 341 342 /* choose cheapest traversal */ 343 by_list = (uobj->uo_npages <= 344 ((end - start) >> PAGE_SHIFT) * UKM_HASH_PENALTY); 345 346 if (by_list) 347 goto loop_by_list; 348 349 /* by hash */ 350 351 for (curoff = start ; curoff < end ; curoff += PAGE_SIZE) { 352 pp = uvm_pagelookup(uobj, curoff); 353 if (pp == NULL) 354 continue; 355 356 UVMHIST_LOG(maphist," page 0x%x, busy=%d", pp, 357 pp->flags & PG_BUSY, 0, 0); 358 359 /* now do the actual work */ 360 if (pp->flags & PG_BUSY) { 361 /* owner must check for this when done */ 362 pp->flags |= PG_RELEASED; 363 } else { 364 /* free the swap slot... */ 365 uao_dropswap(uobj, curoff >> PAGE_SHIFT); 366 367 /* 368 * ...and free the page; note it may be on the 369 * active or inactive queues. 370 */ 371 uvm_lock_pageq(); 372 uvm_pagefree(pp); 373 uvm_unlock_pageq(); 374 } 375 /* done */ 376 } 377 simple_unlock(&uobj->vmobjlock); 378 return; 379 380 loop_by_list: 381 382 for (pp = uobj->memq.tqh_first ; pp != NULL ; pp = ppnext) { 383 ppnext = pp->listq.tqe_next; 384 if (pp->offset < start || pp->offset >= end) { 385 continue; 386 } 387 388 UVMHIST_LOG(maphist," page 0x%x, busy=%d", pp, 389 pp->flags & PG_BUSY, 0, 0); 390 391 /* now do the actual work */ 392 if (pp->flags & PG_BUSY) { 393 /* owner must check for this when done */ 394 pp->flags |= PG_RELEASED; 395 } else { 396 /* free the swap slot... */ 397 uao_dropswap(uobj, pp->offset >> PAGE_SHIFT); 398 399 /* 400 * ...and free the page; note it may be on the 401 * active or inactive queues. 402 */ 403 uvm_lock_pageq(); 404 uvm_pagefree(pp); 405 uvm_unlock_pageq(); 406 } 407 /* done */ 408 } 409 simple_unlock(&uobj->vmobjlock); 410 return; 411 } 412 413 414 /* 415 * uvm_km_pgremove_intrsafe: like uvm_km_pgremove(), but for "intrsafe" 416 * objects 417 * 418 * => when you unmap a part of anonymous kernel memory you want to toss 419 * the pages right away. (this gets called from uvm_unmap_...). 420 * => none of the pages will ever be busy, and none of them will ever 421 * be on the active or inactive queues (because these objects are 422 * never allowed to "page"). 423 */ 424 425 void 426 uvm_km_pgremove_intrsafe(uobj, start, end) 427 struct uvm_object *uobj; 428 vaddr_t start, end; 429 { 430 boolean_t by_list; 431 struct vm_page *pp, *ppnext; 432 vaddr_t curoff; 433 UVMHIST_FUNC("uvm_km_pgremove_intrsafe"); UVMHIST_CALLED(maphist); 434 435 simple_lock(&uobj->vmobjlock); /* lock object */ 436 437 #ifdef DIAGNOSTIC 438 if (__predict_false(UVM_OBJ_IS_INTRSAFE_OBJECT(uobj) == 0)) 439 panic("uvm_km_pgremove_intrsafe: object %p not intrsafe", uobj); 440 #endif 441 442 /* choose cheapest traversal */ 443 by_list = (uobj->uo_npages <= 444 ((end - start) >> PAGE_SHIFT) * UKM_HASH_PENALTY); 445 446 if (by_list) 447 goto loop_by_list; 448 449 /* by hash */ 450 451 for (curoff = start ; curoff < end ; curoff += PAGE_SIZE) { 452 pp = uvm_pagelookup(uobj, curoff); 453 if (pp == NULL) 454 continue; 455 456 UVMHIST_LOG(maphist," page 0x%x, busy=%d", pp, 457 pp->flags & PG_BUSY, 0, 0); 458 #ifdef DIAGNOSTIC 459 if (__predict_false(pp->flags & PG_BUSY)) 460 panic("uvm_km_pgremove_intrsafe: busy page"); 461 if (__predict_false(pp->pqflags & PQ_ACTIVE)) 462 panic("uvm_km_pgremove_intrsafe: active page"); 463 if (__predict_false(pp->pqflags & PQ_INACTIVE)) 464 panic("uvm_km_pgremove_intrsafe: inactive page"); 465 #endif 466 467 /* free the page */ 468 uvm_pagefree(pp); 469 } 470 simple_unlock(&uobj->vmobjlock); 471 return; 472 473 loop_by_list: 474 475 for (pp = uobj->memq.tqh_first ; pp != NULL ; pp = ppnext) { 476 ppnext = pp->listq.tqe_next; 477 if (pp->offset < start || pp->offset >= end) { 478 continue; 479 } 480 481 UVMHIST_LOG(maphist," page 0x%x, busy=%d", pp, 482 pp->flags & PG_BUSY, 0, 0); 483 484 #ifdef DIAGNOSTIC 485 if (__predict_false(pp->flags & PG_BUSY)) 486 panic("uvm_km_pgremove_intrsafe: busy page"); 487 if (__predict_false(pp->pqflags & PQ_ACTIVE)) 488 panic("uvm_km_pgremove_intrsafe: active page"); 489 if (__predict_false(pp->pqflags & PQ_INACTIVE)) 490 panic("uvm_km_pgremove_intrsafe: inactive page"); 491 #endif 492 493 /* free the page */ 494 uvm_pagefree(pp); 495 } 496 simple_unlock(&uobj->vmobjlock); 497 return; 498 } 499 500 501 /* 502 * uvm_km_kmemalloc: lower level kernel memory allocator for malloc() 503 * 504 * => we map wired memory into the specified map using the obj passed in 505 * => NOTE: we can return NULL even if we can wait if there is not enough 506 * free VM space in the map... caller should be prepared to handle 507 * this case. 508 * => we return KVA of memory allocated 509 * => flags: NOWAIT, VALLOC - just allocate VA, TRYLOCK - fail if we can't 510 * lock the map 511 */ 512 513 vaddr_t 514 uvm_km_kmemalloc(map, obj, size, flags) 515 vm_map_t map; 516 struct uvm_object *obj; 517 vsize_t size; 518 int flags; 519 { 520 vaddr_t kva, loopva; 521 vaddr_t offset; 522 struct vm_page *pg; 523 UVMHIST_FUNC("uvm_km_kmemalloc"); UVMHIST_CALLED(maphist); 524 525 526 UVMHIST_LOG(maphist," (map=0x%x, obj=0x%x, size=0x%x, flags=%d)", 527 map, obj, size, flags); 528 #ifdef DIAGNOSTIC 529 /* sanity check */ 530 if (__predict_false(vm_map_pmap(map) != pmap_kernel())) 531 panic("uvm_km_kmemalloc: invalid map"); 532 #endif 533 534 /* 535 * setup for call 536 */ 537 538 size = round_page(size); 539 kva = vm_map_min(map); /* hint */ 540 541 /* 542 * allocate some virtual space 543 */ 544 545 if (__predict_false(uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET, 546 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 547 UVM_ADV_RANDOM, (flags & UVM_KMF_TRYLOCK))) 548 != KERN_SUCCESS)) { 549 UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0); 550 return(0); 551 } 552 553 /* 554 * if all we wanted was VA, return now 555 */ 556 557 if (flags & UVM_KMF_VALLOC) { 558 UVMHIST_LOG(maphist,"<- done valloc (kva=0x%x)", kva,0,0,0); 559 return(kva); 560 } 561 /* 562 * recover object offset from virtual address 563 */ 564 565 offset = kva - vm_map_min(kernel_map); 566 UVMHIST_LOG(maphist, " kva=0x%x, offset=0x%x", kva, offset,0,0); 567 568 /* 569 * now allocate and map in the memory... note that we are the only ones 570 * whom should ever get a handle on this area of VM. 571 */ 572 573 loopva = kva; 574 while (size) { 575 simple_lock(&obj->vmobjlock); 576 pg = uvm_pagealloc(obj, offset, NULL, 0); 577 if (pg) { 578 pg->flags &= ~PG_BUSY; /* new page */ 579 UVM_PAGE_OWN(pg, NULL); 580 } 581 simple_unlock(&obj->vmobjlock); 582 583 /* 584 * out of memory? 585 */ 586 587 if (__predict_false(pg == NULL)) { 588 if (flags & UVM_KMF_NOWAIT) { 589 /* free everything! */ 590 uvm_unmap(map, kva, kva + size); 591 return(0); 592 } else { 593 uvm_wait("km_getwait2"); /* sleep here */ 594 continue; 595 } 596 } 597 598 /* 599 * map it in: note that we call pmap_enter with the map and 600 * object unlocked in case we are kmem_map/kmem_object 601 * (because if pmap_enter wants to allocate out of kmem_object 602 * it will need to lock it itself!) 603 */ 604 if (UVM_OBJ_IS_INTRSAFE_OBJECT(obj)) { 605 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), 606 VM_PROT_ALL); 607 } else { 608 pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg), 609 UVM_PROT_ALL, 610 PMAP_WIRED | VM_PROT_READ | VM_PROT_WRITE); 611 } 612 loopva += PAGE_SIZE; 613 offset += PAGE_SIZE; 614 size -= PAGE_SIZE; 615 } 616 617 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 618 return(kva); 619 } 620 621 /* 622 * uvm_km_free: free an area of kernel memory 623 */ 624 625 void 626 uvm_km_free(map, addr, size) 627 vm_map_t map; 628 vaddr_t addr; 629 vsize_t size; 630 { 631 632 uvm_unmap(map, trunc_page(addr), round_page(addr+size)); 633 } 634 635 /* 636 * uvm_km_free_wakeup: free an area of kernel memory and wake up 637 * anyone waiting for vm space. 638 * 639 * => XXX: "wanted" bit + unlock&wait on other end? 640 */ 641 642 void 643 uvm_km_free_wakeup(map, addr, size) 644 vm_map_t map; 645 vaddr_t addr; 646 vsize_t size; 647 { 648 vm_map_entry_t dead_entries; 649 650 vm_map_lock(map); 651 (void)uvm_unmap_remove(map, trunc_page(addr), round_page(addr+size), 652 &dead_entries); 653 wakeup(map); 654 vm_map_unlock(map); 655 656 if (dead_entries != NULL) 657 uvm_unmap_detach(dead_entries, 0); 658 } 659 660 /* 661 * uvm_km_alloc1: allocate wired down memory in the kernel map. 662 * 663 * => we can sleep if needed 664 */ 665 666 vaddr_t 667 uvm_km_alloc1(map, size, zeroit) 668 vm_map_t map; 669 vsize_t size; 670 boolean_t zeroit; 671 { 672 vaddr_t kva, loopva, offset; 673 struct vm_page *pg; 674 UVMHIST_FUNC("uvm_km_alloc1"); UVMHIST_CALLED(maphist); 675 676 UVMHIST_LOG(maphist,"(map=0x%x, size=0x%x)", map, size,0,0); 677 678 #ifdef DIAGNOSTIC 679 if (vm_map_pmap(map) != pmap_kernel()) 680 panic("uvm_km_alloc1"); 681 #endif 682 683 size = round_page(size); 684 kva = vm_map_min(map); /* hint */ 685 686 /* 687 * allocate some virtual space 688 */ 689 690 if (__predict_false(uvm_map(map, &kva, size, uvm.kernel_object, 691 UVM_UNKNOWN_OFFSET, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 692 UVM_INH_NONE, UVM_ADV_RANDOM, 693 0)) != KERN_SUCCESS)) { 694 UVMHIST_LOG(maphist,"<- done (no VM)",0,0,0,0); 695 return(0); 696 } 697 698 /* 699 * recover object offset from virtual address 700 */ 701 702 offset = kva - vm_map_min(kernel_map); 703 UVMHIST_LOG(maphist," kva=0x%x, offset=0x%x", kva, offset,0,0); 704 705 /* 706 * now allocate the memory. we must be careful about released pages. 707 */ 708 709 loopva = kva; 710 while (size) { 711 simple_lock(&uvm.kernel_object->vmobjlock); 712 pg = uvm_pagelookup(uvm.kernel_object, offset); 713 714 /* 715 * if we found a page in an unallocated region, it must be 716 * released 717 */ 718 if (pg) { 719 if ((pg->flags & PG_RELEASED) == 0) 720 panic("uvm_km_alloc1: non-released page"); 721 pg->flags |= PG_WANTED; 722 UVM_UNLOCK_AND_WAIT(pg, &uvm.kernel_object->vmobjlock, 723 FALSE, "km_alloc", 0); 724 continue; /* retry */ 725 } 726 727 /* allocate ram */ 728 pg = uvm_pagealloc(uvm.kernel_object, offset, NULL, 0); 729 if (pg) { 730 pg->flags &= ~PG_BUSY; /* new page */ 731 UVM_PAGE_OWN(pg, NULL); 732 } 733 simple_unlock(&uvm.kernel_object->vmobjlock); 734 if (__predict_false(pg == NULL)) { 735 uvm_wait("km_alloc1w"); /* wait for memory */ 736 continue; 737 } 738 739 /* 740 * map it in; note we're never called with an intrsafe 741 * object, so we always use regular old pmap_enter(). 742 */ 743 pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg), 744 UVM_PROT_ALL, PMAP_WIRED | VM_PROT_READ | VM_PROT_WRITE); 745 746 loopva += PAGE_SIZE; 747 offset += PAGE_SIZE; 748 size -= PAGE_SIZE; 749 } 750 751 /* 752 * zero on request (note that "size" is now zero due to the above loop 753 * so we need to subtract kva from loopva to reconstruct the size). 754 */ 755 756 if (zeroit) 757 memset((caddr_t)kva, 0, loopva - kva); 758 759 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 760 return(kva); 761 } 762 763 /* 764 * uvm_km_valloc: allocate zero-fill memory in the kernel's address space 765 * 766 * => memory is not allocated until fault time 767 */ 768 769 vaddr_t 770 uvm_km_valloc(map, size) 771 vm_map_t map; 772 vsize_t size; 773 { 774 vaddr_t kva; 775 UVMHIST_FUNC("uvm_km_valloc"); UVMHIST_CALLED(maphist); 776 777 UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0); 778 779 #ifdef DIAGNOSTIC 780 if (__predict_false(vm_map_pmap(map) != pmap_kernel())) 781 panic("uvm_km_valloc"); 782 #endif 783 784 size = round_page(size); 785 kva = vm_map_min(map); /* hint */ 786 787 /* 788 * allocate some virtual space. will be demand filled by kernel_object. 789 */ 790 791 if (__predict_false(uvm_map(map, &kva, size, uvm.kernel_object, 792 UVM_UNKNOWN_OFFSET, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 793 UVM_INH_NONE, UVM_ADV_RANDOM, 794 0)) != KERN_SUCCESS)) { 795 UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0); 796 return(0); 797 } 798 799 UVMHIST_LOG(maphist, "<- done (kva=0x%x)", kva,0,0,0); 800 return(kva); 801 } 802 803 /* 804 * uvm_km_valloc_wait: allocate zero-fill memory in the kernel's address space 805 * 806 * => memory is not allocated until fault time 807 * => if no room in map, wait for space to free, unless requested size 808 * is larger than map (in which case we return 0) 809 */ 810 811 vaddr_t 812 uvm_km_valloc_wait(map, size) 813 vm_map_t map; 814 vsize_t size; 815 { 816 vaddr_t kva; 817 UVMHIST_FUNC("uvm_km_valloc_wait"); UVMHIST_CALLED(maphist); 818 819 UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0); 820 821 #ifdef DIAGNOSTIC 822 if (__predict_false(vm_map_pmap(map) != pmap_kernel())) 823 panic("uvm_km_valloc_wait"); 824 #endif 825 826 size = round_page(size); 827 if (size > vm_map_max(map) - vm_map_min(map)) 828 return(0); 829 830 while (1) { 831 kva = vm_map_min(map); /* hint */ 832 833 /* 834 * allocate some virtual space. will be demand filled 835 * by kernel_object. 836 */ 837 838 if (__predict_true(uvm_map(map, &kva, size, uvm.kernel_object, 839 UVM_UNKNOWN_OFFSET, UVM_MAPFLAG(UVM_PROT_ALL, 840 UVM_PROT_ALL, UVM_INH_NONE, UVM_ADV_RANDOM, 0)) 841 == KERN_SUCCESS)) { 842 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 843 return(kva); 844 } 845 846 /* 847 * failed. sleep for a while (on map) 848 */ 849 850 UVMHIST_LOG(maphist,"<<<sleeping>>>",0,0,0,0); 851 tsleep((caddr_t)map, PVM, "vallocwait", 0); 852 } 853 /*NOTREACHED*/ 854 } 855 856 /* Sanity; must specify both or none. */ 857 #if (defined(PMAP_MAP_POOLPAGE) || defined(PMAP_UNMAP_POOLPAGE)) && \ 858 (!defined(PMAP_MAP_POOLPAGE) || !defined(PMAP_UNMAP_POOLPAGE)) 859 #error Must specify MAP and UNMAP together. 860 #endif 861 862 /* 863 * uvm_km_alloc_poolpage: allocate a page for the pool allocator 864 * 865 * => if the pmap specifies an alternate mapping method, we use it. 866 */ 867 868 /* ARGSUSED */ 869 vaddr_t 870 uvm_km_alloc_poolpage1(map, obj, waitok) 871 vm_map_t map; 872 struct uvm_object *obj; 873 boolean_t waitok; 874 { 875 #if defined(PMAP_MAP_POOLPAGE) 876 struct vm_page *pg; 877 vaddr_t va; 878 879 again: 880 pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_USERESERVE); 881 if (__predict_false(pg == NULL)) { 882 if (waitok) { 883 uvm_wait("plpg"); 884 goto again; 885 } else 886 return (0); 887 } 888 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 889 if (__predict_false(va == 0)) 890 uvm_pagefree(pg); 891 return (va); 892 #else 893 vaddr_t va; 894 int s; 895 896 /* 897 * NOTE: We may be called with a map that doens't require splimp 898 * protection (e.g. kernel_map). However, it does not hurt to 899 * go to splimp in this case (since unprocted maps will never be 900 * accessed in interrupt context). 901 * 902 * XXX We may want to consider changing the interface to this 903 * XXX function. 904 */ 905 906 s = splimp(); 907 va = uvm_km_kmemalloc(map, obj, PAGE_SIZE, waitok ? 0 : UVM_KMF_NOWAIT); 908 splx(s); 909 return (va); 910 #endif /* PMAP_MAP_POOLPAGE */ 911 } 912 913 /* 914 * uvm_km_free_poolpage: free a previously allocated pool page 915 * 916 * => if the pmap specifies an alternate unmapping method, we use it. 917 */ 918 919 /* ARGSUSED */ 920 void 921 uvm_km_free_poolpage1(map, addr) 922 vm_map_t map; 923 vaddr_t addr; 924 { 925 #if defined(PMAP_UNMAP_POOLPAGE) 926 paddr_t pa; 927 928 pa = PMAP_UNMAP_POOLPAGE(addr); 929 uvm_pagefree(PHYS_TO_VM_PAGE(pa)); 930 #else 931 int s; 932 933 /* 934 * NOTE: We may be called with a map that doens't require splimp 935 * protection (e.g. kernel_map). However, it does not hurt to 936 * go to splimp in this case (since unprocted maps will never be 937 * accessed in interrupt context). 938 * 939 * XXX We may want to consider changing the interface to this 940 * XXX function. 941 */ 942 943 s = splimp(); 944 uvm_km_free(map, addr, PAGE_SIZE); 945 splx(s); 946 #endif /* PMAP_UNMAP_POOLPAGE */ 947 } 948