uvm_km.c revision 1.7
1 /* $NetBSD: uvm_km.c,v 1.7 1998/02/24 15:58:09 chuck Exp $ */ 2 3 /* 4 * XXXCDC: "ROUGH DRAFT" QUALITY UVM PRE-RELEASE FILE! 5 * >>>USE AT YOUR OWN RISK, WORK IS NOT FINISHED<<< 6 */ 7 /* 8 * Copyright (c) 1997 Charles D. Cranor and Washington University. 9 * Copyright (c) 1991, 1993, The Regents of the University of California. 10 * 11 * All rights reserved. 12 * 13 * This code is derived from software contributed to Berkeley by 14 * The Mach Operating System project at Carnegie-Mellon University. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 3. All advertising materials mentioning features or use of this software 25 * must display the following acknowledgement: 26 * This product includes software developed by Charles D. Cranor, 27 * Washington University, the University of California, Berkeley and 28 * its contributors. 29 * 4. Neither the name of the University nor the names of its contributors 30 * may be used to endorse or promote products derived from this software 31 * without specific prior written permission. 32 * 33 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 34 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 35 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 36 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 37 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 38 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 39 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 40 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 41 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 42 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 43 * SUCH DAMAGE. 44 * 45 * @(#)vm_kern.c 8.3 (Berkeley) 1/12/94 46 * from: Id: uvm_km.c,v 1.1.2.14 1998/02/06 05:19:27 chs Exp 47 * 48 * 49 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 50 * All rights reserved. 51 * 52 * Permission to use, copy, modify and distribute this software and 53 * its documentation is hereby granted, provided that both the copyright 54 * notice and this permission notice appear in all copies of the 55 * software, derivative works or modified versions, and any portions 56 * thereof, and that both notices appear in supporting documentation. 57 * 58 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 59 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 60 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 61 * 62 * Carnegie Mellon requests users of this software to return to 63 * 64 * Software Distribution Coordinator or Software.Distribution (at) CS.CMU.EDU 65 * School of Computer Science 66 * Carnegie Mellon University 67 * Pittsburgh PA 15213-3890 68 * 69 * any improvements or extensions that they make and grant Carnegie the 70 * rights to redistribute these changes. 71 */ 72 73 #include "opt_uvmhist.h" 74 #include "opt_pmap_new.h" 75 76 /* 77 * uvm_km.c: handle kernel memory allocation and management 78 */ 79 80 /* 81 * overview of kernel memory management: 82 * 83 * the kernel virtual address space is mapped by "kernel_map." kernel_map 84 * starts at VM_MIN_KERNEL_ADDRESS and goes to VM_MAX_KERNEL_ADDRESS. 85 * note that VM_MIN_KERNEL_ADDRESS is equal to vm_map_min(kernel_map). 86 * 87 * the kernel_map has several "submaps." submaps can only appear in 88 * the kernel_map (user processes can't use them). submaps "take over" 89 * the management of a sub-range of the kernel's address space. submaps 90 * are typically allocated at boot time and are never released. kernel 91 * virtual address space that is mapped by a submap is locked by the 92 * submap's lock -- not the kernel_map's lock. 93 * 94 * thus, the useful feature of submaps is that they allow us to break 95 * up the locking and protection of the kernel address space into smaller 96 * chunks. 97 * 98 * the vm system has several standard kernel submaps, including: 99 * kmem_map => contains only wired kernel memory for the kernel 100 * malloc. *** access to kmem_map must be protected 101 * by splimp() because we are allowed to call malloc() 102 * at interrupt time *** 103 * mb_map => memory for large mbufs, *** protected by splimp *** 104 * pager_map => used to map "buf" structures into kernel space 105 * exec_map => used during exec to handle exec args 106 * etc... 107 * 108 * the kernel allocates its private memory out of special uvm_objects whose 109 * reference count is set to UVM_OBJ_KERN (thus indicating that the objects 110 * are "special" and never die). all kernel objects should be thought of 111 * as large, fixed-sized, sparsely populated uvm_objects. each kernel 112 * object is equal to the size of kernel virtual address space (i.e. the 113 * value "VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS"). 114 * 115 * most kernel private memory lives in kernel_object. the only exception 116 * to this is for memory that belongs to submaps that must be protected 117 * by splimp(). each of these submaps has their own private kernel 118 * object (e.g. kmem_object, mb_object). 119 * 120 * note that just because a kernel object spans the entire kernel virutal 121 * address space doesn't mean that it has to be mapped into the entire space. 122 * large chunks of a kernel object's space go unused either because 123 * that area of kernel VM is unmapped, or there is some other type of 124 * object mapped into that range (e.g. a vnode). for submap's kernel 125 * objects, the only part of the object that can ever be populated is the 126 * offsets that are managed by the submap. 127 * 128 * note that the "offset" in a kernel object is always the kernel virtual 129 * address minus the VM_MIN_KERNEL_ADDRESS (aka vm_map_min(kernel_map)). 130 * example: 131 * suppose VM_MIN_KERNEL_ADDRESS is 0xf8000000 and the kernel does a 132 * uvm_km_alloc(kernel_map, PAGE_SIZE) [allocate 1 wired down page in the 133 * kernel map]. if uvm_km_alloc returns virtual address 0xf8235000, 134 * then that means that the page at offset 0x235000 in kernel_object is 135 * mapped at 0xf8235000. 136 * 137 * note that the offsets in kmem_object and mb_object also follow this 138 * rule. this means that the offsets for kmem_object must fall in the 139 * range of [vm_map_min(kmem_object) - vm_map_min(kernel_map)] to 140 * [vm_map_max(kmem_object) - vm_map_min(kernel_map)], so the offsets 141 * in those objects will typically not start at zero. 142 * 143 * kernel object have one other special property: when the kernel virtual 144 * memory mapping them is unmapped, the backing memory in the object is 145 * freed right away. this is done with the uvm_km_pgremove() function. 146 * this has to be done because there is no backing store for kernel pages 147 * and no need to save them after they are no longer referenced. 148 */ 149 150 #include <sys/param.h> 151 #include <sys/systm.h> 152 #include <sys/proc.h> 153 154 #include <vm/vm.h> 155 #include <vm/vm_page.h> 156 #include <vm/vm_kern.h> 157 158 #include <uvm/uvm.h> 159 160 /* 161 * global data structures 162 */ 163 164 vm_map_t kernel_map = NULL; 165 166 /* 167 * local functions 168 */ 169 170 static int uvm_km_get __P((struct uvm_object *, vm_offset_t, 171 vm_page_t *, int *, int, vm_prot_t, int, int)); 172 /* 173 * local data structues 174 */ 175 176 static struct vm_map kernel_map_store; 177 static struct uvm_object kmem_object_store; 178 static struct uvm_object mb_object_store; 179 180 static struct uvm_pagerops km_pager = { 181 NULL, /* init */ 182 NULL, /* attach */ 183 NULL, /* reference */ 184 NULL, /* detach */ 185 NULL, /* fault */ 186 NULL, /* flush */ 187 uvm_km_get, /* get */ 188 /* ... rest are NULL */ 189 }; 190 191 /* 192 * uvm_km_get: pager get function for kernel objects 193 * 194 * => currently we do not support pageout to the swap area, so this 195 * pager is very simple. eventually we may want an anonymous 196 * object pager which will do paging. 197 * => XXXCDC: this pager should be phased out in favor of the aobj pager 198 */ 199 200 201 static int uvm_km_get(uobj, offset, pps, npagesp, centeridx, access_type, 202 advice, flags) 203 204 struct uvm_object *uobj; 205 vm_offset_t offset; 206 struct vm_page **pps; 207 int *npagesp; 208 int centeridx, advice, flags; 209 vm_prot_t access_type; 210 211 { 212 vm_offset_t current_offset; 213 vm_page_t ptmp; 214 int lcv, gotpages, maxpages; 215 boolean_t done; 216 UVMHIST_FUNC("uvm_km_get"); UVMHIST_CALLED(maphist); 217 218 UVMHIST_LOG(maphist, "flags=%d", flags,0,0,0); 219 220 /* 221 * get number of pages 222 */ 223 224 maxpages = *npagesp; 225 226 /* 227 * step 1: handled the case where fault data structures are locked. 228 */ 229 230 if (flags & PGO_LOCKED) { 231 232 /* 233 * step 1a: get pages that are already resident. only do this 234 * if the data structures are locked (i.e. the first time through). 235 */ 236 237 done = TRUE; /* be optimistic */ 238 gotpages = 0; /* # of pages we got so far */ 239 240 for (lcv = 0, current_offset = offset ; 241 lcv < maxpages ; lcv++, current_offset += PAGE_SIZE) { 242 243 /* do we care about this page? if not, skip it */ 244 if (pps[lcv] == PGO_DONTCARE) 245 continue; 246 247 /* lookup page */ 248 ptmp = uvm_pagelookup(uobj, current_offset); 249 250 /* null? attempt to allocate the page */ 251 if (ptmp == NULL) { 252 ptmp = uvm_pagealloc(uobj, current_offset, NULL); 253 if (ptmp) { 254 ptmp->flags &= ~(PG_BUSY|PG_FAKE); /* new page */ 255 UVM_PAGE_OWN(ptmp, NULL); 256 ptmp->wire_count = 1; /* XXX: prevents pageout attempts */ 257 uvm_pagezero(ptmp); 258 } 259 } 260 261 /* to be useful must get a non-busy, non-released page */ 262 if (ptmp == NULL || (ptmp->flags & (PG_BUSY|PG_RELEASED)) != 0) { 263 if (lcv == centeridx || (flags & PGO_ALLPAGES) != 0) 264 done = FALSE; /* need to do a wait or I/O! */ 265 continue; 266 } 267 268 /* useful page: busy/lock it and plug it in our result array */ 269 ptmp->flags |= PG_BUSY; /* caller must un-busy this page */ 270 UVM_PAGE_OWN(ptmp, "uvm_km_get1"); 271 pps[lcv] = ptmp; 272 gotpages++; 273 274 } /* "for" lcv loop */ 275 276 /* 277 * step 1b: now we've either done everything needed or we to unlock 278 * and do some waiting or I/O. 279 */ 280 281 UVMHIST_LOG(maphist, "<- done (done=%d)", done, 0,0,0); 282 283 *npagesp = gotpages; 284 if (done) 285 return(VM_PAGER_OK); /* bingo! */ 286 else 287 return(VM_PAGER_UNLOCK); /* EEK! Need to unlock and I/O */ 288 } 289 290 /* 291 * step 2: get non-resident or busy pages. 292 * object is locked. data structures are unlocked. 293 */ 294 295 for (lcv = 0, current_offset = offset ; 296 lcv < maxpages ; lcv++, current_offset += PAGE_SIZE) { 297 298 /* skip over pages we've already gotten or don't want */ 299 /* skip over pages we don't _have_ to get */ 300 if (pps[lcv] != NULL || 301 (lcv != centeridx && (flags & PGO_ALLPAGES) == 0)) 302 continue; 303 304 /* 305 * we have yet to locate the current page (pps[lcv]). we first 306 * look for a page that is already at the current offset. if we 307 * find a page, we check to see if it is busy or released. if that 308 * is the case, then we sleep on the page until it is no longer busy 309 * or released and repeat the lookup. if the page we found is 310 * neither busy nor released, then we busy it (so we own it) and 311 * plug it into pps[lcv]. this 'break's the following while loop 312 * and indicates we are ready to move on to the next page in the 313 * "lcv" loop above. 314 * 315 * if we exit the while loop with pps[lcv] still set to NULL, then 316 * it means that we allocated a new busy/fake/clean page ptmp in the 317 * object and we need to do I/O to fill in the data. 318 */ 319 320 while (pps[lcv] == NULL) { /* top of "pps" while loop */ 321 322 /* look for a current page */ 323 ptmp = uvm_pagelookup(uobj, current_offset); 324 325 /* nope? allocate one now (if we can) */ 326 if (ptmp == NULL) { 327 328 ptmp = uvm_pagealloc(uobj, current_offset, NULL); /* alloc */ 329 330 /* out of RAM? */ 331 if (ptmp == NULL) { 332 simple_unlock(&uobj->vmobjlock); 333 uvm_wait("kmgetwait1"); 334 simple_lock(&uobj->vmobjlock); 335 continue; /* goto top of pps while loop */ 336 } 337 338 /* 339 * got new page ready for I/O. break pps while loop. pps[lcv] is 340 * still NULL. 341 */ 342 break; 343 } 344 345 /* page is there, see if we need to wait on it */ 346 if ((ptmp->flags & (PG_BUSY|PG_RELEASED)) != 0) { 347 ptmp->flags |= PG_WANTED; 348 UVM_UNLOCK_AND_WAIT(ptmp,&uobj->vmobjlock,0,"uvn_get",0); 349 simple_lock(&uobj->vmobjlock); 350 continue; /* goto top of pps while loop */ 351 } 352 353 /* 354 * if we get here then the page has become resident and unbusy 355 * between steps 1 and 2. we busy it now (so we own it) and set 356 * pps[lcv] (so that we exit the while loop). 357 */ 358 ptmp->flags |= PG_BUSY; /* we own it, caller must un-busy */ 359 UVM_PAGE_OWN(ptmp, "uvm_km_get2"); 360 pps[lcv] = ptmp; 361 } 362 363 /* 364 * if we own the a valid page at the correct offset, pps[lcv] will 365 * point to it. nothing more to do except go to the next page. 366 */ 367 368 if (pps[lcv]) 369 continue; /* next lcv */ 370 371 /* 372 * we have a "fake/busy/clean" page that we just allocated. 373 * do the needed "i/o" (in this case that means zero it). 374 */ 375 376 uvm_pagezero(ptmp); 377 ptmp->flags &= ~(PG_FAKE); 378 ptmp->wire_count = 1; /* XXX: prevents pageout attempts */ 379 pps[lcv] = ptmp; 380 381 } /* lcv loop */ 382 383 /* 384 * finally, unlock object and return. 385 */ 386 387 simple_unlock(&uobj->vmobjlock); 388 UVMHIST_LOG(maphist, "<- done (OK)",0,0,0,0); 389 return(VM_PAGER_OK); 390 } 391 392 /* 393 * uvm_km_init: init kernel maps and objects to reflect reality (i.e. 394 * KVM already allocated for text, data, bss, and static data structures). 395 * 396 * => KVM is defined by VM_MIN_KERNEL_ADDRESS/VM_MAX_KERNEL_ADDRESS. 397 * we assume that [min -> start] has already been allocated and that 398 * "end" is the end. 399 */ 400 401 void uvm_km_init(start, end) 402 403 vm_offset_t start, end; 404 405 { 406 vm_offset_t base = VM_MIN_KERNEL_ADDRESS; 407 408 /* 409 * first, init kernel memory objects. 410 */ 411 412 /* kernel_object: for pageable anonymous kernel memory */ 413 uvm.kernel_object = uao_create(VM_MAX_KERNEL_ADDRESS - 414 VM_MIN_KERNEL_ADDRESS, UAO_FLAG_KERNOBJ); 415 416 /* kmem_object: for malloc'd memory (always wired, protected by splimp) */ 417 simple_lock_init(&kmem_object_store.vmobjlock); 418 kmem_object_store.pgops = &km_pager; 419 TAILQ_INIT(&kmem_object_store.memq); 420 kmem_object_store.uo_npages = 0; 421 kmem_object_store.uo_refs = UVM_OBJ_KERN; 422 /* we are special. we never die */ 423 uvmexp.kmem_object = &kmem_object_store; 424 425 /* mb_object: for mbuf memory (always wired, protected by splimp) */ 426 simple_lock_init(&mb_object_store.vmobjlock); 427 mb_object_store.pgops = &km_pager; 428 TAILQ_INIT(&mb_object_store.memq); 429 mb_object_store.uo_npages = 0; 430 mb_object_store.uo_refs = UVM_OBJ_KERN; 431 /* we are special. we never die */ 432 uvmexp.mb_object = &mb_object_store; 433 434 /* 435 * init the map and reserve allready allocated kernel space 436 * before installing. 437 */ 438 439 uvm_map_setup(&kernel_map_store, base, end, FALSE); 440 kernel_map_store.pmap = pmap_kernel(); 441 if (uvm_map(&kernel_map_store, &base, start - base, NULL, UVM_UNKNOWN_OFFSET, 442 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 443 UVM_ADV_RANDOM,UVM_FLAG_FIXED)) != KERN_SUCCESS) 444 panic("uvm_km_init: could not reserve space for kernel"); 445 446 /* 447 * install! 448 */ 449 450 kernel_map = &kernel_map_store; 451 } 452 453 /* 454 * uvm_km_suballoc: allocate a submap in the kernel map. once a submap 455 * is allocated all references to that area of VM must go through it. this 456 * allows the locking of VAs in kernel_map to be broken up into regions. 457 * 458 * => if `fixed' is true, *min specifies where the region described 459 * by the submap must start 460 * => if submap is non NULL we use that as the submap, otherwise we 461 * alloc a new map 462 */ 463 464 struct vm_map *uvm_km_suballoc(map, min, max, size, pageable, fixed, submap) 465 466 struct vm_map *map; 467 vm_offset_t *min, *max; /* OUT, OUT */ 468 vm_size_t size; 469 boolean_t pageable; 470 boolean_t fixed; 471 struct vm_map *submap; 472 473 { 474 int mapflags = UVM_FLAG_NOMERGE | (fixed ? UVM_FLAG_FIXED : 0); 475 476 size = round_page(size); /* round up to pagesize */ 477 478 /* 479 * first allocate a blank spot in the parent map 480 */ 481 482 if (uvm_map(map, min, size, NULL, UVM_UNKNOWN_OFFSET, 483 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 484 UVM_ADV_RANDOM, mapflags)) != KERN_SUCCESS) { 485 panic("uvm_km_suballoc: unable to allocate space in parent map"); 486 } 487 488 /* 489 * set VM bounds (min is filled in by uvm_map) 490 */ 491 492 *max = *min + size; 493 494 /* 495 * add references to pmap and create or init the submap 496 */ 497 498 pmap_reference(vm_map_pmap(map)); 499 if (submap == NULL) { 500 submap = uvm_map_create(vm_map_pmap(map), *min, *max, pageable); 501 if (submap == NULL) 502 panic("uvm_km_suballoc: unable to create submap"); 503 } else { 504 uvm_map_setup(submap, *min, *max, pageable); 505 submap->pmap = vm_map_pmap(map); 506 } 507 508 /* 509 * now let uvm_map_submap plug in it... 510 */ 511 512 if (uvm_map_submap(map, *min, *max, submap) != KERN_SUCCESS) 513 panic("uvm_km_suballoc: submap allocation failed"); 514 515 return(submap); 516 } 517 518 /* 519 * uvm_km_pgremove: remove pages from a kernel uvm_object. 520 * 521 * => when you unmap a part of anonymous kernel memory you want to toss 522 * the pages right away. (this gets called from uvm_unmap_...). 523 */ 524 525 #define UKM_HASH_PENALTY 4 /* a guess */ 526 527 void uvm_km_pgremove(uobj, start, end) 528 529 struct uvm_object *uobj; 530 vm_offset_t start, end; 531 532 { 533 boolean_t by_list, is_aobj; 534 struct vm_page *pp, *ppnext; 535 vm_offset_t curoff; 536 UVMHIST_FUNC("uvm_km_pgremove"); UVMHIST_CALLED(maphist); 537 538 simple_lock(&uobj->vmobjlock); /* lock object */ 539 540 /* is uobj an aobj? */ 541 is_aobj = uobj->pgops == &aobj_pager; 542 543 /* choose cheapest traversal */ 544 by_list = (uobj->uo_npages <= 545 ((end - start) / PAGE_SIZE) * UKM_HASH_PENALTY); 546 547 if (by_list) 548 goto loop_by_list; 549 550 /* by hash */ 551 552 for (curoff = start ; curoff < end ; curoff += PAGE_SIZE) { 553 pp = uvm_pagelookup(uobj, curoff); 554 if (pp == NULL) 555 continue; 556 557 UVMHIST_LOG(maphist," page 0x%x, busy=%d", pp,pp->flags & PG_BUSY,0,0); 558 /* now do the actual work */ 559 if (pp->flags & PG_BUSY) 560 pp->flags |= PG_RELEASED; /* owner must check for this when done */ 561 else { 562 pmap_page_protect(PMAP_PGARG(pp), VM_PROT_NONE); 563 564 /* 565 * if this kernel object is an aobj, free the swap slot. 566 */ 567 if (is_aobj) { 568 int slot = uao_set_swslot(uobj, curoff / PAGE_SIZE, 0); 569 570 if (slot) 571 uvm_swap_free(slot, 1); 572 } 573 574 uvm_lock_pageq(); 575 uvm_pagefree(pp); 576 uvm_unlock_pageq(); 577 } 578 /* done */ 579 580 } 581 simple_unlock(&uobj->vmobjlock); 582 return; 583 584 loop_by_list: 585 586 for (pp = uobj->memq.tqh_first ; pp != NULL ; pp = ppnext) { 587 588 ppnext = pp->listq.tqe_next; 589 if (pp->offset < start || pp->offset >= end) { 590 continue; 591 } 592 593 UVMHIST_LOG(maphist," page 0x%x, busy=%d", pp,pp->flags & PG_BUSY,0,0); 594 /* now do the actual work */ 595 if (pp->flags & PG_BUSY) 596 pp->flags |= PG_RELEASED; /* owner must check for this when done */ 597 else { 598 pmap_page_protect(PMAP_PGARG(pp), VM_PROT_NONE); 599 600 /* 601 * if this kernel object is an aobj, free the swap slot. 602 */ 603 if (is_aobj) { 604 int slot = uao_set_swslot(uobj, pp->offset / PAGE_SIZE, 0); 605 606 if (slot) 607 uvm_swap_free(slot, 1); 608 } 609 610 uvm_lock_pageq(); 611 uvm_pagefree(pp); 612 uvm_unlock_pageq(); 613 } 614 /* done */ 615 616 } 617 simple_unlock(&uobj->vmobjlock); 618 return; 619 } 620 621 622 /* 623 * uvm_km_kmemalloc: lower level kernel memory allocator for malloc() 624 * 625 * => we map wired memory into the specified map using the obj passed in 626 * => NOTE: we can return NULL even if we can wait if there is not enough 627 * free VM space in the map... caller should be prepared to handle 628 * this case. 629 * => we return KVA of memory allocated 630 * => flags: NOWAIT, VALLOC - just allocate VA, TRYLOCK - fail if we can't 631 * lock the map 632 */ 633 634 vm_offset_t uvm_km_kmemalloc(map, obj, size, flags) 635 636 vm_map_t map; 637 struct uvm_object *obj; 638 vm_size_t size; 639 int flags; 640 641 { 642 vm_offset_t kva, loopva; 643 vm_offset_t offset; 644 struct vm_page *pg; 645 UVMHIST_FUNC("uvm_km_kmemalloc"); UVMHIST_CALLED(maphist); 646 647 648 UVMHIST_LOG(maphist," (map=0x%x, obj=0x%x, size=0x%x, flags=%d)", 649 map, obj, size, flags); 650 #ifdef DIAGNOSTIC 651 /* sanity check */ 652 if (vm_map_pmap(map) != pmap_kernel()) 653 panic("uvm_km_kmemalloc: invalid map"); 654 #endif 655 656 /* 657 * setup for call 658 */ 659 660 size = round_page(size); 661 kva = vm_map_min(map); /* hint */ 662 663 /* 664 * allocate some virtual space 665 */ 666 667 if (uvm_map(map, &kva, size, obj, UVM_UNKNOWN_OFFSET, 668 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 669 UVM_ADV_RANDOM, (flags & UVM_KMF_TRYLOCK))) 670 != KERN_SUCCESS) { 671 UVMHIST_LOG(maphist, "<- done (no VM)",0,0,0,0); 672 return(0); 673 } 674 675 /* 676 * if all we wanted was VA, return now 677 */ 678 679 if (flags & UVM_KMF_VALLOC) { 680 UVMHIST_LOG(maphist,"<- done valloc (kva=0x%x)", kva,0,0,0); 681 return(kva); 682 } 683 /* 684 * recover object offset from virtual address 685 */ 686 687 offset = kva - vm_map_min(kernel_map); 688 UVMHIST_LOG(maphist, " kva=0x%x, offset=0x%x", kva, offset,0,0); 689 690 /* 691 * now allocate and map in the memory... note that we are the only ones 692 * whom should ever get a handle on this area of VM. 693 */ 694 695 loopva = kva; 696 while (size) { 697 simple_lock(&obj->vmobjlock); 698 pg = uvm_pagealloc(obj, offset, NULL); 699 if (pg) { 700 pg->flags &= ~PG_BUSY; /* new page */ 701 UVM_PAGE_OWN(pg, NULL); 702 703 pg->wire_count = 1; 704 uvmexp.wired++; 705 } 706 simple_unlock(&obj->vmobjlock); 707 708 /* 709 * out of memory? 710 */ 711 712 if (pg == NULL) { 713 if (flags & UVM_KMF_NOWAIT) { 714 uvm_unmap(map, kva, kva + size, 0); /* free everything! */ 715 return(0); 716 } else { 717 uvm_wait("km_getwait2"); /* sleep here */ 718 continue; 719 } 720 } 721 722 /* 723 * map it in: note that we call pmap_enter with the map and object 724 * unlocked in case we are kmem_map/kmem_object (because if pmap_enter 725 * wants to allocate out of kmem_object it will need to lock it itself!) 726 */ 727 #if defined(PMAP_NEW) 728 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), VM_PROT_ALL); 729 #else 730 pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg), UVM_PROT_ALL, TRUE); 731 #endif 732 loopva += PAGE_SIZE; 733 offset += PAGE_SIZE; 734 size -= PAGE_SIZE; 735 } 736 737 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 738 return(kva); 739 } 740 741 /* 742 * uvm_km_free: free an area of kernel memory 743 */ 744 745 void uvm_km_free(map, addr, size) 746 747 vm_map_t map; 748 vm_offset_t addr; 749 vm_size_t size; 750 751 { 752 uvm_unmap(map, trunc_page(addr), round_page(addr+size), 1); 753 } 754 755 /* 756 * uvm_km_free_wakeup: free an area of kernel memory and wake up 757 * anyone waiting for vm space. 758 * 759 * => XXX: "wanted" bit + unlock&wait on other end? 760 */ 761 762 void uvm_km_free_wakeup(map, addr, size) 763 764 vm_map_t map; 765 vm_offset_t addr; 766 vm_size_t size; 767 768 { 769 vm_map_entry_t dead_entries; 770 771 vm_map_lock(map); 772 (void)uvm_unmap_remove(map, trunc_page(addr), round_page(addr+size), 1, 773 &dead_entries); 774 thread_wakeup(map); 775 vm_map_unlock(map); 776 777 if (dead_entries != NULL) 778 uvm_unmap_detach(dead_entries, 0); 779 } 780 781 /* 782 * uvm_km_alloc1: allocate wired down memory in the kernel map. 783 * 784 * => we can sleep if needed 785 */ 786 787 vm_offset_t uvm_km_alloc1(map, size, zeroit) 788 789 vm_map_t map; 790 vm_size_t size; 791 boolean_t zeroit; 792 793 { 794 vm_offset_t kva, loopva, offset; 795 struct vm_page *pg; 796 UVMHIST_FUNC("uvm_km_alloc1"); UVMHIST_CALLED(maphist); 797 798 UVMHIST_LOG(maphist,"(map=0x%x, size=0x%x)", map, size,0,0); 799 800 #ifdef DIAGNOSTIC 801 if (vm_map_pmap(map) != pmap_kernel()) 802 panic("uvm_km_alloc1"); 803 #endif 804 805 size = round_page(size); 806 kva = vm_map_min(map); /* hint */ 807 808 /* 809 * allocate some virtual space 810 */ 811 812 if (uvm_map(map, &kva, size, uvm.kernel_object, UVM_UNKNOWN_OFFSET, 813 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 814 UVM_ADV_RANDOM, 0)) != KERN_SUCCESS) { 815 UVMHIST_LOG(maphist,"<- done (no VM)",0,0,0,0); 816 return(0); 817 } 818 819 /* 820 * recover object offset from virtual address 821 */ 822 823 offset = kva - vm_map_min(kernel_map); 824 UVMHIST_LOG(maphist," kva=0x%x, offset=0x%x", kva, offset,0,0); 825 826 /* 827 * now allocate the memory. we must be careful about released pages. 828 */ 829 830 loopva = kva; 831 while (size) { 832 simple_lock(&uvm.kernel_object->vmobjlock); 833 pg = uvm_pagelookup(uvm.kernel_object, offset); 834 835 /* if we found a page in an unallocated region, it must be released */ 836 if (pg) { 837 if ((pg->flags & PG_RELEASED) == 0) 838 panic("uvm_km_alloc1: non-released page"); 839 pg->flags |= PG_WANTED; 840 UVM_UNLOCK_AND_WAIT(pg, &uvm.kernel_object->vmobjlock,0,"km_alloc",0); 841 continue; /* retry */ 842 } 843 844 /* allocate ram */ 845 pg = uvm_pagealloc(uvm.kernel_object, offset, NULL); 846 if (pg) { 847 pg->flags &= ~PG_BUSY; /* new page */ 848 UVM_PAGE_OWN(pg, NULL); 849 } 850 simple_unlock(&uvm.kernel_object->vmobjlock); 851 if (pg == NULL) { 852 uvm_wait("km_alloc1w"); /* wait for memory */ 853 continue; 854 } 855 856 /* map it in */ 857 #if defined(PMAP_NEW) 858 pmap_kenter_pa(loopva, VM_PAGE_TO_PHYS(pg), UVM_PROT_ALL); 859 #else 860 pmap_enter(map->pmap, loopva, VM_PAGE_TO_PHYS(pg), UVM_PROT_ALL, TRUE); 861 #endif 862 loopva += PAGE_SIZE; 863 offset += PAGE_SIZE; 864 size -= PAGE_SIZE; 865 } 866 867 /* 868 * zero on request (note that "size" is now zero due to the above loop 869 * so we need to subtract kva from loopva to reconstruct the size). 870 */ 871 872 if (zeroit) 873 bzero((caddr_t)kva, loopva - kva); 874 875 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 876 return(kva); 877 } 878 879 /* 880 * uvm_km_valloc: allocate zero-fill memory in the kernel's address space 881 * 882 * => memory is not allocated until fault time 883 */ 884 885 vm_offset_t uvm_km_valloc(map, size) 886 887 vm_map_t map; 888 vm_size_t size; 889 890 { 891 vm_offset_t kva; 892 UVMHIST_FUNC("uvm_km_valloc"); UVMHIST_CALLED(maphist); 893 894 UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0); 895 896 #ifdef DIAGNOSTIC 897 if (vm_map_pmap(map) != pmap_kernel()) 898 panic("uvm_km_valloc"); 899 #endif 900 901 size = round_page(size); 902 kva = vm_map_min(map); /* hint */ 903 904 /* 905 * allocate some virtual space. will be demand filled by kernel_object. 906 */ 907 908 if (uvm_map(map, &kva, size, uvm.kernel_object, UVM_UNKNOWN_OFFSET, 909 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 910 UVM_ADV_RANDOM, 0)) != KERN_SUCCESS) { 911 UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0); 912 return(0); 913 } 914 915 UVMHIST_LOG(maphist, "<- done (kva=0x%x)", kva,0,0,0); 916 return(kva); 917 } 918 919 /* 920 * uvm_km_valloc_wait: allocate zero-fill memory in the kernel's address space 921 * 922 * => memory is not allocated until fault time 923 * => if no room in map, wait for space to free, unless requested size 924 * is larger than map (in which case we return 0) 925 */ 926 927 vm_offset_t uvm_km_valloc_wait(map, size) 928 929 vm_map_t map; 930 vm_size_t size; 931 932 { 933 vm_offset_t kva; 934 UVMHIST_FUNC("uvm_km_valloc_wait"); UVMHIST_CALLED(maphist); 935 936 UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x)", map, size, 0,0); 937 938 #ifdef DIAGNOSTIC 939 if (vm_map_pmap(map) != pmap_kernel()) 940 panic("uvm_km_valloc_wait"); 941 #endif 942 943 size = round_page(size); 944 if (size > vm_map_max(map) - vm_map_min(map)) 945 return(0); 946 947 while (1) { 948 kva = vm_map_min(map); /* hint */ 949 950 /* 951 * allocate some virtual space. will be demand filled by kernel_object. 952 */ 953 954 if (uvm_map(map, &kva, size, uvm.kernel_object, UVM_UNKNOWN_OFFSET, 955 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 956 UVM_ADV_RANDOM, 0)) == KERN_SUCCESS){ 957 UVMHIST_LOG(maphist,"<- done (kva=0x%x)", kva,0,0,0); 958 return(kva); 959 } 960 961 /* 962 * failed. sleep for a while (on map) 963 */ 964 965 UVMHIST_LOG(maphist,"<<<sleeping>>>",0,0,0,0); 966 tsleep((caddr_t)map, PVM, "vallocwait", 0); 967 } 968 /*NOTREACHED*/ 969 } 970
Indexes created Mon Sep 22 21:09:42 GMT 2025