vm_page.c revision 10542
1/* 2 * Copyright (c) 1991 Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91 37 * $Id: vm_page.c,v 1.34 1995/07/20 05:28:07 davidg Exp $ 38 */ 39 40/* 41 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 42 * All rights reserved. 43 * 44 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 45 * 46 * Permission to use, copy, modify and distribute this software and 47 * its documentation is hereby granted, provided that both the copyright 48 * notice and this permission notice appear in all copies of the 49 * software, derivative works or modified versions, and any portions 50 * thereof, and that both notices appear in supporting documentation. 51 * 52 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 53 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 54 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 55 * 56 * Carnegie Mellon requests users of this software to return to 57 * 58 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 59 * School of Computer Science 60 * Carnegie Mellon University 61 * Pittsburgh PA 15213-3890 62 * 63 * any improvements or extensions that they make and grant Carnegie the 64 * rights to redistribute these changes. 65 */ 66 67/* 68 * Resident memory management module. 69 */ 70 71#include <sys/param.h> 72#include <sys/systm.h> 73#include <sys/proc.h> 74 75#include <vm/vm.h> 76#include <vm/vm_kern.h> 77#include <vm/vm_page.h> 78#include <vm/vm_map.h> 79#include <vm/vm_pageout.h> 80 81/* 82 * Associated with page of user-allocatable memory is a 83 * page structure. 84 */ 85 86struct pglist *vm_page_buckets; /* Array of buckets */ 87int vm_page_bucket_count; /* How big is array? */ 88int vm_page_hash_mask; /* Mask for hash function */ 89 90struct pglist vm_page_queue_free; 91struct pglist vm_page_queue_active; 92struct pglist vm_page_queue_inactive; 93struct pglist vm_page_queue_cache; 94 95/* has physical page allocation been initialized? */ 96boolean_t vm_page_startup_initialized; 97 98vm_page_t vm_page_array; 99int vm_page_array_size; 100long first_page; 101long last_page; 102vm_offset_t first_phys_addr; 103vm_offset_t last_phys_addr; 104vm_size_t page_mask; 105int page_shift; 106 107/* 108 * map of contiguous valid DEV_BSIZE chunks in a page 109 * (this list is valid for page sizes upto 16*DEV_BSIZE) 110 */ 111static u_short vm_page_dev_bsize_chunks[] = { 112 0x0, 0x1, 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 113 0x1ff, 0x3ff, 0x7ff, 0xfff, 0x1fff, 0x3fff, 0x7fff, 0xffff 114}; 115 116 117/* 118 * vm_set_page_size: 119 * 120 * Sets the page size, perhaps based upon the memory 121 * size. Must be called before any use of page-size 122 * dependent functions. 123 * 124 * Sets page_shift and page_mask from cnt.v_page_size. 125 */ 126void 127vm_set_page_size() 128{ 129 130 if (cnt.v_page_size == 0) 131 cnt.v_page_size = DEFAULT_PAGE_SIZE; 132 page_mask = cnt.v_page_size - 1; 133 if ((page_mask & cnt.v_page_size) != 0) 134 panic("vm_set_page_size: page size not a power of two"); 135 for (page_shift = 0;; page_shift++) 136 if ((1 << page_shift) == cnt.v_page_size) 137 break; 138} 139 140/* 141 * vm_page_startup: 142 * 143 * Initializes the resident memory module. 144 * 145 * Allocates memory for the page cells, and 146 * for the object/offset-to-page hash table headers. 147 * Each page cell is initialized and placed on the free list. 148 */ 149 150vm_offset_t 151vm_page_startup(starta, enda, vaddr) 152 register vm_offset_t starta; 153 vm_offset_t enda; 154 register vm_offset_t vaddr; 155{ 156 register vm_offset_t mapped; 157 register vm_page_t m; 158 register struct pglist *bucket; 159 vm_size_t npages, page_range; 160 register vm_offset_t new_start; 161 int i; 162 vm_offset_t pa; 163 int nblocks; 164 vm_offset_t first_managed_page; 165 166 /* the biggest memory array is the second group of pages */ 167 vm_offset_t start; 168 vm_offset_t biggestone, biggestsize; 169 170 vm_offset_t total; 171 172 total = 0; 173 biggestsize = 0; 174 biggestone = 0; 175 nblocks = 0; 176 vaddr = round_page(vaddr); 177 178 for (i = 0; phys_avail[i + 1]; i += 2) { 179 phys_avail[i] = round_page(phys_avail[i]); 180 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]); 181 } 182 183 for (i = 0; phys_avail[i + 1]; i += 2) { 184 int size = phys_avail[i + 1] - phys_avail[i]; 185 186 if (size > biggestsize) { 187 biggestone = i; 188 biggestsize = size; 189 } 190 ++nblocks; 191 total += size; 192 } 193 194 start = phys_avail[biggestone]; 195 196 /* 197 * Initialize the queue headers for the free queue, the active queue 198 * and the inactive queue. 199 */ 200 201 TAILQ_INIT(&vm_page_queue_free); 202 TAILQ_INIT(&vm_page_queue_active); 203 TAILQ_INIT(&vm_page_queue_inactive); 204 TAILQ_INIT(&vm_page_queue_cache); 205 206 /* 207 * Allocate (and initialize) the hash table buckets. 208 * 209 * The number of buckets MUST BE a power of 2, and the actual value is 210 * the next power of 2 greater than the number of physical pages in 211 * the system. 212 * 213 * Note: This computation can be tweaked if desired. 214 */ 215 vm_page_buckets = (struct pglist *) vaddr; 216 bucket = vm_page_buckets; 217 if (vm_page_bucket_count == 0) { 218 vm_page_bucket_count = 1; 219 while (vm_page_bucket_count < atop(total)) 220 vm_page_bucket_count <<= 1; 221 } 222 vm_page_hash_mask = vm_page_bucket_count - 1; 223 224 /* 225 * Validate these addresses. 226 */ 227 228 new_start = start + vm_page_bucket_count * sizeof(struct pglist); 229 new_start = round_page(new_start); 230 mapped = vaddr; 231 vaddr = pmap_map(mapped, start, new_start, 232 VM_PROT_READ | VM_PROT_WRITE); 233 start = new_start; 234 bzero((caddr_t) mapped, vaddr - mapped); 235 mapped = vaddr; 236 237 for (i = 0; i < vm_page_bucket_count; i++) { 238 TAILQ_INIT(bucket); 239 bucket++; 240 } 241 242 /* 243 * round (or truncate) the addresses to our page size. 244 */ 245 246 /* 247 * Pre-allocate maps and map entries that cannot be dynamically 248 * allocated via malloc(). The maps include the kernel_map and 249 * kmem_map which must be initialized before malloc() will work 250 * (obviously). Also could include pager maps which would be 251 * allocated before kmeminit. 252 * 253 * Allow some kernel map entries... this should be plenty since people 254 * shouldn't be cluttering up the kernel map (they should use their 255 * own maps). 256 */ 257 258 kentry_data_size = MAX_KMAP * sizeof(struct vm_map) + 259 MAX_KMAPENT * sizeof(struct vm_map_entry); 260 kentry_data_size = round_page(kentry_data_size); 261 kentry_data = (vm_offset_t) vaddr; 262 vaddr += kentry_data_size; 263 264 /* 265 * Validate these zone addresses. 266 */ 267 268 new_start = start + (vaddr - mapped); 269 pmap_map(mapped, start, new_start, VM_PROT_READ | VM_PROT_WRITE); 270 bzero((caddr_t) mapped, (vaddr - mapped)); 271 start = round_page(new_start); 272 273 /* 274 * Compute the number of pages of memory that will be available for 275 * use (taking into account the overhead of a page structure per 276 * page). 277 */ 278 279 first_page = phys_avail[0] / PAGE_SIZE; 280 last_page = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE; 281 282 page_range = last_page - (phys_avail[0] / PAGE_SIZE); 283 npages = (total - (page_range * sizeof(struct vm_page)) - 284 (start - phys_avail[biggestone])) / PAGE_SIZE; 285 286 /* 287 * Initialize the mem entry structures now, and put them in the free 288 * queue. 289 */ 290 291 vm_page_array = (vm_page_t) vaddr; 292 mapped = vaddr; 293 294 295 /* 296 * Validate these addresses. 297 */ 298 299 new_start = round_page(start + page_range * sizeof(struct vm_page)); 300 mapped = pmap_map(mapped, start, new_start, 301 VM_PROT_READ | VM_PROT_WRITE); 302 start = new_start; 303 304 first_managed_page = start / PAGE_SIZE; 305 306 /* 307 * Clear all of the page structures 308 */ 309 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page)); 310 vm_page_array_size = page_range; 311 312 cnt.v_page_count = 0; 313 cnt.v_free_count = 0; 314 for (i = 0; phys_avail[i + 1] && npages > 0; i += 2) { 315 if (i == biggestone) 316 pa = ptoa(first_managed_page); 317 else 318 pa = phys_avail[i]; 319 while (pa < phys_avail[i + 1] && npages-- > 0) { 320 ++cnt.v_page_count; 321 ++cnt.v_free_count; 322 m = PHYS_TO_VM_PAGE(pa); 323 m->flags = PG_FREE; 324 m->phys_addr = pa; 325 TAILQ_INSERT_TAIL(&vm_page_queue_free, m, pageq); 326 pa += PAGE_SIZE; 327 } 328 } 329 330 return (mapped); 331} 332 333/* 334 * vm_page_hash: 335 * 336 * Distributes the object/offset key pair among hash buckets. 337 * 338 * NOTE: This macro depends on vm_page_bucket_count being a power of 2. 339 */ 340inline const int 341vm_page_hash(object, offset) 342 vm_object_t object; 343 vm_offset_t offset; 344{ 345 return ((unsigned) object + offset / NBPG) & vm_page_hash_mask; 346} 347 348/* 349 * vm_page_insert: [ internal use only ] 350 * 351 * Inserts the given mem entry into the object/object-page 352 * table and object list. 353 * 354 * The object and page must be locked, and must be splhigh. 355 */ 356 357inline void 358vm_page_insert(mem, object, offset) 359 register vm_page_t mem; 360 register vm_object_t object; 361 register vm_offset_t offset; 362{ 363 register struct pglist *bucket; 364 365 if (mem->flags & PG_TABLED) 366 panic("vm_page_insert: already inserted"); 367 368 /* 369 * Record the object/offset pair in this page 370 */ 371 372 mem->object = object; 373 mem->offset = offset; 374 375 /* 376 * Insert it into the object_object/offset hash table 377 */ 378 379 bucket = &vm_page_buckets[vm_page_hash(object, offset)]; 380 TAILQ_INSERT_TAIL(bucket, mem, hashq); 381 382 /* 383 * Now link into the object's list of backed pages. 384 */ 385 386 TAILQ_INSERT_TAIL(&object->memq, mem, listq); 387 mem->flags |= PG_TABLED; 388 389 /* 390 * And show that the object has one more resident page. 391 */ 392 393 object->resident_page_count++; 394} 395 396/* 397 * vm_page_remove: [ internal use only ] 398 * NOTE: used by device pager as well -wfj 399 * 400 * Removes the given mem entry from the object/offset-page 401 * table and the object page list. 402 * 403 * The object and page must be locked, and at splhigh. 404 */ 405 406inline void 407vm_page_remove(mem) 408 register vm_page_t mem; 409{ 410 register struct pglist *bucket; 411 412 if (!(mem->flags & PG_TABLED)) 413 return; 414 415 /* 416 * Remove from the object_object/offset hash table 417 */ 418 419 bucket = &vm_page_buckets[vm_page_hash(mem->object, mem->offset)]; 420 TAILQ_REMOVE(bucket, mem, hashq); 421 422 /* 423 * Now remove from the object's list of backed pages. 424 */ 425 426 TAILQ_REMOVE(&mem->object->memq, mem, listq); 427 428 /* 429 * And show that the object has one fewer resident page. 430 */ 431 432 mem->object->resident_page_count--; 433 434 mem->flags &= ~PG_TABLED; 435} 436 437/* 438 * vm_page_lookup: 439 * 440 * Returns the page associated with the object/offset 441 * pair specified; if none is found, NULL is returned. 442 * 443 * The object must be locked. No side effects. 444 */ 445 446vm_page_t 447vm_page_lookup(object, offset) 448 register vm_object_t object; 449 register vm_offset_t offset; 450{ 451 register vm_page_t mem; 452 register struct pglist *bucket; 453 int s; 454 455 /* 456 * Search the hash table for this object/offset pair 457 */ 458 459 bucket = &vm_page_buckets[vm_page_hash(object, offset)]; 460 461 s = splhigh(); 462 for (mem = bucket->tqh_first; mem != NULL; mem = mem->hashq.tqe_next) { 463 if ((mem->object == object) && (mem->offset == offset)) { 464 splx(s); 465 return (mem); 466 } 467 } 468 469 splx(s); 470 return (NULL); 471} 472 473/* 474 * vm_page_rename: 475 * 476 * Move the given memory entry from its 477 * current object to the specified target object/offset. 478 * 479 * The object must be locked. 480 */ 481void 482vm_page_rename(mem, new_object, new_offset) 483 register vm_page_t mem; 484 register vm_object_t new_object; 485 vm_offset_t new_offset; 486{ 487 int s; 488 489 if (mem->object == new_object) 490 return; 491 492 s = splhigh(); 493 vm_page_remove(mem); 494 vm_page_insert(mem, new_object, new_offset); 495 splx(s); 496} 497 498/* 499 * vm_page_unqueue must be called at splhigh(); 500 */ 501inline void 502vm_page_unqueue(vm_page_t mem) 503{ 504 int origflags; 505 506 origflags = mem->flags; 507 508 if ((origflags & (PG_ACTIVE|PG_INACTIVE|PG_CACHE)) == 0) 509 return; 510 511 if (origflags & PG_ACTIVE) { 512 TAILQ_REMOVE(&vm_page_queue_active, mem, pageq); 513 cnt.v_active_count--; 514 mem->flags &= ~PG_ACTIVE; 515 } else if (origflags & PG_INACTIVE) { 516 TAILQ_REMOVE(&vm_page_queue_inactive, mem, pageq); 517 cnt.v_inactive_count--; 518 mem->flags &= ~PG_INACTIVE; 519 } else if (origflags & PG_CACHE) { 520 TAILQ_REMOVE(&vm_page_queue_cache, mem, pageq); 521 cnt.v_cache_count--; 522 mem->flags &= ~PG_CACHE; 523 if (cnt.v_cache_count + cnt.v_free_count < cnt.v_free_reserved) 524 pagedaemon_wakeup(); 525 } 526 return; 527} 528 529/* 530 * vm_page_alloc: 531 * 532 * Allocate and return a memory cell associated 533 * with this VM object/offset pair. 534 * 535 * page_req classes: 536 * VM_ALLOC_NORMAL normal process request 537 * VM_ALLOC_SYSTEM system *really* needs a page 538 * VM_ALLOC_INTERRUPT interrupt time request 539 * 540 * Object must be locked. 541 */ 542vm_page_t 543vm_page_alloc(object, offset, page_req) 544 vm_object_t object; 545 vm_offset_t offset; 546 int page_req; 547{ 548 register vm_page_t mem; 549 int s; 550 551#ifdef DIAGNOSTIC 552 if (offset != trunc_page(offset)) 553 panic("vm_page_alloc: offset not page aligned"); 554 555#if 0 556 mem = vm_page_lookup(object, offset); 557 if (mem) 558 panic("vm_page_alloc: page already allocated"); 559#endif 560#endif 561 562 if ((curproc == pageproc) && (page_req != VM_ALLOC_INTERRUPT)) { 563 page_req = VM_ALLOC_SYSTEM; 564 }; 565 566 s = splhigh(); 567 568 mem = vm_page_queue_free.tqh_first; 569 570 switch (page_req) { 571 case VM_ALLOC_NORMAL: 572 if (cnt.v_free_count >= cnt.v_free_reserved) { 573 TAILQ_REMOVE(&vm_page_queue_free, mem, pageq); 574 cnt.v_free_count--; 575 } else { 576 mem = vm_page_queue_cache.tqh_first; 577 if (mem != NULL) { 578 TAILQ_REMOVE(&vm_page_queue_cache, mem, pageq); 579 vm_page_remove(mem); 580 cnt.v_cache_count--; 581 } else { 582 splx(s); 583 pagedaemon_wakeup(); 584 return (NULL); 585 } 586 } 587 break; 588 589 case VM_ALLOC_SYSTEM: 590 if ((cnt.v_free_count >= cnt.v_free_reserved) || 591 ((cnt.v_cache_count == 0) && 592 (cnt.v_free_count >= cnt.v_interrupt_free_min))) { 593 TAILQ_REMOVE(&vm_page_queue_free, mem, pageq); 594 cnt.v_free_count--; 595 } else { 596 mem = vm_page_queue_cache.tqh_first; 597 if (mem != NULL) { 598 TAILQ_REMOVE(&vm_page_queue_cache, mem, pageq); 599 vm_page_remove(mem); 600 cnt.v_cache_count--; 601 } else { 602 splx(s); 603 pagedaemon_wakeup(); 604 return (NULL); 605 } 606 } 607 break; 608 609 case VM_ALLOC_INTERRUPT: 610 if (mem != NULL) { 611 TAILQ_REMOVE(&vm_page_queue_free, mem, pageq); 612 cnt.v_free_count--; 613 } else { 614 splx(s); 615 pagedaemon_wakeup(); 616 return NULL; 617 } 618 break; 619 620 default: 621 panic("vm_page_alloc: invalid allocation class"); 622 } 623 624 mem->flags = PG_BUSY; 625 mem->wire_count = 0; 626 mem->hold_count = 0; 627 mem->act_count = 0; 628 mem->busy = 0; 629 mem->valid = 0; 630 mem->dirty = 0; 631 mem->bmapped = 0; 632 633 /* XXX before splx until vm_page_insert is safe */ 634 vm_page_insert(mem, object, offset); 635 636 splx(s); 637 638 /* 639 * Don't wakeup too often - wakeup the pageout daemon when 640 * we would be nearly out of memory. 641 */ 642 if (((cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min) || 643 (cnt.v_free_count < cnt.v_pageout_free_min)) 644 pagedaemon_wakeup(); 645 646 return (mem); 647} 648 649vm_offset_t 650vm_page_alloc_contig(size, low, high, alignment) 651 vm_offset_t size; 652 vm_offset_t low; 653 vm_offset_t high; 654 vm_offset_t alignment; 655{ 656 int i, s, start; 657 vm_offset_t addr, phys, tmp_addr; 658 vm_page_t pga = vm_page_array; 659 660 if ((alignment & (alignment - 1)) != 0) 661 panic("vm_page_alloc_contig: alignment must be a power of 2"); 662 663 start = 0; 664 s = splhigh(); 665again: 666 /* 667 * Find first page in array that is free, within range, and aligned. 668 */ 669 for (i = start; i < cnt.v_page_count; i++) { 670 phys = VM_PAGE_TO_PHYS(&pga[i]); 671 if (((pga[i].flags & PG_FREE) == PG_FREE) && 672 (phys >= low) && (phys < high) && 673 ((phys & (alignment - 1)) == 0)) 674 break; 675 } 676 677 /* 678 * If the above failed or we will exceed the upper bound, fail. 679 */ 680 if ((i == cnt.v_page_count) || ((VM_PAGE_TO_PHYS(&pga[i]) + size) > high)) { 681 splx(s); 682 return (NULL); 683 } 684 start = i; 685 686 /* 687 * Check successive pages for contiguous and free. 688 */ 689 for (i = start + 1; i < (start + size / PAGE_SIZE); i++) { 690 if ((VM_PAGE_TO_PHYS(&pga[i]) != 691 (VM_PAGE_TO_PHYS(&pga[i - 1]) + PAGE_SIZE)) || 692 ((pga[i].flags & PG_FREE) != PG_FREE)) { 693 start++; 694 goto again; 695 } 696 } 697 698 /* 699 * We've found a contiguous chunk that meets are requirements. 700 * Allocate kernel VM, unfree and assign the physical pages to it and 701 * return kernel VM pointer. 702 */ 703 tmp_addr = addr = kmem_alloc_pageable(kernel_map, size); 704 705 for (i = start; i < (start + size / PAGE_SIZE); i++) { 706 vm_page_t m = &pga[i]; 707 708 TAILQ_REMOVE(&vm_page_queue_free, m, pageq); 709 cnt.v_free_count--; 710 m->valid = VM_PAGE_BITS_ALL; 711 m->flags = 0; 712 m->dirty = 0; 713 m->wire_count = 0; 714 m->act_count = 0; 715 m->bmapped = 0; 716 m->busy = 0; 717 vm_page_insert(m, kernel_object, tmp_addr - VM_MIN_KERNEL_ADDRESS); 718 vm_page_wire(m); 719 pmap_kenter(tmp_addr, VM_PAGE_TO_PHYS(m)); 720 tmp_addr += PAGE_SIZE; 721 } 722 723 splx(s); 724 return (addr); 725} 726 727/* 728 * vm_page_free: 729 * 730 * Returns the given page to the free list, 731 * disassociating it with any VM object. 732 * 733 * Object and page must be locked prior to entry. 734 */ 735void 736vm_page_free(mem) 737 register vm_page_t mem; 738{ 739 int s; 740 int flags; 741 742 s = splhigh(); 743 vm_page_remove(mem); 744 vm_page_unqueue(mem); 745 746 flags = mem->flags; 747 if (mem->bmapped || mem->busy || flags & (PG_BUSY|PG_FREE)) { 748 if (flags & PG_FREE) 749 panic("vm_page_free: freeing free page"); 750 printf("vm_page_free: offset(%d), bmapped(%d), busy(%d), PG_BUSY(%d)\n", 751 mem->offset, mem->bmapped, mem->busy, (flags & PG_BUSY) ? 1 : 0); 752 panic("vm_page_free: freeing busy page"); 753 } 754 755 if ((flags & PG_WANTED) != 0) 756 wakeup(mem); 757 if ((flags & PG_FICTITIOUS) == 0) { 758 if (mem->wire_count) { 759 if (mem->wire_count > 1) { 760 printf("vm_page_free: wire count > 1 (%d)", mem->wire_count); 761 panic("vm_page_free: invalid wire count"); 762 } 763 cnt.v_wire_count--; 764 mem->wire_count = 0; 765 } 766 mem->flags |= PG_FREE; 767 TAILQ_INSERT_TAIL(&vm_page_queue_free, mem, pageq); 768 splx(s); 769 /* 770 * if pageout daemon needs pages, then tell it that there are 771 * some free. 772 */ 773 if (vm_pageout_pages_needed) { 774 wakeup(&vm_pageout_pages_needed); 775 vm_pageout_pages_needed = 0; 776 } 777 778 cnt.v_free_count++; 779 /* 780 * wakeup processes that are waiting on memory if we hit a 781 * high water mark. And wakeup scheduler process if we have 782 * lots of memory. this process will swapin processes. 783 */ 784 if ((cnt.v_free_count + cnt.v_cache_count) == cnt.v_free_min) { 785 wakeup(&cnt.v_free_count); 786 wakeup(&proc0); 787 } 788 } else { 789 splx(s); 790 } 791 cnt.v_tfree++; 792} 793 794 795/* 796 * vm_page_wire: 797 * 798 * Mark this page as wired down by yet 799 * another map, removing it from paging queues 800 * as necessary. 801 * 802 * The page queues must be locked. 803 */ 804void 805vm_page_wire(mem) 806 register vm_page_t mem; 807{ 808 int s; 809 810 if (mem->wire_count == 0) { 811 s = splhigh(); 812 vm_page_unqueue(mem); 813 splx(s); 814 cnt.v_wire_count++; 815 } 816 mem->flags |= PG_WRITEABLE|PG_MAPPED; 817 mem->wire_count++; 818} 819 820/* 821 * vm_page_unwire: 822 * 823 * Release one wiring of this page, potentially 824 * enabling it to be paged again. 825 * 826 * The page queues must be locked. 827 */ 828void 829vm_page_unwire(mem) 830 register vm_page_t mem; 831{ 832 int s; 833 834 s = splhigh(); 835 836 if (mem->wire_count) 837 mem->wire_count--; 838 if (mem->wire_count == 0) { 839 TAILQ_INSERT_TAIL(&vm_page_queue_active, mem, pageq); 840 cnt.v_active_count++; 841 mem->flags |= PG_ACTIVE; 842 cnt.v_wire_count--; 843 } 844 splx(s); 845} 846 847/* 848 * vm_page_activate: 849 * 850 * Put the specified page on the active list (if appropriate). 851 * 852 * The page queues must be locked. 853 */ 854void 855vm_page_activate(m) 856 register vm_page_t m; 857{ 858 int s; 859 860 s = splhigh(); 861 if (m->flags & PG_ACTIVE) 862 panic("vm_page_activate: already active"); 863 864 if (m->flags & PG_CACHE) 865 cnt.v_reactivated++; 866 867 vm_page_unqueue(m); 868 869 if (m->wire_count == 0) { 870 TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq); 871 m->flags |= PG_ACTIVE; 872 if (m->act_count < 5) 873 m->act_count = 5; 874 else if( m->act_count < ACT_MAX) 875 m->act_count += 1; 876 cnt.v_active_count++; 877 } 878 splx(s); 879} 880 881/* 882 * vm_page_deactivate: 883 * 884 * Returns the given page to the inactive list, 885 * indicating that no physical maps have access 886 * to this page. [Used by the physical mapping system.] 887 * 888 * The page queues must be locked. 889 */ 890void 891vm_page_deactivate(m) 892 register vm_page_t m; 893{ 894 int spl; 895 896 /* 897 * Only move active pages -- ignore locked or already inactive ones. 898 * 899 * XXX: sometimes we get pages which aren't wired down or on any queue - 900 * we need to put them on the inactive queue also, otherwise we lose 901 * track of them. Paul Mackerras (paulus@cs.anu.edu.au) 9-Jan-93. 902 */ 903 904 spl = splhigh(); 905 if (!(m->flags & PG_INACTIVE) && m->wire_count == 0 && 906 m->hold_count == 0) { 907 pmap_clear_reference(VM_PAGE_TO_PHYS(m)); 908 if (m->flags & PG_CACHE) 909 cnt.v_reactivated++; 910 vm_page_unqueue(m); 911 TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq); 912 m->flags |= PG_INACTIVE; 913 cnt.v_inactive_count++; 914 m->act_count = 0; 915 } 916 splx(spl); 917} 918 919/* 920 * vm_page_cache 921 * 922 * Put the specified page onto the page cache queue (if appropriate). 923 */ 924void 925vm_page_cache(m) 926 register vm_page_t m; 927{ 928 int s; 929 930 if ((m->flags & (PG_CACHE | PG_BUSY)) || m->busy || m->wire_count || 931 m->bmapped) 932 return; 933 934 s = splhigh(); 935 vm_page_unqueue(m); 936 vm_page_protect(m, VM_PROT_NONE); 937 938 TAILQ_INSERT_TAIL(&vm_page_queue_cache, m, pageq); 939 m->flags |= PG_CACHE; 940 cnt.v_cache_count++; 941 if ((cnt.v_free_count + cnt.v_cache_count) == cnt.v_free_min) { 942 wakeup(&cnt.v_free_count); 943 wakeup(&proc0); 944 } 945 if (vm_pageout_pages_needed) { 946 wakeup(&vm_pageout_pages_needed); 947 vm_pageout_pages_needed = 0; 948 } 949 950 splx(s); 951} 952 953/* 954 * vm_page_zero_fill: 955 * 956 * Zero-fill the specified page. 957 * Written as a standard pagein routine, to 958 * be used by the zero-fill object. 959 */ 960boolean_t 961vm_page_zero_fill(m) 962 vm_page_t m; 963{ 964 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 965 m->valid = VM_PAGE_BITS_ALL; 966 return (TRUE); 967} 968 969/* 970 * vm_page_copy: 971 * 972 * Copy one page to another 973 */ 974void 975vm_page_copy(src_m, dest_m) 976 vm_page_t src_m; 977 vm_page_t dest_m; 978{ 979 pmap_copy_page(VM_PAGE_TO_PHYS(src_m), VM_PAGE_TO_PHYS(dest_m)); 980 dest_m->valid = VM_PAGE_BITS_ALL; 981} 982 983 984/* 985 * mapping function for valid bits or for dirty bits in 986 * a page 987 */ 988inline int 989vm_page_bits(int base, int size) 990{ 991 u_short chunk; 992 993 if ((base == 0) && (size >= PAGE_SIZE)) 994 return VM_PAGE_BITS_ALL; 995 size = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); 996 base = (base % PAGE_SIZE) / DEV_BSIZE; 997 chunk = vm_page_dev_bsize_chunks[size / DEV_BSIZE]; 998 return (chunk << base) & VM_PAGE_BITS_ALL; 999} 1000 1001/* 1002 * set a page valid and clean 1003 */ 1004void 1005vm_page_set_validclean(m, base, size) 1006 vm_page_t m; 1007 int base; 1008 int size; 1009{ 1010 int pagebits = vm_page_bits(base, size); 1011 m->valid |= pagebits; 1012 m->dirty &= ~pagebits; 1013 if( base == 0 && size == PAGE_SIZE) 1014 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 1015} 1016 1017/* 1018 * set a page (partially) valid 1019 */ 1020void 1021vm_page_set_valid(m, base, size) 1022 vm_page_t m; 1023 int base; 1024 int size; 1025{ 1026 m->valid |= vm_page_bits(base, size); 1027} 1028 1029/* 1030 * set a page (partially) invalid 1031 */ 1032void 1033vm_page_set_invalid(m, base, size) 1034 vm_page_t m; 1035 int base; 1036 int size; 1037{ 1038 int bits; 1039 1040 m->valid &= ~(bits = vm_page_bits(base, size)); 1041 if (m->valid == 0) 1042 m->dirty &= ~bits; 1043} 1044 1045/* 1046 * is (partial) page valid? 1047 */ 1048int 1049vm_page_is_valid(m, base, size) 1050 vm_page_t m; 1051 int base; 1052 int size; 1053{ 1054 int bits = vm_page_bits(base, size); 1055 1056 if (m->valid && ((m->valid & bits) == bits)) 1057 return 1; 1058 else 1059 return 0; 1060} 1061 1062 1063/* 1064 * set a page (partially) dirty 1065 */ 1066void 1067vm_page_set_dirty(m, base, size) 1068 vm_page_t m; 1069 int base; 1070 int size; 1071{ 1072 if ((base != 0) || (size != PAGE_SIZE)) { 1073 if (pmap_is_modified(VM_PAGE_TO_PHYS(m))) { 1074 m->dirty = VM_PAGE_BITS_ALL; 1075 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 1076 return; 1077 } 1078 m->dirty |= vm_page_bits(base, size); 1079 } else { 1080 m->dirty = VM_PAGE_BITS_ALL; 1081 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 1082 } 1083} 1084 1085void 1086vm_page_test_dirty(m) 1087 vm_page_t m; 1088{ 1089 if ((m->dirty != VM_PAGE_BITS_ALL) && 1090 pmap_is_modified(VM_PAGE_TO_PHYS(m))) { 1091 m->dirty = VM_PAGE_BITS_ALL; 1092 } 1093} 1094 1095/* 1096 * set a page (partially) clean 1097 */ 1098void 1099vm_page_set_clean(m, base, size) 1100 vm_page_t m; 1101 int base; 1102 int size; 1103{ 1104 m->dirty &= ~vm_page_bits(base, size); 1105 if( base == 0 && size == PAGE_SIZE) 1106 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 1107} 1108 1109/* 1110 * is (partial) page clean 1111 */ 1112int 1113vm_page_is_clean(m, base, size) 1114 vm_page_t m; 1115 int base; 1116 int size; 1117{ 1118 if (pmap_is_modified(VM_PAGE_TO_PHYS(m))) { 1119 m->dirty = VM_PAGE_BITS_ALL; 1120 pmap_clear_modify(VM_PAGE_TO_PHYS(m)); 1121 } 1122 if ((m->dirty & m->valid & vm_page_bits(base, size)) == 0) 1123 return 1; 1124 else 1125 return 0; 1126} 1127 1128#ifdef DDB 1129void 1130print_page_info() 1131{ 1132 printf("cnt.v_free_count: %d\n", cnt.v_free_count); 1133 printf("cnt.v_cache_count: %d\n", cnt.v_cache_count); 1134 printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count); 1135 printf("cnt.v_active_count: %d\n", cnt.v_active_count); 1136 printf("cnt.v_wire_count: %d\n", cnt.v_wire_count); 1137 printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved); 1138 printf("cnt.v_free_min: %d\n", cnt.v_free_min); 1139 printf("cnt.v_free_target: %d\n", cnt.v_free_target); 1140 printf("cnt.v_cache_min: %d\n", cnt.v_cache_min); 1141 printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target); 1142} 1143#endif 1144