1 /* 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. 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.h 8.2 (Berkeley) 12/13/93 37 * 38 * 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 43 * 44 * Permission to use, copy, modify and distribute this software and 45 * its documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 * 64 * $FreeBSD$ 65 */ 66 67 /* 68 * Resident memory system definitions. 69 */ 70 71 #ifndef _VM_PAGE_ 72 #define _VM_PAGE_ 73 74 #if !defined(KLD_MODULE) 75 #include "opt_vmpage.h" 76 #endif 77 78 #include <vm/pmap.h> 79 #include <machine/atomic.h> 80 81 /* 82 * Management of resident (logical) pages. 83 * 84 * A small structure is kept for each resident 85 * page, indexed by page number. Each structure 86 * is an element of several lists: 87 * 88 * A hash table bucket used to quickly 89 * perform object/offset lookups 90 * 91 * A list of all pages for a given object, 92 * so they can be quickly deactivated at 93 * time of deallocation. 94 * 95 * An ordered list of pages due for pageout. 96 * 97 * In addition, the structure contains the object 98 * and offset to which this page belongs (for pageout), 99 * and sundry status bits. 100 * 101 * Fields in this structure are locked either by the lock on the 102 * object that the page belongs to (O) or by the lock on the page 103 * queues (P). 104 * 105 * The 'valid' and 'dirty' fields are distinct. A page may have dirty 106 * bits set without having associated valid bits set. This is used by 107 * NFS to implement piecemeal writes. 108 */ 109 110 TAILQ_HEAD(pglist, vm_page); 111 112 struct vm_page { 113 TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (P) */ 114 struct vm_page *hnext; /* hash table link (O,P) */ 115 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */ 116 117 vm_object_t object; /* which object am I in (O,P)*/ 118 vm_pindex_t pindex; /* offset into object (O,P) */ 119 vm_offset_t phys_addr; /* physical address of page */ 120 struct md_page md; /* machine dependant stuff */ 121 u_short queue; /* page queue index */ 122 u_short flags, /* see below */ 123 pc; /* page color */ 124 u_short wire_count; /* wired down maps refs (P) */ 125 short hold_count; /* page hold count */ 126 u_char act_count; /* page usage count */ 127 u_char busy; /* page busy count */ 128 /* NOTE that these must support one bit per DEV_BSIZE in a page!!! */ 129 /* so, on normal X86 kernels, they must be at least 8 bits wide */ 130 #if PAGE_SIZE == 4096 131 u_char valid; /* map of valid DEV_BSIZE chunks */ 132 u_char dirty; /* map of dirty DEV_BSIZE chunks */ 133 #elif PAGE_SIZE == 8192 134 u_short valid; /* map of valid DEV_BSIZE chunks */ 135 u_short dirty; /* map of dirty DEV_BSIZE chunks */ 136 #endif 137 }; 138 139 /* 140 * note: currently use SWAPBLK_NONE as an absolute value rather then 141 * a flag bit. 142 */ 143 144 #define SWAPBLK_MASK ((daddr_t)((u_daddr_t)-1 >> 1)) /* mask */ 145 #define SWAPBLK_NONE ((daddr_t)((u_daddr_t)SWAPBLK_MASK + 1))/* flag */ 146 147 #if !defined(KLD_MODULE) 148 149 /* 150 * Page coloring parameters 151 */ 152 /* Each of PQ_FREE, and PQ_CACHE have PQ_HASH_SIZE entries */ 153 154 /* Define one of the following */ 155 #if defined(PQ_HUGECACHE) 156 #define PQ_PRIME1 31 /* Prime number somewhat less than PQ_HASH_SIZE */ 157 #define PQ_PRIME2 23 /* Prime number somewhat less than PQ_HASH_SIZE */ 158 #define PQ_L2_SIZE 256 /* A number of colors opt for 1M cache */ 159 #endif 160 161 /* Define one of the following */ 162 #if defined(PQ_LARGECACHE) 163 #define PQ_PRIME1 31 /* Prime number somewhat less than PQ_HASH_SIZE */ 164 #define PQ_PRIME2 23 /* Prime number somewhat less than PQ_HASH_SIZE */ 165 #define PQ_L2_SIZE 128 /* A number of colors opt for 512K cache */ 166 #endif 167 168 169 /* 170 * Use 'options PQ_NOOPT' to disable page coloring 171 */ 172 #if defined(PQ_NOOPT) 173 #define PQ_PRIME1 1 174 #define PQ_PRIME2 1 175 #define PQ_L2_SIZE 1 176 #endif 177 178 #if defined(PQ_NORMALCACHE) 179 #define PQ_PRIME1 5 /* Prime number somewhat less than PQ_HASH_SIZE */ 180 #define PQ_PRIME2 3 /* Prime number somewhat less than PQ_HASH_SIZE */ 181 #define PQ_L2_SIZE 16 /* A reasonable number of colors (opt for 64K cache) */ 182 #endif 183 184 #if defined(PQ_MEDIUMCACHE) 185 #define PQ_PRIME1 13 /* Prime number somewhat less than PQ_HASH_SIZE */ 186 #define PQ_PRIME2 7 /* Prime number somewhat less than PQ_HASH_SIZE */ 187 #define PQ_L2_SIZE 64 /* A number of colors opt for 256K cache */ 188 #endif 189 190 #if !defined(PQ_L2_SIZE) 191 #define PQ_PRIME1 9 /* Produces a good PQ_L2_SIZE/3 + PQ_PRIME1 */ 192 #define PQ_PRIME2 5 /* Prime number somewhat less than PQ_HASH_SIZE */ 193 #define PQ_L2_SIZE 32 /* 512KB or smaller, 4-way set-associative cache */ 194 #endif 195 196 #define PQ_L2_MASK (PQ_L2_SIZE - 1) 197 198 #if 1 199 #define PQ_NONE 0 200 #define PQ_FREE 1 201 #define PQ_INACTIVE (1 + 1*PQ_L2_SIZE) 202 #define PQ_ACTIVE (2 + 1*PQ_L2_SIZE) 203 #define PQ_CACHE (3 + 1*PQ_L2_SIZE) 204 #define PQ_COUNT (3 + 2*PQ_L2_SIZE) 205 #else 206 #define PQ_NONE PQ_COUNT 207 #define PQ_FREE 0 208 #define PQ_INACTIVE PQ_L2_SIZE 209 #define PQ_ACTIVE (1 + PQ_L2_SIZE) 210 #define PQ_CACHE (2 + PQ_L2_SIZE) 211 #define PQ_COUNT (2 + 2*PQ_L2_SIZE) 212 #endif 213 214 struct vpgqueues { 215 struct pglist pl; 216 int *cnt; 217 int lcnt; 218 }; 219 220 extern struct vpgqueues vm_page_queues[PQ_COUNT]; 221 222 #endif 223 224 /* 225 * These are the flags defined for vm_page. 226 * 227 * Note: PG_FILLED and PG_DIRTY are added for the filesystems. 228 * 229 * Note: PG_UNMANAGED (used by OBJT_PHYS) indicates that the page is 230 * not under PV management but otherwise should be treated as a 231 * normal page. Pages not under PV management cannot be paged out 232 * via the object/vm_page_t because there is no knowledge of their 233 * pte mappings, nor can they be removed from their objects via 234 * the object, and such pages are also not on any PQ queue. 235 */ 236 #define PG_BUSY 0x0001 /* page is in transit (O) */ 237 #define PG_WANTED 0x0002 /* someone is waiting for page (O) */ 238 #define PG_FICTITIOUS 0x0008 /* physical page doesn't exist (O) */ 239 #define PG_WRITEABLE 0x0010 /* page is mapped writeable */ 240 #define PG_MAPPED 0x0020 /* page is mapped */ 241 #define PG_ZERO 0x0040 /* page is zeroed */ 242 #define PG_REFERENCED 0x0080 /* page has been referenced */ 243 #define PG_CLEANCHK 0x0100 /* page will be checked for cleaning */ 244 #define PG_SWAPINPROG 0x0200 /* swap I/O in progress on page */ 245 #define PG_NOSYNC 0x0400 /* do not collect for syncer */ 246 #define PG_UNMANAGED 0x0800 /* No PV management for page */ 247 248 /* 249 * Misc constants. 250 */ 251 252 #define ACT_DECLINE 1 253 #define ACT_ADVANCE 3 254 #define ACT_INIT 5 255 #define ACT_MAX 64 256 #define PFCLUSTER_BEHIND 3 257 #define PFCLUSTER_AHEAD 3 258 259 #ifdef _KERNEL 260 /* 261 * Each pageable resident page falls into one of four lists: 262 * 263 * free 264 * Available for allocation now. 265 * 266 * The following are all LRU sorted: 267 * 268 * cache 269 * Almost available for allocation. Still in an 270 * object, but clean and immediately freeable at 271 * non-interrupt times. 272 * 273 * inactive 274 * Low activity, candidates for reclamation. 275 * This is the list of pages that should be 276 * paged out next. 277 * 278 * active 279 * Pages that are "active" i.e. they have been 280 * recently referenced. 281 * 282 * zero 283 * Pages that are really free and have been pre-zeroed 284 * 285 */ 286 287 extern int vm_page_zero_count; 288 289 extern vm_page_t vm_page_array; /* First resident page in table */ 290 extern int vm_page_array_size; /* number of vm_page_t's */ 291 extern long first_page; /* first physical page number */ 292 293 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr) 294 295 #define PHYS_TO_VM_PAGE(pa) \ 296 (&vm_page_array[atop(pa) - first_page ]) 297 298 /* 299 * Functions implemented as macros 300 */ 301 302 static __inline void 303 vm_page_flag_set(vm_page_t m, unsigned int bits) 304 { 305 atomic_set_short(&(m)->flags, bits); 306 } 307 308 static __inline void 309 vm_page_flag_clear(vm_page_t m, unsigned int bits) 310 { 311 atomic_clear_short(&(m)->flags, bits); 312 } 313 314 #if 0 315 static __inline void 316 vm_page_assert_wait(vm_page_t m, int interruptible) 317 { 318 vm_page_flag_set(m, PG_WANTED); 319 assert_wait((int) m, interruptible); 320 } 321 #endif 322 323 static __inline void 324 vm_page_busy(vm_page_t m) 325 { 326 KASSERT((m->flags & PG_BUSY) == 0, ("vm_page_busy: page already busy!!!")); 327 vm_page_flag_set(m, PG_BUSY); 328 } 329 330 /* 331 * vm_page_flash: 332 * 333 * wakeup anyone waiting for the page. 334 */ 335 336 static __inline void 337 vm_page_flash(vm_page_t m) 338 { 339 if (m->flags & PG_WANTED) { 340 vm_page_flag_clear(m, PG_WANTED); 341 wakeup(m); 342 } 343 } 344 345 /* 346 * vm_page_wakeup: 347 * 348 * clear the PG_BUSY flag and wakeup anyone waiting for the 349 * page. 350 * 351 */ 352 353 static __inline void 354 vm_page_wakeup(vm_page_t m) 355 { 356 KASSERT(m->flags & PG_BUSY, ("vm_page_wakeup: page not busy!!!")); 357 vm_page_flag_clear(m, PG_BUSY); 358 vm_page_flash(m); 359 } 360 361 /* 362 * 363 * 364 */ 365 366 static __inline void 367 vm_page_io_start(vm_page_t m) 368 { 369 atomic_add_char(&(m)->busy, 1); 370 } 371 372 static __inline void 373 vm_page_io_finish(vm_page_t m) 374 { 375 atomic_subtract_char(&m->busy, 1); 376 if (m->busy == 0) 377 vm_page_flash(m); 378 } 379 380 381 #if PAGE_SIZE == 4096 382 #define VM_PAGE_BITS_ALL 0xff 383 #endif 384 385 #if PAGE_SIZE == 8192 386 #define VM_PAGE_BITS_ALL 0xffff 387 #endif 388 389 #define VM_ALLOC_NORMAL 0 390 #define VM_ALLOC_INTERRUPT 1 391 #define VM_ALLOC_SYSTEM 2 392 #define VM_ALLOC_ZERO 3 393 #define VM_ALLOC_RETRY 0x80 394 395 void vm_page_activate __P((vm_page_t)); 396 vm_page_t vm_page_alloc __P((vm_object_t, vm_pindex_t, int)); 397 vm_page_t vm_page_grab __P((vm_object_t, vm_pindex_t, int)); 398 void vm_page_cache __P((register vm_page_t)); 399 void vm_page_dontneed __P((register vm_page_t)); 400 static __inline void vm_page_copy __P((vm_page_t, vm_page_t)); 401 static __inline void vm_page_free __P((vm_page_t)); 402 static __inline void vm_page_free_zero __P((vm_page_t)); 403 void vm_page_deactivate __P((vm_page_t)); 404 void vm_page_insert __P((vm_page_t, vm_object_t, vm_pindex_t)); 405 vm_page_t vm_page_lookup __P((vm_object_t, vm_pindex_t)); 406 void vm_page_remove __P((vm_page_t)); 407 void vm_page_rename __P((vm_page_t, vm_object_t, vm_pindex_t)); 408 vm_offset_t vm_page_startup __P((vm_offset_t, vm_offset_t, vm_offset_t)); 409 vm_page_t vm_add_new_page __P((vm_offset_t pa)); 410 void vm_page_unmanage __P((vm_page_t)); 411 void vm_page_unwire __P((vm_page_t, int)); 412 void vm_page_wire __P((vm_page_t)); 413 void vm_page_unqueue __P((vm_page_t)); 414 void vm_page_unqueue_nowakeup __P((vm_page_t)); 415 void vm_page_set_validclean __P((vm_page_t, int, int)); 416 void vm_page_set_dirty __P((vm_page_t, int, int)); 417 void vm_page_clear_dirty __P((vm_page_t, int, int)); 418 void vm_page_set_invalid __P((vm_page_t, int, int)); 419 static __inline boolean_t vm_page_zero_fill __P((vm_page_t)); 420 int vm_page_is_valid __P((vm_page_t, int, int)); 421 void vm_page_test_dirty __P((vm_page_t)); 422 int vm_page_bits __P((int, int)); 423 vm_page_t _vm_page_list_find __P((int, int)); 424 #if 0 425 int vm_page_sleep(vm_page_t m, char *msg, char *busy); 426 int vm_page_asleep(vm_page_t m, char *msg, char *busy); 427 #endif 428 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid); 429 void vm_page_free_toq(vm_page_t m); 430 431 /* 432 * Keep page from being freed by the page daemon 433 * much of the same effect as wiring, except much lower 434 * overhead and should be used only for *very* temporary 435 * holding ("wiring"). 436 */ 437 static __inline void 438 vm_page_hold(vm_page_t mem) 439 { 440 mem->hold_count++; 441 } 442 443 static __inline void 444 vm_page_unhold(vm_page_t mem) 445 { 446 --mem->hold_count; 447 KASSERT(mem->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!")); 448 } 449 450 /* 451 * vm_page_protect: 452 * 453 * Reduce the protection of a page. This routine never raises the 454 * protection and therefore can be safely called if the page is already 455 * at VM_PROT_NONE (it will be a NOP effectively ). 456 */ 457 458 static __inline void 459 vm_page_protect(vm_page_t mem, int prot) 460 { 461 if (prot == VM_PROT_NONE) { 462 if (mem->flags & (PG_WRITEABLE|PG_MAPPED)) { 463 pmap_page_protect(mem, VM_PROT_NONE); 464 vm_page_flag_clear(mem, PG_WRITEABLE|PG_MAPPED); 465 } 466 } else if ((prot == VM_PROT_READ) && (mem->flags & PG_WRITEABLE)) { 467 pmap_page_protect(mem, VM_PROT_READ); 468 vm_page_flag_clear(mem, PG_WRITEABLE); 469 } 470 } 471 472 /* 473 * vm_page_zero_fill: 474 * 475 * Zero-fill the specified page. 476 * Written as a standard pagein routine, to 477 * be used by the zero-fill object. 478 */ 479 static __inline boolean_t 480 vm_page_zero_fill(m) 481 vm_page_t m; 482 { 483 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 484 return (TRUE); 485 } 486 487 /* 488 * vm_page_copy: 489 * 490 * Copy one page to another 491 */ 492 static __inline void 493 vm_page_copy(src_m, dest_m) 494 vm_page_t src_m; 495 vm_page_t dest_m; 496 { 497 pmap_copy_page(VM_PAGE_TO_PHYS(src_m), VM_PAGE_TO_PHYS(dest_m)); 498 dest_m->valid = VM_PAGE_BITS_ALL; 499 } 500 501 /* 502 * vm_page_free: 503 * 504 * Free a page 505 * 506 * The clearing of PG_ZERO is a temporary safety until the code can be 507 * reviewed to determine that PG_ZERO is being properly cleared on 508 * write faults or maps. PG_ZERO was previously cleared in 509 * vm_page_alloc(). 510 */ 511 static __inline void 512 vm_page_free(m) 513 vm_page_t m; 514 { 515 vm_page_flag_clear(m, PG_ZERO); 516 vm_page_free_toq(m); 517 } 518 519 /* 520 * vm_page_free_zero: 521 * 522 * Free a page to the zerod-pages queue 523 */ 524 static __inline void 525 vm_page_free_zero(m) 526 vm_page_t m; 527 { 528 vm_page_flag_set(m, PG_ZERO); 529 vm_page_free_toq(m); 530 } 531 532 /* 533 * vm_page_sleep_busy: 534 * 535 * Wait until page is no longer PG_BUSY or (if also_m_busy is TRUE) 536 * m->busy is zero. Returns TRUE if it had to sleep ( including if 537 * it almost had to sleep and made temporary spl*() mods), FALSE 538 * otherwise. 539 * 540 * This routine assumes that interrupts can only remove the busy 541 * status from a page, not set the busy status or change it from 542 * PG_BUSY to m->busy or vise versa (which would create a timing 543 * window). 544 * 545 * Note that being an inline, this code will be well optimized. 546 */ 547 548 static __inline int 549 vm_page_sleep_busy(vm_page_t m, int also_m_busy, const char *msg) 550 { 551 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) { 552 int s = splvm(); 553 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) { 554 /* 555 * Page is busy. Wait and retry. 556 */ 557 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 558 tsleep(m, PVM, msg, 0); 559 } 560 splx(s); 561 return(TRUE); 562 /* not reached */ 563 } 564 return(FALSE); 565 } 566 567 /* 568 * vm_page_dirty: 569 * 570 * make page all dirty 571 */ 572 573 static __inline void 574 vm_page_dirty(vm_page_t m) 575 { 576 #if !defined(KLD_MODULE) 577 KASSERT(m->queue - m->pc != PQ_CACHE, ("vm_page_dirty: page in cache!")); 578 #endif 579 m->dirty = VM_PAGE_BITS_ALL; 580 } 581 582 /* 583 * vm_page_undirty: 584 * 585 * Set page to not be dirty. Note: does not clear pmap modify bits 586 */ 587 588 static __inline void 589 vm_page_undirty(vm_page_t m) 590 { 591 m->dirty = 0; 592 } 593 594 #if !defined(KLD_MODULE) 595 596 static __inline vm_page_t 597 vm_page_list_find(int basequeue, int index, boolean_t prefer_zero) 598 { 599 vm_page_t m; 600 601 #if PQ_L2_SIZE > 1 602 if (prefer_zero) { 603 m = TAILQ_LAST(&vm_page_queues[basequeue+index].pl, pglist); 604 } else { 605 m = TAILQ_FIRST(&vm_page_queues[basequeue+index].pl); 606 } 607 if (m == NULL) 608 m = _vm_page_list_find(basequeue, index); 609 #else 610 if (prefer_zero) { 611 m = TAILQ_LAST(&vm_page_queues[basequeue].pl, pglist); 612 } else { 613 m = TAILQ_FIRST(&vm_page_queues[basequeue].pl); 614 } 615 #endif 616 return(m); 617 } 618 619 #endif 620 621 #endif /* _KERNEL */ 622 #endif /* !_VM_PAGE_ */ 623