1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 28 /* All Rights Reserved */ 29 30 /* 31 * University Copyright- Copyright (c) 1982, 1986, 1988 32 * The Regents of the University of California 33 * All Rights Reserved 34 * 35 * University Acknowledgment- Portions of this document are derived from 36 * software developed by the University of California, Berkeley, and its 37 * contributors. 38 */ 39 40 #ifndef _VM_PAGE_H 41 #define _VM_PAGE_H 42 43 #pragma ident "%Z%%M% %I% %E% SMI" 44 45 #include <vm/seg.h> 46 47 #ifdef __cplusplus 48 extern "C" { 49 #endif 50 51 #if defined(_KERNEL) || defined(_KMEMUSER) 52 53 /* 54 * Shared/Exclusive lock. 55 */ 56 57 /* 58 * Types of page locking supported by page_lock & friends. 59 */ 60 typedef enum { 61 SE_SHARED, 62 SE_EXCL /* exclusive lock (value == -1) */ 63 } se_t; 64 65 /* 66 * For requesting that page_lock reclaim the page from the free list. 67 */ 68 typedef enum { 69 P_RECLAIM, /* reclaim page from free list */ 70 P_NO_RECLAIM /* DON`T reclaim the page */ 71 } reclaim_t; 72 73 /* 74 * Callers of page_try_reclaim_lock and page_lock_es can use this flag 75 * to get SE_EXCL access before reader/writers are given access. 76 */ 77 #define SE_EXCL_WANTED 0x02 78 79 /* 80 * All page_*lock() requests will be denied unless this flag is set in 81 * the 'es' parameter. 82 */ 83 #define SE_RETIRED 0x04 84 85 #endif /* _KERNEL | _KMEMUSER */ 86 87 typedef int selock_t; 88 89 /* 90 * Define VM_STATS to turn on all sorts of statistic gathering about 91 * the VM layer. By default, it is only turned on when DEBUG is 92 * also defined. 93 */ 94 #ifdef DEBUG 95 #define VM_STATS 96 #endif /* DEBUG */ 97 98 #ifdef VM_STATS 99 #define VM_STAT_ADD(stat) (stat)++ 100 #define VM_STAT_COND_ADD(cond, stat) ((void) (!(cond) || (stat)++)) 101 #else 102 #define VM_STAT_ADD(stat) 103 #define VM_STAT_COND_ADD(cond, stat) 104 #endif /* VM_STATS */ 105 106 #ifdef _KERNEL 107 108 /* 109 * Macros to acquire and release the page logical lock. 110 */ 111 #define page_struct_lock(pp) mutex_enter(&page_llock) 112 #define page_struct_unlock(pp) mutex_exit(&page_llock) 113 114 #endif /* _KERNEL */ 115 116 #include <sys/t_lock.h> 117 118 struct as; 119 120 /* 121 * Each physical page has a page structure, which is used to maintain 122 * these pages as a cache. A page can be found via a hashed lookup 123 * based on the [vp, offset]. If a page has an [vp, offset] identity, 124 * then it is entered on a doubly linked circular list off the 125 * vnode using the vpnext/vpprev pointers. If the p_free bit 126 * is on, then the page is also on a doubly linked circular free 127 * list using next/prev pointers. If the "p_selock" and "p_iolock" 128 * are held, then the page is currently being read in (exclusive p_selock) 129 * or written back (shared p_selock). In this case, the next/prev pointers 130 * are used to link the pages together for a consecutive i/o request. If 131 * the page is being brought in from its backing store, then other processes 132 * will wait for the i/o to complete before attaching to the page since it 133 * will have an "exclusive" lock. 134 * 135 * Each page structure has the locks described below along with 136 * the fields they protect: 137 * 138 * p_selock This is a per-page shared/exclusive lock that is 139 * used to implement the logical shared/exclusive 140 * lock for each page. The "shared" lock is normally 141 * used in most cases while the "exclusive" lock is 142 * required to destroy or retain exclusive access to 143 * a page (e.g., while reading in pages). The appropriate 144 * lock is always held whenever there is any reference 145 * to a page structure (e.g., during i/o). 146 * (Note that with the addition of the "writer-lock-wanted" 147 * semantics (via SE_EWANTED), threads must not acquire 148 * multiple reader locks or else a deadly embrace will 149 * occur in the following situation: thread 1 obtains a 150 * reader lock; next thread 2 fails to get a writer lock 151 * but specified SE_EWANTED so it will wait by either 152 * blocking (when using page_lock_es) or spinning while 153 * retrying (when using page_try_reclaim_lock) until the 154 * reader lock is released; then thread 1 attempts to 155 * get another reader lock but is denied due to 156 * SE_EWANTED being set, and now both threads are in a 157 * deadly embrace.) 158 * 159 * p_hash 160 * p_vnode 161 * p_offset 162 * 163 * p_free 164 * p_age 165 * 166 * p_iolock This is a binary semaphore lock that provides 167 * exclusive access to the i/o list links in each 168 * page structure. It is always held while the page 169 * is on an i/o list (i.e., involved in i/o). That is, 170 * even though a page may be only `shared' locked 171 * while it is doing a write, the following fields may 172 * change anyway. Normally, the page must be 173 * `exclusively' locked to change anything in it. 174 * 175 * p_next 176 * p_prev 177 * 178 * The following fields are protected by the global page_llock: 179 * 180 * p_lckcnt 181 * p_cowcnt 182 * 183 * The following lists are protected by the global page_freelock: 184 * 185 * page_cachelist 186 * page_freelist 187 * 188 * The following, for our purposes, are protected by 189 * the global freemem_lock: 190 * 191 * freemem 192 * freemem_wait 193 * freemem_cv 194 * 195 * The following fields are protected by hat layer lock(s). When a page 196 * structure is not mapped and is not associated with a vnode (after a call 197 * to page_hashout() for example) the p_nrm field may be modified with out 198 * holding the hat layer lock: 199 * 200 * p_nrm 201 * p_mapping 202 * p_share 203 * 204 * The following field is file system dependent. How it is used and 205 * the locking strategies applied are up to the individual file system 206 * implementation. 207 * 208 * p_fsdata 209 * 210 * The page structure is used to represent and control the system's 211 * physical pages. There is one instance of the structure for each 212 * page that is not permenately allocated. For example, the pages that 213 * hold the page structures are permanently held by the kernel 214 * and hence do not need page structures to track them. The array 215 * of page structures is allocated early on in the kernel's life and 216 * is based on the amount of available physical memory. 217 * 218 * Each page structure may simultaneously appear on several linked lists. 219 * The lists are: hash list, free or in i/o list, and a vnode's page list. 220 * Each type of list is protected by a different group of mutexes as described 221 * below: 222 * 223 * The hash list is used to quickly find a page when the page's vnode and 224 * offset within the vnode are known. Each page that is hashed is 225 * connected via the `p_hash' field. The anchor for each hash is in the 226 * array `page_hash'. An array of mutexes, `ph_mutex', protects the 227 * lists anchored by page_hash[]. To either search or modify a given hash 228 * list, the appropriate mutex in the ph_mutex array must be held. 229 * 230 * The free list contains pages that are `free to be given away'. For 231 * efficiency reasons, pages on this list are placed in two catagories: 232 * pages that are still associated with a vnode, and pages that are not 233 * associated with a vnode. Free pages always have their `p_free' bit set, 234 * free pages that are still associated with a vnode also have their 235 * `p_age' bit set. Pages on the free list are connected via their 236 * `p_next' and `p_prev' fields. When a page is involved in some sort 237 * of i/o, it is not free and these fields may be used to link associated 238 * pages together. At the moment, the free list is protected by a 239 * single mutex `page_freelock'. The list of free pages still associated 240 * with a vnode is anchored by `page_cachelist' while other free pages 241 * are anchored in architecture dependent ways (to handle page coloring etc.). 242 * 243 * Pages associated with a given vnode appear on a list anchored in the 244 * vnode by the `v_pages' field. They are linked together with 245 * `p_vpnext' and `p_vpprev'. The field `p_offset' contains a page's 246 * offset within the vnode. The pages on this list are not kept in 247 * offset order. These lists, in a manner similar to the hash lists, 248 * are protected by an array of mutexes called `vph_hash'. Before 249 * searching or modifying this chain the appropriate mutex in the 250 * vph_hash[] array must be held. 251 * 252 * Again, each of the lists that a page can appear on is protected by a 253 * mutex. Before reading or writing any of the fields comprising the 254 * list, the appropriate lock must be held. These list locks should only 255 * be held for very short intervals. 256 * 257 * In addition to the list locks, each page structure contains a 258 * shared/exclusive lock that protects various fields within it. 259 * To modify one of these fields, the `p_selock' must be exclusively held. 260 * To read a field with a degree of certainty, the lock must be at least 261 * held shared. 262 * 263 * Removing a page structure from one of the lists requires holding 264 * the appropriate list lock and the page's p_selock. A page may be 265 * prevented from changing identity, being freed, or otherwise modified 266 * by acquiring p_selock shared. 267 * 268 * To avoid deadlocks, a strict locking protocol must be followed. Basically 269 * there are two cases: In the first case, the page structure in question 270 * is known ahead of time (e.g., when the page is to be added or removed 271 * from a list). In the second case, the page structure is not known and 272 * must be found by searching one of the lists. 273 * 274 * When adding or removing a known page to one of the lists, first the 275 * page must be exclusively locked (since at least one of its fields 276 * will be modified), second the lock protecting the list must be acquired, 277 * third the page inserted or deleted, and finally the list lock dropped. 278 * 279 * The more interesting case occures when the particular page structure 280 * is not known ahead of time. For example, when a call is made to 281 * page_lookup(), it is not known if a page with the desired (vnode and 282 * offset pair) identity exists. So the appropriate mutex in ph_mutex is 283 * acquired, the hash list searched, and if the desired page is found 284 * an attempt is made to lock it. The attempt to acquire p_selock must 285 * not block while the hash list lock is held. A deadlock could occure 286 * if some other process was trying to remove the page from the list. 287 * The removing process (following the above protocol) would have exclusively 288 * locked the page, and be spinning waiting to acquire the lock protecting 289 * the hash list. Since the searching process holds the hash list lock 290 * and is waiting to acquire the page lock, a deadlock occurs. 291 * 292 * The proper scheme to follow is: first, lock the appropriate list, 293 * search the list, and if the desired page is found either use 294 * page_trylock() (which will not block) or pass the address of the 295 * list lock to page_lock(). If page_lock() can not acquire the page's 296 * lock, it will drop the list lock before going to sleep. page_lock() 297 * returns a value to indicate if the list lock was dropped allowing the 298 * calling program to react appropriately (i.e., retry the operation). 299 * 300 * If the list lock was dropped before the attempt at locking the page 301 * was made, checks would have to be made to ensure that the page had 302 * not changed identity before its lock was obtained. This is because 303 * the interval between dropping the list lock and acquiring the page 304 * lock is indeterminate. 305 * 306 * In addition, when both a hash list lock (ph_mutex[]) and a vnode list 307 * lock (vph_mutex[]) are needed, the hash list lock must be acquired first. 308 * The routine page_hashin() is a good example of this sequence. 309 * This sequence is ASSERTed by checking that the vph_mutex[] is not held 310 * just before each acquisition of one of the mutexs in ph_mutex[]. 311 * 312 * So, as a quick summary: 313 * 314 * pse_mutex[]'s protect the p_selock and p_cv fields. 315 * 316 * p_selock protects the p_free, p_age, p_vnode, p_offset and p_hash, 317 * 318 * ph_mutex[]'s protect the page_hash[] array and its chains. 319 * 320 * vph_mutex[]'s protect the v_pages field and the vp page chains. 321 * 322 * First lock the page, then the hash chain, then the vnode chain. When 323 * this is not possible `trylocks' must be used. Sleeping while holding 324 * any of these mutexes (p_selock is not a mutex) is not allowed. 325 * 326 * 327 * field reading writing ordering 328 * ====================================================================== 329 * p_vnode p_selock(E,S) p_selock(E) 330 * p_offset 331 * p_free 332 * p_age 333 * ===================================================================== 334 * p_hash p_selock(E,S) p_selock(E) && p_selock, ph_mutex 335 * ph_mutex[] 336 * ===================================================================== 337 * p_vpnext p_selock(E,S) p_selock(E) && p_selock, vph_mutex 338 * p_vpprev vph_mutex[] 339 * ===================================================================== 340 * When the p_free bit is set: 341 * 342 * p_next p_selock(E,S) p_selock(E) && p_selock, 343 * p_prev page_freelock page_freelock 344 * 345 * When the p_free bit is not set: 346 * 347 * p_next p_selock(E,S) p_selock(E) && p_selock, p_iolock 348 * p_prev p_iolock 349 * ===================================================================== 350 * p_selock pse_mutex[] pse_mutex[] can`t acquire any 351 * p_cv other mutexes or 352 * sleep while holding 353 * this lock. 354 * ===================================================================== 355 * p_lckcnt p_selock(E,S) p_selock(E) && 356 * p_cowcnt page_llock 357 * ===================================================================== 358 * p_nrm hat layer lock hat layer lock 359 * p_mapping 360 * p_pagenum 361 * ===================================================================== 362 * 363 * where: 364 * E----> exclusive version of p_selock. 365 * S----> shared version of p_selock. 366 * 367 * 368 * Global data structures and variable: 369 * 370 * field reading writing ordering 371 * ===================================================================== 372 * page_hash[] ph_mutex[] ph_mutex[] can hold this lock 373 * before acquiring 374 * a vph_mutex or 375 * pse_mutex. 376 * ===================================================================== 377 * vp->v_pages vph_mutex[] vph_mutex[] can only acquire 378 * a pse_mutex while 379 * holding this lock. 380 * ===================================================================== 381 * page_cachelist page_freelock page_freelock can't acquire any 382 * page_freelist page_freelock page_freelock 383 * ===================================================================== 384 * freemem freemem_lock freemem_lock can't acquire any 385 * freemem_wait other mutexes while 386 * freemem_cv holding this mutex. 387 * ===================================================================== 388 * 389 * Page relocation, PG_NORELOC and P_NORELOC. 390 * 391 * Pages may be relocated using the page_relocate() interface. Relocation 392 * involves moving the contents and identity of a page to another, free page. 393 * To relocate a page, the SE_EXCL lock must be obtained. The way to prevent 394 * a page from being relocated is to hold the SE_SHARED lock (the SE_EXCL 395 * lock must not be held indefinitely). If the page is going to be held 396 * SE_SHARED indefinitely, then the PG_NORELOC hint should be passed 397 * to page_create_va so that pages that are prevented from being relocated 398 * can be managed differently by the platform specific layer. 399 * 400 * Pages locked in memory using page_pp_lock (p_lckcnt/p_cowcnt != 0) 401 * are guaranteed to be held in memory, but can still be relocated 402 * providing the SE_EXCL lock can be obtained. 403 * 404 * The P_NORELOC bit in the page_t.p_state field is provided for use by 405 * the platform specific code in managing pages when the PG_NORELOC 406 * hint is used. 407 * 408 * Memory delete and page locking. 409 * 410 * The set of all usable pages is managed using the global page list as 411 * implemented by the memseg structure defined below. When memory is added 412 * or deleted this list changes. Additions to this list guarantee that the 413 * list is never corrupt. In order to avoid the necessity of an additional 414 * lock to protect against failed accesses to the memseg being deleted and, 415 * more importantly, the page_ts, the memseg structure is never freed and the 416 * page_t virtual address space is remapped to a page (or pages) of 417 * zeros. If a page_t is manipulated while it is p_selock'd, or if it is 418 * locked indirectly via a hash or freelist lock, it is not possible for 419 * memory delete to collect the page and so that part of the page list is 420 * prevented from being deleted. If the page is referenced outside of one 421 * of these locks, it is possible for the page_t being referenced to be 422 * deleted. Examples of this are page_t pointers returned by 423 * page_numtopp_nolock, page_first and page_next. Providing the page_t 424 * is re-checked after taking the p_selock (for p_vnode != NULL), the 425 * remapping to the zero pages will be detected. 426 * 427 * 428 * Page size (p_szc field) and page locking. 429 * 430 * p_szc field of free pages is changed by free list manager under freelist 431 * locks and is of no concern to the rest of VM subsystem. 432 * 433 * p_szc changes of allocated anonymous (swapfs) can only be done only after 434 * exclusively locking all constituent pages and calling hat_pageunload() on 435 * each of them. To prevent p_szc changes of non free anonymous (swapfs) large 436 * pages it's enough to either lock SHARED any of constituent pages or prevent 437 * hat_pageunload() by holding hat level lock that protects mapping lists (this 438 * method is for hat code only) 439 * 440 * To increase (promote) p_szc of allocated non anonymous file system pages 441 * one has to first lock exclusively all involved constituent pages and call 442 * hat_pageunload() on each of them. To prevent p_szc promote it's enough to 443 * either lock SHARED any of constituent pages that will be needed to make a 444 * large page or prevent hat_pageunload() by holding hat level lock that 445 * protects mapping lists (this method is for hat code only). 446 * 447 * To decrease (demote) p_szc of an allocated non anonymous file system large 448 * page one can either use the same method as used for changeing p_szc of 449 * anonymous large pages or if it's not possible to lock all constituent pages 450 * exclusively a different method can be used. In the second method one only 451 * has to exclusively lock one of constituent pages but then one has to 452 * acquire further locks by calling page_szc_lock() and 453 * hat_page_demote(). hat_page_demote() acquires hat level locks and then 454 * demotes the page. This mechanism relies on the fact that any code that 455 * needs to prevent p_szc of a file system large page from changeing either 456 * locks all constituent large pages at least SHARED or locks some pages at 457 * least SHARED and calls page_szc_lock() or uses hat level page locks. 458 * Demotion using this method is implemented by page_demote_vp_pages(). 459 * Please see comments in front of page_demote_vp_pages(), hat_page_demote() 460 * and page_szc_lock() for more details. 461 * 462 * Lock order: p_selock, page_szc_lock, ph_mutex/vph_mutex/freelist, 463 * hat level locks. 464 */ 465 466 typedef struct page { 467 u_offset_t p_offset; /* offset into vnode for this page */ 468 struct vnode *p_vnode; /* vnode that this page is named by */ 469 selock_t p_selock; /* shared/exclusive lock on the page */ 470 #if defined(_LP64) 471 int p_selockpad; /* pad for growing selock */ 472 #endif 473 struct page *p_hash; /* hash by [vnode, offset] */ 474 struct page *p_vpnext; /* next page in vnode list */ 475 struct page *p_vpprev; /* prev page in vnode list */ 476 struct page *p_next; /* next page in free/intrans lists */ 477 struct page *p_prev; /* prev page in free/intrans lists */ 478 ushort_t p_lckcnt; /* number of locks on page data */ 479 ushort_t p_cowcnt; /* number of copy on write lock */ 480 kcondvar_t p_cv; /* page struct's condition var */ 481 kcondvar_t p_io_cv; /* for iolock */ 482 uchar_t p_iolock_state; /* replaces p_iolock */ 483 volatile uchar_t p_szc; /* page size code */ 484 uchar_t p_fsdata; /* file system dependent byte */ 485 uchar_t p_state; /* p_free, p_noreloc */ 486 uchar_t p_nrm; /* non-cache, ref, mod readonly bits */ 487 #if defined(__sparc) 488 uchar_t p_vcolor; /* virtual color */ 489 #else 490 uchar_t p_embed; /* x86 - changes p_mapping & p_index */ 491 #endif 492 uchar_t p_index; /* MPSS mapping info. Not used on x86 */ 493 uchar_t p_toxic; /* page has an unrecoverable error */ 494 void *p_mapping; /* hat specific translation info */ 495 pfn_t p_pagenum; /* physical page number */ 496 497 uint_t p_share; /* number of translations */ 498 #if defined(_LP64) 499 uint_t p_sharepad; /* pad for growing p_share */ 500 #endif 501 uint_t p_msresv_1; /* reserved for future use */ 502 #if defined(__sparc) 503 uint_t p_kpmref; /* number of kpm mapping sharers */ 504 struct kpme *p_kpmelist; /* kpm specific mapping info */ 505 #else 506 /* index of entry in p_map when p_embed is set */ 507 uint_t p_mlentry; 508 #endif 509 uint64_t p_msresv_2; /* page allocation debugging */ 510 } page_t; 511 512 513 typedef page_t devpage_t; 514 #define devpage page 515 516 517 /* 518 * Page hash table is a power-of-two in size, externally chained 519 * through the hash field. PAGE_HASHAVELEN is the average length 520 * desired for this chain, from which the size of the page_hash 521 * table is derived at boot time and stored in the kernel variable 522 * page_hashsz. In the hash function it is given by PAGE_HASHSZ. 523 * 524 * PAGE_HASH_FUNC returns an index into the page_hash[] array. This 525 * index is also used to derive the mutex that protects the chain. 526 * 527 * In constructing the hash function, first we dispose of unimportant bits 528 * (page offset from "off" and the low 3 bits of "vp" which are zero for 529 * struct alignment). Then shift and sum the remaining bits a couple times 530 * in order to get as many source bits from the two source values into the 531 * resulting hashed value. Note that this will perform quickly, since the 532 * shifting/summing are fast register to register operations with no additional 533 * memory references). 534 */ 535 #if NCPU < 4 536 #define PH_TABLE_SIZE 16 537 #define VP_SHIFT 7 538 #else 539 #define PH_TABLE_SIZE 128 540 #define VP_SHIFT 9 541 #endif 542 543 /* 544 * The amount to use for the successive shifts in the hash function below. 545 * The actual value is LOG2(PH_TABLE_SIZE), so that as many bits as 546 * possible will filter thru PAGE_HASH_FUNC() and PAGE_HASH_MUTEX(). 547 */ 548 #define PH_SHIFT_SIZE (7) 549 550 #define PAGE_HASHSZ page_hashsz 551 #define PAGE_HASHAVELEN 4 552 #define PAGE_HASH_FUNC(vp, off) \ 553 ((((uintptr_t)(off) >> PAGESHIFT) + \ 554 ((uintptr_t)(off) >> (PAGESHIFT + PH_SHIFT_SIZE)) + \ 555 ((uintptr_t)(vp) >> 3) + \ 556 ((uintptr_t)(vp) >> (3 + PH_SHIFT_SIZE)) + \ 557 ((uintptr_t)(vp) >> (3 + 2 * PH_SHIFT_SIZE))) & \ 558 (PAGE_HASHSZ - 1)) 559 #ifdef _KERNEL 560 561 /* 562 * The page hash value is re-hashed to an index for the ph_mutex array. 563 * 564 * For 64 bit kernels, the mutex array is padded out to prevent false 565 * sharing of cache sub-blocks (64 bytes) of adjacent mutexes. 566 * 567 * For 32 bit kernels, we don't want to waste kernel address space with 568 * padding, so instead we rely on the hash function to introduce skew of 569 * adjacent vnode/offset indexes (the left shift part of the hash function). 570 * Since sizeof (kmutex_t) is 8, we shift an additional 3 to skew to a different 571 * 64 byte sub-block. 572 */ 573 typedef struct pad_mutex { 574 kmutex_t pad_mutex; 575 #ifdef _LP64 576 char pad_pad[64 - sizeof (kmutex_t)]; 577 #endif 578 } pad_mutex_t; 579 extern pad_mutex_t ph_mutex[]; 580 581 #define PAGE_HASH_MUTEX(x) \ 582 &(ph_mutex[((x) + ((x) >> VP_SHIFT) + ((x) << 3)) & \ 583 (PH_TABLE_SIZE - 1)].pad_mutex) 584 585 /* 586 * Flags used while creating pages. 587 */ 588 #define PG_EXCL 0x0001 589 #define PG_WAIT 0x0002 590 #define PG_PHYSCONTIG 0x0004 /* NOT SUPPORTED */ 591 #define PG_MATCH_COLOR 0x0008 /* SUPPORTED by free list routines */ 592 #define PG_NORELOC 0x0010 /* Non-relocatable alloc hint. */ 593 /* Page must be PP_ISNORELOC */ 594 #define PG_PANIC 0x0020 /* system will panic if alloc fails */ 595 #define PG_PUSHPAGE 0x0040 /* alloc may use reserve */ 596 597 /* 598 * When p_selock has the SE_EWANTED bit set, threads waiting for SE_EXCL 599 * access are given priority over all other waiting threads. 600 */ 601 #define SE_EWANTED 0x40000000 602 #define PAGE_LOCKED(pp) (((pp)->p_selock & ~SE_EWANTED) != 0) 603 #define PAGE_SHARED(pp) (((pp)->p_selock & ~SE_EWANTED) > 0) 604 #define PAGE_EXCL(pp) ((pp)->p_selock < 0) 605 #define PAGE_LOCKED_SE(pp, se) \ 606 ((se) == SE_EXCL ? PAGE_EXCL(pp) : PAGE_SHARED(pp)) 607 608 extern long page_hashsz; 609 extern page_t **page_hash; 610 611 extern kmutex_t page_llock; /* page logical lock mutex */ 612 extern kmutex_t freemem_lock; /* freemem lock */ 613 614 extern pgcnt_t total_pages; /* total pages in the system */ 615 616 /* 617 * Variables controlling locking of physical memory. 618 */ 619 extern pgcnt_t pages_pp_maximum; /* tuning: lock + claim <= max */ 620 extern void init_pages_pp_maximum(void); 621 622 struct lgrp; 623 624 /* page_list_{add,sub} flags */ 625 626 /* which list */ 627 #define PG_FREE_LIST 0x0001 628 #define PG_CACHE_LIST 0x0002 629 630 /* where on list */ 631 #define PG_LIST_TAIL 0x0010 632 #define PG_LIST_HEAD 0x0020 633 634 /* called from */ 635 #define PG_LIST_ISINIT 0x1000 636 637 /* 638 * Page frame operations. 639 */ 640 page_t *page_lookup(struct vnode *, u_offset_t, se_t); 641 page_t *page_lookup_create(struct vnode *, u_offset_t, se_t, page_t *, 642 spgcnt_t *, int); 643 page_t *page_lookup_nowait(struct vnode *, u_offset_t, se_t); 644 page_t *page_find(struct vnode *, u_offset_t); 645 page_t *page_exists(struct vnode *, u_offset_t); 646 int page_exists_physcontig(vnode_t *, u_offset_t, uint_t, page_t *[]); 647 int page_exists_forreal(struct vnode *, u_offset_t, uint_t *); 648 void page_needfree(spgcnt_t); 649 page_t *page_create(struct vnode *, u_offset_t, size_t, uint_t); 650 int page_alloc_pages(struct vnode *, struct seg *, caddr_t, page_t **, 651 page_t **, uint_t, int); 652 page_t *page_create_va_large(vnode_t *vp, u_offset_t off, size_t bytes, 653 uint_t flags, struct seg *seg, caddr_t vaddr, void *arg); 654 page_t *page_create_va(struct vnode *, u_offset_t, size_t, uint_t, 655 struct seg *, caddr_t); 656 int page_create_wait(size_t npages, uint_t flags); 657 void page_create_putback(ssize_t npages); 658 void page_free(page_t *, int); 659 void page_free_at_startup(page_t *); 660 void page_free_pages(page_t *); 661 void free_vp_pages(struct vnode *, u_offset_t, size_t); 662 int page_reclaim(page_t *, kmutex_t *); 663 void page_destroy(page_t *, int); 664 void page_destroy_pages(page_t *); 665 void page_destroy_free(page_t *); 666 void page_rename(page_t *, struct vnode *, u_offset_t); 667 int page_hashin(page_t *, struct vnode *, u_offset_t, kmutex_t *); 668 void page_hashout(page_t *, kmutex_t *); 669 int page_num_hashin(pfn_t, struct vnode *, u_offset_t); 670 void page_add(page_t **, page_t *); 671 void page_add_common(page_t **, page_t *); 672 void page_sub(page_t **, page_t *); 673 void page_sub_common(page_t **, page_t *); 674 page_t *page_get_freelist(struct vnode *, u_offset_t, struct seg *, 675 caddr_t, size_t, uint_t, struct lgrp *); 676 677 page_t *page_get_cachelist(struct vnode *, u_offset_t, struct seg *, 678 caddr_t, uint_t, struct lgrp *); 679 void page_list_add(page_t *, int); 680 void page_boot_demote(page_t *); 681 void page_promote_size(page_t *, uint_t); 682 void page_list_add_pages(page_t *, int); 683 void page_list_sub(page_t *, int); 684 void page_list_sub_pages(page_t *, uint_t); 685 void page_list_xfer(page_t *, int, int); 686 void page_list_break(page_t **, page_t **, size_t); 687 void page_list_concat(page_t **, page_t **); 688 void page_vpadd(page_t **, page_t *); 689 void page_vpsub(page_t **, page_t *); 690 int page_lock(page_t *, se_t, kmutex_t *, reclaim_t); 691 int page_lock_es(page_t *, se_t, kmutex_t *, reclaim_t, int); 692 void page_lock_clr_exclwanted(page_t *); 693 int page_trylock(page_t *, se_t); 694 int page_try_reclaim_lock(page_t *, se_t, int); 695 int page_tryupgrade(page_t *); 696 void page_downgrade(page_t *); 697 void page_unlock(page_t *); 698 void page_unlock_noretire(page_t *); 699 void page_lock_delete(page_t *); 700 int page_pp_lock(page_t *, int, int); 701 void page_pp_unlock(page_t *, int, int); 702 int page_resv(pgcnt_t, uint_t); 703 void page_unresv(pgcnt_t); 704 void page_pp_useclaim(page_t *, page_t *, uint_t); 705 int page_addclaim(page_t *); 706 int page_subclaim(page_t *); 707 int page_addclaim_pages(page_t **); 708 int page_subclaim_pages(page_t **); 709 pfn_t page_pptonum(page_t *); 710 page_t *page_numtopp(pfn_t, se_t); 711 page_t *page_numtopp_noreclaim(pfn_t, se_t); 712 page_t *page_numtopp_nolock(pfn_t); 713 page_t *page_numtopp_nowait(pfn_t, se_t); 714 page_t *page_first(); 715 page_t *page_next(page_t *); 716 page_t *page_list_next(page_t *); 717 page_t *page_nextn(page_t *, ulong_t); 718 page_t *page_next_scan_init(void **); 719 page_t *page_next_scan_large(page_t *, ulong_t *, void **); 720 void prefetch_page_r(void *); 721 void ppcopy(page_t *, page_t *); 722 void page_relocate_hash(page_t *, page_t *); 723 void pagezero(page_t *, uint_t, uint_t); 724 void pagescrub(page_t *, uint_t, uint_t); 725 void page_io_lock(page_t *); 726 void page_io_unlock(page_t *); 727 int page_io_trylock(page_t *); 728 int page_iolock_assert(page_t *); 729 void page_iolock_init(page_t *); 730 pgcnt_t page_busy(int); 731 void page_lock_init(void); 732 ulong_t page_share_cnt(page_t *); 733 int page_isshared(page_t *); 734 int page_isfree(page_t *); 735 int page_isref(page_t *); 736 int page_ismod(page_t *); 737 int page_release(page_t *, int); 738 void page_retire_init(void); 739 int page_retire(uint64_t, uchar_t); 740 int page_retire_check(uint64_t, uint64_t *); 741 int page_unretire(uint64_t); 742 int page_unretire_pp(page_t *, int); 743 void page_tryretire(page_t *); 744 void page_retire_hunt(void (*)(page_t *)); 745 void page_retire_mdboot_cb(page_t *); 746 void page_clrtoxic(page_t *, uchar_t); 747 void page_settoxic(page_t *, uchar_t); 748 749 int page_mem_avail(pgcnt_t); 750 751 void page_set_props(page_t *, uint_t); 752 void page_clr_all_props(page_t *); 753 int page_clear_lck_cow(page_t *, int); 754 755 kmutex_t *page_vnode_mutex(struct vnode *); 756 kmutex_t *page_se_mutex(struct page *); 757 kmutex_t *page_szc_lock(struct page *); 758 int page_szc_lock_assert(struct page *pp); 759 760 /* 761 * Page relocation interfaces. page_relocate() is generic. 762 * page_get_replacement_page() is provided by the PSM. 763 * page_free_replacement_page() is generic. 764 */ 765 int group_page_trylock(page_t *, se_t); 766 void group_page_unlock(page_t *); 767 int page_relocate(page_t **, page_t **, int, int, spgcnt_t *, struct lgrp *); 768 int do_page_relocate(page_t **, page_t **, int, spgcnt_t *, struct lgrp *); 769 page_t *page_get_replacement_page(page_t *, struct lgrp *, uint_t); 770 void page_free_replacement_page(page_t *); 771 int page_relocate_cage(page_t **, page_t **); 772 773 int page_try_demote_pages(page_t *); 774 int page_try_demote_free_pages(page_t *); 775 void page_demote_free_pages(page_t *); 776 777 struct anon_map; 778 779 void page_mark_migrate(struct seg *, caddr_t, size_t, struct anon_map *, 780 ulong_t, vnode_t *, u_offset_t, int); 781 void page_migrate(struct seg *, caddr_t, page_t **, pgcnt_t); 782 783 /* 784 * Tell the PIM we are adding physical memory 785 */ 786 void add_physmem(page_t *, size_t, pfn_t); 787 void add_physmem_cb(page_t *, pfn_t); /* callback for page_t part */ 788 789 /* 790 * hw_page_array[] is configured with hardware supported page sizes by 791 * platform specific code. 792 */ 793 typedef struct { 794 size_t hp_size; 795 uint_t hp_shift; 796 pgcnt_t hp_pgcnt; /* base pagesize cnt */ 797 } hw_pagesize_t; 798 799 extern hw_pagesize_t hw_page_array[]; 800 extern uint_t page_colors, page_colors_mask; 801 extern uint_t page_coloring_shift; 802 extern int cpu_page_colors; 803 804 uint_t page_num_pagesizes(void); 805 uint_t page_num_user_pagesizes(void); 806 size_t page_get_pagesize(uint_t); 807 size_t page_get_user_pagesize(uint_t n); 808 pgcnt_t page_get_pagecnt(uint_t); 809 uint_t page_get_shift(uint_t); 810 int page_szc(size_t); 811 int page_szc_user_filtered(size_t); 812 813 814 /* page_get_replacement page flags */ 815 #define PGR_SAMESZC 0x1 /* only look for page size same as orig */ 816 #define PGR_NORELOC 0x2 /* allocate a P_NORELOC page */ 817 818 #endif /* _KERNEL */ 819 820 /* 821 * Constants used for the p_iolock_state 822 */ 823 #define PAGE_IO_INUSE 0x1 824 #define PAGE_IO_WANTED 0x2 825 826 /* 827 * Constants used for page_release status 828 */ 829 #define PGREL_NOTREL 0x1 830 #define PGREL_CLEAN 0x2 831 #define PGREL_MOD 0x3 832 833 /* 834 * The p_state field holds what used to be the p_age and p_free 835 * bits. These fields are protected by p_selock (see above). 836 */ 837 #define P_FREE 0x80 /* Page on free list */ 838 #define P_NORELOC 0x40 /* Page is non-relocatable */ 839 #define P_MIGRATE 0x20 /* Migrate page on next touch */ 840 #define P_SWAP 0x10 /* belongs to vnode that is V_ISSWAP */ 841 842 #define PP_ISFREE(pp) ((pp)->p_state & P_FREE) 843 #define PP_ISAGED(pp) (((pp)->p_state & P_FREE) && \ 844 ((pp)->p_vnode == NULL)) 845 #define PP_ISNORELOC(pp) ((pp)->p_state & P_NORELOC) 846 #define PP_ISKVP(pp) ((pp)->p_vnode == &kvp) 847 #define PP_ISNORELOCKERNEL(pp) (PP_ISNORELOC(pp) && PP_ISKVP(pp)) 848 #define PP_ISMIGRATE(pp) ((pp)->p_state & P_MIGRATE) 849 #define PP_ISSWAP(pp) ((pp)->p_state & P_SWAP) 850 851 #define PP_SETFREE(pp) ((pp)->p_state = ((pp)->p_state & ~P_MIGRATE) \ 852 | P_FREE) 853 #define PP_SETAGED(pp) ASSERT(PP_ISAGED(pp)) 854 #define PP_SETNORELOC(pp) ((pp)->p_state |= P_NORELOC) 855 #define PP_SETMIGRATE(pp) ((pp)->p_state |= P_MIGRATE) 856 #define PP_SETSWAP(pp) ((pp)->p_state |= P_SWAP) 857 858 #define PP_CLRFREE(pp) ((pp)->p_state &= ~P_FREE) 859 #define PP_CLRAGED(pp) ASSERT(!PP_ISAGED(pp)) 860 #define PP_CLRNORELOC(pp) ((pp)->p_state &= ~P_NORELOC) 861 #define PP_CLRMIGRATE(pp) ((pp)->p_state &= ~P_MIGRATE) 862 #define PP_CLRSWAP(pp) ((pp)->p_state &= ~P_SWAP) 863 864 /* 865 * Flags for page_t p_toxic, for tracking memory hardware errors. 866 * 867 * These flags are OR'ed into p_toxic with page_settoxic() to track which 868 * error(s) have occurred on a given page. The flags are cleared with 869 * page_clrtoxic(). Both page_settoxic() and page_cleartoxic use atomic 870 * primitives to manipulate the p_toxic field so no other locking is needed. 871 * 872 * When an error occurs on a page, p_toxic is set to record the error. The 873 * error could be a memory error or something else (i.e. a datapath). The Page 874 * Retire mechanism does not try to determine the exact cause of the error; 875 * Page Retire rightly leaves that sort of determination to FMA's Diagnostic 876 * Engine (DE). 877 * 878 * Note that, while p_toxic bits can be set without holding any locks, they 879 * should only be cleared while holding the page exclusively locked. 880 * 881 * Pages with PR_UE or PR_FMA flags are retired unconditionally, while pages 882 * with PR_MCE are retired if the system has not retired too many of them. 883 * 884 * A page must be exclusively locked to be retired. Pages can be retired if 885 * they are mapped, modified, or both, as long as they are not marked PR_UE, 886 * since pages with uncorrectable errors cannot be relocated in memory. 887 * Once a page has been successfully retired it is zeroed, attached to the 888 * retired_pages vnode and, finally, PR_RETIRED is set in p_toxic. The other 889 * p_toxic bits are NOT cleared. Pages are not left locked after retiring them 890 * to avoid special case code throughout the kernel; rather, page_*lock() will 891 * fail to lock the page, unless SE_RETIRED is passed as an argument. 892 * 893 * While we have your attention, go take a look at the comments at the 894 * beginning of page_retire.c too. 895 */ 896 #define PR_OK 0x00 /* no problem */ 897 #define PR_MCE 0x01 /* page has seen two or more CEs */ 898 #define PR_UE 0x02 /* page has an unhandled UE */ 899 #define PR_UE_SCRUBBED 0x04 /* page has seen a UE but was cleaned */ 900 #define PR_FMA 0x08 /* A DE wants this page retired */ 901 #define PR_RESV 0x10 /* Reserved for future use */ 902 #define PR_BUSY 0x20 /* Page retire is in progress */ 903 #define PR_MSG 0x40 /* message(s) already printed for this page */ 904 #define PR_RETIRED 0x80 /* This page has been retired */ 905 906 #define PR_REASONS (PR_UE | PR_MCE | PR_FMA) 907 #define PR_TOXIC (PR_UE) 908 #define PR_ERRMASK (PR_UE | PR_UE_SCRUBBED | PR_MCE | PR_FMA) 909 #define PR_ALLFLAGS (0xFF) 910 911 #define PP_RETIRED(pp) ((pp)->p_toxic & PR_RETIRED) 912 #define PP_TOXIC(pp) ((pp)->p_toxic & PR_TOXIC) 913 #define PP_PR_REQ(pp) (((pp)->p_toxic & PR_REASONS) && !PP_RETIRED(pp)) 914 #define PP_PR_NOSHARE(pp) \ 915 ((((pp)->p_toxic & (PR_RETIRED | PR_FMA | PR_UE)) == PR_FMA) && \ 916 !PP_ISKVP(pp)) 917 918 /* 919 * kpm large page description. 920 * The virtual address range of segkpm is divided into chunks of 921 * kpm_pgsz. Each chunk is controlled by a kpm_page_t. The ushort 922 * is sufficient for 2^^15 * PAGESIZE, so e.g. the maximum kpm_pgsz 923 * for 8K is 256M and 2G for 64K pages. It it kept as small as 924 * possible to save physical memory space. 925 * 926 * There are 2 segkpm mapping windows within in the virtual address 927 * space when we have to prevent VAC alias conflicts. The so called 928 * Alias window (mappings are always by PAGESIZE) is controlled by 929 * kp_refcnta. The regular window is controlled by kp_refcnt for the 930 * normal operation, which is to use the largest available pagesize. 931 * When VAC alias conflicts are present within a chunk in the regular 932 * window the large page mapping is broken up into smaller PAGESIZE 933 * mappings. kp_refcntc is used to control the pages that are invoked 934 * in the conflict and kp_refcnts holds the active mappings done 935 * with the small page size. In non vac conflict mode kp_refcntc is 936 * also used as "go" indication (-1) for the trap level tsbmiss 937 * handler. 938 */ 939 typedef struct kpm_page { 940 short kp_refcnt; /* pages mapped large */ 941 short kp_refcnta; /* pages mapped in Alias window */ 942 short kp_refcntc; /* TL-tsbmiss flag; #vac alias conflict pages */ 943 short kp_refcnts; /* vac alias: pages mapped small */ 944 } kpm_page_t; 945 946 /* 947 * Note: khl_lock offset changes must be reflected in sfmmu_asm.s 948 */ 949 typedef struct kpm_hlk { 950 kmutex_t khl_mutex; /* kpm_page mutex */ 951 uint_t khl_lock; /* trap level tsbmiss handling */ 952 } kpm_hlk_t; 953 954 /* 955 * kpm small page description. 956 * When kpm_pgsz is equal to PAGESIZE a smaller representation is used 957 * to save memory space. Alias range mappings and regular segkpm 958 * mappings are done in units of PAGESIZE and can share the mapping 959 * information and the mappings are always distinguishable by their 960 * virtual address. Other information neeeded for VAC conflict prevention 961 * is already available on a per page basis. There are basically 3 states 962 * a kpm_spage can have: not mapped (0), mapped in Alias range or virtually 963 * uncached (1) and mapped in the regular segkpm window (-1). The -1 value 964 * is also used as "go" indication for the segkpm trap level tsbmiss 965 * handler for small pages (value is kept the same as it is used for large 966 * mappings). 967 */ 968 typedef struct kpm_spage { 969 char kp_mapped; /* page mapped small */ 970 } kpm_spage_t; 971 972 /* 973 * Note: kshl_lock offset changes must be reflected in sfmmu_asm.s 974 */ 975 typedef struct kpm_shlk { 976 uint_t kshl_lock; /* trap level tsbmiss handling */ 977 } kpm_shlk_t; 978 979 /* 980 * Each segment of physical memory is described by a memseg struct. 981 * Within a segment, memory is considered contiguous. The members 982 * can be categorized as follows: 983 * . Platform independent: 984 * pages, epages, pages_base, pages_end, next, lnext. 985 * . 64bit only but platform independent: 986 * kpm_pbase, kpm_nkpmpgs, kpm_pages, kpm_spages. 987 * . Really platform or mmu specific: 988 * pagespa, epagespa, nextpa, kpm_pagespa. 989 * . Mixed: 990 * msegflags. 991 */ 992 struct memseg { 993 page_t *pages, *epages; /* [from, to] in page array */ 994 pfn_t pages_base, pages_end; /* [from, to] in page numbers */ 995 struct memseg *next; /* next segment in list */ 996 #if defined(__sparc) 997 struct memseg *lnext; /* next segment in deleted list */ 998 uint64_t pagespa, epagespa; /* [from, to] page array physical */ 999 uint64_t nextpa; /* physical next pointer */ 1000 pfn_t kpm_pbase; /* start of kpm range */ 1001 pgcnt_t kpm_nkpmpgs; /* # of kpm_pgsz pages */ 1002 union _mseg_un { 1003 kpm_page_t *kpm_lpgs; /* ptr to kpm_page array */ 1004 kpm_spage_t *kpm_spgs; /* ptr to kpm_spage array */ 1005 } mseg_un; 1006 uint64_t kpm_pagespa; /* physical ptr to kpm (s)pages array */ 1007 uint_t msegflags; /* memseg flags */ 1008 #endif /* __sparc */ 1009 }; 1010 1011 /* memseg union aliases */ 1012 #define kpm_pages mseg_un.kpm_lpgs 1013 #define kpm_spages mseg_un.kpm_spgs 1014 1015 /* msegflags */ 1016 #define MEMSEG_DYNAMIC 0x1 /* DR: memory was added dynamically */ 1017 1018 /* memseg support macros */ 1019 #define MSEG_NPAGES(SEG) ((SEG)->pages_end - (SEG)->pages_base) 1020 1021 /* memseg hash */ 1022 #define MEM_HASH_SHIFT 0x9 1023 #define N_MEM_SLOTS 0x200 /* must be a power of 2 */ 1024 #define MEMSEG_PFN_HASH(pfn) (((pfn)/mhash_per_slot) & (N_MEM_SLOTS - 1)) 1025 1026 /* memseg externals */ 1027 extern struct memseg *memsegs; /* list of memory segments */ 1028 extern ulong_t mhash_per_slot; 1029 extern uint64_t memsegspa; /* memsegs as physical address */ 1030 1031 void build_pfn_hash(); 1032 extern struct memseg *page_numtomemseg_nolock(pfn_t pfnum); 1033 1034 1035 #ifdef __cplusplus 1036 } 1037 #endif 1038 1039 #endif /* _VM_PAGE_H */ 1040