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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)vm_page.h 8.2 (Berkeley) 12/13/93 33 * 34 * 35 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 36 * All rights reserved. 37 * 38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 39 * 40 * Permission to use, copy, modify and distribute this software and 41 * its documentation is hereby granted, provided that both the copyright 42 * notice and this permission notice appear in all copies of the 43 * software, derivative works or modified versions, and any portions 44 * thereof, and that both notices appear in supporting documentation. 45 * 46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 49 * 50 * Carnegie Mellon requests users of this software to return to 51 * 52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 53 * School of Computer Science 54 * Carnegie Mellon University 55 * Pittsburgh PA 15213-3890 56 * 57 * any improvements or extensions that they make and grant Carnegie the 58 * rights to redistribute these changes. 59 * 60 * $FreeBSD$ 61 */ 62 63 /* 64 * Resident memory system definitions. 65 */ 66 67 #ifndef _VM_PAGE_ 68 #define _VM_PAGE_ 69 70 #include <vm/pmap.h> 71 72 /* 73 * Management of resident (logical) pages. 74 * 75 * A small structure is kept for each resident 76 * page, indexed by page number. Each structure 77 * is an element of several lists: 78 * 79 * A hash table bucket used to quickly 80 * perform object/offset lookups 81 * 82 * A list of all pages for a given object, 83 * so they can be quickly deactivated at 84 * time of deallocation. 85 * 86 * An ordered list of pages due for pageout. 87 * 88 * In addition, the structure contains the object 89 * and offset to which this page belongs (for pageout), 90 * and sundry status bits. 91 * 92 * In general, operations on this structure's mutable fields are 93 * synchronized using either one of or a combination of the lock on the 94 * object that the page belongs to (O), the pool lock for the page (P), 95 * or the lock for either the free or paging queues (Q). If a field is 96 * annotated below with two of these locks, then holding either lock is 97 * sufficient for read access, but both locks are required for write 98 * access. 99 * 100 * In contrast, the synchronization of accesses to the page's dirty field 101 * is machine dependent (M). In the machine-independent layer, the lock 102 * on the object that the page belongs to must be held in order to 103 * operate on the field. However, the pmap layer is permitted to set 104 * all bits within the field without holding that lock. Therefore, if 105 * the underlying architecture does not support atomic read-modify-write 106 * operations on the field's type, then the machine-independent layer 107 * must also hold the page queues lock when performing read-modify-write 108 * operations and the pmap layer must hold the page queues lock when 109 * setting the field. In the machine-independent layer, the 110 * implementation of read-modify-write operations on the field is 111 * encapsulated in vm_page_clear_dirty_mask(). 112 */ 113 114 TAILQ_HEAD(pglist, vm_page); 115 116 struct vm_page { 117 TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (Q) */ 118 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */ 119 struct vm_page *left; /* splay tree link (O) */ 120 struct vm_page *right; /* splay tree link (O) */ 121 122 vm_object_t object; /* which object am I in (O,P)*/ 123 vm_pindex_t pindex; /* offset into object (O,P) */ 124 vm_paddr_t phys_addr; /* physical address of page */ 125 struct md_page md; /* machine dependant stuff */ 126 uint8_t queue; /* page queue index (P,Q) */ 127 int8_t segind; 128 u_short flags; /* see below */ 129 uint8_t order; /* index of the buddy queue */ 130 uint8_t pool; 131 u_short cow; /* page cow mapping count (P) */ 132 u_int wire_count; /* wired down maps refs (P) */ 133 short hold_count; /* page hold count (P) */ 134 u_short oflags; /* page flags (O) */ 135 u_char act_count; /* page usage count (O) */ 136 u_char busy; /* page busy count (O) */ 137 /* NOTE that these must support one bit per DEV_BSIZE in a page!!! */ 138 /* so, on normal X86 kernels, they must be at least 8 bits wide */ 139 /* In reality, support for 32KB pages is not fully implemented. */ 140 #if PAGE_SIZE == 4096 141 u_char valid; /* map of valid DEV_BSIZE chunks (O) */ 142 u_char dirty; /* map of dirty DEV_BSIZE chunks (M) */ 143 #elif PAGE_SIZE == 8192 144 u_short valid; /* map of valid DEV_BSIZE chunks (O) */ 145 u_short dirty; /* map of dirty DEV_BSIZE chunks (M) */ 146 #elif PAGE_SIZE == 16384 147 u_int valid; /* map of valid DEV_BSIZE chunks (O) */ 148 u_int dirty; /* map of dirty DEV_BSIZE chunks (M) */ 149 #elif PAGE_SIZE == 32768 150 u_long valid; /* map of valid DEV_BSIZE chunks (O) */ 151 u_long dirty; /* map of dirty DEV_BSIZE chunks (M) */ 152 #endif 153 }; 154 155 /* 156 * Page flags stored in oflags: 157 * 158 * Access to these page flags is synchronized by the lock on the object 159 * containing the page (O). 160 */ 161 #define VPO_BUSY 0x0001 /* page is in transit */ 162 #define VPO_WANTED 0x0002 /* someone is waiting for page */ 163 #define VPO_SWAPINPROG 0x0200 /* swap I/O in progress on page */ 164 #define VPO_NOSYNC 0x0400 /* do not collect for syncer */ 165 166 #define PQ_NONE 255 167 #define PQ_INACTIVE 0 168 #define PQ_ACTIVE 1 169 #define PQ_HOLD 2 170 #define PQ_COUNT 3 171 172 struct vpgqueues { 173 struct pglist pl; 174 int *cnt; 175 }; 176 177 extern struct vpgqueues vm_page_queues[PQ_COUNT]; 178 179 struct vpglocks { 180 struct mtx data; 181 char pad[CACHE_LINE_SIZE - sizeof(struct mtx)]; 182 } __aligned(CACHE_LINE_SIZE); 183 184 extern struct vpglocks vm_page_queue_free_lock; 185 extern struct vpglocks pa_lock[]; 186 187 #if defined(__arm__) 188 #define PDRSHIFT PDR_SHIFT 189 #elif !defined(PDRSHIFT) 190 #define PDRSHIFT 21 191 #endif 192 193 #define pa_index(pa) ((pa) >> PDRSHIFT) 194 #define PA_LOCKPTR(pa) &pa_lock[pa_index((pa)) % PA_LOCK_COUNT].data 195 #define PA_LOCKOBJPTR(pa) ((struct lock_object *)PA_LOCKPTR((pa))) 196 #define PA_LOCK(pa) mtx_lock(PA_LOCKPTR(pa)) 197 #define PA_TRYLOCK(pa) mtx_trylock(PA_LOCKPTR(pa)) 198 #define PA_UNLOCK(pa) mtx_unlock(PA_LOCKPTR(pa)) 199 #define PA_UNLOCK_COND(pa) \ 200 do { \ 201 if ((pa) != 0) { \ 202 PA_UNLOCK((pa)); \ 203 (pa) = 0; \ 204 } \ 205 } while (0) 206 207 #define PA_LOCK_ASSERT(pa, a) mtx_assert(PA_LOCKPTR(pa), (a)) 208 209 #define vm_page_lockptr(m) (PA_LOCKPTR(VM_PAGE_TO_PHYS((m)))) 210 #define vm_page_lock(m) mtx_lock(vm_page_lockptr((m))) 211 #define vm_page_unlock(m) mtx_unlock(vm_page_lockptr((m))) 212 #define vm_page_trylock(m) mtx_trylock(vm_page_lockptr((m))) 213 #define vm_page_lock_assert(m, a) mtx_assert(vm_page_lockptr((m)), (a)) 214 215 #define vm_page_queue_free_mtx vm_page_queue_free_lock.data 216 /* 217 * These are the flags defined for vm_page. 218 * 219 * Note: PG_UNMANAGED (used by OBJT_PHYS) indicates that the page is 220 * not under PV management but otherwise should be treated as a 221 * normal page. Pages not under PV management cannot be paged out 222 * via the object/vm_page_t because there is no knowledge of their 223 * pte mappings, nor can they be removed from their objects via 224 * the object, and such pages are also not on any PQ queue. 225 * 226 * PG_REFERENCED may be cleared only if the object containing the page is 227 * locked. 228 * 229 * PG_WRITEABLE is set exclusively on managed pages by pmap_enter(). When it 230 * does so, the page must be VPO_BUSY. 231 */ 232 #define PG_CACHED 0x0001 /* page is cached */ 233 #define PG_FREE 0x0002 /* page is free */ 234 #define PG_WINATCFLS 0x0004 /* flush dirty page on inactive q */ 235 #define PG_FICTITIOUS 0x0008 /* physical page doesn't exist (O) */ 236 #define PG_WRITEABLE 0x0010 /* page is mapped writeable */ 237 #define PG_ZERO 0x0040 /* page is zeroed */ 238 #define PG_REFERENCED 0x0080 /* page has been referenced */ 239 #define PG_UNMANAGED 0x0800 /* No PV management for page */ 240 #define PG_MARKER 0x1000 /* special queue marker page */ 241 #define PG_SLAB 0x2000 /* object pointer is actually a slab */ 242 243 /* 244 * Misc constants. 245 */ 246 #define ACT_DECLINE 1 247 #define ACT_ADVANCE 3 248 #define ACT_INIT 5 249 #define ACT_MAX 64 250 251 #ifdef _KERNEL 252 253 #include <vm/vm_param.h> 254 255 /* 256 * Each pageable resident page falls into one of five lists: 257 * 258 * free 259 * Available for allocation now. 260 * 261 * cache 262 * Almost available for allocation. Still associated with 263 * an object, but clean and immediately freeable. 264 * 265 * hold 266 * Will become free after a pending I/O operation 267 * completes. 268 * 269 * The following lists are LRU sorted: 270 * 271 * inactive 272 * Low activity, candidates for reclamation. 273 * This is the list of pages that should be 274 * paged out next. 275 * 276 * active 277 * Pages that are "active" i.e. they have been 278 * recently referenced. 279 * 280 */ 281 282 struct vnode; 283 extern int vm_page_zero_count; 284 285 extern vm_page_t vm_page_array; /* First resident page in table */ 286 extern int vm_page_array_size; /* number of vm_page_t's */ 287 extern long first_page; /* first physical page number */ 288 289 #define VM_PAGE_IS_FREE(m) (((m)->flags & PG_FREE) != 0) 290 291 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr) 292 293 vm_page_t vm_phys_paddr_to_vm_page(vm_paddr_t pa); 294 295 static __inline vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa); 296 297 static __inline vm_page_t 298 PHYS_TO_VM_PAGE(vm_paddr_t pa) 299 { 300 #ifdef VM_PHYSSEG_SPARSE 301 return (vm_phys_paddr_to_vm_page(pa)); 302 #elif defined(VM_PHYSSEG_DENSE) 303 return (&vm_page_array[atop(pa) - first_page]); 304 #else 305 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined." 306 #endif 307 } 308 309 extern struct vpglocks vm_page_queue_lock; 310 311 #define vm_page_queue_mtx vm_page_queue_lock.data 312 #define vm_page_lock_queues() mtx_lock(&vm_page_queue_mtx) 313 #define vm_page_unlock_queues() mtx_unlock(&vm_page_queue_mtx) 314 315 #if PAGE_SIZE == 4096 316 #define VM_PAGE_BITS_ALL 0xffu 317 #elif PAGE_SIZE == 8192 318 #define VM_PAGE_BITS_ALL 0xffffu 319 #elif PAGE_SIZE == 16384 320 #define VM_PAGE_BITS_ALL 0xffffffffu 321 #elif PAGE_SIZE == 32768 322 #define VM_PAGE_BITS_ALL 0xfffffffffffffffflu 323 #endif 324 325 /* page allocation classes: */ 326 #define VM_ALLOC_NORMAL 0 327 #define VM_ALLOC_INTERRUPT 1 328 #define VM_ALLOC_SYSTEM 2 329 #define VM_ALLOC_CLASS_MASK 3 330 /* page allocation flags: */ 331 #define VM_ALLOC_WIRED 0x0020 /* non pageable */ 332 #define VM_ALLOC_ZERO 0x0040 /* Try to obtain a zeroed page */ 333 #define VM_ALLOC_RETRY 0x0080 /* Mandatory with vm_page_grab() */ 334 #define VM_ALLOC_NOOBJ 0x0100 /* No associated object */ 335 #define VM_ALLOC_NOBUSY 0x0200 /* Do not busy the page */ 336 #define VM_ALLOC_IFCACHED 0x0400 /* Fail if the page is not cached */ 337 #define VM_ALLOC_IFNOTCACHED 0x0800 /* Fail if the page is cached */ 338 #define VM_ALLOC_IGN_SBUSY 0x1000 /* vm_page_grab() only */ 339 340 #define VM_ALLOC_COUNT_SHIFT 16 341 #define VM_ALLOC_COUNT(count) ((count) << VM_ALLOC_COUNT_SHIFT) 342 343 void vm_page_flag_set(vm_page_t m, unsigned short bits); 344 void vm_page_flag_clear(vm_page_t m, unsigned short bits); 345 void vm_page_busy(vm_page_t m); 346 void vm_page_flash(vm_page_t m); 347 void vm_page_io_start(vm_page_t m); 348 void vm_page_io_finish(vm_page_t m); 349 void vm_page_hold(vm_page_t mem); 350 void vm_page_unhold(vm_page_t mem); 351 void vm_page_free(vm_page_t m); 352 void vm_page_free_zero(vm_page_t m); 353 void vm_page_dirty(vm_page_t m); 354 void vm_page_wakeup(vm_page_t m); 355 356 void vm_pageq_remove(vm_page_t m); 357 358 void vm_page_activate (vm_page_t); 359 vm_page_t vm_page_alloc (vm_object_t, vm_pindex_t, int); 360 vm_page_t vm_page_alloc_freelist(int, int); 361 struct vnode *vm_page_alloc_init(vm_page_t); 362 vm_page_t vm_page_grab (vm_object_t, vm_pindex_t, int); 363 void vm_page_cache(vm_page_t); 364 void vm_page_cache_free(vm_object_t, vm_pindex_t, vm_pindex_t); 365 void vm_page_cache_remove(vm_page_t); 366 void vm_page_cache_transfer(vm_object_t, vm_pindex_t, vm_object_t); 367 int vm_page_try_to_cache (vm_page_t); 368 int vm_page_try_to_free (vm_page_t); 369 void vm_page_dontneed(vm_page_t); 370 void vm_page_deactivate (vm_page_t); 371 vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t); 372 vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr); 373 void vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t); 374 vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t); 375 vm_page_t vm_page_next(vm_page_t m); 376 int vm_page_pa_tryrelock(pmap_t, vm_paddr_t, vm_paddr_t *); 377 vm_page_t vm_page_prev(vm_page_t m); 378 void vm_page_putfake(vm_page_t m); 379 void vm_page_remove (vm_page_t); 380 void vm_page_rename (vm_page_t, vm_object_t, vm_pindex_t); 381 void vm_page_requeue(vm_page_t m); 382 void vm_page_set_valid(vm_page_t m, int base, int size); 383 void vm_page_sleep(vm_page_t m, const char *msg); 384 vm_page_t vm_page_splay(vm_pindex_t, vm_page_t); 385 vm_offset_t vm_page_startup(vm_offset_t vaddr); 386 void vm_page_unhold_pages(vm_page_t *ma, int count); 387 void vm_page_unwire (vm_page_t, int); 388 void vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr); 389 void vm_page_wire (vm_page_t); 390 void vm_page_set_validclean (vm_page_t, int, int); 391 void vm_page_clear_dirty (vm_page_t, int, int); 392 void vm_page_set_invalid (vm_page_t, int, int); 393 int vm_page_is_valid (vm_page_t, int, int); 394 void vm_page_test_dirty (vm_page_t); 395 int vm_page_bits (int, int); 396 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid); 397 void vm_page_free_toq(vm_page_t m); 398 void vm_page_zero_idle_wakeup(void); 399 void vm_page_cowfault (vm_page_t); 400 int vm_page_cowsetup(vm_page_t); 401 void vm_page_cowclear (vm_page_t); 402 403 #ifdef INVARIANTS 404 void vm_page_object_lock_assert(vm_page_t m); 405 #define VM_PAGE_OBJECT_LOCK_ASSERT(m) vm_page_object_lock_assert(m) 406 #else 407 #define VM_PAGE_OBJECT_LOCK_ASSERT(m) (void)0 408 #endif 409 410 /* 411 * vm_page_sleep_if_busy: 412 * 413 * Sleep and release the page queues lock if VPO_BUSY is set or, 414 * if also_m_busy is TRUE, busy is non-zero. Returns TRUE if the 415 * thread slept and the page queues lock was released. 416 * Otherwise, retains the page queues lock and returns FALSE. 417 * 418 * The object containing the given page must be locked. 419 */ 420 static __inline int 421 vm_page_sleep_if_busy(vm_page_t m, int also_m_busy, const char *msg) 422 { 423 424 if ((m->oflags & VPO_BUSY) || (also_m_busy && m->busy)) { 425 vm_page_sleep(m, msg); 426 return (TRUE); 427 } 428 return (FALSE); 429 } 430 431 /* 432 * vm_page_undirty: 433 * 434 * Set page to not be dirty. Note: does not clear pmap modify bits 435 */ 436 static __inline void 437 vm_page_undirty(vm_page_t m) 438 { 439 440 VM_PAGE_OBJECT_LOCK_ASSERT(m); 441 m->dirty = 0; 442 } 443 444 #endif /* _KERNEL */ 445 #endif /* !_VM_PAGE_ */ 446