osfmk/vm/vm_page.h

   1 /*
   2  * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * @OSF_COPYRIGHT@
  25  */
  26 /*
  27  * Mach Operating System
  28  * Copyright (c) 1991,1990,1989,1988 Carnegie Mellon University
  29  * All Rights Reserved.
  30  *
  31  * Permission to use, copy, modify and distribute this software and its
  32  * documentation is hereby granted, provided that both the copyright
  33  * notice and this permission notice appear in all copies of the
  34  * software, derivative works or modified versions, and any portions
  35  * thereof, and that both notices appear in supporting documentation.
  36  *
  37  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  38  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  39  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  40  *
  41  * Carnegie Mellon requests users of this software to return to
  42  *
  43  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  44  *  School of Computer Science
  45  *  Carnegie Mellon University
  46  *  Pittsburgh PA 15213-3890
  47  *
  48  * any improvements or extensions that they make and grant Carnegie Mellon
  49  * the rights to redistribute these changes.
  50  */
  51 /*
  52  */
  53 /*
  54  *      File:   vm/vm_page.h
  55  *      Author: Avadis Tevanian, Jr., Michael Wayne Young
  56  *      Date:   1985
  57  *
  58  *      Resident memory system definitions.
  59  */
  60
  61 #ifndef _VM_VM_PAGE_H_
  62 #define _VM_VM_PAGE_H_
  63
  64 #include <debug.h>
  65
  66 #include <mach/boolean.h>
  67 #include <mach/vm_prot.h>
  68 #include <mach/vm_param.h>
  69 #include <vm/vm_object.h>
  70 #include <kern/queue.h>
  71 #include <kern/lock.h>
  72
  73 #include <kern/macro_help.h>
  74
  75 /*
  76  * Each page entered on the inactive queue obtains a ticket from a
  77  * particular ticket roll.  Pages granted tickets from a particular
  78  * roll  generally flow through the queue as a group.  In this way when a
  79  * page with a ticket from a particular roll is pulled from the top of the
  80  * queue it is extremely likely that the pages near the top will have tickets
  81  * from the same or adjacent rolls.  In this way the proximity to the top
  82  * of the queue can be loosely ascertained by determining the identity of
  83  * the roll the pages ticket came from.
  84  */
  85
  86
  87 extern unsigned int     vm_page_ticket_roll;
  88 extern unsigned int     vm_page_ticket;
  89
  90
  91 #define VM_PAGE_TICKETS_IN_ROLL  512
  92 #define VM_PAGE_TICKET_ROLL_IDS  16
  93
  94 /*
  95  *      Management of resident (logical) pages.
  96  *
  97  *      A small structure is kept for each resident
  98  *      page, indexed by page number.  Each structure
  99  *      is an element of several lists:
 100  *
 101  *              A hash table bucket used to quickly
 102  *              perform object/offset lookups
 103  *
 104  *              A list of all pages for a given object,
 105  *              so they can be quickly deactivated at
 106  *              time of deallocation.
 107  *
 108  *              An ordered list of pages due for pageout.
 109  *
 110  *      In addition, the structure contains the object
 111  *      and offset to which this page belongs (for pageout),
 112  *      and sundry status bits.
 113  *
 114  *      Fields in this structure are locked either by the lock on the
 115  *      object that the page belongs to (O) or by the lock on the page
 116  *      queues (P).  [Some fields require that both locks be held to
 117  *      change that field; holding either lock is sufficient to read.]
 118  */
 119
 120 struct vm_page {
 121         queue_chain_t   pageq;          /* queue info for FIFO
 122                                          * queue or free list (P) */
 123         queue_chain_t   listq;          /* all pages in same object (O) */
 124         struct vm_page  *next;          /* VP bucket link (O) */
 125
 126         vm_object_t     object;         /* which object am I in (O&P) */
 127         vm_object_offset_t offset;      /* offset into that object (O,P) */
 128
 129         /*
 130          * The following word of flags is protected
 131          * by the "page queues" lock.
 132          */
 133         unsigned int    wire_count:16,  /* how many wired down maps use me? (O&P) */
 134                         page_ticket:4,  /* age of the page on the       */
 135                                         /* inactive queue.                  */
 136         /* boolean_t */ inactive:1,     /* page is in inactive list (P) */
 137                         active:1,       /* page is in active list (P) */
 138                         pageout_queue:1,/* page is on queue for pageout (P) */
 139                         laundry:1,      /* page is being cleaned now (P)*/
 140                         free:1,         /* page is on free list (P) */
 141                         reference:1,    /* page has been used (P) */
 142                         pageout:1,      /* page wired & busy for pageout (P) */
 143                         gobbled:1,      /* page used internally (P) */
 144                         private:1,      /* Page should not be returned to
 145                                          *  the free list (P) */
 146                         zero_fill:1,
 147                         :0;
 148
 149         /*
 150          * The following word of flags is protected
 151          * by the "VM object" lock.
 152          */
 153         unsigned int
 154                         page_error:8,   /* error from I/O operations */
 155         /* boolean_t */ busy:1,         /* page is in transit (O) */
 156                         wanted:1,       /* someone is waiting for page (O) */
 157                         tabled:1,       /* page is in VP table (O) */
 158                         fictitious:1,   /* Physical page doesn't exist (O) */
 159                         no_isync:1,     /* page has not been instruction synced */
 160                         absent:1,       /* Data has been requested, but is
 161                                          *  not yet available (O) */
 162                         error:1,        /* Data manager was unable to provide
 163                                          *  data due to error (O) */
 164                         dirty:1,        /* Page must be cleaned (O) */
 165                         cleaning:1,     /* Page clean has begun (O) */
 166                         precious:1,     /* Page is precious; data must be
 167                                          *  returned even if clean (O) */
 168                         clustered:1,    /* page is not the faulted page (O) */
 169                         overwriting:1,  /* Request to unlock has been made
 170                                          * without having data. (O)
 171                                          * [See vm_fault_page_overwrite] */
 172                         restart:1,      /* Page was pushed higher in shadow
 173                                            chain by copy_call-related pagers;
 174                                            start again at top of chain */
 175                         lock_supplied:1,/* protection supplied by pager (O) */
 176         /* vm_prot_t */ page_lock:3,    /* Uses prohibited by pager (O) */
 177         /* vm_prot_t */ unlock_request:3,/* Outstanding unlock request (O) */
 178                         unusual:1,      /* Page is absent, error, restart or
 179                                            page locked */
 180                         encrypted:1,    /* encrypted for secure swap (O) */
 181                         list_req_pending:1, /* pagein/pageout alt mechanism */
 182                                             /* allows creation of list      */
 183                                             /* requests on pages that are   */
 184                                             /* actively being paged.        */
 185                         dump_cleaning:1;   /* set by the pageout daemon when */
 186                                            /* a page being cleaned is       */
 187                                            /* encountered and targeted as   */
 188                                            /* a pageout candidate           */
 189         /* we've used up all 32 bits */
 190
 191         ppnum_t         phys_page;      /* Physical address of page, passed
 192                                          *  to pmap_enter (read-only) */
 193 };
 194
 195 #define DEBUG_ENCRYPTED_SWAP    1
 196 #if DEBUG_ENCRYPTED_SWAP
 197 #define ASSERT_PAGE_DECRYPTED(page)                                     \
 198         MACRO_BEGIN                                                     \
 199         if ((page)->encrypted) {                                        \
 200                 panic("VM page %p should not be encrypted here\n",      \
 201                       (page));                                          \
 202         }                                                               \
 203         MACRO_END
 204 #else   /* DEBUG_ENCRYPTED_SWAP */
 205 #define ASSERT_PAGE_DECRYPTED(page) assert(!(page)->encrypted)
 206 #endif  /* DEBUG_ENCRYPTED_SWAP */
 207
 208 typedef struct vm_page  *vm_page_t;
 209
 210 #define VM_PAGE_NULL            ((vm_page_t) 0)
 211 #define NEXT_PAGE(m)            ((vm_page_t) (m)->pageq.next)
 212 #define NEXT_PAGE_PTR(m)        ((vm_page_t *) &(m)->pageq.next)
 213
 214 /*
 215  * XXX  The unusual bit should not be necessary.  Most of the bit
 216  * XXX  fields above really want to be masks.
 217  */
 218
 219 /*
 220  *      For debugging, this macro can be defined to perform
 221  *      some useful check on a page structure.
 222  */
 223
 224 #define VM_PAGE_CHECK(mem)
 225
 226 /*
 227  *      Each pageable resident page falls into one of three lists:
 228  *
 229  *      free
 230  *              Available for allocation now.
 231  *      inactive
 232  *              Not referenced in any map, but still has an
 233  *              object/offset-page mapping, and may be dirty.
 234  *              This is the list of pages that should be
 235  *              paged out next.
 236  *      active
 237  *              A list of pages which have been placed in
 238  *              at least one physical map.  This list is
 239  *              ordered, in LRU-like fashion.
 240  */
 241
 242 extern
 243 vm_page_t       vm_page_queue_free;     /* memory free queue */
 244 extern
 245 vm_page_t       vm_page_queue_fictitious;       /* fictitious free queue */
 246 extern
 247 queue_head_t    vm_page_queue_active;   /* active memory queue */
 248 extern
 249 queue_head_t    vm_page_queue_inactive; /* inactive memory queue */
 250 queue_head_t    vm_page_queue_zf;       /* inactive memory queue for zero fill */
 251
 252 extern
 253 vm_offset_t     first_phys_addr;        /* physical address for first_page */
 254 extern
 255 vm_offset_t     last_phys_addr;         /* physical address for last_page */
 256
 257 extern
 258 unsigned int    vm_page_free_count;     /* How many pages are free? */
 259 extern
 260 unsigned int    vm_page_fictitious_count;/* How many fictitious pages are free? */
 261 extern
 262 unsigned int    vm_page_active_count;   /* How many pages are active? */
 263 extern
 264 unsigned int    vm_page_inactive_count; /* How many pages are inactive? */
 265 extern
 266 unsigned int    vm_page_wire_count;     /* How many pages are wired? */
 267 extern
 268 unsigned int    vm_page_free_target;    /* How many do we want free? */
 269 extern
 270 unsigned int    vm_page_free_min;       /* When to wakeup pageout */
 271 extern
 272 unsigned int    vm_page_inactive_target;/* How many do we want inactive? */
 273 extern
 274 unsigned int    vm_page_free_reserved;  /* How many pages reserved to do pageout */
 275 extern
 276 unsigned int    vm_page_throttled_count;/* Count of zero-fill allocations throttled */
 277 extern
 278 unsigned int    vm_page_gobble_count;
 279
 280 extern
 281 unsigned int    vm_page_purgeable_count;/* How many pages are purgeable now ? */
 282 extern
 283 uint64_t        vm_page_purged_count;   /* How many pages got purged so far ? */
 284
 285 decl_mutex_data(,vm_page_queue_lock)
 286                                 /* lock on active and inactive page queues */
 287 decl_mutex_data(,vm_page_queue_free_lock)
 288                                 /* lock on free page queue */
 289
 290 extern unsigned int     vm_page_free_wanted;
 291                                 /* how many threads are waiting for memory */
 292
 293 extern vm_offset_t      vm_page_fictitious_addr;
 294                                 /* (fake) phys_addr of fictitious pages */
 295
 296 extern boolean_t        vm_page_deactivate_hint;
 297
 298 /*
 299  * Prototypes for functions exported by this module.
 300  */
 301 extern void             vm_page_bootstrap(
 302                                         vm_offset_t     *startp,
 303                                         vm_offset_t     *endp);
 304
 305 extern void             vm_page_module_init(void);
 306
 307 extern void             vm_page_create(
 308                                         ppnum_t         start,
 309                                         ppnum_t         end);
 310
 311 extern vm_page_t        vm_page_lookup(
 312                                         vm_object_t             object,
 313                                         vm_object_offset_t      offset);
 314
 315 extern vm_page_t        vm_page_grab_fictitious(void);
 316
 317 extern void             vm_page_release_fictitious(
 318                                         vm_page_t page);
 319
 320 extern boolean_t        vm_page_convert(
 321                                         vm_page_t       page);
 322
 323 extern void             vm_page_more_fictitious(void);
 324
 325 extern int              vm_pool_low(void);
 326
 327 extern vm_page_t        vm_page_grab(void);
 328
 329 extern void             vm_page_release(
 330                                         vm_page_t       page);
 331
 332 extern boolean_t        vm_page_wait(
 333                                         int             interruptible );
 334
 335 extern vm_page_t        vm_page_alloc(
 336                                         vm_object_t             object,
 337                                         vm_object_offset_t      offset);
 338
 339 extern void             vm_page_init(
 340                                         vm_page_t       page,
 341                                         ppnum_t         phys_page);
 342
 343 extern void             vm_page_free(
 344                                         vm_page_t       page);
 345
 346 extern void             vm_page_activate(
 347                                         vm_page_t       page);
 348
 349 extern void             vm_page_deactivate(
 350                                         vm_page_t       page);
 351
 352 extern void             vm_page_rename(
 353                                         vm_page_t               page,
 354                                         vm_object_t             new_object,
 355                                         vm_object_offset_t      new_offset);
 356
 357 extern void             vm_page_insert(
 358                                         vm_page_t               page,
 359                                         vm_object_t             object,
 360                                         vm_object_offset_t      offset);
 361
 362 extern void             vm_page_replace(
 363                                         vm_page_t               mem,
 364                                         vm_object_t             object,
 365                                         vm_object_offset_t      offset);
 366
 367 extern void             vm_page_remove(
 368                                         vm_page_t       page);
 369
 370 extern void             vm_page_zero_fill(
 371                                         vm_page_t       page);
 372
 373 extern void             vm_page_part_zero_fill(
 374                                         vm_page_t       m,
 375                                         vm_offset_t     m_pa,
 376                                         vm_size_t       len);
 377
 378 extern void             vm_page_copy(
 379                                         vm_page_t       src_page,
 380                                         vm_page_t       dest_page);
 381
 382 extern void             vm_page_part_copy(
 383                                         vm_page_t       src_m,
 384                                         vm_offset_t     src_pa,
 385                                         vm_page_t       dst_m,
 386                                         vm_offset_t     dst_pa,
 387                                         vm_size_t       len);
 388
 389 extern void             vm_page_wire(
 390                                         vm_page_t       page);
 391
 392 extern void             vm_page_unwire(
 393                                         vm_page_t       page);
 394
 395 extern void             vm_set_page_size(void);
 396
 397 extern void             vm_page_gobble(
 398                                         vm_page_t      page);
 399
 400 /*
 401  *      Functions implemented as macros. m->wanted and m->busy are
 402  *      protected by the object lock.
 403  */
 404
 405 #define PAGE_ASSERT_WAIT(m, interruptible)                      \
 406                 (((m)->wanted = TRUE),                          \
 407                  assert_wait((event_t) (m), (interruptible)))
 408
 409 #define PAGE_SLEEP(o, m, interruptible)                         \
 410                 (((m)->wanted = TRUE),                          \
 411                  thread_sleep_vm_object((o), (m), (interruptible)))
 412
 413 #define PAGE_WAKEUP_DONE(m)                                     \
 414                 MACRO_BEGIN                                     \
 415                 (m)->busy = FALSE;                              \
 416                 if ((m)->wanted) {                              \
 417                         (m)->wanted = FALSE;                    \
 418                         thread_wakeup((event_t) (m));           \
 419                 }                                               \
 420                 MACRO_END
 421
 422 #define PAGE_WAKEUP(m)                                          \
 423                 MACRO_BEGIN                                     \
 424                 if ((m)->wanted) {                              \
 425                         (m)->wanted = FALSE;                    \
 426                         thread_wakeup((event_t) (m));           \
 427                 }                                               \
 428                 MACRO_END
 429
 430 #define VM_PAGE_FREE(p)                         \
 431                 MACRO_BEGIN                     \
 432                 vm_page_lock_queues();          \
 433                 vm_page_free(p);                \
 434                 vm_page_unlock_queues();        \
 435                 MACRO_END
 436
 437 #define VM_PAGE_GRAB_FICTITIOUS(M)                                      \
 438                 MACRO_BEGIN                                             \
 439                 while ((M = vm_page_grab_fictitious()) == VM_PAGE_NULL) \
 440                         vm_page_more_fictitious();                      \
 441                 MACRO_END
 442
 443 #define VM_PAGE_THROTTLED()                                             \
 444                 (vm_page_free_count < vm_page_free_min &&               \
 445                  !(current_thread()->options & TH_OPT_VMPRIV) &&                        \
 446                  ++vm_page_throttled_count)
 447
 448 #define VM_PAGE_WAIT()          ((void)vm_page_wait(THREAD_UNINT))
 449
 450 #define vm_page_lock_queues()   mutex_lock(&vm_page_queue_lock)
 451 #define vm_page_unlock_queues() mutex_unlock(&vm_page_queue_lock)
 452
 453 #define VM_PAGE_QUEUES_REMOVE(mem)                              \
 454         MACRO_BEGIN                                             \
 455         assert(!mem->laundry);                                  \
 456         if (mem->active) {                                      \
 457                 assert(mem->object != kernel_object);           \
 458                 assert(!mem->inactive);                         \
 459                 queue_remove(&vm_page_queue_active,             \
 460                         mem, vm_page_t, pageq);                 \
 461                 mem->pageq.next = NULL;                         \
 462                 mem->pageq.prev = NULL;                         \
 463                 mem->active = FALSE;                            \
 464                 if (!mem->fictitious)                           \
 465                         vm_page_active_count--;                 \
 466         }                                                       \
 467                                                                 \
 468         if (mem->inactive) {                                    \
 469                 assert(mem->object != kernel_object);           \
 470                 assert(!mem->active);                           \
 471                 if (mem->zero_fill) {                           \
 472                         queue_remove(&vm_page_queue_zf,         \
 473                         mem, vm_page_t, pageq);                 \
 474                 } else {                                        \
 475                         queue_remove(&vm_page_queue_inactive,   \
 476                         mem, vm_page_t, pageq);                 \
 477                 }                                               \
 478                 mem->pageq.next = NULL;                         \
 479                 mem->pageq.prev = NULL;                         \
 480                 mem->inactive = FALSE;                          \
 481                 if (!mem->fictitious)                           \
 482                         vm_page_inactive_count--;               \
 483         }                                                       \
 484         MACRO_END
 485
 486 #endif  /* _VM_VM_PAGE_H_ */