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  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_COPYRIGHT@
  24  */
  25 /*
  26  * Mach Operating System
  27  * Copyright (c) 1991,1990,1989,1988 Carnegie Mellon University
  28  * All Rights Reserved.
  29  *
  30  * Permission to use, copy, modify and distribute this software and its
  31  * documentation is hereby granted, provided that both the copyright
  32  * notice and this permission notice appear in all copies of the
  33  * software, derivative works or modified versions, and any portions
  34  * thereof, and that both notices appear in supporting documentation.
  35  *
  36  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  37  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  38  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  39  *
  40  * Carnegie Mellon requests users of this software to return to
  41  *
  42  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  43  *  School of Computer Science
  44  *  Carnegie Mellon University
  45  *  Pittsburgh PA 15213-3890
  46  *
  47  * any improvements or extensions that they make and grant Carnegie Mellon
  48  * the rights to redistribute these changes.
  49  */
  50 /*
  51  */
  52 /*
  53  *      File:   vm/vm_page.h
  54  *      Author: Avadis Tevanian, Jr., Michael Wayne Young
  55  *      Date:   1985
  56  *
  57  *      Resident memory system definitions.
  58  */
  59
  60 #ifndef _VM_VM_PAGE_H_
  61 #define _VM_VM_PAGE_H_
  62
  63 #include <debug.h>
  64
  65 #include <mach/boolean.h>
  66 #include <mach/vm_prot.h>
  67 #include <mach/vm_param.h>
  68 #include <vm/vm_object.h>
  69 #include <kern/queue.h>
  70 #include <kern/lock.h>
  71
  72 #include <kern/macro_help.h>
  73
  74 /*
  75  * Each page entered on the inactive queue obtains a ticket from a
  76  * particular ticket roll.  Pages granted tickets from a particular
  77  * roll  generally flow through the queue as a group.  In this way when a
  78  * page with a ticket from a particular roll is pulled from the top of the
  79  * queue it is extremely likely that the pages near the top will have tickets
  80  * from the same or adjacent rolls.  In this way the proximity to the top
  81  * of the queue can be loosely ascertained by determining the identity of
  82  * the roll the pages ticket came from.
  83  */
  84
  85
  86 extern unsigned int     vm_page_ticket_roll;
  87 extern unsigned int     vm_page_ticket;
  88
  89
  90 #define VM_PAGE_TICKETS_IN_ROLL  512
  91 #define VM_PAGE_TICKET_ROLL_IDS  16
  92
  93 /*
  94  *      Management of resident (logical) pages.
  95  *
  96  *      A small structure is kept for each resident
  97  *      page, indexed by page number.  Each structure
  98  *      is an element of several lists:
  99  *
 100  *              A hash table bucket used to quickly
 101  *              perform object/offset lookups
 102  *
 103  *              A list of all pages for a given object,
 104  *              so they can be quickly deactivated at
 105  *              time of deallocation.
 106  *
 107  *              An ordered list of pages due for pageout.
 108  *
 109  *      In addition, the structure contains the object
 110  *      and offset to which this page belongs (for pageout),
 111  *      and sundry status bits.
 112  *
 113  *      Fields in this structure are locked either by the lock on the
 114  *      object that the page belongs to (O) or by the lock on the page
 115  *      queues (P).  [Some fields require that both locks be held to
 116  *      change that field; holding either lock is sufficient to read.]
 117  */
 118
 119 struct vm_page {
 120         queue_chain_t   pageq;          /* queue info for FIFO
 121                                          * queue or free list (P) */
 122         queue_chain_t   listq;          /* all pages in same object (O) */
 123         struct vm_page  *next;          /* VP bucket link (O) */
 124
 125         vm_object_t     object;         /* which object am I in (O&P) */
 126         vm_object_offset_t offset;      /* offset into that object (O,P) */
 127
 128         /*
 129          * The following word of flags is protected
 130          * by the "page queues" lock.
 131          */
 132         unsigned int    wire_count:16,  /* how many wired down maps use me? (O&P) */
 133                         page_ticket:4,  /* age of the page on the       */
 134                                         /* inactive queue.                  */
 135         /* boolean_t */ inactive:1,     /* page is in inactive list (P) */
 136                         active:1,       /* page is in active list (P) */
 137                         pageout_queue:1,/* page is on queue for pageout (P) */
 138                         laundry:1,      /* page is being cleaned now (P)*/
 139                         free:1,         /* page is on free list (P) */
 140                         reference:1,    /* page has been used (P) */
 141                         pageout:1,      /* page wired & busy for pageout (P) */
 142                         gobbled:1,      /* page used internally (P) */
 143                         private:1,      /* Page should not be returned to
 144                                          *  the free list (P) */
 145                         zero_fill:1,
 146                         :0;
 147
 148         /*
 149          * The following word of flags is protected
 150          * by the "VM object" lock.
 151          */
 152         unsigned int
 153                         page_error:8,   /* error from I/O operations */
 154         /* boolean_t */ busy:1,         /* page is in transit (O) */
 155                         wanted:1,       /* someone is waiting for page (O) */
 156                         tabled:1,       /* page is in VP table (O) */
 157                         fictitious:1,   /* Physical page doesn't exist (O) */
 158                         no_isync:1,     /* page has not been instruction synced */
 159                         absent:1,       /* Data has been requested, but is
 160                                          *  not yet available (O) */
 161                         error:1,        /* Data manager was unable to provide
 162                                          *  data due to error (O) */
 163                         dirty:1,        /* Page must be cleaned (O) */
 164                         cleaning:1,     /* Page clean has begun (O) */
 165                         precious:1,     /* Page is precious; data must be
 166                                          *  returned even if clean (O) */
 167                         clustered:1,    /* page is not the faulted page (O) */
 168                         overwriting:1,  /* Request to unlock has been made
 169                                          * without having data. (O)
 170                                          * [See vm_fault_page_overwrite] */
 171                         restart:1,      /* Page was pushed higher in shadow
 172                                            chain by copy_call-related pagers;
 173                                            start again at top of chain */
 174                         lock_supplied:1,/* protection supplied by pager (O) */
 175         /* vm_prot_t */ page_lock:3,    /* Uses prohibited by pager (O) */
 176         /* vm_prot_t */ unlock_request:3,/* Outstanding unlock request (O) */
 177                         unusual:1,      /* Page is absent, error, restart or
 178                                            page locked */
 179                         encrypted:1,    /* encrypted for secure swap (O) */
 180                         list_req_pending:1, /* pagein/pageout alt mechanism */
 181                                             /* allows creation of list      */
 182                                             /* requests on pages that are   */
 183                                             /* actively being paged.        */
 184                         dump_cleaning:1;   /* set by the pageout daemon when */
 185                                            /* a page being cleaned is       */
 186                                            /* encountered and targeted as   */
 187                                            /* a pageout candidate           */
 188         /* we've used up all 32 bits */
 189
 190         ppnum_t         phys_page;      /* Physical address of page, passed
 191                                          *  to pmap_enter (read-only) */
 192 };
 193
 194 #define DEBUG_ENCRYPTED_SWAP    1
 195 #if DEBUG_ENCRYPTED_SWAP
 196 #define ASSERT_PAGE_DECRYPTED(page)                                     \
 197         MACRO_BEGIN                                                     \
 198         if ((page)->encrypted) {                                        \
 199                 panic("VM page %p should not be encrypted here\n",      \
 200                       (page));                                          \
 201         }                                                               \
 202         MACRO_END
 203 #else   /* DEBUG_ENCRYPTED_SWAP */
 204 #define ASSERT_PAGE_DECRYPTED(page) assert(!(page)->encrypted)
 205 #endif  /* DEBUG_ENCRYPTED_SWAP */
 206
 207 typedef struct vm_page  *vm_page_t;
 208
 209 #define VM_PAGE_NULL            ((vm_page_t) 0)
 210 #define NEXT_PAGE(m)            ((vm_page_t) (m)->pageq.next)
 211 #define NEXT_PAGE_PTR(m)        ((vm_page_t *) &(m)->pageq.next)
 212
 213 /*
 214  * XXX  The unusual bit should not be necessary.  Most of the bit
 215  * XXX  fields above really want to be masks.
 216  */
 217
 218 /*
 219  *      For debugging, this macro can be defined to perform
 220  *      some useful check on a page structure.
 221  */
 222
 223 #define VM_PAGE_CHECK(mem)
 224
 225 /*
 226  *      Each pageable resident page falls into one of three lists:
 227  *
 228  *      free
 229  *              Available for allocation now.
 230  *      inactive
 231  *              Not referenced in any map, but still has an
 232  *              object/offset-page mapping, and may be dirty.
 233  *              This is the list of pages that should be
 234  *              paged out next.
 235  *      active
 236  *              A list of pages which have been placed in
 237  *              at least one physical map.  This list is
 238  *              ordered, in LRU-like fashion.
 239  */
 240
 241 extern
 242 vm_page_t       vm_page_queue_free;     /* memory free queue */
 243 extern
 244 vm_page_t       vm_page_queue_fictitious;       /* fictitious free queue */
 245 extern
 246 queue_head_t    vm_page_queue_active;   /* active memory queue */
 247 extern
 248 queue_head_t    vm_page_queue_inactive; /* inactive memory queue */
 249 queue_head_t    vm_page_queue_zf;       /* inactive memory queue for zero fill */
 250
 251 extern
 252 vm_offset_t     first_phys_addr;        /* physical address for first_page */
 253 extern
 254 vm_offset_t     last_phys_addr;         /* physical address for last_page */
 255
 256 extern
 257 unsigned int    vm_page_free_count;     /* How many pages are free? */
 258 extern
 259 unsigned int    vm_page_fictitious_count;/* How many fictitious pages are free? */
 260 extern
 261 unsigned int    vm_page_active_count;   /* How many pages are active? */
 262 extern
 263 unsigned int    vm_page_inactive_count; /* How many pages are inactive? */
 264 extern
 265 unsigned int    vm_page_wire_count;     /* How many pages are wired? */
 266 extern
 267 unsigned int    vm_page_free_target;    /* How many do we want free? */
 268 extern
 269 unsigned int    vm_page_free_min;       /* When to wakeup pageout */
 270 extern
 271 unsigned int    vm_page_inactive_target;/* How many do we want inactive? */
 272 extern
 273 unsigned int    vm_page_free_reserved;  /* How many pages reserved to do pageout */
 274 extern
 275 unsigned int    vm_page_throttled_count;/* Count of zero-fill allocations throttled */
 276 extern
 277 unsigned int    vm_page_gobble_count;
 278
 279 extern
 280 unsigned int    vm_page_purgeable_count;/* How many pages are purgeable now ? */
 281 extern
 282 uint64_t        vm_page_purged_count;   /* How many pages got purged so far ? */
 283
 284 decl_mutex_data(,vm_page_queue_lock)
 285                                 /* lock on active and inactive page queues */
 286 decl_mutex_data(,vm_page_queue_free_lock)
 287                                 /* lock on free page queue */
 288
 289 extern unsigned int     vm_page_free_wanted;
 290                                 /* how many threads are waiting for memory */
 291
 292 extern vm_offset_t      vm_page_fictitious_addr;
 293                                 /* (fake) phys_addr of fictitious pages */
 294
 295 extern boolean_t        vm_page_deactivate_hint;
 296
 297 /*
 298  * Prototypes for functions exported by this module.
 299  */
 300 extern void             vm_page_bootstrap(
 301                                         vm_offset_t     *startp,
 302                                         vm_offset_t     *endp);
 303
 304 extern void             vm_page_module_init(void);
 305
 306 extern void             vm_page_create(
 307                                         ppnum_t         start,
 308                                         ppnum_t         end);
 309
 310 extern vm_page_t        vm_page_lookup(
 311                                         vm_object_t             object,
 312                                         vm_object_offset_t      offset);
 313
 314 extern vm_page_t        vm_page_grab_fictitious(void);
 315
 316 extern void             vm_page_release_fictitious(
 317                                         vm_page_t page);
 318
 319 extern boolean_t        vm_page_convert(
 320                                         vm_page_t       page);
 321
 322 extern void             vm_page_more_fictitious(void);
 323
 324 extern int              vm_pool_low(void);
 325
 326 extern vm_page_t        vm_page_grab(void);
 327
 328 extern void             vm_page_release(
 329                                         vm_page_t       page);
 330
 331 extern boolean_t        vm_page_wait(
 332                                         int             interruptible );
 333
 334 extern vm_page_t        vm_page_alloc(
 335                                         vm_object_t             object,
 336                                         vm_object_offset_t      offset);
 337
 338 extern void             vm_page_init(
 339                                         vm_page_t       page,
 340                                         ppnum_t         phys_page);
 341
 342 extern void             vm_page_free(
 343                                         vm_page_t       page);
 344
 345 extern void             vm_page_activate(
 346                                         vm_page_t       page);
 347
 348 extern void             vm_page_deactivate(
 349                                         vm_page_t       page);
 350
 351 extern void             vm_page_rename(
 352                                         vm_page_t               page,
 353                                         vm_object_t             new_object,
 354                                         vm_object_offset_t      new_offset);
 355
 356 extern void             vm_page_insert(
 357                                         vm_page_t               page,
 358                                         vm_object_t             object,
 359                                         vm_object_offset_t      offset);
 360
 361 extern void             vm_page_replace(
 362                                         vm_page_t               mem,
 363                                         vm_object_t             object,
 364                                         vm_object_offset_t      offset);
 365
 366 extern void             vm_page_remove(
 367                                         vm_page_t       page);
 368
 369 extern void             vm_page_zero_fill(
 370                                         vm_page_t       page);
 371
 372 extern void             vm_page_part_zero_fill(
 373                                         vm_page_t       m,
 374                                         vm_offset_t     m_pa,
 375                                         vm_size_t       len);
 376
 377 extern void             vm_page_copy(
 378                                         vm_page_t       src_page,
 379                                         vm_page_t       dest_page);
 380
 381 extern void             vm_page_part_copy(
 382                                         vm_page_t       src_m,
 383                                         vm_offset_t     src_pa,
 384                                         vm_page_t       dst_m,
 385                                         vm_offset_t     dst_pa,
 386                                         vm_size_t       len);
 387
 388 extern void             vm_page_wire(
 389                                         vm_page_t       page);
 390
 391 extern void             vm_page_unwire(
 392                                         vm_page_t       page);
 393
 394 extern void             vm_set_page_size(void);
 395
 396 extern void             vm_page_gobble(
 397                                         vm_page_t      page);
 398
 399 /*
 400  *      Functions implemented as macros. m->wanted and m->busy are
 401  *      protected by the object lock.
 402  */
 403
 404 #define PAGE_ASSERT_WAIT(m, interruptible)                      \
 405                 (((m)->wanted = TRUE),                          \
 406                  assert_wait((event_t) (m), (interruptible)))
 407
 408 #define PAGE_SLEEP(o, m, interruptible)                         \
 409                 (((m)->wanted = TRUE),                          \
 410                  thread_sleep_vm_object((o), (m), (interruptible)))
 411
 412 #define PAGE_WAKEUP_DONE(m)                                     \
 413                 MACRO_BEGIN                                     \
 414                 (m)->busy = FALSE;                              \
 415                 if ((m)->wanted) {                              \
 416                         (m)->wanted = FALSE;                    \
 417                         thread_wakeup((event_t) (m));           \
 418                 }                                               \
 419                 MACRO_END
 420
 421 #define PAGE_WAKEUP(m)                                          \
 422                 MACRO_BEGIN                                     \
 423                 if ((m)->wanted) {                              \
 424                         (m)->wanted = FALSE;                    \
 425                         thread_wakeup((event_t) (m));           \
 426                 }                                               \
 427                 MACRO_END
 428
 429 #define VM_PAGE_FREE(p)                         \
 430                 MACRO_BEGIN                     \
 431                 vm_page_lock_queues();          \
 432                 vm_page_free(p);                \
 433                 vm_page_unlock_queues();        \
 434                 MACRO_END
 435
 436 #define VM_PAGE_GRAB_FICTITIOUS(M)                                      \
 437                 MACRO_BEGIN                                             \
 438                 while ((M = vm_page_grab_fictitious()) == VM_PAGE_NULL) \
 439                         vm_page_more_fictitious();                      \
 440                 MACRO_END
 441
 442 #define VM_PAGE_THROTTLED()                                             \
 443                 (vm_page_free_count < vm_page_free_min &&               \
 444                  !(current_thread()->options & TH_OPT_VMPRIV) &&                        \
 445                  ++vm_page_throttled_count)
 446
 447 #define VM_PAGE_WAIT()          ((void)vm_page_wait(THREAD_UNINT))
 448
 449 #define vm_page_lock_queues()   mutex_lock(&vm_page_queue_lock)
 450 #define vm_page_unlock_queues() mutex_unlock(&vm_page_queue_lock)
 451
 452 #define VM_PAGE_QUEUES_REMOVE(mem)                              \
 453         MACRO_BEGIN                                             \
 454         assert(!mem->laundry);                                  \
 455         if (mem->active) {                                      \
 456                 assert(mem->object != kernel_object);           \
 457                 assert(!mem->inactive);                         \
 458                 queue_remove(&vm_page_queue_active,             \
 459                         mem, vm_page_t, pageq);                 \
 460                 mem->pageq.next = NULL;                         \
 461                 mem->pageq.prev = NULL;                         \
 462                 mem->active = FALSE;                            \
 463                 if (!mem->fictitious)                           \
 464                         vm_page_active_count--;                 \
 465         }                                                       \
 466                                                                 \
 467         if (mem->inactive) {                                    \
 468                 assert(mem->object != kernel_object);           \
 469                 assert(!mem->active);                           \
 470                 if (mem->zero_fill) {                           \
 471                         queue_remove(&vm_page_queue_zf,         \
 472                         mem, vm_page_t, pageq);                 \
 473                 } else {                                        \
 474                         queue_remove(&vm_page_queue_inactive,   \
 475                         mem, vm_page_t, pageq);                 \
 476                 }                                               \
 477                 mem->pageq.next = NULL;                         \
 478                 mem->pageq.prev = NULL;                         \
 479                 mem->inactive = FALSE;                          \
 480                 if (!mem->fictitious)                           \
 481                         vm_page_inactive_count--;               \
 482         }                                                       \
 483         MACRO_END
 484
 485 #endif  /* _VM_VM_PAGE_H_ */