linux/include/linux/mm.h
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   1#ifndef _LINUX_MM_H
   2#define _LINUX_MM_H
   3
   4#include <linux/errno.h>
   5
   6#ifdef __KERNEL__
   7
   8#include <linux/gfp.h>
   9#include <linux/list.h>
  10#include <linux/mmzone.h>
  11#include <linux/rbtree.h>
  12#include <linux/prio_tree.h>
  13#include <linux/debug_locks.h>
  14#include <linux/mm_types.h>
  15
  16struct mempolicy;
  17struct anon_vma;
  18struct file_ra_state;
  19struct user_struct;
  20struct writeback_control;
  21
  22#ifndef CONFIG_DISCONTIGMEM          /* Don't use mapnrs, do it properly */
  23extern unsigned long max_mapnr;
  24#endif
  25
  26extern unsigned long num_physpages;
  27extern void * high_memory;
  28extern int page_cluster;
  29
  30#ifdef CONFIG_SYSCTL
  31extern int sysctl_legacy_va_layout;
  32#else
  33#define sysctl_legacy_va_layout 0
  34#endif
  35
  36extern unsigned long mmap_min_addr;
  37
  38#include <asm/page.h>
  39#include <asm/pgtable.h>
  40#include <asm/processor.h>
  41
  42#define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
  43
  44/*
  45 * Linux kernel virtual memory manager primitives.
  46 * The idea being to have a "virtual" mm in the same way
  47 * we have a virtual fs - giving a cleaner interface to the
  48 * mm details, and allowing different kinds of memory mappings
  49 * (from shared memory to executable loading to arbitrary
  50 * mmap() functions).
  51 */
  52
  53extern struct kmem_cache *vm_area_cachep;
  54
  55/*
  56 * This struct defines the per-mm list of VMAs for uClinux. If CONFIG_MMU is
  57 * disabled, then there's a single shared list of VMAs maintained by the
  58 * system, and mm's subscribe to these individually
  59 */
  60struct vm_list_struct {
  61        struct vm_list_struct   *next;
  62        struct vm_area_struct   *vma;
  63};
  64
  65#ifndef CONFIG_MMU
  66extern struct rb_root nommu_vma_tree;
  67extern struct rw_semaphore nommu_vma_sem;
  68
  69extern unsigned int kobjsize(const void *objp);
  70#endif
  71
  72/*
  73 * vm_flags..
  74 */
  75#define VM_READ         0x00000001      /* currently active flags */
  76#define VM_WRITE        0x00000002
  77#define VM_EXEC         0x00000004
  78#define VM_SHARED       0x00000008
  79
  80/* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
  81#define VM_MAYREAD      0x00000010      /* limits for mprotect() etc */
  82#define VM_MAYWRITE     0x00000020
  83#define VM_MAYEXEC      0x00000040
  84#define VM_MAYSHARE     0x00000080
  85
  86#define VM_GROWSDOWN    0x00000100      /* general info on the segment */
  87#define VM_GROWSUP      0x00000200
  88#define VM_PFNMAP       0x00000400      /* Page-ranges managed without "struct page", just pure PFN */
  89#define VM_DENYWRITE    0x00000800      /* ETXTBSY on write attempts.. */
  90
  91#define VM_EXECUTABLE   0x00001000
  92#define VM_LOCKED       0x00002000
  93#define VM_IO           0x00004000      /* Memory mapped I/O or similar */
  94
  95                                        /* Used by sys_madvise() */
  96#define VM_SEQ_READ     0x00008000      /* App will access data sequentially */
  97#define VM_RAND_READ    0x00010000      /* App will not benefit from clustered reads */
  98
  99#define VM_DONTCOPY     0x00020000      /* Do not copy this vma on fork */
 100#define VM_DONTEXPAND   0x00040000      /* Cannot expand with mremap() */
 101#define VM_RESERVED     0x00080000      /* Count as reserved_vm like IO */
 102#define VM_ACCOUNT      0x00100000      /* Is a VM accounted object */
 103#define VM_HUGETLB      0x00400000      /* Huge TLB Page VM */
 104#define VM_NONLINEAR    0x00800000      /* Is non-linear (remap_file_pages) */
 105#define VM_MAPPED_COPY  0x01000000      /* T if mapped copy of data (nommu mmap) */
 106#define VM_INSERTPAGE   0x02000000      /* The vma has had "vm_insert_page()" done on it */
 107#define VM_ALWAYSDUMP   0x04000000      /* Always include in core dumps */
 108
 109#define VM_CAN_NONLINEAR 0x08000000     /* Has ->fault & does nonlinear pages */
 110#define VM_MIXEDMAP     0x10000000      /* Can contain "struct page" and pure PFN pages */
 111
 112#ifndef VM_STACK_DEFAULT_FLAGS          /* arch can override this */
 113#define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
 114#endif
 115
 116#ifdef CONFIG_STACK_GROWSUP
 117#define VM_STACK_FLAGS  (VM_GROWSUP | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
 118#else
 119#define VM_STACK_FLAGS  (VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
 120#endif
 121
 122#define VM_READHINTMASK                 (VM_SEQ_READ | VM_RAND_READ)
 123#define VM_ClearReadHint(v)             (v)->vm_flags &= ~VM_READHINTMASK
 124#define VM_NormalReadHint(v)            (!((v)->vm_flags & VM_READHINTMASK))
 125#define VM_SequentialReadHint(v)        ((v)->vm_flags & VM_SEQ_READ)
 126#define VM_RandomReadHint(v)            ((v)->vm_flags & VM_RAND_READ)
 127
 128/*
 129 * mapping from the currently active vm_flags protection bits (the
 130 * low four bits) to a page protection mask..
 131 */
 132extern pgprot_t protection_map[16];
 133
 134#define FAULT_FLAG_WRITE        0x01    /* Fault was a write access */
 135#define FAULT_FLAG_NONLINEAR    0x02    /* Fault was via a nonlinear mapping */
 136
 137
 138/*
 139 * vm_fault is filled by the the pagefault handler and passed to the vma's
 140 * ->fault function. The vma's ->fault is responsible for returning a bitmask
 141 * of VM_FAULT_xxx flags that give details about how the fault was handled.
 142 *
 143 * pgoff should be used in favour of virtual_address, if possible. If pgoff
 144 * is used, one may set VM_CAN_NONLINEAR in the vma->vm_flags to get nonlinear
 145 * mapping support.
 146 */
 147struct vm_fault {
 148        unsigned int flags;             /* FAULT_FLAG_xxx flags */
 149        pgoff_t pgoff;                  /* Logical page offset based on vma */
 150        void __user *virtual_address;   /* Faulting virtual address */
 151
 152        struct page *page;              /* ->fault handlers should return a
 153                                         * page here, unless VM_FAULT_NOPAGE
 154                                         * is set (which is also implied by
 155                                         * VM_FAULT_ERROR).
 156                                         */
 157};
 158
 159/*
 160 * These are the virtual MM functions - opening of an area, closing and
 161 * unmapping it (needed to keep files on disk up-to-date etc), pointer
 162 * to the functions called when a no-page or a wp-page exception occurs. 
 163 */
 164struct vm_operations_struct {
 165        void (*open)(struct vm_area_struct * area);
 166        void (*close)(struct vm_area_struct * area);
 167        int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
 168        unsigned long (*nopfn)(struct vm_area_struct *area,
 169                        unsigned long address);
 170
 171        /* notification that a previously read-only page is about to become
 172         * writable, if an error is returned it will cause a SIGBUS */
 173        int (*page_mkwrite)(struct vm_area_struct *vma, struct page *page);
 174#ifdef CONFIG_NUMA
 175        /*
 176         * set_policy() op must add a reference to any non-NULL @new mempolicy
 177         * to hold the policy upon return.  Caller should pass NULL @new to
 178         * remove a policy and fall back to surrounding context--i.e. do not
 179         * install a MPOL_DEFAULT policy, nor the task or system default
 180         * mempolicy.
 181         */
 182        int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
 183
 184        /*
 185         * get_policy() op must add reference [mpol_get()] to any policy at
 186         * (vma,addr) marked as MPOL_SHARED.  The shared policy infrastructure
 187         * in mm/mempolicy.c will do this automatically.
 188         * get_policy() must NOT add a ref if the policy at (vma,addr) is not
 189         * marked as MPOL_SHARED. vma policies are protected by the mmap_sem.
 190         * If no [shared/vma] mempolicy exists at the addr, get_policy() op
 191         * must return NULL--i.e., do not "fallback" to task or system default
 192         * policy.
 193         */
 194        struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
 195                                        unsigned long addr);
 196        int (*migrate)(struct vm_area_struct *vma, const nodemask_t *from,
 197                const nodemask_t *to, unsigned long flags);
 198#endif
 199};
 200
 201struct mmu_gather;
 202struct inode;
 203
 204#define page_private(page)              ((page)->private)
 205#define set_page_private(page, v)       ((page)->private = (v))
 206
 207/*
 208 * FIXME: take this include out, include page-flags.h in
 209 * files which need it (119 of them)
 210 */
 211#include <linux/page-flags.h>
 212
 213#ifdef CONFIG_DEBUG_VM
 214#define VM_BUG_ON(cond) BUG_ON(cond)
 215#else
 216#define VM_BUG_ON(condition) do { } while(0)
 217#endif
 218
 219/*
 220 * Methods to modify the page usage count.
 221 *
 222 * What counts for a page usage:
 223 * - cache mapping   (page->mapping)
 224 * - private data    (page->private)
 225 * - page mapped in a task's page tables, each mapping
 226 *   is counted separately
 227 *
 228 * Also, many kernel routines increase the page count before a critical
 229 * routine so they can be sure the page doesn't go away from under them.
 230 */
 231
 232/*
 233 * Drop a ref, return true if the refcount fell to zero (the page has no users)
 234 */
 235static inline int put_page_testzero(struct page *page)
 236{
 237        VM_BUG_ON(atomic_read(&page->_count) == 0);
 238        return atomic_dec_and_test(&page->_count);
 239}
 240
 241/*
 242 * Try to grab a ref unless the page has a refcount of zero, return false if
 243 * that is the case.
 244 */
 245static inline int get_page_unless_zero(struct page *page)
 246{
 247        VM_BUG_ON(PageTail(page));
 248        return atomic_inc_not_zero(&page->_count);
 249}
 250
 251/* Support for virtually mapped pages */
 252struct page *vmalloc_to_page(const void *addr);
 253unsigned long vmalloc_to_pfn(const void *addr);
 254
 255/*
 256 * Determine if an address is within the vmalloc range
 257 *
 258 * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
 259 * is no special casing required.
 260 */
 261static inline int is_vmalloc_addr(const void *x)
 262{
 263#ifdef CONFIG_MMU
 264        unsigned long addr = (unsigned long)x;
 265
 266        return addr >= VMALLOC_START && addr < VMALLOC_END;
 267#else
 268        return 0;
 269#endif
 270}
 271
 272static inline struct page *compound_head(struct page *page)
 273{
 274        if (unlikely(PageTail(page)))
 275                return page->first_page;
 276        return page;
 277}
 278
 279static inline int page_count(struct page *page)
 280{
 281        return atomic_read(&compound_head(page)->_count);
 282}
 283
 284static inline void get_page(struct page *page)
 285{
 286        page = compound_head(page);
 287        VM_BUG_ON(atomic_read(&page->_count) == 0);
 288        atomic_inc(&page->_count);
 289}
 290
 291static inline struct page *virt_to_head_page(const void *x)
 292{
 293        struct page *page = virt_to_page(x);
 294        return compound_head(page);
 295}
 296
 297/*
 298 * Setup the page count before being freed into the page allocator for
 299 * the first time (boot or memory hotplug)
 300 */
 301static inline void init_page_count(struct page *page)
 302{
 303        atomic_set(&page->_count, 1);
 304}
 305
 306void put_page(struct page *page);
 307void put_pages_list(struct list_head *pages);
 308
 309void split_page(struct page *page, unsigned int order);
 310
 311/*
 312 * Compound pages have a destructor function.  Provide a
 313 * prototype for that function and accessor functions.
 314 * These are _only_ valid on the head of a PG_compound page.
 315 */
 316typedef void compound_page_dtor(struct page *);
 317
 318static inline void set_compound_page_dtor(struct page *page,
 319                                                compound_page_dtor *dtor)
 320{
 321        page[1].lru.next = (void *)dtor;
 322}
 323
 324static inline compound_page_dtor *get_compound_page_dtor(struct page *page)
 325{
 326        return (compound_page_dtor *)page[1].lru.next;
 327}
 328
 329static inline int compound_order(struct page *page)
 330{
 331        if (!PageHead(page))
 332                return 0;
 333        return (unsigned long)page[1].lru.prev;
 334}
 335
 336static inline void set_compound_order(struct page *page, unsigned long order)
 337{
 338        page[1].lru.prev = (void *)order;
 339}
 340
 341/*
 342 * Multiple processes may "see" the same page. E.g. for untouched
 343 * mappings of /dev/null, all processes see the same page full of
 344 * zeroes, and text pages of executables and shared libraries have
 345 * only one copy in memory, at most, normally.
 346 *
 347 * For the non-reserved pages, page_count(page) denotes a reference count.
 348 *   page_count() == 0 means the page is free. page->lru is then used for
 349 *   freelist management in the buddy allocator.
 350 *   page_count() > 0  means the page has been allocated.
 351 *
 352 * Pages are allocated by the slab allocator in order to provide memory
 353 * to kmalloc and kmem_cache_alloc. In this case, the management of the
 354 * page, and the fields in 'struct page' are the responsibility of mm/slab.c
 355 * unless a particular usage is carefully commented. (the responsibility of
 356 * freeing the kmalloc memory is the caller's, of course).
 357 *
 358 * A page may be used by anyone else who does a __get_free_page().
 359 * In this case, page_count still tracks the references, and should only
 360 * be used through the normal accessor functions. The top bits of page->flags
 361 * and page->virtual store page management information, but all other fields
 362 * are unused and could be used privately, carefully. The management of this
 363 * page is the responsibility of the one who allocated it, and those who have
 364 * subsequently been given references to it.
 365 *
 366 * The other pages (we may call them "pagecache pages") are completely
 367 * managed by the Linux memory manager: I/O, buffers, swapping etc.
 368 * The following discussion applies only to them.
 369 *
 370 * A pagecache page contains an opaque `private' member, which belongs to the
 371 * page's address_space. Usually, this is the address of a circular list of
 372 * the page's disk buffers. PG_private must be set to tell the VM to call
 373 * into the filesystem to release these pages.
 374 *
 375 * A page may belong to an inode's memory mapping. In this case, page->mapping
 376 * is the pointer to the inode, and page->index is the file offset of the page,
 377 * in units of PAGE_CACHE_SIZE.
 378 *
 379 * If pagecache pages are not associated with an inode, they are said to be
 380 * anonymous pages. These may become associated with the swapcache, and in that
 381 * case PG_swapcache is set, and page->private is an offset into the swapcache.
 382 *
 383 * In either case (swapcache or inode backed), the pagecache itself holds one
 384 * reference to the page. Setting PG_private should also increment the
 385 * refcount. The each user mapping also has a reference to the page.
 386 *
 387 * The pagecache pages are stored in a per-mapping radix tree, which is
 388 * rooted at mapping->page_tree, and indexed by offset.
 389 * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
 390 * lists, we instead now tag pages as dirty/writeback in the radix tree.
 391 *
 392 * All pagecache pages may be subject to I/O:
 393 * - inode pages may need to be read from disk,
 394 * - inode pages which have been modified and are MAP_SHARED may need
 395 *   to be written back to the inode on disk,
 396 * - anonymous pages (including MAP_PRIVATE file mappings) which have been
 397 *   modified may need to be swapped out to swap space and (later) to be read
 398 *   back into memory.
 399 */
 400
 401/*
 402 * The zone field is never updated after free_area_init_core()
 403 * sets it, so none of the operations on it need to be atomic.
 404 */
 405
 406
 407/*
 408 * page->flags layout:
 409 *
 410 * There are three possibilities for how page->flags get
 411 * laid out.  The first is for the normal case, without
 412 * sparsemem.  The second is for sparsemem when there is
 413 * plenty of space for node and section.  The last is when
 414 * we have run out of space and have to fall back to an
 415 * alternate (slower) way of determining the node.
 416 *
 417 * No sparsemem or sparsemem vmemmap: |       NODE     | ZONE | ... | FLAGS |
 418 * classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS |
 419 * classic sparse no space for node:  | SECTION |     ZONE    | ... | FLAGS |
 420 */
 421#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
 422#define SECTIONS_WIDTH          SECTIONS_SHIFT
 423#else
 424#define SECTIONS_WIDTH          0
 425#endif
 426
 427#define ZONES_WIDTH             ZONES_SHIFT
 428
 429#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
 430#define NODES_WIDTH             NODES_SHIFT
 431#else
 432#ifdef CONFIG_SPARSEMEM_VMEMMAP
 433#error "Vmemmap: No space for nodes field in page flags"
 434#endif
 435#define NODES_WIDTH             0
 436#endif
 437
 438/* Page flags: | [SECTION] | [NODE] | ZONE | ... | FLAGS | */
 439#define SECTIONS_PGOFF          ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
 440#define NODES_PGOFF             (SECTIONS_PGOFF - NODES_WIDTH)
 441#define ZONES_PGOFF             (NODES_PGOFF - ZONES_WIDTH)
 442
 443/*
 444 * We are going to use the flags for the page to node mapping if its in
 445 * there.  This includes the case where there is no node, so it is implicit.
 446 */
 447#if !(NODES_WIDTH > 0 || NODES_SHIFT == 0)
 448#define NODE_NOT_IN_PAGE_FLAGS
 449#endif
 450
 451#ifndef PFN_SECTION_SHIFT
 452#define PFN_SECTION_SHIFT 0
 453#endif
 454
 455/*
 456 * Define the bit shifts to access each section.  For non-existant
 457 * sections we define the shift as 0; that plus a 0 mask ensures
 458 * the compiler will optimise away reference to them.
 459 */
 460#define SECTIONS_PGSHIFT        (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
 461#define NODES_PGSHIFT           (NODES_PGOFF * (NODES_WIDTH != 0))
 462#define ZONES_PGSHIFT           (ZONES_PGOFF * (ZONES_WIDTH != 0))
 463
 464/* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allcator */
 465#ifdef NODE_NOT_IN_PAGEFLAGS
 466#define ZONEID_SHIFT            (SECTIONS_SHIFT + ZONES_SHIFT)
 467#define ZONEID_PGOFF            ((SECTIONS_PGOFF < ZONES_PGOFF)? \
 468                                                SECTIONS_PGOFF : ZONES_PGOFF)
 469#else
 470#define ZONEID_SHIFT            (NODES_SHIFT + ZONES_SHIFT)
 471#define ZONEID_PGOFF            ((NODES_PGOFF < ZONES_PGOFF)? \
 472                                                NODES_PGOFF : ZONES_PGOFF)
 473#endif
 474
 475#define ZONEID_PGSHIFT          (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
 476
 477#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
 478#error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
 479#endif
 480
 481#define ZONES_MASK              ((1UL << ZONES_WIDTH) - 1)
 482#define NODES_MASK              ((1UL << NODES_WIDTH) - 1)
 483#define SECTIONS_MASK           ((1UL << SECTIONS_WIDTH) - 1)
 484#define ZONEID_MASK             ((1UL << ZONEID_SHIFT) - 1)
 485
 486static inline enum zone_type page_zonenum(struct page *page)
 487{
 488        return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
 489}
 490
 491/*
 492 * The identification function is only used by the buddy allocator for
 493 * determining if two pages could be buddies. We are not really
 494 * identifying a zone since we could be using a the section number
 495 * id if we have not node id available in page flags.
 496 * We guarantee only that it will return the same value for two
 497 * combinable pages in a zone.
 498 */
 499static inline int page_zone_id(struct page *page)
 500{
 501        return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
 502}
 503
 504static inline int zone_to_nid(struct zone *zone)
 505{
 506#ifdef CONFIG_NUMA
 507        return zone->node;
 508#else
 509        return 0;
 510#endif
 511}
 512
 513#ifdef NODE_NOT_IN_PAGE_FLAGS
 514extern int page_to_nid(struct page *page);
 515#else
 516static inline int page_to_nid(struct page *page)
 517{
 518        return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
 519}
 520#endif
 521
 522static inline struct zone *page_zone(struct page *page)
 523{
 524        return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
 525}
 526
 527#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
 528static inline unsigned long page_to_section(struct page *page)
 529{
 530        return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
 531}
 532#endif
 533
 534static inline void set_page_zone(struct page *page, enum zone_type zone)
 535{
 536        page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
 537        page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
 538}
 539
 540static inline void set_page_node(struct page *page, unsigned long node)
 541{
 542        page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
 543        page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
 544}
 545
 546static inline void set_page_section(struct page *page, unsigned long section)
 547{
 548        page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
 549        page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
 550}
 551
 552static inline void set_page_links(struct page *page, enum zone_type zone,
 553        unsigned long node, unsigned long pfn)
 554{
 555        set_page_zone(page, zone);
 556        set_page_node(page, node);
 557        set_page_section(page, pfn_to_section_nr(pfn));
 558}
 559
 560/*
 561 * If a hint addr is less than mmap_min_addr change hint to be as
 562 * low as possible but still greater than mmap_min_addr
 563 */
 564static inline unsigned long round_hint_to_min(unsigned long hint)
 565{
 566#ifdef CONFIG_SECURITY
 567        hint &= PAGE_MASK;
 568        if (((void *)hint != NULL) &&
 569            (hint < mmap_min_addr))
 570                return PAGE_ALIGN(mmap_min_addr);
 571#endif
 572        return hint;
 573}
 574
 575/*
 576 * Some inline functions in vmstat.h depend on page_zone()
 577 */
 578#include <linux/vmstat.h>
 579
 580static __always_inline void *lowmem_page_address(struct page *page)
 581{
 582        return __va(page_to_pfn(page) << PAGE_SHIFT);
 583}
 584
 585#if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
 586#define HASHED_PAGE_VIRTUAL
 587#endif
 588
 589#if defined(WANT_PAGE_VIRTUAL)
 590#define page_address(page) ((page)->virtual)
 591#define set_page_address(page, address)                 \
 592        do {                                            \
 593                (page)->virtual = (address);            \
 594        } while(0)
 595#define page_address_init()  do { } while(0)
 596#endif
 597
 598#if defined(HASHED_PAGE_VIRTUAL)
 599void *page_address(struct page *page);
 600void set_page_address(struct page *page, void *virtual);
 601void page_address_init(void);
 602#endif
 603
 604#if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
 605#define page_address(page) lowmem_page_address(page)
 606#define set_page_address(page, address)  do { } while(0)
 607#define page_address_init()  do { } while(0)
 608#endif
 609
 610/*
 611 * On an anonymous page mapped into a user virtual memory area,
 612 * page->mapping points to its anon_vma, not to a struct address_space;
 613 * with the PAGE_MAPPING_ANON bit set to distinguish it.
 614 *
 615 * Please note that, confusingly, "page_mapping" refers to the inode
 616 * address_space which maps the page from disk; whereas "page_mapped"
 617 * refers to user virtual address space into which the page is mapped.
 618 */
 619#define PAGE_MAPPING_ANON       1
 620
 621extern struct address_space swapper_space;
 622static inline struct address_space *page_mapping(struct page *page)
 623{
 624        struct address_space *mapping = page->mapping;
 625
 626        VM_BUG_ON(PageSlab(page));
 627#ifdef CONFIG_SWAP
 628        if (unlikely(PageSwapCache(page)))
 629                mapping = &swapper_space;
 630        else
 631#endif
 632        if (unlikely((unsigned long)mapping & PAGE_MAPPING_ANON))
 633                mapping = NULL;
 634        return mapping;
 635}
 636
 637static inline int PageAnon(struct page *page)
 638{
 639        return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
 640}
 641
 642/*
 643 * Return the pagecache index of the passed page.  Regular pagecache pages
 644 * use ->index whereas swapcache pages use ->private
 645 */
 646static inline pgoff_t page_index(struct page *page)
 647{
 648        if (unlikely(PageSwapCache(page)))
 649                return page_private(page);
 650        return page->index;
 651}
 652
 653/*
 654 * The atomic page->_mapcount, like _count, starts from -1:
 655 * so that transitions both from it and to it can be tracked,
 656 * using atomic_inc_and_test and atomic_add_negative(-1).
 657 */
 658static inline void reset_page_mapcount(struct page *page)
 659{
 660        atomic_set(&(page)->_mapcount, -1);
 661}
 662
 663static inline int page_mapcount(struct page *page)
 664{
 665        return atomic_read(&(page)->_mapcount) + 1;
 666}
 667
 668/*
 669 * Return true if this page is mapped into pagetables.
 670 */
 671static inline int page_mapped(struct page *page)
 672{
 673        return atomic_read(&(page)->_mapcount) >= 0;
 674}
 675
 676/*
 677 * Error return values for the *_nopfn functions
 678 */
 679#define NOPFN_SIGBUS    ((unsigned long) -1)
 680#define NOPFN_OOM       ((unsigned long) -2)
 681#define NOPFN_REFAULT   ((unsigned long) -3)
 682
 683/*
 684 * Different kinds of faults, as returned by handle_mm_fault().
 685 * Used to decide whether a process gets delivered SIGBUS or
 686 * just gets major/minor fault counters bumped up.
 687 */
 688
 689#define VM_FAULT_MINOR  0 /* For backwards compat. Remove me quickly. */
 690
 691#define VM_FAULT_OOM    0x0001
 692#define VM_FAULT_SIGBUS 0x0002
 693#define VM_FAULT_MAJOR  0x0004
 694#define VM_FAULT_WRITE  0x0008  /* Special case for get_user_pages */
 695
 696#define VM_FAULT_NOPAGE 0x0100  /* ->fault installed the pte, not return page */
 697#define VM_FAULT_LOCKED 0x0200  /* ->fault locked the returned page */
 698
 699#define VM_FAULT_ERROR  (VM_FAULT_OOM | VM_FAULT_SIGBUS)
 700
 701#define offset_in_page(p)       ((unsigned long)(p) & ~PAGE_MASK)
 702
 703extern void show_free_areas(void);
 704
 705#ifdef CONFIG_SHMEM
 706int shmem_lock(struct file *file, int lock, struct user_struct *user);
 707#else
 708static inline int shmem_lock(struct file *file, int lock,
 709                             struct user_struct *user)
 710{
 711        return 0;
 712}
 713#endif
 714struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags);
 715
 716int shmem_zero_setup(struct vm_area_struct *);
 717
 718#ifndef CONFIG_MMU
 719extern unsigned long shmem_get_unmapped_area(struct file *file,
 720                                             unsigned long addr,
 721                                             unsigned long len,
 722                                             unsigned long pgoff,
 723                                             unsigned long flags);
 724#endif
 725
 726extern int can_do_mlock(void);
 727extern int user_shm_lock(size_t, struct user_struct *);
 728extern void user_shm_unlock(size_t, struct user_struct *);
 729
 730/*
 731 * Parameter block passed down to zap_pte_range in exceptional cases.
 732 */
 733struct zap_details {
 734        struct vm_area_struct *nonlinear_vma;   /* Check page->index if set */
 735        struct address_space *check_mapping;    /* Check page->mapping if set */
 736        pgoff_t first_index;                    /* Lowest page->index to unmap */
 737        pgoff_t last_index;                     /* Highest page->index to unmap */
 738        spinlock_t *i_mmap_lock;                /* For unmap_mapping_range: */
 739        unsigned long truncate_count;           /* Compare vm_truncate_count */
 740};
 741
 742struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 743                pte_t pte);
 744
 745unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
 746                unsigned long size, struct zap_details *);
 747unsigned long unmap_vmas(struct mmu_gather **tlb,
 748                struct vm_area_struct *start_vma, unsigned long start_addr,
 749                unsigned long end_addr, unsigned long *nr_accounted,
 750                struct zap_details *);
 751
 752/**
 753 * mm_walk - callbacks for walk_page_range
 754 * @pgd_entry: if set, called for each non-empty PGD (top-level) entry
 755 * @pud_entry: if set, called for each non-empty PUD (2nd-level) entry
 756 * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry
 757 * @pte_entry: if set, called for each non-empty PTE (4th-level) entry
 758 * @pte_hole: if set, called for each hole at all levels
 759 *
 760 * (see walk_page_range for more details)
 761 */
 762struct mm_walk {
 763        int (*pgd_entry)(pgd_t *, unsigned long, unsigned long, struct mm_walk *);
 764        int (*pud_entry)(pud_t *, unsigned long, unsigned long, struct mm_walk *);
 765        int (*pmd_entry)(pmd_t *, unsigned long, unsigned long, struct mm_walk *);
 766        int (*pte_entry)(pte_t *, unsigned long, unsigned long, struct mm_walk *);
 767        int (*pte_hole)(unsigned long, unsigned long, struct mm_walk *);
 768        struct mm_struct *mm;
 769        void *private;
 770};
 771
 772int walk_page_range(unsigned long addr, unsigned long end,
 773                struct mm_walk *walk);
 774void free_pgd_range(struct mmu_gather **tlb, unsigned long addr,
 775                unsigned long end, unsigned long floor, unsigned long ceiling);
 776void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *start_vma,
 777                unsigned long floor, unsigned long ceiling);
 778int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
 779                        struct vm_area_struct *vma);
 780void unmap_mapping_range(struct address_space *mapping,
 781                loff_t const holebegin, loff_t const holelen, int even_cows);
 782
 783static inline void unmap_shared_mapping_range(struct address_space *mapping,
 784                loff_t const holebegin, loff_t const holelen)
 785{
 786        unmap_mapping_range(mapping, holebegin, holelen, 0);
 787}
 788
 789extern int vmtruncate(struct inode * inode, loff_t offset);
 790extern int vmtruncate_range(struct inode * inode, loff_t offset, loff_t end);
 791
 792#ifdef CONFIG_MMU
 793extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 794                        unsigned long address, int write_access);
 795#else
 796static inline int handle_mm_fault(struct mm_struct *mm,
 797                        struct vm_area_struct *vma, unsigned long address,
 798                        int write_access)
 799{
 800        /* should never happen if there's no MMU */
 801        BUG();
 802        return VM_FAULT_SIGBUS;
 803}
 804#endif
 805
 806extern int make_pages_present(unsigned long addr, unsigned long end);
 807extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
 808
 809int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start,
 810                int len, int write, int force, struct page **pages, struct vm_area_struct **vmas);
 811void print_bad_pte(struct vm_area_struct *, pte_t, unsigned long);
 812
 813extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
 814extern void do_invalidatepage(struct page *page, unsigned long offset);
 815
 816int __set_page_dirty_nobuffers(struct page *page);
 817int __set_page_dirty_no_writeback(struct page *page);
 818int redirty_page_for_writepage(struct writeback_control *wbc,
 819                                struct page *page);
 820int set_page_dirty(struct page *page);
 821int set_page_dirty_lock(struct page *page);
 822int clear_page_dirty_for_io(struct page *page);
 823
 824extern unsigned long move_page_tables(struct vm_area_struct *vma,
 825                unsigned long old_addr, struct vm_area_struct *new_vma,
 826                unsigned long new_addr, unsigned long len);
 827extern unsigned long do_mremap(unsigned long addr,
 828                               unsigned long old_len, unsigned long new_len,
 829                               unsigned long flags, unsigned long new_addr);
 830extern int mprotect_fixup(struct vm_area_struct *vma,
 831                          struct vm_area_struct **pprev, unsigned long start,
 832                          unsigned long end, unsigned long newflags);
 833
 834/*
 835 * A callback you can register to apply pressure to ageable caches.
 836 *
 837 * 'shrink' is passed a count 'nr_to_scan' and a 'gfpmask'.  It should
 838 * look through the least-recently-used 'nr_to_scan' entries and
 839 * attempt to free them up.  It should return the number of objects
 840 * which remain in the cache.  If it returns -1, it means it cannot do
 841 * any scanning at this time (eg. there is a risk of deadlock).
 842 *
 843 * The 'gfpmask' refers to the allocation we are currently trying to
 844 * fulfil.
 845 *
 846 * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
 847 * querying the cache size, so a fastpath for that case is appropriate.
 848 */
 849struct shrinker {
 850        int (*shrink)(int nr_to_scan, gfp_t gfp_mask);
 851        int seeks;      /* seeks to recreate an obj */
 852
 853        /* These are for internal use */
 854        struct list_head list;
 855        long nr;        /* objs pending delete */
 856};
 857#define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
 858extern void register_shrinker(struct shrinker *);
 859extern void unregister_shrinker(struct shrinker *);
 860
 861int vma_wants_writenotify(struct vm_area_struct *vma);
 862
 863extern pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl);
 864
 865#ifdef __PAGETABLE_PUD_FOLDED
 866static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd,
 867                                                unsigned long address)
 868{
 869        return 0;
 870}
 871#else
 872int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
 873#endif
 874
 875#ifdef __PAGETABLE_PMD_FOLDED
 876static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
 877                                                unsigned long address)
 878{
 879        return 0;
 880}
 881#else
 882int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
 883#endif
 884
 885int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
 886int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
 887
 888/*
 889 * The following ifdef needed to get the 4level-fixup.h header to work.
 890 * Remove it when 4level-fixup.h has been removed.
 891 */
 892#if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
 893static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
 894{
 895        return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))?
 896                NULL: pud_offset(pgd, address);
 897}
 898
 899static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 900{
 901        return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
 902                NULL: pmd_offset(pud, address);
 903}
 904#endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
 905
 906#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
 907/*
 908 * We tuck a spinlock to guard each pagetable page into its struct page,
 909 * at page->private, with BUILD_BUG_ON to make sure that this will not
 910 * overflow into the next struct page (as it might with DEBUG_SPINLOCK).
 911 * When freeing, reset page->mapping so free_pages_check won't complain.
 912 */
 913#define __pte_lockptr(page)     &((page)->ptl)
 914#define pte_lock_init(_page)    do {                                    \
 915        spin_lock_init(__pte_lockptr(_page));                           \
 916} while (0)
 917#define pte_lock_deinit(page)   ((page)->mapping = NULL)
 918#define pte_lockptr(mm, pmd)    ({(void)(mm); __pte_lockptr(pmd_page(*(pmd)));})
 919#else
 920/*
 921 * We use mm->page_table_lock to guard all pagetable pages of the mm.
 922 */
 923#define pte_lock_init(page)     do {} while (0)
 924#define pte_lock_deinit(page)   do {} while (0)
 925#define pte_lockptr(mm, pmd)    ({(void)(pmd); &(mm)->page_table_lock;})
 926#endif /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
 927
 928static inline void pgtable_page_ctor(struct page *page)
 929{
 930        pte_lock_init(page);
 931        inc_zone_page_state(page, NR_PAGETABLE);
 932}
 933
 934static inline void pgtable_page_dtor(struct page *page)
 935{
 936        pte_lock_deinit(page);
 937        dec_zone_page_state(page, NR_PAGETABLE);
 938}
 939
 940#define pte_offset_map_lock(mm, pmd, address, ptlp)     \
 941({                                                      \
 942        spinlock_t *__ptl = pte_lockptr(mm, pmd);       \
 943        pte_t *__pte = pte_offset_map(pmd, address);    \
 944        *(ptlp) = __ptl;                                \
 945        spin_lock(__ptl);                               \
 946        __pte;                                          \
 947})
 948
 949#define pte_unmap_unlock(pte, ptl)      do {            \
 950        spin_unlock(ptl);                               \
 951        pte_unmap(pte);                                 \
 952} while (0)
 953
 954#define pte_alloc_map(mm, pmd, address)                 \
 955        ((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
 956                NULL: pte_offset_map(pmd, address))
 957
 958#define pte_alloc_map_lock(mm, pmd, address, ptlp)      \
 959        ((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
 960                NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
 961
 962#define pte_alloc_kernel(pmd, address)                  \
 963        ((unlikely(!pmd_present(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
 964                NULL: pte_offset_kernel(pmd, address))
 965
 966extern void free_area_init(unsigned long * zones_size);
 967extern void free_area_init_node(int nid, pg_data_t *pgdat,
 968        unsigned long * zones_size, unsigned long zone_start_pfn, 
 969        unsigned long *zholes_size);
 970#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
 971/*
 972 * With CONFIG_ARCH_POPULATES_NODE_MAP set, an architecture may initialise its
 973 * zones, allocate the backing mem_map and account for memory holes in a more
 974 * architecture independent manner. This is a substitute for creating the
 975 * zone_sizes[] and zholes_size[] arrays and passing them to
 976 * free_area_init_node()
 977 *
 978 * An architecture is expected to register range of page frames backed by
 979 * physical memory with add_active_range() before calling
 980 * free_area_init_nodes() passing in the PFN each zone ends at. At a basic
 981 * usage, an architecture is expected to do something like
 982 *
 983 * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
 984 *                                                       max_highmem_pfn};
 985 * for_each_valid_physical_page_range()
 986 *      add_active_range(node_id, start_pfn, end_pfn)
 987 * free_area_init_nodes(max_zone_pfns);
 988 *
 989 * If the architecture guarantees that there are no holes in the ranges
 990 * registered with add_active_range(), free_bootmem_active_regions()
 991 * will call free_bootmem_node() for each registered physical page range.
 992 * Similarly sparse_memory_present_with_active_regions() calls
 993 * memory_present() for each range when SPARSEMEM is enabled.
 994 *
 995 * See mm/page_alloc.c for more information on each function exposed by
 996 * CONFIG_ARCH_POPULATES_NODE_MAP
 997 */
 998extern void free_area_init_nodes(unsigned long *max_zone_pfn);
 999extern void add_active_range(unsigned int nid, unsigned long start_pfn,
1000                                        unsigned long end_pfn);
1001extern void shrink_active_range(unsigned int nid, unsigned long old_end_pfn,
1002                                                unsigned long new_end_pfn);
1003extern void push_node_boundaries(unsigned int nid, unsigned long start_pfn,
1004                                        unsigned long end_pfn);
1005extern void remove_all_active_ranges(void);
1006extern unsigned long absent_pages_in_range(unsigned long start_pfn,
1007                                                unsigned long end_pfn);
1008extern void get_pfn_range_for_nid(unsigned int nid,
1009                        unsigned long *start_pfn, unsigned long *end_pfn);
1010extern unsigned long find_min_pfn_with_active_regions(void);
1011extern unsigned long find_max_pfn_with_active_regions(void);
1012extern void free_bootmem_with_active_regions(int nid,
1013                                                unsigned long max_low_pfn);
1014extern void sparse_memory_present_with_active_regions(int nid);
1015#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
1016extern int early_pfn_to_nid(unsigned long pfn);
1017#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
1018#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
1019extern void set_dma_reserve(unsigned long new_dma_reserve);
1020extern void memmap_init_zone(unsigned long, int, unsigned long,
1021                                unsigned long, enum memmap_context);
1022extern void setup_per_zone_pages_min(void);
1023extern void mem_init(void);
1024extern void show_mem(void);
1025extern void si_meminfo(struct sysinfo * val);
1026extern void si_meminfo_node(struct sysinfo *val, int nid);
1027
1028#ifdef CONFIG_NUMA
1029extern void setup_per_cpu_pageset(void);
1030#else
1031static inline void setup_per_cpu_pageset(void) {}
1032#endif
1033
1034/* prio_tree.c */
1035void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old);
1036void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *);
1037void vma_prio_tree_remove(struct vm_area_struct *, struct prio_tree_root *);
1038struct vm_area_struct *vma_prio_tree_next(struct vm_area_struct *vma,
1039        struct prio_tree_iter *iter);
1040
1041#define vma_prio_tree_foreach(vma, iter, root, begin, end)      \
1042        for (prio_tree_iter_init(iter, root, begin, end), vma = NULL;   \
1043                (vma = vma_prio_tree_next(vma, iter)); )
1044
1045static inline void vma_nonlinear_insert(struct vm_area_struct *vma,
1046                                        struct list_head *list)
1047{
1048        vma->shared.vm_set.parent = NULL;
1049        list_add_tail(&vma->shared.vm_set.list, list);
1050}
1051
1052/* mmap.c */
1053extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
1054extern void vma_adjust(struct vm_area_struct *vma, unsigned long start,
1055        unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
1056extern struct vm_area_struct *vma_merge(struct mm_struct *,
1057        struct vm_area_struct *prev, unsigned long addr, unsigned long end,
1058        unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
1059        struct mempolicy *);
1060extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
1061extern int split_vma(struct mm_struct *,
1062        struct vm_area_struct *, unsigned long addr, int new_below);
1063extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
1064extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
1065        struct rb_node **, struct rb_node *);
1066extern void unlink_file_vma(struct vm_area_struct *);
1067extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
1068        unsigned long addr, unsigned long len, pgoff_t pgoff);
1069extern void exit_mmap(struct mm_struct *);
1070
1071#ifdef CONFIG_PROC_FS
1072/* From fs/proc/base.c. callers must _not_ hold the mm's exe_file_lock */
1073extern void added_exe_file_vma(struct mm_struct *mm);
1074extern void removed_exe_file_vma(struct mm_struct *mm);
1075#else
1076static inline void added_exe_file_vma(struct mm_struct *mm)
1077{}
1078
1079static inline void removed_exe_file_vma(struct mm_struct *mm)
1080{}
1081#endif /* CONFIG_PROC_FS */
1082
1083extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
1084extern int install_special_mapping(struct mm_struct *mm,
1085                                   unsigned long addr, unsigned long len,
1086                                   unsigned long flags, struct page **pages);
1087
1088extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1089
1090extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
1091        unsigned long len, unsigned long prot,
1092        unsigned long flag, unsigned long pgoff);
1093extern unsigned long mmap_region(struct file *file, unsigned long addr,
1094        unsigned long len, unsigned long flags,
1095        unsigned int vm_flags, unsigned long pgoff,
1096        int accountable);
1097
1098static inline unsigned long do_mmap(struct file *file, unsigned long addr,
1099        unsigned long len, unsigned long prot,
1100        unsigned long flag, unsigned long offset)
1101{
1102        unsigned long ret = -EINVAL;
1103        if ((offset + PAGE_ALIGN(len)) < offset)
1104                goto out;
1105        if (!(offset & ~PAGE_MASK))
1106                ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
1107out:
1108        return ret;
1109}
1110
1111extern int do_munmap(struct mm_struct *, unsigned long, size_t);
1112
1113extern unsigned long do_brk(unsigned long, unsigned long);
1114
1115/* filemap.c */
1116extern unsigned long page_unuse(struct page *);
1117extern void truncate_inode_pages(struct address_space *, loff_t);
1118extern void truncate_inode_pages_range(struct address_space *,
1119                                       loff_t lstart, loff_t lend);
1120
1121/* generic vm_area_ops exported for stackable file systems */
1122extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
1123
1124/* mm/page-writeback.c */
1125int write_one_page(struct page *page, int wait);
1126
1127/* readahead.c */
1128#define VM_MAX_READAHEAD        128     /* kbytes */
1129#define VM_MIN_READAHEAD        16      /* kbytes (includes current page) */
1130
1131int do_page_cache_readahead(struct address_space *mapping, struct file *filp,
1132                        pgoff_t offset, unsigned long nr_to_read);
1133int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
1134                        pgoff_t offset, unsigned long nr_to_read);
1135
1136void page_cache_sync_readahead(struct address_space *mapping,
1137                               struct file_ra_state *ra,
1138                               struct file *filp,
1139                               pgoff_t offset,
1140                               unsigned long size);
1141
1142void page_cache_async_readahead(struct address_space *mapping,
1143                                struct file_ra_state *ra,
1144                                struct file *filp,
1145                                struct page *pg,
1146                                pgoff_t offset,
1147                                unsigned long size);
1148
1149unsigned long max_sane_readahead(unsigned long nr);
1150
1151/* Do stack extension */
1152extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
1153#ifdef CONFIG_IA64
1154extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
1155#endif
1156extern int expand_stack_downwards(struct vm_area_struct *vma,
1157                                  unsigned long address);
1158
1159/* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
1160extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
1161extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
1162                                             struct vm_area_struct **pprev);
1163
1164/* Look up the first VMA which intersects the interval start_addr..end_addr-1,
1165   NULL if none.  Assume start_addr < end_addr. */
1166static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
1167{
1168        struct vm_area_struct * vma = find_vma(mm,start_addr);
1169
1170        if (vma && end_addr <= vma->vm_start)
1171                vma = NULL;
1172        return vma;
1173}
1174
1175static inline unsigned long vma_pages(struct vm_area_struct *vma)
1176{
1177        return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
1178}
1179
1180pgprot_t vm_get_page_prot(unsigned long vm_flags);
1181struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
1182int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
1183                        unsigned long pfn, unsigned long size, pgprot_t);
1184int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
1185int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
1186                        unsigned long pfn);
1187int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
1188                        unsigned long pfn);
1189
1190struct page *follow_page(struct vm_area_struct *, unsigned long address,
1191                        unsigned int foll_flags);
1192#define FOLL_WRITE      0x01    /* check pte is writable */
1193#define FOLL_TOUCH      0x02    /* mark page accessed */
1194#define FOLL_GET        0x04    /* do get_page on page */
1195#define FOLL_ANON       0x08    /* give ZERO_PAGE if no pgtable */
1196
1197typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
1198                        void *data);
1199extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
1200                               unsigned long size, pte_fn_t fn, void *data);
1201
1202#ifdef CONFIG_PROC_FS
1203void vm_stat_account(struct mm_struct *, unsigned long, struct file *, long);
1204#else
1205static inline void vm_stat_account(struct mm_struct *mm,
1206                        unsigned long flags, struct file *file, long pages)
1207{
1208}
1209#endif /* CONFIG_PROC_FS */
1210
1211#ifdef CONFIG_DEBUG_PAGEALLOC
1212extern int debug_pagealloc_enabled;
1213
1214extern void kernel_map_pages(struct page *page, int numpages, int enable);
1215
1216static inline void enable_debug_pagealloc(void)
1217{
1218        debug_pagealloc_enabled = 1;
1219}
1220#ifdef CONFIG_HIBERNATION
1221extern bool kernel_page_present(struct page *page);
1222#endif /* CONFIG_HIBERNATION */
1223#else
1224static inline void
1225kernel_map_pages(struct page *page, int numpages, int enable) {}
1226static inline void enable_debug_pagealloc(void)
1227{
1228}
1229#ifdef CONFIG_HIBERNATION
1230static inline bool kernel_page_present(struct page *page) { return true; }
1231#endif /* CONFIG_HIBERNATION */
1232#endif
1233
1234extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk);
1235#ifdef  __HAVE_ARCH_GATE_AREA
1236int in_gate_area_no_task(unsigned long addr);
1237int in_gate_area(struct task_struct *task, unsigned long addr);
1238#else
1239int in_gate_area_no_task(unsigned long addr);
1240#define in_gate_area(task, addr) ({(void)task; in_gate_area_no_task(addr);})
1241#endif  /* __HAVE_ARCH_GATE_AREA */
1242
1243int drop_caches_sysctl_handler(struct ctl_table *, int, struct file *,
1244                                        void __user *, size_t *, loff_t *);
1245unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
1246                        unsigned long lru_pages);
1247
1248#ifndef CONFIG_MMU
1249#define randomize_va_space 0
1250#else
1251extern int randomize_va_space;
1252#endif
1253
1254const char * arch_vma_name(struct vm_area_struct *vma);
1255void print_vma_addr(char *prefix, unsigned long rip);
1256
1257struct page *sparse_mem_map_populate(unsigned long pnum, int nid);
1258pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
1259pud_t *vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node);
1260pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
1261pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node);
1262void *vmemmap_alloc_block(unsigned long size, int node);
1263void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
1264int vmemmap_populate_basepages(struct page *start_page,
1265                                                unsigned long pages, int node);
1266int vmemmap_populate(struct page *start_page, unsigned long pages, int node);
1267void vmemmap_populate_print_last(void);
1268
1269#endif /* __KERNEL__ */
1270#endif /* _LINUX_MM_H */
1271
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