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/mmdebug.h>
  11#include <linux/mmzone.h>
  12#include <linux/rbtree.h>
  13#include <linux/prio_tree.h>
  14#include <linux/debug_locks.h>
  15#include <linux/mm_types.h>
  16
  17struct mempolicy;
  18struct anon_vma;
  19struct file_ra_state;
  20struct user_struct;
  21struct writeback_control;
  22
  23#ifndef CONFIG_DISCONTIGMEM          /* Don't use mapnrs, do it properly */
  24extern unsigned long max_mapnr;
  25#endif
  26
  27extern unsigned long num_physpages;
  28extern void * high_memory;
  29extern int page_cluster;
  30
  31#ifdef CONFIG_SYSCTL
  32extern int sysctl_legacy_va_layout;
  33#else
  34#define sysctl_legacy_va_layout 0
  35#endif
  36
  37extern unsigned long mmap_min_addr;
  38
  39#include <asm/page.h>
  40#include <asm/pgtable.h>
  41#include <asm/processor.h>
  42
  43#define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
  44
  45/* to align the pointer to the (next) page boundary */
  46#define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
  47
  48/*
  49 * Linux kernel virtual memory manager primitives.
  50 * The idea being to have a "virtual" mm in the same way
  51 * we have a virtual fs - giving a cleaner interface to the
  52 * mm details, and allowing different kinds of memory mappings
  53 * (from shared memory to executable loading to arbitrary
  54 * mmap() functions).
  55 */
  56
  57extern struct kmem_cache *vm_area_cachep;
  58
  59#ifndef CONFIG_MMU
  60extern struct rb_root nommu_region_tree;
  61extern struct rw_semaphore nommu_region_sem;
  62
  63extern unsigned int kobjsize(const void *objp);
  64#endif
  65
  66/*
  67 * vm_flags in vm_area_struct, see mm_types.h.
  68 */
  69#define VM_READ         0x00000001      /* currently active flags */
  70#define VM_WRITE        0x00000002
  71#define VM_EXEC         0x00000004
  72#define VM_SHARED       0x00000008
  73
  74/* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
  75#define VM_MAYREAD      0x00000010      /* limits for mprotect() etc */
  76#define VM_MAYWRITE     0x00000020
  77#define VM_MAYEXEC      0x00000040
  78#define VM_MAYSHARE     0x00000080
  79
  80#define VM_GROWSDOWN    0x00000100      /* general info on the segment */
  81#define VM_GROWSUP      0x00000200
  82#define VM_PFNMAP       0x00000400      /* Page-ranges managed without "struct page", just pure PFN */
  83#define VM_DENYWRITE    0x00000800      /* ETXTBSY on write attempts.. */
  84
  85#define VM_EXECUTABLE   0x00001000
  86#define VM_LOCKED       0x00002000
  87#define VM_IO           0x00004000      /* Memory mapped I/O or similar */
  88
  89                                        /* Used by sys_madvise() */
  90#define VM_SEQ_READ     0x00008000      /* App will access data sequentially */
  91#define VM_RAND_READ    0x00010000      /* App will not benefit from clustered reads */
  92
  93#define VM_DONTCOPY     0x00020000      /* Do not copy this vma on fork */
  94#define VM_DONTEXPAND   0x00040000      /* Cannot expand with mremap() */
  95#define VM_RESERVED     0x00080000      /* Count as reserved_vm like IO */
  96#define VM_ACCOUNT      0x00100000      /* Is a VM accounted object */
  97#define VM_NORESERVE    0x00200000      /* should the VM suppress accounting */
  98#define VM_HUGETLB      0x00400000      /* Huge TLB Page VM */
  99#define VM_NONLINEAR    0x00800000      /* Is non-linear (remap_file_pages) */
 100#define VM_MAPPED_COPY  0x01000000      /* T if mapped copy of data (nommu mmap) */
 101#define VM_INSERTPAGE   0x02000000      /* The vma has had "vm_insert_page()" done on it */
 102#define VM_ALWAYSDUMP   0x04000000      /* Always include in core dumps */
 103
 104#define VM_CAN_NONLINEAR 0x08000000     /* Has ->fault & does nonlinear pages */
 105#define VM_MIXEDMAP     0x10000000      /* Can contain "struct page" and pure PFN pages */
 106#define VM_SAO          0x20000000      /* Strong Access Ordering (powerpc) */
 107#define VM_PFN_AT_MMAP  0x40000000      /* PFNMAP vma that is fully mapped at mmap time */
 108
 109#ifndef VM_STACK_DEFAULT_FLAGS          /* arch can override this */
 110#define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
 111#endif
 112
 113#ifdef CONFIG_STACK_GROWSUP
 114#define VM_STACK_FLAGS  (VM_GROWSUP | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
 115#else
 116#define VM_STACK_FLAGS  (VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
 117#endif
 118
 119#define VM_READHINTMASK                 (VM_SEQ_READ | VM_RAND_READ)
 120#define VM_ClearReadHint(v)             (v)->vm_flags &= ~VM_READHINTMASK
 121#define VM_NormalReadHint(v)            (!((v)->vm_flags & VM_READHINTMASK))
 122#define VM_SequentialReadHint(v)        ((v)->vm_flags & VM_SEQ_READ)
 123#define VM_RandomReadHint(v)            ((v)->vm_flags & VM_RAND_READ)
 124
 125/*
 126 * special vmas that are non-mergable, non-mlock()able
 127 */
 128#define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP)
 129
 130/*
 131 * mapping from the currently active vm_flags protection bits (the
 132 * low four bits) to a page protection mask..
 133 */
 134extern pgprot_t protection_map[16];
 135
 136#define FAULT_FLAG_WRITE        0x01    /* Fault was a write access */
 137#define FAULT_FLAG_NONLINEAR    0x02    /* Fault was via a nonlinear mapping */
 138#define FAULT_FLAG_MKWRITE      0x04    /* Fault was mkwrite of existing pte */
 139
 140/*
 141 * This interface is used by x86 PAT code to identify a pfn mapping that is
 142 * linear over entire vma. This is to optimize PAT code that deals with
 143 * marking the physical region with a particular prot. This is not for generic
 144 * mm use. Note also that this check will not work if the pfn mapping is
 145 * linear for a vma starting at physical address 0. In which case PAT code
 146 * falls back to slow path of reserving physical range page by page.
 147 */
 148static inline int is_linear_pfn_mapping(struct vm_area_struct *vma)
 149{
 150        return (vma->vm_flags & VM_PFN_AT_MMAP);
 151}
 152
 153static inline int is_pfn_mapping(struct vm_area_struct *vma)
 154{
 155        return (vma->vm_flags & VM_PFNMAP);
 156}
 157
 158/*
 159 * vm_fault is filled by the the pagefault handler and passed to the vma's
 160 * ->fault function. The vma's ->fault is responsible for returning a bitmask
 161 * of VM_FAULT_xxx flags that give details about how the fault was handled.
 162 *
 163 * pgoff should be used in favour of virtual_address, if possible. If pgoff
 164 * is used, one may set VM_CAN_NONLINEAR in the vma->vm_flags to get nonlinear
 165 * mapping support.
 166 */
 167struct vm_fault {
 168        unsigned int flags;             /* FAULT_FLAG_xxx flags */
 169        pgoff_t pgoff;                  /* Logical page offset based on vma */
 170        void __user *virtual_address;   /* Faulting virtual address */
 171
 172        struct page *page;              /* ->fault handlers should return a
 173                                         * page here, unless VM_FAULT_NOPAGE
 174                                         * is set (which is also implied by
 175                                         * VM_FAULT_ERROR).
 176                                         */
 177};
 178
 179/*
 180 * These are the virtual MM functions - opening of an area, closing and
 181 * unmapping it (needed to keep files on disk up-to-date etc), pointer
 182 * to the functions called when a no-page or a wp-page exception occurs. 
 183 */
 184struct vm_operations_struct {
 185        void (*open)(struct vm_area_struct * area);
 186        void (*close)(struct vm_area_struct * area);
 187        int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
 188
 189        /* notification that a previously read-only page is about to become
 190         * writable, if an error is returned it will cause a SIGBUS */
 191        int (*page_mkwrite)(struct vm_area_struct *vma, struct vm_fault *vmf);
 192
 193        /* called by access_process_vm when get_user_pages() fails, typically
 194         * for use by special VMAs that can switch between memory and hardware
 195         */
 196        int (*access)(struct vm_area_struct *vma, unsigned long addr,
 197                      void *buf, int len, int write);
 198#ifdef CONFIG_NUMA
 199        /*
 200         * set_policy() op must add a reference to any non-NULL @new mempolicy
 201         * to hold the policy upon return.  Caller should pass NULL @new to
 202         * remove a policy and fall back to surrounding context--i.e. do not
 203         * install a MPOL_DEFAULT policy, nor the task or system default
 204         * mempolicy.
 205         */
 206        int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
 207
 208        /*
 209         * get_policy() op must add reference [mpol_get()] to any policy at
 210         * (vma,addr) marked as MPOL_SHARED.  The shared policy infrastructure
 211         * in mm/mempolicy.c will do this automatically.
 212         * get_policy() must NOT add a ref if the policy at (vma,addr) is not
 213         * marked as MPOL_SHARED. vma policies are protected by the mmap_sem.
 214         * If no [shared/vma] mempolicy exists at the addr, get_policy() op
 215         * must return NULL--i.e., do not "fallback" to task or system default
 216         * policy.
 217         */
 218        struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
 219                                        unsigned long addr);
 220        int (*migrate)(struct vm_area_struct *vma, const nodemask_t *from,
 221                const nodemask_t *to, unsigned long flags);
 222#endif
 223};
 224
 225struct mmu_gather;
 226struct inode;
 227
 228#define page_private(page)              ((page)->private)
 229#define set_page_private(page, v)       ((page)->private = (v))
 230
 231/*
 232 * FIXME: take this include out, include page-flags.h in
 233 * files which need it (119 of them)
 234 */
 235#include <linux/page-flags.h>
 236
 237/*
 238 * Methods to modify the page usage count.
 239 *
 240 * What counts for a page usage:
 241 * - cache mapping   (page->mapping)
 242 * - private data    (page->private)
 243 * - page mapped in a task's page tables, each mapping
 244 *   is counted separately
 245 *
 246 * Also, many kernel routines increase the page count before a critical
 247 * routine so they can be sure the page doesn't go away from under them.
 248 */
 249
 250/*
 251 * Drop a ref, return true if the refcount fell to zero (the page has no users)
 252 */
 253static inline int put_page_testzero(struct page *page)
 254{
 255        VM_BUG_ON(atomic_read(&page->_count) == 0);
 256        return atomic_dec_and_test(&page->_count);
 257}
 258
 259/*
 260 * Try to grab a ref unless the page has a refcount of zero, return false if
 261 * that is the case.
 262 */
 263static inline int get_page_unless_zero(struct page *page)
 264{
 265        return atomic_inc_not_zero(&page->_count);
 266}
 267
 268/* Support for virtually mapped pages */
 269struct page *vmalloc_to_page(const void *addr);
 270unsigned long vmalloc_to_pfn(const void *addr);
 271
 272/*
 273 * Determine if an address is within the vmalloc range
 274 *
 275 * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
 276 * is no special casing required.
 277 */
 278static inline int is_vmalloc_addr(const void *x)
 279{
 280#ifdef CONFIG_MMU
 281        unsigned long addr = (unsigned long)x;
 282
 283        return addr >= VMALLOC_START && addr < VMALLOC_END;
 284#else
 285        return 0;
 286#endif
 287}
 288
 289static inline struct page *compound_head(struct page *page)
 290{
 291        if (unlikely(PageTail(page)))
 292                return page->first_page;
 293        return page;
 294}
 295
 296static inline int page_count(struct page *page)
 297{
 298        return atomic_read(&compound_head(page)->_count);
 299}
 300
 301static inline void get_page(struct page *page)
 302{
 303        page = compound_head(page);
 304        VM_BUG_ON(atomic_read(&page->_count) == 0);
 305        atomic_inc(&page->_count);
 306}
 307
 308static inline struct page *virt_to_head_page(const void *x)
 309{
 310        struct page *page = virt_to_page(x);
 311        return compound_head(page);
 312}
 313
 314/*
 315 * Setup the page count before being freed into the page allocator for
 316 * the first time (boot or memory hotplug)
 317 */
 318static inline void init_page_count(struct page *page)
 319{
 320        atomic_set(&page->_count, 1);
 321}
 322
 323void put_page(struct page *page);
 324void put_pages_list(struct list_head *pages);
 325
 326void split_page(struct page *page, unsigned int order);
 327
 328/*
 329 * Compound pages have a destructor function.  Provide a
 330 * prototype for that function and accessor functions.
 331 * These are _only_ valid on the head of a PG_compound page.
 332 */
 333typedef void compound_page_dtor(struct page *);
 334
 335static inline void set_compound_page_dtor(struct page *page,
 336                                                compound_page_dtor *dtor)
 337{
 338        page[1].lru.next = (void *)dtor;
 339}
 340
 341static inline compound_page_dtor *get_compound_page_dtor(struct page *page)
 342{
 343        return (compound_page_dtor *)page[1].lru.next;
 344}
 345
 346static inline int compound_order(struct page *page)
 347{
 348        if (!PageHead(page))
 349                return 0;
 350        return (unsigned long)page[1].lru.prev;
 351}
 352
 353static inline void set_compound_order(struct page *page, unsigned long order)
 354{
 355        page[1].lru.prev = (void *)order;
 356}
 357
 358/*
 359 * Multiple processes may "see" the same page. E.g. for untouched
 360 * mappings of /dev/null, all processes see the same page full of
 361 * zeroes, and text pages of executables and shared libraries have
 362 * only one copy in memory, at most, normally.
 363 *
 364 * For the non-reserved pages, page_count(page) denotes a reference count.
 365 *   page_count() == 0 means the page is free. page->lru is then used for
 366 *   freelist management in the buddy allocator.
 367 *   page_count() > 0  means the page has been allocated.
 368 *
 369 * Pages are allocated by the slab allocator in order to provide memory
 370 * to kmalloc and kmem_cache_alloc. In this case, the management of the
 371 * page, and the fields in 'struct page' are the responsibility of mm/slab.c
 372 * unless a particular usage is carefully commented. (the responsibility of
 373 * freeing the kmalloc memory is the caller's, of course).
 374 *
 375 * A page may be used by anyone else who does a __get_free_page().
 376 * In this case, page_count still tracks the references, and should only
 377 * be used through the normal accessor functions. The top bits of page->flags
 378 * and page->virtual store page management information, but all other fields
 379 * are unused and could be used privately, carefully. The management of this
 380 * page is the responsibility of the one who allocated it, and those who have
 381 * subsequently been given references to it.
 382 *
 383 * The other pages (we may call them "pagecache pages") are completely
 384 * managed by the Linux memory manager: I/O, buffers, swapping etc.
 385 * The following discussion applies only to them.
 386 *
 387 * A pagecache page contains an opaque `private' member, which belongs to the
 388 * page's address_space. Usually, this is the address of a circular list of
 389 * the page's disk buffers. PG_private must be set to tell the VM to call
 390 * into the filesystem to release these pages.
 391 *
 392 * A page may belong to an inode's memory mapping. In this case, page->mapping
 393 * is the pointer to the inode, and page->index is the file offset of the page,
 394 * in units of PAGE_CACHE_SIZE.
 395 *
 396 * If pagecache pages are not associated with an inode, they are said to be
 397 * anonymous pages. These may become associated with the swapcache, and in that
 398 * case PG_swapcache is set, and page->private is an offset into the swapcache.
 399 *
 400 * In either case (swapcache or inode backed), the pagecache itself holds one
 401 * reference to the page. Setting PG_private should also increment the
 402 * refcount. The each user mapping also has a reference to the page.
 403 *
 404 * The pagecache pages are stored in a per-mapping radix tree, which is
 405 * rooted at mapping->page_tree, and indexed by offset.
 406 * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
 407 * lists, we instead now tag pages as dirty/writeback in the radix tree.
 408 *
 409 * All pagecache pages may be subject to I/O:
 410 * - inode pages may need to be read from disk,
 411 * - inode pages which have been modified and are MAP_SHARED may need
 412 *   to be written back to the inode on disk,
 413 * - anonymous pages (including MAP_PRIVATE file mappings) which have been
 414 *   modified may need to be swapped out to swap space and (later) to be read
 415 *   back into memory.
 416 */
 417
 418/*
 419 * The zone field is never updated after free_area_init_core()
 420 * sets it, so none of the operations on it need to be atomic.
 421 */
 422
 423
 424/*
 425 * page->flags layout:
 426 *
 427 * There are three possibilities for how page->flags get
 428 * laid out.  The first is for the normal case, without
 429 * sparsemem.  The second is for sparsemem when there is
 430 * plenty of space for node and section.  The last is when
 431 * we have run out of space and have to fall back to an
 432 * alternate (slower) way of determining the node.
 433 *
 434 * No sparsemem or sparsemem vmemmap: |       NODE     | ZONE | ... | FLAGS |
 435 * classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS |
 436 * classic sparse no space for node:  | SECTION |     ZONE    | ... | FLAGS |
 437 */
 438#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
 439#define SECTIONS_WIDTH          SECTIONS_SHIFT
 440#else
 441#define SECTIONS_WIDTH          0
 442#endif
 443
 444#define ZONES_WIDTH             ZONES_SHIFT
 445
 446#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
 447#define NODES_WIDTH             NODES_SHIFT
 448#else
 449#ifdef CONFIG_SPARSEMEM_VMEMMAP
 450#error "Vmemmap: No space for nodes field in page flags"
 451#endif
 452#define NODES_WIDTH             0
 453#endif
 454
 455/* Page flags: | [SECTION] | [NODE] | ZONE | ... | FLAGS | */
 456#define SECTIONS_PGOFF          ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
 457#define NODES_PGOFF             (SECTIONS_PGOFF - NODES_WIDTH)
 458#define ZONES_PGOFF             (NODES_PGOFF - ZONES_WIDTH)
 459
 460/*
 461 * We are going to use the flags for the page to node mapping if its in
 462 * there.  This includes the case where there is no node, so it is implicit.
 463 */
 464#if !(NODES_WIDTH > 0 || NODES_SHIFT == 0)
 465#define NODE_NOT_IN_PAGE_FLAGS
 466#endif
 467
 468#ifndef PFN_SECTION_SHIFT
 469#define PFN_SECTION_SHIFT 0
 470#endif
 471
 472/*
 473 * Define the bit shifts to access each section.  For non-existant
 474 * sections we define the shift as 0; that plus a 0 mask ensures
 475 * the compiler will optimise away reference to them.
 476 */
 477#define SECTIONS_PGSHIFT        (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
 478#define NODES_PGSHIFT           (NODES_PGOFF * (NODES_WIDTH != 0))
 479#define ZONES_PGSHIFT           (ZONES_PGOFF * (ZONES_WIDTH != 0))
 480
 481/* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allcator */
 482#ifdef NODE_NOT_IN_PAGEFLAGS
 483#define ZONEID_SHIFT            (SECTIONS_SHIFT + ZONES_SHIFT)
 484#define ZONEID_PGOFF            ((SECTIONS_PGOFF < ZONES_PGOFF)? \
 485                                                SECTIONS_PGOFF : ZONES_PGOFF)
 486#else
 487#define ZONEID_SHIFT            (NODES_SHIFT + ZONES_SHIFT)
 488#define ZONEID_PGOFF            ((NODES_PGOFF < ZONES_PGOFF)? \
 489                                                NODES_PGOFF : ZONES_PGOFF)
 490#endif
 491
 492#define ZONEID_PGSHIFT          (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
 493
 494#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
 495#error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
 496#endif
 497
 498#define ZONES_MASK              ((1UL << ZONES_WIDTH) - 1)
 499#define NODES_MASK              ((1UL << NODES_WIDTH) - 1)
 500#define SECTIONS_MASK           ((1UL << SECTIONS_WIDTH) - 1)
 501#define ZONEID_MASK             ((1UL << ZONEID_SHIFT) - 1)
 502
 503static inline enum zone_type page_zonenum(struct page *page)
 504{
 505        return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
 506}
 507
 508/*
 509 * The identification function is only used by the buddy allocator for
 510 * determining if two pages could be buddies. We are not really
 511 * identifying a zone since we could be using a the section number
 512 * id if we have not node id available in page flags.
 513 * We guarantee only that it will return the same value for two
 514 * combinable pages in a zone.
 515 */
 516static inline int page_zone_id(struct page *page)
 517{
 518        return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
 519}
 520
 521static inline int zone_to_nid(struct zone *zone)
 522{
 523#ifdef CONFIG_NUMA
 524        return zone->node;
 525#else
 526        return 0;
 527#endif
 528}
 529
 530#ifdef NODE_NOT_IN_PAGE_FLAGS
 531extern int page_to_nid(struct page *page);
 532#else
 533static inline int page_to_nid(struct page *page)
 534{
 535        return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
 536}
 537#endif
 538
 539static inline struct zone *page_zone(struct page *page)
 540{
 541        return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
 542}
 543
 544#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
 545static inline unsigned long page_to_section(struct page *page)
 546{
 547        return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
 548}
 549#endif
 550
 551static inline void set_page_zone(struct page *page, enum zone_type zone)
 552{
 553        page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
 554        page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
 555}
 556
 557static inline void set_page_node(struct page *page, unsigned long node)
 558{
 559        page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
 560        page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
 561}
 562
 563static inline void set_page_section(struct page *page, unsigned long section)
 564{
 565        page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
 566        page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
 567}
 568
 569static inline void set_page_links(struct page *page, enum zone_type zone,
 570        unsigned long node, unsigned long pfn)
 571{
 572        set_page_zone(page, zone);
 573        set_page_node(page, node);
 574        set_page_section(page, pfn_to_section_nr(pfn));
 575}
 576
 577/*
 578 * If a hint addr is less than mmap_min_addr change hint to be as
 579 * low as possible but still greater than mmap_min_addr
 580 */
 581static inline unsigned long round_hint_to_min(unsigned long hint)
 582{
 583#ifdef CONFIG_SECURITY
 584        hint &= PAGE_MASK;
 585        if (((void *)hint != NULL) &&
 586            (hint < mmap_min_addr))
 587                return PAGE_ALIGN(mmap_min_addr);
 588#endif
 589        return hint;
 590}
 591
 592/*
 593 * Some inline functions in vmstat.h depend on page_zone()
 594 */
 595#include <linux/vmstat.h>
 596
 597static __always_inline void *lowmem_page_address(struct page *page)
 598{
 599        return __va(page_to_pfn(page) << PAGE_SHIFT);
 600}
 601
 602#if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
 603#define HASHED_PAGE_VIRTUAL
 604#endif
 605
 606#if defined(WANT_PAGE_VIRTUAL)
 607#define page_address(page) ((page)->virtual)
 608#define set_page_address(page, address)                 \
 609        do {                                            \
 610                (page)->virtual = (address);            \
 611        } while(0)
 612#define page_address_init()  do { } while(0)
 613#endif
 614
 615#if defined(HASHED_PAGE_VIRTUAL)
 616void *page_address(struct page *page);
 617void set_page_address(struct page *page, void *virtual);
 618void page_address_init(void);
 619#endif
 620
 621#if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
 622#define page_address(page) lowmem_page_address(page)
 623#define set_page_address(page, address)  do { } while(0)
 624#define page_address_init()  do { } while(0)
 625#endif
 626
 627/*
 628 * On an anonymous page mapped into a user virtual memory area,
 629 * page->mapping points to its anon_vma, not to a struct address_space;
 630 * with the PAGE_MAPPING_ANON bit set to distinguish it.
 631 *
 632 * Please note that, confusingly, "page_mapping" refers to the inode
 633 * address_space which maps the page from disk; whereas "page_mapped"
 634 * refers to user virtual address space into which the page is mapped.
 635 */
 636#define PAGE_MAPPING_ANON       1
 637
 638extern struct address_space swapper_space;
 639static inline struct address_space *page_mapping(struct page *page)
 640{
 641        struct address_space *mapping = page->mapping;
 642
 643        VM_BUG_ON(PageSlab(page));
 644#ifdef CONFIG_SWAP
 645        if (unlikely(PageSwapCache(page)))
 646                mapping = &swapper_space;
 647        else
 648#endif
 649        if (unlikely((unsigned long)mapping & PAGE_MAPPING_ANON))
 650                mapping = NULL;
 651        return mapping;
 652}
 653
 654static inline int PageAnon(struct page *page)
 655{
 656        return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
 657}
 658
 659/*
 660 * Return the pagecache index of the passed page.  Regular pagecache pages
 661 * use ->index whereas swapcache pages use ->private
 662 */
 663static inline pgoff_t page_index(struct page *page)
 664{
 665        if (unlikely(PageSwapCache(page)))
 666                return page_private(page);
 667        return page->index;
 668}
 669
 670/*
 671 * The atomic page->_mapcount, like _count, starts from -1:
 672 * so that transitions both from it and to it can be tracked,
 673 * using atomic_inc_and_test and atomic_add_negative(-1).
 674 */
 675static inline void reset_page_mapcount(struct page *page)
 676{
 677        atomic_set(&(page)->_mapcount, -1);
 678}
 679
 680static inline int page_mapcount(struct page *page)
 681{
 682        return atomic_read(&(page)->_mapcount) + 1;
 683}
 684
 685/*
 686 * Return true if this page is mapped into pagetables.
 687 */
 688static inline int page_mapped(struct page *page)
 689{
 690        return atomic_read(&(page)->_mapcount) >= 0;
 691}
 692
 693/*
 694 * Different kinds of faults, as returned by handle_mm_fault().
 695 * Used to decide whether a process gets delivered SIGBUS or
 696 * just gets major/minor fault counters bumped up.
 697 */
 698
 699#define VM_FAULT_MINOR  0 /* For backwards compat. Remove me quickly. */
 700
 701#define VM_FAULT_OOM    0x0001
 702#define VM_FAULT_SIGBUS 0x0002
 703#define VM_FAULT_MAJOR  0x0004
 704#define VM_FAULT_WRITE  0x0008  /* Special case for get_user_pages */
 705
 706#define VM_FAULT_NOPAGE 0x0100  /* ->fault installed the pte, not return page */
 707#define VM_FAULT_LOCKED 0x0200  /* ->fault locked the returned page */
 708
 709#define VM_FAULT_ERROR  (VM_FAULT_OOM | VM_FAULT_SIGBUS)
 710
 711/*
 712 * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
 713 */
 714extern void pagefault_out_of_memory(void);
 715
 716#define offset_in_page(p)       ((unsigned long)(p) & ~PAGE_MASK)
 717
 718extern void show_free_areas(void);
 719
 720#ifdef CONFIG_SHMEM
 721extern int shmem_lock(struct file *file, int lock, struct user_struct *user);
 722#else
 723static inline int shmem_lock(struct file *file, int lock,
 724                            struct user_struct *user)
 725{
 726        return 0;
 727}
 728#endif
 729struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags);
 730
 731int shmem_zero_setup(struct vm_area_struct *);
 732
 733#ifndef CONFIG_MMU
 734extern unsigned long shmem_get_unmapped_area(struct file *file,
 735                                             unsigned long addr,
 736                                             unsigned long len,
 737                                             unsigned long pgoff,
 738                                             unsigned long flags);
 739#endif
 740
 741extern int can_do_mlock(void);
 742extern int user_shm_lock(size_t, struct user_struct *);
 743extern void user_shm_unlock(size_t, struct user_struct *);
 744
 745/*
 746 * Parameter block passed down to zap_pte_range in exceptional cases.
 747 */
 748struct zap_details {
 749        struct vm_area_struct *nonlinear_vma;   /* Check page->index if set */
 750        struct address_space *check_mapping;    /* Check page->mapping if set */
 751        pgoff_t first_index;                    /* Lowest page->index to unmap */
 752        pgoff_t last_index;                     /* Highest page->index to unmap */
 753        spinlock_t *i_mmap_lock;                /* For unmap_mapping_range: */
 754        unsigned long truncate_count;           /* Compare vm_truncate_count */
 755};
 756
 757struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 758                pte_t pte);
 759
 760int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
 761                unsigned long size);
 762unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
 763                unsigned long size, struct zap_details *);
 764unsigned long unmap_vmas(struct mmu_gather **tlb,
 765                struct vm_area_struct *start_vma, unsigned long start_addr,
 766                unsigned long end_addr, unsigned long *nr_accounted,
 767                struct zap_details *);
 768
 769/**
 770 * mm_walk - callbacks for walk_page_range
 771 * @pgd_entry: if set, called for each non-empty PGD (top-level) entry
 772 * @pud_entry: if set, called for each non-empty PUD (2nd-level) entry
 773 * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry
 774 * @pte_entry: if set, called for each non-empty PTE (4th-level) entry
 775 * @pte_hole: if set, called for each hole at all levels
 776 *
 777 * (see walk_page_range for more details)
 778 */
 779struct mm_walk {
 780        int (*pgd_entry)(pgd_t *, unsigned long, unsigned long, struct mm_walk *);
 781        int (*pud_entry)(pud_t *, unsigned long, unsigned long, struct mm_walk *);
 782        int (*pmd_entry)(pmd_t *, unsigned long, unsigned long, struct mm_walk *);
 783        int (*pte_entry)(pte_t *, unsigned long, unsigned long, struct mm_walk *);
 784        int (*pte_hole)(unsigned long, unsigned long, struct mm_walk *);
 785        struct mm_struct *mm;
 786        void *private;
 787};
 788
 789int walk_page_range(unsigned long addr, unsigned long end,
 790                struct mm_walk *walk);
 791void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
 792                unsigned long end, unsigned long floor, unsigned long ceiling);
 793int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
 794                        struct vm_area_struct *vma);
 795void unmap_mapping_range(struct address_space *mapping,
 796                loff_t const holebegin, loff_t const holelen, int even_cows);
 797int follow_phys(struct vm_area_struct *vma, unsigned long address,
 798                unsigned int flags, unsigned long *prot, resource_size_t *phys);
 799int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
 800                        void *buf, int len, int write);
 801
 802static inline void unmap_shared_mapping_range(struct address_space *mapping,
 803                loff_t const holebegin, loff_t const holelen)
 804{
 805        unmap_mapping_range(mapping, holebegin, holelen, 0);
 806}
 807
 808extern int vmtruncate(struct inode * inode, loff_t offset);
 809extern int vmtruncate_range(struct inode * inode, loff_t offset, loff_t end);
 810
 811#ifdef CONFIG_MMU
 812extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 813                        unsigned long address, int write_access);
 814#else
 815static inline int handle_mm_fault(struct mm_struct *mm,
 816                        struct vm_area_struct *vma, unsigned long address,
 817                        int write_access)
 818{
 819        /* should never happen if there's no MMU */
 820        BUG();
 821        return VM_FAULT_SIGBUS;
 822}
 823#endif
 824
 825extern int make_pages_present(unsigned long addr, unsigned long end);
 826extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
 827
 828int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start,
 829                int len, int write, int force, struct page **pages, struct vm_area_struct **vmas);
 830
 831extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
 832extern void do_invalidatepage(struct page *page, unsigned long offset);
 833
 834int __set_page_dirty_nobuffers(struct page *page);
 835int __set_page_dirty_no_writeback(struct page *page);
 836int redirty_page_for_writepage(struct writeback_control *wbc,
 837                                struct page *page);
 838void account_page_dirtied(struct page *page, struct address_space *mapping);
 839int set_page_dirty(struct page *page);
 840int set_page_dirty_lock(struct page *page);
 841int clear_page_dirty_for_io(struct page *page);
 842
 843extern unsigned long move_page_tables(struct vm_area_struct *vma,
 844                unsigned long old_addr, struct vm_area_struct *new_vma,
 845                unsigned long new_addr, unsigned long len);
 846extern unsigned long do_mremap(unsigned long addr,
 847                               unsigned long old_len, unsigned long new_len,
 848                               unsigned long flags, unsigned long new_addr);
 849extern int mprotect_fixup(struct vm_area_struct *vma,
 850                          struct vm_area_struct **pprev, unsigned long start,
 851                          unsigned long end, unsigned long newflags);
 852
 853/*
 854 * get_user_pages_fast provides equivalent functionality to get_user_pages,
 855 * operating on current and current->mm (force=0 and doesn't return any vmas).
 856 *
 857 * get_user_pages_fast may take mmap_sem and page tables, so no assumptions
 858 * can be made about locking. get_user_pages_fast is to be implemented in a
 859 * way that is advantageous (vs get_user_pages()) when the user memory area is
 860 * already faulted in and present in ptes. However if the pages have to be
 861 * faulted in, it may turn out to be slightly slower).
 862 */
 863int get_user_pages_fast(unsigned long start, int nr_pages, int write,
 864                        struct page **pages);
 865
 866/*
 867 * A callback you can register to apply pressure to ageable caches.
 868 *
 869 * 'shrink' is passed a count 'nr_to_scan' and a 'gfpmask'.  It should
 870 * look through the least-recently-used 'nr_to_scan' entries and
 871 * attempt to free them up.  It should return the number of objects
 872 * which remain in the cache.  If it returns -1, it means it cannot do
 873 * any scanning at this time (eg. there is a risk of deadlock).
 874 *
 875 * The 'gfpmask' refers to the allocation we are currently trying to
 876 * fulfil.
 877 *
 878 * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
 879 * querying the cache size, so a fastpath for that case is appropriate.
 880 */
 881struct shrinker {
 882        int (*shrink)(int nr_to_scan, gfp_t gfp_mask);
 883        int seeks;      /* seeks to recreate an obj */
 884
 885        /* These are for internal use */
 886        struct list_head list;
 887        long nr;        /* objs pending delete */
 888};
 889#define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
 890extern void register_shrinker(struct shrinker *);
 891extern void unregister_shrinker(struct shrinker *);
 892
 893int vma_wants_writenotify(struct vm_area_struct *vma);
 894
 895extern pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl);
 896
 897#ifdef __PAGETABLE_PUD_FOLDED
 898static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd,
 899                                                unsigned long address)
 900{
 901        return 0;
 902}
 903#else
 904int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
 905#endif
 906
 907#ifdef __PAGETABLE_PMD_FOLDED
 908static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
 909                                                unsigned long address)
 910{
 911        return 0;
 912}
 913#else
 914int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
 915#endif
 916
 917int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
 918int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
 919
 920/*
 921 * The following ifdef needed to get the 4level-fixup.h header to work.
 922 * Remove it when 4level-fixup.h has been removed.
 923 */
 924#if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
 925static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
 926{
 927        return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))?
 928                NULL: pud_offset(pgd, address);
 929}
 930
 931static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 932{
 933        return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
 934                NULL: pmd_offset(pud, address);
 935}
 936#endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
 937
 938#if USE_SPLIT_PTLOCKS
 939/*
 940 * We tuck a spinlock to guard each pagetable page into its struct page,
 941 * at page->private, with BUILD_BUG_ON to make sure that this will not
 942 * overflow into the next struct page (as it might with DEBUG_SPINLOCK).
 943 * When freeing, reset page->mapping so free_pages_check won't complain.
 944 */
 945#define __pte_lockptr(page)     &((page)->ptl)
 946#define pte_lock_init(_page)    do {                                    \
 947        spin_lock_init(__pte_lockptr(_page));                           \
 948} while (0)
 949#define pte_lock_deinit(page)   ((page)->mapping = NULL)
 950#define pte_lockptr(mm, pmd)    ({(void)(mm); __pte_lockptr(pmd_page(*(pmd)));})
 951#else   /* !USE_SPLIT_PTLOCKS */
 952/*
 953 * We use mm->page_table_lock to guard all pagetable pages of the mm.
 954 */
 955#define pte_lock_init(page)     do {} while (0)
 956#define pte_lock_deinit(page)   do {} while (0)
 957#define pte_lockptr(mm, pmd)    ({(void)(pmd); &(mm)->page_table_lock;})
 958#endif /* USE_SPLIT_PTLOCKS */
 959
 960static inline void pgtable_page_ctor(struct page *page)
 961{
 962        pte_lock_init(page);
 963        inc_zone_page_state(page, NR_PAGETABLE);
 964}
 965
 966static inline void pgtable_page_dtor(struct page *page)
 967{
 968        pte_lock_deinit(page);
 969        dec_zone_page_state(page, NR_PAGETABLE);
 970}
 971
 972#define pte_offset_map_lock(mm, pmd, address, ptlp)     \
 973({                                                      \
 974        spinlock_t *__ptl = pte_lockptr(mm, pmd);       \
 975        pte_t *__pte = pte_offset_map(pmd, address);    \
 976        *(ptlp) = __ptl;                                \
 977        spin_lock(__ptl);                               \
 978        __pte;                                          \
 979})
 980
 981#define pte_unmap_unlock(pte, ptl)      do {            \
 982        spin_unlock(ptl);                               \
 983        pte_unmap(pte);                                 \
 984} while (0)
 985
 986#define pte_alloc_map(mm, pmd, address)                 \
 987        ((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
 988                NULL: pte_offset_map(pmd, address))
 989
 990#define pte_alloc_map_lock(mm, pmd, address, ptlp)      \
 991        ((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
 992                NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
 993
 994#define pte_alloc_kernel(pmd, address)                  \
 995        ((unlikely(!pmd_present(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
 996                NULL: pte_offset_kernel(pmd, address))
 997
 998extern void free_area_init(unsigned long * zones_size);
 999extern void free_area_init_node(int nid, unsigned long * zones_size,
1000                unsigned long zone_start_pfn, unsigned long *zholes_size);
1001#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
1002/*
1003 * With CONFIG_ARCH_POPULATES_NODE_MAP set, an architecture may initialise its
1004 * zones, allocate the backing mem_map and account for memory holes in a more
1005 * architecture independent manner. This is a substitute for creating the
1006 * zone_sizes[] and zholes_size[] arrays and passing them to
1007 * free_area_init_node()
1008 *
1009 * An architecture is expected to register range of page frames backed by
1010 * physical memory with add_active_range() before calling
1011 * free_area_init_nodes() passing in the PFN each zone ends at. At a basic
1012 * usage, an architecture is expected to do something like
1013 *
1014 * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
1015 *                                                       max_highmem_pfn};
1016 * for_each_valid_physical_page_range()
1017 *      add_active_range(node_id, start_pfn, end_pfn)
1018 * free_area_init_nodes(max_zone_pfns);
1019 *
1020 * If the architecture guarantees that there are no holes in the ranges
1021 * registered with add_active_range(), free_bootmem_active_regions()
1022 * will call free_bootmem_node() for each registered physical page range.
1023 * Similarly sparse_memory_present_with_active_regions() calls
1024 * memory_present() for each range when SPARSEMEM is enabled.
1025 *
1026 * See mm/page_alloc.c for more information on each function exposed by
1027 * CONFIG_ARCH_POPULATES_NODE_MAP
1028 */
1029extern void free_area_init_nodes(unsigned long *max_zone_pfn);
1030extern void add_active_range(unsigned int nid, unsigned long start_pfn,
1031                                        unsigned long end_pfn);
1032extern void remove_active_range(unsigned int nid, unsigned long start_pfn,
1033                                        unsigned long end_pfn);
1034extern void push_node_boundaries(unsigned int nid, unsigned long start_pfn,
1035                                        unsigned long end_pfn);
1036extern void remove_all_active_ranges(void);
1037extern unsigned long absent_pages_in_range(unsigned long start_pfn,
1038                                                unsigned long end_pfn);
1039extern void get_pfn_range_for_nid(unsigned int nid,
1040                        unsigned long *start_pfn, unsigned long *end_pfn);
1041extern unsigned long find_min_pfn_with_active_regions(void);
1042extern void free_bootmem_with_active_regions(int nid,
1043                                                unsigned long max_low_pfn);
1044typedef int (*work_fn_t)(unsigned long, unsigned long, void *);
1045extern void work_with_active_regions(int nid, work_fn_t work_fn, void *data);
1046extern void sparse_memory_present_with_active_regions(int nid);
1047#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
1048
1049#if !defined(CONFIG_ARCH_POPULATES_NODE_MAP) && \
1050    !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID)
1051static inline int __early_pfn_to_nid(unsigned long pfn)
1052{
1053        return 0;
1054}
1055#else
1056/* please see mm/page_alloc.c */
1057extern int __meminit early_pfn_to_nid(unsigned long pfn);
1058#ifdef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
1059/* there is a per-arch backend function. */
1060extern int __meminit __early_pfn_to_nid(unsigned long pfn);
1061#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
1062#endif
1063
1064extern void set_dma_reserve(unsigned long new_dma_reserve);
1065extern void memmap_init_zone(unsigned long, int, unsigned long,
1066                                unsigned long, enum memmap_context);
1067extern void setup_per_zone_pages_min(void);
1068extern void mem_init(void);
1069extern void __init mmap_init(void);
1070extern void show_mem(void);
1071extern void si_meminfo(struct sysinfo * val);
1072extern void si_meminfo_node(struct sysinfo *val, int nid);
1073extern int after_bootmem;
1074
1075#ifdef CONFIG_NUMA
1076extern void setup_per_cpu_pageset(void);
1077#else
1078static inline void setup_per_cpu_pageset(void) {}
1079#endif
1080
1081/* nommu.c */
1082extern atomic_long_t mmap_pages_allocated;
1083
1084/* prio_tree.c */
1085void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old);
1086void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *);
1087void vma_prio_tree_remove(struct vm_area_struct *, struct prio_tree_root *);
1088struct vm_area_struct *vma_prio_tree_next(struct vm_area_struct *vma,
1089        struct prio_tree_iter *iter);
1090
1091#define vma_prio_tree_foreach(vma, iter, root, begin, end)      \
1092        for (prio_tree_iter_init(iter, root, begin, end), vma = NULL;   \
1093                (vma = vma_prio_tree_next(vma, iter)); )
1094
1095static inline void vma_nonlinear_insert(struct vm_area_struct *vma,
1096                                        struct list_head *list)
1097{
1098        vma->shared.vm_set.parent = NULL;
1099        list_add_tail(&vma->shared.vm_set.list, list);
1100}
1101
1102/* mmap.c */
1103extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
1104extern void vma_adjust(struct vm_area_struct *vma, unsigned long start,
1105        unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
1106extern struct vm_area_struct *vma_merge(struct mm_struct *,
1107        struct vm_area_struct *prev, unsigned long addr, unsigned long end,
1108        unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
1109        struct mempolicy *);
1110extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
1111extern int split_vma(struct mm_struct *,
1112        struct vm_area_struct *, unsigned long addr, int new_below);
1113extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
1114extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
1115        struct rb_node **, struct rb_node *);
1116extern void unlink_file_vma(struct vm_area_struct *);
1117extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
1118        unsigned long addr, unsigned long len, pgoff_t pgoff);
1119extern void exit_mmap(struct mm_struct *);
1120
1121extern int mm_take_all_locks(struct mm_struct *mm);
1122extern void mm_drop_all_locks(struct mm_struct *mm);
1123
1124#ifdef CONFIG_PROC_FS
1125/* From fs/proc/base.c. callers must _not_ hold the mm's exe_file_lock */
1126extern void added_exe_file_vma(struct mm_struct *mm);
1127extern void removed_exe_file_vma(struct mm_struct *mm);
1128#else
1129static inline void added_exe_file_vma(struct mm_struct *mm)
1130{}
1131
1132static inline void removed_exe_file_vma(struct mm_struct *mm)
1133{}
1134#endif /* CONFIG_PROC_FS */
1135
1136extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
1137extern int install_special_mapping(struct mm_struct *mm,
1138                                   unsigned long addr, unsigned long len,
1139                                   unsigned long flags, struct page **pages);
1140
1141extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1142
1143extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
1144        unsigned long len, unsigned long prot,
1145        unsigned long flag, unsigned long pgoff);
1146extern unsigned long mmap_region(struct file *file, unsigned long addr,
1147        unsigned long len, unsigned long flags,
1148        unsigned int vm_flags, unsigned long pgoff);
1149
1150static inline unsigned long do_mmap(struct file *file, unsigned long addr,
1151        unsigned long len, unsigned long prot,
1152        unsigned long flag, unsigned long offset)
1153{
1154        unsigned long ret = -EINVAL;
1155        if ((offset + PAGE_ALIGN(len)) < offset)
1156                goto out;
1157        if (!(offset & ~PAGE_MASK))
1158                ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
1159out:
1160        return ret;
1161}
1162
1163extern int do_munmap(struct mm_struct *, unsigned long, size_t);
1164
1165extern unsigned long do_brk(unsigned long, unsigned long);
1166
1167/* filemap.c */
1168extern unsigned long page_unuse(struct page *);
1169extern void truncate_inode_pages(struct address_space *, loff_t);
1170extern void truncate_inode_pages_range(struct address_space *,
1171                                       loff_t lstart, loff_t lend);
1172
1173/* generic vm_area_ops exported for stackable file systems */
1174extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
1175
1176/* mm/page-writeback.c */
1177int write_one_page(struct page *page, int wait);
1178void task_dirty_inc(struct task_struct *tsk);
1179
1180/* readahead.c */
1181#define VM_MAX_READAHEAD        128     /* kbytes */
1182#define VM_MIN_READAHEAD        16      /* kbytes (includes current page) */
1183
1184int do_page_cache_readahead(struct address_space *mapping, struct file *filp,
1185                        pgoff_t offset, unsigned long nr_to_read);
1186int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
1187                        pgoff_t offset, unsigned long nr_to_read);
1188
1189void page_cache_sync_readahead(struct address_space *mapping,
1190                               struct file_ra_state *ra,
1191                               struct file *filp,
1192                               pgoff_t offset,
1193                               unsigned long size);
1194
1195void page_cache_async_readahead(struct address_space *mapping,
1196                                struct file_ra_state *ra,
1197                                struct file *filp,
1198                                struct page *pg,
1199                                pgoff_t offset,
1200                                unsigned long size);
1201
1202unsigned long max_sane_readahead(unsigned long nr);
1203
1204/* Do stack extension */
1205extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
1206#ifdef CONFIG_IA64
1207extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
1208#endif
1209extern int expand_stack_downwards(struct vm_area_struct *vma,
1210                                  unsigned long address);
1211
1212/* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
1213extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
1214extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
1215                                             struct vm_area_struct **pprev);
1216
1217/* Look up the first VMA which intersects the interval start_addr..end_addr-1,
1218   NULL if none.  Assume start_addr < end_addr. */
1219static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
1220{
1221        struct vm_area_struct * vma = find_vma(mm,start_addr);
1222
1223        if (vma && end_addr <= vma->vm_start)
1224                vma = NULL;
1225        return vma;
1226}
1227
1228static inline unsigned long vma_pages(struct vm_area_struct *vma)
1229{
1230        return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
1231}
1232
1233pgprot_t vm_get_page_prot(unsigned long vm_flags);
1234struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
1235int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
1236                        unsigned long pfn, unsigned long size, pgprot_t);
1237int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
1238int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
1239                        unsigned long pfn);
1240int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
1241                        unsigned long pfn);
1242
1243struct page *follow_page(struct vm_area_struct *, unsigned long address,
1244                        unsigned int foll_flags);
1245#define FOLL_WRITE      0x01    /* check pte is writable */
1246#define FOLL_TOUCH      0x02    /* mark page accessed */
1247#define FOLL_GET        0x04    /* do get_page on page */
1248#define FOLL_ANON       0x08    /* give ZERO_PAGE if no pgtable */
1249
1250typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
1251                        void *data);
1252extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
1253                               unsigned long size, pte_fn_t fn, void *data);
1254
1255#ifdef CONFIG_PROC_FS
1256void vm_stat_account(struct mm_struct *, unsigned long, struct file *, long);
1257#else
1258static inline void vm_stat_account(struct mm_struct *mm,
1259                        unsigned long flags, struct file *file, long pages)
1260{
1261}
1262#endif /* CONFIG_PROC_FS */
1263
1264#ifdef CONFIG_DEBUG_PAGEALLOC
1265extern int debug_pagealloc_enabled;
1266
1267extern void kernel_map_pages(struct page *page, int numpages, int enable);
1268
1269static inline void enable_debug_pagealloc(void)
1270{
1271        debug_pagealloc_enabled = 1;
1272}
1273#ifdef CONFIG_HIBERNATION
1274extern bool kernel_page_present(struct page *page);
1275#endif /* CONFIG_HIBERNATION */
1276#else
1277static inline void
1278kernel_map_pages(struct page *page, int numpages, int enable) {}
1279static inline void enable_debug_pagealloc(void)
1280{
1281}
1282#ifdef CONFIG_HIBERNATION
1283static inline bool kernel_page_present(struct page *page) { return true; }
1284#endif /* CONFIG_HIBERNATION */
1285#endif
1286
1287extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk);
1288#ifdef  __HAVE_ARCH_GATE_AREA
1289int in_gate_area_no_task(unsigned long addr);
1290int in_gate_area(struct task_struct *task, unsigned long addr);
1291#else
1292int in_gate_area_no_task(unsigned long addr);
1293#define in_gate_area(task, addr) ({(void)task; in_gate_area_no_task(addr);})
1294#endif  /* __HAVE_ARCH_GATE_AREA */
1295
1296int drop_caches_sysctl_handler(struct ctl_table *, int, struct file *,
1297                                        void __user *, size_t *, loff_t *);
1298unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
1299                        unsigned long lru_pages);
1300
1301#ifndef CONFIG_MMU
1302#define randomize_va_space 0
1303#else
1304extern int randomize_va_space;
1305#endif
1306
1307const char * arch_vma_name(struct vm_area_struct *vma);
1308void print_vma_addr(char *prefix, unsigned long rip);
1309
1310struct page *sparse_mem_map_populate(unsigned long pnum, int nid);
1311pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
1312pud_t *vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node);
1313pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
1314pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node);
1315void *vmemmap_alloc_block(unsigned long size, int node);
1316void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
1317int vmemmap_populate_basepages(struct page *start_page,
1318                                                unsigned long pages, int node);
1319int vmemmap_populate(struct page *start_page, unsigned long pages, int node);
1320void vmemmap_populate_print_last(void);
1321
1322extern void *alloc_locked_buffer(size_t size);
1323extern void free_locked_buffer(void *buffer, size_t size);
1324extern void release_locked_buffer(void *buffer, size_t size);
1325#endif /* __KERNEL__ */
1326#endif /* _LINUX_MM_H */
1327
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