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/atomic.h>
  14#include <linux/debug_locks.h>
  15#include <linux/mm_types.h>
  16#include <linux/range.h>
  17#include <linux/pfn.h>
  18#include <linux/bit_spinlock.h>
  19#include <linux/shrinker.h>
  20
  21struct mempolicy;
  22struct anon_vma;
  23struct file_ra_state;
  24struct user_struct;
  25struct writeback_control;
  26
  27#ifndef CONFIG_DISCONTIGMEM          /* Don't use mapnrs, do it properly */
  28extern unsigned long max_mapnr;
  29#endif
  30
  31extern unsigned long num_physpages;
  32extern unsigned long totalram_pages;
  33extern void * high_memory;
  34extern int page_cluster;
  35
  36#ifdef CONFIG_SYSCTL
  37extern int sysctl_legacy_va_layout;
  38#else
  39#define sysctl_legacy_va_layout 0
  40#endif
  41
  42#include <asm/page.h>
  43#include <asm/pgtable.h>
  44#include <asm/processor.h>
  45
  46#define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
  47
  48/* to align the pointer to the (next) page boundary */
  49#define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
  50
  51/*
  52 * Linux kernel virtual memory manager primitives.
  53 * The idea being to have a "virtual" mm in the same way
  54 * we have a virtual fs - giving a cleaner interface to the
  55 * mm details, and allowing different kinds of memory mappings
  56 * (from shared memory to executable loading to arbitrary
  57 * mmap() functions).
  58 */
  59
  60extern struct kmem_cache *vm_area_cachep;
  61
  62#ifndef CONFIG_MMU
  63extern struct rb_root nommu_region_tree;
  64extern struct rw_semaphore nommu_region_sem;
  65
  66extern unsigned int kobjsize(const void *objp);
  67#endif
  68
  69/*
  70 * vm_flags in vm_area_struct, see mm_types.h.
  71 */
  72#define VM_READ         0x00000001      /* currently active flags */
  73#define VM_WRITE        0x00000002
  74#define VM_EXEC         0x00000004
  75#define VM_SHARED       0x00000008
  76
  77/* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
  78#define VM_MAYREAD      0x00000010      /* limits for mprotect() etc */
  79#define VM_MAYWRITE     0x00000020
  80#define VM_MAYEXEC      0x00000040
  81#define VM_MAYSHARE     0x00000080
  82
  83#define VM_GROWSDOWN    0x00000100      /* general info on the segment */
  84#if defined(CONFIG_STACK_GROWSUP) || defined(CONFIG_IA64)
  85#define VM_GROWSUP      0x00000200
  86#else
  87#define VM_GROWSUP      0x00000000
  88#define VM_NOHUGEPAGE   0x00000200      /* MADV_NOHUGEPAGE marked this vma */
  89#endif
  90#define VM_PFNMAP       0x00000400      /* Page-ranges managed without "struct page", just pure PFN */
  91#define VM_DENYWRITE    0x00000800      /* ETXTBSY on write attempts.. */
  92
  93#define VM_EXECUTABLE   0x00001000
  94#define VM_LOCKED       0x00002000
  95#define VM_IO           0x00004000      /* Memory mapped I/O or similar */
  96
  97                                        /* Used by sys_madvise() */
  98#define VM_SEQ_READ     0x00008000      /* App will access data sequentially */
  99#define VM_RAND_READ    0x00010000      /* App will not benefit from clustered reads */
 100
 101#define VM_DONTCOPY     0x00020000      /* Do not copy this vma on fork */
 102#define VM_DONTEXPAND   0x00040000      /* Cannot expand with mremap() */
 103#define VM_RESERVED     0x00080000      /* Count as reserved_vm like IO */
 104#define VM_ACCOUNT      0x00100000      /* Is a VM accounted object */
 105#define VM_NORESERVE    0x00200000      /* should the VM suppress accounting */
 106#define VM_HUGETLB      0x00400000      /* Huge TLB Page VM */
 107#define VM_NONLINEAR    0x00800000      /* Is non-linear (remap_file_pages) */
 108#ifndef CONFIG_TRANSPARENT_HUGEPAGE
 109#define VM_MAPPED_COPY  0x01000000      /* T if mapped copy of data (nommu mmap) */
 110#else
 111#define VM_HUGEPAGE     0x01000000      /* MADV_HUGEPAGE marked this vma */
 112#endif
 113#define VM_INSERTPAGE   0x02000000      /* The vma has had "vm_insert_page()" done on it */
 114#define VM_ALWAYSDUMP   0x04000000      /* Always include in core dumps */
 115
 116#define VM_CAN_NONLINEAR 0x08000000     /* Has ->fault & does nonlinear pages */
 117#define VM_MIXEDMAP     0x10000000      /* Can contain "struct page" and pure PFN pages */
 118#define VM_SAO          0x20000000      /* Strong Access Ordering (powerpc) */
 119#define VM_PFN_AT_MMAP  0x40000000      /* PFNMAP vma that is fully mapped at mmap time */
 120#define VM_MERGEABLE    0x80000000      /* KSM may merge identical pages */
 121
 122/* Bits set in the VMA until the stack is in its final location */
 123#define VM_STACK_INCOMPLETE_SETUP       (VM_RAND_READ | VM_SEQ_READ)
 124
 125#ifndef VM_STACK_DEFAULT_FLAGS          /* arch can override this */
 126#define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
 127#endif
 128
 129#ifdef CONFIG_STACK_GROWSUP
 130#define VM_STACK_FLAGS  (VM_GROWSUP | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
 131#else
 132#define VM_STACK_FLAGS  (VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
 133#endif
 134
 135#define VM_READHINTMASK                 (VM_SEQ_READ | VM_RAND_READ)
 136#define VM_ClearReadHint(v)             (v)->vm_flags &= ~VM_READHINTMASK
 137#define VM_NormalReadHint(v)            (!((v)->vm_flags & VM_READHINTMASK))
 138#define VM_SequentialReadHint(v)        ((v)->vm_flags & VM_SEQ_READ)
 139#define VM_RandomReadHint(v)            ((v)->vm_flags & VM_RAND_READ)
 140
 141/*
 142 * Special vmas that are non-mergable, non-mlock()able.
 143 * Note: mm/huge_memory.c VM_NO_THP depends on this definition.
 144 */
 145#define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP)
 146
 147/*
 148 * mapping from the currently active vm_flags protection bits (the
 149 * low four bits) to a page protection mask..
 150 */
 151extern pgprot_t protection_map[16];
 152
 153#define FAULT_FLAG_WRITE        0x01    /* Fault was a write access */
 154#define FAULT_FLAG_NONLINEAR    0x02    /* Fault was via a nonlinear mapping */
 155#define FAULT_FLAG_MKWRITE      0x04    /* Fault was mkwrite of existing pte */
 156#define FAULT_FLAG_ALLOW_RETRY  0x08    /* Retry fault if blocking */
 157#define FAULT_FLAG_RETRY_NOWAIT 0x10    /* Don't drop mmap_sem and wait when retrying */
 158#define FAULT_FLAG_KILLABLE     0x20    /* The fault task is in SIGKILL killable region */
 159
 160/*
 161 * This interface is used by x86 PAT code to identify a pfn mapping that is
 162 * linear over entire vma. This is to optimize PAT code that deals with
 163 * marking the physical region with a particular prot. This is not for generic
 164 * mm use. Note also that this check will not work if the pfn mapping is
 165 * linear for a vma starting at physical address 0. In which case PAT code
 166 * falls back to slow path of reserving physical range page by page.
 167 */
 168static inline int is_linear_pfn_mapping(struct vm_area_struct *vma)
 169{
 170        return !!(vma->vm_flags & VM_PFN_AT_MMAP);
 171}
 172
 173static inline int is_pfn_mapping(struct vm_area_struct *vma)
 174{
 175        return !!(vma->vm_flags & VM_PFNMAP);
 176}
 177
 178/*
 179 * vm_fault is filled by the the pagefault handler and passed to the vma's
 180 * ->fault function. The vma's ->fault is responsible for returning a bitmask
 181 * of VM_FAULT_xxx flags that give details about how the fault was handled.
 182 *
 183 * pgoff should be used in favour of virtual_address, if possible. If pgoff
 184 * is used, one may set VM_CAN_NONLINEAR in the vma->vm_flags to get nonlinear
 185 * mapping support.
 186 */
 187struct vm_fault {
 188        unsigned int flags;             /* FAULT_FLAG_xxx flags */
 189        pgoff_t pgoff;                  /* Logical page offset based on vma */
 190        void __user *virtual_address;   /* Faulting virtual address */
 191
 192        struct page *page;              /* ->fault handlers should return a
 193                                         * page here, unless VM_FAULT_NOPAGE
 194                                         * is set (which is also implied by
 195                                         * VM_FAULT_ERROR).
 196                                         */
 197};
 198
 199/*
 200 * These are the virtual MM functions - opening of an area, closing and
 201 * unmapping it (needed to keep files on disk up-to-date etc), pointer
 202 * to the functions called when a no-page or a wp-page exception occurs. 
 203 */
 204struct vm_operations_struct {
 205        void (*open)(struct vm_area_struct * area);
 206        void (*close)(struct vm_area_struct * area);
 207        int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
 208
 209        /* notification that a previously read-only page is about to become
 210         * writable, if an error is returned it will cause a SIGBUS */
 211        int (*page_mkwrite)(struct vm_area_struct *vma, struct vm_fault *vmf);
 212
 213        /* called by access_process_vm when get_user_pages() fails, typically
 214         * for use by special VMAs that can switch between memory and hardware
 215         */
 216        int (*access)(struct vm_area_struct *vma, unsigned long addr,
 217                      void *buf, int len, int write);
 218#ifdef CONFIG_NUMA
 219        /*
 220         * set_policy() op must add a reference to any non-NULL @new mempolicy
 221         * to hold the policy upon return.  Caller should pass NULL @new to
 222         * remove a policy and fall back to surrounding context--i.e. do not
 223         * install a MPOL_DEFAULT policy, nor the task or system default
 224         * mempolicy.
 225         */
 226        int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
 227
 228        /*
 229         * get_policy() op must add reference [mpol_get()] to any policy at
 230         * (vma,addr) marked as MPOL_SHARED.  The shared policy infrastructure
 231         * in mm/mempolicy.c will do this automatically.
 232         * get_policy() must NOT add a ref if the policy at (vma,addr) is not
 233         * marked as MPOL_SHARED. vma policies are protected by the mmap_sem.
 234         * If no [shared/vma] mempolicy exists at the addr, get_policy() op
 235         * must return NULL--i.e., do not "fallback" to task or system default
 236         * policy.
 237         */
 238        struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
 239                                        unsigned long addr);
 240        int (*migrate)(struct vm_area_struct *vma, const nodemask_t *from,
 241                const nodemask_t *to, unsigned long flags);
 242#endif
 243};
 244
 245struct mmu_gather;
 246struct inode;
 247
 248#define page_private(page)              ((page)->private)
 249#define set_page_private(page, v)       ((page)->private = (v))
 250
 251/*
 252 * FIXME: take this include out, include page-flags.h in
 253 * files which need it (119 of them)
 254 */
 255#include <linux/page-flags.h>
 256#include <linux/huge_mm.h>
 257
 258/*
 259 * Methods to modify the page usage count.
 260 *
 261 * What counts for a page usage:
 262 * - cache mapping   (page->mapping)
 263 * - private data    (page->private)
 264 * - page mapped in a task's page tables, each mapping
 265 *   is counted separately
 266 *
 267 * Also, many kernel routines increase the page count before a critical
 268 * routine so they can be sure the page doesn't go away from under them.
 269 */
 270
 271/*
 272 * Drop a ref, return true if the refcount fell to zero (the page has no users)
 273 */
 274static inline int put_page_testzero(struct page *page)
 275{
 276        VM_BUG_ON(atomic_read(&page->_count) == 0);
 277        return atomic_dec_and_test(&page->_count);
 278}
 279
 280/*
 281 * Try to grab a ref unless the page has a refcount of zero, return false if
 282 * that is the case.
 283 */
 284static inline int get_page_unless_zero(struct page *page)
 285{
 286        return atomic_inc_not_zero(&page->_count);
 287}
 288
 289extern int page_is_ram(unsigned long pfn);
 290
 291/* Support for virtually mapped pages */
 292struct page *vmalloc_to_page(const void *addr);
 293unsigned long vmalloc_to_pfn(const void *addr);
 294
 295/*
 296 * Determine if an address is within the vmalloc range
 297 *
 298 * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
 299 * is no special casing required.
 300 */
 301static inline int is_vmalloc_addr(const void *x)
 302{
 303#ifdef CONFIG_MMU
 304        unsigned long addr = (unsigned long)x;
 305
 306        return addr >= VMALLOC_START && addr < VMALLOC_END;
 307#else
 308        return 0;
 309#endif
 310}
 311#ifdef CONFIG_MMU
 312extern int is_vmalloc_or_module_addr(const void *x);
 313#else
 314static inline int is_vmalloc_or_module_addr(const void *x)
 315{
 316        return 0;
 317}
 318#endif
 319
 320static inline void compound_lock(struct page *page)
 321{
 322#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 323        bit_spin_lock(PG_compound_lock, &page->flags);
 324#endif
 325}
 326
 327static inline void compound_unlock(struct page *page)
 328{
 329#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 330        bit_spin_unlock(PG_compound_lock, &page->flags);
 331#endif
 332}
 333
 334static inline unsigned long compound_lock_irqsave(struct page *page)
 335{
 336        unsigned long uninitialized_var(flags);
 337#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 338        local_irq_save(flags);
 339        compound_lock(page);
 340#endif
 341        return flags;
 342}
 343
 344static inline void compound_unlock_irqrestore(struct page *page,
 345                                              unsigned long flags)
 346{
 347#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 348        compound_unlock(page);
 349        local_irq_restore(flags);
 350#endif
 351}
 352
 353static inline struct page *compound_head(struct page *page)
 354{
 355        if (unlikely(PageTail(page)))
 356                return page->first_page;
 357        return page;
 358}
 359
 360/*
 361 * The atomic page->_mapcount, starts from -1: so that transitions
 362 * both from it and to it can be tracked, using atomic_inc_and_test
 363 * and atomic_add_negative(-1).
 364 */
 365static inline void reset_page_mapcount(struct page *page)
 366{
 367        atomic_set(&(page)->_mapcount, -1);
 368}
 369
 370static inline int page_mapcount(struct page *page)
 371{
 372        return atomic_read(&(page)->_mapcount) + 1;
 373}
 374
 375static inline int page_count(struct page *page)
 376{
 377        return atomic_read(&compound_head(page)->_count);
 378}
 379
 380static inline void get_huge_page_tail(struct page *page)
 381{
 382        /*
 383         * __split_huge_page_refcount() cannot run
 384         * from under us.
 385         */
 386        VM_BUG_ON(page_mapcount(page) < 0);
 387        VM_BUG_ON(atomic_read(&page->_count) != 0);
 388        atomic_inc(&page->_mapcount);
 389}
 390
 391extern bool __get_page_tail(struct page *page);
 392
 393static inline void get_page(struct page *page)
 394{
 395        if (unlikely(PageTail(page)))
 396                if (likely(__get_page_tail(page)))
 397                        return;
 398        /*
 399         * Getting a normal page or the head of a compound page
 400         * requires to already have an elevated page->_count.
 401         */
 402        VM_BUG_ON(atomic_read(&page->_count) <= 0);
 403        atomic_inc(&page->_count);
 404}
 405
 406static inline struct page *virt_to_head_page(const void *x)
 407{
 408        struct page *page = virt_to_page(x);
 409        return compound_head(page);
 410}
 411
 412/*
 413 * Setup the page count before being freed into the page allocator for
 414 * the first time (boot or memory hotplug)
 415 */
 416static inline void init_page_count(struct page *page)
 417{
 418        atomic_set(&page->_count, 1);
 419}
 420
 421/*
 422 * PageBuddy() indicate that the page is free and in the buddy system
 423 * (see mm/page_alloc.c).
 424 *
 425 * PAGE_BUDDY_MAPCOUNT_VALUE must be <= -2 but better not too close to
 426 * -2 so that an underflow of the page_mapcount() won't be mistaken
 427 * for a genuine PAGE_BUDDY_MAPCOUNT_VALUE. -128 can be created very
 428 * efficiently by most CPU architectures.
 429 */
 430#define PAGE_BUDDY_MAPCOUNT_VALUE (-128)
 431
 432static inline int PageBuddy(struct page *page)
 433{
 434        return atomic_read(&page->_mapcount) == PAGE_BUDDY_MAPCOUNT_VALUE;
 435}
 436
 437static inline void __SetPageBuddy(struct page *page)
 438{
 439        VM_BUG_ON(atomic_read(&page->_mapcount) != -1);
 440        atomic_set(&page->_mapcount, PAGE_BUDDY_MAPCOUNT_VALUE);
 441}
 442
 443static inline void __ClearPageBuddy(struct page *page)
 444{
 445        VM_BUG_ON(!PageBuddy(page));
 446        atomic_set(&page->_mapcount, -1);
 447}
 448
 449void put_page(struct page *page);
 450void put_pages_list(struct list_head *pages);
 451
 452void split_page(struct page *page, unsigned int order);
 453int split_free_page(struct page *page);
 454
 455/*
 456 * Compound pages have a destructor function.  Provide a
 457 * prototype for that function and accessor functions.
 458 * These are _only_ valid on the head of a PG_compound page.
 459 */
 460typedef void compound_page_dtor(struct page *);
 461
 462static inline void set_compound_page_dtor(struct page *page,
 463                                                compound_page_dtor *dtor)
 464{
 465        page[1].lru.next = (void *)dtor;
 466}
 467
 468static inline compound_page_dtor *get_compound_page_dtor(struct page *page)
 469{
 470        return (compound_page_dtor *)page[1].lru.next;
 471}
 472
 473static inline int compound_order(struct page *page)
 474{
 475        if (!PageHead(page))
 476                return 0;
 477        return (unsigned long)page[1].lru.prev;
 478}
 479
 480static inline int compound_trans_order(struct page *page)
 481{
 482        int order;
 483        unsigned long flags;
 484
 485        if (!PageHead(page))
 486                return 0;
 487
 488        flags = compound_lock_irqsave(page);
 489        order = compound_order(page);
 490        compound_unlock_irqrestore(page, flags);
 491        return order;
 492}
 493
 494static inline void set_compound_order(struct page *page, unsigned long order)
 495{
 496        page[1].lru.prev = (void *)order;
 497}
 498
 499#ifdef CONFIG_MMU
 500/*
 501 * Do pte_mkwrite, but only if the vma says VM_WRITE.  We do this when
 502 * servicing faults for write access.  In the normal case, do always want
 503 * pte_mkwrite.  But get_user_pages can cause write faults for mappings
 504 * that do not have writing enabled, when used by access_process_vm.
 505 */
 506static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
 507{
 508        if (likely(vma->vm_flags & VM_WRITE))
 509                pte = pte_mkwrite(pte);
 510        return pte;
 511}
 512#endif
 513
 514/*
 515 * Multiple processes may "see" the same page. E.g. for untouched
 516 * mappings of /dev/null, all processes see the same page full of
 517 * zeroes, and text pages of executables and shared libraries have
 518 * only one copy in memory, at most, normally.
 519 *
 520 * For the non-reserved pages, page_count(page) denotes a reference count.
 521 *   page_count() == 0 means the page is free. page->lru is then used for
 522 *   freelist management in the buddy allocator.
 523 *   page_count() > 0  means the page has been allocated.
 524 *
 525 * Pages are allocated by the slab allocator in order to provide memory
 526 * to kmalloc and kmem_cache_alloc. In this case, the management of the
 527 * page, and the fields in 'struct page' are the responsibility of mm/slab.c
 528 * unless a particular usage is carefully commented. (the responsibility of
 529 * freeing the kmalloc memory is the caller's, of course).
 530 *
 531 * A page may be used by anyone else who does a __get_free_page().
 532 * In this case, page_count still tracks the references, and should only
 533 * be used through the normal accessor functions. The top bits of page->flags
 534 * and page->virtual store page management information, but all other fields
 535 * are unused and could be used privately, carefully. The management of this
 536 * page is the responsibility of the one who allocated it, and those who have
 537 * subsequently been given references to it.
 538 *
 539 * The other pages (we may call them "pagecache pages") are completely
 540 * managed by the Linux memory manager: I/O, buffers, swapping etc.
 541 * The following discussion applies only to them.
 542 *
 543 * A pagecache page contains an opaque `private' member, which belongs to the
 544 * page's address_space. Usually, this is the address of a circular list of
 545 * the page's disk buffers. PG_private must be set to tell the VM to call
 546 * into the filesystem to release these pages.
 547 *
 548 * A page may belong to an inode's memory mapping. In this case, page->mapping
 549 * is the pointer to the inode, and page->index is the file offset of the page,
 550 * in units of PAGE_CACHE_SIZE.
 551 *
 552 * If pagecache pages are not associated with an inode, they are said to be
 553 * anonymous pages. These may become associated with the swapcache, and in that
 554 * case PG_swapcache is set, and page->private is an offset into the swapcache.
 555 *
 556 * In either case (swapcache or inode backed), the pagecache itself holds one
 557 * reference to the page. Setting PG_private should also increment the
 558 * refcount. The each user mapping also has a reference to the page.
 559 *
 560 * The pagecache pages are stored in a per-mapping radix tree, which is
 561 * rooted at mapping->page_tree, and indexed by offset.
 562 * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
 563 * lists, we instead now tag pages as dirty/writeback in the radix tree.
 564 *
 565 * All pagecache pages may be subject to I/O:
 566 * - inode pages may need to be read from disk,
 567 * - inode pages which have been modified and are MAP_SHARED may need
 568 *   to be written back to the inode on disk,
 569 * - anonymous pages (including MAP_PRIVATE file mappings) which have been
 570 *   modified may need to be swapped out to swap space and (later) to be read
 571 *   back into memory.
 572 */
 573
 574/*
 575 * The zone field is never updated after free_area_init_core()
 576 * sets it, so none of the operations on it need to be atomic.
 577 */
 578
 579
 580/*
 581 * page->flags layout:
 582 *
 583 * There are three possibilities for how page->flags get
 584 * laid out.  The first is for the normal case, without
 585 * sparsemem.  The second is for sparsemem when there is
 586 * plenty of space for node and section.  The last is when
 587 * we have run out of space and have to fall back to an
 588 * alternate (slower) way of determining the node.
 589 *
 590 * No sparsemem or sparsemem vmemmap: |       NODE     | ZONE | ... | FLAGS |
 591 * classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS |
 592 * classic sparse no space for node:  | SECTION |     ZONE    | ... | FLAGS |
 593 */
 594#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
 595#define SECTIONS_WIDTH          SECTIONS_SHIFT
 596#else
 597#define SECTIONS_WIDTH          0
 598#endif
 599
 600#define ZONES_WIDTH             ZONES_SHIFT
 601
 602#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
 603#define NODES_WIDTH             NODES_SHIFT
 604#else
 605#ifdef CONFIG_SPARSEMEM_VMEMMAP
 606#error "Vmemmap: No space for nodes field in page flags"
 607#endif
 608#define NODES_WIDTH             0
 609#endif
 610
 611/* Page flags: | [SECTION] | [NODE] | ZONE | ... | FLAGS | */
 612#define SECTIONS_PGOFF          ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
 613#define NODES_PGOFF             (SECTIONS_PGOFF - NODES_WIDTH)
 614#define ZONES_PGOFF             (NODES_PGOFF - ZONES_WIDTH)
 615
 616/*
 617 * We are going to use the flags for the page to node mapping if its in
 618 * there.  This includes the case where there is no node, so it is implicit.
 619 */
 620#if !(NODES_WIDTH > 0 || NODES_SHIFT == 0)
 621#define NODE_NOT_IN_PAGE_FLAGS
 622#endif
 623
 624/*
 625 * Define the bit shifts to access each section.  For non-existent
 626 * sections we define the shift as 0; that plus a 0 mask ensures
 627 * the compiler will optimise away reference to them.
 628 */
 629#define SECTIONS_PGSHIFT        (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
 630#define NODES_PGSHIFT           (NODES_PGOFF * (NODES_WIDTH != 0))
 631#define ZONES_PGSHIFT           (ZONES_PGOFF * (ZONES_WIDTH != 0))
 632
 633/* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */
 634#ifdef NODE_NOT_IN_PAGE_FLAGS
 635#define ZONEID_SHIFT            (SECTIONS_SHIFT + ZONES_SHIFT)
 636#define ZONEID_PGOFF            ((SECTIONS_PGOFF < ZONES_PGOFF)? \
 637                                                SECTIONS_PGOFF : ZONES_PGOFF)
 638#else
 639#define ZONEID_SHIFT            (NODES_SHIFT + ZONES_SHIFT)
 640#define ZONEID_PGOFF            ((NODES_PGOFF < ZONES_PGOFF)? \
 641                                                NODES_PGOFF : ZONES_PGOFF)
 642#endif
 643
 644#define ZONEID_PGSHIFT          (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
 645
 646#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
 647#error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
 648#endif
 649
 650#define ZONES_MASK              ((1UL << ZONES_WIDTH) - 1)
 651#define NODES_MASK              ((1UL << NODES_WIDTH) - 1)
 652#define SECTIONS_MASK           ((1UL << SECTIONS_WIDTH) - 1)
 653#define ZONEID_MASK             ((1UL << ZONEID_SHIFT) - 1)
 654
 655static inline enum zone_type page_zonenum(const struct page *page)
 656{
 657        return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
 658}
 659
 660/*
 661 * The identification function is only used by the buddy allocator for
 662 * determining if two pages could be buddies. We are not really
 663 * identifying a zone since we could be using a the section number
 664 * id if we have not node id available in page flags.
 665 * We guarantee only that it will return the same value for two
 666 * combinable pages in a zone.
 667 */
 668static inline int page_zone_id(struct page *page)
 669{
 670        return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
 671}
 672
 673static inline int zone_to_nid(struct zone *zone)
 674{
 675#ifdef CONFIG_NUMA
 676        return zone->node;
 677#else
 678        return 0;
 679#endif
 680}
 681
 682#ifdef NODE_NOT_IN_PAGE_FLAGS
 683extern int page_to_nid(const struct page *page);
 684#else
 685static inline int page_to_nid(const struct page *page)
 686{
 687        return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
 688}
 689#endif
 690
 691static inline struct zone *page_zone(const struct page *page)
 692{
 693        return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
 694}
 695
 696#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
 697static inline void set_page_section(struct page *page, unsigned long section)
 698{
 699        page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
 700        page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
 701}
 702
 703static inline unsigned long page_to_section(const struct page *page)
 704{
 705        return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
 706}
 707#endif
 708
 709static inline void set_page_zone(struct page *page, enum zone_type zone)
 710{
 711        page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
 712        page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
 713}
 714
 715static inline void set_page_node(struct page *page, unsigned long node)
 716{
 717        page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
 718        page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
 719}
 720
 721static inline void set_page_links(struct page *page, enum zone_type zone,
 722        unsigned long node, unsigned long pfn)
 723{
 724        set_page_zone(page, zone);
 725        set_page_node(page, node);
 726#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
 727        set_page_section(page, pfn_to_section_nr(pfn));
 728#endif
 729}
 730
 731/*
 732 * Some inline functions in vmstat.h depend on page_zone()
 733 */
 734#include <linux/vmstat.h>
 735
 736static __always_inline void *lowmem_page_address(const struct page *page)
 737{
 738        return __va(PFN_PHYS(page_to_pfn(page)));
 739}
 740
 741#if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
 742#define HASHED_PAGE_VIRTUAL
 743#endif
 744
 745#if defined(WANT_PAGE_VIRTUAL)
 746#define page_address(page) ((page)->virtual)
 747#define set_page_address(page, address)                 \
 748        do {                                            \
 749                (page)->virtual = (address);            \
 750        } while(0)
 751#define page_address_init()  do { } while(0)
 752#endif
 753
 754#if defined(HASHED_PAGE_VIRTUAL)
 755void *page_address(const struct page *page);
 756void set_page_address(struct page *page, void *virtual);
 757void page_address_init(void);
 758#endif
 759
 760#if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
 761#define page_address(page) lowmem_page_address(page)
 762#define set_page_address(page, address)  do { } while(0)
 763#define page_address_init()  do { } while(0)
 764#endif
 765
 766/*
 767 * On an anonymous page mapped into a user virtual memory area,
 768 * page->mapping points to its anon_vma, not to a struct address_space;
 769 * with the PAGE_MAPPING_ANON bit set to distinguish it.  See rmap.h.
 770 *
 771 * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled,
 772 * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit;
 773 * and then page->mapping points, not to an anon_vma, but to a private
 774 * structure which KSM associates with that merged page.  See ksm.h.
 775 *
 776 * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used.
 777 *
 778 * Please note that, confusingly, "page_mapping" refers to the inode
 779 * address_space which maps the page from disk; whereas "page_mapped"
 780 * refers to user virtual address space into which the page is mapped.
 781 */
 782#define PAGE_MAPPING_ANON       1
 783#define PAGE_MAPPING_KSM        2
 784#define PAGE_MAPPING_FLAGS      (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM)
 785
 786extern struct address_space swapper_space;
 787static inline struct address_space *page_mapping(struct page *page)
 788{
 789        struct address_space *mapping = page->mapping;
 790
 791        VM_BUG_ON(PageSlab(page));
 792        if (unlikely(PageSwapCache(page)))
 793                mapping = &swapper_space;
 794        else if ((unsigned long)mapping & PAGE_MAPPING_ANON)
 795                mapping = NULL;
 796        return mapping;
 797}
 798
 799/* Neutral page->mapping pointer to address_space or anon_vma or other */
 800static inline void *page_rmapping(struct page *page)
 801{
 802        return (void *)((unsigned long)page->mapping & ~PAGE_MAPPING_FLAGS);
 803}
 804
 805static inline int PageAnon(struct page *page)
 806{
 807        return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
 808}
 809
 810/*
 811 * Return the pagecache index of the passed page.  Regular pagecache pages
 812 * use ->index whereas swapcache pages use ->private
 813 */
 814static inline pgoff_t page_index(struct page *page)
 815{
 816        if (unlikely(PageSwapCache(page)))
 817                return page_private(page);
 818        return page->index;
 819}
 820
 821/*
 822 * Return true if this page is mapped into pagetables.
 823 */
 824static inline int page_mapped(struct page *page)
 825{
 826        return atomic_read(&(page)->_mapcount) >= 0;
 827}
 828
 829/*
 830 * Different kinds of faults, as returned by handle_mm_fault().
 831 * Used to decide whether a process gets delivered SIGBUS or
 832 * just gets major/minor fault counters bumped up.
 833 */
 834
 835#define VM_FAULT_MINOR  0 /* For backwards compat. Remove me quickly. */
 836
 837#define VM_FAULT_OOM    0x0001
 838#define VM_FAULT_SIGBUS 0x0002
 839#define VM_FAULT_MAJOR  0x0004
 840#define VM_FAULT_WRITE  0x0008  /* Special case for get_user_pages */
 841#define VM_FAULT_HWPOISON 0x0010        /* Hit poisoned small page */
 842#define VM_FAULT_HWPOISON_LARGE 0x0020  /* Hit poisoned large page. Index encoded in upper bits */
 843
 844#define VM_FAULT_NOPAGE 0x0100  /* ->fault installed the pte, not return page */
 845#define VM_FAULT_LOCKED 0x0200  /* ->fault locked the returned page */
 846#define VM_FAULT_RETRY  0x0400  /* ->fault blocked, must retry */
 847
 848#define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */
 849
 850#define VM_FAULT_ERROR  (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON | \
 851                         VM_FAULT_HWPOISON_LARGE)
 852
 853/* Encode hstate index for a hwpoisoned large page */
 854#define VM_FAULT_SET_HINDEX(x) ((x) << 12)
 855#define VM_FAULT_GET_HINDEX(x) (((x) >> 12) & 0xf)
 856
 857/*
 858 * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
 859 */
 860extern void pagefault_out_of_memory(void);
 861
 862#define offset_in_page(p)       ((unsigned long)(p) & ~PAGE_MASK)
 863
 864/*
 865 * Flags passed to show_mem() and show_free_areas() to suppress output in
 866 * various contexts.
 867 */
 868#define SHOW_MEM_FILTER_NODES   (0x0001u)       /* filter disallowed nodes */
 869
 870extern void show_free_areas(unsigned int flags);
 871extern bool skip_free_areas_node(unsigned int flags, int nid);
 872
 873int shmem_lock(struct file *file, int lock, struct user_struct *user);
 874struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags);
 875int shmem_zero_setup(struct vm_area_struct *);
 876
 877extern int can_do_mlock(void);
 878extern int user_shm_lock(size_t, struct user_struct *);
 879extern void user_shm_unlock(size_t, struct user_struct *);
 880
 881/*
 882 * Parameter block passed down to zap_pte_range in exceptional cases.
 883 */
 884struct zap_details {
 885        struct vm_area_struct *nonlinear_vma;   /* Check page->index if set */
 886        struct address_space *check_mapping;    /* Check page->mapping if set */
 887        pgoff_t first_index;                    /* Lowest page->index to unmap */
 888        pgoff_t last_index;                     /* Highest page->index to unmap */
 889};
 890
 891struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 892                pte_t pte);
 893
 894int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
 895                unsigned long size);
 896unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
 897                unsigned long size, struct zap_details *);
 898unsigned long unmap_vmas(struct mmu_gather *tlb,
 899                struct vm_area_struct *start_vma, unsigned long start_addr,
 900                unsigned long end_addr, unsigned long *nr_accounted,
 901                struct zap_details *);
 902
 903/**
 904 * mm_walk - callbacks for walk_page_range
 905 * @pgd_entry: if set, called for each non-empty PGD (top-level) entry
 906 * @pud_entry: if set, called for each non-empty PUD (2nd-level) entry
 907 * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry
 908 *             this handler is required to be able to handle
 909 *             pmd_trans_huge() pmds.  They may simply choose to
 910 *             split_huge_page() instead of handling it explicitly.
 911 * @pte_entry: if set, called for each non-empty PTE (4th-level) entry
 912 * @pte_hole: if set, called for each hole at all levels
 913 * @hugetlb_entry: if set, called for each hugetlb entry
 914 *                 *Caution*: The caller must hold mmap_sem() if @hugetlb_entry
 915 *                            is used.
 916 *
 917 * (see walk_page_range for more details)
 918 */
 919struct mm_walk {
 920        int (*pgd_entry)(pgd_t *, unsigned long, unsigned long, struct mm_walk *);
 921        int (*pud_entry)(pud_t *, unsigned long, unsigned long, struct mm_walk *);
 922        int (*pmd_entry)(pmd_t *, unsigned long, unsigned long, struct mm_walk *);
 923        int (*pte_entry)(pte_t *, unsigned long, unsigned long, struct mm_walk *);
 924        int (*pte_hole)(unsigned long, unsigned long, struct mm_walk *);
 925        int (*hugetlb_entry)(pte_t *, unsigned long,
 926                             unsigned long, unsigned long, struct mm_walk *);
 927        struct mm_struct *mm;
 928        void *private;
 929};
 930
 931int walk_page_range(unsigned long addr, unsigned long end,
 932                struct mm_walk *walk);
 933void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
 934                unsigned long end, unsigned long floor, unsigned long ceiling);
 935int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
 936                        struct vm_area_struct *vma);
 937void unmap_mapping_range(struct address_space *mapping,
 938                loff_t const holebegin, loff_t const holelen, int even_cows);
 939int follow_pfn(struct vm_area_struct *vma, unsigned long address,
 940        unsigned long *pfn);
 941int follow_phys(struct vm_area_struct *vma, unsigned long address,
 942                unsigned int flags, unsigned long *prot, resource_size_t *phys);
 943int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
 944                        void *buf, int len, int write);
 945
 946static inline void unmap_shared_mapping_range(struct address_space *mapping,
 947                loff_t const holebegin, loff_t const holelen)
 948{
 949        unmap_mapping_range(mapping, holebegin, holelen, 0);
 950}
 951
 952extern void truncate_pagecache(struct inode *inode, loff_t old, loff_t new);
 953extern void truncate_setsize(struct inode *inode, loff_t newsize);
 954extern int vmtruncate(struct inode *inode, loff_t offset);
 955extern int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end);
 956
 957int truncate_inode_page(struct address_space *mapping, struct page *page);
 958int generic_error_remove_page(struct address_space *mapping, struct page *page);
 959
 960int invalidate_inode_page(struct page *page);
 961
 962#ifdef CONFIG_MMU
 963extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 964                        unsigned long address, unsigned int flags);
 965extern int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
 966                            unsigned long address, unsigned int fault_flags);
 967#else
 968static inline int handle_mm_fault(struct mm_struct *mm,
 969                        struct vm_area_struct *vma, unsigned long address,
 970                        unsigned int flags)
 971{
 972        /* should never happen if there's no MMU */
 973        BUG();
 974        return VM_FAULT_SIGBUS;
 975}
 976static inline int fixup_user_fault(struct task_struct *tsk,
 977                struct mm_struct *mm, unsigned long address,
 978                unsigned int fault_flags)
 979{
 980        /* should never happen if there's no MMU */
 981        BUG();
 982        return -EFAULT;
 983}
 984#endif
 985
 986extern int make_pages_present(unsigned long addr, unsigned long end);
 987extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
 988extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,
 989                void *buf, int len, int write);
 990
 991int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 992                     unsigned long start, int len, unsigned int foll_flags,
 993                     struct page **pages, struct vm_area_struct **vmas,
 994                     int *nonblocking);
 995int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 996                        unsigned long start, int nr_pages, int write, int force,
 997                        struct page **pages, struct vm_area_struct **vmas);
 998int get_user_pages_fast(unsigned long start, int nr_pages, int write,
 999                        struct page **pages);
1000struct page *get_dump_page(unsigned long addr);
1001
1002extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
1003extern void do_invalidatepage(struct page *page, unsigned long offset);
1004
1005int __set_page_dirty_nobuffers(struct page *page);
1006int __set_page_dirty_no_writeback(struct page *page);
1007int redirty_page_for_writepage(struct writeback_control *wbc,
1008                                struct page *page);
1009void account_page_dirtied(struct page *page, struct address_space *mapping);
1010void account_page_writeback(struct page *page);
1011int set_page_dirty(struct page *page);
1012int set_page_dirty_lock(struct page *page);
1013int clear_page_dirty_for_io(struct page *page);
1014
1015/* Is the vma a continuation of the stack vma above it? */
1016static inline int vma_growsdown(struct vm_area_struct *vma, unsigned long addr)
1017{
1018        return vma && (vma->vm_end == addr) && (vma->vm_flags & VM_GROWSDOWN);
1019}
1020
1021static inline int stack_guard_page_start(struct vm_area_struct *vma,
1022                                             unsigned long addr)
1023{
1024        return (vma->vm_flags & VM_GROWSDOWN) &&
1025                (vma->vm_start == addr) &&
1026                !vma_growsdown(vma->vm_prev, addr);
1027}
1028
1029/* Is the vma a continuation of the stack vma below it? */
1030static inline int vma_growsup(struct vm_area_struct *vma, unsigned long addr)
1031{
1032        return vma && (vma->vm_start == addr) && (vma->vm_flags & VM_GROWSUP);
1033}
1034
1035static inline int stack_guard_page_end(struct vm_area_struct *vma,
1036                                           unsigned long addr)
1037{
1038        return (vma->vm_flags & VM_GROWSUP) &&
1039                (vma->vm_end == addr) &&
1040                !vma_growsup(vma->vm_next, addr);
1041}
1042
1043extern unsigned long move_page_tables(struct vm_area_struct *vma,
1044                unsigned long old_addr, struct vm_area_struct *new_vma,
1045                unsigned long new_addr, unsigned long len);
1046extern unsigned long do_mremap(unsigned long addr,
1047                               unsigned long old_len, unsigned long new_len,
1048                               unsigned long flags, unsigned long new_addr);
1049extern int mprotect_fixup(struct vm_area_struct *vma,
1050                          struct vm_area_struct **pprev, unsigned long start,
1051                          unsigned long end, unsigned long newflags);
1052
1053/*
1054 * doesn't attempt to fault and will return short.
1055 */
1056int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
1057                          struct page **pages);
1058/*
1059 * per-process(per-mm_struct) statistics.
1060 */
1061static inline void set_mm_counter(struct mm_struct *mm, int member, long value)
1062{
1063        atomic_long_set(&mm->rss_stat.count[member], value);
1064}
1065
1066#if defined(SPLIT_RSS_COUNTING)
1067unsigned long get_mm_counter(struct mm_struct *mm, int member);
1068#else
1069static inline unsigned long get_mm_counter(struct mm_struct *mm, int member)
1070{
1071        return atomic_long_read(&mm->rss_stat.count[member]);
1072}
1073#endif
1074
1075static inline void add_mm_counter(struct mm_struct *mm, int member, long value)
1076{
1077        atomic_long_add(value, &mm->rss_stat.count[member]);
1078}
1079
1080static inline void inc_mm_counter(struct mm_struct *mm, int member)
1081{
1082        atomic_long_inc(&mm->rss_stat.count[member]);
1083}
1084
1085static inline void dec_mm_counter(struct mm_struct *mm, int member)
1086{
1087        atomic_long_dec(&mm->rss_stat.count[member]);
1088}
1089
1090static inline unsigned long get_mm_rss(struct mm_struct *mm)
1091{
1092        return get_mm_counter(mm, MM_FILEPAGES) +
1093                get_mm_counter(mm, MM_ANONPAGES);
1094}
1095
1096static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
1097{
1098        return max(mm->hiwater_rss, get_mm_rss(mm));
1099}
1100
1101static inline unsigned long get_mm_hiwater_vm(struct mm_struct *mm)
1102{
1103        return max(mm->hiwater_vm, mm->total_vm);
1104}
1105
1106static inline void update_hiwater_rss(struct mm_struct *mm)
1107{
1108        unsigned long _rss = get_mm_rss(mm);
1109
1110        if ((mm)->hiwater_rss < _rss)
1111                (mm)->hiwater_rss = _rss;
1112}
1113
1114static inline void update_hiwater_vm(struct mm_struct *mm)
1115{
1116        if (mm->hiwater_vm < mm->total_vm)
1117                mm->hiwater_vm = mm->total_vm;
1118}
1119
1120static inline void setmax_mm_hiwater_rss(unsigned long *maxrss,
1121                                         struct mm_struct *mm)
1122{
1123        unsigned long hiwater_rss = get_mm_hiwater_rss(mm);
1124
1125        if (*maxrss < hiwater_rss)
1126                *maxrss = hiwater_rss;
1127}
1128
1129#if defined(SPLIT_RSS_COUNTING)
1130void sync_mm_rss(struct task_struct *task, struct mm_struct *mm);
1131#else
1132static inline void sync_mm_rss(struct task_struct *task, struct mm_struct *mm)
1133{
1134}
1135#endif
1136
1137int vma_wants_writenotify(struct vm_area_struct *vma);
1138
1139extern pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
1140                               spinlock_t **ptl);
1141static inline pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
1142                                    spinlock_t **ptl)
1143{
1144        pte_t *ptep;
1145        __cond_lock(*ptl, ptep = __get_locked_pte(mm, addr, ptl));
1146        return ptep;
1147}
1148
1149#ifdef __PAGETABLE_PUD_FOLDED
1150static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd,
1151                                                unsigned long address)
1152{
1153        return 0;
1154}
1155#else
1156int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
1157#endif
1158
1159#ifdef __PAGETABLE_PMD_FOLDED
1160static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
1161                                                unsigned long address)
1162{
1163        return 0;
1164}
1165#else
1166int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
1167#endif
1168
1169int __pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
1170                pmd_t *pmd, unsigned long address);
1171int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
1172
1173/*
1174 * The following ifdef needed to get the 4level-fixup.h header to work.
1175 * Remove it when 4level-fixup.h has been removed.
1176 */
1177#if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
1178static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
1179{
1180        return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))?
1181                NULL: pud_offset(pgd, address);
1182}
1183
1184static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
1185{
1186        return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
1187                NULL: pmd_offset(pud, address);
1188}
1189#endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
1190
1191#if USE_SPLIT_PTLOCKS
1192/*
1193 * We tuck a spinlock to guard each pagetable page into its struct page,
1194 * at page->private, with BUILD_BUG_ON to make sure that this will not
1195 * overflow into the next struct page (as it might with DEBUG_SPINLOCK).
1196 * When freeing, reset page->mapping so free_pages_check won't complain.
1197 */
1198#define __pte_lockptr(page)     &((page)->ptl)
1199#define pte_lock_init(_page)    do {                                    \
1200        spin_lock_init(__pte_lockptr(_page));                           \
1201} while (0)
1202#define pte_lock_deinit(page)   ((page)->mapping = NULL)
1203#define pte_lockptr(mm, pmd)    ({(void)(mm); __pte_lockptr(pmd_page(*(pmd)));})
1204#else   /* !USE_SPLIT_PTLOCKS */
1205/*
1206 * We use mm->page_table_lock to guard all pagetable pages of the mm.
1207 */
1208#define pte_lock_init(page)     do {} while (0)
1209#define pte_lock_deinit(page)   do {} while (0)
1210#define pte_lockptr(mm, pmd)    ({(void)(pmd); &(mm)->page_table_lock;})
1211#endif /* USE_SPLIT_PTLOCKS */
1212
1213static inline void pgtable_page_ctor(struct page *page)
1214{
1215        pte_lock_init(page);
1216        inc_zone_page_state(page, NR_PAGETABLE);
1217}
1218
1219static inline void pgtable_page_dtor(struct page *page)
1220{
1221        pte_lock_deinit(page);
1222        dec_zone_page_state(page, NR_PAGETABLE);
1223}
1224
1225#define pte_offset_map_lock(mm, pmd, address, ptlp)     \
1226({                                                      \
1227        spinlock_t *__ptl = pte_lockptr(mm, pmd);       \
1228        pte_t *__pte = pte_offset_map(pmd, address);    \
1229        *(ptlp) = __ptl;                                \
1230        spin_lock(__ptl);                               \
1231        __pte;                                          \
1232})
1233
1234#define pte_unmap_unlock(pte, ptl)      do {            \
1235        spin_unlock(ptl);                               \
1236        pte_unmap(pte);                                 \
1237} while (0)
1238
1239#define pte_alloc_map(mm, vma, pmd, address)                            \
1240        ((unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, vma,    \
1241                                                        pmd, address))? \
1242         NULL: pte_offset_map(pmd, address))
1243
1244#define pte_alloc_map_lock(mm, pmd, address, ptlp)      \
1245        ((unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, NULL,   \
1246                                                        pmd, address))? \
1247                NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
1248
1249#define pte_alloc_kernel(pmd, address)                  \
1250        ((unlikely(pmd_none(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
1251                NULL: pte_offset_kernel(pmd, address))
1252
1253extern void free_area_init(unsigned long * zones_size);
1254extern void free_area_init_node(int nid, unsigned long * zones_size,
1255                unsigned long zone_start_pfn, unsigned long *zholes_size);
1256#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
1257/*
1258 * With CONFIG_HAVE_MEMBLOCK_NODE_MAP set, an architecture may initialise its
1259 * zones, allocate the backing mem_map and account for memory holes in a more
1260 * architecture independent manner. This is a substitute for creating the
1261 * zone_sizes[] and zholes_size[] arrays and passing them to
1262 * free_area_init_node()
1263 *
1264 * An architecture is expected to register range of page frames backed by
1265 * physical memory with memblock_add[_node]() before calling
1266 * free_area_init_nodes() passing in the PFN each zone ends at. At a basic
1267 * usage, an architecture is expected to do something like
1268 *
1269 * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
1270 *                                                       max_highmem_pfn};
1271 * for_each_valid_physical_page_range()
1272 *      memblock_add_node(base, size, nid)
1273 * free_area_init_nodes(max_zone_pfns);
1274 *
1275 * free_bootmem_with_active_regions() calls free_bootmem_node() for each
1276 * registered physical page range.  Similarly
1277 * sparse_memory_present_with_active_regions() calls memory_present() for
1278 * each range when SPARSEMEM is enabled.
1279 *
1280 * See mm/page_alloc.c for more information on each function exposed by
1281 * CONFIG_HAVE_MEMBLOCK_NODE_MAP.
1282 */
1283extern void free_area_init_nodes(unsigned long *max_zone_pfn);
1284unsigned long node_map_pfn_alignment(void);
1285unsigned long __absent_pages_in_range(int nid, unsigned long start_pfn,
1286                                                unsigned long end_pfn);
1287extern unsigned long absent_pages_in_range(unsigned long start_pfn,
1288                                                unsigned long end_pfn);
1289extern void get_pfn_range_for_nid(unsigned int nid,
1290                        unsigned long *start_pfn, unsigned long *end_pfn);
1291extern unsigned long find_min_pfn_with_active_regions(void);
1292extern void free_bootmem_with_active_regions(int nid,
1293                                                unsigned long max_low_pfn);
1294int add_from_early_node_map(struct range *range, int az,
1295                                   int nr_range, int nid);
1296extern void sparse_memory_present_with_active_regions(int nid);
1297
1298#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
1299
1300#if !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) && \
1301    !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID)
1302static inline int __early_pfn_to_nid(unsigned long pfn)
1303{
1304        return 0;
1305}
1306#else
1307/* please see mm/page_alloc.c */
1308extern int __meminit early_pfn_to_nid(unsigned long pfn);
1309#ifdef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
1310/* there is a per-arch backend function. */
1311extern int __meminit __early_pfn_to_nid(unsigned long pfn);
1312#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
1313#endif
1314
1315extern void set_dma_reserve(unsigned long new_dma_reserve);
1316extern void memmap_init_zone(unsigned long, int, unsigned long,
1317                                unsigned long, enum memmap_context);
1318extern void setup_per_zone_wmarks(void);
1319extern int __meminit init_per_zone_wmark_min(void);
1320extern void mem_init(void);
1321extern void __init mmap_init(void);
1322extern void show_mem(unsigned int flags);
1323extern void si_meminfo(struct sysinfo * val);
1324extern void si_meminfo_node(struct sysinfo *val, int nid);
1325extern int after_bootmem;
1326
1327extern __printf(3, 4)
1328void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...);
1329
1330extern void setup_per_cpu_pageset(void);
1331
1332extern void zone_pcp_update(struct zone *zone);
1333
1334/* nommu.c */
1335extern atomic_long_t mmap_pages_allocated;
1336extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
1337
1338/* prio_tree.c */
1339void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old);
1340void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *);
1341void vma_prio_tree_remove(struct vm_area_struct *, struct prio_tree_root *);
1342struct vm_area_struct *vma_prio_tree_next(struct vm_area_struct *vma,
1343        struct prio_tree_iter *iter);
1344
1345#define vma_prio_tree_foreach(vma, iter, root, begin, end)      \
1346        for (prio_tree_iter_init(iter, root, begin, end), vma = NULL;   \
1347                (vma = vma_prio_tree_next(vma, iter)); )
1348
1349static inline void vma_nonlinear_insert(struct vm_area_struct *vma,
1350                                        struct list_head *list)
1351{
1352        vma->shared.vm_set.parent = NULL;
1353        list_add_tail(&vma->shared.vm_set.list, list);
1354}
1355
1356/* mmap.c */
1357extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
1358extern int vma_adjust(struct vm_area_struct *vma, unsigned long start,
1359        unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
1360extern struct vm_area_struct *vma_merge(struct mm_struct *,
1361        struct vm_area_struct *prev, unsigned long addr, unsigned long end,
1362        unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
1363        struct mempolicy *);
1364extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
1365extern int split_vma(struct mm_struct *,
1366        struct vm_area_struct *, unsigned long addr, int new_below);
1367extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
1368extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
1369        struct rb_node **, struct rb_node *);
1370extern void unlink_file_vma(struct vm_area_struct *);
1371extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
1372        unsigned long addr, unsigned long len, pgoff_t pgoff);
1373extern void exit_mmap(struct mm_struct *);
1374
1375extern int mm_take_all_locks(struct mm_struct *mm);
1376extern void mm_drop_all_locks(struct mm_struct *mm);
1377
1378/* From fs/proc/base.c. callers must _not_ hold the mm's exe_file_lock */
1379extern void added_exe_file_vma(struct mm_struct *mm);
1380extern void removed_exe_file_vma(struct mm_struct *mm);
1381extern void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
1382extern struct file *get_mm_exe_file(struct mm_struct *mm);
1383
1384extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
1385extern int install_special_mapping(struct mm_struct *mm,
1386                                   unsigned long addr, unsigned long len,
1387                                   unsigned long flags, struct page **pages);
1388
1389extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1390
1391extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
1392        unsigned long len, unsigned long prot,
1393        unsigned long flag, unsigned long pgoff);
1394extern unsigned long mmap_region(struct file *file, unsigned long addr,
1395        unsigned long len, unsigned long flags,
1396        vm_flags_t vm_flags, unsigned long pgoff);
1397
1398static inline unsigned long do_mmap(struct file *file, unsigned long addr,
1399        unsigned long len, unsigned long prot,
1400        unsigned long flag, unsigned long offset)
1401{
1402        unsigned long ret = -EINVAL;
1403        if ((offset + PAGE_ALIGN(len)) < offset)
1404                goto out;
1405        if (!(offset & ~PAGE_MASK))
1406                ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
1407out:
1408        return ret;
1409}
1410
1411extern int do_munmap(struct mm_struct *, unsigned long, size_t);
1412
1413extern unsigned long do_brk(unsigned long, unsigned long);
1414
1415/* truncate.c */
1416extern void truncate_inode_pages(struct address_space *, loff_t);
1417extern void truncate_inode_pages_range(struct address_space *,
1418                                       loff_t lstart, loff_t lend);
1419
1420/* generic vm_area_ops exported for stackable file systems */
1421extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
1422
1423/* mm/page-writeback.c */
1424int write_one_page(struct page *page, int wait);
1425void task_dirty_inc(struct task_struct *tsk);
1426
1427/* readahead.c */
1428#define VM_MAX_READAHEAD        128     /* kbytes */
1429#define VM_MIN_READAHEAD        16      /* kbytes (includes current page) */
1430
1431int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
1432                        pgoff_t offset, unsigned long nr_to_read);
1433
1434void page_cache_sync_readahead(struct address_space *mapping,
1435                               struct file_ra_state *ra,
1436                               struct file *filp,
1437                               pgoff_t offset,
1438                               unsigned long size);
1439
1440void page_cache_async_readahead(struct address_space *mapping,
1441                                struct file_ra_state *ra,
1442                                struct file *filp,
1443                                struct page *pg,
1444                                pgoff_t offset,
1445                                unsigned long size);
1446
1447unsigned long max_sane_readahead(unsigned long nr);
1448unsigned long ra_submit(struct file_ra_state *ra,
1449                        struct address_space *mapping,
1450                        struct file *filp);
1451
1452/* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */
1453extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
1454
1455/* CONFIG_STACK_GROWSUP still needs to to grow downwards at some places */
1456extern int expand_downwards(struct vm_area_struct *vma,
1457                unsigned long address);
1458#if VM_GROWSUP
1459extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
1460#else
1461  #define expand_upwards(vma, address) do { } while (0)
1462#endif
1463
1464/* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
1465extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
1466extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
1467                                             struct vm_area_struct **pprev);
1468
1469/* Look up the first VMA which intersects the interval start_addr..end_addr-1,
1470   NULL if none.  Assume start_addr < end_addr. */
1471static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
1472{
1473        struct vm_area_struct * vma = find_vma(mm,start_addr);
1474
1475        if (vma && end_addr <= vma->vm_start)
1476                vma = NULL;
1477        return vma;
1478}
1479
1480static inline unsigned long vma_pages(struct vm_area_struct *vma)
1481{
1482        return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
1483}
1484
1485/* Look up the first VMA which exactly match the interval vm_start ... vm_end */
1486static inline struct vm_area_struct *find_exact_vma(struct mm_struct *mm,
1487                                unsigned long vm_start, unsigned long vm_end)
1488{
1489        struct vm_area_struct *vma = find_vma(mm, vm_start);
1490
1491        if (vma && (vma->vm_start != vm_start || vma->vm_end != vm_end))
1492                vma = NULL;
1493
1494        return vma;
1495}
1496
1497#ifdef CONFIG_MMU
1498pgprot_t vm_get_page_prot(unsigned long vm_flags);
1499#else
1500static inline pgprot_t vm_get_page_prot(unsigned long vm_flags)
1501{
1502        return __pgprot(0);
1503}
1504#endif
1505
1506struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
1507int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
1508                        unsigned long pfn, unsigned long size, pgprot_t);
1509int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
1510int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
1511                        unsigned long pfn);
1512int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
1513                        unsigned long pfn);
1514
1515struct page *follow_page(struct vm_area_struct *, unsigned long address,
1516                        unsigned int foll_flags);
1517#define FOLL_WRITE      0x01    /* check pte is writable */
1518#define FOLL_TOUCH      0x02    /* mark page accessed */
1519#define FOLL_GET        0x04    /* do get_page on page */
1520#define FOLL_DUMP       0x08    /* give error on hole if it would be zero */
1521#define FOLL_FORCE      0x10    /* get_user_pages read/write w/o permission */
1522#define FOLL_NOWAIT     0x20    /* if a disk transfer is needed, start the IO
1523                                 * and return without waiting upon it */
1524#define FOLL_MLOCK      0x40    /* mark page as mlocked */
1525#define FOLL_SPLIT      0x80    /* don't return transhuge pages, split them */
1526#define FOLL_HWPOISON   0x100   /* check page is hwpoisoned */
1527
1528typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
1529                        void *data);
1530extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
1531                               unsigned long size, pte_fn_t fn, void *data);
1532
1533#ifdef CONFIG_PROC_FS
1534void vm_stat_account(struct mm_struct *, unsigned long, struct file *, long);
1535#else
1536static inline void vm_stat_account(struct mm_struct *mm,
1537                        unsigned long flags, struct file *file, long pages)
1538{
1539}
1540#endif /* CONFIG_PROC_FS */
1541
1542#ifdef CONFIG_DEBUG_PAGEALLOC
1543extern void kernel_map_pages(struct page *page, int numpages, int enable);
1544#ifdef CONFIG_HIBERNATION
1545extern bool kernel_page_present(struct page *page);
1546#endif /* CONFIG_HIBERNATION */
1547#else
1548static inline void
1549kernel_map_pages(struct page *page, int numpages, int enable) {}
1550#ifdef CONFIG_HIBERNATION
1551static inline bool kernel_page_present(struct page *page) { return true; }
1552#endif /* CONFIG_HIBERNATION */
1553#endif
1554
1555extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm);
1556#ifdef  __HAVE_ARCH_GATE_AREA
1557int in_gate_area_no_mm(unsigned long addr);
1558int in_gate_area(struct mm_struct *mm, unsigned long addr);
1559#else
1560int in_gate_area_no_mm(unsigned long addr);
1561#define in_gate_area(mm, addr) ({(void)mm; in_gate_area_no_mm(addr);})
1562#endif  /* __HAVE_ARCH_GATE_AREA */
1563
1564int drop_caches_sysctl_handler(struct ctl_table *, int,
1565                                        void __user *, size_t *, loff_t *);
1566unsigned long shrink_slab(struct shrink_control *shrink,
1567                          unsigned long nr_pages_scanned,
1568                          unsigned long lru_pages);
1569
1570#ifndef CONFIG_MMU
1571#define randomize_va_space 0
1572#else
1573extern int randomize_va_space;
1574#endif
1575
1576const char * arch_vma_name(struct vm_area_struct *vma);
1577void print_vma_addr(char *prefix, unsigned long rip);
1578
1579void sparse_mem_maps_populate_node(struct page **map_map,
1580                                   unsigned long pnum_begin,
1581                                   unsigned long pnum_end,
1582                                   unsigned long map_count,
1583                                   int nodeid);
1584
1585struct page *sparse_mem_map_populate(unsigned long pnum, int nid);
1586pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
1587pud_t *vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node);
1588pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
1589pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node);
1590void *vmemmap_alloc_block(unsigned long size, int node);
1591void *vmemmap_alloc_block_buf(unsigned long size, int node);
1592void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
1593int vmemmap_populate_basepages(struct page *start_page,
1594                                                unsigned long pages, int node);
1595int vmemmap_populate(struct page *start_page, unsigned long pages, int node);
1596void vmemmap_populate_print_last(void);
1597
1598
1599enum mf_flags {
1600        MF_COUNT_INCREASED = 1 << 0,
1601};
1602extern void memory_failure(unsigned long pfn, int trapno);
1603extern int __memory_failure(unsigned long pfn, int trapno, int flags);
1604extern void memory_failure_queue(unsigned long pfn, int trapno, int flags);
1605extern int unpoison_memory(unsigned long pfn);
1606extern int sysctl_memory_failure_early_kill;
1607extern int sysctl_memory_failure_recovery;
1608extern void shake_page(struct page *p, int access);
1609extern atomic_long_t mce_bad_pages;
1610extern int soft_offline_page(struct page *page, int flags);
1611
1612extern void dump_page(struct page *page);
1613
1614#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
1615extern void clear_huge_page(struct page *page,
1616                            unsigned long addr,
1617                            unsigned int pages_per_huge_page);
1618extern void copy_user_huge_page(struct page *dst, struct page *src,
1619                                unsigned long addr, struct vm_area_struct *vma,
1620                                unsigned int pages_per_huge_page);
1621#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
1622
1623#ifdef CONFIG_DEBUG_PAGEALLOC
1624extern unsigned int _debug_guardpage_minorder;
1625
1626static inline unsigned int debug_guardpage_minorder(void)
1627{
1628        return _debug_guardpage_minorder;
1629}
1630
1631static inline bool page_is_guard(struct page *page)
1632{
1633        return test_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
1634}
1635#else
1636static inline unsigned int debug_guardpage_minorder(void) { return 0; }
1637static inline bool page_is_guard(struct page *page) { return false; }
1638#endif /* CONFIG_DEBUG_PAGEALLOC */
1639
1640#endif /* __KERNEL__ */
1641#endif /* _LINUX_MM_H */
1642
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