LCOV - code coverage report
Current view: top level - include/linux - mm.h (source / functions) Hit Total Coverage
Test: coverage.info Lines: 8 8 100.0 %
Date: 2017-01-25 Functions: 2 2 100.0 %

          Line data    Source code
       1             : #ifndef _LINUX_MM_H
       2             : #define _LINUX_MM_H
       3             : 
       4             : #include <linux/errno.h>
       5             : 
       6             : #ifdef __KERNEL__
       7             : 
       8             : #include <linux/gfp.h>
       9             : #include <linux/list.h>
      10             : #include <linux/mmzone.h>
      11             : #include <linux/rbtree.h>
      12             : #include <linux/prio_tree.h>
      13             : #include <linux/debug_locks.h>
      14             : #include <linux/mm_types.h>
      15             : 
      16             : struct mempolicy;
      17             : struct anon_vma;
      18             : struct file_ra_state;
      19             : struct user_struct;
      20             : struct writeback_control;
      21             : struct rlimit;
      22             : 
      23             : #ifndef CONFIG_DISCONTIGMEM          /* Don't use mapnrs, do it properly */
      24             : extern unsigned long max_mapnr;
      25             : #endif
      26             : 
      27             : extern unsigned long num_physpages;
      28             : extern unsigned long totalram_pages;
      29             : extern void * high_memory;
      30             : extern int page_cluster;
      31             : 
      32             : #ifdef CONFIG_SYSCTL
      33             : extern int sysctl_legacy_va_layout;
      34             : #else
      35             : #define sysctl_legacy_va_layout 0
      36             : #endif
      37             : 
      38             : #include <asm/page.h>
      39             : #include <asm/pgtable.h>
      40             : #include <asm/processor.h>
      41             : 
      42             : #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
      43             : 
      44             : /* to align the pointer to the (next) page boundary */
      45             : #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
      46             : 
      47             : /*
      48             :  * Linux kernel virtual memory manager primitives.
      49             :  * The idea being to have a "virtual" mm in the same way
      50             :  * we have a virtual fs - giving a cleaner interface to the
      51             :  * mm details, and allowing different kinds of memory mappings
      52             :  * (from shared memory to executable loading to arbitrary
      53             :  * mmap() functions).
      54             :  */
      55             : 
      56             : extern struct kmem_cache *vm_area_cachep;
      57             : 
      58             : #ifndef CONFIG_MMU
      59             : extern struct rb_root nommu_region_tree;
      60             : extern struct rw_semaphore nommu_region_sem;
      61             : 
      62             : extern unsigned int kobjsize(const void *objp);
      63             : #endif
      64             : 
      65             : /*
      66             :  * vm_flags in vm_area_struct, see mm_types.h.
      67             :  */
      68             : #define VM_READ         0x00000001      /* currently active flags */
      69             : #define VM_WRITE        0x00000002
      70             : #define VM_EXEC         0x00000004
      71             : #define VM_SHARED       0x00000008
      72             : 
      73             : /* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
      74             : #define VM_MAYREAD      0x00000010      /* limits for mprotect() etc */
      75             : #define VM_MAYWRITE     0x00000020
      76             : #define VM_MAYEXEC      0x00000040
      77             : #define VM_MAYSHARE     0x00000080
      78             : 
      79             : #define VM_GROWSDOWN    0x00000100      /* general info on the segment */
      80             : #define VM_GROWSUP      0x00000200
      81             : #define VM_PFNMAP       0x00000400      /* Page-ranges managed without "struct page", just pure PFN */
      82             : #define VM_DENYWRITE    0x00000800      /* ETXTBSY on write attempts.. */
      83             : 
      84             : #define VM_EXECUTABLE   0x00001000
      85             : #define VM_LOCKED       0x00002000
      86             : #define VM_IO           0x00004000      /* Memory mapped I/O or similar */
      87             : 
      88             :                                         /* Used by sys_madvise() */
      89             : #define VM_SEQ_READ     0x00008000      /* App will access data sequentially */
      90             : #define VM_RAND_READ    0x00010000      /* App will not benefit from clustered reads */
      91             : 
      92             : #define VM_DONTCOPY     0x00020000      /* Do not copy this vma on fork */
      93             : #define VM_DONTEXPAND   0x00040000      /* Cannot expand with mremap() */
      94             : #define VM_RESERVED     0x00080000      /* Count as reserved_vm like IO */
      95             : #define VM_ACCOUNT      0x00100000      /* Is a VM accounted object */
      96             : #define VM_NORESERVE    0x00200000      /* should the VM suppress accounting */
      97             : #define VM_HUGETLB      0x00400000      /* Huge TLB Page VM */
      98             : #define VM_NONLINEAR    0x00800000      /* Is non-linear (remap_file_pages) */
      99             : #define VM_MAPPED_COPY  0x01000000      /* T if mapped copy of data (nommu mmap) */
     100             : #define VM_INSERTPAGE   0x02000000      /* The vma has had "vm_insert_page()" done on it */
     101             : #define VM_ALWAYSDUMP   0x04000000      /* Always include in core dumps */
     102             : 
     103             : #define VM_CAN_NONLINEAR 0x08000000     /* Has ->fault & does nonlinear pages */
     104             : #define VM_MIXEDMAP     0x10000000      /* Can contain "struct page" and pure PFN pages */
     105             : #define VM_SAO          0x20000000      /* Strong Access Ordering (powerpc) */
     106             : #define VM_PFN_AT_MMAP  0x40000000      /* PFNMAP vma that is fully mapped at mmap time */
     107             : #define VM_MERGEABLE    0x80000000      /* KSM may merge identical pages */
     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             :  */
     134             : extern 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             :  */
     148             : static inline int is_linear_pfn_mapping(struct vm_area_struct *vma)
     149             : {
     150             :         return (vma->vm_flags & VM_PFN_AT_MMAP);
     151             : }
     152             : 
     153             : static inline int is_pfn_mapping(struct vm_area_struct *vma)
     154             : {
     155             :         return (vma->vm_flags & VM_PFNMAP);
     156             : }
     157           1 : 
     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             :  */
     167             : struct 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           1 :                                          * 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             :  */
     184             : struct 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             : 
     225             : struct mmu_gather;
     226             : struct 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             :  */
     253             : static 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             :  */
     263             : static 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 */
     269             : struct page *vmalloc_to_page(const void *addr);
     270             : unsigned 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             :  */
     278             : static 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             : #ifdef CONFIG_MMU
     289             : extern int is_vmalloc_or_module_addr(const void *x);
     290             : #else
     291             : static inline int is_vmalloc_or_module_addr(const void *x)
     292             : {
     293             :         return 0;
     294             : }
     295             : #endif
     296             : 
     297             : static inline struct page *compound_head(struct page *page)
     298             : {
     299             :         if (unlikely(PageTail(page)))
     300             :                 return page->first_page;
     301             :         return page;
     302             : }
     303             : 
     304             : static inline int page_count(struct page *page)
     305             : {
     306             :         return atomic_read(&compound_head(page)->_count);
     307             : }
     308             : 
     309             : static inline void get_page(struct page *page)
     310             : {
     311             :         page = compound_head(page);
     312             :         VM_BUG_ON(atomic_read(&page->_count) == 0);
     313             :         atomic_inc(&page->_count);
     314             : }
     315             : 
     316             : static inline struct page *virt_to_head_page(const void *x)
     317             : {
     318             :         struct page *page = virt_to_page(x);
     319             :         return compound_head(page);
     320             : }
     321             : 
     322             : /*
     323             :  * Setup the page count before being freed into the page allocator for
     324             :  * the first time (boot or memory hotplug)
     325             :  */
     326             : static inline void init_page_count(struct page *page)
     327             : {
     328             :         atomic_set(&page->_count, 1);
     329             : }
     330             : 
     331             : void put_page(struct page *page);
     332             : void put_pages_list(struct list_head *pages);
     333             : 
     334             : void split_page(struct page *page, unsigned int order);
     335             : 
     336             : /*
     337             :  * Compound pages have a destructor function.  Provide a
     338             :  * prototype for that function and accessor functions.
     339             :  * These are _only_ valid on the head of a PG_compound page.
     340             :  */
     341             : typedef void compound_page_dtor(struct page *);
     342             : 
     343             : static inline void set_compound_page_dtor(struct page *page,
     344             :                                                 compound_page_dtor *dtor)
     345             : {
     346             :         page[1].lru.next = (void *)dtor;
     347             : }
     348             : 
     349             : static inline compound_page_dtor *get_compound_page_dtor(struct page *page)
     350             : {
     351             :         return (compound_page_dtor *)page[1].lru.next;
     352             : }
     353             : 
     354             : static inline int compound_order(struct page *page)
     355             : {
     356             :         if (!PageHead(page))
     357             :                 return 0;
     358             :         return (unsigned long)page[1].lru.prev;
     359             : }
     360             : 
     361             : static inline void set_compound_order(struct page *page, unsigned long order)
     362             : {
     363             :         page[1].lru.prev = (void *)order;
     364             : }
     365             : 
     366             : /*
     367             :  * Multiple processes may "see" the same page. E.g. for untouched
     368             :  * mappings of /dev/null, all processes see the same page full of
     369             :  * zeroes, and text pages of executables and shared libraries have
     370             :  * only one copy in memory, at most, normally.
     371             :  *
     372             :  * For the non-reserved pages, page_count(page) denotes a reference count.
     373             :  *   page_count() == 0 means the page is free. page->lru is then used for
     374             :  *   freelist management in the buddy allocator.
     375             :  *   page_count() > 0  means the page has been allocated.
     376             :  *
     377             :  * Pages are allocated by the slab allocator in order to provide memory
     378             :  * to kmalloc and kmem_cache_alloc. In this case, the management of the
     379             :  * page, and the fields in 'struct page' are the responsibility of mm/slab.c
     380             :  * unless a particular usage is carefully commented. (the responsibility of
     381             :  * freeing the kmalloc memory is the caller's, of course).
     382             :  *
     383             :  * A page may be used by anyone else who does a __get_free_page().
     384             :  * In this case, page_count still tracks the references, and should only
     385             :  * be used through the normal accessor functions. The top bits of page->flags
     386             :  * and page->virtual store page management information, but all other fields
     387             :  * are unused and could be used privately, carefully. The management of this
     388             :  * page is the responsibility of the one who allocated it, and those who have
     389             :  * subsequently been given references to it.
     390             :  *
     391             :  * The other pages (we may call them "pagecache pages") are completely
     392             :  * managed by the Linux memory manager: I/O, buffers, swapping etc.
     393             :  * The following discussion applies only to them.
     394             :  *
     395             :  * A pagecache page contains an opaque `private' member, which belongs to the
     396             :  * page's address_space. Usually, this is the address of a circular list of
     397             :  * the page's disk buffers. PG_private must be set to tell the VM to call
     398             :  * into the filesystem to release these pages.
     399             :  *
     400             :  * A page may belong to an inode's memory mapping. In this case, page->mapping
     401             :  * is the pointer to the inode, and page->index is the file offset of the page,
     402             :  * in units of PAGE_CACHE_SIZE.
     403             :  *
     404             :  * If pagecache pages are not associated with an inode, they are said to be
     405             :  * anonymous pages. These may become associated with the swapcache, and in that
     406             :  * case PG_swapcache is set, and page->private is an offset into the swapcache.
     407             :  *
     408             :  * In either case (swapcache or inode backed), the pagecache itself holds one
     409             :  * reference to the page. Setting PG_private should also increment the
     410             :  * refcount. The each user mapping also has a reference to the page.
     411             :  *
     412             :  * The pagecache pages are stored in a per-mapping radix tree, which is
     413             :  * rooted at mapping->page_tree, and indexed by offset.
     414             :  * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
     415             :  * lists, we instead now tag pages as dirty/writeback in the radix tree.
     416             :  *
     417             :  * All pagecache pages may be subject to I/O:
     418             :  * - inode pages may need to be read from disk,
     419             :  * - inode pages which have been modified and are MAP_SHARED may need
     420             :  *   to be written back to the inode on disk,
     421             :  * - anonymous pages (including MAP_PRIVATE file mappings) which have been
     422             :  *   modified may need to be swapped out to swap space and (later) to be read
     423             :  *   back into memory.
     424             :  */
     425             : 
     426             : /*
     427             :  * The zone field is never updated after free_area_init_core()
     428             :  * sets it, so none of the operations on it need to be atomic.
     429             :  */
     430             : 
     431             : 
     432             : /*
     433             :  * page->flags layout:
     434             :  *
     435             :  * There are three possibilities for how page->flags get
     436             :  * laid out.  The first is for the normal case, without
     437             :  * sparsemem.  The second is for sparsemem when there is
     438             :  * plenty of space for node and section.  The last is when
     439             :  * we have run out of space and have to fall back to an
     440             :  * alternate (slower) way of determining the node.
     441             :  *
     442             :  * No sparsemem or sparsemem vmemmap: |       NODE     | ZONE | ... | FLAGS |
     443             :  * classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS |
     444             :  * classic sparse no space for node:  | SECTION |     ZONE    | ... | FLAGS |
     445             :  */
     446             : #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
     447             : #define SECTIONS_WIDTH          SECTIONS_SHIFT
     448             : #else
     449             : #define SECTIONS_WIDTH          0
     450             : #endif
     451             : 
     452             : #define ZONES_WIDTH             ZONES_SHIFT
     453             : 
     454             : #if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
     455             : #define NODES_WIDTH             NODES_SHIFT
     456             : #else
     457             : #ifdef CONFIG_SPARSEMEM_VMEMMAP
     458             : #error "Vmemmap: No space for nodes field in page flags"
     459             : #endif
     460             : #define NODES_WIDTH             0
     461             : #endif
     462             : 
     463             : /* Page flags: | [SECTION] | [NODE] | ZONE | ... | FLAGS | */
     464             : #define SECTIONS_PGOFF          ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
     465             : #define NODES_PGOFF             (SECTIONS_PGOFF - NODES_WIDTH)
     466             : #define ZONES_PGOFF             (NODES_PGOFF - ZONES_WIDTH)
     467             : 
     468             : /*
     469             :  * We are going to use the flags for the page to node mapping if its in
     470             :  * there.  This includes the case where there is no node, so it is implicit.
     471             :  */
     472             : #if !(NODES_WIDTH > 0 || NODES_SHIFT == 0)
     473             : #define NODE_NOT_IN_PAGE_FLAGS
     474             : #endif
     475             : 
     476             : #ifndef PFN_SECTION_SHIFT
     477             : #define PFN_SECTION_SHIFT 0
     478             : #endif
     479             : 
     480             : /*
     481             :  * Define the bit shifts to access each section.  For non-existant
     482             :  * sections we define the shift as 0; that plus a 0 mask ensures
     483             :  * the compiler will optimise away reference to them.
     484             :  */
     485             : #define SECTIONS_PGSHIFT        (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
     486             : #define NODES_PGSHIFT           (NODES_PGOFF * (NODES_WIDTH != 0))
     487             : #define ZONES_PGSHIFT           (ZONES_PGOFF * (ZONES_WIDTH != 0))
     488             : 
     489             : /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allcator */
     490             : #ifdef NODE_NOT_IN_PAGEFLAGS
     491             : #define ZONEID_SHIFT            (SECTIONS_SHIFT + ZONES_SHIFT)
     492             : #define ZONEID_PGOFF            ((SECTIONS_PGOFF < ZONES_PGOFF)? \
     493             :                                                 SECTIONS_PGOFF : ZONES_PGOFF)
     494             : #else
     495             : #define ZONEID_SHIFT            (NODES_SHIFT + ZONES_SHIFT)
     496             : #define ZONEID_PGOFF            ((NODES_PGOFF < ZONES_PGOFF)? \
     497             :                                                 NODES_PGOFF : ZONES_PGOFF)
     498             : #endif
     499             : 
     500             : #define ZONEID_PGSHIFT          (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
     501             : 
     502             : #if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
     503             : #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
     504             : #endif
     505             : 
     506             : #define ZONES_MASK              ((1UL << ZONES_WIDTH) - 1)
     507             : #define NODES_MASK              ((1UL << NODES_WIDTH) - 1)
     508             : #define SECTIONS_MASK           ((1UL << SECTIONS_WIDTH) - 1)
     509             : #define ZONEID_MASK             ((1UL << ZONEID_SHIFT) - 1)
     510             : 
     511             : static inline enum zone_type page_zonenum(struct page *page)
     512             : {
     513             :         return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
     514             : }
     515             : 
     516             : /*
     517             :  * The identification function is only used by the buddy allocator for
     518             :  * determining if two pages could be buddies. We are not really
     519             :  * identifying a zone since we could be using a the section number
     520             :  * id if we have not node id available in page flags.
     521             :  * We guarantee only that it will return the same value for two
     522             :  * combinable pages in a zone.
     523             :  */
     524             : static inline int page_zone_id(struct page *page)
     525             : {
     526             :         return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
     527             : }
     528             : 
     529             : static inline int zone_to_nid(struct zone *zone)
     530             : {
     531             : #ifdef CONFIG_NUMA
     532             :         return zone->node;
     533             : #else
     534             :         return 0;
     535             : #endif
     536             : }
     537             : 
     538             : #ifdef NODE_NOT_IN_PAGE_FLAGS
     539             : extern int page_to_nid(struct page *page);
     540             : #else
     541             : static inline int page_to_nid(struct page *page)
     542             : {
     543             :         return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
     544             : }
     545             : #endif
     546             : 
     547             : static inline struct zone *page_zone(struct page *page)
     548             : {
     549             :         return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
     550             : }
     551             : 
     552             : #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
     553             : static inline unsigned long page_to_section(struct page *page)
     554             : {
     555           2 :         return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
     556             : }
     557             : #endif
     558             : 
     559             : static inline void set_page_zone(struct page *page, enum zone_type zone)
     560             : {
     561             :         page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
     562             :         page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
     563             : }
     564             : 
     565             : static inline void set_page_node(struct page *page, unsigned long node)
     566             : {
     567             :         page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
     568             :         page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
     569             : }
     570             : 
     571             : static inline void set_page_section(struct page *page, unsigned long section)
     572             : {
     573             :         page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
     574             :         page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
     575             : }
     576             : 
     577             : static inline void set_page_links(struct page *page, enum zone_type zone,
     578             :         unsigned long node, unsigned long pfn)
     579             : {
     580             :         set_page_zone(page, zone);
     581             :         set_page_node(page, node);
     582             :         set_page_section(page, pfn_to_section_nr(pfn));
     583             : }
     584             : 
     585             : /*
     586             :  * Some inline functions in vmstat.h depend on page_zone()
     587             :  */
     588             : #include <linux/vmstat.h>
     589             : 
     590             : static __always_inline void *lowmem_page_address(struct page *page)
     591             : {
     592          20 :         return __va(page_to_pfn(page) << PAGE_SHIFT);
     593           2 : }
     594           2 : 
     595           2 : #if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
     596           2 : #define HASHED_PAGE_VIRTUAL
     597             : #endif
     598             : 
     599             : #if defined(WANT_PAGE_VIRTUAL)
     600             : #define page_address(page) ((page)->virtual)
     601             : #define set_page_address(page, address)                 \
     602             :         do {                                            \
     603             :                 (page)->virtual = (address);         \
     604             :         } while(0)
     605             : #define page_address_init()  do { } while(0)
     606             : #endif
     607             : 
     608             : #if defined(HASHED_PAGE_VIRTUAL)
     609             : void *page_address(struct page *page);
     610             : void set_page_address(struct page *page, void *virtual);
     611             : void page_address_init(void);
     612             : #endif
     613             : 
     614             : #if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
     615             : #define page_address(page) lowmem_page_address(page)
     616             : #define set_page_address(page, address)  do { } while(0)
     617             : #define page_address_init()  do { } while(0)
     618             : #endif
     619             : 
     620             : /*
     621             :  * On an anonymous page mapped into a user virtual memory area,
     622             :  * page->mapping points to its anon_vma, not to a struct address_space;
     623             :  * with the PAGE_MAPPING_ANON bit set to distinguish it.  See rmap.h.
     624             :  *
     625             :  * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled,
     626             :  * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit;
     627             :  * and then page->mapping points, not to an anon_vma, but to a private
     628             :  * structure which KSM associates with that merged page.  See ksm.h.
     629             :  *
     630             :  * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used.
     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             : #define PAGE_MAPPING_KSM        2
     638             : #define PAGE_MAPPING_FLAGS      (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM)
     639             : 
     640             : extern struct address_space swapper_space;
     641             : static inline struct address_space *page_mapping(struct page *page)
     642             : {
     643             :         struct address_space *mapping = page->mapping;
     644             : 
     645             :         VM_BUG_ON(PageSlab(page));
     646             :         if (unlikely(PageSwapCache(page)))
     647             :                 mapping = &swapper_space;
     648             :         else if (unlikely((unsigned long)mapping & PAGE_MAPPING_ANON))
     649             :                 mapping = NULL;
     650             :         return mapping;
     651             : }
     652             : 
     653             : /* Neutral page->mapping pointer to address_space or anon_vma or other */
     654             : static inline void *page_rmapping(struct page *page)
     655             : {
     656             :         return (void *)((unsigned long)page->mapping & ~PAGE_MAPPING_FLAGS);
     657             : }
     658             : 
     659             : static inline int PageAnon(struct page *page)
     660             : {
     661             :         return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
     662             : }
     663             : 
     664             : /*
     665             :  * Return the pagecache index of the passed page.  Regular pagecache pages
     666             :  * use ->index whereas swapcache pages use ->private
     667             :  */
     668             : static inline pgoff_t page_index(struct page *page)
     669             : {
     670             :         if (unlikely(PageSwapCache(page)))
     671             :                 return page_private(page);
     672             :         return page->index;
     673             : }
     674             : 
     675             : /*
     676             :  * The atomic page->_mapcount, like _count, starts from -1:
     677             :  * so that transitions both from it and to it can be tracked,
     678             :  * using atomic_inc_and_test and atomic_add_negative(-1).
     679             :  */
     680             : static inline void reset_page_mapcount(struct page *page)
     681             : {
     682             :         atomic_set(&(page)->_mapcount, -1);
     683             : }
     684             : 
     685             : static inline int page_mapcount(struct page *page)
     686             : {
     687             :         return atomic_read(&(page)->_mapcount) + 1;
     688             : }
     689             : 
     690             : /*
     691             :  * Return true if this page is mapped into pagetables.
     692             :  */
     693             : static inline int page_mapped(struct page *page)
     694             : {
     695             :         return atomic_read(&(page)->_mapcount) >= 0;
     696             : }
     697             : 
     698             : /*
     699             :  * Different kinds of faults, as returned by handle_mm_fault().
     700             :  * Used to decide whether a process gets delivered SIGBUS or
     701             :  * just gets major/minor fault counters bumped up.
     702             :  */
     703             : 
     704             : #define VM_FAULT_MINOR  0 /* For backwards compat. Remove me quickly. */
     705             : 
     706             : #define VM_FAULT_OOM    0x0001
     707             : #define VM_FAULT_SIGBUS 0x0002
     708             : #define VM_FAULT_MAJOR  0x0004
     709             : #define VM_FAULT_WRITE  0x0008  /* Special case for get_user_pages */
     710             : #define VM_FAULT_HWPOISON 0x0010        /* Hit poisoned page */
     711             : 
     712             : #define VM_FAULT_NOPAGE 0x0100  /* ->fault installed the pte, not return page */
     713             : #define VM_FAULT_LOCKED 0x0200  /* ->fault locked the returned page */
     714             : 
     715             : #define VM_FAULT_ERROR  (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON)
     716             : 
     717             : /*
     718             :  * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
     719             :  */
     720             : extern void pagefault_out_of_memory(void);
     721             : 
     722             : #define offset_in_page(p)       ((unsigned long)(p) & ~PAGE_MASK)
     723             : 
     724             : extern void show_free_areas(void);
     725             : 
     726             : int shmem_lock(struct file *file, int lock, struct user_struct *user);
     727             : struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags);
     728             : int shmem_zero_setup(struct vm_area_struct *);
     729             : 
     730             : #ifndef CONFIG_MMU
     731             : extern unsigned long shmem_get_unmapped_area(struct file *file,
     732             :                                              unsigned long addr,
     733             :                                              unsigned long len,
     734             :                                              unsigned long pgoff,
     735             :                                              unsigned long flags);
     736             : #endif
     737             : 
     738             : extern int can_do_mlock(void);
     739             : extern int user_shm_lock(size_t, struct user_struct *);
     740             : extern void user_shm_unlock(size_t, struct user_struct *);
     741             : 
     742             : /*
     743             :  * Parameter block passed down to zap_pte_range in exceptional cases.
     744             :  */
     745             : struct zap_details {
     746             :         struct vm_area_struct *nonlinear_vma;   /* Check page->index if set */
     747             :         struct address_space *check_mapping;    /* Check page->mapping if set */
     748             :         pgoff_t first_index;                    /* Lowest page->index to unmap */
     749             :         pgoff_t last_index;                     /* Highest page->index to unmap */
     750             :         spinlock_t *i_mmap_lock;                /* For unmap_mapping_range: */
     751             :         unsigned long truncate_count;           /* Compare vm_truncate_count */
     752             : };
     753             : 
     754             : struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
     755             :                 pte_t pte);
     756             : 
     757             : int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
     758             :                 unsigned long size);
     759             : unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
     760             :                 unsigned long size, struct zap_details *);
     761             : unsigned long unmap_vmas(struct mmu_gather **tlb,
     762             :                 struct vm_area_struct *start_vma, unsigned long start_addr,
     763             :                 unsigned long end_addr, unsigned long *nr_accounted,
     764             :                 struct zap_details *);
     765             : 
     766             : /**
     767             :  * mm_walk - callbacks for walk_page_range
     768             :  * @pgd_entry: if set, called for each non-empty PGD (top-level) entry
     769             :  * @pud_entry: if set, called for each non-empty PUD (2nd-level) entry
     770             :  * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry
     771             :  * @pte_entry: if set, called for each non-empty PTE (4th-level) entry
     772             :  * @pte_hole: if set, called for each hole at all levels
     773             :  * @hugetlb_entry: if set, called for each hugetlb entry
     774             :  *
     775             :  * (see walk_page_range for more details)
     776             :  */
     777             : struct mm_walk {
     778             :         int (*pgd_entry)(pgd_t *, unsigned long, unsigned long, struct mm_walk *);
     779             :         int (*pud_entry)(pud_t *, unsigned long, unsigned long, struct mm_walk *);
     780             :         int (*pmd_entry)(pmd_t *, unsigned long, unsigned long, struct mm_walk *);
     781             :         int (*pte_entry)(pte_t *, unsigned long, unsigned long, struct mm_walk *);
     782             :         int (*pte_hole)(unsigned long, unsigned long, struct mm_walk *);
     783             :         int (*hugetlb_entry)(pte_t *, unsigned long, unsigned long,
     784             :                              struct mm_walk *);
     785             :         struct mm_struct *mm;
     786             :         void *private;
     787             : };
     788             : 
     789             : int walk_page_range(unsigned long addr, unsigned long end,
     790             :                 struct mm_walk *walk);
     791             : void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
     792             :                 unsigned long end, unsigned long floor, unsigned long ceiling);
     793             : int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
     794             :                         struct vm_area_struct *vma);
     795             : void unmap_mapping_range(struct address_space *mapping,
     796             :                 loff_t const holebegin, loff_t const holelen, int even_cows);
     797             : int follow_pfn(struct vm_area_struct *vma, unsigned long address,
     798             :         unsigned long *pfn);
     799             : int follow_phys(struct vm_area_struct *vma, unsigned long address,
     800             :                 unsigned int flags, unsigned long *prot, resource_size_t *phys);
     801             : int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
     802             :                         void *buf, int len, int write);
     803             : 
     804             : static inline void unmap_shared_mapping_range(struct address_space *mapping,
     805             :                 loff_t const holebegin, loff_t const holelen)
     806             : {
     807             :         unmap_mapping_range(mapping, holebegin, holelen, 0);
     808             : }
     809             : 
     810             : extern void truncate_pagecache(struct inode *inode, loff_t old, loff_t new);
     811             : extern int vmtruncate(struct inode *inode, loff_t offset);
     812             : extern int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end);
     813             : 
     814             : int truncate_inode_page(struct address_space *mapping, struct page *page);
     815             : int generic_error_remove_page(struct address_space *mapping, struct page *page);
     816             : 
     817             : int invalidate_inode_page(struct page *page);
     818             : 
     819             : #ifdef CONFIG_MMU
     820             : extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
     821             :                         unsigned long address, unsigned int flags);
     822             : #else
     823             : static inline int handle_mm_fault(struct mm_struct *mm,
     824             :                         struct vm_area_struct *vma, unsigned long address,
     825             :                         unsigned int flags)
     826             : {
     827             :         /* should never happen if there's no MMU */
     828             :         BUG();
     829             :         return VM_FAULT_SIGBUS;
     830             : }
     831             : #endif
     832             : 
     833             : extern int make_pages_present(unsigned long addr, unsigned long end);
     834             : extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
     835             : 
     836             : int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
     837             :                         unsigned long start, int nr_pages, int write, int force,
     838             :                         struct page **pages, struct vm_area_struct **vmas);
     839             : int get_user_pages_fast(unsigned long start, int nr_pages, int write,
     840             :                         struct page **pages);
     841             : struct page *get_dump_page(unsigned long addr);
     842             : 
     843             : extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
     844             : extern void do_invalidatepage(struct page *page, unsigned long offset);
     845             : 
     846             : int __set_page_dirty_nobuffers(struct page *page);
     847             : int __set_page_dirty_no_writeback(struct page *page);
     848             : int redirty_page_for_writepage(struct writeback_control *wbc,
     849             :                                 struct page *page);
     850             : void account_page_dirtied(struct page *page, struct address_space *mapping);
     851             : int set_page_dirty(struct page *page);
     852             : int set_page_dirty_lock(struct page *page);
     853             : int clear_page_dirty_for_io(struct page *page);
     854             : 
     855             : extern unsigned long move_page_tables(struct vm_area_struct *vma,
     856             :                 unsigned long old_addr, struct vm_area_struct *new_vma,
     857             :                 unsigned long new_addr, unsigned long len);
     858             : extern unsigned long do_mremap(unsigned long addr,
     859             :                                unsigned long old_len, unsigned long new_len,
     860             :                                unsigned long flags, unsigned long new_addr);
     861             : extern int mprotect_fixup(struct vm_area_struct *vma,
     862             :                           struct vm_area_struct **pprev, unsigned long start,
     863             :                           unsigned long end, unsigned long newflags);
     864             : 
     865             : /*
     866             :  * doesn't attempt to fault and will return short.
     867             :  */
     868             : int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
     869             :                           struct page **pages);
     870             : 
     871             : /*
     872             :  * A callback you can register to apply pressure to ageable caches.
     873             :  *
     874             :  * 'shrink' is passed a count 'nr_to_scan' and a 'gfpmask'.  It should
     875             :  * look through the least-recently-used 'nr_to_scan' entries and
     876             :  * attempt to free them up.  It should return the number of objects
     877             :  * which remain in the cache.  If it returns -1, it means it cannot do
     878             :  * any scanning at this time (eg. there is a risk of deadlock).
     879             :  *
     880             :  * The 'gfpmask' refers to the allocation we are currently trying to
     881             :  * fulfil.
     882             :  *
     883             :  * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
     884             :  * querying the cache size, so a fastpath for that case is appropriate.
     885             :  */
     886             : struct shrinker {
     887             :         int (*shrink)(int nr_to_scan, gfp_t gfp_mask);
     888             :         int seeks;      /* seeks to recreate an obj */
     889             : 
     890             :         /* These are for internal use */
     891             :         struct list_head list;
     892             :         long nr;        /* objs pending delete */
     893             : };
     894             : #define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
     895             : extern void register_shrinker(struct shrinker *);
     896             : extern void unregister_shrinker(struct shrinker *);
     897             : 
     898             : int vma_wants_writenotify(struct vm_area_struct *vma);
     899             : 
     900             : extern pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl);
     901             : 
     902             : #ifdef __PAGETABLE_PUD_FOLDED
     903             : static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd,
     904             :                                                 unsigned long address)
     905             : {
     906             :         return 0;
     907             : }
     908             : #else
     909             : int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
     910             : #endif
     911             : 
     912             : #ifdef __PAGETABLE_PMD_FOLDED
     913             : static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
     914             :                                                 unsigned long address)
     915             : {
     916             :         return 0;
     917             : }
     918             : #else
     919             : int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
     920             : #endif
     921             : 
     922             : int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
     923             : int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
     924             : 
     925             : /*
     926             :  * The following ifdef needed to get the 4level-fixup.h header to work.
     927             :  * Remove it when 4level-fixup.h has been removed.
     928             :  */
     929             : #if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
     930             : static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
     931             : {
     932             :         return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))?
     933             :                 NULL: pud_offset(pgd, address);
     934             : }
     935             : 
     936             : static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
     937             : {
     938             :         return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
     939             :                 NULL: pmd_offset(pud, address);
     940             : }
     941             : #endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
     942             : 
     943             : #if USE_SPLIT_PTLOCKS
     944             : /*
     945             :  * We tuck a spinlock to guard each pagetable page into its struct page,
     946             :  * at page->private, with BUILD_BUG_ON to make sure that this will not
     947             :  * overflow into the next struct page (as it might with DEBUG_SPINLOCK).
     948             :  * When freeing, reset page->mapping so free_pages_check won't complain.
     949             :  */
     950             : #define __pte_lockptr(page)     &((page)->ptl)
     951             : #define pte_lock_init(_page)    do {                                    \
     952             :         spin_lock_init(__pte_lockptr(_page));                           \
     953             : } while (0)
     954             : #define pte_lock_deinit(page)   ((page)->mapping = NULL)
     955             : #define pte_lockptr(mm, pmd)    ({(void)(mm); __pte_lockptr(pmd_page(*(pmd)));})
     956             : #else   /* !USE_SPLIT_PTLOCKS */
     957             : /*
     958             :  * We use mm->page_table_lock to guard all pagetable pages of the mm.
     959             :  */
     960             : #define pte_lock_init(page)     do {} while (0)
     961             : #define pte_lock_deinit(page)   do {} while (0)
     962             : #define pte_lockptr(mm, pmd)    ({(void)(pmd); &(mm)->page_table_lock;})
     963             : #endif /* USE_SPLIT_PTLOCKS */
     964             : 
     965             : static inline void pgtable_page_ctor(struct page *page)
     966             : {
     967             :         pte_lock_init(page);
     968             :         inc_zone_page_state(page, NR_PAGETABLE);
     969             : }
     970             : 
     971             : static inline void pgtable_page_dtor(struct page *page)
     972             : {
     973             :         pte_lock_deinit(page);
     974             :         dec_zone_page_state(page, NR_PAGETABLE);
     975             : }
     976             : 
     977             : #define pte_offset_map_lock(mm, pmd, address, ptlp)     \
     978             : ({                                                      \
     979             :         spinlock_t *__ptl = pte_lockptr(mm, pmd);       \
     980             :         pte_t *__pte = pte_offset_map(pmd, address);    \
     981             :         *(ptlp) = __ptl;                                \
     982             :         spin_lock(__ptl);                               \
     983             :         __pte;                                          \
     984             : })
     985             : 
     986             : #define pte_unmap_unlock(pte, ptl)      do {            \
     987             :         spin_unlock(ptl);                               \
     988             :         pte_unmap(pte);                                 \
     989             : } while (0)
     990             : 
     991             : #define pte_alloc_map(mm, pmd, address)                 \
     992             :         ((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
     993             :                 NULL: pte_offset_map(pmd, address))
     994             : 
     995             : #define pte_alloc_map_lock(mm, pmd, address, ptlp)      \
     996             :         ((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
     997             :                 NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
     998             : 
     999             : #define pte_alloc_kernel(pmd, address)                  \
    1000             :         ((unlikely(!pmd_present(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
    1001             :                 NULL: pte_offset_kernel(pmd, address))
    1002             : 
    1003             : extern void free_area_init(unsigned long * zones_size);
    1004             : extern void free_area_init_node(int nid, unsigned long * zones_size,
    1005             :                 unsigned long zone_start_pfn, unsigned long *zholes_size);
    1006             : #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
    1007             : /*
    1008             :  * With CONFIG_ARCH_POPULATES_NODE_MAP set, an architecture may initialise its
    1009             :  * zones, allocate the backing mem_map and account for memory holes in a more
    1010             :  * architecture independent manner. This is a substitute for creating the
    1011             :  * zone_sizes[] and zholes_size[] arrays and passing them to
    1012             :  * free_area_init_node()
    1013             :  *
    1014             :  * An architecture is expected to register range of page frames backed by
    1015             :  * physical memory with add_active_range() before calling
    1016             :  * free_area_init_nodes() passing in the PFN each zone ends at. At a basic
    1017             :  * usage, an architecture is expected to do something like
    1018             :  *
    1019             :  * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
    1020             :  *                                                       max_highmem_pfn};
    1021             :  * for_each_valid_physical_page_range()
    1022             :  *      add_active_range(node_id, start_pfn, end_pfn)
    1023             :  * free_area_init_nodes(max_zone_pfns);
    1024             :  *
    1025             :  * If the architecture guarantees that there are no holes in the ranges
    1026             :  * registered with add_active_range(), free_bootmem_active_regions()
    1027             :  * will call free_bootmem_node() for each registered physical page range.
    1028             :  * Similarly sparse_memory_present_with_active_regions() calls
    1029             :  * memory_present() for each range when SPARSEMEM is enabled.
    1030             :  *
    1031             :  * See mm/page_alloc.c for more information on each function exposed by
    1032             :  * CONFIG_ARCH_POPULATES_NODE_MAP
    1033             :  */
    1034             : extern void free_area_init_nodes(unsigned long *max_zone_pfn);
    1035             : extern void add_active_range(unsigned int nid, unsigned long start_pfn,
    1036             :                                         unsigned long end_pfn);
    1037             : extern void remove_active_range(unsigned int nid, unsigned long start_pfn,
    1038             :                                         unsigned long end_pfn);
    1039             : extern void remove_all_active_ranges(void);
    1040             : void sort_node_map(void);
    1041             : unsigned long __absent_pages_in_range(int nid, unsigned long start_pfn,
    1042             :                                                 unsigned long end_pfn);
    1043             : extern unsigned long absent_pages_in_range(unsigned long start_pfn,
    1044             :                                                 unsigned long end_pfn);
    1045             : extern void get_pfn_range_for_nid(unsigned int nid,
    1046             :                         unsigned long *start_pfn, unsigned long *end_pfn);
    1047             : extern unsigned long find_min_pfn_with_active_regions(void);
    1048             : extern void free_bootmem_with_active_regions(int nid,
    1049             :                                                 unsigned long max_low_pfn);
    1050             : typedef int (*work_fn_t)(unsigned long, unsigned long, void *);
    1051             : extern void work_with_active_regions(int nid, work_fn_t work_fn, void *data);
    1052             : extern void sparse_memory_present_with_active_regions(int nid);
    1053             : #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
    1054             : 
    1055             : #if !defined(CONFIG_ARCH_POPULATES_NODE_MAP) && \
    1056             :     !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID)
    1057             : static inline int __early_pfn_to_nid(unsigned long pfn)
    1058             : {
    1059             :         return 0;
    1060             : }
    1061             : #else
    1062             : /* please see mm/page_alloc.c */
    1063             : extern int __meminit early_pfn_to_nid(unsigned long pfn);
    1064             : #ifdef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
    1065             : /* there is a per-arch backend function. */
    1066             : extern int __meminit __early_pfn_to_nid(unsigned long pfn);
    1067             : #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
    1068             : #endif
    1069             : 
    1070             : extern void set_dma_reserve(unsigned long new_dma_reserve);
    1071             : extern void memmap_init_zone(unsigned long, int, unsigned long,
    1072             :                                 unsigned long, enum memmap_context);
    1073             : extern void setup_per_zone_wmarks(void);
    1074             : extern void calculate_zone_inactive_ratio(struct zone *zone);
    1075             : extern void mem_init(void);
    1076             : extern void __init mmap_init(void);
    1077             : extern void show_mem(void);
    1078             : extern void si_meminfo(struct sysinfo * val);
    1079             : extern void si_meminfo_node(struct sysinfo *val, int nid);
    1080             : extern int after_bootmem;
    1081             : 
    1082             : #ifdef CONFIG_NUMA
    1083             : extern void setup_per_cpu_pageset(void);
    1084             : #else
    1085             : static inline void setup_per_cpu_pageset(void) {}
    1086             : #endif
    1087             : 
    1088             : extern void zone_pcp_update(struct zone *zone);
    1089             : 
    1090             : /* nommu.c */
    1091             : extern atomic_long_t mmap_pages_allocated;
    1092             : extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
    1093             : 
    1094             : /* prio_tree.c */
    1095             : void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old);
    1096             : void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *);
    1097             : void vma_prio_tree_remove(struct vm_area_struct *, struct prio_tree_root *);
    1098             : struct vm_area_struct *vma_prio_tree_next(struct vm_area_struct *vma,
    1099             :         struct prio_tree_iter *iter);
    1100             : 
    1101             : #define vma_prio_tree_foreach(vma, iter, root, begin, end)      \
    1102             :         for (prio_tree_iter_init(iter, root, begin, end), vma = NULL;   \
    1103             :                 (vma = vma_prio_tree_next(vma, iter)); )
    1104             : 
    1105             : static inline void vma_nonlinear_insert(struct vm_area_struct *vma,
    1106             :                                         struct list_head *list)
    1107             : {
    1108             :         vma->shared.vm_set.parent = NULL;
    1109             :         list_add_tail(&vma->shared.vm_set.list, list);
    1110             : }
    1111             : 
    1112             : /* mmap.c */
    1113             : extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
    1114             : extern void vma_adjust(struct vm_area_struct *vma, unsigned long start,
    1115             :         unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
    1116             : extern struct vm_area_struct *vma_merge(struct mm_struct *,
    1117             :         struct vm_area_struct *prev, unsigned long addr, unsigned long end,
    1118             :         unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
    1119             :         struct mempolicy *);
    1120             : extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
    1121             : extern int split_vma(struct mm_struct *,
    1122             :         struct vm_area_struct *, unsigned long addr, int new_below);
    1123             : extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
    1124             : extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
    1125             :         struct rb_node **, struct rb_node *);
    1126             : extern void unlink_file_vma(struct vm_area_struct *);
    1127             : extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
    1128             :         unsigned long addr, unsigned long len, pgoff_t pgoff);
    1129             : extern void exit_mmap(struct mm_struct *);
    1130             : 
    1131             : extern int mm_take_all_locks(struct mm_struct *mm);
    1132             : extern void mm_drop_all_locks(struct mm_struct *mm);
    1133             : 
    1134             : #ifdef CONFIG_PROC_FS
    1135             : /* From fs/proc/base.c. callers must _not_ hold the mm's exe_file_lock */
    1136             : extern void added_exe_file_vma(struct mm_struct *mm);
    1137             : extern void removed_exe_file_vma(struct mm_struct *mm);
    1138             : #else
    1139             : static inline void added_exe_file_vma(struct mm_struct *mm)
    1140             : {}
    1141             : 
    1142             : static inline void removed_exe_file_vma(struct mm_struct *mm)
    1143             : {}
    1144             : #endif /* CONFIG_PROC_FS */
    1145             : 
    1146             : extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
    1147             : extern int install_special_mapping(struct mm_struct *mm,
    1148             :                                    unsigned long addr, unsigned long len,
    1149             :                                    unsigned long flags, struct page **pages);
    1150             : 
    1151             : extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
    1152             : 
    1153             : extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
    1154             :         unsigned long len, unsigned long prot,
    1155             :         unsigned long flag, unsigned long pgoff);
    1156             : extern unsigned long mmap_region(struct file *file, unsigned long addr,
    1157             :         unsigned long len, unsigned long flags,
    1158             :         unsigned int vm_flags, unsigned long pgoff);
    1159             : 
    1160             : static inline unsigned long do_mmap(struct file *file, unsigned long addr,
    1161             :         unsigned long len, unsigned long prot,
    1162             :         unsigned long flag, unsigned long offset)
    1163             : {
    1164             :         unsigned long ret = -EINVAL;
    1165             :         if ((offset + PAGE_ALIGN(len)) < offset)
    1166             :                 goto out;
    1167             :         if (!(offset & ~PAGE_MASK))
    1168             :                 ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
    1169             : out:
    1170             :         return ret;
    1171             : }
    1172             : 
    1173             : extern int do_munmap(struct mm_struct *, unsigned long, size_t);
    1174             : 
    1175             : extern unsigned long do_brk(unsigned long, unsigned long);
    1176             : 
    1177             : /* filemap.c */
    1178             : extern unsigned long page_unuse(struct page *);
    1179             : extern void truncate_inode_pages(struct address_space *, loff_t);
    1180             : extern void truncate_inode_pages_range(struct address_space *,
    1181             :                                        loff_t lstart, loff_t lend);
    1182             : 
    1183             : /* generic vm_area_ops exported for stackable file systems */
    1184             : extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
    1185             : 
    1186             : /* mm/page-writeback.c */
    1187             : int write_one_page(struct page *page, int wait);
    1188             : void task_dirty_inc(struct task_struct *tsk);
    1189             : 
    1190             : /* readahead.c */
    1191             : #define VM_MAX_READAHEAD        128     /* kbytes */
    1192             : #define VM_MIN_READAHEAD        16      /* kbytes (includes current page) */
    1193             : 
    1194             : int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
    1195             :                         pgoff_t offset, unsigned long nr_to_read);
    1196             : 
    1197             : void page_cache_sync_readahead(struct address_space *mapping,
    1198             :                                struct file_ra_state *ra,
    1199             :                                struct file *filp,
    1200             :                                pgoff_t offset,
    1201             :                                unsigned long size);
    1202             : 
    1203             : void page_cache_async_readahead(struct address_space *mapping,
    1204             :                                 struct file_ra_state *ra,
    1205             :                                 struct file *filp,
    1206             :                                 struct page *pg,
    1207             :                                 pgoff_t offset,
    1208             :                                 unsigned long size);
    1209             : 
    1210             : unsigned long max_sane_readahead(unsigned long nr);
    1211             : unsigned long ra_submit(struct file_ra_state *ra,
    1212             :                         struct address_space *mapping,
    1213             :                         struct file *filp);
    1214             : 
    1215             : /* Do stack extension */
    1216             : extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
    1217             : #ifdef CONFIG_IA64
    1218             : extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
    1219             : #endif
    1220             : extern int expand_stack_downwards(struct vm_area_struct *vma,
    1221             :                                   unsigned long address);
    1222             : 
    1223             : /* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
    1224             : extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
    1225             : extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
    1226             :                                              struct vm_area_struct **pprev);
    1227             : 
    1228             : /* Look up the first VMA which intersects the interval start_addr..end_addr-1,
    1229             :    NULL if none.  Assume start_addr < end_addr. */
    1230             : static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
    1231             : {
    1232             :         struct vm_area_struct * vma = find_vma(mm,start_addr);
    1233             : 
    1234             :         if (vma && end_addr <= vma->vm_start)
    1235             :                 vma = NULL;
    1236             :         return vma;
    1237             : }
    1238             : 
    1239             : static inline unsigned long vma_pages(struct vm_area_struct *vma)
    1240             : {
    1241             :         return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
    1242             : }
    1243             : 
    1244             : pgprot_t vm_get_page_prot(unsigned long vm_flags);
    1245             : struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
    1246             : int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
    1247             :                         unsigned long pfn, unsigned long size, pgprot_t);
    1248             : int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
    1249             : int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
    1250             :                         unsigned long pfn);
    1251             : int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
    1252             :                         unsigned long pfn);
    1253             : 
    1254             : struct page *follow_page(struct vm_area_struct *, unsigned long address,
    1255             :                         unsigned int foll_flags);
    1256             : #define FOLL_WRITE      0x01    /* check pte is writable */
    1257             : #define FOLL_TOUCH      0x02    /* mark page accessed */
    1258             : #define FOLL_GET        0x04    /* do get_page on page */
    1259             : #define FOLL_DUMP       0x08    /* give error on hole if it would be zero */
    1260             : #define FOLL_FORCE      0x10    /* get_user_pages read/write w/o permission */
    1261             : 
    1262             : typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
    1263             :                         void *data);
    1264             : extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
    1265             :                                unsigned long size, pte_fn_t fn, void *data);
    1266             : 
    1267             : #ifdef CONFIG_PROC_FS
    1268             : void vm_stat_account(struct mm_struct *, unsigned long, struct file *, long);
    1269             : #else
    1270             : static inline void vm_stat_account(struct mm_struct *mm,
    1271             :                         unsigned long flags, struct file *file, long pages)
    1272             : {
    1273             : }
    1274             : #endif /* CONFIG_PROC_FS */
    1275             : 
    1276             : #ifdef CONFIG_DEBUG_PAGEALLOC
    1277             : extern int debug_pagealloc_enabled;
    1278             : 
    1279             : extern void kernel_map_pages(struct page *page, int numpages, int enable);
    1280             : 
    1281             : static inline void enable_debug_pagealloc(void)
    1282             : {
    1283             :         debug_pagealloc_enabled = 1;
    1284             : }
    1285             : #ifdef CONFIG_HIBERNATION
    1286             : extern bool kernel_page_present(struct page *page);
    1287             : #endif /* CONFIG_HIBERNATION */
    1288             : #else
    1289             : static inline void
    1290             : kernel_map_pages(struct page *page, int numpages, int enable) {}
    1291             : static inline void enable_debug_pagealloc(void)
    1292             : {
    1293             : }
    1294             : #ifdef CONFIG_HIBERNATION
    1295             : static inline bool kernel_page_present(struct page *page) { return true; }
    1296             : #endif /* CONFIG_HIBERNATION */
    1297             : #endif
    1298             : 
    1299             : extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk);
    1300             : #ifdef  __HAVE_ARCH_GATE_AREA
    1301             : int in_gate_area_no_task(unsigned long addr);
    1302             : int in_gate_area(struct task_struct *task, unsigned long addr);
    1303             : #else
    1304             : int in_gate_area_no_task(unsigned long addr);
    1305             : #define in_gate_area(task, addr) ({(void)task; in_gate_area_no_task(addr);})
    1306             : #endif  /* __HAVE_ARCH_GATE_AREA */
    1307             : 
    1308             : int drop_caches_sysctl_handler(struct ctl_table *, int,
    1309             :                                         void __user *, size_t *, loff_t *);
    1310             : unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
    1311             :                         unsigned long lru_pages);
    1312             : 
    1313             : #ifndef CONFIG_MMU
    1314             : #define randomize_va_space 0
    1315             : #else
    1316             : extern int randomize_va_space;
    1317             : #endif
    1318             : 
    1319             : const char * arch_vma_name(struct vm_area_struct *vma);
    1320             : void print_vma_addr(char *prefix, unsigned long rip);
    1321             : 
    1322             : struct page *sparse_mem_map_populate(unsigned long pnum, int nid);
    1323             : pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
    1324             : pud_t *vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node);
    1325             : pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
    1326             : pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node);
    1327             : void *vmemmap_alloc_block(unsigned long size, int node);
    1328             : void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
    1329             : int vmemmap_populate_basepages(struct page *start_page,
    1330             :                                                 unsigned long pages, int node);
    1331             : int vmemmap_populate(struct page *start_page, unsigned long pages, int node);
    1332             : void vmemmap_populate_print_last(void);
    1333             : 
    1334             : extern int account_locked_memory(struct mm_struct *mm, struct rlimit *rlim,
    1335             :                                  size_t size);
    1336             : extern void refund_locked_memory(struct mm_struct *mm, size_t size);
    1337             : 
    1338             : enum mf_flags {
    1339             :         MF_COUNT_INCREASED = 1 << 0,
    1340             : };
    1341             : extern void memory_failure(unsigned long pfn, int trapno);
    1342             : extern int __memory_failure(unsigned long pfn, int trapno, int flags);
    1343             : extern int unpoison_memory(unsigned long pfn);
    1344             : extern int sysctl_memory_failure_early_kill;
    1345             : extern int sysctl_memory_failure_recovery;
    1346             : extern void shake_page(struct page *p, int access);
    1347             : extern atomic_long_t mce_bad_pages;
    1348             : extern int soft_offline_page(struct page *page, int flags);
    1349             : 
    1350             : #endif /* __KERNEL__ */
    1351             : #endif /* _LINUX_MM_H */

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