File: /Users/paulross/dev/linux/linux-3.13/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/bug.h>
      10: #include <linux/list.h>
      11: #include <linux/mmzone.h>
      12: #include <linux/rbtree.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: 
      21: struct mempolicy;
      22: struct anon_vma;
      23: struct anon_vma_chain;
      24: struct file_ra_state;
      25: struct user_struct;
      26: struct writeback_control;
      27: 
      28: #ifndef CONFIG_NEED_MULTIPLE_NODES    /* Don't use mapnrs, do it properly */
      29: extern unsigned long max_mapnr;
      30: 
      31: static inline void set_max_mapnr(unsigned long limit)
      32: {
      33:     max_mapnr = limit;
      34: }
      35: #else
      36: static inline void set_max_mapnr(unsigned long limit) { }
      37: #endif
      38: 
      39: extern unsigned long totalram_pages;
      40: extern void * high_memory;
      41: extern int page_cluster;
      42: 
      43: #ifdef CONFIG_SYSCTL
      44: extern int sysctl_legacy_va_layout;
      45: #else
      46: #define sysctl_legacy_va_layout 0
      47: #endif
      48: 
      49: #include <asm/page.h>
      50: #include <asm/pgtable.h>
      51: #include <asm/processor.h>
      52: 
      53: #ifndef __pa_symbol
      54: #define __pa_symbol(x)  __pa(RELOC_HIDE((unsigned long)(x), 0))
      55: #endif
      56: 
      57: extern unsigned long sysctl_user_reserve_kbytes;
      58: extern unsigned long sysctl_admin_reserve_kbytes;
      59: 
      60: #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
      61: 
      62: /* to align the pointer to the (next) page boundary */
      63: #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
      64: 
      65: /* test whether an address (unsigned long or pointer) is aligned to PAGE_SIZE */
      66: #define PAGE_ALIGNED(addr)    IS_ALIGNED((unsigned long)addr, PAGE_SIZE)
      67: 
      68: /*
      69:  * Linux kernel virtual memory manager primitives.
      70:  * The idea being to have a "virtual" mm in the same way
      71:  * we have a virtual fs - giving a cleaner interface to the
      72:  * mm details, and allowing different kinds of memory mappings
      73:  * (from shared memory to executable loading to arbitrary
      74:  * mmap() functions).
      75:  */
      76: 
      77: extern struct kmem_cache *vm_area_cachep;
      78: 
      79: #ifndef CONFIG_MMU
      80: extern struct rb_root nommu_region_tree;
      81: extern struct rw_semaphore nommu_region_sem;
      82: 
      83: extern unsigned int kobjsize(const void *objp);
      84: #endif
      85: 
      86: /*
      87:  * vm_flags in vm_area_struct, see mm_types.h.
      88:  */
      89: #define VM_NONE        0x00000000
      90: 
      91: #define VM_READ        0x00000001    /* currently active flags */
      92: #define VM_WRITE    0x00000002
      93: #define VM_EXEC        0x00000004
      94: #define VM_SHARED    0x00000008
      95: 
      96: /* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
      97: #define VM_MAYREAD    0x00000010    /* limits for mprotect() etc */
      98: #define VM_MAYWRITE    0x00000020
      99: #define VM_MAYEXEC    0x00000040
     100: #define VM_MAYSHARE    0x00000080
     101: 
     102: #define VM_GROWSDOWN    0x00000100    /* general info on the segment */
     103: #define VM_PFNMAP    0x00000400    /* Page-ranges managed without "struct page", just pure PFN */
     104: #define VM_DENYWRITE    0x00000800    /* ETXTBSY on write attempts.. */
     105: 
     106: #define VM_LOCKED    0x00002000
     107: #define VM_IO           0x00004000    /* Memory mapped I/O or similar */
     108: 
     109:                     /* Used by sys_madvise() */
     110: #define VM_SEQ_READ    0x00008000    /* App will access data sequentially */
     111: #define VM_RAND_READ    0x00010000    /* App will not benefit from clustered reads */
     112: 
     113: #define VM_DONTCOPY    0x00020000      /* Do not copy this vma on fork */
     114: #define VM_DONTEXPAND    0x00040000    /* Cannot expand with mremap() */
     115: #define VM_ACCOUNT    0x00100000    /* Is a VM accounted object */
     116: #define VM_NORESERVE    0x00200000    /* should the VM suppress accounting */
     117: #define VM_HUGETLB    0x00400000    /* Huge TLB Page VM */
     118: #define VM_NONLINEAR    0x00800000    /* Is non-linear (remap_file_pages) */
     119: #define VM_ARCH_1    0x01000000    /* Architecture-specific flag */
     120: #define VM_DONTDUMP    0x04000000    /* Do not include in the core dump */
     121: 
     122: #ifdef CONFIG_MEM_SOFT_DIRTY
     123: # define VM_SOFTDIRTY    0x08000000    /* Not soft dirty clean area */
     124: #else
     125: # define VM_SOFTDIRTY    0
     126: #endif
     127: 
     128: #define VM_MIXEDMAP    0x10000000    /* Can contain "struct page" and pure PFN pages */
     129: #define VM_HUGEPAGE    0x20000000    /* MADV_HUGEPAGE marked this vma */
     130: #define VM_NOHUGEPAGE    0x40000000    /* MADV_NOHUGEPAGE marked this vma */
     131: #define VM_MERGEABLE    0x80000000    /* KSM may merge identical pages */
     132: 
     133: #if defined(CONFIG_X86)
     134: # define VM_PAT        VM_ARCH_1    /* PAT reserves whole VMA at once (x86) */
     135: #elif defined(CONFIG_PPC)
     136: # define VM_SAO        VM_ARCH_1    /* Strong Access Ordering (powerpc) */
     137: #elif defined(CONFIG_PARISC)
     138: # define VM_GROWSUP    VM_ARCH_1
     139: #elif defined(CONFIG_METAG)
     140: # define VM_GROWSUP    VM_ARCH_1
     141: #elif defined(CONFIG_IA64)
     142: # define VM_GROWSUP    VM_ARCH_1
     143: #elif !defined(CONFIG_MMU)
     144: # define VM_MAPPED_COPY    VM_ARCH_1    /* T if mapped copy of data (nommu mmap) */
     145: #endif
     146: 
     147: #ifndef VM_GROWSUP
     148: # define VM_GROWSUP    VM_NONE
     149: #endif
     150: 
     151: /* Bits set in the VMA until the stack is in its final location */
     152: #define VM_STACK_INCOMPLETE_SETUP    (VM_RAND_READ | VM_SEQ_READ)
     153: 
     154: #ifndef VM_STACK_DEFAULT_FLAGS        /* arch can override this */
     155: #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
     156: #endif
     157: 
     158: #ifdef CONFIG_STACK_GROWSUP
     159: #define VM_STACK_FLAGS    (VM_GROWSUP | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
     160: #else
     161: #define VM_STACK_FLAGS    (VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
     162: #endif
     163: 
     164: /*
     165:  * Special vmas that are non-mergable, non-mlock()able.
     166:  * Note: mm/huge_memory.c VM_NO_THP depends on this definition.
     167:  */
     168: #define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP)
     169: 
     170: /*
     171:  * mapping from the currently active vm_flags protection bits (the
     172:  * low four bits) to a page protection mask..
     173:  */
     174: extern pgprot_t protection_map[16];
     175: 
     176: #define FAULT_FLAG_WRITE    0x01    /* Fault was a write access */
     177: #define FAULT_FLAG_NONLINEAR    0x02    /* Fault was via a nonlinear mapping */
     178: #define FAULT_FLAG_MKWRITE    0x04    /* Fault was mkwrite of existing pte */
     179: #define FAULT_FLAG_ALLOW_RETRY    0x08    /* Retry fault if blocking */
     180: #define FAULT_FLAG_RETRY_NOWAIT    0x10    /* Don't drop mmap_sem and wait when retrying */
     181: #define FAULT_FLAG_KILLABLE    0x20    /* The fault task is in SIGKILL killable region */
     182: #define FAULT_FLAG_TRIED    0x40    /* second try */
     183: #define FAULT_FLAG_USER        0x80    /* The fault originated in userspace */
     184: 
     185: /*
     186:  * vm_fault is filled by the the pagefault handler and passed to the vma's
     187:  * ->fault function. The vma's ->fault is responsible for returning a bitmask
     188:  * of VM_FAULT_xxx flags that give details about how the fault was handled.
     189:  *
     190:  * pgoff should be used in favour of virtual_address, if possible. If pgoff
     191:  * is used, one may implement ->remap_pages to get nonlinear mapping support.
     192:  */
     193: struct vm_fault {
     194:     unsigned int flags;        /* FAULT_FLAG_xxx flags */
     195:     pgoff_t pgoff;            /* Logical page offset based on vma */
     196:     void __user *virtual_address;    /* Faulting virtual address */
     197: 
     198:     struct page *page;        /* ->fault handlers should return a
     199:                      * page here, unless VM_FAULT_NOPAGE
     200:                      * is set (which is also implied by
     201:                      * VM_FAULT_ERROR).
     202:                      */
     203: };
     204: 
     205: /*
     206:  * These are the virtual MM functions - opening of an area, closing and
     207:  * unmapping it (needed to keep files on disk up-to-date etc), pointer
     208:  * to the functions called when a no-page or a wp-page exception occurs. 
     209:  */
     210: struct vm_operations_struct {
     211:     void (*open)(struct vm_area_struct * area);
     212:     void (*close)(struct vm_area_struct * area);
     213:     int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
     214: 
     215:     /* notification that a previously read-only page is about to become
     216:      * writable, if an error is returned it will cause a SIGBUS */
     217:     int (*page_mkwrite)(struct vm_area_struct *vma, struct vm_fault *vmf);
     218: 
     219:     /* called by access_process_vm when get_user_pages() fails, typically
     220:      * for use by special VMAs that can switch between memory and hardware
     221:      */
     222:     int (*access)(struct vm_area_struct *vma, unsigned long addr,
     223:               void *buf, int len, int write);
     224: #ifdef CONFIG_NUMA
     225:     /*
     226:      * set_policy() op must add a reference to any non-NULL @new mempolicy
     227:      * to hold the policy upon return.  Caller should pass NULL @new to
     228:      * remove a policy and fall back to surrounding context--i.e. do not
     229:      * install a MPOL_DEFAULT policy, nor the task or system default
     230:      * mempolicy.
     231:      */
     232:     int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
     233: 
     234:     /*
     235:      * get_policy() op must add reference [mpol_get()] to any policy at
     236:      * (vma,addr) marked as MPOL_SHARED.  The shared policy infrastructure
     237:      * in mm/mempolicy.c will do this automatically.
     238:      * get_policy() must NOT add a ref if the policy at (vma,addr) is not
     239:      * marked as MPOL_SHARED. vma policies are protected by the mmap_sem.
     240:      * If no [shared/vma] mempolicy exists at the addr, get_policy() op
     241:      * must return NULL--i.e., do not "fallback" to task or system default
     242:      * policy.
     243:      */
     244:     struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
     245:                     unsigned long addr);
     246:     int (*migrate)(struct vm_area_struct *vma, const nodemask_t *from,
     247:         const nodemask_t *to, unsigned long flags);
     248: #endif
     249:     /* called by sys_remap_file_pages() to populate non-linear mapping */
     250:     int (*remap_pages)(struct vm_area_struct *vma, unsigned long addr,
     251:                unsigned long size, pgoff_t pgoff);
     252: };
     253: 
     254: struct mmu_gather;
     255: struct inode;
     256: 
     257: #define page_private(page)        ((page)->private)
     258: #define set_page_private(page, v)    ((page)->private = (v))
     259: 
     260: /* It's valid only if the page is free path or free_list */
     261: static inline void set_freepage_migratetype(struct page *page, int migratetype)
     262: {
     263:     page->index = migratetype;
     264: }
     265: 
     266: /* It's valid only if the page is free path or free_list */
     267: static inline int get_freepage_migratetype(struct page *page)
     268: {
     269:     return page->index;
     270: }
     271: 
     272: /*
     273:  * FIXME: take this include out, include page-flags.h in
     274:  * files which need it (119 of them)
     275:  */
     276: #include <linux/page-flags.h>
     277: #include <linux/huge_mm.h>
     278: 
     279: /*
     280:  * Methods to modify the page usage count.
     281:  *
     282:  * What counts for a page usage:
     283:  * - cache mapping   (page->mapping)
     284:  * - private data    (page->private)
     285:  * - page mapped in a task's page tables, each mapping
     286:  *   is counted separately
     287:  *
     288:  * Also, many kernel routines increase the page count before a critical
     289:  * routine so they can be sure the page doesn't go away from under them.
     290:  */
     291: 
     292: /*
     293:  * Drop a ref, return true if the refcount fell to zero (the page has no users)
     294:  */
     295: static inline int put_page_testzero(struct page *page)
     296: {
     297:     VM_BUG_ON(atomic_read(&page->_count) == 0);
     298:     return atomic_dec_and_test(&page->_count);
     299: }
     300: 
     301: /*
     302:  * Try to grab a ref unless the page has a refcount of zero, return false if
     303:  * that is the case.
     304:  * This can be called when MMU is off so it must not access
     305:  * any of the virtual mappings.
     306:  */
     307: static inline int get_page_unless_zero(struct page *page)
     308: {
     309:     return atomic_inc_not_zero(&page->_count);
     310: }
     311: 
     312: /*
     313:  * Try to drop a ref unless the page has a refcount of one, return false if
     314:  * that is the case.
     315:  * This is to make sure that the refcount won't become zero after this drop.
     316:  * This can be called when MMU is off so it must not access
     317:  * any of the virtual mappings.
     318:  */
     319: static inline int put_page_unless_one(struct page *page)
     320: {
     321:     return atomic_add_unless(&page->_count, -1, 1);
     322: }
     323: 
     324: extern int page_is_ram(unsigned long pfn);
     325: 
     326: /* Support for virtually mapped pages */
     327: struct page *vmalloc_to_page(const void *addr);
     328: unsigned long vmalloc_to_pfn(const void *addr);
     329: 
     330: /*
     331:  * Determine if an address is within the vmalloc range
     332:  *
     333:  * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
     334:  * is no special casing required.
     335:  */
     336: static inline int is_vmalloc_addr(const void *x)
     337: {
     338: #ifdef CONFIG_MMU
     339:     unsigned long addr = (unsigned long)x;
     340: 
     341:     return addr >= VMALLOC_START && addr < VMALLOC_END;
     342: #else
     343:     return 0;
     344: #endif
     345: }
     346: #ifdef CONFIG_MMU
     347: extern int is_vmalloc_or_module_addr(const void *x);
     348: #else
     349: static inline int is_vmalloc_or_module_addr(const void *x)
     350: {
     351:     return 0;
     352: }
     353: #endif
     354: 
     355: static inline void compound_lock(struct page *page)
     356: {
     357: #ifdef CONFIG_TRANSPARENT_HUGEPAGE
     358:     VM_BUG_ON(PageSlab(page));
     359:     bit_spin_lock(PG_compound_lock, &page->flags);
     360: #endif
     361: }
     362: 
     363: static inline void compound_unlock(struct page *page)
     364: {
     365: #ifdef CONFIG_TRANSPARENT_HUGEPAGE
     366:     VM_BUG_ON(PageSlab(page));
     367:     bit_spin_unlock(PG_compound_lock, &page->flags);
     368: #endif
     369: }
     370: 
     371: static inline unsigned long compound_lock_irqsave(struct page *page)
     372: {
     373:     unsigned long uninitialized_var(flags);
     374: #ifdef CONFIG_TRANSPARENT_HUGEPAGE
     375:     local_irq_save(flags);
     376:     compound_lock(page);
     377: #endif
     378:     return flags;
     379: }
     380: 
     381: static inline void compound_unlock_irqrestore(struct page *page,
     382:                           unsigned long flags)
     383: {
     384: #ifdef CONFIG_TRANSPARENT_HUGEPAGE
     385:     compound_unlock(page);
     386:     local_irq_restore(flags);
     387: #endif
     388: }
     389: 
     390: static inline struct page *compound_head(struct page *page)
     391: {
     392:     if (unlikely(PageTail(page)))
     393:         return page->first_page;
     394:     return page;
     395: }
     396: 
     397: /*
     398:  * The atomic page->_mapcount, starts from -1: so that transitions
     399:  * both from it and to it can be tracked, using atomic_inc_and_test
     400:  * and atomic_add_negative(-1).
     401:  */
     402: static inline void page_mapcount_reset(struct page *page)
     403: {
     404:     atomic_set(&(page)->_mapcount, -1);
     405: }
     406: 
     407: static inline int page_mapcount(struct page *page)
     408: {
     409:     return atomic_read(&(page)->_mapcount) + 1;
     410: }
     411: 
     412: static inline int page_count(struct page *page)
     413: {
     414:     return atomic_read(&compound_head(page)->_count);
     415: }
     416: 
     417: static inline void get_huge_page_tail(struct page *page)
     418: {
     419:     /*
     420:      * __split_huge_page_refcount() cannot run
     421:      * from under us.
     422:      */
     423:     VM_BUG_ON(page_mapcount(page) < 0);
     424:     VM_BUG_ON(atomic_read(&page->_count) != 0);
     425:     atomic_inc(&page->_mapcount);
     426: }
     427: 
     428: extern bool __get_page_tail(struct page *page);
     429: 
     430: static inline void get_page(struct page *page)
     431: {
     432:     if (unlikely(PageTail(page)))
     433:         if (likely(__get_page_tail(page)))
     434:             return;
     435:     /*
     436:      * Getting a normal page or the head of a compound page
     437:      * requires to already have an elevated page->_count.
     438:      */
     439:     VM_BUG_ON(atomic_read(&page->_count) <= 0);
     440:     atomic_inc(&page->_count);
     441: }
     442: 
     443: static inline struct page *virt_to_head_page(const void *x)
     444: {
     445:     struct page *page = virt_to_page(x);
     446:     return compound_head(page);
     447: }
     448: 
     449: /*
     450:  * Setup the page count before being freed into the page allocator for
     451:  * the first time (boot or memory hotplug)
     452:  */
     453: static inline void init_page_count(struct page *page)
     454: {
     455:     atomic_set(&page->_count, 1);
     456: }
     457: 
     458: /*
     459:  * PageBuddy() indicate that the page is free and in the buddy system
     460:  * (see mm/page_alloc.c).
     461:  *
     462:  * PAGE_BUDDY_MAPCOUNT_VALUE must be <= -2 but better not too close to
     463:  * -2 so that an underflow of the page_mapcount() won't be mistaken
     464:  * for a genuine PAGE_BUDDY_MAPCOUNT_VALUE. -128 can be created very
     465:  * efficiently by most CPU architectures.
     466:  */
     467: #define PAGE_BUDDY_MAPCOUNT_VALUE (-128)
     468: 
     469: static inline int PageBuddy(struct page *page)
     470: {
     471:     return atomic_read(&page->_mapcount) == PAGE_BUDDY_MAPCOUNT_VALUE;
     472: }
     473: 
     474: static inline void __SetPageBuddy(struct page *page)
     475: {
     476:     VM_BUG_ON(atomic_read(&page->_mapcount) != -1);
     477:     atomic_set(&page->_mapcount, PAGE_BUDDY_MAPCOUNT_VALUE);
     478: }
     479: 
     480: static inline void __ClearPageBuddy(struct page *page)
     481: {
     482:     VM_BUG_ON(!PageBuddy(page));
     483:     atomic_set(&page->_mapcount, -1);
     484: }
     485: 
     486: void put_page(struct page *page);
     487: void put_pages_list(struct list_head *pages);
     488: 
     489: void split_page(struct page *page, unsigned int order);
     490: int split_free_page(struct page *page);
     491: 
     492: /*
     493:  * Compound pages have a destructor function.  Provide a
     494:  * prototype for that function and accessor functions.
     495:  * These are _only_ valid on the head of a PG_compound page.
     496:  */
     497: typedef void compound_page_dtor(struct page *);
     498: 
     499: static inline void set_compound_page_dtor(struct page *page,
     500:                         compound_page_dtor *dtor)
     501: {
     502:     page[1].lru.next = (void *)dtor;
     503: }
     504: 
     505: static inline compound_page_dtor *get_compound_page_dtor(struct page *page)
     506: {
     507:     return (compound_page_dtor *)page[1].lru.next;
     508: }
     509: 
     510: static inline int compound_order(struct page *page)
     511: {
     512:     if (!PageHead(page))
     513:         return 0;
     514:     return (unsigned long)page[1].lru.prev;
     515: }
     516: 
     517: static inline void set_compound_order(struct page *page, unsigned long order)
     518: {
     519:     page[1].lru.prev = (void *)order;
     520: }
     521: 
     522: #ifdef CONFIG_MMU
     523: /*
     524:  * Do pte_mkwrite, but only if the vma says VM_WRITE.  We do this when
     525:  * servicing faults for write access.  In the normal case, do always want
     526:  * pte_mkwrite.  But get_user_pages can cause write faults for mappings
     527:  * that do not have writing enabled, when used by access_process_vm.
     528:  */
     529: static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
     530: {
     531:     if (likely(vma->vm_flags & VM_WRITE))
     532:         pte = pte_mkwrite(pte);
     533:     return pte;
     534: }
     535: #endif
     536: 
     537: /*
     538:  * Multiple processes may "see" the same page. E.g. for untouched
     539:  * mappings of /dev/null, all processes see the same page full of
     540:  * zeroes, and text pages of executables and shared libraries have
     541:  * only one copy in memory, at most, normally.
     542:  *
     543:  * For the non-reserved pages, page_count(page) denotes a reference count.
     544:  *   page_count() == 0 means the page is free. page->lru is then used for
     545:  *   freelist management in the buddy allocator.
     546:  *   page_count() > 0  means the page has been allocated.
     547:  *
     548:  * Pages are allocated by the slab allocator in order to provide memory
     549:  * to kmalloc and kmem_cache_alloc. In this case, the management of the
     550:  * page, and the fields in 'struct page' are the responsibility of mm/slab.c
     551:  * unless a particular usage is carefully commented. (the responsibility of
     552:  * freeing the kmalloc memory is the caller's, of course).
     553:  *
     554:  * A page may be used by anyone else who does a __get_free_page().
     555:  * In this case, page_count still tracks the references, and should only
     556:  * be used through the normal accessor functions. The top bits of page->flags
     557:  * and page->virtual store page management information, but all other fields
     558:  * are unused and could be used privately, carefully. The management of this
     559:  * page is the responsibility of the one who allocated it, and those who have
     560:  * subsequently been given references to it.
     561:  *
     562:  * The other pages (we may call them "pagecache pages") are completely
     563:  * managed by the Linux memory manager: I/O, buffers, swapping etc.
     564:  * The following discussion applies only to them.
     565:  *
     566:  * A pagecache page contains an opaque `private' member, which belongs to the
     567:  * page's address_space. Usually, this is the address of a circular list of
     568:  * the page's disk buffers. PG_private must be set to tell the VM to call
     569:  * into the filesystem to release these pages.
     570:  *
     571:  * A page may belong to an inode's memory mapping. In this case, page->mapping
     572:  * is the pointer to the inode, and page->index is the file offset of the page,
     573:  * in units of PAGE_CACHE_SIZE.
     574:  *
     575:  * If pagecache pages are not associated with an inode, they are said to be
     576:  * anonymous pages. These may become associated with the swapcache, and in that
     577:  * case PG_swapcache is set, and page->private is an offset into the swapcache.
     578:  *
     579:  * In either case (swapcache or inode backed), the pagecache itself holds one
     580:  * reference to the page. Setting PG_private should also increment the
     581:  * refcount. The each user mapping also has a reference to the page.
     582:  *
     583:  * The pagecache pages are stored in a per-mapping radix tree, which is
     584:  * rooted at mapping->page_tree, and indexed by offset.
     585:  * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
     586:  * lists, we instead now tag pages as dirty/writeback in the radix tree.
     587:  *
     588:  * All pagecache pages may be subject to I/O:
     589:  * - inode pages may need to be read from disk,
     590:  * - inode pages which have been modified and are MAP_SHARED may need
     591:  *   to be written back to the inode on disk,
     592:  * - anonymous pages (including MAP_PRIVATE file mappings) which have been
     593:  *   modified may need to be swapped out to swap space and (later) to be read
     594:  *   back into memory.
     595:  */
     596: 
     597: /*
     598:  * The zone field is never updated after free_area_init_core()
     599:  * sets it, so none of the operations on it need to be atomic.
     600:  */
     601: 
     602: /* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_CPUPID] | ... | FLAGS | */
     603: #define SECTIONS_PGOFF        ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
     604: #define NODES_PGOFF        (SECTIONS_PGOFF - NODES_WIDTH)
     605: #define ZONES_PGOFF        (NODES_PGOFF - ZONES_WIDTH)
     606: #define LAST_CPUPID_PGOFF    (ZONES_PGOFF - LAST_CPUPID_WIDTH)
     607: 
     608: /*
     609:  * Define the bit shifts to access each section.  For non-existent
     610:  * sections we define the shift as 0; that plus a 0 mask ensures
     611:  * the compiler will optimise away reference to them.
     612:  */
     613: #define SECTIONS_PGSHIFT    (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
     614: #define NODES_PGSHIFT        (NODES_PGOFF * (NODES_WIDTH != 0))
     615: #define ZONES_PGSHIFT        (ZONES_PGOFF * (ZONES_WIDTH != 0))
     616: #define LAST_CPUPID_PGSHIFT    (LAST_CPUPID_PGOFF * (LAST_CPUPID_WIDTH != 0))
     617: 
     618: /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */
     619: #ifdef NODE_NOT_IN_PAGE_FLAGS
     620: #define ZONEID_SHIFT        (SECTIONS_SHIFT + ZONES_SHIFT)
     621: #define ZONEID_PGOFF        ((SECTIONS_PGOFF < ZONES_PGOFF)? \
     622:                         SECTIONS_PGOFF : ZONES_PGOFF)
     623: #else
     624: #define ZONEID_SHIFT        (NODES_SHIFT + ZONES_SHIFT)
     625: #define ZONEID_PGOFF        ((NODES_PGOFF < ZONES_PGOFF)? \
     626:                         NODES_PGOFF : ZONES_PGOFF)
     627: #endif
     628: 
     629: #define ZONEID_PGSHIFT        (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
     630: 
     631: #if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
     632: #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
     633: #endif
     634: 
     635: #define ZONES_MASK        ((1UL << ZONES_WIDTH) - 1)
     636: #define NODES_MASK        ((1UL << NODES_WIDTH) - 1)
     637: #define SECTIONS_MASK        ((1UL << SECTIONS_WIDTH) - 1)
     638: #define LAST_CPUPID_MASK    ((1UL << LAST_CPUPID_WIDTH) - 1)
     639: #define ZONEID_MASK        ((1UL << ZONEID_SHIFT) - 1)
     640: 
     641: static inline enum zone_type page_zonenum(const struct page *page)
     642: {
     643:     return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
     644: }
     645: 
     646: #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
     647: #define SECTION_IN_PAGE_FLAGS
     648: #endif
     649: 
     650: /*
     651:  * The identification function is mainly used by the buddy allocator for
     652:  * determining if two pages could be buddies. We are not really identifying
     653:  * the zone since we could be using the section number id if we do not have
     654:  * node id available in page flags.
     655:  * We only guarantee that it will return the same value for two combinable
     656:  * pages in a zone.
     657:  */
     658: static inline int page_zone_id(struct page *page)
     659: {
     660:     return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
     661: }
     662: 
     663: static inline int zone_to_nid(struct zone *zone)
     664: {
     665: #ifdef CONFIG_NUMA
     666:     return zone->node;
     667: #else
     668:     return 0;
     669: #endif
     670: }
     671: 
     672: #ifdef NODE_NOT_IN_PAGE_FLAGS
     673: extern int page_to_nid(const struct page *page);
     674: #else
     675: static inline int page_to_nid(const struct page *page)
     676: {
     677:     return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
     678: }
     679: #endif
     680: 
     681: #ifdef CONFIG_NUMA_BALANCING
     682: static inline int cpu_pid_to_cpupid(int cpu, int pid)
     683: {
     684:     return ((cpu & LAST__CPU_MASK) << LAST__PID_SHIFT) | (pid & LAST__PID_MASK);
     685: }
     686: 
     687: static inline int cpupid_to_pid(int cpupid)
     688: {
     689:     return cpupid & LAST__PID_MASK;
     690: }
     691: 
     692: static inline int cpupid_to_cpu(int cpupid)
     693: {
     694:     return (cpupid >> LAST__PID_SHIFT) & LAST__CPU_MASK;
     695: }
     696: 
     697: static inline int cpupid_to_nid(int cpupid)
     698: {
     699:     return cpu_to_node(cpupid_to_cpu(cpupid));
     700: }
     701: 
     702: static inline bool cpupid_pid_unset(int cpupid)
     703: {
     704:     return cpupid_to_pid(cpupid) == (-1 & LAST__PID_MASK);
     705: }
     706: 
     707: static inline bool cpupid_cpu_unset(int cpupid)
     708: {
     709:     return cpupid_to_cpu(cpupid) == (-1 & LAST__CPU_MASK);
     710: }
     711: 
     712: static inline bool __cpupid_match_pid(pid_t task_pid, int cpupid)
     713: {
     714:     return (task_pid & LAST__PID_MASK) == cpupid_to_pid(cpupid);
     715: }
     716: 
     717: #define cpupid_match_pid(task, cpupid) __cpupid_match_pid(task->pid, cpupid)
     718: #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
     719: static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
     720: {
     721:     return xchg(&page->_last_cpupid, cpupid);
     722: }
     723: 
     724: static inline int page_cpupid_last(struct page *page)
     725: {
     726:     return page->_last_cpupid;
     727: }
     728: static inline void page_cpupid_reset_last(struct page *page)
     729: {
     730:     page->_last_cpupid = -1;
     731: }
     732: #else
     733: static inline int page_cpupid_last(struct page *page)
     734: {
     735:     return (page->flags >> LAST_CPUPID_PGSHIFT) & LAST_CPUPID_MASK;
     736: }
     737: 
     738: extern int page_cpupid_xchg_last(struct page *page, int cpupid);
     739: 
     740: static inline void page_cpupid_reset_last(struct page *page)
     741: {
     742:     int cpupid = (1 << LAST_CPUPID_SHIFT) - 1;
     743: 
     744:     page->flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT);
     745:     page->flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT;
     746: }
     747: #endif /* LAST_CPUPID_NOT_IN_PAGE_FLAGS */
     748: #else /* !CONFIG_NUMA_BALANCING */
     749: static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
     750: {
     751:     return page_to_nid(page); /* XXX */
     752: }
     753: 
     754: static inline int page_cpupid_last(struct page *page)
     755: {
     756:     return page_to_nid(page); /* XXX */
     757: }
     758: 
     759: static inline int cpupid_to_nid(int cpupid)
     760: {
     761:     return -1;
     762: }
     763: 
     764: static inline int cpupid_to_pid(int cpupid)
     765: {
     766:     return -1;
     767: }
     768: 
     769: static inline int cpupid_to_cpu(int cpupid)
     770: {
     771:     return -1;
     772: }
     773: 
     774: static inline int cpu_pid_to_cpupid(int nid, int pid)
     775: {
     776:     return -1;
     777: }
     778: 
     779: static inline bool cpupid_pid_unset(int cpupid)
     780: {
     781:     return 1;
     782: }
     783: 
     784: static inline void page_cpupid_reset_last(struct page *page)
     785: {
     786: }
     787: 
     788: static inline bool cpupid_match_pid(struct task_struct *task, int cpupid)
     789: {
     790:     return false;
     791: }
     792: #endif /* CONFIG_NUMA_BALANCING */
     793: 
     794: static inline struct zone *page_zone(const struct page *page)
     795: {
     796:     return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
     797: }
     798: 
     799: #ifdef SECTION_IN_PAGE_FLAGS
     800: static inline void set_page_section(struct page *page, unsigned long section)
     801: {
     802:     page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
     803:     page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
     804: }
     805: 
     806: static inline unsigned long page_to_section(const struct page *page)
     807: {
     808:     return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
     809: }
     810: #endif
     811: 
     812: static inline void set_page_zone(struct page *page, enum zone_type zone)
     813: {
     814:     page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
     815:     page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
     816: }
     817: 
     818: static inline void set_page_node(struct page *page, unsigned long node)
     819: {
     820:     page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
     821:     page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
     822: }
     823: 
     824: static inline void set_page_links(struct page *page, enum zone_type zone,
     825:     unsigned long node, unsigned long pfn)
     826: {
     827:     set_page_zone(page, zone);
     828:     set_page_node(page, node);
     829: #ifdef SECTION_IN_PAGE_FLAGS
     830:     set_page_section(page, pfn_to_section_nr(pfn));
     831: #endif
     832: }
     833: 
     834: /*
     835:  * Some inline functions in vmstat.h depend on page_zone()
     836:  */
     837: #include <linux/vmstat.h>
     838: 
     839: static __always_inline void *lowmem_page_address(const struct page *page)
     840: {
     841:     return __va(PFN_PHYS(page_to_pfn(page)));
     842: }
     843: 
     844: #if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
     845: #define HASHED_PAGE_VIRTUAL
     846: #endif
     847: 
     848: #if defined(WANT_PAGE_VIRTUAL)
     849: #define page_address(page) ((page)->virtual)
     850: #define set_page_address(page, address)            \
     851:     do {                        \
     852:         (page)->virtual = (address);        \
     853:     } while(0)
     854: #define page_address_init()  do { } while(0)
     855: #endif
     856: 
     857: #if defined(HASHED_PAGE_VIRTUAL)
     858: void *page_address(const struct page *page);
     859: void set_page_address(struct page *page, void *virtual);
     860: void page_address_init(void);
     861: #endif
     862: 
     863: #if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
     864: #define page_address(page) lowmem_page_address(page)
     865: #define set_page_address(page, address)  do { } while(0)
     866: #define page_address_init()  do { } while(0)
     867: #endif
     868: 
     869: /*
     870:  * On an anonymous page mapped into a user virtual memory area,
     871:  * page->mapping points to its anon_vma, not to a struct address_space;
     872:  * with the PAGE_MAPPING_ANON bit set to distinguish it.  See rmap.h.
     873:  *
     874:  * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled,
     875:  * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit;
     876:  * and then page->mapping points, not to an anon_vma, but to a private
     877:  * structure which KSM associates with that merged page.  See ksm.h.
     878:  *
     879:  * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used.
     880:  *
     881:  * Please note that, confusingly, "page_mapping" refers to the inode
     882:  * address_space which maps the page from disk; whereas "page_mapped"
     883:  * refers to user virtual address space into which the page is mapped.
     884:  */
     885: #define PAGE_MAPPING_ANON    1
     886: #define PAGE_MAPPING_KSM    2
     887: #define PAGE_MAPPING_FLAGS    (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM)
     888: 
     889: extern struct address_space *page_mapping(struct page *page);
     890: 
     891: /* Neutral page->mapping pointer to address_space or anon_vma or other */
     892: static inline void *page_rmapping(struct page *page)
     893: {
     894:     return (void *)((unsigned long)page->mapping & ~PAGE_MAPPING_FLAGS);
     895: }
     896: 
     897: extern struct address_space *__page_file_mapping(struct page *);
     898: 
     899: static inline
     900: struct address_space *page_file_mapping(struct page *page)
     901: {
     902:     if (unlikely(PageSwapCache(page)))
     903:         return __page_file_mapping(page);
     904: 
     905:     return page->mapping;
     906: }
     907: 
     908: static inline int PageAnon(struct page *page)
     909: {
     910:     return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
     911: }
     912: 
     913: /*
     914:  * Return the pagecache index of the passed page.  Regular pagecache pages
     915:  * use ->index whereas swapcache pages use ->private
     916:  */
     917: static inline pgoff_t page_index(struct page *page)
     918: {
     919:     if (unlikely(PageSwapCache(page)))
     920:         return page_private(page);
     921:     return page->index;
     922: }
     923: 
     924: extern pgoff_t __page_file_index(struct page *page);
     925: 
     926: /*
     927:  * Return the file index of the page. Regular pagecache pages use ->index
     928:  * whereas swapcache pages use swp_offset(->private)
     929:  */
     930: static inline pgoff_t page_file_index(struct page *page)
     931: {
     932:     if (unlikely(PageSwapCache(page)))
     933:         return __page_file_index(page);
     934: 
     935:     return page->index;
     936: }
     937: 
     938: /*
     939:  * Return true if this page is mapped into pagetables.
     940:  */
     941: static inline int page_mapped(struct page *page)
     942: {
     943:     return atomic_read(&(page)->_mapcount) >= 0;
     944: }
     945: 
     946: /*
     947:  * Different kinds of faults, as returned by handle_mm_fault().
     948:  * Used to decide whether a process gets delivered SIGBUS or
     949:  * just gets major/minor fault counters bumped up.
     950:  */
     951: 
     952: #define VM_FAULT_MINOR    0 /* For backwards compat. Remove me quickly. */
     953: 
     954: #define VM_FAULT_OOM    0x0001
     955: #define VM_FAULT_SIGBUS    0x0002
     956: #define VM_FAULT_MAJOR    0x0004
     957: #define VM_FAULT_WRITE    0x0008    /* Special case for get_user_pages */
     958: #define VM_FAULT_HWPOISON 0x0010    /* Hit poisoned small page */
     959: #define VM_FAULT_HWPOISON_LARGE 0x0020  /* Hit poisoned large page. Index encoded in upper bits */
     960: 
     961: #define VM_FAULT_NOPAGE    0x0100    /* ->fault installed the pte, not return page */
     962: #define VM_FAULT_LOCKED    0x0200    /* ->fault locked the returned page */
     963: #define VM_FAULT_RETRY    0x0400    /* ->fault blocked, must retry */
     964: #define VM_FAULT_FALLBACK 0x0800    /* huge page fault failed, fall back to small */
     965: 
     966: #define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */
     967: 
     968: #define VM_FAULT_ERROR    (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON | \
     969:              VM_FAULT_FALLBACK | VM_FAULT_HWPOISON_LARGE)
     970: 
     971: /* Encode hstate index for a hwpoisoned large page */
     972: #define VM_FAULT_SET_HINDEX(x) ((x) << 12)
     973: #define VM_FAULT_GET_HINDEX(x) (((x) >> 12) & 0xf)
     974: 
     975: /*
     976:  * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
     977:  */
     978: extern void pagefault_out_of_memory(void);
     979: 
     980: #define offset_in_page(p)    ((unsigned long)(p) & ~PAGE_MASK)
     981: 
     982: /*
     983:  * Flags passed to show_mem() and show_free_areas() to suppress output in
     984:  * various contexts.
     985:  */
     986: #define SHOW_MEM_FILTER_NODES        (0x0001u)    /* disallowed nodes */
     987: #define SHOW_MEM_FILTER_PAGE_COUNT    (0x0002u)    /* page type count */
     988: 
     989: extern void show_free_areas(unsigned int flags);
     990: extern bool skip_free_areas_node(unsigned int flags, int nid);
     991: 
     992: int shmem_zero_setup(struct vm_area_struct *);
     993: 
     994: extern int can_do_mlock(void);
     995: extern int user_shm_lock(size_t, struct user_struct *);
     996: extern void user_shm_unlock(size_t, struct user_struct *);
     997: 
     998: /*
     999:  * Parameter block passed down to zap_pte_range in exceptional cases.
    1000:  */
    1001: struct zap_details {
    1002:     struct vm_area_struct *nonlinear_vma;    /* Check page->index if set */
    1003:     struct address_space *check_mapping;    /* Check page->mapping if set */
    1004:     pgoff_t    first_index;            /* Lowest page->index to unmap */
    1005:     pgoff_t last_index;            /* Highest page->index to unmap */
    1006: };
    1007: 
    1008: struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
    1009:         pte_t pte);
    1010: 
    1011: int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
    1012:         unsigned long size);
    1013: void zap_page_range(struct vm_area_struct *vma, unsigned long address,
    1014:         unsigned long size, struct zap_details *);
    1015: void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
    1016:         unsigned long start, unsigned long end);
    1017: 
    1018: /**
    1019:  * mm_walk - callbacks for walk_page_range
    1020:  * @pgd_entry: if set, called for each non-empty PGD (top-level) entry
    1021:  * @pud_entry: if set, called for each non-empty PUD (2nd-level) entry
    1022:  * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry
    1023:  *           this handler is required to be able to handle
    1024:  *           pmd_trans_huge() pmds.  They may simply choose to
    1025:  *           split_huge_page() instead of handling it explicitly.
    1026:  * @pte_entry: if set, called for each non-empty PTE (4th-level) entry
    1027:  * @pte_hole: if set, called for each hole at all levels
    1028:  * @hugetlb_entry: if set, called for each hugetlb entry
    1029:  *           *Caution*: The caller must hold mmap_sem() if @hugetlb_entry
    1030:  *                   is used.
    1031:  *
    1032:  * (see walk_page_range for more details)
    1033:  */
    1034: struct mm_walk {
    1035:     int (*pgd_entry)(pgd_t *pgd, unsigned long addr,
    1036:              unsigned long next, struct mm_walk *walk);
    1037:     int (*pud_entry)(pud_t *pud, unsigned long addr,
    1038:                      unsigned long next, struct mm_walk *walk);
    1039:     int (*pmd_entry)(pmd_t *pmd, unsigned long addr,
    1040:              unsigned long next, struct mm_walk *walk);
    1041:     int (*pte_entry)(pte_t *pte, unsigned long addr,
    1042:              unsigned long next, struct mm_walk *walk);
    1043:     int (*pte_hole)(unsigned long addr, unsigned long next,
    1044:             struct mm_walk *walk);
    1045:     int (*hugetlb_entry)(pte_t *pte, unsigned long hmask,
    1046:                  unsigned long addr, unsigned long next,
    1047:                  struct mm_walk *walk);
    1048:     struct mm_struct *mm;
    1049:     void *private;
    1050: };
    1051: 
    1052: int walk_page_range(unsigned long addr, unsigned long end,
    1053:         struct mm_walk *walk);
    1054: void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
    1055:         unsigned long end, unsigned long floor, unsigned long ceiling);
    1056: int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
    1057:             struct vm_area_struct *vma);
    1058: void unmap_mapping_range(struct address_space *mapping,
    1059:         loff_t const holebegin, loff_t const holelen, int even_cows);
    1060: int follow_pfn(struct vm_area_struct *vma, unsigned long address,
    1061:     unsigned long *pfn);
    1062: int follow_phys(struct vm_area_struct *vma, unsigned long address,
    1063:         unsigned int flags, unsigned long *prot, resource_size_t *phys);
    1064: int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
    1065:             void *buf, int len, int write);
    1066: 
    1067: static inline void unmap_shared_mapping_range(struct address_space *mapping,
    1068:         loff_t const holebegin, loff_t const holelen)
    1069: {
    1070:     unmap_mapping_range(mapping, holebegin, holelen, 0);
    1071: }
    1072: 
    1073: extern void truncate_pagecache(struct inode *inode, loff_t new);
    1074: extern void truncate_setsize(struct inode *inode, loff_t newsize);
    1075: void truncate_pagecache_range(struct inode *inode, loff_t offset, loff_t end);
    1076: int truncate_inode_page(struct address_space *mapping, struct page *page);
    1077: int generic_error_remove_page(struct address_space *mapping, struct page *page);
    1078: int invalidate_inode_page(struct page *page);
    1079: 
    1080: #ifdef CONFIG_MMU
    1081: extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
    1082:             unsigned long address, unsigned int flags);
    1083: extern int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
    1084:                 unsigned long address, unsigned int fault_flags);
    1085: #else
    1086: static inline int handle_mm_fault(struct mm_struct *mm,
    1087:             struct vm_area_struct *vma, unsigned long address,
    1088:             unsigned int flags)
    1089: {
    1090:     /* should never happen if there's no MMU */
    1091:     BUG();
    1092:     return VM_FAULT_SIGBUS;
    1093: }
    1094: static inline int fixup_user_fault(struct task_struct *tsk,
    1095:         struct mm_struct *mm, unsigned long address,
    1096:         unsigned int fault_flags)
    1097: {
    1098:     /* should never happen if there's no MMU */
    1099:     BUG();
    1100:     return -EFAULT;
    1101: }
    1102: #endif
    1103: 
    1104: extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
    1105: extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,
    1106:         void *buf, int len, int write);
    1107: 
    1108: long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
    1109:               unsigned long start, unsigned long nr_pages,
    1110:               unsigned int foll_flags, struct page **pages,
    1111:               struct vm_area_struct **vmas, int *nonblocking);
    1112: long get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
    1113:             unsigned long start, unsigned long nr_pages,
    1114:             int write, int force, struct page **pages,
    1115:             struct vm_area_struct **vmas);
    1116: int get_user_pages_fast(unsigned long start, int nr_pages, int write,
    1117:             struct page **pages);
    1118: struct kvec;
    1119: int get_kernel_pages(const struct kvec *iov, int nr_pages, int write,
    1120:             struct page **pages);
    1121: int get_kernel_page(unsigned long start, int write, struct page **pages);
    1122: struct page *get_dump_page(unsigned long addr);
    1123: 
    1124: extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
    1125: extern void do_invalidatepage(struct page *page, unsigned int offset,
    1126:                   unsigned int length);
    1127: 
    1128: int __set_page_dirty_nobuffers(struct page *page);
    1129: int __set_page_dirty_no_writeback(struct page *page);
    1130: int redirty_page_for_writepage(struct writeback_control *wbc,
    1131:                 struct page *page);
    1132: void account_page_dirtied(struct page *page, struct address_space *mapping);
    1133: void account_page_writeback(struct page *page);
    1134: int set_page_dirty(struct page *page);
    1135: int set_page_dirty_lock(struct page *page);
    1136: int clear_page_dirty_for_io(struct page *page);
    1137: 
    1138: /* Is the vma a continuation of the stack vma above it? */
    1139: static inline int vma_growsdown(struct vm_area_struct *vma, unsigned long addr)
    1140: {
    1141:     return vma && (vma->vm_end == addr) && (vma->vm_flags & VM_GROWSDOWN);
    1142: }
    1143: 
    1144: static inline int stack_guard_page_start(struct vm_area_struct *vma,
    1145:                          unsigned long addr)
    1146: {
    1147:     return (vma->vm_flags & VM_GROWSDOWN) &&
    1148:         (vma->vm_start == addr) &&
    1149:         !vma_growsdown(vma->vm_prev, addr);
    1150: }
    1151: 
    1152: /* Is the vma a continuation of the stack vma below it? */
    1153: static inline int vma_growsup(struct vm_area_struct *vma, unsigned long addr)
    1154: {
    1155:     return vma && (vma->vm_start == addr) && (vma->vm_flags & VM_GROWSUP);
    1156: }
    1157: 
    1158: static inline int stack_guard_page_end(struct vm_area_struct *vma,
    1159:                        unsigned long addr)
    1160: {
    1161:     return (vma->vm_flags & VM_GROWSUP) &&
    1162:         (vma->vm_end == addr) &&
    1163:         !vma_growsup(vma->vm_next, addr);
    1164: }
    1165: 
    1166: extern pid_t
    1167: vm_is_stack(struct task_struct *task, struct vm_area_struct *vma, int in_group);
    1168: 
    1169: extern unsigned long move_page_tables(struct vm_area_struct *vma,
    1170:         unsigned long old_addr, struct vm_area_struct *new_vma,
    1171:         unsigned long new_addr, unsigned long len,
    1172:         bool need_rmap_locks);
    1173: extern unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
    1174:                   unsigned long end, pgprot_t newprot,
    1175:                   int dirty_accountable, int prot_numa);
    1176: extern int mprotect_fixup(struct vm_area_struct *vma,
    1177:               struct vm_area_struct **pprev, unsigned long start,
    1178:               unsigned long end, unsigned long newflags);
    1179: 
    1180: /*
    1181:  * doesn't attempt to fault and will return short.
    1182:  */
    1183: int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
    1184:               struct page **pages);
    1185: /*
    1186:  * per-process(per-mm_struct) statistics.
    1187:  */
    1188: static inline unsigned long get_mm_counter(struct mm_struct *mm, int member)
    1189: {
    1190:     long val = atomic_long_read(&mm->rss_stat.count[member]);
    1191: 
    1192: #ifdef SPLIT_RSS_COUNTING
    1193:     /*
    1194:      * counter is updated in asynchronous manner and may go to minus.
    1195:      * But it's never be expected number for users.
    1196:      */
    1197:     if (val < 0)
    1198:         val = 0;
    1199: #endif
    1200:     return (unsigned long)val;
    1201: }
    1202: 
    1203: static inline void add_mm_counter(struct mm_struct *mm, int member, long value)
    1204: {
    1205:     atomic_long_add(value, &mm->rss_stat.count[member]);
    1206: }
    1207: 
    1208: static inline void inc_mm_counter(struct mm_struct *mm, int member)
    1209: {
    1210:     atomic_long_inc(&mm->rss_stat.count[member]);
    1211: }
    1212: 
    1213: static inline void dec_mm_counter(struct mm_struct *mm, int member)
    1214: {
    1215:     atomic_long_dec(&mm->rss_stat.count[member]);
    1216: }
    1217: 
    1218: static inline unsigned long get_mm_rss(struct mm_struct *mm)
    1219: {
    1220:     return get_mm_counter(mm, MM_FILEPAGES) +
    1221:         get_mm_counter(mm, MM_ANONPAGES);
    1222: }
    1223: 
    1224: static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
    1225: {
    1226:     return max(mm->hiwater_rss, get_mm_rss(mm));
    1227: }
    1228: 
    1229: static inline unsigned long get_mm_hiwater_vm(struct mm_struct *mm)
    1230: {
    1231:     return max(mm->hiwater_vm, mm->total_vm);
    1232: }
    1233: 
    1234: static inline void update_hiwater_rss(struct mm_struct *mm)
    1235: {
    1236:     unsigned long _rss = get_mm_rss(mm);
    1237: 
    1238:     if ((mm)->hiwater_rss < _rss)
    1239:         (mm)->hiwater_rss = _rss;
    1240: }
    1241: 
    1242: static inline void update_hiwater_vm(struct mm_struct *mm)
    1243: {
    1244:     if (mm->hiwater_vm < mm->total_vm)
    1245:         mm->hiwater_vm = mm->total_vm;
    1246: }
    1247: 
    1248: static inline void setmax_mm_hiwater_rss(unsigned long *maxrss,
    1249:                      struct mm_struct *mm)
    1250: {
    1251:     unsigned long hiwater_rss = get_mm_hiwater_rss(mm);
    1252: 
    1253:     if (*maxrss < hiwater_rss)
    1254:         *maxrss = hiwater_rss;
    1255: }
    1256: 
    1257: #if defined(SPLIT_RSS_COUNTING)
    1258: void sync_mm_rss(struct mm_struct *mm);
    1259: #else
    1260: static inline void sync_mm_rss(struct mm_struct *mm)
    1261: {
    1262: }
    1263: #endif
    1264: 
    1265: int vma_wants_writenotify(struct vm_area_struct *vma);
    1266: 
    1267: extern pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
    1268:                    spinlock_t **ptl);
    1269: static inline pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
    1270:                     spinlock_t **ptl)
    1271: {
    1272:     pte_t *ptep;
    1273:     __cond_lock(*ptl, ptep = __get_locked_pte(mm, addr, ptl));
    1274:     return ptep;
    1275: }
    1276: 
    1277: #ifdef __PAGETABLE_PUD_FOLDED
    1278: static inline int __pud_alloc(struct mm_struct *mm, pgd_t *pgd,
    1279:                         unsigned long address)
    1280: {
    1281:     return 0;
    1282: }
    1283: #else
    1284: int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
    1285: #endif
    1286: 
    1287: #ifdef __PAGETABLE_PMD_FOLDED
    1288: static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
    1289:                         unsigned long address)
    1290: {
    1291:     return 0;
    1292: }
    1293: #else
    1294: int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
    1295: #endif
    1296: 
    1297: int __pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
    1298:         pmd_t *pmd, unsigned long address);
    1299: int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
    1300: 
    1301: /*
    1302:  * The following ifdef needed to get the 4level-fixup.h header to work.
    1303:  * Remove it when 4level-fixup.h has been removed.
    1304:  */
    1305: #if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
    1306: static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
    1307: {
    1308:     return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))?
    1309:         NULL: pud_offset(pgd, address);
    1310: }
    1311: 
    1312: static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
    1313: {
    1314:     return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
    1315:         NULL: pmd_offset(pud, address);
    1316: }
    1317: #endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
    1318: 
    1319: #if USE_SPLIT_PTE_PTLOCKS
    1320: #if ALLOC_SPLIT_PTLOCKS
    1321: extern bool ptlock_alloc(struct page *page);
    1322: extern void ptlock_free(struct page *page);
    1323: 
    1324: static inline spinlock_t *ptlock_ptr(struct page *page)
    1325: {
    1326:     return page->ptl;
    1327: }
    1328: #else /* ALLOC_SPLIT_PTLOCKS */
    1329: static inline bool ptlock_alloc(struct page *page)
    1330: {
    1331:     return true;
    1332: }
    1333: 
    1334: static inline void ptlock_free(struct page *page)
    1335: {
    1336: }
    1337: 
    1338: static inline spinlock_t *ptlock_ptr(struct page *page)
    1339: {
    1340:     return &page->ptl;
    1341: }
    1342: #endif /* ALLOC_SPLIT_PTLOCKS */
    1343: 
    1344: static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
    1345: {
    1346:     return ptlock_ptr(pmd_page(*pmd));
    1347: }
    1348: 
    1349: static inline bool ptlock_init(struct page *page)
    1350: {
    1351:     /*
    1352:      * prep_new_page() initialize page->private (and therefore page->ptl)
    1353:      * with 0. Make sure nobody took it in use in between.
    1354:      *
    1355:      * It can happen if arch try to use slab for page table allocation:
    1356:      * slab code uses page->slab_cache and page->first_page (for tail
    1357:      * pages), which share storage with page->ptl.
    1358:      */
    1359:     VM_BUG_ON(*(unsigned long *)&page->ptl);
    1360:     if (!ptlock_alloc(page))
    1361:         return false;
    1362:     spin_lock_init(ptlock_ptr(page));
    1363:     return true;
    1364: }
    1365: 
    1366: /* Reset page->mapping so free_pages_check won't complain. */
    1367: static inline void pte_lock_deinit(struct page *page)
    1368: {
    1369:     page->mapping = NULL;
    1370:     ptlock_free(page);
    1371: }
    1372: 
    1373: #else    /* !USE_SPLIT_PTE_PTLOCKS */
    1374: /*
    1375:  * We use mm->page_table_lock to guard all pagetable pages of the mm.
    1376:  */
    1377: static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
    1378: {
    1379:     return &mm->page_table_lock;
    1380: }
    1381: static inline bool ptlock_init(struct page *page) { return true; }
    1382: static inline void pte_lock_deinit(struct page *page) {}
    1383: #endif /* USE_SPLIT_PTE_PTLOCKS */
    1384: 
    1385: static inline bool pgtable_page_ctor(struct page *page)
    1386: {
    1387:     inc_zone_page_state(page, NR_PAGETABLE);
    1388:     return ptlock_init(page);
    1389: }
    1390: 
    1391: static inline void pgtable_page_dtor(struct page *page)
    1392: {
    1393:     pte_lock_deinit(page);
    1394:     dec_zone_page_state(page, NR_PAGETABLE);
    1395: }
    1396: 
    1397: #define pte_offset_map_lock(mm, pmd, address, ptlp)    \
    1398: ({                            \
    1399:     spinlock_t *__ptl = pte_lockptr(mm, pmd);    \
    1400:     pte_t *__pte = pte_offset_map(pmd, address);    \
    1401:     *(ptlp) = __ptl;                \
    1402:     spin_lock(__ptl);                \
    1403:     __pte;                        \
    1404: })
    1405: 
    1406: #define pte_unmap_unlock(pte, ptl)    do {        \
    1407:     spin_unlock(ptl);                \
    1408:     pte_unmap(pte);                    \
    1409: } while (0)
    1410: 
    1411: #define pte_alloc_map(mm, vma, pmd, address)                \
    1412:     ((unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, vma,    \
    1413:                             pmd, address))?    \
    1414:      NULL: pte_offset_map(pmd, address))
    1415: 
    1416: #define pte_alloc_map_lock(mm, pmd, address, ptlp)    \
    1417:     ((unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, NULL,    \
    1418:                             pmd, address))?    \
    1419:         NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
    1420: 
    1421: #define pte_alloc_kernel(pmd, address)            \
    1422:     ((unlikely(pmd_none(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
    1423:         NULL: pte_offset_kernel(pmd, address))
    1424: 
    1425: #if USE_SPLIT_PMD_PTLOCKS
    1426: 
    1427: static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
    1428: {
    1429:     return ptlock_ptr(virt_to_page(pmd));
    1430: }
    1431: 
    1432: static inline bool pgtable_pmd_page_ctor(struct page *page)
    1433: {
    1434: #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    1435:     page->pmd_huge_pte = NULL;
    1436: #endif
    1437:     return ptlock_init(page);
    1438: }
    1439: 
    1440: static inline void pgtable_pmd_page_dtor(struct page *page)
    1441: {
    1442: #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    1443:     VM_BUG_ON(page->pmd_huge_pte);
    1444: #endif
    1445:     ptlock_free(page);
    1446: }
    1447: 
    1448: #define pmd_huge_pte(mm, pmd) (virt_to_page(pmd)->pmd_huge_pte)
    1449: 
    1450: #else
    1451: 
    1452: static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
    1453: {
    1454:     return &mm->page_table_lock;
    1455: }
    1456: 
    1457: static inline bool pgtable_pmd_page_ctor(struct page *page) { return true; }
    1458: static inline void pgtable_pmd_page_dtor(struct page *page) {}
    1459: 
    1460: #define pmd_huge_pte(mm, pmd) ((mm)->pmd_huge_pte)
    1461: 
    1462: #endif
    1463: 
    1464: static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
    1465: {
    1466:     spinlock_t *ptl = pmd_lockptr(mm, pmd);
    1467:     spin_lock(ptl);
    1468:     return ptl;
    1469: }
    1470: 
    1471: extern void free_area_init(unsigned long * zones_size);
    1472: extern void free_area_init_node(int nid, unsigned long * zones_size,
    1473:         unsigned long zone_start_pfn, unsigned long *zholes_size);
    1474: extern void free_initmem(void);
    1475: 
    1476: /*
    1477:  * Free reserved pages within range [PAGE_ALIGN(start), end & PAGE_MASK)
    1478:  * into the buddy system. The freed pages will be poisoned with pattern
    1479:  * "poison" if it's within range [0, UCHAR_MAX].
    1480:  * Return pages freed into the buddy system.
    1481:  */
    1482: extern unsigned long free_reserved_area(void *start, void *end,
    1483:                     int poison, char *s);
    1484: 
    1485: #ifdef    CONFIG_HIGHMEM
    1486: /*
    1487:  * Free a highmem page into the buddy system, adjusting totalhigh_pages
    1488:  * and totalram_pages.
    1489:  */
    1490: extern void free_highmem_page(struct page *page);
    1491: #endif
    1492: 
    1493: extern void adjust_managed_page_count(struct page *page, long count);
    1494: extern void mem_init_print_info(const char *str);
    1495: 
    1496: /* Free the reserved page into the buddy system, so it gets managed. */
    1497: static inline void __free_reserved_page(struct page *page)
    1498: {
    1499:     ClearPageReserved(page);
    1500:     init_page_count(page);
    1501:     __free_page(page);
    1502: }
    1503: 
    1504: static inline void free_reserved_page(struct page *page)
    1505: {
    1506:     __free_reserved_page(page);
    1507:     adjust_managed_page_count(page, 1);
    1508: }
    1509: 
    1510: static inline void mark_page_reserved(struct page *page)
    1511: {
    1512:     SetPageReserved(page);
    1513:     adjust_managed_page_count(page, -1);
    1514: }
    1515: 
    1516: /*
    1517:  * Default method to free all the __init memory into the buddy system.
    1518:  * The freed pages will be poisoned with pattern "poison" if it's within
    1519:  * range [0, UCHAR_MAX].
    1520:  * Return pages freed into the buddy system.
    1521:  */
    1522: static inline unsigned long free_initmem_default(int poison)
    1523: {
    1524:     extern char __init_begin[], __init_end[];
    1525: 
    1526:     return free_reserved_area(&__init_begin, &__init_end,
    1527:                   poison, "unused kernel");
    1528: }
    1529: 
    1530: static inline unsigned long get_num_physpages(void)
    1531: {
    1532:     int nid;
    1533:     unsigned long phys_pages = 0;
    1534: 
    1535:     for_each_online_node(nid)
    1536:         phys_pages += node_present_pages(nid);
    1537: 
    1538:     return phys_pages;
    1539: }
    1540: 
    1541: #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
    1542: /*
    1543:  * With CONFIG_HAVE_MEMBLOCK_NODE_MAP set, an architecture may initialise its
    1544:  * zones, allocate the backing mem_map and account for memory holes in a more
    1545:  * architecture independent manner. This is a substitute for creating the
    1546:  * zone_sizes[] and zholes_size[] arrays and passing them to
    1547:  * free_area_init_node()
    1548:  *
    1549:  * An architecture is expected to register range of page frames backed by
    1550:  * physical memory with memblock_add[_node]() before calling
    1551:  * free_area_init_nodes() passing in the PFN each zone ends at. At a basic
    1552:  * usage, an architecture is expected to do something like
    1553:  *
    1554:  * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
    1555:  *                              max_highmem_pfn};
    1556:  * for_each_valid_physical_page_range()
    1557:  *     memblock_add_node(base, size, nid)
    1558:  * free_area_init_nodes(max_zone_pfns);
    1559:  *
    1560:  * free_bootmem_with_active_regions() calls free_bootmem_node() for each
    1561:  * registered physical page range.  Similarly
    1562:  * sparse_memory_present_with_active_regions() calls memory_present() for
    1563:  * each range when SPARSEMEM is enabled.
    1564:  *
    1565:  * See mm/page_alloc.c for more information on each function exposed by
    1566:  * CONFIG_HAVE_MEMBLOCK_NODE_MAP.
    1567:  */
    1568: extern void free_area_init_nodes(unsigned long *max_zone_pfn);
    1569: unsigned long node_map_pfn_alignment(void);
    1570: unsigned long __absent_pages_in_range(int nid, unsigned long start_pfn,
    1571:                         unsigned long end_pfn);
    1572: extern unsigned long absent_pages_in_range(unsigned long start_pfn,
    1573:                         unsigned long end_pfn);
    1574: extern void get_pfn_range_for_nid(unsigned int nid,
    1575:             unsigned long *start_pfn, unsigned long *end_pfn);
    1576: extern unsigned long find_min_pfn_with_active_regions(void);
    1577: extern void free_bootmem_with_active_regions(int nid,
    1578:                         unsigned long max_low_pfn);
    1579: extern void sparse_memory_present_with_active_regions(int nid);
    1580: 
    1581: #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
    1582: 
    1583: #if !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) && \
    1584:     !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID)
    1585: static inline int __early_pfn_to_nid(unsigned long pfn)
    1586: {
    1587:     return 0;
    1588: }
    1589: #else
    1590: /* please see mm/page_alloc.c */
    1591: extern int __meminit early_pfn_to_nid(unsigned long pfn);
    1592: #ifdef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
    1593: /* there is a per-arch backend function. */
    1594: extern int __meminit __early_pfn_to_nid(unsigned long pfn);
    1595: #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
    1596: #endif
    1597: 
    1598: extern void set_dma_reserve(unsigned long new_dma_reserve);
    1599: extern void memmap_init_zone(unsigned long, int, unsigned long,
    1600:                 unsigned long, enum memmap_context);
    1601: extern void setup_per_zone_wmarks(void);
    1602: extern int __meminit init_per_zone_wmark_min(void);
    1603: extern void mem_init(void);
    1604: extern void __init mmap_init(void);
    1605: extern void show_mem(unsigned int flags);
    1606: extern void si_meminfo(struct sysinfo * val);
    1607: extern void si_meminfo_node(struct sysinfo *val, int nid);
    1608: 
    1609: extern __printf(3, 4)
    1610: void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...);
    1611: 
    1612: extern void setup_per_cpu_pageset(void);
    1613: 
    1614: extern void zone_pcp_update(struct zone *zone);
    1615: extern void zone_pcp_reset(struct zone *zone);
    1616: 
    1617: /* page_alloc.c */
    1618: extern int min_free_kbytes;
    1619: 
    1620: /* nommu.c */
    1621: extern atomic_long_t mmap_pages_allocated;
    1622: extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
    1623: 
    1624: /* interval_tree.c */
    1625: void vma_interval_tree_insert(struct vm_area_struct *node,
    1626:                   struct rb_root *root);
    1627: void vma_interval_tree_insert_after(struct vm_area_struct *node,
    1628:                     struct vm_area_struct *prev,
    1629:                     struct rb_root *root);
    1630: void vma_interval_tree_remove(struct vm_area_struct *node,
    1631:                   struct rb_root *root);
    1632: struct vm_area_struct *vma_interval_tree_iter_first(struct rb_root *root,
    1633:                 unsigned long start, unsigned long last);
    1634: struct vm_area_struct *vma_interval_tree_iter_next(struct vm_area_struct *node,
    1635:                 unsigned long start, unsigned long last);
    1636: 
    1637: #define vma_interval_tree_foreach(vma, root, start, last)        \
    1638:     for (vma = vma_interval_tree_iter_first(root, start, last);    \
    1639:          vma; vma = vma_interval_tree_iter_next(vma, start, last))
    1640: 
    1641: static inline void vma_nonlinear_insert(struct vm_area_struct *vma,
    1642:                     struct list_head *list)
    1643: {
    1644:     list_add_tail(&vma->shared.nonlinear, list);
    1645: }
    1646: 
    1647: void anon_vma_interval_tree_insert(struct anon_vma_chain *node,
    1648:                    struct rb_root *root);
    1649: void anon_vma_interval_tree_remove(struct anon_vma_chain *node,
    1650:                    struct rb_root *root);
    1651: struct anon_vma_chain *anon_vma_interval_tree_iter_first(
    1652:     struct rb_root *root, unsigned long start, unsigned long last);
    1653: struct anon_vma_chain *anon_vma_interval_tree_iter_next(
    1654:     struct anon_vma_chain *node, unsigned long start, unsigned long last);
    1655: #ifdef CONFIG_DEBUG_VM_RB
    1656: void anon_vma_interval_tree_verify(struct anon_vma_chain *node);
    1657: #endif
    1658: 
    1659: #define anon_vma_interval_tree_foreach(avc, root, start, last)         \
    1660:     for (avc = anon_vma_interval_tree_iter_first(root, start, last); \
    1661:          avc; avc = anon_vma_interval_tree_iter_next(avc, start, last))
    1662: 
    1663: /* mmap.c */
    1664: extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
    1665: extern int vma_adjust(struct vm_area_struct *vma, unsigned long start,
    1666:     unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
    1667: extern struct vm_area_struct *vma_merge(struct mm_struct *,
    1668:     struct vm_area_struct *prev, unsigned long addr, unsigned long end,
    1669:     unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
    1670:     struct mempolicy *);
    1671: extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
    1672: extern int split_vma(struct mm_struct *,
    1673:     struct vm_area_struct *, unsigned long addr, int new_below);
    1674: extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
    1675: extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
    1676:     struct rb_node **, struct rb_node *);
    1677: extern void unlink_file_vma(struct vm_area_struct *);
    1678: extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
    1679:     unsigned long addr, unsigned long len, pgoff_t pgoff,
    1680:     bool *need_rmap_locks);
    1681: extern void exit_mmap(struct mm_struct *);
    1682: 
    1683: extern int mm_take_all_locks(struct mm_struct *mm);
    1684: extern void mm_drop_all_locks(struct mm_struct *mm);
    1685: 
    1686: extern void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
    1687: extern struct file *get_mm_exe_file(struct mm_struct *mm);
    1688: 
    1689: extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
    1690: extern int install_special_mapping(struct mm_struct *mm,
    1691:                    unsigned long addr, unsigned long len,
    1692:                    unsigned long flags, struct page **pages);
    1693: 
    1694: extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
    1695: 
    1696: extern unsigned long mmap_region(struct file *file, unsigned long addr,
    1697:     unsigned long len, vm_flags_t vm_flags, unsigned long pgoff);
    1698: extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
    1699:     unsigned long len, unsigned long prot, unsigned long flags,
    1700:     unsigned long pgoff, unsigned long *populate);
    1701: extern int do_munmap(struct mm_struct *, unsigned long, size_t);
    1702: 
    1703: #ifdef CONFIG_MMU
    1704: extern int __mm_populate(unsigned long addr, unsigned long len,
    1705:              int ignore_errors);
    1706: static inline void mm_populate(unsigned long addr, unsigned long len)
    1707: {
    1708:     /* Ignore errors */
    1709:     (void) __mm_populate(addr, len, 1);
    1710: }
    1711: #else
    1712: static inline void mm_populate(unsigned long addr, unsigned long len) {}
    1713: #endif
    1714: 
    1715: /* These take the mm semaphore themselves */
    1716: extern unsigned long vm_brk(unsigned long, unsigned long);
    1717: extern int vm_munmap(unsigned long, size_t);
    1718: extern unsigned long vm_mmap(struct file *, unsigned long,
    1719:         unsigned long, unsigned long,
    1720:         unsigned long, unsigned long);
    1721: 
    1722: struct vm_unmapped_area_info {
    1723: #define VM_UNMAPPED_AREA_TOPDOWN 1
    1724:     unsigned long flags;
    1725:     unsigned long length;
    1726:     unsigned long low_limit;
    1727:     unsigned long high_limit;
    1728:     unsigned long align_mask;
    1729:     unsigned long align_offset;
    1730: };
    1731: 
    1732: extern unsigned long unmapped_area(struct vm_unmapped_area_info *info);
    1733: extern unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info);
    1734: 
    1735: /*
    1736:  * Search for an unmapped address range.
    1737:  *
    1738:  * We are looking for a range that:
    1739:  * - does not intersect with any VMA;
    1740:  * - is contained within the [low_limit, high_limit) interval;
    1741:  * - is at least the desired size.
    1742:  * - satisfies (begin_addr & align_mask) == (align_offset & align_mask)
    1743:  */
    1744: static inline unsigned long
    1745: vm_unmapped_area(struct vm_unmapped_area_info *info)
    1746: {
    1747:     if (!(info->flags & VM_UNMAPPED_AREA_TOPDOWN))
    1748:         return unmapped_area(info);
    1749:     else
    1750:         return unmapped_area_topdown(info);
    1751: }
    1752: 
    1753: /* truncate.c */
    1754: extern void truncate_inode_pages(struct address_space *, loff_t);
    1755: extern void truncate_inode_pages_range(struct address_space *,
    1756:                        loff_t lstart, loff_t lend);
    1757: 
    1758: /* generic vm_area_ops exported for stackable file systems */
    1759: extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
    1760: extern int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
    1761: 
    1762: /* mm/page-writeback.c */
    1763: int write_one_page(struct page *page, int wait);
    1764: void task_dirty_inc(struct task_struct *tsk);
    1765: 
    1766: /* readahead.c */
    1767: #define VM_MAX_READAHEAD    128    /* kbytes */
    1768: #define VM_MIN_READAHEAD    16    /* kbytes (includes current page) */
    1769: 
    1770: int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
    1771:             pgoff_t offset, unsigned long nr_to_read);
    1772: 
    1773: void page_cache_sync_readahead(struct address_space *mapping,
    1774:                    struct file_ra_state *ra,
    1775:                    struct file *filp,
    1776:                    pgoff_t offset,
    1777:                    unsigned long size);
    1778: 
    1779: void page_cache_async_readahead(struct address_space *mapping,
    1780:                 struct file_ra_state *ra,
    1781:                 struct file *filp,
    1782:                 struct page *pg,
    1783:                 pgoff_t offset,
    1784:                 unsigned long size);
    1785: 
    1786: unsigned long max_sane_readahead(unsigned long nr);
    1787: unsigned long ra_submit(struct file_ra_state *ra,
    1788:             struct address_space *mapping,
    1789:             struct file *filp);
    1790: 
    1791: /* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */
    1792: extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
    1793: 
    1794: /* CONFIG_STACK_GROWSUP still needs to to grow downwards at some places */
    1795: extern int expand_downwards(struct vm_area_struct *vma,
    1796:         unsigned long address);
    1797: #if VM_GROWSUP
    1798: extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
    1799: #else
    1800:   #define expand_upwards(vma, address) do { } while (0)
    1801: #endif
    1802: 
    1803: /* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
    1804: extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
    1805: extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
    1806:                          struct vm_area_struct **pprev);
    1807: 
    1808: /* Look up the first VMA which intersects the interval start_addr..end_addr-1,
    1809:    NULL if none.  Assume start_addr < end_addr. */
    1810: static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
    1811: {
    1812:     struct vm_area_struct * vma = find_vma(mm,start_addr);
    1813: 
    1814:     if (vma && end_addr <= vma->vm_start)
    1815:         vma = NULL;
    1816:     return vma;
    1817: }
    1818: 
    1819: static inline unsigned long vma_pages(struct vm_area_struct *vma)
    1820: {
    1821:     return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
    1822: }
    1823: 
    1824: /* Look up the first VMA which exactly match the interval vm_start ... vm_end */
    1825: static inline struct vm_area_struct *find_exact_vma(struct mm_struct *mm,
    1826:                 unsigned long vm_start, unsigned long vm_end)
    1827: {
    1828:     struct vm_area_struct *vma = find_vma(mm, vm_start);
    1829: 
    1830:     if (vma && (vma->vm_start != vm_start || vma->vm_end != vm_end))
    1831:         vma = NULL;
    1832: 
    1833:     return vma;
    1834: }
    1835: 
    1836: #ifdef CONFIG_MMU
    1837: pgprot_t vm_get_page_prot(unsigned long vm_flags);
    1838: #else
    1839: static inline pgprot_t vm_get_page_prot(unsigned long vm_flags)
    1840: {
    1841:     return __pgprot(0);
    1842: }
    1843: #endif
    1844: 
    1845: #ifdef CONFIG_ARCH_USES_NUMA_PROT_NONE
    1846: unsigned long change_prot_numa(struct vm_area_struct *vma,
    1847:             unsigned long start, unsigned long end);
    1848: #endif
    1849: 
    1850: struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
    1851: int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
    1852:             unsigned long pfn, unsigned long size, pgprot_t);
    1853: int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
    1854: int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
    1855:             unsigned long pfn);
    1856: int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
    1857:             unsigned long pfn);
    1858: int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
    1859: 
    1860: 
    1861: struct page *follow_page_mask(struct vm_area_struct *vma,
    1862:                   unsigned long address, unsigned int foll_flags,
    1863:                   unsigned int *page_mask);
    1864: 
    1865: static inline struct page *follow_page(struct vm_area_struct *vma,
    1866:         unsigned long address, unsigned int foll_flags)
    1867: {
    1868:     unsigned int unused_page_mask;
    1869:     return follow_page_mask(vma, address, foll_flags, &unused_page_mask);
    1870: }
    1871: 
    1872: #define FOLL_WRITE    0x01    /* check pte is writable */
    1873: #define FOLL_TOUCH    0x02    /* mark page accessed */
    1874: #define FOLL_GET    0x04    /* do get_page on page */
    1875: #define FOLL_DUMP    0x08    /* give error on hole if it would be zero */
    1876: #define FOLL_FORCE    0x10    /* get_user_pages read/write w/o permission */
    1877: #define FOLL_NOWAIT    0x20    /* if a disk transfer is needed, start the IO
    1878:                  * and return without waiting upon it */
    1879: #define FOLL_MLOCK    0x40    /* mark page as mlocked */
    1880: #define FOLL_SPLIT    0x80    /* don't return transhuge pages, split them */
    1881: #define FOLL_HWPOISON    0x100    /* check page is hwpoisoned */
    1882: #define FOLL_NUMA    0x200    /* force NUMA hinting page fault */
    1883: #define FOLL_MIGRATION    0x400    /* wait for page to replace migration entry */
    1884: 
    1885: typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
    1886:             void *data);
    1887: extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
    1888:                    unsigned long size, pte_fn_t fn, void *data);
    1889: 
    1890: #ifdef CONFIG_PROC_FS
    1891: void vm_stat_account(struct mm_struct *, unsigned long, struct file *, long);
    1892: #else
    1893: static inline void vm_stat_account(struct mm_struct *mm,
    1894:             unsigned long flags, struct file *file, long pages)
    1895: {
    1896:     mm->total_vm += pages;
    1897: }
    1898: #endif /* CONFIG_PROC_FS */
    1899: 
    1900: #ifdef CONFIG_DEBUG_PAGEALLOC
    1901: extern void kernel_map_pages(struct page *page, int numpages, int enable);
    1902: #ifdef CONFIG_HIBERNATION
    1903: extern bool kernel_page_present(struct page *page);
    1904: #endif /* CONFIG_HIBERNATION */
    1905: #else
    1906: static inline void
    1907: kernel_map_pages(struct page *page, int numpages, int enable) {}
    1908: #ifdef CONFIG_HIBERNATION
    1909: static inline bool kernel_page_present(struct page *page) { return true; }
    1910: #endif /* CONFIG_HIBERNATION */
    1911: #endif
    1912: 
    1913: extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm);
    1914: #ifdef    __HAVE_ARCH_GATE_AREA
    1915: int in_gate_area_no_mm(unsigned long addr);
    1916: int in_gate_area(struct mm_struct *mm, unsigned long addr);
    1917: #else
    1918: int in_gate_area_no_mm(unsigned long addr);
    1919: #define in_gate_area(mm, addr) ({(void)mm; in_gate_area_no_mm(addr);})
    1920: #endif    /* __HAVE_ARCH_GATE_AREA */
    1921: 
    1922: #ifdef CONFIG_SYSCTL
    1923: extern int sysctl_drop_caches;
    1924: int drop_caches_sysctl_handler(struct ctl_table *, int,
    1925:                     void __user *, size_t *, loff_t *);
    1926: #endif
    1927: 
    1928: unsigned long shrink_slab(struct shrink_control *shrink,
    1929:               unsigned long nr_pages_scanned,
    1930:               unsigned long lru_pages);
    1931: 
    1932: #ifndef CONFIG_MMU
    1933: #define randomize_va_space 0
    1934: #else
    1935: extern int randomize_va_space;
    1936: #endif
    1937: 
    1938: const char * arch_vma_name(struct vm_area_struct *vma);
    1939: void print_vma_addr(char *prefix, unsigned long rip);
    1940: 
    1941: void sparse_mem_maps_populate_node(struct page **map_map,
    1942:                    unsigned long pnum_begin,
    1943:                    unsigned long pnum_end,
    1944:                    unsigned long map_count,
    1945:                    int nodeid);
    1946: 
    1947: struct page *sparse_mem_map_populate(unsigned long pnum, int nid);
    1948: pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
    1949: pud_t *vmemmap_pud_populate(pgd_t *pgd, unsigned long addr, int node);
    1950: pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
    1951: pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node);
    1952: void *vmemmap_alloc_block(unsigned long size, int node);
    1953: void *vmemmap_alloc_block_buf(unsigned long size, int node);
    1954: void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
    1955: int vmemmap_populate_basepages(unsigned long start, unsigned long end,
    1956:                    int node);
    1957: int vmemmap_populate(unsigned long start, unsigned long end, int node);
    1958: void vmemmap_populate_print_last(void);
    1959: #ifdef CONFIG_MEMORY_HOTPLUG
    1960: void vmemmap_free(unsigned long start, unsigned long end);
    1961: #endif
    1962: void register_page_bootmem_memmap(unsigned long section_nr, struct page *map,
    1963:                   unsigned long size);
    1964: 
    1965: enum mf_flags {
    1966:     MF_COUNT_INCREASED = 1 << 0,
    1967:     MF_ACTION_REQUIRED = 1 << 1,
    1968:     MF_MUST_KILL = 1 << 2,
    1969:     MF_SOFT_OFFLINE = 1 << 3,
    1970: };
    1971: extern int memory_failure(unsigned long pfn, int trapno, int flags);
    1972: extern void memory_failure_queue(unsigned long pfn, int trapno, int flags);
    1973: extern int unpoison_memory(unsigned long pfn);
    1974: extern int sysctl_memory_failure_early_kill;
    1975: extern int sysctl_memory_failure_recovery;
    1976: extern void shake_page(struct page *p, int access);
    1977: extern atomic_long_t num_poisoned_pages;
    1978: extern int soft_offline_page(struct page *page, int flags);
    1979: 
    1980: extern void dump_page(struct page *page);
    1981: 
    1982: #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
    1983: extern void clear_huge_page(struct page *page,
    1984:                 unsigned long addr,
    1985:                 unsigned int pages_per_huge_page);
    1986: extern void copy_user_huge_page(struct page *dst, struct page *src,
    1987:                 unsigned long addr, struct vm_area_struct *vma,
    1988:                 unsigned int pages_per_huge_page);
    1989: #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
    1990: 
    1991: #ifdef CONFIG_DEBUG_PAGEALLOC
    1992: extern unsigned int _debug_guardpage_minorder;
    1993: 
    1994: static inline unsigned int debug_guardpage_minorder(void)
    1995: {
    1996:     return _debug_guardpage_minorder;
    1997: }
    1998: 
    1999: static inline bool page_is_guard(struct page *page)
    2000: {
    2001:     return test_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
    2002: }
    2003: #else
    2004: static inline unsigned int debug_guardpage_minorder(void) { return 0; }
    2005: static inline bool page_is_guard(struct page *page) { return false; }
    2006: #endif /* CONFIG_DEBUG_PAGEALLOC */
    2007: 
    2008: #if MAX_NUMNODES > 1
    2009: void __init setup_nr_node_ids(void);
    2010: #else
    2011: static inline void setup_nr_node_ids(void) {}
    2012: #endif
    2013: 
    2014: #endif /* __KERNEL__ */
    2015: #endif /* _LINUX_MM_H */
    2016: