4 #include <linux/sched.h>
5 #include <linux/errno.h>
9 #include <linux/config.h>
10 #include <linux/gfp.h>
11 #include <linux/list.h>
12 #include <linux/mmzone.h>
13 #include <linux/rbtree.h>
14 #include <linux/prio_tree.h>
20 #ifndef CONFIG_DISCONTIGMEM /* Don't use mapnrs, do it properly */
21 extern unsigned long max_mapnr;
24 extern unsigned long num_physpages;
25 extern void * high_memory;
26 extern unsigned long vmalloc_earlyreserve;
27 extern int page_cluster;
29 extern int sysctl_legacy_va_layout;
32 #include <asm/pgtable.h>
33 #include <asm/processor.h>
34 #include <asm/atomic.h>
37 #define MM_VM_SIZE(mm) TASK_SIZE
41 * Linux kernel virtual memory manager primitives.
42 * The idea being to have a "virtual" mm in the same way
43 * we have a virtual fs - giving a cleaner interface to the
44 * mm details, and allowing different kinds of memory mappings
45 * (from shared memory to executable loading to arbitrary
50 * This struct defines a memory VMM memory area. There is one of these
51 * per VM-area/task. A VM area is any part of the process virtual memory
52 * space that has a special rule for the page-fault handlers (ie a shared
53 * library, the executable area etc).
55 struct vm_area_struct {
56 struct mm_struct * vm_mm; /* The address space we belong to. */
57 unsigned long vm_start; /* Our start address within vm_mm. */
58 unsigned long vm_end; /* The first byte after our end address
61 /* linked list of VM areas per task, sorted by address */
62 struct vm_area_struct *vm_next;
64 pgprot_t vm_page_prot; /* Access permissions of this VMA. */
65 unsigned long vm_flags; /* Flags, listed below. */
70 * For areas with an address space and backing store,
71 * linkage into the address_space->i_mmap prio tree, or
72 * linkage to the list of like vmas hanging off its node, or
73 * linkage of vma in the address_space->i_mmap_nonlinear list.
77 struct list_head list;
78 void *parent; /* aligns with prio_tree_node parent */
79 struct vm_area_struct *head;
82 struct prio_tree_node prio_tree_node;
86 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
87 * list, after a COW of one of the file pages. A MAP_SHARED vma
88 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
89 * or brk vma (with NULL file) can only be in an anon_vma list.
91 struct list_head anon_vma_node; /* Serialized by anon_vma->lock */
92 struct anon_vma *anon_vma; /* Serialized by page_table_lock */
94 /* Function pointers to deal with this struct. */
95 struct vm_operations_struct * vm_ops;
97 /* Information about our backing store: */
98 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
99 units, *not* PAGE_CACHE_SIZE */
100 struct file * vm_file; /* File we map to (can be NULL). */
101 void * vm_private_data; /* was vm_pte (shared mem) */
104 struct mempolicy *vm_policy; /* NUMA policy for the VMA */
111 #define VM_READ 0x00000001 /* currently active flags */
112 #define VM_WRITE 0x00000002
113 #define VM_EXEC 0x00000004
114 #define VM_SHARED 0x00000008
116 #define VM_MAYREAD 0x00000010 /* limits for mprotect() etc */
117 #define VM_MAYWRITE 0x00000020
118 #define VM_MAYEXEC 0x00000040
119 #define VM_MAYSHARE 0x00000080
121 #define VM_GROWSDOWN 0x00000100 /* general info on the segment */
122 #define VM_GROWSUP 0x00000200
123 #define VM_SHM 0x00000400 /* shared memory area, don't swap out */
124 #define VM_DENYWRITE 0x00000800 /* ETXTBSY on write attempts.. */
126 #define VM_EXECUTABLE 0x00001000
127 #define VM_LOCKED 0x00002000
128 #define VM_IO 0x00004000 /* Memory mapped I/O or similar */
130 /* Used by sys_madvise() */
131 #define VM_SEQ_READ 0x00008000 /* App will access data sequentially */
132 #define VM_RAND_READ 0x00010000 /* App will not benefit from clustered reads */
134 #define VM_DONTCOPY 0x00020000 /* Do not copy this vma on fork */
135 #define VM_DONTEXPAND 0x00040000 /* Cannot expand with mremap() */
136 #define VM_RESERVED 0x00080000 /* Don't unmap it from swap_out */
137 #define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */
138 #define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
139 #define VM_NONLINEAR 0x00800000 /* Is non-linear (remap_file_pages) */
141 #ifndef VM_STACK_DEFAULT_FLAGS /* arch can override this */
142 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
145 #ifdef CONFIG_STACK_GROWSUP
146 #define VM_STACK_FLAGS (VM_GROWSUP | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
148 #define VM_STACK_FLAGS (VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
151 #define VM_READHINTMASK (VM_SEQ_READ | VM_RAND_READ)
152 #define VM_ClearReadHint(v) (v)->vm_flags &= ~VM_READHINTMASK
153 #define VM_NormalReadHint(v) (!((v)->vm_flags & VM_READHINTMASK))
154 #define VM_SequentialReadHint(v) ((v)->vm_flags & VM_SEQ_READ)
155 #define VM_RandomReadHint(v) ((v)->vm_flags & VM_RAND_READ)
158 * mapping from the currently active vm_flags protection bits (the
159 * low four bits) to a page protection mask..
161 extern pgprot_t protection_map[16];
165 * These are the virtual MM functions - opening of an area, closing and
166 * unmapping it (needed to keep files on disk up-to-date etc), pointer
167 * to the functions called when a no-page or a wp-page exception occurs.
169 struct vm_operations_struct {
170 void (*open)(struct vm_area_struct * area);
171 void (*close)(struct vm_area_struct * area);
172 struct page * (*nopage)(struct vm_area_struct * area, unsigned long address, int *type);
173 int (*populate)(struct vm_area_struct * area, unsigned long address, unsigned long len, pgprot_t prot, unsigned long pgoff, int nonblock);
175 int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
176 struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
184 #ifdef ARCH_HAS_ATOMIC_UNSIGNED
185 typedef unsigned page_flags_t;
187 typedef unsigned long page_flags_t;
191 * Each physical page in the system has a struct page associated with
192 * it to keep track of whatever it is we are using the page for at the
193 * moment. Note that we have no way to track which tasks are using
197 page_flags_t flags; /* Atomic flags, some possibly
198 * updated asynchronously */
199 atomic_t _count; /* Usage count, see below. */
200 unsigned int mapcount; /* Count of ptes mapped in mms,
201 * to show when page is mapped
202 * & limit reverse map searches,
203 * protected by PG_maplock.
205 unsigned long private; /* Mapping-private opaque data:
206 * usually used for buffer_heads
207 * if PagePrivate set; used for
208 * swp_entry_t if PageSwapCache
210 struct address_space *mapping; /* If PG_anon clear, points to
211 * inode address_space, or NULL.
212 * If page mapped as anonymous
213 * memory, PG_anon is set, and
214 * it points to anon_vma object.
216 pgoff_t index; /* Our offset within mapping. */
217 struct list_head lru; /* Pageout list, eg. active_list
218 * protected by zone->lru_lock !
221 * On machines where all RAM is mapped into kernel address space,
222 * we can simply calculate the virtual address. On machines with
223 * highmem some memory is mapped into kernel virtual memory
224 * dynamically, so we need a place to store that address.
225 * Note that this field could be 16 bits on x86 ... ;)
227 * Architectures with slow multiplication can define
228 * WANT_PAGE_VIRTUAL in asm/page.h
230 #if defined(WANT_PAGE_VIRTUAL)
231 void *virtual; /* Kernel virtual address (NULL if
232 not kmapped, ie. highmem) */
233 #endif /* WANT_PAGE_VIRTUAL */
237 * FIXME: take this include out, include page-flags.h in
238 * files which need it (119 of them)
240 #include <linux/page-flags.h>
243 * Methods to modify the page usage count.
245 * What counts for a page usage:
246 * - cache mapping (page->mapping)
247 * - private data (page->private)
248 * - page mapped in a task's page tables, each mapping
249 * is counted separately
251 * Also, many kernel routines increase the page count before a critical
252 * routine so they can be sure the page doesn't go away from under them.
254 * Since 2.6.6 (approx), a free page has ->_count = -1. This is so that we
255 * can use atomic_add_negative(-1, page->_count) to detect when the page
256 * becomes free and so that we can also use atomic_inc_and_test to atomically
257 * detect when we just tried to grab a ref on a page which some other CPU has
258 * already deemed to be freeable.
260 * NO code should make assumptions about this internal detail! Use the provided
261 * macros which retain the old rules: page_count(page) == 0 is a free page.
265 * Drop a ref, return true if the logical refcount fell to zero (the page has
268 #define put_page_testzero(p) \
270 BUG_ON(page_count(p) == 0); \
271 atomic_add_negative(-1, &(p)->_count); \
275 * Grab a ref, return true if the page previously had a logical refcount of
276 * zero. ie: returns true if we just grabbed an already-deemed-to-be-free page
278 #define get_page_testone(p) atomic_inc_and_test(&(p)->_count)
280 #define set_page_count(p,v) atomic_set(&(p)->_count, v - 1)
281 #define __put_page(p) atomic_dec(&(p)->_count)
283 extern void FASTCALL(__page_cache_release(struct page *));
285 #ifdef CONFIG_HUGETLB_PAGE
287 static inline int page_count(struct page *p)
290 p = (struct page *)p->private;
291 return atomic_read(&(p)->_count) + 1;
294 static inline void get_page(struct page *page)
296 if (unlikely(PageCompound(page)))
297 page = (struct page *)page->private;
298 atomic_inc(&page->_count);
301 void put_page(struct page *page);
303 #else /* CONFIG_HUGETLB_PAGE */
305 #define page_count(p) (atomic_read(&(p)->_count) + 1)
307 static inline void get_page(struct page *page)
309 atomic_inc(&page->_count);
312 static inline void put_page(struct page *page)
314 if (!PageReserved(page) && put_page_testzero(page))
315 __page_cache_release(page);
318 #endif /* CONFIG_HUGETLB_PAGE */
321 * Multiple processes may "see" the same page. E.g. for untouched
322 * mappings of /dev/null, all processes see the same page full of
323 * zeroes, and text pages of executables and shared libraries have
324 * only one copy in memory, at most, normally.
326 * For the non-reserved pages, page_count(page) denotes a reference count.
327 * page_count() == 0 means the page is free.
328 * page_count() == 1 means the page is used for exactly one purpose
329 * (e.g. a private data page of one process).
331 * A page may be used for kmalloc() or anyone else who does a
332 * __get_free_page(). In this case the page_count() is at least 1, and
333 * all other fields are unused but should be 0 or NULL. The
334 * management of this page is the responsibility of the one who uses
337 * The other pages (we may call them "process pages") are completely
338 * managed by the Linux memory manager: I/O, buffers, swapping etc.
339 * The following discussion applies only to them.
341 * A page may belong to an inode's memory mapping. In this case,
342 * page->mapping is the pointer to the inode, and page->index is the
343 * file offset of the page, in units of PAGE_CACHE_SIZE.
345 * A page contains an opaque `private' member, which belongs to the
346 * page's address_space. Usually, this is the address of a circular
347 * list of the page's disk buffers.
349 * For pages belonging to inodes, the page_count() is the number of
350 * attaches, plus 1 if `private' contains something, plus one for
351 * the page cache itself.
353 * All pages belonging to an inode are in these doubly linked lists:
354 * mapping->clean_pages, mapping->dirty_pages and mapping->locked_pages;
355 * using the page->list list_head. These fields are also used for
356 * freelist managemet (when page_count()==0).
358 * There is also a per-mapping radix tree mapping index to the page
359 * in memory if present. The tree is rooted at mapping->root.
361 * All process pages can do I/O:
362 * - inode pages may need to be read from disk,
363 * - inode pages which have been modified and are MAP_SHARED may need
364 * to be written to disk,
365 * - private pages which have been modified may need to be swapped out
366 * to swap space and (later) to be read back into memory.
370 * The zone field is never updated after free_area_init_core()
371 * sets it, so none of the operations on it need to be atomic.
372 * We'll have up to (MAX_NUMNODES * MAX_NR_ZONES) zones total,
373 * so we use (MAX_NODES_SHIFT + MAX_ZONES_SHIFT) here to get enough bits.
375 #define NODEZONE_SHIFT (sizeof(page_flags_t)*8 - MAX_NODES_SHIFT - MAX_ZONES_SHIFT)
376 #define NODEZONE(node, zone) ((node << ZONES_SHIFT) | zone)
378 static inline unsigned long page_zonenum(struct page *page)
380 return (page->flags >> NODEZONE_SHIFT) & (~(~0UL << ZONES_SHIFT));
382 static inline unsigned long page_to_nid(struct page *page)
384 return (page->flags >> (NODEZONE_SHIFT + ZONES_SHIFT));
388 extern struct zone *zone_table[];
390 static inline struct zone *page_zone(struct page *page)
392 return zone_table[page->flags >> NODEZONE_SHIFT];
395 static inline void set_page_zone(struct page *page, unsigned long nodezone_num)
397 page->flags &= ~(~0UL << NODEZONE_SHIFT);
398 page->flags |= nodezone_num << NODEZONE_SHIFT;
401 #ifndef CONFIG_DISCONTIGMEM
402 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
403 extern struct page *mem_map;
406 static inline void *lowmem_page_address(struct page *page)
408 return __va(page_to_pfn(page) << PAGE_SHIFT);
411 #if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
412 #define HASHED_PAGE_VIRTUAL
415 #if defined(WANT_PAGE_VIRTUAL)
416 #define page_address(page) ((page)->virtual)
417 #define set_page_address(page, address) \
419 (page)->virtual = (address); \
421 #define page_address_init() do { } while(0)
424 #if defined(HASHED_PAGE_VIRTUAL)
425 void *page_address(struct page *page);
426 void set_page_address(struct page *page, void *virtual);
427 void page_address_init(void);
430 #if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
431 #define page_address(page) lowmem_page_address(page)
432 #define set_page_address(page, address) do { } while(0)
433 #define page_address_init() do { } while(0)
437 * On an anonymous page mapped into a user virtual memory area,
438 * page->mapping points to its anon_vma, not to a struct address_space.
440 * Please note that, confusingly, "page_mapping" refers to the inode
441 * address_space which maps the page from disk; whereas "page_mapped"
442 * refers to user virtual address space into which the page is mapped.
444 extern struct address_space swapper_space;
445 static inline struct address_space *page_mapping(struct page *page)
447 struct address_space *mapping = NULL;
449 if (unlikely(PageSwapCache(page)))
450 mapping = &swapper_space;
451 else if (likely(!PageAnon(page)))
452 mapping = page->mapping;
457 * Return the pagecache index of the passed page. Regular pagecache pages
458 * use ->index whereas swapcache pages use ->private
460 static inline pgoff_t page_index(struct page *page)
462 if (unlikely(PageSwapCache(page)))
463 return page->private;
468 * Return true if this page is mapped into pagetables.
470 static inline int page_mapped(struct page *page)
472 return page->mapcount != 0;
476 * Error return values for the *_nopage functions
478 #define NOPAGE_SIGBUS (NULL)
479 #define NOPAGE_OOM ((struct page *) (-1))
482 * Different kinds of faults, as returned by handle_mm_fault().
483 * Used to decide whether a process gets delivered SIGBUS or
484 * just gets major/minor fault counters bumped up.
486 #define VM_FAULT_OOM (-1)
487 #define VM_FAULT_SIGBUS 0
488 #define VM_FAULT_MINOR 1
489 #define VM_FAULT_MAJOR 2
491 #define offset_in_page(p) ((unsigned long)(p) & ~PAGE_MASK)
493 extern void show_free_areas(void);
495 struct page *shmem_nopage(struct vm_area_struct * vma,
496 unsigned long address, int *type);
497 int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *new);
498 struct mempolicy *shmem_get_policy(struct vm_area_struct *vma,
500 struct file *shmem_file_setup(char * name, loff_t size, unsigned long flags);
501 int shmem_lock(struct file *file, int lock, struct user_struct *user);
502 int shmem_zero_setup(struct vm_area_struct *);
504 static inline int can_do_mlock(void)
506 if (capable(CAP_IPC_LOCK))
508 if (current->rlim[RLIMIT_MEMLOCK].rlim_cur != 0)
512 extern int user_shm_lock(size_t, struct user_struct *);
513 extern void user_shm_unlock(size_t, struct user_struct *);
516 * Parameter block passed down to zap_pte_range in exceptional cases.
519 struct vm_area_struct *nonlinear_vma; /* Check page->index if set */
520 struct address_space *check_mapping; /* Check page->mapping if set */
521 pgoff_t first_index; /* Lowest page->index to unmap */
522 pgoff_t last_index; /* Highest page->index to unmap */
523 int atomic; /* May not schedule() */
526 void zap_page_range(struct vm_area_struct *vma, unsigned long address,
527 unsigned long size, struct zap_details *);
528 int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,
529 struct vm_area_struct *start_vma, unsigned long start_addr,
530 unsigned long end_addr, unsigned long *nr_accounted,
531 struct zap_details *);
532 void clear_page_tables(struct mmu_gather *tlb, unsigned long first, int nr);
533 int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
534 struct vm_area_struct *vma);
535 int zeromap_page_range(struct vm_area_struct *vma, unsigned long from,
536 unsigned long size, pgprot_t prot);
537 void unmap_mapping_range(struct address_space *mapping,
538 loff_t const holebegin, loff_t const holelen, int even_cows);
540 static inline void unmap_shared_mapping_range(struct address_space *mapping,
541 loff_t const holebegin, loff_t const holelen)
543 unmap_mapping_range(mapping, holebegin, holelen, 0);
546 extern int vmtruncate(struct inode * inode, loff_t offset);
547 extern pmd_t *FASTCALL(__pmd_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address));
548 extern pte_t *FASTCALL(pte_alloc_kernel(struct mm_struct *mm, pmd_t *pmd, unsigned long address));
549 extern pte_t *FASTCALL(pte_alloc_map(struct mm_struct *mm, pmd_t *pmd, unsigned long address));
550 extern int install_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, struct page *page, pgprot_t prot);
551 extern int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, unsigned long pgoff, pgprot_t prot);
552 extern int handle_mm_fault(struct mm_struct *mm,struct vm_area_struct *vma, unsigned long address, int write_access);
553 extern int make_pages_present(unsigned long addr, unsigned long end);
554 extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
555 void install_arg_page(struct vm_area_struct *, struct page *, unsigned long);
557 int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start,
558 int len, int write, int force, struct page **pages, struct vm_area_struct **vmas);
560 int __set_page_dirty_buffers(struct page *page);
561 int __set_page_dirty_nobuffers(struct page *page);
562 int redirty_page_for_writepage(struct writeback_control *wbc,
564 int FASTCALL(set_page_dirty(struct page *page));
565 int set_page_dirty_lock(struct page *page);
566 int clear_page_dirty_for_io(struct page *page);
569 * Prototype to add a shrinker callback for ageable caches.
571 * These functions are passed a count `nr_to_scan' and a gfpmask. They should
572 * scan `nr_to_scan' objects, attempting to free them.
574 * The callback must the number of objects which remain in the cache.
576 * The callback will be passes nr_to_scan == 0 when the VM is querying the
577 * cache size, so a fastpath for that case is appropriate.
579 typedef int (*shrinker_t)(int nr_to_scan, unsigned int gfp_mask);
581 extern long do_mprotect(struct mm_struct *mm, unsigned long start,
582 size_t len, unsigned long prot);
585 * Add an aging callback. The int is the number of 'seeks' it takes
586 * to recreate one of the objects that these functions age.
589 #define DEFAULT_SEEKS 2
591 extern struct shrinker *set_shrinker(int, shrinker_t);
592 extern void remove_shrinker(struct shrinker *shrinker);
595 * On a two-level page table, this ends up being trivial. Thus the
596 * inlining and the symmetry break with pte_alloc_map() that does all
597 * of this out-of-line.
599 static inline pmd_t *pmd_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
602 return __pmd_alloc(mm, pgd, address);
603 return pmd_offset(pgd, address);
606 extern void free_area_init(unsigned long * zones_size);
607 extern void free_area_init_node(int nid, pg_data_t *pgdat, struct page *pmap,
608 unsigned long * zones_size, unsigned long zone_start_pfn,
609 unsigned long *zholes_size);
610 extern void memmap_init_zone(struct page *, unsigned long, int,
611 unsigned long, unsigned long);
612 extern void mem_init(void);
613 extern void show_mem(void);
614 extern void si_meminfo(struct sysinfo * val);
615 extern void si_meminfo_node(struct sysinfo *val, int nid);
617 static inline void vma_prio_tree_init(struct vm_area_struct *vma)
619 vma->shared.vm_set.list.next = NULL;
620 vma->shared.vm_set.list.prev = NULL;
621 vma->shared.vm_set.parent = NULL;
622 vma->shared.vm_set.head = NULL;
626 void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old);
627 void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *);
628 void vma_prio_tree_remove(struct vm_area_struct *, struct prio_tree_root *);
629 struct vm_area_struct *vma_prio_tree_next(
630 struct vm_area_struct *, struct prio_tree_root *,
631 struct prio_tree_iter *, pgoff_t begin, pgoff_t end);
634 extern void vma_adjust(struct vm_area_struct *vma, unsigned long start,
635 unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
636 extern struct vm_area_struct *vma_merge(struct mm_struct *,
637 struct vm_area_struct *prev, unsigned long addr, unsigned long end,
638 unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
640 extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
641 extern int split_vma(struct mm_struct *,
642 struct vm_area_struct *, unsigned long addr, int new_below);
643 extern void insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
644 extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
645 struct rb_node **, struct rb_node *);
646 extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
647 unsigned long addr, unsigned long len, pgoff_t pgoff);
648 extern void exit_mmap(struct mm_struct *);
650 extern unsigned long get_unmapped_area_prot(struct file *, unsigned long, unsigned long, unsigned long, unsigned long, int);
653 static inline unsigned long get_unmapped_area(struct file * file, unsigned long addr,
654 unsigned long len, unsigned long pgoff, unsigned long flags)
656 return get_unmapped_area_prot(file, addr, len, pgoff, flags, 0);
659 extern unsigned long do_mmap_pgoff(struct mm_struct *mm, struct file *file,
660 unsigned long addr, unsigned long len,
661 unsigned long prot, unsigned long flag,
662 unsigned long pgoff);
664 static inline unsigned long do_mmap(struct file *file, unsigned long addr,
665 unsigned long len, unsigned long prot,
666 unsigned long flag, unsigned long offset)
668 unsigned long ret = -EINVAL;
669 if ((offset + PAGE_ALIGN(len)) < offset)
671 if (!(offset & ~PAGE_MASK))
672 ret = do_mmap_pgoff(current->mm, file, addr, len, prot, flag,
673 offset >> PAGE_SHIFT);
678 extern int do_munmap(struct mm_struct *, unsigned long, size_t);
680 extern unsigned long do_brk(unsigned long, unsigned long);
683 extern unsigned long page_unuse(struct page *);
684 extern void truncate_inode_pages(struct address_space *, loff_t);
686 /* generic vm_area_ops exported for stackable file systems */
687 struct page *filemap_nopage(struct vm_area_struct *, unsigned long, int *);
689 /* mm/page-writeback.c */
690 int write_one_page(struct page *page, int wait);
693 #define VM_MAX_READAHEAD 128 /* kbytes */
694 #define VM_MIN_READAHEAD 16 /* kbytes (includes current page) */
696 int do_page_cache_readahead(struct address_space *mapping, struct file *filp,
697 unsigned long offset, unsigned long nr_to_read);
698 int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
699 unsigned long offset, unsigned long nr_to_read);
700 void page_cache_readahead(struct address_space *mapping,
701 struct file_ra_state *ra,
703 unsigned long offset);
704 void handle_ra_miss(struct address_space *mapping,
705 struct file_ra_state *ra, pgoff_t offset);
706 unsigned long max_sane_readahead(unsigned long nr);
708 /* Do stack extension */
709 extern int expand_stack(struct vm_area_struct * vma, unsigned long address);
711 /* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
712 extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
713 extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
714 struct vm_area_struct **pprev);
716 /* Look up the first VMA which intersects the interval start_addr..end_addr-1,
717 NULL if none. Assume start_addr < end_addr. */
718 static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
720 struct vm_area_struct * vma = find_vma(mm,start_addr);
722 if (vma && end_addr <= vma->vm_start)
727 static inline unsigned long vma_pages(struct vm_area_struct *vma)
729 return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
732 extern struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr);
734 extern struct page * vmalloc_to_page(void *addr);
735 extern struct page * follow_page(struct mm_struct *mm, unsigned long address,
737 extern struct page * follow_page_pfn(struct mm_struct *mm,
738 unsigned long address, int write, unsigned long *pfn);
739 extern int remap_page_range(struct vm_area_struct *vma, unsigned long from,
740 unsigned long to, unsigned long size, pgprot_t prot);
742 #ifndef CONFIG_DEBUG_PAGEALLOC
744 kernel_map_pages(struct page *page, int numpages, int enable)
749 #ifndef CONFIG_ARCH_GATE_AREA
750 extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk);
751 int in_gate_area(struct task_struct *task, unsigned long addr);
754 #endif /* __KERNEL__ */
755 #endif /* _LINUX_MM_H */