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 int page_cluster;
29 #include <asm/pgtable.h>
30 #include <asm/processor.h>
31 #include <asm/atomic.h>
34 #define MM_VM_SIZE(mm) TASK_SIZE
38 * Linux kernel virtual memory manager primitives.
39 * The idea being to have a "virtual" mm in the same way
40 * we have a virtual fs - giving a cleaner interface to the
41 * mm details, and allowing different kinds of memory mappings
42 * (from shared memory to executable loading to arbitrary
47 * This struct defines a memory VMM memory area. There is one of these
48 * per VM-area/task. A VM area is any part of the process virtual memory
49 * space that has a special rule for the page-fault handlers (ie a shared
50 * library, the executable area etc).
52 struct vm_area_struct {
53 struct mm_struct * vm_mm; /* The address space we belong to. */
54 unsigned long vm_start; /* Our start address within vm_mm. */
55 unsigned long vm_end; /* The first byte after our end address
58 /* linked list of VM areas per task, sorted by address */
59 struct vm_area_struct *vm_next;
61 pgprot_t vm_page_prot; /* Access permissions of this VMA. */
62 unsigned long vm_flags; /* Flags, listed below. */
67 * For areas with an address space and backing store,
68 * linkage into the address_space->i_mmap prio tree, or
69 * linkage to the list of like vmas hanging off its node, or
70 * linkage of vma in the address_space->i_mmap_nonlinear list.
74 struct list_head list;
75 void *parent; /* aligns with prio_tree_node parent */
76 struct vm_area_struct *head;
79 struct prio_tree_node prio_tree_node;
83 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
84 * list, after a COW of one of the file pages. A MAP_SHARED vma
85 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
86 * or brk vma (with NULL file) can only be in an anon_vma list.
88 struct list_head anon_vma_node; /* Serialized by anon_vma->lock */
89 struct anon_vma *anon_vma; /* Serialized by page_table_lock */
91 /* Function pointers to deal with this struct. */
92 struct vm_operations_struct * vm_ops;
94 /* Information about our backing store: */
95 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
96 units, *not* PAGE_CACHE_SIZE */
97 struct file * vm_file; /* File we map to (can be NULL). */
98 void * vm_private_data; /* was vm_pte (shared mem) */
101 struct mempolicy *vm_policy; /* NUMA policy for the VMA */
108 #define VM_READ 0x00000001 /* currently active flags */
109 #define VM_WRITE 0x00000002
110 #define VM_EXEC 0x00000004
111 #define VM_SHARED 0x00000008
113 #define VM_MAYREAD 0x00000010 /* limits for mprotect() etc */
114 #define VM_MAYWRITE 0x00000020
115 #define VM_MAYEXEC 0x00000040
116 #define VM_MAYSHARE 0x00000080
118 #define VM_GROWSDOWN 0x00000100 /* general info on the segment */
119 #define VM_GROWSUP 0x00000200
120 #define VM_SHM 0x00000400 /* shared memory area, don't swap out */
121 #define VM_DENYWRITE 0x00000800 /* ETXTBSY on write attempts.. */
123 #define VM_EXECUTABLE 0x00001000
124 #define VM_LOCKED 0x00002000
125 #define VM_IO 0x00004000 /* Memory mapped I/O or similar */
127 /* Used by sys_madvise() */
128 #define VM_SEQ_READ 0x00008000 /* App will access data sequentially */
129 #define VM_RAND_READ 0x00010000 /* App will not benefit from clustered reads */
131 #define VM_DONTCOPY 0x00020000 /* Do not copy this vma on fork */
132 #define VM_DONTEXPAND 0x00040000 /* Cannot expand with mremap() */
133 #define VM_RESERVED 0x00080000 /* Don't unmap it from swap_out */
134 #define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */
135 #define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
136 #define VM_NONLINEAR 0x00800000 /* Is non-linear (remap_file_pages) */
138 #ifndef VM_STACK_DEFAULT_FLAGS /* arch can override this */
139 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
142 #ifdef CONFIG_STACK_GROWSUP
143 #define VM_STACK_FLAGS (VM_GROWSUP | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
145 #define VM_STACK_FLAGS (VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
148 #define VM_READHINTMASK (VM_SEQ_READ | VM_RAND_READ)
149 #define VM_ClearReadHint(v) (v)->vm_flags &= ~VM_READHINTMASK
150 #define VM_NormalReadHint(v) (!((v)->vm_flags & VM_READHINTMASK))
151 #define VM_SequentialReadHint(v) ((v)->vm_flags & VM_SEQ_READ)
152 #define VM_RandomReadHint(v) ((v)->vm_flags & VM_RAND_READ)
155 * mapping from the currently active vm_flags protection bits (the
156 * low four bits) to a page protection mask..
158 extern pgprot_t protection_map[16];
162 * These are the virtual MM functions - opening of an area, closing and
163 * unmapping it (needed to keep files on disk up-to-date etc), pointer
164 * to the functions called when a no-page or a wp-page exception occurs.
166 struct vm_operations_struct {
167 void (*open)(struct vm_area_struct * area);
168 void (*close)(struct vm_area_struct * area);
169 struct page * (*nopage)(struct vm_area_struct * area, unsigned long address, int *type);
170 int (*populate)(struct vm_area_struct * area, unsigned long address, unsigned long len, pgprot_t prot, unsigned long pgoff, int nonblock);
172 int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
173 struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
181 #ifdef ARCH_HAS_ATOMIC_UNSIGNED
182 typedef unsigned page_flags_t;
184 typedef unsigned long page_flags_t;
188 * Each physical page in the system has a struct page associated with
189 * it to keep track of whatever it is we are using the page for at the
190 * moment. Note that we have no way to track which tasks are using
194 page_flags_t flags; /* Atomic flags, some possibly
195 * updated asynchronously */
196 atomic_t _count; /* Usage count, see below. */
197 unsigned int mapcount; /* Count of ptes mapped in mms,
198 * to show when page is mapped
199 * & limit reverse map searches,
200 * protected by PG_maplock.
202 unsigned long private; /* Mapping-private opaque data:
203 * usually used for buffer_heads
204 * if PagePrivate set; used for
205 * swp_entry_t if PageSwapCache
207 struct address_space *mapping; /* If PG_anon clear, points to
208 * inode address_space, or NULL.
209 * If page mapped as anonymous
210 * memory, PG_anon is set, and
211 * it points to anon_vma object.
213 pgoff_t index; /* Our offset within mapping. */
214 struct list_head lru; /* Pageout list, eg. active_list
215 * protected by zone->lru_lock !
218 * On machines where all RAM is mapped into kernel address space,
219 * we can simply calculate the virtual address. On machines with
220 * highmem some memory is mapped into kernel virtual memory
221 * dynamically, so we need a place to store that address.
222 * Note that this field could be 16 bits on x86 ... ;)
224 * Architectures with slow multiplication can define
225 * WANT_PAGE_VIRTUAL in asm/page.h
227 #if defined(WANT_PAGE_VIRTUAL)
228 void *virtual; /* Kernel virtual address (NULL if
229 not kmapped, ie. highmem) */
230 #endif /* WANT_PAGE_VIRTUAL */
234 * FIXME: take this include out, include page-flags.h in
235 * files which need it (119 of them)
237 #include <linux/page-flags.h>
240 * Methods to modify the page usage count.
242 * What counts for a page usage:
243 * - cache mapping (page->mapping)
244 * - private data (page->private)
245 * - page mapped in a task's page tables, each mapping
246 * is counted separately
248 * Also, many kernel routines increase the page count before a critical
249 * routine so they can be sure the page doesn't go away from under them.
251 * Since 2.6.6 (approx), a free page has ->_count = -1. This is so that we
252 * can use atomic_add_negative(-1, page->_count) to detect when the page
253 * becomes free and so that we can also use atomic_inc_and_test to atomically
254 * detect when we just tried to grab a ref on a page which some other CPU has
255 * already deemed to be freeable.
257 * NO code should make assumptions about this internal detail! Use the provided
258 * macros which retain the old rules: page_count(page) == 0 is a free page.
262 * Drop a ref, return true if the logical refcount fell to zero (the page has
265 #define put_page_testzero(p) \
267 BUG_ON(page_count(p) == 0); \
268 atomic_add_negative(-1, &(p)->_count); \
272 * Grab a ref, return true if the page previously had a logical refcount of
273 * zero. ie: returns true if we just grabbed an already-deemed-to-be-free page
275 #define get_page_testone(p) atomic_inc_and_test(&(p)->_count)
277 #define set_page_count(p,v) atomic_set(&(p)->_count, v - 1)
278 #define __put_page(p) atomic_dec(&(p)->_count)
280 extern void FASTCALL(__page_cache_release(struct page *));
282 #ifdef CONFIG_HUGETLB_PAGE
284 static inline int page_count(struct page *p)
287 p = (struct page *)p->private;
288 return atomic_read(&(p)->_count) + 1;
291 static inline void get_page(struct page *page)
293 if (unlikely(PageCompound(page)))
294 page = (struct page *)page->private;
295 atomic_inc(&page->_count);
298 void put_page(struct page *page);
300 #else /* CONFIG_HUGETLB_PAGE */
302 #define page_count(p) (atomic_read(&(p)->_count) + 1)
304 static inline void get_page(struct page *page)
306 atomic_inc(&page->_count);
309 static inline void put_page(struct page *page)
311 if (!PageReserved(page) && put_page_testzero(page))
312 __page_cache_release(page);
315 #endif /* CONFIG_HUGETLB_PAGE */
318 * Multiple processes may "see" the same page. E.g. for untouched
319 * mappings of /dev/null, all processes see the same page full of
320 * zeroes, and text pages of executables and shared libraries have
321 * only one copy in memory, at most, normally.
323 * For the non-reserved pages, page_count(page) denotes a reference count.
324 * page_count() == 0 means the page is free.
325 * page_count() == 1 means the page is used for exactly one purpose
326 * (e.g. a private data page of one process).
328 * A page may be used for kmalloc() or anyone else who does a
329 * __get_free_page(). In this case the page_count() is at least 1, and
330 * all other fields are unused but should be 0 or NULL. The
331 * management of this page is the responsibility of the one who uses
334 * The other pages (we may call them "process pages") are completely
335 * managed by the Linux memory manager: I/O, buffers, swapping etc.
336 * The following discussion applies only to them.
338 * A page may belong to an inode's memory mapping. In this case,
339 * page->mapping is the pointer to the inode, and page->index is the
340 * file offset of the page, in units of PAGE_CACHE_SIZE.
342 * A page contains an opaque `private' member, which belongs to the
343 * page's address_space. Usually, this is the address of a circular
344 * list of the page's disk buffers.
346 * For pages belonging to inodes, the page_count() is the number of
347 * attaches, plus 1 if `private' contains something, plus one for
348 * the page cache itself.
350 * All pages belonging to an inode are in these doubly linked lists:
351 * mapping->clean_pages, mapping->dirty_pages and mapping->locked_pages;
352 * using the page->list list_head. These fields are also used for
353 * freelist managemet (when page_count()==0).
355 * There is also a per-mapping radix tree mapping index to the page
356 * in memory if present. The tree is rooted at mapping->root.
358 * All process pages can do I/O:
359 * - inode pages may need to be read from disk,
360 * - inode pages which have been modified and are MAP_SHARED may need
361 * to be written to disk,
362 * - private pages which have been modified may need to be swapped out
363 * to swap space and (later) to be read back into memory.
367 * The zone field is never updated after free_area_init_core()
368 * sets it, so none of the operations on it need to be atomic.
369 * We'll have up to (MAX_NUMNODES * MAX_NR_ZONES) zones total,
370 * so we use (MAX_NODES_SHIFT + MAX_ZONES_SHIFT) here to get enough bits.
372 #define NODEZONE_SHIFT (sizeof(page_flags_t)*8 - MAX_NODES_SHIFT - MAX_ZONES_SHIFT)
373 #define NODEZONE(node, zone) ((node << ZONES_SHIFT) | zone)
375 static inline unsigned long page_zonenum(struct page *page)
377 return (page->flags >> NODEZONE_SHIFT) & (~(~0UL << ZONES_SHIFT));
379 static inline unsigned long page_to_nid(struct page *page)
381 return (page->flags >> (NODEZONE_SHIFT + ZONES_SHIFT));
385 extern struct zone *zone_table[];
387 static inline struct zone *page_zone(struct page *page)
389 return zone_table[page->flags >> NODEZONE_SHIFT];
392 static inline void set_page_zone(struct page *page, unsigned long nodezone_num)
394 page->flags &= ~(~0UL << NODEZONE_SHIFT);
395 page->flags |= nodezone_num << NODEZONE_SHIFT;
398 #ifndef CONFIG_DISCONTIGMEM
399 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
400 extern struct page *mem_map;
403 static inline void *lowmem_page_address(struct page *page)
405 return __va(page_to_pfn(page) << PAGE_SHIFT);
408 #if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
409 #define HASHED_PAGE_VIRTUAL
412 #if defined(WANT_PAGE_VIRTUAL)
413 #define page_address(page) ((page)->virtual)
414 #define set_page_address(page, address) \
416 (page)->virtual = (address); \
418 #define page_address_init() do { } while(0)
421 #if defined(HASHED_PAGE_VIRTUAL)
422 void *page_address(struct page *page);
423 void set_page_address(struct page *page, void *virtual);
424 void page_address_init(void);
427 #if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
428 #define page_address(page) lowmem_page_address(page)
429 #define set_page_address(page, address) do { } while(0)
430 #define page_address_init() do { } while(0)
434 * On an anonymous page mapped into a user virtual memory area,
435 * page->mapping points to its anon_vma, not to a struct address_space.
437 * Please note that, confusingly, "page_mapping" refers to the inode
438 * address_space which maps the page from disk; whereas "page_mapped"
439 * refers to user virtual address space into which the page is mapped.
441 extern struct address_space swapper_space;
442 static inline struct address_space *page_mapping(struct page *page)
444 struct address_space *mapping = NULL;
446 if (unlikely(PageSwapCache(page)))
447 mapping = &swapper_space;
448 else if (likely(!PageAnon(page)))
449 mapping = page->mapping;
454 * Return the pagecache index of the passed page. Regular pagecache pages
455 * use ->index whereas swapcache pages use ->private
457 static inline pgoff_t page_index(struct page *page)
459 if (unlikely(PageSwapCache(page)))
460 return page->private;
465 * Return true if this page is mapped into pagetables.
467 static inline int page_mapped(struct page *page)
469 return page->mapcount != 0;
473 * Error return values for the *_nopage functions
475 #define NOPAGE_SIGBUS (NULL)
476 #define NOPAGE_OOM ((struct page *) (-1))
479 * Different kinds of faults, as returned by handle_mm_fault().
480 * Used to decide whether a process gets delivered SIGBUS or
481 * just gets major/minor fault counters bumped up.
483 #define VM_FAULT_OOM (-1)
484 #define VM_FAULT_SIGBUS 0
485 #define VM_FAULT_MINOR 1
486 #define VM_FAULT_MAJOR 2
488 #define offset_in_page(p) ((unsigned long)(p) & ~PAGE_MASK)
490 extern void show_free_areas(void);
492 struct page *shmem_nopage(struct vm_area_struct * vma,
493 unsigned long address, int *type);
494 int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *new);
495 struct mempolicy *shmem_get_policy(struct vm_area_struct *vma,
497 struct file *shmem_file_setup(char * name, loff_t size, unsigned long flags);
498 void shmem_lock(struct file * file, int lock);
499 int shmem_zero_setup(struct vm_area_struct *);
502 * Parameter block passed down to zap_pte_range in exceptional cases.
505 struct vm_area_struct *nonlinear_vma; /* Check page->index if set */
506 struct address_space *check_mapping; /* Check page->mapping if set */
507 pgoff_t first_index; /* Lowest page->index to unmap */
508 pgoff_t last_index; /* Highest page->index to unmap */
509 int atomic; /* May not schedule() */
512 void zap_page_range(struct vm_area_struct *vma, unsigned long address,
513 unsigned long size, struct zap_details *);
514 int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,
515 struct vm_area_struct *start_vma, unsigned long start_addr,
516 unsigned long end_addr, unsigned long *nr_accounted,
517 struct zap_details *);
518 void clear_page_tables(struct mmu_gather *tlb, unsigned long first, int nr);
519 int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
520 struct vm_area_struct *vma);
521 int zeromap_page_range(struct vm_area_struct *vma, unsigned long from,
522 unsigned long size, pgprot_t prot);
523 void unmap_mapping_range(struct address_space *mapping,
524 loff_t const holebegin, loff_t const holelen, int even_cows);
526 static inline void unmap_shared_mapping_range(struct address_space *mapping,
527 loff_t const holebegin, loff_t const holelen)
529 unmap_mapping_range(mapping, holebegin, holelen, 0);
532 extern int vmtruncate(struct inode * inode, loff_t offset);
533 extern pmd_t *FASTCALL(__pmd_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address));
534 extern pte_t *FASTCALL(pte_alloc_kernel(struct mm_struct *mm, pmd_t *pmd, unsigned long address));
535 extern pte_t *FASTCALL(pte_alloc_map(struct mm_struct *mm, pmd_t *pmd, unsigned long address));
536 extern int install_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, struct page *page, pgprot_t prot);
537 extern int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, unsigned long pgoff, pgprot_t prot);
538 extern int handle_mm_fault(struct mm_struct *mm,struct vm_area_struct *vma, unsigned long address, int write_access);
539 extern int make_pages_present(unsigned long addr, unsigned long end);
540 extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
541 void install_arg_page(struct vm_area_struct *, struct page *, unsigned long);
543 int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start,
544 int len, int write, int force, struct page **pages, struct vm_area_struct **vmas);
546 int __set_page_dirty_buffers(struct page *page);
547 int __set_page_dirty_nobuffers(struct page *page);
548 int redirty_page_for_writepage(struct writeback_control *wbc,
550 int FASTCALL(set_page_dirty(struct page *page));
551 int set_page_dirty_lock(struct page *page);
552 int clear_page_dirty_for_io(struct page *page);
555 * Prototype to add a shrinker callback for ageable caches.
557 * These functions are passed a count `nr_to_scan' and a gfpmask. They should
558 * scan `nr_to_scan' objects, attempting to free them.
560 * The callback must the number of objects which remain in the cache.
562 * The callback will be passes nr_to_scan == 0 when the VM is querying the
563 * cache size, so a fastpath for that case is appropriate.
565 typedef int (*shrinker_t)(int nr_to_scan, unsigned int gfp_mask);
568 * Add an aging callback. The int is the number of 'seeks' it takes
569 * to recreate one of the objects that these functions age.
572 #define DEFAULT_SEEKS 2
574 extern struct shrinker *set_shrinker(int, shrinker_t);
575 extern void remove_shrinker(struct shrinker *shrinker);
578 * On a two-level page table, this ends up being trivial. Thus the
579 * inlining and the symmetry break with pte_alloc_map() that does all
580 * of this out-of-line.
582 static inline pmd_t *pmd_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
585 return __pmd_alloc(mm, pgd, address);
586 return pmd_offset(pgd, address);
589 extern void free_area_init(unsigned long * zones_size);
590 extern void free_area_init_node(int nid, pg_data_t *pgdat, struct page *pmap,
591 unsigned long * zones_size, unsigned long zone_start_pfn,
592 unsigned long *zholes_size);
593 extern void memmap_init_zone(struct page *, unsigned long, int,
594 unsigned long, unsigned long);
595 extern void mem_init(void);
596 extern void show_mem(void);
597 extern void si_meminfo(struct sysinfo * val);
598 extern void si_meminfo_node(struct sysinfo *val, int nid);
600 static inline void vma_prio_tree_init(struct vm_area_struct *vma)
602 vma->shared.vm_set.list.next = NULL;
603 vma->shared.vm_set.list.prev = NULL;
604 vma->shared.vm_set.parent = NULL;
605 vma->shared.vm_set.head = NULL;
609 void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old);
610 void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *);
611 void vma_prio_tree_remove(struct vm_area_struct *, struct prio_tree_root *);
612 struct vm_area_struct *vma_prio_tree_next(
613 struct vm_area_struct *, struct prio_tree_root *,
614 struct prio_tree_iter *, pgoff_t begin, pgoff_t end);
617 extern void vma_adjust(struct vm_area_struct *vma, unsigned long start,
618 unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
619 extern struct vm_area_struct *vma_merge(struct mm_struct *,
620 struct vm_area_struct *prev, unsigned long addr, unsigned long end,
621 unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
623 extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
624 extern int split_vma(struct mm_struct *,
625 struct vm_area_struct *, unsigned long addr, int new_below);
626 extern void insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
627 extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
628 struct rb_node **, struct rb_node *);
629 extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
630 unsigned long addr, unsigned long len, pgoff_t pgoff);
631 extern void exit_mmap(struct mm_struct *);
633 extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
635 extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
636 unsigned long len, unsigned long prot,
637 unsigned long flag, unsigned long pgoff);
639 static inline unsigned long do_mmap(struct file *file, unsigned long addr,
640 unsigned long len, unsigned long prot,
641 unsigned long flag, unsigned long offset)
643 unsigned long ret = -EINVAL;
644 if ((offset + PAGE_ALIGN(len)) < offset)
646 if (!(offset & ~PAGE_MASK))
647 ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
652 extern int do_munmap(struct mm_struct *, unsigned long, size_t);
654 extern unsigned long do_brk(unsigned long, unsigned long);
657 extern unsigned long page_unuse(struct page *);
658 extern void truncate_inode_pages(struct address_space *, loff_t);
660 /* generic vm_area_ops exported for stackable file systems */
661 struct page *filemap_nopage(struct vm_area_struct *, unsigned long, int *);
663 /* mm/page-writeback.c */
664 int write_one_page(struct page *page, int wait);
667 #define VM_MAX_READAHEAD 128 /* kbytes */
668 #define VM_MIN_READAHEAD 16 /* kbytes (includes current page) */
670 int do_page_cache_readahead(struct address_space *mapping, struct file *filp,
671 unsigned long offset, unsigned long nr_to_read);
672 int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
673 unsigned long offset, unsigned long nr_to_read);
674 void page_cache_readahead(struct address_space *mapping,
675 struct file_ra_state *ra,
677 unsigned long offset);
678 void handle_ra_miss(struct address_space *mapping,
679 struct file_ra_state *ra, pgoff_t offset);
680 unsigned long max_sane_readahead(unsigned long nr);
682 /* Do stack extension */
683 extern int expand_stack(struct vm_area_struct * vma, unsigned long address);
685 /* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
686 extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
687 extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
688 struct vm_area_struct **pprev);
690 /* Look up the first VMA which intersects the interval start_addr..end_addr-1,
691 NULL if none. Assume start_addr < end_addr. */
692 static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
694 struct vm_area_struct * vma = find_vma(mm,start_addr);
696 if (vma && end_addr <= vma->vm_start)
701 static inline unsigned long vma_pages(struct vm_area_struct *vma)
703 return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
706 extern struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr);
708 extern unsigned int nr_used_zone_pages(void);
710 extern struct page * vmalloc_to_page(void *addr);
711 extern struct page * follow_page(struct mm_struct *mm, unsigned long address,
713 extern int remap_page_range(struct vm_area_struct *vma, unsigned long from,
714 unsigned long to, unsigned long size, pgprot_t prot);
716 #ifndef CONFIG_DEBUG_PAGEALLOC
718 kernel_map_pages(struct page *page, int numpages, int enable)
723 #ifndef CONFIG_ARCH_GATE_AREA
724 extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk);
725 int in_gate_area(struct task_struct *task, unsigned long addr);
728 #endif /* __KERNEL__ */
729 #endif /* _LINUX_MM_H */