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author | Andreas Baumann <mail@andreasbaumann.cc> | 2015-01-03 12:04:58 +0100 |
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committer | Andreas Baumann <mail@andreasbaumann.cc> | 2015-01-03 12:04:58 +0100 |
commit | 008d0be72b2f160382c6e880765e96b64a050c65 (patch) | |
tree | 36f48a98a3815a408e2ce1693dd182af90f80305 /release/src/linux/linux/include/linux/mm.h | |
parent | 611becfb8726c60cb060368541ad98191d4532f5 (diff) | |
download | tomato-008d0be72b2f160382c6e880765e96b64a050c65.tar.gz tomato-008d0be72b2f160382c6e880765e96b64a050c65.tar.bz2 |
imported original firmware WRT54GL_v4.30.11_11_US
Diffstat (limited to 'release/src/linux/linux/include/linux/mm.h')
-rw-r--r-- | release/src/linux/linux/include/linux/mm.h | 677 |
1 files changed, 677 insertions, 0 deletions
diff --git a/release/src/linux/linux/include/linux/mm.h b/release/src/linux/linux/include/linux/mm.h new file mode 100644 index 00000000..dd303239 --- /dev/null +++ b/release/src/linux/linux/include/linux/mm.h @@ -0,0 +1,677 @@ +#ifndef _LINUX_MM_H +#define _LINUX_MM_H + +#include <linux/sched.h> +#include <linux/errno.h> + +#ifdef __KERNEL__ + +#include <linux/config.h> +#include <linux/string.h> +#include <linux/list.h> +#include <linux/mmzone.h> +#include <linux/swap.h> +#include <linux/rbtree.h> + +extern unsigned long max_mapnr; +extern unsigned long num_physpages; +extern unsigned long num_mappedpages; +extern void * high_memory; +extern int page_cluster; +/* The inactive_clean lists are per zone. */ +extern struct list_head active_list; +extern struct list_head inactive_list; + +#include <asm/page.h> +#include <asm/pgtable.h> +#include <asm/atomic.h> + +/* + * Linux kernel virtual memory manager primitives. + * The idea being to have a "virtual" mm in the same way + * we have a virtual fs - giving a cleaner interface to the + * mm details, and allowing different kinds of memory mappings + * (from shared memory to executable loading to arbitrary + * mmap() functions). + */ + +/* + * This struct defines a memory VMM memory area. There is one of these + * per VM-area/task. A VM area is any part of the process virtual memory + * space that has a special rule for the page-fault handlers (ie a shared + * library, the executable area etc). + */ +struct vm_area_struct { + struct mm_struct * vm_mm; /* The address space we belong to. */ + unsigned long vm_start; /* Our start address within vm_mm. */ + unsigned long vm_end; /* The first byte after our end address + within vm_mm. */ + + /* linked list of VM areas per task, sorted by address */ + struct vm_area_struct *vm_next; + + pgprot_t vm_page_prot; /* Access permissions of this VMA. */ + unsigned long vm_flags; /* Flags, listed below. */ + + rb_node_t vm_rb; + + /* + * For areas with an address space and backing store, + * one of the address_space->i_mmap{,shared} lists, + * for shm areas, the list of attaches, otherwise unused. + */ + struct vm_area_struct *vm_next_share; + struct vm_area_struct **vm_pprev_share; + + /* Function pointers to deal with this struct. */ + struct vm_operations_struct * vm_ops; + + /* Information about our backing store: */ + unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE + units, *not* PAGE_CACHE_SIZE */ + struct file * vm_file; /* File we map to (can be NULL). */ + unsigned long vm_raend; + void * vm_private_data; /* was vm_pte (shared mem) */ +}; + +/* + * vm_flags.. + */ +#define VM_READ 0x00000001 /* currently active flags */ +#define VM_WRITE 0x00000002 +#define VM_EXEC 0x00000004 +#define VM_SHARED 0x00000008 + +#define VM_MAYREAD 0x00000010 /* limits for mprotect() etc */ +#define VM_MAYWRITE 0x00000020 +#define VM_MAYEXEC 0x00000040 +#define VM_MAYSHARE 0x00000080 + +#define VM_GROWSDOWN 0x00000100 /* general info on the segment */ +#define VM_GROWSUP 0x00000200 +#define VM_SHM 0x00000400 /* shared memory area, don't swap out */ +#define VM_DENYWRITE 0x00000800 /* ETXTBSY on write attempts.. */ + +#define VM_EXECUTABLE 0x00001000 +#define VM_LOCKED 0x00002000 +#define VM_IO 0x00004000 /* Memory mapped I/O or similar */ + + /* Used by sys_madvise() */ +#define VM_SEQ_READ 0x00008000 /* App will access data sequentially */ +#define VM_RAND_READ 0x00010000 /* App will not benefit from clustered reads */ + +#define VM_DONTCOPY 0x00020000 /* Do not copy this vma on fork */ +#define VM_DONTEXPAND 0x00040000 /* Cannot expand with mremap() */ +#define VM_RESERVED 0x00080000 /* Don't unmap it from swap_out */ + +#define VM_STACK_FLAGS 0x00000177 + +#define VM_READHINTMASK (VM_SEQ_READ | VM_RAND_READ) +#define VM_ClearReadHint(v) (v)->vm_flags &= ~VM_READHINTMASK +#define VM_NormalReadHint(v) (!((v)->vm_flags & VM_READHINTMASK)) +#define VM_SequentialReadHint(v) ((v)->vm_flags & VM_SEQ_READ) +#define VM_RandomReadHint(v) ((v)->vm_flags & VM_RAND_READ) + +/* read ahead limits */ +extern int vm_min_readahead; +extern int vm_max_readahead; + +/* + * mapping from the currently active vm_flags protection bits (the + * low four bits) to a page protection mask.. + */ +extern pgprot_t protection_map[16]; + + +/* + * These are the virtual MM functions - opening of an area, closing and + * unmapping it (needed to keep files on disk up-to-date etc), pointer + * to the functions called when a no-page or a wp-page exception occurs. + */ +struct vm_operations_struct { + void (*open)(struct vm_area_struct * area); + void (*close)(struct vm_area_struct * area); + struct page * (*nopage)(struct vm_area_struct * area, unsigned long address, int unused); +}; + +/* + * Each physical page in the system has a struct page associated with + * it to keep track of whatever it is we are using the page for at the + * moment. Note that we have no way to track which tasks are using + * a page. + * + * Try to keep the most commonly accessed fields in single cache lines + * here (16 bytes or greater). This ordering should be particularly + * beneficial on 32-bit processors. + * + * The first line is data used in page cache lookup, the second line + * is used for linear searches (eg. clock algorithm scans). + * + * TODO: make this structure smaller, it could be as small as 32 bytes. + */ +typedef struct page { + struct list_head list; /* ->mapping has some page lists. */ + struct address_space *mapping; /* The inode (or ...) we belong to. */ + unsigned long index; /* Our offset within mapping. */ + struct page *next_hash; /* Next page sharing our hash bucket in + the pagecache hash table. */ + atomic_t count; /* Usage count, see below. */ + unsigned long flags; /* atomic flags, some possibly + updated asynchronously */ + struct list_head lru; /* Pageout list, eg. active_list; + protected by pagemap_lru_lock !! */ + struct page **pprev_hash; /* Complement to *next_hash. */ + struct buffer_head * buffers; /* Buffer maps us to a disk block. */ + + /* + * On machines where all RAM is mapped into kernel address space, + * we can simply calculate the virtual address. On machines with + * highmem some memory is mapped into kernel virtual memory + * dynamically, so we need a place to store that address. + * Note that this field could be 16 bits on x86 ... ;) + * + * Architectures with slow multiplication can define + * WANT_PAGE_VIRTUAL in asm/page.h + */ +#if defined(CONFIG_HIGHMEM) || defined(WANT_PAGE_VIRTUAL) + void *virtual; /* Kernel virtual address (NULL if + not kmapped, ie. highmem) */ +#endif /* CONFIG_HIGMEM || WANT_PAGE_VIRTUAL */ +} mem_map_t; + +/* + * Methods to modify the page usage count. + * + * What counts for a page usage: + * - cache mapping (page->mapping) + * - disk mapping (page->buffers) + * - page mapped in a task's page tables, each mapping + * is counted separately + * + * Also, many kernel routines increase the page count before a critical + * routine so they can be sure the page doesn't go away from under them. + */ +#define get_page(p) atomic_inc(&(p)->count) +#define put_page(p) __free_page(p) +#define put_page_testzero(p) atomic_dec_and_test(&(p)->count) +#define page_count(p) atomic_read(&(p)->count) +#define set_page_count(p,v) atomic_set(&(p)->count, v) + +/* + * Various page->flags bits: + * + * PG_reserved is set for special pages, which can never be swapped + * out. Some of them might not even exist (eg empty_bad_page)... + * + * Multiple processes may "see" the same page. E.g. for untouched + * mappings of /dev/null, all processes see the same page full of + * zeroes, and text pages of executables and shared libraries have + * only one copy in memory, at most, normally. + * + * For the non-reserved pages, page->count denotes a reference count. + * page->count == 0 means the page is free. + * page->count == 1 means the page is used for exactly one purpose + * (e.g. a private data page of one process). + * + * A page may be used for kmalloc() or anyone else who does a + * __get_free_page(). In this case the page->count is at least 1, and + * all other fields are unused but should be 0 or NULL. The + * management of this page is the responsibility of the one who uses + * it. + * + * The other pages (we may call them "process pages") are completely + * managed by the Linux memory manager: I/O, buffers, swapping etc. + * The following discussion applies only to them. + * + * A page may belong to an inode's memory mapping. In this case, + * page->mapping is the pointer to the inode, and page->index is the + * file offset of the page, in units of PAGE_CACHE_SIZE. + * + * A page may have buffers allocated to it. In this case, + * page->buffers is a circular list of these buffer heads. Else, + * page->buffers == NULL. + * + * For pages belonging to inodes, the page->count is the number of + * attaches, plus 1 if buffers are allocated to the page, plus one + * for the page cache itself. + * + * All pages belonging to an inode are in these doubly linked lists: + * mapping->clean_pages, mapping->dirty_pages and mapping->locked_pages; + * using the page->list list_head. These fields are also used for + * freelist managemet (when page->count==0). + * + * There is also a hash table mapping (mapping,index) to the page + * in memory if present. The lists for this hash table use the fields + * page->next_hash and page->pprev_hash. + * + * All process pages can do I/O: + * - inode pages may need to be read from disk, + * - inode pages which have been modified and are MAP_SHARED may need + * to be written to disk, + * - private pages which have been modified may need to be swapped out + * to swap space and (later) to be read back into memory. + * During disk I/O, PG_locked is used. This bit is set before I/O + * and reset when I/O completes. page_waitqueue(page) is a wait queue of all + * tasks waiting for the I/O on this page to complete. + * PG_uptodate tells whether the page's contents is valid. + * When a read completes, the page becomes uptodate, unless a disk I/O + * error happened. + * + * For choosing which pages to swap out, inode pages carry a + * PG_referenced bit, which is set any time the system accesses + * that page through the (mapping,index) hash table. This referenced + * bit, together with the referenced bit in the page tables, is used + * to manipulate page->age and move the page across the active, + * inactive_dirty and inactive_clean lists. + * + * Note that the referenced bit, the page->lru list_head and the + * active, inactive_dirty and inactive_clean lists are protected by + * the pagemap_lru_lock, and *NOT* by the usual PG_locked bit! + * + * PG_skip is used on sparc/sparc64 architectures to "skip" certain + * parts of the address space. + * + * PG_error is set to indicate that an I/O error occurred on this page. + * + * PG_arch_1 is an architecture specific page state bit. The generic + * code guarantees that this bit is cleared for a page when it first + * is entered into the page cache. + * + * PG_highmem pages are not permanently mapped into the kernel virtual + * address space, they need to be kmapped separately for doing IO on + * the pages. The struct page (these bits with information) are always + * mapped into kernel address space... + */ +#define PG_locked 0 /* Page is locked. Don't touch. */ +#define PG_error 1 +#define PG_referenced 2 +#define PG_uptodate 3 +#define PG_dirty 4 +#define PG_unused 5 +#define PG_lru 6 +#define PG_active 7 +#define PG_slab 8 +#define PG_skip 10 +#define PG_highmem 11 +#define PG_checked 12 /* kill me in 2.5.<early>. */ +#define PG_arch_1 13 +#define PG_reserved 14 +#define PG_launder 15 /* written out by VM pressure.. */ + +/* Make it prettier to test the above... */ +#define UnlockPage(page) unlock_page(page) +#define Page_Uptodate(page) test_bit(PG_uptodate, &(page)->flags) +#define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags) +#define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags) +#define PageDirty(page) test_bit(PG_dirty, &(page)->flags) +#define SetPageDirty(page) set_bit(PG_dirty, &(page)->flags) +#define ClearPageDirty(page) clear_bit(PG_dirty, &(page)->flags) +#define PageLocked(page) test_bit(PG_locked, &(page)->flags) +#define LockPage(page) set_bit(PG_locked, &(page)->flags) +#define TryLockPage(page) test_and_set_bit(PG_locked, &(page)->flags) +#define PageChecked(page) test_bit(PG_checked, &(page)->flags) +#define SetPageChecked(page) set_bit(PG_checked, &(page)->flags) +#define PageLaunder(page) test_bit(PG_launder, &(page)->flags) +#define SetPageLaunder(page) set_bit(PG_launder, &(page)->flags) +#define ClearPageLaunder(page) clear_bit(PG_launder, &(page)->flags) + +/* + * The zone field is never updated after free_area_init_core() + * sets it, so none of the operations on it need to be atomic. + */ +#define NODE_SHIFT 4 +#define ZONE_SHIFT (BITS_PER_LONG - 8) + +struct zone_struct; +extern struct zone_struct *zone_table[]; + +static inline zone_t *page_zone(struct page *page) +{ + return zone_table[page->flags >> ZONE_SHIFT]; +} + +static inline void set_page_zone(struct page *page, unsigned long zone_num) +{ + page->flags &= ~(~0UL << ZONE_SHIFT); + page->flags |= zone_num << ZONE_SHIFT; +} + +/* + * In order to avoid #ifdefs within C code itself, we define + * set_page_address to a noop for non-highmem machines, where + * the field isn't useful. + * The same is true for page_address() in arch-dependent code. + */ +#if defined(CONFIG_HIGHMEM) || defined(WANT_PAGE_VIRTUAL) + +#define set_page_address(page, address) \ + do { \ + (page)->virtual = (address); \ + } while(0) + +#else /* CONFIG_HIGHMEM || WANT_PAGE_VIRTUAL */ +#define set_page_address(page, address) do { } while(0) +#endif /* CONFIG_HIGHMEM || WANT_PAGE_VIRTUAL */ + +/* + * Permanent address of a page. Obviously must never be + * called on a highmem page. + */ +#if defined(CONFIG_HIGHMEM) || defined(WANT_PAGE_VIRTUAL) + +#define page_address(page) ((page)->virtual) + +#else /* CONFIG_HIGHMEM || WANT_PAGE_VIRTUAL */ + +#define page_address(page) \ + __va( (((page) - page_zone(page)->zone_mem_map) << PAGE_SHIFT) \ + + page_zone(page)->zone_start_paddr) + +#endif /* CONFIG_HIGHMEM || WANT_PAGE_VIRTUAL */ + +extern void FASTCALL(set_page_dirty(struct page *)); + +/* + * The first mb is necessary to safely close the critical section opened by the + * TryLockPage(), the second mb is necessary to enforce ordering between + * the clear_bit and the read of the waitqueue (to avoid SMP races with a + * parallel wait_on_page). + */ +#define PageError(page) test_bit(PG_error, &(page)->flags) +#define SetPageError(page) set_bit(PG_error, &(page)->flags) +#define ClearPageError(page) clear_bit(PG_error, &(page)->flags) +#define PageReferenced(page) test_bit(PG_referenced, &(page)->flags) +#define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags) +#define ClearPageReferenced(page) clear_bit(PG_referenced, &(page)->flags) +#define PageTestandClearReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags) +#define PageSlab(page) test_bit(PG_slab, &(page)->flags) +#define PageSetSlab(page) set_bit(PG_slab, &(page)->flags) +#define PageClearSlab(page) clear_bit(PG_slab, &(page)->flags) +#define PageReserved(page) test_bit(PG_reserved, &(page)->flags) + +#define PageActive(page) test_bit(PG_active, &(page)->flags) +#define SetPageActive(page) set_bit(PG_active, &(page)->flags) +#define ClearPageActive(page) clear_bit(PG_active, &(page)->flags) + +#define PageLRU(page) test_bit(PG_lru, &(page)->flags) +#define TestSetPageLRU(page) test_and_set_bit(PG_lru, &(page)->flags) +#define TestClearPageLRU(page) test_and_clear_bit(PG_lru, &(page)->flags) + +#ifdef CONFIG_HIGHMEM +#define PageHighMem(page) test_bit(PG_highmem, &(page)->flags) +#else +#define PageHighMem(page) 0 /* needed to optimize away at compile time */ +#endif + +#define SetPageReserved(page) set_bit(PG_reserved, &(page)->flags) +#define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags) + +/* + * Error return values for the *_nopage functions + */ +#define NOPAGE_SIGBUS (NULL) +#define NOPAGE_OOM ((struct page *) (-1)) + +/* The array of struct pages */ +extern mem_map_t * mem_map; + +/* + * There is only one page-allocator function, and two main namespaces to + * it. The alloc_page*() variants return 'struct page *' and as such + * can allocate highmem pages, the *get*page*() variants return + * virtual kernel addresses to the allocated page(s). + */ +extern struct page * FASTCALL(_alloc_pages(unsigned int gfp_mask, unsigned int order)); +extern struct page * FASTCALL(__alloc_pages(unsigned int gfp_mask, unsigned int order, zonelist_t *zonelist)); +extern struct page * alloc_pages_node(int nid, unsigned int gfp_mask, unsigned int order); + +static inline struct page * alloc_pages(unsigned int gfp_mask, unsigned int order) +{ + /* + * Gets optimized away by the compiler. + */ + if (order >= MAX_ORDER) + return NULL; + return _alloc_pages(gfp_mask, order); +} + +#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0) + +extern unsigned long FASTCALL(__get_free_pages(unsigned int gfp_mask, unsigned int order)); +extern unsigned long FASTCALL(get_zeroed_page(unsigned int gfp_mask)); + +#define __get_free_page(gfp_mask) \ + __get_free_pages((gfp_mask),0) + +#define __get_dma_pages(gfp_mask, order) \ + __get_free_pages((gfp_mask) | GFP_DMA,(order)) + +/* + * The old interface name will be removed in 2.5: + */ +#define get_free_page get_zeroed_page + +/* + * There is only one 'core' page-freeing function. + */ +extern void FASTCALL(__free_pages(struct page *page, unsigned int order)); +extern void FASTCALL(free_pages(unsigned long addr, unsigned int order)); + +#define __free_page(page) __free_pages((page), 0) +#define free_page(addr) free_pages((addr),0) + +extern void show_free_areas(void); +extern void show_free_areas_node(pg_data_t *pgdat); + +extern void clear_page_tables(struct mm_struct *, unsigned long, int); + +extern int fail_writepage(struct page *); +struct page * shmem_nopage(struct vm_area_struct * vma, unsigned long address, int unused); +struct file *shmem_file_setup(char * name, loff_t size); +extern void shmem_lock(struct file * file, int lock); +extern int shmem_zero_setup(struct vm_area_struct *); + +extern void zap_page_range(struct mm_struct *mm, unsigned long address, unsigned long size); +extern int copy_page_range(struct mm_struct *dst, struct mm_struct *src, struct vm_area_struct *vma); +extern int remap_page_range(unsigned long from, unsigned long to, unsigned long size, pgprot_t prot); +extern int zeromap_page_range(unsigned long from, unsigned long size, pgprot_t prot); + +extern int vmtruncate(struct inode * inode, loff_t offset); +extern pmd_t *FASTCALL(__pmd_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)); +extern pte_t *FASTCALL(pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address)); +extern int handle_mm_fault(struct mm_struct *mm,struct vm_area_struct *vma, unsigned long address, int write_access); +extern int make_pages_present(unsigned long addr, unsigned long end); +extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write); +extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char *dst, int len); +extern int ptrace_writedata(struct task_struct *tsk, char * src, unsigned long dst, int len); +extern int ptrace_attach(struct task_struct *tsk); +extern int ptrace_detach(struct task_struct *, unsigned int); +extern void ptrace_disable(struct task_struct *); +extern int ptrace_check_attach(struct task_struct *task, int kill); + +int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, + int len, int write, int force, struct page **pages, struct vm_area_struct **vmas); + +/* + * On a two-level page table, this ends up being trivial. Thus the + * inlining and the symmetry break with pte_alloc() that does all + * of this out-of-line. + */ +static inline pmd_t *pmd_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address) +{ + if (pgd_none(*pgd)) + return __pmd_alloc(mm, pgd, address); + return pmd_offset(pgd, address); +} + +extern int pgt_cache_water[2]; +extern int check_pgt_cache(void); + +extern void free_area_init(unsigned long * zones_size); +extern void free_area_init_node(int nid, pg_data_t *pgdat, struct page *pmap, + unsigned long * zones_size, unsigned long zone_start_paddr, + unsigned long *zholes_size); +extern void mem_init(void); +extern void show_mem(void); +extern void si_meminfo(struct sysinfo * val); +extern void swapin_readahead(swp_entry_t); + +extern struct address_space swapper_space; +#define PageSwapCache(page) ((page)->mapping == &swapper_space) + +static inline int is_page_cache_freeable(struct page * page) +{ + return page_count(page) - !!page->buffers == 1; +} + +extern int can_share_swap_page(struct page *); +extern int remove_exclusive_swap_page(struct page *); + +extern void __free_pte(pte_t); + +/* mmap.c */ +extern void lock_vma_mappings(struct vm_area_struct *); +extern void unlock_vma_mappings(struct vm_area_struct *); +extern void insert_vm_struct(struct mm_struct *, struct vm_area_struct *); +extern void __insert_vm_struct(struct mm_struct *, struct vm_area_struct *); +extern void build_mmap_rb(struct mm_struct *); +extern void exit_mmap(struct mm_struct *); + +extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long); + +extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr, + unsigned long len, unsigned long prot, + unsigned long flag, unsigned long pgoff); + +static inline unsigned long do_mmap(struct file *file, unsigned long addr, + unsigned long len, unsigned long prot, + unsigned long flag, unsigned long offset) +{ + unsigned long ret = -EINVAL; + if ((offset + PAGE_ALIGN(len)) < offset) + goto out; + if (!(offset & ~PAGE_MASK)) + ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT); +out: + return ret; +} + +extern int do_munmap(struct mm_struct *, unsigned long, size_t); + +extern unsigned long do_brk(unsigned long, unsigned long); + +static inline void __vma_unlink(struct mm_struct * mm, struct vm_area_struct * vma, struct vm_area_struct * prev) +{ + prev->vm_next = vma->vm_next; + rb_erase(&vma->vm_rb, &mm->mm_rb); + if (mm->mmap_cache == vma) + mm->mmap_cache = prev; +} + +static inline int can_vma_merge(struct vm_area_struct * vma, unsigned long vm_flags) +{ + if (!vma->vm_file && vma->vm_flags == vm_flags) + return 1; + else + return 0; +} + +struct zone_t; +/* filemap.c */ +extern void remove_inode_page(struct page *); +extern unsigned long page_unuse(struct page *); +extern void truncate_inode_pages(struct address_space *, loff_t); + +/* generic vm_area_ops exported for stackable file systems */ +extern int filemap_sync(struct vm_area_struct *, unsigned long, size_t, unsigned int); +extern struct page *filemap_nopage(struct vm_area_struct *, unsigned long, int); + +/* + * GFP bitmasks.. + */ +/* Zone modifiers in GFP_ZONEMASK (see linux/mmzone.h - low four bits) */ +#define __GFP_DMA 0x01 +#define __GFP_HIGHMEM 0x02 + +/* Action modifiers - doesn't change the zoning */ +#define __GFP_WAIT 0x10 /* Can wait and reschedule? */ +#define __GFP_HIGH 0x20 /* Should access emergency pools? */ +#define __GFP_IO 0x40 /* Can start low memory physical IO? */ +#define __GFP_HIGHIO 0x80 /* Can start high mem physical IO? */ +#define __GFP_FS 0x100 /* Can call down to low-level FS? */ + +#define GFP_NOHIGHIO (__GFP_HIGH | __GFP_WAIT | __GFP_IO) +#define GFP_NOIO (__GFP_HIGH | __GFP_WAIT) +#define GFP_NOFS (__GFP_HIGH | __GFP_WAIT | __GFP_IO | __GFP_HIGHIO) +#define GFP_ATOMIC (__GFP_HIGH) +#define GFP_USER ( __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS) +#define GFP_HIGHUSER ( __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS | __GFP_HIGHMEM) +#define GFP_KERNEL (__GFP_HIGH | __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS) +#define GFP_NFS (__GFP_HIGH | __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS) +#define GFP_KSWAPD ( __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS) + +/* Flag - indicates that the buffer will be suitable for DMA. Ignored on some + platforms, used as appropriate on others */ + +#define GFP_DMA __GFP_DMA + +static inline unsigned int pf_gfp_mask(unsigned int gfp_mask) +{ + /* avoid all memory balancing I/O methods if this task cannot block on I/O */ + if (current->flags & PF_NOIO) + gfp_mask &= ~(__GFP_IO | __GFP_HIGHIO | __GFP_FS); + + return gfp_mask; +} + +/* vma is the first one with address < vma->vm_end, + * and even address < vma->vm_start. Have to extend vma. */ +static inline int expand_stack(struct vm_area_struct * vma, unsigned long address) +{ + unsigned long grow; + + /* + * vma->vm_start/vm_end cannot change under us because the caller is required + * to hold the mmap_sem in write mode. We need to get the spinlock only + * before relocating the vma range ourself. + */ + address &= PAGE_MASK; + spin_lock(&vma->vm_mm->page_table_lock); + grow = (vma->vm_start - address) >> PAGE_SHIFT; + if (vma->vm_end - address > current->rlim[RLIMIT_STACK].rlim_cur || + ((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) > current->rlim[RLIMIT_AS].rlim_cur) { + spin_unlock(&vma->vm_mm->page_table_lock); + return -ENOMEM; + } + vma->vm_start = address; + vma->vm_pgoff -= grow; + vma->vm_mm->total_vm += grow; + if (vma->vm_flags & VM_LOCKED) + vma->vm_mm->locked_vm += grow; + spin_unlock(&vma->vm_mm->page_table_lock); + return 0; +} + +/* Look up the first VMA which satisfies addr < vm_end, NULL if none. */ +extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr); +extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr, + struct vm_area_struct **pprev); + +/* Look up the first VMA which intersects the interval start_addr..end_addr-1, + NULL if none. Assume start_addr < end_addr. */ +static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr) +{ + struct vm_area_struct * vma = find_vma(mm,start_addr); + + if (vma && end_addr <= vma->vm_start) + vma = NULL; + return vma; +} + +extern struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr); + +extern struct page * vmalloc_to_page(void *addr); + +#endif /* __KERNEL__ */ + +#endif |