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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/mm.h | |
download | lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/linux/mm.h')
-rw-r--r-- | include/linux/mm.h | 861 |
1 files changed, 861 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h new file mode 100644 index 000000000000..6a931374d6c4 --- /dev/null +++ b/include/linux/mm.h @@ -0,0 +1,861 @@ +#ifndef _LINUX_MM_H +#define _LINUX_MM_H + +#include <linux/sched.h> +#include <linux/errno.h> + +#ifdef __KERNEL__ + +#include <linux/config.h> +#include <linux/gfp.h> +#include <linux/list.h> +#include <linux/mmzone.h> +#include <linux/rbtree.h> +#include <linux/prio_tree.h> +#include <linux/fs.h> + +struct mempolicy; +struct anon_vma; + +#ifndef CONFIG_DISCONTIGMEM /* Don't use mapnrs, do it properly */ +extern unsigned long max_mapnr; +#endif + +extern unsigned long num_physpages; +extern void * high_memory; +extern unsigned long vmalloc_earlyreserve; +extern int page_cluster; + +#ifdef CONFIG_SYSCTL +extern int sysctl_legacy_va_layout; +#else +#define sysctl_legacy_va_layout 0 +#endif + +#include <asm/page.h> +#include <asm/pgtable.h> +#include <asm/processor.h> +#include <asm/atomic.h> + +#ifndef MM_VM_SIZE +#define MM_VM_SIZE(mm) ((TASK_SIZE + PGDIR_SIZE - 1) & PGDIR_MASK) +#endif + +#define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n)) + +/* + * 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. */ + + struct rb_node vm_rb; + + /* + * For areas with an address space and backing store, + * linkage into the address_space->i_mmap prio tree, or + * linkage to the list of like vmas hanging off its node, or + * linkage of vma in the address_space->i_mmap_nonlinear list. + */ + union { + struct { + struct list_head list; + void *parent; /* aligns with prio_tree_node parent */ + struct vm_area_struct *head; + } vm_set; + + struct raw_prio_tree_node prio_tree_node; + } shared; + + /* + * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma + * list, after a COW of one of the file pages. A MAP_SHARED vma + * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack + * or brk vma (with NULL file) can only be in an anon_vma list. + */ + struct list_head anon_vma_node; /* Serialized by anon_vma->lock */ + struct anon_vma *anon_vma; /* Serialized by page_table_lock */ + + /* 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). */ + void * vm_private_data; /* was vm_pte (shared mem) */ + unsigned long vm_truncate_count;/* truncate_count or restart_addr */ + +#ifndef CONFIG_MMU + atomic_t vm_usage; /* refcount (VMAs shared if !MMU) */ +#endif +#ifdef CONFIG_NUMA + struct mempolicy *vm_policy; /* NUMA policy for the VMA */ +#endif +}; + +/* + * This struct defines the per-mm list of VMAs for uClinux. If CONFIG_MMU is + * disabled, then there's a single shared list of VMAs maintained by the + * system, and mm's subscribe to these individually + */ +struct vm_list_struct { + struct vm_list_struct *next; + struct vm_area_struct *vma; +}; + +#ifndef CONFIG_MMU +extern struct rb_root nommu_vma_tree; +extern struct rw_semaphore nommu_vma_sem; + +extern unsigned int kobjsize(const void *objp); +#endif + +/* + * 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_ACCOUNT 0x00100000 /* Is a VM accounted object */ +#define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */ +#define VM_NONLINEAR 0x00800000 /* Is non-linear (remap_file_pages) */ +#define VM_MAPPED_COPY 0x01000000 /* T if mapped copy of data (nommu mmap) */ + +#ifndef VM_STACK_DEFAULT_FLAGS /* arch can override this */ +#define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS +#endif + +#ifdef CONFIG_STACK_GROWSUP +#define VM_STACK_FLAGS (VM_GROWSUP | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT) +#else +#define VM_STACK_FLAGS (VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT) +#endif + +#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) + +/* + * 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 *type); + int (*populate)(struct vm_area_struct * area, unsigned long address, unsigned long len, pgprot_t prot, unsigned long pgoff, int nonblock); +#ifdef CONFIG_NUMA + int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new); + struct mempolicy *(*get_policy)(struct vm_area_struct *vma, + unsigned long addr); +#endif +}; + +struct mmu_gather; +struct inode; + +#ifdef ARCH_HAS_ATOMIC_UNSIGNED +typedef unsigned page_flags_t; +#else +typedef unsigned long page_flags_t; +#endif + +/* + * 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. + */ +struct page { + page_flags_t flags; /* Atomic flags, some possibly + * updated asynchronously */ + atomic_t _count; /* Usage count, see below. */ + atomic_t _mapcount; /* Count of ptes mapped in mms, + * to show when page is mapped + * & limit reverse map searches. + */ + unsigned long private; /* Mapping-private opaque data: + * usually used for buffer_heads + * if PagePrivate set; used for + * swp_entry_t if PageSwapCache + * When page is free, this indicates + * order in the buddy system. + */ + struct address_space *mapping; /* If low bit clear, points to + * inode address_space, or NULL. + * If page mapped as anonymous + * memory, low bit is set, and + * it points to anon_vma object: + * see PAGE_MAPPING_ANON below. + */ + pgoff_t index; /* Our offset within mapping. */ + struct list_head lru; /* Pageout list, eg. active_list + * protected by zone->lru_lock ! + */ + /* + * 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(WANT_PAGE_VIRTUAL) + void *virtual; /* Kernel virtual address (NULL if + not kmapped, ie. highmem) */ +#endif /* WANT_PAGE_VIRTUAL */ +}; + +/* + * FIXME: take this include out, include page-flags.h in + * files which need it (119 of them) + */ +#include <linux/page-flags.h> + +/* + * Methods to modify the page usage count. + * + * What counts for a page usage: + * - cache mapping (page->mapping) + * - private data (page->private) + * - 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. + * + * Since 2.6.6 (approx), a free page has ->_count = -1. This is so that we + * can use atomic_add_negative(-1, page->_count) to detect when the page + * becomes free and so that we can also use atomic_inc_and_test to atomically + * detect when we just tried to grab a ref on a page which some other CPU has + * already deemed to be freeable. + * + * NO code should make assumptions about this internal detail! Use the provided + * macros which retain the old rules: page_count(page) == 0 is a free page. + */ + +/* + * Drop a ref, return true if the logical refcount fell to zero (the page has + * no users) + */ +#define put_page_testzero(p) \ + ({ \ + BUG_ON(page_count(p) == 0); \ + atomic_add_negative(-1, &(p)->_count); \ + }) + +/* + * Grab a ref, return true if the page previously had a logical refcount of + * zero. ie: returns true if we just grabbed an already-deemed-to-be-free page + */ +#define get_page_testone(p) atomic_inc_and_test(&(p)->_count) + +#define set_page_count(p,v) atomic_set(&(p)->_count, v - 1) +#define __put_page(p) atomic_dec(&(p)->_count) + +extern void FASTCALL(__page_cache_release(struct page *)); + +#ifdef CONFIG_HUGETLB_PAGE + +static inline int page_count(struct page *p) +{ + if (PageCompound(p)) + p = (struct page *)p->private; + return atomic_read(&(p)->_count) + 1; +} + +static inline void get_page(struct page *page) +{ + if (unlikely(PageCompound(page))) + page = (struct page *)page->private; + atomic_inc(&page->_count); +} + +void put_page(struct page *page); + +#else /* CONFIG_HUGETLB_PAGE */ + +#define page_count(p) (atomic_read(&(p)->_count) + 1) + +static inline void get_page(struct page *page) +{ + atomic_inc(&page->_count); +} + +static inline void put_page(struct page *page) +{ + if (!PageReserved(page) && put_page_testzero(page)) + __page_cache_release(page); +} + +#endif /* CONFIG_HUGETLB_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(page) 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 contains an opaque `private' member, which belongs to the + * page's address_space. Usually, this is the address of a circular + * list of the page's disk buffers. + * + * For pages belonging to inodes, the page_count() is the number of + * attaches, plus 1 if `private' contains something, 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 per-mapping radix tree mapping index to the page + * in memory if present. The tree is rooted at mapping->root. + * + * 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. + */ + +/* + * The zone field is never updated after free_area_init_core() + * sets it, so none of the operations on it need to be atomic. + * We'll have up to (MAX_NUMNODES * MAX_NR_ZONES) zones total, + * so we use (MAX_NODES_SHIFT + MAX_ZONES_SHIFT) here to get enough bits. + */ +#define NODEZONE_SHIFT (sizeof(page_flags_t)*8 - MAX_NODES_SHIFT - MAX_ZONES_SHIFT) +#define NODEZONE(node, zone) ((node << ZONES_SHIFT) | zone) + +static inline unsigned long page_zonenum(struct page *page) +{ + return (page->flags >> NODEZONE_SHIFT) & (~(~0UL << ZONES_SHIFT)); +} +static inline unsigned long page_to_nid(struct page *page) +{ + return (page->flags >> (NODEZONE_SHIFT + ZONES_SHIFT)); +} + +struct zone; +extern struct zone *zone_table[]; + +static inline struct zone *page_zone(struct page *page) +{ + return zone_table[page->flags >> NODEZONE_SHIFT]; +} + +static inline void set_page_zone(struct page *page, unsigned long nodezone_num) +{ + page->flags &= ~(~0UL << NODEZONE_SHIFT); + page->flags |= nodezone_num << NODEZONE_SHIFT; +} + +#ifndef CONFIG_DISCONTIGMEM +/* The array of struct pages - for discontigmem use pgdat->lmem_map */ +extern struct page *mem_map; +#endif + +static inline void *lowmem_page_address(struct page *page) +{ + return __va(page_to_pfn(page) << PAGE_SHIFT); +} + +#if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL) +#define HASHED_PAGE_VIRTUAL +#endif + +#if defined(WANT_PAGE_VIRTUAL) +#define page_address(page) ((page)->virtual) +#define set_page_address(page, address) \ + do { \ + (page)->virtual = (address); \ + } while(0) +#define page_address_init() do { } while(0) +#endif + +#if defined(HASHED_PAGE_VIRTUAL) +void *page_address(struct page *page); +void set_page_address(struct page *page, void *virtual); +void page_address_init(void); +#endif + +#if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL) +#define page_address(page) lowmem_page_address(page) +#define set_page_address(page, address) do { } while(0) +#define page_address_init() do { } while(0) +#endif + +/* + * On an anonymous page mapped into a user virtual memory area, + * page->mapping points to its anon_vma, not to a struct address_space; + * with the PAGE_MAPPING_ANON bit set to distinguish it. + * + * Please note that, confusingly, "page_mapping" refers to the inode + * address_space which maps the page from disk; whereas "page_mapped" + * refers to user virtual address space into which the page is mapped. + */ +#define PAGE_MAPPING_ANON 1 + +extern struct address_space swapper_space; +static inline struct address_space *page_mapping(struct page *page) +{ + struct address_space *mapping = page->mapping; + + if (unlikely(PageSwapCache(page))) + mapping = &swapper_space; + else if (unlikely((unsigned long)mapping & PAGE_MAPPING_ANON)) + mapping = NULL; + return mapping; +} + +static inline int PageAnon(struct page *page) +{ + return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; +} + +/* + * Return the pagecache index of the passed page. Regular pagecache pages + * use ->index whereas swapcache pages use ->private + */ +static inline pgoff_t page_index(struct page *page) +{ + if (unlikely(PageSwapCache(page))) + return page->private; + return page->index; +} + +/* + * The atomic page->_mapcount, like _count, starts from -1: + * so that transitions both from it and to it can be tracked, + * using atomic_inc_and_test and atomic_add_negative(-1). + */ +static inline void reset_page_mapcount(struct page *page) +{ + atomic_set(&(page)->_mapcount, -1); +} + +static inline int page_mapcount(struct page *page) +{ + return atomic_read(&(page)->_mapcount) + 1; +} + +/* + * Return true if this page is mapped into pagetables. + */ +static inline int page_mapped(struct page *page) +{ + return atomic_read(&(page)->_mapcount) >= 0; +} + +/* + * Error return values for the *_nopage functions + */ +#define NOPAGE_SIGBUS (NULL) +#define NOPAGE_OOM ((struct page *) (-1)) + +/* + * Different kinds of faults, as returned by handle_mm_fault(). + * Used to decide whether a process gets delivered SIGBUS or + * just gets major/minor fault counters bumped up. + */ +#define VM_FAULT_OOM (-1) +#define VM_FAULT_SIGBUS 0 +#define VM_FAULT_MINOR 1 +#define VM_FAULT_MAJOR 2 + +#define offset_in_page(p) ((unsigned long)(p) & ~PAGE_MASK) + +extern void show_free_areas(void); + +#ifdef CONFIG_SHMEM +struct page *shmem_nopage(struct vm_area_struct *vma, + unsigned long address, int *type); +int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *new); +struct mempolicy *shmem_get_policy(struct vm_area_struct *vma, + unsigned long addr); +int shmem_lock(struct file *file, int lock, struct user_struct *user); +#else +#define shmem_nopage filemap_nopage +#define shmem_lock(a, b, c) ({0;}) /* always in memory, no need to lock */ +#define shmem_set_policy(a, b) (0) +#define shmem_get_policy(a, b) (NULL) +#endif +struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags); + +int shmem_zero_setup(struct vm_area_struct *); + +static inline int can_do_mlock(void) +{ + if (capable(CAP_IPC_LOCK)) + return 1; + if (current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur != 0) + return 1; + return 0; +} +extern int user_shm_lock(size_t, struct user_struct *); +extern void user_shm_unlock(size_t, struct user_struct *); + +/* + * Parameter block passed down to zap_pte_range in exceptional cases. + */ +struct zap_details { + struct vm_area_struct *nonlinear_vma; /* Check page->index if set */ + struct address_space *check_mapping; /* Check page->mapping if set */ + pgoff_t first_index; /* Lowest page->index to unmap */ + pgoff_t last_index; /* Highest page->index to unmap */ + spinlock_t *i_mmap_lock; /* For unmap_mapping_range: */ + unsigned long break_addr; /* Where unmap_vmas stopped */ + unsigned long truncate_count; /* Compare vm_truncate_count */ +}; + +void zap_page_range(struct vm_area_struct *vma, unsigned long address, + unsigned long size, struct zap_details *); +int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm, + struct vm_area_struct *start_vma, unsigned long start_addr, + unsigned long end_addr, unsigned long *nr_accounted, + struct zap_details *); +void clear_page_range(struct mmu_gather *tlb, unsigned long addr, unsigned long end); +int copy_page_range(struct mm_struct *dst, struct mm_struct *src, + struct vm_area_struct *vma); +int zeromap_page_range(struct vm_area_struct *vma, unsigned long from, + unsigned long size, pgprot_t prot); +void unmap_mapping_range(struct address_space *mapping, + loff_t const holebegin, loff_t const holelen, int even_cows); + +static inline void unmap_shared_mapping_range(struct address_space *mapping, + loff_t const holebegin, loff_t const holelen) +{ + unmap_mapping_range(mapping, holebegin, holelen, 0); +} + +extern int vmtruncate(struct inode * inode, loff_t offset); +extern pud_t *FASTCALL(__pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)); +extern pmd_t *FASTCALL(__pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)); +extern pte_t *FASTCALL(pte_alloc_kernel(struct mm_struct *mm, pmd_t *pmd, unsigned long address)); +extern pte_t *FASTCALL(pte_alloc_map(struct mm_struct *mm, pmd_t *pmd, unsigned long address)); +extern int install_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, struct page *page, pgprot_t prot); +extern int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, unsigned long pgoff, pgprot_t prot); +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); +void install_arg_page(struct vm_area_struct *, struct page *, unsigned long); + +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); + +int __set_page_dirty_buffers(struct page *page); +int __set_page_dirty_nobuffers(struct page *page); +int redirty_page_for_writepage(struct writeback_control *wbc, + struct page *page); +int FASTCALL(set_page_dirty(struct page *page)); +int set_page_dirty_lock(struct page *page); +int clear_page_dirty_for_io(struct page *page); + +extern unsigned long do_mremap(unsigned long addr, + unsigned long old_len, unsigned long new_len, + unsigned long flags, unsigned long new_addr); + +/* + * Prototype to add a shrinker callback for ageable caches. + * + * These functions are passed a count `nr_to_scan' and a gfpmask. They should + * scan `nr_to_scan' objects, attempting to free them. + * + * The callback must the number of objects which remain in the cache. + * + * The callback will be passes nr_to_scan == 0 when the VM is querying the + * cache size, so a fastpath for that case is appropriate. + */ +typedef int (*shrinker_t)(int nr_to_scan, unsigned int gfp_mask); + +/* + * Add an aging callback. The int is the number of 'seeks' it takes + * to recreate one of the objects that these functions age. + */ + +#define DEFAULT_SEEKS 2 +struct shrinker; +extern struct shrinker *set_shrinker(int, shrinker_t); +extern void remove_shrinker(struct shrinker *shrinker); + +/* + * On a two-level or three-level page table, this ends up being trivial. Thus + * the inlining and the symmetry break with pte_alloc_map() that does all + * of this out-of-line. + */ +/* + * The following ifdef needed to get the 4level-fixup.h header to work. + * Remove it when 4level-fixup.h has been removed. + */ +#ifdef CONFIG_MMU +#ifndef __ARCH_HAS_4LEVEL_HACK +static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address) +{ + if (pgd_none(*pgd)) + return __pud_alloc(mm, pgd, address); + return pud_offset(pgd, address); +} + +static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) +{ + if (pud_none(*pud)) + return __pmd_alloc(mm, pud, address); + return pmd_offset(pud, address); +} +#endif +#endif /* CONFIG_MMU */ + +extern void free_area_init(unsigned long * zones_size); +extern void free_area_init_node(int nid, pg_data_t *pgdat, + unsigned long * zones_size, unsigned long zone_start_pfn, + unsigned long *zholes_size); +extern void memmap_init_zone(unsigned long, int, unsigned long, unsigned long); +extern void mem_init(void); +extern void show_mem(void); +extern void si_meminfo(struct sysinfo * val); +extern void si_meminfo_node(struct sysinfo *val, int nid); + +/* prio_tree.c */ +void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old); +void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *); +void vma_prio_tree_remove(struct vm_area_struct *, struct prio_tree_root *); +struct vm_area_struct *vma_prio_tree_next(struct vm_area_struct *vma, + struct prio_tree_iter *iter); + +#define vma_prio_tree_foreach(vma, iter, root, begin, end) \ + for (prio_tree_iter_init(iter, root, begin, end), vma = NULL; \ + (vma = vma_prio_tree_next(vma, iter)); ) + +static inline void vma_nonlinear_insert(struct vm_area_struct *vma, + struct list_head *list) +{ + vma->shared.vm_set.parent = NULL; + list_add_tail(&vma->shared.vm_set.list, list); +} + +/* mmap.c */ +extern int __vm_enough_memory(long pages, int cap_sys_admin); +extern void vma_adjust(struct vm_area_struct *vma, unsigned long start, + unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert); +extern struct vm_area_struct *vma_merge(struct mm_struct *, + struct vm_area_struct *prev, unsigned long addr, unsigned long end, + unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t, + struct mempolicy *); +extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *); +extern int split_vma(struct mm_struct *, + struct vm_area_struct *, unsigned long addr, int new_below); +extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *); +extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *, + struct rb_node **, struct rb_node *); +extern struct vm_area_struct *copy_vma(struct vm_area_struct **, + unsigned long addr, unsigned long len, pgoff_t pgoff); +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); + +/* filemap.c */ +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 struct page *filemap_nopage(struct vm_area_struct *, unsigned long, int *); +extern int filemap_populate(struct vm_area_struct *, unsigned long, + unsigned long, pgprot_t, unsigned long, int); + +/* mm/page-writeback.c */ +int write_one_page(struct page *page, int wait); + +/* readahead.c */ +#define VM_MAX_READAHEAD 128 /* kbytes */ +#define VM_MIN_READAHEAD 16 /* kbytes (includes current page) */ +#define VM_MAX_CACHE_HIT 256 /* max pages in a row in cache before + * turning readahead off */ + +int do_page_cache_readahead(struct address_space *mapping, struct file *filp, + unsigned long offset, unsigned long nr_to_read); +int force_page_cache_readahead(struct address_space *mapping, struct file *filp, + unsigned long offset, unsigned long nr_to_read); +unsigned long page_cache_readahead(struct address_space *mapping, + struct file_ra_state *ra, + struct file *filp, + unsigned long offset, + unsigned long size); +void handle_ra_miss(struct address_space *mapping, + struct file_ra_state *ra, pgoff_t offset); +unsigned long max_sane_readahead(unsigned long nr); + +/* Do stack extension */ +extern int expand_stack(struct vm_area_struct * vma, unsigned long address); + +/* 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; +} + +static inline unsigned long vma_pages(struct vm_area_struct *vma) +{ + return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; +} + +extern struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr); + +extern struct page * vmalloc_to_page(void *addr); +extern unsigned long vmalloc_to_pfn(void *addr); +extern struct page * follow_page(struct mm_struct *mm, unsigned long address, + int write); +extern int check_user_page_readable(struct mm_struct *mm, unsigned long address); +int remap_pfn_range(struct vm_area_struct *, unsigned long, + unsigned long, unsigned long, pgprot_t); + +#ifdef CONFIG_PROC_FS +void __vm_stat_account(struct mm_struct *, unsigned long, struct file *, long); +#else +static inline void __vm_stat_account(struct mm_struct *mm, + unsigned long flags, struct file *file, long pages) +{ +} +#endif /* CONFIG_PROC_FS */ + +static inline void vm_stat_account(struct vm_area_struct *vma) +{ + __vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file, + vma_pages(vma)); +} + +static inline void vm_stat_unaccount(struct vm_area_struct *vma) +{ + __vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file, + -vma_pages(vma)); +} + +/* update per process rss and vm hiwater data */ +extern void update_mem_hiwater(struct task_struct *tsk); + +#ifndef CONFIG_DEBUG_PAGEALLOC +static inline void +kernel_map_pages(struct page *page, int numpages, int enable) +{ +} +#endif + +extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk); +#ifdef __HAVE_ARCH_GATE_AREA +int in_gate_area_no_task(unsigned long addr); +int in_gate_area(struct task_struct *task, unsigned long addr); +#else +int in_gate_area_no_task(unsigned long addr); +#define in_gate_area(task, addr) ({(void)task; in_gate_area_no_task(addr);}) +#endif /* __HAVE_ARCH_GATE_AREA */ + +#endif /* __KERNEL__ */ +#endif /* _LINUX_MM_H */ |