#ifndef _LINUX_MM_H #define _LINUX_MM_H #include #include #ifdef __KERNEL__ #include #include #include #include #include #include #include #include extern unsigned long max_mapnr; extern unsigned long num_physpages; 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 #include #include /* * 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. */ list_t shared; /* 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; /* XXX: put full readahead info here. */ 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_ACCOUNT 0x00100000 /* Is a VM accounted object */ #define VM_STACK_FLAGS (0x00000100 | VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT) #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 unused); }; /* forward declaration; pte_chain is meant to be internal to rmap.c */ struct pte_chain; /* * 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. */ struct page { unsigned long flags; /* atomic flags, some possibly updated asynchronously */ atomic_t count; /* Usage count, see below. */ 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 list_head lru; /* Pageout list, eg. active_list; protected by pagemap_lru_lock !! */ union { struct pte_chain * chain; /* Reverse pte mapping pointer. * protected by PG_chainlock */ pte_t * direct; } pte; unsigned long private; /* mapping-private opaque data */ /* * 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 */ }; /* * 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. */ #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) /* * 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 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. */ /* * FIXME: take this include out, include page-flags.h in * files which need it (119 of them) */ #include /* * 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 */ /* * 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 /* The array of struct pages */ extern struct page *mem_map; extern void show_free_areas(void); 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, unsigned long flags); extern void shmem_lock(struct file * file, int lock); extern int shmem_zero_setup(struct vm_area_struct *); extern void zap_page_range(struct vm_area_struct *vma, 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(struct vm_area_struct *vma, unsigned long from, unsigned long to, unsigned long size, pgprot_t prot); extern int zeromap_page_range(struct vm_area_struct *vma, 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_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 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); int __set_page_dirty_buffers(struct page *page); int __set_page_dirty_nobuffers(struct page *page); /* * If the mapping doesn't provide a set_page_dirty a_op, then * just fall through and assume that it wants buffer_heads. * FIXME: make the method unconditional. */ static inline int set_page_dirty(struct page *page) { if (page->mapping) { int (*spd)(struct page *); spd = page->mapping->a_ops->set_page_dirty; if (spd) return (*spd)(page); } return __set_page_dirty_buffers(page); } /* * On a two-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. */ 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 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 int can_share_swap_page(struct page *); extern int remove_exclusive_swap_page(struct page *); /* 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); /* 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) */ int do_page_cache_readahead(struct file *file, unsigned long offset, unsigned long nr_to_read); void page_cache_readahead(struct file *file, unsigned long offset); void page_cache_readaround(struct file *file, unsigned long offset); void handle_ra_miss(struct file *file); /* 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; } 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 get_page_cache_size(void); #endif /* __KERNEL__ */ #endif