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#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/fs.h>

#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 int page_cluster;

#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

#endif

/*

 * 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).

 *

 * This structure is exactly 64 bytes on ia32.  Please think very, very hard

 * before adding anything to it.

 */

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,

         * one of the address_space->i_mmap{,shared} lists,

         * for shm areas, the list of attaches, otherwise unused.

         */

        struct list_head 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). */

        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_HUGETLB      0x00400000      /* Huge TLB Page VM */

#define VM_NONLINEAR    0x00800000      /* Is non-linear (remap_file_pages) */

#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 unused);

        int (*populate)(struct vm_area_struct * area, unsigned long address, unsigned long len, pgprot_t prot, unsigned long pgoff, int nonblock);

};

/* forward declaration; pte_chain is meant to be internal to rmap.c */

struct pte_chain;

struct mmu_gather;

struct inode;

/*

 * 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 zone->lru_lock !! */

        union {

                struct pte_chain *chain;/* Reverse pte mapping pointer.

                                         * protected by PG_chainlock */

                pte_addr_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(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.

 */

#define put_page_testzero(p)                            \

        ({                                              \

                BUG_ON(page_count(p) == 0);             \

                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)

#define __put_page(p)           atomic_dec(&(p)->count)

extern void FASTCALL(__page_cache_release(struct page *));

#ifdef CONFIG_HUGETLB_PAGE

static inline void get_page(struct page *page)

{

        if (PageCompound(page))

                page = (struct page *)page->lru.next;

        atomic_inc(&page->count);

}

static inline void put_page(struct page *page)

{

        if (PageCompound(page)) {

                page = (struct page *)page->lru.next;

                if (put_page_testzero(page)) {

                        if (page->lru.prev) {   /* destructor? */

                                (*(void (*)(struct page *))page->lru.prev)(page);

                        } else {

                                __page_cache_release(page);

                        }

                }

                return;

        }

        if (!PageReserved(page) && put_page_testzero(page))

                __page_cache_release(page);

}

#else           /* CONFIG_HUGETLB_PAGE */

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 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.

 */

#define ZONE_SHIFT (BITS_PER_LONG - 8)

struct zone;

extern struct zone *zone_table[];

static inline struct zone *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;

}

#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

/*

 * Return true if this page is mapped into pagetables.  Subtle: test pte.direct

 * rather than pte.chain.  Because sometimes pte.direct is 64-bit, and .chain

 * is only 32-bit.

 */

static inline int page_mapped(struct page *page)

{

        return page->pte.direct != 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);

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);

void shmem_lock(struct file * file, int lock);

int shmem_zero_setup(struct vm_area_struct *);

void zap_page_range(struct vm_area_struct *vma, unsigned long address,

                        unsigned long size);

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);

void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma,

                        unsigned long address, unsigned long size);

void clear_page_tables(struct mmu_gather *tlb, unsigned long first, int nr);

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);

extern void invalidate_mmap_range(struct address_space *mapping,

                                  loff_t const holebegin,

                                  loff_t const holelen);

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 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);

extern long sys_remap_file_pages(unsigned long start, unsigned long size, unsigned long prot, unsigned long pgoff, unsigned long nonblock);

extern long sys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice);

void put_dirty_page(struct task_struct *tsk, struct page *page,

                        unsigned long address, pgprot_t prot);

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 set_page_dirty_lock(struct page *page);

/*

 * 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);

/*

 * 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_pfn,

        unsigned long *zholes_size);

extern void memmap_init_zone(struct page *, 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);

/* mmap.c */

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)

{

#ifdef CONFIG_MMU

        if (!vma->vm_file && vma->vm_flags == vm_flags)

                return 1;

#endif

        return 0;

}

/* 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);

/* 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 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);

void page_cache_readahead(struct address_space *mapping,

                          struct file_ra_state *ra,

                          struct file *filp,

                          unsigned long offset);

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);

extern int split_vma(struct mm_struct * mm, struct vm_area_struct * vma,

                     unsigned long addr, int new_below);

/* 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 unsigned int nr_used_zone_pages(void);

extern struct page * vmalloc_to_page(void *addr);

extern struct page * follow_page(struct mm_struct *mm, unsigned long address,

                int write);

extern int remap_page_range(struct vm_area_struct *vma, unsigned long from,

                unsigned long to, unsigned long size, pgprot_t prot);

#ifndef CONFIG_DEBUG_PAGEALLOC

static inline void

kernel_map_pages(struct page *page, int numpages, int enable)

{

}

#endif

#endif /* __KERNEL__ */

#endif /* _LINUX_MM_H */