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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 */