kernel-ark/include/linux/mm.h
Andy Whitcroft 33f2ef89f8 [PATCH] mm: make compound page destructor handling explicit
Currently we we use the lru head link of the second page of a compound page
to hold its destructor.  This was ok when it was purely an internal
implmentation detail.  However, hugetlbfs overrides this destructor
violating the layering.  Abstract this out as explicit calls, also
introduce a type for the callback function allowing them to be type
checked.  For each callback we pre-declare the function, causing a type
error on definition rather than on use elsewhere.

[akpm@osdl.org: cleanups]
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:25 -08:00

1170 lines
40 KiB
C

#ifndef _LINUX_MM_H
#define _LINUX_MM_H
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/capability.h>
#ifdef __KERNEL__
#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>
#include <linux/mutex.h>
#include <linux/debug_locks.h>
#include <linux/backing-dev.h>
#include <linux/mm_types.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>
#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
};
extern struct kmem_cache *vm_area_cachep;
/*
* 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
/* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
#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_PFNMAP 0x00000400 /* Page-ranges managed without "struct page", just pure PFN */
#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 /* Count as reserved_vm like IO */
#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) */
#define VM_INSERTPAGE 0x02000000 /* The vma has had "vm_insert_page()" done on it */
#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);
unsigned long (*nopfn)(struct vm_area_struct * area, unsigned long address);
int (*populate)(struct vm_area_struct * area, unsigned long address, unsigned long len, pgprot_t prot, unsigned long pgoff, int nonblock);
/* notification that a previously read-only page is about to become
* writable, if an error is returned it will cause a SIGBUS */
int (*page_mkwrite)(struct vm_area_struct *vma, struct page *page);
#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);
int (*migrate)(struct vm_area_struct *vma, const nodemask_t *from,
const nodemask_t *to, unsigned long flags);
#endif
};
struct mmu_gather;
struct inode;
#define page_private(page) ((page)->private)
#define set_page_private(page, v) ((page)->private = (v))
/*
* FIXME: take this include out, include page-flags.h in
* files which need it (119 of them)
*/
#include <linux/page-flags.h>
#ifdef CONFIG_DEBUG_VM
#define VM_BUG_ON(cond) BUG_ON(cond)
#else
#define VM_BUG_ON(condition) do { } while(0)
#endif
/*
* 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.
*/
/*
* Drop a ref, return true if the refcount fell to zero (the page has no users)
*/
static inline int put_page_testzero(struct page *page)
{
VM_BUG_ON(atomic_read(&page->_count) == 0);
return atomic_dec_and_test(&page->_count);
}
/*
* Try to grab a ref unless the page has a refcount of zero, return false if
* that is the case.
*/
static inline int get_page_unless_zero(struct page *page)
{
VM_BUG_ON(PageCompound(page));
return atomic_inc_not_zero(&page->_count);
}
static inline int page_count(struct page *page)
{
if (unlikely(PageCompound(page)))
page = (struct page *)page_private(page);
return atomic_read(&page->_count);
}
static inline void get_page(struct page *page)
{
if (unlikely(PageCompound(page)))
page = (struct page *)page_private(page);
VM_BUG_ON(atomic_read(&page->_count) == 0);
atomic_inc(&page->_count);
}
/*
* Setup the page count before being freed into the page allocator for
* the first time (boot or memory hotplug)
*/
static inline void init_page_count(struct page *page)
{
atomic_set(&page->_count, 1);
}
void put_page(struct page *page);
void put_pages_list(struct list_head *pages);
void split_page(struct page *page, unsigned int order);
/*
* Compound pages have a destructor function. Provide a
* prototype for that function and accessor functions.
* These are _only_ valid on the head of a PG_compound page.
*/
typedef void compound_page_dtor(struct page *);
static inline void set_compound_page_dtor(struct page *page,
compound_page_dtor *dtor)
{
page[1].lru.next = (void *)dtor;
}
static inline compound_page_dtor *get_compound_page_dtor(struct page *page)
{
return (compound_page_dtor *)page[1].lru.next;
}
/*
* 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->lru is then used for
* freelist management in the buddy allocator.
* page_count() > 0 means the page has been allocated.
*
* Pages are allocated by the slab allocator in order to provide memory
* to kmalloc and kmem_cache_alloc. In this case, the management of the
* page, and the fields in 'struct page' are the responsibility of mm/slab.c
* unless a particular usage is carefully commented. (the responsibility of
* freeing the kmalloc memory is the caller's, of course).
*
* A page may be used by anyone else who does a __get_free_page().
* In this case, page_count still tracks the references, and should only
* be used through the normal accessor functions. The top bits of page->flags
* and page->virtual store page management information, but all other fields
* are unused and could be used privately, carefully. The management of this
* page is the responsibility of the one who allocated it, and those who have
* subsequently been given references to it.
*
* The other pages (we may call them "pagecache pages") are completely
* managed by the Linux memory manager: I/O, buffers, swapping etc.
* The following discussion applies only to them.
*
* A pagecache 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. PG_private must be set to tell the VM to call
* into the filesystem to release these pages.
*
* 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.
*
* If pagecache pages are not associated with an inode, they are said to be
* anonymous pages. These may become associated with the swapcache, and in that
* case PG_swapcache is set, and page->private is an offset into the swapcache.
*
* In either case (swapcache or inode backed), the pagecache itself holds one
* reference to the page. Setting PG_private should also increment the
* refcount. The each user mapping also has a reference to the page.
*
* The pagecache pages are stored in a per-mapping radix tree, which is
* rooted at mapping->page_tree, and indexed by offset.
* Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
* lists, we instead now tag pages as dirty/writeback in the radix tree.
*
* All pagecache pages may be subject to 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 back to the inode on disk,
* - anonymous pages (including MAP_PRIVATE file mappings) 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.
*/
/*
* page->flags layout:
*
* There are three possibilities for how page->flags get
* laid out. The first is for the normal case, without
* sparsemem. The second is for sparsemem when there is
* plenty of space for node and section. The last is when
* we have run out of space and have to fall back to an
* alternate (slower) way of determining the node.
*
* No sparsemem: | NODE | ZONE | ... | FLAGS |
* with space for node: | SECTION | NODE | ZONE | ... | FLAGS |
* no space for node: | SECTION | ZONE | ... | FLAGS |
*/
#ifdef CONFIG_SPARSEMEM
#define SECTIONS_WIDTH SECTIONS_SHIFT
#else
#define SECTIONS_WIDTH 0
#endif
#define ZONES_WIDTH ZONES_SHIFT
#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= FLAGS_RESERVED
#define NODES_WIDTH NODES_SHIFT
#else
#define NODES_WIDTH 0
#endif
/* Page flags: | [SECTION] | [NODE] | ZONE | ... | FLAGS | */
#define SECTIONS_PGOFF ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
#define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH)
#define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH)
/*
* We are going to use the flags for the page to node mapping if its in
* there. This includes the case where there is no node, so it is implicit.
*/
#if !(NODES_WIDTH > 0 || NODES_SHIFT == 0)
#define NODE_NOT_IN_PAGE_FLAGS
#endif
#ifndef PFN_SECTION_SHIFT
#define PFN_SECTION_SHIFT 0
#endif
/*
* Define the bit shifts to access each section. For non-existant
* sections we define the shift as 0; that plus a 0 mask ensures
* the compiler will optimise away reference to them.
*/
#define SECTIONS_PGSHIFT (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
#define NODES_PGSHIFT (NODES_PGOFF * (NODES_WIDTH != 0))
#define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_WIDTH != 0))
/* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allcator */
#ifdef NODE_NOT_IN_PAGEFLAGS
#define ZONEID_SHIFT (SECTIONS_SHIFT + ZONES_SHIFT)
#else
#define ZONEID_SHIFT (NODES_SHIFT + ZONES_SHIFT)
#endif
#if ZONES_WIDTH > 0
#define ZONEID_PGSHIFT ZONES_PGSHIFT
#else
#define ZONEID_PGSHIFT NODES_PGOFF
#endif
#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED
#error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED
#endif
#define ZONES_MASK ((1UL << ZONES_WIDTH) - 1)
#define NODES_MASK ((1UL << NODES_WIDTH) - 1)
#define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1)
#define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1)
static inline enum zone_type page_zonenum(struct page *page)
{
return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
}
/*
* The identification function is only used by the buddy allocator for
* determining if two pages could be buddies. We are not really
* identifying a zone since we could be using a the section number
* id if we have not node id available in page flags.
* We guarantee only that it will return the same value for two
* combinable pages in a zone.
*/
static inline int page_zone_id(struct page *page)
{
BUILD_BUG_ON(ZONEID_PGSHIFT == 0 && ZONEID_MASK);
return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
}
static inline int zone_to_nid(struct zone *zone)
{
#ifdef CONFIG_NUMA
return zone->node;
#else
return 0;
#endif
}
#ifdef NODE_NOT_IN_PAGE_FLAGS
extern int page_to_nid(struct page *page);
#else
static inline int page_to_nid(struct page *page)
{
return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
}
#endif
static inline struct zone *page_zone(struct page *page)
{
return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
}
static inline unsigned long page_to_section(struct page *page)
{
return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
}
static inline void set_page_zone(struct page *page, enum zone_type zone)
{
page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
}
static inline void set_page_node(struct page *page, unsigned long node)
{
page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
}
static inline void set_page_section(struct page *page, unsigned long section)
{
page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
}
static inline void set_page_links(struct page *page, enum zone_type zone,
unsigned long node, unsigned long pfn)
{
set_page_zone(page, zone);
set_page_node(page, node);
set_page_section(page, pfn_to_section_nr(pfn));
}
/*
* Some inline functions in vmstat.h depend on page_zone()
*/
#include <linux/vmstat.h>
static __always_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(page);
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))
#define NOPAGE_REFAULT ((struct page *) (-2)) /* Return to userspace, rerun */
/*
* Error return values for the *_nopfn functions
*/
#define NOPFN_SIGBUS ((unsigned long) -1)
#define NOPFN_OOM ((unsigned long) -2)
/*
* 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 0x00
#define VM_FAULT_SIGBUS 0x01
#define VM_FAULT_MINOR 0x02
#define VM_FAULT_MAJOR 0x03
/*
* Special case for get_user_pages.
* Must be in a distinct bit from the above VM_FAULT_ flags.
*/
#define VM_FAULT_WRITE 0x10
#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
static inline int shmem_lock(struct file *file, int lock,
struct user_struct *user)
{
return 0;
}
static inline int shmem_set_policy(struct vm_area_struct *vma,
struct mempolicy *new)
{
return 0;
}
static inline struct mempolicy *shmem_get_policy(struct vm_area_struct *vma,
unsigned long addr)
{
return NULL;
}
#endif
struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags);
extern int shmem_mmap(struct file *file, struct vm_area_struct *vma);
int shmem_zero_setup(struct vm_area_struct *);
#ifndef CONFIG_MMU
extern unsigned long shmem_get_unmapped_area(struct file *file,
unsigned long addr,
unsigned long len,
unsigned long pgoff,
unsigned long flags);
#endif
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 truncate_count; /* Compare vm_truncate_count */
};
struct page *vm_normal_page(struct vm_area_struct *, unsigned long, pte_t);
unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
unsigned long size, struct zap_details *);
unsigned long unmap_vmas(struct mmu_gather **tlb,
struct vm_area_struct *start_vma, unsigned long start_addr,
unsigned long end_addr, unsigned long *nr_accounted,
struct zap_details *);
void free_pgd_range(struct mmu_gather **tlb, unsigned long addr,
unsigned long end, unsigned long floor, unsigned long ceiling);
void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *start_vma,
unsigned long floor, unsigned long ceiling);
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 int vmtruncate_range(struct inode * inode, loff_t offset, loff_t end);
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);
#ifdef CONFIG_MMU
extern int __handle_mm_fault(struct mm_struct *mm,struct vm_area_struct *vma,
unsigned long address, int write_access);
static inline int handle_mm_fault(struct mm_struct *mm,
struct vm_area_struct *vma, unsigned long address,
int write_access)
{
return __handle_mm_fault(mm, vma, address, write_access) &
(~VM_FAULT_WRITE);
}
#else
static inline int handle_mm_fault(struct mm_struct *mm,
struct vm_area_struct *vma, unsigned long address,
int write_access)
{
/* should never happen if there's no MMU */
BUG();
return VM_FAULT_SIGBUS;
}
#endif
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);
void print_bad_pte(struct vm_area_struct *, pte_t, unsigned long);
extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
extern void do_invalidatepage(struct page *page, unsigned long offset);
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 return the number of objects which remain in the cache.
*
* The callback will be passed 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, gfp_t 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);
/*
* Some shared mappigns will want the pages marked read-only
* to track write events. If so, we'll downgrade vm_page_prot
* to the private version (using protection_map[] without the
* VM_SHARED bit).
*/
static inline int vma_wants_writenotify(struct vm_area_struct *vma)
{
unsigned int vm_flags = vma->vm_flags;
/* If it was private or non-writable, the write bit is already clear */
if ((vm_flags & (VM_WRITE|VM_SHARED)) != ((VM_WRITE|VM_SHARED)))
return 0;
/* The backer wishes to know when pages are first written to? */
if (vma->vm_ops && vma->vm_ops->page_mkwrite)
return 1;
/* The open routine did something to the protections already? */
if (pgprot_val(vma->vm_page_prot) !=
pgprot_val(protection_map[vm_flags &
(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]))
return 0;
/* Specialty mapping? */
if (vm_flags & (VM_PFNMAP|VM_INSERTPAGE))
return 0;
/* Can the mapping track the dirty pages? */
return vma->vm_file && vma->vm_file->f_mapping &&
mapping_cap_account_dirty(vma->vm_file->f_mapping);
}
extern pte_t *FASTCALL(get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl));
int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
int __pte_alloc_kernel(pmd_t *pmd, unsigned long address);
/*
* The following ifdef needed to get the 4level-fixup.h header to work.
* Remove it when 4level-fixup.h has been removed.
*/
#if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
static inline pud_t *pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
{
return (unlikely(pgd_none(*pgd)) && __pud_alloc(mm, pgd, address))?
NULL: pud_offset(pgd, address);
}
static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
{
return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
NULL: pmd_offset(pud, address);
}
#endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
/*
* We tuck a spinlock to guard each pagetable page into its struct page,
* at page->private, with BUILD_BUG_ON to make sure that this will not
* overflow into the next struct page (as it might with DEBUG_SPINLOCK).
* When freeing, reset page->mapping so free_pages_check won't complain.
*/
#define __pte_lockptr(page) &((page)->ptl)
#define pte_lock_init(_page) do { \
spin_lock_init(__pte_lockptr(_page)); \
} while (0)
#define pte_lock_deinit(page) ((page)->mapping = NULL)
#define pte_lockptr(mm, pmd) ({(void)(mm); __pte_lockptr(pmd_page(*(pmd)));})
#else
/*
* We use mm->page_table_lock to guard all pagetable pages of the mm.
*/
#define pte_lock_init(page) do {} while (0)
#define pte_lock_deinit(page) do {} while (0)
#define pte_lockptr(mm, pmd) ({(void)(pmd); &(mm)->page_table_lock;})
#endif /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
#define pte_offset_map_lock(mm, pmd, address, ptlp) \
({ \
spinlock_t *__ptl = pte_lockptr(mm, pmd); \
pte_t *__pte = pte_offset_map(pmd, address); \
*(ptlp) = __ptl; \
spin_lock(__ptl); \
__pte; \
})
#define pte_unmap_unlock(pte, ptl) do { \
spin_unlock(ptl); \
pte_unmap(pte); \
} while (0)
#define pte_alloc_map(mm, pmd, address) \
((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
NULL: pte_offset_map(pmd, address))
#define pte_alloc_map_lock(mm, pmd, address, ptlp) \
((unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, pmd, address))? \
NULL: pte_offset_map_lock(mm, pmd, address, ptlp))
#define pte_alloc_kernel(pmd, address) \
((unlikely(!pmd_present(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
NULL: pte_offset_kernel(pmd, address))
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);
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
/*
* With CONFIG_ARCH_POPULATES_NODE_MAP set, an architecture may initialise its
* zones, allocate the backing mem_map and account for memory holes in a more
* architecture independent manner. This is a substitute for creating the
* zone_sizes[] and zholes_size[] arrays and passing them to
* free_area_init_node()
*
* An architecture is expected to register range of page frames backed by
* physical memory with add_active_range() before calling
* free_area_init_nodes() passing in the PFN each zone ends at. At a basic
* usage, an architecture is expected to do something like
*
* unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
* max_highmem_pfn};
* for_each_valid_physical_page_range()
* add_active_range(node_id, start_pfn, end_pfn)
* free_area_init_nodes(max_zone_pfns);
*
* If the architecture guarantees that there are no holes in the ranges
* registered with add_active_range(), free_bootmem_active_regions()
* will call free_bootmem_node() for each registered physical page range.
* Similarly sparse_memory_present_with_active_regions() calls
* memory_present() for each range when SPARSEMEM is enabled.
*
* See mm/page_alloc.c for more information on each function exposed by
* CONFIG_ARCH_POPULATES_NODE_MAP
*/
extern void free_area_init_nodes(unsigned long *max_zone_pfn);
extern void add_active_range(unsigned int nid, unsigned long start_pfn,
unsigned long end_pfn);
extern void shrink_active_range(unsigned int nid, unsigned long old_end_pfn,
unsigned long new_end_pfn);
extern void push_node_boundaries(unsigned int nid, unsigned long start_pfn,
unsigned long end_pfn);
extern void remove_all_active_ranges(void);
extern unsigned long absent_pages_in_range(unsigned long start_pfn,
unsigned long end_pfn);
extern void get_pfn_range_for_nid(unsigned int nid,
unsigned long *start_pfn, unsigned long *end_pfn);
extern unsigned long find_min_pfn_with_active_regions(void);
extern unsigned long find_max_pfn_with_active_regions(void);
extern void free_bootmem_with_active_regions(int nid,
unsigned long max_low_pfn);
extern void sparse_memory_present_with_active_regions(int nid);
#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
extern int early_pfn_to_nid(unsigned long pfn);
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
extern void set_dma_reserve(unsigned long new_dma_reserve);
extern void memmap_init_zone(unsigned long, int, unsigned long, unsigned long);
extern void setup_per_zone_pages_min(void);
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);
#ifdef CONFIG_NUMA
extern void setup_per_cpu_pageset(void);
#else
static inline void setup_per_cpu_pageset(void) {}
#endif
/* 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 void unlink_file_vma(struct vm_area_struct *);
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 int may_expand_vm(struct mm_struct *mm, unsigned long npages);
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);
extern void truncate_inode_pages_range(struct address_space *,
loff_t lstart, loff_t lend);
/* 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,
pgoff_t offset, unsigned long nr_to_read);
int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
pgoff_t offset, unsigned long nr_to_read);
unsigned long page_cache_readahead(struct address_space *mapping,
struct file_ra_state *ra,
struct file *filp,
pgoff_t 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);
#ifdef CONFIG_IA64
extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
#endif
/* 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;
}
pgprot_t vm_get_page_prot(unsigned long vm_flags);
struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
struct page *vmalloc_to_page(void *addr);
unsigned long vmalloc_to_pfn(void *addr);
int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
unsigned long pfn, unsigned long size, pgprot_t);
int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
struct page *follow_page(struct vm_area_struct *, unsigned long address,
unsigned int foll_flags);
#define FOLL_WRITE 0x01 /* check pte is writable */
#define FOLL_TOUCH 0x02 /* mark page accessed */
#define FOLL_GET 0x04 /* do get_page on page */
#define FOLL_ANON 0x08 /* give ZERO_PAGE if no pgtable */
#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 */
#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 */
int drop_caches_sysctl_handler(struct ctl_table *, int, struct file *,
void __user *, size_t *, loff_t *);
unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
unsigned long lru_pages);
void drop_pagecache(void);
void drop_slab(void);
#ifndef CONFIG_MMU
#define randomize_va_space 0
#else
extern int randomize_va_space;
#endif
__attribute__((weak)) const char *arch_vma_name(struct vm_area_struct *vma);
#endif /* __KERNEL__ */
#endif /* _LINUX_MM_H */