#ifndef _LINUX_MM_H
#define _LINUX_MM_H
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#ifdef __KERNEL__
#include <linux/string.h>
extern unsigned long high_memory;
#include <asm/page.h>
#include <asm/atomic.h>
#define VERIFY_READ 0
#define VERIFY_WRITE 1
extern int verify_area(int, const void *, unsigned long);
/*
* 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; /* VM area parameters */
unsigned long vm_start;
unsigned long vm_end;
pgprot_t vm_page_prot;
unsigned short vm_flags;
/* AVL tree of VM areas per task, sorted by address */
short vm_avl_height;
struct vm_area_struct * vm_avl_left;
struct vm_area_struct * vm_avl_right;
/* linked list of VM areas per task, sorted by address */
struct vm_area_struct * vm_next;
/* for areas with inode, the circular list inode->i_mmap */
/* for shm areas, the circular list of attaches */
/* otherwise unused */
struct vm_area_struct * vm_next_share;
struct vm_area_struct * vm_prev_share;
/* more */
struct vm_operations_struct * vm_ops;
unsigned long vm_offset;
struct inode * vm_inode;
unsigned long vm_pte; /* shared mem */
};
/*
* vm_flags..
*/
#define VM_READ 0x0001 /* currently active flags */
#define VM_WRITE 0x0002
#define VM_EXEC 0x0004
#define VM_SHARED 0x0008
#define VM_MAYREAD 0x0010 /* limits for mprotect() etc */
#define VM_MAYWRITE 0x0020
#define VM_MAYEXEC 0x0040
#define VM_MAYSHARE 0x0080
#define VM_GROWSDOWN 0x0100 /* general info on the segment */
#define VM_GROWSUP 0x0200
#define VM_SHM 0x0400 /* shared memory area, don't swap out */
#define VM_DENYWRITE 0x0800 /* ETXTBSY on write attempts.. */
#define VM_EXECUTABLE 0x1000
#define VM_LOCKED 0x2000
#define VM_STACK_FLAGS 0x0177
/*
* 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);
void (*unmap)(struct vm_area_struct *area, unsigned long, size_t);
void (*protect)(struct vm_area_struct *area, unsigned long, size_t, unsigned int newprot);
int (*sync)(struct vm_area_struct *area, unsigned long, size_t, unsigned int flags);
void (*advise)(struct vm_area_struct *area, unsigned long, size_t, unsigned int advise);
unsigned long (*nopage)(struct vm_area_struct * area, unsigned long address, int write_access);
unsigned long (*wppage)(struct vm_area_struct * area, unsigned long address,
unsigned long page);
int (*swapout)(struct vm_area_struct *, unsigned long, pte_t *);
pte_t (*swapin)(struct vm_area_struct *, unsigned long, unsigned long);
};
/*
* 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).
*/
typedef struct page {
struct inode *inode;
unsigned long offset;
struct page *next_hash;
atomic_t count;
unsigned flags; /* atomic flags, some possibly updated asynchronously */
unsigned dirty:16,
age:8;
struct wait_queue *wait;
struct page *next;
struct page *prev;
struct page *prev_hash;
struct buffer_head * buffers;
unsigned long swap_unlock_entry;
unsigned long map_nr; /* page->map_nr == page - mem_map */
} mem_map_t;
/* Page flag bit values */
#define PG_locked 0
#define PG_error 1
#define PG_referenced 2
#define PG_uptodate 3
#define PG_free_after 4
#define PG_decr_after 5
#define PG_swap_unlock_after 6
#define PG_DMA 7
#define PG_reserved 31
/* Make it prettier to test the above... */
#define PageLocked(page) (test_bit(PG_locked, &(page)->flags))
#define PageError(page) (test_bit(PG_error, &(page)->flags))
#define PageReferenced(page) (test_bit(PG_referenced, &(page)->flags))
#define PageDirty(page) (test_bit(PG_dirty, &(page)->flags))
#define PageUptodate(page) (test_bit(PG_uptodate, &(page)->flags))
#define PageFreeAfter(page) (test_bit(PG_free_after, &(page)->flags))
#define PageDecrAfter(page) (test_bit(PG_decr_after, &(page)->flags))
#define PageSwapUnlockAfter(page) (test_bit(PG_swap_unlock_after, &(page)->flags))
#define PageDMA(page) (test_bit(PG_DMA, &(page)->flags))
#define PageReserved(page) (test_bit(PG_reserved, &(page)->flags))
/*
* page->reserved denotes a page which must never be accessed (which
* may not even be present).
*
* page->dma is set for those pages which lie in the range of
* physical addresses capable of carrying DMA transfers.
*
* 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->inode is the inode, and page->offset is the file offset
* of the page (not necessarily a multiple of PAGE_SIZE).
*
* A page may have buffers allocated to it. In this case,
* page->buffers is a circular list of these buffer heads. Else,
* page->buffers == NULL.
*
* For pages belonging to inodes, the page->count is the number of
* attaches, plus 1 if buffers are allocated to the page.
*
* All pages belonging to an inode make up a doubly linked list
* inode->i_pages, using the fields page->next and page->prev. (These
* fields are also used for freelist management when page->count==0.)
* There is also a hash table mapping (inode,offset) to the page
* in memory if present. The lists for this hash table use the fields
* page->next_hash and page->prev_hash.
*
* 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.
* During disk I/O, page->locked is true. This bit is set before I/O
* and reset when I/O completes. page->wait is a wait queue of all
* tasks waiting for the I/O on this page to complete.
* page->uptodate tells whether the page's contents is valid.
* When a read completes, the page becomes uptodate, unless a disk I/O
* error happened.
* When a write completes, and page->free_after is true, the page is
* freed without any further delay.
*
* For choosing which pages to swap out, inode pages carry a
* page->referenced bit, which is set any time the system accesses
* that page through the (inode,offset) hash table.
* There is also the page->age counter, which implements a linear
* decay (why not an exponential decay?), see swapctl.h.
*/
extern mem_map_t * mem_map;
/*
* This is timing-critical - most of the time in getting a new page
* goes to clearing the page. If you want a page without the clearing
* overhead, just use __get_free_page() directly..
*/
#define __get_free_page(priority) __get_free_pages((priority),0,0)
#define __get_dma_pages(priority, order) __get_free_pages((priority),(order),1)
extern unsigned long __get_free_pages(int priority, unsigned long gfporder, int dma);
extern inline unsigned long get_free_page(int priority)
{
unsigned long page;
page = __get_free_page(priority);
if (page)
memset((void *) page, 0, PAGE_SIZE);
return page;
}
/* memory.c & swap.c*/
#define free_page(addr) free_pages((addr),0)
extern void free_pages(unsigned long addr, unsigned long order);
extern void show_free_areas(void);
extern unsigned long put_dirty_page(struct task_struct * tsk,unsigned long page,
unsigned long address);
extern void free_page_tables(struct mm_struct * mm);
extern void clear_page_tables(struct task_struct * tsk);
extern int new_page_tables(struct task_struct * tsk);
extern int copy_page_tables(struct task_struct * to);
extern int zap_page_range(struct mm_struct *mm, 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(unsigned long from, unsigned long to, unsigned long size, pgprot_t prot);
extern int zeromap_page_range(unsigned long from, unsigned long size, pgprot_t prot);
extern void vmtruncate(struct inode * inode, unsigned long offset);
extern void handle_mm_fault(struct vm_area_struct *vma, unsigned long address, int write_access);
extern void do_wp_page(struct task_struct * tsk, struct vm_area_struct * vma, unsigned long address, int write_access);
extern void do_no_page(struct task_struct * tsk, struct vm_area_struct * vma, unsigned long address, int write_access);
extern unsigned long paging_init(unsigned long start_mem, unsigned long end_mem);
extern void mem_init(unsigned long start_mem, unsigned long end_mem);
extern void show_mem(void);
extern void oom(struct task_struct * tsk);
extern void si_meminfo(struct sysinfo * val);
/* vmalloc.c */
extern void * vmalloc(unsigned long size);
extern void * vremap(unsigned long offset, unsigned long size);
extern void vfree(void * addr);
extern int vread(char *buf, char *addr, int count);
/* mmap.c */
extern unsigned long do_mmap(struct file * file, unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags, unsigned long off);
extern void merge_segments(struct task_struct *, unsigned long, unsigned long);
extern void insert_vm_struct(struct task_struct *, struct vm_area_struct *);
extern void remove_shared_vm_struct(struct vm_area_struct *);
extern void build_mmap_avl(struct mm_struct *);
extern void exit_mmap(struct mm_struct *);
extern int do_munmap(unsigned long, size_t);
extern unsigned long get_unmapped_area(unsigned long, unsigned long);
/* filemap.c */
extern unsigned long page_unuse(unsigned long);
extern int shrink_mmap(int, int);
extern void truncate_inode_pages(struct inode *, unsigned long);
#define GFP_BUFFER 0x00
#define GFP_ATOMIC 0x01
#define GFP_USER 0x02
#define GFP_KERNEL 0x03
#define GFP_NOBUFFER 0x04
#define GFP_NFS 0x05
/* Flag - indicates that the buffer will be suitable for DMA. Ignored on some
platforms, used as appropriate on others */
#define GFP_DMA 0x80
#define GFP_LEVEL_MASK 0xf
/* vma is the first one with address < vma->vm_end,
* and even address < vma->vm_start. Have to extend vma. */
static inline int expand_stack(struct vm_area_struct * vma, unsigned long address)
{
unsigned long grow;
address &= PAGE_MASK;
if (vma->vm_end - address
> (unsigned long) current->rlim[RLIMIT_STACK].rlim_cur)
return -ENOMEM;
grow = vma->vm_start - address;
vma->vm_start = address;
vma->vm_offset -= grow;
vma->vm_mm->total_vm += grow >> PAGE_SHIFT;
if (vma->vm_flags & VM_LOCKED)
vma->vm_mm->locked_vm += grow >> PAGE_SHIFT;
return 0;
}
#define avl_empty (struct vm_area_struct *) NULL
/* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
static inline struct vm_area_struct * find_vma (struct task_struct * task, unsigned long addr)
{
struct vm_area_struct * result = NULL;
if (task->mm) {
struct vm_area_struct * tree = task->mm->mmap_avl;
for (;;) {
if (tree == avl_empty)
break;
if (tree->vm_end > addr) {
result = tree;
if (tree->vm_start <= addr)
break;
tree = tree->vm_avl_left;
} else
tree = tree->vm_avl_right;
}
}
return result;
}
/* 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 task_struct * task, unsigned long start_addr, unsigned long end_addr)
{
struct vm_area_struct * vma;
vma = find_vma(task,start_addr);
if (!vma || end_addr <= vma->vm_start)
return NULL;
return vma;
}
#endif /* __KERNEL__ */
#endif
(/pre>