mm.h

unxi下共享内存的使用

#else /* CONFIG_HIGHMEM || WANT_PAGE_VIRTUAL */

#define set_page_address(page, address)  do { } while(0)
#ifdef CONFIG_DISCONTIGMEM
#define page_address(page)					\
	__va( ((page) - page_zone(page)->zone_mem_map) +	\
	       page_zone(page)->zone_start_pfn << PAGE_SHIFT)
#else
#define page_address(page) __va(((page) - mem_map) << PAGE_SHIFT)
#endif

#endif /* CONFIG_HIGHMEM || WANT_PAGE_VIRTUAL */

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

/*
 * The first mb is necessary to safely close the critical section opened by the
 * TryLockPage(), the second mb is necessary to enforce ordering between
 * the clear_bit and the read of the waitqueue (to avoid SMP races with a
 * parallel wait_on_page).
 */
#define PageError(page)		test_bit(PG_error, &(page)->flags)
#define SetPageError(page)	set_bit(PG_error, &(page)->flags)
#define ClearPageError(page)	clear_bit(PG_error, &(page)->flags)
#define PageReferenced(page)	test_bit(PG_referenced, &(page)->flags)
#define SetPageReferenced(page)	set_bit(PG_referenced, &(page)->flags)
#define ClearPageReferenced(page)	clear_bit(PG_referenced, &(page)->flags)
#define PageTestandClearReferenced(page)	test_and_clear_bit(PG_referenced, &(page)->flags)
#define PageSlab(page)		test_bit(PG_slab, &(page)->flags)
#define PageSetSlab(page)	set_bit(PG_slab, &(page)->flags)
#define PageClearSlab(page)	clear_bit(PG_slab, &(page)->flags)
#define PageReserved(page)	test_bit(PG_reserved, &(page)->flags)

#define PageActive(page)	test_bit(PG_active, &(page)->flags)
#define SetPageActive(page)	set_bit(PG_active, &(page)->flags)
#define ClearPageActive(page)	clear_bit(PG_active, &(page)->flags)

#define PageLRU(page)		test_bit(PG_lru, &(page)->flags)
#define TestSetPageLRU(page)	test_and_set_bit(PG_lru, &(page)->flags)
#define TestClearPageLRU(page)	test_and_clear_bit(PG_lru, &(page)->flags)

#ifdef CONFIG_HIGHMEM
#define PageHighMem(page)		test_bit(PG_highmem, &(page)->flags)
#else
#define PageHighMem(page)		0 /* needed to optimize away at compile time */
#endif

#define SetPageReserved(page)		set_bit(PG_reserved, &(page)->flags)
#define ClearPageReserved(page)		clear_bit(PG_reserved, &(page)->flags)

/*
 * Error return values for the *_nopage functions
 */
#define NOPAGE_SIGBUS	(NULL)
#define NOPAGE_OOM	((struct page *) (-1))

/* The array of struct pages */
extern mem_map_t * mem_map;

/*
 * There is only one page-allocator function, and two main namespaces to
 * it. The alloc_page*() variants return 'struct page *' and as such
 * can allocate highmem pages, the *get*page*() variants return
 * virtual kernel addresses to the allocated page(s).
 */
extern struct page * FASTCALL(__alloc_pages(unsigned int gfp_mask, unsigned int order, zonelist_t *zonelist));
extern struct page * alloc_pages_node(int nid, unsigned int gfp_mask, unsigned int order);

static inline struct page * alloc_pages(unsigned int gfp_mask, unsigned int order)
{
	/*
	 * Gets optimized away by the compiler.
	 */
	if (order >= MAX_ORDER)
		return NULL;
	/*
	 * we get the zone list from the current node and the gfp_mask.
	 * This zone list contains a maximum of
	 * MAXNODES*MAX_NR_ZONES zones.
	 */
#ifndef HAVE_ARCH_VALIDATE
	return __alloc_pages(gfp_mask, order,
			     NODE_DATA(numa_node_id())->node_zonelists + (gfp_mask & GFP_ZONEMASK));
#else
	return arch_validate(__alloc_pages(gfp_mask, order,
			     NODE_DATA(numa_node_id())->node_zonelists + (gfp_mask & GFP_ZONEMASK)), gfp_mask, order);
#endif
}

#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)

extern unsigned long FASTCALL(__get_free_pages(unsigned int gfp_mask, unsigned int order));
extern unsigned long FASTCALL(get_zeroed_page(unsigned int gfp_mask));

#define __get_free_page(gfp_mask) \
		__get_free_pages((gfp_mask),0)

#define __get_dma_pages(gfp_mask, order) \
		__get_free_pages((gfp_mask) | GFP_DMA,(order))

/*
 * The old interface name will be removed in 2.5:
 */
#define get_free_page get_zeroed_page

/*
 * There is only one 'core' page-freeing function.
 */
extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));

extern void * FASTCALL(alloc_exact(unsigned int size));
extern void FASTCALL(free_exact(void * addr, unsigned int size));

#define __free_page(page) __free_pages((page), 0)
#define free_page(addr) free_pages((addr),0)

extern int start_aggressive_readahead(unsigned int);

extern void show_free_areas(void);
extern void show_free_areas_node(pg_data_t *pgdat);

extern void clear_page_tables(struct mm_struct *, unsigned long, int);

extern int fail_writepage(struct page *);
struct page * shmem_nopage(struct vm_area_struct * vma, unsigned long address, int unused);
struct file *shmem_file_setup(char * name, loff_t size);
extern void shmem_lock(struct file * file, int lock);
extern int shmem_zero_setup(struct vm_area_struct *);

extern void 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 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(struct mm_struct *mm, pmd_t *pmd, unsigned long address));
extern pte_t *FASTCALL(pte_alloc_atomic(struct mm_struct *mm, pmd_t *pmd, unsigned long address));
extern int handle_mm_fault(struct mm_struct *mm,struct vm_area_struct *vma, unsigned long address, int write_access);
extern int make_pages_present(unsigned long addr, unsigned long end);
extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char *dst, int len);
extern int ptrace_writedata(struct task_struct *tsk, char * src, unsigned long dst, int len);
extern int ptrace_attach(struct task_struct *tsk);
extern int ptrace_detach(struct task_struct *, unsigned int);
extern void ptrace_disable(struct task_struct *);
extern int ptrace_check_attach(struct task_struct *task, int kill);

int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start,
		int len, int write, int force, struct page **pages, struct vm_area_struct **vmas);

/*
 * On a two-level page table, this ends up being trivial. Thus the
 * inlining and the symmetry break with pte_alloc() 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 int pgt_cache_water[2];
extern int check_pgt_cache(void);

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 mem_init(void);
extern void show_mem(void);
extern void si_meminfo(struct sysinfo * val);
extern void swapin_readahead(swp_entry_t);

extern struct address_space swapper_space;
#define PageSwapCache(page) ((page)->mapping == &swapper_space)

static inline int is_page_cache_freeable(struct page * page)
{
	return page_count(page) - !!page->buffers == 1;
}

extern int FASTCALL(make_exclusive_page(struct page *, int));
extern int FASTCALL(remove_exclusive_swap_page(struct page *));

extern void __free_pte(pte_t);

/* mmap.c */
extern void lock_vma_mappings(struct vm_area_struct *);
extern void unlock_vma_mappings(struct vm_area_struct *);
extern void insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
extern void __insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
extern void build_mmap_rb(struct mm_struct *);
extern void exit_mmap(struct mm_struct *);

extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);

extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
	unsigned long len, unsigned long prot,
	unsigned long flag, unsigned long pgoff);

static inline unsigned long do_mmap(struct file *file, unsigned long addr,
	unsigned long len, unsigned long prot,
	unsigned long flag, unsigned long offset)
{
	unsigned long ret = -EINVAL;
	if ((offset + PAGE_ALIGN(len)) < offset)
		goto out;
	if (!(offset & ~PAGE_MASK))
		ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
out:
	return ret;
}

extern int do_munmap(struct mm_struct *, unsigned long, size_t);

extern unsigned long do_brk(unsigned long, unsigned long);

static inline void __vma_unlink(struct mm_struct * mm, struct vm_area_struct * vma, struct vm_area_struct * prev)
{
	prev->vm_next = vma->vm_next;
	rb_erase(&vma->vm_rb, &mm->mm_rb);
	if (mm->mmap_cache == vma)
		mm->mmap_cache = prev;
}

static inline int can_vma_merge(struct vm_area_struct * vma, unsigned long vm_flags)
{
	if (!vma->vm_file && vma->vm_flags == vm_flags)
		return 1;
	else
		return 0;
}

struct zone_t;
/* filemap.c */
extern void remove_inode_page(struct page *);
extern unsigned long page_unuse(struct page *);
extern void truncate_inode_pages(struct address_space *, loff_t);

/* generic vm_area_ops exported for stackable file systems */
extern int filemap_sync(struct vm_area_struct *, unsigned long,	size_t, unsigned int);
extern struct page *filemap_nopage(struct vm_area_struct *, unsigned long, int);

/*
 * GFP bitmasks..
 */
/* Zone modifiers in GFP_ZONEMASK (see linux/mmzone.h - low four bits) */
#define __GFP_DMA	0x01
#define __GFP_HIGHMEM	0x02

/* Action modifiers - doesn't change the zoning */
#define __GFP_WAIT	0x10	/* Can wait and reschedule? */
#define __GFP_HIGH	0x20	/* Should access emergency pools? */
#define __GFP_IO	0x40	/* Can start low memory physical IO? */
#define __GFP_HIGHIO	0x80	/* Can start high mem physical IO? */
#define __GFP_FS	0x100	/* Can call down to low-level FS? */

#define GFP_NOHIGHIO	(__GFP_HIGH | __GFP_WAIT | __GFP_IO)
#define GFP_NOIO	(__GFP_HIGH | __GFP_WAIT)
#define GFP_NOFS	(__GFP_HIGH | __GFP_WAIT | __GFP_IO | __GFP_HIGHIO)
#define GFP_ATOMIC	(__GFP_HIGH)
#define GFP_USER	(             __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS)
#define GFP_HIGHUSER	(             __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS | __GFP_HIGHMEM)
#define GFP_KERNEL	(__GFP_HIGH | __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS)
#define GFP_NFS		(__GFP_HIGH | __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS)
#define GFP_KSWAPD	(             __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS)

/* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
   platforms, used as appropriate on others */

#define GFP_DMA		__GFP_DMA

static inline unsigned int pf_gfp_mask(unsigned int gfp_mask)
{
	/* avoid all memory balancing I/O methods if this task cannot block on I/O */
	if (current->flags & PF_NOIO)
		gfp_mask &= ~(__GFP_IO | __GFP_HIGHIO | __GFP_FS);

	return gfp_mask;
}

extern int heap_stack_gap;

/*
 * vma is the first one with  address < vma->vm_end,
 * and even  address < vma->vm_start. Have to extend vma.
 *
 * Locking: vm_start can decrease under you if you only hold
 * the read semaphore, you either need the write semaphore
 * or both the read semaphore and the page_table_lock acquired
 * if you want vm_start consistent. vm_end and the vma layout
 * are just consistent with only the read semaphore acquired
 * instead.
 */
#define EXPAND_STACK_HAS_3_ARGS
static inline int expand_stack(struct vm_area_struct * vma, unsigned long address,
			       struct vm_area_struct * prev_vma)
{
	unsigned long grow;
	int err = -ENOMEM;

	/*
	 * vma->vm_start/vm_end cannot change under us because the caller is required
	 * to hold the mmap_sem in write mode. We need to get the spinlock only
	 * before relocating the vma range ourself.
	 */
	address &= PAGE_MASK;
	if (prev_vma && prev_vma->vm_end + (heap_stack_gap << PAGE_SHIFT) > address)
		goto out;
	spin_lock(&vma->vm_mm->page_table_lock);
	grow = (vma->vm_start - address) >> PAGE_SHIFT;
	if (vma->vm_end - address > current->rlim[RLIMIT_STACK].rlim_cur ||
	    ((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) > current->rlim[RLIMIT_AS].rlim_cur)
		goto out_unlock;
	vma->vm_start = address;
	vma->vm_pgoff -= grow;
	vma->vm_mm->total_vm += grow;
	if (vma->vm_flags & VM_LOCKED)
		vma->vm_mm->locked_vm += grow;
	err = 0;
 out_unlock:
	spin_unlock(&vma->vm_mm->page_table_lock);
 out:
	return err;
}

/* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
					     struct vm_area_struct **pprev);

/* Look up the first VMA which intersects the interval start_addr..end_addr-1,
   NULL if none.  Assume start_addr < end_addr. */
static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
{
	struct vm_area_struct * vma = find_vma(mm,start_addr);

	if (vma && end_addr <= vma->vm_start)
		vma = NULL;
	return vma;
}

extern struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr);

extern struct page * vmalloc_to_page(void *addr);

#endif /* __KERNEL__ */

#endif