[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / pipe_fs_i.h

#ifndef _LINUX_PIPE_FS_I_H
#define _LINUX_PIPE_FS_I_H

#define PIPEFS_MAGIC 0x50495045

#define PIPE_BUFFERS (16)

#define PIPE_BUF_FLAG_LRU	0x01	/* page is on the LRU */
#define PIPE_BUF_FLAG_ATOMIC	0x02	/* was atomically mapped */
#define PIPE_BUF_FLAG_GIFT	0x04	/* page is a gift */

struct pipe_buffer {
	struct page *page;
	unsigned int offset, len;
	const struct pipe_buf_operations *ops;
	unsigned int flags;
};

struct pipe_inode_info {
	wait_queue_head_t wait;
	unsigned int nrbufs, curbuf;
	struct page *tmp_page;
	unsigned int readers;
	unsigned int writers;
	unsigned int waiting_writers;
	unsigned int r_counter;
	unsigned int w_counter;
	struct fasync_struct *fasync_readers;
	struct fasync_struct *fasync_writers;
	struct inode *inode;
	struct pipe_buffer bufs[PIPE_BUFFERS];
};

/*
 * Note on the nesting of these functions:
 *
 * ->pin()
 *	->steal()
 *	...
 *	->map()
 *	...
 *	->unmap()
 *
 * That is, ->map() must be called on a pinned buffer, same goes for ->steal().
 */
struct pipe_buf_operations {
	int can_merge;
	void * (*map)(struct pipe_inode_info *, struct pipe_buffer *, int);
	void (*unmap)(struct pipe_inode_info *, struct pipe_buffer *, void *);
	int (*pin)(struct pipe_inode_info *, struct pipe_buffer *);
	void (*release)(struct pipe_inode_info *, struct pipe_buffer *);
	int (*steal)(struct pipe_inode_info *, struct pipe_buffer *);
	void (*get)(struct pipe_inode_info *, struct pipe_buffer *);
};

/* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
   memory allocation, whereas PIPE_BUF makes atomicity guarantees.  */
#define PIPE_SIZE		PAGE_SIZE

/* Drop the inode semaphore and wait for a pipe event, atomically */
void pipe_wait(struct pipe_inode_info *pipe);

struct pipe_inode_info * alloc_pipe_info(struct inode * inode);
void free_pipe_info(struct inode * inode);
void __free_pipe_info(struct pipe_inode_info *);

/* Generic pipe buffer ops functions */
void *generic_pipe_buf_map(struct pipe_inode_info *, struct pipe_buffer *, int);
void generic_pipe_buf_unmap(struct pipe_inode_info *, struct pipe_buffer *, void *);
void generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *);
int generic_pipe_buf_pin(struct pipe_inode_info *, struct pipe_buffer *);
int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *);

#endif
Commit	Line	Data
1da177e4 LT	1	#ifndef _LINUX_PIPE_FS_I_H
	2	#define _LINUX_PIPE_FS_I_H
	3
	4	#define PIPEFS_MAGIC 0x50495045
	5
	6	#define PIPE_BUFFERS (16)
	7
1432873a JA	8	#define PIPE_BUF_FLAG_LRU 0x01 /* page is on the LRU */
	9	#define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */
	10	#define PIPE_BUF_FLAG_GIFT 0x04 /* page is a gift */
3e7ee3e7	11
1da177e4 LT	12	struct pipe_buffer {
	13	struct page *page;
	14	unsigned int offset, len;
d4c3cca9	15	const struct pipe_buf_operations *ops;
3e7ee3e7	16	unsigned int flags;
1da177e4 LT	17	};
1da177e4 LT	18
17374ff1 JA	19	struct pipe_inode_info {
	20	wait_queue_head_t wait;
	21	unsigned int nrbufs, curbuf;
	22	struct page *tmp_page;
	23	unsigned int readers;
	24	unsigned int writers;
	25	unsigned int waiting_writers;
	26	unsigned int r_counter;
	27	unsigned int w_counter;
	28	struct fasync_struct *fasync_readers;
	29	struct fasync_struct *fasync_writers;
	30	struct inode *inode;
	31	struct pipe_buffer bufs[PIPE_BUFFERS];
	32	};
	33
f84d7519 JA	34	/*
	35	* Note on the nesting of these functions:
	36	*
	37	* ->pin()
	38	* ->steal()
	39	* ...
	40	* ->map()
	41	* ...
	42	* ->unmap()
	43	*
	44	* That is, ->map() must be called on a pinned buffer, same goes for ->steal().
	45	*/
1da177e4 LT	46	struct pipe_buf_operations {
1da177e4 LT	47	int can_merge;
f6762b7a JA	48	void * (map)(struct pipe_inode_info , struct pipe_buffer *, int);
f6762b7a JA	49	void (unmap)(struct pipe_inode_info , struct pipe_buffer , void );
f84d7519	50	int (pin)(struct pipe_inode_info , struct pipe_buffer *);
1da177e4	51	void (release)(struct pipe_inode_info , struct pipe_buffer *);
5abc97aa	52	int (steal)(struct pipe_inode_info , struct pipe_buffer *);
70524490	53	void (get)(struct pipe_inode_info , struct pipe_buffer *);
1da177e4 LT	54	};
1da177e4 LT	55
1da177e4 LT	56	/* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
	57	memory allocation, whereas PIPE_BUF makes atomicity guarantees. */
	58	#define PIPE_SIZE PAGE_SIZE
	59
1da177e4	60	/* Drop the inode semaphore and wait for a pipe event, atomically */
3a326a2c	61	void pipe_wait(struct pipe_inode_info *pipe);
1da177e4	62
3a326a2c IM	63	struct pipe_inode_info * alloc_pipe_info(struct inode * inode);
3a326a2c IM	64	void free_pipe_info(struct inode * inode);
b92ce558	65	void __free_pipe_info(struct pipe_inode_info *);
1da177e4	66
f84d7519	67	/* Generic pipe buffer ops functions */
f6762b7a JA	68	void generic_pipe_buf_map(struct pipe_inode_info , struct pipe_buffer *, int);
f6762b7a JA	69	void generic_pipe_buf_unmap(struct pipe_inode_info , struct pipe_buffer , void *);
f84d7519 JA	70	void generic_pipe_buf_get(struct pipe_inode_info , struct pipe_buffer );
f84d7519 JA	71	int generic_pipe_buf_pin(struct pipe_inode_info , struct pipe_buffer );
330ab716	72	int generic_pipe_buf_steal(struct pipe_inode_info , struct pipe_buffer );
f84d7519	73
1da177e4	74	#endif