[deliverable/linux.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;
	struct pipe_buf_operations *ops;
	unsigned int flags;
};

/*
 * 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 *);
};

struct pipe_inode_info {
	wait_queue_head_t wait;
	unsigned int nrbufs, curbuf;
	struct pipe_buffer bufs[PIPE_BUFFERS];
	struct page *tmp_page;
	unsigned int start;
	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;
};

/* 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 *);

/*
 * splice is tied to pipes as a transport (at least for now), so we'll just
 * add the splice flags here.
 */
#define SPLICE_F_MOVE	(0x01)	/* move pages instead of copying */
#define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */
				 /* we may still block on the fd we splice */
				 /* from/to, of course */
#define SPLICE_F_MORE	(0x04)	/* expect more data */
#define SPLICE_F_GIFT	(0x08)	/* pages passed in are a gift */

/*
 * Passed to the actors
 */
struct splice_desc {
	unsigned int len, total_len;	/* current and remaining length */
	unsigned int flags;		/* splice flags */
	struct file *file;		/* file to read/write */
	loff_t pos;			/* file position */
};

typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
			   struct splice_desc *);

extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,
				loff_t *, size_t, unsigned int,
				splice_actor *);

#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;
	15	struct pipe_buf_operations *ops;
3e7ee3e7	16	unsigned int flags;
1da177e4 LT	17	};
1da177e4 LT	18
f84d7519 JA	19	/*
	20	* Note on the nesting of these functions:
	21	*
	22	* ->pin()
	23	* ->steal()
	24	* ...
	25	* ->map()
	26	* ...
	27	* ->unmap()
	28	*
	29	* That is, ->map() must be called on a pinned buffer, same goes for ->steal().
	30	*/
1da177e4 LT	31	struct pipe_buf_operations {
1da177e4 LT	32	int can_merge;
f6762b7a JA	33	void * (map)(struct pipe_inode_info , struct pipe_buffer *, int);
f6762b7a JA	34	void (unmap)(struct pipe_inode_info , struct pipe_buffer , void );
f84d7519	35	int (pin)(struct pipe_inode_info , struct pipe_buffer *);
1da177e4	36	void (release)(struct pipe_inode_info , struct pipe_buffer *);
5abc97aa	37	int (steal)(struct pipe_inode_info , struct pipe_buffer *);
70524490	38	void (get)(struct pipe_inode_info , struct pipe_buffer *);
1da177e4 LT	39	};
	40
	41	struct pipe_inode_info {
	42	wait_queue_head_t wait;
	43	unsigned int nrbufs, curbuf;
	44	struct pipe_buffer bufs[PIPE_BUFFERS];
	45	struct page *tmp_page;
	46	unsigned int start;
	47	unsigned int readers;
	48	unsigned int writers;
	49	unsigned int waiting_writers;
	50	unsigned int r_counter;
	51	unsigned int w_counter;
	52	struct fasync_struct *fasync_readers;
	53	struct fasync_struct *fasync_writers;
3a326a2c	54	struct inode *inode;
1da177e4 LT	55	};
	56
	57	/* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
	58	memory allocation, whereas PIPE_BUF makes atomicity guarantees. */
	59	#define PIPE_SIZE PAGE_SIZE
	60
1da177e4	61	/* Drop the inode semaphore and wait for a pipe event, atomically */
3a326a2c	62	void pipe_wait(struct pipe_inode_info *pipe);
1da177e4	63
3a326a2c IM	64	struct pipe_inode_info * alloc_pipe_info(struct inode * inode);
3a326a2c IM	65	void free_pipe_info(struct inode * inode);
b92ce558	66	void __free_pipe_info(struct pipe_inode_info *);
1da177e4	67
f84d7519	68	/* Generic pipe buffer ops functions */
f6762b7a JA	69	void generic_pipe_buf_map(struct pipe_inode_info , struct pipe_buffer *, int);
f6762b7a JA	70	void generic_pipe_buf_unmap(struct pipe_inode_info , struct pipe_buffer , void *);
f84d7519 JA	71	void generic_pipe_buf_get(struct pipe_inode_info , struct pipe_buffer );
f84d7519 JA	72	int generic_pipe_buf_pin(struct pipe_inode_info , struct pipe_buffer );
330ab716	73	int generic_pipe_buf_steal(struct pipe_inode_info , struct pipe_buffer );
f84d7519	74
5abc97aa JA	75	/*
	76	* splice is tied to pipes as a transport (at least for now), so we'll just
	77	* add the splice flags here.
	78	*/
	79	#define SPLICE_F_MOVE (0x01) /* move pages instead of copying */
29e35094 LT	80	#define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */
	81	/* we may still block on the fd we splice */
	82	/* from/to, of course */
b2b39fa4	83	#define SPLICE_F_MORE (0x04) /* expect more data */
7afa6fd0	84	#define SPLICE_F_GIFT (0x08) /* pages passed in are a gift */
5abc97aa	85
00522fb4 JA	86	/*
	87	* Passed to the actors
	88	*/
	89	struct splice_desc {
	90	unsigned int len, total_len; /* current and remaining length */
	91	unsigned int flags; /* splice flags */
	92	struct file file; / file to read/write */
	93	loff_t pos; /* file position */
	94	};
	95
	96	typedef int (splice_actor)(struct pipe_inode_info , struct pipe_buffer ,
	97	struct splice_desc *);
	98
	99	extern ssize_t splice_from_pipe(struct pipe_inode_info , struct file ,
	100	loff_t *, size_t, unsigned int,
	101	splice_actor *);
	102
1da177e4	103	#endif