[mirror_ubuntu-bionic-kernel.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_ATOMIC	0x01	/* was atomically mapped */
#define PIPE_BUF_FLAG_GIFT	0x02	/* 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
a893b99b JA	8	#define PIPE_BUF_FLAG_ATOMIC 0x01 /* was atomically mapped */
a893b99b JA	9	#define PIPE_BUF_FLAG_GIFT 0x02 /* page is a gift */
3e7ee3e7	10
1da177e4 LT	11	struct pipe_buffer {
	12	struct page *page;
	13	unsigned int offset, len;
	14	struct pipe_buf_operations *ops;
3e7ee3e7	15	unsigned int flags;
1da177e4 LT	16	};
1da177e4 LT	17
f84d7519 JA	18	/*
	19	* Note on the nesting of these functions:
	20	*
	21	* ->pin()
	22	* ->steal()
	23	* ...
	24	* ->map()
	25	* ...
	26	* ->unmap()
	27	*
	28	* That is, ->map() must be called on a pinned buffer, same goes for ->steal().
	29	*/
1da177e4 LT	30	struct pipe_buf_operations {
1da177e4 LT	31	int can_merge;
f6762b7a JA	32	void * (map)(struct pipe_inode_info , struct pipe_buffer *, int);
f6762b7a JA	33	void (unmap)(struct pipe_inode_info , struct pipe_buffer , void );
f84d7519	34	int (pin)(struct pipe_inode_info , struct pipe_buffer *);
1da177e4	35	void (release)(struct pipe_inode_info , struct pipe_buffer *);
5abc97aa	36	int (steal)(struct pipe_inode_info , struct pipe_buffer *);
70524490	37	void (get)(struct pipe_inode_info , struct pipe_buffer *);
1da177e4 LT	38	};
	39
	40	struct pipe_inode_info {
	41	wait_queue_head_t wait;
	42	unsigned int nrbufs, curbuf;
	43	struct pipe_buffer bufs[PIPE_BUFFERS];
	44	struct page *tmp_page;
	45	unsigned int start;
	46	unsigned int readers;
	47	unsigned int writers;
	48	unsigned int waiting_writers;
	49	unsigned int r_counter;
	50	unsigned int w_counter;
	51	struct fasync_struct *fasync_readers;
	52	struct fasync_struct *fasync_writers;
3a326a2c	53	struct inode *inode;
1da177e4 LT	54	};
	55
	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
5abc97aa JA	74	/*
	75	* splice is tied to pipes as a transport (at least for now), so we'll just
	76	* add the splice flags here.
	77	*/
	78	#define SPLICE_F_MOVE (0x01) /* move pages instead of copying */
29e35094 LT	79	#define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */
	80	/* we may still block on the fd we splice */
	81	/* from/to, of course */
b2b39fa4	82	#define SPLICE_F_MORE (0x04) /* expect more data */
7afa6fd0	83	#define SPLICE_F_GIFT (0x08) /* pages passed in are a gift */
5abc97aa	84
00522fb4 JA	85	/*
	86	* Passed to the actors
	87	*/
	88	struct splice_desc {
	89	unsigned int len, total_len; /* current and remaining length */
	90	unsigned int flags; /* splice flags */
	91	struct file file; / file to read/write */
	92	loff_t pos; /* file position */
	93	};
	94
	95	typedef int (splice_actor)(struct pipe_inode_info , struct pipe_buffer ,
	96	struct splice_desc *);
	97
	98	extern ssize_t splice_from_pipe(struct pipe_inode_info , struct file ,
	99	loff_t *, size_t, unsigned int,
	100	splice_actor *);
	101
1da177e4	102	#endif