[lttng-modules.git] / lib / ringbuffer / vfs.h

#ifndef _LIB_RING_BUFFER_VFS_H
#define _LIB_RING_BUFFER_VFS_H

/*
 * lib/ringbuffer/vfs.h
 *
 * Wait-free ring buffer VFS file operations.
 *
 * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; only
 * version 2.1 of the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * Author:
 *	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

#include <linux/fs.h>
#include <linux/poll.h>

/* VFS API */

extern const struct file_operations lib_ring_buffer_file_operations;

/*
 * Internal file operations.
 */

struct lib_ring_buffer;

int lib_ring_buffer_open(struct inode *inode, struct file *file,
		struct lib_ring_buffer *buf);
int lib_ring_buffer_release(struct inode *inode, struct file *file,
		struct lib_ring_buffer *buf);
unsigned int lib_ring_buffer_poll(struct file *filp, poll_table *wait,
		struct lib_ring_buffer *buf);
ssize_t lib_ring_buffer_splice_read(struct file *in, loff_t *ppos,
		struct pipe_inode_info *pipe, size_t len,
		unsigned int flags, struct lib_ring_buffer *buf);
int lib_ring_buffer_mmap(struct file *filp, struct vm_area_struct *vma,
		struct lib_ring_buffer *buf);

/* Ring Buffer ioctl() and ioctl numbers */
long lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd,
		unsigned long arg, struct lib_ring_buffer *buf);
#ifdef CONFIG_COMPAT
long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd,
		unsigned long arg, struct lib_ring_buffer *buf);
#endif

ssize_t vfs_lib_ring_buffer_file_splice_read(struct file *in, loff_t *ppos,
		struct pipe_inode_info *pipe, size_t len, unsigned int flags);
loff_t vfs_lib_ring_buffer_no_llseek(struct file *file, loff_t offset,
		int origin);
int vfs_lib_ring_buffer_mmap(struct file *filp, struct vm_area_struct *vma);
ssize_t vfs_lib_ring_buffer_splice_read(struct file *in, loff_t *ppos,
		struct pipe_inode_info *pipe, size_t len,
		unsigned int flags);

/*
 * Use RING_BUFFER_GET_NEXT_SUBBUF / RING_BUFFER_PUT_NEXT_SUBBUF to read and
 * consume sub-buffers sequentially.
 *
 * Reading sub-buffers without consuming them can be performed with:
 *
 * RING_BUFFER_SNAPSHOT
 * RING_BUFFER_SNAPSHOT_GET_CONSUMED
 * RING_BUFFER_SNAPSHOT_GET_PRODUCED
 *
 * to get the offset range to consume, and then by passing each sub-buffer
 * offset to RING_BUFFER_GET_SUBBUF, read the sub-buffer, and then release it
 * with RING_BUFFER_PUT_SUBBUF.
 *
 * Note that the "snapshot" API can be used to read the sub-buffer in reverse
 * order, which is useful for flight recorder snapshots.
 */

/* Get a snapshot of the current ring buffer producer and consumer positions */
#define RING_BUFFER_SNAPSHOT			_IO(0xF6, 0x00)
/* Get the consumer position (iteration start) */
#define RING_BUFFER_SNAPSHOT_GET_CONSUMED	_IOR(0xF6, 0x01, unsigned long)
/* Get the producer position (iteration end) */
#define RING_BUFFER_SNAPSHOT_GET_PRODUCED	_IOR(0xF6, 0x02, unsigned long)
/* Get exclusive read access to the specified sub-buffer position */
#define RING_BUFFER_GET_SUBBUF			_IOW(0xF6, 0x03, unsigned long)
/* Release exclusive sub-buffer access */
#define RING_BUFFER_PUT_SUBBUF			_IO(0xF6, 0x04)

/* Get exclusive read access to the next sub-buffer that can be read. */
#define RING_BUFFER_GET_NEXT_SUBBUF		_IO(0xF6, 0x05)
/* Release exclusive sub-buffer access, move consumer forward. */
#define RING_BUFFER_PUT_NEXT_SUBBUF		_IO(0xF6, 0x06)
/* returns the size of the current sub-buffer, without padding (for mmap). */
#define RING_BUFFER_GET_SUBBUF_SIZE		_IOR(0xF6, 0x07, unsigned long)
/* returns the size of the current sub-buffer, with padding (for splice). */
#define RING_BUFFER_GET_PADDED_SUBBUF_SIZE	_IOR(0xF6, 0x08, unsigned long)
/* returns the maximum size for sub-buffers. */
#define RING_BUFFER_GET_MAX_SUBBUF_SIZE		_IOR(0xF6, 0x09, unsigned long)
/* returns the length to mmap. */
#define RING_BUFFER_GET_MMAP_LEN		_IOR(0xF6, 0x0A, unsigned long)
/* returns the offset of the subbuffer belonging to the mmap reader. */
#define RING_BUFFER_GET_MMAP_READ_OFFSET	_IOR(0xF6, 0x0B, unsigned long)
/* flush the current sub-buffer */
#define RING_BUFFER_FLUSH			_IO(0xF6, 0x0C)
/* Get the current version of the metadata cache (after a get_next). */
#define RING_BUFFER_GET_METADATA_VERSION	_IOR(0xF6, 0x0D, uint64_t)

#ifdef CONFIG_COMPAT
/* Get a snapshot of the current ring buffer producer and consumer positions */
#define RING_BUFFER_COMPAT_SNAPSHOT		RING_BUFFER_SNAPSHOT
/* Get the consumer position (iteration start) */
#define RING_BUFFER_COMPAT_SNAPSHOT_GET_CONSUMED \
	_IOR(0xF6, 0x01, compat_ulong_t)
/* Get the producer position (iteration end) */
#define RING_BUFFER_COMPAT_SNAPSHOT_GET_PRODUCED \
	_IOR(0xF6, 0x02, compat_ulong_t)
/* Get exclusive read access to the specified sub-buffer position */
#define RING_BUFFER_COMPAT_GET_SUBBUF		_IOW(0xF6, 0x03, compat_ulong_t)
/* Release exclusive sub-buffer access */
#define RING_BUFFER_COMPAT_PUT_SUBBUF		RING_BUFFER_PUT_SUBBUF

/* Get exclusive read access to the next sub-buffer that can be read. */
#define RING_BUFFER_COMPAT_GET_NEXT_SUBBUF	RING_BUFFER_GET_NEXT_SUBBUF
/* Release exclusive sub-buffer access, move consumer forward. */
#define RING_BUFFER_COMPAT_PUT_NEXT_SUBBUF	RING_BUFFER_PUT_NEXT_SUBBUF
/* returns the size of the current sub-buffer, without padding (for mmap). */
#define RING_BUFFER_COMPAT_GET_SUBBUF_SIZE	_IOR(0xF6, 0x07, compat_ulong_t)
/* returns the size of the current sub-buffer, with padding (for splice). */
#define RING_BUFFER_COMPAT_GET_PADDED_SUBBUF_SIZE \
	_IOR(0xF6, 0x08, compat_ulong_t)
/* returns the maximum size for sub-buffers. */
#define RING_BUFFER_COMPAT_GET_MAX_SUBBUF_SIZE	_IOR(0xF6, 0x09, compat_ulong_t)
/* returns the length to mmap. */
#define RING_BUFFER_COMPAT_GET_MMAP_LEN		_IOR(0xF6, 0x0A, compat_ulong_t)
/* returns the offset of the subbuffer belonging to the mmap reader. */
#define RING_BUFFER_COMPAT_GET_MMAP_READ_OFFSET	_IOR(0xF6, 0x0B, compat_ulong_t)
/* flush the current sub-buffer */
#define RING_BUFFER_COMPAT_FLUSH		RING_BUFFER_FLUSH
/* Get the current version of the metadata cache (after a get_next). */
#define RING_BUFFER_COMPAT_GET_METADATA_VERSION	RING_BUFFER_GET_METADATA_VERSION
#endif /* CONFIG_COMPAT */

#endif /* _LIB_RING_BUFFER_VFS_H */
Commit	Line	Data
886d51a3 MD	1	#ifndef _LIB_RING_BUFFER_VFS_H
886d51a3 MD	2	#define _LIB_RING_BUFFER_VFS_H
f3bc08c5 MD	3
f3bc08c5 MD	4	/*
886d51a3	5	* lib/ringbuffer/vfs.h
f3bc08c5 MD	6	*
	7	* Wait-free ring buffer VFS file operations.
	8	*
886d51a3 MD	9	* Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	10	*
	11	* This library is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU Lesser General Public
	13	* License as published by the Free Software Foundation; only
	14	* version 2.1 of the License.
	15	*
	16	* This library is distributed in the hope that it will be useful,
	17	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	18	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	19	* Lesser General Public License for more details.
	20	*
	21	* You should have received a copy of the GNU Lesser General Public
	22	* License along with this library; if not, write to the Free Software
	23	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	24	*
f3bc08c5 MD	25	* Author:
f3bc08c5 MD	26	* Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
f3bc08c5 MD	27	*/
	28
	29	#include <linux/fs.h>
	30	#include <linux/poll.h>
	31
	32	/* VFS API */
	33
	34	extern const struct file_operations lib_ring_buffer_file_operations;
	35
	36	/*
	37	* Internal file operations.
	38	*/
	39
d83004aa JD	40	struct lib_ring_buffer;
	41
	42	int lib_ring_buffer_open(struct inode inode, struct file file,
	43	struct lib_ring_buffer *buf);
	44	int lib_ring_buffer_release(struct inode inode, struct file file,
	45	struct lib_ring_buffer *buf);
	46	unsigned int lib_ring_buffer_poll(struct file filp, poll_table wait,
	47	struct lib_ring_buffer *buf);
f3bc08c5	48	ssize_t lib_ring_buffer_splice_read(struct file in, loff_t ppos,
d83004aa JD	49	struct pipe_inode_info *pipe, size_t len,
	50	unsigned int flags, struct lib_ring_buffer *buf);
	51	int lib_ring_buffer_mmap(struct file filp, struct vm_area_struct vma,
	52	struct lib_ring_buffer *buf);
f3bc08c5 MD	53
f3bc08c5 MD	54	/* Ring Buffer ioctl() and ioctl numbers */
d83004aa JD	55	long lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd,
d83004aa JD	56	unsigned long arg, struct lib_ring_buffer *buf);
f3bc08c5 MD	57	#ifdef CONFIG_COMPAT
f3bc08c5 MD	58	long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd,
d83004aa	59	unsigned long arg, struct lib_ring_buffer *buf);
f3bc08c5 MD	60	#endif
f3bc08c5 MD	61
d83004aa JD	62	ssize_t vfs_lib_ring_buffer_file_splice_read(struct file in, loff_t ppos,
	63	struct pipe_inode_info *pipe, size_t len, unsigned int flags);
	64	loff_t vfs_lib_ring_buffer_no_llseek(struct file *file, loff_t offset,
	65	int origin);
	66	int vfs_lib_ring_buffer_mmap(struct file filp, struct vm_area_struct vma);
	67	ssize_t vfs_lib_ring_buffer_splice_read(struct file in, loff_t ppos,
	68	struct pipe_inode_info *pipe, size_t len,
	69	unsigned int flags);
	70
f3bc08c5 MD	71	/*
	72	* Use RING_BUFFER_GET_NEXT_SUBBUF / RING_BUFFER_PUT_NEXT_SUBBUF to read and
	73	* consume sub-buffers sequentially.
	74	*
	75	* Reading sub-buffers without consuming them can be performed with:
	76	*
	77	* RING_BUFFER_SNAPSHOT
	78	* RING_BUFFER_SNAPSHOT_GET_CONSUMED
	79	* RING_BUFFER_SNAPSHOT_GET_PRODUCED
	80	*
	81	* to get the offset range to consume, and then by passing each sub-buffer
	82	* offset to RING_BUFFER_GET_SUBBUF, read the sub-buffer, and then release it
	83	* with RING_BUFFER_PUT_SUBBUF.
	84	*
	85	* Note that the "snapshot" API can be used to read the sub-buffer in reverse
	86	* order, which is useful for flight recorder snapshots.
	87	*/
	88
	89	/* Get a snapshot of the current ring buffer producer and consumer positions */
	90	#define RING_BUFFER_SNAPSHOT _IO(0xF6, 0x00)
	91	/* Get the consumer position (iteration start) */
	92	#define RING_BUFFER_SNAPSHOT_GET_CONSUMED _IOR(0xF6, 0x01, unsigned long)
76447e2f JD	93	/* Get the producer position (iteration end) */
	94	#define RING_BUFFER_SNAPSHOT_GET_PRODUCED _IOR(0xF6, 0x02, unsigned long)
	95	/* Get exclusive read access to the specified sub-buffer position */
	96	#define RING_BUFFER_GET_SUBBUF _IOW(0xF6, 0x03, unsigned long)
	97	/* Release exclusive sub-buffer access */
	98	#define RING_BUFFER_PUT_SUBBUF _IO(0xF6, 0x04)
	99
	100	/* Get exclusive read access to the next sub-buffer that can be read. */
	101	#define RING_BUFFER_GET_NEXT_SUBBUF _IO(0xF6, 0x05)
	102	/* Release exclusive sub-buffer access, move consumer forward. */
	103	#define RING_BUFFER_PUT_NEXT_SUBBUF _IO(0xF6, 0x06)
	104	/* returns the size of the current sub-buffer, without padding (for mmap). */
	105	#define RING_BUFFER_GET_SUBBUF_SIZE _IOR(0xF6, 0x07, unsigned long)
	106	/* returns the size of the current sub-buffer, with padding (for splice). */
	107	#define RING_BUFFER_GET_PADDED_SUBBUF_SIZE _IOR(0xF6, 0x08, unsigned long)
	108	/* returns the maximum size for sub-buffers. */
	109	#define RING_BUFFER_GET_MAX_SUBBUF_SIZE _IOR(0xF6, 0x09, unsigned long)
	110	/* returns the length to mmap. */
	111	#define RING_BUFFER_GET_MMAP_LEN _IOR(0xF6, 0x0A, unsigned long)
	112	/* returns the offset of the subbuffer belonging to the mmap reader. */
	113	#define RING_BUFFER_GET_MMAP_READ_OFFSET _IOR(0xF6, 0x0B, unsigned long)
	114	/* flush the current sub-buffer */
	115	#define RING_BUFFER_FLUSH _IO(0xF6, 0x0C)
9616f0bf JD	116	/* Get the current version of the metadata cache (after a get_next). */
9616f0bf JD	117	#define RING_BUFFER_GET_METADATA_VERSION _IOR(0xF6, 0x0D, uint64_t)
76447e2f JD	118
	119	#ifdef CONFIG_COMPAT
	120	/* Get a snapshot of the current ring buffer producer and consumer positions */
	121	#define RING_BUFFER_COMPAT_SNAPSHOT RING_BUFFER_SNAPSHOT
	122	/* Get the consumer position (iteration start) */
216f7feb JD	123	#define RING_BUFFER_COMPAT_SNAPSHOT_GET_CONSUMED \
216f7feb JD	124	_IOR(0xF6, 0x01, compat_ulong_t)
f3bc08c5	125	/* Get the producer position (iteration end) */
216f7feb JD	126	#define RING_BUFFER_COMPAT_SNAPSHOT_GET_PRODUCED \
216f7feb JD	127	_IOR(0xF6, 0x02, compat_ulong_t)
f3bc08c5	128	/* Get exclusive read access to the specified sub-buffer position */
216f7feb	129	#define RING_BUFFER_COMPAT_GET_SUBBUF _IOW(0xF6, 0x03, compat_ulong_t)
f3bc08c5	130	/* Release exclusive sub-buffer access */
216f7feb	131	#define RING_BUFFER_COMPAT_PUT_SUBBUF RING_BUFFER_PUT_SUBBUF
f3bc08c5 MD	132
f3bc08c5 MD	133	/* Get exclusive read access to the next sub-buffer that can be read. */
216f7feb	134	#define RING_BUFFER_COMPAT_GET_NEXT_SUBBUF RING_BUFFER_GET_NEXT_SUBBUF
f3bc08c5	135	/* Release exclusive sub-buffer access, move consumer forward. */
216f7feb	136	#define RING_BUFFER_COMPAT_PUT_NEXT_SUBBUF RING_BUFFER_PUT_NEXT_SUBBUF
f3bc08c5	137	/* returns the size of the current sub-buffer, without padding (for mmap). */
216f7feb	138	#define RING_BUFFER_COMPAT_GET_SUBBUF_SIZE _IOR(0xF6, 0x07, compat_ulong_t)
f3bc08c5	139	/* returns the size of the current sub-buffer, with padding (for splice). */
216f7feb JD	140	#define RING_BUFFER_COMPAT_GET_PADDED_SUBBUF_SIZE \
216f7feb JD	141	_IOR(0xF6, 0x08, compat_ulong_t)
f3bc08c5	142	/* returns the maximum size for sub-buffers. */
216f7feb	143	#define RING_BUFFER_COMPAT_GET_MAX_SUBBUF_SIZE _IOR(0xF6, 0x09, compat_ulong_t)
f3bc08c5	144	/* returns the length to mmap. */
216f7feb	145	#define RING_BUFFER_COMPAT_GET_MMAP_LEN _IOR(0xF6, 0x0A, compat_ulong_t)
f3bc08c5	146	/* returns the offset of the subbuffer belonging to the mmap reader. */
216f7feb	147	#define RING_BUFFER_COMPAT_GET_MMAP_READ_OFFSET _IOR(0xF6, 0x0B, compat_ulong_t)
5c055266	148	/* flush the current sub-buffer */
216f7feb	149	#define RING_BUFFER_COMPAT_FLUSH RING_BUFFER_FLUSH
9616f0bf JD	150	/* Get the current version of the metadata cache (after a get_next). */
9616f0bf JD	151	#define RING_BUFFER_COMPAT_GET_METADATA_VERSION RING_BUFFER_GET_METADATA_VERSION
76447e2f	152	#endif /* CONFIG_COMPAT */
f3bc08c5	153
886d51a3	154	#endif /* _LIB_RING_BUFFER_VFS_H */