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1 | #ifndef _LIB_RING_BUFFER_VFS_H |
2 | #define _LIB_RING_BUFFER_VFS_H | |
f3bc08c5 MD |
3 | |
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 | * | |
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25 | * Author: |
26 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
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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 | ||
40 | int lib_ring_buffer_open(struct inode *inode, struct file *file); | |
41 | int lib_ring_buffer_release(struct inode *inode, struct file *file); | |
42 | unsigned int lib_ring_buffer_poll(struct file *filp, poll_table *wait); | |
43 | ssize_t lib_ring_buffer_splice_read(struct file *in, loff_t *ppos, | |
44 | struct pipe_inode_info *pipe, size_t len, | |
45 | unsigned int flags); | |
46 | int lib_ring_buffer_mmap(struct file *filp, struct vm_area_struct *vma); | |
47 | ||
48 | /* Ring Buffer ioctl() and ioctl numbers */ | |
49 | long lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd, unsigned long arg); | |
50 | #ifdef CONFIG_COMPAT | |
51 | long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd, | |
52 | unsigned long arg); | |
53 | #endif | |
54 | ||
55 | /* | |
56 | * Use RING_BUFFER_GET_NEXT_SUBBUF / RING_BUFFER_PUT_NEXT_SUBBUF to read and | |
57 | * consume sub-buffers sequentially. | |
58 | * | |
59 | * Reading sub-buffers without consuming them can be performed with: | |
60 | * | |
61 | * RING_BUFFER_SNAPSHOT | |
62 | * RING_BUFFER_SNAPSHOT_GET_CONSUMED | |
63 | * RING_BUFFER_SNAPSHOT_GET_PRODUCED | |
64 | * | |
65 | * to get the offset range to consume, and then by passing each sub-buffer | |
66 | * offset to RING_BUFFER_GET_SUBBUF, read the sub-buffer, and then release it | |
67 | * with RING_BUFFER_PUT_SUBBUF. | |
68 | * | |
69 | * Note that the "snapshot" API can be used to read the sub-buffer in reverse | |
70 | * order, which is useful for flight recorder snapshots. | |
71 | */ | |
72 | ||
73 | /* Get a snapshot of the current ring buffer producer and consumer positions */ | |
74 | #define RING_BUFFER_SNAPSHOT _IO(0xF6, 0x00) | |
75 | /* Get the consumer position (iteration start) */ | |
76 | #define RING_BUFFER_SNAPSHOT_GET_CONSUMED _IOR(0xF6, 0x01, unsigned long) | |
77 | /* Get the producer position (iteration end) */ | |
78 | #define RING_BUFFER_SNAPSHOT_GET_PRODUCED _IOR(0xF6, 0x02, unsigned long) | |
79 | /* Get exclusive read access to the specified sub-buffer position */ | |
80 | #define RING_BUFFER_GET_SUBBUF _IOW(0xF6, 0x03, unsigned long) | |
81 | /* Release exclusive sub-buffer access */ | |
82 | #define RING_BUFFER_PUT_SUBBUF _IO(0xF6, 0x04) | |
83 | ||
84 | /* Get exclusive read access to the next sub-buffer that can be read. */ | |
85 | #define RING_BUFFER_GET_NEXT_SUBBUF _IO(0xF6, 0x05) | |
86 | /* Release exclusive sub-buffer access, move consumer forward. */ | |
87 | #define RING_BUFFER_PUT_NEXT_SUBBUF _IO(0xF6, 0x06) | |
88 | /* returns the size of the current sub-buffer, without padding (for mmap). */ | |
89 | #define RING_BUFFER_GET_SUBBUF_SIZE _IOR(0xF6, 0x07, unsigned long) | |
90 | /* returns the size of the current sub-buffer, with padding (for splice). */ | |
91 | #define RING_BUFFER_GET_PADDED_SUBBUF_SIZE _IOR(0xF6, 0x08, unsigned long) | |
92 | /* returns the maximum size for sub-buffers. */ | |
93 | #define RING_BUFFER_GET_MAX_SUBBUF_SIZE _IOR(0xF6, 0x09, unsigned long) | |
94 | /* returns the length to mmap. */ | |
95 | #define RING_BUFFER_GET_MMAP_LEN _IOR(0xF6, 0x0A, unsigned long) | |
96 | /* returns the offset of the subbuffer belonging to the mmap reader. */ | |
97 | #define RING_BUFFER_GET_MMAP_READ_OFFSET _IOR(0xF6, 0x0B, unsigned long) | |
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98 | /* flush the current sub-buffer */ |
99 | #define RING_BUFFER_FLUSH _IO(0xF6, 0x0C) | |
f3bc08c5 | 100 | |
886d51a3 | 101 | #endif /* _LIB_RING_BUFFER_VFS_H */ |