| 1 | /* SPDX-License-Identifier: (GPL-2.0 OR LGPL-2.1) |
| 2 | * |
| 3 | * lib/ringbuffer/vfs.h |
| 4 | * |
| 5 | * Wait-free ring buffer VFS file operations. |
| 6 | * |
| 7 | * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 8 | */ |
| 9 | |
| 10 | #ifndef _LIB_RING_BUFFER_VFS_H |
| 11 | #define _LIB_RING_BUFFER_VFS_H |
| 12 | |
| 13 | #include <linux/fs.h> |
| 14 | #include <linux/poll.h> |
| 15 | |
| 16 | /* VFS API */ |
| 17 | |
| 18 | extern const struct file_operations lib_ring_buffer_file_operations; |
| 19 | |
| 20 | /* |
| 21 | * Internal file operations. |
| 22 | */ |
| 23 | |
| 24 | struct lib_ring_buffer; |
| 25 | |
| 26 | int lib_ring_buffer_open(struct inode *inode, struct file *file, |
| 27 | struct lib_ring_buffer *buf); |
| 28 | int lib_ring_buffer_release(struct inode *inode, struct file *file, |
| 29 | struct lib_ring_buffer *buf); |
| 30 | unsigned int lib_ring_buffer_poll(struct file *filp, poll_table *wait, |
| 31 | struct lib_ring_buffer *buf); |
| 32 | ssize_t lib_ring_buffer_splice_read(struct file *in, loff_t *ppos, |
| 33 | struct pipe_inode_info *pipe, size_t len, |
| 34 | unsigned int flags, struct lib_ring_buffer *buf); |
| 35 | int lib_ring_buffer_mmap(struct file *filp, struct vm_area_struct *vma, |
| 36 | struct lib_ring_buffer *buf); |
| 37 | |
| 38 | /* Ring Buffer ioctl() and ioctl numbers */ |
| 39 | long lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd, |
| 40 | unsigned long arg, struct lib_ring_buffer *buf); |
| 41 | #ifdef CONFIG_COMPAT |
| 42 | long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd, |
| 43 | unsigned long arg, struct lib_ring_buffer *buf); |
| 44 | #endif |
| 45 | |
| 46 | ssize_t vfs_lib_ring_buffer_file_splice_read(struct file *in, loff_t *ppos, |
| 47 | struct pipe_inode_info *pipe, size_t len, unsigned int flags); |
| 48 | loff_t vfs_lib_ring_buffer_no_llseek(struct file *file, loff_t offset, |
| 49 | int origin); |
| 50 | int vfs_lib_ring_buffer_mmap(struct file *filp, struct vm_area_struct *vma); |
| 51 | ssize_t vfs_lib_ring_buffer_splice_read(struct file *in, loff_t *ppos, |
| 52 | struct pipe_inode_info *pipe, size_t len, |
| 53 | unsigned int flags); |
| 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) |
| 98 | /* Flush the current sub-buffer, if non-empty. */ |
| 99 | #define RING_BUFFER_FLUSH _IO(0xF6, 0x0C) |
| 100 | /* Get the current version of the metadata cache (after a get_next). */ |
| 101 | #define RING_BUFFER_GET_METADATA_VERSION _IOR(0xF6, 0x0D, uint64_t) |
| 102 | /* |
| 103 | * Get a snapshot of the current ring buffer producer and consumer positions, |
| 104 | * regardless of whether or not the two positions are contained within the same |
| 105 | * sub-buffer. |
| 106 | */ |
| 107 | #define RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS _IO(0xF6, 0x0E) |
| 108 | /* Flush the current sub-buffer, even if empty. */ |
| 109 | #define RING_BUFFER_FLUSH_EMPTY _IO(0xF6, 0x0F) |
| 110 | /* |
| 111 | * Reset the position of what has been consumed from the metadata cache to 0 |
| 112 | * so it can be read again. |
| 113 | */ |
| 114 | #define RING_BUFFER_METADATA_CACHE_DUMP _IO(0xF6, 0x10) |
| 115 | /* |
| 116 | * Get next metadata subbuffer, returning a flag indicating whether the |
| 117 | * metadata is guaranteed to be in a consistent state at the end of this |
| 118 | * sub-buffer (can be parsed). |
| 119 | */ |
| 120 | #define RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK _IOR(0xF6, 0x12, uint32_t) |
| 121 | |
| 122 | #ifdef CONFIG_COMPAT |
| 123 | /* Get a snapshot of the current ring buffer producer and consumer positions */ |
| 124 | #define RING_BUFFER_COMPAT_SNAPSHOT RING_BUFFER_SNAPSHOT |
| 125 | /* Get the consumer position (iteration start) */ |
| 126 | #define RING_BUFFER_COMPAT_SNAPSHOT_GET_CONSUMED \ |
| 127 | _IOR(0xF6, 0x01, compat_ulong_t) |
| 128 | /* Get the producer position (iteration end) */ |
| 129 | #define RING_BUFFER_COMPAT_SNAPSHOT_GET_PRODUCED \ |
| 130 | _IOR(0xF6, 0x02, compat_ulong_t) |
| 131 | /* Get exclusive read access to the specified sub-buffer position */ |
| 132 | #define RING_BUFFER_COMPAT_GET_SUBBUF _IOW(0xF6, 0x03, compat_ulong_t) |
| 133 | /* Release exclusive sub-buffer access */ |
| 134 | #define RING_BUFFER_COMPAT_PUT_SUBBUF RING_BUFFER_PUT_SUBBUF |
| 135 | |
| 136 | /* Get exclusive read access to the next sub-buffer that can be read. */ |
| 137 | #define RING_BUFFER_COMPAT_GET_NEXT_SUBBUF RING_BUFFER_GET_NEXT_SUBBUF |
| 138 | /* Release exclusive sub-buffer access, move consumer forward. */ |
| 139 | #define RING_BUFFER_COMPAT_PUT_NEXT_SUBBUF RING_BUFFER_PUT_NEXT_SUBBUF |
| 140 | /* returns the size of the current sub-buffer, without padding (for mmap). */ |
| 141 | #define RING_BUFFER_COMPAT_GET_SUBBUF_SIZE _IOR(0xF6, 0x07, compat_ulong_t) |
| 142 | /* returns the size of the current sub-buffer, with padding (for splice). */ |
| 143 | #define RING_BUFFER_COMPAT_GET_PADDED_SUBBUF_SIZE \ |
| 144 | _IOR(0xF6, 0x08, compat_ulong_t) |
| 145 | /* returns the maximum size for sub-buffers. */ |
| 146 | #define RING_BUFFER_COMPAT_GET_MAX_SUBBUF_SIZE _IOR(0xF6, 0x09, compat_ulong_t) |
| 147 | /* returns the length to mmap. */ |
| 148 | #define RING_BUFFER_COMPAT_GET_MMAP_LEN _IOR(0xF6, 0x0A, compat_ulong_t) |
| 149 | /* returns the offset of the subbuffer belonging to the mmap reader. */ |
| 150 | #define RING_BUFFER_COMPAT_GET_MMAP_READ_OFFSET _IOR(0xF6, 0x0B, compat_ulong_t) |
| 151 | /* Flush the current sub-buffer, if non-empty. */ |
| 152 | #define RING_BUFFER_COMPAT_FLUSH RING_BUFFER_FLUSH |
| 153 | /* Get the current version of the metadata cache (after a get_next). */ |
| 154 | #define RING_BUFFER_COMPAT_GET_METADATA_VERSION RING_BUFFER_GET_METADATA_VERSION |
| 155 | /* |
| 156 | * Get a snapshot of the current ring buffer producer and consumer positions, |
| 157 | * regardless of whether or not the two positions are contained within the same |
| 158 | * sub-buffer. |
| 159 | */ |
| 160 | #define RING_BUFFER_COMPAT_SNAPSHOT_SAMPLE_POSITIONS \ |
| 161 | RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS |
| 162 | /* Flush the current sub-buffer, even if empty. */ |
| 163 | #define RING_BUFFER_COMPAT_FLUSH_EMPTY \ |
| 164 | RING_BUFFER_FLUSH_EMPTY |
| 165 | /* |
| 166 | * Get next metadata subbuffer, returning a flag indicating whether the |
| 167 | * metadata is guaranteed to be in a consistent state at the end of this |
| 168 | * sub-buffer (can be parsed). |
| 169 | */ |
| 170 | #define RING_BUFFER_COMPAT_GET_NEXT_SUBBUF_METADATA_CHECK \ |
| 171 | RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK |
| 172 | #endif /* CONFIG_COMPAT */ |
| 173 | |
| 174 | #endif /* _LIB_RING_BUFFER_VFS_H */ |