/* SPDX-License-Identifier: (GPL-2.0 OR LGPL-2.1) * * lib/ringbuffer/vfs.h * * Wait-free ring buffer VFS file operations. * * Copyright (C) 2005-2012 Mathieu Desnoyers */ #ifndef _LIB_RING_BUFFER_VFS_H #define _LIB_RING_BUFFER_VFS_H #include #include /* 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, if non-empty. */ #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) /* * Get a snapshot of the current ring buffer producer and consumer positions, * regardless of whether or not the two positions are contained within the same * sub-buffer. */ #define RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS _IO(0xF6, 0x0E) /* Flush the current sub-buffer, even if empty. */ #define RING_BUFFER_FLUSH_EMPTY _IO(0xF6, 0x0F) /* * Reset the position of what has been consumed from the metadata cache to 0 * so it can be read again. */ #define RING_BUFFER_METADATA_CACHE_DUMP _IO(0xF6, 0x10) /* * Get next metadata subbuffer, returning a flag indicating whether the * metadata is guaranteed to be in a consistent state at the end of this * sub-buffer (can be parsed). */ #define RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK _IOR(0xF6, 0x12, uint32_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, if non-empty. */ #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 /* * Get a snapshot of the current ring buffer producer and consumer positions, * regardless of whether or not the two positions are contained within the same * sub-buffer. */ #define RING_BUFFER_COMPAT_SNAPSHOT_SAMPLE_POSITIONS \ RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS /* Flush the current sub-buffer, even if empty. */ #define RING_BUFFER_COMPAT_FLUSH_EMPTY \ RING_BUFFER_FLUSH_EMPTY /* * Get next metadata subbuffer, returning a flag indicating whether the * metadata is guaranteed to be in a consistent state at the end of this * sub-buffer (can be parsed). */ #define RING_BUFFER_COMPAT_GET_NEXT_SUBBUF_METADATA_CHECK \ RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK #endif /* CONFIG_COMPAT */ #endif /* _LIB_RING_BUFFER_VFS_H */