-/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) */
-#include <lib/ringbuffer/vfs.h>
+/* SPDX-License-Identifier: (GPL-2.0-only OR LGPL-2.1-only)
+ *
+ * lib/ringbuffer/vfs.h
+ *
+ * Wait-free ring buffer VFS file operations.
+ *
+ * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef _LIB_RING_BUFFER_VFS_H
+#define _LIB_RING_BUFFER_VFS_H
+
+#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, 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)
+/* Clear ring buffer content. */
+#define RING_BUFFER_CLEAR _IO(0xF6, 0x11)
+
+#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
+/* Clear ring buffer content. */
+#define RING_BUFFER_COMPAT_CLEAR \
+ RING_BUFFER_CLEAR
+#endif /* CONFIG_COMPAT */
+
+#endif /* _LIB_RING_BUFFER_VFS_H */
projects / lttng-modules.git / blobdiff