[PATCH] remove relayfs_fs.h (e5123609) · Commits · e / devices / android_kernel_oneplus_sm8150

include/linux/relayfs_fs.h

deleted100644 → 0

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	/*
	* linux/include/linux/relayfs_fs.h
	*
	* Copyright (C) 2002, 2003 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
	* Copyright (C) 1999, 2000, 2001, 2002 - Karim Yaghmour (karim@opersys.com)
	*
	* RelayFS definitions and declarations
	*/

	#ifndef _LINUX_RELAYFS_FS_H
	#define _LINUX_RELAYFS_FS_H

	#include <linux/config.h>
	#include <linux/types.h>
	#include <linux/sched.h>
	#include <linux/wait.h>
	#include <linux/list.h>
	#include <linux/fs.h>
	#include <linux/poll.h>
	#include <linux/kref.h>

	/*
	* Tracks changes to rchan/rchan_buf structs
	*/
	#define RELAYFS_CHANNEL_VERSION 6

	/*
	* Per-cpu relay channel buffer
	*/
	struct rchan_buf
	{
	void start; / start of channel buffer */
	void data; / start of current sub-buffer */
	size_t offset; /* current offset into sub-buffer */
	size_t subbufs_produced; /* count of sub-buffers produced */
	size_t subbufs_consumed; /* count of sub-buffers consumed */
	struct rchan chan; / associated channel */
	wait_queue_head_t read_wait; /* reader wait queue */
	struct work_struct wake_readers; /* reader wake-up work struct */
	struct dentry dentry; / channel file dentry */
	struct kref kref; /* channel buffer refcount */
	struct page *page_array; / array of current buffer pages */
	unsigned int page_count; /* number of current buffer pages */
	unsigned int finalized; /* buffer has been finalized */
	size_t padding; / padding counts per sub-buffer */
	size_t prev_padding; /* temporary variable */
	size_t bytes_consumed; /* bytes consumed in cur read subbuf */
	unsigned int cpu; /* this buf's cpu */
	} ____cacheline_aligned;

	/*
	* Relay channel data structure
	*/
	struct rchan
	{
	u32 version; /* the version of this struct */
	size_t subbuf_size; /* sub-buffer size */
	size_t n_subbufs; /* number of sub-buffers per buffer */
	size_t alloc_size; /* total buffer size allocated */
	struct rchan_callbacks cb; / client callbacks */
	struct kref kref; /* channel refcount */
	void private_data; / for user-defined data */
	size_t last_toobig; /* tried to log event > subbuf size */
	struct rchan_buf buf[NR_CPUS]; / per-cpu channel buffers */
	};

	/*
	* Relay channel client callbacks
	*/
	struct rchan_callbacks
	{
	/*
	* subbuf_start - called on buffer-switch to a new sub-buffer
	* @buf: the channel buffer containing the new sub-buffer
	* @subbuf: the start of the new sub-buffer
	* @prev_subbuf: the start of the previous sub-buffer
	* @prev_padding: unused space at the end of previous sub-buffer
	*
	* The client should return 1 to continue logging, 0 to stop
	* logging.
	*
	* NOTE: subbuf_start will also be invoked when the buffer is
	* created, so that the first sub-buffer can be initialized
	* if necessary. In this case, prev_subbuf will be NULL.
	*
	* NOTE: the client can reserve bytes at the beginning of the new
	* sub-buffer by calling subbuf_start_reserve() in this callback.
	*/
	int (subbuf_start) (struct rchan_buf buf,
	void *subbuf,
	void *prev_subbuf,
	size_t prev_padding);

	/*
	* buf_mapped - relayfs buffer mmap notification
	* @buf: the channel buffer
	* @filp: relayfs file pointer
	*
	* Called when a relayfs file is successfully mmapped
	*/
	void (buf_mapped)(struct rchan_buf buf,
	struct file *filp);

	/*
	* buf_unmapped - relayfs buffer unmap notification
	* @buf: the channel buffer
	* @filp: relayfs file pointer
	*
	* Called when a relayfs file is successfully unmapped
	*/
	void (buf_unmapped)(struct rchan_buf buf,
	struct file *filp);
	/*
	* create_buf_file - create file to represent a relayfs channel buffer
	* @filename: the name of the file to create
	* @parent: the parent of the file to create
	* @mode: the mode of the file to create
	* @buf: the channel buffer
	* @is_global: outparam - set non-zero if the buffer should be global
	*
	* Called during relay_open(), once for each per-cpu buffer,
	* to allow the client to create a file to be used to
	* represent the corresponding channel buffer. If the file is
	* created outside of relayfs, the parent must also exist in
	* that filesystem.
	*
	* The callback should return the dentry of the file created
	* to represent the relay buffer.
	*
	* Setting the is_global outparam to a non-zero value will
	* cause relay_open() to create a single global buffer rather
	* than the default set of per-cpu buffers.
	*
	* See Documentation/filesystems/relayfs.txt for more info.
	*/
	struct dentry (create_buf_file)(const char *filename,
	struct dentry *parent,
	int mode,
	struct rchan_buf *buf,
	int *is_global);

	/*
	* remove_buf_file - remove file representing a relayfs channel buffer
	* @dentry: the dentry of the file to remove
	*
	* Called during relay_close(), once for each per-cpu buffer,
	* to allow the client to remove a file used to represent a
	* channel buffer.
	*
	* The callback should return 0 if successful, negative if not.
	*/
	int (remove_buf_file)(struct dentry dentry);
	};

	/*
	* relayfs kernel API, fs/relayfs/relay.c
	*/

	struct rchan relay_open(const char base_filename,
	struct dentry *parent,
	size_t subbuf_size,
	size_t n_subbufs,
	struct rchan_callbacks *cb);
	extern void relay_close(struct rchan *chan);
	extern void relay_flush(struct rchan *chan);
	extern void relay_subbufs_consumed(struct rchan *chan,
	unsigned int cpu,
	size_t consumed);
	extern void relay_reset(struct rchan *chan);
	extern int relay_buf_full(struct rchan_buf *buf);

	extern size_t relay_switch_subbuf(struct rchan_buf *buf,
	size_t length);
	extern struct dentry relayfs_create_dir(const char name,
	struct dentry *parent);
	extern int relayfs_remove_dir(struct dentry *dentry);
	extern struct dentry relayfs_create_file(const char name,
	struct dentry *parent,
	int mode,
	struct file_operations *fops,
	void *data);
	extern int relayfs_remove_file(struct dentry *dentry);

	/**
	* relay_write - write data into the channel
	* @chan: relay channel
	* @data: data to be written
	* @length: number of bytes to write
	*
	* Writes data into the current cpu's channel buffer.
	*
	* Protects the buffer by disabling interrupts. Use this
	* if you might be logging from interrupt context. Try
	* __relay_write() if you know you won't be logging from
	* interrupt context.
	*/
	static inline void relay_write(struct rchan *chan,
	const void *data,
	size_t length)
	{
	unsigned long flags;
	struct rchan_buf *buf;

	local_irq_save(flags);
	buf = chan->buf[smp_processor_id()];
	if (unlikely(buf->offset + length > chan->subbuf_size))
	length = relay_switch_subbuf(buf, length);
	memcpy(buf->data + buf->offset, data, length);
	buf->offset += length;
	local_irq_restore(flags);
	}

	/**
	* __relay_write - write data into the channel
	* @chan: relay channel
	* @data: data to be written
	* @length: number of bytes to write
	*
	* Writes data into the current cpu's channel buffer.
	*
	* Protects the buffer by disabling preemption. Use
	* relay_write() if you might be logging from interrupt
	* context.
	*/
	static inline void __relay_write(struct rchan *chan,
	const void *data,
	size_t length)
	{
	struct rchan_buf *buf;

	buf = chan->buf[get_cpu()];
	if (unlikely(buf->offset + length > buf->chan->subbuf_size))
	length = relay_switch_subbuf(buf, length);
	memcpy(buf->data + buf->offset, data, length);
	buf->offset += length;
	put_cpu();
	}

	/**
	* relay_reserve - reserve slot in channel buffer
	* @chan: relay channel
	* @length: number of bytes to reserve
	*
	* Returns pointer to reserved slot, NULL if full.
	*
	* Reserves a slot in the current cpu's channel buffer.
	* Does not protect the buffer at all - caller must provide
	* appropriate synchronization.
	*/
	static inline void relay_reserve(struct rchan chan, size_t length)
	{
	void *reserved;
	struct rchan_buf *buf = chan->buf[smp_processor_id()];

	if (unlikely(buf->offset + length > buf->chan->subbuf_size)) {
	length = relay_switch_subbuf(buf, length);
	if (!length)
	return NULL;
	}
	reserved = buf->data + buf->offset;
	buf->offset += length;

	return reserved;
	}

	/**
	* subbuf_start_reserve - reserve bytes at the start of a sub-buffer
	* @buf: relay channel buffer
	* @length: number of bytes to reserve
	*
	* Helper function used to reserve bytes at the beginning of
	* a sub-buffer in the subbuf_start() callback.
	*/
	static inline void subbuf_start_reserve(struct rchan_buf *buf,
	size_t length)
	{
	BUG_ON(length >= buf->chan->subbuf_size - 1);
	buf->offset = length;
	}

	/*
	* exported relay file operations, fs/relayfs/inode.c
	*/
	extern struct file_operations relay_file_operations;

	#endif /* _LINUX_RELAYFS_FS_H */