140 lines
4.4 KiB
C
140 lines
4.4 KiB
C
#ifndef _LINUX_RING_BUFFER_H
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#define _LINUX_RING_BUFFER_H
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#include <linux/mm.h>
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#include <linux/seq_file.h>
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struct ring_buffer;
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struct ring_buffer_iter;
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/*
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* Don't refer to this struct directly, use functions below.
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*/
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struct ring_buffer_event {
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u32 type:2, len:3, time_delta:27;
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u32 array[];
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};
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/**
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* enum ring_buffer_type - internal ring buffer types
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*
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* @RINGBUF_TYPE_PADDING: Left over page padding
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* array is ignored
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* size is variable depending on how much
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* padding is needed
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*
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* @RINGBUF_TYPE_TIME_EXTEND: Extend the time delta
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* array[0] = time delta (28 .. 59)
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* size = 8 bytes
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*
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* @RINGBUF_TYPE_TIME_STAMP: Sync time stamp with external clock
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* array[0] = tv_nsec
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* array[1..2] = tv_sec
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* size = 16 bytes
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*
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* @RINGBUF_TYPE_DATA: Data record
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* If len is zero:
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* array[0] holds the actual length
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* array[1..(length+3)/4] holds data
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* size = 4 + 4 + length (bytes)
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* else
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* length = len << 2
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* array[0..(length+3)/4-1] holds data
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* size = 4 + length (bytes)
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*/
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enum ring_buffer_type {
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RINGBUF_TYPE_PADDING,
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RINGBUF_TYPE_TIME_EXTEND,
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/* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */
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RINGBUF_TYPE_TIME_STAMP,
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RINGBUF_TYPE_DATA,
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};
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unsigned ring_buffer_event_length(struct ring_buffer_event *event);
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void *ring_buffer_event_data(struct ring_buffer_event *event);
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/**
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* ring_buffer_event_time_delta - return the delta timestamp of the event
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* @event: the event to get the delta timestamp of
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*
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* The delta timestamp is the 27 bit timestamp since the last event.
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*/
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static inline unsigned
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ring_buffer_event_time_delta(struct ring_buffer_event *event)
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{
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return event->time_delta;
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}
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/*
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* size is in bytes for each per CPU buffer.
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*/
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struct ring_buffer *
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ring_buffer_alloc(unsigned long size, unsigned flags);
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void ring_buffer_free(struct ring_buffer *buffer);
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int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size);
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struct ring_buffer_event *ring_buffer_lock_reserve(struct ring_buffer *buffer,
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unsigned long length);
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int ring_buffer_unlock_commit(struct ring_buffer *buffer,
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struct ring_buffer_event *event);
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int ring_buffer_write(struct ring_buffer *buffer,
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unsigned long length, void *data);
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struct ring_buffer_event *
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ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts);
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struct ring_buffer_event *
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ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts);
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struct ring_buffer_iter *
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ring_buffer_read_start(struct ring_buffer *buffer, int cpu);
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void ring_buffer_read_finish(struct ring_buffer_iter *iter);
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struct ring_buffer_event *
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ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts);
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struct ring_buffer_event *
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ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts);
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void ring_buffer_iter_reset(struct ring_buffer_iter *iter);
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int ring_buffer_iter_empty(struct ring_buffer_iter *iter);
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unsigned long ring_buffer_size(struct ring_buffer *buffer);
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void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu);
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void ring_buffer_reset(struct ring_buffer *buffer);
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int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
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struct ring_buffer *buffer_b, int cpu);
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int ring_buffer_empty(struct ring_buffer *buffer);
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int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu);
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void ring_buffer_record_disable(struct ring_buffer *buffer);
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void ring_buffer_record_enable(struct ring_buffer *buffer);
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void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu);
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void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu);
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unsigned long ring_buffer_entries(struct ring_buffer *buffer);
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unsigned long ring_buffer_overruns(struct ring_buffer *buffer);
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unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu);
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unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu);
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u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu);
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void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer,
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int cpu, u64 *ts);
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void ring_buffer_set_clock(struct ring_buffer *buffer,
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u64 (*clock)(void));
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size_t ring_buffer_page_len(void *page);
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void *ring_buffer_alloc_read_page(struct ring_buffer *buffer);
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void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data);
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int ring_buffer_read_page(struct ring_buffer *buffer, void **data_page,
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size_t len, int cpu, int full);
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enum ring_buffer_flags {
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RB_FL_OVERWRITE = 1 << 0,
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};
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#endif /* _LINUX_RING_BUFFER_H */
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