1 #ifndef _LINUX_RING_BUFFER_H
2 #define _LINUX_RING_BUFFER_H
5 #include <linux/seq_file.h>
8 struct ring_buffer_iter;
11 * Don't reference this struct directly, use functions below.
13 struct ring_buffer_event {
14 u32 type:2, len:3, time_delta:27;
19 * enum ring_buffer_type - internal ring buffer types
21 * @RINGBUF_TYPE_PADDING: Left over page padding
23 * size is variable depending on how much
26 * @RINGBUF_TYPE_TIME_EXTEND: Extend the time delta
27 * array[0] = time delta (28 .. 59)
30 * @RINGBUF_TYPE_TIME_STAMP: Sync time stamp with external clock
35 * @RINGBUF_TYPE_DATA: Data record
37 * array[0] holds the actual length
38 * array[1..(length+3)/4-1] holds data
41 * array[0..(length+3)/4] holds data
43 enum ring_buffer_type {
45 RINGBUF_TYPE_TIME_EXTEND,
46 /* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */
47 RINGBUF_TYPE_TIME_STAMP,
51 unsigned ring_buffer_event_length(struct ring_buffer_event *event);
52 void *ring_buffer_event_data(struct ring_buffer_event *event);
55 * ring_buffer_event_time_delta - return the delta timestamp of the event
56 * @event: the event to get the delta timestamp of
58 * The delta timestamp is the 27 bit timestamp since the last event.
60 static inline unsigned
61 ring_buffer_event_time_delta(struct ring_buffer_event *event)
63 return event->time_delta;
66 void ring_buffer_lock(struct ring_buffer *buffer, unsigned long *flags);
67 void ring_buffer_unlock(struct ring_buffer *buffer, unsigned long flags);
70 * size is in bytes for each per CPU buffer.
73 ring_buffer_alloc(unsigned long size, unsigned flags);
74 void ring_buffer_free(struct ring_buffer *buffer);
76 int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size);
78 struct ring_buffer_event *
79 ring_buffer_lock_reserve(struct ring_buffer *buffer,
81 unsigned long *flags);
82 int ring_buffer_unlock_commit(struct ring_buffer *buffer,
83 struct ring_buffer_event *event,
85 int ring_buffer_write(struct ring_buffer *buffer,
86 unsigned long length, void *data);
88 struct ring_buffer_event *
89 ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts);
90 struct ring_buffer_event *
91 ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts);
93 struct ring_buffer_iter *
94 ring_buffer_read_start(struct ring_buffer *buffer, int cpu);
95 void ring_buffer_read_finish(struct ring_buffer_iter *iter);
97 struct ring_buffer_event *
98 ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts);
99 struct ring_buffer_event *
100 ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts);
101 void ring_buffer_iter_reset(struct ring_buffer_iter *iter);
102 int ring_buffer_iter_empty(struct ring_buffer_iter *iter);
104 unsigned long ring_buffer_size(struct ring_buffer *buffer);
106 void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu);
107 void ring_buffer_reset(struct ring_buffer *buffer);
109 int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
110 struct ring_buffer *buffer_b, int cpu);
112 int ring_buffer_empty(struct ring_buffer *buffer);
113 int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu);
115 void ring_buffer_record_disable(struct ring_buffer *buffer);
116 void ring_buffer_record_enable(struct ring_buffer *buffer);
117 void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu);
118 void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu);
120 unsigned long ring_buffer_entries(struct ring_buffer *buffer);
121 unsigned long ring_buffer_overruns(struct ring_buffer *buffer);
123 u64 ring_buffer_time_stamp(int cpu);
124 void ring_buffer_normalize_time_stamp(int cpu, u64 *ts);
126 enum ring_buffer_flags {
127 RB_FL_OVERWRITE = 1 << 0,
130 #endif /* _LINUX_RING_BUFFER_H */