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 refer to 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
32 * array[1..2] = tv_sec
35 * @RINGBUF_TYPE_DATA: Data record
37 * array[0] holds the actual length
38 * array[1..(length+3)/4] holds data
39 * size = 4 + 4 + length (bytes)
42 * array[0..(length+3)/4-1] holds data
43 * size = 4 + length (bytes)
45 enum ring_buffer_type {
47 RINGBUF_TYPE_TIME_EXTEND,
48 /* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */
49 RINGBUF_TYPE_TIME_STAMP,
53 unsigned ring_buffer_event_length(struct ring_buffer_event *event);
54 void *ring_buffer_event_data(struct ring_buffer_event *event);
57 * ring_buffer_event_time_delta - return the delta timestamp of the event
58 * @event: the event to get the delta timestamp of
60 * The delta timestamp is the 27 bit timestamp since the last event.
62 static inline unsigned
63 ring_buffer_event_time_delta(struct ring_buffer_event *event)
65 return event->time_delta;
69 * size is in bytes for each per CPU buffer.
72 ring_buffer_alloc(unsigned long size, unsigned flags);
73 void ring_buffer_free(struct ring_buffer *buffer);
75 int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size);
77 struct ring_buffer_event *ring_buffer_lock_reserve(struct ring_buffer *buffer,
78 unsigned long length);
79 int ring_buffer_unlock_commit(struct ring_buffer *buffer,
80 struct ring_buffer_event *event);
81 int ring_buffer_write(struct ring_buffer *buffer,
82 unsigned long length, void *data);
84 struct ring_buffer_event *
85 ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts);
86 struct ring_buffer_event *
87 ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts);
89 struct ring_buffer_iter *
90 ring_buffer_read_start(struct ring_buffer *buffer, int cpu);
91 void ring_buffer_read_finish(struct ring_buffer_iter *iter);
93 struct ring_buffer_event *
94 ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts);
95 struct ring_buffer_event *
96 ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts);
97 void ring_buffer_iter_reset(struct ring_buffer_iter *iter);
98 int ring_buffer_iter_empty(struct ring_buffer_iter *iter);
100 unsigned long ring_buffer_size(struct ring_buffer *buffer);
102 void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu);
103 void ring_buffer_reset(struct ring_buffer *buffer);
105 int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
106 struct ring_buffer *buffer_b, int cpu);
108 int ring_buffer_empty(struct ring_buffer *buffer);
109 int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu);
111 void ring_buffer_record_disable(struct ring_buffer *buffer);
112 void ring_buffer_record_enable(struct ring_buffer *buffer);
113 void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu);
114 void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu);
116 unsigned long ring_buffer_entries(struct ring_buffer *buffer);
117 unsigned long ring_buffer_overruns(struct ring_buffer *buffer);
118 unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu);
119 unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu);
121 u64 ring_buffer_time_stamp(int cpu);
122 void ring_buffer_normalize_time_stamp(int cpu, u64 *ts);
125 * The below functions are fine to use outside the tracing facility.
127 #ifdef CONFIG_RING_BUFFER
128 void tracing_on(void);
129 void tracing_off(void);
130 void tracing_off_permanent(void);
131 int tracing_is_on(void);
133 static inline void tracing_on(void) { }
134 static inline void tracing_off(void) { }
135 static inline void tracing_off_permanent(void) { }
136 static inline int tracing_is_on(void) { return 0; }
139 void *ring_buffer_alloc_read_page(struct ring_buffer *buffer);
140 void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data);
141 int ring_buffer_read_page(struct ring_buffer *buffer,
142 void **data_page, int cpu, int full);
144 enum ring_buffer_flags {
145 RB_FL_OVERWRITE = 1 << 0,
148 #endif /* _LINUX_RING_BUFFER_H */