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7a8e76a3 SR |
1 | #ifndef _LINUX_RING_BUFFER_H |
2 | #define _LINUX_RING_BUFFER_H | |
3 | ||
4 | #include <linux/mm.h> | |
5 | #include <linux/seq_file.h> | |
6 | ||
7 | struct ring_buffer; | |
8 | struct ring_buffer_iter; | |
9 | ||
10 | /* | |
11 | * Don't reference this struct directly, use functions below. | |
12 | */ | |
13 | struct ring_buffer_event { | |
14 | u32 type:2, len:3, time_delta:27; | |
15 | u32 array[]; | |
16 | }; | |
17 | ||
18 | /** | |
19 | * enum ring_buffer_type - internal ring buffer types | |
20 | * | |
21 | * @RINGBUF_TYPE_PADDING: Left over page padding | |
22 | * array is ignored | |
23 | * size is variable depending on how much | |
24 | * padding is needed | |
25 | * | |
26 | * @RINGBUF_TYPE_TIME_EXTEND: Extend the time delta | |
27 | * array[0] = time delta (28 .. 59) | |
28 | * size = 8 bytes | |
29 | * | |
30 | * @RINGBUF_TYPE_TIME_STAMP: Sync time stamp with external clock | |
31 | * array[0] = tv_nsec | |
32 | * array[1] = tv_sec | |
33 | * size = 16 bytes | |
34 | * | |
35 | * @RINGBUF_TYPE_DATA: Data record | |
36 | * If len is zero: | |
37 | * array[0] holds the actual length | |
38 | * array[1..(length+3)/4-1] holds data | |
39 | * else | |
40 | * length = len << 2 | |
41 | * array[0..(length+3)/4] holds data | |
42 | */ | |
43 | enum ring_buffer_type { | |
44 | RINGBUF_TYPE_PADDING, | |
45 | RINGBUF_TYPE_TIME_EXTEND, | |
46 | /* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */ | |
47 | RINGBUF_TYPE_TIME_STAMP, | |
48 | RINGBUF_TYPE_DATA, | |
49 | }; | |
50 | ||
51 | unsigned ring_buffer_event_length(struct ring_buffer_event *event); | |
52 | void *ring_buffer_event_data(struct ring_buffer_event *event); | |
53 | ||
54 | /** | |
55 | * ring_buffer_event_time_delta - return the delta timestamp of the event | |
56 | * @event: the event to get the delta timestamp of | |
57 | * | |
58 | * The delta timestamp is the 27 bit timestamp since the last event. | |
59 | */ | |
60 | static inline unsigned | |
61 | ring_buffer_event_time_delta(struct ring_buffer_event *event) | |
62 | { | |
63 | return event->time_delta; | |
64 | } | |
65 | ||
7a8e76a3 SR |
66 | /* |
67 | * size is in bytes for each per CPU buffer. | |
68 | */ | |
69 | struct ring_buffer * | |
70 | ring_buffer_alloc(unsigned long size, unsigned flags); | |
71 | void ring_buffer_free(struct ring_buffer *buffer); | |
72 | ||
73 | int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size); | |
74 | ||
75 | struct ring_buffer_event * | |
76 | ring_buffer_lock_reserve(struct ring_buffer *buffer, | |
77 | unsigned long length, | |
78 | unsigned long *flags); | |
79 | int ring_buffer_unlock_commit(struct ring_buffer *buffer, | |
80 | struct ring_buffer_event *event, | |
81 | unsigned long flags); | |
82 | int ring_buffer_write(struct ring_buffer *buffer, | |
83 | unsigned long length, void *data); | |
84 | ||
85 | struct ring_buffer_event * | |
86 | ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts); | |
87 | struct ring_buffer_event * | |
88 | ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts); | |
89 | ||
90 | struct ring_buffer_iter * | |
91 | ring_buffer_read_start(struct ring_buffer *buffer, int cpu); | |
92 | void ring_buffer_read_finish(struct ring_buffer_iter *iter); | |
93 | ||
94 | struct ring_buffer_event * | |
95 | ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts); | |
96 | struct ring_buffer_event * | |
97 | ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts); | |
98 | void ring_buffer_iter_reset(struct ring_buffer_iter *iter); | |
99 | int ring_buffer_iter_empty(struct ring_buffer_iter *iter); | |
100 | ||
101 | unsigned long ring_buffer_size(struct ring_buffer *buffer); | |
102 | ||
103 | void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu); | |
104 | void ring_buffer_reset(struct ring_buffer *buffer); | |
105 | ||
106 | int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, | |
107 | struct ring_buffer *buffer_b, int cpu); | |
108 | ||
109 | int ring_buffer_empty(struct ring_buffer *buffer); | |
110 | int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu); | |
111 | ||
112 | void ring_buffer_record_disable(struct ring_buffer *buffer); | |
113 | void ring_buffer_record_enable(struct ring_buffer *buffer); | |
114 | void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu); | |
115 | void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu); | |
116 | ||
117 | unsigned long ring_buffer_entries(struct ring_buffer *buffer); | |
118 | unsigned long ring_buffer_overruns(struct ring_buffer *buffer); | |
119 | ||
120 | u64 ring_buffer_time_stamp(int cpu); | |
121 | void ring_buffer_normalize_time_stamp(int cpu, u64 *ts); | |
122 | ||
a3583244 SR |
123 | void tracing_on(void); |
124 | void tracing_off(void); | |
125 | ||
7a8e76a3 SR |
126 | enum ring_buffer_flags { |
127 | RB_FL_OVERWRITE = 1 << 0, | |
128 | }; | |
129 | ||
130 | #endif /* _LINUX_RING_BUFFER_H */ |