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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 | |
361b73d5 LJ |
31 | * array[0] = tv_nsec |
32 | * array[1..2] = tv_sec | |
7a8e76a3 SR |
33 | * size = 16 bytes |
34 | * | |
35 | * @RINGBUF_TYPE_DATA: Data record | |
36 | * If len is zero: | |
37 | * array[0] holds the actual length | |
361b73d5 LJ |
38 | * array[1..(length+3)/4] holds data |
39 | * size = 4 + 4 + length (bytes) | |
7a8e76a3 SR |
40 | * else |
41 | * length = len << 2 | |
361b73d5 LJ |
42 | * array[0..(length+3)/4-1] holds data |
43 | * size = 4 + length (bytes) | |
7a8e76a3 SR |
44 | */ |
45 | enum ring_buffer_type { | |
46 | RINGBUF_TYPE_PADDING, | |
47 | RINGBUF_TYPE_TIME_EXTEND, | |
48 | /* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */ | |
49 | RINGBUF_TYPE_TIME_STAMP, | |
50 | RINGBUF_TYPE_DATA, | |
51 | }; | |
52 | ||
53 | unsigned ring_buffer_event_length(struct ring_buffer_event *event); | |
54 | void *ring_buffer_event_data(struct ring_buffer_event *event); | |
55 | ||
56 | /** | |
57 | * ring_buffer_event_time_delta - return the delta timestamp of the event | |
58 | * @event: the event to get the delta timestamp of | |
59 | * | |
60 | * The delta timestamp is the 27 bit timestamp since the last event. | |
61 | */ | |
62 | static inline unsigned | |
63 | ring_buffer_event_time_delta(struct ring_buffer_event *event) | |
64 | { | |
65 | return event->time_delta; | |
66 | } | |
67 | ||
7a8e76a3 SR |
68 | /* |
69 | * size is in bytes for each per CPU buffer. | |
70 | */ | |
71 | struct ring_buffer * | |
72 | ring_buffer_alloc(unsigned long size, unsigned flags); | |
73 | void ring_buffer_free(struct ring_buffer *buffer); | |
74 | ||
75 | int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size); | |
76 | ||
77 | struct ring_buffer_event * | |
78 | ring_buffer_lock_reserve(struct ring_buffer *buffer, | |
79 | unsigned long length, | |
80 | unsigned long *flags); | |
81 | int ring_buffer_unlock_commit(struct ring_buffer *buffer, | |
82 | struct ring_buffer_event *event, | |
83 | unsigned long flags); | |
84 | int ring_buffer_write(struct ring_buffer *buffer, | |
85 | unsigned long length, void *data); | |
86 | ||
87 | struct ring_buffer_event * | |
88 | ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts); | |
89 | struct ring_buffer_event * | |
90 | ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts); | |
91 | ||
92 | struct ring_buffer_iter * | |
93 | ring_buffer_read_start(struct ring_buffer *buffer, int cpu); | |
94 | void ring_buffer_read_finish(struct ring_buffer_iter *iter); | |
95 | ||
96 | struct ring_buffer_event * | |
97 | ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts); | |
98 | struct ring_buffer_event * | |
99 | ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts); | |
100 | void ring_buffer_iter_reset(struct ring_buffer_iter *iter); | |
101 | int ring_buffer_iter_empty(struct ring_buffer_iter *iter); | |
102 | ||
103 | unsigned long ring_buffer_size(struct ring_buffer *buffer); | |
104 | ||
105 | void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu); | |
106 | void ring_buffer_reset(struct ring_buffer *buffer); | |
107 | ||
108 | int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, | |
109 | struct ring_buffer *buffer_b, int cpu); | |
110 | ||
111 | int ring_buffer_empty(struct ring_buffer *buffer); | |
112 | int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu); | |
113 | ||
114 | void ring_buffer_record_disable(struct ring_buffer *buffer); | |
115 | void ring_buffer_record_enable(struct ring_buffer *buffer); | |
116 | void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu); | |
117 | void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu); | |
118 | ||
119 | unsigned long ring_buffer_entries(struct ring_buffer *buffer); | |
120 | unsigned long ring_buffer_overruns(struct ring_buffer *buffer); | |
e09373f2 RR |
121 | unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu); |
122 | unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu); | |
7a8e76a3 SR |
123 | |
124 | u64 ring_buffer_time_stamp(int cpu); | |
125 | void ring_buffer_normalize_time_stamp(int cpu, u64 *ts); | |
126 | ||
a3583244 SR |
127 | void tracing_on(void); |
128 | void tracing_off(void); | |
033601a3 | 129 | void tracing_off_permanent(void); |
a3583244 | 130 | |
8789a9e7 SR |
131 | void *ring_buffer_alloc_read_page(struct ring_buffer *buffer); |
132 | void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data); | |
133 | int ring_buffer_read_page(struct ring_buffer *buffer, | |
134 | void **data_page, int cpu, int full); | |
135 | ||
7a8e76a3 SR |
136 | enum ring_buffer_flags { |
137 | RB_FL_OVERWRITE = 1 << 0, | |
138 | }; | |
139 | ||
140 | #endif /* _LINUX_RING_BUFFER_H */ |