diff options
Diffstat (limited to 'include/linux/ring_buffer.h')
-rw-r--r-- | include/linux/ring_buffer.h | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h new file mode 100644 index 000000000000..c52375b8330d --- /dev/null +++ b/include/linux/ring_buffer.h | |||
@@ -0,0 +1,130 @@ | |||
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 | |||
66 | void ring_buffer_lock(struct ring_buffer *buffer, unsigned long *flags); | ||
67 | void ring_buffer_unlock(struct ring_buffer *buffer, unsigned long flags); | ||
68 | |||
69 | /* | ||
70 | * size is in bytes for each per CPU buffer. | ||
71 | */ | ||
72 | struct ring_buffer * | ||
73 | ring_buffer_alloc(unsigned long size, unsigned flags); | ||
74 | void ring_buffer_free(struct ring_buffer *buffer); | ||
75 | |||
76 | int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size); | ||
77 | |||
78 | struct ring_buffer_event * | ||
79 | ring_buffer_lock_reserve(struct ring_buffer *buffer, | ||
80 | unsigned long length, | ||
81 | unsigned long *flags); | ||
82 | int ring_buffer_unlock_commit(struct ring_buffer *buffer, | ||
83 | struct ring_buffer_event *event, | ||
84 | unsigned long flags); | ||
85 | int ring_buffer_write(struct ring_buffer *buffer, | ||
86 | unsigned long length, void *data); | ||
87 | |||
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); | ||
92 | |||
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); | ||
96 | |||
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); | ||
103 | |||
104 | unsigned long ring_buffer_size(struct ring_buffer *buffer); | ||
105 | |||
106 | void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu); | ||
107 | void ring_buffer_reset(struct ring_buffer *buffer); | ||
108 | |||
109 | int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, | ||
110 | struct ring_buffer *buffer_b, int cpu); | ||
111 | |||
112 | int ring_buffer_empty(struct ring_buffer *buffer); | ||
113 | int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu); | ||
114 | |||
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); | ||
119 | |||
120 | unsigned long ring_buffer_entries(struct ring_buffer *buffer); | ||
121 | unsigned long ring_buffer_overruns(struct ring_buffer *buffer); | ||
122 | |||
123 | u64 ring_buffer_time_stamp(int cpu); | ||
124 | void ring_buffer_normalize_time_stamp(int cpu, u64 *ts); | ||
125 | |||
126 | enum ring_buffer_flags { | ||
127 | RB_FL_OVERWRITE = 1 << 0, | ||
128 | }; | ||
129 | |||
130 | #endif /* _LINUX_RING_BUFFER_H */ | ||