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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 | /* | |
c3706f00 | 11 | * Don't refer to this struct directly, use functions below. |
7a8e76a3 SR |
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 | * | |
2d622719 TZ |
21 | * @RINGBUF_TYPE_PADDING: Left over page padding or discarded event |
22 | * If time_delta is 0: | |
23 | * array is ignored | |
24 | * size is variable depending on how much | |
7a8e76a3 | 25 | * padding is needed |
2d622719 TZ |
26 | * If time_delta is non zero: |
27 | * everything else same as RINGBUF_TYPE_DATA | |
7a8e76a3 SR |
28 | * |
29 | * @RINGBUF_TYPE_TIME_EXTEND: Extend the time delta | |
30 | * array[0] = time delta (28 .. 59) | |
31 | * size = 8 bytes | |
32 | * | |
33 | * @RINGBUF_TYPE_TIME_STAMP: Sync time stamp with external clock | |
361b73d5 LJ |
34 | * array[0] = tv_nsec |
35 | * array[1..2] = tv_sec | |
7a8e76a3 SR |
36 | * size = 16 bytes |
37 | * | |
38 | * @RINGBUF_TYPE_DATA: Data record | |
39 | * If len is zero: | |
40 | * array[0] holds the actual length | |
361b73d5 LJ |
41 | * array[1..(length+3)/4] holds data |
42 | * size = 4 + 4 + length (bytes) | |
7a8e76a3 SR |
43 | * else |
44 | * length = len << 2 | |
361b73d5 LJ |
45 | * array[0..(length+3)/4-1] holds data |
46 | * size = 4 + length (bytes) | |
7a8e76a3 SR |
47 | */ |
48 | enum ring_buffer_type { | |
49 | RINGBUF_TYPE_PADDING, | |
50 | RINGBUF_TYPE_TIME_EXTEND, | |
51 | /* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */ | |
52 | RINGBUF_TYPE_TIME_STAMP, | |
53 | RINGBUF_TYPE_DATA, | |
54 | }; | |
55 | ||
56 | unsigned ring_buffer_event_length(struct ring_buffer_event *event); | |
57 | void *ring_buffer_event_data(struct ring_buffer_event *event); | |
58 | ||
59 | /** | |
60 | * ring_buffer_event_time_delta - return the delta timestamp of the event | |
61 | * @event: the event to get the delta timestamp of | |
62 | * | |
63 | * The delta timestamp is the 27 bit timestamp since the last event. | |
64 | */ | |
65 | static inline unsigned | |
66 | ring_buffer_event_time_delta(struct ring_buffer_event *event) | |
67 | { | |
68 | return event->time_delta; | |
69 | } | |
70 | ||
fa1b47dd SR |
71 | /* |
72 | * ring_buffer_event_discard can discard any event in the ring buffer. | |
73 | * it is up to the caller to protect against a reader from | |
74 | * consuming it or a writer from wrapping and replacing it. | |
75 | * | |
76 | * No external protection is needed if this is called before | |
77 | * the event is commited. But in that case it would be better to | |
78 | * use ring_buffer_discard_commit. | |
79 | * | |
80 | * Note, if an event that has not been committed is discarded | |
81 | * with ring_buffer_event_discard, it must still be committed. | |
82 | */ | |
2d622719 TZ |
83 | void ring_buffer_event_discard(struct ring_buffer_event *event); |
84 | ||
fa1b47dd SR |
85 | /* |
86 | * ring_buffer_discard_commit will remove an event that has not | |
87 | * ben committed yet. If this is used, then ring_buffer_unlock_commit | |
88 | * must not be called on the discarded event. This function | |
89 | * will try to remove the event from the ring buffer completely | |
90 | * if another event has not been written after it. | |
91 | * | |
92 | * Example use: | |
93 | * | |
94 | * if (some_condition) | |
95 | * ring_buffer_discard_commit(buffer, event); | |
96 | * else | |
97 | * ring_buffer_unlock_commit(buffer, event); | |
98 | */ | |
99 | void ring_buffer_discard_commit(struct ring_buffer *buffer, | |
100 | struct ring_buffer_event *event); | |
101 | ||
7a8e76a3 SR |
102 | /* |
103 | * size is in bytes for each per CPU buffer. | |
104 | */ | |
105 | struct ring_buffer * | |
106 | ring_buffer_alloc(unsigned long size, unsigned flags); | |
107 | void ring_buffer_free(struct ring_buffer *buffer); | |
108 | ||
109 | int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size); | |
110 | ||
0a987751 ACM |
111 | struct ring_buffer_event *ring_buffer_lock_reserve(struct ring_buffer *buffer, |
112 | unsigned long length); | |
7a8e76a3 | 113 | int ring_buffer_unlock_commit(struct ring_buffer *buffer, |
0a987751 | 114 | struct ring_buffer_event *event); |
7a8e76a3 SR |
115 | int ring_buffer_write(struct ring_buffer *buffer, |
116 | unsigned long length, void *data); | |
117 | ||
118 | struct ring_buffer_event * | |
119 | ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts); | |
120 | struct ring_buffer_event * | |
121 | ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts); | |
122 | ||
123 | struct ring_buffer_iter * | |
124 | ring_buffer_read_start(struct ring_buffer *buffer, int cpu); | |
125 | void ring_buffer_read_finish(struct ring_buffer_iter *iter); | |
126 | ||
127 | struct ring_buffer_event * | |
128 | ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts); | |
129 | struct ring_buffer_event * | |
130 | ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts); | |
131 | void ring_buffer_iter_reset(struct ring_buffer_iter *iter); | |
132 | int ring_buffer_iter_empty(struct ring_buffer_iter *iter); | |
133 | ||
134 | unsigned long ring_buffer_size(struct ring_buffer *buffer); | |
135 | ||
136 | void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu); | |
137 | void ring_buffer_reset(struct ring_buffer *buffer); | |
138 | ||
139 | int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, | |
140 | struct ring_buffer *buffer_b, int cpu); | |
141 | ||
142 | int ring_buffer_empty(struct ring_buffer *buffer); | |
143 | int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu); | |
144 | ||
145 | void ring_buffer_record_disable(struct ring_buffer *buffer); | |
146 | void ring_buffer_record_enable(struct ring_buffer *buffer); | |
147 | void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu); | |
148 | void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu); | |
149 | ||
150 | unsigned long ring_buffer_entries(struct ring_buffer *buffer); | |
151 | unsigned long ring_buffer_overruns(struct ring_buffer *buffer); | |
e09373f2 RR |
152 | unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu); |
153 | unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu); | |
7a8e76a3 | 154 | |
37886f6a SR |
155 | u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu); |
156 | void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer, | |
157 | int cpu, u64 *ts); | |
158 | void ring_buffer_set_clock(struct ring_buffer *buffer, | |
159 | u64 (*clock)(void)); | |
7a8e76a3 | 160 | |
ef7a4a16 SR |
161 | size_t ring_buffer_page_len(void *page); |
162 | ||
163 | ||
8789a9e7 SR |
164 | void *ring_buffer_alloc_read_page(struct ring_buffer *buffer); |
165 | void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data); | |
ef7a4a16 SR |
166 | int ring_buffer_read_page(struct ring_buffer *buffer, void **data_page, |
167 | size_t len, int cpu, int full); | |
8789a9e7 | 168 | |
7a8e76a3 SR |
169 | enum ring_buffer_flags { |
170 | RB_FL_OVERWRITE = 1 << 0, | |
171 | }; | |
172 | ||
173 | #endif /* _LINUX_RING_BUFFER_H */ |