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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 { | |
334d4169 | 14 | u32 type_len:5, time_delta:27; |
7a8e76a3 SR |
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 | 26 | * If time_delta is non zero: |
334d4169 LJ |
27 | * array[0] holds the actual length |
28 | * size = 4 + length (bytes) | |
7a8e76a3 SR |
29 | * |
30 | * @RINGBUF_TYPE_TIME_EXTEND: Extend the time delta | |
31 | * array[0] = time delta (28 .. 59) | |
32 | * size = 8 bytes | |
33 | * | |
34 | * @RINGBUF_TYPE_TIME_STAMP: Sync time stamp with external clock | |
361b73d5 LJ |
35 | * array[0] = tv_nsec |
36 | * array[1..2] = tv_sec | |
7a8e76a3 SR |
37 | * size = 16 bytes |
38 | * | |
334d4169 LJ |
39 | * <= @RINGBUF_TYPE_DATA_TYPE_LEN_MAX: |
40 | * Data record | |
41 | * If type_len is zero: | |
7a8e76a3 | 42 | * array[0] holds the actual length |
361b73d5 | 43 | * array[1..(length+3)/4] holds data |
334d4169 | 44 | * size = 4 + length (bytes) |
7a8e76a3 | 45 | * else |
334d4169 | 46 | * length = type_len << 2 |
361b73d5 LJ |
47 | * array[0..(length+3)/4-1] holds data |
48 | * size = 4 + length (bytes) | |
7a8e76a3 SR |
49 | */ |
50 | enum ring_buffer_type { | |
334d4169 | 51 | RINGBUF_TYPE_DATA_TYPE_LEN_MAX = 28, |
7a8e76a3 SR |
52 | RINGBUF_TYPE_PADDING, |
53 | RINGBUF_TYPE_TIME_EXTEND, | |
54 | /* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */ | |
55 | RINGBUF_TYPE_TIME_STAMP, | |
7a8e76a3 SR |
56 | }; |
57 | ||
58 | unsigned ring_buffer_event_length(struct ring_buffer_event *event); | |
59 | void *ring_buffer_event_data(struct ring_buffer_event *event); | |
60 | ||
61 | /** | |
62 | * ring_buffer_event_time_delta - return the delta timestamp of the event | |
63 | * @event: the event to get the delta timestamp of | |
64 | * | |
65 | * The delta timestamp is the 27 bit timestamp since the last event. | |
66 | */ | |
67 | static inline unsigned | |
68 | ring_buffer_event_time_delta(struct ring_buffer_event *event) | |
69 | { | |
70 | return event->time_delta; | |
71 | } | |
72 | ||
fa1b47dd SR |
73 | /* |
74 | * ring_buffer_event_discard can discard any event in the ring buffer. | |
75 | * it is up to the caller to protect against a reader from | |
76 | * consuming it or a writer from wrapping and replacing it. | |
77 | * | |
78 | * No external protection is needed if this is called before | |
79 | * the event is commited. But in that case it would be better to | |
80 | * use ring_buffer_discard_commit. | |
81 | * | |
82 | * Note, if an event that has not been committed is discarded | |
83 | * with ring_buffer_event_discard, it must still be committed. | |
84 | */ | |
2d622719 TZ |
85 | void ring_buffer_event_discard(struct ring_buffer_event *event); |
86 | ||
fa1b47dd SR |
87 | /* |
88 | * ring_buffer_discard_commit will remove an event that has not | |
89 | * ben committed yet. If this is used, then ring_buffer_unlock_commit | |
90 | * must not be called on the discarded event. This function | |
91 | * will try to remove the event from the ring buffer completely | |
92 | * if another event has not been written after it. | |
93 | * | |
94 | * Example use: | |
95 | * | |
96 | * if (some_condition) | |
97 | * ring_buffer_discard_commit(buffer, event); | |
98 | * else | |
99 | * ring_buffer_unlock_commit(buffer, event); | |
100 | */ | |
101 | void ring_buffer_discard_commit(struct ring_buffer *buffer, | |
102 | struct ring_buffer_event *event); | |
103 | ||
7a8e76a3 SR |
104 | /* |
105 | * size is in bytes for each per CPU buffer. | |
106 | */ | |
107 | struct ring_buffer * | |
1f8a6a10 PZ |
108 | __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *key); |
109 | ||
110 | /* | |
111 | * Because the ring buffer is generic, if other users of the ring buffer get | |
112 | * traced by ftrace, it can produce lockdep warnings. We need to keep each | |
113 | * ring buffer's lock class separate. | |
114 | */ | |
115 | #define ring_buffer_alloc(size, flags) \ | |
116 | ({ \ | |
117 | static struct lock_class_key __key; \ | |
118 | __ring_buffer_alloc((size), (flags), &__key); \ | |
119 | }) | |
120 | ||
7a8e76a3 SR |
121 | void ring_buffer_free(struct ring_buffer *buffer); |
122 | ||
123 | int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size); | |
124 | ||
0a987751 ACM |
125 | struct ring_buffer_event *ring_buffer_lock_reserve(struct ring_buffer *buffer, |
126 | unsigned long length); | |
7a8e76a3 | 127 | int ring_buffer_unlock_commit(struct ring_buffer *buffer, |
0a987751 | 128 | struct ring_buffer_event *event); |
7a8e76a3 SR |
129 | int ring_buffer_write(struct ring_buffer *buffer, |
130 | unsigned long length, void *data); | |
131 | ||
132 | struct ring_buffer_event * | |
133 | ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts); | |
134 | struct ring_buffer_event * | |
135 | ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts); | |
136 | ||
137 | struct ring_buffer_iter * | |
138 | ring_buffer_read_start(struct ring_buffer *buffer, int cpu); | |
139 | void ring_buffer_read_finish(struct ring_buffer_iter *iter); | |
140 | ||
141 | struct ring_buffer_event * | |
142 | ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts); | |
143 | struct ring_buffer_event * | |
144 | ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts); | |
145 | void ring_buffer_iter_reset(struct ring_buffer_iter *iter); | |
146 | int ring_buffer_iter_empty(struct ring_buffer_iter *iter); | |
147 | ||
148 | unsigned long ring_buffer_size(struct ring_buffer *buffer); | |
149 | ||
150 | void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu); | |
151 | void ring_buffer_reset(struct ring_buffer *buffer); | |
152 | ||
153 | int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, | |
154 | struct ring_buffer *buffer_b, int cpu); | |
155 | ||
156 | int ring_buffer_empty(struct ring_buffer *buffer); | |
157 | int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu); | |
158 | ||
159 | void ring_buffer_record_disable(struct ring_buffer *buffer); | |
160 | void ring_buffer_record_enable(struct ring_buffer *buffer); | |
161 | void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu); | |
162 | void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu); | |
163 | ||
164 | unsigned long ring_buffer_entries(struct ring_buffer *buffer); | |
165 | unsigned long ring_buffer_overruns(struct ring_buffer *buffer); | |
e09373f2 RR |
166 | unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu); |
167 | unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu); | |
f0d2c681 SR |
168 | unsigned long ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu); |
169 | unsigned long ring_buffer_nmi_dropped_cpu(struct ring_buffer *buffer, int cpu); | |
7a8e76a3 | 170 | |
37886f6a SR |
171 | u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu); |
172 | void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer, | |
173 | int cpu, u64 *ts); | |
174 | void ring_buffer_set_clock(struct ring_buffer *buffer, | |
175 | u64 (*clock)(void)); | |
7a8e76a3 | 176 | |
ef7a4a16 SR |
177 | size_t ring_buffer_page_len(void *page); |
178 | ||
179 | ||
8789a9e7 SR |
180 | void *ring_buffer_alloc_read_page(struct ring_buffer *buffer); |
181 | void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data); | |
ef7a4a16 SR |
182 | int ring_buffer_read_page(struct ring_buffer *buffer, void **data_page, |
183 | size_t len, int cpu, int full); | |
8789a9e7 | 184 | |
d1b182a8 SR |
185 | struct trace_seq; |
186 | ||
187 | int ring_buffer_print_entry_header(struct trace_seq *s); | |
188 | int ring_buffer_print_page_header(struct trace_seq *s); | |
189 | ||
7a8e76a3 SR |
190 | enum ring_buffer_flags { |
191 | RB_FL_OVERWRITE = 1 << 0, | |
192 | }; | |
193 | ||
194 | #endif /* _LINUX_RING_BUFFER_H */ |