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7a8e76a3 SR |
1 | #ifndef _LINUX_RING_BUFFER_H |
2 | #define _LINUX_RING_BUFFER_H | |
3 | ||
1744a21d | 4 | #include <linux/kmemcheck.h> |
7a8e76a3 SR |
5 | #include <linux/mm.h> |
6 | #include <linux/seq_file.h> | |
7 | ||
8 | struct ring_buffer; | |
9 | struct ring_buffer_iter; | |
10 | ||
11 | /* | |
c3706f00 | 12 | * Don't refer to this struct directly, use functions below. |
7a8e76a3 SR |
13 | */ |
14 | struct ring_buffer_event { | |
1744a21d | 15 | kmemcheck_bitfield_begin(bitfield); |
334d4169 | 16 | u32 type_len:5, time_delta:27; |
1744a21d VN |
17 | kmemcheck_bitfield_end(bitfield); |
18 | ||
7a8e76a3 SR |
19 | u32 array[]; |
20 | }; | |
21 | ||
22 | /** | |
23 | * enum ring_buffer_type - internal ring buffer types | |
24 | * | |
2d622719 TZ |
25 | * @RINGBUF_TYPE_PADDING: Left over page padding or discarded event |
26 | * If time_delta is 0: | |
27 | * array is ignored | |
28 | * size is variable depending on how much | |
7a8e76a3 | 29 | * padding is needed |
2d622719 | 30 | * If time_delta is non zero: |
334d4169 LJ |
31 | * array[0] holds the actual length |
32 | * size = 4 + length (bytes) | |
7a8e76a3 SR |
33 | * |
34 | * @RINGBUF_TYPE_TIME_EXTEND: Extend the time delta | |
35 | * array[0] = time delta (28 .. 59) | |
36 | * size = 8 bytes | |
37 | * | |
38 | * @RINGBUF_TYPE_TIME_STAMP: Sync time stamp with external clock | |
361b73d5 LJ |
39 | * array[0] = tv_nsec |
40 | * array[1..2] = tv_sec | |
7a8e76a3 SR |
41 | * size = 16 bytes |
42 | * | |
334d4169 LJ |
43 | * <= @RINGBUF_TYPE_DATA_TYPE_LEN_MAX: |
44 | * Data record | |
45 | * If type_len is zero: | |
7a8e76a3 | 46 | * array[0] holds the actual length |
361b73d5 | 47 | * array[1..(length+3)/4] holds data |
334d4169 | 48 | * size = 4 + length (bytes) |
7a8e76a3 | 49 | * else |
334d4169 | 50 | * length = type_len << 2 |
361b73d5 LJ |
51 | * array[0..(length+3)/4-1] holds data |
52 | * size = 4 + length (bytes) | |
7a8e76a3 SR |
53 | */ |
54 | enum ring_buffer_type { | |
334d4169 | 55 | RINGBUF_TYPE_DATA_TYPE_LEN_MAX = 28, |
7a8e76a3 SR |
56 | RINGBUF_TYPE_PADDING, |
57 | RINGBUF_TYPE_TIME_EXTEND, | |
58 | /* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */ | |
59 | RINGBUF_TYPE_TIME_STAMP, | |
7a8e76a3 SR |
60 | }; |
61 | ||
62 | unsigned ring_buffer_event_length(struct ring_buffer_event *event); | |
63 | void *ring_buffer_event_data(struct ring_buffer_event *event); | |
64 | ||
65 | /** | |
66 | * ring_buffer_event_time_delta - return the delta timestamp of the event | |
67 | * @event: the event to get the delta timestamp of | |
68 | * | |
69 | * The delta timestamp is the 27 bit timestamp since the last event. | |
70 | */ | |
71 | static inline unsigned | |
72 | ring_buffer_event_time_delta(struct ring_buffer_event *event) | |
73 | { | |
74 | return event->time_delta; | |
75 | } | |
76 | ||
fa1b47dd SR |
77 | /* |
78 | * ring_buffer_event_discard can discard any event in the ring buffer. | |
79 | * it is up to the caller to protect against a reader from | |
80 | * consuming it or a writer from wrapping and replacing it. | |
81 | * | |
82 | * No external protection is needed if this is called before | |
83 | * the event is commited. But in that case it would be better to | |
84 | * use ring_buffer_discard_commit. | |
85 | * | |
86 | * Note, if an event that has not been committed is discarded | |
87 | * with ring_buffer_event_discard, it must still be committed. | |
88 | */ | |
2d622719 TZ |
89 | void ring_buffer_event_discard(struct ring_buffer_event *event); |
90 | ||
fa1b47dd SR |
91 | /* |
92 | * ring_buffer_discard_commit will remove an event that has not | |
93 | * ben committed yet. If this is used, then ring_buffer_unlock_commit | |
94 | * must not be called on the discarded event. This function | |
95 | * will try to remove the event from the ring buffer completely | |
96 | * if another event has not been written after it. | |
97 | * | |
98 | * Example use: | |
99 | * | |
100 | * if (some_condition) | |
101 | * ring_buffer_discard_commit(buffer, event); | |
102 | * else | |
103 | * ring_buffer_unlock_commit(buffer, event); | |
104 | */ | |
105 | void ring_buffer_discard_commit(struct ring_buffer *buffer, | |
106 | struct ring_buffer_event *event); | |
107 | ||
7a8e76a3 SR |
108 | /* |
109 | * size is in bytes for each per CPU buffer. | |
110 | */ | |
111 | struct ring_buffer * | |
1f8a6a10 PZ |
112 | __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *key); |
113 | ||
114 | /* | |
115 | * Because the ring buffer is generic, if other users of the ring buffer get | |
116 | * traced by ftrace, it can produce lockdep warnings. We need to keep each | |
117 | * ring buffer's lock class separate. | |
118 | */ | |
119 | #define ring_buffer_alloc(size, flags) \ | |
120 | ({ \ | |
121 | static struct lock_class_key __key; \ | |
122 | __ring_buffer_alloc((size), (flags), &__key); \ | |
123 | }) | |
124 | ||
7a8e76a3 SR |
125 | void ring_buffer_free(struct ring_buffer *buffer); |
126 | ||
127 | int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size); | |
128 | ||
0a987751 ACM |
129 | struct ring_buffer_event *ring_buffer_lock_reserve(struct ring_buffer *buffer, |
130 | unsigned long length); | |
7a8e76a3 | 131 | int ring_buffer_unlock_commit(struct ring_buffer *buffer, |
0a987751 | 132 | struct ring_buffer_event *event); |
7a8e76a3 SR |
133 | int ring_buffer_write(struct ring_buffer *buffer, |
134 | unsigned long length, void *data); | |
135 | ||
136 | struct ring_buffer_event * | |
137 | ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts); | |
138 | struct ring_buffer_event * | |
139 | ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts); | |
140 | ||
141 | struct ring_buffer_iter * | |
142 | ring_buffer_read_start(struct ring_buffer *buffer, int cpu); | |
143 | void ring_buffer_read_finish(struct ring_buffer_iter *iter); | |
144 | ||
145 | struct ring_buffer_event * | |
146 | ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts); | |
147 | struct ring_buffer_event * | |
148 | ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts); | |
149 | void ring_buffer_iter_reset(struct ring_buffer_iter *iter); | |
150 | int ring_buffer_iter_empty(struct ring_buffer_iter *iter); | |
151 | ||
152 | unsigned long ring_buffer_size(struct ring_buffer *buffer); | |
153 | ||
154 | void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu); | |
155 | void ring_buffer_reset(struct ring_buffer *buffer); | |
156 | ||
157 | int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, | |
158 | struct ring_buffer *buffer_b, int cpu); | |
159 | ||
160 | int ring_buffer_empty(struct ring_buffer *buffer); | |
161 | int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu); | |
162 | ||
163 | void ring_buffer_record_disable(struct ring_buffer *buffer); | |
164 | void ring_buffer_record_enable(struct ring_buffer *buffer); | |
165 | void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu); | |
166 | void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu); | |
167 | ||
168 | unsigned long ring_buffer_entries(struct ring_buffer *buffer); | |
169 | unsigned long ring_buffer_overruns(struct ring_buffer *buffer); | |
e09373f2 RR |
170 | unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu); |
171 | unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu); | |
f0d2c681 SR |
172 | unsigned long ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu); |
173 | unsigned long ring_buffer_nmi_dropped_cpu(struct ring_buffer *buffer, int cpu); | |
7a8e76a3 | 174 | |
37886f6a SR |
175 | u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu); |
176 | void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer, | |
177 | int cpu, u64 *ts); | |
178 | void ring_buffer_set_clock(struct ring_buffer *buffer, | |
179 | u64 (*clock)(void)); | |
7a8e76a3 | 180 | |
ef7a4a16 SR |
181 | size_t ring_buffer_page_len(void *page); |
182 | ||
183 | ||
8789a9e7 SR |
184 | void *ring_buffer_alloc_read_page(struct ring_buffer *buffer); |
185 | void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data); | |
ef7a4a16 SR |
186 | int ring_buffer_read_page(struct ring_buffer *buffer, void **data_page, |
187 | size_t len, int cpu, int full); | |
8789a9e7 | 188 | |
d1b182a8 SR |
189 | struct trace_seq; |
190 | ||
191 | int ring_buffer_print_entry_header(struct trace_seq *s); | |
192 | int ring_buffer_print_page_header(struct trace_seq *s); | |
193 | ||
7a8e76a3 SR |
194 | enum ring_buffer_flags { |
195 | RB_FL_OVERWRITE = 1 << 0, | |
196 | }; | |
197 | ||
198 | #endif /* _LINUX_RING_BUFFER_H */ |