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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 | ||
fa1b47dd SR |
65 | /* |
66 | * ring_buffer_discard_commit will remove an event that has not | |
67 | * ben committed yet. If this is used, then ring_buffer_unlock_commit | |
68 | * must not be called on the discarded event. This function | |
69 | * will try to remove the event from the ring buffer completely | |
70 | * if another event has not been written after it. | |
71 | * | |
72 | * Example use: | |
73 | * | |
74 | * if (some_condition) | |
75 | * ring_buffer_discard_commit(buffer, event); | |
76 | * else | |
77 | * ring_buffer_unlock_commit(buffer, event); | |
78 | */ | |
79 | void ring_buffer_discard_commit(struct ring_buffer *buffer, | |
80 | struct ring_buffer_event *event); | |
81 | ||
7a8e76a3 SR |
82 | /* |
83 | * size is in bytes for each per CPU buffer. | |
84 | */ | |
85 | struct ring_buffer * | |
1f8a6a10 PZ |
86 | __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *key); |
87 | ||
88 | /* | |
89 | * Because the ring buffer is generic, if other users of the ring buffer get | |
90 | * traced by ftrace, it can produce lockdep warnings. We need to keep each | |
91 | * ring buffer's lock class separate. | |
92 | */ | |
93 | #define ring_buffer_alloc(size, flags) \ | |
94 | ({ \ | |
95 | static struct lock_class_key __key; \ | |
96 | __ring_buffer_alloc((size), (flags), &__key); \ | |
97 | }) | |
98 | ||
7a8e76a3 SR |
99 | void ring_buffer_free(struct ring_buffer *buffer); |
100 | ||
101 | int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size); | |
102 | ||
0a987751 ACM |
103 | struct ring_buffer_event *ring_buffer_lock_reserve(struct ring_buffer *buffer, |
104 | unsigned long length); | |
7a8e76a3 | 105 | int ring_buffer_unlock_commit(struct ring_buffer *buffer, |
0a987751 | 106 | struct ring_buffer_event *event); |
7a8e76a3 SR |
107 | int ring_buffer_write(struct ring_buffer *buffer, |
108 | unsigned long length, void *data); | |
109 | ||
110 | struct ring_buffer_event * | |
66a8cb95 SR |
111 | ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts, |
112 | unsigned long *lost_events); | |
7a8e76a3 | 113 | struct ring_buffer_event * |
66a8cb95 SR |
114 | ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts, |
115 | unsigned long *lost_events); | |
7a8e76a3 SR |
116 | |
117 | struct ring_buffer_iter * | |
72c9ddfd DM |
118 | ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu); |
119 | void ring_buffer_read_prepare_sync(void); | |
120 | void ring_buffer_read_start(struct ring_buffer_iter *iter); | |
7a8e76a3 SR |
121 | void ring_buffer_read_finish(struct ring_buffer_iter *iter); |
122 | ||
123 | struct ring_buffer_event * | |
124 | ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts); | |
125 | struct ring_buffer_event * | |
126 | ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts); | |
127 | void ring_buffer_iter_reset(struct ring_buffer_iter *iter); | |
128 | int ring_buffer_iter_empty(struct ring_buffer_iter *iter); | |
129 | ||
130 | unsigned long ring_buffer_size(struct ring_buffer *buffer); | |
131 | ||
132 | void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu); | |
133 | void ring_buffer_reset(struct ring_buffer *buffer); | |
134 | ||
85bac32c | 135 | #ifdef CONFIG_RING_BUFFER_ALLOW_SWAP |
7a8e76a3 SR |
136 | int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, |
137 | struct ring_buffer *buffer_b, int cpu); | |
85bac32c SR |
138 | #else |
139 | static inline int | |
140 | ring_buffer_swap_cpu(struct ring_buffer *buffer_a, | |
141 | struct ring_buffer *buffer_b, int cpu) | |
142 | { | |
143 | return -ENODEV; | |
144 | } | |
145 | #endif | |
7a8e76a3 SR |
146 | |
147 | int ring_buffer_empty(struct ring_buffer *buffer); | |
148 | int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu); | |
149 | ||
150 | void ring_buffer_record_disable(struct ring_buffer *buffer); | |
151 | void ring_buffer_record_enable(struct ring_buffer *buffer); | |
152 | void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu); | |
153 | void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu); | |
154 | ||
155 | unsigned long ring_buffer_entries(struct ring_buffer *buffer); | |
156 | unsigned long ring_buffer_overruns(struct ring_buffer *buffer); | |
e09373f2 RR |
157 | unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu); |
158 | unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu); | |
f0d2c681 | 159 | unsigned long ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu); |
7a8e76a3 | 160 | |
37886f6a SR |
161 | u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu); |
162 | void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer, | |
163 | int cpu, u64 *ts); | |
164 | void ring_buffer_set_clock(struct ring_buffer *buffer, | |
165 | u64 (*clock)(void)); | |
7a8e76a3 | 166 | |
ef7a4a16 SR |
167 | size_t ring_buffer_page_len(void *page); |
168 | ||
169 | ||
8789a9e7 SR |
170 | void *ring_buffer_alloc_read_page(struct ring_buffer *buffer); |
171 | void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data); | |
ef7a4a16 SR |
172 | int ring_buffer_read_page(struct ring_buffer *buffer, void **data_page, |
173 | size_t len, int cpu, int full); | |
8789a9e7 | 174 | |
d1b182a8 SR |
175 | struct trace_seq; |
176 | ||
177 | int ring_buffer_print_entry_header(struct trace_seq *s); | |
178 | int ring_buffer_print_page_header(struct trace_seq *s); | |
179 | ||
7a8e76a3 SR |
180 | enum ring_buffer_flags { |
181 | RB_FL_OVERWRITE = 1 << 0, | |
182 | }; | |
183 | ||
184 | #endif /* _LINUX_RING_BUFFER_H */ |