Commit | Line | Data |
---|---|---|
b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
7a8e76a3 SR |
2 | #ifndef _LINUX_RING_BUFFER_H |
3 | #define _LINUX_RING_BUFFER_H | |
4 | ||
5 | #include <linux/mm.h> | |
6 | #include <linux/seq_file.h> | |
15693458 | 7 | #include <linux/poll.h> |
7a8e76a3 | 8 | |
13292494 | 9 | struct trace_buffer; |
7a8e76a3 SR |
10 | struct ring_buffer_iter; |
11 | ||
12 | /* | |
c3706f00 | 13 | * Don't refer to this struct directly, use functions below. |
7a8e76a3 SR |
14 | */ |
15 | struct ring_buffer_event { | |
334d4169 | 16 | u32 type_len:5, time_delta:27; |
1744a21d | 17 | |
7a8e76a3 SR |
18 | u32 array[]; |
19 | }; | |
20 | ||
21 | /** | |
22 | * enum ring_buffer_type - internal ring buffer types | |
23 | * | |
2d622719 TZ |
24 | * @RINGBUF_TYPE_PADDING: Left over page padding or discarded event |
25 | * If time_delta is 0: | |
26 | * array is ignored | |
27 | * size is variable depending on how much | |
7a8e76a3 | 28 | * padding is needed |
2d622719 | 29 | * If time_delta is non zero: |
334d4169 LJ |
30 | * array[0] holds the actual length |
31 | * size = 4 + length (bytes) | |
7a8e76a3 SR |
32 | * |
33 | * @RINGBUF_TYPE_TIME_EXTEND: Extend the time delta | |
34 | * array[0] = time delta (28 .. 59) | |
35 | * size = 8 bytes | |
36 | * | |
dc4e2801 TZ |
37 | * @RINGBUF_TYPE_TIME_STAMP: Absolute timestamp |
38 | * Same format as TIME_EXTEND except that the | |
39 | * value is an absolute timestamp, not a delta | |
40 | * event.time_delta contains bottom 27 bits | |
41 | * array[0] = top (28 .. 59) bits | |
42 | * size = 8 bytes | |
7a8e76a3 | 43 | * |
334d4169 LJ |
44 | * <= @RINGBUF_TYPE_DATA_TYPE_LEN_MAX: |
45 | * Data record | |
46 | * If type_len is zero: | |
7a8e76a3 | 47 | * array[0] holds the actual length |
361b73d5 | 48 | * array[1..(length+3)/4] holds data |
334d4169 | 49 | * size = 4 + length (bytes) |
7a8e76a3 | 50 | * else |
334d4169 | 51 | * length = type_len << 2 |
361b73d5 LJ |
52 | * array[0..(length+3)/4-1] holds data |
53 | * size = 4 + length (bytes) | |
7a8e76a3 SR |
54 | */ |
55 | enum ring_buffer_type { | |
334d4169 | 56 | RINGBUF_TYPE_DATA_TYPE_LEN_MAX = 28, |
7a8e76a3 SR |
57 | RINGBUF_TYPE_PADDING, |
58 | RINGBUF_TYPE_TIME_EXTEND, | |
7a8e76a3 | 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); | |
efe6196a SRV |
64 | u64 ring_buffer_event_time_stamp(struct trace_buffer *buffer, |
65 | struct ring_buffer_event *event); | |
7a8e76a3 | 66 | |
fa1b47dd SR |
67 | /* |
68 | * ring_buffer_discard_commit will remove an event that has not | |
a9235b54 | 69 | * been committed yet. If this is used, then ring_buffer_unlock_commit |
fa1b47dd SR |
70 | * must not be called on the discarded event. This function |
71 | * will try to remove the event from the ring buffer completely | |
72 | * if another event has not been written after it. | |
73 | * | |
74 | * Example use: | |
75 | * | |
76 | * if (some_condition) | |
77 | * ring_buffer_discard_commit(buffer, event); | |
78 | * else | |
79 | * ring_buffer_unlock_commit(buffer, event); | |
80 | */ | |
13292494 | 81 | void ring_buffer_discard_commit(struct trace_buffer *buffer, |
fa1b47dd SR |
82 | struct ring_buffer_event *event); |
83 | ||
7a8e76a3 SR |
84 | /* |
85 | * size is in bytes for each per CPU buffer. | |
86 | */ | |
13292494 | 87 | struct trace_buffer * |
1f8a6a10 PZ |
88 | __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *key); |
89 | ||
90 | /* | |
91 | * Because the ring buffer is generic, if other users of the ring buffer get | |
92 | * traced by ftrace, it can produce lockdep warnings. We need to keep each | |
93 | * ring buffer's lock class separate. | |
94 | */ | |
95 | #define ring_buffer_alloc(size, flags) \ | |
96 | ({ \ | |
97 | static struct lock_class_key __key; \ | |
98 | __ring_buffer_alloc((size), (flags), &__key); \ | |
99 | }) | |
100 | ||
13292494 SRV |
101 | int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full); |
102 | __poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu, | |
15693458 SRRH |
103 | struct file *filp, poll_table *poll_table); |
104 | ||
105 | ||
438ced17 VN |
106 | #define RING_BUFFER_ALL_CPUS -1 |
107 | ||
13292494 | 108 | void ring_buffer_free(struct trace_buffer *buffer); |
7a8e76a3 | 109 | |
13292494 | 110 | int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, int cpu); |
7a8e76a3 | 111 | |
13292494 | 112 | void ring_buffer_change_overwrite(struct trace_buffer *buffer, int val); |
750912fa | 113 | |
13292494 | 114 | struct ring_buffer_event *ring_buffer_lock_reserve(struct trace_buffer *buffer, |
0a987751 | 115 | unsigned long length); |
13292494 | 116 | int ring_buffer_unlock_commit(struct trace_buffer *buffer, |
0a987751 | 117 | struct ring_buffer_event *event); |
13292494 | 118 | int ring_buffer_write(struct trace_buffer *buffer, |
7a8e76a3 SR |
119 | unsigned long length, void *data); |
120 | ||
13292494 SRV |
121 | void ring_buffer_nest_start(struct trace_buffer *buffer); |
122 | void ring_buffer_nest_end(struct trace_buffer *buffer); | |
8e012066 | 123 | |
7a8e76a3 | 124 | struct ring_buffer_event * |
13292494 | 125 | ring_buffer_peek(struct trace_buffer *buffer, int cpu, u64 *ts, |
66a8cb95 | 126 | unsigned long *lost_events); |
7a8e76a3 | 127 | struct ring_buffer_event * |
13292494 | 128 | ring_buffer_consume(struct trace_buffer *buffer, int cpu, u64 *ts, |
66a8cb95 | 129 | unsigned long *lost_events); |
7a8e76a3 SR |
130 | |
131 | struct ring_buffer_iter * | |
13292494 | 132 | ring_buffer_read_prepare(struct trace_buffer *buffer, int cpu, gfp_t flags); |
72c9ddfd DM |
133 | void ring_buffer_read_prepare_sync(void); |
134 | void ring_buffer_read_start(struct ring_buffer_iter *iter); | |
7a8e76a3 SR |
135 | void ring_buffer_read_finish(struct ring_buffer_iter *iter); |
136 | ||
137 | struct ring_buffer_event * | |
138 | ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts); | |
bc1a72af | 139 | void ring_buffer_iter_advance(struct ring_buffer_iter *iter); |
7a8e76a3 SR |
140 | void ring_buffer_iter_reset(struct ring_buffer_iter *iter); |
141 | int ring_buffer_iter_empty(struct ring_buffer_iter *iter); | |
c9b7a4a7 | 142 | bool ring_buffer_iter_dropped(struct ring_buffer_iter *iter); |
7a8e76a3 | 143 | |
13292494 | 144 | unsigned long ring_buffer_size(struct trace_buffer *buffer, int cpu); |
7a8e76a3 | 145 | |
13292494 | 146 | void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu); |
b23d7a5f | 147 | void ring_buffer_reset_online_cpus(struct trace_buffer *buffer); |
13292494 | 148 | void ring_buffer_reset(struct trace_buffer *buffer); |
7a8e76a3 | 149 | |
85bac32c | 150 | #ifdef CONFIG_RING_BUFFER_ALLOW_SWAP |
13292494 SRV |
151 | int ring_buffer_swap_cpu(struct trace_buffer *buffer_a, |
152 | struct trace_buffer *buffer_b, int cpu); | |
85bac32c SR |
153 | #else |
154 | static inline int | |
13292494 SRV |
155 | ring_buffer_swap_cpu(struct trace_buffer *buffer_a, |
156 | struct trace_buffer *buffer_b, int cpu) | |
85bac32c SR |
157 | { |
158 | return -ENODEV; | |
159 | } | |
160 | #endif | |
7a8e76a3 | 161 | |
13292494 SRV |
162 | bool ring_buffer_empty(struct trace_buffer *buffer); |
163 | bool ring_buffer_empty_cpu(struct trace_buffer *buffer, int cpu); | |
164 | ||
165 | void ring_buffer_record_disable(struct trace_buffer *buffer); | |
166 | void ring_buffer_record_enable(struct trace_buffer *buffer); | |
167 | void ring_buffer_record_off(struct trace_buffer *buffer); | |
168 | void ring_buffer_record_on(struct trace_buffer *buffer); | |
169 | bool ring_buffer_record_is_on(struct trace_buffer *buffer); | |
170 | bool ring_buffer_record_is_set_on(struct trace_buffer *buffer); | |
171 | void ring_buffer_record_disable_cpu(struct trace_buffer *buffer, int cpu); | |
172 | void ring_buffer_record_enable_cpu(struct trace_buffer *buffer, int cpu); | |
173 | ||
174 | u64 ring_buffer_oldest_event_ts(struct trace_buffer *buffer, int cpu); | |
175 | unsigned long ring_buffer_bytes_cpu(struct trace_buffer *buffer, int cpu); | |
176 | unsigned long ring_buffer_entries(struct trace_buffer *buffer); | |
177 | unsigned long ring_buffer_overruns(struct trace_buffer *buffer); | |
178 | unsigned long ring_buffer_entries_cpu(struct trace_buffer *buffer, int cpu); | |
179 | unsigned long ring_buffer_overrun_cpu(struct trace_buffer *buffer, int cpu); | |
180 | unsigned long ring_buffer_commit_overrun_cpu(struct trace_buffer *buffer, int cpu); | |
181 | unsigned long ring_buffer_dropped_events_cpu(struct trace_buffer *buffer, int cpu); | |
182 | unsigned long ring_buffer_read_events_cpu(struct trace_buffer *buffer, int cpu); | |
183 | ||
184 | u64 ring_buffer_time_stamp(struct trace_buffer *buffer, int cpu); | |
185 | void ring_buffer_normalize_time_stamp(struct trace_buffer *buffer, | |
37886f6a | 186 | int cpu, u64 *ts); |
13292494 | 187 | void ring_buffer_set_clock(struct trace_buffer *buffer, |
37886f6a | 188 | u64 (*clock)(void)); |
13292494 SRV |
189 | void ring_buffer_set_time_stamp_abs(struct trace_buffer *buffer, bool abs); |
190 | bool ring_buffer_time_stamp_abs(struct trace_buffer *buffer); | |
7a8e76a3 | 191 | |
13292494 SRV |
192 | size_t ring_buffer_nr_pages(struct trace_buffer *buffer, int cpu); |
193 | size_t ring_buffer_nr_dirty_pages(struct trace_buffer *buffer, int cpu); | |
ef7a4a16 | 194 | |
13292494 SRV |
195 | void *ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu); |
196 | void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, void *data); | |
197 | int ring_buffer_read_page(struct trace_buffer *buffer, void **data_page, | |
ef7a4a16 | 198 | size_t len, int cpu, int full); |
8789a9e7 | 199 | |
d1b182a8 SR |
200 | struct trace_seq; |
201 | ||
202 | int ring_buffer_print_entry_header(struct trace_seq *s); | |
203 | int ring_buffer_print_page_header(struct trace_seq *s); | |
204 | ||
7a8e76a3 SR |
205 | enum ring_buffer_flags { |
206 | RB_FL_OVERWRITE = 1 << 0, | |
207 | }; | |
208 | ||
b32614c0 SAS |
209 | #ifdef CONFIG_RING_BUFFER |
210 | int trace_rb_cpu_prepare(unsigned int cpu, struct hlist_node *node); | |
211 | #else | |
212 | #define trace_rb_cpu_prepare NULL | |
213 | #endif | |
214 | ||
7a8e76a3 | 215 | #endif /* _LINUX_RING_BUFFER_H */ |