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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 SR |
8 | |
9 | struct ring_buffer; | |
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); | |
dc4e2801 | 64 | u64 ring_buffer_event_time_stamp(struct ring_buffer_event *event); |
7a8e76a3 | 65 | |
fa1b47dd SR |
66 | /* |
67 | * ring_buffer_discard_commit will remove an event that has not | |
a9235b54 | 68 | * been committed yet. If this is used, then ring_buffer_unlock_commit |
fa1b47dd SR |
69 | * must not be called on the discarded event. This function |
70 | * will try to remove the event from the ring buffer completely | |
71 | * if another event has not been written after it. | |
72 | * | |
73 | * Example use: | |
74 | * | |
75 | * if (some_condition) | |
76 | * ring_buffer_discard_commit(buffer, event); | |
77 | * else | |
78 | * ring_buffer_unlock_commit(buffer, event); | |
79 | */ | |
80 | void ring_buffer_discard_commit(struct ring_buffer *buffer, | |
81 | struct ring_buffer_event *event); | |
82 | ||
7a8e76a3 SR |
83 | /* |
84 | * size is in bytes for each per CPU buffer. | |
85 | */ | |
86 | struct ring_buffer * | |
1f8a6a10 PZ |
87 | __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *key); |
88 | ||
89 | /* | |
90 | * Because the ring buffer is generic, if other users of the ring buffer get | |
91 | * traced by ftrace, it can produce lockdep warnings. We need to keep each | |
92 | * ring buffer's lock class separate. | |
93 | */ | |
94 | #define ring_buffer_alloc(size, flags) \ | |
95 | ({ \ | |
96 | static struct lock_class_key __key; \ | |
97 | __ring_buffer_alloc((size), (flags), &__key); \ | |
98 | }) | |
99 | ||
2c2b0a78 | 100 | int ring_buffer_wait(struct ring_buffer *buffer, int cpu, int full); |
ecf92700 | 101 | __poll_t ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu, |
15693458 SRRH |
102 | struct file *filp, poll_table *poll_table); |
103 | ||
104 | ||
438ced17 VN |
105 | #define RING_BUFFER_ALL_CPUS -1 |
106 | ||
7a8e76a3 SR |
107 | void ring_buffer_free(struct ring_buffer *buffer); |
108 | ||
438ced17 | 109 | int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size, int cpu); |
7a8e76a3 | 110 | |
750912fa DS |
111 | void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val); |
112 | ||
0a987751 ACM |
113 | struct ring_buffer_event *ring_buffer_lock_reserve(struct ring_buffer *buffer, |
114 | unsigned long length); | |
7a8e76a3 | 115 | int ring_buffer_unlock_commit(struct ring_buffer *buffer, |
0a987751 | 116 | struct ring_buffer_event *event); |
7a8e76a3 SR |
117 | int ring_buffer_write(struct ring_buffer *buffer, |
118 | unsigned long length, void *data); | |
119 | ||
8e012066 SRV |
120 | void ring_buffer_nest_start(struct ring_buffer *buffer); |
121 | void ring_buffer_nest_end(struct ring_buffer *buffer); | |
122 | ||
7a8e76a3 | 123 | struct ring_buffer_event * |
66a8cb95 SR |
124 | ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts, |
125 | unsigned long *lost_events); | |
7a8e76a3 | 126 | struct ring_buffer_event * |
66a8cb95 SR |
127 | ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts, |
128 | unsigned long *lost_events); | |
7a8e76a3 SR |
129 | |
130 | struct ring_buffer_iter * | |
31b265b3 | 131 | ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu, gfp_t flags); |
72c9ddfd DM |
132 | void ring_buffer_read_prepare_sync(void); |
133 | void ring_buffer_read_start(struct ring_buffer_iter *iter); | |
7a8e76a3 SR |
134 | void ring_buffer_read_finish(struct ring_buffer_iter *iter); |
135 | ||
136 | struct ring_buffer_event * | |
137 | ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts); | |
138 | struct ring_buffer_event * | |
139 | ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts); | |
140 | void ring_buffer_iter_reset(struct ring_buffer_iter *iter); | |
141 | int ring_buffer_iter_empty(struct ring_buffer_iter *iter); | |
142 | ||
438ced17 | 143 | unsigned long ring_buffer_size(struct ring_buffer *buffer, int cpu); |
7a8e76a3 SR |
144 | |
145 | void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu); | |
146 | void ring_buffer_reset(struct ring_buffer *buffer); | |
147 | ||
85bac32c | 148 | #ifdef CONFIG_RING_BUFFER_ALLOW_SWAP |
7a8e76a3 SR |
149 | int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, |
150 | struct ring_buffer *buffer_b, int cpu); | |
85bac32c SR |
151 | #else |
152 | static inline int | |
153 | ring_buffer_swap_cpu(struct ring_buffer *buffer_a, | |
154 | struct ring_buffer *buffer_b, int cpu) | |
155 | { | |
156 | return -ENODEV; | |
157 | } | |
158 | #endif | |
7a8e76a3 | 159 | |
3d4e204d YB |
160 | bool ring_buffer_empty(struct ring_buffer *buffer); |
161 | bool ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu); | |
7a8e76a3 SR |
162 | |
163 | void ring_buffer_record_disable(struct ring_buffer *buffer); | |
164 | void ring_buffer_record_enable(struct ring_buffer *buffer); | |
499e5470 SR |
165 | void ring_buffer_record_off(struct ring_buffer *buffer); |
166 | void ring_buffer_record_on(struct ring_buffer *buffer); | |
3ebea280 | 167 | bool ring_buffer_record_is_on(struct ring_buffer *buffer); |
d7224c0e | 168 | bool ring_buffer_record_is_set_on(struct ring_buffer *buffer); |
7a8e76a3 SR |
169 | void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu); |
170 | void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu); | |
171 | ||
50ecf2c3 | 172 | u64 ring_buffer_oldest_event_ts(struct ring_buffer *buffer, int cpu); |
c64e148a | 173 | unsigned long ring_buffer_bytes_cpu(struct ring_buffer *buffer, int cpu); |
7a8e76a3 SR |
174 | unsigned long ring_buffer_entries(struct ring_buffer *buffer); |
175 | unsigned long ring_buffer_overruns(struct ring_buffer *buffer); | |
e09373f2 RR |
176 | unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu); |
177 | unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu); | |
f0d2c681 | 178 | unsigned long ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu); |
884bfe89 | 179 | unsigned long ring_buffer_dropped_events_cpu(struct ring_buffer *buffer, int cpu); |
ad964704 | 180 | unsigned long ring_buffer_read_events_cpu(struct ring_buffer *buffer, int cpu); |
7a8e76a3 | 181 | |
37886f6a SR |
182 | u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu); |
183 | void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer, | |
184 | int cpu, u64 *ts); | |
185 | void ring_buffer_set_clock(struct ring_buffer *buffer, | |
186 | u64 (*clock)(void)); | |
00b41452 TZ |
187 | void ring_buffer_set_time_stamp_abs(struct ring_buffer *buffer, bool abs); |
188 | bool ring_buffer_time_stamp_abs(struct ring_buffer *buffer); | |
7a8e76a3 | 189 | |
2c2b0a78 SRV |
190 | size_t ring_buffer_nr_pages(struct ring_buffer *buffer, int cpu); |
191 | size_t ring_buffer_nr_dirty_pages(struct ring_buffer *buffer, int cpu); | |
ef7a4a16 | 192 | |
7ea59064 | 193 | void *ring_buffer_alloc_read_page(struct ring_buffer *buffer, int cpu); |
73a757e6 | 194 | void ring_buffer_free_read_page(struct ring_buffer *buffer, int cpu, void *data); |
ef7a4a16 SR |
195 | int ring_buffer_read_page(struct ring_buffer *buffer, void **data_page, |
196 | size_t len, int cpu, int full); | |
8789a9e7 | 197 | |
d1b182a8 SR |
198 | struct trace_seq; |
199 | ||
200 | int ring_buffer_print_entry_header(struct trace_seq *s); | |
201 | int ring_buffer_print_page_header(struct trace_seq *s); | |
202 | ||
7a8e76a3 SR |
203 | enum ring_buffer_flags { |
204 | RB_FL_OVERWRITE = 1 << 0, | |
205 | }; | |
206 | ||
b32614c0 SAS |
207 | #ifdef CONFIG_RING_BUFFER |
208 | int trace_rb_cpu_prepare(unsigned int cpu, struct hlist_node *node); | |
209 | #else | |
210 | #define trace_rb_cpu_prepare NULL | |
211 | #endif | |
212 | ||
7a8e76a3 | 213 | #endif /* _LINUX_RING_BUFFER_H */ |