Commit | Line | Data |
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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 | * | |
37 | * @RINGBUF_TYPE_TIME_STAMP: Sync time stamp with external clock | |
361b73d5 LJ |
38 | * array[0] = tv_nsec |
39 | * array[1..2] = tv_sec | |
7a8e76a3 SR |
40 | * size = 16 bytes |
41 | * | |
334d4169 LJ |
42 | * <= @RINGBUF_TYPE_DATA_TYPE_LEN_MAX: |
43 | * Data record | |
44 | * If type_len is zero: | |
7a8e76a3 | 45 | * array[0] holds the actual length |
361b73d5 | 46 | * array[1..(length+3)/4] holds data |
334d4169 | 47 | * size = 4 + length (bytes) |
7a8e76a3 | 48 | * else |
334d4169 | 49 | * length = type_len << 2 |
361b73d5 LJ |
50 | * array[0..(length+3)/4-1] holds data |
51 | * size = 4 + length (bytes) | |
7a8e76a3 SR |
52 | */ |
53 | enum ring_buffer_type { | |
334d4169 | 54 | RINGBUF_TYPE_DATA_TYPE_LEN_MAX = 28, |
7a8e76a3 SR |
55 | RINGBUF_TYPE_PADDING, |
56 | RINGBUF_TYPE_TIME_EXTEND, | |
57 | /* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */ | |
58 | RINGBUF_TYPE_TIME_STAMP, | |
7a8e76a3 SR |
59 | }; |
60 | ||
61 | unsigned ring_buffer_event_length(struct ring_buffer_event *event); | |
62 | void *ring_buffer_event_data(struct ring_buffer_event *event); | |
63 | ||
fa1b47dd SR |
64 | /* |
65 | * ring_buffer_discard_commit will remove an event that has not | |
66 | * ben committed yet. If this is used, then ring_buffer_unlock_commit | |
67 | * must not be called on the discarded event. This function | |
68 | * will try to remove the event from the ring buffer completely | |
69 | * if another event has not been written after it. | |
70 | * | |
71 | * Example use: | |
72 | * | |
73 | * if (some_condition) | |
74 | * ring_buffer_discard_commit(buffer, event); | |
75 | * else | |
76 | * ring_buffer_unlock_commit(buffer, event); | |
77 | */ | |
78 | void ring_buffer_discard_commit(struct ring_buffer *buffer, | |
79 | struct ring_buffer_event *event); | |
80 | ||
7a8e76a3 SR |
81 | /* |
82 | * size is in bytes for each per CPU buffer. | |
83 | */ | |
84 | struct ring_buffer * | |
1f8a6a10 PZ |
85 | __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *key); |
86 | ||
87 | /* | |
88 | * Because the ring buffer is generic, if other users of the ring buffer get | |
89 | * traced by ftrace, it can produce lockdep warnings. We need to keep each | |
90 | * ring buffer's lock class separate. | |
91 | */ | |
92 | #define ring_buffer_alloc(size, flags) \ | |
93 | ({ \ | |
94 | static struct lock_class_key __key; \ | |
95 | __ring_buffer_alloc((size), (flags), &__key); \ | |
96 | }) | |
97 | ||
e30f53aa | 98 | int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full); |
ecf92700 | 99 | __poll_t ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu, |
15693458 SRRH |
100 | struct file *filp, poll_table *poll_table); |
101 | ||
102 | ||
438ced17 VN |
103 | #define RING_BUFFER_ALL_CPUS -1 |
104 | ||
7a8e76a3 SR |
105 | void ring_buffer_free(struct ring_buffer *buffer); |
106 | ||
438ced17 | 107 | int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size, int cpu); |
7a8e76a3 | 108 | |
750912fa DS |
109 | void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val); |
110 | ||
0a987751 ACM |
111 | struct ring_buffer_event *ring_buffer_lock_reserve(struct ring_buffer *buffer, |
112 | unsigned long length); | |
7a8e76a3 | 113 | int ring_buffer_unlock_commit(struct ring_buffer *buffer, |
0a987751 | 114 | struct ring_buffer_event *event); |
7a8e76a3 SR |
115 | int ring_buffer_write(struct ring_buffer *buffer, |
116 | unsigned long length, void *data); | |
117 | ||
118 | struct ring_buffer_event * | |
66a8cb95 SR |
119 | ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts, |
120 | unsigned long *lost_events); | |
7a8e76a3 | 121 | struct ring_buffer_event * |
66a8cb95 SR |
122 | ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts, |
123 | unsigned long *lost_events); | |
7a8e76a3 SR |
124 | |
125 | struct ring_buffer_iter * | |
72c9ddfd DM |
126 | ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu); |
127 | void ring_buffer_read_prepare_sync(void); | |
128 | void ring_buffer_read_start(struct ring_buffer_iter *iter); | |
7a8e76a3 SR |
129 | void ring_buffer_read_finish(struct ring_buffer_iter *iter); |
130 | ||
131 | struct ring_buffer_event * | |
132 | ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts); | |
133 | struct ring_buffer_event * | |
134 | ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts); | |
135 | void ring_buffer_iter_reset(struct ring_buffer_iter *iter); | |
136 | int ring_buffer_iter_empty(struct ring_buffer_iter *iter); | |
137 | ||
438ced17 | 138 | unsigned long ring_buffer_size(struct ring_buffer *buffer, int cpu); |
7a8e76a3 SR |
139 | |
140 | void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu); | |
141 | void ring_buffer_reset(struct ring_buffer *buffer); | |
142 | ||
85bac32c | 143 | #ifdef CONFIG_RING_BUFFER_ALLOW_SWAP |
7a8e76a3 SR |
144 | int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, |
145 | struct ring_buffer *buffer_b, int cpu); | |
85bac32c SR |
146 | #else |
147 | static inline int | |
148 | ring_buffer_swap_cpu(struct ring_buffer *buffer_a, | |
149 | struct ring_buffer *buffer_b, int cpu) | |
150 | { | |
151 | return -ENODEV; | |
152 | } | |
153 | #endif | |
7a8e76a3 | 154 | |
3d4e204d YB |
155 | bool ring_buffer_empty(struct ring_buffer *buffer); |
156 | bool ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu); | |
7a8e76a3 SR |
157 | |
158 | void ring_buffer_record_disable(struct ring_buffer *buffer); | |
159 | void ring_buffer_record_enable(struct ring_buffer *buffer); | |
499e5470 SR |
160 | void ring_buffer_record_off(struct ring_buffer *buffer); |
161 | void ring_buffer_record_on(struct ring_buffer *buffer); | |
162 | int ring_buffer_record_is_on(struct ring_buffer *buffer); | |
7a8e76a3 SR |
163 | void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu); |
164 | void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu); | |
165 | ||
50ecf2c3 | 166 | u64 ring_buffer_oldest_event_ts(struct ring_buffer *buffer, int cpu); |
c64e148a | 167 | unsigned long ring_buffer_bytes_cpu(struct ring_buffer *buffer, int cpu); |
7a8e76a3 SR |
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 | 172 | unsigned long ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu); |
884bfe89 | 173 | unsigned long ring_buffer_dropped_events_cpu(struct ring_buffer *buffer, int cpu); |
ad964704 | 174 | unsigned long ring_buffer_read_events_cpu(struct ring_buffer *buffer, int cpu); |
7a8e76a3 | 175 | |
37886f6a SR |
176 | u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu); |
177 | void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer, | |
178 | int cpu, u64 *ts); | |
179 | void ring_buffer_set_clock(struct ring_buffer *buffer, | |
180 | u64 (*clock)(void)); | |
7a8e76a3 | 181 | |
ef7a4a16 SR |
182 | size_t ring_buffer_page_len(void *page); |
183 | ||
184 | ||
7ea59064 | 185 | void *ring_buffer_alloc_read_page(struct ring_buffer *buffer, int cpu); |
73a757e6 | 186 | void ring_buffer_free_read_page(struct ring_buffer *buffer, int cpu, void *data); |
ef7a4a16 SR |
187 | int ring_buffer_read_page(struct ring_buffer *buffer, void **data_page, |
188 | size_t len, int cpu, int full); | |
8789a9e7 | 189 | |
d1b182a8 SR |
190 | struct trace_seq; |
191 | ||
192 | int ring_buffer_print_entry_header(struct trace_seq *s); | |
193 | int ring_buffer_print_page_header(struct trace_seq *s); | |
194 | ||
7a8e76a3 SR |
195 | enum ring_buffer_flags { |
196 | RB_FL_OVERWRITE = 1 << 0, | |
197 | }; | |
198 | ||
b32614c0 SAS |
199 | #ifdef CONFIG_RING_BUFFER |
200 | int trace_rb_cpu_prepare(unsigned int cpu, struct hlist_node *node); | |
201 | #else | |
202 | #define trace_rb_cpu_prepare NULL | |
203 | #endif | |
204 | ||
7a8e76a3 | 205 | #endif /* _LINUX_RING_BUFFER_H */ |