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Steven Rostedt7a8e76a2008-09-29 23:02:38 -04001#ifndef _LINUX_RING_BUFFER_H
2#define _LINUX_RING_BUFFER_H
3
Vegard Nossum1744a212009-02-28 08:29:44 +01004#include <linux/kmemcheck.h>
Steven Rostedt7a8e76a2008-09-29 23:02:38 -04005#include <linux/mm.h>
6#include <linux/seq_file.h>
Steven Rostedt (Red Hat)15693452013-02-28 19:59:17 -05007#include <linux/poll.h>
Steven Rostedt7a8e76a2008-09-29 23:02:38 -04008
9struct ring_buffer;
10struct ring_buffer_iter;
11
12/*
Wenji Huangc3706f02009-02-10 01:03:18 -050013 * Don't refer to this struct directly, use functions below.
Steven Rostedt7a8e76a2008-09-29 23:02:38 -040014 */
15struct ring_buffer_event {
Vegard Nossum1744a212009-02-28 08:29:44 +010016 kmemcheck_bitfield_begin(bitfield);
Lai Jiangshan334d4162009-04-24 11:27:05 +080017 u32 type_len:5, time_delta:27;
Vegard Nossum1744a212009-02-28 08:29:44 +010018 kmemcheck_bitfield_end(bitfield);
19
Steven Rostedt7a8e76a2008-09-29 23:02:38 -040020 u32 array[];
21};
22
23/**
24 * enum ring_buffer_type - internal ring buffer types
25 *
Tom Zanussi2d622712009-03-22 03:30:49 -050026 * @RINGBUF_TYPE_PADDING: Left over page padding or discarded event
27 * If time_delta is 0:
28 * array is ignored
29 * size is variable depending on how much
Steven Rostedt7a8e76a2008-09-29 23:02:38 -040030 * padding is needed
Tom Zanussi2d622712009-03-22 03:30:49 -050031 * If time_delta is non zero:
Lai Jiangshan334d4162009-04-24 11:27:05 +080032 * array[0] holds the actual length
33 * size = 4 + length (bytes)
Steven Rostedt7a8e76a2008-09-29 23:02:38 -040034 *
35 * @RINGBUF_TYPE_TIME_EXTEND: Extend the time delta
36 * array[0] = time delta (28 .. 59)
37 * size = 8 bytes
38 *
39 * @RINGBUF_TYPE_TIME_STAMP: Sync time stamp with external clock
Lai Jiangshan361b73d2008-12-08 10:58:08 +080040 * array[0] = tv_nsec
41 * array[1..2] = tv_sec
Steven Rostedt7a8e76a2008-09-29 23:02:38 -040042 * size = 16 bytes
43 *
Lai Jiangshan334d4162009-04-24 11:27:05 +080044 * <= @RINGBUF_TYPE_DATA_TYPE_LEN_MAX:
45 * Data record
46 * If type_len is zero:
Steven Rostedt7a8e76a2008-09-29 23:02:38 -040047 * array[0] holds the actual length
Lai Jiangshan361b73d2008-12-08 10:58:08 +080048 * array[1..(length+3)/4] holds data
Lai Jiangshan334d4162009-04-24 11:27:05 +080049 * size = 4 + length (bytes)
Steven Rostedt7a8e76a2008-09-29 23:02:38 -040050 * else
Lai Jiangshan334d4162009-04-24 11:27:05 +080051 * length = type_len << 2
Lai Jiangshan361b73d2008-12-08 10:58:08 +080052 * array[0..(length+3)/4-1] holds data
53 * size = 4 + length (bytes)
Steven Rostedt7a8e76a2008-09-29 23:02:38 -040054 */
55enum ring_buffer_type {
Lai Jiangshan334d4162009-04-24 11:27:05 +080056 RINGBUF_TYPE_DATA_TYPE_LEN_MAX = 28,
Steven Rostedt7a8e76a2008-09-29 23:02:38 -040057 RINGBUF_TYPE_PADDING,
58 RINGBUF_TYPE_TIME_EXTEND,
59 /* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */
60 RINGBUF_TYPE_TIME_STAMP,
Steven Rostedt7a8e76a2008-09-29 23:02:38 -040061};
62
63unsigned ring_buffer_event_length(struct ring_buffer_event *event);
64void *ring_buffer_event_data(struct ring_buffer_event *event);
65
Steven Rostedtfa1b47d2009-04-02 00:09:41 -040066/*
Steven Rostedtfa1b47d2009-04-02 00:09:41 -040067 * ring_buffer_discard_commit will remove an event that has not
68 * ben committed yet. If this is used, then ring_buffer_unlock_commit
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 */
80void ring_buffer_discard_commit(struct ring_buffer *buffer,
81 struct ring_buffer_event *event);
82
83/*
Steven Rostedt7a8e76a2008-09-29 23:02:38 -040084 * size is in bytes for each per CPU buffer.
85 */
86struct ring_buffer *
Peter Zijlstra1f8a6a12009-06-08 18:18:39 +020087__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
Rabin Vincente30f53a2014-11-10 19:46:34 +0100100int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full);
Steven Rostedt (Red Hat)15693452013-02-28 19:59:17 -0500101int ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
102 struct file *filp, poll_table *poll_table);
103
104
Vaibhav Nagarnaik438ced12012-02-02 12:00:41 -0800105#define RING_BUFFER_ALL_CPUS -1
106
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400107void ring_buffer_free(struct ring_buffer *buffer);
108
Vaibhav Nagarnaik438ced12012-02-02 12:00:41 -0800109int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size, int cpu);
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400110
David Sharp750912f2010-12-08 13:46:47 -0800111void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val);
112
Arnaldo Carvalho de Melo0a987752009-02-05 16:12:56 -0200113struct ring_buffer_event *ring_buffer_lock_reserve(struct ring_buffer *buffer,
114 unsigned long length);
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400115int ring_buffer_unlock_commit(struct ring_buffer *buffer,
Arnaldo Carvalho de Melo0a987752009-02-05 16:12:56 -0200116 struct ring_buffer_event *event);
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400117int ring_buffer_write(struct ring_buffer *buffer,
118 unsigned long length, void *data);
119
120struct ring_buffer_event *
Steven Rostedt66a8cb92010-03-31 13:21:56 -0400121ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts,
122 unsigned long *lost_events);
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400123struct ring_buffer_event *
Steven Rostedt66a8cb92010-03-31 13:21:56 -0400124ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts,
125 unsigned long *lost_events);
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400126
127struct ring_buffer_iter *
David Miller72c9ddf2010-04-20 15:47:11 -0700128ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu);
129void ring_buffer_read_prepare_sync(void);
130void ring_buffer_read_start(struct ring_buffer_iter *iter);
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400131void ring_buffer_read_finish(struct ring_buffer_iter *iter);
132
133struct ring_buffer_event *
134ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts);
135struct ring_buffer_event *
136ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts);
137void ring_buffer_iter_reset(struct ring_buffer_iter *iter);
138int ring_buffer_iter_empty(struct ring_buffer_iter *iter);
139
Vaibhav Nagarnaik438ced12012-02-02 12:00:41 -0800140unsigned long ring_buffer_size(struct ring_buffer *buffer, int cpu);
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400141
142void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu);
143void ring_buffer_reset(struct ring_buffer *buffer);
144
Steven Rostedt85bac322009-09-04 14:24:40 -0400145#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400146int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
147 struct ring_buffer *buffer_b, int cpu);
Steven Rostedt85bac322009-09-04 14:24:40 -0400148#else
149static inline int
150ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
151 struct ring_buffer *buffer_b, int cpu)
152{
153 return -ENODEV;
154}
155#endif
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400156
Yaowei Bai3d4e2042015-09-29 22:43:32 +0800157bool ring_buffer_empty(struct ring_buffer *buffer);
158bool ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu);
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400159
160void ring_buffer_record_disable(struct ring_buffer *buffer);
161void ring_buffer_record_enable(struct ring_buffer *buffer);
Steven Rostedt499e5472012-02-22 15:50:28 -0500162void ring_buffer_record_off(struct ring_buffer *buffer);
163void ring_buffer_record_on(struct ring_buffer *buffer);
164int ring_buffer_record_is_on(struct ring_buffer *buffer);
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400165void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu);
166void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu);
167
Yoshihiro YUNOMAE50ecf2c2012-10-11 16:27:54 -0700168u64 ring_buffer_oldest_event_ts(struct ring_buffer *buffer, int cpu);
Vaibhav Nagarnaikc64e1482011-08-16 14:46:16 -0700169unsigned long ring_buffer_bytes_cpu(struct ring_buffer *buffer, int cpu);
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400170unsigned long ring_buffer_entries(struct ring_buffer *buffer);
171unsigned long ring_buffer_overruns(struct ring_buffer *buffer);
Robert Richtere09373f2008-11-26 14:04:19 +0100172unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu);
173unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu);
Steven Rostedtf0d2c682009-04-29 13:43:37 -0400174unsigned long ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu);
Slava Pestov884bfe82011-07-15 14:23:58 -0700175unsigned long ring_buffer_dropped_events_cpu(struct ring_buffer *buffer, int cpu);
Steven Rostedt (Red Hat)ad964702013-01-29 17:45:49 -0500176unsigned long ring_buffer_read_events_cpu(struct ring_buffer *buffer, int cpu);
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400177
Steven Rostedt37886f62009-03-17 17:22:06 -0400178u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu);
179void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer,
180 int cpu, u64 *ts);
181void ring_buffer_set_clock(struct ring_buffer *buffer,
182 u64 (*clock)(void));
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400183
Steven Rostedtef7a4a12009-03-03 00:27:49 -0500184size_t ring_buffer_page_len(void *page);
185
186
Vaibhav Nagarnaik7ea59062011-05-03 17:56:42 -0700187void *ring_buffer_alloc_read_page(struct ring_buffer *buffer, int cpu);
Steven Rostedt8789a9e2008-12-02 15:34:07 -0500188void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data);
Steven Rostedtef7a4a12009-03-03 00:27:49 -0500189int ring_buffer_read_page(struct ring_buffer *buffer, void **data_page,
190 size_t len, int cpu, int full);
Steven Rostedt8789a9e2008-12-02 15:34:07 -0500191
Steven Rostedtd1b182a2009-04-15 16:53:47 -0400192struct trace_seq;
193
194int ring_buffer_print_entry_header(struct trace_seq *s);
195int ring_buffer_print_page_header(struct trace_seq *s);
196
Steven Rostedt7a8e76a2008-09-29 23:02:38 -0400197enum ring_buffer_flags {
198 RB_FL_OVERWRITE = 1 << 0,
199};
200
201#endif /* _LINUX_RING_BUFFER_H */