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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - include/linux/ring_buffer.h
1 #ifndef _LINUX_RING_BUFFER_H
2 #define _LINUX_RING_BUFFER_H
5 #include <linux/seq_file.h>
8 struct ring_buffer_iter
;
11 * Don't refer to this struct directly, use functions below.
13 struct ring_buffer_event
{
14 u32 type
:2, len
:3, time_delta
:27;
19 * enum ring_buffer_type - internal ring buffer types
21 * @RINGBUF_TYPE_PADDING: Left over page padding or discarded event
24 * size is variable depending on how much
26 * If time_delta is non zero:
27 * everything else same as RINGBUF_TYPE_DATA
29 * @RINGBUF_TYPE_TIME_EXTEND: Extend the time delta
30 * array[0] = time delta (28 .. 59)
33 * @RINGBUF_TYPE_TIME_STAMP: Sync time stamp with external clock
35 * array[1..2] = tv_sec
38 * @RINGBUF_TYPE_DATA: Data record
40 * array[0] holds the actual length
41 * array[1..(length+3)/4] holds data
42 * size = 4 + 4 + length (bytes)
45 * array[0..(length+3)/4-1] holds data
46 * size = 4 + length (bytes)
48 enum ring_buffer_type
{
50 RINGBUF_TYPE_TIME_EXTEND
,
51 /* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */
52 RINGBUF_TYPE_TIME_STAMP
,
56 unsigned ring_buffer_event_length(struct ring_buffer_event
*event
);
57 void *ring_buffer_event_data(struct ring_buffer_event
*event
);
60 * ring_buffer_event_time_delta - return the delta timestamp of the event
61 * @event: the event to get the delta timestamp of
63 * The delta timestamp is the 27 bit timestamp since the last event.
65 static inline unsigned
66 ring_buffer_event_time_delta(struct ring_buffer_event
*event
)
68 return event
->time_delta
;
71 void ring_buffer_event_discard(struct ring_buffer_event
*event
);
74 * size is in bytes for each per CPU buffer.
77 ring_buffer_alloc(unsigned long size
, unsigned flags
);
78 void ring_buffer_free(struct ring_buffer
*buffer
);
80 int ring_buffer_resize(struct ring_buffer
*buffer
, unsigned long size
);
82 struct ring_buffer_event
*ring_buffer_lock_reserve(struct ring_buffer
*buffer
,
83 unsigned long length
);
84 int ring_buffer_unlock_commit(struct ring_buffer
*buffer
,
85 struct ring_buffer_event
*event
);
86 int ring_buffer_write(struct ring_buffer
*buffer
,
87 unsigned long length
, void *data
);
89 struct ring_buffer_event
*
90 ring_buffer_peek(struct ring_buffer
*buffer
, int cpu
, u64
*ts
);
91 struct ring_buffer_event
*
92 ring_buffer_consume(struct ring_buffer
*buffer
, int cpu
, u64
*ts
);
94 struct ring_buffer_iter
*
95 ring_buffer_read_start(struct ring_buffer
*buffer
, int cpu
);
96 void ring_buffer_read_finish(struct ring_buffer_iter
*iter
);
98 struct ring_buffer_event
*
99 ring_buffer_iter_peek(struct ring_buffer_iter
*iter
, u64
*ts
);
100 struct ring_buffer_event
*
101 ring_buffer_read(struct ring_buffer_iter
*iter
, u64
*ts
);
102 void ring_buffer_iter_reset(struct ring_buffer_iter
*iter
);
103 int ring_buffer_iter_empty(struct ring_buffer_iter
*iter
);
105 unsigned long ring_buffer_size(struct ring_buffer
*buffer
);
107 void ring_buffer_reset_cpu(struct ring_buffer
*buffer
, int cpu
);
108 void ring_buffer_reset(struct ring_buffer
*buffer
);
110 int ring_buffer_swap_cpu(struct ring_buffer
*buffer_a
,
111 struct ring_buffer
*buffer_b
, int cpu
);
113 int ring_buffer_empty(struct ring_buffer
*buffer
);
114 int ring_buffer_empty_cpu(struct ring_buffer
*buffer
, int cpu
);
116 void ring_buffer_record_disable(struct ring_buffer
*buffer
);
117 void ring_buffer_record_enable(struct ring_buffer
*buffer
);
118 void ring_buffer_record_disable_cpu(struct ring_buffer
*buffer
, int cpu
);
119 void ring_buffer_record_enable_cpu(struct ring_buffer
*buffer
, int cpu
);
121 unsigned long ring_buffer_entries(struct ring_buffer
*buffer
);
122 unsigned long ring_buffer_overruns(struct ring_buffer
*buffer
);
123 unsigned long ring_buffer_entries_cpu(struct ring_buffer
*buffer
, int cpu
);
124 unsigned long ring_buffer_overrun_cpu(struct ring_buffer
*buffer
, int cpu
);
126 u64
ring_buffer_time_stamp(struct ring_buffer
*buffer
, int cpu
);
127 void ring_buffer_normalize_time_stamp(struct ring_buffer
*buffer
,
129 void ring_buffer_set_clock(struct ring_buffer
*buffer
,
132 size_t ring_buffer_page_len(void *page
);
135 void *ring_buffer_alloc_read_page(struct ring_buffer
*buffer
);
136 void ring_buffer_free_read_page(struct ring_buffer
*buffer
, void *data
);
137 int ring_buffer_read_page(struct ring_buffer
*buffer
, void **data_page
,
138 size_t len
, int cpu
, int full
);
140 enum ring_buffer_flags
{
141 RB_FL_OVERWRITE
= 1 << 0,
144 #endif /* _LINUX_RING_BUFFER_H */