diff options
Diffstat (limited to 'include/linux/ring_buffer.h')
-rw-r--r-- | include/linux/ring_buffer.h | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h new file mode 100644 index 0000000..536b0ca --- /dev/null +++ b/include/linux/ring_buffer.h @@ -0,0 +1,127 @@ +#ifndef _LINUX_RING_BUFFER_H +#define _LINUX_RING_BUFFER_H + +#include <linux/mm.h> +#include <linux/seq_file.h> + +struct ring_buffer; +struct ring_buffer_iter; + +/* + * Don't reference this struct directly, use functions below. + */ +struct ring_buffer_event { + u32 type:2, len:3, time_delta:27; + u32 array[]; +}; + +/** + * enum ring_buffer_type - internal ring buffer types + * + * @RINGBUF_TYPE_PADDING: Left over page padding + * array is ignored + * size is variable depending on how much + * padding is needed + * + * @RINGBUF_TYPE_TIME_EXTEND: Extend the time delta + * array[0] = time delta (28 .. 59) + * size = 8 bytes + * + * @RINGBUF_TYPE_TIME_STAMP: Sync time stamp with external clock + * array[0] = tv_nsec + * array[1] = tv_sec + * size = 16 bytes + * + * @RINGBUF_TYPE_DATA: Data record + * If len is zero: + * array[0] holds the actual length + * array[1..(length+3)/4-1] holds data + * else + * length = len << 2 + * array[0..(length+3)/4] holds data + */ +enum ring_buffer_type { + RINGBUF_TYPE_PADDING, + RINGBUF_TYPE_TIME_EXTEND, + /* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */ + RINGBUF_TYPE_TIME_STAMP, + RINGBUF_TYPE_DATA, +}; + +unsigned ring_buffer_event_length(struct ring_buffer_event *event); +void *ring_buffer_event_data(struct ring_buffer_event *event); + +/** + * ring_buffer_event_time_delta - return the delta timestamp of the event + * @event: the event to get the delta timestamp of + * + * The delta timestamp is the 27 bit timestamp since the last event. + */ +static inline unsigned +ring_buffer_event_time_delta(struct ring_buffer_event *event) +{ + return event->time_delta; +} + +/* + * size is in bytes for each per CPU buffer. + */ +struct ring_buffer * +ring_buffer_alloc(unsigned long size, unsigned flags); +void ring_buffer_free(struct ring_buffer *buffer); + +int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size); + +struct ring_buffer_event * +ring_buffer_lock_reserve(struct ring_buffer *buffer, + unsigned long length, + unsigned long *flags); +int ring_buffer_unlock_commit(struct ring_buffer *buffer, + struct ring_buffer_event *event, + unsigned long flags); +int ring_buffer_write(struct ring_buffer *buffer, + unsigned long length, void *data); + +struct ring_buffer_event * +ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts); +struct ring_buffer_event * +ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts); + +struct ring_buffer_iter * +ring_buffer_read_start(struct ring_buffer *buffer, int cpu); +void ring_buffer_read_finish(struct ring_buffer_iter *iter); + +struct ring_buffer_event * +ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts); +struct ring_buffer_event * +ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts); +void ring_buffer_iter_reset(struct ring_buffer_iter *iter); +int ring_buffer_iter_empty(struct ring_buffer_iter *iter); + +unsigned long ring_buffer_size(struct ring_buffer *buffer); + +void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu); +void ring_buffer_reset(struct ring_buffer *buffer); + +int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, + struct ring_buffer *buffer_b, int cpu); + +int ring_buffer_empty(struct ring_buffer *buffer); +int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu); + +void ring_buffer_record_disable(struct ring_buffer *buffer); +void ring_buffer_record_enable(struct ring_buffer *buffer); +void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu); +void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu); + +unsigned long ring_buffer_entries(struct ring_buffer *buffer); +unsigned long ring_buffer_overruns(struct ring_buffer *buffer); + +u64 ring_buffer_time_stamp(int cpu); +void ring_buffer_normalize_time_stamp(int cpu, u64 *ts); + +enum ring_buffer_flags { + RB_FL_OVERWRITE = 1 << 0, +}; + +#endif /* _LINUX_RING_BUFFER_H */ |