| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _LINUX_RING_BUFFER_H |
| #define _LINUX_RING_BUFFER_H |
| |
| #include <linux/mm.h> |
| #include <linux/seq_file.h> |
| #include <linux/poll.h> |
| |
| struct trace_buffer; |
| struct ring_buffer_iter; |
| |
| /* |
| * Don't refer to this struct directly, use functions below. |
| */ |
| struct ring_buffer_event { |
| u32 type_len:5, time_delta:27; |
| |
| u32 array[]; |
| }; |
| |
| /** |
| * enum ring_buffer_type - internal ring buffer types |
| * |
| * @RINGBUF_TYPE_PADDING: Left over page padding or discarded event |
| * If time_delta is 0: |
| * array is ignored |
| * size is variable depending on how much |
| * padding is needed |
| * If time_delta is non zero: |
| * array[0] holds the actual length |
| * size = 4 + length (bytes) |
| * |
| * @RINGBUF_TYPE_TIME_EXTEND: Extend the time delta |
| * array[0] = time delta (28 .. 59) |
| * size = 8 bytes |
| * |
| * @RINGBUF_TYPE_TIME_STAMP: Absolute timestamp |
| * Same format as TIME_EXTEND except that the |
| * value is an absolute timestamp, not a delta |
| * event.time_delta contains bottom 27 bits |
| * array[0] = top (28 .. 59) bits |
| * size = 8 bytes |
| * |
| * <= @RINGBUF_TYPE_DATA_TYPE_LEN_MAX: |
| * Data record |
| * If type_len is zero: |
| * array[0] holds the actual length |
| * array[1..(length+3)/4] holds data |
| * size = 4 + length (bytes) |
| * else |
| * length = type_len << 2 |
| * array[0..(length+3)/4-1] holds data |
| * size = 4 + length (bytes) |
| */ |
| enum ring_buffer_type { |
| RINGBUF_TYPE_DATA_TYPE_LEN_MAX = 28, |
| RINGBUF_TYPE_PADDING, |
| RINGBUF_TYPE_TIME_EXTEND, |
| RINGBUF_TYPE_TIME_STAMP, |
| }; |
| |
| unsigned ring_buffer_event_length(struct ring_buffer_event *event); |
| void *ring_buffer_event_data(struct ring_buffer_event *event); |
| u64 ring_buffer_event_time_stamp(struct ring_buffer_event *event); |
| |
| /* |
| * ring_buffer_discard_commit will remove an event that has not |
| * been committed yet. If this is used, then ring_buffer_unlock_commit |
| * must not be called on the discarded event. This function |
| * will try to remove the event from the ring buffer completely |
| * if another event has not been written after it. |
| * |
| * Example use: |
| * |
| * if (some_condition) |
| * ring_buffer_discard_commit(buffer, event); |
| * else |
| * ring_buffer_unlock_commit(buffer, event); |
| */ |
| void ring_buffer_discard_commit(struct trace_buffer *buffer, |
| struct ring_buffer_event *event); |
| |
| /* |
| * size is in bytes for each per CPU buffer. |
| */ |
| struct trace_buffer * |
| __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *key); |
| |
| /* |
| * Because the ring buffer is generic, if other users of the ring buffer get |
| * traced by ftrace, it can produce lockdep warnings. We need to keep each |
| * ring buffer's lock class separate. |
| */ |
| #define ring_buffer_alloc(size, flags) \ |
| ({ \ |
| static struct lock_class_key __key; \ |
| __ring_buffer_alloc((size), (flags), &__key); \ |
| }) |
| |
| int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full); |
| __poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu, |
| struct file *filp, poll_table *poll_table); |
| |
| |
| #define RING_BUFFER_ALL_CPUS -1 |
| |
| void ring_buffer_free(struct trace_buffer *buffer); |
| |
| int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, int cpu); |
| |
| void ring_buffer_change_overwrite(struct trace_buffer *buffer, int val); |
| |
| struct ring_buffer_event *ring_buffer_lock_reserve(struct trace_buffer *buffer, |
| unsigned long length); |
| int ring_buffer_unlock_commit(struct trace_buffer *buffer, |
| struct ring_buffer_event *event); |
| int ring_buffer_write(struct trace_buffer *buffer, |
| unsigned long length, void *data); |
| |
| void ring_buffer_nest_start(struct trace_buffer *buffer); |
| void ring_buffer_nest_end(struct trace_buffer *buffer); |
| |
| struct ring_buffer_event * |
| ring_buffer_peek(struct trace_buffer *buffer, int cpu, u64 *ts, |
| unsigned long *lost_events); |
| struct ring_buffer_event * |
| ring_buffer_consume(struct trace_buffer *buffer, int cpu, u64 *ts, |
| unsigned long *lost_events); |
| |
| struct ring_buffer_iter * |
| ring_buffer_read_prepare(struct trace_buffer *buffer, int cpu, gfp_t flags); |
| void ring_buffer_read_prepare_sync(void); |
| void ring_buffer_read_start(struct ring_buffer_iter *iter); |
| 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); |
| void ring_buffer_iter_advance(struct ring_buffer_iter *iter); |
| void ring_buffer_iter_reset(struct ring_buffer_iter *iter); |
| int ring_buffer_iter_empty(struct ring_buffer_iter *iter); |
| bool ring_buffer_iter_dropped(struct ring_buffer_iter *iter); |
| |
| unsigned long ring_buffer_size(struct trace_buffer *buffer, int cpu); |
| |
| void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu); |
| void ring_buffer_reset_online_cpus(struct trace_buffer *buffer); |
| void ring_buffer_reset(struct trace_buffer *buffer); |
| |
| #ifdef CONFIG_RING_BUFFER_ALLOW_SWAP |
| int ring_buffer_swap_cpu(struct trace_buffer *buffer_a, |
| struct trace_buffer *buffer_b, int cpu); |
| #else |
| static inline int |
| ring_buffer_swap_cpu(struct trace_buffer *buffer_a, |
| struct trace_buffer *buffer_b, int cpu) |
| { |
| return -ENODEV; |
| } |
| #endif |
| |
| bool ring_buffer_empty(struct trace_buffer *buffer); |
| bool ring_buffer_empty_cpu(struct trace_buffer *buffer, int cpu); |
| |
| void ring_buffer_record_disable(struct trace_buffer *buffer); |
| void ring_buffer_record_enable(struct trace_buffer *buffer); |
| void ring_buffer_record_off(struct trace_buffer *buffer); |
| void ring_buffer_record_on(struct trace_buffer *buffer); |
| bool ring_buffer_record_is_on(struct trace_buffer *buffer); |
| bool ring_buffer_record_is_set_on(struct trace_buffer *buffer); |
| void ring_buffer_record_disable_cpu(struct trace_buffer *buffer, int cpu); |
| void ring_buffer_record_enable_cpu(struct trace_buffer *buffer, int cpu); |
| |
| u64 ring_buffer_oldest_event_ts(struct trace_buffer *buffer, int cpu); |
| unsigned long ring_buffer_bytes_cpu(struct trace_buffer *buffer, int cpu); |
| unsigned long ring_buffer_entries(struct trace_buffer *buffer); |
| unsigned long ring_buffer_overruns(struct trace_buffer *buffer); |
| unsigned long ring_buffer_entries_cpu(struct trace_buffer *buffer, int cpu); |
| unsigned long ring_buffer_overrun_cpu(struct trace_buffer *buffer, int cpu); |
| unsigned long ring_buffer_commit_overrun_cpu(struct trace_buffer *buffer, int cpu); |
| unsigned long ring_buffer_dropped_events_cpu(struct trace_buffer *buffer, int cpu); |
| unsigned long ring_buffer_read_events_cpu(struct trace_buffer *buffer, int cpu); |
| |
| u64 ring_buffer_time_stamp(struct trace_buffer *buffer, int cpu); |
| void ring_buffer_normalize_time_stamp(struct trace_buffer *buffer, |
| int cpu, u64 *ts); |
| void ring_buffer_set_clock(struct trace_buffer *buffer, |
| u64 (*clock)(void)); |
| void ring_buffer_set_time_stamp_abs(struct trace_buffer *buffer, bool abs); |
| bool ring_buffer_time_stamp_abs(struct trace_buffer *buffer); |
| |
| size_t ring_buffer_nr_pages(struct trace_buffer *buffer, int cpu); |
| size_t ring_buffer_nr_dirty_pages(struct trace_buffer *buffer, int cpu); |
| |
| void *ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu); |
| void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, void *data); |
| int ring_buffer_read_page(struct trace_buffer *buffer, void **data_page, |
| size_t len, int cpu, int full); |
| |
| struct trace_seq; |
| |
| int ring_buffer_print_entry_header(struct trace_seq *s); |
| int ring_buffer_print_page_header(struct trace_seq *s); |
| |
| enum ring_buffer_flags { |
| RB_FL_OVERWRITE = 1 << 0, |
| }; |
| |
| #ifdef CONFIG_RING_BUFFER |
| int trace_rb_cpu_prepare(unsigned int cpu, struct hlist_node *node); |
| #else |
| #define trace_rb_cpu_prepare NULL |
| #endif |
| |
| #endif /* _LINUX_RING_BUFFER_H */ |