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| author | Vincent Donnefort <vdonnefort@google.com> | 2026-03-09 19:24:58 +0300 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2026-03-09 19:33:55 +0300 |
| commit | 93ae1b76fff9e745f870a2f2cd32f472328c4a8f (patch) | |
| tree | bbc1a566ae08f486a595ac29947f3ce03fc3dee0 /include/linux | |
| parent | 5f3efd1dcebc35d44cce39630ae00980a45d9247 (diff) | |
| download | linux-93ae1b76fff9e745f870a2f2cd32f472328c4a8f.tar.xz | |
ring-buffer: Export buffer_data_page and macros
In preparation for allowing the writing of ring-buffer compliant pages
outside of ring_buffer.c, move buffer_data_page and timestamps encoding
macros into the publicly available ring_buffer_types.h.
Link: https://patch.msgid.link/20260309162516.2623589-13-vdonnefort@google.com
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/ring_buffer_types.h | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/include/linux/ring_buffer_types.h b/include/linux/ring_buffer_types.h new file mode 100644 index 000000000000..54577021a49d --- /dev/null +++ b/include/linux/ring_buffer_types.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_RING_BUFFER_TYPES_H +#define _LINUX_RING_BUFFER_TYPES_H + +#include <asm/local.h> + +#define TS_SHIFT 27 +#define TS_MASK ((1ULL << TS_SHIFT) - 1) +#define TS_DELTA_TEST (~TS_MASK) + +/* + * We need to fit the time_stamp delta into 27 bits. + */ +static inline bool test_time_stamp(u64 delta) +{ + return !!(delta & TS_DELTA_TEST); +} + +#define BUF_PAGE_HDR_SIZE offsetof(struct buffer_data_page, data) + +#define RB_EVNT_HDR_SIZE (offsetof(struct ring_buffer_event, array)) +#define RB_ALIGNMENT 4U +#define RB_MAX_SMALL_DATA (RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX) +#define RB_EVNT_MIN_SIZE 8U /* two 32bit words */ + +#ifndef CONFIG_HAVE_64BIT_ALIGNED_ACCESS +# define RB_FORCE_8BYTE_ALIGNMENT 0 +# define RB_ARCH_ALIGNMENT RB_ALIGNMENT +#else +# define RB_FORCE_8BYTE_ALIGNMENT 1 +# define RB_ARCH_ALIGNMENT 8U +#endif + +#define RB_ALIGN_DATA __aligned(RB_ARCH_ALIGNMENT) + +struct buffer_data_page { + u64 time_stamp; /* page time stamp */ + local_t commit; /* write committed index */ + unsigned char data[] RB_ALIGN_DATA; /* data of buffer page */ +}; +#endif |