Commit 93ae1b76 authored by Vincent Donnefort's avatar Vincent Donnefort Committed by Steven Rostedt (Google)
Browse files

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: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: default avatarVincent Donnefort <vdonnefort@google.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 5f3efd1d

include/linux/ring_buffer_types.h

0 → 100644
+41 −0
Original line number Diff line number Diff line 
/* 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

kernel/trace/ring_buffer.c

+1 −35
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
 *

 * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>

 */

#include <linux/ring_buffer_types.h>

#include <linux/sched/isolation.h>

#include <linux/trace_recursion.h>

#include <linux/trace_events.h>
@@ -157,23 +158,6 @@ int ring_buffer_print_entry_header(struct trace_seq *s) 
/* Used for individual buffers (after the counter) */

#define RB_BUFFER_OFF		(1 << 20)



#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)



/* define RINGBUF_TYPE_DATA for 'case RINGBUF_TYPE_DATA:' */

#define RINGBUF_TYPE_DATA 0 ... RINGBUF_TYPE_DATA_TYPE_LEN_MAX
@@ -316,10 +300,6 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_data); 
#define for_each_online_buffer_cpu(buffer, cpu)		\

	for_each_cpu_and(cpu, buffer->cpumask, cpu_online_mask)



#define TS_SHIFT	27

#define TS_MASK		((1ULL << TS_SHIFT) - 1)

#define TS_DELTA_TEST	(~TS_MASK)



static u64 rb_event_time_stamp(struct ring_buffer_event *event)

{

	u64 ts;
@@ -338,12 +318,6 @@ static u64 rb_event_time_stamp(struct ring_buffer_event *event) 


#define RB_MISSED_MASK		(3 << 30)



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 */

};



struct buffer_data_read_page {

	unsigned		order;	/* order of the page */

	struct buffer_data_page	*data;	/* actual data, stored in this page */
@@ -437,14 +411,6 @@ static struct buffer_data_page *alloc_cpu_data(int cpu, int order) 
	return dpage;

}



/*

 * We need to fit the time_stamp delta into 27 bits.

 */

static inline bool test_time_stamp(u64 delta)

{

	return !!(delta & TS_DELTA_TEST);

}



struct rb_irq_work {

	struct irq_work			work;

	wait_queue_head_t		waiters;