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Commit d9e2557f authored by Neil Leeder's avatar Neil Leeder Committed by Matt Wagantall
Browse files

arm64: perf: add debug patch logging framework 



Provide a mechanism to track which msm perf patches
are present in a kernel. Some kernel branches do not
include all patches which causes problems trying
to debug perf issues. This framework provides a way
to keep track of which patches have been included
in a build.

Change-Id: I7d3e3022dcdec6204f8d2ba3c49fc37c674db221
Signed-off-by: default avatarNeil Leeder <nleeder@codeaurora.org>
parent 2d1400d6

arch/arm64/kernel/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -25,7 +25,7 @@ arm64-obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o entry-ftrace.o 
arm64-obj-$(CONFIG_MODULES)		+= arm64ksyms.o module.o

arm64-obj-$(CONFIG_SMP)			+= smp.o smp_spin_table.o topology.o

arm64-obj-$(CONFIG_PERF_EVENTS)		+= perf_regs.o

arm64-obj-$(CONFIG_HW_PERF_EVENTS)	+= perf_event.o

arm64-obj-$(CONFIG_HW_PERF_EVENTS)	+= perf_event.o perf_debug.o

arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint.o

arm64-obj-$(CONFIG_ARM64_CPU_SUSPEND)	+= sleep.o suspend.o

arm64-obj-$(CONFIG_CPU_IDLE)		+= cpuidle.o

arch/arm64/kernel/perf_debug.c

0 → 100644
+64 −0
Original line number Diff line number Diff line 
/* Copyright (c) 2014, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only version 2 as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */



#include <linux/types.h>

#include <linux/uaccess.h>

#include <linux/debugfs.h>



/*

 * Subsequent patches should add an entry to end of this string.

 * Format is incrementing sequence number followed by text of

 * patch commit title with newline.

 * Note trailing ';' is on its own line to simplify addition of

 * future strings.

 */

static char *descriptions =

	" 0 arm64: perf: add debug patch logging framework\n"

;



static ssize_t desc_read(struct file *fp, char __user *buf,

			 size_t count, loff_t *pos)

{

	return simple_read_from_buffer(buf, count, pos, descriptions,

				       strlen(descriptions));

}



static const struct file_operations perf_debug_desc_fops = {

	.read = desc_read,

};



static int perf_debugfs_init(void)

{

	int ret = 0;

	struct dentry *dir;

	struct dentry *file;



	dir = debugfs_create_dir("msm-perf-patches", NULL);

	if (IS_ERR_OR_NULL(dir)) {

		pr_err("failed to create msm-perf-patches dir in debugfs\n");

		ret = PTR_ERR(dir);

		goto init_exit;

	}



	file = debugfs_create_file("descriptions", 0444, dir, NULL,

				   &perf_debug_desc_fops);

	if (IS_ERR_OR_NULL(file)) {

		debugfs_remove(dir);

		pr_err("failed to create descriptions file for msm-perf-patches\n");

		ret = PTR_ERR(file);

		goto init_exit;

	}



init_exit:

	return ret;

}

late_initcall(perf_debugfs_init);