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Commit 7aee3d64 authored by Patrick Daly's avatar Patrick Daly
Browse files

soc: qcom: Add debugfs interface for enabling SOC debug events 



Other processors/execution environments may support debug events. Implement
an 'smc instruction' based communications protocol and hook it up to
debugfs.

Change-Id: I3a99dfdac5df7edb874bd449d9abc5a929787758
Signed-off-by: default avatarPatrick Daly <pdaly@codeaurora.org>
parent d171201f

drivers/soc/qcom/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -739,6 +739,15 @@ config MSM_KERNEL_PROTECT_TEST 
          read-only.  This test is FATAL whether it passes or fails!

          Success is signaled by a stage-2 fault.



config MSM_REMOTEQDSS

	bool "Allow debug tools to enable events on other processors"

	depends on MSM_SCM && DEBUG_FS

	help

	  Other onchip processors/execution environments may support debug

	  events. Provide a sysfs interface for debug tools to dynamically

	  enable/disable these events. Interface located in

	  /sys/class/remoteqdss.



source "drivers/soc/qcom/memshare/Kconfig"



endif # ARCH_MSM

drivers/soc/qcom/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -93,3 +93,4 @@ obj-$(CONFIG_MSM_QBT1000) += qbt1000.o 
obj-$(CONFIG_MSM_SCM_XPU) += scm-xpu.o

obj-$(CONFIG_MSM_KERNEL_PROTECT) += kernel_protect.o

obj-$(CONFIG_MSM_RTB) += msm_rtb-hotplug.o

obj-$(CONFIG_MSM_REMOTEQDSS) += remoteqdss.o

drivers/soc/qcom/remoteqdss.c

0 → 100644
+228 −0
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2015-2016, 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/kernel.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <soc/qcom/scm.h>

#include <linux/debugfs.h>

#include <linux/ratelimit.h>



#define REMOTEQDSS_FLAG_QUIET (BIT(0))



static unsigned long remoteqdss_dbg_flags;

module_param_named(dbg_flags, remoteqdss_dbg_flags, ulong, 0644);



static struct dentry *remoteqdss_dir;



#define REMOTEQDSS_ERR(fmt, ...) \

	pr_err("%s: " fmt, __func__, ## __VA_ARGS__)



#define REMOTEQDSS_ERR_CALLER(fmt, ...) \

	pr_err("%pf: " fmt, __builtin_return_address(0), ## __VA_ARGS__)



struct qdss_msg_translation {

	u64 val;

	char *msg;

};



/*

 * id			Unique identifier

 * sw_entity_group	Array index

 * sw_event_group	Array index

 * dir			Parent debugfs directory

 */

struct remoteqdss_data {

	u8 id;

	u64 sw_entity_group;

	u64 sw_event_group;

	struct dentry *dir;

};



/* msgs is a null terminated array */

static void remoteqdss_err_translation(struct qdss_msg_translation *msgs,

								u64 err)

{

	static DEFINE_RATELIMIT_STATE(rl, 5 * HZ, 2);

	struct qdss_msg_translation *msg;



	if (!err)

		return;



	if (remoteqdss_dbg_flags & REMOTEQDSS_FLAG_QUIET)

		return;



	for (msg = msgs; msg->msg; msg++) {

		if (err == msg->val && __ratelimit(&rl)) {

			REMOTEQDSS_ERR_CALLER("0x%llx: %s\n", err, msg->msg);

			return;

		}

	}



	REMOTEQDSS_ERR_CALLER("Error 0x%llx\n", err);

}



/* SCM based devices */

#define SCM_FILTER_SWTRACE_ID (0x1)

#define SCM_QUERY_SWTRACE_ID  (0x2)



/* Response Values */

#define SCM_CMD_FAIL		(0x80)

#define SCM_QDSS_UNAVAILABLE	(0x81)

#define SCM_UNINITIALIZED	(0x82)

#define SCM_BAD_ARG		(0x83)

#define SCM_BAD_SUBSYS		(0x85)



static struct qdss_msg_translation remoteqdss_scm_msgs[] = {

	{SCM_CMD_FAIL,

		"Command failed"},

	{SCM_QDSS_UNAVAILABLE,

		"QDSS not available or cannot turn QDSS (clock) on"},

	{SCM_UNINITIALIZED,

		"Tracer not initialized or unable to initialize"},

	{SCM_BAD_ARG,

		"Invalid parameter value"},

	{SCM_BAD_SUBSYS,

		"Incorrect subsys ID"},

	{}

};



static struct remoteqdss_data *create_remoteqdss_data(u32 id)

{

	struct remoteqdss_data *data;



	data = kzalloc(sizeof(*data), GFP_KERNEL);

	if (!data)

		return NULL;



	data->id = id;

	return data;

}



static void free_remoteqdss_data(struct remoteqdss_data *data)

{

	kfree(data);

}



static int remoteqdss_scm_query_swtrace(void *priv, u64 *val)

{

	struct remoteqdss_data *data = priv;

	int ret;

	struct scm_desc desc;



	memset(&desc, 0, sizeof(desc));

	desc.args[0] = data->id;

	desc.arginfo = SCM_ARGS(1, SCM_VAL);



	ret = scm_call2(

		SCM_SIP_FNID(SCM_SVC_QDSS, SCM_QUERY_SWTRACE_ID),

		&desc);

	if (ret)

		return ret;



	remoteqdss_err_translation(remoteqdss_scm_msgs, desc.ret[0]);

	ret = desc.ret[0] ? -EINVAL : 0;

	*val = desc.ret[1];

	return ret;

}



static int remoteqdss_scm_filter_swtrace(void *priv, u64 val)

{

	struct remoteqdss_data *data = priv;

	int ret;

	struct scm_desc desc;



	memset(&desc, 0, sizeof(desc));

	desc.args[0] = data->id;

	desc.args[1] = val;

	desc.arginfo = SCM_ARGS(2, SCM_VAL, SCM_VAL);



	ret = scm_call2(

		SCM_SIP_FNID(SCM_SVC_QDSS, SCM_FILTER_SWTRACE_ID),

		&desc);

	if (ret)

		return ret;



	remoteqdss_err_translation(remoteqdss_scm_msgs, desc.ret[0]);

	ret = desc.ret[0] ? -EINVAL : 0;

	return ret;

}

DEFINE_SIMPLE_ATTRIBUTE(fops_sw_trace_output,

			remoteqdss_scm_query_swtrace,

			remoteqdss_scm_filter_swtrace,

			"%llu\n");



static void __init enumerate_scm_devices(struct dentry *parent)

{

	u64 unused;

	int ret;

	struct remoteqdss_data *data;

	struct dentry *dentry;



	if (!is_scm_armv8())

		return;



	data = create_remoteqdss_data(0);

	if (!data)

		return;



	/* Assume failure means device not present */

	ret = remoteqdss_scm_query_swtrace(data, &unused);

	if (ret)

		goto out;



	data->dir = debugfs_create_dir("tz", parent);

	if (IS_ERR_OR_NULL(data->dir))

		goto out;



	dentry = debugfs_create_file("sw_trace_output", S_IRUGO | S_IWUSR,

			data->dir, data, &fops_sw_trace_output);

	if (IS_ERR_OR_NULL(dentry))

		goto out;



	dentry = debugfs_create_u64("sw_entity_group", S_IRUGO | S_IWUSR,

			data->dir, &data->sw_entity_group);

	if (IS_ERR_OR_NULL(dentry))

		goto out;



	dentry = debugfs_create_u64("sw_event_group", S_IRUGO | S_IWUSR,

			data->dir, &data->sw_event_group);

	if (IS_ERR_OR_NULL(dentry))

		goto out;



	return;



out:

	debugfs_remove_recursive(data->dir);

	free_remoteqdss_data(data);

}



static int __init remoteqdss_init(void)

{

	unsigned long old_flags = remoteqdss_dbg_flags;



	/*

	 * disable normal error messages while checking

	 * if support is present.

	 */

	remoteqdss_dbg_flags |= REMOTEQDSS_FLAG_QUIET;



	remoteqdss_dir = debugfs_create_dir("remoteqdss", NULL);

	if (!remoteqdss_dir)

		return 0;



	enumerate_scm_devices(remoteqdss_dir);



	remoteqdss_dbg_flags = old_flags;

	return 0;

}

module_init(remoteqdss_init);

include/soc/qcom/scm.h

+2 −1
Original line number Diff line number Diff line 
/* Copyright (c) 2010-2015, The Linux Foundation. All rights reserved.

/* Copyright (c) 2010-2016, 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
@@ -28,6 +28,7 @@ 
#define SCM_SVC_MDTP			0x12

#define SCM_SVC_LMH			0x13

#define SCM_SVC_SMMU_PROGRAM		0x15

#define SCM_SVC_QDSS			0x16

#define SCM_SVC_TZSCHEDULER		0xFC



#define SCM_FUSE_READ			0x7