Add sysfs mode selftest for ARM Coresight hardware tracer.

Signed-off-by: Linu Cherian <lcherian@marvell.com>
---
 .../drivers/hwtracing/coresight/Makefile      |   5 +
 .../hwtracing/coresight/sysfs_test_trace.sh   | 144 ++++++++++++++++++
 2 files changed, 149 insertions(+)
 create mode 100644 tools/testing/selftests/drivers/hwtracing/coresight/Makefile
 create mode 100755 tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh

diff --git a/tools/testing/selftests/drivers/hwtracing/coresight/Makefile b/tools/testing/selftests/drivers/hwtracing/coresight/Makefile
new file mode 100644
index 000000000000..7dc68ae1c0a9
--- /dev/null
+++ b/tools/testing/selftests/drivers/hwtracing/coresight/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+
+TEST_PROGS = sysfs_test_trace.sh
+
+include ../../../lib.mk
diff --git a/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh b/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
new file mode 100755
index 000000000000..0d6307fff1d2
--- /dev/null
+++ b/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
@@ -0,0 +1,144 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2024 Marvell.
+
+# Test Arm CoreSight trace capture in sysfs mode
+# Based on tools/perf/tests/shell/test_arm_coresight.sh
+
+glb_err=0
+
+arm_cs_report() {
+	if [ $2 != 0 ]; then
+		echo "$1: FAIL"
+		glb_err=$2
+	else
+		echo "$1: PASS"
+	fi
+}
+
+is_device_sink() {
+	# If the node of "enable_sink" is existed under the device path, this
+	# means the device is a sink device.
+
+	if [ -e "$1/enable_sink" ]; then
+
+		return 0
+	else
+		return 1
+	fi
+}
+
+# Configure sink for buffer mode
+cfg_sink_buf_mode() {
+	sink_dev=$1
+	mode=$2
+	# Set buffer mode if supported
+	if [ -e "$sink_dev/buf_modes_available" ]; then
+		cat $sink_dev/buf_modes_available | grep -E -q $mode
+		if [ $? -eq 0 ]; then
+			echo $mode > $sink_dev/buf_mode_preferred
+			return 0
+		fi
+	fi
+
+	return 1
+}
+
+run_app() {
+
+	taskset -c $1 dd if=/dev/urandom  of=/dev/null bs=1M count=64
+}
+
+sysfs_trace() {
+	src_dev=$1
+	sink_dev=$2
+	cpu=$3
+
+	# Enable sink device
+	echo 1 > $sink_dev/enable_sink
+	# Enable source device
+	echo 1 > $src_dev/enable_source
+
+	# Run app to be traced
+	run_app $cpu
+
+	# Read back trace data
+	dd if=/dev/$sink_dev_name of=/tmp/tracedata
+
+	# Verify if read is successful
+	err=$?
+
+	# Disable source device
+	echo 0 > $src_dev/enable_source
+
+	# Diskable sink device
+	echo 0 > $sink_dev/enable_sink
+
+	arm_cs_report "CoreSight path testing (CPU$cpu -> $sink_dev_name)" $err
+}
+
+try_sysfs_trace_resrv_buf() {
+	src_dev=$1
+	sink_dev=$2
+	cpu=$3
+
+	# Configure the resrved buffer mode if available
+	cfg_sink_buf_mode $sink_dev "resrv"
+	if [ $? -eq 0 ]; then
+		echo "Running sysfs trace with resrv buf mode"
+		sysfs_trace $src_dev $sink_dev $cpu
+		# Restore buffer mode
+		cfg_sink_buf_mode $sink_dev "auto"
+		if [ $? -eq 1 ]; then
+			echo "Failed to restore default buf mode"
+		fi
+	fi
+}
+
+arm_cs_iterate_devices() {
+	src_dev=$1
+	cpu=$3
+	for cdev in $2/connections/out\:*; do
+
+		# Skip testing if it's not a directory
+		! [ -d $cdev ] && continue;
+
+		# Read out its symbol link file name
+		sink_dev=`readlink -f $cdev`
+
+		# Extract device name from path, e.g.
+		#   sink_dev = '/sys/devices/platform/20010000.etf/tmc_etf0'
+		#     `> sink_dev_name = 'tmc_etf0'
+		sink_dev_name=$(basename $sink_dev)
+
+		if is_device_sink $sink_dev; then
+			# Run trace with resrv buf mode (if available)
+			try_sysfs_trace_resrv_buf $src_dev $sink_dev $cpu
+
+			# Run the default mode
+			echo "Running sysfs trace with default settings"
+			sysfs_trace $src_dev $sink_dev $cpu
+		fi
+
+		arm_cs_iterate_devices $src_dev $cdev $cpu
+
+	done
+}
+
+arm_cs_etm_traverse_path_test() {
+	# Iterate for every ETM device
+	for dev in /sys/bus/event_source/devices/cs_etm/cpu*; do
+		# Canonicalize the path
+		dev=`readlink -f $dev`
+
+		# Find the ETM device belonging to which CPU
+		cpu=`cat $dev/cpu`
+
+		# Use depth-first search (DFS) to iterate outputs
+		arm_cs_iterate_devices $dev $dev $cpu
+	done
+}
+
+arm_cs_etm_traverse_path_test
+
+exit $glb_err
-- 
2.34.1

On 29/11/2024 8:38 am, Linu Cherian wrote:
> Add sysfs mode selftest for ARM Coresight hardware tracer.
> 
> Signed-off-by: Linu Cherian <lcherian@marvell.com>
> ---
>   .../drivers/hwtracing/coresight/Makefile      |   5 +
>   .../hwtracing/coresight/sysfs_test_trace.sh   | 144 ++++++++++++++++++
>   2 files changed, 149 insertions(+)
>   create mode 100644 tools/testing/selftests/drivers/hwtracing/coresight/Makefile

Hi Linu,

You need to add this path into TARGETS for make install to work:

  TARGETS += drivers/dma-buf
+TARGETS += drivers/hwtracing/coresight
  TARGETS += drivers/s390x/uvdevice


>   create mode 100755 tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> 
> diff --git a/tools/testing/selftests/drivers/hwtracing/coresight/Makefile b/tools/testing/selftests/drivers/hwtracing/coresight/Makefile
> new file mode 100644
> index 000000000000..7dc68ae1c0a9
> --- /dev/null
> +++ b/tools/testing/selftests/drivers/hwtracing/coresight/Makefile
> @@ -0,0 +1,5 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +TEST_PROGS = sysfs_test_trace.sh
> +
> +include ../../../lib.mk
> diff --git a/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh b/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> new file mode 100755
> index 000000000000..0d6307fff1d2
> --- /dev/null
> +++ b/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> @@ -0,0 +1,144 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (C) 2024 Marvell.
> +
> +# Test Arm CoreSight trace capture in sysfs mode
> +# Based on tools/perf/tests/shell/test_arm_coresight.sh
> +
> +glb_err=0
> +
> +arm_cs_report() {
> +	if [ $2 != 0 ]; then
> +		echo "$1: FAIL"
> +		glb_err=$2
> +	else
> +		echo "$1: PASS"
> +	fi
> +}
> +
> +is_device_sink() {
> +	# If the node of "enable_sink" is existed under the device path, this
> +	# means the device is a sink device.
> +

Looks like you still need the skip for TPIU here the same as the Perf 
test. It's an external sink and doesn't have a readable file so the test 
fails.

With those changes, looks good. Thanks for adding the first sysfs test. 
Hopefully we can expand them more in the future.

Reviewed-by: James Clark <james.clark@linaro.org>

On 2024-12-04 at 16:45:42, James Clark (james.clark@linaro.org) wrote:
> 
> 
> On 29/11/2024 8:38 am, Linu Cherian wrote:
> > Add sysfs mode selftest for ARM Coresight hardware tracer.
> > 
> > Signed-off-by: Linu Cherian <lcherian@marvell.com>
> > ---
> >   .../drivers/hwtracing/coresight/Makefile      |   5 +
> >   .../hwtracing/coresight/sysfs_test_trace.sh   | 144 ++++++++++++++++++
> >   2 files changed, 149 insertions(+)
> >   create mode 100644 tools/testing/selftests/drivers/hwtracing/coresight/Makefile
> 
> Hi Linu,
> 
> You need to add this path into TARGETS for make install to work:
> 
>  TARGETS += drivers/dma-buf
> +TARGETS += drivers/hwtracing/coresight
>  TARGETS += drivers/s390x/uvdevice
> 
> 
> >   create mode 100755 tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> > 
> > diff --git a/tools/testing/selftests/drivers/hwtracing/coresight/Makefile b/tools/testing/selftests/drivers/hwtracing/coresight/Makefile
> > new file mode 100644
> > index 000000000000..7dc68ae1c0a9
> > --- /dev/null
> > +++ b/tools/testing/selftests/drivers/hwtracing/coresight/Makefile
> > @@ -0,0 +1,5 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +
> > +TEST_PROGS = sysfs_test_trace.sh
> > +
> > +include ../../../lib.mk
> > diff --git a/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh b/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> > new file mode 100755
> > index 000000000000..0d6307fff1d2
> > --- /dev/null
> > +++ b/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> > @@ -0,0 +1,144 @@
> > +#!/bin/sh
> > +# SPDX-License-Identifier: GPL-2.0
> > +# Copyright (C) 2024 Marvell.
> > +
> > +# Test Arm CoreSight trace capture in sysfs mode
> > +# Based on tools/perf/tests/shell/test_arm_coresight.sh
> > +
> > +glb_err=0
> > +
> > +arm_cs_report() {
> > +	if [ $2 != 0 ]; then
> > +		echo "$1: FAIL"
> > +		glb_err=$2
> > +	else
> > +		echo "$1: PASS"
> > +	fi
> > +}
> > +
> > +is_device_sink() {
> > +	# If the node of "enable_sink" is existed under the device path, this
> > +	# means the device is a sink device.
> > +
> 
> Looks like you still need the skip for TPIU here the same as the Perf test.
> It's an external sink and doesn't have a readable file so the test fails.
> 

Okay will skip.

> With those changes, looks good. Thanks for adding the first sysfs test.
> Hopefully we can expand them more in the future.
> 
> Reviewed-by: James Clark <james.clark@linaro.org>
> 

Thanks.
Linu Cherian.

Hi James,

On 2024-12-04 at 16:45:42, James Clark (james.clark@linaro.org) wrote:
> 
> 
> On 29/11/2024 8:38 am, Linu Cherian wrote:
> > Add sysfs mode selftest for ARM Coresight hardware tracer.
> > 
> > Signed-off-by: Linu Cherian <lcherian@marvell.com>
> > ---
> >   .../drivers/hwtracing/coresight/Makefile      |   5 +
> >   .../hwtracing/coresight/sysfs_test_trace.sh   | 144 ++++++++++++++++++
> >   2 files changed, 149 insertions(+)
> >   create mode 100644 tools/testing/selftests/drivers/hwtracing/coresight/Makefile
> 
> Hi Linu,
> 
> You need to add this path into TARGETS for make install to work:
> 
>  TARGETS += drivers/dma-buf
> +TARGETS += drivers/hwtracing/coresight
>  TARGETS += drivers/s390x/uvdevice


Sure will add that.
Thanks.

> 
> 
> >   create mode 100755 tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> > 
> > diff --git a/tools/testing/selftests/drivers/hwtracing/coresight/Makefile b/tools/testing/selftests/drivers/hwtracing/coresight/Makefile
> > new file mode 100644
> > index 000000000000..7dc68ae1c0a9
> > --- /dev/null
> > +++ b/tools/testing/selftests/drivers/hwtracing/coresight/Makefile
> > @@ -0,0 +1,5 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +
> > +TEST_PROGS = sysfs_test_trace.sh
> > +
> > +include ../../../lib.mk
> > diff --git a/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh b/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> > new file mode 100755
> > index 000000000000..0d6307fff1d2
> > --- /dev/null
> > +++ b/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> > @@ -0,0 +1,144 @@
> > +#!/bin/sh
> > +# SPDX-License-Identifier: GPL-2.0
> > +# Copyright (C) 2024 Marvell.
> > +
> > +# Test Arm CoreSight trace capture in sysfs mode
> > +# Based on tools/perf/tests/shell/test_arm_coresight.sh
> > +
> > +glb_err=0
> > +
> > +arm_cs_report() {
> > +	if [ $2 != 0 ]; then
> > +		echo "$1: FAIL"
> > +		glb_err=$2
> > +	else
> > +		echo "$1: PASS"
> > +	fi
> > +}
> > +
> > +is_device_sink() {
> > +	# If the node of "enable_sink" is existed under the device path, this
> > +	# means the device is a sink device.
> > +
> 
> Looks like you still need the skip for TPIU here the same as the Perf test.
> It's an external sink and doesn't have a readable file so the test fails.
> 
> With those changes, looks good. Thanks for adding the first sysfs test.
> Hopefully we can expand them more in the future.
> 
> Reviewed-by: James Clark <james.clark@linaro.org>
> 
>

On 11/29/24 01:38, Linu Cherian wrote:
> Add sysfs mode selftest for ARM Coresight hardware tracer.

Please add details on what this test does in here. Include
the output from the test?

Does this test have dependencies on config? If it does, does
this test detect and skip if config isn't enabled?

> 
> Signed-off-by: Linu Cherian <lcherian@marvell.com>
> ---
>   .../drivers/hwtracing/coresight/Makefile      |   5 +
>   .../hwtracing/coresight/sysfs_test_trace.sh   | 144 ++++++++++++++++++
>   2 files changed, 149 insertions(+)
>   create mode 100644 tools/testing/selftests/drivers/hwtracing/coresight/Makefile
>   create mode 100755 tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> 
> diff --git a/tools/testing/selftests/drivers/hwtracing/coresight/Makefile b/tools/testing/selftests/drivers/hwtracing/coresight/Makefile
> new file mode 100644
> index 000000000000..7dc68ae1c0a9
> --- /dev/null
> +++ b/tools/testing/selftests/drivers/hwtracing/coresight/Makefile
> @@ -0,0 +1,5 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +TEST_PROGS = sysfs_test_trace.sh
> +
> +include ../../../lib.mk
> diff --git a/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh b/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> new file mode 100755
> index 000000000000..0d6307fff1d2
> --- /dev/null
> +++ b/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> @@ -0,0 +1,144 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (C) 2024 Marvell.
> +
> +# Test Arm CoreSight trace capture in sysfs mode
> +# Based on tools/perf/tests/shell/test_arm_coresight.sh
> +
> +glb_err=0
> +
> +arm_cs_report() {
> +	if [ $2 != 0 ]; then
> +		echo "$1: FAIL"
> +		glb_err=$2
> +	else
> +		echo "$1: PASS"
> +	fi
> +}
> +
> +is_device_sink() {
> +	# If the node of "enable_sink" is existed under the device path, this
> +	# means the device is a sink device.
> +
> +	if [ -e "$1/enable_sink" ]; then
> +
> +		return 0
> +	else
> +		return 1
> +	fi
> +}
> +
> +# Configure sink for buffer mode
> +cfg_sink_buf_mode() {
> +	sink_dev=$1
> +	mode=$2
> +	# Set buffer mode if supported
> +	if [ -e "$sink_dev/buf_modes_available" ]; then
> +		cat $sink_dev/buf_modes_available | grep -E -q $mode
> +		if [ $? -eq 0 ]; then
> +			echo $mode > $sink_dev/buf_mode_preferred
> +			return 0
> +		fi
> +	fi
> +
> +	return 1
> +}
> +
> +run_app() {
> +
> +	taskset -c $1 dd if=/dev/urandom  of=/dev/null bs=1M count=64
> +}
> +
> +sysfs_trace() {
> +	src_dev=$1
> +	sink_dev=$2
> +	cpu=$3
> +
> +	# Enable sink device
> +	echo 1 > $sink_dev/enable_sink
> +	# Enable source device
> +	echo 1 > $src_dev/enable_source
> +
> +	# Run app to be traced
> +	run_app $cpu
> +
> +	# Read back trace data
> +	dd if=/dev/$sink_dev_name of=/tmp/tracedata
> +
> +	# Verify if read is successful
> +	err=$?
> +
> +	# Disable source device
> +	echo 0 > $src_dev/enable_source
> +
> +	# Diskable sink device
> +	echo 0 > $sink_dev/enable_sink
> +
> +	arm_cs_report "CoreSight path testing (CPU$cpu -> $sink_dev_name)" $err
> +}
> +
> +try_sysfs_trace_resrv_buf() {
> +	src_dev=$1
> +	sink_dev=$2
> +	cpu=$3
> +
> +	# Configure the resrved buffer mode if available
> +	cfg_sink_buf_mode $sink_dev "resrv"
> +	if [ $? -eq 0 ]; then
> +		echo "Running sysfs trace with resrv buf mode"
> +		sysfs_trace $src_dev $sink_dev $cpu
> +		# Restore buffer mode
> +		cfg_sink_buf_mode $sink_dev "auto"
> +		if [ $? -eq 1 ]; then
> +			echo "Failed to restore default buf mode"
> +		fi
> +	fi
> +}
> +
> +arm_cs_iterate_devices() {
> +	src_dev=$1
> +	cpu=$3
> +	for cdev in $2/connections/out\:*; do
> +
> +		# Skip testing if it's not a directory
> +		! [ -d $cdev ] && continue;
> +
> +		# Read out its symbol link file name
> +		sink_dev=`readlink -f $cdev`
> +
> +		# Extract device name from path, e.g.
> +		#   sink_dev = '/sys/devices/platform/20010000.etf/tmc_etf0'
> +		#     `> sink_dev_name = 'tmc_etf0'
> +		sink_dev_name=$(basename $sink_dev)
> +
> +		if is_device_sink $sink_dev; then
> +			# Run trace with resrv buf mode (if available)
> +			try_sysfs_trace_resrv_buf $src_dev $sink_dev $cpu
> +
> +			# Run the default mode
> +			echo "Running sysfs trace with default settings"
> +			sysfs_trace $src_dev $sink_dev $cpu
> +		fi
> +
> +		arm_cs_iterate_devices $src_dev $cdev $cpu
> +
> +	done
> +}
> +
> +arm_cs_etm_traverse_path_test() {
> +	# Iterate for every ETM device
> +	for dev in /sys/bus/event_source/devices/cs_etm/cpu*; do
> +		# Canonicalize the path
> +		dev=`readlink -f $dev`
> +
> +		# Find the ETM device belonging to which CPU
> +		cpu=`cat $dev/cpu`
> +
> +		# Use depth-first search (DFS) to iterate outputs
> +		arm_cs_iterate_devices $dev $dev $cpu
> +	done
> +}
> +
> +arm_cs_etm_traverse_path_test
> +
> +exit $glb_err

thanks,
-- Shuah

Hi,

On 2024-12-04 at 05:53:56, Shuah Khan (skhan@linuxfoundation.org) wrote:
> On 11/29/24 01:38, Linu Cherian wrote:
> > Add sysfs mode selftest for ARM Coresight hardware tracer.
> 
> Please add details on what this test does in here. Include
> the output from the test?

Ack. Will add test descripion here. 

> 
> Does this test have dependencies on config? If it does, does
> this test detect and skip if config isn't enabled?

Will add dependency.

Thanks.

> 
> > 
> > Signed-off-by: Linu Cherian <lcherian@marvell.com>
> > ---
> >   .../drivers/hwtracing/coresight/Makefile      |   5 +
> >   .../hwtracing/coresight/sysfs_test_trace.sh   | 144 ++++++++++++++++++
> >   2 files changed, 149 insertions(+)
> >   create mode 100644 tools/testing/selftests/drivers/hwtracing/coresight/Makefile
> >   create mode 100755 tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> > 
> > diff --git a/tools/testing/selftests/drivers/hwtracing/coresight/Makefile b/tools/testing/selftests/drivers/hwtracing/coresight/Makefile
> > new file mode 100644
> > index 000000000000..7dc68ae1c0a9
> > --- /dev/null
> > +++ b/tools/testing/selftests/drivers/hwtracing/coresight/Makefile
> > @@ -0,0 +1,5 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +
> > +TEST_PROGS = sysfs_test_trace.sh
> > +
> > +include ../../../lib.mk
> > diff --git a/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh b/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> > new file mode 100755
> > index 000000000000..0d6307fff1d2
> > --- /dev/null
> > +++ b/tools/testing/selftests/drivers/hwtracing/coresight/sysfs_test_trace.sh
> > @@ -0,0 +1,144 @@
> > +#!/bin/sh
> > +# SPDX-License-Identifier: GPL-2.0
> > +# Copyright (C) 2024 Marvell.
> > +
> > +# Test Arm CoreSight trace capture in sysfs mode
> > +# Based on tools/perf/tests/shell/test_arm_coresight.sh
> > +
> > +glb_err=0
> > +
> > +arm_cs_report() {
> > +	if [ $2 != 0 ]; then
> > +		echo "$1: FAIL"
> > +		glb_err=$2
> > +	else
> > +		echo "$1: PASS"
> > +	fi
> > +}
> > +
> > +is_device_sink() {
> > +	# If the node of "enable_sink" is existed under the device path, this
> > +	# means the device is a sink device.
> > +
> > +	if [ -e "$1/enable_sink" ]; then
> > +
> > +		return 0
> > +	else
> > +		return 1
> > +	fi
> > +}
> > +
> > +# Configure sink for buffer mode
> > +cfg_sink_buf_mode() {
> > +	sink_dev=$1
> > +	mode=$2
> > +	# Set buffer mode if supported
> > +	if [ -e "$sink_dev/buf_modes_available" ]; then
> > +		cat $sink_dev/buf_modes_available | grep -E -q $mode
> > +		if [ $? -eq 0 ]; then
> > +			echo $mode > $sink_dev/buf_mode_preferred
> > +			return 0
> > +		fi
> > +	fi
> > +
> > +	return 1
> > +}
> > +
> > +run_app() {
> > +
> > +	taskset -c $1 dd if=/dev/urandom  of=/dev/null bs=1M count=64
> > +}
> > +
> > +sysfs_trace() {
> > +	src_dev=$1
> > +	sink_dev=$2
> > +	cpu=$3
> > +
> > +	# Enable sink device
> > +	echo 1 > $sink_dev/enable_sink
> > +	# Enable source device
> > +	echo 1 > $src_dev/enable_source
> > +
> > +	# Run app to be traced
> > +	run_app $cpu
> > +
> > +	# Read back trace data
> > +	dd if=/dev/$sink_dev_name of=/tmp/tracedata
> > +
> > +	# Verify if read is successful
> > +	err=$?
> > +
> > +	# Disable source device
> > +	echo 0 > $src_dev/enable_source
> > +
> > +	# Diskable sink device
> > +	echo 0 > $sink_dev/enable_sink
> > +
> > +	arm_cs_report "CoreSight path testing (CPU$cpu -> $sink_dev_name)" $err
> > +}
> > +
> > +try_sysfs_trace_resrv_buf() {
> > +	src_dev=$1
> > +	sink_dev=$2
> > +	cpu=$3
> > +
> > +	# Configure the resrved buffer mode if available
> > +	cfg_sink_buf_mode $sink_dev "resrv"
> > +	if [ $? -eq 0 ]; then
> > +		echo "Running sysfs trace with resrv buf mode"
> > +		sysfs_trace $src_dev $sink_dev $cpu
> > +		# Restore buffer mode
> > +		cfg_sink_buf_mode $sink_dev "auto"
> > +		if [ $? -eq 1 ]; then
> > +			echo "Failed to restore default buf mode"
> > +		fi
> > +	fi
> > +}
> > +
> > +arm_cs_iterate_devices() {
> > +	src_dev=$1
> > +	cpu=$3
> > +	for cdev in $2/connections/out\:*; do
> > +
> > +		# Skip testing if it's not a directory
> > +		! [ -d $cdev ] && continue;
> > +
> > +		# Read out its symbol link file name
> > +		sink_dev=`readlink -f $cdev`
> > +
> > +		# Extract device name from path, e.g.
> > +		#   sink_dev = '/sys/devices/platform/20010000.etf/tmc_etf0'
> > +		#     `> sink_dev_name = 'tmc_etf0'
> > +		sink_dev_name=$(basename $sink_dev)
> > +
> > +		if is_device_sink $sink_dev; then
> > +			# Run trace with resrv buf mode (if available)
> > +			try_sysfs_trace_resrv_buf $src_dev $sink_dev $cpu
> > +
> > +			# Run the default mode
> > +			echo "Running sysfs trace with default settings"
> > +			sysfs_trace $src_dev $sink_dev $cpu
> > +		fi
> > +
> > +		arm_cs_iterate_devices $src_dev $cdev $cpu
> > +
> > +	done
> > +}
> > +
> > +arm_cs_etm_traverse_path_test() {
> > +	# Iterate for every ETM device
> > +	for dev in /sys/bus/event_source/devices/cs_etm/cpu*; do
> > +		# Canonicalize the path
> > +		dev=`readlink -f $dev`
> > +
> > +		# Find the ETM device belonging to which CPU
> > +		cpu=`cat $dev/cpu`
> > +
> > +		# Use depth-first search (DFS) to iterate outputs
> > +		arm_cs_iterate_devices $dev $dev $cpu
> > +	done
> > +}
> > +
> > +arm_cs_etm_traverse_path_test
> > +
> > +exit $glb_err
> 
> thanks,
> -- Shuah
>

On 04/12/2024 12:23 am, Shuah Khan wrote:
> On 11/29/24 01:38, Linu Cherian wrote:
>> Add sysfs mode selftest for ARM Coresight hardware tracer.
> 
> Please add details on what this test does in here. Include
> the output from the test?
> 
> Does this test have dependencies on config? If it does, does
> this test detect and skip if config isn't enabled?
> 

Without the config the test won't find any devices and it will still 
pass. But yes it would still be good to explicitly mark the dependency.

>>
>> Signed-off-by: Linu Cherian <lcherian@marvell.com>
>> ---
>>   .../drivers/hwtracing/coresight/Makefile      |   5 +
>>   .../hwtracing/coresight/sysfs_test_trace.sh   | 144 ++++++++++++++++++
>>   2 files changed, 149 insertions(+)
>>   create mode 100644 tools/testing/selftests/drivers/hwtracing/ 
>> coresight/Makefile
>>   create mode 100755 tools/testing/selftests/drivers/hwtracing/ 
>> coresight/sysfs_test_trace.sh
>>
>> diff --git a/tools/testing/selftests/drivers/hwtracing/coresight/ 
>> Makefile b/tools/testing/selftests/drivers/hwtracing/coresight/Makefile
>> new file mode 100644
>> index 000000000000..7dc68ae1c0a9
>> --- /dev/null
>> +++ b/tools/testing/selftests/drivers/hwtracing/coresight/Makefile
>> @@ -0,0 +1,5 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +
>> +TEST_PROGS = sysfs_test_trace.sh
>> +
>> +include ../../../lib.mk
>> diff --git a/tools/testing/selftests/drivers/hwtracing/coresight/ 
>> sysfs_test_trace.sh b/tools/testing/selftests/drivers/hwtracing/ 
>> coresight/sysfs_test_trace.sh
>> new file mode 100755
>> index 000000000000..0d6307fff1d2
>> --- /dev/null
>> +++ b/tools/testing/selftests/drivers/hwtracing/coresight/ 
>> sysfs_test_trace.sh
>> @@ -0,0 +1,144 @@
>> +#!/bin/sh
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Copyright (C) 2024 Marvell.
>> +
>> +# Test Arm CoreSight trace capture in sysfs mode
>> +# Based on tools/perf/tests/shell/test_arm_coresight.sh
>> +
>> +glb_err=0
>> +
>> +arm_cs_report() {
>> +    if [ $2 != 0 ]; then
>> +        echo "$1: FAIL"
>> +        glb_err=$2
>> +    else
>> +        echo "$1: PASS"
>> +    fi
>> +}
>> +
>> +is_device_sink() {
>> +    # If the node of "enable_sink" is existed under the device path, 
>> this
>> +    # means the device is a sink device.
>> +
>> +    if [ -e "$1/enable_sink" ]; then
>> +
>> +        return 0
>> +    else
>> +        return 1
>> +    fi
>> +}
>> +
>> +# Configure sink for buffer mode
>> +cfg_sink_buf_mode() {
>> +    sink_dev=$1
>> +    mode=$2
>> +    # Set buffer mode if supported
>> +    if [ -e "$sink_dev/buf_modes_available" ]; then
>> +        cat $sink_dev/buf_modes_available | grep -E -q $mode
>> +        if [ $? -eq 0 ]; then
>> +            echo $mode > $sink_dev/buf_mode_preferred
>> +            return 0
>> +        fi
>> +    fi
>> +
>> +    return 1
>> +}
>> +
>> +run_app() {
>> +
>> +    taskset -c $1 dd if=/dev/urandom  of=/dev/null bs=1M count=64
>> +}
>> +
>> +sysfs_trace() {
>> +    src_dev=$1
>> +    sink_dev=$2
>> +    cpu=$3
>> +
>> +    # Enable sink device
>> +    echo 1 > $sink_dev/enable_sink
>> +    # Enable source device
>> +    echo 1 > $src_dev/enable_source
>> +
>> +    # Run app to be traced
>> +    run_app $cpu
>> +
>> +    # Read back trace data
>> +    dd if=/dev/$sink_dev_name of=/tmp/tracedata
>> +
>> +    # Verify if read is successful
>> +    err=$?
>> +
>> +    # Disable source device
>> +    echo 0 > $src_dev/enable_source
>> +
>> +    # Diskable sink device
>> +    echo 0 > $sink_dev/enable_sink
>> +
>> +    arm_cs_report "CoreSight path testing (CPU$cpu -> 
>> $sink_dev_name)" $err
>> +}
>> +
>> +try_sysfs_trace_resrv_buf() {
>> +    src_dev=$1
>> +    sink_dev=$2
>> +    cpu=$3
>> +
>> +    # Configure the resrved buffer mode if available
>> +    cfg_sink_buf_mode $sink_dev "resrv"
>> +    if [ $? -eq 0 ]; then
>> +        echo "Running sysfs trace with resrv buf mode"
>> +        sysfs_trace $src_dev $sink_dev $cpu
>> +        # Restore buffer mode
>> +        cfg_sink_buf_mode $sink_dev "auto"
>> +        if [ $? -eq 1 ]; then
>> +            echo "Failed to restore default buf mode"
>> +        fi
>> +    fi
>> +}
>> +
>> +arm_cs_iterate_devices() {
>> +    src_dev=$1
>> +    cpu=$3
>> +    for cdev in $2/connections/out\:*; do
>> +
>> +        # Skip testing if it's not a directory
>> +        ! [ -d $cdev ] && continue;
>> +
>> +        # Read out its symbol link file name
>> +        sink_dev=`readlink -f $cdev`
>> +
>> +        # Extract device name from path, e.g.
>> +        #   sink_dev = '/sys/devices/platform/20010000.etf/tmc_etf0'
>> +        #     `> sink_dev_name = 'tmc_etf0'
>> +        sink_dev_name=$(basename $sink_dev)
>> +
>> +        if is_device_sink $sink_dev; then
>> +            # Run trace with resrv buf mode (if available)
>> +            try_sysfs_trace_resrv_buf $src_dev $sink_dev $cpu
>> +
>> +            # Run the default mode
>> +            echo "Running sysfs trace with default settings"
>> +            sysfs_trace $src_dev $sink_dev $cpu
>> +        fi
>> +
>> +        arm_cs_iterate_devices $src_dev $cdev $cpu
>> +
>> +    done
>> +}
>> +
>> +arm_cs_etm_traverse_path_test() {
>> +    # Iterate for every ETM device
>> +    for dev in /sys/bus/event_source/devices/cs_etm/cpu*; do
>> +        # Canonicalize the path
>> +        dev=`readlink -f $dev`
>> +
>> +        # Find the ETM device belonging to which CPU
>> +        cpu=`cat $dev/cpu`
>> +
>> +        # Use depth-first search (DFS) to iterate outputs
>> +        arm_cs_iterate_devices $dev $dev $cpu
>> +    done
>> +}
>> +
>> +arm_cs_etm_traverse_path_test
>> +
>> +exit $glb_err
> 
> thanks,
> -- Shuah
>