hwtracing: hisi_ptt: Export available filters through sysfs

The PTT can only filter the traced TLP headers by the Root Ports or the
Requester ID of the Endpoint, which are located on the same PCIe core of
the PTT device. The filter value used is derived from the BDF number of
the supported Root Port or the Endpoint. It's not friendly enough for the
users since it requires the user to be familiar enough with the platform
and calculate the filter value manually.

This patch export the available filters through sysfs. Each available
filters is presented as an individual file with the name of the BDF
number of the related PCIe device. The files are created under
$(PTT PMU dir)/available_root_port_filters and
$(PTT PMU dir)/available_requester_filters respectively. The filter
value can be known by reading the related file.

Then the users can easily know the available filters for trace and get
the filter values without calculating.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230621092804.15120-4-yangyicong@huawei.com

1 files changed, 52 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-devices-hisi_ptt b/Documentation/ABI/testing/sysfs-devices-hisi_ptt
index 82de6d710266..d7e206b4901c 100644
--- a/Documentation/ABI/testing/sysfs-devices-hisi_ptt
+++ b/Documentation/ABI/testing/sysfs-devices-hisi_ptt
@@ -59,3 +59,55 @@ Description:	(RW) Control the allocated buffer watermark of outbound packets.
 		The available tune data is [0, 1, 2]. Writing a negative value
 		will return an error, and out of range values will be converted
 		to 2. The value indicates a probable level of the event.
+
+What:		/sys/devices/hisi_ptt<sicl_id>_<core_id>/root_port_filters
+Date:		May 2023
+KernelVersion:	6.5
+Contact:	Yicong Yang <yangyicong@hisilicon.com>
+Description:	This directory contains the files providing the PCIe Root Port filters
+		information used for PTT trace. Each file is named after the supported
+		Root Port device name <domain>:<bus>:<device>.<function>.
+
+		See the description of the "filter" in Documentation/trace/hisi-ptt.rst
+		for more information.
+
+What:		/sys/devices/hisi_ptt<sicl_id>_<core_id>/root_port_filters/multiselect
+Date:		May 2023
+KernelVersion:	6.5
+Contact:	Yicong Yang <yangyicong@hisilicon.com>
+Description:	(Read) Indicates if this kind of filter can be selected at the same
+		time as others filters, or must be used on it's own. 1 indicates
+		the former case and 0 indicates the latter.
+
+What:		/sys/devices/hisi_ptt<sicl_id>_<core_id>/root_port_filters/<bdf>
+Date:		May 2023
+KernelVersion:	6.5
+Contact:	Yicong Yang <yangyicong@hisilicon.com>
+Description:	(Read) Indicates the filter value of this Root Port filter, which
+		can be used to control the TLP headers to trace by the PTT trace.
+
+What:		/sys/devices/hisi_ptt<sicl_id>_<core_id>/requester_filters
+Date:		May 2023
+KernelVersion:	6.5
+Contact:	Yicong Yang <yangyicong@hisilicon.com>
+Description:	This directory contains the files providing the PCIe Requester filters
+		information used for PTT trace. Each file is named after the supported
+		Endpoint device name <domain>:<bus>:<device>.<function>.
+
+		See the description of the "filter" in Documentation/trace/hisi-ptt.rst
+		for more information.
+
+What:		/sys/devices/hisi_ptt<sicl_id>_<core_id>/requester_filters/multiselect
+Date:		May 2023
+KernelVersion:	6.5
+Contact:	Yicong Yang <yangyicong@hisilicon.com>
+Description:	(Read) Indicates if this kind of filter can be selected at the same
+		time as others filters, or must be used on it's own. 1 indicates
+		the former case and 0 indicates the latter.
+
+What:		/sys/devices/hisi_ptt<sicl_id>_<core_id>/requester_filters/<bdf>
+Date:		May 2023
+KernelVersion:	6.5
+Contact:	Yicong Yang <yangyicong@hisilicon.com>
+Description:	(Read) Indicates the filter value of this Requester filter, which
+		can be used to control the TLP headers to trace by the PTT trace.