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
The PCIe devices supported by the PTT trace can be removed/rescanned by
hotplug or through sysfs. Add support for dynamically updating the
available filter list by registering a PCI bus notifier block. Then user
can always get latest information about available tracing filters and
driver can block the invalid filters of which related devices no longer
exist in the system.
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/20230621092804.15120-3-yangyicong@huawei.com
Document the introduction and usage of HiSilicon PTT device driver as well
as the sysfs attributes description provided by the driver.
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
[Fixed month and kernel version]
Link: https://lore.kernel.org/r/20220816114414.4092-5-yangyicong@huawei.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Yicong Yang