Re: [PATCH v2 1/4] Documentation/ABI: Add document for Mellanox PMC driver

Ilpo Järvinen
2024-05-27T10:33:55Z

On Mon, 20 May 2024, Shravan Kumar Ramani wrote:

> The sysfs interface is created for programming and monitoring the

This patch is not creating interface. I suggest you change the wording to:

"Document the sysfs interface for ...

> performance counters in various HW blocks of Mellanox BlueField-1,
> BlueField-2 and BlueField-3.
>
> Signed-off-by: Shravan Kumar Ramani <shravankr@nvidia.com>
> Reviewed-by: David Thompson <davthompson@nvidia.com>
> ---
> .../ABI/testing/sysfs-platform-mellanox-pmc | 49 +++++++++++++++++++
> 1 file changed, 49 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-platform-mellanox-pmc
>
> diff --git a/Documentation/ABI/testing/sysfs-platform-mellanox-pmc b/Documentation/ABI/testing/sysfs-platform-mellanox-pmc
> new file mode 100644
> index 000000000000..47094024dbeb
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-platform-mellanox-pmc
> @@ -0,0 +1,49 @@
> +HID Driver Description
> +MLNXBFD0 mlxbf-pmc Performance counters (BlueField-1)
> +MLNXBFD1 mlxbf-pmc Performance counters (BlueField-2)
> +MLNXBFD2 mlxbf-pmc Performance counters (BlueField-3)
> +
> +What: /sys/bus/platform/devices/<HID>/hwmon/hwmonX/<block>/event_list
> +Date: Dec 2020
> +KernelVersion: 5.10
> +Contact: "Shravan Kumar Ramani <shravankr@nvidia.com>"
> +Description:
> + List of events supported by the counters in the specific block.
> + It is used to extract the event number or ID associated with
> + each event.
> +
> +What: /sys/bus/platform/devices/<HID>/hwmon/hwmonX/<block>/event<N>
> +Date: Dec 2020
> +KernelVersion: 5.10
> +Contact: "Shravan Kumar Ramani <shravankr@nvidia.com>"
> +Description:
> + Event monitored by corresponding counter. This is used to
> + program or read back the event that should be or is currently
> + being monitored by counter<N>.
> +
> +What: /sys/bus/platform/devices/<HID>/hwmon/hwmonX/<block>/counter<N>
> +Date: Dec 2020
> +KernelVersion: 5.10
> +Contact: "Shravan Kumar Ramani <shravankr@nvidia.com>"
> +Description:
> + Counter value of the event being monitored. This is used to
> + read the counter value of the event which was programmed using
> + event<N>. This is also used to clear or reset the counter value.

Please document how to clear/reset it in more concrete terms (I didn't
check the code but my guess would one writes zero there to reset the
counter?).

> +What: /sys/bus/platform/devices/<HID>/hwmon/hwmonX/<block>/enable
> +Date: Dec 2020
> +KernelVersion: 5.10
> +Contact: "Shravan Kumar Ramani <shravankr@nvidia.com>"
> +Description:
> + Start or stop counters. This is used to start the counters
> + for monitoring the programmed events and also to stop the
> + counters after the desired duration.
> +
> +What: /sys/bus/platform/devices/<HID>/hwmon/hwmonX/<block>/<reg>
> +Date: Dec 2020
> +KernelVersion: 5.10
> +Contact: "Shravan Kumar Ramani <shravankr@nvidia.com>"
> +Description:
> + Value of register. This is used to read or reset the registers
> + where various performance statistics are counted for each block.

Ditto for the reset part.

--
i.