Re: [PATCH v2 02/10] docs: ABI: sysfs-bus-event_source-devices-hv_gpci: Document processor_bus_topology sysfs interface file

From: Randy Dunlap
Date: Tue Jul 11 2023 - 16:53:09 EST


Hi--

On 7/10/23 02:27, Kajol Jain wrote:
> Add details of the new hv-gpci interface file called
> "processor_bus_topology" in the ABI documentation.
>
> Signed-off-by: Kajol Jain <kjain@xxxxxxxxxxxxx>
> ---
> .../sysfs-bus-event_source-devices-hv_gpci | 32 +++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_gpci b/Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_gpci
> index 12e2bf92783f..2eeeab9a20fa 100644
> --- a/Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_gpci
> +++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_gpci
> @@ -80,3 +80,35 @@ Contact: Linux on PowerPC Developer List <linuxppc-dev@xxxxxxxxxxxxxxxx>
> Description: read only
> This sysfs file exposes the cpumask which is designated to make
> HCALLs to retrieve hv-gpci pmu event counter data.
> +
> +What: /sys/devices/hv_gpci/interface/processor_bus_topology
> +Date: July 2023
> +Contact: Linux on PowerPC Developer List <linuxppc-dev@xxxxxxxxxxxxxxxx>
> +Description: admin read only
> + This sysfs file exposes the system topology information by making HCALL
> + H_GET_PERF_COUNTER_INFO. The HCALL is made with counter request value
> + PROCESSOR_BUS_TOPOLOGY(0xD0).
> +
> + * This sysfs file will be created only for power10 and above platforms.
> +
> + * User needs root privileges to read data from this sysfs file.
> +
> + * This sysfs file will be created, only when the HCALL returns "H_SUCESS",

H_SUCCESS

> + "H_AUTHORITY" and "H_PARAMETER" as the return type.

s/and/or/

> +
> + HCALL with return error type "H_AUTHORITY", can be resolved during

Drop the comma ^

> + runtime by setting "Enable Performance Information Collection" option.
> +
> + * The end user reading this sysfs file must decode the content as per
> + underlying platform/firmware.
> +
> + Possible error codes while reading this sysfs file:
> +
> + * "-EPERM" : Partition is not permitted to retrieve performance information,
> + required to set "Enable Performance Information Collection" option.
> +
> + * "-EIO" : Can't retrieve system information because of invalid buffer length/invalid address
> + or because of some hardware error. Refer getPerfCountInfo documentation for

Refer to

> + more information.
> +
> + * "-EFBIG" : System information exceeds PAGE_SIZE.

--
~Randy