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Message-ID: <d91cee25-19d6-2eaa-1ad3-94718fa253cb@linux.ibm.com>
Date:   Fri, 14 Jul 2023 12:32:02 +0530
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Subject: Re: [PATCH v2 02/10] docs: ABI:
 sysfs-bus-event_source-devices-hv_gpci: Document processor_bus_topology sysfs
 interface file
To:     Randy Dunlap <rdunlap@infradead.org>, mpe@ellerman.id.au
Cc:     linuxppc-dev@lists.ozlabs.org, maddy@linux.ibm.com,
        atrajeev@linux.vnet.ibm.com, disgoel@linux.ibm.com,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20230710092717.55317-1-kjain@linux.ibm.com>
 <20230710092717.55317-3-kjain@linux.ibm.com>
 <4418618a-ac75-f824-ec6d-984421dd5c6b@infradead.org>
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From:   kajoljain <kjain@linux.ibm.com>
In-Reply-To: <4418618a-ac75-f824-ec6d-984421dd5c6b@infradead.org>
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Thanks Randy for the review comments, I will do these updates
for all documentation patches in my next version of patchset.

Thanks,
Kajol Jain

On 7/12/23 02:22, Randy Dunlap wrote:
> 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@linux.ibm.com>
>> ---
>>  .../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@lists.ozlabs.org>
>>  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@lists.ozlabs.org>
>> +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.
>