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| author | Kajol Jain <kjain@linux.ibm.com> | 2023-07-29 13:04:47 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-08-16 23:54:49 +1000 |
| commit | 9caf9e2b8bae58e39501f6fb1fc9189009538ccc (patch) | |
| tree | c471122cfefb188e85da402dac2e4ccb10cf3f24 /Documentation/ABI | |
| parent | 71f1c39647d8c9d4d54a861ec81f1ff17544bcb6 (diff) | |
| download | lwn-9caf9e2b8bae58e39501f6fb1fc9189009538ccc.tar.gz lwn-9caf9e2b8bae58e39501f6fb1fc9189009538ccc.zip | |
docs: ABI: sysfs-bus-event_source-devices-hv_gpci: Document processor_bus_topology sysfs interface file
Add details of the new hv-gpci interface file called
"processor_bus_topology" in the ABI documentation.
Reviewed-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230729073455.7918-3-kjain@linux.ibm.com
Diffstat (limited to 'Documentation/ABI')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_gpci | 32 |
1 files changed, 32 insertions, 0 deletions
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..ba3f9aa3d68e 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_SUCCESS", + "H_AUTHORITY" or "H_PARAMETER" as the return type. + + HCALL with return error type "H_AUTHORITY" can be resolved during + 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 to getPerfCountInfo documentation for + more information. + + * "-EFBIG" : System information exceeds PAGE_SIZE. |