mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

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
This commit is contained in:
Kajol Jain 2023-07-29 13:04:47 +05:30 committed by Michael Ellerman
parent 71f1c39647
commit 9caf9e2b8b
1 changed files with 32 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_gpci
View File

@ -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.