[PATCH 02/10] docs: ABI: sysfs-bus-event_source-devices-hv_gpci: Document processor_bus_topology sysfs interface file
From: Kajol Jain <hidden>
Date: 2023-06-09 11:43:05
Subsystem:
the rest · Maintainer:
Linus Torvalds
Add details of the new hv-gpci interface file called "processor_bus_topology" in the ABI documentation. Signed-off-by: Kajol Jain <redacted> --- .../sysfs-bus-event_source-devices-hv_gpci | 29 +++++++++++++++++++ 1 file changed, 29 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..6d633167268e 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 +80,32 @@ 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: June 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 is only be created for power10 and above platforms. + * User need root access to read data from this sysfs file. + * Incase the HCALL fails with hardware/permission issue, or the support for + PROCESSOR_BUS_TOPOLOGY counter request value removed, this sysfs file still be + created and give error when reading it. + * The end user reading this sysfs file need to decode sysfs file data as per + underneath 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. + + * "-EOPNOTSUPP" : Requested system information is not available for the firmware + level and platform. + + * "-EIO" : Can't retrieve system information because of invalid buffer length/invalid address + or because of some hardware error. Refer getPerfCountInfo documentation for + more information. + + * "-EFBIG" : System information exceeds PAGE_SIZE.
--
2.35.3