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authorKajol Jain <kjain@linux.ibm.com>2023-07-29 10:34:47 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2023-08-16 16:54:49 +0300
commit9caf9e2b8bae58e39501f6fb1fc9189009538ccc (patch)
treec471122cfefb188e85da402dac2e4ccb10cf3f24 /Documentation/ABI
parent71f1c39647d8c9d4d54a861ec81f1ff17544bcb6 (diff)
downloadlinux-9caf9e2b8bae58e39501f6fb1fc9189009538ccc.tar.xz
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_gpci32
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.