[PATCH V2 5/6] docs: ABI: sysfs-bus-event_source-devices-htm: Document sysfs event format entries for htm pmu

[Athira Rajeev <atrajeev@linux.ibm.com>]

Add ABI documentation for the sysfs entries exposed by the "htm" PMU
under /sys/bus/event_source/devices/htm/.

Document the format attribute group, which describes the bit layout of
perf_event_attr.config accepted by the htm PMU:

  htm_type         config bits  0-3   (HTM_CORE=2, HTM_NEST=1)
  nodeindex        config bits  4-11
  nodalchipindex   config bits 12-19
  coreindexonchip  config bits 20-27

Document the events attribute group, which lists the named events
available on the PMU.  Users can pass these names directly to perf:

  # perf record -e htm/nodalchipindex=2,nodeindex=0,htm_type=1/ ...

Signed-off-by: Athira Rajeev <atrajeev@linux.ibm.com>
---
Changes in V2:
- Updated the bit-range descriptions to match the V2 config layout:
  htm_type is bits 0-3 (was listed inconsistently in V1), nodeindex
  is bits 4-11, nodalchipindex is bits 12-19, coreindexonchip is
  bits 20-27.
- Added documentation for the events/ sysfs group which lists named
  events users can pass directly to perf (e.g.
  htm/nodalchipindex=2,nodeindex=0,htm_type=1/).  This group was not
  documented in V1.
- Patch is now 5/6 instead of 4/5.

 .../sysfs-bus-event_source-devices-htm        | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-event_source-devices-htm

diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-htm b/Documentation/ABI/testing/sysfs-bus-event_source-devices-htm
new file mode 100644
index 000000000000..784ba7c31b89
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-htm
@@ -0,0 +1,21 @@
+What:           /sys/bus/event_source/devices/htm/format
+Date:           June 2026
+Contact:        Linux on PowerPC Developer List <linuxppc-dev at lists.ozlabs.org>
+Description:    Read-only. Attribute group to describe the magic bits
+                that go into perf_event_attr.config for a particular pmu.
+                (See ABI/testing/sysfs-bus-event_source-devices-format).
+
+                Each attribute under this group defines a bit range of the
+                perf_event_attr.config. Supported attribute are listed
+                below::
+
+				event  = "config:0-27"  - event ID
+
+What:           /sys/bus/event_source/devices/htm/events
+Date:           June 2026
+Contact:        Linux on PowerPC Developer List <linuxppc-dev at lists.ozlabs.org>
+Description:	(RO) Attribute group to describe performance monitoring events
+                for the Hardware Trace Macro (HTM) trace. Each attribute in
+		this group describes a single performance monitoring event
+		supported by htm pmu.  The name of the file is the name of
+		the event (See ABI/testing/sysfs-bus-event_source-devices-events).
-- 
2.43.0