perf/x86/intel: Rename DMR offcore_rsp attribute to offmodule_rspgrafted

DMR introduces Offmodule Response events in place of the legacy
Offcore Response events, but it still exposes the inherited
offcore_rsp PMU attribute for programming the corresponding MSR data.

Rename the DMR PMU attribute to offmodule_rsp so the sysfs interface
matches the underlying event name and avoids user & tooling confusion.

Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://patch.msgid.link/20260917015234.981153-12-dapeng1.mi@linux.intel.com

1 files changed, 44 insertions, 0 deletions

diff --git a/Documentation/admin-guide/perf/thunderx2-pmu.rst b/Documentation/admin-guide/perf/thunderx2-pmu.rst
new file mode 100644
index 000000000..9255f7bf9
--- /dev/null
+++ b/Documentation/admin-guide/perf/thunderx2-pmu.rst
@@ -0,0 +1,44 @@
+=============================================================
+Cavium ThunderX2 SoC Performance Monitoring Unit (PMU UNCORE)
+=============================================================
+
+The ThunderX2 SoC PMU consists of independent, system-wide, per-socket
+PMUs such as the Level 3 Cache (L3C), DDR4 Memory Controller (DMC) and
+Cavium Coherent Processor Interconnect (CCPI2).
+
+The DMC has 8 interleaved channels and the L3C has 16 interleaved tiles.
+Events are counted for the default channel (i.e. channel 0) and prorated
+to the total number of channels/tiles.
+
+The DMC and L3C support up to 4 counters, while the CCPI2 supports up to 8
+counters. Counters are independently programmable to different events and
+can be started and stopped individually. None of the counters support an
+overflow interrupt. DMC and L3C counters are 32-bit and read every 2 seconds.
+The CCPI2 counters are 64-bit and assumed not to overflow in normal operation.
+
+PMU UNCORE (perf) driver:
+
+The thunderx2_pmu driver registers per-socket perf PMUs for the DMC and
+L3C devices.  Each PMU can be used to count up to 4 (DMC/L3C) or up to 8
+(CCPI2) events simultaneously. The PMUs provide a description of their
+available events and configuration options under sysfs, see
+/sys/bus/event_source/devices/uncore_<l3c_S/dmc_S/ccpi2_S/>; S is the socket id.
+
+The driver does not support sampling, therefore "perf record" will not
+work. Per-task perf sessions are also not supported.
+
+Examples::
+
+  # perf stat -a -e uncore_dmc_0/cnt_cycles/ sleep 1
+
+  # perf stat -a -e \
+  uncore_dmc_0/cnt_cycles/,\
+  uncore_dmc_0/data_transfers/,\
+  uncore_dmc_0/read_txns/,\
+  uncore_dmc_0/write_txns/ sleep 1
+
+  # perf stat -a -e \
+  uncore_l3c_0/read_request/,\
+  uncore_l3c_0/read_hit/,\
+  uncore_l3c_0/inv_request/,\
+  uncore_l3c_0/inv_hit/ sleep 1