Merge branch 'for-next/perf' into for-next/core

* for-next/perf: (29 commits)
  perf docs: arm_spe: Document new discard mode
  perf: arm_spe: Add format option for discard mode
  MAINTAINERS: Add perf list for drivers/perf/
  drivers/perf: apple_m1: Map generic branch events
  drivers/perf: hisi: Set correct IRQ affinity for PMUs with no association
  perf: imx9_perf: Introduce AXI filter version to refactor the driver and better extension
  perf/arm-cmn: Permit more exhaustive groups
  perf/dwc_pcie: Qualify RAS DES VSEC Capability by Vendor, Revision
  drivers/perf: hisi: Delete redundant blank line of DDRC PMU
  drivers/perf: hisi: Fix incorrect variable name "hha_pmu" in DDRC PMU driver
  drivers/perf: hisi: Export associated CPUs of each PMU through sysfs
  drivers/perf: hisi: Provide a generic implementation of cpumask/identifier
  drivers/perf: hisi: Add a common function to retrieve topology from firmware
  drivers/perf: hisi: Extract topology information to a separate structure
  drivers/perf: hisi: Refactor the detection of associated CPUs
  drivers/perf: hisi: Migrate to one online CPU if no associated one online
  drivers/perf: hisi: Don't update the associated_cpus on CPU offline
  drivers/perf: hisi: Define a symbol namespace for HiSilicon Uncore PMUs
  perf/marvell: Odyssey LLC-TAD performance monitor support
  perf/marvell: Refactor to extract platform data
  ...

1 files changed, 26 insertions, 0 deletions

diff --git a/tools/perf/Documentation/perf-arm-spe.txt b/tools/perf/Documentation/perf-arm-spe.txt
index de2b0b479249..37afade4f1b2 100644
--- a/tools/perf/Documentation/perf-arm-spe.txt
+++ b/tools/perf/Documentation/perf-arm-spe.txt
@@ -150,6 +150,7 @@ arm_spe/load_filter=1,min_latency=10/'
   pct_enable=1        - collect physical timestamp instead of virtual timestamp (PMSCR.PCT) - requires privilege
   store_filter=1      - collect stores only (PMSFCR.ST)
   ts_enable=1         - enable timestamping with value of generic timer (PMSCR.TS)
+  discard=1           - enable SPE PMU events but don't collect sample data - see 'Discard mode' (PMBLIMITR.FM = DISCARD)
 
 +++*+++ Latency is the total latency from the point at which sampling started on that instruction, rather
 than only the execution latency.
@@ -220,6 +221,31 @@ Common errors
 
    Increase sampling interval (see above)
 
+PMU events
+~~~~~~~~~~
+
+SPE has events that can be counted on core PMUs. These are prefixed with
+SAMPLE_, for example SAMPLE_POP, SAMPLE_FEED, SAMPLE_COLLISION and
+SAMPLE_FEED_BR.
+
+These events will only count when an SPE event is running on the same core that
+the PMU event is opened on, otherwise they read as 0. There are various ways to
+ensure that the PMU event and SPE event are scheduled together depending on the
+way the event is opened. For example opening both events as per-process events
+on the same process, although it's not guaranteed that the PMU event is enabled
+first when context switching. For that reason it may be better to open the PMU
+event as a systemwide event and then open SPE on the process of interest.
+
+Discard mode
+~~~~~~~~~~~~
+
+SPE related (SAMPLE_* etc) core PMU events can be used without the overhead of
+collecting sample data if discard mode is supported (optional from Armv8.6).
+First run a system wide SPE session (or on the core of interest) using options
+to minimize output. Then run perf stat:
+
+  perf record -e arm_spe/discard/ -a -N -B --no-bpf-event -o - > /dev/null &
+  perf stat -e SAMPLE_FEED_LD
 
 SEE ALSO
 --------