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[v5,20/21] tools/perf: Pass the Counter constraint values in the pmu events

Message ID 20250327-counter_delegation-v5-20-1ee538468d1b@rivosinc.com (mailing list archive)
State New
Headers show
Series Add Counter delegation ISA extension support | expand

Commit Message

Atish Patra March 27, 2025, 7:36 p.m. UTC 
RISC-V doesn't have any standard event to counter mapping discovery
mechanism in the ISA. The ISA defines 29 programmable counters and
platforms can choose to implement any number of them and map any
events to any counters. Thus, the perf tool need to inform the driver
about the counter mapping of each events.

The current perf infrastructure only parses the 'Counter' constraints
in metrics. This patch extends that to pass in the pmu events so that
any driver can retrieve those values via perf attributes if defined
accordingly.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 tools/perf/pmu-events/jevents.py | 9 +++++++++
 1 file changed, 9 insertions(+)
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Patch

diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
index fdb7ddf093d2..f9f274678a32 100755
--- a/tools/perf/pmu-events/jevents.py
+++ b/tools/perf/pmu-events/jevents.py
@@ -274,6 +274,11 @@  class JsonEvent:
         return fixed[name.lower()]
       return event
 
+    def counter_list_to_bitmask(counterlist):
+      counter_ids = list(map(int, counterlist.split(',')))
+      bitmask = sum(1 << pos for pos in counter_ids)
+      return bitmask
+
     def unit_to_pmu(unit: str) -> Optional[str]:
       """Convert a JSON Unit to Linux PMU name."""
       if not unit or unit == "core":
@@ -427,6 +432,10 @@  class JsonEvent:
       else:
         raise argparse.ArgumentTypeError('Cannot find arch std event:', arch_std)
 
+    if self.counters['list']:
+      bitmask = counter_list_to_bitmask(self.counters['list'])
+      event += f',counterid_mask={bitmask:#x}'
+
     self.event = real_event(self.name, event)
 
   def __repr__(self) -> str: