[PATCH V6 7/7] drivers: perf: arm_pmu: Enable branch stack sampling event

From: Anshuman Khandual
Date: Thu Dec 08 2022 - 03:45:56 EST


Now that all the required pieces are already in place, just enable the perf
branch stack sampling event on supported platforms, removing the gate which
blocks it unconditionally in armpmu_event_init(). Instead a quick probe can
be initiated first via arm_pmu_branch_stack_supported().

Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
drivers/perf/arm_pmu.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 66880a4bb248..52a93b9bcbda 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -510,8 +510,7 @@ static int armpmu_event_init(struct perf_event *event)
!cpumask_test_cpu(event->cpu, &armpmu->supported_cpus))
return -ENOENT;

- /* does not support taken branch sampling */
- if (has_branch_stack(event))
+ if (has_branch_stack(event) && !arm_pmu_branch_stack_supported(armpmu))
return -EOPNOTSUPP;

if (armpmu->map_event(event) == -ENOENT)
--
2.25.1