perf/arm_dsu: Allow standard cycles events

Since we do not use the divide-by-64 option, there should be no
significant difference between the dedicated cycle counter and the
standard cycles event. Since using the latter on DSU-120 now has
the side-effect of allowing multiple cycles events to be scheduled
simultaneously (beneficial for multiple cycle-based metrics), there
seems little reason not to allow the same on older DSUs as well.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/perf/arm_dsu_pmu.c b/drivers/perf/arm_dsu_pmu.c
index 56c592f0dae3af790b18709dc3cb84f3a3833e4c..32b0dd7c693b3ddb6be184bc90facc85d5e192c5 100644 (file)
--- a/drivers/perf/arm_dsu_pmu.c
+++ b/drivers/perf/arm_dsu_pmu.c
@@ -284,9 +284,8 @@ static int dsu_pmu_get_event_idx(struct dsu_hw_events *hw_events,
        unsigned long *used_mask = hw_events->used_mask;
 
        if (evtype == DSU_PMU_EVT_CYCLES && dsu_pmu->has_pmccntr) {
-               if (test_and_set_bit(DSU_PMU_IDX_CYCLE_COUNTER, used_mask))
-                       return -EAGAIN;
-               return DSU_PMU_IDX_CYCLE_COUNTER;
+               if (!test_and_set_bit(DSU_PMU_IDX_CYCLE_COUNTER, used_mask))
+                       return DSU_PMU_IDX_CYCLE_COUNTER;
        }
 
        idx = find_first_zero_bit(used_mask, dsu_pmu->num_counters);