[PATCH] drivers/perf: arm_spe: Expose saturating counter to 16-bit

Shaokun Zhang zhangshaokun at hisilicon.com
Thu Apr 28 23:33:07 PDT 2022


In order to acquire more accurate latency, Armv8.8[1] has defined the
CountSize field to 16-bit saturating counters when it's 0b0011.

Let's support this new feature and expose its to user under sysfs.

[1] https://developer.arm.com/documentation/ddi0487/latest

Cc: Will Deacon <will at kernel.org>
Cc: Mark Rutland <mark.rutland at arm.com>
Signed-off-by: Shaokun Zhang <zhangshaokun at hisilicon.com>
---
 drivers/perf/arm_spe_pmu.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c
index d44bcc29d99c..db670b265897 100644
--- a/drivers/perf/arm_spe_pmu.c
+++ b/drivers/perf/arm_spe_pmu.c
@@ -1035,6 +1035,9 @@ static void __arm_spe_pmu_dev_probe(void *info)
 		fallthrough;
 	case 2:
 		spe_pmu->counter_sz = 12;
+		break;
+	case 3:
+		spe_pmu->counter_sz = 16;
 	}
 
 	dev_info(dev,
-- 
2.33.0




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