[PATCH v3 01/14] drivers/perf: arm_spe: Expose event filter

Leo Yan leo.yan at arm.com
Mon Jul 7 06:39:23 PDT 2025


Expose an "event_filter" entry in the caps folder to inform user space
about which events can be filtered.

Change the return type of arm_spe_pmu_cap_get() from u32 to u64 to
accommodate the added event filter entry.

Signed-off-by: Leo Yan <leo.yan at arm.com>
---
 drivers/perf/arm_spe_pmu.c | 36 ++++++++++++++++++++----------------
 1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c
index 3efed8839a4ec5604eba242cb620327cd2a6a87d..78d8cb59b66d7bc6319eb4ee40e6d2d32ffb8bdf 100644
--- a/drivers/perf/arm_spe_pmu.c
+++ b/drivers/perf/arm_spe_pmu.c
@@ -115,6 +115,7 @@ enum arm_spe_pmu_capabilities {
 	SPE_PMU_CAP_FEAT_MAX,
 	SPE_PMU_CAP_CNT_SZ = SPE_PMU_CAP_FEAT_MAX,
 	SPE_PMU_CAP_MIN_IVAL,
+	SPE_PMU_CAP_EVENT_FILTER,
 };
 
 static int arm_spe_pmu_feat_caps[SPE_PMU_CAP_FEAT_MAX] = {
@@ -122,7 +123,21 @@ static int arm_spe_pmu_feat_caps[SPE_PMU_CAP_FEAT_MAX] = {
 	[SPE_PMU_CAP_ERND]	= SPE_PMU_FEAT_ERND,
 };
 
-static u32 arm_spe_pmu_cap_get(struct arm_spe_pmu *spe_pmu, int cap)
+static u64 arm_spe_pmsevfr_res0(u16 pmsver)
+{
+	switch (pmsver) {
+	case ID_AA64DFR0_EL1_PMSVer_IMP:
+		return PMSEVFR_EL1_RES0_IMP;
+	case ID_AA64DFR0_EL1_PMSVer_V1P1:
+		return PMSEVFR_EL1_RES0_V1P1;
+	case ID_AA64DFR0_EL1_PMSVer_V1P2:
+	/* Return the highest version we support in default */
+	default:
+		return PMSEVFR_EL1_RES0_V1P2;
+	}
+}
+
+static u64 arm_spe_pmu_cap_get(struct arm_spe_pmu *spe_pmu, int cap)
 {
 	if (cap < SPE_PMU_CAP_FEAT_MAX)
 		return !!(spe_pmu->features & arm_spe_pmu_feat_caps[cap]);
@@ -132,6 +147,8 @@ static u32 arm_spe_pmu_cap_get(struct arm_spe_pmu *spe_pmu, int cap)
 		return spe_pmu->counter_sz;
 	case SPE_PMU_CAP_MIN_IVAL:
 		return spe_pmu->min_period;
+	case SPE_PMU_CAP_EVENT_FILTER:
+		return ~arm_spe_pmsevfr_res0(spe_pmu->pmsver);
 	default:
 		WARN(1, "unknown cap %d\n", cap);
 	}
@@ -148,7 +165,7 @@ static ssize_t arm_spe_pmu_cap_show(struct device *dev,
 		container_of(attr, struct dev_ext_attribute, attr);
 	int cap = (long)ea->var;
 
-	return sysfs_emit(buf, "%u\n", arm_spe_pmu_cap_get(spe_pmu, cap));
+	return sysfs_emit(buf, "%llu\n", arm_spe_pmu_cap_get(spe_pmu, cap));
 }
 
 #define SPE_EXT_ATTR_ENTRY(_name, _func, _var)				\
@@ -164,6 +181,7 @@ static struct attribute *arm_spe_pmu_cap_attr[] = {
 	SPE_CAP_EXT_ATTR_ENTRY(ernd, SPE_PMU_CAP_ERND),
 	SPE_CAP_EXT_ATTR_ENTRY(count_size, SPE_PMU_CAP_CNT_SZ),
 	SPE_CAP_EXT_ATTR_ENTRY(min_interval, SPE_PMU_CAP_MIN_IVAL),
+	SPE_CAP_EXT_ATTR_ENTRY(event_filter, SPE_PMU_CAP_EVENT_FILTER),
 	NULL,
 };
 
@@ -693,20 +711,6 @@ static irqreturn_t arm_spe_pmu_irq_handler(int irq, void *dev)
 	return IRQ_HANDLED;
 }
 
-static u64 arm_spe_pmsevfr_res0(u16 pmsver)
-{
-	switch (pmsver) {
-	case ID_AA64DFR0_EL1_PMSVer_IMP:
-		return PMSEVFR_EL1_RES0_IMP;
-	case ID_AA64DFR0_EL1_PMSVer_V1P1:
-		return PMSEVFR_EL1_RES0_V1P1;
-	case ID_AA64DFR0_EL1_PMSVer_V1P2:
-	/* Return the highest version we support in default */
-	default:
-		return PMSEVFR_EL1_RES0_V1P2;
-	}
-}
-
 /* Perf callbacks */
 static int arm_spe_pmu_event_init(struct perf_event *event)
 {

-- 
2.34.1




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