perf/smmuv3: Enable HiSilicon Erratum 162001900 quirk for HIP08/09

Some HiSilicon SMMU PMCG suffers the erratum 162001900 that the PMU
disable control sometimes fail to disable the counters. This will lead
to error or inaccurate data since before we enable the counters the
counter's still counting for the event used in last perf session.

This patch tries to fix this by hardening the global disable process.
Before disable the PMU, writing an invalid event type (0xffff) to
focibly stop the counters. Correspondingly restore each events on
pmu::pmu_enable().

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20230814124012.58013-1-yangyicong@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 45 insertions, 1 deletions

diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c
index 25a269d431e4..0e17c57ddb87 100644
--- a/drivers/perf/arm_smmuv3_pmu.c
+++ b/drivers/perf/arm_smmuv3_pmu.c
@@ -115,6 +115,7 @@
 #define SMMU_PMCG_PA_SHIFT              12
 
 #define SMMU_PMCG_EVCNTR_RDONLY         BIT(0)
+#define SMMU_PMCG_HARDEN_DISABLE        BIT(1)
 
 static int cpuhp_state_num;
 
@@ -159,6 +160,20 @@ static inline void smmu_pmu_enable(struct pmu *pmu)
 	writel(SMMU_PMCG_CR_ENABLE, smmu_pmu->reg_base + SMMU_PMCG_CR);
 }
 
+static int smmu_pmu_apply_event_filter(struct smmu_pmu *smmu_pmu,
+				       struct perf_event *event, int idx);
+
+static inline void smmu_pmu_enable_quirk_hip08_09(struct pmu *pmu)
+{
+	struct smmu_pmu *smmu_pmu = to_smmu_pmu(pmu);
+	unsigned int idx;
+
+	for_each_set_bit(idx, smmu_pmu->used_counters, smmu_pmu->num_counters)
+		smmu_pmu_apply_event_filter(smmu_pmu, smmu_pmu->events[idx], idx);
+
+	smmu_pmu_enable(pmu);
+}
+
 static inline void smmu_pmu_disable(struct pmu *pmu)
 {
 	struct smmu_pmu *smmu_pmu = to_smmu_pmu(pmu);
@@ -167,6 +182,22 @@ static inline void smmu_pmu_disable(struct pmu *pmu)
 	writel(0, smmu_pmu->reg_base + SMMU_PMCG_IRQ_CTRL);
 }
 
+static inline void smmu_pmu_disable_quirk_hip08_09(struct pmu *pmu)
+{
+	struct smmu_pmu *smmu_pmu = to_smmu_pmu(pmu);
+	unsigned int idx;
+
+	/*
+	 * The global disable of PMU sometimes fail to stop the counting.
+	 * Harden this by writing an invalid event type to each used counter
+	 * to forcibly stop counting.
+	 */
+	for_each_set_bit(idx, smmu_pmu->used_counters, smmu_pmu->num_counters)
+		writel(0xffff, smmu_pmu->reg_base + SMMU_PMCG_EVTYPER(idx));
+
+	smmu_pmu_disable(pmu);
+}
+
 static inline void smmu_pmu_counter_set_value(struct smmu_pmu *smmu_pmu,
 					      u32 idx, u64 value)
 {
@@ -765,7 +796,10 @@ static void smmu_pmu_get_acpi_options(struct smmu_pmu *smmu_pmu)
 	switch (model) {
 	case IORT_SMMU_V3_PMCG_HISI_HIP08:
 		/* HiSilicon Erratum 162001800 */
-		smmu_pmu->options |= SMMU_PMCG_EVCNTR_RDONLY;
+		smmu_pmu->options |= SMMU_PMCG_EVCNTR_RDONLY | SMMU_PMCG_HARDEN_DISABLE;
+		break;
+	case IORT_SMMU_V3_PMCG_HISI_HIP09:
+		smmu_pmu->options |= SMMU_PMCG_HARDEN_DISABLE;
 		break;
 	}
 
@@ -890,6 +924,16 @@ static int smmu_pmu_probe(struct platform_device *pdev)
 	if (!dev->of_node)
 		smmu_pmu_get_acpi_options(smmu_pmu);
 
+	/*
+	 * For platforms suffer this quirk, the PMU disable sometimes fails to
+	 * stop the counters. This will leads to inaccurate or error counting.
+	 * Forcibly disable the counters with these quirk handler.
+	 */
+	if (smmu_pmu->options & SMMU_PMCG_HARDEN_DISABLE) {
+		smmu_pmu->pmu.pmu_enable = smmu_pmu_enable_quirk_hip08_09;
+		smmu_pmu->pmu.pmu_disable = smmu_pmu_disable_quirk_hip08_09;
+	}
+
 	/* Pick one CPU to be the preferred one to use */
 	smmu_pmu->on_cpu = raw_smp_processor_id();
 	WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(smmu_pmu->on_cpu)));