Re: [PATCH] perf/smmuv3: Enable HiSilicon Erratum 162001900 quirk for HIP08/09

[Will Deacon <will@kernel.org>]

On Wed, Aug 09, 2023 at 06:06:54PM +0800, Yicong Yang wrote:
> diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c
> index 25a269d431e4..b854b67b81fc 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;
>  
> @@ -150,6 +151,22 @@ SMMU_PMU_EVENT_ATTR_EXTRACTOR(filter_stream_id, config1, 0, 31);
>  SMMU_PMU_EVENT_ATTR_EXTRACTOR(filter_span, config1, 32, 32);
>  SMMU_PMU_EVENT_ATTR_EXTRACTOR(filter_enable, config1, 33, 33);
>  
> +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);
> +
> +	writel(SMMU_PMCG_IRQ_CTRL_IRQEN,
> +	       smmu_pmu->reg_base + SMMU_PMCG_IRQ_CTRL);
> +	writel(SMMU_PMCG_CR_ENABLE, smmu_pmu->reg_base + SMMU_PMCG_CR);

Can you tail-call smmu_pmu_enable() instead of duplicating it here?

> +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));
> +
> +	writel(0, smmu_pmu->reg_base + SMMU_PMCG_CR);
> +	writel(0, smmu_pmu->reg_base + SMMU_PMCG_IRQ_CTRL);

Same things here, but with smmu_pmu_disable()

Will