Re: [PATCH 3/3] perf/arm_cspmu: Add PMEVFILT2R support

[James Clark <james.clark@linaro.org>]

On 05/03/2025 4:10 pm, Robin Murphy wrote:
> Architecturally we have two filters for each regular event counter,
> so add generic support for the second one too.
> 
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
>   drivers/perf/arm_cspmu/arm_cspmu.c | 7 +++++--
>   drivers/perf/arm_cspmu/arm_cspmu.h | 3 +++
>   2 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c b/drivers/perf/arm_cspmu/arm_cspmu.c
> index 053bb7920df6..efa9b229e701 100644
> --- a/drivers/perf/arm_cspmu/arm_cspmu.c
> +++ b/drivers/perf/arm_cspmu/arm_cspmu.c
> @@ -183,6 +183,7 @@ arm_cspmu_event_attr_is_visible(struct kobject *kobj,
>   static struct attribute *arm_cspmu_format_attrs[] = {
>   	ARM_CSPMU_FORMAT_EVENT_ATTR,
>   	ARM_CSPMU_FORMAT_FILTER_ATTR,
> +	ARM_CSPMU_FORMAT_FILTER2_ATTR,
>   	NULL,
>   };
>   
> @@ -767,9 +768,11 @@ static void arm_cspmu_set_ev_filter(struct arm_cspmu *cspmu,
>   				    const struct perf_event *event)
>   {
>   	u32 filter = event->attr.config1 & ARM_CSPMU_FILTER_MASK;
> -	u32 offset = PMEVFILTR + (4 * hwc->idx);
> +	u32 filter2 = event->attr.config2 & ARM_CSPMU_FILTER_MASK;
> +	u32 offset = 4 * event->hw.idx;
>   
> -	writel(filter, cspmu->base0 + offset);
> +	writel(filter, cspmu->base0 + PMEVFILTR + offset);
> +	writel(filter2, cspmu->base0 + PMEVFILT2R + offset);
>   }
>   
>   static void arm_cspmu_set_cc_filter(struct arm_cspmu *cspmu,
> diff --git a/drivers/perf/arm_cspmu/arm_cspmu.h b/drivers/perf/arm_cspmu/arm_cspmu.h
> index d59040d6a7e3..19684b76bd96 100644
> --- a/drivers/perf/arm_cspmu/arm_cspmu.h
> +++ b/drivers/perf/arm_cspmu/arm_cspmu.h
> @@ -47,6 +47,8 @@
>   /* Default filter format */
>   #define ARM_CSPMU_FORMAT_FILTER_ATTR	\
>   	ARM_CSPMU_FORMAT_ATTR(filter, "config1:0-31")
> +#define ARM_CSPMU_FORMAT_FILTER2_ATTR	\
> +	ARM_CSPMU_FORMAT_ATTR(filter2, "config2:0-31")
>   
>   /*
>    * This is the default event number for cycle count, if supported, since the
> @@ -72,6 +74,7 @@
>   #define PMEVCNTR_HI			0x4
>   #define PMEVTYPER			0x400
>   #define PMCCFILTR			0x47C
> +#define PMEVFILT2R			0x800
>   #define PMEVFILTR			0xA00
>   #define PMCNTENSET			0xC00
>   #define PMCNTENCLR			0xC20

Reviewed-by: James Clark <james.clark@linaro.org>

Minor comment that the doc linked at the beginning of the file "ARM IHI 
0091 A.a-00bet0" doesn't have PMEVFILT2R, you need the latest version 
for that.