Re: [PATCH 3/5] perf/arm_cspmu: Add pmpidr support

[Ilkka Koskinen]

On Tue, 12 Aug 2025, Besar Wicaksono wrote:

> The PMIIDR value is composed by the values in PMPIDR registers.
> We can use PMPIDR registers as alternative for device
> identification for systems that do not implement PMIIDR.
>
> Signed-off-by: Besar Wicaksono <bwicaksono@xxxxxxxxxx>

Looks good to me

Reviewed-by: Ilkka Koskinen <ilkka@xxxxxxxxxxxxxxxxxxxxxx>

> ---
> drivers/perf/arm_cspmu/arm_cspmu.c    | 44 +++++++++++++++++++++++++--
> drivers/perf/arm_cspmu/arm_cspmu.h    | 35 +++++++++++++++++++--
> drivers/perf/arm_cspmu/nvidia_cspmu.c |  2 +-
> 3 files changed, 75 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c b/drivers/perf/arm_cspmu/arm_cspmu.c
> index 595e4bdd0b4b..347aefbd1704 100644
> --- a/drivers/perf/arm_cspmu/arm_cspmu.c
> +++ b/drivers/perf/arm_cspmu/arm_cspmu.c
> @@ -323,14 +323,14 @@ static struct arm_cspmu_impl_match impl_match[] = {
> 	{
> 		.module_name	= "nvidia_cspmu",
> 		.pmiidr_val	= ARM_CSPMU_IMPL_ID_NVIDIA,
> -		.pmiidr_mask	= ARM_CSPMU_PMIIDR_IMPLEMENTER,
> +		.pmiidr_mask	= PMIIDR_IMPLEMENTER,
> 		.module		= NULL,
> 		.impl_init_ops	= NULL,
> 	},
> 	{
> 		.module_name	= "ampere_cspmu",
> 		.pmiidr_val	= ARM_CSPMU_IMPL_ID_AMPERE,
> -		.pmiidr_mask	= ARM_CSPMU_PMIIDR_IMPLEMENTER,
> +		.pmiidr_mask	= PMIIDR_IMPLEMENTER,
> 		.module		= NULL,
> 		.impl_init_ops	= NULL,
> 	},
> @@ -352,6 +352,44 @@ static struct arm_cspmu_impl_match *arm_cspmu_impl_match_get(u32 pmiidr)
> 	return NULL;
> }
>
> +static u32 arm_cspmu_get_pmiidr(struct arm_cspmu *cspmu)
> +{
> +	u32 pmiidr, pmpidr;
> +
> +	pmiidr = readl(cspmu->base0 + PMIIDR);
> +
> +	if (pmiidr != 0)
> +		return pmiidr;
> +
> +	/* Construct PMIIDR value from PMPIDRs. */
> +
> +	pmpidr = readl(cspmu->base0 + PMPIDR0);
> +	pmiidr |= FIELD_PREP(PMIIDR_PRODUCTID_PART_0,
> +				FIELD_GET(PMPIDR0_PART_0, pmpidr));
> +
> +	pmpidr = readl(cspmu->base0 + PMPIDR1);
> +	pmiidr |= FIELD_PREP(PMIIDR_PRODUCTID_PART_1,
> +				FIELD_GET(PMPIDR1_PART_1, pmpidr));
> +	pmiidr |= FIELD_PREP(PMIIDR_IMPLEMENTER_DES_0,
> +				FIELD_GET(PMPIDR1_DES_0, pmpidr));
> +
> +	pmpidr = readl(cspmu->base0 + PMPIDR2);
> +	pmiidr |= FIELD_PREP(PMIIDR_VARIANT,
> +				FIELD_GET(PMPIDR2_REVISION, pmpidr));
> +	pmiidr |= FIELD_PREP(PMIIDR_IMPLEMENTER_DES_1,
> +				FIELD_GET(PMPIDR2_DES_1, pmpidr));
> +
> +	pmpidr = readl(cspmu->base0 + PMPIDR3);
> +	pmiidr |= FIELD_PREP(PMIIDR_REVISION,
> +				FIELD_GET(PMPIDR3_REVAND, pmpidr));
> +
> +	pmpidr = readl(cspmu->base0 + PMPIDR4);
> +	pmiidr |= FIELD_PREP(PMIIDR_IMPLEMENTER_DES_2,
> +				FIELD_GET(PMPIDR4_DES_2, pmpidr));
> +
> +	return pmiidr;
> +}
> +
> #define DEFAULT_IMPL_OP(name)	.name = arm_cspmu_##name
>
> static int arm_cspmu_init_impl_ops(struct arm_cspmu *cspmu)
> @@ -362,7 +400,7 @@ static int arm_cspmu_init_impl_ops(struct arm_cspmu *cspmu)
>
> 	/* Start with a default PMU implementation */
> 	cspmu->impl.module = THIS_MODULE;
> -	cspmu->impl.pmiidr = readl(cspmu->base0 + PMIIDR);
> +	cspmu->impl.pmiidr = arm_cspmu_get_pmiidr(cspmu);
> 	cspmu->impl.ops = (struct arm_cspmu_impl_ops) {
> 		DEFAULT_IMPL_OP(get_event_attrs),
> 		DEFAULT_IMPL_OP(get_format_attrs),
> diff --git a/drivers/perf/arm_cspmu/arm_cspmu.h b/drivers/perf/arm_cspmu/arm_cspmu.h
> index e3a4dd068805..7eb150abc3b7 100644
> --- a/drivers/perf/arm_cspmu/arm_cspmu.h
> +++ b/drivers/perf/arm_cspmu/arm_cspmu.h
> @@ -87,6 +87,11 @@
> #define PMCFGR				0xE00
> #define PMCR				0xE04
> #define PMIIDR				0xE08
> +#define PMPIDR0				0xFE0
> +#define PMPIDR1				0xFE4
> +#define PMPIDR2				0xFE8
> +#define PMPIDR3				0xFEC
> +#define PMPIDR4				0xFD0
>
> /* PMCFGR register field */
> #define PMCFGR_NCG			GENMASK(31, 28)
> @@ -116,8 +121,34 @@
> #define PMCR_E				BIT(0)
>
> /* PMIIDR register field */
> -#define ARM_CSPMU_PMIIDR_IMPLEMENTER	GENMASK(11, 0)
> -#define ARM_CSPMU_PMIIDR_PRODUCTID	GENMASK(31, 20)
> +#define PMIIDR_IMPLEMENTER		GENMASK(11, 0)
> +#define PMIIDR_IMPLEMENTER_DES_0	GENMASK(3, 0)
> +#define PMIIDR_IMPLEMENTER_DES_1	GENMASK(6, 4)
> +#define PMIIDR_IMPLEMENTER_DES_2	GENMASK(11, 8)
> +#define PMIIDR_REVISION			GENMASK(15, 12)
> +#define PMIIDR_VARIANT			GENMASK(19, 16)
> +#define PMIIDR_PRODUCTID		GENMASK(31, 20)
> +#define PMIIDR_PRODUCTID_PART_0		GENMASK(27, 20)
> +#define PMIIDR_PRODUCTID_PART_1		GENMASK(31, 28)
> +
> +/* PMPIDR0 register field */
> +#define PMPIDR0_PART_0			GENMASK(7, 0)
> +
> +/* PMPIDR1 register field */
> +#define PMPIDR1_DES_0			GENMASK(7, 4)
> +#define PMPIDR1_PART_1			GENMASK(3, 0)
> +
> +/* PMPIDR2 register field */
> +#define PMPIDR2_REVISION		GENMASK(7, 4)
> +#define PMPIDR2_DES_1			GENMASK(2, 0)
> +
> +/* PMPIDR3 register field */
> +#define PMPIDR3_REVAND			GENMASK(7, 4)
> +#define PMPIDR3_CMOD			GENMASK(3, 0)
> +
> +/* PMPIDR4 register field */
> +#define PMPIDR4_SIZE			GENMASK(7, 4)
> +#define PMPIDR4_DES_2			GENMASK(3, 0)
>
> /* JEDEC-assigned JEP106 identification code */
> #define ARM_CSPMU_IMPL_ID_NVIDIA	0x36B
> diff --git a/drivers/perf/arm_cspmu/nvidia_cspmu.c b/drivers/perf/arm_cspmu/nvidia_cspmu.c
> index dc6d4e3e2a1b..b6cec351a142 100644
> --- a/drivers/perf/arm_cspmu/nvidia_cspmu.c
> +++ b/drivers/perf/arm_cspmu/nvidia_cspmu.c
> @@ -322,7 +322,7 @@ static int nv_cspmu_init_ops(struct arm_cspmu *cspmu)
> 	if (!ctx)
> 		return -ENOMEM;
>
> -	prodid = FIELD_GET(ARM_CSPMU_PMIIDR_PRODUCTID, cspmu->impl.pmiidr);
> +	prodid = FIELD_GET(PMIIDR_PRODUCTID, cspmu->impl.pmiidr);
>
> 	/* Find matching PMU. */
> 	for (; match->prodid; match++) {
> --
> 2.47.0