[PATCH] powerpc/perf: fix Threshold Event CounterMultiplier width for P10

[Michal Suchánek]

Hello,

On Mon, Oct 12, 2020 at 04:01:28PM +0530, Madhavan Srinivasan wrote:
> Power9 and isa v3.1 has 7bit mantissa field for Threshold Event Counter
                  ^^^ Shouldn't his be 3.0?

> Multiplier (TECM). TECM is part of Monitor Mode Control Register A (MMCRA).
> This field along with Threshold Event Counter Exponent (TECE) is used to
> get threshould counter value. In Power10, the width of TECM field is
> increase to 8bits. Patch fixes the current code to modify the MMCRA[TECM]
> extraction macro to handling this changes.
> 
> Fixes: 170a315f41c64 ('powerpc/perf: Support to export MMCRA[TEC*] field to userspace')
> Signed-off-by: Madhavan Srinivasan <maddy at linux.ibm.com>
> ---
>  arch/powerpc/perf/isa207-common.c | 3 +++
>  arch/powerpc/perf/isa207-common.h | 4 ++++
>  2 files changed, 7 insertions(+)
> 
> diff --git a/arch/powerpc/perf/isa207-common.c b/arch/powerpc/perf/isa207-common.c
> index 964437adec18..5fe129f02290 100644
> --- a/arch/powerpc/perf/isa207-common.c
> +++ b/arch/powerpc/perf/isa207-common.c
> @@ -247,6 +247,9 @@ void isa207_get_mem_weight(u64 *weight)
>  	u64 sier = mfspr(SPRN_SIER);
>  	u64 val = (sier & ISA207_SIER_TYPE_MASK) >> ISA207_SIER_TYPE_SHIFT;
>  
> +	if (cpu_has_feature(CPU_FTR_ARCH_31))
> +		mantissa = P10_MMCRA_THR_CTR_MANT(mmcra);
> +
>  	if (val == 0 || val == 7)
>  		*weight = 0;
>  	else
> diff --git a/arch/powerpc/perf/isa207-common.h b/arch/powerpc/perf/isa207-common.h
> index 044de65e96b9..71380e854f48 100644
> --- a/arch/powerpc/perf/isa207-common.h
> +++ b/arch/powerpc/perf/isa207-common.h
> @@ -219,6 +219,10 @@
>  #define MMCRA_THR_CTR_EXP(v)		(((v) >> MMCRA_THR_CTR_EXP_SHIFT) &\
>  						MMCRA_THR_CTR_EXP_MASK)
>  
> +#define P10_MMCRA_THR_CTR_MANT_MASK	0xFFul
> +#define P10_MMCRA_THR_CTR_MANT(v)	(((v) >> MMCRA_THR_CTR_MANT_SHIFT) &\
> +						P10_MMCRA_THR_CTR_MANT_MASK)
> +
>  /* MMCRA Threshold Compare bit constant for power9 */
>  #define p9_MMCRA_THR_CMP_SHIFT	45
>  
> -- 
> 2.26.2
>