[PATCH 1/4] perf: arm_cspmu: Split 64-bit write to 32-bit writes

[Besar Wicaksono]

> -----Original Message-----
> From: Ilkka Koskinen <ilkka at os.amperecomputing.com>
> Sent: Thursday, June 22, 2023 8:12 AM
> To: Will Deacon <will at kernel.org>; Robin Murphy <robin.murphy at arm.com>;
> Besar Wicaksono <bwicaksono at nvidia.com>; Suzuki K Poulose
> <suzuki.poulose at arm.com>; Mark Rutland <mark.rutland at arm.com>
> Cc: Ilkka Koskinen <ilkka at os.amperecomputing.com>; linux-arm-
> kernel at lists.infradead.org; linux-kernel at vger.kernel.org
> Subject: [PATCH 1/4] perf: arm_cspmu: Split 64-bit write to 32-bit writes
> 
> External email: Use caution opening links or attachments
> 
> 
> Split the 64-bit register accesses if 64-bit access is not supported
> by the PMU.
> 
> Signed-off-by: Ilkka Koskinen <ilkka at os.amperecomputing.com>

Reviewed-by: Besar Wicaksono <bwicaksono at nvidia.com>

Thanks,
Besar

> ---
>  drivers/perf/arm_cspmu/arm_cspmu.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c
> b/drivers/perf/arm_cspmu/arm_cspmu.c
> index e2b7827c4563..0f517152cb4e 100644
> --- a/drivers/perf/arm_cspmu/arm_cspmu.c
> +++ b/drivers/perf/arm_cspmu/arm_cspmu.c
> @@ -696,7 +696,10 @@ static void arm_cspmu_write_counter(struct
> perf_event *event, u64 val)
>         if (use_64b_counter_reg(cspmu)) {
>                 offset = counter_offset(sizeof(u64), event->hw.idx);
> 
> -               writeq(val, cspmu->base1 + offset);
> +               if (cspmu->has_atomic_dword)
> +                       writeq(val, cspmu->base1 + offset);
> +               else
> +                       lo_hi_writeq(val, cspmu->base1 + offset);
>         } else {
>                 offset = counter_offset(sizeof(u32), event->hw.idx);
> 
> --
> 2.40.1