RE: [PATCH v3 1/4] perf: arm_cspmu: Split 64-bit write to 32-bit writes

[Ilkka Koskinen]

Hi Besar,

On Tue, 20 Jun 2023, Besar Wicaksono wrote:
> > -----Original Message-----
> > From: Ilkka Koskinen <ilkka@xxxxxxxxxxxxxxxxxxxxxx>
> > Sent: Wednesday, June 7, 2023 3:32 PM
> > To: Jonathan Corbet <corbet@xxxxxxx>; Will Deacon <will@xxxxxxxxxx>; Mark
> > Rutland <mark.rutland@xxxxxxx>; Besar Wicaksono
> > <bwicaksono@xxxxxxxxxx>; Suzuki K Poulose <suzuki.poulose@xxxxxxx>;
> > Robin Murphy <robin.murphy@xxxxxxx>
> > Cc: linux-doc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-arm-
> > kernel@xxxxxxxxxxxxxxxxxxx; Ilkka Koskinen <ilkka@xxxxxxxxxxxxxxxxxxxxxx>
> > Subject: [PATCH v3 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@xxxxxxxxxxxxxxxxxxxxxx>
> > ---
> >  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 a3f1c410b417..f8b4a149eb88 100644
> > --- a/drivers/perf/arm_cspmu/arm_cspmu.c
> > +++ b/drivers/perf/arm_cspmu/arm_cspmu.c
> > @@ -702,7 +702,10 @@ 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 (supports_64bit_atomics(cspmu))
>
> Looks good to me, but this function was recently replaced by
> arm_cspmu::has_atomic_dword. Please rebase the patch.

Sure, I do that.

Cheers, Ilkka

> Thanks,
> Besar
>
> > +                       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