Re: [PATCH v2] add pmu to amlogic meson sm1

[Robin Murphy]

On 2022-02-07 08:14, Neil Armstrong wrote:
> Hi,
>
> On 06/02/2022 15:43, Benjamin Mordaunt wrote:
> > ---
> > The dts for meson sm1 appears to omit the SoC's PMU,
> > which is essential for accessing perf events regarding
> > e.g. cache on e.g. the Odroid C4 platform. Add it.
> >
> >   arch/arm64/boot/dts/amlogic/meson-sm1.dtsi | 13 ++++++++++++-
> >   1 file changed, 12 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi 
> > b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
> > index 3d8b1f4f2..4147eecd2 100644
> > --- a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
> > +++ b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
> > @@ -6,6 +6,8 @@
> >   #include "meson-g12-common.dtsi"
> >   #include <dt-bindings/clock/axg-audio-clkc.h>
> > +#include <dt-bindings/interrupt-controller/irq.h>
> > +#include <dt-bindings/interrupt-controller/arm-gic.h>
> >   #include <dt-bindings/power/meson-sm1-power.h>
> >   #include <dt-bindings/reset/amlogic,meson-axg-audio-arb.h>
> >   #include <dt-bindings/reset/amlogic,meson-g12a-audio-reset.h>
> > @@ -90,7 +92,16 @@ l2: l2-cache0 {
> >               compatible = "cache";
> >           };
> >       };
> > -
> > +
> > +    arm-pmu {
> > +        compatible = "arm,cortex-a55-pmu";
> > +        interrupts = <GIC_SPI 137 IRQ_TYPE_LEVEL_HIGH>,
> > +                 <GIC_SPI 138 IRQ_TYPE_LEVEL_HIGH>,
> > +                 <GIC_SPI 153 IRQ_TYPE_LEVEL_HIGH>,
> > +                 <GIC_SPI 154 IRQ_TYPE_LEVEL_HIGH>;
> > +        interrupt-affinity = <&cpu0>, <&cpu1>, <&cpu2>, <&cpu3>;
> > +    };
> > +
> >       cpu_opp_table: opp-table {
> >           compatible = "operating-points-v2";
> >           opp-shared;
>
> Please see Marc's comments about PMU support:
> http://lore.kernel.org/r/8735pcq63o.wl-maz@xxxxxxxxxx

If SM1 actually has distinct per-core interrupts as the patch implies 
then it's fine - it's only G12B and anything else that combines multiple 
PMU IRQs into a single SPI which are unsupportable.

Robin.