RE: [PATCH] arm64: dts: renesas: r9a07g044: Add Cortex-A55 PMU node

From: Biju Das <biju.das.jz@bp.renesas.com>
To: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>,
	Magnus Damm <magnus.damm@gmail.com>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	"linux-renesas-soc@vger.kernel.org" 
	<linux-renesas-soc@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>
Subject: RE: [PATCH] arm64: dts: renesas: r9a07g044: Add Cortex-A55 PMU node
Date: Fri, 27 Jan 2023 21:48:04 +0000	[thread overview]
Message-ID: <OS0PR01MB5922943C1E1D9329691DB02F86CC9@OS0PR01MB5922.jpnprd01.prod.outlook.com> (raw)
In-Reply-To: <CA+V-a8s+cZpuUXWRa573a373n7YPsHrdLnUVXHjez6O101oneQ@mail.gmail.com>

Hi Prabhakar,

> Subject: Re: [PATCH] arm64: dts: renesas: r9a07g044: Add Cortex-A55 PMU node
> 
> Hi Biju,
> 
> Thank you for the review.
> 
> On Fri, Jan 27, 2023 at 6:38 PM Biju Das <biju.das.jz@bp.renesas.com> wrote:
> >
> > Hi Prabhakar,
> >
> > Thanks for the patch.
> >
> > > Subject: [PATCH] arm64: dts: renesas: r9a07g044: Add Cortex-A55 PMU
> > > node
> > >
> > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > >
> > > Enable the performance monitor unit for the Cortex-A55 cores on the
> > > RZ/G2L
> > > (r9a07g044) SoC.
> > >
> > > Signed-off-by: Lad Prabhakar
> > > <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > ---
> > >  arch/arm64/boot/dts/renesas/r9a07g044.dtsi | 5 +++++
> > >  1 file changed, 5 insertions(+)
> > >
> > > diff --git a/arch/arm64/boot/dts/renesas/r9a07g044.dtsi
> > > b/arch/arm64/boot/dts/renesas/r9a07g044.dtsi
> > > index 80b2332798d9..ff9bdc03a3ed 100644
> > > --- a/arch/arm64/boot/dts/renesas/r9a07g044.dtsi
> > > +++ b/arch/arm64/boot/dts/renesas/r9a07g044.dtsi
> > > @@ -161,6 +161,11 @@ opp-50000000 {
> > >               };
> > >       };
> > >
> > > +     pmu_a55 {
> > > +             compatible = "arm,cortex-a55-pmu";
> > > +             interrupts-extended = <&gic GIC_PPI 7
> > > + IRQ_TYPE_LEVEL_HIGH>;
> >
> > Just a question, Is it tested?
> Yes this was tested with perf test
> 
> > timer node[1] defines irq type as LOW, here it is high.
> You are right looking at the RZG2L_InterruptMapping_rev01.xlsx this should
> be LOW. (I followed the SPI IRQS where all the LEVEL interrupts are HIGH)
> 
> > Also do we need to define (GIC_CPU_MASK_SIMPLE(2) | IRQ_TYPE_LEVEL_LOW) as
> it has 2 cores??
> >
> No this is not required for example here [0] where it has 6 cores.

I may be wrong, That is the only example[1], where the A55 PMU per cpu interrupts and number of a55 cores in the DT 
are not matching.

[1]
https://elixir.bootlin.com/linux/latest/B/ident/arm%2Ccortex-a55-pmu

Cheers,
Biju