Re: [PATCH] arm64: dts: renesas: r8a779f0: Add GICv3 ITS

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: magnus.damm@gmail.com, linux-renesas-soc@vger.kernel.org
Subject: Re: [PATCH] arm64: dts: renesas: r8a779f0: Add GICv3 ITS
Date: Wed, 14 Feb 2024 15:28:45 +0100	[thread overview]
Message-ID: <CAMuHMdXYKE+UjiJgdN3zQs-dKXrfBbkR1cMp1KYMuU=OPKL3Zw@mail.gmail.com> (raw)
In-Reply-To: <20240214052144.1966569-1-yoshihiro.shimoda.uh@renesas.com>

Hi Shimoda-san,

Thanks for your patch!

On Wed, Feb 14, 2024 at 6:21 AM Yoshihiro Shimoda
<yoshihiro.shimoda.uh@renesas.com> wrote:
> This SoC has GICv3 ITS and PCIe host mode on this SoC can use it.
> So, add GIC ITS node into GIC node and update interrupt-map in PCIe node.
>
> Note that PCIe nodes need msi-parent property to use the ITS for MSI.
> However, it requires PCIe driver's update. Especially, vendor-specific
> registers' setting is needed. So, this patch doesn't add msi-parent
> properties into PCIe nodes.
>
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

Is there any value in adding the GICv3 ITS node now, without msi-parent
properties pointing to it?
I.e. does applying this patch enable extra functionality yet?

> --- a/arch/arm64/boot/dts/renesas/r8a779f0.dtsi
> +++ b/arch/arm64/boot/dts/renesas/r8a779f0.dtsi
> @@ -1262,11 +1262,19 @@ ipmmu_mm: iommu@eefc0000 {
>                 gic: interrupt-controller@f1000000 {
>                         compatible = "arm,gic-v3";
>                         #interrupt-cells = <3>;
> -                       #address-cells = <0>;
> +                       #address-cells = <2>;
> +                       #size-cells = <2>;
> +                       ranges;
>                         interrupt-controller;
>                         reg = <0x0 0xf1000000 0 0x20000>,
>                               <0x0 0xf1060000 0 0x110000>;
>                         interrupts = <GIC_PPI 9 IRQ_TYPE_LEVEL_HIGH>;
> +
> +                       gic_its: msi-controller@f1040000 {
> +                               compatible = "arm,gic-v3-its";
> +                               reg = <0x0 0xf1040000 0 0x20000>;
> +                               msi-controller;

Missing "#msi-cells = <1>", which is a required property.

> +                       };
>                 };
>
>                 prr: chipid@fff00044 {

The rest LGTM.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds