Re: [PATCH] arm64: dts: renesas: r8a779h0: Add GICv3 ITS and update PCIe node

[Geert Uytterhoeven]

Hi Marek,

On Sun, 6 Sept 2026 at 16:01, Marek Vasut
<marek.vasut+renesas@xxxxxxxxxxx> wrote:
> This SoC implements GIC600 with GICv3 ITS and PCIe host mode on this
> SoC can use it. Add GIC ITS node into GIC node, update interrupt-map
> and add msi-map into PCIe controller node.
>
> The GIC ITS does have master interface to issue transactions to RAM.
> The interface does support cacheable transactions, however, it does
> not support shareable attribute, because the AXI port signals are tied
> to inactive in this implementation. Therefore, add "dma-noncoherent"
> DT property into the GIC ITS subnode.
>
> The GIC redistributor does not have cacheable/shareable, therefore
> add "dma-noncoherent" DT property into the GIC node.
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxxxx>

Thanks for your patch!

As I am not PCIe DT expert, I am comparing this to the corresponding
patch for R-Car V4H, which I have already queued as commit
7fe73a3a3f2c3718 ("arm64: dts: renesas: r8a779g0: Add GICv3 ITS and
update PCIe nodes") in renesas-devel, but which probably needs some
updates.

> --- a/arch/arm64/boot/dts/renesas/r8a779h0.dtsi
> +++ b/arch/arm64/boot/dts/renesas/r8a779h0.dtsi
> @@ -691,6 +691,8 @@ pciec0: pcie@e65d0000 {
>                         resets = <&cpg 624>, <&cpg 1121>;
>                         reset-names = "pwr", "core";
>                         max-link-speed = <4>;
> +                       msi-parent = <&its 0>;

This has an extra cell "0", which is probably correct, given
"#msi-cells = <1>" below.

> +                       msi-map = <0x0 &its 0x0 0x10000>;

This is not present on R-Car V4H (which is probably wrong).

Interestingly, Documentation/devicetree/bindings/pci/pci-ep.yaml
documents msi-map for endpoint node, so should it be added to the
pcie-ep node, too?

>                         num-lanes = <2>;
>                         #address-cells = <3>;
>                         #size-cells = <2>;

Gr{oetje,eeting}s,

                        Geert


--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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