Re: [PATCH v3 1/2] ARM: dts: bcm2711: force CMA into first GB of memory

From: Catalin Marinas
Date: Thu Nov 07 2019 - 06:20:26 EST


Hi Nicolas,

On Thu, Nov 07, 2019 at 10:56:10AM +0100, Nicolas Saenz Julienne wrote:
> diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi
> index ac83dac2e6ba..667658497898 100644
> --- a/arch/arm/boot/dts/bcm2711.dtsi
> +++ b/arch/arm/boot/dts/bcm2711.dtsi
> @@ -12,6 +12,26 @@
>
> interrupt-parent = <&gicv2>;
>
> + reserved-memory {
> + #address-cells = <2>;
> + #size-cells = <1>;
> + ranges;
> +
> + /*
> + * arm64 reserves the CMA by default somewhere in ZONE_DMA32,
> + * that's not good enough for bcm2711 as some devices can
> + * only address the lower 1G of memory (ZONE_DMA).
> + */
> + linux,cma {
> + compatible = "shared-dma-pool";
> + size = <0x2000000>; /* 32MB */
> + alloc-ranges = <0x0 0x00000000 0x40000000>;
> + reusable;
> + linux,cma-default;
> + };
> + };
> +
> +
> soc {
> /*
> * Defined ranges:

Sorry, I just realised I can't merge this as it depends on a patch
that's only in -next: 7dbe8c62ceeb ("ARM: dts: Add minimal Raspberry Pi
4 support").

I'll queue the second patch in the series to fix the regression
introduces by the ZONE_DMA patches and, AFAICT, the dts update can be
queued independently.

--
Catalin