From 4bcb99a967998d255ef009bb0b6880ae99c6f6bf Mon Sep 17 00:00:00 2001 From: Nicolas Saenz Julienne Date: Wed, 6 Nov 2019 10:59:44 +0100 Subject: [PATCH] ARM: dts: bcm2711: force CMA into first GB of memory arm64 places the CMA in ZONE_DMA32, which is not good enough for the Raspberry Pi 4 since it contains peripherals that can only address the first GB of memory. Explicitly place the CMA into that area. Signed-off-by: Nicolas Saenz Julienne Acked-by: Stefan Wahren Signed-off-by: Florian Fainelli --- arch/arm/boot/dts/bcm2711.dtsi | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) --- 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 the 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: