target/linux/bcm27xx/patches-5.4/950-0420-ARM-dts-bcm2711-force-CMA-into-first-GB-of-memory.patch

   1 From 4bcb99a967998d255ef009bb0b6880ae99c6f6bf Mon Sep 17 00:00:00 2001
   2 From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
   3 Date: Wed, 6 Nov 2019 10:59:44 +0100
   4 Subject: [PATCH] ARM: dts: bcm2711: force CMA into first GB of memory
   5
   6 arm64 places the CMA in ZONE_DMA32, which is not good enough for the
   7 Raspberry Pi 4 since it contains peripherals that can only address the
   8 first GB of memory. Explicitly place the CMA into that area.
   9
  10 Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
  11 Acked-by: Stefan Wahren <wahrenst@gmx.net>
  12 Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
  13 ---
  14  arch/arm/boot/dts/bcm2711.dtsi | 20 ++++++++++++++++++++
  15  1 file changed, 20 insertions(+)
  16
  17 --- a/arch/arm/boot/dts/bcm2711.dtsi
  18 +++ b/arch/arm/boot/dts/bcm2711.dtsi
  19 @@ -12,6 +12,26 @@
  20
  21         interrupt-parent = <&gicv2>;
  22
  23 +       reserved-memory {
  24 +               #address-cells = <2>;
  25 +               #size-cells = <1>;
  26 +               ranges;
  27 +
  28 +               /*
  29 +                * arm64 reserves the CMA by default somewhere in ZONE_DMA32,
  30 +                * that's not good enough for the BCM2711 as some devices can
  31 +                * only address the lower 1G of memory (ZONE_DMA).
  32 +                */
  33 +               linux,cma {
  34 +                       compatible = "shared-dma-pool";
  35 +                       size = <0x2000000>; /* 32MB */
  36 +                       alloc-ranges = <0x0 0x00000000 0x40000000>;
  37 +                       reusable;
  38 +                       linux,cma-default;
  39 +               };
  40 +       };
  41 +
  42 +
  43         soc {
  44                 /*
  45                  * Defined ranges: