target/linux/bcm27xx/patches-4.19/950-0616-arm64-mm-Limit-the-DMA-zone-for-arm64.patch

   1 From 2722f08c4c59901bd506184e2dcbbbd532aef0b3 Mon Sep 17 00:00:00 2001
   2 From: Andrei Gherzan <andrei@balena.io>
   3 Date: Tue, 16 Jul 2019 13:28:22 +0100
   4 Subject: [PATCH] arm64/mm: Limit the DMA zone for arm64
   5
   6 On RaspberryPi, only the first 1Gb can be used for DMA[1].
   7
   8 [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2019-July/665986.html
   9
  10 Signed-off-by: Andrei Gherzan <andrei@balena.io>
  11 ---
  12  arch/arm64/mm/init.c | 2 +-
  13  1 file changed, 1 insertion(+), 1 deletion(-)
  14
  15 --- a/arch/arm64/mm/init.c
  16 +++ b/arch/arm64/mm/init.c
  17 @@ -224,7 +224,7 @@ static void __init reserve_elfcorehdr(vo
  18  static phys_addr_t __init max_zone_dma_phys(void)
  19  {
  20         phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
  21 -       return min(offset + (1ULL << 32), memblock_end_of_DRAM());
  22 +       return min(offset + (1ULL << 30), memblock_end_of_DRAM());
  23  }
  24
  25  #ifdef CONFIG_NUMA