[PATCH v3 2/2] arm64: mm: reserve CMA and crashkernel in ZONE_DMA32

From: Nicolas Saenz Julienne
Date: Thu Nov 07 2019 - 04:56:26 EST


With the introduction of ZONE_DMA in arm64 we moved the default CMA and
crashkernel reservation into that area. This caused a regression on big
machines that need big CMA and crashkernel reservations. Note that
ZONE_DMA is only 1GB big.

Restore the previous behavior as the wide majority of devices are OK
with reserving these in ZONE_DMA32. The ones that need them in ZONE_DMA
will configure it explicitly.

Reported-by: Qian Cai <cai@xxxxxx>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
---
arch/arm64/mm/init.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 580d1052ac34..8385d3c0733f 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -88,7 +88,7 @@ static void __init reserve_crashkernel(void)

if (crash_base == 0) {
/* Current arm64 boot protocol requires 2MB alignment */
- crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT,
+ crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit,
crash_size, SZ_2M);
if (crash_base == 0) {
pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
@@ -454,7 +454,7 @@ void __init arm64_memblock_init(void)

high_memory = __va(memblock_end_of_DRAM() - 1) + 1;

- dma_contiguous_reserve(arm64_dma_phys_limit ? : arm64_dma32_phys_limit);
+ dma_contiguous_reserve(arm64_dma32_phys_limit);
}

void __init bootmem_init(void)
--
2.23.0