path: root/arch/arm64/Kconfig
diff options
authorNicolas Saenz Julienne <nsaenzjulienne@suse.de>2019-09-11 20:25:45 +0200
committerCatalin Marinas <catalin.marinas@arm.com>2019-10-14 10:56:28 +0100
commit1a8e1cef7603e218339ac63cb3178b25554524e5 (patch)
tree99551151197c340df1954232793d142149717b72 /arch/arm64/Kconfig
parentarm64: rename variables used to calculate ZONE_DMA32's size (diff)
arm64: use both ZONE_DMA and ZONE_DMA32
So far all arm64 devices have supported 32 bit DMA masks for their peripherals. This is not true anymore for the Raspberry Pi 4 as most of it's peripherals can only address the first GB of memory on a total of up to 4 GB. This goes against ZONE_DMA32's intent, as it's expected for ZONE_DMA32 to be addressable with a 32 bit mask. So it was decided to re-introduce ZONE_DMA in arm64. ZONE_DMA will contain the lower 1G of memory, which is currently the memory area addressable by any peripheral on an arm64 device. ZONE_DMA32 will contain the rest of the 32 bit addressable memory. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/Kconfig')
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 950a56b71ff0..1b6ea5a9d1a6 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -266,6 +266,10 @@ config GENERIC_CSUM
def_bool y
+config ZONE_DMA
+ bool "Support DMA zone" if EXPERT
+ default y
config ZONE_DMA32
bool "Support DMA32 zone" if EXPERT
default y