diff options
| author | Nicolas Saenz Julienne <nsaenzjulienne@suse.de> | 2019-09-11 20:25:45 +0200 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2019-10-14 10:56:28 +0100 |
| commit | 1a8e1cef7603e218339ac63cb3178b25554524e5 (patch) | |
| tree | 99551151197c340df1954232793d142149717b72 /arch/arm64/Kconfig | |
| parent | a573cdd7973dedd87e62196c400332896bb236c8 (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')
| -rw-r--r-- | arch/arm64/Kconfig | 4 |
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 config GENERIC_CALIBRATE_DELAY 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 |