riscv: only enable ZONE_DMA32 for 64-bit

Until we actually support > 32bit physical addresses for 32-bit using
highmem there is no point in enabling ZONE_DMA32.  And even if such
support is ever added it probably should be conditional to not burden
low end embedded devices.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 7817bbe0cfacf90d31e7e96f8e8e25d0e565de3d..c4488ce8c2fa4c98c985c1e18db2c1b05a16dc01 100644 (file)
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -48,7 +48,7 @@ config MMU
 
 config ZONE_DMA32
        bool
-       default y
+       default y if 64BIT
 
 config PAGE_OFFSET
        hex