From: Christoph Hellwig <hch@lst.de>
Date: Fri, 27 Apr 2018 06:41:09 +0000 (+0200)
Subject: riscv: only enable ZONE_DMA32 for 64-bit
X-Git-Tag: v4.18-rc1~187^2~19
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f1306f0423ec02a1da31bab34006323fcadf2e06;p=thirdparty%2Fkernel%2Fstable.git

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 7817bbe0cfacf..c4488ce8c2fa4 100644
--- 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