arm64: mm: Fix unused variable warning in zone_sizes_init

When building arm64 allnoconfig, CONFIG_ZONE_DMA and CONFIG_ZONE_DMA32
get disabled so there is a warning about max_dma being unused.

../arch/arm64/mm/init.c:215:16: warning: unused variable 'max_dma'
[-Wunused-variable]
        unsigned long max_dma = min;
                      ^
1 warning generated.

Add __maybe_unused to make this clear to the compiler.

Fixes: 1a8e1cef7603 ("arm64: use both ZONE_DMA and ZONE_DMA32")
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 44f07fdf7a596d76ed7685c58624a78bf6e0529e..71b45c58218b8bac7677bfcc43dd5e53cd3df150 100644 (file)
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -212,7 +212,7 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
        struct memblock_region *reg;
        unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
        unsigned long max_dma32 = min;
-       unsigned long max_dma = min;
+       unsigned long __maybe_unused max_dma = min;
 
        memset(zone_size, 0, sizeof(zone_size));