[PATCH] arm64: csum: cast to the proper type

* [PATCH] arm64: csum: cast to the proper type
@ 2021-03-15  1:26 ` Alex Elder
  0 siblings, 0 replies; 6+ messages in thread
From: Alex Elder @ 2021-03-15  1:26 UTC (permalink / raw)
  To: catalin.marinas, will, robin.murphy; +Cc: linux-arm-kernel, linux-kernel

The last line of ip_fast_csum() calls csum_fold(), forcing the
type of the argument passed to be u32.  But csum_fold() takes a
__wsum argument (which is __u32 __bitwise for arm64).  As long
as we're forcing the cast, cast it to the right type.

Signed-off-by: Alex Elder <elder@linaro.org>
---

With this patch in place, quite a few "different base types" sparse
warnings go away on a full arm64 kernel build.  More specifically:
  warning: incorrect type in argument 1 (different base types)
     expected restricted __wsum [usertype] csum
     got unsigned int [usertype]

					-Alex

 arch/arm64/include/asm/checksum.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/checksum.h b/arch/arm64/include/asm/checksum.h
index 93a161b3bf3fe..dc52b733675db 100644
--- a/arch/arm64/include/asm/checksum.h
+++ b/arch/arm64/include/asm/checksum.h
@@ -37,7 +37,7 @@ static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
 	} while (--n > 0);
 
 	sum += ((sum >> 32) | (sum << 32));
-	return csum_fold((__force u32)(sum >> 32));
+	return csum_fold((__force __wsum)(sum >> 32));
 }
 #define ip_fast_csum ip_fast_csum
 
-- 
2.27.0


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