X-Git-Url: http://git.cascardo.eti.br/?a=blobdiff_plain;f=lib%2Fchecksum.c;h=8b39e86dbab5ea2a1afad17f6a15368f846916d6;hb=e08400b707739f0eca1645413924743466ea70b8;hp=129775eb6de63a6155cea830df17b6c2476eb024;hpb=831bbbeb2b0341a82a464896be49493c104d78f0;p=cascardo%2Flinux.git

diff --git a/lib/checksum.c b/lib/checksum.c
index 129775eb6de6..8b39e86dbab5 100644
--- a/lib/checksum.c
+++ b/lib/checksum.c
@@ -181,6 +181,15 @@ csum_partial_copy(const void *src, void *dst, int len, __wsum sum)
 EXPORT_SYMBOL(csum_partial_copy);
 
 #ifndef csum_tcpudp_nofold
+static inline u32 from64to32(u64 x)
+{
+	/* add up 32-bit and 32-bit for 32+c bit */
+	x = (x & 0xffffffff) + (x >> 32);
+	/* add up carry.. */
+	x = (x & 0xffffffff) + (x >> 32);
+	return (u32)x;
+}
+
 __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
 			unsigned short len,
 			unsigned short proto,
@@ -195,8 +204,7 @@ __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
 #else
 	s += (proto + len) << 8;
 #endif
-	s += (s >> 32);
-	return (__force __wsum)s;
+	return (__force __wsum)from64to32(s);
 }
 EXPORT_SYMBOL(csum_tcpudp_nofold);
 #endif