X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=lib%2Fchecksum.c;h=62282bba0e51d0bb2983a1ec517f8eac4c3251bb;hp=8df2f91e6d98efff3b6c6c704a697a9cb9b31bfa;hb=f8c5af060edec5c5d8277b162a49cd53c780b247;hpb=bdc2209fd246820de2816691ac0e82600885e1a8

diff --git a/lib/checksum.c b/lib/checksum.c
index 8df2f91e6d98..62282bba0e51 100644
--- a/lib/checksum.c
+++ b/lib/checksum.c
@@ -179,6 +179,15 @@ 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,
@@ -193,8 +202,7 @@ __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