11  * and adds in "sum" (32-bit)
21 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
25  * sum: 32bit unfolded sum
31 static inline __sum16 csum_fold(__wsum sum)  in csum_fold()  argument
36 		: "=r" (sum)  in csum_fold()
37 		: "r" ((__force u32)sum << 16),  in csum_fold()
38 		  "0" ((__force u32)sum & 0xffff0000)  in csum_fold()
40 	return (__force __sum16)(~(__force u32)sum >> 16);  in csum_fold()
49  * @sum: initial sum to be added in (32bit unfolded)
56 		  __u8 proto, __wsum sum)  in csum_tcpudp_nofold()  argument
62 		: "=r" (sum)  in csum_tcpudp_nofold()
63 	    : "g" (daddr), "g" (saddr), "g" ((len + proto) << 8), "0" (sum));  in csum_tcpudp_nofold()
64 	return sum;  in csum_tcpudp_nofold()
73 					__wsum sum)  in csum_tcpudp_magic()  argument
75 	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));  in csum_tcpudp_magic()
85 	unsigned int sum;  in ip_fast_csum()  local
107 	: "=r" (sum), "=r" (iph), "=r" (ihl)  in ip_fast_csum()
110 	return (__force __sum16)sum;  in ip_fast_csum()