13  * and adds in "sum" (32-bit), while copying the block to dst.
39 static inline __sum16 csum_fold(__wsum sum)  in csum_fold()  argument
41 	u32 tmp = (__force u32)sum;  in csum_fold()
44 	 * swap the two 16-bit halves of sum  in csum_fold()
47 	 * giving us the correct sum in the upper half.  in csum_fold()
58 					__u8 proto, __wsum sum)  in csum_tcpudp_nofold()  argument
61 	u64 s = (__force u32)sum;  in csum_tcpudp_nofold()
78 	: "=r" (sum)  in csum_tcpudp_nofold()
79 	: "r" (daddr), "r"(saddr), "r"(proto + len), "0"(sum));  in csum_tcpudp_nofold()
80 	return sum;  in csum_tcpudp_nofold()
89 					__u8 proto, __wsum sum)  in csum_tcpudp_magic()  argument
91 	return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));  in csum_tcpudp_magic()
116 static __always_inline __wsum csum_shift(__wsum sum, int offset)  in csum_shift()  argument
118 	/* rotate sum to align it with a 16b boundary */  in csum_shift()
119 	return (__force __wsum)rol32((__force u32)sum, (offset & 1) << 3);  in csum_shift()
138 	__wsum sum, tmp;  in ip_fast_csum_nofold()  local
146 	    : "=r" (sum), "=r" (tmp), "+b" (ptr)  in ip_fast_csum_nofold()
150 	return sum;  in ip_fast_csum_nofold()
161  * and adds in "sum" (32-bit)
171 __wsum __csum_partial(const void *buff, int len, __wsum sum);
173 static __always_inline __wsum csum_partial(const void *buff, int len, __wsum sum)  in csum_partial()  argument
177 			sum = csum_add(sum, (__force __wsum)*(const u16 *)buff);  in csum_partial()
179 			sum = csum_add(sum, (__force __wsum)*(const u32 *)buff);  in csum_partial()
181 			sum = csum_add(sum, (__force __wsum)  in csum_partial()
184 			sum = csum_add(sum, (__force __wsum)  in csum_partial()
187 			sum = csum_add(sum, (__force __wsum)  in csum_partial()
190 			sum = csum_add(sum, (__force __wsum)  in csum_partial()
193 			sum = csum_add(sum, (__force __wsum)  in csum_partial()
196 			sum = csum_add(sum, (__force __wsum)  in csum_partial()
199 		sum = csum_add(sum, ip_fast_csum_nofold(buff, len >> 2));  in csum_partial()
201 		sum = __csum_partial(buff, len, sum);  in csum_partial()
203 	return sum;  in csum_partial()
218 			__u32 len, __u8 proto, __wsum sum);