blob: eb186be4fb3243c14ae52bb80435cefea1452196 [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0 */
/* Checksum some values used in TCP/UDP headers.
* The gain by doing this in asm is that C will not generate carry-additions
* for the 32-bit components of the checksum, so otherwise we would have had
* to split all of those into 16-bit components, then add.
static inline __wsum
csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
__u8 proto, __wsum sum)
__wsum res;
__asm__ ("add.d %2, %0\n\t"
"add.d %3, %0\n\t"
"add.d %4, %0\n\t"
"addq 0, %0\n"
: "=r" (res)
: "0" (sum), "r" (daddr), "r" (saddr), "r" ((len + proto) << 8));
return res;