blob: e5dcfce6e0dc1a5267739b67d9c8bab4233fb777 [file] [log] [blame]
* Check values used in TCP/UDP headers.
* The gain of doing this in assembler instead of C, is that C doesn't
* generate carry-additions for the 32-bit components of the
* checksum. Which means it would be necessary to split all those into
* 16-bit components and then add.
static inline __wsum
csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
unsigned short len, unsigned short proto, __wsum sum)
__wsum res;
__asm__ __volatile__ ("add.d %2, %0\n\t"
"addc %3, %0\n\t"
"addc %4, %0\n\t"
"addc 0, %0\n\t"
: "=r" (res)
: "0" (sum), "r" (daddr), "r" (saddr), \
"r" ((len + proto) << 8));
return res;