linux/include/asm-cris/arch-v10/checksum.h
Al Viro 3532010bcf [NET]: Cris checksum annotations and cleanups.
* sanitize prototypes and annotate
* kill cast-as-lvalue abuses in csum_partial()
* usual ntohs-equals-shift for checksum purposes

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:23:02 -08:00

30 lines
706 B
C

#ifndef _CRIS_ARCH_CHECKSUM_H
#define _CRIS_ARCH_CHECKSUM_H
/* 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, unsigned short len,
unsigned short proto, __wsum sum)
{
__wsum res;
__asm__ ("add.d %2, %0\n\t"
"ax\n\t"
"add.d %3, %0\n\t"
"ax\n\t"
"add.d %4, %0\n\t"
"ax\n\t"
"addq 0, %0\n"
: "=r" (res)
: "0" (sum), "r" (daddr), "r" (saddr), "r" ((len + proto) << 8));
return res;
}
#endif