linux/include/asm-cris/arch-v32/checksum.h
Adrian Bunk d9b5444eeb [PATCH] cris: "extern inline" -> "static inline"
"extern inline" doesn't make much sense.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Mikael Starvik <starvik@axis.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:53:30 -08:00

30 lines
825 B
C

#ifndef _ASM_CRIS_ARCH_CHECKSUM_H
#define _ASM_CRIS_ARCH_CHECKSUM_H
/*
* 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 unsigned int
csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr,
unsigned short len, unsigned short proto, unsigned int sum)
{
int 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" ((ntohs(len) << 16) + (proto << 8)));
return res;
}
#endif /* _ASM_CRIS_ARCH_CHECKSUM_H */