30 lines
787 B
C
30 lines
787 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 __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;
|
|
}
|
|
|
|
#endif /* _ASM_CRIS_ARCH_CHECKSUM_H */
|