[deliverable/linux.git] / arch / cris / include / arch-v32 / arch / checksum.h

#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,
		   __u32 len, __u8 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 */
Commit	Line	Data
51533b61 MS	1	#ifndef _ASM_CRIS_ARCH_CHECKSUM_H
	2	#define _ASM_CRIS_ARCH_CHECKSUM_H
	3
	4	/*
	5	* Check values used in TCP/UDP headers.
	6	*
	7	* The gain of doing this in assembler instead of C, is that C doesn't
	8	* generate carry-additions for the 32-bit components of the
	9	* checksum. Which means it would be necessary to split all those into
	10	* 16-bit components and then add.
	11	*/
3532010b AV	12	static inline __wsum
3532010b AV	13	csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
01cfbad7	14	__u32 len, __u8 proto, __wsum sum)
51533b61	15	{
3532010b	16	__wsum res;
51533b61 MS	17
	18	__asm__ __volatile__ ("add.d %2, %0\n\t"
	19	"addc %3, %0\n\t"
	20	"addc %4, %0\n\t"
	21	"addc 0, %0\n\t"
	22	: "=r" (res)
	23	: "0" (sum), "r" (daddr), "r" (saddr), \
3532010b	24	"r" ((len + proto) << 8));
51533b61 MS	25
	26	return res;
	27	}
	28
	29	#endif /* _ASM_CRIS_ARCH_CHECKSUM_H */