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/*
* Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
* Copyright (C) 2004 Microtronix Datacom Ltd.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#ifndef _ASM_NIOS_CHECKSUM_H
#define _ASM_NIOS_CHECKSUM_H
/* Take these from lib/checksum.c */
extern __wsum csum_partial(const void *buff, int len, __wsum sum);
extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
extern __sum16 ip_compute_csum(const void *buff, int len);
/*
* Fold a partial checksum
*/
static inline __sum16 csum_fold(__wsum sum)
{
__asm__ __volatile__(
"add %0, %1, %0\n"
"cmpltu r8, %0, %1\n"
"srli %0, %0, 16\n"
"add %0, %0, r8\n"
"nor %0, %0, %0\n"
: "=r" (sum)
: "r" (sum << 16), "0" (sum)
: "r8");
return (__force __sum16) sum;
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
#define csum_tcpudp_nofold csum_tcpudp_nofold
static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
__u32 len, __u8 proto,
__wsum sum)
{
__asm__ __volatile__(
"add %0, %1, %0\n"
"cmpltu r8, %0, %1\n"
"add %0, %0, r8\n" /* add carry */
"add %0, %2, %0\n"
"cmpltu r8, %0, %2\n"
"add %0, %0, r8\n" /* add carry */
"add %0, %3, %0\n"
"cmpltu r8, %0, %3\n"
"add %0, %0, r8\n" /* add carry */
: "=r" (sum), "=r" (saddr)
: "r" (daddr), "r" ((len + proto) << 8),
"0" (sum),
"1" (saddr)
: "r8");
return sum;
}
static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
__u32 len, __u8 proto,
__wsum sum)
{
return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
}
#endif /* _ASM_NIOS_CHECKSUM_H */
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