/* MN10300 Optimised checksumming code
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells ([email protected])
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#ifndef _ASM_CHECKSUM_H
#define _ASM_CHECKSUM_H

extern __wsum csum_partial(const void *buff, int len, __wsum sum);
extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
int len, __wsum sum);
extern __wsum csum_partial_copy_from_user(const void *src, void *dst,
int len, __wsum sum,
int *err_ptr);
extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
extern __wsum csum_partial(const void *buff, int len, __wsum sum);
extern __sum16 ip_compute_csum(const void *buff, int len);

#define csum_partial_copy_fromuser csum_partial_copy
extern __wsum csum_partial_copy(const void *src, void *dst, int len,
__wsum sum);

static inline __sum16 csum_fold(__wsum sum)
{
asm(
" add %1,%0 \n"
" addc 0xffff,%0 \n"
: "=r" (sum)
: "r" (sum << 16), "0" (sum & 0xffff0000)
: "cc"
);
return (~sum) >> 16;
}

static inline __wsum csum_tcpudp_nofold(unsigned long saddr,
unsigned long daddr,
unsigned short len,
unsigned short proto,
__wsum sum)
{
__wsum tmp;

tmp = (__wsum) ntohs(len) << 16;
tmp += (__wsum) proto << 8;

asm(
" add %1,%0 \n"
" addc %2,%0 \n"
" addc %3,%0 \n"
" addc 0,%0 \n"
: "=r" (sum)
: "r" (daddr), "r"(saddr), "r"(tmp), "0"(sum)
: "cc"
);
return sum;
}

/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
static inline __sum16 csum_tcpudp_magic(unsigned long saddr,
unsigned long daddr,
unsigned short len,
unsigned short proto,
__wsum sum)
{
return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
}

#undef _HAVE_ARCH_IPV6_CSUM

/*
* Copy and checksum to user
*/
#define HAVE_CSUM_COPY_USER
extern __wsum csum_and_copy_to_user(const void *src, void *dst, int len,
__wsum sum, int *err_ptr);


#endif /* _ASM_CHECKSUM_H */