/*
* Copyright 2004-2009 Analog Devices Inc.
* akbar.hussain@lineo.com
*
* Licensed under the GPL-2 or later.
*/
#ifndef _BFIN_CHECKSUM_H
#define _BFIN_CHECKSUM_H
/*
* computes the checksum of a memory block at buff, length len,
* and adds in "sum" (32-bit)
*
* returns a 32-bit number suitable for feeding into itself
* or csum_tcpudp_magic
*
* this function must be called with even lengths, except
* for the last fragment, which may be odd
*
* it's best to have buff aligned on a 32-bit boundary
*/
__wsum csum_partial(const void *buff, int len, __wsum sum);
/*
* the same as csum_partial, but copies from src while it
* checksums
*
* here even more important to align src and dst on a 32-bit (or even
* better 64-bit) boundary
*/
__wsum csum_partial_copy(const void *src, void *dst,
int len, __wsum sum);
/*
* the same as csum_partial_copy, but copies from user space.
*
* here even more important to align src and dst on a 32-bit (or even
* better 64-bit) boundary
*/
extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
int len, __wsum sum, int *csum_err);
#define csum_partial_copy_nocheck(src, dst, len, sum) \
csum_partial_copy((src), (dst), (len), (sum))
__sum16 ip_fast_csum(unsigned char *iph, unsigned int ihl);
/*
* Fold a partial checksum
*/
static inline __sum16 csum_fold(__wsum sum)
{
while (sum >> 16)
sum = (sum & 0xffff) + (sum >> 16);
return ((~(sum << 16)) >> 16);
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
static inline __wsum
csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
unsigned short proto, __wsum sum)
{
unsigned int carry;
__asm__ ("%0 = %0 + %2;\n\t"
"CC = AC0;\n\t"
"%1 = CC;\n\t"
"%0 = %0 + %1;\n\t"
"%0 = %0 + %3;\n\t"
"CC = AC0;\n\t"
"%1 = CC;\n\t"
"%0 = %0 + %1;\n\t"
"%0 = %0 + %4;\n\t"
"CC = AC0;\n\t"
"%1 = CC;\n\t"
"%0 = %0 + %1;\n\t"
: "=d" (sum), "=&d" (carry)
: "d" (daddr), "d" (saddr), "d" ((len + proto) << 8), "0"(sum)
: "CC");
return (sum);
}
static inline __sum16
csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
unsigned short proto, __wsum sum)
{
return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
}
/*
* this routine is used for miscellaneous IP-like checksums, mainly
* in icmp.c
*/
extern __sum16 ip_compute_csum(const void *buff, int len);
#endif /* _BFIN_CHECKSUM_H */
