/*
* include/asm-v850/checksum.h -- Checksum ops
*
* Copyright (C) 2001 NEC Corporation
* Copyright (C) 2001 Miles Bader
*
* 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.
*
* Written by Miles Bader
*/
#ifndef __V850_CHECKSUM_H__
#define __V850_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
*/
extern unsigned int csum_partial (const unsigned char * buff, int len,
unsigned int 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
*/
extern unsigned csum_partial_copy (const char *src, char *dst, int len,
unsigned 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 unsigned csum_partial_copy_from_user (const char *src, char *dst,
int len, unsigned sum,
int *csum_err);
#define csum_partial_copy_nocheck(src, dst, len, sum) \
csum_partial_copy ((src), (dst), (len), (sum))
unsigned short ip_fast_csum (unsigned char *iph, unsigned int ihl);
/*
* Fold a partial checksum
*/
static inline unsigned int csum_fold (unsigned long sum)
{
unsigned int result;
/*
%0 %1
hsw %1, %0 H L L H
add %1, %0 H L H+L+C H+L
*/
asm ("hsw %1, %0; add %1, %0" : "=&r" (result) : "r" (sum));
return (~result) >> 16;
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
static inline unsigned int
csum_tcpudp_nofold (unsigned long saddr, unsigned long daddr,
unsigned short len,
unsigned short proto, unsigned int sum)
{
int __carry;
__asm__ ("add %2, %0;"
"setf c, %1;"
"add %1, %0;"
"add %3, %0;"
"setf c, %1;"
"add %1, %0;"
"add %4, %0;"
"setf c, %1;"
"add %1, %0"
: "=&r" (sum), "=&r" (__carry)
: "r" (daddr), "r" (saddr),
"r" (ntohs (len) + (proto << 8)),
"0" (sum));
return sum;
}
static inline unsigned short int
csum_tcpudp_magic (unsigned long saddr, unsigned long daddr,
unsigned short len,
unsigned short proto, unsigned int 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 unsigned short ip_compute_csum (const unsigned char * buff, int len);
#endif /* __V850_CHECKSUM_H__ */