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#ifndef _M68K_CHECKSUM_H
#define _M68K_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
*/
unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
/*
* the same as csum_partial_copy, 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
*/
unsigned int csum_partial_copy(const char *src, char *dst, int len, int 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
*/
unsigned int csum_partial_copy_fromuser(const char *src, char *dst, int len, int sum);
/*
* This is a version of ip_compute_csum() optimized for IP headers,
* which always checksum on 4 octet boundaries.
*
*/
static inline unsigned short
ip_fast_csum(unsigned char *iph, unsigned int ihl)
{
unsigned int sum = 0;
__asm__ ("subqw #1,%2\n"
"1:\t"
"movel %1@+,%/d0\n\t"
"addxl %/d0,%0\n\t"
"dbra %2,1b\n\t"
"movel %0,%/d0\n\t"
"swap %/d0\n\t"
"addxw %/d0,%0\n\t"
"clrw %/d0\n\t"
"addxw %/d0,%0\n\t"
: "=d" (sum), "=a" (iph), "=d" (ihl)
: "0" (sum), "1" (iph), "2" (ihl)
: "d0");
return ~sum;
}
/*
* Fold a partial checksum
*/
static inline unsigned int csum_fold(unsigned int sum)
{
unsigned int tmp = sum;
__asm__("swap %1\n\t"
"addw %1, %0\n\t"
"clrw %1\n\t"
"addxw %1, %0"
: "=&d" (sum), "=&d" (tmp)
: "0" (sum), "1" (sum));
return ~sum;
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
static inline unsigned short int
csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,
unsigned short proto, unsigned int sum)
{
__asm__ ("addl %1,%0\n\t"
"addxl %4,%0\n\t"
"addxl %5,%0\n\t"
"clrl %1\n\t"
"addxl %1,%0"
: "=&d" (sum), "=&d" (saddr)
: "0" (daddr), "1" (saddr), "d" (len + proto),
"d"(sum));
return csum_fold(sum);
}
/*
* this routine is used for miscellaneous IP-like checksums, mainly
* in icmp.c
*/
static inline unsigned short
ip_compute_csum(unsigned char * buff, int len)
{
return csum_fold (csum_partial(buff, len, 0));
}
#endif /* _M68K_CHECKSUM_H */
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