Subversion Repositories or1k

#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, 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

 */

extern unsigned int csum_partial_copy_from_user(const char *src, char *dst,

                                                int len, int sum, int *csum_err);

#define csum_partial_copy_nocheck(src, dst, len, sum)   \

        csum_partial_copy((src), (dst), (len), (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 int

csum_tcpudp_nofold(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 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

 */

static inline unsigned short

ip_compute_csum(unsigned char * buff, int len)

{

        return csum_fold (csum_partial(buff, len, 0));

}

#define _HAVE_ARCH_IPV6_CSUM

static __inline__ unsigned short int

csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr,

                __u32 len, unsigned short proto, unsigned int sum)

{

        register unsigned long tmp;

        __asm__("addl %2@,%0\n\t"

                "movel %2@(4),%1\n\t"

                "addxl %1,%0\n\t"

                "movel %2@(8),%1\n\t"

                "addxl %1,%0\n\t"

                "movel %2@(12),%1\n\t"

                "addxl %1,%0\n\t"

                "movel %3@,%1\n\t"

                "addxl %1,%0\n\t"

                "movel %3@(4),%1\n\t"

                "addxl %1,%0\n\t"

                "movel %3@(8),%1\n\t"

                "addxl %1,%0\n\t"

                "movel %3@(12),%1\n\t"

                "addxl %1,%0\n\t"

                "addxl %4,%0\n\t"

                "clrl %1\n\t"

                "addxl %1,%0"

                : "=&d" (sum), "=&d" (tmp)

                : "a" (saddr), "a" (daddr), "d" (len + proto),

                  "0" (sum));

        return csum_fold(sum);

}

#endif /* _M68K_CHECKSUM_H */