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#ifndef _PPC64_CHECKSUM_H

#define _PPC64_CHECKSUM_H

/*

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version

 * 2 of the License, or (at your option) any later version.

 */

/*

 * This is a version of ip_compute_csum() optimized for IP headers,

 * which always checksum on 4 octet boundaries.  ihl is the number

 * of 32-bit words and is always >= 5.

 */

extern unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl);

/*

 * computes the checksum of the TCP/UDP pseudo-header

 * returns a 16-bit checksum, already complemented

 */

extern unsigned short csum_tcpudp_magic(unsigned long saddr,

                                        unsigned long daddr,

                                        unsigned short len,

                                        unsigned short proto,

                                        unsigned int sum);

/*

 * 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 to dst while it

 * checksums

 */

unsigned int csum_partial_copy(const char *src, char *dst,

                               int len, unsigned int sum);

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

                                              int len, unsigned int sum,

                                              int *src_err, int *dst_err);

/*

 * the same as csum_partial, but copies from user space.

 */

unsigned int csum_partial_copy_fromuser(const char *src,

                                        char *dst,

                                        int len,

                                        unsigned int sum,

                                        int *src_err);

unsigned int csum_partial_copy_nocheck(const char *src,

                                       char *dst,

                                       int len,

                                       unsigned int sum);

/*

 * turns a 32-bit partial checksum (e.g. from csum_partial) into a

 * 1's complement 16-bit checksum.

 */

static inline unsigned int csum_fold(unsigned int sum)

{

        unsigned int tmp;

        /* swap the two 16-bit halves of sum */

        __asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum));

        /* if there is a carry from adding the two 16-bit halves,

           it will carry from the lower half into the upper half,

           giving us the correct sum in the upper half. */

        sum = ~(sum + tmp) >> 16;

        return 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 csum_partial_copy_from_user(src, dst, len, sum, errp)   \

        csum_partial_copy_generic((src), (dst), (len), (sum), (errp), 0)

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

        csum_partial_copy_generic((src), (dst), (len), (sum), 0, 0)

static inline u32 csum_tcpudp_nofold(u32 saddr,

                                     u32 daddr,

                                     unsigned short len,

                                     unsigned short proto,

                                     unsigned int sum)

{

        unsigned long s = sum;

        s += saddr;

        s += daddr;

        s += (proto << 16) + len;

        s += (s >> 32);

        return (u32) s;

}

#endif