LXR linux/arch/mn10300/include/asm/checksum.h

   1/* MN10300 Optimised checksumming code
   2 *
   3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4 * Written by David Howells (dhowells@redhat.com)
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public Licence
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the Licence, or (at your option) any later version.
  10 */
  11#ifndef _ASM_CHECKSUM_H
  12#define _ASM_CHECKSUM_H
  13
  14extern __wsum csum_partial(const void *buff, int len, __wsum sum);
  15extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
  16                                        int len, __wsum sum);
  17extern __wsum csum_partial_copy_from_user(const void *src, void *dst,
  18                                          int len, __wsum sum,
  19                                          int *err_ptr);
  20extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
  21extern __wsum csum_partial(const void *buff, int len, __wsum sum);
  22extern __sum16 ip_compute_csum(const void *buff, int len);
  23
  24#define csum_partial_copy_fromuser csum_partial_copy
  25extern __wsum csum_partial_copy(const void *src, void *dst, int len,
  26                                __wsum sum);
  27
  28static inline __sum16 csum_fold(__wsum sum)
  29{
  30        asm(
  31                "       add     %1,%0           \n"
  32                "       addc    0xffff,%0       \n"
  33                : "=r" (sum)
  34                : "r" (sum << 16), "0" (sum & 0xffff0000)
  35                : "cc"
  36            );
  37        return (~sum) >> 16;
  38}
  39
  40static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
  41                                        __u32 len, __u8 proto,
  42                                        __wsum sum)
  43{
  44        __wsum tmp = (__wsum)((len + proto) << 8);
  45
  46        asm(
  47                "       add     %1,%0           \n"
  48                "       addc    %2,%0           \n"
  49                "       addc    %3,%0           \n"
  50                "       addc    0,%0            \n"
  51                : "=r" (sum)
  52                : "r" (daddr), "r"(saddr), "r"(tmp), "0"(sum)
  53                : "cc"
  54            );
  55        return sum;
  56}
  57
  58/*
  59 * computes the checksum of the TCP/UDP pseudo-header
  60 * returns a 16-bit checksum, already complemented
  61 */
  62static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
  63                                        __u32 len, __u8 proto,
  64                                        __wsum sum)
  65{
  66        return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
  67}
  68
  69#undef _HAVE_ARCH_IPV6_CSUM
  70
  71/*
  72 *      Copy and checksum to user
  73 */
  74#define HAVE_CSUM_COPY_USER
  75extern __wsum csum_and_copy_to_user(const void *src, void *dst, int len,
  76                                    __wsum sum, int *err_ptr);
  77
  78
  79#endif /* _ASM_CHECKSUM_H */
  80