include/asm-mn10300/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
  14 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
  15 extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
  16                                         int len, __wsum sum);
  17 extern __wsum csum_partial_copy_from_user(const void *src, void *dst,
  18                                           int len, __wsum sum,
  19                                           int *err_ptr);
  20 extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
  21 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
  22 extern __sum16 ip_compute_csum(const void *buff, int len);
  23
  24 #define csum_partial_copy_fromuser csum_partial_copy
  25 extern __wsum csum_partial_copy(const void *src, void *dst, int len,
  26                                 __wsum sum);
  27
  28 static 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
  40 static inline __wsum csum_tcpudp_nofold(unsigned long saddr,
  41                                         unsigned long daddr,
  42                                         unsigned short len,
  43                                         unsigned short proto,
  44                                         __wsum sum)
  45 {
  46         __wsum tmp;
  47
  48         tmp = (__wsum) ntohs(len) << 16;
  49         tmp += (__wsum) proto << 8;
  50
  51         asm(
  52                 "       add     %1,%0           \n"
  53                 "       addc    %2,%0           \n"
  54                 "       addc    %3,%0           \n"
  55                 "       addc    0,%0            \n"
  56                 : "=r" (sum)
  57                 : "r" (daddr), "r"(saddr), "r"(tmp), "0"(sum)
  58                 : "cc"
  59             );
  60         return sum;
  61 }
  62
  63 /*
  64  * computes the checksum of the TCP/UDP pseudo-header
  65  * returns a 16-bit checksum, already complemented
  66  */
  67 static inline __sum16 csum_tcpudp_magic(unsigned long saddr,
  68                                         unsigned long daddr,
  69                                         unsigned short len,
  70                                         unsigned short proto,
  71                                         __wsum sum)
  72 {
  73         return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
  74 }
  75
  76 #undef _HAVE_ARCH_IPV6_CSUM
  77
  78 /*
  79  *      Copy and checksum to user
  80  */
  81 #define HAVE_CSUM_COPY_USER
  82 extern __wsum csum_and_copy_to_user(const void *src, void *dst, int len,
  83                                     __wsum sum, int *err_ptr);
  84
  85
  86 #endif /* _ASM_CHECKSUM_H */