arch/tile/include/asm/checksum.h

   1 /*
   2  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  */
  14
  15 #ifndef _ASM_TILE_CHECKSUM_H
  16 #define _ASM_TILE_CHECKSUM_H
  17
  18 #include <asm-generic/checksum.h>
  19
  20 /* Allow us to provide a more optimized do_csum(). */
  21 __wsum do_csum(const unsigned char *buff, int len);
  22 #define do_csum do_csum
  23
  24 /*
  25  * Return the sum of all the 16-bit subwords in a long.
  26  * This sums two subwords on a 32-bit machine, and four on 64 bits.
  27  * The implementation does two vector adds to capture any overflow.
  28  */
  29 static inline unsigned int csum_long(unsigned long x)
  30 {
  31         unsigned long ret;
  32 #ifdef __tilegx__
  33         ret = __insn_v2sadu(x, 0);
  34         ret = __insn_v2sadu(ret, 0);
  35 #else
  36         ret = __insn_sadh_u(x, 0);
  37         ret = __insn_sadh_u(ret, 0);
  38 #endif
  39         return ret;
  40 }
  41
  42 #endif /* _ASM_TILE_CHECKSUM_H */