include/asm-microblaze/byteorder.h

   1 /*
   2  * include/asm-microblaze/byteorder.h -- Endian id and conversion ops
   3  *
   4  *  Copyright (C) 2003  John Williams <jwilliams@itee.uq.edu.au>
   5  *  Copyright (C) 2001  NEC Corporation
   6  *  Copyright (C) 2001  Miles Bader <miles@gnu.org>
   7  *
   8  * This file is subject to the terms and conditions of the GNU General
   9  * Public License.  See the file COPYING in the main directory of this
  10  * archive for more details.
  11  *
  12  * Written by Miles Bader <miles@gnu.org>
  13  * Microblaze port by John Williams
  14  */
  15
  16 #ifndef __MICROBLAZE_BYTEORDER_H__
  17 #define __MICROBLAZE_BYTEORDER_H__
  18
  19 #include <asm/types.h>
  20
  21 #ifdef __GNUC__
  22
  23 /* This is effectively a dupe of the arch-independent byteswap
  24    code in include/linux/byteorder/swab.h, however we force a cast
  25    of the result up to 32 bits.  This in turn forces the compiler
  26    to explicitly clear the high 16 bits, which it wasn't doing otherwise.
  27
  28    I think this is a symptom of a bug in mb-gcc.  JW 20040303
  29 */
  30 static __inline__ __const__ __u16 ___arch__swab16 (__u16 half_word)
  31 {
  32         /* 32 bit temp to cast result, forcing clearing of high word */
  33         __u32 temp;
  34
  35         temp = ((half_word & 0x00FFU) << 8) | ((half_word & 0xFF00U) >> 8);
  36
  37         return (__u16) temp;
  38 }
  39
  40 #define __arch__swab16(x) ___arch__swab16(x)
  41
  42 /* Microblaze has no arch-specific endian conversion insns */
  43
  44 #if !defined(__STRICT_ANSI__) || defined(__KERNEL__)
  45 #  define __BYTEORDER_HAS_U64__
  46 #  define __SWAB_64_THRU_32__
  47 #endif
  48
  49 #endif /* __GNUC__ */
  50
  51 #include <linux/byteorder/big_endian.h>
  52
  53 #endif /* __MICROBLAZE_BYTEORDER_H__ */