LXR uboot/include/linux/byteorder/swab.h

   1#ifndef _LINUX_BYTEORDER_SWAB_H
   2#define _LINUX_BYTEORDER_SWAB_H
   3
   4/*
   5 * linux/byteorder/swab.h
   6 * Byte-swapping, independently from CPU endianness
   7 *      swabXX[ps]?(foo)
   8 *
   9 * Francois-Rene Rideau <fare@tunes.org> 19971205
  10 *    separated swab functions from cpu_to_XX,
  11 *    to clean up support for bizarre-endian architectures.
  12 *
  13 * See asm-i386/byteorder.h and suches for examples of how to provide
  14 * architecture-dependent optimized versions
  15 *
  16 */
  17
  18/* casts are necessary for constants, because we never know how for sure
  19 * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.
  20 */
  21#define ___swab16(x) \
  22        ((__u16)( \
  23                (((__u16)(x) & (__u16)0x00ffU) << 8) | \
  24                (((__u16)(x) & (__u16)0xff00U) >> 8) ))
  25#define ___swab32(x) \
  26        ((__u32)( \
  27                (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \
  28                (((__u32)(x) & (__u32)0x0000ff00UL) <<  8) | \
  29                (((__u32)(x) & (__u32)0x00ff0000UL) >>  8) | \
  30                (((__u32)(x) & (__u32)0xff000000UL) >> 24) ))
  31#define ___swab64(x) \
  32        ((__u64)( \
  33                (__u64)(((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \
  34                (__u64)(((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \
  35                (__u64)(((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \
  36                (__u64)(((__u64)(x) & (__u64)0x00000000ff000000ULL) <<  8) | \
  37                (__u64)(((__u64)(x) & (__u64)0x000000ff00000000ULL) >>  8) | \
  38                (__u64)(((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \
  39                (__u64)(((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \
  40                (__u64)(((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56) ))
  41
  42/*
  43 * provide defaults when no architecture-specific optimization is detected
  44 */
  45#ifndef __arch__swab16
  46#  define __arch__swab16(x) ___swab16(x)
  47#endif
  48#ifndef __arch__swab32
  49#  define __arch__swab32(x) ___swab32(x)
  50#endif
  51#ifndef __arch__swab64
  52#  define __arch__swab64(x) ___swab64(x)
  53#endif
  54
  55#ifndef __arch__swab16p
  56#  define __arch__swab16p(x) __swab16(*(x))
  57#endif
  58#ifndef __arch__swab32p
  59#  define __arch__swab32p(x) __swab32(*(x))
  60#endif
  61#ifndef __arch__swab64p
  62#  define __arch__swab64p(x) __swab64(*(x))
  63#endif
  64
  65#ifndef __arch__swab16s
  66#  define __arch__swab16s(x) do { *(x) = __swab16p((x)); } while (0)
  67#endif
  68#ifndef __arch__swab32s
  69#  define __arch__swab32s(x) do { *(x) = __swab32p((x)); } while (0)
  70#endif
  71#ifndef __arch__swab64s
  72#  define __arch__swab64s(x) do { *(x) = __swab64p((x)); } while (0)
  73#endif
  74
  75
  76/*
  77 * Allow constant folding
  78 */
  79#if defined(__GNUC__) && (__GNUC__ >= 2) && defined(__OPTIMIZE__)
  80#  define __swab16(x) \
  81(__builtin_constant_p((__u16)(x)) ? \
  82 ___swab16((x)) : \
  83 __fswab16((x)))
  84#  define __swab32(x) \
  85(__builtin_constant_p((__u32)(x)) ? \
  86 ___swab32((x)) : \
  87 __fswab32((x)))
  88#  define __swab64(x) \
  89(__builtin_constant_p((__u64)(x)) ? \
  90 ___swab64((x)) : \
  91 __fswab64((x)))
  92#else
  93#  define __swab16(x) __fswab16(x)
  94#  define __swab32(x) __fswab32(x)
  95#  define __swab64(x) __fswab64(x)
  96#endif /* OPTIMIZE */
  97
  98
  99static __inline__ __attribute__((const)) __u16 __fswab16(__u16 x)
 100{
 101        return __arch__swab16(x);
 102}
 103static __inline__ __u16 __swab16p(const __u16 *x)
 104{
 105        return __arch__swab16p(x);
 106}
 107static __inline__ void __swab16s(__u16 *addr)
 108{
 109        __arch__swab16s(addr);
 110}
 111
 112static __inline__ __attribute__((const)) __u32 __fswab32(__u32 x)
 113{
 114        return __arch__swab32(x);
 115}
 116static __inline__ __u32 __swab32p(const __u32 *x)
 117{
 118        return __arch__swab32p(x);
 119}
 120static __inline__ void __swab32s(__u32 *addr)
 121{
 122        __arch__swab32s(addr);
 123}
 124
 125static __inline__ __attribute__((const)) __u64 __fswab64(__u64 x)
 126{
 127#  ifdef __SWAB_64_THRU_32__
 128        __u32 h = x >> 32;
 129        __u32 l = x & ((1ULL<<32)-1);
 130        return (((__u64)__swab32(l)) << 32) | ((__u64)(__swab32(h)));
 131#  else
 132        return __arch__swab64(x);
 133#  endif
 134}
 135static __inline__ __u64 __swab64p(const __u64 *x)
 136{
 137        return __arch__swab64p(x);
 138}
 139static __inline__ void __swab64s(__u64 *addr)
 140{
 141        __arch__swab64s(addr);
 142}
 143
 144#if defined(__KERNEL__)
 145#define swab16 __swab16
 146#define swab32 __swab32
 147#define swab64 __swab64
 148#define swab16p __swab16p
 149#define swab32p __swab32p
 150#define swab64p __swab64p
 151#define swab16s __swab16s
 152#define swab32s __swab32s
 153#define swab64s __swab64s
 154#endif
 155
 156#endif /* _LINUX_BYTEORDER_SWAB_H */
 157