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#ifndef _LINUX_BYTEORDER_SWAB_H

#define _LINUX_BYTEORDER_SWAB_H

/*

 * linux/byteorder/swab.h

 * Byte-swapping, independently from CPU endianness

 *      swabXX[ps]?(foo)

 *

 * Francois-Rene Rideau <fare@tunes.org> 19971205

 *    separated swab functions from cpu_to_XX,

 *    to clean up support for bizarre-endian architectures.

 *

 * Trent Piepho <xyzzy@speakeasy.org> 2007114

 *    make constant-folding work, provide C versions that

 *    gcc can optimize better, explain different versions

 *

 * See asm-i386/byteorder.h and suches for examples of how to provide

 * architecture-dependent optimized versions

 *

 */

#include <linux/compiler.h>

/* Functions/macros defined, there are a lot:

 *

 * ___swabXX

 *    Generic C versions of the swab functions.

 *

 * ___constant_swabXX

 *    C versions that gcc can fold into a compile-time constant when

 *    the argument is a compile-time constant.

 *

 * __arch__swabXX[sp]?

 *    Architecture optimized versions of all the swab functions

 *    (including the s and p versions).  These can be defined in

 *    asm-arch/byteorder.h.  Any which are not, are defined here.

 *    __arch__swabXXs() is defined in terms of __arch__swabXXp(), which

 *    is defined in terms of __arch__swabXX(), which is in turn defined

 *    in terms of ___swabXX(x).

 *    These must be macros.  They may be unsafe for arguments with

 *    side-effects.

 *

 * __fswabXX

 *    Inline function versions of the __arch__ macros.  These _are_ safe

 *    if the arguments have side-effects.  Note there are no s and p

 *    versions of these.

 *

 * __swabXX[sb]

 *    There are the ones you should actually use.  The __swabXX versions

 *    will be a constant given a constant argument and use the arch

 *    specific code (if any) for non-constant arguments.  The s and p

 *    versions always use the arch specific code (constant folding

 *    doesn't apply).  They are safe to use with arguments with

 *    side-effects.

 *

 * swabXX[sb]

 *    Nicknames for __swabXX[sb] to use in the kernel.

 */

/* casts are necessary for constants, because we never know how for sure

 * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.

 */

static __inline__ __attribute_const__ __u16 ___swab16(__u16 x)

{

        return x<<8 | x>>8;

}

static __inline__ __attribute_const__ __u32 ___swab32(__u32 x)

{

        return x<<24 | x>>24 |

                (x & (__u32)0x0000ff00UL)<<8 |

                (x & (__u32)0x00ff0000UL)>>8;

}

static __inline__ __attribute_const__ __u64 ___swab64(__u64 x)

{

        return x<<56 | x>>56 |

                (x & (__u64)0x000000000000ff00ULL)<<40 |

                (x & (__u64)0x0000000000ff0000ULL)<<24 |

                (x & (__u64)0x00000000ff000000ULL)<< 8 |

                (x & (__u64)0x000000ff00000000ULL)>> 8 |

                (x & (__u64)0x0000ff0000000000ULL)>>24 |

                (x & (__u64)0x00ff000000000000ULL)>>40;

}

#define ___constant_swab16(x) \

        ((__u16)( \

                (((__u16)(x) & (__u16)0x00ffU) << 8) | \

                (((__u16)(x) & (__u16)0xff00U) >> 8) ))

#define ___constant_swab32(x) \

        ((__u32)( \

                (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \

                (((__u32)(x) & (__u32)0x0000ff00UL) <<  8) | \

                (((__u32)(x) & (__u32)0x00ff0000UL) >>  8) | \

                (((__u32)(x) & (__u32)0xff000000UL) >> 24) ))

#define ___constant_swab64(x) \

        ((__u64)( \

                (__u64)(((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \

                (__u64)(((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \

                (__u64)(((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \

                (__u64)(((__u64)(x) & (__u64)0x00000000ff000000ULL) <<  8) | \

                (__u64)(((__u64)(x) & (__u64)0x000000ff00000000ULL) >>  8) | \

                (__u64)(((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \

                (__u64)(((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \

                (__u64)(((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56) ))

/*

 * provide defaults when no architecture-specific optimization is detected

 */

#ifndef __arch__swab16

#  define __arch__swab16(x) ___swab16(x)

#endif

#ifndef __arch__swab32

#  define __arch__swab32(x) ___swab32(x)

#endif

#ifndef __arch__swab64

#  define __arch__swab64(x) ___swab64(x)

#endif

#ifndef __arch__swab16p

#  define __arch__swab16p(x) __arch__swab16(*(x))

#endif

#ifndef __arch__swab32p

#  define __arch__swab32p(x) __arch__swab32(*(x))

#endif

#ifndef __arch__swab64p

#  define __arch__swab64p(x) __arch__swab64(*(x))

#endif

#ifndef __arch__swab16s

#  define __arch__swab16s(x) ((void)(*(x) = __arch__swab16p(x)))

#endif

#ifndef __arch__swab32s

#  define __arch__swab32s(x) ((void)(*(x) = __arch__swab32p(x)))

#endif

#ifndef __arch__swab64s

#  define __arch__swab64s(x) ((void)(*(x) = __arch__swab64p(x)))

#endif

/*

 * Allow constant folding

 */

#if defined(__GNUC__) && defined(__OPTIMIZE__)

#  define __swab16(x) \

(__builtin_constant_p((__u16)(x)) ? \

 ___constant_swab16((x)) : \

 __fswab16((x)))

#  define __swab32(x) \

(__builtin_constant_p((__u32)(x)) ? \

 ___constant_swab32((x)) : \

 __fswab32((x)))

#  define __swab64(x) \

(__builtin_constant_p((__u64)(x)) ? \

 ___constant_swab64((x)) : \

 __fswab64((x)))

#else

#  define __swab16(x) __fswab16(x)

#  define __swab32(x) __fswab32(x)

#  define __swab64(x) __fswab64(x)

#endif /* OPTIMIZE */

static __inline__ __attribute_const__ __u16 __fswab16(__u16 x)

{

        return __arch__swab16(x);

}

static __inline__ __u16 __swab16p(const __u16 *x)

{

        return __arch__swab16p(x);

}

static __inline__ void __swab16s(__u16 *addr)

{

        __arch__swab16s(addr);

}

static __inline__ __attribute_const__ __u32 __fswab32(__u32 x)

{

        return __arch__swab32(x);

}

static __inline__ __u32 __swab32p(const __u32 *x)

{

        return __arch__swab32p(x);

}

static __inline__ void __swab32s(__u32 *addr)

{

        __arch__swab32s(addr);

}

#ifdef __BYTEORDER_HAS_U64__

static __inline__ __attribute_const__ __u64 __fswab64(__u64 x)

{

#  ifdef __SWAB_64_THRU_32__

        __u32 h = x >> 32;

        __u32 l = x & ((1ULL<<32)-1);

        return (((__u64)__swab32(l)) << 32) | ((__u64)(__swab32(h)));

#  else

        return __arch__swab64(x);

#  endif

}

static __inline__ __u64 __swab64p(const __u64 *x)

{

        return __arch__swab64p(x);

}

static __inline__ void __swab64s(__u64 *addr)

{

        __arch__swab64s(addr);

}

#endif /* __BYTEORDER_HAS_U64__ */

#if defined(__KERNEL__)

#define swab16 __swab16

#define swab32 __swab32

#define swab64 __swab64

#define swab16p __swab16p

#define swab32p __swab32p

#define swab64p __swab64p

#define swab16s __swab16s

#define swab32s __swab32s

#define swab64s __swab64s

#endif

#endif /* _LINUX_BYTEORDER_SWAB_H */