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#define ___constant_swab16(x) ___swab16(x) 43#define ___constant_swab32(x) ___swab32(x) 44#define ___constant_swab64(x) ___swab64(x) 45 46/* 47 * provide defaults when no architecture-specific optimization is detected 48 */ 49#ifndef __arch__swab16 50# define __arch__swab16(x) ___swab16(x) 51#endif 52#ifndef __arch__swab32 53# define __arch__swab32(x) ___swab32(x) 54#endif 55#ifndef __arch__swab64 56# define __arch__swab64(x) ___swab64(x) 57#endif 58 59#ifndef __arch__swab16p 60# define __arch__swab16p(x) __swab16(*(x)) 61#endif 62#ifndef __arch__swab32p 63# define __arch__swab32p(x) __swab32(*(x)) 64#endif 65#ifndef __arch__swab64p 66# define __arch__swab64p(x) __swab64(*(x)) 67#endif 68 69#ifndef __arch__swab16s 70# define __arch__swab16s(x) do { *(x) = __swab16p((x)); } while (0) 71#endif 72#ifndef __arch__swab32s 73# define __arch__swab32s(x) do { *(x) = __swab32p((x)); } while (0) 74#endif 75#ifndef __arch__swab64s 76# define __arch__swab64s(x) do { *(x) = __swab64p((x)); } while (0) 77#endif 78 79 80/* 81 * Allow constant folding 82 */ 83#if defined(__GNUC__) && (__GNUC__ >= 2) && defined(__OPTIMIZE__) 84# define __swab16(x) \ 85(__builtin_constant_p((__u16)(x)) ? \ 86 ___swab16((x)) : \ 87 __fswab16((x))) 88# define __swab32(x) \ 89(__builtin_constant_p((__u32)(x)) ? \ 90 ___swab32((x)) : \ 91 __fswab32((x))) 92# define __swab64(x) \ 93(__builtin_constant_p((__u64)(x)) ? \ 94 ___swab64((x)) : \ 95 __fswab64((x))) 96#else 97# define __swab16(x) __fswab16(x) 98# define __swab32(x) __fswab32(x) 99# define __swab64(x) __fswab64(x) 100#endif /* OPTIMIZE */ 101 102 103static __inline__ __attribute__((const)) __u16 __fswab16(__u16 x) 104{ 105 return __arch__swab16(x); 106} 107static __inline__ __u16 __swab16p(const __u16 *x) 108{ 109 return __arch__swab16p(x); 110} 111static __inline__ void __swab16s(__u16 *addr) 112{ 113 __arch__swab16s(addr); 114} 115 116static __inline__ __attribute__((const)) __u32 __fswab32(__u32 x) 117{ 118 return __arch__swab32(x); 119} 120static __inline__ __u32 __swab32p(const __u32 *x) 121{ 122 return __arch__swab32p(x); 123} 124static __inline__ void __swab32s(__u32 *addr) 125{ 126 __arch__swab32s(addr); 127} 128 129static __inline__ __attribute__((const)) __u64 __fswab64(__u64 x) 130{ 131# ifdef __SWAB_64_THRU_32__ 132 __u32 h = x >> 32; 133 __u32 l = x & ((1ULL<<32)-1); 134 return (((__u64)__swab32(l)) << 32) | ((__u64)(__swab32(h))); 135# else 136 return __arch__swab64(x); 137# endif 138} 139static __inline__ __u64 __swab64p(const __u64 *x) 140{ 141 return __arch__swab64p(x); 142} 143static __inline__ void __swab64s(__u64 *addr) 144{ 145 __arch__swab64s(addr); 146} 147 148#if defined(__KERNEL__) 149#define swab16 __swab16 150#define swab32 __swab32 151#define swab64 __swab64 152#define swab16p __swab16p 153#define swab32p __swab32p 154#define swab64p __swab64p 155#define swab16s __swab16s 156#define swab32s __swab32s 157#define swab64s __swab64s 158#endif 159 160#endif /* _LINUX_BYTEORDER_SWAB_H */ 161