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 __fswab16(__u16 x)103static __inline__ __attribute__((const)) __u16 __fswab16(__u16 x) 104 { 105 return __arch__swab16(x); 106 } __swab16p(const __u16 * x)107static __inline__ __u16 __swab16p(const __u16 *x) 108 { 109 return __arch__swab16p(x); 110 } __swab16s(__u16 * addr)111static __inline__ void __swab16s(__u16 *addr) 112 { 113 __arch__swab16s(addr); 114 } 115 __fswab32(__u32 x)116static __inline__ __attribute__((const)) __u32 __fswab32(__u32 x) 117 { 118 return __arch__swab32(x); 119 } __swab32p(const __u32 * x)120static __inline__ __u32 __swab32p(const __u32 *x) 121 { 122 return __arch__swab32p(x); 123 } __swab32s(__u32 * addr)124static __inline__ void __swab32s(__u32 *addr) 125 { 126 __arch__swab32s(addr); 127 } 128 __fswab64(__u64 x)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 } __swab64p(const __u64 * x)139static __inline__ __u64 __swab64p(const __u64 *x) 140 { 141 return __arch__swab64p(x); 142 } __swab64s(__u64 * addr)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