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 (at) 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 #include <linux/compiler.h> 19 20 /* casts are necessary for constants, because we never know how for sure 21 * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way. 22 */ 23 #define ___swab16(x) \ 24 ({ \ 25 __u16 __x = (x); \ 26 ((__u16)( \ 27 (((__u16)(__x) & (__u16)0x00ffU) << 8) | \ 28 (((__u16)(__x) & (__u16)0xff00U) >> 8) )); \ 29 }) 30 31 #define ___swab32(x) \ 32 ({ \ 33 __u32 __x = (x); \ 34 ((__u32)( \ 35 (((__u32)(__x) & (__u32)0x000000ffUL) << 24) | \ 36 (((__u32)(__x) & (__u32)0x0000ff00UL) << 8) | \ 37 (((__u32)(__x) & (__u32)0x00ff0000UL) >> 8) | \ 38 (((__u32)(__x) & (__u32)0xff000000UL) >> 24) )); \ 39 }) 40 41 #define ___swab64(x) \ 42 ({ \ 43 __u64 __x = (x); \ 44 ((__u64)( \ 45 (__u64)(((__u64)(__x) & (__u64)0x00000000000000ffULL) << 56) | \ 46 (__u64)(((__u64)(__x) & (__u64)0x000000000000ff00ULL) << 40) | \ 47 (__u64)(((__u64)(__x) & (__u64)0x0000000000ff0000ULL) << 24) | \ 48 (__u64)(((__u64)(__x) & (__u64)0x00000000ff000000ULL) << 8) | \ 49 (__u64)(((__u64)(__x) & (__u64)0x000000ff00000000ULL) >> 8) | \ 50 (__u64)(((__u64)(__x) & (__u64)0x0000ff0000000000ULL) >> 24) | \ 51 (__u64)(((__u64)(__x) & (__u64)0x00ff000000000000ULL) >> 40) | \ 52 (__u64)(((__u64)(__x) & (__u64)0xff00000000000000ULL) >> 56) )); \ 53 }) 54 55 #define ___constant_swab16(x) \ 56 ((__u16)( \ 57 (((__u16)(x) & (__u16)0x00ffU) << 8) | \ 58 (((__u16)(x) & (__u16)0xff00U) >> 8) )) 59 #define ___constant_swab32(x) \ 60 ((__u32)( \ 61 (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \ 62 (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \ 63 (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \ 64 (((__u32)(x) & (__u32)0xff000000UL) >> 24) )) 65 #define ___constant_swab64(x) \ 66 ((__u64)( \ 67 (__u64)(((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \ 68 (__u64)(((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \ 69 (__u64)(((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \ 70 (__u64)(((__u64)(x) & (__u64)0x00000000ff000000ULL) << 8) | \ 71 (__u64)(((__u64)(x) & (__u64)0x000000ff00000000ULL) >> 8) | \ 72 (__u64)(((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \ 73 (__u64)(((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \ 74 (__u64)(((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56) )) 75 76 /* 77 * provide defaults when no architecture-specific optimization is detected 78 */ 79 #ifndef __arch__swab16 80 # define __arch__swab16(x) ({ __u16 __tmp = (x) ; ___swab16(__tmp); }) 81 #endif 82 #ifndef __arch__swab32 83 # define __arch__swab32(x) ({ __u32 __tmp = (x) ; ___swab32(__tmp); }) 84 #endif 85 #ifndef __arch__swab64 86 # define __arch__swab64(x) ({ __u64 __tmp = (x) ; ___swab64(__tmp); }) 87 #endif 88 89 #ifndef __arch__swab16p 90 # define __arch__swab16p(x) __arch__swab16(*(x)) 91 #endif 92 #ifndef __arch__swab32p 93 # define __arch__swab32p(x) __arch__swab32(*(x)) 94 #endif 95 #ifndef __arch__swab64p 96 # define __arch__swab64p(x) __arch__swab64(*(x)) 97 #endif 98 99 #ifndef __arch__swab16s 100 # define __arch__swab16s(x) do { *(x) = __arch__swab16p((x)); } while (0) 101 #endif 102 #ifndef __arch__swab32s 103 # define __arch__swab32s(x) do { *(x) = __arch__swab32p((x)); } while (0) 104 #endif 105 #ifndef __arch__swab64s 106 # define __arch__swab64s(x) do { *(x) = __arch__swab64p((x)); } while (0) 107 #endif 108 109 110 /* 111 * Allow constant folding 112 */ 113 #if defined(__GNUC__) && defined(__OPTIMIZE__) 114 # define __swab16(x) \ 115 (__builtin_constant_p((__u16)(x)) ? \ 116 ___swab16((x)) : \ 117 __fswab16((x))) 118 # define __swab32(x) \ 119 (__builtin_constant_p((__u32)(x)) ? \ 120 ___swab32((x)) : \ 121 __fswab32((x))) 122 # define __swab64(x) \ 123 (__builtin_constant_p((__u64)(x)) ? \ 124 ___swab64((x)) : \ 125 __fswab64((x))) 126 #else 127 # define __swab16(x) __fswab16(x) 128 # define __swab32(x) __fswab32(x) 129 # define __swab64(x) __fswab64(x) 130 #endif /* OPTIMIZE */ 131 132 133 static __inline__ __attribute_const__ __u16 __fswab16(__u16 x) 134 { 135 return __arch__swab16(x); 136 } 137 static __inline__ __u16 __swab16p(const __u16 *x) 138 { 139 return __arch__swab16p(x); 140 } 141 static __inline__ void __swab16s(__u16 *addr) 142 { 143 __arch__swab16s(addr); 144 } 145 146 static __inline__ __attribute_const__ __u32 __fswab32(__u32 x) 147 { 148 return __arch__swab32(x); 149 } 150 static __inline__ __u32 __swab32p(const __u32 *x) 151 { 152 return __arch__swab32p(x); 153 } 154 static __inline__ void __swab32s(__u32 *addr) 155 { 156 __arch__swab32s(addr); 157 } 158 159 #ifdef __BYTEORDER_HAS_U64__ 160 static __inline__ __attribute_const__ __u64 __fswab64(__u64 x) 161 { 162 # ifdef __SWAB_64_THRU_32__ 163 __u32 h = x >> 32; 164 __u32 l = x & ((1ULL<<32)-1); 165 return (((__u64)__swab32(l)) << 32) | ((__u64)(__swab32(h))); 166 # else 167 return __arch__swab64(x); 168 # endif 169 } 170 static __inline__ __u64 __swab64p(const __u64 *x) 171 { 172 return __arch__swab64p(x); 173 } 174 static __inline__ void __swab64s(__u64 *addr) 175 { 176 __arch__swab64s(addr); 177 } 178 #endif /* __BYTEORDER_HAS_U64__ */ 179 180 #if defined(__KERNEL__) 181 #define swab16 __swab16 182 #define swab32 __swab32 183 #define swab64 __swab64 184 #define swab16p __swab16p 185 #define swab32p __swab32p 186 #define swab64p __swab64p 187 #define swab16s __swab16s 188 #define swab32s __swab32s 189 #define swab64s __swab64s 190 #endif 191 192 #endif /* _LINUX_BYTEORDER_SWAB_H */ 193
