1 #ifndef __XEN_BYTEORDER_SWAB_H__ 2 #define __XEN_BYTEORDER_SWAB_H__ 3 4 /* 5 * Byte-swapping, independently from CPU endianness 6 * swabXX[ps]?(foo) 7 * 8 * Francois-Rene Rideau <fare@tunes.org> 19971205 9 * separated swab functions from cpu_to_XX, 10 * to clean up support for bizarre-endian architectures. 11 */ 12 13 /* casts are necessary for constants, because we never know how for sure 14 * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way. 15 */ 16 #define ___swab16(x) \ 17 ({ \ 18 __u16 __x = (x); \ 19 ((__u16)( \ 20 (((__u16)(__x) & (__u16)0x00ffU) << 8) | \ 21 (((__u16)(__x) & (__u16)0xff00U) >> 8) )); \ 22 }) 23 24 #define ___swab32(x) \ 25 ({ \ 26 __u32 __x = (x); \ 27 ((__u32)( \ 28 (((__u32)(__x) & (__u32)0x000000ffUL) << 24) | \ 29 (((__u32)(__x) & (__u32)0x0000ff00UL) << 8) | \ 30 (((__u32)(__x) & (__u32)0x00ff0000UL) >> 8) | \ 31 (((__u32)(__x) & (__u32)0xff000000UL) >> 24) )); \ 32 }) 33 34 #define ___swab64(x) \ 35 ({ \ 36 __u64 __x = (x); \ 37 ((__u64)( \ 38 (__u64)(((__u64)(__x) & (__u64)0x00000000000000ffULL) << 56) | \ 39 (__u64)(((__u64)(__x) & (__u64)0x000000000000ff00ULL) << 40) | \ 40 (__u64)(((__u64)(__x) & (__u64)0x0000000000ff0000ULL) << 24) | \ 41 (__u64)(((__u64)(__x) & (__u64)0x00000000ff000000ULL) << 8) | \ 42 (__u64)(((__u64)(__x) & (__u64)0x000000ff00000000ULL) >> 8) | \ 43 (__u64)(((__u64)(__x) & (__u64)0x0000ff0000000000ULL) >> 24) | \ 44 (__u64)(((__u64)(__x) & (__u64)0x00ff000000000000ULL) >> 40) | \ 45 (__u64)(((__u64)(__x) & (__u64)0xff00000000000000ULL) >> 56) )); \ 46 }) 47 48 #define ___constant_swab16(x) \ 49 ((__u16)( \ 50 (((__u16)(x) & (__u16)0x00ffU) << 8) | \ 51 (((__u16)(x) & (__u16)0xff00U) >> 8) )) 52 #define ___constant_swab32(x) \ 53 ((__u32)( \ 54 (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \ 55 (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \ 56 (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \ 57 (((__u32)(x) & (__u32)0xff000000UL) >> 24) )) 58 #define ___constant_swab64(x) \ 59 ((__u64)( \ 60 (__u64)(((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \ 61 (__u64)(((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \ 62 (__u64)(((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \ 63 (__u64)(((__u64)(x) & (__u64)0x00000000ff000000ULL) << 8) | \ 64 (__u64)(((__u64)(x) & (__u64)0x000000ff00000000ULL) >> 8) | \ 65 (__u64)(((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \ 66 (__u64)(((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \ 67 (__u64)(((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56) )) 68 69 /* 70 * provide defaults when no architecture-specific optimization is detected 71 */ 72 #ifndef __arch__swab16 73 # define __arch__swab16(x) ({ __u16 __tmp = (x) ; ___swab16(__tmp); }) 74 #endif 75 #ifndef __arch__swab32 76 # define __arch__swab32(x) ({ __u32 __tmp = (x) ; ___swab32(__tmp); }) 77 #endif 78 #ifndef __arch__swab64 79 # define __arch__swab64(x) ({ __u64 __tmp = (x) ; ___swab64(__tmp); }) 80 #endif 81 82 #ifndef __arch__swab16p 83 # define __arch__swab16p(x) __arch__swab16(*(x)) 84 #endif 85 #ifndef __arch__swab32p 86 # define __arch__swab32p(x) __arch__swab32(*(x)) 87 #endif 88 #ifndef __arch__swab64p 89 # define __arch__swab64p(x) __arch__swab64(*(x)) 90 #endif 91 92 #ifndef __arch__swab16s 93 # define __arch__swab16s(x) do { *(x) = __arch__swab16p((x)); } while (0) 94 #endif 95 #ifndef __arch__swab32s 96 # define __arch__swab32s(x) do { *(x) = __arch__swab32p((x)); } while (0) 97 #endif 98 #ifndef __arch__swab64s 99 # define __arch__swab64s(x) do { *(x) = __arch__swab64p((x)); } while (0) 100 #endif 101 102 103 /* 104 * Allow constant folding 105 */ 106 #if defined(__GNUC__) && defined(__OPTIMIZE__) 107 # define __swab16(x) \ 108 (__builtin_constant_p((__u16)(x)) ? \ 109 ___swab16((x)) : \ 110 __fswab16((x))) 111 # define __swab32(x) \ 112 (__builtin_constant_p((__u32)(x)) ? \ 113 ___swab32((x)) : \ 114 __fswab32((x))) 115 # define __swab64(x) \ 116 (__builtin_constant_p((__u64)(x)) ? \ 117 ___swab64((x)) : \ 118 __fswab64((x))) 119 #else 120 # define __swab16(x) __fswab16(x) 121 # define __swab32(x) __fswab32(x) 122 # define __swab64(x) __fswab64(x) 123 #endif /* OPTIMIZE */ 124 125 __fswab16(__u16 x)126static inline __attribute_const__ __u16 __fswab16(__u16 x) 127 { 128 return __arch__swab16(x); 129 } __swab16p(const __u16 * x)130static inline __u16 __swab16p(const __u16 *x) 131 { 132 return __arch__swab16p(x); 133 } __swab16s(__u16 * addr)134static inline void __swab16s(__u16 *addr) 135 { 136 __arch__swab16s(addr); 137 } 138 __fswab32(__u32 x)139static inline __attribute_const__ __u32 __fswab32(__u32 x) 140 { 141 return __arch__swab32(x); 142 } __swab32p(const __u32 * x)143static inline __u32 __swab32p(const __u32 *x) 144 { 145 return __arch__swab32p(x); 146 } __swab32s(__u32 * addr)147static inline void __swab32s(__u32 *addr) 148 { 149 __arch__swab32s(addr); 150 } 151 152 #ifdef __BYTEORDER_HAS_U64__ __fswab64(__u64 x)153static inline __attribute_const__ __u64 __fswab64(__u64 x) 154 { 155 # ifdef __SWAB_64_THRU_32__ 156 __u32 h = x >> 32; 157 __u32 l = x & ((1ULL<<32)-1); 158 return (((__u64)__swab32(l)) << 32) | ((__u64)(__swab32(h))); 159 # else 160 return __arch__swab64(x); 161 # endif 162 } __swab64p(const __u64 * x)163static inline __u64 __swab64p(const __u64 *x) 164 { 165 return __arch__swab64p(x); 166 } __swab64s(__u64 * addr)167static inline void __swab64s(__u64 *addr) 168 { 169 __arch__swab64s(addr); 170 } 171 #endif /* __BYTEORDER_HAS_U64__ */ 172 173 #define swab16 __swab16 174 #define swab32 __swab32 175 #define swab64 __swab64 176 #define swab16p __swab16p 177 #define swab32p __swab32p 178 #define swab64p __swab64p 179 #define swab16s __swab16s 180 #define swab32s __swab32s 181 #define swab64s __swab64s 182 183 #endif /* __XEN_BYTEORDER_SWAB_H__ */ 184