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 /* 43 * provide defaults when no architecture-specific optimization is detected 44 */ 45 #ifndef __arch__swab16 46 # define __arch__swab16(x) ___swab16(x) 47 #endif 48 #ifndef __arch__swab32 49 # define __arch__swab32(x) ___swab32(x) 50 #endif 51 #ifndef __arch__swab64 52 # define __arch__swab64(x) ___swab64(x) 53 #endif 54 55 #ifndef __arch__swab16p 56 # define __arch__swab16p(x) __swab16(*(x)) 57 #endif 58 #ifndef __arch__swab32p 59 # define __arch__swab32p(x) __swab32(*(x)) 60 #endif 61 #ifndef __arch__swab64p 62 # define __arch__swab64p(x) __swab64(*(x)) 63 #endif 64 65 #ifndef __arch__swab16s 66 # define __arch__swab16s(x) do { *(x) = __swab16p((x)); } while (0) 67 #endif 68 #ifndef __arch__swab32s 69 # define __arch__swab32s(x) do { *(x) = __swab32p((x)); } while (0) 70 #endif 71 #ifndef __arch__swab64s 72 # define __arch__swab64s(x) do { *(x) = __swab64p((x)); } while (0) 73 #endif 74 75 76 /* 77 * Allow constant folding 78 */ 79 #if defined(__GNUC__) && (__GNUC__ >= 2) && defined(__OPTIMIZE__) 80 # define __swab16(x) \ 81 (__builtin_constant_p((__u16)(x)) ? \ 82 ___swab16((x)) : \ 83 __fswab16((x))) 84 # define __swab32(x) \ 85 (__builtin_constant_p((__u32)(x)) ? \ 86 ___swab32((x)) : \ 87 __fswab32((x))) 88 # define __swab64(x) \ 89 (__builtin_constant_p((__u64)(x)) ? \ 90 ___swab64((x)) : \ 91 __fswab64((x))) 92 #else 93 # define __swab16(x) __fswab16(x) 94 # define __swab32(x) __fswab32(x) 95 # define __swab64(x) __fswab64(x) 96 #endif /* OPTIMIZE */ 97 98 99 static __inline__ __attribute__((const)) __u16 __fswab16(__u16 x) 100 { 101 return __arch__swab16(x); 102 } 103 static __inline__ __u16 __swab16p(__u16 *x) 104 { 105 return __arch__swab16p(x); 106 } 107 static __inline__ void __swab16s(__u16 *addr) 108 { 109 __arch__swab16s(addr); 110 } 111 112 static __inline__ __attribute__((const)) __u32 __fswab32(__u32 x) 113 { 114 return __arch__swab32(x); 115 } 116 static __inline__ __u32 __swab32p(__u32 *x) 117 { 118 return __arch__swab32p(x); 119 } 120 static __inline__ void __swab32s(__u32 *addr) 121 { 122 __arch__swab32s(addr); 123 } 124 125 #ifdef __BYTEORDER_HAS_U64__ 126 static __inline__ __attribute__((const)) __u64 __fswab64(__u64 x) 127 { 128 # ifdef __SWAB_64_THRU_32__ 129 __u32 h = x >> 32; 130 __u32 l = x & ((1ULL<<32)-1); 131 return (((__u64)__swab32(l)) << 32) | ((__u64)(__swab32(h))); 132 # else 133 return __arch__swab64(x); 134 # endif 135 } 136 static __inline__ __u64 __swab64p(__u64 *x) 137 { 138 return __arch__swab64p(x); 139 } 140 static __inline__ void __swab64s(__u64 *addr) 141 { 142 __arch__swab64s(addr); 143 } 144 #endif /* __BYTEORDER_HAS_U64__ */ 145 146 #if defined(__KERNEL__) 147 #define swab16 __swab16 148 #define swab32 __swab32 149 #define swab64 __swab64 150 #define swab16p __swab16p 151 #define swab32p __swab32p 152 #define swab64p __swab64p 153 #define swab16s __swab16s 154 #define swab32s __swab32s 155 #define swab64s __swab64s 156 #endif 157 158 #endif /* _LINUX_BYTEORDER_SWAB_H */ 159