1 #ifndef _UAPI_LINUX_SWAB_H 2 #define _UAPI_LINUX_SWAB_H 3 4 #include <linux/types.h> 5 #include <linux/compiler.h> 6 #include <asm/swab.h> 7 8 /* 9 * casts are necessary for constants, because we never know how for sure 10 * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way. 11 */ 12 #define ___constant_swab16(x) ((__u16)( \ 13 (((__u16)(x) & (__u16)0x00ffU) << 8) | \ 14 (((__u16)(x) & (__u16)0xff00U) >> 8))) 15 16 #define ___constant_swab32(x) ((__u32)( \ 17 (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \ 18 (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \ 19 (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \ 20 (((__u32)(x) & (__u32)0xff000000UL) >> 24))) 21 22 #define ___constant_swab64(x) ((__u64)( \ 23 (((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \ 24 (((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \ 25 (((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \ 26 (((__u64)(x) & (__u64)0x00000000ff000000ULL) << 8) | \ 27 (((__u64)(x) & (__u64)0x000000ff00000000ULL) >> 8) | \ 28 (((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \ 29 (((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \ 30 (((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56))) 31 32 #define ___constant_swahw32(x) ((__u32)( \ 33 (((__u32)(x) & (__u32)0x0000ffffUL) << 16) | \ 34 (((__u32)(x) & (__u32)0xffff0000UL) >> 16))) 35 36 #define ___constant_swahb32(x) ((__u32)( \ 37 (((__u32)(x) & (__u32)0x00ff00ffUL) << 8) | \ 38 (((__u32)(x) & (__u32)0xff00ff00UL) >> 8))) 39 40 /* 41 * Implement the following as inlines, but define the interface using 42 * macros to allow constant folding when possible: 43 * ___swab16, ___swab32, ___swab64, ___swahw32, ___swahb32 44 */ 45 46 static inline __attribute_const__ __u16 __fswab16(__u16 val) 47 { 48 #if defined (__arch_swab16) 49 return __arch_swab16(val); 50 #else 51 return ___constant_swab16(val); 52 #endif 53 } 54 55 static inline __attribute_const__ __u32 __fswab32(__u32 val) 56 { 57 #if defined(__arch_swab32) 58 return __arch_swab32(val); 59 #else 60 return ___constant_swab32(val); 61 #endif 62 } 63 64 static inline __attribute_const__ __u64 __fswab64(__u64 val) 65 { 66 #if defined (__arch_swab64) 67 return __arch_swab64(val); 68 #elif defined(__SWAB_64_THRU_32__) 69 __u32 h = val >> 32; 70 __u32 l = val & ((1ULL << 32) - 1); 71 return (((__u64)__fswab32(l)) << 32) | ((__u64)(__fswab32(h))); 72 #else 73 return ___constant_swab64(val); 74 #endif 75 } 76 77 static inline __attribute_const__ __u32 __fswahw32(__u32 val) 78 { 79 #ifdef __arch_swahw32 80 return __arch_swahw32(val); 81 #else 82 return ___constant_swahw32(val); 83 #endif 84 } 85 86 static inline __attribute_const__ __u32 __fswahb32(__u32 val) 87 { 88 #ifdef __arch_swahb32 89 return __arch_swahb32(val); 90 #else 91 return ___constant_swahb32(val); 92 #endif 93 } 94 95 /** 96 * __swab16 - return a byteswapped 16-bit value 97 * @x: value to byteswap 98 */ 99 #ifdef __HAVE_BUILTIN_BSWAP16__ 100 #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x)) 101 #else 102 #define __swab16(x) \ 103 (__builtin_constant_p((__u16)(x)) ? \ 104 ___constant_swab16(x) : \ 105 __fswab16(x)) 106 #endif 107 108 /** 109 * __swab32 - return a byteswapped 32-bit value 110 * @x: value to byteswap 111 */ 112 #ifdef __HAVE_BUILTIN_BSWAP32__ 113 #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x)) 114 #else 115 #define __swab32(x) \ 116 (__builtin_constant_p((__u32)(x)) ? \ 117 ___constant_swab32(x) : \ 118 __fswab32(x)) 119 #endif 120 121 /** 122 * __swab64 - return a byteswapped 64-bit value 123 * @x: value to byteswap 124 */ 125 #ifdef __HAVE_BUILTIN_BSWAP64__ 126 #define __swab64(x) (__u64)__builtin_bswap64((__u64)(x)) 127 #else 128 #define __swab64(x) \ 129 (__builtin_constant_p((__u64)(x)) ? \ 130 ___constant_swab64(x) : \ 131 __fswab64(x)) 132 #endif 133 134 /** 135 * __swahw32 - return a word-swapped 32-bit value 136 * @x: value to wordswap 137 * 138 * __swahw32(0x12340000) is 0x00001234 139 */ 140 #define __swahw32(x) \ 141 (__builtin_constant_p((__u32)(x)) ? \ 142 ___constant_swahw32(x) : \ 143 __fswahw32(x)) 144 145 /** 146 * __swahb32 - return a high and low byte-swapped 32-bit value 147 * @x: value to byteswap 148 * 149 * __swahb32(0x12345678) is 0x34127856 150 */ 151 #define __swahb32(x) \ 152 (__builtin_constant_p((__u32)(x)) ? \ 153 ___constant_swahb32(x) : \ 154 __fswahb32(x)) 155 156 /** 157 * __swab16p - return a byteswapped 16-bit value from a pointer 158 * @p: pointer to a naturally-aligned 16-bit value 159 */ 160 static __always_inline __u16 __swab16p(const __u16 *p) 161 { 162 #ifdef __arch_swab16p 163 return __arch_swab16p(p); 164 #else 165 return __swab16(*p); 166 #endif 167 } 168 169 /** 170 * __swab32p - return a byteswapped 32-bit value from a pointer 171 * @p: pointer to a naturally-aligned 32-bit value 172 */ 173 static __always_inline __u32 __swab32p(const __u32 *p) 174 { 175 #ifdef __arch_swab32p 176 return __arch_swab32p(p); 177 #else 178 return __swab32(*p); 179 #endif 180 } 181 182 /** 183 * __swab64p - return a byteswapped 64-bit value from a pointer 184 * @p: pointer to a naturally-aligned 64-bit value 185 */ 186 static __always_inline __u64 __swab64p(const __u64 *p) 187 { 188 #ifdef __arch_swab64p 189 return __arch_swab64p(p); 190 #else 191 return __swab64(*p); 192 #endif 193 } 194 195 /** 196 * __swahw32p - return a wordswapped 32-bit value from a pointer 197 * @p: pointer to a naturally-aligned 32-bit value 198 * 199 * See __swahw32() for details of wordswapping. 200 */ 201 static inline __u32 __swahw32p(const __u32 *p) 202 { 203 #ifdef __arch_swahw32p 204 return __arch_swahw32p(p); 205 #else 206 return __swahw32(*p); 207 #endif 208 } 209 210 /** 211 * __swahb32p - return a high and low byteswapped 32-bit value from a pointer 212 * @p: pointer to a naturally-aligned 32-bit value 213 * 214 * See __swahb32() for details of high/low byteswapping. 215 */ 216 static inline __u32 __swahb32p(const __u32 *p) 217 { 218 #ifdef __arch_swahb32p 219 return __arch_swahb32p(p); 220 #else 221 return __swahb32(*p); 222 #endif 223 } 224 225 /** 226 * __swab16s - byteswap a 16-bit value in-place 227 * @p: pointer to a naturally-aligned 16-bit value 228 */ 229 static inline void __swab16s(__u16 *p) 230 { 231 #ifdef __arch_swab16s 232 __arch_swab16s(p); 233 #else 234 *p = __swab16p(p); 235 #endif 236 } 237 /** 238 * __swab32s - byteswap a 32-bit value in-place 239 * @p: pointer to a naturally-aligned 32-bit value 240 */ 241 static __always_inline void __swab32s(__u32 *p) 242 { 243 #ifdef __arch_swab32s 244 __arch_swab32s(p); 245 #else 246 *p = __swab32p(p); 247 #endif 248 } 249 250 /** 251 * __swab64s - byteswap a 64-bit value in-place 252 * @p: pointer to a naturally-aligned 64-bit value 253 */ 254 static __always_inline void __swab64s(__u64 *p) 255 { 256 #ifdef __arch_swab64s 257 __arch_swab64s(p); 258 #else 259 *p = __swab64p(p); 260 #endif 261 } 262 263 /** 264 * __swahw32s - wordswap a 32-bit value in-place 265 * @p: pointer to a naturally-aligned 32-bit value 266 * 267 * See __swahw32() for details of wordswapping 268 */ 269 static inline void __swahw32s(__u32 *p) 270 { 271 #ifdef __arch_swahw32s 272 __arch_swahw32s(p); 273 #else 274 *p = __swahw32p(p); 275 #endif 276 } 277 278 /** 279 * __swahb32s - high and low byteswap a 32-bit value in-place 280 * @p: pointer to a naturally-aligned 32-bit value 281 * 282 * See __swahb32() for details of high and low byte swapping 283 */ 284 static inline void __swahb32s(__u32 *p) 285 { 286 #ifdef __arch_swahb32s 287 __arch_swahb32s(p); 288 #else 289 *p = __swahb32p(p); 290 #endif 291 } 292 293 294 #endif /* _UAPI_LINUX_SWAB_H */ 295