1 #ifndef _LINUX_SWAB_H 2 #define _LINUX_SWAB_H 3 4 #include <linux/types.h> 5 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__ __u16 __fswab16(__u16 val) 47 { 48 #ifdef __arch_swab16 49 return __arch_swab16(val); 50 #else 51 return ___constant_swab16(val); 52 #endif 53 } 54 55 static __inline__ __u32 __fswab32(__u32 val) 56 { 57 #ifdef __arch_swab32 58 return __arch_swab32(val); 59 #else 60 return ___constant_swab32(val); 61 #endif 62 } 63 64 static __inline__ __u64 __fswab64(__u64 val) 65 { 66 #ifdef __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__ __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__ __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 #define __swab16(x) \ 100 (__builtin_constant_p((__u16)(x)) ? \ 101 ___constant_swab16(x) : \ 102 __fswab16(x)) 103 104 /** 105 * __swab32 - return a byteswapped 32-bit value 106 * @x: value to byteswap 107 */ 108 #define __swab32(x) \ 109 (__builtin_constant_p((__u32)(x)) ? \ 110 ___constant_swab32(x) : \ 111 __fswab32(x)) 112 113 /** 114 * __swab64 - return a byteswapped 64-bit value 115 * @x: value to byteswap 116 */ 117 #define __swab64(x) \ 118 (__builtin_constant_p((__u64)(x)) ? \ 119 ___constant_swab64(x) : \ 120 __fswab64(x)) 121 122 /** 123 * __swahw32 - return a word-swapped 32-bit value 124 * @x: value to wordswap 125 * 126 * __swahw32(0x12340000) is 0x00001234 127 */ 128 #define __swahw32(x) \ 129 (__builtin_constant_p((__u32)(x)) ? \ 130 ___constant_swahw32(x) : \ 131 __fswahw32(x)) 132 133 /** 134 * __swahb32 - return a high and low byte-swapped 32-bit value 135 * @x: value to byteswap 136 * 137 * __swahb32(0x12345678) is 0x34127856 138 */ 139 #define __swahb32(x) \ 140 (__builtin_constant_p((__u32)(x)) ? \ 141 ___constant_swahb32(x) : \ 142 __fswahb32(x)) 143 144 /** 145 * __swab16p - return a byteswapped 16-bit value from a pointer 146 * @p: pointer to a naturally-aligned 16-bit value 147 */ 148 static __inline__ __u16 __swab16p(const __u16 *p) 149 { 150 #ifdef __arch_swab16p 151 return __arch_swab16p(p); 152 #else 153 return __swab16(*p); 154 #endif 155 } 156 157 /** 158 * __swab32p - return a byteswapped 32-bit value from a pointer 159 * @p: pointer to a naturally-aligned 32-bit value 160 */ 161 static __inline__ __u32 __swab32p(const __u32 *p) 162 { 163 #ifdef __arch_swab32p 164 return __arch_swab32p(p); 165 #else 166 return __swab32(*p); 167 #endif 168 } 169 170 /** 171 * __swab64p - return a byteswapped 64-bit value from a pointer 172 * @p: pointer to a naturally-aligned 64-bit value 173 */ 174 static __inline__ __u64 __swab64p(const __u64 *p) 175 { 176 #ifdef __arch_swab64p 177 return __arch_swab64p(p); 178 #else 179 return __swab64(*p); 180 #endif 181 } 182 183 /** 184 * __swahw32p - return a wordswapped 32-bit value from a pointer 185 * @p: pointer to a naturally-aligned 32-bit value 186 * 187 * See __swahw32() for details of wordswapping. 188 */ 189 static __inline__ __u32 __swahw32p(const __u32 *p) 190 { 191 #ifdef __arch_swahw32p 192 return __arch_swahw32p(p); 193 #else 194 return __swahw32(*p); 195 #endif 196 } 197 198 /** 199 * __swahb32p - return a high and low byteswapped 32-bit value from a pointer 200 * @p: pointer to a naturally-aligned 32-bit value 201 * 202 * See __swahb32() for details of high/low byteswapping. 203 */ 204 static __inline__ __u32 __swahb32p(const __u32 *p) 205 { 206 #ifdef __arch_swahb32p 207 return __arch_swahb32p(p); 208 #else 209 return __swahb32(*p); 210 #endif 211 } 212 213 /** 214 * __swab16s - byteswap a 16-bit value in-place 215 * @p: pointer to a naturally-aligned 16-bit value 216 */ 217 static __inline__ void __swab16s(__u16 *p) 218 { 219 #ifdef __arch_swab16s 220 __arch_swab16s(p); 221 #else 222 *p = __swab16p(p); 223 #endif 224 } 225 /** 226 * __swab32s - byteswap a 32-bit value in-place 227 * @p: pointer to a naturally-aligned 32-bit value 228 */ 229 static __inline__ void __swab32s(__u32 *p) 230 { 231 #ifdef __arch_swab32s 232 __arch_swab32s(p); 233 #else 234 *p = __swab32p(p); 235 #endif 236 } 237 238 /** 239 * __swab64s - byteswap a 64-bit value in-place 240 * @p: pointer to a naturally-aligned 64-bit value 241 */ 242 static __inline__ void __swab64s(__u64 *p) 243 { 244 #ifdef __arch_swab64s 245 __arch_swab64s(p); 246 #else 247 *p = __swab64p(p); 248 #endif 249 } 250 251 /** 252 * __swahw32s - wordswap a 32-bit value in-place 253 * @p: pointer to a naturally-aligned 32-bit value 254 * 255 * See __swahw32() for details of wordswapping 256 */ 257 static __inline__ void __swahw32s(__u32 *p) 258 { 259 #ifdef __arch_swahw32s 260 __arch_swahw32s(p); 261 #else 262 *p = __swahw32p(p); 263 #endif 264 } 265 266 /** 267 * __swahb32s - high and low byteswap a 32-bit value in-place 268 * @p: pointer to a naturally-aligned 32-bit value 269 * 270 * See __swahb32() for details of high and low byte swapping 271 */ 272 static __inline__ void __swahb32s(__u32 *p) 273 { 274 #ifdef __arch_swahb32s 275 __arch_swahb32s(p); 276 #else 277 *p = __swahb32p(p); 278 #endif 279 } 280 281 282 #endif /* _LINUX_SWAB_H */ 283
