swab.h (6939B) - Raw
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 #ifndef _LINUX_SWAB_H 3 #define _LINUX_SWAB_H 4 5 #include <linux/types.h> 6 #include <linux/stddef.h> 7 #include <asm/bitsperlong.h> 8 #include <asm/swab.h> 9 10 /* 11 * casts are necessary for constants, because we never know how for sure 12 * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way. 13 */ 14 #define ___constant_swab16(x) ((__u16)( \ 15 (((__u16)(x) & (__u16)0x00ffU) << 8) | \ 16 (((__u16)(x) & (__u16)0xff00U) >> 8))) 17 18 #define ___constant_swab32(x) ((__u32)( \ 19 (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \ 20 (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \ 21 (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \ 22 (((__u32)(x) & (__u32)0xff000000UL) >> 24))) 23 24 #define ___constant_swab64(x) ((__u64)( \ 25 (((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \ 26 (((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \ 27 (((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \ 28 (((__u64)(x) & (__u64)0x00000000ff000000ULL) << 8) | \ 29 (((__u64)(x) & (__u64)0x000000ff00000000ULL) >> 8) | \ 30 (((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \ 31 (((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \ 32 (((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56))) 33 34 #define ___constant_swahw32(x) ((__u32)( \ 35 (((__u32)(x) & (__u32)0x0000ffffUL) << 16) | \ 36 (((__u32)(x) & (__u32)0xffff0000UL) >> 16))) 37 38 #define ___constant_swahb32(x) ((__u32)( \ 39 (((__u32)(x) & (__u32)0x00ff00ffUL) << 8) | \ 40 (((__u32)(x) & (__u32)0xff00ff00UL) >> 8))) 41 42 /* 43 * Implement the following as inlines, but define the interface using 44 * macros to allow constant folding when possible: 45 * ___swab16, ___swab32, ___swab64, ___swahw32, ___swahb32 46 */ 47 48 static __inline__ __u16 __fswab16(__u16 val) 49 { 50 #if defined (__arch_swab16) 51 return __arch_swab16(val); 52 #else 53 return ___constant_swab16(val); 54 #endif 55 } 56 57 static __inline__ __u32 __fswab32(__u32 val) 58 { 59 #if defined(__arch_swab32) 60 return __arch_swab32(val); 61 #else 62 return ___constant_swab32(val); 63 #endif 64 } 65 66 static __inline__ __u64 __fswab64(__u64 val) 67 { 68 #if defined (__arch_swab64) 69 return __arch_swab64(val); 70 #elif defined(__SWAB_64_THRU_32__) 71 __u32 h = val >> 32; 72 __u32 l = val & ((1ULL << 32) - 1); 73 return (((__u64)__fswab32(l)) << 32) | ((__u64)(__fswab32(h))); 74 #else 75 return ___constant_swab64(val); 76 #endif 77 } 78 79 static __inline__ __u32 __fswahw32(__u32 val) 80 { 81 #ifdef __arch_swahw32 82 return __arch_swahw32(val); 83 #else 84 return ___constant_swahw32(val); 85 #endif 86 } 87 88 static __inline__ __u32 __fswahb32(__u32 val) 89 { 90 #ifdef __arch_swahb32 91 return __arch_swahb32(val); 92 #else 93 return ___constant_swahb32(val); 94 #endif 95 } 96 97 /** 98 * __swab16 - return a byteswapped 16-bit value 99 * @x: value to byteswap 100 */ 101 #ifdef __HAVE_BUILTIN_BSWAP16__ 102 #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x)) 103 #else 104 #define __swab16(x) \ 105 (__u16)(__builtin_constant_p(x) ? \ 106 ___constant_swab16(x) : \ 107 __fswab16(x)) 108 #endif 109 110 /** 111 * __swab32 - return a byteswapped 32-bit value 112 * @x: value to byteswap 113 */ 114 #ifdef __HAVE_BUILTIN_BSWAP32__ 115 #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x)) 116 #else 117 #define __swab32(x) \ 118 (__u32)(__builtin_constant_p(x) ? \ 119 ___constant_swab32(x) : \ 120 __fswab32(x)) 121 #endif 122 123 /** 124 * __swab64 - return a byteswapped 64-bit value 125 * @x: value to byteswap 126 */ 127 #ifdef __HAVE_BUILTIN_BSWAP64__ 128 #define __swab64(x) (__u64)__builtin_bswap64((__u64)(x)) 129 #else 130 #define __swab64(x) \ 131 (__u64)(__builtin_constant_p(x) ? \ 132 ___constant_swab64(x) : \ 133 __fswab64(x)) 134 #endif 135 136 static __always_inline unsigned long __swab(const unsigned long y) 137 { 138 #if __BITS_PER_LONG == 64 139 return __swab64(y); 140 #else /* __BITS_PER_LONG == 32 */ 141 return __swab32(y); 142 #endif 143 } 144 145 /** 146 * __swahw32 - return a word-swapped 32-bit value 147 * @x: value to wordswap 148 * 149 * __swahw32(0x12340000) is 0x00001234 150 */ 151 #define __swahw32(x) \ 152 (__builtin_constant_p((__u32)(x)) ? \ 153 ___constant_swahw32(x) : \ 154 __fswahw32(x)) 155 156 /** 157 * __swahb32 - return a high and low byte-swapped 32-bit value 158 * @x: value to byteswap 159 * 160 * __swahb32(0x12345678) is 0x34127856 161 */ 162 #define __swahb32(x) \ 163 (__builtin_constant_p((__u32)(x)) ? \ 164 ___constant_swahb32(x) : \ 165 __fswahb32(x)) 166 167 /** 168 * __swab16p - return a byteswapped 16-bit value from a pointer 169 * @p: pointer to a naturally-aligned 16-bit value 170 */ 171 static __always_inline __u16 __swab16p(const __u16 *p) 172 { 173 #ifdef __arch_swab16p 174 return __arch_swab16p(p); 175 #else 176 return __swab16(*p); 177 #endif 178 } 179 180 /** 181 * __swab32p - return a byteswapped 32-bit value from a pointer 182 * @p: pointer to a naturally-aligned 32-bit value 183 */ 184 static __always_inline __u32 __swab32p(const __u32 *p) 185 { 186 #ifdef __arch_swab32p 187 return __arch_swab32p(p); 188 #else 189 return __swab32(*p); 190 #endif 191 } 192 193 /** 194 * __swab64p - return a byteswapped 64-bit value from a pointer 195 * @p: pointer to a naturally-aligned 64-bit value 196 */ 197 static __always_inline __u64 __swab64p(const __u64 *p) 198 { 199 #ifdef __arch_swab64p 200 return __arch_swab64p(p); 201 #else 202 return __swab64(*p); 203 #endif 204 } 205 206 /** 207 * __swahw32p - return a wordswapped 32-bit value from a pointer 208 * @p: pointer to a naturally-aligned 32-bit value 209 * 210 * See __swahw32() for details of wordswapping. 211 */ 212 static __inline__ __u32 __swahw32p(const __u32 *p) 213 { 214 #ifdef __arch_swahw32p 215 return __arch_swahw32p(p); 216 #else 217 return __swahw32(*p); 218 #endif 219 } 220 221 /** 222 * __swahb32p - return a high and low byteswapped 32-bit value from a pointer 223 * @p: pointer to a naturally-aligned 32-bit value 224 * 225 * See __swahb32() for details of high/low byteswapping. 226 */ 227 static __inline__ __u32 __swahb32p(const __u32 *p) 228 { 229 #ifdef __arch_swahb32p 230 return __arch_swahb32p(p); 231 #else 232 return __swahb32(*p); 233 #endif 234 } 235 236 /** 237 * __swab16s - byteswap a 16-bit value in-place 238 * @p: pointer to a naturally-aligned 16-bit value 239 */ 240 static __inline__ void __swab16s(__u16 *p) 241 { 242 #ifdef __arch_swab16s 243 __arch_swab16s(p); 244 #else 245 *p = __swab16p(p); 246 #endif 247 } 248 /** 249 * __swab32s - byteswap a 32-bit value in-place 250 * @p: pointer to a naturally-aligned 32-bit value 251 */ 252 static __always_inline void __swab32s(__u32 *p) 253 { 254 #ifdef __arch_swab32s 255 __arch_swab32s(p); 256 #else 257 *p = __swab32p(p); 258 #endif 259 } 260 261 /** 262 * __swab64s - byteswap a 64-bit value in-place 263 * @p: pointer to a naturally-aligned 64-bit value 264 */ 265 static __always_inline void __swab64s(__u64 *p) 266 { 267 #ifdef __arch_swab64s 268 __arch_swab64s(p); 269 #else 270 *p = __swab64p(p); 271 #endif 272 } 273 274 /** 275 * __swahw32s - wordswap a 32-bit value in-place 276 * @p: pointer to a naturally-aligned 32-bit value 277 * 278 * See __swahw32() for details of wordswapping 279 */ 280 static __inline__ void __swahw32s(__u32 *p) 281 { 282 #ifdef __arch_swahw32s 283 __arch_swahw32s(p); 284 #else 285 *p = __swahw32p(p); 286 #endif 287 } 288 289 /** 290 * __swahb32s - high and low byteswap a 32-bit value in-place 291 * @p: pointer to a naturally-aligned 32-bit value 292 * 293 * See __swahb32() for details of high and low byte swapping 294 */ 295 static __inline__ void __swahb32s(__u32 *p) 296 { 297 #ifdef __arch_swahb32s 298 __arch_swahb32s(p); 299 #else 300 *p = __swahb32p(p); 301 #endif 302 } 303 304 305 #endif /* _LINUX_SWAB_H */