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