github.com/cilium/cilium@v1.16.2/bpf/include/linux/swab.h (about) 1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 /* Copyright Authors of the Linux kernel */ 3 #pragma once 4 5 #include <linux/types.h> 6 7 /* 8 * casts are necessary for constants, because we never know how for sure 9 * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way. 10 */ 11 #define ___constant_swab16(x) ((__u16)( \ 12 (((__u16)(x) & (__u16)0x00ffU) << 8) | \ 13 (((__u16)(x) & (__u16)0xff00U) >> 8))) 14 15 #define ___constant_swab32(x) ((__u32)( \ 16 (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \ 17 (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \ 18 (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \ 19 (((__u32)(x) & (__u32)0xff000000UL) >> 24))) 20 21 #define ___constant_swab64(x) ((__u64)( \ 22 (((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \ 23 (((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \ 24 (((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \ 25 (((__u64)(x) & (__u64)0x00000000ff000000ULL) << 8) | \ 26 (((__u64)(x) & (__u64)0x000000ff00000000ULL) >> 8) | \ 27 (((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \ 28 (((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \ 29 (((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56))) 30 31 #define ___constant_swahw32(x) ((__u32)( \ 32 (((__u32)(x) & (__u32)0x0000ffffUL) << 16) | \ 33 (((__u32)(x) & (__u32)0xffff0000UL) >> 16))) 34 35 #define ___constant_swahb32(x) ((__u32)( \ 36 (((__u32)(x) & (__u32)0x00ff00ffUL) << 8) | \ 37 (((__u32)(x) & (__u32)0xff00ff00UL) >> 8))) 38 39 /* 40 * Implement the following as inlines, but define the interface using 41 * macros to allow constant folding when possible: 42 * ___swab16, ___swab32, ___swab64, ___swahw32, ___swahb32 43 */ 44 45 static __inline__ __u16 __fswab16(__u16 val) 46 { 47 #ifdef __HAVE_BUILTIN_BSWAP16__ 48 return __builtin_bswap16(val); 49 #elif defined (__arch_swab16) 50 return __arch_swab16(val); 51 #else 52 return ___constant_swab16(val); 53 #endif 54 } 55 56 static __inline__ __u32 __fswab32(__u32 val) 57 { 58 #ifdef __HAVE_BUILTIN_BSWAP32__ 59 return __builtin_bswap32(val); 60 #elif defined(__arch_swab32) 61 return __arch_swab32(val); 62 #else 63 return ___constant_swab32(val); 64 #endif 65 } 66 67 static __inline__ __u64 __fswab64(__u64 val) 68 { 69 #ifdef __HAVE_BUILTIN_BSWAP64__ 70 return __builtin_bswap64(val); 71 #elif defined (__arch_swab64) 72 return __arch_swab64(val); 73 #elif defined(__SWAB_64_THRU_32__) 74 __u32 h = val >> 32; 75 __u32 l = val & ((1ULL << 32) - 1); 76 return (((__u64)__fswab32(l)) << 32) | ((__u64)(__fswab32(h))); 77 #else 78 return ___constant_swab64(val); 79 #endif 80 } 81 82 static __inline__ __u32 __fswahw32(__u32 val) 83 { 84 #ifdef __arch_swahw32 85 return __arch_swahw32(val); 86 #else 87 return ___constant_swahw32(val); 88 #endif 89 } 90 91 static __inline__ __u32 __fswahb32(__u32 val) 92 { 93 #ifdef __arch_swahb32 94 return __arch_swahb32(val); 95 #else 96 return ___constant_swahb32(val); 97 #endif 98 } 99 100 /** 101 * __swab16 - return a byteswapped 16-bit value 102 * @x: value to byteswap 103 */ 104 #define __swab16(x) \ 105 (__builtin_constant_p((__u16)(x)) ? \ 106 ___constant_swab16(x) : \ 107 __fswab16(x)) 108 109 /** 110 * __swab32 - return a byteswapped 32-bit value 111 * @x: value to byteswap 112 */ 113 #define __swab32(x) \ 114 (__builtin_constant_p((__u32)(x)) ? \ 115 ___constant_swab32(x) : \ 116 __fswab32(x)) 117 118 /** 119 * __swab64 - return a byteswapped 64-bit value 120 * @x: value to byteswap 121 */ 122 #define __swab64(x) \ 123 (__builtin_constant_p((__u64)(x)) ? \ 124 ___constant_swab64(x) : \ 125 __fswab64(x)) 126 127 /** 128 * __swahw32 - return a word-swapped 32-bit value 129 * @x: value to wordswap 130 * 131 * __swahw32(0x12340000) is 0x00001234 132 */ 133 #define __swahw32(x) \ 134 (__builtin_constant_p((__u32)(x)) ? \ 135 ___constant_swahw32(x) : \ 136 __fswahw32(x)) 137 138 /** 139 * __swahb32 - return a high and low byte-swapped 32-bit value 140 * @x: value to byteswap 141 * 142 * __swahb32(0x12345678) is 0x34127856 143 */ 144 #define __swahb32(x) \ 145 (__builtin_constant_p((__u32)(x)) ? \ 146 ___constant_swahb32(x) : \ 147 __fswahb32(x)) 148 149 /** 150 * __swab16p - return a byteswapped 16-bit value from a pointer 151 * @p: pointer to a naturally-aligned 16-bit value 152 */ 153 static __inline__ __u16 __swab16p(const __u16 *p) 154 { 155 #ifdef __arch_swab16p 156 return __arch_swab16p(p); 157 #else 158 return __swab16(*p); 159 #endif 160 } 161 162 /** 163 * __swab32p - return a byteswapped 32-bit value from a pointer 164 * @p: pointer to a naturally-aligned 32-bit value 165 */ 166 static __inline__ __u32 __swab32p(const __u32 *p) 167 { 168 #ifdef __arch_swab32p 169 return __arch_swab32p(p); 170 #else 171 return __swab32(*p); 172 #endif 173 } 174 175 /** 176 * __swab64p - return a byteswapped 64-bit value from a pointer 177 * @p: pointer to a naturally-aligned 64-bit value 178 */ 179 static __inline__ __u64 __swab64p(const __u64 *p) 180 { 181 #ifdef __arch_swab64p 182 return __arch_swab64p(p); 183 #else 184 return __swab64(*p); 185 #endif 186 } 187 188 /** 189 * __swahw32p - return a wordswapped 32-bit value from a pointer 190 * @p: pointer to a naturally-aligned 32-bit value 191 * 192 * See __swahw32() for details of wordswapping. 193 */ 194 static __inline__ __u32 __swahw32p(const __u32 *p) 195 { 196 #ifdef __arch_swahw32p 197 return __arch_swahw32p(p); 198 #else 199 return __swahw32(*p); 200 #endif 201 } 202 203 /** 204 * __swahb32p - return a high and low byteswapped 32-bit value from a pointer 205 * @p: pointer to a naturally-aligned 32-bit value 206 * 207 * See __swahb32() for details of high/low byteswapping. 208 */ 209 static __inline__ __u32 __swahb32p(const __u32 *p) 210 { 211 #ifdef __arch_swahb32p 212 return __arch_swahb32p(p); 213 #else 214 return __swahb32(*p); 215 #endif 216 } 217 218 /** 219 * __swab16s - byteswap a 16-bit value in-place 220 * @p: pointer to a naturally-aligned 16-bit value 221 */ 222 static __inline__ void __swab16s(__u16 *p) 223 { 224 #ifdef __arch_swab16s 225 __arch_swab16s(p); 226 #else 227 *p = __swab16p(p); 228 #endif 229 } 230 /** 231 * __swab32s - byteswap a 32-bit value in-place 232 * @p: pointer to a naturally-aligned 32-bit value 233 */ 234 static __inline__ void __swab32s(__u32 *p) 235 { 236 #ifdef __arch_swab32s 237 __arch_swab32s(p); 238 #else 239 *p = __swab32p(p); 240 #endif 241 } 242 243 /** 244 * __swab64s - byteswap a 64-bit value in-place 245 * @p: pointer to a naturally-aligned 64-bit value 246 */ 247 static __inline__ void __swab64s(__u64 *p) 248 { 249 #ifdef __arch_swab64s 250 __arch_swab64s(p); 251 #else 252 *p = __swab64p(p); 253 #endif 254 } 255 256 /** 257 * __swahw32s - wordswap a 32-bit value in-place 258 * @p: pointer to a naturally-aligned 32-bit value 259 * 260 * See __swahw32() for details of wordswapping 261 */ 262 static __inline__ void __swahw32s(__u32 *p) 263 { 264 #ifdef __arch_swahw32s 265 __arch_swahw32s(p); 266 #else 267 *p = __swahw32p(p); 268 #endif 269 } 270 271 /** 272 * __swahb32s - high and low byteswap a 32-bit value in-place 273 * @p: pointer to a naturally-aligned 32-bit value 274 * 275 * See __swahb32() for details of high and low byte swapping 276 */ 277 static __inline__ void __swahb32s(__u32 *p) 278 { 279 #ifdef __arch_swahb32s 280 __arch_swahb32s(p); 281 #else 282 *p = __swahb32p(p); 283 #endif 284 }