1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 3 #ifndef _SWAB_H 4 #define _SWAB_H 5 6 /* 7 * linux/byteorder/swab.h 8 * Byte-swapping, independently from CPU endianness 9 * swabXX[ps]?(foo) 10 * 11 * Francois-Rene Rideau <[email protected]> 19971205 12 * separated swab functions from cpu_to_XX, 13 * to clean up support for bizarre-endian architectures. 14 * 15 * See asm-i386/byteorder.h and such for examples of how to provide 16 * architecture-dependent optimized versions 17 * 18 */ 19 20 /* casts are necessary for constants, because we never know how for sure 21 * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way. 22 */ 23 #define swab16(x) \ 24 ((unsigned short)( \ 25 (((unsigned short)(x) & (unsigned short)0x00ffU) << 8) | \ 26 (((unsigned short)(x) & (unsigned short)0xff00U) >> 8) )) 27 28 #define swab32(x) \ 29 ((unsigned int)( \ 30 (((unsigned int)(x) & (unsigned int)0x000000ffUL) << 24) | \ 31 (((unsigned int)(x) & (unsigned int)0x0000ff00UL) << 8) | \ 32 (((unsigned int)(x) & (unsigned int)0x00ff0000UL) >> 8) | \ 33 (((unsigned int)(x) & (unsigned int)0xff000000UL) >> 24) )) 34 35 #define swab64(x) \ 36 ((uint64_t)( \ 37 (((uint64_t)(x) & (uint64_t)0x00000000000000ffULL) << 56) | \ 38 (((uint64_t)(x) & (uint64_t)0x000000000000ff00ULL) << 40) | \ 39 (((uint64_t)(x) & (uint64_t)0x0000000000ff0000ULL) << 24) | \ 40 (((uint64_t)(x) & (uint64_t)0x00000000ff000000ULL) << 8) | \ 41 (((uint64_t)(x) & (uint64_t)0x000000ff00000000ULL) >> 8) | \ 42 (((uint64_t)(x) & (uint64_t)0x0000ff0000000000ULL) >> 24) | \ 43 (((uint64_t)(x) & (uint64_t)0x00ff000000000000ULL) >> 40) | \ 44 (((uint64_t)(x) & (uint64_t)0xff00000000000000ULL) >> 56) )) 45 46 #endif /* _SWAB_H */ 47