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/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 48static inline __attribute_const__ __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 57static inline __attribute_const__ __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 66static inline __attribute_const__ __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 79static inline __attribute_const__ __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 88static inline __attribute_const__ __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 (__builtin_constant_p((__u16)(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 (__builtin_constant_p((__u32)(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 (__builtin_constant_p((__u64)(x)) ? \ 132 ___constant_swab64(x) : \ 133 __fswab64(x)) 134#endif 135 136static __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 */ 171static __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 */ 184static __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 */ 197static __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 */ 212static 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 */ 227static 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 */ 240static 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 */ 252static __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 */ 265static __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 */ 280static 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 */ 295static 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 /* _UAPI_LINUX_SWAB_H */ 306