#ifndef _LINUX_BYTEORDER_SWAB_H #define _LINUX_BYTEORDER_SWAB_H /* * linux/byteorder/swab.h * Byte-swapping, independently from CPU endianness * swabXX[ps]?(foo) * * Francois-Rene Rideau <fare@tunes.org> 19971205 * separated swab functions from cpu_to_XX, * to clean up support for bizarre-endian architectures. * * Trent Piepho <xyzzy@speakeasy.org> 2007114 * make constant-folding work, provide C versions that * gcc can optimize better, explain different versions * * See asm-i386/byteorder.h and suches for examples of how to provide * architecture-dependent optimized versions * */ #include <linux/compiler.h> /* Functions/macros defined, there are a lot: * * ___swabXX * Generic C versions of the swab functions. * * ___constant_swabXX * C versions that gcc can fold into a compile-time constant when * the argument is a compile-time constant. * * __arch__swabXX[sp]? * Architecture optimized versions of all the swab functions * (including the s and p versions). These can be defined in * asm-arch/byteorder.h. Any which are not, are defined here. * __arch__swabXXs() is defined in terms of __arch__swabXXp(), which * is defined in terms of __arch__swabXX(), which is in turn defined * in terms of ___swabXX(x). * These must be macros. They may be unsafe for arguments with * side-effects. * * __fswabXX * Inline function versions of the __arch__ macros. These _are_ safe * if the arguments have side-effects. Note there are no s and p * versions of these. * * __swabXX[sb] * There are the ones you should actually use. The __swabXX versions * will be a constant given a constant argument and use the arch * specific code (if any) for non-constant arguments. The s and p * versions always use the arch specific code (constant folding * doesn't apply). They are safe to use with arguments with * side-effects. * * swabXX[sb] * Nicknames for __swabXX[sb] to use in the kernel. */ /* casts are necessary for constants, because we never know how for sure * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way. */ static __inline__ __attribute_const__ __u16 ___swab16(__u16 x) { return x<<8 | x>>8; } static __inline__ __attribute_const__ __u32 ___swab32(__u32 x) { return x<<24 | x>>24 | (x & (__u32)0x0000ff00UL)<<8 | (x & (__u32)0x00ff0000UL)>>8; } static __inline__ __attribute_const__ __u64 ___swab64(__u64 x) { return x<<56 | x>>56 | (x & (__u64)0x000000000000ff00ULL)<<40 | (x & (__u64)0x0000000000ff0000ULL)<<24 | (x & (__u64)0x00000000ff000000ULL)<< 8 | (x & (__u64)0x000000ff00000000ULL)>> 8 | (x & (__u64)0x0000ff0000000000ULL)>>24 | (x & (__u64)0x00ff000000000000ULL)>>40; } #define ___constant_swab16(x) \ ((__u16)( \ (((__u16)(x) & (__u16)0x00ffU) << 8) | \ (((__u16)(x) & (__u16)0xff00U) >> 8) )) #define ___constant_swab32(x) \ ((__u32)( \ (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \ (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \ (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \ (((__u32)(x) & (__u32)0xff000000UL) >> 24) )) #define ___constant_swab64(x) \ ((__u64)( \ (__u64)(((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \ (__u64)(((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \ (__u64)(((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \ (__u64)(((__u64)(x) & (__u64)0x00000000ff000000ULL) << 8) | \ (__u64)(((__u64)(x) & (__u64)0x000000ff00000000ULL) >> 8) | \ (__u64)(((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \ (__u64)(((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \ (__u64)(((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56) )) /* * provide defaults when no architecture-specific optimization is detected */ #ifndef __arch__swab16 # define __arch__swab16(x) ___swab16(x) #endif #ifndef __arch__swab32 # define __arch__swab32(x) ___swab32(x) #endif #ifndef __arch__swab64 # define __arch__swab64(x) ___swab64(x) #endif #ifndef __arch__swab16p # define __arch__swab16p(x) __arch__swab16(*(x)) #endif #ifndef __arch__swab32p # define __arch__swab32p(x) __arch__swab32(*(x)) #endif #ifndef __arch__swab64p # define __arch__swab64p(x) __arch__swab64(*(x)) #endif #ifndef __arch__swab16s # define __arch__swab16s(x) ((void)(*(x) = __arch__swab16p(x))) #endif #ifndef __arch__swab32s # define __arch__swab32s(x) ((void)(*(x) = __arch__swab32p(x))) #endif #ifndef __arch__swab64s # define __arch__swab64s(x) ((void)(*(x) = __arch__swab64p(x))) #endif /* * Allow constant folding */ #if defined(__GNUC__) && defined(__OPTIMIZE__) # define __swab16(x) \ (__builtin_constant_p((__u16)(x)) ? \ ___constant_swab16((x)) : \ __fswab16((x))) # define __swab32(x) \ (__builtin_constant_p((__u32)(x)) ? \ ___constant_swab32((x)) : \ __fswab32((x))) # define __swab64(x) \ (__builtin_constant_p((__u64)(x)) ? \ ___constant_swab64((x)) : \ __fswab64((x))) #else # define __swab16(x) __fswab16(x) # define __swab32(x) __fswab32(x) # define __swab64(x) __fswab64(x) #endif /* OPTIMIZE */ static __inline__ __attribute_const__ __u16 __fswab16(__u16 x) { return __arch__swab16(x); } static __inline__ __u16 __swab16p(const __u16 *x) { return __arch__swab16p(x); } static __inline__ void __swab16s(__u16 *addr) { __arch__swab16s(addr); } static __inline__ __attribute_const__ __u32 __fswab32(__u32 x) { return __arch__swab32(x); } static __inline__ __u32 __swab32p(const __u32 *x) { return __arch__swab32p(x); } static __inline__ void __swab32s(__u32 *addr) { __arch__swab32s(addr); } #ifdef __BYTEORDER_HAS_U64__ static __inline__ __attribute_const__ __u64 __fswab64(__u64 x) { # ifdef __SWAB_64_THRU_32__ __u32 h = x >> 32; __u32 l = x & ((1ULL<<32)-1); return (((__u64)__swab32(l)) << 32) | ((__u64)(__swab32(h))); # else return __arch__swab64(x); # endif } static __inline__ __u64 __swab64p(const __u64 *x) { return __arch__swab64p(x); } static __inline__ void __swab64s(__u64 *addr) { __arch__swab64s(addr); } #endif /* __BYTEORDER_HAS_U64__ */ #if defined(__KERNEL__) #define swab16 __swab16 #define swab32 __swab32 #define swab64 __swab64 #define swab16p __swab16p #define swab32p __swab32p #define swab64p __swab64p #define swab16s __swab16s #define swab32s __swab32s #define swab64s __swab64s #endif #endif /* _LINUX_BYTEORDER_SWAB_H */