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| -rw-r--r-- | include/linux/swab.h | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/include/linux/swab.h b/include/linux/swab.h new file mode 100644 index 000000000000..270d5c208a89 --- /dev/null +++ b/include/linux/swab.h @@ -0,0 +1,309 @@ +#ifndef _LINUX_SWAB_H +#define _LINUX_SWAB_H + +#include <linux/types.h> +#include <linux/compiler.h> +#include <asm/byteorder.h> + +/* + * 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. + */ +#define __const_swab16(x) ((__u16)( \ + (((__u16)(x) & (__u16)0x00ffU) << 8) | \ + (((__u16)(x) & (__u16)0xff00U) >> 8))) + +#define __const_swab32(x) ((__u32)( \ + (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \ + (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \ + (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \ + (((__u32)(x) & (__u32)0xff000000UL) >> 24))) + +#define __const_swab64(x) ((__u64)( \ + (((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \ + (((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \ + (((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \ + (((__u64)(x) & (__u64)0x00000000ff000000ULL) << 8) | \ + (((__u64)(x) & (__u64)0x000000ff00000000ULL) >> 8) | \ + (((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \ + (((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \ + (((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56))) + +#define __const_swahw32(x) ((__u32)( \ + (((__u32)(x) & (__u32)0x0000ffffUL) << 16) | \ + (((__u32)(x) & (__u32)0xffff0000UL) >> 16))) + +#define __const_swahb32(x) ((__u32)( \ + (((__u32)(x) & (__u32)0x00ff00ffUL) << 8) | \ + (((__u32)(x) & (__u32)0xff00ff00UL) >> 8))) + +/* + * Implement the following as inlines, but define the interface using + * macros to allow constant folding when possible: + * ___swab16, ___swab32, ___swab64, ___swahw32, ___swahb32 + */ + +static inline __attribute_const__ __u16 ___swab16(__u16 val) +{ +#ifdef __arch_swab16 + return __arch_swab16(val); +#elif defined(__arch_swab16p) + return __arch_swab16p(&val); +#else + return __const_swab16(val); +#endif +} + +static inline __attribute_const__ __u32 ___swab32(__u32 val) +{ +#ifdef __arch_swab32 + return __arch_swab32(val); +#elif defined(__arch_swab32p) + return __arch_swab32p(&val); +#else + return __const_swab32(val); +#endif +} + +static inline __attribute_const__ __u64 ___swab64(__u64 val) +{ +#ifdef __arch_swab64 + return __arch_swab64(val); +#elif defined(__arch_swab64p) + return __arch_swab64p(&val); +#elif defined(__SWAB_64_THRU_32__) + __u32 h = val >> 32; + __u32 l = val & ((1ULL << 32) - 1); + return (((__u64)___swab32(l)) << 32) | ((__u64)(___swab32(h))); +#else + return __const_swab64(val); +#endif +} + +static inline __attribute_const__ __u32 ___swahw32(__u32 val) +{ +#ifdef __arch_swahw32 + return __arch_swahw32(val); +#elif defined(__arch_swahw32p) + return __arch_swahw32p(&val); +#else + return __const_swahw32(val); +#endif +} + +static inline __attribute_const__ __u32 ___swahb32(__u32 val) +{ +#ifdef __arch_swahb32 + return __arch_swahb32(val); +#elif defined(__arch_swahb32p) + return __arch_swahb32p(&val); +#else + return __const_swahb32(val); +#endif +} + +/** + * __swab16 - return a byteswapped 16-bit value + * @x: value to byteswap + */ +#define __swab16(x) \ + (__builtin_constant_p((__u16)(x)) ? \ + __const_swab16((x)) : \ + ___swab16((x))) + +/** + * __swab32 - return a byteswapped 32-bit value + * @x: value to byteswap + */ +#define __swab32(x) \ + (__builtin_constant_p((__u32)(x)) ? \ + __const_swab32((x)) : \ + ___swab32((x))) + +/** + * __swab64 - return a byteswapped 64-bit value + * @x: value to byteswap + */ +#define __swab64(x) \ + (__builtin_constant_p((__u64)(x)) ? \ + __const_swab64((x)) : \ + ___swab64((x))) + +/** + * __swahw32 - return a word-swapped 32-bit value + * @x: value to wordswap + * + * __swahw32(0x12340000) is 0x00001234 + */ +#define __swahw32(x) \ + (__builtin_constant_p((__u32)(x)) ? \ + __const_swahw32((x)) : \ + ___swahw32((x))) + +/** + * __swahb32 - return a high and low byte-swapped 32-bit value + * @x: value to byteswap + * + * __swahb32(0x12345678) is 0x34127856 + */ +#define __swahb32(x) \ + (__builtin_constant_p((__u32)(x)) ? \ + __const_swahb32((x)) : \ + ___swahb32((x))) + +/** + * __swab16p - return a byteswapped 16-bit value from a pointer + * @p: pointer to a naturally-aligned 16-bit value + */ +static inline __u16 __swab16p(const __u16 *p) +{ +#ifdef __arch_swab16p + return __arch_swab16p(p); +#else + return __swab16(*p); +#endif +} + +/** + * __swab32p - return a byteswapped 32-bit value from a pointer + * @p: pointer to a naturally-aligned 32-bit value + */ +static inline __u32 __swab32p(const __u32 *p) +{ +#ifdef __arch_swab32p + return __arch_swab32p(p); +#else + return __swab32(*p); +#endif +} + +/** + * __swab64p - return a byteswapped 64-bit value from a pointer + * @p: pointer to a naturally-aligned 64-bit value + */ +static inline __u64 __swab64p(const __u64 *p) +{ +#ifdef __arch_swab64p + return __arch_swab64p(p); +#else + return __swab64(*p); +#endif +} + +/** + * __swahw32p - return a wordswapped 32-bit value from a pointer + * @p: pointer to a naturally-aligned 32-bit value + * + * See __swahw32() for details of wordswapping. + */ +static inline __u32 __swahw32p(const __u32 *p) +{ +#ifdef __arch_swahw32p + return __arch_swahw32p(p); +#else + return __swahw32(*p); +#endif +} + +/** + * __swahb32p - return a high and low byteswapped 32-bit value from a pointer + * @p: pointer to a naturally-aligned 32-bit value + * + * See __swahb32() for details of high/low byteswapping. + */ +static inline __u32 __swahb32p(const __u32 *p) +{ +#ifdef __arch_swahb32p + return __arch_swahb32p(p); +#else + return __swahb32(*p); +#endif +} + +/** + * __swab16s - byteswap a 16-bit value in-place + * @p: pointer to a naturally-aligned 16-bit value + */ +static inline void __swab16s(__u16 *p) +{ +#ifdef __arch_swab16s + __arch_swab16s(p); +#else + *p = __swab16p(p); +#endif +} +/** + * __swab32s - byteswap a 32-bit value in-place + * @p: pointer to a naturally-aligned 32-bit value + */ +static inline void __swab32s(__u32 *p) +{ +#ifdef __arch_swab32s + __arch_swab32s(p); +#else + *p = __swab32p(p); +#endif +} + +/** + * __swab64s - byteswap a 64-bit value in-place + * @p: pointer to a naturally-aligned 64-bit value + */ +static inline void __swab64s(__u64 *p) +{ +#ifdef __arch_swab64s + __arch_swab64s(p); +#else + *p = __swab64p(p); +#endif +} + +/** + * __swahw32s - wordswap a 32-bit value in-place + * @p: pointer to a naturally-aligned 32-bit value + * + * See __swahw32() for details of wordswapping + */ +static inline void __swahw32s(__u32 *p) +{ +#ifdef __arch_swahw32s + __arch_swahw32s(p); +#else + *p = __swahw32p(p); +#endif +} + +/** + * __swahb32s - high and low byteswap a 32-bit value in-place + * @p: pointer to a naturally-aligned 32-bit value + * + * See __swahb32() for details of high and low byte swapping + */ +static inline void __swahb32s(__u32 *p) +{ +#ifdef __arch_swahb32s + __arch_swahb32s(p); +#else + *p = __swahb32p(p); +#endif +} + +#ifdef __KERNEL__ +# define swab16 __swab16 +# define swab32 __swab32 +# define swab64 __swab64 +# define swahw32 __swahw32 +# define swahb32 __swahb32 +# define swab16p __swab16p +# define swab32p __swab32p +# define swab64p __swab64p +# define swahw32p __swahw32p +# define swahb32p __swahb32p +# define swab16s __swab16s +# define swab32s __swab32s +# define swab64s __swab64s +# define swahw32s __swahw32s +# define swahb32s __swahb32s +#endif /* __KERNEL__ */ + +#endif /* _LINUX_SWAB_H */ |