diff options
Diffstat (limited to 'arch/x86/include/asm/byteorder.h')
| -rw-r--r-- | arch/x86/include/asm/byteorder.h | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/x86/include/asm/byteorder.h b/arch/x86/include/asm/byteorder.h new file mode 100644 index 000000000000..722f27d68105 --- /dev/null +++ b/arch/x86/include/asm/byteorder.h @@ -0,0 +1,81 @@ +#ifndef ASM_X86__BYTEORDER_H +#define ASM_X86__BYTEORDER_H + +#include <asm/types.h> +#include <linux/compiler.h> + +#ifdef __GNUC__ + +#ifdef __i386__ + +static inline __attribute_const__ __u32 ___arch__swab32(__u32 x) +{ +#ifdef CONFIG_X86_BSWAP + asm("bswap %0" : "=r" (x) : "0" (x)); +#else + asm("xchgb %b0,%h0\n\t" /* swap lower bytes */ + "rorl $16,%0\n\t" /* swap words */ + "xchgb %b0,%h0" /* swap higher bytes */ + : "=q" (x) + : "0" (x)); +#endif + return x; +} + +static inline __attribute_const__ __u64 ___arch__swab64(__u64 val) +{ + union { + struct { + __u32 a; + __u32 b; + } s; + __u64 u; + } v; + v.u = val; +#ifdef CONFIG_X86_BSWAP + asm("bswapl %0 ; bswapl %1 ; xchgl %0,%1" + : "=r" (v.s.a), "=r" (v.s.b) + : "0" (v.s.a), "1" (v.s.b)); +#else + v.s.a = ___arch__swab32(v.s.a); + v.s.b = ___arch__swab32(v.s.b); + asm("xchgl %0,%1" + : "=r" (v.s.a), "=r" (v.s.b) + : "0" (v.s.a), "1" (v.s.b)); +#endif + return v.u; +} + +#else /* __i386__ */ + +static inline __attribute_const__ __u64 ___arch__swab64(__u64 x) +{ + asm("bswapq %0" + : "=r" (x) + : "0" (x)); + return x; +} + +static inline __attribute_const__ __u32 ___arch__swab32(__u32 x) +{ + asm("bswapl %0" + : "=r" (x) + : "0" (x)); + return x; +} + +#endif + +/* Do not define swab16. Gcc is smart enough to recognize "C" version and + convert it into rotation or exhange. */ + +#define __arch__swab64(x) ___arch__swab64(x) +#define __arch__swab32(x) ___arch__swab32(x) + +#define __BYTEORDER_HAS_U64__ + +#endif /* __GNUC__ */ + +#include <linux/byteorder/little_endian.h> + +#endif /* ASM_X86__BYTEORDER_H */ |