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author | Srikant Patnaik | 2015-01-13 15:08:24 +0530 |
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committer | Srikant Patnaik | 2015-01-13 15:08:24 +0530 |
commit | 97327692361306d1e6259021bc425e32832fdb50 (patch) | |
tree | fe9088f3248ec61e24f404f21b9793cb644b7f01 /arch/arm/include/asm/swab.h | |
parent | 2d05a8f663478a44e088d122e0d62109bbc801d0 (diff) | |
parent | a3a8b90b61e21be3dde9101c4e86c881e0f06210 (diff) | |
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dirty fix to merging
Diffstat (limited to 'arch/arm/include/asm/swab.h')
-rw-r--r-- | arch/arm/include/asm/swab.h | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/arch/arm/include/asm/swab.h b/arch/arm/include/asm/swab.h new file mode 100644 index 00000000..b859d82e --- /dev/null +++ b/arch/arm/include/asm/swab.h @@ -0,0 +1,73 @@ +/* + * arch/arm/include/asm/byteorder.h + * + * ARM Endian-ness. In little endian mode, the data bus is connected such + * that byte accesses appear as: + * 0 = d0...d7, 1 = d8...d15, 2 = d16...d23, 3 = d24...d31 + * and word accesses (data or instruction) appear as: + * d0...d31 + * + * When in big endian mode, byte accesses appear as: + * 0 = d24...d31, 1 = d16...d23, 2 = d8...d15, 3 = d0...d7 + * and word accesses (data or instruction) appear as: + * d0...d31 + */ +#ifndef __ASM_ARM_SWAB_H +#define __ASM_ARM_SWAB_H + +#include <linux/compiler.h> +#include <linux/types.h> + +#if !defined(__STRICT_ANSI__) || defined(__KERNEL__) +# define __SWAB_64_THRU_32__ +#endif + +#if defined(__KERNEL__) +#if __LINUX_ARM_ARCH__ >= 6 + +static inline __attribute_const__ __u32 __arch_swahb32(__u32 x) +{ + __asm__ ("rev16 %0, %1" : "=r" (x) : "r" (x)); + return x; +} +#define __arch_swahb32 __arch_swahb32 +#define __arch_swab16(x) ((__u16)__arch_swahb32(x)) + +static inline __attribute_const__ __u32 __arch_swab32(__u32 x) +{ + __asm__ ("rev %0, %1" : "=r" (x) : "r" (x)); + return x; +} +#define __arch_swab32 __arch_swab32 + +#endif +#endif + +#if !defined(__KERNEL__) || __LINUX_ARM_ARCH__ < 6 +static inline __attribute_const__ __u32 __arch_swab32(__u32 x) +{ + __u32 t; + +#ifndef __thumb__ + if (!__builtin_constant_p(x)) { + /* + * The compiler needs a bit of a hint here to always do the + * right thing and not screw it up to different degrees + * depending on the gcc version. + */ + asm ("eor\t%0, %1, %1, ror #16" : "=r" (t) : "r" (x)); + } else +#endif + t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */ + + x = (x << 24) | (x >> 8); /* mov r0,r0,ror #8 */ + t &= ~0x00FF0000; /* bic r1,r1,#0x00FF0000 */ + x ^= (t >> 8); /* eor r0,r0,r1,lsr #8 */ + + return x; +} +#define __arch_swab32 __arch_swab32 + +#endif + +#endif |