diff options
author | Ben Dooks <ben-linux@fluff.org> | 2008-08-08 21:10:12 +0100 |
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committer | Ben Dooks <ben-linux@fluff.org> | 2008-08-08 21:10:12 +0100 |
commit | af7a535688a758d15f06a98833e6a143b29af9de (patch) | |
tree | bac5ab210bbbbe276f0e44ed84194d7c8bb16aae /arch/arm/include/asm/byteorder.h | |
parent | 0c17e4ceedd35c78b1c7413dbd16279a350be6bc (diff) | |
parent | c41107c2d4fd31924533f4dbc4c3428acc2b5894 (diff) |
Merge http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm into for-rmk
Diffstat (limited to 'arch/arm/include/asm/byteorder.h')
-rw-r--r-- | arch/arm/include/asm/byteorder.h | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/arch/arm/include/asm/byteorder.h b/arch/arm/include/asm/byteorder.h new file mode 100644 index 00000000000..4fbfb22f65a --- /dev/null +++ b/arch/arm/include/asm/byteorder.h @@ -0,0 +1,58 @@ +/* + * 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_BYTEORDER_H +#define __ASM_ARM_BYTEORDER_H + +#include <linux/compiler.h> +#include <asm/types.h> + +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(x) ___arch__swab32(x) + +#if !defined(__STRICT_ANSI__) || defined(__KERNEL__) +# define __BYTEORDER_HAS_U64__ +# define __SWAB_64_THRU_32__ +#endif + +#ifdef __ARMEB__ +#include <linux/byteorder/big_endian.h> +#else +#include <linux/byteorder/little_endian.h> +#endif + +#endif + |