diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-13 17:18:53 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-13 17:18:53 -0700 |
commit | 3d6ee36dfb2d40c72071f68173f67c728a0e19f3 (patch) | |
tree | 262130e0f3381c3d409817fdc4abec8852f10e7c /arch/arm/include/uapi/asm/swab.h | |
parent | 0b381a286e5d748b1fd80095d3dd52326819742f (diff) | |
parent | 244acb1ba3777c2eb4d33ddc246cab5419656442 (diff) |
Merge branch 'late-for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM update from Russell King:
"This is the final round of stuff for ARM, left until the end of the
merge window to reduce the number of conflicts. This set contains the
ARM part of David Howells UAPI changes, and a fix to the ordering of
'select' statements in ARM Kconfig files (see the appropriate commit
for why this happened - thanks to Andrew Morton for pointing out the
problem.)
I've left this as long as I dare for this window to avoid conflicts,
and I regenerated the config patch yesterday, posting it to our
mailing list for review and testing. I have several acks which
include successful test reports for it.
However, today I notice we've got new conflicts with previously unseen
code... though that conflict should be trivial (it's my changes vs a
one liner.)"
* 'late-for-linus' of git://git.linaro.org/people/rmk/linux-arm:
ARM: config: make sure that platforms are ordered by option string
ARM: config: sort select statements alphanumerically
UAPI: (Scripted) Disintegrate arch/arm/include/asm
Fix up fairly conflict in arch/arm/Kconfig (the select re-organization
vs recent addition of GENERIC_KERNEL_EXECVE)
Diffstat (limited to 'arch/arm/include/uapi/asm/swab.h')
-rw-r--r-- | arch/arm/include/uapi/asm/swab.h | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/arm/include/uapi/asm/swab.h b/arch/arm/include/uapi/asm/swab.h new file mode 100644 index 00000000000..6fcb32a5c45 --- /dev/null +++ b/arch/arm/include/uapi/asm/swab.h @@ -0,0 +1,53 @@ +/* + * 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 _UAPI__ASM_ARM_SWAB_H +#define _UAPI__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__) || __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 /* _UAPI__ASM_ARM_SWAB_H */ |