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| author | Rabin Vincent <rabin@rab.in> | 2009-10-25 16:55:33 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-10-25 16:59:53 +0100 |
| commit | 40f5b07832ce29e66f42b61a2e9a1fd94783c136 (patch) | |
| tree | ae197b0653a565754e741e505c826773d6a2353f | |
| parent | Revert "[ARM] unconditionally define __virt_to_phys and __phys_to_virt" (diff) | |
| download | linux-40f5b07832ce29e66f42b61a2e9a1fd94783c136.tar.xz linux-40f5b07832ce29e66f42b61a2e9a1fd94783c136.zip | |
ARM: 5772/1: Use REV and REV16 for byte swapping on ARMv6+
ARMv6 introduced the REV and REV16 instructions that reverse bytes in
words and halfwords. Use them for the arch-specific implementation of
the byte swapping helpers on ARMv6+.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/include/asm/swab.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/arm/include/asm/swab.h b/arch/arm/include/asm/swab.h index ca2bf2f6d6ea..9997ad20eff1 100644 --- a/arch/arm/include/asm/swab.h +++ b/arch/arm/include/asm/swab.h @@ -22,6 +22,24 @@ # define __SWAB_64_THRU_32__ #endif +#if defined(__KERNEL__) && __LINUX_ARM_ARCH__ >= 6 + +static inline __attribute_const__ __u16 __arch_swab16(__u16 x) +{ + __asm__ ("rev16 %0, %1" : "=r" (x) : "r" (x)); + return x; +} +#define __arch_swab16 __arch_swab16 + +static inline __attribute_const__ __u32 __arch_swab32(__u32 x) +{ + __asm__ ("rev %0, %1" : "=r" (x) : "r" (x)); + return x; +} +#define __arch_swab32 __arch_swab32 + +#else + static inline __attribute_const__ __u32 __arch_swab32(__u32 x) { __u32 t; @@ -48,3 +66,4 @@ static inline __attribute_const__ __u32 __arch_swab32(__u32 x) #endif +#endif |