From 40f5b07832ce29e66f42b61a2e9a1fd94783c136 Mon Sep 17 00:00:00 2001 From: Rabin Vincent Date: Sun, 25 Oct 2009 16:55:33 +0100 Subject: 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 Signed-off-by: Russell King --- arch/arm/include/asm/swab.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'arch/arm/include/asm') 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 -- cgit v1.2.3