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authorRabin Vincent <rabin@rab.in>2009-10-25 16:55:33 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2009-10-25 15:59:53 +0000
commit40f5b07832ce29e66f42b61a2e9a1fd94783c136 (patch)
treeae197b0653a565754e741e505c826773d6a2353f /arch/arm/include/asm/swab.h
parenta8cf81ffe0284660fe405e7189f47f1b032f5261 (diff)
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>
Diffstat (limited to 'arch/arm/include/asm/swab.h')
-rw-r--r--arch/arm/include/asm/swab.h19
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