Messages in this thread Patch in this message | | | From | "Wang, Yalin" <> | Date | Fri, 31 Oct 2014 13:42:44 +0800 | Subject | [RFC V6 2/3] arm:add bitrev.h file to support rbit instruction |
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This patch add bitrev.h file to support rbit instruction, so that we can do bitrev operation by hardware. Signed-off-by: Yalin Wang <yalin.wang@sonymobile.com> --- arch/arm/Kconfig | 1 + arch/arm/include/asm/bitrev.h | 21 +++++++++++++++++++++ 2 files changed, 22 insertions(+) create mode 100644 arch/arm/include/asm/bitrev.h
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 89c4b5c..be92b3b 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -28,6 +28,7 @@ config ARM select HANDLE_DOMAIN_IRQ select HARDIRQS_SW_RESEND select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT) + select HAVE_ARCH_BITREVERSE if (CPU_V7M || CPU_V7) select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL select HAVE_ARCH_KGDB select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT) diff --git a/arch/arm/include/asm/bitrev.h b/arch/arm/include/asm/bitrev.h new file mode 100644 index 0000000..e9b2571 --- /dev/null +++ b/arch/arm/include/asm/bitrev.h @@ -0,0 +1,21 @@ +#ifndef __ASM_ARM_BITREV_H +#define __ASM_ARM_BITREV_H + +static __always_inline __attribute_const__ u32 __arch_bitrev32(u32 x) +{ + __asm__ ("rbit %0, %1" : "=r" (x) : "r" (x)); + return x; +} + +static __always_inline __attribute_const__ u16 __arch_bitrev16(u16 x) +{ + return __arch_bitrev32((u32)x) >> 16; +} + +static __always_inline __attribute_const__ u8 __arch_bitrev8(u8 x) +{ + return __arch_bitrev32((u32)x) >> 24; +} + +#endif + -- 2.1.1
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