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ARM: 8287/1: add bitrev.h file to support rbit instruction 

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>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Yalin Wang 2015-01-16 02:45:55 +01:00 committed by Russell King
parent 8e7a4cef71
commit 0b7857dbeb
2 changed files with 21 additions and 0 deletions
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1
arch/arm/Kconfig
View File

@ -29,6 +29,7 @@ config ARM
select HANDLE_DOMAIN_IRQ
select HARDIRQS_SW_RESEND
select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT)
select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
select HAVE_ARCH_KGDB
select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT)

20
arch/arm/include/asm/bitrev.h Normal file
View File

@ -0,0 +1,20 @@
#ifndef __ASM_BITREV_H
#define __ASM_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