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authorYalin Wang <Yalin.Wang@sonymobile.com>2014-11-03 02:02:23 (GMT)
committerRussell King <rmk+kernel@arm.linux.org.uk>2014-12-22 16:47:32 (GMT)
commit8e7a4cef71790d9406a7bd85aea6cfb12bc07d3c (patch)
tree11f2f81b33b47bbd5d82afae69721ce98dda5f52
parent556d2f055bf6d79ce81587dfe774d4dd10da473f (diff)
downloadlinux-8e7a4cef71790d9406a7bd85aea6cfb12bc07d3c.tar.xz
ARM: 8189/1: arm64: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> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm64/Kconfig1
-rw-r--r--arch/arm64/include/asm/bitrev.h19
2 files changed, 20 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b1f9a20..0ed36d1 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -39,6 +39,7 @@ config ARM64
select HARDIRQS_SW_RESEND
select HAVE_ALIGNED_STRUCT_PAGE if SLUB
select HAVE_ARCH_AUDITSYSCALL
+ select HAVE_ARCH_BITREVERSE
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_KGDB
select HAVE_ARCH_SECCOMP_FILTER
diff --git a/arch/arm64/include/asm/bitrev.h b/arch/arm64/include/asm/bitrev.h
new file mode 100644
index 0000000..a5a0c36
--- /dev/null
+++ b/arch/arm64/include/asm/bitrev.h
@@ -0,0 +1,19 @@
+#ifndef __ASM_BITREV_H
+#define __ASM_BITREV_H
+static __always_inline __attribute_const__ u32 __arch_bitrev32(u32 x)
+{
+ __asm__ ("rbit %w0, %w1" : "=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