summaryrefslogtreecommitdiffstats
path: root/arch/arm64/include/asm/bitrev.h
diff options
context:
space:
mode:
authorYalin Wang <Yalin.Wang@sonymobile.com>2014-11-03 03:02:23 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2014-12-22 17:47:32 +0100
commit8e7a4cef71790d9406a7bd85aea6cfb12bc07d3c (patch)
tree11f2f81b33b47bbd5d82afae69721ce98dda5f52 /arch/arm64/include/asm/bitrev.h
parentARM: 8187/1: add CONFIG_HAVE_ARCH_BITREVERSE to support rbit instruction (diff)
downloadlinux-8e7a4cef71790d9406a7bd85aea6cfb12bc07d3c.tar.xz
linux-8e7a4cef71790d9406a7bd85aea6cfb12bc07d3c.zip
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>
Diffstat (limited to 'arch/arm64/include/asm/bitrev.h')
-rw-r--r--arch/arm64/include/asm/bitrev.h19
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/bitrev.h b/arch/arm64/include/asm/bitrev.h
new file mode 100644
index 000000000000..a5a0c3660137
--- /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