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-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 b1f9a20a3677..0ed36d1f536d 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 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