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-rw-r--r--arch/arm/include/asm/swab.h39
1 files changed, 39 insertions, 0 deletions
diff --git a/arch/arm/include/asm/swab.h b/arch/arm/include/asm/swab.h
new file mode 100644
index 0000000000..c605182304
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+++ b/arch/arm/include/asm/swab.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * arch/arm/include/asm/byteorder.h
+ *
+ * ARM Endian-ness. In little endian mode, the data bus is connected such
+ * that byte accesses appear as:
+ * 0 = d0...d7, 1 = d8...d15, 2 = d16...d23, 3 = d24...d31
+ * and word accesses (data or instruction) appear as:
+ * d0...d31
+ *
+ * When in big endian mode, byte accesses appear as:
+ * 0 = d24...d31, 1 = d16...d23, 2 = d8...d15, 3 = d0...d7
+ * and word accesses (data or instruction) appear as:
+ * d0...d31
+ */
+#ifndef __ASM_ARM_SWAB_H
+#define __ASM_ARM_SWAB_H
+
+#include <uapi/asm/swab.h>
+
+#if __LINUX_ARM_ARCH__ >= 6
+
+static inline __attribute_const__ __u32 __arch_swahb32(__u32 x)
+{
+ __asm__ ("rev16 %0, %1" : "=r" (x) : "r" (x));
+ return x;
+}
+#define __arch_swahb32 __arch_swahb32
+#define __arch_swab16(x) ((__u16)__arch_swahb32(x))
+
+static inline __attribute_const__ __u32 __arch_swab32(__u32 x)
+{
+ __asm__ ("rev %0, %1" : "=r" (x) : "r" (x));
+ return x;
+}
+#define __arch_swab32 __arch_swab32
+
+#endif
+#endif