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-rw-r--r--arch/arm/include/uapi/asm/swab.h53
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/arm/include/uapi/asm/swab.h b/arch/arm/include/uapi/asm/swab.h
new file mode 100644
index 0000000..6fcb32a
--- /dev/null
+++ b/arch/arm/include/uapi/asm/swab.h
@@ -0,0 +1,53 @@
+/*
+ * 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 _UAPI__ASM_ARM_SWAB_H
+#define _UAPI__ASM_ARM_SWAB_H
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+
+#if !defined(__STRICT_ANSI__) || defined(__KERNEL__)
+# define __SWAB_64_THRU_32__
+#endif
+
+
+#if !defined(__KERNEL__) || __LINUX_ARM_ARCH__ < 6
+static inline __attribute_const__ __u32 __arch_swab32(__u32 x)
+{
+ __u32 t;
+
+#ifndef __thumb__
+ if (!__builtin_constant_p(x)) {
+ /*
+ * The compiler needs a bit of a hint here to always do the
+ * right thing and not screw it up to different degrees
+ * depending on the gcc version.
+ */
+ asm ("eor\t%0, %1, %1, ror #16" : "=r" (t) : "r" (x));
+ } else
+#endif
+ t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */
+
+ x = (x << 24) | (x >> 8); /* mov r0,r0,ror #8 */
+ t &= ~0x00FF0000; /* bic r1,r1,#0x00FF0000 */
+ x ^= (t >> 8); /* eor r0,r0,r1,lsr #8 */
+
+ return x;
+}
+#define __arch_swab32 __arch_swab32
+
+#endif
+
+#endif /* _UAPI__ASM_ARM_SWAB_H */