1 files changed, 81 insertions, 0 deletions

diff --git a/arch/x86/include/asm/byteorder.h b/arch/x86/include/asm/byteorder.h
new file mode 100644
index 00000000000..722f27d6810
--- /dev/null
+++ b/arch/x86/include/asm/byteorder.h
@@ -0,0 +1,81 @@
+#ifndef ASM_X86__BYTEORDER_H
+#define ASM_X86__BYTEORDER_H
+
+#include <asm/types.h>
+#include <linux/compiler.h>
+
+#ifdef __GNUC__
+
+#ifdef __i386__
+
+static inline __attribute_const__ __u32 ___arch__swab32(__u32 x)
+{
+#ifdef CONFIG_X86_BSWAP
+        asm("bswap %0" : "=r" (x) : "0" (x));
+#else
+        asm("xchgb %b0,%h0\n\t" /* swap lower bytes     */
+            "rorl $16,%0\n\t"   /* swap words           */
+            "xchgb %b0,%h0"     /* swap higher bytes    */
+            : "=q" (x)
+            : "0" (x));
+#endif
+        return x;
+}
+
+static inline __attribute_const__ __u64 ___arch__swab64(__u64 val)
+{
+        union {
+                struct {
+                        __u32 a;
+                        __u32 b;
+                } s;
+                __u64 u;
+        } v;
+        v.u = val;
+#ifdef CONFIG_X86_BSWAP
+        asm("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
+            : "=r" (v.s.a), "=r" (v.s.b)
+            : "0" (v.s.a), "1" (v.s.b));
+#else
+        v.s.a = ___arch__swab32(v.s.a);
+        v.s.b = ___arch__swab32(v.s.b);
+        asm("xchgl %0,%1"
+            : "=r" (v.s.a), "=r" (v.s.b)
+            : "0" (v.s.a), "1" (v.s.b));
+#endif
+        return v.u;
+}
+
+#else /* __i386__ */
+
+static inline __attribute_const__ __u64 ___arch__swab64(__u64 x)
+{
+        asm("bswapq %0"
+            : "=r" (x)
+            : "0" (x));
+        return x;
+}
+
+static inline __attribute_const__ __u32 ___arch__swab32(__u32 x)
+{
+        asm("bswapl %0"
+            : "=r" (x)
+            : "0" (x));
+        return x;
+}
+
+#endif
+
+/* Do not define swab16.  Gcc is smart enough to recognize "C" version and
+   convert it into rotation or exhange.  */
+
+#define __arch__swab64(x) ___arch__swab64(x)
+#define __arch__swab32(x) ___arch__swab32(x)
+
+#define __BYTEORDER_HAS_U64__
+
+#endif /* __GNUC__ */
+
+#include <linux/byteorder/little_endian.h>
+
+#endif /* ASM_X86__BYTEORDER_H */