[XEN] Include byteorder functions from Linux.

Signed-off-by: Keir Fraser <keir@xensource.com>

1 files changed, 36 insertions, 0 deletions

diff --git a/xen/include/asm-x86/byteorder.h b/xen/include/asm-x86/byteorder.h
new file mode 100644
index 0000000000..eb52ae2f11
--- /dev/null
+++ b/xen/include/asm-x86/byteorder.h
@@ -0,0 +1,36 @@
+#ifndef __ASM_X86_BYTEORDER_H__
+#define __ASM_X86_BYTEORDER_H__
+
+#include <asm/types.h>
+#include <xen/compiler.h>
+
+static inline __attribute_const__ __u32 ___arch__swab32(__u32 x)
+{
+    asm("bswap %0" : "=r" (x) : "0" (x));
+    return x;
+}
+
+static inline __attribute_const__ __u64 ___arch__swab64(__u64 val)
+{ 
+    union { 
+        struct { __u32 a,b; } s;
+        __u64 u;
+    } v;
+    v.u = val;
+    asm("bswapl %0 ; bswapl %1 ; xchgl %0,%1" 
+        : "=r" (v.s.a), "=r" (v.s.b) 
+        : "0" (v.s.a), "1" (v.s.b)); 
+    return v.u;	
+} 
+
+/* 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__
+
+#include <xen/byteorder/little_endian.h>
+
+#endif /* __ASM_X86_BYTEORDER_H__ */