x86: Fix up byteorder.h for x86_64

Remove the very old x86 code and add support for 64-bit.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/arch/x86/include/asm/byteorder.h b/arch/x86/include/asm/byteorder.h
index 7dfeb8bbed2b4cdc69a0e4c3943b4ad0e9d241ed..a2d1fd8703bd1418f20673f097e3f81ce5781bd6 100644 (file)
--- a/arch/x86/include/asm/byteorder.h
+++ b/arch/x86/include/asm/byteorder.h
@@ -8,24 +8,25 @@
 
 static __inline__ __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;
 }
 
+#define _constant_swab16(x) ((__u16)(                          \
+       (((__u16)(x) & (__u16)0x00ffU) << 8) |                  \
+       (((__u16)(x) & (__u16)0xff00U) >> 8)))
+
 static __inline__ __u16 ___arch__swab16(__u16 x)
 {
+#if CONFIG_IS_ENABLED(X86_64)
+       return _constant_swab16(x);
+#else
        __asm__("xchgb %b0,%h0"         /* swap bytes           */ \
                : "=q" (x) \
                :  "0" (x)); \
                return x;
+#endif
 }
 
 #define __arch__swab32(x) ___arch__swab32(x)