From bb8985586b7a906e116db835c64773b7a7d51663 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sun, 17 Aug 2008 21:05:42 -0400
Subject: x86, um: ... and asm-x86 move

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 arch/x86/include/asm/byteorder.h | 81 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 arch/x86/include/asm/byteorder.h

(limited to 'arch/x86/include/asm/byteorder.h')

diff --git a/arch/x86/include/asm/byteorder.h b/arch/x86/include/asm/byteorder.h
new file mode 100644
index 000000000000..722f27d68105
--- /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 */
-- 
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