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-rw-r--r--arch/x86/include/asm/byteorder.h81
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 */