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/string_64.h

@@ -0,0 +1,60 @@
+#ifndef ASM_X86__STRING_64_H
+#define ASM_X86__STRING_64_H
+
+#ifdef __KERNEL__
+
+/* Written 2002 by Andi Kleen */
+
+/* Only used for special circumstances. Stolen from i386/string.h */
+static __always_inline void *__inline_memcpy(void *to, const void *from, size_t n)
+{
+	unsigned long d0, d1, d2;
+	asm volatile("rep ; movsl\n\t"
+		     "testb $2,%b4\n\t"
+		     "je 1f\n\t"
+		     "movsw\n"
+		     "1:\ttestb $1,%b4\n\t"
+		     "je 2f\n\t"
+		     "movsb\n"
+		     "2:"
+		     : "=&c" (d0), "=&D" (d1), "=&S" (d2)
+		     : "0" (n / 4), "q" (n), "1" ((long)to), "2" ((long)from)
+		     : "memory");
+	return to;
+}
+
+/* Even with __builtin_ the compiler may decide to use the out of line
+   function. */
+
+#define __HAVE_ARCH_MEMCPY 1
+#if (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) || __GNUC__ > 4
+extern void *memcpy(void *to, const void *from, size_t len);
+#else
+extern void *__memcpy(void *to, const void *from, size_t len);
+#define memcpy(dst, src, len)					\
+({								\
+	size_t __len = (len);					\
+	void *__ret;						\
+	if (__builtin_constant_p(len) && __len >= 64)		\
+		__ret = __memcpy((dst), (src), __len);		\
+	else							\
+		__ret = __builtin_memcpy((dst), (src), __len);	\
+	__ret;							\
+})
+#endif
+
+#define __HAVE_ARCH_MEMSET
+void *memset(void *s, int c, size_t n);
+
+#define __HAVE_ARCH_MEMMOVE
+void *memmove(void *dest, const void *src, size_t count);
+
+int memcmp(const void *cs, const void *ct, size_t count);
+size_t strlen(const char *s);
+char *strcpy(char *dest, const char *src);
+char *strcat(char *dest, const char *src);
+int strcmp(const char *cs, const char *ct);
+
+#endif /* __KERNEL__ */
+
+#endif /* ASM_X86__STRING_64_H */