[PATCH v2 02/20] lib: move memcpy()

[Jan Beulich <jbeulich@xxxxxxxx>]

By moving the function into an archive, x86 doesn't need to announce
anymore that is has its own implementation - symbol resolution by the
linker will now guarantee that the generic function remains unused, and
the forwarding to the compiler built-in gets done by the common header
anyway.

Allow the function to be individually linkable, discardable, and
overridable.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/common/string.c
+++ b/xen/common/string.c
@@ -311,27 +311,6 @@ char *(strstr)(const char *s1, const cha
 }
 #endif
 
-#ifndef __HAVE_ARCH_MEMCPY
-/**
- * memcpy - Copy one area of memory to another
- * @dest: Where to copy to
- * @src: Where to copy from
- * @count: The size of the area.
- *
- * You should not use this function to access IO space, use memcpy_toio()
- * or memcpy_fromio() instead.
- */
-void *(memcpy)(void *dest, const void *src, size_t count)
-{
-       char *tmp = (char *) dest, *s = (char *) src;
-
-       while (count--)
-               *tmp++ = *s++;
-
-       return dest;
-}
-#endif
-
 #ifndef __HAVE_ARCH_MEMMOVE
 /**
  * memmove - Copy one area of memory to another
--- a/xen/include/asm-x86/string.h
+++ b/xen/include/asm-x86/string.h
@@ -1,9 +1,6 @@
 #ifndef __X86_STRING_H__
 #define __X86_STRING_H__
 
-#define __HAVE_ARCH_MEMCPY
-#define memcpy(d, s, n) __builtin_memcpy(d, s, n)
-
 #define __HAVE_ARCH_MEMMOVE
 #define memmove(d, s, n) __builtin_memmove(d, s, n)
 
--- a/xen/lib/Makefile
+++ b/xen/lib/Makefile
@@ -4,6 +4,7 @@ lib-y += bsearch.o
 lib-y += ctors.o
 lib-y += ctype.o
 lib-y += list-sort.o
+lib-y += memcpy.o
 lib-y += memset.o
 lib-y += muldiv64.o
 lib-y += parse-size.o
--- /dev/null
+++ b/xen/lib/memcpy.c
@@ -0,0 +1,34 @@
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <xen/string.h>
+
+/**
+ * memcpy - Copy one area of memory to another
+ * @dest: Where to copy to
+ * @src: Where to copy from
+ * @count: The size of the area.
+ *
+ * You should not use this function to access IO space, use memcpy_toio()
+ * or memcpy_fromio() instead.
+ */
+void *(memcpy)(void *dest, const void *src, size_t count)
+{
+       char *tmp = (char *) dest, *s = (char *) src;
+
+       while (count--)
+               *tmp++ = *s++;
+
+       return dest;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 8
+ * tab-width: 8
+ * indent-tabs-mode: t
+ * End:
+ */