rename div64_64 to div64_u64

Rename div64_64 to div64_u64 to make it consistent with the other divide
functions, so it clearly includes the type of the divide.  Move its definition
to math64.h as currently no architecture overrides the generic implementation.
 They can still override it of course, but the duplicated declarations are
avoided.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Avi Kivity <avi@qumranet.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/div64.c b/lib/div64.c
index 689bd76..bb5bd0c 100644
--- a/lib/div64.c
+++ b/lib/div64.c
@@ -78,9 +78,10 @@
 #endif
 
 /* 64bit divisor, dividend and result. dynamic precision */
-uint64_t div64_64(uint64_t dividend, uint64_t divisor)
+#ifndef div64_u64
+u64 div64_u64(u64 dividend, u64 divisor)
 {
-	uint32_t high, d;
+	u32 high, d;
 
 	high = divisor >> 32;
 	if (high) {
@@ -91,10 +92,9 @@
 	} else
 		d = divisor;
 
-	do_div(dividend, d);
-
-	return dividend;
+	return div_u64(dividend, d);
 }
-EXPORT_SYMBOL(div64_64);
+EXPORT_SYMBOL(div64_u64);
+#endif
 
 #endif /* BITS_PER_LONG == 32 */