[PATCH] ppc64: Fix issue with gcc 4.0 compiled kernels

I recently had a BUG_ON() go off spuriously on a gcc 4.0 compiled kernel.
It turns out gcc-4.0 was removing a sign extension while earlier gcc
versions would not.  Thinking this to be a compiler bug, I submitted a
report:

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23422

It turns out we need to cast the input in order to tell gcc to sign extend
it.

Thanks to Andrew Pinski for his help on this bug.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/asm-ppc64/bug.h

@@ -43,8 +43,8 @@ struct bug_entry *find_bug(unsigned long bugaddr);
 		".section __bug_table,\"a\"\n\t"		\
 		"	.llong 1b,%1,%2,%3\n"			\
 		".previous"					\
-		: : "r" (x), "i" (__LINE__), "i" (__FILE__),	\
-		    "i" (__FUNCTION__));			\
+		: : "r" ((long long)(x)), "i" (__LINE__),	\
+		    "i" (__FILE__), "i" (__FUNCTION__));	\
 } while (0)
 
 #define WARN_ON(x) do {						\
@@ -53,7 +53,8 @@ struct bug_entry *find_bug(unsigned long bugaddr);
 		".section __bug_table,\"a\"\n\t"		\
 		"	.llong 1b,%1,%2,%3\n"			\
 		".previous"					\
-		: : "r" (x), "i" (__LINE__ + BUG_WARNING_TRAP),	\
+		: : "r" ((long long)(x)),			\
+		    "i" (__LINE__ + BUG_WARNING_TRAP),		\
 		    "i" (__FILE__), "i" (__FUNCTION__));	\
 } while (0)