debug: introduce __WARN()

Introduce __WARN() in the generic case, so the generic WARN_ON()
can use arch-specific code for when the condition is true.
Signed-off-by: Olof Johansson <olof@lixom.net>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/asm-generic/bug.h

@@ -31,14 +31,19 @@ struct bug_entry {
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while(0)
 #endif
 
-#ifndef HAVE_ARCH_WARN_ON
-#define WARN_ON(condition) ({						\
-	int __ret_warn_on = !!(condition);				\
-	if (unlikely(__ret_warn_on)) {					\
+#ifndef __WARN
+#define __WARN() do {							\
 	printk("WARNING: at %s:%d %s()\n", __FILE__,			\
 		__LINE__, __FUNCTION__);				\
 	dump_stack();							\
-	}								\
+} while (0)
+#endif
+
+#ifndef WARN_ON
+#define WARN_ON(condition) ({						\
+	int __ret_warn_on = !!(condition);				\
+	if (unlikely(__ret_warn_on))					\
+		__WARN();						\
 	unlikely(__ret_warn_on);					\
 })
 #endif