bug.h: Move ratelimit warn interfaces to ratelimit.h

As reported by Ingo Molnar, we still have configuration combinations
where use of the WARN_RATELIMIT interfaces break the build because
dependencies don't get met.

Instead of going down the long road of trying to make it so that
ratelimit.h can get included by kernel.h or asm-generic/bug.h,
just move the interface into ratelimit.h and make users have
to include that.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
diff --git a/include/linux/ratelimit.h b/include/linux/ratelimit.h
index 03ff67b..2f00715 100644
--- a/include/linux/ratelimit.h
+++ b/include/linux/ratelimit.h
@@ -41,4 +41,44 @@
 extern int ___ratelimit(struct ratelimit_state *rs, const char *func);
 #define __ratelimit(state) ___ratelimit(state, __func__)
 
+#ifdef CONFIG_PRINTK
+
+#define WARN_ON_RATELIMIT(condition, state)			\
+		WARN_ON((condition) && __ratelimit(state))
+
+#define __WARN_RATELIMIT(condition, state, format...)		\
+({								\
+	int rtn = 0;						\
+	if (unlikely(__ratelimit(state)))			\
+		rtn = WARN(condition, format);			\
+	rtn;							\
+})
+
+#define WARN_RATELIMIT(condition, format...)			\
+({								\
+	static DEFINE_RATELIMIT_STATE(_rs,			\
+				      DEFAULT_RATELIMIT_INTERVAL,	\
+				      DEFAULT_RATELIMIT_BURST);	\
+	__WARN_RATELIMIT(condition, &_rs, format);		\
+})
+
+#else
+
+#define WARN_ON_RATELIMIT(condition, state)			\
+	WARN_ON(condition)
+
+#define __WARN_RATELIMIT(condition, state, format...)		\
+({								\
+	int rtn = WARN(condition, format);			\
+	rtn;							\
+})
+
+#define WARN_RATELIMIT(condition, format...)			\
+({								\
+	int rtn = WARN(condition, format);			\
+	rtn;							\
+})
+
+#endif
+
 #endif /* _LINUX_RATELIMIT_H */