[PATCH] include: <asm-generic/bug.h>: implement WARN_ON_ONCE

[Ahmad Fatoum]

We have WARN_ON and WARN_ONCE. Add WARN_ON_ONCE as well to accommodate
Linux driver code using it.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 include/asm-generic/bug.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index f20e1b4d65ac..5d0a458eae74 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -50,4 +50,16 @@
 	}					\
 	unlikely(__ret_warn_once);		\
 })
+
+#define WARN_ON_ONCE(condition) ({			\
+	static int __warned;				\
+	int __ret_warn_once = !!(condition);		\
+							\
+	if (unlikely(__ret_warn_once && !__warned)) {	\
+		__warned = 1;				\
+		__WARN();				\
+	}						\
+	unlikely(__ret_warn_once);			\
+})
+
 #endif
-- 
2.30.2