bug.h: Add WARN_RATELIMIT

Add a generic mechanism to ratelimit WARN(foo, fmt, ...) messages
using a hidden per call site static struct ratelimit_state.

Also add an __WARN_RATELIMIT variant to be able to use a specific
struct ratelimit_state.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 0 deletions

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index e5a3f588000..12b250cdda8 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -165,6 +165,22 @@ extern void warn_slowpath_null(const char *file, const int line);
 #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);              \
+})
+
 /*
  * WARN_ON_SMP() is for cases that the warning is either
  * meaningless for !SMP or may even cause failures.