1 files changed, 81 insertions, 0 deletions
diff --git a/include/linux/ratelimit.h b/include/linux/ratelimit.h
new file mode 100644
index 000000000..181025292
--- /dev/null
+++ b/include/linux/ratelimit.h
@@ -0,0 +1,81 @@
+#ifndef _LINUX_RATELIMIT_H
+#define _LINUX_RATELIMIT_H
+
+#include <linux/param.h>
+#include <linux/spinlock.h>
+
+#define DEFAULT_RATELIMIT_INTERVAL	(5 * HZ)
+#define DEFAULT_RATELIMIT_BURST		10
+
+struct ratelimit_state {
+	raw_spinlock_t	lock;		/* protect the state */
+
+	int		interval;
+	int		burst;
+	int		printed;
+	int		missed;
+	unsigned long	begin;
+};
+
+#define RATELIMIT_STATE_INIT(name, interval_init, burst_init) {		\
+		.lock		= __RAW_SPIN_LOCK_UNLOCKED(name.lock),	\
+		.interval	= interval_init,			\
+		.burst		= burst_init,				\
+	}
+
+#define RATELIMIT_STATE_INIT_DISABLED					\
+	RATELIMIT_STATE_INIT(ratelimit_state, 0, DEFAULT_RATELIMIT_BURST)
+
+#define DEFINE_RATELIMIT_STATE(name, interval_init, burst_init)		\
+									\
+	struct ratelimit_state name =					\
+		RATELIMIT_STATE_INIT(name, interval_init, burst_init)	\
+
+static inline void ratelimit_state_init(struct ratelimit_state *rs,
+					int interval, int burst)
+{
+	raw_spin_lock_init(&rs->lock);
+	rs->interval = interval;
+	rs->burst = burst;
+	rs->printed = 0;
+	rs->missed = 0;
+	rs->begin = 0;
+}
+
+extern struct ratelimit_state printk_ratelimit_state;
+
+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, format, ...)			\
+({								\
+	static DEFINE_RATELIMIT_STATE(_rs,			\
+				      DEFAULT_RATELIMIT_INTERVAL,	\
+				      DEFAULT_RATELIMIT_BURST);	\
+	int rtn = !!(condition);				\
+								\
+	if (unlikely(rtn && __ratelimit(&_rs)))			\
+		WARN(rtn, format, ##__VA_ARGS__);		\
+								\
+	rtn;							\
+})
+
+#else
+
+#define WARN_ON_RATELIMIT(condition, state)			\
+	WARN_ON(condition)
+
+#define WARN_RATELIMIT(condition, format, ...)			\
+({								\
+	int rtn = WARN(condition, format, ##__VA_ARGS__);	\
+	rtn;							\
+})
+
+#endif
+
+#endif /* _LINUX_RATELIMIT_H */