1 #ifndef _LINUX_RATELIMIT_H
2 #define _LINUX_RATELIMIT_H
3 
4 #include <linux/param.h>
5 #include <linux/spinlock.h>
6 
7 #define DEFAULT_RATELIMIT_INTERVAL	(5 * HZ)
8 #define DEFAULT_RATELIMIT_BURST		10
9 
10 struct ratelimit_state {
11 	spinlock_t	lock;		/* protect the state */
12 
13 	int		interval;
14 	int		burst;
15 	int		printed;
16 	int		missed;
17 	unsigned long	begin;
18 };
19 
20 #define DEFINE_RATELIMIT_STATE(name, interval_init, burst_init)		\
21 									\
22 	struct ratelimit_state name = {					\
23 		.lock		= __SPIN_LOCK_UNLOCKED(name.lock),	\
24 		.interval	= interval_init,			\
25 		.burst		= burst_init,				\
26 	}
27 
ratelimit_state_init(struct ratelimit_state * rs,int interval,int burst)28 static inline void ratelimit_state_init(struct ratelimit_state *rs,
29 					int interval, int burst)
30 {
31 	spin_lock_init(&rs->lock);
32 	rs->interval = interval;
33 	rs->burst = burst;
34 	rs->printed = 0;
35 	rs->missed = 0;
36 	rs->begin = 0;
37 }
38 
39 extern struct ratelimit_state printk_ratelimit_state;
40 
41 extern int ___ratelimit(struct ratelimit_state *rs, const char *func);
42 #define __ratelimit(state) ___ratelimit(state, __func__)
43 
44 #endif /* _LINUX_RATELIMIT_H */
45