#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 DEFINE_RATELIMIT_STATE(name, interval_init, burst_init)		\
  									\
  	struct ratelimit_state name = {					\

  		.lock		= __RAW_SPIN_LOCK_UNLOCKED(name.lock),	\

  		.interval	= interval_init,			\
  		.burst		= 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, 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 */