ratelimit.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _LINUX_RATELIMIT_H
  3#define _LINUX_RATELIMIT_H
  4
  5#include <linux/ratelimit_types.h>
  6#include <linux/sched.h>
  7#include <linux/spinlock.h>
  8
  9static inline void ratelimit_state_init(struct ratelimit_state *rs,
 10					int interval, int burst)
 11{
 12	memset(rs, 0, sizeof(*rs));
 13
 14	raw_spin_lock_init(&rs->lock);
 15	rs->interval	= interval;
 16	rs->burst	= burst;
 17}
 18
 19static inline void ratelimit_default_init(struct ratelimit_state *rs)
 20{
 21	return ratelimit_state_init(rs, DEFAULT_RATELIMIT_INTERVAL,
 22					DEFAULT_RATELIMIT_BURST);
 23}
 24
 25static inline void ratelimit_state_inc_miss(struct ratelimit_state *rs)
 26{
 27	atomic_inc(&rs->missed);
 28}
 29
 30static inline int ratelimit_state_get_miss(struct ratelimit_state *rs)
 31{
 32	return atomic_read(&rs->missed);
 33}
 34
 35static inline int ratelimit_state_reset_miss(struct ratelimit_state *rs)
 36{
 37	return atomic_xchg_relaxed(&rs->missed, 0);
 38}
 39
 40static inline void ratelimit_state_reset_interval(struct ratelimit_state *rs, int interval_init)
 41{
 42	unsigned long flags;
 43
 44	raw_spin_lock_irqsave(&rs->lock, flags);
 45	rs->interval = interval_init;
 46	rs->flags &= ~RATELIMIT_INITIALIZED;
 47	atomic_set(&rs->rs_n_left, rs->burst);
 48	ratelimit_state_reset_miss(rs);
 49	raw_spin_unlock_irqrestore(&rs->lock, flags);
 50}
 51
 52static inline void ratelimit_state_exit(struct ratelimit_state *rs)
 53{
 54	int m;
 55
 56	if (!(rs->flags & RATELIMIT_MSG_ON_RELEASE))
 57		return;
 58
 59	m = ratelimit_state_reset_miss(rs);
 60	if (m)
 61		pr_warn("%s: %d output lines suppressed due to ratelimiting\n", current->comm, m);
 62}
 63
 64static inline void
 65ratelimit_set_flags(struct ratelimit_state *rs, unsigned long flags)
 66{
 67	rs->flags = flags;
 68}
 69
 70extern struct ratelimit_state printk_ratelimit_state;
 71
 72#ifdef CONFIG_PRINTK
 73
 74#define WARN_ON_RATELIMIT(condition, state)	({		\
 75	bool __rtn_cond = !!(condition);			\
 76	WARN_ON(__rtn_cond && __ratelimit(state));		\
 77	__rtn_cond;						\
 78})
 79
 80#define WARN_RATELIMIT(condition, format, ...)			\
 81({								\
 82	static DEFINE_RATELIMIT_STATE(_rs,			\
 83				      DEFAULT_RATELIMIT_INTERVAL,	\
 84				      DEFAULT_RATELIMIT_BURST);	\
 85	int rtn = !!(condition);				\
 86								\
 87	if (unlikely(rtn && __ratelimit(&_rs)))			\
 88		WARN(rtn, format, ##__VA_ARGS__);		\
 89								\
 90	rtn;							\
 91})
 92
 93#else
 94
 95#define WARN_ON_RATELIMIT(condition, state)			\
 96	WARN_ON(condition)
 97
 98#define WARN_RATELIMIT(condition, format, ...)			\
 99({								\
100	int rtn = WARN(condition, format, ##__VA_ARGS__);	\
101	rtn;							\
102})
103
104#endif
105
106#endif /* _LINUX_RATELIMIT_H */