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 
ratelimit_state_init(struct ratelimit_state * rs,int interval,int burst)9 static 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 
ratelimit_default_init(struct ratelimit_state * rs)19 static 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 
ratelimit_state_exit(struct ratelimit_state * rs)25 static inline void ratelimit_state_exit(struct ratelimit_state *rs)
26 {
27 	if (!(rs->flags & RATELIMIT_MSG_ON_RELEASE))
28 		return;
29 
30 	if (rs->missed) {
31 		pr_warn("%s: %d output lines suppressed due to ratelimiting\n",
32 			current->comm, rs->missed);
33 		rs->missed = 0;
34 	}
35 }
36 
37 static inline void
ratelimit_set_flags(struct ratelimit_state * rs,unsigned long flags)38 ratelimit_set_flags(struct ratelimit_state *rs, unsigned long flags)
39 {
40 	rs->flags = flags;
41 }
42 
43 extern struct ratelimit_state printk_ratelimit_state;
44 
45 #ifdef CONFIG_PRINTK
46 
47 #define WARN_ON_RATELIMIT(condition, state)	({		\
48 	bool __rtn_cond = !!(condition);			\
49 	WARN_ON(__rtn_cond && __ratelimit(state));		\
50 	__rtn_cond;						\
51 })
52 
53 #define WARN_RATELIMIT(condition, format, ...)			\
54 ({								\
55 	static DEFINE_RATELIMIT_STATE(_rs,			\
56 				      DEFAULT_RATELIMIT_INTERVAL,	\
57 				      DEFAULT_RATELIMIT_BURST);	\
58 	int rtn = !!(condition);				\
59 								\
60 	if (unlikely(rtn && __ratelimit(&_rs)))			\
61 		WARN(rtn, format, ##__VA_ARGS__);		\
62 								\
63 	rtn;							\
64 })
65 
66 #else
67 
68 #define WARN_ON_RATELIMIT(condition, state)			\
69 	WARN_ON(condition)
70 
71 #define WARN_RATELIMIT(condition, format, ...)			\
72 ({								\
73 	int rtn = WARN(condition, format, ##__VA_ARGS__);	\
74 	rtn;							\
75 })
76 
77 #endif
78 
79 #endif /* _LINUX_RATELIMIT_H */
80