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_inc_miss(struct ratelimit_state * rs)25 static inline void ratelimit_state_inc_miss(struct ratelimit_state *rs)
26 {
27 atomic_inc(&rs->missed);
28 }
29
ratelimit_state_get_miss(struct ratelimit_state * rs)30 static inline int ratelimit_state_get_miss(struct ratelimit_state *rs)
31 {
32 return atomic_read(&rs->missed);
33 }
34
ratelimit_state_reset_miss(struct ratelimit_state * rs)35 static inline int ratelimit_state_reset_miss(struct ratelimit_state *rs)
36 {
37 return atomic_xchg_relaxed(&rs->missed, 0);
38 }
39
ratelimit_state_reset_interval(struct ratelimit_state * rs,int interval_init)40 static 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
ratelimit_state_exit(struct ratelimit_state * rs)52 static 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
64 static inline void
ratelimit_set_flags(struct ratelimit_state * rs,unsigned long flags)65 ratelimit_set_flags(struct ratelimit_state *rs, unsigned long flags)
66 {
67 rs->flags = flags;
68 }
69
70 extern 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 */
107