include/linux/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
   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
  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
  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
  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 */