include/linux/rcu_notifier.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * Read-Copy Update notifiers, initially RCU CPU stall notifier.
   4  * Separate from rcupdate.h to avoid #include loops.
   5  *
   6  * Copyright (C) 2023 Paul E. McKenney.
   7  */
   8
   9 #ifndef __LINUX_RCU_NOTIFIER_H
  10 #define __LINUX_RCU_NOTIFIER_H
  11
  12 // Actions for RCU CPU stall notifier calls.
  13 #define RCU_STALL_NOTIFY_NORM   1
  14 #define RCU_STALL_NOTIFY_EXP    2
  15
  16 #if defined(CONFIG_RCU_STALL_COMMON) && defined(CONFIG_RCU_CPU_STALL_NOTIFIER)
  17
  18 #include <linux/notifier.h>
  19 #include <linux/types.h>
  20
  21 int rcu_stall_chain_notifier_register(struct notifier_block *n);
  22 int rcu_stall_chain_notifier_unregister(struct notifier_block *n);
  23
  24 #else // #if defined(CONFIG_RCU_STALL_COMMON) && defined(CONFIG_RCU_CPU_STALL_NOTIFIER)
  25
  26 // No RCU CPU stall warnings in Tiny RCU.
  27 static inline int rcu_stall_chain_notifier_register(struct notifier_block *n) { return -EEXIST; }
  28 static inline int rcu_stall_chain_notifier_unregister(struct notifier_block *n) { return -ENOENT; }
  29
  30 #endif // #else // #if defined(CONFIG_RCU_STALL_COMMON) && defined(CONFIG_RCU_CPU_STALL_NOTIFIER)
  31
  32 #endif /* __LINUX_RCU_NOTIFIER_H */