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.
rcu_stall_chain_notifier_register(struct notifier_block * n)27 static inline int rcu_stall_chain_notifier_register(struct notifier_block *n) { return -EEXIST; }
rcu_stall_chain_notifier_unregister(struct notifier_block * n)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 */
33