1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Read-Copy Update mechanism for mutual exclusion (tree-based version)
4  *
5  * Copyright IBM Corporation, 2008
6  *
7  * Author: Dipankar Sarma <dipankar@in.ibm.com>
8  *	   Paul E. McKenney <paulmck@linux.ibm.com> Hierarchical algorithm
9  *
10  * Based on the original work by Paul McKenney <paulmck@linux.ibm.com>
11  * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
12  *
13  * For detailed explanation of Read-Copy Update mechanism see -
14  *	Documentation/RCU
15  */
16 
17 #ifndef __LINUX_RCUTREE_H
18 #define __LINUX_RCUTREE_H
19 
20 void rcu_softirq_qs(void);
21 void rcu_note_context_switch(bool preempt);
22 int rcu_needs_cpu(u64 basem, u64 *nextevt);
23 void rcu_cpu_stall_reset(void);
24 
25 /*
26  * Note a virtualization-based context switch.  This is simply a
27  * wrapper around rcu_note_context_switch(), which allows TINY_RCU
28  * to save a few bytes. The caller must have disabled interrupts.
29  */
rcu_virt_note_context_switch(int cpu)30 static inline void rcu_virt_note_context_switch(int cpu)
31 {
32 	rcu_note_context_switch(false);
33 }
34 
35 void synchronize_rcu_expedited(void);
36 void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func);
37 
38 void rcu_barrier(void);
39 bool rcu_eqs_special_set(int cpu);
40 void rcu_momentary_dyntick_idle(void);
41 void kfree_rcu_scheduler_running(void);
42 bool rcu_gp_might_be_stalled(void);
43 unsigned long get_state_synchronize_rcu(void);
44 unsigned long start_poll_synchronize_rcu(void);
45 bool poll_state_synchronize_rcu(unsigned long oldstate);
46 void cond_synchronize_rcu(unsigned long oldstate);
47 
48 void rcu_idle_enter(void);
49 void rcu_idle_exit(void);
50 void rcu_irq_enter(void);
51 void rcu_irq_exit(void);
52 void rcu_irq_enter_irqson(void);
53 void rcu_irq_exit_irqson(void);
54 bool rcu_is_idle_cpu(int cpu);
55 
56 #ifdef CONFIG_PROVE_RCU
57 void rcu_irq_exit_check_preempt(void);
58 #else
rcu_irq_exit_check_preempt(void)59 static inline void rcu_irq_exit_check_preempt(void) { }
60 #endif
61 
62 void exit_rcu(void);
63 
64 void rcu_scheduler_starting(void);
65 extern int rcu_scheduler_active __read_mostly;
66 void rcu_end_inkernel_boot(void);
67 bool rcu_inkernel_boot_has_ended(void);
68 bool rcu_is_watching(void);
69 #ifndef CONFIG_PREEMPTION
70 void rcu_all_qs(void);
71 #endif
72 
73 /* RCUtree hotplug events */
74 int rcutree_prepare_cpu(unsigned int cpu);
75 int rcutree_online_cpu(unsigned int cpu);
76 int rcutree_offline_cpu(unsigned int cpu);
77 int rcutree_dead_cpu(unsigned int cpu);
78 int rcutree_dying_cpu(unsigned int cpu);
79 void rcu_cpu_starting(unsigned int cpu);
80 
81 #endif /* __LINUX_RCUTREE_H */
82