1 /* SPDX-License-Identifier: GPL-2.0+ */ 1
2 /*
3 * Read-Copy Update mechanism for mutual exclu
4 *
5 * Copyright IBM Corporation, 2008
6 *
7 * Author: Dipankar Sarma <dipankar@in.ibm.com
8 * Paul E. McKenney <paulmck@linux.ibm
9 *
10 * Based on the original work by Paul McKenney
11 * and inputs from Rusty Russell, Andrea Arcan
12 *
13 * For detailed explanation of Read-Copy Updat
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(void);
23 void rcu_cpu_stall_reset(void);
24 void rcu_request_urgent_qs_task(struct task_st
25
26 /*
27 * Note a virtualization-based context switch.
28 * wrapper around rcu_note_context_switch(), w
29 * to save a few bytes. The caller must have d
30 */
31 static inline void rcu_virt_note_context_switc
32 {
33 rcu_note_context_switch(false);
34 }
35
36 void synchronize_rcu_expedited(void);
37 void kvfree_call_rcu(struct rcu_head *head, vo
38 void kvfree_rcu_barrier(void);
39
40 void rcu_barrier(void);
41 void rcu_momentary_eqs(void);
42 void kfree_rcu_scheduler_running(void);
43 bool rcu_gp_might_be_stalled(void);
44
45 struct rcu_gp_oldstate {
46 unsigned long rgos_norm;
47 unsigned long rgos_exp;
48 };
49
50 // Maximum number of rcu_gp_oldstate values co
51 // not-yet-completed RCU grace periods.
52 #define NUM_ACTIVE_RCU_POLL_FULL_OLDSTATE 4
53
54 /**
55 * same_state_synchronize_rcu_full - Are two o
56 * @rgosp1: First old-state value.
57 * @rgosp2: Second old-state value.
58 *
59 * The two old-state values must have been obt
60 * get_state_synchronize_rcu_full(), start_pol
61 * or get_completed_synchronize_rcu_full(). R
62 * values are identical and @false otherwise.
63 * whose lifetimes are tracked by old-state va
64 * to a list header, allowing those structures
65 *
66 * Note that equality is judged on a bitwise b
67 * @rcu_gp_oldstate structure with an already-
68 * will compare not-equal to a structure with
69 * in the other field. After all, the @rcu_gp
70 * so how did such a situation come to pass in
71 */
72 static inline bool same_state_synchronize_rcu_
73
74 {
75 return rgosp1->rgos_norm == rgosp2->rg
76 }
77
78 unsigned long start_poll_synchronize_rcu_exped
79 void start_poll_synchronize_rcu_expedited_full
80 void cond_synchronize_rcu_expedited(unsigned l
81 void cond_synchronize_rcu_expedited_full(struc
82 unsigned long get_state_synchronize_rcu(void);
83 void get_state_synchronize_rcu_full(struct rcu
84 unsigned long start_poll_synchronize_rcu(void)
85 void start_poll_synchronize_rcu_full(struct rc
86 bool poll_state_synchronize_rcu(unsigned long
87 bool poll_state_synchronize_rcu_full(struct rc
88 void cond_synchronize_rcu(unsigned long oldsta
89 void cond_synchronize_rcu_full(struct rcu_gp_o
90
91 #ifdef CONFIG_PROVE_RCU
92 void rcu_irq_exit_check_preempt(void);
93 #else
94 static inline void rcu_irq_exit_check_preempt(
95 #endif
96
97 struct task_struct;
98 void rcu_preempt_deferred_qs(struct task_struc
99
100 void exit_rcu(void);
101
102 void rcu_scheduler_starting(void);
103 extern int rcu_scheduler_active;
104 void rcu_end_inkernel_boot(void);
105 bool rcu_inkernel_boot_has_ended(void);
106 bool rcu_is_watching(void);
107 #ifndef CONFIG_PREEMPTION
108 void rcu_all_qs(void);
109 #endif
110
111 /* RCUtree hotplug events */
112 int rcutree_prepare_cpu(unsigned int cpu);
113 int rcutree_online_cpu(unsigned int cpu);
114 void rcutree_report_cpu_starting(unsigned int
115
116 #ifdef CONFIG_HOTPLUG_CPU
117 int rcutree_dead_cpu(unsigned int cpu);
118 int rcutree_dying_cpu(unsigned int cpu);
119 int rcutree_offline_cpu(unsigned int cpu);
120 #else
121 #define rcutree_dead_cpu NULL
122 #define rcutree_dying_cpu NULL
123 #define rcutree_offline_cpu NULL
124 #endif
125
126 void rcutree_migrate_callbacks(int cpu);
127
128 /* Called from hotplug and also arm64 early se
129 void rcutree_report_cpu_dead(void);
130
131 #endif /* __LINUX_RCUTREE_H */
132
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