1 /* SPDX-License-Identifier: GPL-2.0+ */ 1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /* 2 /*
3 * Read-Copy Update mechanism for mutual exclu 3 * Read-Copy Update mechanism for mutual exclusion (tree-based version)
4 * 4 *
5 * Copyright IBM Corporation, 2008 5 * Copyright IBM Corporation, 2008
6 * 6 *
7 * Author: Dipankar Sarma <dipankar@in.ibm.com 7 * Author: Dipankar Sarma <dipankar@in.ibm.com>
8 * Paul E. McKenney <paulmck@linux.ibm 8 * Paul E. McKenney <paulmck@linux.ibm.com> Hierarchical algorithm
9 * 9 *
10 * Based on the original work by Paul McKenney 10 * Based on the original work by Paul McKenney <paulmck@linux.ibm.com>
11 * and inputs from Rusty Russell, Andrea Arcan 11 * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
12 * 12 *
13 * For detailed explanation of Read-Copy Updat 13 * For detailed explanation of Read-Copy Update mechanism see -
14 * Documentation/RCU 14 * Documentation/RCU
15 */ 15 */
16 16
17 #ifndef __LINUX_RCUTREE_H 17 #ifndef __LINUX_RCUTREE_H
18 #define __LINUX_RCUTREE_H 18 #define __LINUX_RCUTREE_H
19 19
20 void rcu_softirq_qs(void); 20 void rcu_softirq_qs(void);
21 void rcu_note_context_switch(bool preempt); 21 void rcu_note_context_switch(bool preempt);
22 int rcu_needs_cpu(void); 22 int rcu_needs_cpu(void);
23 void rcu_cpu_stall_reset(void); 23 void rcu_cpu_stall_reset(void);
24 void rcu_request_urgent_qs_task(struct task_st <<
25 24
26 /* 25 /*
27 * Note a virtualization-based context switch. 26 * Note a virtualization-based context switch. This is simply a
28 * wrapper around rcu_note_context_switch(), w 27 * wrapper around rcu_note_context_switch(), which allows TINY_RCU
29 * to save a few bytes. The caller must have d 28 * to save a few bytes. The caller must have disabled interrupts.
30 */ 29 */
31 static inline void rcu_virt_note_context_switc !! 30 static inline void rcu_virt_note_context_switch(int cpu)
32 { 31 {
33 rcu_note_context_switch(false); 32 rcu_note_context_switch(false);
34 } 33 }
35 34
36 void synchronize_rcu_expedited(void); 35 void synchronize_rcu_expedited(void);
37 void kvfree_call_rcu(struct rcu_head *head, vo !! 36 void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func);
38 void kvfree_rcu_barrier(void); <<
39 37
40 void rcu_barrier(void); 38 void rcu_barrier(void);
41 void rcu_momentary_eqs(void); !! 39 bool rcu_eqs_special_set(int cpu);
>> 40 void rcu_momentary_dyntick_idle(void);
42 void kfree_rcu_scheduler_running(void); 41 void kfree_rcu_scheduler_running(void);
43 bool rcu_gp_might_be_stalled(void); 42 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 43 unsigned long start_poll_synchronize_rcu_expedited(void);
79 void start_poll_synchronize_rcu_expedited_full <<
80 void cond_synchronize_rcu_expedited(unsigned l 44 void cond_synchronize_rcu_expedited(unsigned long oldstate);
81 void cond_synchronize_rcu_expedited_full(struc <<
82 unsigned long get_state_synchronize_rcu(void); 45 unsigned long get_state_synchronize_rcu(void);
83 void get_state_synchronize_rcu_full(struct rcu <<
84 unsigned long start_poll_synchronize_rcu(void) 46 unsigned long start_poll_synchronize_rcu(void);
85 void start_poll_synchronize_rcu_full(struct rc <<
86 bool poll_state_synchronize_rcu(unsigned long 47 bool poll_state_synchronize_rcu(unsigned long oldstate);
87 bool poll_state_synchronize_rcu_full(struct rc <<
88 void cond_synchronize_rcu(unsigned long oldsta 48 void cond_synchronize_rcu(unsigned long oldstate);
89 void cond_synchronize_rcu_full(struct rcu_gp_o !! 49
>> 50 bool rcu_is_idle_cpu(int cpu);
90 51
91 #ifdef CONFIG_PROVE_RCU 52 #ifdef CONFIG_PROVE_RCU
92 void rcu_irq_exit_check_preempt(void); 53 void rcu_irq_exit_check_preempt(void);
93 #else 54 #else
94 static inline void rcu_irq_exit_check_preempt( 55 static inline void rcu_irq_exit_check_preempt(void) { }
95 #endif 56 #endif
96 57
97 struct task_struct; 58 struct task_struct;
98 void rcu_preempt_deferred_qs(struct task_struc 59 void rcu_preempt_deferred_qs(struct task_struct *t);
99 60
100 void exit_rcu(void); 61 void exit_rcu(void);
101 62
102 void rcu_scheduler_starting(void); 63 void rcu_scheduler_starting(void);
103 extern int rcu_scheduler_active; 64 extern int rcu_scheduler_active;
104 void rcu_end_inkernel_boot(void); 65 void rcu_end_inkernel_boot(void);
105 bool rcu_inkernel_boot_has_ended(void); 66 bool rcu_inkernel_boot_has_ended(void);
106 bool rcu_is_watching(void); 67 bool rcu_is_watching(void);
107 #ifndef CONFIG_PREEMPTION 68 #ifndef CONFIG_PREEMPTION
108 void rcu_all_qs(void); 69 void rcu_all_qs(void);
109 #endif 70 #endif
110 71
111 /* RCUtree hotplug events */ 72 /* RCUtree hotplug events */
112 int rcutree_prepare_cpu(unsigned int cpu); 73 int rcutree_prepare_cpu(unsigned int cpu);
113 int rcutree_online_cpu(unsigned int cpu); 74 int rcutree_online_cpu(unsigned int cpu);
114 void rcutree_report_cpu_starting(unsigned int !! 75 int rcutree_offline_cpu(unsigned int cpu);
115 <<
116 #ifdef CONFIG_HOTPLUG_CPU <<
117 int rcutree_dead_cpu(unsigned int cpu); 76 int rcutree_dead_cpu(unsigned int cpu);
118 int rcutree_dying_cpu(unsigned int cpu); 77 int rcutree_dying_cpu(unsigned int cpu);
119 int rcutree_offline_cpu(unsigned int cpu); !! 78 void rcu_cpu_starting(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 79
131 #endif /* __LINUX_RCUTREE_H */ 80 #endif /* __LINUX_RCUTREE_H */
132 81
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