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64db4cff PM |
1 | /* |
2 | * Read-Copy Update mechanism for mutual exclusion (tree-based version) | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | * | |
18 | * Copyright IBM Corporation, 2008 | |
19 | * | |
20 | * Author: Dipankar Sarma <dipankar@in.ibm.com> | |
21 | * Paul E. McKenney <paulmck@linux.vnet.ibm.com> Hierarchical algorithm | |
22 | * | |
23 | * Based on the original work by Paul McKenney <paulmck@us.ibm.com> | |
24 | * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. | |
25 | * | |
26 | * For detailed explanation of Read-Copy Update mechanism see - | |
a71fca58 | 27 | * Documentation/RCU |
64db4cff PM |
28 | */ |
29 | ||
30 | #ifndef __LINUX_RCUTREE_H | |
31 | #define __LINUX_RCUTREE_H | |
32 | ||
9b2619af PM |
33 | struct notifier_block; |
34 | ||
d6714c22 PM |
35 | extern void rcu_sched_qs(int cpu); |
36 | extern void rcu_bh_qs(int cpu); | |
64db4cff | 37 | extern int rcu_needs_cpu(int cpu); |
6ebb237b | 38 | extern void rcu_scheduler_starting(void); |
9b2619af | 39 | extern int rcu_expedited_torture_stats(char *page); |
64db4cff | 40 | |
f41d911f PM |
41 | #ifdef CONFIG_TREE_PREEMPT_RCU |
42 | ||
43 | extern void __rcu_read_lock(void); | |
44 | extern void __rcu_read_unlock(void); | |
6ebb237b | 45 | extern void synchronize_rcu(void); |
f41d911f PM |
46 | extern void exit_rcu(void); |
47 | ||
234da7bc FW |
48 | /* |
49 | * Defined as macro as it is a very low level header | |
50 | * included from areas that don't even know about current | |
51 | */ | |
52 | #define rcu_preempt_depth() (current->rcu_read_lock_nesting) | |
53 | ||
f41d911f PM |
54 | #else /* #ifdef CONFIG_TREE_PREEMPT_RCU */ |
55 | ||
64db4cff PM |
56 | static inline void __rcu_read_lock(void) |
57 | { | |
58 | preempt_disable(); | |
64db4cff | 59 | } |
f41d911f | 60 | |
64db4cff PM |
61 | static inline void __rcu_read_unlock(void) |
62 | { | |
64db4cff PM |
63 | preempt_enable(); |
64 | } | |
f41d911f | 65 | |
6ebb237b | 66 | #define synchronize_rcu synchronize_sched |
16e30811 | 67 | |
f41d911f PM |
68 | static inline void exit_rcu(void) |
69 | { | |
70 | } | |
71 | ||
234da7bc FW |
72 | static inline int rcu_preempt_depth(void) |
73 | { | |
74 | return 0; | |
75 | } | |
76 | ||
f41d911f PM |
77 | #endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */ |
78 | ||
64db4cff PM |
79 | static inline void __rcu_read_lock_bh(void) |
80 | { | |
81 | local_bh_disable(); | |
64db4cff PM |
82 | } |
83 | static inline void __rcu_read_unlock_bh(void) | |
84 | { | |
64db4cff PM |
85 | local_bh_enable(); |
86 | } | |
87 | ||
d6714c22 PM |
88 | extern void call_rcu_sched(struct rcu_head *head, |
89 | void (*func)(struct rcu_head *rcu)); | |
019129d5 | 90 | extern void synchronize_rcu_expedited(void); |
03b042bf PM |
91 | |
92 | static inline void synchronize_rcu_bh_expedited(void) | |
64db4cff | 93 | { |
03b042bf | 94 | synchronize_sched_expedited(); |
64db4cff PM |
95 | } |
96 | ||
64db4cff | 97 | extern void rcu_check_callbacks(int cpu, int user); |
64db4cff PM |
98 | |
99 | extern long rcu_batches_completed(void); | |
100 | extern long rcu_batches_completed_bh(void); | |
d6714c22 | 101 | extern long rcu_batches_completed_sched(void); |
bf66f18e PM |
102 | extern void rcu_force_quiescent_state(void); |
103 | extern void rcu_bh_force_quiescent_state(void); | |
104 | extern void rcu_sched_force_quiescent_state(void); | |
64db4cff PM |
105 | |
106 | #ifdef CONFIG_NO_HZ | |
107 | void rcu_enter_nohz(void); | |
108 | void rcu_exit_nohz(void); | |
109 | #else /* CONFIG_NO_HZ */ | |
110 | static inline void rcu_enter_nohz(void) | |
111 | { | |
112 | } | |
113 | static inline void rcu_exit_nohz(void) | |
114 | { | |
115 | } | |
116 | #endif /* CONFIG_NO_HZ */ | |
117 | ||
1eba8f84 | 118 | /* A context switch is a grace period for RCU-sched and RCU-bh. */ |
a6826048 PM |
119 | static inline int rcu_blocking_is_gp(void) |
120 | { | |
121 | return num_online_cpus() == 1; | |
122 | } | |
123 | ||
64db4cff | 124 | #endif /* __LINUX_RCUTREE_H */ |