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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 | ||
d6714c22 PM |
33 | extern void rcu_sched_qs(int cpu); |
34 | extern void rcu_bh_qs(int cpu); | |
64db4cff | 35 | |
64db4cff PM |
36 | extern int rcu_needs_cpu(int cpu); |
37 | ||
f41d911f PM |
38 | #ifdef CONFIG_TREE_PREEMPT_RCU |
39 | ||
40 | extern void __rcu_read_lock(void); | |
41 | extern void __rcu_read_unlock(void); | |
42 | extern void exit_rcu(void); | |
43 | ||
44 | #else /* #ifdef CONFIG_TREE_PREEMPT_RCU */ | |
45 | ||
64db4cff PM |
46 | static inline void __rcu_read_lock(void) |
47 | { | |
48 | preempt_disable(); | |
64db4cff | 49 | } |
f41d911f | 50 | |
64db4cff PM |
51 | static inline void __rcu_read_unlock(void) |
52 | { | |
64db4cff PM |
53 | preempt_enable(); |
54 | } | |
f41d911f | 55 | |
16e30811 PM |
56 | #define __synchronize_sched() synchronize_rcu() |
57 | ||
f41d911f PM |
58 | static inline void exit_rcu(void) |
59 | { | |
60 | } | |
61 | ||
62 | #endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */ | |
63 | ||
64db4cff PM |
64 | static inline void __rcu_read_lock_bh(void) |
65 | { | |
66 | local_bh_disable(); | |
64db4cff PM |
67 | } |
68 | static inline void __rcu_read_unlock_bh(void) | |
69 | { | |
64db4cff PM |
70 | local_bh_enable(); |
71 | } | |
72 | ||
d6714c22 PM |
73 | extern void call_rcu_sched(struct rcu_head *head, |
74 | void (*func)(struct rcu_head *rcu)); | |
64db4cff | 75 | |
03b042bf PM |
76 | static inline void synchronize_rcu_expedited(void) |
77 | { | |
78 | synchronize_sched_expedited(); | |
79 | } | |
80 | ||
81 | static inline void synchronize_rcu_bh_expedited(void) | |
64db4cff | 82 | { |
03b042bf | 83 | synchronize_sched_expedited(); |
64db4cff PM |
84 | } |
85 | ||
86 | extern void __rcu_init(void); | |
87 | extern void rcu_check_callbacks(int cpu, int user); | |
88 | extern void rcu_restart_cpu(int cpu); | |
89 | ||
90 | extern long rcu_batches_completed(void); | |
91 | extern long rcu_batches_completed_bh(void); | |
d6714c22 | 92 | extern long rcu_batches_completed_sched(void); |
64db4cff | 93 | |
03b042bf PM |
94 | static inline void rcu_init_sched(void) |
95 | { | |
96 | } | |
97 | ||
64db4cff PM |
98 | #ifdef CONFIG_NO_HZ |
99 | void rcu_enter_nohz(void); | |
100 | void rcu_exit_nohz(void); | |
101 | #else /* CONFIG_NO_HZ */ | |
102 | static inline void rcu_enter_nohz(void) | |
103 | { | |
104 | } | |
105 | static inline void rcu_exit_nohz(void) | |
106 | { | |
107 | } | |
108 | #endif /* CONFIG_NO_HZ */ | |
109 | ||
a6826048 PM |
110 | /* A context switch is a grace period for rcutree. */ |
111 | static inline int rcu_blocking_is_gp(void) | |
112 | { | |
113 | return num_online_cpus() == 1; | |
114 | } | |
115 | ||
64db4cff | 116 | #endif /* __LINUX_RCUTREE_H */ |