Paul E. McKenney | 64db4cf | 2008-12-18 21:55:32 +0100 | [diff] [blame] | 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 - |
| 27 | * Documentation/RCU |
| 28 | */ |
| 29 | |
| 30 | #ifndef __LINUX_RCUTREE_H |
| 31 | #define __LINUX_RCUTREE_H |
| 32 | |
Paul E. McKenney | d6714c2 | 2009-08-22 13:56:46 -0700 | [diff] [blame^] | 33 | extern void rcu_sched_qs(int cpu); |
| 34 | extern void rcu_bh_qs(int cpu); |
Paul E. McKenney | 64db4cf | 2008-12-18 21:55:32 +0100 | [diff] [blame] | 35 | |
| 36 | extern int rcu_pending(int cpu); |
| 37 | extern int rcu_needs_cpu(int cpu); |
| 38 | |
| 39 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| 40 | extern struct lockdep_map rcu_lock_map; |
| 41 | # define rcu_read_acquire() \ |
| 42 | lock_acquire(&rcu_lock_map, 0, 0, 2, 1, NULL, _THIS_IP_) |
| 43 | # define rcu_read_release() lock_release(&rcu_lock_map, 1, _THIS_IP_) |
| 44 | #else |
| 45 | # define rcu_read_acquire() do { } while (0) |
| 46 | # define rcu_read_release() do { } while (0) |
| 47 | #endif |
| 48 | |
| 49 | static inline void __rcu_read_lock(void) |
| 50 | { |
| 51 | preempt_disable(); |
| 52 | __acquire(RCU); |
| 53 | rcu_read_acquire(); |
| 54 | } |
| 55 | static inline void __rcu_read_unlock(void) |
| 56 | { |
| 57 | rcu_read_release(); |
| 58 | __release(RCU); |
| 59 | preempt_enable(); |
| 60 | } |
| 61 | static inline void __rcu_read_lock_bh(void) |
| 62 | { |
| 63 | local_bh_disable(); |
| 64 | __acquire(RCU_BH); |
| 65 | rcu_read_acquire(); |
| 66 | } |
| 67 | static inline void __rcu_read_unlock_bh(void) |
| 68 | { |
| 69 | rcu_read_release(); |
| 70 | __release(RCU_BH); |
| 71 | local_bh_enable(); |
| 72 | } |
| 73 | |
| 74 | #define __synchronize_sched() synchronize_rcu() |
| 75 | |
Paul E. McKenney | d6714c2 | 2009-08-22 13:56:46 -0700 | [diff] [blame^] | 76 | extern void call_rcu_sched(struct rcu_head *head, |
| 77 | void (*func)(struct rcu_head *rcu)); |
Paul E. McKenney | 64db4cf | 2008-12-18 21:55:32 +0100 | [diff] [blame] | 78 | |
Paul E. McKenney | 03b042b | 2009-06-25 09:08:16 -0700 | [diff] [blame] | 79 | static inline void synchronize_rcu_expedited(void) |
Paul E. McKenney | 64db4cf | 2008-12-18 21:55:32 +0100 | [diff] [blame] | 80 | { |
Paul E. McKenney | 03b042b | 2009-06-25 09:08:16 -0700 | [diff] [blame] | 81 | synchronize_sched_expedited(); |
| 82 | } |
| 83 | |
| 84 | static inline void synchronize_rcu_bh_expedited(void) |
| 85 | { |
| 86 | synchronize_sched_expedited(); |
Paul E. McKenney | 64db4cf | 2008-12-18 21:55:32 +0100 | [diff] [blame] | 87 | } |
| 88 | |
| 89 | extern void __rcu_init(void); |
| 90 | extern void rcu_check_callbacks(int cpu, int user); |
| 91 | extern void rcu_restart_cpu(int cpu); |
| 92 | |
| 93 | extern long rcu_batches_completed(void); |
| 94 | extern long rcu_batches_completed_bh(void); |
Paul E. McKenney | d6714c2 | 2009-08-22 13:56:46 -0700 | [diff] [blame^] | 95 | extern long rcu_batches_completed_sched(void); |
Paul E. McKenney | 64db4cf | 2008-12-18 21:55:32 +0100 | [diff] [blame] | 96 | |
Paul E. McKenney | 03b042b | 2009-06-25 09:08:16 -0700 | [diff] [blame] | 97 | static inline void rcu_init_sched(void) |
| 98 | { |
| 99 | } |
| 100 | |
Paul E. McKenney | 64db4cf | 2008-12-18 21:55:32 +0100 | [diff] [blame] | 101 | #ifdef CONFIG_NO_HZ |
| 102 | void rcu_enter_nohz(void); |
| 103 | void rcu_exit_nohz(void); |
| 104 | #else /* CONFIG_NO_HZ */ |
| 105 | static inline void rcu_enter_nohz(void) |
| 106 | { |
| 107 | } |
| 108 | static inline void rcu_exit_nohz(void) |
| 109 | { |
| 110 | } |
| 111 | #endif /* CONFIG_NO_HZ */ |
| 112 | |
Paul E. McKenney | a682604 | 2009-02-25 18:03:42 -0800 | [diff] [blame] | 113 | /* A context switch is a grace period for rcutree. */ |
| 114 | static inline int rcu_blocking_is_gp(void) |
| 115 | { |
| 116 | return num_online_cpus() == 1; |
| 117 | } |
| 118 | |
Paul E. McKenney | 64db4cf | 2008-12-18 21:55:32 +0100 | [diff] [blame] | 119 | #endif /* __LINUX_RCUTREE_H */ |