118 lines
3.0 KiB
C
118 lines
3.0 KiB
C
/*
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* Read-Copy Update mechanism for mutual exclusion (tree-based version)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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* Copyright IBM Corporation, 2008
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*
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* Author: Dipankar Sarma <dipankar@in.ibm.com>
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* Paul E. McKenney <paulmck@linux.vnet.ibm.com> Hierarchical algorithm
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*
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* Based on the original work by Paul McKenney <paulmck@us.ibm.com>
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* and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
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*
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* For detailed explanation of Read-Copy Update mechanism see -
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* Documentation/RCU
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*/
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#ifndef __LINUX_RCUTREE_H
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#define __LINUX_RCUTREE_H
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extern void rcu_qsctr_inc(int cpu);
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extern void rcu_bh_qsctr_inc(int cpu);
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extern int rcu_pending(int cpu);
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extern int rcu_needs_cpu(int cpu);
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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extern struct lockdep_map rcu_lock_map;
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# define rcu_read_acquire() \
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lock_acquire(&rcu_lock_map, 0, 0, 2, 1, NULL, _THIS_IP_)
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# define rcu_read_release() lock_release(&rcu_lock_map, 1, _THIS_IP_)
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#else
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# define rcu_read_acquire() do { } while (0)
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# define rcu_read_release() do { } while (0)
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#endif
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static inline void __rcu_read_lock(void)
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{
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preempt_disable();
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__acquire(RCU);
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rcu_read_acquire();
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}
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static inline void __rcu_read_unlock(void)
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{
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rcu_read_release();
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__release(RCU);
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preempt_enable();
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}
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static inline void __rcu_read_lock_bh(void)
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{
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local_bh_disable();
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__acquire(RCU_BH);
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rcu_read_acquire();
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}
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static inline void __rcu_read_unlock_bh(void)
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{
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rcu_read_release();
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__release(RCU_BH);
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local_bh_enable();
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}
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#define __synchronize_sched() synchronize_rcu()
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#define call_rcu_sched(head, func) call_rcu(head, func)
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static inline void synchronize_rcu_expedited(void)
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{
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synchronize_sched_expedited();
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}
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static inline void synchronize_rcu_bh_expedited(void)
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{
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synchronize_sched_expedited();
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}
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extern void __rcu_init(void);
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extern void rcu_check_callbacks(int cpu, int user);
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extern void rcu_restart_cpu(int cpu);
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extern long rcu_batches_completed(void);
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extern long rcu_batches_completed_bh(void);
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static inline void rcu_init_sched(void)
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{
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}
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#ifdef CONFIG_NO_HZ
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void rcu_enter_nohz(void);
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void rcu_exit_nohz(void);
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#else /* CONFIG_NO_HZ */
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static inline void rcu_enter_nohz(void)
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{
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}
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static inline void rcu_exit_nohz(void)
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{
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}
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#endif /* CONFIG_NO_HZ */
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/* A context switch is a grace period for rcutree. */
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static inline int rcu_blocking_is_gp(void)
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{
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return num_online_cpus() == 1;
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}
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#endif /* __LINUX_RCUTREE_H */
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