/*
   * Read-Copy Update mechanism for mutual exclusion (tree-based version)
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
   *
   * Copyright IBM Corporation, 2008
   *
   * Author: Dipankar Sarma <dipankar@in.ibm.com>
   *	   Paul E. McKenney <paulmck@linux.vnet.ibm.com> Hierarchical algorithm
   *
   * Based on the original work by Paul McKenney <paulmck@us.ibm.com>
   * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
   *
   * For detailed explanation of Read-Copy Update mechanism see -
   *	Documentation/RCU
   */
  
  #ifndef __LINUX_RCUTREE_H
  #define __LINUX_RCUTREE_H
  
  void rcu_note_context_switch(int cpu);
  int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies);
  void rcu_cpu_stall_reset(void);
  
  /*
   * Note a virtualization-based context switch.  This is simply a
   * wrapper around rcu_note_context_switch(), which allows TINY_RCU
   * to save a few bytes.
   */
  static inline void rcu_virt_note_context_switch(int cpu)
  {
  	rcu_note_context_switch(cpu);
  }
  
  void synchronize_rcu_bh(void);
  void synchronize_sched_expedited(void);
  void synchronize_rcu_expedited(void);
  
  void kfree_call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
  
  /**
   * synchronize_rcu_bh_expedited - Brute-force RCU-bh grace period
   *
   * Wait for an RCU-bh grace period to elapse, but use a "big hammer"
   * approach to force the grace period to end quickly.  This consumes
   * significant time on all CPUs and is unfriendly to real-time workloads,
   * so is thus not recommended for any sort of common-case code.  In fact,
   * if you are using synchronize_rcu_bh_expedited() in a loop, please
   * restructure your code to batch your updates, and then use a single
   * synchronize_rcu_bh() instead.
   *
   * Note that it is illegal to call this function while holding any lock
   * that is acquired by a CPU-hotplug notifier.  And yes, it is also illegal
   * to call this function from a CPU-hotplug notifier.  Failing to observe
   * these restriction will result in deadlock.
   */
  static inline void synchronize_rcu_bh_expedited(void)
  {
  	synchronize_sched_expedited();
  }
  
  void rcu_barrier(void);
  void rcu_barrier_bh(void);
  void rcu_barrier_sched(void);
  
  extern unsigned long rcutorture_testseq;
  extern unsigned long rcutorture_vernum;
  long rcu_batches_completed(void);
  long rcu_batches_completed_bh(void);
  long rcu_batches_completed_sched(void);
  
  void rcu_force_quiescent_state(void);
  void rcu_bh_force_quiescent_state(void);
  void rcu_sched_force_quiescent_state(void);
  
  void exit_rcu(void);
  
  void rcu_scheduler_starting(void);
  extern int rcu_scheduler_active __read_mostly;
  
  bool rcu_is_watching(void);
  
  #endif /* __LINUX_RCUTREE_H */