include/linux/rcutiny.h

   1 /*
   2  * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition.
   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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
  21  *
  22  * For detailed explanation of Read-Copy Update mechanism see -
  23  *              Documentation/RCU
  24  */
  25 #ifndef __LINUX_TINY_H
  26 #define __LINUX_TINY_H
  27
  28 #include <linux/cache.h>
  29
  30 void rcu_sched_qs(int cpu);
  31 void rcu_bh_qs(int cpu);
  32
  33 #define __rcu_read_lock()       preempt_disable()
  34 #define __rcu_read_unlock()     preempt_enable()
  35 #define __rcu_read_lock_bh()    local_bh_disable()
  36 #define __rcu_read_unlock_bh()  local_bh_enable()
  37 #define call_rcu_sched          call_rcu
  38
  39 #define rcu_init_sched()        do { } while (0)
  40 extern void rcu_check_callbacks(int cpu, int user);
  41 extern void __rcu_init(void);
  42
  43 /*
  44  * Return the number of grace periods.
  45  */
  46 static inline long rcu_batches_completed(void)
  47 {
  48         return 0;
  49 }
  50
  51 /*
  52  * Return the number of bottom-half grace periods.
  53  */
  54 static inline long rcu_batches_completed_bh(void)
  55 {
  56         return 0;
  57 }
  58
  59 extern int rcu_expedited_torture_stats(char *page);
  60
  61 static inline void synchronize_rcu_expedited(void)
  62 {
  63         synchronize_sched();
  64 }
  65
  66 static inline void synchronize_rcu_bh_expedited(void)
  67 {
  68         synchronize_sched();
  69 }
  70
  71 struct notifier_block;
  72 extern int rcu_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu);
  73
  74 #ifdef CONFIG_NO_HZ
  75
  76 extern void rcu_enter_nohz(void);
  77 extern void rcu_exit_nohz(void);
  78
  79 #else /* #ifdef CONFIG_NO_HZ */
  80
  81 static inline void rcu_enter_nohz(void)
  82 {
  83 }
  84
  85 static inline void rcu_exit_nohz(void)
  86 {
  87 }
  88
  89 #endif /* #else #ifdef CONFIG_NO_HZ */
  90
  91 static inline void exit_rcu(void)
  92 {
  93 }
  94
  95 #endif /* __LINUX_RCUTINY_H */