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 <[email protected]> 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 42 static inline int rcu_needs_cpu(int cpu) 43 { 44 return 0; 45 } 46 47 /* 48 * Return the number of grace periods. 49 */ 50 static inline long rcu_batches_completed(void) 51 { 52 return 0; 53 } 54 55 /* 56 * Return the number of bottom-half grace periods. 57 */ 58 static inline long rcu_batches_completed_bh(void) 59 { 60 return 0; 61 } 62 63 extern int rcu_expedited_torture_stats(char *page); 64 65 static inline void rcu_force_quiescent_state(void) 66 { 67 } 68 69 static inline void rcu_bh_force_quiescent_state(void) 70 { 71 } 72 73 static inline void rcu_sched_force_quiescent_state(void) 74 { 75 } 76 77 #define synchronize_rcu synchronize_sched 78 79 static inline void synchronize_rcu_expedited(void) 80 { 81 synchronize_sched(); 82 } 83 84 static inline void synchronize_rcu_bh_expedited(void) 85 { 86 synchronize_sched(); 87 } 88 89 struct notifier_block; 90 91 #ifdef CONFIG_NO_HZ 92 93 extern void rcu_enter_nohz(void); 94 extern void rcu_exit_nohz(void); 95 96 #else /* #ifdef CONFIG_NO_HZ */ 97 98 static inline void rcu_enter_nohz(void) 99 { 100 } 101 102 static inline void rcu_exit_nohz(void) 103 { 104 } 105 106 #endif /* #else #ifdef CONFIG_NO_HZ */ 107 108 static inline void exit_rcu(void) 109 { 110 } 111 112 static inline int rcu_preempt_depth(void) 113 { 114 return 0; 115 } 116 117 #endif /* __LINUX_RCUTINY_H */ 118