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 static inline void rcu_note_context_switch(int cpu) 33 { 34 rcu_sched_qs(cpu); 35 } 36 37 #define __rcu_read_lock() preempt_disable() 38 #define __rcu_read_unlock() preempt_enable() 39 #define __rcu_read_lock_bh() local_bh_disable() 40 #define __rcu_read_unlock_bh() local_bh_enable() 41 #define call_rcu_sched call_rcu 42 43 #define rcu_init_sched() do { } while (0) 44 extern void rcu_check_callbacks(int cpu, int user); 45 46 static inline int rcu_needs_cpu(int cpu) 47 { 48 return 0; 49 } 50 51 /* 52 * Return the number of grace periods. 53 */ 54 static inline long rcu_batches_completed(void) 55 { 56 return 0; 57 } 58 59 /* 60 * Return the number of bottom-half grace periods. 61 */ 62 static inline long rcu_batches_completed_bh(void) 63 { 64 return 0; 65 } 66 67 static inline void rcu_force_quiescent_state(void) 68 { 69 } 70 71 static inline void rcu_bh_force_quiescent_state(void) 72 { 73 } 74 75 static inline void rcu_sched_force_quiescent_state(void) 76 { 77 } 78 79 extern void synchronize_sched(void); 80 81 static inline void synchronize_rcu(void) 82 { 83 synchronize_sched(); 84 } 85 86 static inline void synchronize_rcu_bh(void) 87 { 88 synchronize_sched(); 89 } 90 91 static inline void synchronize_rcu_expedited(void) 92 { 93 synchronize_sched(); 94 } 95 96 static inline void synchronize_rcu_bh_expedited(void) 97 { 98 synchronize_sched(); 99 } 100 101 struct notifier_block; 102 103 #ifdef CONFIG_NO_HZ 104 105 extern void rcu_enter_nohz(void); 106 extern void rcu_exit_nohz(void); 107 108 #else /* #ifdef CONFIG_NO_HZ */ 109 110 static inline void rcu_enter_nohz(void) 111 { 112 } 113 114 static inline void rcu_exit_nohz(void) 115 { 116 } 117 118 #endif /* #else #ifdef CONFIG_NO_HZ */ 119 120 static inline void exit_rcu(void) 121 { 122 } 123 124 static inline int rcu_preempt_depth(void) 125 { 126 return 0; 127 } 128 129 #ifdef CONFIG_DEBUG_LOCK_ALLOC 130 131 extern int rcu_scheduler_active __read_mostly; 132 extern void rcu_scheduler_starting(void); 133 134 #else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ 135 136 static inline void rcu_scheduler_starting(void) 137 { 138 } 139 140 #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */ 141 142 #endif /* __LINUX_RCUTINY_H */ 143