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, you can access it online at 16 * http://www.gnu.org/licenses/gpl-2.0.html. 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 30struct rcu_dynticks; 31static inline int rcu_dynticks_snap(struct rcu_dynticks *rdtp) 32{ 33 return 0; 34} 35 36static inline unsigned long get_state_synchronize_rcu(void) 37{ 38 return 0; 39} 40 41static inline void cond_synchronize_rcu(unsigned long oldstate) 42{ 43 might_sleep(); 44} 45 46static inline unsigned long get_state_synchronize_sched(void) 47{ 48 return 0; 49} 50 51static inline void cond_synchronize_sched(unsigned long oldstate) 52{ 53 might_sleep(); 54} 55 56extern void rcu_barrier_bh(void); 57extern void rcu_barrier_sched(void); 58 59static inline void synchronize_rcu_expedited(void) 60{ 61 synchronize_sched(); /* Only one CPU, so pretty fast anyway!!! */ 62} 63 64static inline void rcu_barrier(void) 65{ 66 rcu_barrier_sched(); /* Only one CPU, so only one list of callbacks! */ 67} 68 69static inline void synchronize_rcu_bh(void) 70{ 71 synchronize_sched(); 72} 73 74static inline void synchronize_rcu_bh_expedited(void) 75{ 76 synchronize_sched(); 77} 78 79static inline void synchronize_sched_expedited(void) 80{ 81 synchronize_sched(); 82} 83 84static inline void kfree_call_rcu(struct rcu_head *head, 85 rcu_callback_t func) 86{ 87 call_rcu(head, func); 88} 89 90static inline void rcu_note_context_switch(void) 91{ 92 rcu_sched_qs(); 93} 94 95/* 96 * Take advantage of the fact that there is only one CPU, which 97 * allows us to ignore virtualization-based context switches. 98 */ 99static inline void rcu_virt_note_context_switch(int cpu) 100{ 101} 102 103/* 104 * Return the number of grace periods started. 105 */ 106static inline unsigned long rcu_batches_started(void) 107{ 108 return 0; 109} 110 111/* 112 * Return the number of bottom-half grace periods started. 113 */ 114static inline unsigned long rcu_batches_started_bh(void) 115{ 116 return 0; 117} 118 119/* 120 * Return the number of sched grace periods started. 121 */ 122static inline unsigned long rcu_batches_started_sched(void) 123{ 124 return 0; 125} 126 127/* 128 * Return the number of grace periods completed. 129 */ 130static inline unsigned long rcu_batches_completed(void) 131{ 132 return 0; 133} 134 135/* 136 * Return the number of bottom-half grace periods completed. 137 */ 138static inline unsigned long rcu_batches_completed_bh(void) 139{ 140 return 0; 141} 142 143/* 144 * Return the number of sched grace periods completed. 145 */ 146static inline unsigned long rcu_batches_completed_sched(void) 147{ 148 return 0; 149} 150 151/* 152 * Return the number of expedited grace periods completed. 153 */ 154static inline unsigned long rcu_exp_batches_completed(void) 155{ 156 return 0; 157} 158 159/* 160 * Return the number of expedited sched grace periods completed. 161 */ 162static inline unsigned long rcu_exp_batches_completed_sched(void) 163{ 164 return 0; 165} 166 167static inline void rcu_force_quiescent_state(void) 168{ 169} 170 171static inline void rcu_bh_force_quiescent_state(void) 172{ 173} 174 175static inline void rcu_sched_force_quiescent_state(void) 176{ 177} 178 179static inline void show_rcu_gp_kthreads(void) 180{ 181} 182 183static inline void rcu_cpu_stall_reset(void) 184{ 185} 186 187static inline void rcu_idle_enter(void) 188{ 189} 190 191static inline void rcu_idle_exit(void) 192{ 193} 194 195static inline void rcu_irq_enter(void) 196{ 197} 198 199static inline void rcu_irq_exit_irqson(void) 200{ 201} 202 203static inline void rcu_irq_enter_irqson(void) 204{ 205} 206 207static inline void rcu_irq_exit(void) 208{ 209} 210 211static inline void exit_rcu(void) 212{ 213} 214 215#ifdef CONFIG_DEBUG_LOCK_ALLOC 216extern int rcu_scheduler_active __read_mostly; 217void rcu_scheduler_starting(void); 218#else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ 219static inline void rcu_scheduler_starting(void) 220{ 221} 222#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */ 223 224#if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) 225 226static inline bool rcu_is_watching(void) 227{ 228 return __rcu_is_watching(); 229} 230 231#else /* defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */ 232 233static inline bool rcu_is_watching(void) 234{ 235 return true; 236} 237 238#endif /* #else defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */ 239 240static inline void rcu_all_qs(void) 241{ 242 barrier(); /* Avoid RCU read-side critical sections leaking across. */ 243} 244 245/* RCUtree hotplug events */ 246#define rcutree_prepare_cpu NULL 247#define rcutree_online_cpu NULL 248#define rcutree_offline_cpu NULL 249#define rcutree_dead_cpu NULL 250#define rcutree_dying_cpu NULL 251 252#endif /* __LINUX_RCUTINY_H */ 253