blob: 09ebcbe9fd780932e2dee223daaa8426395e77d8 [file] [log] [blame]
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -07001/*
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 -
Ingo Molnar4ce5b902009-10-26 07:55:55 +010023 * Documentation/RCU
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -070024 */
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -070025#ifndef __LINUX_TINY_H
26#define __LINUX_TINY_H
27
28#include <linux/cache.h>
29
Paul E. McKenney2c428182011-05-26 22:14:36 -070030static inline void rcu_barrier_bh(void)
31{
32 wait_rcu_gp(call_rcu_bh);
33}
34
35static inline void rcu_barrier_sched(void)
36{
37 wait_rcu_gp(call_rcu_sched);
38}
39
Paul E. McKenneya57eb942010-06-29 16:49:16 -070040static inline void synchronize_rcu_expedited(void)
Paul E. McKenneyda848c42010-03-30 15:46:01 -070041{
Paul E. McKenneya57eb942010-06-29 16:49:16 -070042 synchronize_sched(); /* Only one CPU, so pretty fast anyway!!! */
Paul E. McKenneyda848c42010-03-30 15:46:01 -070043}
Paul E. McKenney6ebb2372009-11-22 08:53:50 -080044
Paul E. McKenneya57eb942010-06-29 16:49:16 -070045static inline void rcu_barrier(void)
46{
47 rcu_barrier_sched(); /* Only one CPU, so only one list of callbacks! */
48}
49
Paul E. McKenneya57eb942010-06-29 16:49:16 -070050static inline void synchronize_rcu_bh(void)
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -070051{
52 synchronize_sched();
53}
54
55static inline void synchronize_rcu_bh_expedited(void)
56{
57 synchronize_sched();
58}
59
Lai Jiangshan7b27d542010-10-21 11:29:05 +080060static inline void synchronize_sched_expedited(void)
61{
62 synchronize_sched();
63}
64
Paul E. McKenney486e2592012-01-06 14:11:30 -080065static inline void kfree_call_rcu(struct rcu_head *head,
66 void (*func)(struct rcu_head *rcu))
67{
68 call_rcu(head, func);
69}
70
Paul E. McKenneyaa9b16302012-05-10 16:41:44 -070071static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies)
Paul E. McKenneya57eb942010-06-29 16:49:16 -070072{
Paul E. McKenneyaa9b16302012-05-10 16:41:44 -070073 *delta_jiffies = ULONG_MAX;
Paul E. McKenneya57eb942010-06-29 16:49:16 -070074 return 0;
75}
76
Paul E. McKenneya57eb942010-06-29 16:49:16 -070077static inline void rcu_note_context_switch(int cpu)
78{
79 rcu_sched_qs(cpu);
Paul E. McKenneya57eb942010-06-29 16:49:16 -070080}
81
Paul E. McKenneya57eb942010-06-29 16:49:16 -070082/*
Gleb Natapov29ce8312011-05-04 16:31:03 +030083 * Take advantage of the fact that there is only one CPU, which
84 * allows us to ignore virtualization-based context switches.
85 */
86static inline void rcu_virt_note_context_switch(int cpu)
87{
88}
89
90/*
Paul E. McKenneya57eb942010-06-29 16:49:16 -070091 * Return the number of grace periods.
92 */
93static inline long rcu_batches_completed(void)
94{
95 return 0;
96}
97
98/*
99 * Return the number of bottom-half grace periods.
100 */
101static inline long rcu_batches_completed_bh(void)
102{
103 return 0;
104}
105
106static inline void rcu_force_quiescent_state(void)
107{
108}
109
110static inline void rcu_bh_force_quiescent_state(void)
111{
112}
113
114static inline void rcu_sched_force_quiescent_state(void)
115{
116}
117
Paul E. McKenney53d84e02010-08-10 14:28:53 -0700118static inline void rcu_cpu_stall_reset(void)
119{
120}
121
Paul E. McKenney2439b692013-04-11 10:15:52 -0700122static inline void exit_rcu(void)
123{
124}
125
Paul E. McKenneybbad9372010-04-02 16:17:17 -0700126#ifdef CONFIG_DEBUG_LOCK_ALLOC
Paul E. McKenneybbad9372010-04-02 16:17:17 -0700127extern int rcu_scheduler_active __read_mostly;
128extern void rcu_scheduler_starting(void);
Paul E. McKenneybbad9372010-04-02 16:17:17 -0700129#else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
Paul E. McKenneybbad9372010-04-02 16:17:17 -0700130static inline void rcu_scheduler_starting(void)
131{
132}
Paul E. McKenneybbad9372010-04-02 16:17:17 -0700133#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
134
Paul E. McKenney5c173eb2013-09-13 17:20:11 -0700135#if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE)
Paul E. McKenneycc6783f2013-09-06 17:39:49 -0700136
Paul E. McKenney5c173eb2013-09-13 17:20:11 -0700137static inline bool rcu_is_watching(void)
Paul E. McKenneycc6783f2013-09-06 17:39:49 -0700138{
Paul E. McKenney5c173eb2013-09-13 17:20:11 -0700139 return __rcu_is_watching();
Paul E. McKenneycc6783f2013-09-06 17:39:49 -0700140}
141
Paul E. McKenney5c173eb2013-09-13 17:20:11 -0700142#else /* defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */
143
144static inline bool rcu_is_watching(void)
145{
146 return true;
147}
148
149
150#endif /* #else defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */
Paul E. McKenneycc6783f2013-09-06 17:39:49 -0700151
Paul E. McKenney9b1d82f2009-10-25 19:03:50 -0700152#endif /* __LINUX_RCUTINY_H */