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
30static inline unsigned long get_state_synchronize_rcu(void)
31{
32	return 0;
33}
34
35static inline void cond_synchronize_rcu(unsigned long oldstate)
36{
37	might_sleep();
38}
39
40static inline void rcu_barrier_bh(void)
41{
42	wait_rcu_gp(call_rcu_bh);
43}
44
45static inline void rcu_barrier_sched(void)
46{
47	wait_rcu_gp(call_rcu_sched);
48}
49
50static inline void synchronize_rcu_expedited(void)
51{
52	synchronize_sched();	/* Only one CPU, so pretty fast anyway!!! */
53}
54
55static inline void rcu_barrier(void)
56{
57	rcu_barrier_sched();  /* Only one CPU, so only one list of callbacks! */
58}
59
60static inline void synchronize_rcu_bh(void)
61{
62	synchronize_sched();
63}
64
65static inline void synchronize_rcu_bh_expedited(void)
66{
67	synchronize_sched();
68}
69
70static inline void synchronize_sched_expedited(void)
71{
72	synchronize_sched();
73}
74
75static inline void kfree_call_rcu(struct rcu_head *head,
76				  void (*func)(struct rcu_head *rcu))
77{
78	call_rcu(head, func);
79}
80
81static inline void rcu_note_context_switch(void)
82{
83	rcu_sched_qs();
84}
85
86/*
87 * Take advantage of the fact that there is only one CPU, which
88 * allows us to ignore virtualization-based context switches.
89 */
90static inline void rcu_virt_note_context_switch(int cpu)
91{
92}
93
94/*
95 * Return the number of grace periods started.
96 */
97static inline unsigned long rcu_batches_started(void)
98{
99	return 0;
100}
101
102/*
103 * Return the number of bottom-half grace periods started.
104 */
105static inline unsigned long rcu_batches_started_bh(void)
106{
107	return 0;
108}
109
110/*
111 * Return the number of sched grace periods started.
112 */
113static inline unsigned long rcu_batches_started_sched(void)
114{
115	return 0;
116}
117
118/*
119 * Return the number of grace periods completed.
120 */
121static inline unsigned long rcu_batches_completed(void)
122{
123	return 0;
124}
125
126/*
127 * Return the number of bottom-half grace periods completed.
128 */
129static inline unsigned long rcu_batches_completed_bh(void)
130{
131	return 0;
132}
133
134/*
135 * Return the number of sched grace periods completed.
136 */
137static inline unsigned long rcu_batches_completed_sched(void)
138{
139	return 0;
140}
141
142static inline void rcu_force_quiescent_state(void)
143{
144}
145
146static inline void rcu_bh_force_quiescent_state(void)
147{
148}
149
150static inline void rcu_sched_force_quiescent_state(void)
151{
152}
153
154static inline void show_rcu_gp_kthreads(void)
155{
156}
157
158static inline void rcu_cpu_stall_reset(void)
159{
160}
161
162static inline void exit_rcu(void)
163{
164}
165
166#ifdef CONFIG_DEBUG_LOCK_ALLOC
167extern int rcu_scheduler_active __read_mostly;
168void rcu_scheduler_starting(void);
169#else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
170static inline void rcu_scheduler_starting(void)
171{
172}
173#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
174
175#if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE)
176
177static inline bool rcu_is_watching(void)
178{
179	return __rcu_is_watching();
180}
181
182#else /* defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */
183
184static inline bool rcu_is_watching(void)
185{
186	return true;
187}
188
189#endif /* #else defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */
190
191static inline void rcu_all_qs(void)
192{
193}
194
195#endif /* __LINUX_RCUTINY_H */
196