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 <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
30 #ifdef CONFIG_RCU_BOOST
rcu_init(void)31 static inline void rcu_init(void)
32 {
33 }
34 #else /* #ifdef CONFIG_RCU_BOOST */
35 void rcu_init(void);
36 #endif /* #else #ifdef CONFIG_RCU_BOOST */
37
rcu_barrier_bh(void)38 static inline void rcu_barrier_bh(void)
39 {
40 wait_rcu_gp(call_rcu_bh);
41 }
42
rcu_barrier_sched(void)43 static inline void rcu_barrier_sched(void)
44 {
45 wait_rcu_gp(call_rcu_sched);
46 }
47
48 #ifdef CONFIG_TINY_RCU
49
synchronize_rcu_expedited(void)50 static inline void synchronize_rcu_expedited(void)
51 {
52 synchronize_sched(); /* Only one CPU, so pretty fast anyway!!! */
53 }
54
rcu_barrier(void)55 static inline void rcu_barrier(void)
56 {
57 rcu_barrier_sched(); /* Only one CPU, so only one list of callbacks! */
58 }
59
60 #else /* #ifdef CONFIG_TINY_RCU */
61
62 void synchronize_rcu_expedited(void);
63
rcu_barrier(void)64 static inline void rcu_barrier(void)
65 {
66 wait_rcu_gp(call_rcu);
67 }
68
69 #endif /* #else #ifdef CONFIG_TINY_RCU */
70
synchronize_rcu_bh(void)71 static inline void synchronize_rcu_bh(void)
72 {
73 synchronize_sched();
74 }
75
synchronize_rcu_bh_expedited(void)76 static inline void synchronize_rcu_bh_expedited(void)
77 {
78 synchronize_sched();
79 }
80
synchronize_sched_expedited(void)81 static inline void synchronize_sched_expedited(void)
82 {
83 synchronize_sched();
84 }
85
86 #ifdef CONFIG_TINY_RCU
87
rcu_preempt_note_context_switch(void)88 static inline void rcu_preempt_note_context_switch(void)
89 {
90 }
91
exit_rcu(void)92 static inline void exit_rcu(void)
93 {
94 }
95
rcu_needs_cpu(int cpu)96 static inline int rcu_needs_cpu(int cpu)
97 {
98 return 0;
99 }
100
101 #else /* #ifdef CONFIG_TINY_RCU */
102
103 void rcu_preempt_note_context_switch(void);
104 extern void exit_rcu(void);
105 int rcu_preempt_needs_cpu(void);
106
rcu_needs_cpu(int cpu)107 static inline int rcu_needs_cpu(int cpu)
108 {
109 return rcu_preempt_needs_cpu();
110 }
111
112 #endif /* #else #ifdef CONFIG_TINY_RCU */
113
rcu_note_context_switch(int cpu)114 static inline void rcu_note_context_switch(int cpu)
115 {
116 rcu_sched_qs(cpu);
117 rcu_preempt_note_context_switch();
118 }
119
120 /*
121 * Take advantage of the fact that there is only one CPU, which
122 * allows us to ignore virtualization-based context switches.
123 */
rcu_virt_note_context_switch(int cpu)124 static inline void rcu_virt_note_context_switch(int cpu)
125 {
126 }
127
128 /*
129 * Return the number of grace periods.
130 */
rcu_batches_completed(void)131 static inline long rcu_batches_completed(void)
132 {
133 return 0;
134 }
135
136 /*
137 * Return the number of bottom-half grace periods.
138 */
rcu_batches_completed_bh(void)139 static inline long rcu_batches_completed_bh(void)
140 {
141 return 0;
142 }
143
rcu_force_quiescent_state(void)144 static inline void rcu_force_quiescent_state(void)
145 {
146 }
147
rcu_bh_force_quiescent_state(void)148 static inline void rcu_bh_force_quiescent_state(void)
149 {
150 }
151
rcu_sched_force_quiescent_state(void)152 static inline void rcu_sched_force_quiescent_state(void)
153 {
154 }
155
rcu_cpu_stall_reset(void)156 static inline void rcu_cpu_stall_reset(void)
157 {
158 }
159
160 #ifdef CONFIG_DEBUG_LOCK_ALLOC
161 extern int rcu_scheduler_active __read_mostly;
162 extern void rcu_scheduler_starting(void);
163 #else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
rcu_scheduler_starting(void)164 static inline void rcu_scheduler_starting(void)
165 {
166 }
167 #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
168
169 #endif /* __LINUX_RCUTINY_H */
170