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