Linux kernel mirror (for testing)
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linux
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/ktime.h>
29
30/* Never flag non-existent other CPUs! */
31static inline bool rcu_eqs_special_set(int cpu) { return false; }
32
33static inline unsigned long get_state_synchronize_rcu(void)
34{
35 return 0;
36}
37
38static inline void cond_synchronize_rcu(unsigned long oldstate)
39{
40 might_sleep();
41}
42
43extern void rcu_barrier(void);
44
45static inline void synchronize_rcu_expedited(void)
46{
47 synchronize_rcu();
48}
49
50static inline void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
51{
52 call_rcu(head, func);
53}
54
55void rcu_qs(void);
56
57static inline void rcu_softirq_qs(void)
58{
59 rcu_qs();
60}
61
62#define rcu_note_context_switch(preempt) \
63 do { \
64 rcu_qs(); \
65 rcu_tasks_qs(current); \
66 } while (0)
67
68static inline int rcu_needs_cpu(u64 basemono, u64 *nextevt)
69{
70 *nextevt = KTIME_MAX;
71 return 0;
72}
73
74/*
75 * Take advantage of the fact that there is only one CPU, which
76 * allows us to ignore virtualization-based context switches.
77 */
78static inline void rcu_virt_note_context_switch(int cpu) { }
79static inline void rcu_cpu_stall_reset(void) { }
80static inline int rcu_jiffies_till_stall_check(void) { return 21 * HZ; }
81static inline void rcu_idle_enter(void) { }
82static inline void rcu_idle_exit(void) { }
83static inline void rcu_irq_enter(void) { }
84static inline void rcu_irq_exit_irqson(void) { }
85static inline void rcu_irq_enter_irqson(void) { }
86static inline void rcu_irq_exit(void) { }
87static inline void exit_rcu(void) { }
88static inline bool rcu_preempt_need_deferred_qs(struct task_struct *t)
89{
90 return false;
91}
92static inline void rcu_preempt_deferred_qs(struct task_struct *t) { }
93#ifdef CONFIG_SRCU
94void rcu_scheduler_starting(void);
95#else /* #ifndef CONFIG_SRCU */
96static inline void rcu_scheduler_starting(void) { }
97#endif /* #else #ifndef CONFIG_SRCU */
98static inline void rcu_end_inkernel_boot(void) { }
99static inline bool rcu_is_watching(void) { return true; }
100
101/* Avoid RCU read-side critical sections leaking across. */
102static inline void rcu_all_qs(void) { barrier(); }
103
104/* RCUtree hotplug events */
105#define rcutree_prepare_cpu NULL
106#define rcutree_online_cpu NULL
107#define rcutree_offline_cpu NULL
108#define rcutree_dead_cpu NULL
109#define rcutree_dying_cpu NULL
110static inline void rcu_cpu_starting(unsigned int cpu) { }
111
112#endif /* __LINUX_RCUTINY_H */