1// SPDX-License-Identifier: GPL-2.0
2/*
3 * syscore.c - Execution of system core operations.
4 *
5 * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
6 */
7
8#include <linux/syscore_ops.h>
9#include <linux/mutex.h>
10#include <linux/module.h>
11#include <linux/suspend.h>
12#include <trace/events/power.h>
13
14static LIST_HEAD(syscore_ops_list);
15static DEFINE_MUTEX(syscore_ops_lock);
16
17/**
18 * register_syscore_ops - Register a set of system core operations.
19 * @ops: System core operations to register.
20 */
21void register_syscore_ops(struct syscore_ops *ops)
22{
23 mutex_lock(&syscore_ops_lock);
24 list_add_tail(new: &ops->node, head: &syscore_ops_list);
25 mutex_unlock(lock: &syscore_ops_lock);
26}
27EXPORT_SYMBOL_GPL(register_syscore_ops);
28
29/**
30 * unregister_syscore_ops - Unregister a set of system core operations.
31 * @ops: System core operations to unregister.
32 */
33void unregister_syscore_ops(struct syscore_ops *ops)
34{
35 mutex_lock(&syscore_ops_lock);
36 list_del(entry: &ops->node);
37 mutex_unlock(lock: &syscore_ops_lock);
38}
39EXPORT_SYMBOL_GPL(unregister_syscore_ops);
40
41#ifdef CONFIG_PM_SLEEP
42/**
43 * syscore_suspend - Execute all the registered system core suspend callbacks.
44 *
45 * This function is executed with one CPU on-line and disabled interrupts.
46 */
47int syscore_suspend(void)
48{
49 struct syscore_ops *ops;
50 int ret = 0;
51
52 trace_suspend_resume(TPS("syscore_suspend"), val: 0, start: true);
53 pm_pr_dbg("Checking wakeup interrupts\n");
54
55 /* Return error code if there are any wakeup interrupts pending. */
56 if (pm_wakeup_pending())
57 return -EBUSY;
58
59 WARN_ONCE(!irqs_disabled(),
60 "Interrupts enabled before system core suspend.\n");
61
62 list_for_each_entry_reverse(ops, &syscore_ops_list, node)
63 if (ops->suspend) {
64 pm_pr_dbg("Calling %pS\n", ops->suspend);
65 ret = ops->suspend();
66 if (ret)
67 goto err_out;
68 WARN_ONCE(!irqs_disabled(),
69 "Interrupts enabled after %pS\n", ops->suspend);
70 }
71
72 trace_suspend_resume(TPS("syscore_suspend"), val: 0, start: false);
73 return 0;
74
75 err_out:
76 pr_err("PM: System core suspend callback %pS failed.\n", ops->suspend);
77
78 list_for_each_entry_continue(ops, &syscore_ops_list, node)
79 if (ops->resume)
80 ops->resume();
81
82 return ret;
83}
84EXPORT_SYMBOL_GPL(syscore_suspend);
85
86/**
87 * syscore_resume - Execute all the registered system core resume callbacks.
88 *
89 * This function is executed with one CPU on-line and disabled interrupts.
90 */
91void syscore_resume(void)
92{
93 struct syscore_ops *ops;
94
95 trace_suspend_resume(TPS("syscore_resume"), val: 0, start: true);
96 WARN_ONCE(!irqs_disabled(),
97 "Interrupts enabled before system core resume.\n");
98
99 list_for_each_entry(ops, &syscore_ops_list, node)
100 if (ops->resume) {
101 pm_pr_dbg("Calling %pS\n", ops->resume);
102 ops->resume();
103 WARN_ONCE(!irqs_disabled(),
104 "Interrupts enabled after %pS\n", ops->resume);
105 }
106 trace_suspend_resume(TPS("syscore_resume"), val: 0, start: false);
107}
108EXPORT_SYMBOL_GPL(syscore_resume);
109#endif /* CONFIG_PM_SLEEP */
110
111/**
112 * syscore_shutdown - Execute all the registered system core shutdown callbacks.
113 */
114void syscore_shutdown(void)
115{
116 struct syscore_ops *ops;
117
118 mutex_lock(&syscore_ops_lock);
119
120 list_for_each_entry_reverse(ops, &syscore_ops_list, node)
121 if (ops->shutdown) {
122 if (initcall_debug)
123 pr_info("PM: Calling %pS\n", ops->shutdown);
124 ops->shutdown();
125 }
126
127 mutex_unlock(lock: &syscore_ops_lock);
128}
129

source code of linux/drivers/base/syscore.c