xref: /linux/drivers/base/syscore.c (revision a8b70ccf10e38775785d9cb12ead916474549f99)
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 
14 static LIST_HEAD(syscore_ops_list);
15 static 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  */
21 void register_syscore_ops(struct syscore_ops *ops)
22 {
23 	mutex_lock(&syscore_ops_lock);
24 	list_add_tail(&ops->node, &syscore_ops_list);
25 	mutex_unlock(&syscore_ops_lock);
26 }
27 EXPORT_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  */
33 void unregister_syscore_ops(struct syscore_ops *ops)
34 {
35 	mutex_lock(&syscore_ops_lock);
36 	list_del(&ops->node);
37 	mutex_unlock(&syscore_ops_lock);
38 }
39 EXPORT_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  */
47 int syscore_suspend(void)
48 {
49 	struct syscore_ops *ops;
50 	int ret = 0;
51 
52 	trace_suspend_resume(TPS("syscore_suspend"), 0, true);
53 	pr_debug("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 			if (initcall_debug)
65 				pr_info("PM: Calling %pF\n", ops->suspend);
66 			ret = ops->suspend();
67 			if (ret)
68 				goto err_out;
69 			WARN_ONCE(!irqs_disabled(),
70 				"Interrupts enabled after %pF\n", ops->suspend);
71 		}
72 
73 	trace_suspend_resume(TPS("syscore_suspend"), 0, false);
74 	return 0;
75 
76  err_out:
77 	pr_err("PM: System core suspend callback %pF failed.\n", ops->suspend);
78 
79 	list_for_each_entry_continue(ops, &syscore_ops_list, node)
80 		if (ops->resume)
81 			ops->resume();
82 
83 	return ret;
84 }
85 EXPORT_SYMBOL_GPL(syscore_suspend);
86 
87 /**
88  * syscore_resume - Execute all the registered system core resume callbacks.
89  *
90  * This function is executed with one CPU on-line and disabled interrupts.
91  */
92 void syscore_resume(void)
93 {
94 	struct syscore_ops *ops;
95 
96 	trace_suspend_resume(TPS("syscore_resume"), 0, true);
97 	WARN_ONCE(!irqs_disabled(),
98 		"Interrupts enabled before system core resume.\n");
99 
100 	list_for_each_entry(ops, &syscore_ops_list, node)
101 		if (ops->resume) {
102 			if (initcall_debug)
103 				pr_info("PM: Calling %pF\n", ops->resume);
104 			ops->resume();
105 			WARN_ONCE(!irqs_disabled(),
106 				"Interrupts enabled after %pF\n", ops->resume);
107 		}
108 	trace_suspend_resume(TPS("syscore_resume"), 0, false);
109 }
110 EXPORT_SYMBOL_GPL(syscore_resume);
111 #endif /* CONFIG_PM_SLEEP */
112 
113 /**
114  * syscore_shutdown - Execute all the registered system core shutdown callbacks.
115  */
116 void syscore_shutdown(void)
117 {
118 	struct syscore_ops *ops;
119 
120 	mutex_lock(&syscore_ops_lock);
121 
122 	list_for_each_entry_reverse(ops, &syscore_ops_list, node)
123 		if (ops->shutdown) {
124 			if (initcall_debug)
125 				pr_info("PM: Calling %pF\n", ops->shutdown);
126 			ops->shutdown();
127 		}
128 
129 	mutex_unlock(&syscore_ops_lock);
130 }
131