1 /*
2  *  syscore.c - Execution of system core operations.
3  *
4  *  Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
5  *
6  *  This file is released under the GPLv2.
7  */
8 
9 #include <linux/syscore_ops.h>
10 #include <linux/mutex.h>
11 #include <linux/module.h>
12 #include <linux/interrupt.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  */
register_syscore_ops(struct syscore_ops * ops)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  */
unregister_syscore_ops(struct syscore_ops * ops)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  */
syscore_suspend(void)47 int syscore_suspend(void)
48 {
49 	struct syscore_ops *ops;
50 	int ret = 0;
51 
52 	pr_debug("Checking wakeup interrupts\n");
53 
54 	/* Return error code if there are any wakeup interrupts pending. */
55 	ret = check_wakeup_irqs();
56 	if (ret)
57 		return ret;
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 	return 0;
74 
75  err_out:
76 	pr_err("PM: System core suspend callback %pF 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 }
84 EXPORT_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  */
syscore_resume(void)91 void syscore_resume(void)
92 {
93 	struct syscore_ops *ops;
94 
95 	WARN_ONCE(!irqs_disabled(),
96 		"Interrupts enabled before system core resume.\n");
97 
98 	list_for_each_entry(ops, &syscore_ops_list, node)
99 		if (ops->resume) {
100 			if (initcall_debug)
101 				pr_info("PM: Calling %pF\n", ops->resume);
102 			ops->resume();
103 			WARN_ONCE(!irqs_disabled(),
104 				"Interrupts enabled after %pF\n", ops->resume);
105 		}
106 }
107 EXPORT_SYMBOL_GPL(syscore_resume);
108 #endif /* CONFIG_PM_SLEEP */
109 
110 /**
111  * syscore_shutdown - Execute all the registered system core shutdown callbacks.
112  */
syscore_shutdown(void)113 void syscore_shutdown(void)
114 {
115 	struct syscore_ops *ops;
116 
117 	mutex_lock(&syscore_ops_lock);
118 
119 	list_for_each_entry_reverse(ops, &syscore_ops_list, node)
120 		if (ops->shutdown) {
121 			if (initcall_debug)
122 				pr_info("PM: Calling %pF\n", ops->shutdown);
123 			ops->shutdown();
124 		}
125 
126 	mutex_unlock(&syscore_ops_lock);
127 }
128