xref: /openbmc/linux/drivers/base/syscore.c (revision d2999e1b)
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 #include <trace/events/power.h>
14 
15 static LIST_HEAD(syscore_ops_list);
16 static DEFINE_MUTEX(syscore_ops_lock);
17 
18 /**
19  * register_syscore_ops - Register a set of system core operations.
20  * @ops: System core operations to register.
21  */
22 void register_syscore_ops(struct syscore_ops *ops)
23 {
24 	mutex_lock(&syscore_ops_lock);
25 	list_add_tail(&ops->node, &syscore_ops_list);
26 	mutex_unlock(&syscore_ops_lock);
27 }
28 EXPORT_SYMBOL_GPL(register_syscore_ops);
29 
30 /**
31  * unregister_syscore_ops - Unregister a set of system core operations.
32  * @ops: System core operations to unregister.
33  */
34 void unregister_syscore_ops(struct syscore_ops *ops)
35 {
36 	mutex_lock(&syscore_ops_lock);
37 	list_del(&ops->node);
38 	mutex_unlock(&syscore_ops_lock);
39 }
40 EXPORT_SYMBOL_GPL(unregister_syscore_ops);
41 
42 #ifdef CONFIG_PM_SLEEP
43 /**
44  * syscore_suspend - Execute all the registered system core suspend callbacks.
45  *
46  * This function is executed with one CPU on-line and disabled interrupts.
47  */
48 int syscore_suspend(void)
49 {
50 	struct syscore_ops *ops;
51 	int ret = 0;
52 
53 	trace_suspend_resume(TPS("syscore_suspend"), 0, true);
54 	pr_debug("Checking wakeup interrupts\n");
55 
56 	/* Return error code if there are any wakeup interrupts pending. */
57 	ret = check_wakeup_irqs();
58 	if (ret)
59 		return ret;
60 
61 	WARN_ONCE(!irqs_disabled(),
62 		"Interrupts enabled before system core suspend.\n");
63 
64 	list_for_each_entry_reverse(ops, &syscore_ops_list, node)
65 		if (ops->suspend) {
66 			if (initcall_debug)
67 				pr_info("PM: Calling %pF\n", ops->suspend);
68 			ret = ops->suspend();
69 			if (ret)
70 				goto err_out;
71 			WARN_ONCE(!irqs_disabled(),
72 				"Interrupts enabled after %pF\n", ops->suspend);
73 		}
74 
75 	trace_suspend_resume(TPS("syscore_suspend"), 0, false);
76 	return 0;
77 
78  err_out:
79 	pr_err("PM: System core suspend callback %pF failed.\n", ops->suspend);
80 
81 	list_for_each_entry_continue(ops, &syscore_ops_list, node)
82 		if (ops->resume)
83 			ops->resume();
84 
85 	return ret;
86 }
87 EXPORT_SYMBOL_GPL(syscore_suspend);
88 
89 /**
90  * syscore_resume - Execute all the registered system core resume callbacks.
91  *
92  * This function is executed with one CPU on-line and disabled interrupts.
93  */
94 void syscore_resume(void)
95 {
96 	struct syscore_ops *ops;
97 
98 	trace_suspend_resume(TPS("syscore_resume"), 0, true);
99 	WARN_ONCE(!irqs_disabled(),
100 		"Interrupts enabled before system core resume.\n");
101 
102 	list_for_each_entry(ops, &syscore_ops_list, node)
103 		if (ops->resume) {
104 			if (initcall_debug)
105 				pr_info("PM: Calling %pF\n", ops->resume);
106 			ops->resume();
107 			WARN_ONCE(!irqs_disabled(),
108 				"Interrupts enabled after %pF\n", ops->resume);
109 		}
110 	trace_suspend_resume(TPS("syscore_resume"), 0, false);
111 }
112 EXPORT_SYMBOL_GPL(syscore_resume);
113 #endif /* CONFIG_PM_SLEEP */
114 
115 /**
116  * syscore_shutdown - Execute all the registered system core shutdown callbacks.
117  */
118 void syscore_shutdown(void)
119 {
120 	struct syscore_ops *ops;
121 
122 	mutex_lock(&syscore_ops_lock);
123 
124 	list_for_each_entry_reverse(ops, &syscore_ops_list, node)
125 		if (ops->shutdown) {
126 			if (initcall_debug)
127 				pr_info("PM: Calling %pF\n", ops->shutdown);
128 			ops->shutdown();
129 		}
130 
131 	mutex_unlock(&syscore_ops_lock);
132 }
133