xref: /openbmc/linux/drivers/base/syscore.c (revision 9cfc5c90)
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/suspend.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 	if (pm_wakeup_pending())
58 		return -EBUSY;
59 
60 	WARN_ONCE(!irqs_disabled(),
61 		"Interrupts enabled before system core suspend.\n");
62 
63 	list_for_each_entry_reverse(ops, &syscore_ops_list, node)
64 		if (ops->suspend) {
65 			if (initcall_debug)
66 				pr_info("PM: Calling %pF\n", ops->suspend);
67 			ret = ops->suspend();
68 			if (ret)
69 				goto err_out;
70 			WARN_ONCE(!irqs_disabled(),
71 				"Interrupts enabled after %pF\n", ops->suspend);
72 		}
73 
74 	trace_suspend_resume(TPS("syscore_suspend"), 0, false);
75 	return 0;
76 
77  err_out:
78 	pr_err("PM: System core suspend callback %pF failed.\n", ops->suspend);
79 
80 	list_for_each_entry_continue(ops, &syscore_ops_list, node)
81 		if (ops->resume)
82 			ops->resume();
83 
84 	return ret;
85 }
86 EXPORT_SYMBOL_GPL(syscore_suspend);
87 
88 /**
89  * syscore_resume - Execute all the registered system core resume callbacks.
90  *
91  * This function is executed with one CPU on-line and disabled interrupts.
92  */
93 void syscore_resume(void)
94 {
95 	struct syscore_ops *ops;
96 
97 	trace_suspend_resume(TPS("syscore_resume"), 0, true);
98 	WARN_ONCE(!irqs_disabled(),
99 		"Interrupts enabled before system core resume.\n");
100 
101 	list_for_each_entry(ops, &syscore_ops_list, node)
102 		if (ops->resume) {
103 			if (initcall_debug)
104 				pr_info("PM: Calling %pF\n", ops->resume);
105 			ops->resume();
106 			WARN_ONCE(!irqs_disabled(),
107 				"Interrupts enabled after %pF\n", ops->resume);
108 		}
109 	trace_suspend_resume(TPS("syscore_resume"), 0, false);
110 }
111 EXPORT_SYMBOL_GPL(syscore_resume);
112 #endif /* CONFIG_PM_SLEEP */
113 
114 /**
115  * syscore_shutdown - Execute all the registered system core shutdown callbacks.
116  */
117 void syscore_shutdown(void)
118 {
119 	struct syscore_ops *ops;
120 
121 	mutex_lock(&syscore_ops_lock);
122 
123 	list_for_each_entry_reverse(ops, &syscore_ops_list, node)
124 		if (ops->shutdown) {
125 			if (initcall_debug)
126 				pr_info("PM: Calling %pF\n", ops->shutdown);
127 			ops->shutdown();
128 		}
129 
130 	mutex_unlock(&syscore_ops_lock);
131 }
132