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   */
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  	trace_suspend_resume(TPS("syscore_suspend"), 0, 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"), 0, 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  }
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  	trace_suspend_resume(TPS("syscore_resume"), 0, 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"), 0, false);
107  }
108  EXPORT_SYMBOL_GPL(syscore_resume);
109  #endif /* CONFIG_PM_SLEEP */
110  
111  /**
112   * syscore_shutdown - Execute all the registered system core shutdown callbacks.
113   */
syscore_shutdown(void)114  void 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(&syscore_ops_lock);
128  }
129