kernel/drivers/base/syscore.c

   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 }