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 #include <linux/wakeup_reason.h>
  15
  16 static LIST_HEAD(syscore_ops_list);
  17 static DEFINE_MUTEX(syscore_ops_lock);
  18
  19 /**
  20  * register_syscore_ops - Register a set of system core operations.
  21  * @ops: System core operations to register.
  22  */
  23 void register_syscore_ops(struct syscore_ops *ops)
  24 {
  25         mutex_lock(&syscore_ops_lock);
  26         list_add_tail(&ops->node, &syscore_ops_list);
  27         mutex_unlock(&syscore_ops_lock);
  28 }
  29 EXPORT_SYMBOL_GPL(register_syscore_ops);
  30
  31 /**
  32  * unregister_syscore_ops - Unregister a set of system core operations.
  33  * @ops: System core operations to unregister.
  34  */
  35 void unregister_syscore_ops(struct syscore_ops *ops)
  36 {
  37         mutex_lock(&syscore_ops_lock);
  38         list_del(&ops->node);
  39         mutex_unlock(&syscore_ops_lock);
  40 }
  41 EXPORT_SYMBOL_GPL(unregister_syscore_ops);
  42
  43 #ifdef CONFIG_PM_SLEEP
  44 /**
  45  * syscore_suspend - Execute all the registered system core suspend callbacks.
  46  *
  47  * This function is executed with one CPU on-line and disabled interrupts.
  48  */
  49 int syscore_suspend(void)
  50 {
  51         struct syscore_ops *ops;
  52         int ret = 0;
  53
  54         trace_suspend_resume(TPS("syscore_suspend"), 0, true);
  55         pr_debug("Checking wakeup interrupts\n");
  56
  57         /* Return error code if there are any wakeup interrupts pending. */
  58         if (pm_wakeup_pending())
  59                 return -EBUSY;
  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         log_suspend_abort_reason("System core suspend callback %pF failed",
  80                 ops->suspend);
  81         pr_err("PM: System core suspend callback %pF failed.\n", ops->suspend);
  82
  83         list_for_each_entry_continue(ops, &syscore_ops_list, node)
  84                 if (ops->resume)
  85                         ops->resume();
  86
  87         return ret;
  88 }
  89 EXPORT_SYMBOL_GPL(syscore_suspend);
  90
  91 /**
  92  * syscore_resume - Execute all the registered system core resume callbacks.
  93  *
  94  * This function is executed with one CPU on-line and disabled interrupts.
  95  */
  96 void syscore_resume(void)
  97 {
  98         struct syscore_ops *ops;
  99
 100         trace_suspend_resume(TPS("syscore_resume"), 0, true);
 101         WARN_ONCE(!irqs_disabled(),
 102                 "Interrupts enabled before system core resume.\n");
 103
 104         list_for_each_entry(ops, &syscore_ops_list, node)
 105                 if (ops->resume) {
 106                         if (initcall_debug)
 107                                 pr_info("PM: Calling %pF\n", ops->resume);
 108                         ops->resume();
 109                         WARN_ONCE(!irqs_disabled(),
 110                                 "Interrupts enabled after %pF\n", ops->resume);
 111                 }
 112         trace_suspend_resume(TPS("syscore_resume"), 0, false);
 113 }
 114 EXPORT_SYMBOL_GPL(syscore_resume);
 115 #endif /* CONFIG_PM_SLEEP */
 116
 117 /**
 118  * syscore_shutdown - Execute all the registered system core shutdown callbacks.
 119  */
 120 void syscore_shutdown(void)
 121 {
 122         struct syscore_ops *ops;
 123
 124         mutex_lock(&syscore_ops_lock);
 125
 126         list_for_each_entry_reverse(ops, &syscore_ops_list, node)
 127                 if (ops->shutdown) {
 128                         if (initcall_debug)
 129                                 pr_info("PM: Calling %pF\n", ops->shutdown);
 130                         ops->shutdown();
 131                 }
 132
 133         mutex_unlock(&syscore_ops_lock);
 134 }