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