drivers/base/syscore.c

   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  */
  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  */
  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  */
  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  */
  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  */
 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 }