linux/drivers/base/syscore.c
Rafael J. Wysocki 40dc166cb5 PM / Core: Introduce struct syscore_ops for core subsystems PM
Some subsystems need to carry out suspend/resume and shutdown
operations with one CPU on-line and interrupts disabled.  The only
way to register such operations is to define a sysdev class and
a sysdev specifically for this purpose which is cumbersome and
inefficient.  Moreover, the arguments taken by sysdev suspend,
resume and shutdown callbacks are practically never necessary.

For this reason, introduce a simpler interface allowing subsystems
to register operations to be executed very late during system suspend
and shutdown and very early during resume in the form of
strcut syscore_ops objects.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-15 00:43:46 +01:00

117 lines
2.7 KiB
C

/*
* syscore.c - Execution of system core operations.
*
* Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
*
* This file is released under the GPLv2.
*/
#include <linux/syscore_ops.h>
#include <linux/mutex.h>
#include <linux/module.h>
static LIST_HEAD(syscore_ops_list);
static DEFINE_MUTEX(syscore_ops_lock);
/**
* register_syscore_ops - Register a set of system core operations.
* @ops: System core operations to register.
*/
void register_syscore_ops(struct syscore_ops *ops)
{
mutex_lock(&syscore_ops_lock);
list_add_tail(&ops->node, &syscore_ops_list);
mutex_unlock(&syscore_ops_lock);
}
EXPORT_SYMBOL_GPL(register_syscore_ops);
/**
* unregister_syscore_ops - Unregister a set of system core operations.
* @ops: System core operations to unregister.
*/
void unregister_syscore_ops(struct syscore_ops *ops)
{
mutex_lock(&syscore_ops_lock);
list_del(&ops->node);
mutex_unlock(&syscore_ops_lock);
}
EXPORT_SYMBOL_GPL(unregister_syscore_ops);
#ifdef CONFIG_PM_SLEEP
/**
* syscore_suspend - Execute all the registered system core suspend callbacks.
*
* This function is executed with one CPU on-line and disabled interrupts.
*/
int syscore_suspend(void)
{
struct syscore_ops *ops;
int ret = 0;
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled before system core suspend.\n");
list_for_each_entry_reverse(ops, &syscore_ops_list, node)
if (ops->suspend) {
if (initcall_debug)
pr_info("PM: Calling %pF\n", ops->suspend);
ret = ops->suspend();
if (ret)
goto err_out;
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled after %pF\n", ops->suspend);
}
return 0;
err_out:
pr_err("PM: System core suspend callback %pF failed.\n", ops->suspend);
list_for_each_entry_continue(ops, &syscore_ops_list, node)
if (ops->resume)
ops->resume();
return ret;
}
/**
* syscore_resume - Execute all the registered system core resume callbacks.
*
* This function is executed with one CPU on-line and disabled interrupts.
*/
void syscore_resume(void)
{
struct syscore_ops *ops;
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled before system core resume.\n");
list_for_each_entry(ops, &syscore_ops_list, node)
if (ops->resume) {
if (initcall_debug)
pr_info("PM: Calling %pF\n", ops->resume);
ops->resume();
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled after %pF\n", ops->resume);
}
}
#endif /* CONFIG_PM_SLEEP */
/**
* syscore_shutdown - Execute all the registered system core shutdown callbacks.
*/
void syscore_shutdown(void)
{
struct syscore_ops *ops;
mutex_lock(&syscore_ops_lock);
list_for_each_entry_reverse(ops, &syscore_ops_list, node)
if (ops->shutdown) {
if (initcall_debug)
pr_info("PM: Calling %pF\n", ops->shutdown);
ops->shutdown();
}
mutex_unlock(&syscore_ops_lock);
}