syscore.c

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/*
 *  syscore.c - Execution of system core operations.
 *
 *  Copyright (C) 2011 Rafael J. Wysocki <[email protected]>, Novell Inc.
 *
 *  This file is released under the GPLv2.
 */

#include <linux/syscore_ops.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/interrupt.h>

static LIST_HEAD(syscore_ops_list);
static DEFINE_MUTEX(syscore_ops_lock);

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);

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

int syscore_suspend(void)
{
    struct syscore_ops *ops;
    int ret = 0;

    pr_debug("Checking wakeup interrupts\n");

    /* Return error code if there are any wakeup interrupts pending. */
    ret = check_wakeup_irqs();
    if (ret)
        return ret;

    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;
}
EXPORT_SYMBOL_GPL(syscore_suspend);

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);
        }
}
EXPORT_SYMBOL_GPL(syscore_resume);
#endif /* CONFIG_PM_SLEEP */

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);
}