linux-imx

// SPDX-License-Identifier: GPL-2.0-only

/*

 * Copyright (C) 2011 Google, Inc.

 *

 * Author:

 *  Colin Cross <ccross@android.com>

 */

​

#include <linux/kernel.h>

#include <linux/cpu_pm.h>

#include <linux/module.h>

#include <linux/notifier.h>

#include <linux/spinlock.h>

#include <linux/syscore_ops.h>

​

static ATOMIC_NOTIFIER_HEAD(cpu_pm_notifier_chain);

​

static int cpu_pm_notify(enum cpu_pm_event event, int nr_to_call, int *nr_calls)

{

    int ret;

​

    /*

     * __atomic_notifier_call_chain has a RCU read critical section, which

     * could be disfunctional in cpu idle. Copy RCU_NONIDLE code to let

     * RCU know this.

     */

    rcu_irq_enter_irqson();

    ret = __atomic_notifier_call_chain(&cpu_pm_notifier_chain, event, NULL,

        nr_to_call, nr_calls);

    rcu_irq_exit_irqson();

​

    return notifier_to_errno(ret);

}

​

/**

 * cpu_pm_register_notifier - register a driver with cpu_pm

 * @nb: notifier block to register

 *

 * Add a driver to a list of drivers that are notified about

 * CPU and CPU cluster low power entry and exit.

 *

 * This function may sleep, and has the same return conditions as

 * raw_notifier_chain_register.

 */

int cpu_pm_register_notifier(struct notifier_block *nb)

{

    return atomic_notifier_chain_register(&cpu_pm_notifier_chain, nb);

}

EXPORT_SYMBOL_GPL(cpu_pm_register_notifier);

​

/**

 * cpu_pm_unregister_notifier - unregister a driver with cpu_pm

 * @nb: notifier block to be unregistered

 *

 * Remove a driver from the CPU PM notifier list.

 *

 * This function may sleep, and has the same return conditions as

 * raw_notifier_chain_unregister.

 */

int cpu_pm_unregister_notifier(struct notifier_block *nb)

{

    return atomic_notifier_chain_unregister(&cpu_pm_notifier_chain, nb);

}