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// SPDX-License-Identifier: GPL-2.0
/*
* cpuidle driver for haltpoll governor.
*
* Copyright 2019 Red Hat, Inc. and/or its affiliates.
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
* Authors: Marcelo Tosatti <mtosatti@redhat.com>
*/
#include <linux/init.h>
#include <linux/cpuidle.h>
#include <linux/module.h>
#include <linux/sched/idle.h>
#include <linux/kvm_para.h>
#include <linux/cpuidle_haltpoll.h>
static int default_enter_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index)
{
if (current_clr_polling_and_test()) {
local_irq_enable();
return index;
}
default_idle();
return index;
}
static struct cpuidle_driver haltpoll_driver = {
.name = "haltpoll",
.owner = THIS_MODULE,
.states = {
{ /* entry 0 is for polling */ },
{
.enter = default_enter_idle,
.exit_latency = 1,
.target_residency = 1,
.power_usage = -1,
.name = "haltpoll idle",
.desc = "default architecture idle",
},
},
.safe_state_index = 0,
.state_count = 2,
};
static int __init haltpoll_init(void)
{
int ret;
struct cpuidle_driver *drv = &haltpoll_driver;
cpuidle_poll_state_init(drv);
if (!kvm_para_available())
return 0;
ret = cpuidle_register(&haltpoll_driver, NULL);
if (ret == 0)
arch_haltpoll_enable();
return ret;
}
static void __exit haltpoll_exit(void)
{
arch_haltpoll_disable();
cpuidle_unregister(&haltpoll_driver);
}
module_init(haltpoll_init);
module_exit(haltpoll_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marcelo Tosatti <mtosatti@redhat.com>");
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