forked from Minki/linux
a1c4423b02
When performing guest side polling, it is not necessary to also perform host side polling. So disable host side polling, via the new MSR interface, when loading cpuidle-haltpoll driver. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
76 lines
1.6 KiB
C
76 lines
1.6 KiB
C
// 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>");
|