Commit 343ce7d4 authored by lishusen's avatar lishusen
Browse files

cpuidle: edit cpuidle-haltpoll driver module parameter 

virt inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/IB7PU3


CVE: NA

----------------------------------------------------

To ensure energy efficiency, haltpoll is disabled by default.
But In some performance scenarios, you can enable haltpoll using
the following methods:

echo Y > /sys/module/cpuidle_haltpoll/parameters/force

Signed-off-by: default avatarXiangyou Xie <xiexiangyou@huawei.com>
Signed-off-by: default avatarlishusen <lishusen2@huawei.com>
parent cab3500b

drivers/cpuidle/cpuidle-haltpoll.c

+93 −2
Original line number Diff line number Diff line
@@ -17,9 +17,16 @@ 
#include <linux/sched/idle.h>

#include <linux/cpuidle_haltpoll.h>



static bool force __read_mostly;

module_param(force, bool, 0444);

static bool force;

MODULE_PARM_DESC(force, "Load unconditionally");

static int enable_haltpoll_driver(const char *val, const struct kernel_param *kp);



static const struct kernel_param_ops enable_haltpoll_ops = {

	.set = enable_haltpoll_driver,

	.get = param_get_bool,

};

module_param_cb(force, &enable_haltpoll_ops, &force, 0644);





static struct cpuidle_device __percpu *haltpoll_cpuidle_devices;

static enum cpuhp_state haltpoll_hp_state;
@@ -129,6 +136,90 @@ static void __exit haltpoll_exit(void) 
	haltpoll_uninit();

}



#ifdef CONFIG_ARM64

static int register_haltpoll_driver(void)

{

	int ret;

	struct cpuidle_driver *drv = &haltpoll_driver;



#ifdef CONFIG_X86

	/* Do not load haltpoll if idle= is passed */

	if (boot_option_idle_override != IDLE_NO_OVERRIDE)

		return -ENODEV;

#endif



	cpuidle_poll_state_init(drv);



	ret = cpuidle_register_driver(drv);

	if (ret < 0)

		return ret;



	haltpoll_cpuidle_devices = alloc_percpu(struct cpuidle_device);

	if (haltpoll_cpuidle_devices == NULL) {

		cpuidle_unregister_driver(drv);

		return -ENOMEM;

	}



	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "cpuidle/haltpoll:online",

			haltpoll_cpu_online, haltpoll_cpu_offline);

	if (ret < 0) {

		haltpoll_uninit();

	} else {

		haltpoll_hp_state = ret;

		ret = 0;

	}



	return ret;

}



static void unregister_haltpoll_driver(void)

{

	if (haltpoll_hp_state)

		cpuhp_remove_state(haltpoll_hp_state);

	cpuidle_unregister_driver(&haltpoll_driver);



	free_percpu(haltpoll_cpuidle_devices);

	haltpoll_cpuidle_devices = NULL;



}



static int enable_haltpoll_driver(const char *val, const struct kernel_param *kp)

{

	int ret;

	bool do_enable;



	if (!val)

		return 0;



	ret = strtobool(val, &do_enable);



	if (ret || force == do_enable)

		return ret;



	if (do_enable) {

		ret = register_haltpoll_driver();



		if (!ret) {

			pr_info("Enable haltpoll driver.\n");

			force = 1;

		} else {

			pr_err("Fail to enable haltpoll driver.\n");

		}

	} else {

		unregister_haltpoll_driver();

		force = 0;

		pr_info("Unregister haltpoll driver.\n");

	}



	return ret;

}

#else

static int enable_haltpoll_driver(const char *val, const struct kernel_param *kp)

{

	return -1;

}

#endif



module_init(haltpoll_init);

module_exit(haltpoll_exit);

MODULE_LICENSE("GPL");