forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
146 lines
3.1 KiB
146 lines
3.1 KiB
// 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 <[email protected]> |
|
*/ |
|
|
|
#include <linux/init.h> |
|
#include <linux/cpu.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 bool force __read_mostly; |
|
module_param(force, bool, 0444); |
|
MODULE_PARM_DESC(force, "Load unconditionally"); |
|
|
|
static struct cpuidle_device __percpu *haltpoll_cpuidle_devices; |
|
static enum cpuhp_state haltpoll_hp_state; |
|
|
|
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", |
|
.governor = "haltpoll", |
|
.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 haltpoll_cpu_online(unsigned int cpu) |
|
{ |
|
struct cpuidle_device *dev; |
|
|
|
dev = per_cpu_ptr(haltpoll_cpuidle_devices, cpu); |
|
if (!dev->registered) { |
|
dev->cpu = cpu; |
|
if (cpuidle_register_device(dev)) { |
|
pr_notice("cpuidle_register_device %d failed!\n", cpu); |
|
return -EIO; |
|
} |
|
arch_haltpoll_enable(cpu); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int haltpoll_cpu_offline(unsigned int cpu) |
|
{ |
|
struct cpuidle_device *dev; |
|
|
|
dev = per_cpu_ptr(haltpoll_cpuidle_devices, cpu); |
|
if (dev->registered) { |
|
arch_haltpoll_disable(cpu); |
|
cpuidle_unregister_device(dev); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void haltpoll_uninit(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 bool haltpoll_want(void) |
|
{ |
|
return kvm_para_has_hint(KVM_HINTS_REALTIME) || force; |
|
} |
|
|
|
static int __init haltpoll_init(void) |
|
{ |
|
int ret; |
|
struct cpuidle_driver *drv = &haltpoll_driver; |
|
|
|
/* Do not load haltpoll if idle= is passed */ |
|
if (boot_option_idle_override != IDLE_NO_OVERRIDE) |
|
return -ENODEV; |
|
|
|
cpuidle_poll_state_init(drv); |
|
|
|
if (!kvm_para_available() || !haltpoll_want()) |
|
return -ENODEV; |
|
|
|
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 __exit haltpoll_exit(void) |
|
{ |
|
haltpoll_uninit(); |
|
} |
|
|
|
module_init(haltpoll_init); |
|
module_exit(haltpoll_exit); |
|
MODULE_LICENSE("GPL"); |
|
MODULE_AUTHOR("Marcelo Tosatti <[email protected]>");
|
|
|