mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-23 04:34:11 +08:00
170 lines
3.4 KiB
C
170 lines
3.4 KiB
C
|
/*
|
||
|
* cpuidle-powernv - idle state cpuidle driver.
|
||
|
* Adapted from drivers/cpuidle/cpuidle-pseries
|
||
|
*
|
||
|
*/
|
||
|
|
||
|
#include <linux/kernel.h>
|
||
|
#include <linux/module.h>
|
||
|
#include <linux/init.h>
|
||
|
#include <linux/moduleparam.h>
|
||
|
#include <linux/cpuidle.h>
|
||
|
#include <linux/cpu.h>
|
||
|
#include <linux/notifier.h>
|
||
|
|
||
|
#include <asm/machdep.h>
|
||
|
#include <asm/firmware.h>
|
||
|
|
||
|
struct cpuidle_driver powernv_idle_driver = {
|
||
|
.name = "powernv_idle",
|
||
|
.owner = THIS_MODULE,
|
||
|
};
|
||
|
|
||
|
static int max_idle_state;
|
||
|
static struct cpuidle_state *cpuidle_state_table;
|
||
|
|
||
|
static int snooze_loop(struct cpuidle_device *dev,
|
||
|
struct cpuidle_driver *drv,
|
||
|
int index)
|
||
|
{
|
||
|
local_irq_enable();
|
||
|
set_thread_flag(TIF_POLLING_NRFLAG);
|
||
|
|
||
|
while (!need_resched()) {
|
||
|
HMT_low();
|
||
|
HMT_very_low();
|
||
|
}
|
||
|
|
||
|
HMT_medium();
|
||
|
clear_thread_flag(TIF_POLLING_NRFLAG);
|
||
|
smp_mb();
|
||
|
return index;
|
||
|
}
|
||
|
|
||
|
static int nap_loop(struct cpuidle_device *dev,
|
||
|
struct cpuidle_driver *drv,
|
||
|
int index)
|
||
|
{
|
||
|
power7_idle();
|
||
|
return index;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* States for dedicated partition case.
|
||
|
*/
|
||
|
static struct cpuidle_state powernv_states[] = {
|
||
|
{ /* Snooze */
|
||
|
.name = "snooze",
|
||
|
.desc = "snooze",
|
||
|
.flags = CPUIDLE_FLAG_TIME_VALID,
|
||
|
.exit_latency = 0,
|
||
|
.target_residency = 0,
|
||
|
.enter = &snooze_loop },
|
||
|
{ /* NAP */
|
||
|
.name = "NAP",
|
||
|
.desc = "NAP",
|
||
|
.flags = CPUIDLE_FLAG_TIME_VALID,
|
||
|
.exit_latency = 10,
|
||
|
.target_residency = 100,
|
||
|
.enter = &nap_loop },
|
||
|
};
|
||
|
|
||
|
static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,
|
||
|
unsigned long action, void *hcpu)
|
||
|
{
|
||
|
int hotcpu = (unsigned long)hcpu;
|
||
|
struct cpuidle_device *dev =
|
||
|
per_cpu(cpuidle_devices, hotcpu);
|
||
|
|
||
|
if (dev && cpuidle_get_driver()) {
|
||
|
switch (action) {
|
||
|
case CPU_ONLINE:
|
||
|
case CPU_ONLINE_FROZEN:
|
||
|
cpuidle_pause_and_lock();
|
||
|
cpuidle_enable_device(dev);
|
||
|
cpuidle_resume_and_unlock();
|
||
|
break;
|
||
|
|
||
|
case CPU_DEAD:
|
||
|
case CPU_DEAD_FROZEN:
|
||
|
cpuidle_pause_and_lock();
|
||
|
cpuidle_disable_device(dev);
|
||
|
cpuidle_resume_and_unlock();
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
return NOTIFY_DONE;
|
||
|
}
|
||
|
}
|
||
|
return NOTIFY_OK;
|
||
|
}
|
||
|
|
||
|
static struct notifier_block setup_hotplug_notifier = {
|
||
|
.notifier_call = powernv_cpuidle_add_cpu_notifier,
|
||
|
};
|
||
|
|
||
|
/*
|
||
|
* powernv_cpuidle_driver_init()
|
||
|
*/
|
||
|
static int powernv_cpuidle_driver_init(void)
|
||
|
{
|
||
|
int idle_state;
|
||
|
struct cpuidle_driver *drv = &powernv_idle_driver;
|
||
|
|
||
|
drv->state_count = 0;
|
||
|
|
||
|
for (idle_state = 0; idle_state < max_idle_state; ++idle_state) {
|
||
|
/* Is the state not enabled? */
|
||
|
if (cpuidle_state_table[idle_state].enter == NULL)
|
||
|
continue;
|
||
|
|
||
|
drv->states[drv->state_count] = /* structure copy */
|
||
|
cpuidle_state_table[idle_state];
|
||
|
|
||
|
drv->state_count += 1;
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* powernv_idle_probe()
|
||
|
* Choose state table for shared versus dedicated partition
|
||
|
*/
|
||
|
static int powernv_idle_probe(void)
|
||
|
{
|
||
|
|
||
|
if (cpuidle_disable != IDLE_NO_OVERRIDE)
|
||
|
return -ENODEV;
|
||
|
|
||
|
if (firmware_has_feature(FW_FEATURE_OPALv3)) {
|
||
|
cpuidle_state_table = powernv_states;
|
||
|
max_idle_state = ARRAY_SIZE(powernv_states);
|
||
|
} else
|
||
|
return -ENODEV;
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int __init powernv_processor_idle_init(void)
|
||
|
{
|
||
|
int retval;
|
||
|
|
||
|
retval = powernv_idle_probe();
|
||
|
if (retval)
|
||
|
return retval;
|
||
|
|
||
|
powernv_cpuidle_driver_init();
|
||
|
retval = cpuidle_register(&powernv_idle_driver, NULL);
|
||
|
if (retval) {
|
||
|
printk(KERN_DEBUG "Registration of powernv driver failed.\n");
|
||
|
return retval;
|
||
|
}
|
||
|
|
||
|
register_cpu_notifier(&setup_hotplug_notifier);
|
||
|
printk(KERN_DEBUG "powernv_idle_driver registered\n");
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
device_initcall(powernv_processor_idle_init);
|