kernel-ark/drivers/cpuidle/driver.c
Daniel Lezcano a06df062a1 cpuidle: initialize the broadcast timer framework
The commit 89878baa73f0f1c679355006bd8632e5d78f96c2 introduced
the CPUIDLE_FLAG_TIMER_STOP flag where we specify a specific idle
state stops the local timer.

Now use this flag to check at init time if one state will need
the broadcast timer and, in this case, setup the broadcast timer
framework. That prevents multiple code duplication in the drivers.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-01 01:10:28 +02:00

271 lines
5.4 KiB
C

/*
* driver.c - driver support
*
* (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
* Shaohua Li <shaohua.li@intel.com>
* Adam Belay <abelay@novell.com>
*
* This code is licenced under the GPL.
*/
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/cpuidle.h>
#include <linux/cpumask.h>
#include <linux/clockchips.h>
#include "cpuidle.h"
DEFINE_SPINLOCK(cpuidle_driver_lock);
static void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu);
static struct cpuidle_driver * __cpuidle_get_cpu_driver(int cpu);
static void cpuidle_setup_broadcast_timer(void *arg)
{
int cpu = smp_processor_id();
clockevents_notify((long)(arg), &cpu);
}
static void __cpuidle_driver_init(struct cpuidle_driver *drv, int cpu)
{
int i;
drv->refcnt = 0;
for (i = drv->state_count - 1; i >= 0 ; i--) {
if (!(drv->states[i].flags & CPUIDLE_FLAG_TIMER_STOP))
continue;
drv->bctimer = 1;
on_each_cpu_mask(get_cpu_mask(cpu), cpuidle_setup_broadcast_timer,
(void *)CLOCK_EVT_NOTIFY_BROADCAST_ON, 1);
break;
}
}
static int __cpuidle_register_driver(struct cpuidle_driver *drv, int cpu)
{
if (!drv || !drv->state_count)
return -EINVAL;
if (cpuidle_disabled())
return -ENODEV;
if (__cpuidle_get_cpu_driver(cpu))
return -EBUSY;
__cpuidle_driver_init(drv, cpu);
__cpuidle_set_cpu_driver(drv, cpu);
return 0;
}
static void __cpuidle_unregister_driver(struct cpuidle_driver *drv, int cpu)
{
if (drv != __cpuidle_get_cpu_driver(cpu))
return;
if (!WARN_ON(drv->refcnt > 0))
__cpuidle_set_cpu_driver(NULL, cpu);
if (drv->bctimer) {
drv->bctimer = 0;
on_each_cpu_mask(get_cpu_mask(cpu), cpuidle_setup_broadcast_timer,
(void *)CLOCK_EVT_NOTIFY_BROADCAST_OFF, 1);
}
}
#ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
static DEFINE_PER_CPU(struct cpuidle_driver *, cpuidle_drivers);
static void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu)
{
per_cpu(cpuidle_drivers, cpu) = drv;
}
static struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu)
{
return per_cpu(cpuidle_drivers, cpu);
}
static void __cpuidle_unregister_all_cpu_driver(struct cpuidle_driver *drv)
{
int cpu;
for_each_present_cpu(cpu)
__cpuidle_unregister_driver(drv, cpu);
}
static int __cpuidle_register_all_cpu_driver(struct cpuidle_driver *drv)
{
int ret = 0;
int i, cpu;
for_each_present_cpu(cpu) {
ret = __cpuidle_register_driver(drv, cpu);
if (ret)
break;
}
if (ret)
for_each_present_cpu(i) {
if (i == cpu)
break;
__cpuidle_unregister_driver(drv, i);
}
return ret;
}
int cpuidle_register_cpu_driver(struct cpuidle_driver *drv, int cpu)
{
int ret;
spin_lock(&cpuidle_driver_lock);
ret = __cpuidle_register_driver(drv, cpu);
spin_unlock(&cpuidle_driver_lock);
return ret;
}
void cpuidle_unregister_cpu_driver(struct cpuidle_driver *drv, int cpu)
{
spin_lock(&cpuidle_driver_lock);
__cpuidle_unregister_driver(drv, cpu);
spin_unlock(&cpuidle_driver_lock);
}
/**
* cpuidle_register_driver - registers a driver
* @drv: the driver
*/
int cpuidle_register_driver(struct cpuidle_driver *drv)
{
int ret;
spin_lock(&cpuidle_driver_lock);
ret = __cpuidle_register_all_cpu_driver(drv);
spin_unlock(&cpuidle_driver_lock);
return ret;
}
EXPORT_SYMBOL_GPL(cpuidle_register_driver);
/**
* cpuidle_unregister_driver - unregisters a driver
* @drv: the driver
*/
void cpuidle_unregister_driver(struct cpuidle_driver *drv)
{
spin_lock(&cpuidle_driver_lock);
__cpuidle_unregister_all_cpu_driver(drv);
spin_unlock(&cpuidle_driver_lock);
}
EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);
#else
static struct cpuidle_driver *cpuidle_curr_driver;
static inline void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu)
{
cpuidle_curr_driver = drv;
}
static inline struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu)
{
return cpuidle_curr_driver;
}
/**
* cpuidle_register_driver - registers a driver
* @drv: the driver
*/
int cpuidle_register_driver(struct cpuidle_driver *drv)
{
int ret, cpu;
cpu = get_cpu();
spin_lock(&cpuidle_driver_lock);
ret = __cpuidle_register_driver(drv, cpu);
spin_unlock(&cpuidle_driver_lock);
put_cpu();
return ret;
}
EXPORT_SYMBOL_GPL(cpuidle_register_driver);
/**
* cpuidle_unregister_driver - unregisters a driver
* @drv: the driver
*/
void cpuidle_unregister_driver(struct cpuidle_driver *drv)
{
int cpu;
cpu = get_cpu();
spin_lock(&cpuidle_driver_lock);
__cpuidle_unregister_driver(drv, cpu);
spin_unlock(&cpuidle_driver_lock);
put_cpu();
}
EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);
#endif
/**
* cpuidle_get_driver - return the current driver
*/
struct cpuidle_driver *cpuidle_get_driver(void)
{
struct cpuidle_driver *drv;
int cpu;
cpu = get_cpu();
drv = __cpuidle_get_cpu_driver(cpu);
put_cpu();
return drv;
}
EXPORT_SYMBOL_GPL(cpuidle_get_driver);
/**
* cpuidle_get_cpu_driver - return the driver tied with a cpu
*/
struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev)
{
if (!dev)
return NULL;
return __cpuidle_get_cpu_driver(dev->cpu);
}
EXPORT_SYMBOL_GPL(cpuidle_get_cpu_driver);
struct cpuidle_driver *cpuidle_driver_ref(void)
{
struct cpuidle_driver *drv;
spin_lock(&cpuidle_driver_lock);
drv = cpuidle_get_driver();
drv->refcnt++;
spin_unlock(&cpuidle_driver_lock);
return drv;
}
void cpuidle_driver_unref(void)
{
struct cpuidle_driver *drv = cpuidle_get_driver();
spin_lock(&cpuidle_driver_lock);
if (drv && !WARN_ON(drv->refcnt <= 0))
drv->refcnt--;
spin_unlock(&cpuidle_driver_lock);
}