[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / cpuidle / driver.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);
}
Commit	Line	Data
4f86d3a8 LB	1	/*
	2	* driver.c - driver support
	3	*
	4	* (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
	5	* Shaohua Li <shaohua.li@intel.com>
	6	* Adam Belay <abelay@novell.com>
	7	*
	8	* This code is licenced under the GPL.
	9	*/
	10
	11	#include <linux/mutex.h>
	12	#include <linux/module.h>
	13	#include <linux/cpuidle.h>
a06df062 DL	14	#include <linux/cpumask.h>
a06df062 DL	15	#include <linux/clockchips.h>
4f86d3a8 LB	16
	17	#include "cpuidle.h"
	18
4f86d3a8 LB	19	DEFINE_SPINLOCK(cpuidle_driver_lock);
4f86d3a8 LB	20
bf4d1b5d DL	21	static void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu);
	22	static struct cpuidle_driver * __cpuidle_get_cpu_driver(int cpu);
	23
a06df062	24	static void cpuidle_setup_broadcast_timer(void *arg)
13dd52f1	25	{
a06df062 DL	26	int cpu = smp_processor_id();
	27	clockevents_notify((long)(arg), &cpu);
	28	}
	29
	30	static void __cpuidle_driver_init(struct cpuidle_driver *drv, int cpu)
	31	{
	32	int i;
	33
13dd52f1	34	drv->refcnt = 0;
a06df062 DL	35
	36	for (i = drv->state_count - 1; i >= 0 ; i--) {
	37
	38	if (!(drv->states[i].flags & CPUIDLE_FLAG_TIMER_STOP))
	39	continue;
	40
	41	drv->bctimer = 1;
	42	on_each_cpu_mask(get_cpu_mask(cpu), cpuidle_setup_broadcast_timer,
	43	(void *)CLOCK_EVT_NOTIFY_BROADCAST_ON, 1);
	44	break;
	45	}
13dd52f1 DL	46	}
13dd52f1 DL	47
bf4d1b5d	48	static int __cpuidle_register_driver(struct cpuidle_driver *drv, int cpu)
4f86d3a8	49	{
fc850f39	50	if (!drv \|\| !drv->state_count)
4f86d3a8 LB	51	return -EINVAL;
4f86d3a8 LB	52
62027aea LB	53	if (cpuidle_disabled())
	54	return -ENODEV;
	55
bf4d1b5d	56	if (__cpuidle_get_cpu_driver(cpu))
4f86d3a8	57	return -EBUSY;
ed953472	58
a06df062	59	__cpuidle_driver_init(drv, cpu);
ed953472	60
bf4d1b5d	61	__cpuidle_set_cpu_driver(drv, cpu);
42f67f2a	62
13dd52f1 DL	63	return 0;
	64	}
	65
bf4d1b5d	66	static void __cpuidle_unregister_driver(struct cpuidle_driver *drv, int cpu)
13dd52f1	67	{
bf4d1b5d	68	if (drv != __cpuidle_get_cpu_driver(cpu))
13dd52f1 DL	69	return;
	70
	71	if (!WARN_ON(drv->refcnt > 0))
bf4d1b5d	72	__cpuidle_set_cpu_driver(NULL, cpu);
a06df062 DL	73
	74	if (drv->bctimer) {
	75	drv->bctimer = 0;
	76	on_each_cpu_mask(get_cpu_mask(cpu), cpuidle_setup_broadcast_timer,
	77	(void *)CLOCK_EVT_NOTIFY_BROADCAST_OFF, 1);
	78	}
bf4d1b5d DL	79	}
	80
	81	#ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
	82
	83	static DEFINE_PER_CPU(struct cpuidle_driver *, cpuidle_drivers);
	84
	85	static void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu)
	86	{
	87	per_cpu(cpuidle_drivers, cpu) = drv;
	88	}
	89
	90	static struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu)
	91	{
	92	return per_cpu(cpuidle_drivers, cpu);
	93	}
	94
	95	static void __cpuidle_unregister_all_cpu_driver(struct cpuidle_driver *drv)
	96	{
	97	int cpu;
	98	for_each_present_cpu(cpu)
	99	__cpuidle_unregister_driver(drv, cpu);
	100	}
	101
	102	static int __cpuidle_register_all_cpu_driver(struct cpuidle_driver *drv)
	103	{
	104	int ret = 0;
	105	int i, cpu;
	106
	107	for_each_present_cpu(cpu) {
	108	ret = __cpuidle_register_driver(drv, cpu);
	109	if (ret)
	110	break;
	111	}
	112
	113	if (ret)
	114	for_each_present_cpu(i) {
	115	if (i == cpu)
	116	break;
	117	__cpuidle_unregister_driver(drv, i);
	118	}
	119
	120
	121	return ret;
	122	}
	123
	124	int cpuidle_register_cpu_driver(struct cpuidle_driver *drv, int cpu)
	125	{
	126	int ret;
	127
	128	spin_lock(&cpuidle_driver_lock);
	129	ret = __cpuidle_register_driver(drv, cpu);
	130	spin_unlock(&cpuidle_driver_lock);
	131
	132	return ret;
	133	}
	134
	135	void cpuidle_unregister_cpu_driver(struct cpuidle_driver *drv, int cpu)
	136	{
	137	spin_lock(&cpuidle_driver_lock);
	138	__cpuidle_unregister_driver(drv, cpu);
	139	spin_unlock(&cpuidle_driver_lock);
13dd52f1	140	}
ed953472	141
13dd52f1 DL	142	/**
	143	* cpuidle_register_driver - registers a driver
	144	* @drv: the driver
	145	*/
	146	int cpuidle_register_driver(struct cpuidle_driver *drv)
	147	{
	148	int ret;
	149
	150	spin_lock(&cpuidle_driver_lock);
bf4d1b5d	151	ret = __cpuidle_register_all_cpu_driver(drv);
4f86d3a8 LB	152	spin_unlock(&cpuidle_driver_lock);
4f86d3a8 LB	153
13dd52f1	154	return ret;
4f86d3a8	155	}
4f86d3a8 LB	156	EXPORT_SYMBOL_GPL(cpuidle_register_driver);
4f86d3a8 LB	157
752138df	158	/**
bf4d1b5d DL	159	* cpuidle_unregister_driver - unregisters a driver
bf4d1b5d DL	160	* @drv: the driver
752138df	161	*/
bf4d1b5d DL	162	void cpuidle_unregister_driver(struct cpuidle_driver *drv)
	163	{
	164	spin_lock(&cpuidle_driver_lock);
	165	__cpuidle_unregister_all_cpu_driver(drv);
	166	spin_unlock(&cpuidle_driver_lock);
	167	}
	168	EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);
	169
	170	#else
	171
	172	static struct cpuidle_driver *cpuidle_curr_driver;
	173
	174	static inline void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu)
	175	{
	176	cpuidle_curr_driver = drv;
	177	}
	178
	179	static inline struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu)
752138df LB	180	{
	181	return cpuidle_curr_driver;
	182	}
bf4d1b5d DL	183
	184	/**
	185	* cpuidle_register_driver - registers a driver
	186	* @drv: the driver
	187	*/
	188	int cpuidle_register_driver(struct cpuidle_driver *drv)
	189	{
	190	int ret, cpu;
	191
	192	cpu = get_cpu();
	193	spin_lock(&cpuidle_driver_lock);
	194	ret = __cpuidle_register_driver(drv, cpu);
	195	spin_unlock(&cpuidle_driver_lock);
	196	put_cpu();
	197
	198	return ret;
	199	}
	200	EXPORT_SYMBOL_GPL(cpuidle_register_driver);
752138df	201
4f86d3a8 LB	202	/**
	203	* cpuidle_unregister_driver - unregisters a driver
	204	* @drv: the driver
	205	*/
	206	void cpuidle_unregister_driver(struct cpuidle_driver *drv)
	207	{
bf4d1b5d DL	208	int cpu;
	209
	210	cpu = get_cpu();
4f86d3a8	211	spin_lock(&cpuidle_driver_lock);
bf4d1b5d	212	__cpuidle_unregister_driver(drv, cpu);
4f86d3a8	213	spin_unlock(&cpuidle_driver_lock);
bf4d1b5d	214	put_cpu();
4f86d3a8	215	}
4f86d3a8	216	EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);
bf4d1b5d DL	217	#endif
	218
	219	/**
	220	* cpuidle_get_driver - return the current driver
	221	*/
	222	struct cpuidle_driver *cpuidle_get_driver(void)
	223	{
	224	struct cpuidle_driver *drv;
	225	int cpu;
	226
	227	cpu = get_cpu();
	228	drv = __cpuidle_get_cpu_driver(cpu);
	229	put_cpu();
	230
	231	return drv;
	232	}
	233	EXPORT_SYMBOL_GPL(cpuidle_get_driver);
	234
	235	/**
	236	* cpuidle_get_cpu_driver - return the driver tied with a cpu
	237	*/
	238	struct cpuidle_driver cpuidle_get_cpu_driver(struct cpuidle_device dev)
	239	{
bf4d1b5d DL	240	if (!dev)
	241	return NULL;
	242
ac34d7c8	243	return __cpuidle_get_cpu_driver(dev->cpu);
bf4d1b5d DL	244	}
bf4d1b5d DL	245	EXPORT_SYMBOL_GPL(cpuidle_get_cpu_driver);
6e797a07 RW	246
	247	struct cpuidle_driver *cpuidle_driver_ref(void)
	248	{
	249	struct cpuidle_driver *drv;
	250
	251	spin_lock(&cpuidle_driver_lock);
	252
13dd52f1	253	drv = cpuidle_get_driver();
42f67f2a	254	drv->refcnt++;
6e797a07 RW	255
	256	spin_unlock(&cpuidle_driver_lock);
	257	return drv;
	258	}
	259
	260	void cpuidle_driver_unref(void)
	261	{
13dd52f1	262	struct cpuidle_driver *drv = cpuidle_get_driver();
42f67f2a	263
6e797a07 RW	264	spin_lock(&cpuidle_driver_lock);
6e797a07 RW	265
42f67f2a DL	266	if (drv && !WARN_ON(drv->refcnt <= 0))
42f67f2a DL	267	drv->refcnt--;
6e797a07 RW	268
	269	spin_unlock(&cpuidle_driver_lock);
	270	}