[mirror_ubuntu-jammy-kernel.git] / kernel / time / clockevents.c

/*
 * linux/kernel/time/clockevents.c
 *
 * This file contains functions which manage clock event devices.
 *
 * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
 * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
 * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
 *
 * This code is licenced under the GPL version 2. For details see
 * kernel-base/COPYING.
 */

#include <linux/clockchips.h>
#include <linux/hrtimer.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/smp.h>

#include "tick-internal.h"

/* The registered clock event devices */
static LIST_HEAD(clockevent_devices);
static LIST_HEAD(clockevents_released);
/* Protection for the above */
static DEFINE_RAW_SPINLOCK(clockevents_lock);

/**
 * clockevents_delta2ns - Convert a latch value (device ticks) to nanoseconds
 * @latch:	value to convert
 * @evt:	pointer to clock event device descriptor
 *
 * Math helper, returns latch value converted to nanoseconds (bound checked)
 */
u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt)
{
	u64 clc = (u64) latch << evt->shift;

	if (unlikely(!evt->mult)) {
		evt->mult = 1;
		WARN_ON(1);
	}

	do_div(clc, evt->mult);
	if (clc < 1000)
		clc = 1000;
	if (clc > KTIME_MAX)
		clc = KTIME_MAX;

	return clc;
}
EXPORT_SYMBOL_GPL(clockevent_delta2ns);

/**
 * clockevents_set_mode - set the operating mode of a clock event device
 * @dev:	device to modify
 * @mode:	new mode
 *
 * Must be called with interrupts disabled !
 */
void clockevents_set_mode(struct clock_event_device *dev,
				 enum clock_event_mode mode)
{
	if (dev->mode != mode) {
		dev->set_mode(mode, dev);
		dev->mode = mode;

		/*
		 * A nsec2cyc multiplicator of 0 is invalid and we'd crash
		 * on it, so fix it up and emit a warning:
		 */
		if (mode == CLOCK_EVT_MODE_ONESHOT) {
			if (unlikely(!dev->mult)) {
				dev->mult = 1;
				WARN_ON(1);
			}
		}
	}
}

/**
 * clockevents_shutdown - shutdown the device and clear next_event
 * @dev:	device to shutdown
 */
void clockevents_shutdown(struct clock_event_device *dev)
{
	clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN);
	dev->next_event.tv64 = KTIME_MAX;
}

#ifdef CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST

/* Limit min_delta to a jiffie */
#define MIN_DELTA_LIMIT		(NSEC_PER_SEC / HZ)

/**
 * clockevents_increase_min_delta - raise minimum delta of a clock event device
 * @dev:       device to increase the minimum delta
 *
 * Returns 0 on success, -ETIME when the minimum delta reached the limit.
 */
static int clockevents_increase_min_delta(struct clock_event_device *dev)
{
	/* Nothing to do if we already reached the limit */
	if (dev->min_delta_ns >= MIN_DELTA_LIMIT) {
		printk(KERN_WARNING "CE: Reprogramming failure. Giving up\n");
		dev->next_event.tv64 = KTIME_MAX;
		return -ETIME;
	}

	if (dev->min_delta_ns < 5000)
		dev->min_delta_ns = 5000;
	else
		dev->min_delta_ns += dev->min_delta_ns >> 1;

	if (dev->min_delta_ns > MIN_DELTA_LIMIT)
		dev->min_delta_ns = MIN_DELTA_LIMIT;

	printk(KERN_WARNING "CE: %s increased min_delta_ns to %llu nsec\n",
	       dev->name ? dev->name : "?",
	       (unsigned long long) dev->min_delta_ns);
	return 0;
}

/**
 * clockevents_program_min_delta - Set clock event device to the minimum delay.
 * @dev:	device to program
 *
 * Returns 0 on success, -ETIME when the retry loop failed.
 */
static int clockevents_program_min_delta(struct clock_event_device *dev)
{
	unsigned long long clc;
	int64_t delta;
	int i;

	for (i = 0;;) {
		delta = dev->min_delta_ns;
		dev->next_event = ktime_add_ns(ktime_get(), delta);

		if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN)
			return 0;

		dev->retries++;
		clc = ((unsigned long long) delta * dev->mult) >> dev->shift;
		if (dev->set_next_event((unsigned long) clc, dev) == 0)
			return 0;

		if (++i > 2) {
			/*
			 * We tried 3 times to program the device with the
			 * given min_delta_ns. Try to increase the minimum
			 * delta, if that fails as well get out of here.
			 */
			if (clockevents_increase_min_delta(dev))
				return -ETIME;
			i = 0;
		}
	}
}

#else  /* CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST */

/**
 * clockevents_program_min_delta - Set clock event device to the minimum delay.
 * @dev:	device to program
 *
 * Returns 0 on success, -ETIME when the retry loop failed.
 */
static int clockevents_program_min_delta(struct clock_event_device *dev)
{
	unsigned long long clc;
	int64_t delta;

	delta = dev->min_delta_ns;
	dev->next_event = ktime_add_ns(ktime_get(), delta);

	if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN)
		return 0;

	dev->retries++;
	clc = ((unsigned long long) delta * dev->mult) >> dev->shift;
	return dev->set_next_event((unsigned long) clc, dev);
}

#endif /* CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST */

/**
 * clockevents_program_event - Reprogram the clock event device.
 * @dev:	device to program
 * @expires:	absolute expiry time (monotonic clock)
 * @force:	program minimum delay if expires can not be set
 *
 * Returns 0 on success, -ETIME when the event is in the past.
 */
int clockevents_program_event(struct clock_event_device *dev, ktime_t expires,
			      bool force)
{
	unsigned long long clc;
	int64_t delta;
	int rc;

	if (unlikely(expires.tv64 < 0)) {
		WARN_ON_ONCE(1);
		return -ETIME;
	}

	dev->next_event = expires;

	if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN)
		return 0;

	/* Shortcut for clockevent devices that can deal with ktime. */
	if (dev->features & CLOCK_EVT_FEAT_KTIME)
		return dev->set_next_ktime(expires, dev);

	delta = ktime_to_ns(ktime_sub(expires, ktime_get()));
	if (delta <= 0)
		return force ? clockevents_program_min_delta(dev) : -ETIME;

	delta = min(delta, (int64_t) dev->max_delta_ns);
	delta = max(delta, (int64_t) dev->min_delta_ns);

	clc = ((unsigned long long) delta * dev->mult) >> dev->shift;
	rc = dev->set_next_event((unsigned long) clc, dev);

	return (rc && force) ? clockevents_program_min_delta(dev) : rc;
}

/*
 * Called after a notify add to make devices available which were
 * released from the notifier call.
 */
static void clockevents_notify_released(void)
{
	struct clock_event_device *dev;

	while (!list_empty(&clockevents_released)) {
		dev = list_entry(clockevents_released.next,
				 struct clock_event_device, list);
		list_del(&dev->list);
		list_add(&dev->list, &clockevent_devices);
		tick_check_new_device(dev);
	}
}

/**
 * clockevents_register_device - register a clock event device
 * @dev:	device to register
 */
void clockevents_register_device(struct clock_event_device *dev)
{
	unsigned long flags;

	BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
	if (!dev->cpumask) {
		WARN_ON(num_possible_cpus() > 1);
		dev->cpumask = cpumask_of(smp_processor_id());
	}

	raw_spin_lock_irqsave(&clockevents_lock, flags);

	list_add(&dev->list, &clockevent_devices);
	tick_check_new_device(dev);
	clockevents_notify_released();

	raw_spin_unlock_irqrestore(&clockevents_lock, flags);
}
EXPORT_SYMBOL_GPL(clockevents_register_device);

void clockevents_config(struct clock_event_device *dev, u32 freq)
{
	u64 sec;

	if (!(dev->features & CLOCK_EVT_FEAT_ONESHOT))
		return;

	/*
	 * Calculate the maximum number of seconds we can sleep. Limit
	 * to 10 minutes for hardware which can program more than
	 * 32bit ticks so we still get reasonable conversion values.
	 */
	sec = dev->max_delta_ticks;
	do_div(sec, freq);
	if (!sec)
		sec = 1;
	else if (sec > 600 && dev->max_delta_ticks > UINT_MAX)
		sec = 600;

	clockevents_calc_mult_shift(dev, freq, sec);
	dev->min_delta_ns = clockevent_delta2ns(dev->min_delta_ticks, dev);
	dev->max_delta_ns = clockevent_delta2ns(dev->max_delta_ticks, dev);
}

/**
 * clockevents_config_and_register - Configure and register a clock event device
 * @dev:	device to register
 * @freq:	The clock frequency
 * @min_delta:	The minimum clock ticks to program in oneshot mode
 * @max_delta:	The maximum clock ticks to program in oneshot mode
 *
 * min/max_delta can be 0 for devices which do not support oneshot mode.
 */
void clockevents_config_and_register(struct clock_event_device *dev,
				     u32 freq, unsigned long min_delta,
				     unsigned long max_delta)
{
	dev->min_delta_ticks = min_delta;
	dev->max_delta_ticks = max_delta;
	clockevents_config(dev, freq);
	clockevents_register_device(dev);
}
EXPORT_SYMBOL_GPL(clockevents_config_and_register);

/**
 * clockevents_update_freq - Update frequency and reprogram a clock event device.
 * @dev:	device to modify
 * @freq:	new device frequency
 *
 * Reconfigure and reprogram a clock event device in oneshot
 * mode. Must be called on the cpu for which the device delivers per
 * cpu timer events with interrupts disabled!  Returns 0 on success,
 * -ETIME when the event is in the past.
 */
int clockevents_update_freq(struct clock_event_device *dev, u32 freq)
{
	clockevents_config(dev, freq);

	if (dev->mode != CLOCK_EVT_MODE_ONESHOT)
		return 0;

	return clockevents_program_event(dev, dev->next_event, false);
}

/*
 * Noop handler when we shut down an event device
 */
void clockevents_handle_noop(struct clock_event_device *dev)
{
}

/**
 * clockevents_exchange_device - release and request clock devices
 * @old:	device to release (can be NULL)
 * @new:	device to request (can be NULL)
 *
 * Called from the notifier chain. clockevents_lock is held already
 */
void clockevents_exchange_device(struct clock_event_device *old,
				 struct clock_event_device *new)
{
	unsigned long flags;

	local_irq_save(flags);
	/*
	 * Caller releases a clock event device. We queue it into the
	 * released list and do a notify add later.
	 */
	if (old) {
		module_put(old->owner);
		clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED);
		list_del(&old->list);
		list_add(&old->list, &clockevents_released);
	}

	if (new) {
		BUG_ON(new->mode != CLOCK_EVT_MODE_UNUSED);
		clockevents_shutdown(new);
	}
	local_irq_restore(flags);
}

/**
 * clockevents_suspend - suspend clock devices
 */
void clockevents_suspend(void)
{
	struct clock_event_device *dev;

	list_for_each_entry_reverse(dev, &clockevent_devices, list)
		if (dev->suspend)
			dev->suspend(dev);
}

/**
 * clockevents_resume - resume clock devices
 */
void clockevents_resume(void)
{
	struct clock_event_device *dev;

	list_for_each_entry(dev, &clockevent_devices, list)
		if (dev->resume)
			dev->resume(dev);
}

#ifdef CONFIG_GENERIC_CLOCKEVENTS
/**
 * clockevents_notify - notification about relevant events
 */
void clockevents_notify(unsigned long reason, void *arg)
{
	struct clock_event_device *dev, *tmp;
	unsigned long flags;
	int cpu;

	raw_spin_lock_irqsave(&clockevents_lock, flags);

	switch (reason) {
	case CLOCK_EVT_NOTIFY_BROADCAST_ON:
	case CLOCK_EVT_NOTIFY_BROADCAST_OFF:
	case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
		tick_broadcast_on_off(reason, arg);
		break;

	case CLOCK_EVT_NOTIFY_BROADCAST_ENTER:
	case CLOCK_EVT_NOTIFY_BROADCAST_EXIT:
		tick_broadcast_oneshot_control(reason);
		break;

	case CLOCK_EVT_NOTIFY_CPU_DYING:
		tick_handover_do_timer(arg);
		break;

	case CLOCK_EVT_NOTIFY_SUSPEND:
		tick_suspend();
		tick_suspend_broadcast();
		break;

	case CLOCK_EVT_NOTIFY_RESUME:
		tick_resume();
		break;

	case CLOCK_EVT_NOTIFY_CPU_DEAD:
		tick_shutdown_broadcast_oneshot(arg);
		tick_shutdown_broadcast(arg);
		tick_shutdown(arg);
		/*
		 * Unregister the clock event devices which were
		 * released from the users in the notify chain.
		 */
		list_for_each_entry_safe(dev, tmp, &clockevents_released, list)
			list_del(&dev->list);
		/*
		 * Now check whether the CPU has left unused per cpu devices
		 */
		cpu = *((int *)arg);
		list_for_each_entry_safe(dev, tmp, &clockevent_devices, list) {
			if (cpumask_test_cpu(cpu, dev->cpumask) &&
			    cpumask_weight(dev->cpumask) == 1 &&
			    !tick_is_broadcast_device(dev)) {
				BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
				list_del(&dev->list);
			}
		}
		break;
	default:
		break;
	}
	raw_spin_unlock_irqrestore(&clockevents_lock, flags);
}
EXPORT_SYMBOL_GPL(clockevents_notify);
#endif
Commit	Line	Data
d316c57f TG	1	/*
	2	* linux/kernel/time/clockevents.c
	3	*
	4	* This file contains functions which manage clock event devices.
	5	*
	6	* Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
	7	* Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
	8	* Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
	9	*
	10	* This code is licenced under the GPL version 2. For details see
	11	* kernel-base/COPYING.
	12	*/
	13
	14	#include <linux/clockchips.h>
	15	#include <linux/hrtimer.h>
	16	#include <linux/init.h>
	17	#include <linux/module.h>
d316c57f	18	#include <linux/smp.h>
d316c57f	19
8e1a928a HS	20	#include "tick-internal.h"
8e1a928a HS	21
d316c57f TG	22	/* The registered clock event devices */
	23	static LIST_HEAD(clockevent_devices);
	24	static LIST_HEAD(clockevents_released);
d316c57f	25	/* Protection for the above */
b5f91da0	26	static DEFINE_RAW_SPINLOCK(clockevents_lock);
d316c57f TG	27
	28	/**
	29	* clockevents_delta2ns - Convert a latch value (device ticks) to nanoseconds
	30	* @latch: value to convert
	31	* @evt: pointer to clock event device descriptor
	32	*
	33	* Math helper, returns latch value converted to nanoseconds (bound checked)
	34	*/
97813f2f	35	u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt)
d316c57f	36	{
97813f2f	37	u64 clc = (u64) latch << evt->shift;
d316c57f	38
45fe4fe1 IM	39	if (unlikely(!evt->mult)) {
	40	evt->mult = 1;
	41	WARN_ON(1);
	42	}
	43
d316c57f TG	44	do_div(clc, evt->mult);
	45	if (clc < 1000)
	46	clc = 1000;
97813f2f JH	47	if (clc > KTIME_MAX)
97813f2f JH	48	clc = KTIME_MAX;
d316c57f	49
97813f2f	50	return clc;
d316c57f	51	}
c81fc2c3	52	EXPORT_SYMBOL_GPL(clockevent_delta2ns);
d316c57f TG	53
	54	/**
	55	* clockevents_set_mode - set the operating mode of a clock event device
	56	* @dev: device to modify
	57	* @mode: new mode
	58	*
	59	* Must be called with interrupts disabled !
	60	*/
	61	void clockevents_set_mode(struct clock_event_device *dev,
	62	enum clock_event_mode mode)
	63	{
	64	if (dev->mode != mode) {
	65	dev->set_mode(mode, dev);
	66	dev->mode = mode;
2d68259d MD	67
	68	/*
	69	* A nsec2cyc multiplicator of 0 is invalid and we'd crash
	70	* on it, so fix it up and emit a warning:
	71	*/
	72	if (mode == CLOCK_EVT_MODE_ONESHOT) {
	73	if (unlikely(!dev->mult)) {
	74	dev->mult = 1;
	75	WARN_ON(1);
	76	}
	77	}
d316c57f TG	78	}
	79	}
	80
2344abbc TG	81	/**
	82	* clockevents_shutdown - shutdown the device and clear next_event
	83	* @dev: device to shutdown
	84	*/
	85	void clockevents_shutdown(struct clock_event_device *dev)
	86	{
	87	clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN);
	88	dev->next_event.tv64 = KTIME_MAX;
	89	}
	90
d1748302 MS	91	#ifdef CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST
	92
	93	/* Limit min_delta to a jiffie */
	94	#define MIN_DELTA_LIMIT (NSEC_PER_SEC / HZ)
	95
	96	/**
	97	* clockevents_increase_min_delta - raise minimum delta of a clock event device
	98	* @dev: device to increase the minimum delta
	99	*
	100	* Returns 0 on success, -ETIME when the minimum delta reached the limit.
	101	*/
	102	static int clockevents_increase_min_delta(struct clock_event_device *dev)
	103	{
	104	/* Nothing to do if we already reached the limit */
	105	if (dev->min_delta_ns >= MIN_DELTA_LIMIT) {
	106	printk(KERN_WARNING "CE: Reprogramming failure. Giving up\n");
	107	dev->next_event.tv64 = KTIME_MAX;
	108	return -ETIME;
	109	}
	110
	111	if (dev->min_delta_ns < 5000)
	112	dev->min_delta_ns = 5000;
	113	else
	114	dev->min_delta_ns += dev->min_delta_ns >> 1;
	115
	116	if (dev->min_delta_ns > MIN_DELTA_LIMIT)
	117	dev->min_delta_ns = MIN_DELTA_LIMIT;
	118
	119	printk(KERN_WARNING "CE: %s increased min_delta_ns to %llu nsec\n",
	120	dev->name ? dev->name : "?",
	121	(unsigned long long) dev->min_delta_ns);
	122	return 0;
	123	}
	124
	125	/**
	126	* clockevents_program_min_delta - Set clock event device to the minimum delay.
	127	* @dev: device to program
	128	*
	129	* Returns 0 on success, -ETIME when the retry loop failed.
	130	*/
	131	static int clockevents_program_min_delta(struct clock_event_device *dev)
	132	{
	133	unsigned long long clc;
	134	int64_t delta;
	135	int i;
	136
	137	for (i = 0;;) {
	138	delta = dev->min_delta_ns;
	139	dev->next_event = ktime_add_ns(ktime_get(), delta);
	140
	141	if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN)
	142	return 0;
	143
	144	dev->retries++;
	145	clc = ((unsigned long long) delta * dev->mult) >> dev->shift;
	146	if (dev->set_next_event((unsigned long) clc, dev) == 0)
	147	return 0;
	148
	149	if (++i > 2) {
	150	/*
	151	* We tried 3 times to program the device with the
	152	* given min_delta_ns. Try to increase the minimum
	153	* delta, if that fails as well get out of here.
	154	*/
155	if (clockevents_increase_min_delta(dev))
156	return -ETIME;
157	i = 0;
158	}
159	}
160	}
161
162	#else /* CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST */
163
164	/**
165	* clockevents_program_min_delta - Set clock event device to the minimum delay.
166	* @dev: device to program
167	*
168	* Returns 0 on success, -ETIME when the retry loop failed.
169	*/
170	static int clockevents_program_min_delta(struct clock_event_device *dev)
171	{
172	unsigned long long clc;
173	int64_t delta;
174
175	delta = dev->min_delta_ns;
176	dev->next_event = ktime_add_ns(ktime_get(), delta);
177
178	if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN)
179	return 0;
180
181	dev->retries++;
182	clc = ((unsigned long long) delta * dev->mult) >> dev->shift;
183	return dev->set_next_event((unsigned long) clc, dev);
184	}
185
186	#endif /* CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST */
187
d316c57f TG	188	/**
d316c57f TG	189	* clockevents_program_event - Reprogram the clock event device.
d1748302	190	* @dev: device to program
d316c57f	191	* @expires: absolute expiry time (monotonic clock)
d1748302	192	* @force: program minimum delay if expires can not be set
d316c57f TG	193	*
	194	* Returns 0 on success, -ETIME when the event is in the past.
	195	*/
	196	int clockevents_program_event(struct clock_event_device *dev, ktime_t expires,
d1748302	197	bool force)
d316c57f TG	198	{
	199	unsigned long long clc;
	200	int64_t delta;
d1748302	201	int rc;
d316c57f	202
167b1de3 TG	203	if (unlikely(expires.tv64 < 0)) {
	204	WARN_ON_ONCE(1);
	205	return -ETIME;
	206	}
	207
d316c57f TG	208	dev->next_event = expires;
	209
	210	if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN)
	211	return 0;
	212
65516f8a MS	213	/* Shortcut for clockevent devices that can deal with ktime. */
	214	if (dev->features & CLOCK_EVT_FEAT_KTIME)
	215	return dev->set_next_ktime(expires, dev);
	216
d1748302 MS	217	delta = ktime_to_ns(ktime_sub(expires, ktime_get()));
	218	if (delta <= 0)
	219	return force ? clockevents_program_min_delta(dev) : -ETIME;
d316c57f	220
d1748302 MS	221	delta = min(delta, (int64_t) dev->max_delta_ns);
d1748302 MS	222	delta = max(delta, (int64_t) dev->min_delta_ns);
d316c57f	223
d1748302 MS	224	clc = ((unsigned long long) delta * dev->mult) >> dev->shift;
	225	rc = dev->set_next_event((unsigned long) clc, dev);
	226
	227	return (rc && force) ? clockevents_program_min_delta(dev) : rc;
d316c57f TG	228	}
d316c57f TG	229
d316c57f	230	/*
3eb05676	231	* Called after a notify add to make devices available which were
d316c57f TG	232	* released from the notifier call.
	233	*/
	234	static void clockevents_notify_released(void)
	235	{
	236	struct clock_event_device *dev;
	237
	238	while (!list_empty(&clockevents_released)) {
	239	dev = list_entry(clockevents_released.next,
	240	struct clock_event_device, list);
	241	list_del(&dev->list);
	242	list_add(&dev->list, &clockevent_devices);
7172a286	243	tick_check_new_device(dev);
d316c57f TG	244	}
	245	}
	246
	247	/**
	248	* clockevents_register_device - register a clock event device
	249	* @dev: device to register
	250	*/
	251	void clockevents_register_device(struct clock_event_device *dev)
	252	{
f833bab8 SS	253	unsigned long flags;
f833bab8 SS	254
d316c57f	255	BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
1b054b67 TG	256	if (!dev->cpumask) {
	257	WARN_ON(num_possible_cpus() > 1);
	258	dev->cpumask = cpumask_of(smp_processor_id());
	259	}
320ab2b0	260
b5f91da0	261	raw_spin_lock_irqsave(&clockevents_lock, flags);
d316c57f TG	262
d316c57f TG	263	list_add(&dev->list, &clockevent_devices);
7172a286	264	tick_check_new_device(dev);
d316c57f TG	265	clockevents_notify_released();
d316c57f TG	266
b5f91da0	267	raw_spin_unlock_irqrestore(&clockevents_lock, flags);
d316c57f	268	}
c81fc2c3	269	EXPORT_SYMBOL_GPL(clockevents_register_device);
d316c57f	270
e5400321	271	void clockevents_config(struct clock_event_device *dev, u32 freq)
57f0fcbe	272	{
c0e299b1	273	u64 sec;
57f0fcbe TG	274
	275	if (!(dev->features & CLOCK_EVT_FEAT_ONESHOT))
	276	return;
	277
	278	/*
	279	* Calculate the maximum number of seconds we can sleep. Limit
	280	* to 10 minutes for hardware which can program more than
	281	* 32bit ticks so we still get reasonable conversion values.
	282	*/
	283	sec = dev->max_delta_ticks;
	284	do_div(sec, freq);
	285	if (!sec)
	286	sec = 1;
	287	else if (sec > 600 && dev->max_delta_ticks > UINT_MAX)
	288	sec = 600;
	289
	290	clockevents_calc_mult_shift(dev, freq, sec);
	291	dev->min_delta_ns = clockevent_delta2ns(dev->min_delta_ticks, dev);
	292	dev->max_delta_ns = clockevent_delta2ns(dev->max_delta_ticks, dev);
	293	}
	294
	295	/**
	296	* clockevents_config_and_register - Configure and register a clock event device
	297	* @dev: device to register
	298	* @freq: The clock frequency
	299	* @min_delta: The minimum clock ticks to program in oneshot mode
	300	* @max_delta: The maximum clock ticks to program in oneshot mode
	301	*
	302	* min/max_delta can be 0 for devices which do not support oneshot mode.
	303	*/
	304	void clockevents_config_and_register(struct clock_event_device *dev,
	305	u32 freq, unsigned long min_delta,
	306	unsigned long max_delta)
	307	{
	308	dev->min_delta_ticks = min_delta;
	309	dev->max_delta_ticks = max_delta;
	310	clockevents_config(dev, freq);
	311	clockevents_register_device(dev);
	312	}
c35ef95c	313	EXPORT_SYMBOL_GPL(clockevents_config_and_register);
57f0fcbe	314
80b816b7 TG	315	/**
	316	* clockevents_update_freq - Update frequency and reprogram a clock event device.
	317	* @dev: device to modify
	318	* @freq: new device frequency
	319	*
	320	* Reconfigure and reprogram a clock event device in oneshot
	321	* mode. Must be called on the cpu for which the device delivers per
	322	* cpu timer events with interrupts disabled! Returns 0 on success,
	323	* -ETIME when the event is in the past.
	324	*/
	325	int clockevents_update_freq(struct clock_event_device *dev, u32 freq)
	326	{
	327	clockevents_config(dev, freq);
	328
	329	if (dev->mode != CLOCK_EVT_MODE_ONESHOT)
	330	return 0;
	331
d1748302	332	return clockevents_program_event(dev, dev->next_event, false);
80b816b7 TG	333	}
80b816b7 TG	334
d316c57f TG	335	/*
	336	* Noop handler when we shut down an event device
	337	*/
7c1e7689	338	void clockevents_handle_noop(struct clock_event_device *dev)
d316c57f TG	339	{
	340	}
	341
	342	/**
	343	* clockevents_exchange_device - release and request clock devices
	344	* @old: device to release (can be NULL)
	345	* @new: device to request (can be NULL)
	346	*
	347	* Called from the notifier chain. clockevents_lock is held already
	348	*/
	349	void clockevents_exchange_device(struct clock_event_device *old,
	350	struct clock_event_device *new)
	351	{
	352	unsigned long flags;
	353
	354	local_irq_save(flags);
	355	/*
	356	* Caller releases a clock event device. We queue it into the
	357	* released list and do a notify add later.
	358	*/
	359	if (old) {
ccf33d68	360	module_put(old->owner);
d316c57f TG	361	clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED);
	362	list_del(&old->list);
	363	list_add(&old->list, &clockevents_released);
	364	}
	365
	366	if (new) {
	367	BUG_ON(new->mode != CLOCK_EVT_MODE_UNUSED);
2344abbc	368	clockevents_shutdown(new);
d316c57f TG	369	}
	370	local_irq_restore(flags);
	371	}
	372
adc78e6b RW	373	/**
	374	* clockevents_suspend - suspend clock devices
	375	*/
	376	void clockevents_suspend(void)
	377	{
	378	struct clock_event_device *dev;
	379
	380	list_for_each_entry_reverse(dev, &clockevent_devices, list)
	381	if (dev->suspend)
	382	dev->suspend(dev);
	383	}
	384
	385	/**
	386	* clockevents_resume - resume clock devices
	387	*/
	388	void clockevents_resume(void)
	389	{
	390	struct clock_event_device *dev;
	391
	392	list_for_each_entry(dev, &clockevent_devices, list)
	393	if (dev->resume)
	394	dev->resume(dev);
	395	}
	396
de68d9b1	397	#ifdef CONFIG_GENERIC_CLOCKEVENTS
d316c57f TG	398	/**
	399	* clockevents_notify - notification about relevant events
	400	*/
	401	void clockevents_notify(unsigned long reason, void *arg)
	402	{
bb6eddf7	403	struct clock_event_device dev, tmp;
f833bab8	404	unsigned long flags;
bb6eddf7	405	int cpu;
0b858e6f	406
b5f91da0	407	raw_spin_lock_irqsave(&clockevents_lock, flags);
d316c57f TG	408
d316c57f TG	409	switch (reason) {
8c53daf6 TG	410	case CLOCK_EVT_NOTIFY_BROADCAST_ON:
	411	case CLOCK_EVT_NOTIFY_BROADCAST_OFF:
	412	case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
	413	tick_broadcast_on_off(reason, arg);
	414	break;
	415
	416	case CLOCK_EVT_NOTIFY_BROADCAST_ENTER:
	417	case CLOCK_EVT_NOTIFY_BROADCAST_EXIT:
	418	tick_broadcast_oneshot_control(reason);
	419	break;
	420
	421	case CLOCK_EVT_NOTIFY_CPU_DYING:
	422	tick_handover_do_timer(arg);
	423	break;
	424
	425	case CLOCK_EVT_NOTIFY_SUSPEND:
	426	tick_suspend();
	427	tick_suspend_broadcast();
	428	break;
	429
	430	case CLOCK_EVT_NOTIFY_RESUME:
	431	tick_resume();
	432	break;
	433
d316c57f	434	case CLOCK_EVT_NOTIFY_CPU_DEAD:
8c53daf6 TG	435	tick_shutdown_broadcast_oneshot(arg);
	436	tick_shutdown_broadcast(arg);
	437	tick_shutdown(arg);
d316c57f TG	438	/*
	439	* Unregister the clock event devices which were
	440	* released from the users in the notify chain.
	441	*/
bb6eddf7 TG	442	list_for_each_entry_safe(dev, tmp, &clockevents_released, list)
	443	list_del(&dev->list);
	444	/*
	445	* Now check whether the CPU has left unused per cpu devices
	446	*/
	447	cpu = ((int )arg);
	448	list_for_each_entry_safe(dev, tmp, &clockevent_devices, list) {
	449	if (cpumask_test_cpu(cpu, dev->cpumask) &&
ea9d8e3f XF	450	cpumask_weight(dev->cpumask) == 1 &&
ea9d8e3f XF	451	!tick_is_broadcast_device(dev)) {
bb6eddf7 TG	452	BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
	453	list_del(&dev->list);
	454	}
	455	}
d316c57f TG	456	break;
	457	default:
	458	break;
	459	}
b5f91da0	460	raw_spin_unlock_irqrestore(&clockevents_lock, flags);
d316c57f TG	461	}
d316c57f TG	462	EXPORT_SYMBOL_GPL(clockevents_notify);
de68d9b1	463	#endif