/*
* Setup the device for a periodic tick
*/
void tick_setup_periodic(struct clock_event_device *dev, int broadcast)
{
tick_set_periodic_handler(dev, broadcast);
/* Broadcast setup ? */
if (!tick_device_is_functional(dev))
return;
if ((dev->features & CLOCK_EVT_FEAT_PERIODIC) &&
!tick_broadcast_oneshot_active()) {
clockevents_set_mode(dev, CLOCK_EVT_MODE_PERIODIC);
} else {
unsigned long seq;
ktime_t next;
do {
seq = read_seqcount_begin(&xtime_seq);
next = tick_next_period;
} while (read_seqcount_retry(&xtime_seq, seq));
clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
for (;;) {
if (!clockevents_program_event(dev, next, ktime_get()))
return;
next = ktime_add(next, tick_period);
}
}
}
/*
* Powerstate information: The system enters/leaves a state, where
* affected devices might stop
*/
static void tick_do_broadcast_on_off(void *why)
{
struct clock_event_device *bc, *dev;
struct tick_device *td;
unsigned long flags, *reason = why;
int cpu;
spin_lock_irqsave(&tick_broadcast_lock, flags);
cpu = smp_processor_id();
td = &per_cpu(tick_cpu_device, cpu);
dev = td->evtdev;
bc = tick_broadcast_device.evtdev;
/*
* Is the device in broadcast mode forever or is it not
* affected by the powerstate ?
*/
if (!dev || !tick_device_is_functional(dev) ||
!(dev->features & CLOCK_EVT_FEAT_C3STOP))
goto out;
if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_ON) {
if (!cpu_isset(cpu, tick_broadcast_mask)) {
cpu_set(cpu, tick_broadcast_mask);
if (td->mode == TICKDEV_MODE_PERIODIC)
clockevents_set_mode(dev,
CLOCK_EVT_MODE_SHUTDOWN);
}
} else {
if (cpu_isset(cpu, tick_broadcast_mask)) {
cpu_clear(cpu, tick_broadcast_mask);
if (td->mode == TICKDEV_MODE_PERIODIC)
tick_setup_periodic(dev, 0);
}
}
if (cpus_empty(tick_broadcast_mask))
clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
else {
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
tick_broadcast_start_periodic(bc);
else
tick_broadcast_setup_oneshot(bc);
}
out:
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}
int tick_resume_broadcast(void)
{
struct clock_event_device *bc;
unsigned long flags;
int broadcast = 0;
spin_lock_irqsave(&tick_broadcast_lock, flags);
bc = tick_broadcast_device.evtdev;
if (bc) {
clockevents_set_mode(bc, CLOCK_EVT_MODE_RESUME);
switch (tick_broadcast_device.mode) {
case TICKDEV_MODE_PERIODIC:
if (!cpumask_empty(tick_get_broadcast_mask()))
tick_broadcast_start_periodic(bc);
broadcast = cpumask_test_cpu(smp_processor_id(),
tick_get_broadcast_mask());
break;
case TICKDEV_MODE_ONESHOT:
broadcast = tick_resume_broadcast_oneshot(bc);
break;
}
}
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
return broadcast;
}
/**
* tick_switch_to_oneshot - switch to oneshot mode
*/
int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *))
{
struct tick_device *td = &__get_cpu_var(tick_cpu_device);
struct clock_event_device *dev = td->evtdev;
if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT) ||
!tick_device_is_functional(dev)) {
printk(KERN_INFO "Clockevents: "
"could not switch to one-shot mode:");
if (!dev) {
printk(" no tick device\n");
} else {
if (!tick_device_is_functional(dev))
printk(" %s is not functional.\n", dev->name);
else
printk(" %s does not support one-shot mode.\n",
dev->name);
}
return -EINVAL;
}
td->mode = TICKDEV_MODE_ONESHOT;
dev->event_handler = handler;
clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
tick_broadcast_switch_to_oneshot();
return 0;
}
/*
* Called from irq_enter() when idle was interrupted to reenable the
* per cpu device.
*/
void tick_check_oneshot_broadcast(int cpu)
{
if (cpumask_test_cpu(cpu, to_cpumask(tick_broadcast_oneshot_mask))) {
struct tick_device *td = &per_cpu(tick_cpu_device, cpu);
clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_ONESHOT);
}
}
/**
* tick_setup_oneshot - setup the event device for oneshot mode (hres or nohz)
*/
void tick_setup_oneshot(struct clock_event_device *newdev,
void (*handler)(struct clock_event_device *),
ktime_t next_event)
{
newdev->event_handler = handler;
clockevents_set_mode(newdev, CLOCK_EVT_MODE_ONESHOT);
clockevents_program_event(newdev, next_event, ktime_get());
}
/**
* tick_resume_onshot - resume oneshot mode
*/
void tick_resume_oneshot(void)
{
struct tick_device *td = &__get_cpu_var(tick_cpu_device);
struct clock_event_device *dev = td->evtdev;
clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
tick_program_event(ktime_get(), 1);
}
static int tick_broadcast_set_event(ktime_t expires, int force)
{
struct clock_event_device *bc = tick_broadcast_device.evtdev;
if (bc->mode != CLOCK_EVT_MODE_ONESHOT)
clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
return clockevents_program_event(bc, expires, force);
}
static void tick_suspend(void)
{
struct tick_device *td = &__get_cpu_var(tick_cpu_device);
unsigned long flags;
spin_lock_irqsave(&tick_device_lock, flags);
clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_SHUTDOWN);
spin_unlock_irqrestore(&tick_device_lock, flags);
}
int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
{
clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
if(!cpus_empty(tick_broadcast_oneshot_mask))
tick_broadcast_set_event(ktime_get(), 1);
return cpu_isset(smp_processor_id(), tick_broadcast_oneshot_mask);
}
static int tick_broadcast_set_event(struct clock_event_device *bc, int cpu,
ktime_t expires, int force)
{
int ret;
if (bc->mode != CLOCK_EVT_MODE_ONESHOT)
clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
ret = clockevents_program_event(bc, expires, force);
if (!ret)
tick_broadcast_set_affinity(bc, cpumask_of(cpu));
return ret;
}
void tick_suspend_broadcast(void)
{
struct clock_event_device *bc;
unsigned long flags;
spin_lock_irqsave(&tick_broadcast_lock, flags);
bc = tick_broadcast_device.evtdev;
if (bc && tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}
void tick_resume(void)
{
struct tick_device *td = &__get_cpu_var(tick_cpu_device);
int broadcast = tick_resume_broadcast();
clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_RESUME);
if (!broadcast) {
if (td->mode == TICKDEV_MODE_PERIODIC)
tick_setup_periodic(td->evtdev, 0);
else
tick_resume_oneshot();
}
}
/**
* tick_switch_to_oneshot - switch to oneshot mode
*/
int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *))
{
struct tick_device *td = &__get_cpu_var(tick_cpu_device);
struct clock_event_device *dev = td->evtdev;
if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT) ||
!tick_device_is_functional(dev))
return -EINVAL;
td->mode = TICKDEV_MODE_ONESHOT;
dev->event_handler = handler;
clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
tick_broadcast_switch_to_oneshot();
return 0;
}
/*
* Called from irq_enter() when idle was interrupted to reenable the
* per cpu device.
*/
void tick_check_oneshot_broadcast(int cpu)
{
if (cpumask_test_cpu(cpu, tick_broadcast_oneshot_mask)) {
struct tick_device *td = &per_cpu(tick_cpu_device, cpu);
/*
* We might be in the middle of switching over from
* periodic to oneshot. If the CPU has not yet
* switched over, leave the device alone.
*/
if (td->mode == TICKDEV_MODE_ONESHOT) {
clockevents_set_mode(td->evtdev,
CLOCK_EVT_MODE_ONESHOT);
}
}
}
static void tick_resume(void)
{
struct tick_device *td = &__get_cpu_var(tick_cpu_device);
unsigned long flags;
int broadcast = tick_resume_broadcast();
raw_spin_lock_irqsave(&tick_device_lock, flags);
clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_RESUME);
if (!broadcast) {
if (td->mode == TICKDEV_MODE_PERIODIC)
tick_setup_periodic(td->evtdev, 0);
else
tick_resume_oneshot();
}
raw_spin_unlock_irqrestore(&tick_device_lock, flags);
}
/*
* Remove a CPU from broadcasting
*/
void tick_shutdown_broadcast(unsigned int *cpup)
{
struct clock_event_device *bc;
unsigned long flags;
unsigned int cpu = *cpup;
spin_lock_irqsave(&tick_broadcast_lock, flags);
bc = tick_broadcast_device.evtdev;
cpu_clear(cpu, tick_broadcast_mask);
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) {
if (bc && cpus_empty(tick_broadcast_mask))
clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
}
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}
/*
* Check, if the new registered device should be used.
*/
static int tick_check_new_device(struct clock_event_device *newdev)
{
struct clock_event_device *curdev;
struct tick_device *td;
int cpu, ret = NOTIFY_OK;
unsigned long flags;
cpumask_t cpumask;
spin_lock_irqsave(&tick_device_lock, flags);
cpu = smp_processor_id();
if (!cpu_isset(cpu, newdev->cpumask))
goto out_bc;
td = &per_cpu(tick_cpu_device, cpu);
curdev = td->evtdev;
cpumask = cpumask_of_cpu(cpu);
/* cpu local device ? */
if (!cpus_equal(newdev->cpumask, cpumask)) {
/*
* If the cpu affinity of the device interrupt can not
* be set, ignore it.
*/
if (!irq_can_set_affinity(newdev->irq))
goto out_bc;
/*
* If we have a cpu local device already, do not replace it
* by a non cpu local device
*/
if (curdev && cpus_equal(curdev->cpumask, cpumask))
goto out_bc;
}
/*
* If we have an active device, then check the rating and the oneshot
* feature.
*/
if (curdev) {
/*
* Prefer one shot capable devices !
*/
if ((curdev->features & CLOCK_EVT_FEAT_ONESHOT) &&
!(newdev->features & CLOCK_EVT_FEAT_ONESHOT))
goto out_bc;
/*
* Check the rating
*/
if (curdev->rating >= newdev->rating)
goto out_bc;
}
/*
* Replace the eventually existing device by the new
* device. If the current device is the broadcast device, do
* not give it back to the clockevents layer !
*/
if (tick_is_broadcast_device(curdev)) {
clockevents_set_mode(curdev, CLOCK_EVT_MODE_SHUTDOWN);
curdev = NULL;
}
clockevents_exchange_device(curdev, newdev);
tick_setup_device(td, newdev, cpu, cpumask);
if (newdev->features & CLOCK_EVT_FEAT_ONESHOT)
tick_oneshot_notify();
spin_unlock_irqrestore(&tick_device_lock, flags);
return NOTIFY_STOP;
out_bc:
/*
* Can the new device be used as a broadcast device ?
*/
if (tick_check_broadcast_device(newdev))
ret = NOTIFY_STOP;
spin_unlock_irqrestore(&tick_device_lock, flags);
return ret;
}
/**
* 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;
}
int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
{
clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
return 0;
}
static void __cpuinit mmp_percpu_timer_stop(struct clock_event_device *clk)
{
clockevents_set_mode(clk, CLOCK_EVT_MODE_SHUTDOWN);
disable_irq(clk->irq);
return;
}
