#include <linux/cpu.h>
#include <linux/err.h>
#include <linux/hrtimer.h>
-#include <linux/irq.h>
+#include <linux/interrupt.h>
#include <linux/percpu.h>
#include <linux/profile.h>
#include <linux/sched.h>
#include <linux/tick.h>
+#include <asm/irq_regs.h>
+
#include "tick-internal.h"
/*
*/
ktime_t tick_next_period;
ktime_t tick_period;
-static int tick_do_timer_cpu = -1;
-DEFINE_SPINLOCK(tick_device_lock);
+int tick_do_timer_cpu __read_mostly = TICK_DO_TIMER_BOOT;
+static DEFINE_RAW_SPINLOCK(tick_device_lock);
+
+/*
+ * Debugging: see timer_list.c
+ */
+struct tick_device *tick_get_device(int cpu)
+{
+ return &per_cpu(tick_cpu_device, cpu);
+}
+
+/**
+ * tick_is_oneshot_available - check for a oneshot capable event device
+ */
+int tick_is_oneshot_available(void)
+{
+ struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
+
+ return dev && (dev->features & CLOCK_EVT_FEAT_ONESHOT);
+}
/*
* Periodic tick
void tick_handle_periodic(struct clock_event_device *dev)
{
int cpu = smp_processor_id();
+ ktime_t next;
tick_periodic(cpu);
* Setup the next period for devices, which do not have
* periodic mode:
*/
+ next = ktime_add(dev->next_event, tick_period);
for (;;) {
- ktime_t next = ktime_add(dev->next_event, tick_period);
-
if (!clockevents_program_event(dev, next, ktime_get()))
return;
- tick_periodic(cpu);
+ /*
+ * Have to be careful here. If we're in oneshot mode,
+ * before we call tick_periodic() in a loop, we need
+ * to be sure we're using a real hardware clocksource.
+ * Otherwise we could get trapped in an infinite
+ * loop, as the tick_periodic() increments jiffies,
+ * when then will increment time, posibly causing
+ * the loop to trigger again and again.
+ */
+ if (timekeeping_valid_for_hres())
+ tick_periodic(cpu);
+ next = ktime_add(next, tick_period);
}
}
if (!tick_device_is_functional(dev))
return;
- if (dev->features & CLOCK_EVT_FEAT_PERIODIC) {
+ if ((dev->features & CLOCK_EVT_FEAT_PERIODIC) &&
+ !tick_broadcast_oneshot_active()) {
clockevents_set_mode(dev, CLOCK_EVT_MODE_PERIODIC);
} else {
unsigned long seq;
*/
static void tick_setup_device(struct tick_device *td,
struct clock_event_device *newdev, int cpu,
- cpumask_t cpumask)
+ const struct cpumask *cpumask)
{
ktime_t next_event;
void (*handler)(struct clock_event_device *) = NULL;
* If no cpu took the do_timer update, assign it to
* this cpu:
*/
- if (tick_do_timer_cpu == -1) {
+ if (tick_do_timer_cpu == TICK_DO_TIMER_BOOT) {
tick_do_timer_cpu = cpu;
tick_next_period = ktime_get();
tick_period = ktime_set(0, NSEC_PER_SEC / HZ);
} else {
handler = td->evtdev->event_handler;
next_event = td->evtdev->next_event;
+ td->evtdev->event_handler = clockevents_handle_noop;
}
td->evtdev = newdev;
* When the device is not per cpu, pin the interrupt to the
* current cpu:
*/
- if (!cpus_equal(newdev->cpumask, cpumask))
+ if (!cpumask_equal(newdev->cpumask, cpumask))
irq_set_affinity(newdev->irq, cpumask);
/*
if (td->mode == TICKDEV_MODE_PERIODIC)
tick_setup_periodic(newdev, 0);
+ else
+ tick_setup_oneshot(newdev, handler, next_event);
}
/*
struct tick_device *td;
int cpu, ret = NOTIFY_OK;
unsigned long flags;
- cpumask_t cpumask;
- spin_lock_irqsave(&tick_device_lock, flags);
+ raw_spin_lock_irqsave(&tick_device_lock, flags);
cpu = smp_processor_id();
- if (!cpu_isset(cpu, newdev->cpumask))
- goto out;
+ if (!cpumask_test_cpu(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 (!cpumask_equal(newdev->cpumask, cpumask_of(cpu))) {
/*
* If the cpu affinity of the device interrupt can not
* 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))
+ if (curdev && cpumask_equal(curdev->cpumask, cpumask_of(cpu)))
goto out_bc;
}
*/
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)
* not give it back to the clockevents layer !
*/
if (tick_is_broadcast_device(curdev)) {
- clockevents_set_mode(curdev, CLOCK_EVT_MODE_SHUTDOWN);
+ clockevents_shutdown(curdev);
curdev = NULL;
}
clockevents_exchange_device(curdev, newdev);
- tick_setup_device(td, newdev, cpu, cpumask);
+ tick_setup_device(td, newdev, cpu, cpumask_of(cpu));
+ if (newdev->features & CLOCK_EVT_FEAT_ONESHOT)
+ tick_oneshot_notify();
- spin_unlock_irqrestore(&tick_device_lock, flags);
+ raw_spin_unlock_irqrestore(&tick_device_lock, flags);
return NOTIFY_STOP;
out_bc:
*/
if (tick_check_broadcast_device(newdev))
ret = NOTIFY_STOP;
-out:
- spin_unlock_irqrestore(&tick_device_lock, flags);
+
+ raw_spin_unlock_irqrestore(&tick_device_lock, flags);
return ret;
}
/*
+ * Transfer the do_timer job away from a dying cpu.
+ *
+ * Called with interrupts disabled.
+ */
+static void tick_handover_do_timer(int *cpup)
+{
+ if (*cpup == tick_do_timer_cpu) {
+ int cpu = cpumask_first(cpu_online_mask);
+
+ tick_do_timer_cpu = (cpu < nr_cpu_ids) ? cpu :
+ TICK_DO_TIMER_NONE;
+ }
+}
+
+/*
* Shutdown an event device on a given cpu:
*
* This is called on a life CPU, when a CPU is dead. So we cannot
struct clock_event_device *dev = td->evtdev;
unsigned long flags;
- spin_lock_irqsave(&tick_device_lock, flags);
+ raw_spin_lock_irqsave(&tick_device_lock, flags);
td->mode = TICKDEV_MODE_PERIODIC;
if (dev) {
/*
clockevents_exchange_device(dev, NULL);
td->evtdev = NULL;
}
- spin_unlock_irqrestore(&tick_device_lock, flags);
+ raw_spin_unlock_irqrestore(&tick_device_lock, flags);
+}
+
+static void tick_suspend(void)
+{
+ struct tick_device *td = &__get_cpu_var(tick_cpu_device);
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&tick_device_lock, flags);
+ clockevents_shutdown(td->evtdev);
+ raw_spin_unlock_irqrestore(&tick_device_lock, flags);
+}
+
+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);
}
/*
case CLOCK_EVT_NOTIFY_BROADCAST_ON:
case CLOCK_EVT_NOTIFY_BROADCAST_OFF:
+ case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
tick_broadcast_on_off(reason, dev);
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(dev);
+ break;
+
case CLOCK_EVT_NOTIFY_CPU_DEAD:
+ tick_shutdown_broadcast_oneshot(dev);
tick_shutdown_broadcast(dev);
tick_shutdown(dev);
break;
+ case CLOCK_EVT_NOTIFY_SUSPEND:
+ tick_suspend();
+ tick_suspend_broadcast();
+ break;
+
+ case CLOCK_EVT_NOTIFY_RESUME:
+ tick_resume();
+ break;
+
default:
break;
}