static int epit_set_oneshot(struct clock_event_device *evt)
{
unsigned long flags;
/*
* The timer interrupt generation is disabled at least
* for enough time to call epit_set_next_event()
*/
local_irq_save(flags);
/* Disable interrupt in GPT module */
epit_irq_disable();
/* Clear pending interrupt, only while switching mode */
if (!clockevent_state_oneshot(evt))
epit_irq_acknowledge();
/*
* Do not put overhead of interrupt enable/disable into
* epit_set_next_event(), the core has about 4 minutes
* to call epit_set_next_event() or shutdown clock after
* mode switching
*/
epit_irq_enable();
local_irq_restore(flags);
return 0;
}
/*
* Event handler for periodic broadcast ticks
*/
static void tick_handle_periodic_broadcast(struct clock_event_device *dev)
{
struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
bool bc_local;
raw_spin_lock(&tick_broadcast_lock);
/* Handle spurious interrupts gracefully */
if (clockevent_state_shutdown(tick_broadcast_device.evtdev)) {
raw_spin_unlock(&tick_broadcast_lock);
return;
}
bc_local = tick_do_periodic_broadcast();
if (clockevent_state_oneshot(dev)) {
ktime_t next = ktime_add(dev->next_event, tick_period);
clockevents_program_event(dev, next, true);
}
raw_spin_unlock(&tick_broadcast_lock);
/*
* We run the handler of the local cpu after dropping
* tick_broadcast_lock because the handler might deadlock when
* trying to switch to oneshot mode.
*/
if (bc_local)
td->evtdev->event_handler(td->evtdev);
}
static irqreturn_t gt_clockevent_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
if (!(readl_relaxed(gt_base + GT_INT_STATUS) &
GT_INT_STATUS_EVENT_FLAG))
return IRQ_NONE;
/**
* ERRATA 740657( Global Timer can send 2 interrupts for
* the same event in single-shot mode)
* Workaround:
* Either disable single-shot mode.
* Or
* Modify the Interrupt Handler to avoid the
* offending sequence. This is achieved by clearing
* the Global Timer flag _after_ having incremented
* the Comparator register value to a higher value.
*/
if (clockevent_state_oneshot(evt))
gt_compare_set(ULONG_MAX, 0);
writel_relaxed(GT_INT_STATUS_EVENT_FLAG, gt_base + GT_INT_STATUS);
evt->event_handler(evt);
return IRQ_HANDLED;
}
static void tick_broadcast_set_event(struct clock_event_device *bc, int cpu,
ktime_t expires)
{
if (!clockevent_state_oneshot(bc))
clockevents_switch_state(bc, CLOCK_EVT_STATE_ONESHOT);
clockevents_program_event(bc, expires, 1);
tick_broadcast_set_affinity(bc, cpumask_of(cpu));
}
static int timer8_clock_event_next(unsigned long delta,
struct clock_event_device *ced)
{
struct timer8_priv *p = ced_to_priv(ced);
BUG_ON(!clockevent_state_oneshot(ced));
timer8_set_next(p, delta - 1);
return 0;
}
static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
/* Stop the timer tick */
if (clockevent_state_oneshot(evt)) {
u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
ctrl &= ~TIMER_ENABLE_EN;
writel_relaxed(ctrl, event_base + TIMER_ENABLE);
}
evt->event_handler(evt);
return IRQ_HANDLED;
}
static irqreturn_t timer8_interrupt(int irq, void *dev_id)
{
struct timer8_priv *p = dev_id;
if (clockevent_state_oneshot(&p->ced))
iowrite16be(0x0000, p->mapbase + _8TCR);
p->ced.event_handler(&p->ced);
bclr(CMFA, p->mapbase + _8TCSR);
return IRQ_HANDLED;
}
static int xen_timerop_set_next_event(unsigned long delta,
struct clock_event_device *evt)
{
WARN_ON(!clockevent_state_oneshot(evt));
if (HYPERVISOR_set_timer_op(get_abs_timeout(delta)) < 0)
BUG();
/* We may have missed the deadline, but there's no real way of
knowing for sure. If the event was in the past, then we'll
get an immediate interrupt. */
return 0;
}
static irqreturn_t ftm_evt_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
ftm_irq_acknowledge(priv->clkevt_base);
if (likely(clockevent_state_oneshot(evt))) {
ftm_irq_disable(priv->clkevt_base);
ftm_counter_disable(priv->clkevt_base);
}
evt->event_handler(evt);
return IRQ_HANDLED;
}
/* timer interrupt handler */
static irqreturn_t sirfsoc_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *ce = dev_id;
int cpu = smp_processor_id();
/* clear timer interrupt */
writel_relaxed(BIT(cpu), sirfsoc_timer_base + SIRFSOC_TIMER_INTR_STATUS);
if (clockevent_state_oneshot(ce))
sirfsoc_timer_count_disable(cpu);
ce->event_handler(ce);
return IRQ_HANDLED;
}
static int xen_vcpuop_set_next_event(unsigned long delta,
struct clock_event_device *evt)
{
int cpu = smp_processor_id();
struct vcpu_set_singleshot_timer single;
int ret;
WARN_ON(!clockevent_state_oneshot(evt));
single.timeout_abs_ns = get_abs_timeout(delta);
single.flags = VCPU_SSHOTTMR_future;
ret = HYPERVISOR_vcpu_op(VCPUOP_set_singleshot_timer, cpu, &single);
BUG_ON(ret != 0 && ret != -ETIME);
return ret;
}
static int xen_vcpuop_set_next_event(unsigned long delta,
struct clock_event_device *evt)
{
int cpu = smp_processor_id();
struct vcpu_set_singleshot_timer single;
int ret;
WARN_ON(!clockevent_state_oneshot(evt));
single.timeout_abs_ns = get_abs_timeout(delta);
/* Get an event anyway, even if the timeout is already expired */
single.flags = 0;
ret = HYPERVISOR_vcpu_op(VCPUOP_set_singleshot_timer, cpu, &single);
BUG_ON(ret != 0);
return ret;
}
static irqreturn_t pit_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
pit_irq_acknowledge();
/*
* pit hardware doesn't support oneshot, it will generate an interrupt
* and reload the counter value from PITLDVAL when PITCVAL reach zero,
* and start the counter again. So software need to disable the timer
* to stop the counter loop in ONESHOT mode.
*/
if (likely(clockevent_state_oneshot(evt)))
pit_timer_disable();
evt->event_handler(evt);
return IRQ_HANDLED;
}
/*
* Event handler for periodic ticks
*/
void tick_handle_periodic(struct clock_event_device *dev)
{
int cpu = smp_processor_id();
ktime_t next = dev->next_event;
tick_periodic(cpu);
#if defined(CONFIG_HIGH_RES_TIMERS) || defined(CONFIG_NO_HZ_COMMON)
/*
* The cpu might have transitioned to HIGHRES or NOHZ mode via
* update_process_times() -> run_local_timers() ->
* hrtimer_run_queues().
*/
if (dev->event_handler != tick_handle_periodic)
return;
#endif
if (!clockevent_state_oneshot(dev))
return;
for (;;) {
/*
* Setup the next period for devices, which do not have
* periodic mode:
*/
next = ktime_add(next, tick_period);
if (!clockevents_program_event(dev, next, false))
return;
/*
* 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,
* which then will increment time, possibly causing
* the loop to trigger again and again.
*/
if (timekeeping_valid_for_hres())
tick_periodic(cpu);
}
}
