static irqreturn_t
timer_interrupt (int irq, void *dev_id, struct pt_regs *regs)
{
unsigned long new_itm;
if (unlikely(cpu_is_offline(smp_processor_id()))) {
return IRQ_HANDLED;
}
platform_timer_interrupt(irq, dev_id, regs);
new_itm = local_cpu_data->itm_next;
if (!time_after(ia64_get_itc(), new_itm))
printk(KERN_ERR "Oops: timer tick before it's due (itc=%lx,itm=%lx)\n",
ia64_get_itc(), new_itm);
profile_tick(CPU_PROFILING, regs);
while (1) {
update_process_times(user_mode(regs));
new_itm += local_cpu_data->itm_delta;
if (smp_processor_id() == TIME_KEEPER_ID) {
/*
* Here we are in the timer irq handler. We have irqs locally
* disabled, but we don't know if the timer_bh is running on
* another CPU. We need to avoid to SMP race by acquiring the
* xtime_lock.
*/
write_seqlock(&xtime_lock);
do_timer(regs);
local_cpu_data->itm_next = new_itm;
write_sequnlock(&xtime_lock);
} else
local_cpu_data->itm_next = new_itm;
if (time_after(new_itm, ia64_get_itc()))
break;
}
do {
/*
* If we're too close to the next clock tick for
* comfort, we increase the safety margin by
* intentionally dropping the next tick(s). We do NOT
* update itm.next because that would force us to call
* do_timer() which in turn would let our clock run
* too fast (with the potentially devastating effect
* of losing monotony of time).
*/
while (!time_after(new_itm, ia64_get_itc() + local_cpu_data->itm_delta/2))
new_itm += local_cpu_data->itm_delta;
ia64_set_itm(new_itm);
/* double check, in case we got hit by a (slow) PMI: */
} while (time_after_eq(ia64_get_itc(), new_itm));
return IRQ_HANDLED;
}
static irqreturn_t
timer_interrupt (int irq, void *dev_id)
{
unsigned long new_itm;
if (cpu_is_offline(smp_processor_id())) {
return IRQ_HANDLED;
}
platform_timer_interrupt(irq, dev_id);
new_itm = local_cpu_data->itm_next;
if (!time_after(ia64_get_itc(), new_itm))
printk(KERN_ERR "Oops: timer tick before it's due (itc=%lx,itm=%lx)\n",
ia64_get_itc(), new_itm);
profile_tick(CPU_PROFILING);
while (1) {
update_process_times(user_mode(get_irq_regs()));
new_itm += local_cpu_data->itm_delta;
if (smp_processor_id() == time_keeper_id)
xtime_update(1);
local_cpu_data->itm_next = new_itm;
if (time_after(new_itm, ia64_get_itc()))
break;
/*
* Allow IPIs to interrupt the timer loop.
*/
local_irq_enable();
local_irq_disable();
}
do {
/*
* If we're too close to the next clock tick for
* comfort, we increase the safety margin by
* intentionally dropping the next tick(s). We do NOT
* update itm.next because that would force us to call
* xtime_update() which in turn would let our clock run
* too fast (with the potentially devastating effect
* of losing monotony of time).
*/
while (!time_after(new_itm, ia64_get_itc() + local_cpu_data->itm_delta/2))
new_itm += local_cpu_data->itm_delta;
ia64_set_itm(new_itm);
/* double check, in case we got hit by a (slow) PMI: */
} while (time_after_eq(ia64_get_itc(), new_itm));
return IRQ_HANDLED;
}
