void h8300_timer_tick(void)
{
if (current->pid)
profile_tick(CPU_PROFILING);
write_atomic_seqlock(&xtime_lock);
do_timer(1);
write_atomic_sequnlock(&xtime_lock);
update_process_times(user_mode(get_irq_regs()));
}
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "do_timer()" routine every clocktick
*/
static irqreturn_t timer_interrupt(int irq, void *dev_id)
{
#ifndef CONFIG_SMP
profile_tick(CPU_PROFILING);
#endif
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(get_irq_regs()));
#endif
/*
* If we have an externally synchronized Linux clock, then update
* CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
* called as close as possible to 500 ms before the new second starts.
*/
write_atomic_seqlock(&xtime_lock);
if (ntp_synced()
&& xtime.tv_sec > last_rtc_update + 660
&& (xtime.tv_nsec / 1000) >= 500000 - ((unsigned)TICK_SIZE) / 2
&& (xtime.tv_nsec / 1000) <= 500000 + ((unsigned)TICK_SIZE) / 2)
{
if (set_rtc_mmss(xtime.tv_sec) == 0)
last_rtc_update = xtime.tv_sec;
else /* do it again in 60 s */
last_rtc_update = xtime.tv_sec - 600;
}
write_atomic_sequnlock(&xtime_lock);
/* As we return to user mode fire off the other CPU schedulers..
this is basically because we don't yet share IRQ's around.
This message is rigged to be safe on the 386 - basically it's
a hack, so don't look closely for now.. */
#ifdef CONFIG_SMP
smp_local_timer_interrupt();
smp_send_timer();
#endif
return IRQ_HANDLED;
}
static irqreturn_t
timer_interrupt (int irq, void *dev_id)
{
unsigned long new_itm;
if (unlikely(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);
if (paravirt_do_steal_accounting(&new_itm))
goto skip_process_time_accounting;
while (1) {
update_process_times(user_mode(get_irq_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_atomic_seqlock(&xtime_lock);
do_timer(1);
local_cpu_data->itm_next = new_itm;
write_atomic_sequnlock(&xtime_lock);
} else
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();
}
skip_process_time_accounting:
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;
}
