/*
* do_IRQ handles IRQ's that have been installed without the
* SA_INTERRUPT flag: it uses the full signal-handling return
* and runs with other interrupts enabled. All relatively slow
* IRQ's should use this format: notably the keyboard/timer
* routines.
*/
asmlinkage void do_IRQ(int irq, struct pt_regs * regs)
{
struct irqaction *action;
int do_random, cpu;
cpu = smp_processor_id();
hardirq_enter(cpu);
kstat.irqs[cpu][irq]++;
action = *(irq + irq_action);
if (action) {
if (!(action->flags & SA_INTERRUPT))
__sti();
action = *(irq + irq_action);
do_random = 0;
do {
do_random |= action->flags;
action->handler(irq, action->dev_id, regs);
action = action->next;
} while (action);
if (do_random & SA_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
__cli();
}
hardirq_exit(cpu);
/* unmasking and bottom half handling is done magically for us. */
}
void TAUException(struct pt_regs * regs)
{
unsigned long cpu = smp_processor_id();
hardirq_enter(cpu);
tau[cpu].interrupts++;
TAUupdate(cpu);
hardirq_exit(cpu);
return;
}
asmlinkage void i8259_do_irq(int irq, struct pt_regs *regs)
{
struct irqaction *action;
int do_random, cpu;
cpu = smp_processor_id();
hardirq_enter(cpu);
if (irq >= 16)
goto out;
i8259_mask_and_ack_irq(irq);
kstat.irqs[cpu][irq]++;
action = *(irq + irq_action);
if (!action)
goto out;
if (!(action->flags & SA_INTERRUPT))
__sti();
action = *(irq + irq_action);
do_random = 0;
do {
do_random |= action->flags;
action->handler(irq, action->dev_id, regs);
action = action->next;
} while (action);
if (do_random & SA_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
__cli();
unmask_irq (irq);
out:
hardirq_exit(cpu);
}
/*
* timer_interrupt - gets called when the decrementer overflows,
* with interrupts disabled.
* We set it up to overflow again in 1/HZ seconds.
*/
int timer_interrupt(struct pt_regs * regs)
{
int next_dec;
unsigned long cpu = smp_processor_id();
unsigned jiffy_stamp = last_jiffy_stamp(cpu);
extern void do_IRQ(struct pt_regs *);
if (atomic_read(&ppc_n_lost_interrupts) != 0)
do_IRQ(regs);
hardirq_enter(cpu);
while ((next_dec = tb_ticks_per_jiffy - tb_delta(&jiffy_stamp)) < 0) {
jiffy_stamp += tb_ticks_per_jiffy;
if (!user_mode(regs))
ppc_do_profile(instruction_pointer(regs));
if (unlikely(!heartbeat_count(cpu)--)
&& heartbeat_reset(cpu)) {
ppc_md.heartbeat();
heartbeat_count(cpu) = heartbeat_reset(cpu);
}
if (cpu)
continue;
/* We are in an interrupt, no need to save/restore flags */
write_lock(&xtime_lock);
tb_last_stamp = jiffy_stamp;
do_timer(regs);
/*
* update the rtc when needed, this should be performed on the
* right fraction of a second. Half or full second ?
* Full second works on mk48t59 clocks, others need testing.
* Note that this update is basically only used through
* the adjtimex system calls. Setting the HW clock in
* any other way is a /dev/rtc and userland business.
* This is still wrong by -0.5/+1.5 jiffies because of the
* timer interrupt resolution and possible delay, but here we
* hit a quantization limit which can only be solved by higher
* resolution timers and decoupling time management from timer
* interrupts. This is also wrong on the clocks
* which require being written at the half second boundary.
* We should have an rtc call that only sets the minutes and
* seconds like on Intel to avoid problems with non UTC clocks.
*/
if ( ppc_md.set_rtc_time && (time_status & STA_UNSYNC) == 0 &&
xtime.tv_sec - last_rtc_update >= 659 &&
abs(xtime.tv_usec - (1000000-1000000/HZ)) < 500000/HZ &&
jiffies - wall_jiffies == 1) {
if (ppc_md.set_rtc_time(xtime.tv_sec+1 + time_offset) == 0)
last_rtc_update = xtime.tv_sec+1;
else
/* Try again one minute later */
last_rtc_update += 60;
}
write_unlock(&xtime_lock);
}
if (!disarm_decr[cpu])
set_dec(next_dec);
last_jiffy_stamp(cpu) = jiffy_stamp;
#ifdef CONFIG_SMP
smp_local_timer_interrupt(regs);
#endif /* CONFIG_SMP */
hardirq_exit(cpu);
if (softirq_pending(cpu))
do_softirq();
return 1; /* lets ret_from_int know we can do checks */
}
