static int nmi_timer_setup(void)
{
int cpu, err;
u64 period;
/* clock cycles per tick: */
period = (u64)cpu_khz * 1000;
do_div(period, HZ);
nmi_timer_attr.sample_period = period;
cpu_notifier_register_begin();
err = __register_cpu_notifier(&nmi_timer_cpu_nb);
if (err)
goto out;
/* can't attach events to offline cpus: */
for_each_online_cpu(cpu) {
err = nmi_timer_start_cpu(cpu);
if (err) {
cpu_notifier_register_done();
nmi_timer_shutdown();
return err;
}
}
out:
cpu_notifier_register_done();
return err;
}
static int nmi_timer_start(void)
{
int cpu;
get_online_cpus();
ctr_running = 1;
for_each_online_cpu(cpu)
nmi_timer_start_cpu(cpu);
put_online_cpus();
return 0;
}
static int nmi_timer_cpu_notifier(struct notifier_block *b, unsigned long action,
void *data)
{
int cpu = (unsigned long)data;
switch (action) {
case CPU_DOWN_FAILED:
case CPU_ONLINE:
nmi_timer_start_cpu(cpu);
break;
case CPU_DOWN_PREPARE:
nmi_timer_stop_cpu(cpu);
break;
}
return NOTIFY_DONE;
}
static int nmi_timer_cpu_online(unsigned int cpu)
{
nmi_timer_start_cpu(cpu);
return 0;
}
