@@ -31,6 +31,7 @@ struct rtc_time;
extern void to_tm(int tim, struct rtc_time * tm);
extern void GregorianDay(struct rtc_time *tm);
extern void decrementer_timer_interrupt(void);
+extern void broadcast_irq_entry(void);
extern void generic_calibrate_decr(void);
@@ -853,6 +853,7 @@ void decrementer_timer_interrupt(void)
{
u64 *next_tb = &__get_cpu_var(decrementers_next_tb);
+ broadcast_irq_entry();
*next_tb = get_tb_or_rtc();
__timer_interrupt();
}
@@ -282,6 +282,12 @@ static int longnap_loop(struct cpuidle_device *dev,
return index;
}
+void broadcast_irq_entry(void)
+{
+ if (smp_processor_id() == bc_cpu)
+ hrtimer_start(bc_hrtimer, ns_to_ktime(0), HRTIMER_MODE_REL_PINNED);
+}
+
/*
* States for dedicated partition case.
*/
@@ -360,6 +366,7 @@ static int power_cpuidle_add_cpu_notifier(struct notifier_block *n,
unsigned long action, void *hcpu)
{
int hotcpu = (unsigned long)hcpu;
+ unsigned long flags;
struct cpuidle_device *dev =
per_cpu(cpuidle_devices, hotcpu);
@@ -372,6 +379,21 @@ static int power_cpuidle_add_cpu_notifier(struct notifier_block *n,
cpuidle_resume_and_unlock();
break;
+ case CPU_DYING:
+ case CPU_DYING_FROZEN:
+ spin_lock_irqsave(&longnap_idle_lock, flags);
+ if (hotcpu == bc_cpu) {
+ bc_cpu = -1;
+ hrtimer_cancel(bc_hrtimer);
+ if (!cpumask_empty(tick_get_broadcast_oneshot_mask())) {
+ bc_cpu = cpumask_first(
+ tick_get_broadcast_oneshot_mask());
+ arch_send_tick_broadcast(cpumask_of(bc_cpu));
+ }
+ }
+ spin_unlock_irqrestore(&longnap_idle_lock, flags);
+ break;
+
case CPU_DEAD:
case CPU_DEAD_FROZEN:
cpuidle_pause_and_lock();
On hotplug of the broadcast cpu, cancel the hrtimer queued to do broadcast and nominate a new broadcast cpu to be the first cpu in the broadcast mask which includes all the cpus that have notified the broadcast framework about entering deep idle state. Since the new broadcast cpu is one of the cpus in deep idle, send an ipi to wake it up to continue the duty of broadcast. The new broadcast cpu needs to find out if it woke up to resume broadcast. If so it needs to restart the broadcast hrtimer on itself. Its possible that the old broadcast cpu was hotplugged out when the broadcast hrtimer was about to fire on it. Therefore the newly nominated broadcast cpu should set the broadcast hrtimer on itself to expire immediately so as to not miss wakeups under such scenarios. Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> --- arch/powerpc/include/asm/time.h | 1 + arch/powerpc/kernel/time.c | 1 + drivers/cpuidle/cpuidle-ibm-power.c | 22 ++++++++++++++++++++++ 3 files changed, 24 insertions(+)