x86/irq: Make irq activate operations symmetric

The recent commit which prevents double activation of interrupts unearthed
interesting code in x86. The code (ab)uses irq_domain_activate_irq() to
reconfigure an already activated interrupt. That trips over the prevention
code now.

Fix it by deactivating the interrupt before activating the new configuration.

Fixes: 08d85f3 "irqdomain: Avoid activating interrupts more than once"
Reported-and-tested-by: Mike Galbraith <[email protected]>
Reported-and-tested-by: Borislav Petkov <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701311901580.3457@nanos

Author: KAGA-KOKO

arch/x86/kernel/apic/io_apic.c

@@ -2117,6 +2117,7 @@ static inline void __init check_timer(void)
 			if (idx != -1 && irq_trigger(idx))
 				unmask_ioapic_irq(irq_get_chip_data(0));
 		}
+		irq_domain_deactivate_irq(irq_data);
 		irq_domain_activate_irq(irq_data);
 		if (timer_irq_works()) {
 			if (disable_timer_pin_1 > 0)
@@ -2138,6 +2139,7 @@ static inline void __init check_timer(void)
 		 * legacy devices should be connected to IO APIC #0
 		 */
 		replace_pin_at_irq_node(data, node, apic1, pin1, apic2, pin2);
+		irq_domain_deactivate_irq(irq_data);
 		irq_domain_activate_irq(irq_data);
 		legacy_pic->unmask(0);
 		if (timer_irq_works()) {

arch/x86/kernel/hpet.c

@@ -352,6 +352,7 @@ static int hpet_resume(struct clock_event_device *evt, int timer)
 	} else {
 		struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
 
+		irq_domain_deactivate_irq(irq_get_irq_data(hdev->irq));
 		irq_domain_activate_irq(irq_get_irq_data(hdev->irq));
 		disable_irq(hdev->irq);
 		irq_set_affinity(hdev->irq, cpumask_of(hdev->cpu));