[PATCH 4.4 28/29] x86/irq: Make irq activate operations symmetric

Greg Kroah-Hartman
2017-02-07T12:49:10Z

From: Thomas Gleixner <tglx@linutronix.de>

commit aaaec6fc755447a1d056765b11b24d8ff2b81366 upstream.

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: 08d85f3ea99f1 "irqdomain: Avoid activating interrupts more than once"
Reported-and-tested-by: Mike Galbraith <efault@gmx.de>
Reported-and-tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701311901580.3457@nanos
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/kernel/apic/io_apic.c | 2 ++
arch/x86/kernel/hpet.c | 1 +
2 files changed, 3 insertions(+)

--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2117,6 +2117,7 @@ static inline void __init check_timer(vo
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(vo
* 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()) {
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -351,6 +351,7 @@ static int hpet_resume(struct clock_even
} 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));