[PATCH 2/2] xen: do not implement irq_mask and irq_unmask in xen_percpu_chip

[<stefano.stabellini@eu.citrix.com>]

From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

irq_mask and irq_unmask are not needed by handle_percpu_irq, but
they are called by fixup_irqs when changing affinity.
At the moment calling fixup_irqs can result in unmasking an interrupt
that was previously masked because of the call to irq_unmask.
However xen_percpu_chip doesn't even support irq_set_affinity, and we
don't need irq_mask and irq_unmask, so we can just change them to noops,
following the example of uv_irq_chip.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 drivers/xen/events.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index bb59651..8eb5316 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -120,6 +120,7 @@ static struct irq_chip xen_percpu_chip;
 static struct irq_chip xen_pirq_chip;
 static void enable_dynirq(struct irq_data *data);
 static void disable_dynirq(struct irq_data *data);
+static void evtchn_noop(struct irq_data *data) { }
 
 /* Get info for IRQ */
 static struct irq_info *info_for_irq(unsigned irq)
@@ -1595,9 +1596,10 @@ static struct irq_chip xen_pirq_chip __read_mostly = {
 static struct irq_chip xen_percpu_chip __read_mostly = {
 	.name			= "xen-percpu",
 
+	.irq_enable		= enable_dynirq,
 	.irq_disable		= disable_dynirq,
-	.irq_mask		= disable_dynirq,
-	.irq_unmask		= enable_dynirq,
+	.irq_mask		= evtchn_noop,
+	.irq_unmask		= evtchn_noop,
 
 	.irq_ack		= ack_dynirq,
 };
-- 
1.7.2.3