xen: Get rid of the last irq_desc abuse

Warn if any PIRQ cannot be bound to an event channel. Remove the check
for irq_desc->action. This hypercall never fails in practice so we can
emit a warning unconditionally.

Remove a check for a valid irq desc. The only caller of
xen_destroy_irq() will only do so if the irq was previously fully
setup, which means the descriptor has been allocated as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Xen <xen-devel@lists.xenproject.org>
Cc: David Vrabel <david.vrabel@citrix.com>
Link: http://lkml.kernel.org/r/20140223212738.579581220@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 7fea02c143ba72b194d3725f4d62d1b3629e22de..5dd2ddf634fb121d1c8292b713f4e52868b1bc21 100644 (file)
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -487,13 +487,6 @@ static void pirq_query_unmask(int irq)
                info->u.pirq.flags |= PIRQ_NEEDS_EOI;
 }
 
-static bool probing_irq(int irq)
-{
-       struct irq_desc *desc = irq_to_desc(irq);
-
-       return desc && desc->action == NULL;
-}
-
 static void eoi_pirq(struct irq_data *data)
 {
        int evtchn = evtchn_from_irq(data->irq);
@@ -535,8 +528,7 @@ static unsigned int __startup_pirq(unsigned int irq)
                                        BIND_PIRQ__WILL_SHARE : 0;
        rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
        if (rc != 0) {
-               if (!probing_irq(irq))
-                       pr_info("Failed to obtain physical IRQ %d\n", irq);
+               pr_warn("Failed to obtain physical IRQ %d\n", irq);
                return 0;
        }
        evtchn = bind_pirq.port;
@@ -769,17 +761,12 @@ error_irq:
 
 int xen_destroy_irq(int irq)
 {
-       struct irq_desc *desc;
        struct physdev_unmap_pirq unmap_irq;
        struct irq_info *info = info_for_irq(irq);
        int rc = -ENOENT;
 
        mutex_lock(&irq_mapping_update_lock);
 
-       desc = irq_to_desc(irq);
-       if (!desc)
-               goto out;
-
        if (xen_initial_domain()) {
                unmap_irq.pirq = info->u.pirq.pirq;
                unmap_irq.domid = info->u.pirq.domid;