Merge commit '683b6c6f82a60fabf47012581c2cfbf1b037ab95' into stable/for-linus-3.15

This merge of the irq-core-for-linus branch broke the ARM build when
Xen is enabled.

Conflicts:
	drivers/xen/events/events_base.c

diff --cc drivers/xen/events/events_base.c
index 7930530656299a28283d8e9ce0155b281349e446,c3458f58de905efb9eb8ae6a611532abda763f9e..d5a3de88ac59df240b09a6c21937eeec7754dd05
--- 1/drivers/xen/events/events_base.c
--- 2/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@@ -788,16 -767,7 +776,12 @@@ int xen_destroy_irq(int irq
  
        mutex_lock(&irq_mapping_update_lock);
  
-       desc = irq_to_desc(irq);
-       if (!desc)
-               goto out;
- 
 -      if (xen_initial_domain()) {
 +      /*
 +       * If trying to remove a vector in a MSI group different
 +       * than the first one skip the PIRQ unmap unless this vector
 +       * is the first one in the group.
 +       */
 +      if (xen_initial_domain() && !(info->u.pirq.flags & PIRQ_MSI_GROUP)) {
                unmap_irq.pirq = info->u.pirq.pirq;
                unmap_irq.domid = info->u.pirq.domid;
                rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);