xen: remap GSIs as pirqs when running as initial domain

Implement xen_register_gsi to setup the correct triggering and polarity
properties of a gsi.
Implement xen_register_pirq to register a particular gsi as pirq and
receive interrupts as events.
Call xen_setup_pirqs to register all the legacy ISA irqs as pirqs.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index efa683ee8840..c649ac0aaeef 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -681,6 +681,8 @@ out:
 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;
 
         spin_lock(&irq_mapping_update_lock);
@@ -689,6 +691,15 @@ int xen_destroy_irq(int irq)
         if (!desc)
                 goto out;
 
+        if (xen_initial_domain()) {
+                unmap_irq.pirq = info->u.pirq.gsi;
+                unmap_irq.domid = DOMID_SELF;
+                rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
+                if (rc) {
+                        printk(KERN_WARNING "unmap irq failed %d\n", rc);
+                        goto out;
+                }
+        }
         irq_info[irq] = mk_unbound_info();
 
         irq_free_desc(irq);
@@ -1425,5 +1436,7 @@ void __init xen_init_IRQ(void)
                 pci_xen_hvm_init();
         } else {
                 irq_ctx_init(smp_processor_id());
+                if (xen_initial_domain())
+                        xen_setup_pirqs();
         }
 }