xen: map MSIs into pirqs

Map MSIs into pirqs, writing 0 in the MSI vector data field and the pirq
number in the MSI destination id field.

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

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 32269bcbd88c..efa683ee8840 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -656,6 +656,28 @@ out:
         return irq;
 }
 
+void xen_allocate_pirq_msi(char *name, int *irq, int *pirq)
+{
+        spin_lock(&irq_mapping_update_lock);
+
+        *irq = find_unbound_irq();
+        if (*irq == -1)
+                goto out;
+
+        *pirq = find_unbound_pirq();
+        if (*pirq == -1)
+                goto out;
+
+        set_irq_chip_and_handler_name(*irq, &xen_pirq_chip,
+                                      handle_level_irq, name);
+
+        irq_info[*irq] = mk_pirq_info(0, *pirq, 0, 0);
+        pirq_to_irq[*pirq] = *irq;
+
+out:
+        spin_unlock(&irq_mapping_update_lock);
+}
+
 int xen_destroy_irq(int irq)
 {
         struct irq_desc *desc;