irqchip/gic-v4.1: Suppress per-VLPI doorbell

Since GICv4.1 gives us a per-VPE doorbell, avoid programming anything
else on VMOVI/VMAPI/VMAPTI and on any other action that would have
otherwise resulted in a per-VLPI doorbell to be programmed.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Link: https://lore.kernel.org/r/20191224111055.11836-15-maz@kernel.org

drivers/irqchip/irq-gic-v3-its.c

@@ -718,7 +718,7 @@ static struct its_vpe *its_build_vmapti_cmd(struct its_node *its,
 {
 	u32 db;
 
-	if (desc->its_vmapti_cmd.db_enabled)
+	if (!is_v4_1(its) && desc->its_vmapti_cmd.db_enabled)
 		db = desc->its_vmapti_cmd.vpe->vpe_db_lpi;
 	else
 		db = 1023;
@@ -741,7 +741,7 @@ static struct its_vpe *its_build_vmovi_cmd(struct its_node *its,
 {
 	u32 db;
 
-	if (desc->its_vmovi_cmd.db_enabled)
+	if (!is_v4_1(its) && desc->its_vmovi_cmd.db_enabled)
 		db = desc->its_vmovi_cmd.vpe->vpe_db_lpi;
 	else
 		db = 1023;
@@ -1353,6 +1353,13 @@ static void its_vlpi_set_doorbell(struct irq_data *d, bool enable)
 	u32 event = its_get_event_id(d);
 	struct its_vlpi_map *map;
 
+	/*
+	 * GICv4.1 does away with the per-LPI nonsense, nothing to do
+	 * here.
+	 */
+	if (is_v4_1(its_dev->its))
+		return;
+
 	map = dev_event_to_vlpi_map(its_dev, event);
 
 	if (map->db_enabled == enable)