Index: sys/arm/arm/gic.c
===================================================================
--- sys/arm/arm/gic.c
+++ sys/arm/arm/gic.c
@@ -914,12 +914,19 @@
 		KASSERT(trig == INTR_TRIGGER_EDGE,
 		    ("%s: MSI interrupts must be edge triggered", __func__));
 	} else if (data != NULL) {
-		u_int irq;
+		if (data->type == INTR_MAP_DATA_FDT) {
+			u_int irq;
 
-		/* Get config for resource. */
-		if (gic_map_intr(dev, data, &irq, &pol, &trig) ||
-		    gi->gi_irq != irq)
-			return (EINVAL);
+			/* Get config for resource. */
+			if (gic_map_intr(dev, data, &irq, &pol, &trig) ||
+			    gi->gi_irq != irq)
+				return (EINVAL);
+		} else if (data->type == INTR_MAP_DATA_MSI) {
+			/* Non-GICv2m MSI */
+			pol = INTR_POLARITY_HIGH;
+			trig = INTR_TRIGGER_EDGE;
+		} else
+			return (ENOTSUP);
 	} else {
 		pol = INTR_POLARITY_CONFORM;
 		trig = INTR_TRIGGER_CONFORM;