iommu/vt-d: Disable IRQ remapping in intel_prepare_irq_remapping

Move it to this function for now, so that the copy routines
for irq remapping take no effect yet.
Tested-by: ZhenHua Li <zhen-hual@hp.com>
Tested-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/intel_irq_remapping.c

@@ -654,6 +654,9 @@ static int __init intel_prepare_irq_remapping(void)
 			pr_info("%s does not support EIM\n", iommu->name);
 			eim = 0;
 		}
+
+		/* Disable IRQ remapping if it is already enabled */
+		iommu_disable_irq_remapping(iommu);
 	}
 
 	eim_mode = eim;
@@ -682,9 +685,6 @@ static int __init intel_enable_irq_remapping(void)
 	struct intel_iommu *iommu;
 	bool setup = false;
 
-	for_each_iommu(iommu, drhd)
-		iommu_disable_irq_remapping(iommu);
-
 	/*
 	 * Setup Interrupt-remapping for all the DRHD's now.
 	 */