iommu/vt-d: Tylersburg isoch identity map check is done too late.

The check to set identity map for tylersburg is done too late. It needs
to be done before the check for identity_map domain is done.

To: Joerg Roedel <[email protected]>
To: David Woodhouse <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: Ashok Raj <[email protected]>

Fixes: 86080cc ("iommu/vt-d: Allocate si_domain in init_dmars()")
Signed-off-by: Ashok Raj <[email protected]>
Reported-by: Yunhong Jiang <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>

Author: Ashok Raj

drivers/iommu/intel-iommu.c

@@ -3325,13 +3325,14 @@ static int __init init_dmars(void)
 	iommu_identity_mapping |= IDENTMAP_GFX;
 #endif
 
+	check_tylersburg_isoch();
+
 	if (iommu_identity_mapping) {
 		ret = si_domain_init(hw_pass_through);
 		if (ret)
 			goto free_iommu;
 	}
 
-	check_tylersburg_isoch();
 
 	/*
 	 * If we copied translations from a previous kernel in the kdump