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

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

commit 21e722c4c8377b5bc82ad058fed12165af739c1b upstream.

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 <joro@8bytes.org>
To: David Woodhouse <dwmw2@infradead.org>
Cc: iommu@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Cc: Ashok Raj <ashok.raj@intel.com>
Fixes: 86080ccc22 ("iommu/vt-d: Allocate si_domain in init_dmars()")
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Reported-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>