intel-iommu: Add device info into list before doing context mapping

Add device info into list before doing context mapping, because device
info will be used by iommu_enable_dev_iotlb(). Without it, ATS won't get
enabled as it should be.

ATS, while a dubious decision from a security point of view, can be very
important for performance.
Signed-off-by: Xudong Hao <xudong.hao@intel.com>
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/iommu/intel-iommu.c

@@ -2287,12 +2287,6 @@ static int domain_add_dev_info(struct dmar_domain *domain,
 	if (!info)
 		return -ENOMEM;
 
-	ret = domain_context_mapping(domain, pdev, translation);
-	if (ret) {
-		free_devinfo_mem(info);
-		return ret;
-	}
-
 	info->segment = pci_domain_nr(pdev->bus);
 	info->bus = pdev->bus->number;
 	info->devfn = pdev->devfn;
@@ -2305,6 +2299,17 @@ static int domain_add_dev_info(struct dmar_domain *domain,
 	pdev->dev.archdata.iommu = info;
 	spin_unlock_irqrestore(&device_domain_lock, flags);
 
+	ret = domain_context_mapping(domain, pdev, translation);
+	if (ret) {
+		spin_lock_irqsave(&device_domain_lock, flags);
+		list_del(&info->link);
+		list_del(&info->global);
+		pdev->dev.archdata.iommu = NULL;
+		spin_unlock_irqrestore(&device_domain_lock, flags);
+		free_devinfo_mem(info);
+		return ret;
+	}
+
 	return 0;
 }