iommu/fsl: Fix the device domain attach condition.

Store the domain information for the device, only if it's not already
attached to a domain.
Signed-off-by: Varun Sethi <Varun.Sethi@freescale.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/fsl_pamu_domain.c

@@ -335,11 +335,6 @@ static struct fsl_dma_domain *iommu_alloc_dma_domain(void)
 	return domain;
 }
 
-static inline struct device_domain_info *find_domain(struct device *dev)
-{
-	return dev->archdata.iommu_domain;
-}
-
 static void remove_device_ref(struct device_domain_info *info, u32 win_cnt)
 {
 	unsigned long flags;
@@ -380,7 +375,7 @@ static void attach_device(struct fsl_dma_domain *dma_domain, int liodn, struct d
 	 * Check here if the device is already attached to domain or not.
 	 * If the device is already attached to a domain detach it.
 	 */
-	old_domain_info = find_domain(dev);
+	old_domain_info = dev->archdata.iommu_domain;
 	if (old_domain_info && old_domain_info->domain != dma_domain) {
 		spin_unlock_irqrestore(&device_domain_lock, flags);
 		detach_device(dev, old_domain_info->domain);
@@ -399,7 +394,7 @@ static void attach_device(struct fsl_dma_domain *dma_domain, int liodn, struct d
 	 * the info for the first LIODN as all
 	 * LIODNs share the same domain
 	 */
-	if (!old_domain_info)
+	if (!dev->archdata.iommu_domain)
 		dev->archdata.iommu_domain = info;
 	spin_unlock_irqrestore(&device_domain_lock, flags);