iommu/amd: Make sure dma_ops are set for hotplug devices

commit c2a2876e863356b092967ea62bebdb4dd663af80 upstream.

There is a bug introduced with commit 27c2127 that causes
devices which are hot unplugged and then hot-replugged to
not have per-device dma_ops set. This causes these devices
to not function correctly. Fixed with this patch.

Reported-by: Andreas Degert <andreas.degert@googlemail.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 0f074e0..07cb1a6 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1874,16 +1874,16 @@ static int device_change_notifier(struct notifier_block *nb,
 
                /* allocate a protection domain if a device is added */
                dma_domain = find_protection_domain(devid);
-               if (dma_domain)
-                       goto out;
-               dma_domain = dma_ops_domain_alloc();
-               if (!dma_domain)
-                       goto out;
-               dma_domain->target_dev = devid;
-
-               spin_lock_irqsave(&iommu_pd_list_lock, flags);
-               list_add_tail(&dma_domain->list, &iommu_pd_list);
-               spin_unlock_irqrestore(&iommu_pd_list_lock, flags);
+               if (!dma_domain) {
+                       dma_domain = dma_ops_domain_alloc();
+                       if (!dma_domain)
+                               goto out;
+                       dma_domain->target_dev = devid;
+
+                       spin_lock_irqsave(&iommu_pd_list_lock, flags);
+                       list_add_tail(&dma_domain->list, &iommu_pd_list);
+                       spin_unlock_irqrestore(&iommu_pd_list_lock, flags);
+               }
 
                dev->archdata.dma_ops = &amd_iommu_dma_ops;