iommu/amd: Fix device_state reference counting

The references to the device state are not dropped
everywhere. This might cause a dead-lock in
amd_iommu_free_device(). Fix it.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Tested-by: Oded Gabbay <oded.gabbay@amd.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 524fd67a85b1..2de13be17268 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -368,6 +368,9 @@ static void free_pasid_states(struct device_state *dev_state)
 
                 put_pasid_state_wait(pasid_state); /* Reference taken in
                                                       amd_iommu_pasid_bind */
+
+                /* Drop reference taken in amd_iommu_bind_pasid */
+                put_device_state(dev_state);
         }
 
         if (dev_state->pasid_levels == 2)
@@ -748,6 +751,10 @@ void amd_iommu_unbind_pasid(struct pci_dev *pdev, int pasid)
         put_pasid_state_wait(pasid_state); /* Reference taken in
                                               amd_iommu_pasid_bind */
 out:
+        /* Drop reference taken in this function */
+        put_device_state(dev_state);
+
+        /* Drop reference taken in amd_iommu_bind_pasid */
         put_device_state(dev_state);
 }
 EXPORT_SYMBOL(amd_iommu_unbind_pasid);