iommu/amd: Don't clear DTE flags when modifying it

[karo-tx-linux.git] / drivers / iommu / amd_iommu.c

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index f82060e778a23bb7a8901ef2356d42b5363d93a6..532e2a211fe1cf9b3d7ff71d36cbcfde49bd29df 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1974,8 +1974,8 @@ static void set_dte_entry(u16 devid, struct protection_domain *domain, bool ats)
 static void clear_dte_entry(u16 devid)
 {
        /* remove entry from the device table seen by the hardware */
-       amd_iommu_dev_table[devid].data[0] = IOMMU_PTE_P | IOMMU_PTE_TV;
-       amd_iommu_dev_table[devid].data[1] = 0;
+       amd_iommu_dev_table[devid].data[0]  = IOMMU_PTE_P | IOMMU_PTE_TV;
+       amd_iommu_dev_table[devid].data[1] &= DTE_FLAG_MASK;
 
        amd_iommu_apply_erratum_63(devid);
 }
@@ -2006,6 +2006,15 @@ static void do_detach(struct iommu_dev_data *dev_data)
 {
        struct amd_iommu *iommu;
 
+       /*
+        * First check if the device is still attached. It might already
+        * be detached from its domain because the generic
+        * iommu_detach_group code detached it and we try again here in
+        * our alias handling.
+        */
+       if (!dev_data->domain)
+               return;
+
        iommu = amd_iommu_rlookup_table[dev_data->devid];
 
        /* decrease reference counters */