iommu/vt-d: Make root entry visible for hardware right after allocation

In case there was an old root entry, make our new one
visible immediately after it was allocated.

Tested-by: ZhenHua Li <zhen-hual@hp.com>
Tested-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 989761c8f017..bf3e450b5b97 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -2817,6 +2817,12 @@ static int __init init_dmars(void)
                 ret = iommu_alloc_root_entry(iommu);
                 if (ret)
                         goto free_iommu;
+
+                iommu_flush_write_buffer(iommu);
+                iommu_set_root_entry(iommu);
+                iommu->flush.flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL);
+                iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
+
                 if (!ecap_pass_through(iommu->ecap))
                         hw_pass_through = 0;
         }
@@ -2893,10 +2899,6 @@ static int __init init_dmars(void)
                 if (ret)
                         goto free_iommu;
 
-                iommu_set_root_entry(iommu);
-
-                iommu->flush.flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL);
-                iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
                 iommu_enable_translation(iommu);
                 iommu_disable_protect_mem_regions(iommu);
         }