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>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 989761c8f01728174b705ba16ad9d3f060ec9ec8..bf3e450b5b976dbe7dadb575f25bd0b697493bea 100644 (file)
--- 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);
        }