iommu/amd: Initialize device table after dma_ops

commit f528d980 upstream.

When dma_ops are initialized the unity mappings are
created. The init_device_table_dma() function makes sure DMA
from all devices is blocked by default. This opens a short
window in time where DMA to unity mapped regions is blocked
by the IOMMU. Make sure this does not happen by initializing
the device table after dma_ops.
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/iommu/amd_iommu_init.c

@@ -1876,11 +1876,6 @@ static int amd_iommu_init_dma(void)
 	struct amd_iommu *iommu;
 	int ret;
 
-	init_device_table_dma();
-
-	for_each_iommu(iommu)
-		iommu_flush_all_caches(iommu);
-
 	if (iommu_pass_through)
 		ret = amd_iommu_init_passthrough();
 	else
@@ -1889,6 +1884,11 @@ static int amd_iommu_init_dma(void)
 	if (ret)
 		return ret;
 
+	init_device_table_dma();
+
+	for_each_iommu(iommu)
+		iommu_flush_all_caches(iommu);
+
 	amd_iommu_init_api();
 
 	amd_iommu_init_notifier();