drm/vmwgfx: fix the check when to use dma_alloc_coherent

Christoph Hellwig · thomashvmw · commit 2b3cd6249b14 · 2019-01-29T12:30:17.000+01:00
Since Linux 4.21 we merged the swiotlb ops into the DMA direct ops, so they would always have a the sync_single methods. But late in the cicle we also removed the direct ops entirely, so we'd see NULL DMA ops. Switch vmw_dma_select_mode to only detect swiotlb presence using swiotlb_nr_tbl() instead. Fixes: 55897af ("dma-direct: merge swiotlb_dma_ops into the dma_direct code") Fixes: 356da6d ("dma-mapping: bypass indirect calls for dma-direct") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com> Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -565,7 +565,6 @@ static int vmw_dma_select_mode(struct vmw_private *dev_priv)
 		[vmw_dma_alloc_coherent] = "Using coherent TTM pages.",
 		[vmw_dma_map_populate] = "Keeping DMA mappings.",
 		[vmw_dma_map_bind] = "Giving up DMA mappings early."};
-	const struct dma_map_ops *dma_ops = get_dma_ops(dev_priv->dev->dev);
 
 	if (intel_iommu_enabled) {
 		dev_priv->map_mode = vmw_dma_map_populate;
@@ -578,14 +577,12 @@ static int vmw_dma_select_mode(struct vmw_private *dev_priv)
 		return 0;
 	}
 
-	dev_priv->map_mode = vmw_dma_map_populate;
-
-	if (dma_ops && dma_ops->sync_single_for_cpu)
-		dev_priv->map_mode = vmw_dma_alloc_coherent;
 #ifdef CONFIG_SWIOTLB
-	if (swiotlb_nr_tbl() == 0)
-		dev_priv->map_mode = vmw_dma_map_populate;
+	if (swiotlb_nr_tbl())
+		dev_priv->map_mode = vmw_dma_alloc_coherent;
+	else
 #endif
+		dev_priv->map_mode = vmw_dma_map_populate;
 
 out_fixup:
 	if (dev_priv->map_mode == vmw_dma_map_populate &&
