drm: disallow legacy dma ioctls for modesetting drivers

Now only legacy ums drivers have the DRIVER_HAVE_DMA driver feature
flag set, so strictly speaking the modesetting check is redundant. But
adding it has the upside that it makes it very clear that the dma
support is legacy stuff.
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_bufs.c

@@ -1305,6 +1305,9 @@ int drm_addbufs(struct drm_device *dev, void *data,
 	struct drm_buf_desc *request = data;
 	int ret;
 
+	if (drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EINVAL;
+
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 		return -EINVAL;
 
@@ -1348,6 +1351,9 @@ int drm_infobufs(struct drm_device *dev, void *data,
 	int i;
 	int count;
 
+	if (drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EINVAL;
+
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 		return -EINVAL;
 
@@ -1427,6 +1433,9 @@ int drm_markbufs(struct drm_device *dev, void *data,
 	int order;
 	struct drm_buf_entry *entry;
 
+	if (drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EINVAL;
+
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 		return -EINVAL;
 
@@ -1472,6 +1481,9 @@ int drm_freebufs(struct drm_device *dev, void *data,
 	int idx;
 	struct drm_buf *buf;
 
+	if (drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EINVAL;
+
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 		return -EINVAL;
 
@@ -1524,6 +1536,9 @@ int drm_mapbufs(struct drm_device *dev, void *data,
 	struct drm_buf_map *request = data;
 	int i;
 
+	if (drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EINVAL;
+
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
 		return -EINVAL;