iommu/dart: Reject identity domain for locked DARTs

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Signed-off-by: Janbne Grunau <j@jannau.net>

Author: alyssarosenzweig

drivers/iommu/apple-dart.c

@@ -681,6 +681,9 @@ static int apple_dart_attach_dev_identity(struct iommu_domain *domain,
 	if (!cfg->stream_maps[0].dart->supports_bypass)
 		return -EINVAL;
 
+	if (cfg->stream_maps[0].dart->locked)
+		return -EINVAL;
+
 	for_each_stream_map(i, cfg, stream_map)
 		apple_dart_hw_enable_bypass(stream_map);
 	return 0;