--- zzzz-none-000/linux-5.4.213/kernel/dma/coherent.c	2022-09-15 10:04:56.000000000 +0000
+++ miami-7690-761/linux-5.4.213/kernel/dma/coherent.c	2024-05-29 11:20:02.000000000 +0000
@@ -122,6 +122,18 @@
 		dma_release_coherent_memory(mem);
 	return ret;
 }
+EXPORT_SYMBOL(dma_declare_coherent_memory);
+
+void dma_release_declared_memory(struct device *dev)
+{
+	struct dma_coherent_mem *mem = dev->dma_mem;
+
+	if (!mem)
+		return;
+	dma_release_coherent_memory(mem);
+	dev->dma_mem = NULL;
+}
+EXPORT_SYMBOL(dma_release_declared_memory);
 
 static void *__dma_alloc_from_coherent(struct device *dev,
 				       struct dma_coherent_mem *mem,