--- zzzz-none-000/linux-4.4.60/include/linux/dmapool.h	2017-04-08 07:53:53.000000000 +0000
+++ hawkeye-5590-729/linux-4.4.60/include/linux/dmapool.h	2022-03-30 14:21:53.000000000 +0000
@@ -16,6 +16,17 @@
 
 struct device;
 
+struct dma_pool {		/* the pool */
+	struct list_head page_list;
+	spinlock_t lock;
+	size_t size;
+	struct device *dev;
+	size_t allocation;
+	size_t boundary;
+	char name[32];
+	struct list_head pools;
+};
+
 struct dma_pool *dma_pool_create(const char *name, struct device *dev, 
 			size_t size, size_t align, size_t allocation);