v4.19.13 snapshot.
diff --git a/include/linux/dmapool.h b/include/linux/dmapool.h
new file mode 100644
index 0000000..f632ecf
--- /dev/null
+++ b/include/linux/dmapool.h
@@ -0,0 +1,59 @@
+/*
+ * include/linux/dmapool.h
+ *
+ * Allocation pools for DMAable (coherent) memory.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef LINUX_DMAPOOL_H
+#define LINUX_DMAPOOL_H
+
+#include <linux/scatterlist.h>
+#include <asm/io.h>
+
+struct device;
+
+#ifdef CONFIG_HAS_DMA
+
+struct dma_pool *dma_pool_create(const char *name, struct device *dev,
+ size_t size, size_t align, size_t allocation);
+
+void dma_pool_destroy(struct dma_pool *pool);
+
+void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
+ dma_addr_t *handle);
+void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t addr);
+
+/*
+ * Managed DMA pool
+ */
+struct dma_pool *dmam_pool_create(const char *name, struct device *dev,
+ size_t size, size_t align, size_t allocation);
+void dmam_pool_destroy(struct dma_pool *pool);
+
+#else /* !CONFIG_HAS_DMA */
+static inline struct dma_pool *dma_pool_create(const char *name,
+ struct device *dev, size_t size, size_t align, size_t allocation)
+{ return NULL; }
+static inline void dma_pool_destroy(struct dma_pool *pool) { }
+static inline void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
+ dma_addr_t *handle) { return NULL; }
+static inline void dma_pool_free(struct dma_pool *pool, void *vaddr,
+ dma_addr_t addr) { }
+static inline struct dma_pool *dmam_pool_create(const char *name,
+ struct device *dev, size_t size, size_t align, size_t allocation)
+{ return NULL; }
+static inline void dmam_pool_destroy(struct dma_pool *pool) { }
+#endif /* !CONFIG_HAS_DMA */
+
+static inline void *dma_pool_zalloc(struct dma_pool *pool, gfp_t mem_flags,
+ dma_addr_t *handle)
+{
+ return dma_pool_alloc(pool, mem_flags | __GFP_ZERO, handle);
+}
+
+#endif
+