v4.19.13 snapshot.
diff --git a/include/linux/cma.h b/include/linux/cma.h
new file mode 100644
index 0000000..190184b
--- /dev/null
+++ b/include/linux/cma.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __CMA_H__
+#define __CMA_H__
+
+#include <linux/init.h>
+#include <linux/types.h>
+
+/*
+ * There is always at least global CMA area and a few optional
+ * areas configured in kernel .config.
+ */
+#ifdef CONFIG_CMA_AREAS
+#define MAX_CMA_AREAS (1 + CONFIG_CMA_AREAS)
+
+#else
+#define MAX_CMA_AREAS (0)
+
+#endif
+
+struct cma;
+
+extern unsigned long totalcma_pages;
+extern phys_addr_t cma_get_base(const struct cma *cma);
+extern unsigned long cma_get_size(const struct cma *cma);
+extern const char *cma_get_name(const struct cma *cma);
+
+extern int __init cma_declare_contiguous(phys_addr_t base,
+ phys_addr_t size, phys_addr_t limit,
+ phys_addr_t alignment, unsigned int order_per_bit,
+ bool fixed, const char *name, struct cma **res_cma);
+extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
+ unsigned int order_per_bit,
+ const char *name,
+ struct cma **res_cma);
+extern struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
+ bool no_warn);
+extern bool cma_release(struct cma *cma, const struct page *pages, unsigned int count);
+
+extern int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data);
+#endif