v4.19.13 snapshot.
diff --git a/tools/testing/nvdimm/dax-dev.c b/tools/testing/nvdimm/dax-dev.c
new file mode 100644
index 0000000..36ee3d8
--- /dev/null
+++ b/tools/testing/nvdimm/dax-dev.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+#include "test/nfit_test.h"
+#include <linux/mm.h>
+#include "../../../drivers/dax/dax-private.h"
+
+phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
+ unsigned long size)
+{
+ struct resource *res;
+ phys_addr_t addr;
+ int i;
+
+ for (i = 0; i < dev_dax->num_resources; i++) {
+ res = &dev_dax->res[i];
+ addr = pgoff * PAGE_SIZE + res->start;
+ if (addr >= res->start && addr <= res->end)
+ break;
+ pgoff -= PHYS_PFN(resource_size(res));
+ }
+
+ if (i < dev_dax->num_resources) {
+ res = &dev_dax->res[i];
+ if (addr + size - 1 <= res->end) {
+ if (get_nfit_res(addr)) {
+ struct page *page;
+
+ if (dev_dax->region->align > PAGE_SIZE)
+ return -1;
+
+ page = vmalloc_to_page((void *)addr);
+ return PFN_PHYS(page_to_pfn(page));
+ } else
+ return addr;
+ }
+ }
+
+ return -1;
+}