1 files changed, 69 insertions, 0 deletions
diff --git a/drivers/dax/pmem/core.c b/drivers/dax/pmem/core.c
new file mode 100644
index 000000000000..bdcff1b14e95
--- /dev/null
+++ b/drivers/dax/pmem/core.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */
+#include <linux/memremap.h>
+#include <linux/module.h>
+#include <linux/pfn_t.h>
+#include "../../nvdimm/pfn.h"
+#include "../../nvdimm/nd.h"
+#include "../bus.h"
+
+struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
+{
+	struct resource res;
+	int rc, id, region_id;
+	resource_size_t offset;
+	struct nd_pfn_sb *pfn_sb;
+	struct dev_dax *dev_dax;
+	struct nd_namespace_io *nsio;
+	struct dax_region *dax_region;
+	struct dev_pagemap pgmap = { 0 };
+	struct nd_namespace_common *ndns;
+	struct nd_dax *nd_dax = to_nd_dax(dev);
+	struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
+
+	ndns = nvdimm_namespace_common_probe(dev);
+	if (IS_ERR(ndns))
+		return ERR_CAST(ndns);
+	nsio = to_nd_namespace_io(&ndns->dev);
+
+	/* parse the 'pfn' info block via ->rw_bytes */
+	rc = devm_nsio_enable(dev, nsio);
+	if (rc)
+		return ERR_PTR(rc);
+	rc = nvdimm_setup_pfn(nd_pfn, &pgmap);
+	if (rc)
+		return ERR_PTR(rc);
+	devm_nsio_disable(dev, nsio);
+
+	/* reserve the metadata area, device-dax will reserve the data */
+        pfn_sb = nd_pfn->pfn_sb;
+	offset = le64_to_cpu(pfn_sb->dataoff);
+	if (!devm_request_mem_region(dev, nsio->res.start, offset,
+				dev_name(&ndns->dev))) {
+                dev_warn(dev, "could not reserve metadata\n");
+		return ERR_PTR(-EBUSY);
+        }
+
+	rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", &region_id, &id);
+	if (rc != 2)
+		return ERR_PTR(-EINVAL);
+
+	/* adjust the dax_region resource to the start of data */
+	memcpy(&res, &pgmap.res, sizeof(res));
+	res.start += offset;
+	dax_region = alloc_dax_region(dev, region_id, &res,
+			le32_to_cpu(pfn_sb->align), PFN_DEV|PFN_MAP);
+	if (!dax_region)
+		return ERR_PTR(-ENOMEM);
+
+	dev_dax = __devm_create_dev_dax(dax_region, id, &pgmap, subsys);
+
+	/* child dev_dax instances now own the lifetime of the dax_region */
+	dax_region_put(dax_region);
+
+	return dev_dax;
+}
+EXPORT_SYMBOL_GPL(__dax_pmem_probe);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Intel Corporation");