1 files changed, 79 insertions, 0 deletions
diff --git a/drivers/dax/pmem/core.c b/drivers/dax/pmem/core.c
new file mode 100644
index 000000000..62b26bfce
--- /dev/null
+++ b/drivers/dax/pmem/core.c
@@ -0,0 +1,79 @@
+// 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 range range;
+	int rc, id, region_id;
+	resource_size_t offset;
+	struct nd_pfn_sb *pfn_sb;
+	struct dev_dax *dev_dax;
+	struct dev_dax_data data;
+	struct nd_namespace_io *nsio;
+	struct dax_region *dax_region;
+	struct dev_pagemap pgmap = { };
+	struct nd_namespace_common *ndns;
+	struct nd_dax *nd_dax = to_nd_dax(dev);
+	struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
+	struct nd_region *nd_region = to_nd_region(dev->parent);
+
+	ndns = nvdimm_namespace_common_probe(dev);
+	if (IS_ERR(ndns))
+		return ERR_CAST(ndns);
+
+	/* parse the 'pfn' info block via ->rw_bytes */
+	rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
+	if (rc)
+		return ERR_PTR(rc);
+	rc = nvdimm_setup_pfn(nd_pfn, &pgmap);
+	if (rc)
+		return ERR_PTR(rc);
+	devm_namespace_disable(dev, ndns);
+
+	/* reserve the metadata area, device-dax will reserve the data */
+	pfn_sb = nd_pfn->pfn_sb;
+	offset = le64_to_cpu(pfn_sb->dataoff);
+	nsio = to_nd_namespace_io(&ndns->dev);
+	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 range to the start of data */
+	range = pgmap.range;
+	range.start += offset,
+	dax_region = alloc_dax_region(dev, region_id, &range,
+			nd_region->target_node, le32_to_cpu(pfn_sb->align),
+			IORESOURCE_DAX_STATIC);
+	if (!dax_region)
+		return ERR_PTR(-ENOMEM);
+
+	data = (struct dev_dax_data) {
+		.dax_region = dax_region,
+		.id = id,
+		.pgmap = &pgmap,
+		.subsys = subsys,
+		.size = range_len(&range),
+	};
+	dev_dax = devm_create_dev_dax(&data);
+
+	/* 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");