1// SPDX-License-Identifier: GPL-2.0
 2/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */
 3#include <linux/memremap.h>
 4#include <linux/module.h>
 5#include <linux/pfn_t.h>
 6#include "../../nvdimm/pfn.h"
 7#include "../../nvdimm/nd.h"
 8#include "../bus.h"
 9
10struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
11{
12	struct resource res;
13	int rc, id, region_id;
14	resource_size_t offset;
15	struct nd_pfn_sb *pfn_sb;
16	struct dev_dax *dev_dax;
17	struct nd_namespace_io *nsio;
18	struct dax_region *dax_region;
19	struct dev_pagemap pgmap = { };
20	struct nd_namespace_common *ndns;
21	struct nd_dax *nd_dax = to_nd_dax(dev);
22	struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
23	struct nd_region *nd_region = to_nd_region(dev->parent);
24
25	ndns = nvdimm_namespace_common_probe(dev);
26	if (IS_ERR(ndns))
27		return ERR_CAST(ndns);
28	nsio = to_nd_namespace_io(&ndns->dev);
29
30	/* parse the 'pfn' info block via ->rw_bytes */
31	rc = devm_nsio_enable(dev, nsio);
32	if (rc)
33		return ERR_PTR(rc);
34	rc = nvdimm_setup_pfn(nd_pfn, &pgmap);
35	if (rc)
36		return ERR_PTR(rc);
37	devm_nsio_disable(dev, nsio);
38
39	/* reserve the metadata area, device-dax will reserve the data */
40	pfn_sb = nd_pfn->pfn_sb;
41	offset = le64_to_cpu(pfn_sb->dataoff);
42	if (!devm_request_mem_region(dev, nsio->res.start, offset,
43				dev_name(&ndns->dev))) {
44		dev_warn(dev, "could not reserve metadata\n");
45		return ERR_PTR(-EBUSY);
46	}
47
48	rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", &region_id, &id);
49	if (rc != 2)
50		return ERR_PTR(-EINVAL);
51
52	/* adjust the dax_region resource to the start of data */
53	memcpy(&res, &pgmap.res, sizeof(res));
54	res.start += offset;
55	dax_region = alloc_dax_region(dev, region_id, &res,
56			nd_region->target_node, le32_to_cpu(pfn_sb->align),
57			PFN_DEV|PFN_MAP);
58	if (!dax_region)
59		return ERR_PTR(-ENOMEM);
60
61	dev_dax = __devm_create_dev_dax(dax_region, id, &pgmap, subsys);
62
63	/* child dev_dax instances now own the lifetime of the dax_region */
64	dax_region_put(dax_region);
65
66	return dev_dax;
67}
68EXPORT_SYMBOL_GPL(__dax_pmem_probe);
69
70MODULE_LICENSE("GPL v2");
71MODULE_AUTHOR("Intel Corporation");