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
10static struct dev_dax *__dax_pmem_probe(struct device *dev)
11{
12	struct range range;
13	int rc, id, region_id;
14	resource_size_t offset;
15	struct nd_pfn_sb *pfn_sb;
16	struct dev_dax_data data;
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
29	/* parse the 'pfn' info block via ->rw_bytes */
30	rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
31	if (rc)
32		return ERR_PTR(rc);
33	rc = nvdimm_setup_pfn(nd_pfn, &pgmap);
34	if (rc)
35		return ERR_PTR(rc);
36	devm_namespace_disable(dev, ndns);
37
38	/* reserve the metadata area, device-dax will reserve the data */
39	pfn_sb = nd_pfn->pfn_sb;
40	offset = le64_to_cpu(pfn_sb->dataoff);
41	nsio = to_nd_namespace_io(&ndns->dev);
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 range to the start of data */
53	range = pgmap.range;
54	range.start += offset;
55	dax_region = alloc_dax_region(dev, region_id, &range,
56			nd_region->target_node, le32_to_cpu(pfn_sb->align),
57			IORESOURCE_DAX_STATIC);
58	if (!dax_region)
59		return ERR_PTR(-ENOMEM);
60
61	data = (struct dev_dax_data) {
62		.dax_region = dax_region,
63		.id = id,
64		.pgmap = &pgmap,
65		.size = range_len(&range),
66		.memmap_on_memory = false,
67	};
68
69	return devm_create_dev_dax(&data);
70}
71
72static int dax_pmem_probe(struct device *dev)
73{
74	return PTR_ERR_OR_ZERO(__dax_pmem_probe(dev));
75}
76
77static struct nd_device_driver dax_pmem_driver = {
78	.probe = dax_pmem_probe,
79	.drv = {
80		.name = "dax_pmem",
81	},
82	.type = ND_DRIVER_DAX_PMEM,
83};
84
85static int __init dax_pmem_init(void)
86{
87	return nd_driver_register(&dax_pmem_driver);
88}
89module_init(dax_pmem_init);
90
91static void __exit dax_pmem_exit(void)
92{
93	driver_unregister(&dax_pmem_driver.drv);
94}
95module_exit(dax_pmem_exit);
96
97MODULE_LICENSE("GPL v2");
98MODULE_AUTHOR("Intel Corporation");
99MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM);