xref: /linux/drivers/dax/pmem.c (revision e7d759f31ca295d589f7420719c311870bb3166f)
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 
10 static 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 
72 static int dax_pmem_probe(struct device *dev)
73 {
74 	return PTR_ERR_OR_ZERO(__dax_pmem_probe(dev));
75 }
76 
77 static 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 
85 static int __init dax_pmem_init(void)
86 {
87 	return nd_driver_register(&dax_pmem_driver);
88 }
89 module_init(dax_pmem_init);
90 
91 static void __exit dax_pmem_exit(void)
92 {
93 	driver_unregister(&dax_pmem_driver.drv);
94 }
95 module_exit(dax_pmem_exit);
96 
97 MODULE_LICENSE("GPL v2");
98 MODULE_AUTHOR("Intel Corporation");
99 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM);
100