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: dev->parent);
24
25 ndns = nvdimm_namespace_common_probe(dev);
26 if (IS_ERR(ptr: ndns))
27 return ERR_CAST(ptr: ndns);
28
29 /* parse the 'pfn' info block via ->rw_bytes */
30 rc = devm_namespace_enable(dev, ndns, size: nd_info_block_reserve());
31 if (rc)
32 return ERR_PTR(error: rc);
33 rc = nvdimm_setup_pfn(nd_pfn, pgmap: &pgmap);
34 if (rc)
35 return ERR_PTR(error: 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(dev: &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(error: -EBUSY);
46 }
47
48 rc = sscanf(dev_name(dev: &ndns->dev), "namespace%d.%d", &region_id, &id);
49 if (rc != 2)
50 return ERR_PTR(error: -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(parent: dev, region_id, range: &range,
56 target_node: nd_region->target_node, le32_to_cpu(pfn_sb->align),
57 IORESOURCE_DAX_STATIC);
58 if (!dax_region)
59 return ERR_PTR(error: -ENOMEM);
60
61 data = (struct dev_dax_data) {
62 .dax_region = dax_region,
63 .id = id,
64 .pgmap = &pgmap,
65 .size = range_len(range: &range),
66 };
67
68 return devm_create_dev_dax(data: &data);
69}
70
71static int dax_pmem_probe(struct device *dev)
72{
73 return PTR_ERR_OR_ZERO(ptr: __dax_pmem_probe(dev));
74}
75
76static struct nd_device_driver dax_pmem_driver = {
77 .probe = dax_pmem_probe,
78 .drv = {
79 .name = "dax_pmem",
80 },
81 .type = ND_DRIVER_DAX_PMEM,
82};
83
84static int __init dax_pmem_init(void)
85{
86 return nd_driver_register(&dax_pmem_driver);
87}
88module_init(dax_pmem_init);
89
90static void __exit dax_pmem_exit(void)
91{
92 driver_unregister(drv: &dax_pmem_driver.drv);
93}
94module_exit(dax_pmem_exit);
95
96MODULE_LICENSE("GPL v2");
97MODULE_AUTHOR("Intel Corporation");
98MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM);
99

source code of linux/drivers/dax/pmem.c