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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", ®ion_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_DESCRIPTION("PMEM DAX: direct access to persistent memory");
98MODULE_LICENSE("GPL v2");
99MODULE_AUTHOR("Intel Corporation");
100MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM);
1/*
2 * Copyright(c) 2016 Intel Corporation. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 */
13#include <linux/percpu-refcount.h>
14#include <linux/memremap.h>
15#include <linux/module.h>
16#include <linux/pfn_t.h>
17#include "../nvdimm/pfn.h"
18#include "../nvdimm/nd.h"
19#include "dax.h"
20
21struct dax_pmem {
22 struct device *dev;
23 struct percpu_ref ref;
24 struct completion cmp;
25};
26
27static struct dax_pmem *to_dax_pmem(struct percpu_ref *ref)
28{
29 return container_of(ref, struct dax_pmem, ref);
30}
31
32static void dax_pmem_percpu_release(struct percpu_ref *ref)
33{
34 struct dax_pmem *dax_pmem = to_dax_pmem(ref);
35
36 dev_dbg(dax_pmem->dev, "%s\n", __func__);
37 complete(&dax_pmem->cmp);
38}
39
40static void dax_pmem_percpu_exit(void *data)
41{
42 struct percpu_ref *ref = data;
43 struct dax_pmem *dax_pmem = to_dax_pmem(ref);
44
45 dev_dbg(dax_pmem->dev, "%s\n", __func__);
46 percpu_ref_exit(ref);
47}
48
49static void dax_pmem_percpu_kill(void *data)
50{
51 struct percpu_ref *ref = data;
52 struct dax_pmem *dax_pmem = to_dax_pmem(ref);
53
54 dev_dbg(dax_pmem->dev, "%s\n", __func__);
55 percpu_ref_kill(ref);
56 wait_for_completion(&dax_pmem->cmp);
57}
58
59static int dax_pmem_probe(struct device *dev)
60{
61 int rc;
62 void *addr;
63 struct resource res;
64 struct dax_dev *dax_dev;
65 struct nd_pfn_sb *pfn_sb;
66 struct dax_pmem *dax_pmem;
67 struct nd_region *nd_region;
68 struct nd_namespace_io *nsio;
69 struct dax_region *dax_region;
70 struct nd_namespace_common *ndns;
71 struct nd_dax *nd_dax = to_nd_dax(dev);
72 struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
73 struct vmem_altmap __altmap, *altmap = NULL;
74
75 ndns = nvdimm_namespace_common_probe(dev);
76 if (IS_ERR(ndns))
77 return PTR_ERR(ndns);
78 nsio = to_nd_namespace_io(&ndns->dev);
79
80 /* parse the 'pfn' info block via ->rw_bytes */
81 rc = devm_nsio_enable(dev, nsio);
82 if (rc)
83 return rc;
84 altmap = nvdimm_setup_pfn(nd_pfn, &res, &__altmap);
85 if (IS_ERR(altmap))
86 return PTR_ERR(altmap);
87 devm_nsio_disable(dev, nsio);
88
89 pfn_sb = nd_pfn->pfn_sb;
90
91 if (!devm_request_mem_region(dev, nsio->res.start,
92 resource_size(&nsio->res),
93 dev_name(&ndns->dev))) {
94 dev_warn(dev, "could not reserve region %pR\n", &nsio->res);
95 return -EBUSY;
96 }
97
98 dax_pmem = devm_kzalloc(dev, sizeof(*dax_pmem), GFP_KERNEL);
99 if (!dax_pmem)
100 return -ENOMEM;
101
102 dax_pmem->dev = dev;
103 init_completion(&dax_pmem->cmp);
104 rc = percpu_ref_init(&dax_pmem->ref, dax_pmem_percpu_release, 0,
105 GFP_KERNEL);
106 if (rc)
107 return rc;
108
109 rc = devm_add_action_or_reset(dev, dax_pmem_percpu_exit,
110 &dax_pmem->ref);
111 if (rc)
112 return rc;
113
114 addr = devm_memremap_pages(dev, &res, &dax_pmem->ref, altmap);
115 if (IS_ERR(addr))
116 return PTR_ERR(addr);
117
118 rc = devm_add_action_or_reset(dev, dax_pmem_percpu_kill,
119 &dax_pmem->ref);
120 if (rc)
121 return rc;
122
123 /* adjust the dax_region resource to the start of data */
124 res.start += le64_to_cpu(pfn_sb->dataoff);
125
126 nd_region = to_nd_region(dev->parent);
127 dax_region = alloc_dax_region(dev, nd_region->id, &res,
128 le32_to_cpu(pfn_sb->align), addr, PFN_DEV|PFN_MAP);
129 if (!dax_region)
130 return -ENOMEM;
131
132 /* TODO: support for subdividing a dax region... */
133 dax_dev = devm_create_dax_dev(dax_region, &res, 1);
134
135 /* child dax_dev instances now own the lifetime of the dax_region */
136 dax_region_put(dax_region);
137
138 return PTR_ERR_OR_ZERO(dax_dev);
139}
140
141static struct nd_device_driver dax_pmem_driver = {
142 .probe = dax_pmem_probe,
143 .drv = {
144 .name = "dax_pmem",
145 },
146 .type = ND_DRIVER_DAX_PMEM,
147};
148
149static int __init dax_pmem_init(void)
150{
151 return nd_driver_register(&dax_pmem_driver);
152}
153module_init(dax_pmem_init);
154
155static void __exit dax_pmem_exit(void)
156{
157 driver_unregister(&dax_pmem_driver.drv);
158}
159module_exit(dax_pmem_exit);
160
161MODULE_LICENSE("GPL v2");
162MODULE_AUTHOR("Intel Corporation");
163MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM);