xref: /openbmc/linux/drivers/nvdimm/dimm.c (revision a2818ee4)
1 /*
2  * Copyright(c) 2013-2015 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/vmalloc.h>
14 #include <linux/module.h>
15 #include <linux/device.h>
16 #include <linux/sizes.h>
17 #include <linux/ndctl.h>
18 #include <linux/slab.h>
19 #include <linux/mm.h>
20 #include <linux/nd.h>
21 #include "label.h"
22 #include "nd.h"
23 
24 static int nvdimm_probe(struct device *dev)
25 {
26 	struct nvdimm_drvdata *ndd;
27 	int rc;
28 
29 	rc = nvdimm_check_config_data(dev);
30 	if (rc) {
31 		/* not required for non-aliased nvdimm, ex. NVDIMM-N */
32 		if (rc == -ENOTTY)
33 			rc = 0;
34 		return rc;
35 	}
36 
37 	/*
38 	 * The locked status bit reflects explicit status codes from the
39 	 * label reading commands, revalidate it each time the driver is
40 	 * activated and re-reads the label area.
41 	 */
42 	nvdimm_clear_locked(dev);
43 
44 	ndd = kzalloc(sizeof(*ndd), GFP_KERNEL);
45 	if (!ndd)
46 		return -ENOMEM;
47 
48 	dev_set_drvdata(dev, ndd);
49 	ndd->dpa.name = dev_name(dev);
50 	ndd->ns_current = -1;
51 	ndd->ns_next = -1;
52 	ndd->dpa.start = 0;
53 	ndd->dpa.end = -1;
54 	ndd->dev = dev;
55 	get_device(dev);
56 	kref_init(&ndd->kref);
57 
58 	/*
59 	 * Attempt to unlock, if the DIMM supports security commands,
60 	 * otherwise the locked indication is determined by explicit
61 	 * status codes from the label reading commands.
62 	 */
63 	rc = nvdimm_security_unlock(dev);
64 	if (rc < 0)
65 		dev_dbg(dev, "failed to unlock dimm: %d\n", rc);
66 
67 
68 	/*
69 	 * EACCES failures reading the namespace label-area-properties
70 	 * are interpreted as the DIMM capacity being locked but the
71 	 * namespace labels themselves being accessible.
72 	 */
73 	rc = nvdimm_init_nsarea(ndd);
74 	if (rc == -EACCES) {
75 		/*
76 		 * See nvdimm_namespace_common_probe() where we fail to
77 		 * allow namespaces to probe while the DIMM is locked,
78 		 * but we do allow for namespace enumeration.
79 		 */
80 		nvdimm_set_locked(dev);
81 		rc = 0;
82 	}
83 	if (rc)
84 		goto err;
85 
86 	/*
87 	 * EACCES failures reading the namespace label-data are
88 	 * interpreted as the label area being locked in addition to the
89 	 * DIMM capacity. We fail the dimm probe to prevent regions from
90 	 * attempting to parse the label area.
91 	 */
92 	rc = nd_label_data_init(ndd);
93 	if (rc == -EACCES)
94 		nvdimm_set_locked(dev);
95 	if (rc)
96 		goto err;
97 
98 	dev_dbg(dev, "config data size: %d\n", ndd->nsarea.config_size);
99 
100 	nvdimm_bus_lock(dev);
101 	if (ndd->ns_current >= 0) {
102 		rc = nd_label_reserve_dpa(ndd);
103 		if (rc == 0)
104 			nvdimm_set_aliasing(dev);
105 	}
106 	nvdimm_bus_unlock(dev);
107 
108 	if (rc)
109 		goto err;
110 
111 	return 0;
112 
113  err:
114 	put_ndd(ndd);
115 	return rc;
116 }
117 
118 static int nvdimm_remove(struct device *dev)
119 {
120 	struct nvdimm_drvdata *ndd = dev_get_drvdata(dev);
121 
122 	if (!ndd)
123 		return 0;
124 
125 	nvdimm_bus_lock(dev);
126 	dev_set_drvdata(dev, NULL);
127 	nvdimm_bus_unlock(dev);
128 	put_ndd(ndd);
129 
130 	return 0;
131 }
132 
133 static struct nd_device_driver nvdimm_driver = {
134 	.probe = nvdimm_probe,
135 	.remove = nvdimm_remove,
136 	.drv = {
137 		.name = "nvdimm",
138 	},
139 	.type = ND_DRIVER_DIMM,
140 };
141 
142 int __init nvdimm_init(void)
143 {
144 	return nd_driver_register(&nvdimm_driver);
145 }
146 
147 void nvdimm_exit(void)
148 {
149 	driver_unregister(&nvdimm_driver.drv);
150 }
151 
152 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DIMM);
153