xref: /openbmc/linux/drivers/nvdimm/region.c (revision dea54fba)
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/cpumask.h>
14 #include <linux/module.h>
15 #include <linux/device.h>
16 #include <linux/nd.h>
17 #include "nd-core.h"
18 #include "nd.h"
19 
20 static int nd_region_probe(struct device *dev)
21 {
22 	int err, rc;
23 	static unsigned long once;
24 	struct nd_region_data *ndrd;
25 	struct nd_region *nd_region = to_nd_region(dev);
26 
27 	if (nd_region->num_lanes > num_online_cpus()
28 			&& nd_region->num_lanes < num_possible_cpus()
29 			&& !test_and_set_bit(0, &once)) {
30 		dev_info(dev, "online cpus (%d) < concurrent i/o lanes (%d) < possible cpus (%d)\n",
31 				num_online_cpus(), nd_region->num_lanes,
32 				num_possible_cpus());
33 		dev_info(dev, "setting nr_cpus=%d may yield better libnvdimm device performance\n",
34 				nd_region->num_lanes);
35 	}
36 
37 	rc = nd_region_activate(nd_region);
38 	if (rc)
39 		return rc;
40 
41 	rc = nd_blk_region_init(nd_region);
42 	if (rc)
43 		return rc;
44 
45 	rc = nd_region_register_namespaces(nd_region, &err);
46 	if (rc < 0)
47 		return rc;
48 
49 	ndrd = dev_get_drvdata(dev);
50 	ndrd->ns_active = rc;
51 	ndrd->ns_count = rc + err;
52 
53 	if (rc && err && rc == err)
54 		return -ENODEV;
55 
56 	if (is_nd_pmem(&nd_region->dev)) {
57 		struct resource ndr_res;
58 
59 		if (devm_init_badblocks(dev, &nd_region->bb))
60 			return -ENODEV;
61 		nd_region->bb_state = sysfs_get_dirent(nd_region->dev.kobj.sd,
62 						       "badblocks");
63 		if (!nd_region->bb_state)
64 			dev_warn(&nd_region->dev,
65 					"'badblocks' notification disabled\n");
66 		ndr_res.start = nd_region->ndr_start;
67 		ndr_res.end = nd_region->ndr_start + nd_region->ndr_size - 1;
68 		nvdimm_badblocks_populate(nd_region, &nd_region->bb, &ndr_res);
69 	}
70 
71 	nd_region->btt_seed = nd_btt_create(nd_region);
72 	nd_region->pfn_seed = nd_pfn_create(nd_region);
73 	nd_region->dax_seed = nd_dax_create(nd_region);
74 	if (err == 0)
75 		return 0;
76 
77 	/*
78 	 * Given multiple namespaces per region, we do not want to
79 	 * disable all the successfully registered peer namespaces upon
80 	 * a single registration failure.  If userspace is missing a
81 	 * namespace that it expects it can disable/re-enable the region
82 	 * to retry discovery after correcting the failure.
83 	 * <regionX>/namespaces returns the current
84 	 * "<async-registered>/<total>" namespace count.
85 	 */
86 	dev_err(dev, "failed to register %d namespace%s, continuing...\n",
87 			err, err == 1 ? "" : "s");
88 	return 0;
89 }
90 
91 static int child_unregister(struct device *dev, void *data)
92 {
93 	nd_device_unregister(dev, ND_SYNC);
94 	return 0;
95 }
96 
97 static int nd_region_remove(struct device *dev)
98 {
99 	struct nd_region *nd_region = to_nd_region(dev);
100 
101 	device_for_each_child(dev, NULL, child_unregister);
102 
103 	/* flush attribute readers and disable */
104 	nvdimm_bus_lock(dev);
105 	nd_region->ns_seed = NULL;
106 	nd_region->btt_seed = NULL;
107 	nd_region->pfn_seed = NULL;
108 	nd_region->dax_seed = NULL;
109 	dev_set_drvdata(dev, NULL);
110 	nvdimm_bus_unlock(dev);
111 
112 	/*
113 	 * Note, this assumes device_lock() context to not race
114 	 * nd_region_notify()
115 	 */
116 	sysfs_put(nd_region->bb_state);
117 	nd_region->bb_state = NULL;
118 
119 	return 0;
120 }
121 
122 static int child_notify(struct device *dev, void *data)
123 {
124 	nd_device_notify(dev, *(enum nvdimm_event *) data);
125 	return 0;
126 }
127 
128 static void nd_region_notify(struct device *dev, enum nvdimm_event event)
129 {
130 	if (event == NVDIMM_REVALIDATE_POISON) {
131 		struct nd_region *nd_region = to_nd_region(dev);
132 		struct resource res;
133 
134 		if (is_nd_pmem(&nd_region->dev)) {
135 			res.start = nd_region->ndr_start;
136 			res.end = nd_region->ndr_start +
137 				nd_region->ndr_size - 1;
138 			nvdimm_badblocks_populate(nd_region,
139 					&nd_region->bb, &res);
140 			if (nd_region->bb_state)
141 				sysfs_notify_dirent(nd_region->bb_state);
142 		}
143 	}
144 	device_for_each_child(dev, &event, child_notify);
145 }
146 
147 static struct nd_device_driver nd_region_driver = {
148 	.probe = nd_region_probe,
149 	.remove = nd_region_remove,
150 	.notify = nd_region_notify,
151 	.drv = {
152 		.name = "nd_region",
153 	},
154 	.type = ND_DRIVER_REGION_BLK | ND_DRIVER_REGION_PMEM,
155 };
156 
157 int __init nd_region_init(void)
158 {
159 	return nd_driver_register(&nd_region_driver);
160 }
161 
162 void nd_region_exit(void)
163 {
164 	driver_unregister(&nd_region_driver.drv);
165 }
166 
167 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM);
168 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_BLK);
169