xref: /openbmc/linux/drivers/nvdimm/region.c (revision 256ac037)
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 		ndr_res.start = nd_region->ndr_start;
62 		ndr_res.end = nd_region->ndr_start + nd_region->ndr_size - 1;
63 		nvdimm_badblocks_populate(nd_region,
64 				&nd_region->bb, &ndr_res);
65 	}
66 
67 	nd_region->btt_seed = nd_btt_create(nd_region);
68 	nd_region->pfn_seed = nd_pfn_create(nd_region);
69 	nd_region->dax_seed = nd_dax_create(nd_region);
70 	if (err == 0)
71 		return 0;
72 
73 	/*
74 	 * Given multiple namespaces per region, we do not want to
75 	 * disable all the successfully registered peer namespaces upon
76 	 * a single registration failure.  If userspace is missing a
77 	 * namespace that it expects it can disable/re-enable the region
78 	 * to retry discovery after correcting the failure.
79 	 * <regionX>/namespaces returns the current
80 	 * "<async-registered>/<total>" namespace count.
81 	 */
82 	dev_err(dev, "failed to register %d namespace%s, continuing...\n",
83 			err, err == 1 ? "" : "s");
84 	return 0;
85 }
86 
87 static int child_unregister(struct device *dev, void *data)
88 {
89 	nd_device_unregister(dev, ND_SYNC);
90 	return 0;
91 }
92 
93 static int nd_region_remove(struct device *dev)
94 {
95 	struct nd_region *nd_region = to_nd_region(dev);
96 
97 	device_for_each_child(dev, NULL, child_unregister);
98 
99 	/* flush attribute readers and disable */
100 	nvdimm_bus_lock(dev);
101 	nd_region->ns_seed = NULL;
102 	nd_region->btt_seed = NULL;
103 	nd_region->pfn_seed = NULL;
104 	nd_region->dax_seed = NULL;
105 	dev_set_drvdata(dev, NULL);
106 	nvdimm_bus_unlock(dev);
107 
108 	return 0;
109 }
110 
111 static int child_notify(struct device *dev, void *data)
112 {
113 	nd_device_notify(dev, *(enum nvdimm_event *) data);
114 	return 0;
115 }
116 
117 static void nd_region_notify(struct device *dev, enum nvdimm_event event)
118 {
119 	if (event == NVDIMM_REVALIDATE_POISON) {
120 		struct nd_region *nd_region = to_nd_region(dev);
121 		struct resource res;
122 
123 		if (is_nd_pmem(&nd_region->dev)) {
124 			res.start = nd_region->ndr_start;
125 			res.end = nd_region->ndr_start +
126 				nd_region->ndr_size - 1;
127 			nvdimm_badblocks_populate(nd_region,
128 					&nd_region->bb, &res);
129 		}
130 	}
131 	device_for_each_child(dev, &event, child_notify);
132 }
133 
134 static struct nd_device_driver nd_region_driver = {
135 	.probe = nd_region_probe,
136 	.remove = nd_region_remove,
137 	.notify = nd_region_notify,
138 	.drv = {
139 		.name = "nd_region",
140 	},
141 	.type = ND_DRIVER_REGION_BLK | ND_DRIVER_REGION_PMEM,
142 };
143 
144 int __init nd_region_init(void)
145 {
146 	return nd_driver_register(&nd_region_driver);
147 }
148 
149 void nd_region_exit(void)
150 {
151 	driver_unregister(&nd_region_driver.drv);
152 }
153 
154 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM);
155 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_BLK);
156