xref: /openbmc/linux/drivers/nvdimm/region.c (revision c9933d49)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
4  */
5 #include <linux/cpumask.h>
6 #include <linux/module.h>
7 #include <linux/device.h>
8 #include <linux/nd.h>
9 #include "nd-core.h"
10 #include "nd.h"
11 
12 static int nd_region_probe(struct device *dev)
13 {
14 	int err, rc;
15 	static unsigned long once;
16 	struct nd_region_data *ndrd;
17 	struct nd_region *nd_region = to_nd_region(dev);
18 	struct range range = {
19 		.start = nd_region->ndr_start,
20 		.end = nd_region->ndr_start + nd_region->ndr_size - 1,
21 	};
22 
23 	if (nd_region->num_lanes > num_online_cpus()
24 			&& nd_region->num_lanes < num_possible_cpus()
25 			&& !test_and_set_bit(0, &once)) {
26 		dev_dbg(dev, "online cpus (%d) < concurrent i/o lanes (%d) < possible cpus (%d)\n",
27 				num_online_cpus(), nd_region->num_lanes,
28 				num_possible_cpus());
29 		dev_dbg(dev, "setting nr_cpus=%d may yield better libnvdimm device performance\n",
30 				nd_region->num_lanes);
31 	}
32 
33 	rc = nd_region_activate(nd_region);
34 	if (rc)
35 		return rc;
36 
37 	if (devm_init_badblocks(dev, &nd_region->bb))
38 		return -ENODEV;
39 	nd_region->bb_state =
40 		sysfs_get_dirent(nd_region->dev.kobj.sd, "badblocks");
41 	if (!nd_region->bb_state)
42 		dev_warn(dev, "'badblocks' notification disabled\n");
43 	nvdimm_badblocks_populate(nd_region, &nd_region->bb, &range);
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 	nd_region->btt_seed = nd_btt_create(nd_region);
57 	nd_region->pfn_seed = nd_pfn_create(nd_region);
58 	nd_region->dax_seed = nd_dax_create(nd_region);
59 	if (err == 0)
60 		return 0;
61 
62 	/*
63 	 * Given multiple namespaces per region, we do not want to
64 	 * disable all the successfully registered peer namespaces upon
65 	 * a single registration failure.  If userspace is missing a
66 	 * namespace that it expects it can disable/re-enable the region
67 	 * to retry discovery after correcting the failure.
68 	 * <regionX>/namespaces returns the current
69 	 * "<async-registered>/<total>" namespace count.
70 	 */
71 	dev_err(dev, "failed to register %d namespace%s, continuing...\n",
72 			err, err == 1 ? "" : "s");
73 	return 0;
74 }
75 
76 static int child_unregister(struct device *dev, void *data)
77 {
78 	nd_device_unregister(dev, ND_SYNC);
79 	return 0;
80 }
81 
82 static void nd_region_remove(struct device *dev)
83 {
84 	struct nd_region *nd_region = to_nd_region(dev);
85 
86 	device_for_each_child(dev, NULL, child_unregister);
87 
88 	/* flush attribute readers and disable */
89 	nvdimm_bus_lock(dev);
90 	nd_region->ns_seed = NULL;
91 	nd_region->btt_seed = NULL;
92 	nd_region->pfn_seed = NULL;
93 	nd_region->dax_seed = NULL;
94 	dev_set_drvdata(dev, NULL);
95 	nvdimm_bus_unlock(dev);
96 
97 	/*
98 	 * Note, this assumes nd_device_lock() context to not race
99 	 * nd_region_notify()
100 	 */
101 	sysfs_put(nd_region->bb_state);
102 	nd_region->bb_state = NULL;
103 }
104 
105 static int child_notify(struct device *dev, void *data)
106 {
107 	nd_device_notify(dev, *(enum nvdimm_event *) data);
108 	return 0;
109 }
110 
111 static void nd_region_notify(struct device *dev, enum nvdimm_event event)
112 {
113 	if (event == NVDIMM_REVALIDATE_POISON) {
114 		struct nd_region *nd_region = to_nd_region(dev);
115 
116 		if (is_memory(&nd_region->dev)) {
117 			struct range range = {
118 				.start = nd_region->ndr_start,
119 				.end = nd_region->ndr_start +
120 					nd_region->ndr_size - 1,
121 			};
122 
123 			nvdimm_badblocks_populate(nd_region,
124 					&nd_region->bb, &range);
125 			if (nd_region->bb_state)
126 				sysfs_notify_dirent(nd_region->bb_state);
127 		}
128 	}
129 	device_for_each_child(dev, &event, child_notify);
130 }
131 
132 static struct nd_device_driver nd_region_driver = {
133 	.probe = nd_region_probe,
134 	.remove = nd_region_remove,
135 	.notify = nd_region_notify,
136 	.drv = {
137 		.name = "nd_region",
138 	},
139 	.type = ND_DRIVER_REGION_BLK | ND_DRIVER_REGION_PMEM,
140 };
141 
142 int __init nd_region_init(void)
143 {
144 	return nd_driver_register(&nd_region_driver);
145 }
146 
147 void nd_region_exit(void)
148 {
149 	driver_unregister(&nd_region_driver.drv);
150 }
151 
152 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM);
153