GNU Linux-libre 4.9.328-gnu1
[releases.git] / drivers / nvdimm / region.c
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.h"
18
19 static int nd_region_probe(struct device *dev)
20 {
21         int err, rc;
22         static unsigned long once;
23         struct nd_region_data *ndrd;
24         struct nd_region *nd_region = to_nd_region(dev);
25
26         if (nd_region->num_lanes > num_online_cpus()
27                         && nd_region->num_lanes < num_possible_cpus()
28                         && !test_and_set_bit(0, &once)) {
29                 dev_info(dev, "online cpus (%d) < concurrent i/o lanes (%d) < possible cpus (%d)\n",
30                                 num_online_cpus(), nd_region->num_lanes,
31                                 num_possible_cpus());
32                 dev_info(dev, "setting nr_cpus=%d may yield better libnvdimm device performance\n",
33                                 nd_region->num_lanes);
34         }
35
36         rc = nd_region_activate(nd_region);
37         if (rc)
38                 return rc;
39
40         rc = nd_blk_region_init(nd_region);
41         if (rc)
42                 return rc;
43
44         rc = nd_region_register_namespaces(nd_region, &err);
45         if (rc < 0)
46                 return rc;
47
48         ndrd = dev_get_drvdata(dev);
49         ndrd->ns_active = rc;
50         ndrd->ns_count = rc + err;
51
52         if (rc && err && rc == err)
53                 return -ENODEV;
54
55         nd_region->btt_seed = nd_btt_create(nd_region);
56         nd_region->pfn_seed = nd_pfn_create(nd_region);
57         nd_region->dax_seed = nd_dax_create(nd_region);
58         if (err == 0)
59                 return 0;
60
61         /*
62          * Given multiple namespaces per region, we do not want to
63          * disable all the successfully registered peer namespaces upon
64          * a single registration failure.  If userspace is missing a
65          * namespace that it expects it can disable/re-enable the region
66          * to retry discovery after correcting the failure.
67          * <regionX>/namespaces returns the current
68          * "<async-registered>/<total>" namespace count.
69          */
70         dev_err(dev, "failed to register %d namespace%s, continuing...\n",
71                         err, err == 1 ? "" : "s");
72         return 0;
73 }
74
75 static int child_unregister(struct device *dev, void *data)
76 {
77         nd_device_unregister(dev, ND_SYNC);
78         return 0;
79 }
80
81 static int nd_region_remove(struct device *dev)
82 {
83         struct nd_region *nd_region = to_nd_region(dev);
84
85         device_for_each_child(dev, NULL, child_unregister);
86
87         /* flush attribute readers and disable */
88         nvdimm_bus_lock(dev);
89         nd_region->ns_seed = NULL;
90         nd_region->btt_seed = NULL;
91         nd_region->pfn_seed = NULL;
92         nd_region->dax_seed = NULL;
93         dev_set_drvdata(dev, NULL);
94         nvdimm_bus_unlock(dev);
95
96         return 0;
97 }
98
99 static int child_notify(struct device *dev, void *data)
100 {
101         nd_device_notify(dev, *(enum nvdimm_event *) data);
102         return 0;
103 }
104
105 static void nd_region_notify(struct device *dev, enum nvdimm_event event)
106 {
107         device_for_each_child(dev, &event, child_notify);
108 }
109
110 static struct nd_device_driver nd_region_driver = {
111         .probe = nd_region_probe,
112         .remove = nd_region_remove,
113         .notify = nd_region_notify,
114         .drv = {
115                 .name = "nd_region",
116         },
117         .type = ND_DRIVER_REGION_BLK | ND_DRIVER_REGION_PMEM,
118 };
119
120 int __init nd_region_init(void)
121 {
122         return nd_driver_register(&nd_region_driver);
123 }
124
125 void nd_region_exit(void)
126 {
127         driver_unregister(&nd_region_driver.drv);
128 }
129
130 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM);
131 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_BLK);