Merge remote-tracking branches 'asoc/fix/wm8960' and 'asoc/fix/wm8962' into asoc...
[firefly-linux-kernel-4.4.55.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_namespaces *num_ns;
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_blk_region_init(nd_region);
37         if (rc)
38                 return rc;
39
40         rc = nd_region_register_namespaces(nd_region, &err);
41         num_ns = devm_kzalloc(dev, sizeof(*num_ns), GFP_KERNEL);
42         if (!num_ns)
43                 return -ENOMEM;
44
45         if (rc < 0)
46                 return rc;
47
48         num_ns->active = rc;
49         num_ns->count = rc + err;
50         dev_set_drvdata(dev, num_ns);
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         if (err == 0)
58                 return 0;
59
60         /*
61          * Given multiple namespaces per region, we do not want to
62          * disable all the successfully registered peer namespaces upon
63          * a single registration failure.  If userspace is missing a
64          * namespace that it expects it can disable/re-enable the region
65          * to retry discovery after correcting the failure.
66          * <regionX>/namespaces returns the current
67          * "<async-registered>/<total>" namespace count.
68          */
69         dev_err(dev, "failed to register %d namespace%s, continuing...\n",
70                         err, err == 1 ? "" : "s");
71         return 0;
72 }
73
74 static int child_unregister(struct device *dev, void *data)
75 {
76         nd_device_unregister(dev, ND_SYNC);
77         return 0;
78 }
79
80 static int nd_region_remove(struct device *dev)
81 {
82         struct nd_region *nd_region = to_nd_region(dev);
83
84         /* flush attribute readers and disable */
85         nvdimm_bus_lock(dev);
86         nd_region->ns_seed = NULL;
87         nd_region->btt_seed = NULL;
88         nd_region->pfn_seed = NULL;
89         dev_set_drvdata(dev, NULL);
90         nvdimm_bus_unlock(dev);
91
92         device_for_each_child(dev, NULL, child_unregister);
93         return 0;
94 }
95
96 static struct nd_device_driver nd_region_driver = {
97         .probe = nd_region_probe,
98         .remove = nd_region_remove,
99         .drv = {
100                 .name = "nd_region",
101         },
102         .type = ND_DRIVER_REGION_BLK | ND_DRIVER_REGION_PMEM,
103 };
104
105 int __init nd_region_init(void)
106 {
107         return nd_driver_register(&nd_region_driver);
108 }
109
110 void nd_region_exit(void)
111 {
112         driver_unregister(&nd_region_driver.drv);
113 }
114
115 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM);
116 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_BLK);