drivers/nvdimm/core.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/libnvdimm.h>
  14 #include <linux/export.h>
  15 #include <linux/module.h>
  16 #include <linux/device.h>
  17 #include <linux/ndctl.h>
  18 #include <linux/mutex.h>
  19 #include <linux/slab.h>
  20 #include "nd-core.h"
  21 #include "nd.h"
  22
  23 LIST_HEAD(nvdimm_bus_list);
  24 DEFINE_MUTEX(nvdimm_bus_list_mutex);
  25 static DEFINE_IDA(nd_ida);
  26
  27 void nvdimm_bus_lock(struct device *dev)
  28 {
  29         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  30
  31         if (!nvdimm_bus)
  32                 return;
  33         mutex_lock(&nvdimm_bus->reconfig_mutex);
  34 }
  35 EXPORT_SYMBOL(nvdimm_bus_lock);
  36
  37 void nvdimm_bus_unlock(struct device *dev)
  38 {
  39         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  40
  41         if (!nvdimm_bus)
  42                 return;
  43         mutex_unlock(&nvdimm_bus->reconfig_mutex);
  44 }
  45 EXPORT_SYMBOL(nvdimm_bus_unlock);
  46
  47 bool is_nvdimm_bus_locked(struct device *dev)
  48 {
  49         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  50
  51         if (!nvdimm_bus)
  52                 return false;
  53         return mutex_is_locked(&nvdimm_bus->reconfig_mutex);
  54 }
  55 EXPORT_SYMBOL(is_nvdimm_bus_locked);
  56
  57 static void nvdimm_bus_release(struct device *dev)
  58 {
  59         struct nvdimm_bus *nvdimm_bus;
  60
  61         nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
  62         ida_simple_remove(&nd_ida, nvdimm_bus->id);
  63         kfree(nvdimm_bus);
  64 }
  65
  66 struct nvdimm_bus *to_nvdimm_bus(struct device *dev)
  67 {
  68         struct nvdimm_bus *nvdimm_bus;
  69
  70         nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
  71         WARN_ON(nvdimm_bus->dev.release != nvdimm_bus_release);
  72         return nvdimm_bus;
  73 }
  74 EXPORT_SYMBOL_GPL(to_nvdimm_bus);
  75
  76 struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus)
  77 {
  78         /* struct nvdimm_bus definition is private to libnvdimm */
  79         return nvdimm_bus->nd_desc;
  80 }
  81 EXPORT_SYMBOL_GPL(to_nd_desc);
  82
  83 struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
  84 {
  85         struct device *dev;
  86
  87         for (dev = nd_dev; dev; dev = dev->parent)
  88                 if (dev->release == nvdimm_bus_release)
  89                         break;
  90         dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
  91         if (dev)
  92                 return to_nvdimm_bus(dev);
  93         return NULL;
  94 }
  95
  96 static ssize_t commands_show(struct device *dev,
  97                 struct device_attribute *attr, char *buf)
  98 {
  99         int cmd, len = 0;
 100         struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 101         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 102
 103         for_each_set_bit(cmd, &nd_desc->dsm_mask, BITS_PER_LONG)
 104                 len += sprintf(buf + len, "%s ", nvdimm_bus_cmd_name(cmd));
 105         len += sprintf(buf + len, "\n");
 106         return len;
 107 }
 108 static DEVICE_ATTR_RO(commands);
 109
 110 static const char *nvdimm_bus_provider(struct nvdimm_bus *nvdimm_bus)
 111 {
 112         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 113         struct device *parent = nvdimm_bus->dev.parent;
 114
 115         if (nd_desc->provider_name)
 116                 return nd_desc->provider_name;
 117         else if (parent)
 118                 return dev_name(parent);
 119         else
 120                 return "unknown";
 121 }
 122
 123 static ssize_t provider_show(struct device *dev,
 124                 struct device_attribute *attr, char *buf)
 125 {
 126         struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 127
 128         return sprintf(buf, "%s\n", nvdimm_bus_provider(nvdimm_bus));
 129 }
 130 static DEVICE_ATTR_RO(provider);
 131
 132 static int flush_namespaces(struct device *dev, void *data)
 133 {
 134         device_lock(dev);
 135         device_unlock(dev);
 136         return 0;
 137 }
 138
 139 static int flush_regions_dimms(struct device *dev, void *data)
 140 {
 141         device_lock(dev);
 142         device_unlock(dev);
 143         device_for_each_child(dev, NULL, flush_namespaces);
 144         return 0;
 145 }
 146
 147 static ssize_t wait_probe_show(struct device *dev,
 148                 struct device_attribute *attr, char *buf)
 149 {
 150         nd_synchronize();
 151         device_for_each_child(dev, NULL, flush_regions_dimms);
 152         return sprintf(buf, "1\n");
 153 }
 154 static DEVICE_ATTR_RO(wait_probe);
 155
 156 static struct attribute *nvdimm_bus_attributes[] = {
 157         &dev_attr_commands.attr,
 158         &dev_attr_wait_probe.attr,
 159         &dev_attr_provider.attr,
 160         NULL,
 161 };
 162
 163 struct attribute_group nvdimm_bus_attribute_group = {
 164         .attrs = nvdimm_bus_attributes,
 165 };
 166 EXPORT_SYMBOL_GPL(nvdimm_bus_attribute_group);
 167
 168 struct nvdimm_bus *__nvdimm_bus_register(struct device *parent,
 169                 struct nvdimm_bus_descriptor *nd_desc, struct module *module)
 170 {
 171         struct nvdimm_bus *nvdimm_bus;
 172         int rc;
 173
 174         nvdimm_bus = kzalloc(sizeof(*nvdimm_bus), GFP_KERNEL);
 175         if (!nvdimm_bus)
 176                 return NULL;
 177         INIT_LIST_HEAD(&nvdimm_bus->list);
 178         nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
 179         mutex_init(&nvdimm_bus->reconfig_mutex);
 180         if (nvdimm_bus->id < 0) {
 181                 kfree(nvdimm_bus);
 182                 return NULL;
 183         }
 184         nvdimm_bus->nd_desc = nd_desc;
 185         nvdimm_bus->module = module;
 186         nvdimm_bus->dev.parent = parent;
 187         nvdimm_bus->dev.release = nvdimm_bus_release;
 188         nvdimm_bus->dev.groups = nd_desc->attr_groups;
 189         dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
 190         rc = device_register(&nvdimm_bus->dev);
 191         if (rc) {
 192                 dev_dbg(&nvdimm_bus->dev, "registration failed: %d\n", rc);
 193                 goto err;
 194         }
 195
 196         rc = nvdimm_bus_create_ndctl(nvdimm_bus);
 197         if (rc)
 198                 goto err;
 199
 200         mutex_lock(&nvdimm_bus_list_mutex);
 201         list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
 202         mutex_unlock(&nvdimm_bus_list_mutex);
 203
 204         return nvdimm_bus;
 205  err:
 206         put_device(&nvdimm_bus->dev);
 207         return NULL;
 208 }
 209 EXPORT_SYMBOL_GPL(__nvdimm_bus_register);
 210
 211 static int child_unregister(struct device *dev, void *data)
 212 {
 213         /*
 214          * the singular ndctl class device per bus needs to be
 215          * "device_destroy"ed, so skip it here
 216          *
 217          * i.e. remove classless children
 218          */
 219         if (dev->class)
 220                 /* pass */;
 221         else
 222                 nd_device_unregister(dev, ND_SYNC);
 223         return 0;
 224 }
 225
 226 void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
 227 {
 228         if (!nvdimm_bus)
 229                 return;
 230
 231         mutex_lock(&nvdimm_bus_list_mutex);
 232         list_del_init(&nvdimm_bus->list);
 233         mutex_unlock(&nvdimm_bus_list_mutex);
 234
 235         nd_synchronize();
 236         device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
 237         nvdimm_bus_destroy_ndctl(nvdimm_bus);
 238
 239         device_unregister(&nvdimm_bus->dev);
 240 }
 241 EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);
 242
 243 static __init int libnvdimm_init(void)
 244 {
 245         int rc;
 246
 247         rc = nvdimm_bus_init();
 248         if (rc)
 249                 return rc;
 250         rc = nvdimm_init();
 251         if (rc)
 252                 goto err_dimm;
 253         rc = nd_region_init();
 254         if (rc)
 255                 goto err_region;
 256         return 0;
 257  err_region:
 258         nvdimm_exit();
 259  err_dimm:
 260         nvdimm_bus_exit();
 261         return rc;
 262 }
 263
 264 static __exit void libnvdimm_exit(void)
 265 {
 266         WARN_ON(!list_empty(&nvdimm_bus_list));
 267         nd_region_exit();
 268         nvdimm_exit();
 269         nvdimm_bus_exit();
 270 }
 271
 272 MODULE_LICENSE("GPL v2");
 273 MODULE_AUTHOR("Intel Corporation");
 274 subsys_initcall(libnvdimm_init);
 275 module_exit(libnvdimm_exit);