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