drivers/nvdimm/bus.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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14 #include <linux/vmalloc.h>
  15 #include <linux/uaccess.h>
  16 #include <linux/module.h>
  17 #include <linux/blkdev.h>
  18 #include <linux/fcntl.h>
  19 #include <linux/async.h>
  20 #include <linux/genhd.h>
  21 #include <linux/ndctl.h>
  22 #include <linux/sched.h>
  23 #include <linux/slab.h>
  24 #include <linux/fs.h>
  25 #include <linux/io.h>
  26 #include <linux/mm.h>
  27 #include <linux/nd.h>
  28 #include "nd-core.h"
  29 #include "nd.h"
  30
  31 int nvdimm_major;
  32 static int nvdimm_bus_major;
  33 static struct class *nd_class;
  34
  35 static int to_nd_device_type(struct device *dev)
  36 {
  37         if (is_nvdimm(dev))
  38                 return ND_DEVICE_DIMM;
  39         else if (is_nd_pmem(dev))
  40                 return ND_DEVICE_REGION_PMEM;
  41         else if (is_nd_blk(dev))
  42                 return ND_DEVICE_REGION_BLK;
  43         else if (is_nd_pmem(dev->parent) || is_nd_blk(dev->parent))
  44                 return nd_region_to_nstype(to_nd_region(dev->parent));
  45
  46         return 0;
  47 }
  48
  49 static int nvdimm_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
  50 {
  51         /*
  52          * Ensure that region devices always have their numa node set as
  53          * early as possible.
  54          */
  55         if (is_nd_pmem(dev) || is_nd_blk(dev))
  56                 set_dev_node(dev, to_nd_region(dev)->numa_node);
  57         return add_uevent_var(env, "MODALIAS=" ND_DEVICE_MODALIAS_FMT,
  58                         to_nd_device_type(dev));
  59 }
  60
  61 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
  62 {
  63         struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
  64
  65         return test_bit(to_nd_device_type(dev), &nd_drv->type);
  66 }
  67
  68 static struct module *to_bus_provider(struct device *dev)
  69 {
  70         /* pin bus providers while regions are enabled */
  71         if (is_nd_pmem(dev) || is_nd_blk(dev)) {
  72                 struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  73
  74                 return nvdimm_bus->module;
  75         }
  76         return NULL;
  77 }
  78
  79 static void nvdimm_bus_probe_start(struct nvdimm_bus *nvdimm_bus)
  80 {
  81         nvdimm_bus_lock(&nvdimm_bus->dev);
  82         nvdimm_bus->probe_active++;
  83         nvdimm_bus_unlock(&nvdimm_bus->dev);
  84 }
  85
  86 static void nvdimm_bus_probe_end(struct nvdimm_bus *nvdimm_bus)
  87 {
  88         nvdimm_bus_lock(&nvdimm_bus->dev);
  89         if (--nvdimm_bus->probe_active == 0)
  90                 wake_up(&nvdimm_bus->probe_wait);
  91         nvdimm_bus_unlock(&nvdimm_bus->dev);
  92 }
  93
  94 static int nvdimm_bus_probe(struct device *dev)
  95 {
  96         struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
  97         struct module *provider = to_bus_provider(dev);
  98         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  99         int rc;
 100
 101         if (!try_module_get(provider))
 102                 return -ENXIO;
 103
 104         nvdimm_bus_probe_start(nvdimm_bus);
 105         rc = nd_drv->probe(dev);
 106         if (rc == 0)
 107                 nd_region_probe_success(nvdimm_bus, dev);
 108         else
 109                 nd_region_disable(nvdimm_bus, dev);
 110         nvdimm_bus_probe_end(nvdimm_bus);
 111
 112         dev_dbg(&nvdimm_bus->dev, "%s.probe(%s) = %d\n", dev->driver->name,
 113                         dev_name(dev), rc);
 114
 115         if (rc != 0)
 116                 module_put(provider);
 117         return rc;
 118 }
 119
 120 static int nvdimm_bus_remove(struct device *dev)
 121 {
 122         struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
 123         struct module *provider = to_bus_provider(dev);
 124         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 125         int rc;
 126
 127         rc = nd_drv->remove(dev);
 128         nd_region_disable(nvdimm_bus, dev);
 129
 130         dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d\n", dev->driver->name,
 131                         dev_name(dev), rc);
 132         module_put(provider);
 133         return rc;
 134 }
 135
 136 static struct bus_type nvdimm_bus_type = {
 137         .name = "nd",
 138         .uevent = nvdimm_bus_uevent,
 139         .match = nvdimm_bus_match,
 140         .probe = nvdimm_bus_probe,
 141         .remove = nvdimm_bus_remove,
 142 };
 143
 144 static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
 145
 146 void nd_synchronize(void)
 147 {
 148         async_synchronize_full_domain(&nd_async_domain);
 149 }
 150 EXPORT_SYMBOL_GPL(nd_synchronize);
 151
 152 static void nd_async_device_register(void *d, async_cookie_t cookie)
 153 {
 154         struct device *dev = d;
 155
 156         if (device_add(dev) != 0) {
 157                 dev_err(dev, "%s: failed\n", __func__);
 158                 put_device(dev);
 159         }
 160         put_device(dev);
 161 }
 162
 163 static void nd_async_device_unregister(void *d, async_cookie_t cookie)
 164 {
 165         struct device *dev = d;
 166
 167         /* flush bus operations before delete */
 168         nvdimm_bus_lock(dev);
 169         nvdimm_bus_unlock(dev);
 170
 171         device_unregister(dev);
 172         put_device(dev);
 173 }
 174
 175 void __nd_device_register(struct device *dev)
 176 {
 177         dev->bus = &nvdimm_bus_type;
 178         get_device(dev);
 179         async_schedule_domain(nd_async_device_register, dev,
 180                         &nd_async_domain);
 181 }
 182
 183 void nd_device_register(struct device *dev)
 184 {
 185         device_initialize(dev);
 186         __nd_device_register(dev);
 187 }
 188 EXPORT_SYMBOL(nd_device_register);
 189
 190 void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
 191 {
 192         switch (mode) {
 193         case ND_ASYNC:
 194                 get_device(dev);
 195                 async_schedule_domain(nd_async_device_unregister, dev,
 196                                 &nd_async_domain);
 197                 break;
 198         case ND_SYNC:
 199                 nd_synchronize();
 200                 device_unregister(dev);
 201                 break;
 202         }
 203 }
 204 EXPORT_SYMBOL(nd_device_unregister);
 205
 206 /**
 207  * __nd_driver_register() - register a region or a namespace driver
 208  * @nd_drv: driver to register
 209  * @owner: automatically set by nd_driver_register() macro
 210  * @mod_name: automatically set by nd_driver_register() macro
 211  */
 212 int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
 213                 const char *mod_name)
 214 {
 215         struct device_driver *drv = &nd_drv->drv;
 216
 217         if (!nd_drv->type) {
 218                 pr_debug("driver type bitmask not set (%pf)\n",
 219                                 __builtin_return_address(0));
 220                 return -EINVAL;
 221         }
 222
 223         if (!nd_drv->probe || !nd_drv->remove) {
 224                 pr_debug("->probe() and ->remove() must be specified\n");
 225                 return -EINVAL;
 226         }
 227
 228         drv->bus = &nvdimm_bus_type;
 229         drv->owner = owner;
 230         drv->mod_name = mod_name;
 231
 232         return driver_register(drv);
 233 }
 234 EXPORT_SYMBOL(__nd_driver_register);
 235
 236 int nvdimm_revalidate_disk(struct gendisk *disk)
 237 {
 238         struct device *dev = disk->driverfs_dev;
 239         struct nd_region *nd_region = to_nd_region(dev->parent);
 240         const char *pol = nd_region->ro ? "only" : "write";
 241
 242         if (nd_region->ro == get_disk_ro(disk))
 243                 return 0;
 244
 245         dev_info(dev, "%s read-%s, marking %s read-%s\n",
 246                         dev_name(&nd_region->dev), pol, disk->disk_name, pol);
 247         set_disk_ro(disk, nd_region->ro);
 248
 249         return 0;
 250
 251 }
 252 EXPORT_SYMBOL(nvdimm_revalidate_disk);
 253
 254 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 255                 char *buf)
 256 {
 257         return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
 258                         to_nd_device_type(dev));
 259 }
 260 static DEVICE_ATTR_RO(modalias);
 261
 262 static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
 263                 char *buf)
 264 {
 265         return sprintf(buf, "%s\n", dev->type->name);
 266 }
 267 static DEVICE_ATTR_RO(devtype);
 268
 269 static struct attribute *nd_device_attributes[] = {
 270         &dev_attr_modalias.attr,
 271         &dev_attr_devtype.attr,
 272         NULL,
 273 };
 274
 275 /**
 276  * nd_device_attribute_group - generic attributes for all devices on an nd bus
 277  */
 278 struct attribute_group nd_device_attribute_group = {
 279         .attrs = nd_device_attributes,
 280 };
 281 EXPORT_SYMBOL_GPL(nd_device_attribute_group);
 282
 283 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
 284 {
 285         dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
 286         struct device *dev;
 287
 288         dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
 289                         "ndctl%d", nvdimm_bus->id);
 290
 291         if (IS_ERR(dev)) {
 292                 dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld\n",
 293                                 nvdimm_bus->id, PTR_ERR(dev));
 294                 return PTR_ERR(dev);
 295         }
 296         return 0;
 297 }
 298
 299 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
 300 {
 301         device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
 302 }
 303
 304 static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
 305         [ND_CMD_IMPLEMENTED] = { },
 306         [ND_CMD_SMART] = {
 307                 .out_num = 2,
 308                 .out_sizes = { 4, 8, },
 309         },
 310         [ND_CMD_SMART_THRESHOLD] = {
 311                 .out_num = 2,
 312                 .out_sizes = { 4, 8, },
 313         },
 314         [ND_CMD_DIMM_FLAGS] = {
 315                 .out_num = 2,
 316                 .out_sizes = { 4, 4 },
 317         },
 318         [ND_CMD_GET_CONFIG_SIZE] = {
 319                 .out_num = 3,
 320                 .out_sizes = { 4, 4, 4, },
 321         },
 322         [ND_CMD_GET_CONFIG_DATA] = {
 323                 .in_num = 2,
 324                 .in_sizes = { 4, 4, },
 325                 .out_num = 2,
 326                 .out_sizes = { 4, UINT_MAX, },
 327         },
 328         [ND_CMD_SET_CONFIG_DATA] = {
 329                 .in_num = 3,
 330                 .in_sizes = { 4, 4, UINT_MAX, },
 331                 .out_num = 1,
 332                 .out_sizes = { 4, },
 333         },
 334         [ND_CMD_VENDOR] = {
 335                 .in_num = 3,
 336                 .in_sizes = { 4, 4, UINT_MAX, },
 337                 .out_num = 3,
 338                 .out_sizes = { 4, 4, UINT_MAX, },
 339         },
 340 };
 341
 342 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
 343 {
 344         if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
 345                 return &__nd_cmd_dimm_descs[cmd];
 346         return NULL;
 347 }
 348 EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
 349
 350 static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
 351         [ND_CMD_IMPLEMENTED] = { },
 352         [ND_CMD_ARS_CAP] = {
 353                 .in_num = 2,
 354                 .in_sizes = { 8, 8, },
 355                 .out_num = 2,
 356                 .out_sizes = { 4, 4, },
 357         },
 358         [ND_CMD_ARS_START] = {
 359                 .in_num = 4,
 360                 .in_sizes = { 8, 8, 2, 6, },
 361                 .out_num = 1,
 362                 .out_sizes = { 4, },
 363         },
 364         [ND_CMD_ARS_STATUS] = {
 365                 .out_num = 2,
 366                 .out_sizes = { 4, UINT_MAX, },
 367         },
 368 };
 369
 370 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
 371 {
 372         if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
 373                 return &__nd_cmd_bus_descs[cmd];
 374         return NULL;
 375 }
 376 EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
 377
 378 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
 379                 const struct nd_cmd_desc *desc, int idx, void *buf)
 380 {
 381         if (idx >= desc->in_num)
 382                 return UINT_MAX;
 383
 384         if (desc->in_sizes[idx] < UINT_MAX)
 385                 return desc->in_sizes[idx];
 386
 387         if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
 388                 struct nd_cmd_set_config_hdr *hdr = buf;
 389
 390                 return hdr->in_length;
 391         } else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
 392                 struct nd_cmd_vendor_hdr *hdr = buf;
 393
 394                 return hdr->in_length;
 395         }
 396
 397         return UINT_MAX;
 398 }
 399 EXPORT_SYMBOL_GPL(nd_cmd_in_size);
 400
 401 u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
 402                 const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
 403                 const u32 *out_field)
 404 {
 405         if (idx >= desc->out_num)
 406                 return UINT_MAX;
 407
 408         if (desc->out_sizes[idx] < UINT_MAX)
 409                 return desc->out_sizes[idx];
 410
 411         if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
 412                 return in_field[1];
 413         else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
 414                 return out_field[1];
 415         else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 1)
 416                 return ND_CMD_ARS_STATUS_MAX;
 417
 418         return UINT_MAX;
 419 }
 420 EXPORT_SYMBOL_GPL(nd_cmd_out_size);
 421
 422 void wait_nvdimm_bus_probe_idle(struct device *dev)
 423 {
 424         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 425
 426         do {
 427                 if (nvdimm_bus->probe_active == 0)
 428                         break;
 429                 nvdimm_bus_unlock(&nvdimm_bus->dev);
 430                 wait_event(nvdimm_bus->probe_wait,
 431                                 nvdimm_bus->probe_active == 0);
 432                 nvdimm_bus_lock(&nvdimm_bus->dev);
 433         } while (true);
 434 }
 435
 436 /* set_config requires an idle interleave set */
 437 static int nd_cmd_clear_to_send(struct nvdimm *nvdimm, unsigned int cmd)
 438 {
 439         struct nvdimm_bus *nvdimm_bus;
 440
 441         if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
 442                 return 0;
 443
 444         nvdimm_bus = walk_to_nvdimm_bus(&nvdimm->dev);
 445         wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);
 446
 447         if (atomic_read(&nvdimm->busy))
 448                 return -EBUSY;
 449         return 0;
 450 }
 451
 452 static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
 453                 int read_only, unsigned int ioctl_cmd, unsigned long arg)
 454 {
 455         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 456         size_t buf_len = 0, in_len = 0, out_len = 0;
 457         static char out_env[ND_CMD_MAX_ENVELOPE];
 458         static char in_env[ND_CMD_MAX_ENVELOPE];
 459         const struct nd_cmd_desc *desc = NULL;
 460         unsigned int cmd = _IOC_NR(ioctl_cmd);
 461         void __user *p = (void __user *) arg;
 462         struct device *dev = &nvdimm_bus->dev;
 463         const char *cmd_name, *dimm_name;
 464         unsigned long dsm_mask;
 465         void *buf;
 466         int rc, i;
 467
 468         if (nvdimm) {
 469                 desc = nd_cmd_dimm_desc(cmd);
 470                 cmd_name = nvdimm_cmd_name(cmd);
 471                 dsm_mask = nvdimm->dsm_mask ? *(nvdimm->dsm_mask) : 0;
 472                 dimm_name = dev_name(&nvdimm->dev);
 473         } else {
 474                 desc = nd_cmd_bus_desc(cmd);
 475                 cmd_name = nvdimm_bus_cmd_name(cmd);
 476                 dsm_mask = nd_desc->dsm_mask;
 477                 dimm_name = "bus";
 478         }
 479
 480         if (!desc || (desc->out_num + desc->in_num == 0) ||
 481                         !test_bit(cmd, &dsm_mask))
 482                 return -ENOTTY;
 483
 484         /* fail write commands (when read-only) */
 485         if (read_only)
 486                 switch (ioctl_cmd) {
 487                 case ND_IOCTL_VENDOR:
 488                 case ND_IOCTL_SET_CONFIG_DATA:
 489                 case ND_IOCTL_ARS_START:
 490                         dev_dbg(&nvdimm_bus->dev, "'%s' command while read-only.\n",
 491                                         nvdimm ? nvdimm_cmd_name(cmd)
 492                                         : nvdimm_bus_cmd_name(cmd));
 493                         return -EPERM;
 494                 default:
 495                         break;
 496                 }
 497
 498         /* process an input envelope */
 499         for (i = 0; i < desc->in_num; i++) {
 500                 u32 in_size, copy;
 501
 502                 in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
 503                 if (in_size == UINT_MAX) {
 504                         dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
 505                                         __func__, dimm_name, cmd_name, i);
 506                         return -ENXIO;
 507                 }
 508                 if (!access_ok(VERIFY_READ, p + in_len, in_size))
 509                         return -EFAULT;
 510                 if (in_len < sizeof(in_env))
 511                         copy = min_t(u32, sizeof(in_env) - in_len, in_size);
 512                 else
 513                         copy = 0;
 514                 if (copy && copy_from_user(&in_env[in_len], p + in_len, copy))
 515                         return -EFAULT;
 516                 in_len += in_size;
 517         }
 518
 519         /* process an output envelope */
 520         for (i = 0; i < desc->out_num; i++) {
 521                 u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
 522                                 (u32 *) in_env, (u32 *) out_env);
 523                 u32 copy;
 524
 525                 if (out_size == UINT_MAX) {
 526                         dev_dbg(dev, "%s:%s unknown output size cmd: %s field: %d\n",
 527                                         __func__, dimm_name, cmd_name, i);
 528                         return -EFAULT;
 529                 }
 530                 if (!access_ok(VERIFY_WRITE, p + in_len + out_len, out_size))
 531                         return -EFAULT;
 532                 if (out_len < sizeof(out_env))
 533                         copy = min_t(u32, sizeof(out_env) - out_len, out_size);
 534                 else
 535                         copy = 0;
 536                 if (copy && copy_from_user(&out_env[out_len],
 537                                         p + in_len + out_len, copy))
 538                         return -EFAULT;
 539                 out_len += out_size;
 540         }
 541
 542         buf_len = out_len + in_len;
 543         if (!access_ok(VERIFY_WRITE, p, sizeof(buf_len)))
 544                 return -EFAULT;
 545
 546         if (buf_len > ND_IOCTL_MAX_BUFLEN) {
 547                 dev_dbg(dev, "%s:%s cmd: %s buf_len: %zu > %d\n", __func__,
 548                                 dimm_name, cmd_name, buf_len,
 549                                 ND_IOCTL_MAX_BUFLEN);
 550                 return -EINVAL;
 551         }
 552
 553         buf = vmalloc(buf_len);
 554         if (!buf)
 555                 return -ENOMEM;
 556
 557         if (copy_from_user(buf, p, buf_len)) {
 558                 rc = -EFAULT;
 559                 goto out;
 560         }
 561
 562         nvdimm_bus_lock(&nvdimm_bus->dev);
 563         rc = nd_cmd_clear_to_send(nvdimm, cmd);
 564         if (rc)
 565                 goto out_unlock;
 566
 567         rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len);
 568         if (rc < 0)
 569                 goto out_unlock;
 570         if (copy_to_user(p, buf, buf_len))
 571                 rc = -EFAULT;
 572  out_unlock:
 573         nvdimm_bus_unlock(&nvdimm_bus->dev);
 574  out:
 575         vfree(buf);
 576         return rc;
 577 }
 578
 579 static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 580 {
 581         long id = (long) file->private_data;
 582         int rc = -ENXIO, read_only;
 583         struct nvdimm_bus *nvdimm_bus;
 584
 585         read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
 586         mutex_lock(&nvdimm_bus_list_mutex);
 587         list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
 588                 if (nvdimm_bus->id == id) {
 589                         rc = __nd_ioctl(nvdimm_bus, NULL, read_only, cmd, arg);
 590                         break;
 591                 }
 592         }
 593         mutex_unlock(&nvdimm_bus_list_mutex);
 594
 595         return rc;
 596 }
 597
 598 static int match_dimm(struct device *dev, void *data)
 599 {
 600         long id = (long) data;
 601
 602         if (is_nvdimm(dev)) {
 603                 struct nvdimm *nvdimm = to_nvdimm(dev);
 604
 605                 return nvdimm->id == id;
 606         }
 607
 608         return 0;
 609 }
 610
 611 static long nvdimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 612 {
 613         int rc = -ENXIO, read_only;
 614         struct nvdimm_bus *nvdimm_bus;
 615
 616         read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
 617         mutex_lock(&nvdimm_bus_list_mutex);
 618         list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
 619                 struct device *dev = device_find_child(&nvdimm_bus->dev,
 620                                 file->private_data, match_dimm);
 621                 struct nvdimm *nvdimm;
 622
 623                 if (!dev)
 624                         continue;
 625
 626                 nvdimm = to_nvdimm(dev);
 627                 rc = __nd_ioctl(nvdimm_bus, nvdimm, read_only, cmd, arg);
 628                 put_device(dev);
 629                 break;
 630         }
 631         mutex_unlock(&nvdimm_bus_list_mutex);
 632
 633         return rc;
 634 }
 635
 636 static int nd_open(struct inode *inode, struct file *file)
 637 {
 638         long minor = iminor(inode);
 639
 640         file->private_data = (void *) minor;
 641         return 0;
 642 }
 643
 644 static const struct file_operations nvdimm_bus_fops = {
 645         .owner = THIS_MODULE,
 646         .open = nd_open,
 647         .unlocked_ioctl = nd_ioctl,
 648         .compat_ioctl = nd_ioctl,
 649         .llseek = noop_llseek,
 650 };
 651
 652 static const struct file_operations nvdimm_fops = {
 653         .owner = THIS_MODULE,
 654         .open = nd_open,
 655         .unlocked_ioctl = nvdimm_ioctl,
 656         .compat_ioctl = nvdimm_ioctl,
 657         .llseek = noop_llseek,
 658 };
 659
 660 int __init nvdimm_bus_init(void)
 661 {
 662         int rc;
 663
 664         rc = bus_register(&nvdimm_bus_type);
 665         if (rc)
 666                 return rc;
 667
 668         rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
 669         if (rc < 0)
 670                 goto err_bus_chrdev;
 671         nvdimm_bus_major = rc;
 672
 673         rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
 674         if (rc < 0)
 675                 goto err_dimm_chrdev;
 676         nvdimm_major = rc;
 677
 678         nd_class = class_create(THIS_MODULE, "nd");
 679         if (IS_ERR(nd_class))
 680                 goto err_class;
 681
 682         return 0;
 683
 684  err_class:
 685         unregister_chrdev(nvdimm_major, "dimmctl");
 686  err_dimm_chrdev:
 687         unregister_chrdev(nvdimm_bus_major, "ndctl");
 688  err_bus_chrdev:
 689         bus_unregister(&nvdimm_bus_type);
 690
 691         return rc;
 692 }
 693
 694 void nvdimm_bus_exit(void)
 695 {
 696         class_destroy(nd_class);
 697         unregister_chrdev(nvdimm_bus_major, "ndctl");
 698         unregister_chrdev(nvdimm_major, "dimmctl");
 699         bus_unregister(&nvdimm_bus_type);
 700 }