drivers/nvdimm/bus.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
   4  */
   5 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   6 #include <linux/libnvdimm.h>
   7 #include <linux/sched/mm.h>
   8 #include <linux/vmalloc.h>
   9 #include <linux/uaccess.h>
  10 #include <linux/module.h>
  11 #include <linux/blkdev.h>
  12 #include <linux/fcntl.h>
  13 #include <linux/async.h>
  14 #include <linux/genhd.h>
  15 #include <linux/ndctl.h>
  16 #include <linux/sched.h>
  17 #include <linux/slab.h>
  18 #include <linux/cpu.h>
  19 #include <linux/fs.h>
  20 #include <linux/io.h>
  21 #include <linux/mm.h>
  22 #include <linux/nd.h>
  23 #include "nd-core.h"
  24 #include "nd.h"
  25 #include "pfn.h"
  26
  27 int nvdimm_major;
  28 static int nvdimm_bus_major;
  29 struct class *nd_class;
  30 static DEFINE_IDA(nd_ida);
  31
  32 static int to_nd_device_type(struct device *dev)
  33 {
  34         if (is_nvdimm(dev))
  35                 return ND_DEVICE_DIMM;
  36         else if (is_memory(dev))
  37                 return ND_DEVICE_REGION_PMEM;
  38         else if (is_nd_blk(dev))
  39                 return ND_DEVICE_REGION_BLK;
  40         else if (is_nd_dax(dev))
  41                 return ND_DEVICE_DAX_PMEM;
  42         else if (is_nd_region(dev->parent))
  43                 return nd_region_to_nstype(to_nd_region(dev->parent));
  44
  45         return 0;
  46 }
  47
  48 static int nvdimm_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
  49 {
  50         return add_uevent_var(env, "MODALIAS=" ND_DEVICE_MODALIAS_FMT,
  51                         to_nd_device_type(dev));
  52 }
  53
  54 static struct module *to_bus_provider(struct device *dev)
  55 {
  56         /* pin bus providers while regions are enabled */
  57         if (is_nd_region(dev)) {
  58                 struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  59
  60                 return nvdimm_bus->nd_desc->module;
  61         }
  62         return NULL;
  63 }
  64
  65 static void nvdimm_bus_probe_start(struct nvdimm_bus *nvdimm_bus)
  66 {
  67         nvdimm_bus_lock(&nvdimm_bus->dev);
  68         nvdimm_bus->probe_active++;
  69         nvdimm_bus_unlock(&nvdimm_bus->dev);
  70 }
  71
  72 static void nvdimm_bus_probe_end(struct nvdimm_bus *nvdimm_bus)
  73 {
  74         nvdimm_bus_lock(&nvdimm_bus->dev);
  75         if (--nvdimm_bus->probe_active == 0)
  76                 wake_up(&nvdimm_bus->wait);
  77         nvdimm_bus_unlock(&nvdimm_bus->dev);
  78 }
  79
  80 static int nvdimm_bus_probe(struct device *dev)
  81 {
  82         struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
  83         struct module *provider = to_bus_provider(dev);
  84         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  85         int rc;
  86
  87         if (!try_module_get(provider))
  88                 return -ENXIO;
  89
  90         dev_dbg(&nvdimm_bus->dev, "START: %s.probe(%s)\n",
  91                         dev->driver->name, dev_name(dev));
  92
  93         nvdimm_bus_probe_start(nvdimm_bus);
  94         debug_nvdimm_lock(dev);
  95         rc = nd_drv->probe(dev);
  96         debug_nvdimm_unlock(dev);
  97
  98         if ((rc == 0 || rc == -EOPNOTSUPP) &&
  99                         dev->parent && is_nd_region(dev->parent))
 100                 nd_region_advance_seeds(to_nd_region(dev->parent), dev);
 101         nvdimm_bus_probe_end(nvdimm_bus);
 102
 103         dev_dbg(&nvdimm_bus->dev, "END: %s.probe(%s) = %d\n", dev->driver->name,
 104                         dev_name(dev), rc);
 105
 106         if (rc != 0)
 107                 module_put(provider);
 108         return rc;
 109 }
 110
 111 static int nvdimm_bus_remove(struct device *dev)
 112 {
 113         struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
 114         struct module *provider = to_bus_provider(dev);
 115         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 116         int rc = 0;
 117
 118         if (nd_drv->remove) {
 119                 debug_nvdimm_lock(dev);
 120                 rc = nd_drv->remove(dev);
 121                 debug_nvdimm_unlock(dev);
 122         }
 123
 124         dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d\n", dev->driver->name,
 125                         dev_name(dev), rc);
 126         module_put(provider);
 127         return rc;
 128 }
 129
 130 static void nvdimm_bus_shutdown(struct device *dev)
 131 {
 132         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 133         struct nd_device_driver *nd_drv = NULL;
 134
 135         if (dev->driver)
 136                 nd_drv = to_nd_device_driver(dev->driver);
 137
 138         if (nd_drv && nd_drv->shutdown) {
 139                 nd_drv->shutdown(dev);
 140                 dev_dbg(&nvdimm_bus->dev, "%s.shutdown(%s)\n",
 141                                 dev->driver->name, dev_name(dev));
 142         }
 143 }
 144
 145 void nd_device_notify(struct device *dev, enum nvdimm_event event)
 146 {
 147         nd_device_lock(dev);
 148         if (dev->driver) {
 149                 struct nd_device_driver *nd_drv;
 150
 151                 nd_drv = to_nd_device_driver(dev->driver);
 152                 if (nd_drv->notify)
 153                         nd_drv->notify(dev, event);
 154         }
 155         nd_device_unlock(dev);
 156 }
 157 EXPORT_SYMBOL(nd_device_notify);
 158
 159 void nvdimm_region_notify(struct nd_region *nd_region, enum nvdimm_event event)
 160 {
 161         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
 162
 163         if (!nvdimm_bus)
 164                 return;
 165
 166         /* caller is responsible for holding a reference on the device */
 167         nd_device_notify(&nd_region->dev, event);
 168 }
 169 EXPORT_SYMBOL_GPL(nvdimm_region_notify);
 170
 171 struct clear_badblocks_context {
 172         resource_size_t phys, cleared;
 173 };
 174
 175 static int nvdimm_clear_badblocks_region(struct device *dev, void *data)
 176 {
 177         struct clear_badblocks_context *ctx = data;
 178         struct nd_region *nd_region;
 179         resource_size_t ndr_end;
 180         sector_t sector;
 181
 182         /* make sure device is a region */
 183         if (!is_memory(dev))
 184                 return 0;
 185
 186         nd_region = to_nd_region(dev);
 187         ndr_end = nd_region->ndr_start + nd_region->ndr_size - 1;
 188
 189         /* make sure we are in the region */
 190         if (ctx->phys < nd_region->ndr_start
 191                         || (ctx->phys + ctx->cleared) > ndr_end)
 192                 return 0;
 193
 194         sector = (ctx->phys - nd_region->ndr_start) / 512;
 195         badblocks_clear(&nd_region->bb, sector, ctx->cleared / 512);
 196
 197         if (nd_region->bb_state)
 198                 sysfs_notify_dirent(nd_region->bb_state);
 199
 200         return 0;
 201 }
 202
 203 static void nvdimm_clear_badblocks_regions(struct nvdimm_bus *nvdimm_bus,
 204                 phys_addr_t phys, u64 cleared)
 205 {
 206         struct clear_badblocks_context ctx = {
 207                 .phys = phys,
 208                 .cleared = cleared,
 209         };
 210
 211         device_for_each_child(&nvdimm_bus->dev, &ctx,
 212                         nvdimm_clear_badblocks_region);
 213 }
 214
 215 static void nvdimm_account_cleared_poison(struct nvdimm_bus *nvdimm_bus,
 216                 phys_addr_t phys, u64 cleared)
 217 {
 218         if (cleared > 0)
 219                 badrange_forget(&nvdimm_bus->badrange, phys, cleared);
 220
 221         if (cleared > 0 && cleared / 512)
 222                 nvdimm_clear_badblocks_regions(nvdimm_bus, phys, cleared);
 223 }
 224
 225 long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
 226                 unsigned int len)
 227 {
 228         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 229         struct nvdimm_bus_descriptor *nd_desc;
 230         struct nd_cmd_clear_error clear_err;
 231         struct nd_cmd_ars_cap ars_cap;
 232         u32 clear_err_unit, mask;
 233         unsigned int noio_flag;
 234         int cmd_rc, rc;
 235
 236         if (!nvdimm_bus)
 237                 return -ENXIO;
 238
 239         nd_desc = nvdimm_bus->nd_desc;
 240         /*
 241          * if ndctl does not exist, it's PMEM_LEGACY and
 242          * we want to just pretend everything is handled.
 243          */
 244         if (!nd_desc->ndctl)
 245                 return len;
 246
 247         memset(&ars_cap, 0, sizeof(ars_cap));
 248         ars_cap.address = phys;
 249         ars_cap.length = len;
 250         noio_flag = memalloc_noio_save();
 251         rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_CAP, &ars_cap,
 252                         sizeof(ars_cap), &cmd_rc);
 253         memalloc_noio_restore(noio_flag);
 254         if (rc < 0)
 255                 return rc;
 256         if (cmd_rc < 0)
 257                 return cmd_rc;
 258         clear_err_unit = ars_cap.clear_err_unit;
 259         if (!clear_err_unit || !is_power_of_2(clear_err_unit))
 260                 return -ENXIO;
 261
 262         mask = clear_err_unit - 1;
 263         if ((phys | len) & mask)
 264                 return -ENXIO;
 265         memset(&clear_err, 0, sizeof(clear_err));
 266         clear_err.address = phys;
 267         clear_err.length = len;
 268         noio_flag = memalloc_noio_save();
 269         rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_CLEAR_ERROR, &clear_err,
 270                         sizeof(clear_err), &cmd_rc);
 271         memalloc_noio_restore(noio_flag);
 272         if (rc < 0)
 273                 return rc;
 274         if (cmd_rc < 0)
 275                 return cmd_rc;
 276
 277         nvdimm_account_cleared_poison(nvdimm_bus, phys, clear_err.cleared);
 278
 279         return clear_err.cleared;
 280 }
 281 EXPORT_SYMBOL_GPL(nvdimm_clear_poison);
 282
 283 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv);
 284
 285 static struct bus_type nvdimm_bus_type = {
 286         .name = "nd",
 287         .uevent = nvdimm_bus_uevent,
 288         .match = nvdimm_bus_match,
 289         .probe = nvdimm_bus_probe,
 290         .remove = nvdimm_bus_remove,
 291         .shutdown = nvdimm_bus_shutdown,
 292 };
 293
 294 static void nvdimm_bus_release(struct device *dev)
 295 {
 296         struct nvdimm_bus *nvdimm_bus;
 297
 298         nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
 299         ida_simple_remove(&nd_ida, nvdimm_bus->id);
 300         kfree(nvdimm_bus);
 301 }
 302
 303 bool is_nvdimm_bus(struct device *dev)
 304 {
 305         return dev->release == nvdimm_bus_release;
 306 }
 307
 308 struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
 309 {
 310         struct device *dev;
 311
 312         for (dev = nd_dev; dev; dev = dev->parent)
 313                 if (is_nvdimm_bus(dev))
 314                         break;
 315         dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
 316         if (dev)
 317                 return to_nvdimm_bus(dev);
 318         return NULL;
 319 }
 320
 321 struct nvdimm_bus *to_nvdimm_bus(struct device *dev)
 322 {
 323         struct nvdimm_bus *nvdimm_bus;
 324
 325         nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
 326         WARN_ON(!is_nvdimm_bus(dev));
 327         return nvdimm_bus;
 328 }
 329 EXPORT_SYMBOL_GPL(to_nvdimm_bus);
 330
 331 struct nvdimm_bus *nvdimm_to_bus(struct nvdimm *nvdimm)
 332 {
 333         return to_nvdimm_bus(nvdimm->dev.parent);
 334 }
 335 EXPORT_SYMBOL_GPL(nvdimm_to_bus);
 336
 337 struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
 338                 struct nvdimm_bus_descriptor *nd_desc)
 339 {
 340         struct nvdimm_bus *nvdimm_bus;
 341         int rc;
 342
 343         nvdimm_bus = kzalloc(sizeof(*nvdimm_bus), GFP_KERNEL);
 344         if (!nvdimm_bus)
 345                 return NULL;
 346         INIT_LIST_HEAD(&nvdimm_bus->list);
 347         INIT_LIST_HEAD(&nvdimm_bus->mapping_list);
 348         init_waitqueue_head(&nvdimm_bus->wait);
 349         nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
 350         if (nvdimm_bus->id < 0) {
 351                 kfree(nvdimm_bus);
 352                 return NULL;
 353         }
 354         mutex_init(&nvdimm_bus->reconfig_mutex);
 355         badrange_init(&nvdimm_bus->badrange);
 356         nvdimm_bus->nd_desc = nd_desc;
 357         nvdimm_bus->dev.parent = parent;
 358         nvdimm_bus->dev.release = nvdimm_bus_release;
 359         nvdimm_bus->dev.groups = nd_desc->attr_groups;
 360         nvdimm_bus->dev.bus = &nvdimm_bus_type;
 361         nvdimm_bus->dev.of_node = nd_desc->of_node;
 362         dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
 363         rc = device_register(&nvdimm_bus->dev);
 364         if (rc) {
 365                 dev_dbg(&nvdimm_bus->dev, "registration failed: %d\n", rc);
 366                 goto err;
 367         }
 368
 369         return nvdimm_bus;
 370  err:
 371         put_device(&nvdimm_bus->dev);
 372         return NULL;
 373 }
 374 EXPORT_SYMBOL_GPL(nvdimm_bus_register);
 375
 376 void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
 377 {
 378         if (!nvdimm_bus)
 379                 return;
 380         device_unregister(&nvdimm_bus->dev);
 381 }
 382 EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);
 383
 384 static int child_unregister(struct device *dev, void *data)
 385 {
 386         /*
 387          * the singular ndctl class device per bus needs to be
 388          * "device_destroy"ed, so skip it here
 389          *
 390          * i.e. remove classless children
 391          */
 392         if (dev->class)
 393                 return 0;
 394
 395         if (is_nvdimm(dev)) {
 396                 struct nvdimm *nvdimm = to_nvdimm(dev);
 397                 bool dev_put = false;
 398
 399                 /* We are shutting down. Make state frozen artificially. */
 400                 nvdimm_bus_lock(dev);
 401                 set_bit(NVDIMM_SECURITY_FROZEN, &nvdimm->sec.flags);
 402                 if (test_and_clear_bit(NDD_WORK_PENDING, &nvdimm->flags))
 403                         dev_put = true;
 404                 nvdimm_bus_unlock(dev);
 405                 cancel_delayed_work_sync(&nvdimm->dwork);
 406                 if (dev_put)
 407                         put_device(dev);
 408         }
 409         nd_device_unregister(dev, ND_SYNC);
 410
 411         return 0;
 412 }
 413
 414 static void free_badrange_list(struct list_head *badrange_list)
 415 {
 416         struct badrange_entry *bre, *next;
 417
 418         list_for_each_entry_safe(bre, next, badrange_list, list) {
 419                 list_del(&bre->list);
 420                 kfree(bre);
 421         }
 422         list_del_init(badrange_list);
 423 }
 424
 425 static int nd_bus_remove(struct device *dev)
 426 {
 427         struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 428
 429         mutex_lock(&nvdimm_bus_list_mutex);
 430         list_del_init(&nvdimm_bus->list);
 431         mutex_unlock(&nvdimm_bus_list_mutex);
 432
 433         wait_event(nvdimm_bus->wait,
 434                         atomic_read(&nvdimm_bus->ioctl_active) == 0);
 435
 436         nd_synchronize();
 437         device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
 438
 439         spin_lock(&nvdimm_bus->badrange.lock);
 440         free_badrange_list(&nvdimm_bus->badrange.list);
 441         spin_unlock(&nvdimm_bus->badrange.lock);
 442
 443         nvdimm_bus_destroy_ndctl(nvdimm_bus);
 444
 445         return 0;
 446 }
 447
 448 static int nd_bus_probe(struct device *dev)
 449 {
 450         struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 451         int rc;
 452
 453         rc = nvdimm_bus_create_ndctl(nvdimm_bus);
 454         if (rc)
 455                 return rc;
 456
 457         mutex_lock(&nvdimm_bus_list_mutex);
 458         list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
 459         mutex_unlock(&nvdimm_bus_list_mutex);
 460
 461         /* enable bus provider attributes to look up their local context */
 462         dev_set_drvdata(dev, nvdimm_bus->nd_desc);
 463
 464         return 0;
 465 }
 466
 467 static struct nd_device_driver nd_bus_driver = {
 468         .probe = nd_bus_probe,
 469         .remove = nd_bus_remove,
 470         .drv = {
 471                 .name = "nd_bus",
 472                 .suppress_bind_attrs = true,
 473                 .bus = &nvdimm_bus_type,
 474                 .owner = THIS_MODULE,
 475                 .mod_name = KBUILD_MODNAME,
 476         },
 477 };
 478
 479 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
 480 {
 481         struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
 482
 483         if (is_nvdimm_bus(dev) && nd_drv == &nd_bus_driver)
 484                 return true;
 485
 486         return !!test_bit(to_nd_device_type(dev), &nd_drv->type);
 487 }
 488
 489 static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
 490
 491 void nd_synchronize(void)
 492 {
 493         async_synchronize_full_domain(&nd_async_domain);
 494 }
 495 EXPORT_SYMBOL_GPL(nd_synchronize);
 496
 497 static void nd_async_device_register(void *d, async_cookie_t cookie)
 498 {
 499         struct device *dev = d;
 500
 501         if (device_add(dev) != 0) {
 502                 dev_err(dev, "%s: failed\n", __func__);
 503                 put_device(dev);
 504         }
 505         put_device(dev);
 506         if (dev->parent)
 507                 put_device(dev->parent);
 508 }
 509
 510 static void nd_async_device_unregister(void *d, async_cookie_t cookie)
 511 {
 512         struct device *dev = d;
 513
 514         /* flush bus operations before delete */
 515         nvdimm_bus_lock(dev);
 516         nvdimm_bus_unlock(dev);
 517
 518         device_unregister(dev);
 519         put_device(dev);
 520 }
 521
 522 void __nd_device_register(struct device *dev)
 523 {
 524         if (!dev)
 525                 return;
 526
 527         /*
 528          * Ensure that region devices always have their NUMA node set as
 529          * early as possible. This way we are able to make certain that
 530          * any memory associated with the creation and the creation
 531          * itself of the region is associated with the correct node.
 532          */
 533         if (is_nd_region(dev))
 534                 set_dev_node(dev, to_nd_region(dev)->numa_node);
 535
 536         dev->bus = &nvdimm_bus_type;
 537         if (dev->parent) {
 538                 get_device(dev->parent);
 539                 if (dev_to_node(dev) == NUMA_NO_NODE)
 540                         set_dev_node(dev, dev_to_node(dev->parent));
 541         }
 542         get_device(dev);
 543
 544         async_schedule_dev_domain(nd_async_device_register, dev,
 545                                   &nd_async_domain);
 546 }
 547
 548 void nd_device_register(struct device *dev)
 549 {
 550         device_initialize(dev);
 551         __nd_device_register(dev);
 552 }
 553 EXPORT_SYMBOL(nd_device_register);
 554
 555 void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
 556 {
 557         bool killed;
 558
 559         switch (mode) {
 560         case ND_ASYNC:
 561                 /*
 562                  * In the async case this is being triggered with the
 563                  * device lock held and the unregistration work needs to
 564                  * be moved out of line iff this is thread has won the
 565                  * race to schedule the deletion.
 566                  */
 567                 if (!kill_device(dev))
 568                         return;
 569
 570                 get_device(dev);
 571                 async_schedule_domain(nd_async_device_unregister, dev,
 572                                 &nd_async_domain);
 573                 break;
 574         case ND_SYNC:
 575                 /*
 576                  * In the sync case the device is being unregistered due
 577                  * to a state change of the parent. Claim the kill state
 578                  * to synchronize against other unregistration requests,
 579                  * or otherwise let the async path handle it if the
 580                  * unregistration was already queued.
 581                  */
 582                 nd_device_lock(dev);
 583                 killed = kill_device(dev);
 584                 nd_device_unlock(dev);
 585
 586                 if (!killed)
 587                         return;
 588
 589                 nd_synchronize();
 590                 device_unregister(dev);
 591                 break;
 592         }
 593 }
 594 EXPORT_SYMBOL(nd_device_unregister);
 595
 596 /**
 597  * __nd_driver_register() - register a region or a namespace driver
 598  * @nd_drv: driver to register
 599  * @owner: automatically set by nd_driver_register() macro
 600  * @mod_name: automatically set by nd_driver_register() macro
 601  */
 602 int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
 603                 const char *mod_name)
 604 {
 605         struct device_driver *drv = &nd_drv->drv;
 606
 607         if (!nd_drv->type) {
 608                 pr_debug("driver type bitmask not set (%ps)\n",
 609                                 __builtin_return_address(0));
 610                 return -EINVAL;
 611         }
 612
 613         if (!nd_drv->probe) {
 614                 pr_debug("%s ->probe() must be specified\n", mod_name);
 615                 return -EINVAL;
 616         }
 617
 618         drv->bus = &nvdimm_bus_type;
 619         drv->owner = owner;
 620         drv->mod_name = mod_name;
 621
 622         return driver_register(drv);
 623 }
 624 EXPORT_SYMBOL(__nd_driver_register);
 625
 626 int nvdimm_revalidate_disk(struct gendisk *disk)
 627 {
 628         struct device *dev = disk_to_dev(disk)->parent;
 629         struct nd_region *nd_region = to_nd_region(dev->parent);
 630         int disk_ro = get_disk_ro(disk);
 631
 632         /*
 633          * Upgrade to read-only if the region is read-only preserve as
 634          * read-only if the disk is already read-only.
 635          */
 636         if (disk_ro || nd_region->ro == disk_ro)
 637                 return 0;
 638
 639         dev_info(dev, "%s read-only, marking %s read-only\n",
 640                         dev_name(&nd_region->dev), disk->disk_name);
 641         set_disk_ro(disk, 1);
 642
 643         return 0;
 644
 645 }
 646 EXPORT_SYMBOL(nvdimm_revalidate_disk);
 647
 648 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 649                 char *buf)
 650 {
 651         return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
 652                         to_nd_device_type(dev));
 653 }
 654 static DEVICE_ATTR_RO(modalias);
 655
 656 static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
 657                 char *buf)
 658 {
 659         return sprintf(buf, "%s\n", dev->type->name);
 660 }
 661 static DEVICE_ATTR_RO(devtype);
 662
 663 static struct attribute *nd_device_attributes[] = {
 664         &dev_attr_modalias.attr,
 665         &dev_attr_devtype.attr,
 666         NULL,
 667 };
 668
 669 /*
 670  * nd_device_attribute_group - generic attributes for all devices on an nd bus
 671  */
 672 struct attribute_group nd_device_attribute_group = {
 673         .attrs = nd_device_attributes,
 674 };
 675 EXPORT_SYMBOL_GPL(nd_device_attribute_group);
 676
 677 static ssize_t numa_node_show(struct device *dev,
 678                 struct device_attribute *attr, char *buf)
 679 {
 680         return sprintf(buf, "%d\n", dev_to_node(dev));
 681 }
 682 static DEVICE_ATTR_RO(numa_node);
 683
 684 static struct attribute *nd_numa_attributes[] = {
 685         &dev_attr_numa_node.attr,
 686         NULL,
 687 };
 688
 689 static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
 690                 int n)
 691 {
 692         if (!IS_ENABLED(CONFIG_NUMA))
 693                 return 0;
 694
 695         return a->mode;
 696 }
 697
 698 /*
 699  * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
 700  */
 701 struct attribute_group nd_numa_attribute_group = {
 702         .attrs = nd_numa_attributes,
 703         .is_visible = nd_numa_attr_visible,
 704 };
 705 EXPORT_SYMBOL_GPL(nd_numa_attribute_group);
 706
 707 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
 708 {
 709         dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
 710         struct device *dev;
 711
 712         dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
 713                         "ndctl%d", nvdimm_bus->id);
 714
 715         if (IS_ERR(dev))
 716                 dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld\n",
 717                                 nvdimm_bus->id, PTR_ERR(dev));
 718         return PTR_ERR_OR_ZERO(dev);
 719 }
 720
 721 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
 722 {
 723         device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
 724 }
 725
 726 static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
 727         [ND_CMD_IMPLEMENTED] = { },
 728         [ND_CMD_SMART] = {
 729                 .out_num = 2,
 730                 .out_sizes = { 4, 128, },
 731         },
 732         [ND_CMD_SMART_THRESHOLD] = {
 733                 .out_num = 2,
 734                 .out_sizes = { 4, 8, },
 735         },
 736         [ND_CMD_DIMM_FLAGS] = {
 737                 .out_num = 2,
 738                 .out_sizes = { 4, 4 },
 739         },
 740         [ND_CMD_GET_CONFIG_SIZE] = {
 741                 .out_num = 3,
 742                 .out_sizes = { 4, 4, 4, },
 743         },
 744         [ND_CMD_GET_CONFIG_DATA] = {
 745                 .in_num = 2,
 746                 .in_sizes = { 4, 4, },
 747                 .out_num = 2,
 748                 .out_sizes = { 4, UINT_MAX, },
 749         },
 750         [ND_CMD_SET_CONFIG_DATA] = {
 751                 .in_num = 3,
 752                 .in_sizes = { 4, 4, UINT_MAX, },
 753                 .out_num = 1,
 754                 .out_sizes = { 4, },
 755         },
 756         [ND_CMD_VENDOR] = {
 757                 .in_num = 3,
 758                 .in_sizes = { 4, 4, UINT_MAX, },
 759                 .out_num = 3,
 760                 .out_sizes = { 4, 4, UINT_MAX, },
 761         },
 762         [ND_CMD_CALL] = {
 763                 .in_num = 2,
 764                 .in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
 765                 .out_num = 1,
 766                 .out_sizes = { UINT_MAX, },
 767         },
 768 };
 769
 770 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
 771 {
 772         if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
 773                 return &__nd_cmd_dimm_descs[cmd];
 774         return NULL;
 775 }
 776 EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
 777
 778 static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
 779         [ND_CMD_IMPLEMENTED] = { },
 780         [ND_CMD_ARS_CAP] = {
 781                 .in_num = 2,
 782                 .in_sizes = { 8, 8, },
 783                 .out_num = 4,
 784                 .out_sizes = { 4, 4, 4, 4, },
 785         },
 786         [ND_CMD_ARS_START] = {
 787                 .in_num = 5,
 788                 .in_sizes = { 8, 8, 2, 1, 5, },
 789                 .out_num = 2,
 790                 .out_sizes = { 4, 4, },
 791         },
 792         [ND_CMD_ARS_STATUS] = {
 793                 .out_num = 3,
 794                 .out_sizes = { 4, 4, UINT_MAX, },
 795         },
 796         [ND_CMD_CLEAR_ERROR] = {
 797                 .in_num = 2,
 798                 .in_sizes = { 8, 8, },
 799                 .out_num = 3,
 800                 .out_sizes = { 4, 4, 8, },
 801         },
 802         [ND_CMD_CALL] = {
 803                 .in_num = 2,
 804                 .in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
 805                 .out_num = 1,
 806                 .out_sizes = { UINT_MAX, },
 807         },
 808 };
 809
 810 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
 811 {
 812         if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
 813                 return &__nd_cmd_bus_descs[cmd];
 814         return NULL;
 815 }
 816 EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
 817
 818 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
 819                 const struct nd_cmd_desc *desc, int idx, void *buf)
 820 {
 821         if (idx >= desc->in_num)
 822                 return UINT_MAX;
 823
 824         if (desc->in_sizes[idx] < UINT_MAX)
 825                 return desc->in_sizes[idx];
 826
 827         if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
 828                 struct nd_cmd_set_config_hdr *hdr = buf;
 829
 830                 return hdr->in_length;
 831         } else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
 832                 struct nd_cmd_vendor_hdr *hdr = buf;
 833
 834                 return hdr->in_length;
 835         } else if (cmd == ND_CMD_CALL) {
 836                 struct nd_cmd_pkg *pkg = buf;
 837
 838                 return pkg->nd_size_in;
 839         }
 840
 841         return UINT_MAX;
 842 }
 843 EXPORT_SYMBOL_GPL(nd_cmd_in_size);
 844
 845 u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
 846                 const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
 847                 const u32 *out_field, unsigned long remainder)
 848 {
 849         if (idx >= desc->out_num)
 850                 return UINT_MAX;
 851
 852         if (desc->out_sizes[idx] < UINT_MAX)
 853                 return desc->out_sizes[idx];
 854
 855         if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
 856                 return in_field[1];
 857         else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
 858                 return out_field[1];
 859         else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 2) {
 860                 /*
 861                  * Per table 9-276 ARS Data in ACPI 6.1, out_field[1] is
 862                  * "Size of Output Buffer in bytes, including this
 863                  * field."
 864                  */
 865                 if (out_field[1] < 4)
 866                         return 0;
 867                 /*
 868                  * ACPI 6.1 is ambiguous if 'status' is included in the
 869                  * output size. If we encounter an output size that
 870                  * overshoots the remainder by 4 bytes, assume it was
 871                  * including 'status'.
 872                  */
 873                 if (out_field[1] - 4 == remainder)
 874                         return remainder;
 875                 return out_field[1] - 8;
 876         } else if (cmd == ND_CMD_CALL) {
 877                 struct nd_cmd_pkg *pkg = (struct nd_cmd_pkg *) in_field;
 878
 879                 return pkg->nd_size_out;
 880         }
 881
 882
 883         return UINT_MAX;
 884 }
 885 EXPORT_SYMBOL_GPL(nd_cmd_out_size);
 886
 887 void wait_nvdimm_bus_probe_idle(struct device *dev)
 888 {
 889         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 890
 891         do {
 892                 if (nvdimm_bus->probe_active == 0)
 893                         break;
 894                 nvdimm_bus_unlock(dev);
 895                 nd_device_unlock(dev);
 896                 wait_event(nvdimm_bus->wait,
 897                                 nvdimm_bus->probe_active == 0);
 898                 nd_device_lock(dev);
 899                 nvdimm_bus_lock(dev);
 900         } while (true);
 901 }
 902
 903 static int nd_pmem_forget_poison_check(struct device *dev, void *data)
 904 {
 905         struct nd_cmd_clear_error *clear_err =
 906                 (struct nd_cmd_clear_error *)data;
 907         struct nd_btt *nd_btt = is_nd_btt(dev) ? to_nd_btt(dev) : NULL;
 908         struct nd_pfn *nd_pfn = is_nd_pfn(dev) ? to_nd_pfn(dev) : NULL;
 909         struct nd_dax *nd_dax = is_nd_dax(dev) ? to_nd_dax(dev) : NULL;
 910         struct nd_namespace_common *ndns = NULL;
 911         struct nd_namespace_io *nsio;
 912         resource_size_t offset = 0, end_trunc = 0, start, end, pstart, pend;
 913
 914         if (nd_dax || !dev->driver)
 915                 return 0;
 916
 917         start = clear_err->address;
 918         end = clear_err->address + clear_err->cleared - 1;
 919
 920         if (nd_btt || nd_pfn || nd_dax) {
 921                 if (nd_btt)
 922                         ndns = nd_btt->ndns;
 923                 else if (nd_pfn)
 924                         ndns = nd_pfn->ndns;
 925                 else if (nd_dax)
 926                         ndns = nd_dax->nd_pfn.ndns;
 927
 928                 if (!ndns)
 929                         return 0;
 930         } else
 931                 ndns = to_ndns(dev);
 932
 933         nsio = to_nd_namespace_io(&ndns->dev);
 934         pstart = nsio->res.start + offset;
 935         pend = nsio->res.end - end_trunc;
 936
 937         if ((pstart >= start) && (pend <= end))
 938                 return -EBUSY;
 939
 940         return 0;
 941
 942 }
 943
 944 static int nd_ns_forget_poison_check(struct device *dev, void *data)
 945 {
 946         return device_for_each_child(dev, data, nd_pmem_forget_poison_check);
 947 }
 948
 949 /* set_config requires an idle interleave set */
 950 static int nd_cmd_clear_to_send(struct nvdimm_bus *nvdimm_bus,
 951                 struct nvdimm *nvdimm, unsigned int cmd, void *data)
 952 {
 953         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 954
 955         /* ask the bus provider if it would like to block this request */
 956         if (nd_desc->clear_to_send) {
 957                 int rc = nd_desc->clear_to_send(nd_desc, nvdimm, cmd, data);
 958
 959                 if (rc)
 960                         return rc;
 961         }
 962
 963         /* require clear error to go through the pmem driver */
 964         if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR)
 965                 return device_for_each_child(&nvdimm_bus->dev, data,
 966                                 nd_ns_forget_poison_check);
 967
 968         if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
 969                 return 0;
 970
 971         /* prevent label manipulation while the kernel owns label updates */
 972         wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);
 973         if (atomic_read(&nvdimm->busy))
 974                 return -EBUSY;
 975         return 0;
 976 }
 977
 978 static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
 979                 int read_only, unsigned int ioctl_cmd, unsigned long arg)
 980 {
 981         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 982         const struct nd_cmd_desc *desc = NULL;
 983         unsigned int cmd = _IOC_NR(ioctl_cmd);
 984         struct device *dev = &nvdimm_bus->dev;
 985         void __user *p = (void __user *) arg;
 986         char *out_env = NULL, *in_env = NULL;
 987         const char *cmd_name, *dimm_name;
 988         u32 in_len = 0, out_len = 0;
 989         unsigned int func = cmd;
 990         unsigned long cmd_mask;
 991         struct nd_cmd_pkg pkg;
 992         int rc, i, cmd_rc;
 993         void *buf = NULL;
 994         u64 buf_len = 0;
 995
 996         if (nvdimm) {
 997                 desc = nd_cmd_dimm_desc(cmd);
 998                 cmd_name = nvdimm_cmd_name(cmd);
 999                 cmd_mask = nvdimm->cmd_mask;
1000                 dimm_name = dev_name(&nvdimm->dev);
1001         } else {
1002                 desc = nd_cmd_bus_desc(cmd);
1003                 cmd_name = nvdimm_bus_cmd_name(cmd);
1004                 cmd_mask = nd_desc->cmd_mask;
1005                 dimm_name = "bus";
1006         }
1007
1008         if (cmd == ND_CMD_CALL) {
1009                 if (copy_from_user(&pkg, p, sizeof(pkg)))
1010                         return -EFAULT;
1011         }
1012
1013         if (!desc ||
1014             (desc->out_num + desc->in_num == 0) ||
1015             cmd > ND_CMD_CALL ||
1016             !test_bit(cmd, &cmd_mask))
1017                 return -ENOTTY;
1018
1019         /* fail write commands (when read-only) */
1020         if (read_only)
1021                 switch (cmd) {
1022                 case ND_CMD_VENDOR:
1023                 case ND_CMD_SET_CONFIG_DATA:
1024                 case ND_CMD_ARS_START:
1025                 case ND_CMD_CLEAR_ERROR:
1026                 case ND_CMD_CALL:
1027                         dev_dbg(dev, "'%s' command while read-only.\n",
1028                                         nvdimm ? nvdimm_cmd_name(cmd)
1029                                         : nvdimm_bus_cmd_name(cmd));
1030                         return -EPERM;
1031                 default:
1032                         break;
1033                 }
1034
1035         /* process an input envelope */
1036         in_env = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
1037         if (!in_env)
1038                 return -ENOMEM;
1039         for (i = 0; i < desc->in_num; i++) {
1040                 u32 in_size, copy;
1041
1042                 in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
1043                 if (in_size == UINT_MAX) {
1044                         dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
1045                                         __func__, dimm_name, cmd_name, i);
1046                         rc = -ENXIO;
1047                         goto out;
1048                 }
1049                 if (in_len < ND_CMD_MAX_ENVELOPE)
1050                         copy = min_t(u32, ND_CMD_MAX_ENVELOPE - in_len, in_size);
1051                 else
1052                         copy = 0;
1053                 if (copy && copy_from_user(&in_env[in_len], p + in_len, copy)) {
1054                         rc = -EFAULT;
1055                         goto out;
1056                 }
1057                 in_len += in_size;
1058         }
1059
1060         if (cmd == ND_CMD_CALL) {
1061                 func = pkg.nd_command;
1062                 dev_dbg(dev, "%s, idx: %llu, in: %u, out: %u, len %llu\n",
1063                                 dimm_name, pkg.nd_command,
1064                                 in_len, out_len, buf_len);
1065         }
1066
1067         /* process an output envelope */
1068         out_env = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
1069         if (!out_env) {
1070                 rc = -ENOMEM;
1071                 goto out;
1072         }
1073
1074         for (i = 0; i < desc->out_num; i++) {
1075                 u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
1076                                 (u32 *) in_env, (u32 *) out_env, 0);
1077                 u32 copy;
1078
1079                 if (out_size == UINT_MAX) {
1080                         dev_dbg(dev, "%s unknown output size cmd: %s field: %d\n",
1081                                         dimm_name, cmd_name, i);
1082                         rc = -EFAULT;
1083                         goto out;
1084                 }
1085                 if (out_len < ND_CMD_MAX_ENVELOPE)
1086                         copy = min_t(u32, ND_CMD_MAX_ENVELOPE - out_len, out_size);
1087                 else
1088                         copy = 0;
1089                 if (copy && copy_from_user(&out_env[out_len],
1090                                         p + in_len + out_len, copy)) {
1091                         rc = -EFAULT;
1092                         goto out;
1093                 }
1094                 out_len += out_size;
1095         }
1096
1097         buf_len = (u64) out_len + (u64) in_len;
1098         if (buf_len > ND_IOCTL_MAX_BUFLEN) {
1099                 dev_dbg(dev, "%s cmd: %s buf_len: %llu > %d\n", dimm_name,
1100                                 cmd_name, buf_len, ND_IOCTL_MAX_BUFLEN);
1101                 rc = -EINVAL;
1102                 goto out;
1103         }
1104
1105         buf = vmalloc(buf_len);
1106         if (!buf) {
1107                 rc = -ENOMEM;
1108                 goto out;
1109         }
1110
1111         if (copy_from_user(buf, p, buf_len)) {
1112                 rc = -EFAULT;
1113                 goto out;
1114         }
1115
1116         nd_device_lock(dev);
1117         nvdimm_bus_lock(dev);
1118         rc = nd_cmd_clear_to_send(nvdimm_bus, nvdimm, func, buf);
1119         if (rc)
1120                 goto out_unlock;
1121
1122         rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len, &cmd_rc);
1123         if (rc < 0)
1124                 goto out_unlock;
1125
1126         if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR && cmd_rc >= 0) {
1127                 struct nd_cmd_clear_error *clear_err = buf;
1128
1129                 nvdimm_account_cleared_poison(nvdimm_bus, clear_err->address,
1130                                 clear_err->cleared);
1131         }
1132
1133         if (copy_to_user(p, buf, buf_len))
1134                 rc = -EFAULT;
1135
1136 out_unlock:
1137         nvdimm_bus_unlock(dev);
1138         nd_device_unlock(dev);
1139 out:
1140         kfree(in_env);
1141         kfree(out_env);
1142         vfree(buf);
1143         return rc;
1144 }
1145
1146 enum nd_ioctl_mode {
1147         BUS_IOCTL,
1148         DIMM_IOCTL,
1149 };
1150
1151 static int match_dimm(struct device *dev, void *data)
1152 {
1153         long id = (long) data;
1154
1155         if (is_nvdimm(dev)) {
1156                 struct nvdimm *nvdimm = to_nvdimm(dev);
1157
1158                 return nvdimm->id == id;
1159         }
1160
1161         return 0;
1162 }
1163
1164 static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1165                 enum nd_ioctl_mode mode)
1166
1167 {
1168         struct nvdimm_bus *nvdimm_bus, *found = NULL;
1169         long id = (long) file->private_data;
1170         struct nvdimm *nvdimm = NULL;
1171         int rc, ro;
1172
1173         ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);
1174         mutex_lock(&nvdimm_bus_list_mutex);
1175         list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
1176                 if (mode == DIMM_IOCTL) {
1177                         struct device *dev;
1178
1179                         dev = device_find_child(&nvdimm_bus->dev,
1180                                         file->private_data, match_dimm);
1181                         if (!dev)
1182                                 continue;
1183                         nvdimm = to_nvdimm(dev);
1184                         found = nvdimm_bus;
1185                 } else if (nvdimm_bus->id == id) {
1186                         found = nvdimm_bus;
1187                 }
1188
1189                 if (found) {
1190                         atomic_inc(&nvdimm_bus->ioctl_active);
1191                         break;
1192                 }
1193         }
1194         mutex_unlock(&nvdimm_bus_list_mutex);
1195
1196         if (!found)
1197                 return -ENXIO;
1198
1199         nvdimm_bus = found;
1200         rc = __nd_ioctl(nvdimm_bus, nvdimm, ro, cmd, arg);
1201
1202         if (nvdimm)
1203                 put_device(&nvdimm->dev);
1204         if (atomic_dec_and_test(&nvdimm_bus->ioctl_active))
1205                 wake_up(&nvdimm_bus->wait);
1206
1207         return rc;
1208 }
1209
1210 static long bus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1211 {
1212         return nd_ioctl(file, cmd, arg, BUS_IOCTL);
1213 }
1214
1215 static long dimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1216 {
1217         return nd_ioctl(file, cmd, arg, DIMM_IOCTL);
1218 }
1219
1220 static int nd_open(struct inode *inode, struct file *file)
1221 {
1222         long minor = iminor(inode);
1223
1224         file->private_data = (void *) minor;
1225         return 0;
1226 }
1227
1228 static const struct file_operations nvdimm_bus_fops = {
1229         .owner = THIS_MODULE,
1230         .open = nd_open,
1231         .unlocked_ioctl = bus_ioctl,
1232         .compat_ioctl = bus_ioctl,
1233         .llseek = noop_llseek,
1234 };
1235
1236 static const struct file_operations nvdimm_fops = {
1237         .owner = THIS_MODULE,
1238         .open = nd_open,
1239         .unlocked_ioctl = dimm_ioctl,
1240         .compat_ioctl = dimm_ioctl,
1241         .llseek = noop_llseek,
1242 };
1243
1244 int __init nvdimm_bus_init(void)
1245 {
1246         int rc;
1247
1248         rc = bus_register(&nvdimm_bus_type);
1249         if (rc)
1250                 return rc;
1251
1252         rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
1253         if (rc < 0)
1254                 goto err_bus_chrdev;
1255         nvdimm_bus_major = rc;
1256
1257         rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
1258         if (rc < 0)
1259                 goto err_dimm_chrdev;
1260         nvdimm_major = rc;
1261
1262         nd_class = class_create(THIS_MODULE, "nd");
1263         if (IS_ERR(nd_class)) {
1264                 rc = PTR_ERR(nd_class);
1265                 goto err_class;
1266         }
1267
1268         rc = driver_register(&nd_bus_driver.drv);
1269         if (rc)
1270                 goto err_nd_bus;
1271
1272         return 0;
1273
1274  err_nd_bus:
1275         class_destroy(nd_class);
1276  err_class:
1277         unregister_chrdev(nvdimm_major, "dimmctl");
1278  err_dimm_chrdev:
1279         unregister_chrdev(nvdimm_bus_major, "ndctl");
1280  err_bus_chrdev:
1281         bus_unregister(&nvdimm_bus_type);
1282
1283         return rc;
1284 }
1285
1286 void nvdimm_bus_exit(void)
1287 {
1288         driver_unregister(&nd_bus_driver.drv);
1289         class_destroy(nd_class);
1290         unregister_chrdev(nvdimm_bus_major, "ndctl");
1291         unregister_chrdev(nvdimm_major, "dimmctl");
1292         bus_unregister(&nvdimm_bus_type);
1293         ida_destroy(&nd_ida);
1294 }