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)
  99                 nd_region_probe_success(nvdimm_bus, dev);
 100         else
 101                 nd_region_disable(nvdimm_bus, dev);
 102         nvdimm_bus_probe_end(nvdimm_bus);
 103
 104         dev_dbg(&nvdimm_bus->dev, "END: %s.probe(%s) = %d\n", dev->driver->name,
 105                         dev_name(dev), rc);
 106
 107         if (rc != 0)
 108                 module_put(provider);
 109         return rc;
 110 }
 111
 112 static int nvdimm_bus_remove(struct device *dev)
 113 {
 114         struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
 115         struct module *provider = to_bus_provider(dev);
 116         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 117         int rc = 0;
 118
 119         if (nd_drv->remove) {
 120                 debug_nvdimm_lock(dev);
 121                 rc = nd_drv->remove(dev);
 122                 debug_nvdimm_unlock(dev);
 123         }
 124         nd_region_disable(nvdimm_bus, dev);
 125
 126         dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d\n", dev->driver->name,
 127                         dev_name(dev), rc);
 128         module_put(provider);
 129         return rc;
 130 }
 131
 132 static void nvdimm_bus_shutdown(struct device *dev)
 133 {
 134         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 135         struct nd_device_driver *nd_drv = NULL;
 136
 137         if (dev->driver)
 138                 nd_drv = to_nd_device_driver(dev->driver);
 139
 140         if (nd_drv && nd_drv->shutdown) {
 141                 nd_drv->shutdown(dev);
 142                 dev_dbg(&nvdimm_bus->dev, "%s.shutdown(%s)\n",
 143                                 dev->driver->name, dev_name(dev));
 144         }
 145 }
 146
 147 void nd_device_notify(struct device *dev, enum nvdimm_event event)
 148 {
 149         nd_device_lock(dev);
 150         if (dev->driver) {
 151                 struct nd_device_driver *nd_drv;
 152
 153                 nd_drv = to_nd_device_driver(dev->driver);
 154                 if (nd_drv->notify)
 155                         nd_drv->notify(dev, event);
 156         }
 157         nd_device_unlock(dev);
 158 }
 159 EXPORT_SYMBOL(nd_device_notify);
 160
 161 void nvdimm_region_notify(struct nd_region *nd_region, enum nvdimm_event event)
 162 {
 163         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
 164
 165         if (!nvdimm_bus)
 166                 return;
 167
 168         /* caller is responsible for holding a reference on the device */
 169         nd_device_notify(&nd_region->dev, event);
 170 }
 171 EXPORT_SYMBOL_GPL(nvdimm_region_notify);
 172
 173 struct clear_badblocks_context {
 174         resource_size_t phys, cleared;
 175 };
 176
 177 static int nvdimm_clear_badblocks_region(struct device *dev, void *data)
 178 {
 179         struct clear_badblocks_context *ctx = data;
 180         struct nd_region *nd_region;
 181         resource_size_t ndr_end;
 182         sector_t sector;
 183
 184         /* make sure device is a region */
 185         if (!is_memory(dev))
 186                 return 0;
 187
 188         nd_region = to_nd_region(dev);
 189         ndr_end = nd_region->ndr_start + nd_region->ndr_size - 1;
 190
 191         /* make sure we are in the region */
 192         if (ctx->phys < nd_region->ndr_start
 193                         || (ctx->phys + ctx->cleared) > ndr_end)
 194                 return 0;
 195
 196         sector = (ctx->phys - nd_region->ndr_start) / 512;
 197         badblocks_clear(&nd_region->bb, sector, ctx->cleared / 512);
 198
 199         if (nd_region->bb_state)
 200                 sysfs_notify_dirent(nd_region->bb_state);
 201
 202         return 0;
 203 }
 204
 205 static void nvdimm_clear_badblocks_regions(struct nvdimm_bus *nvdimm_bus,
 206                 phys_addr_t phys, u64 cleared)
 207 {
 208         struct clear_badblocks_context ctx = {
 209                 .phys = phys,
 210                 .cleared = cleared,
 211         };
 212
 213         device_for_each_child(&nvdimm_bus->dev, &ctx,
 214                         nvdimm_clear_badblocks_region);
 215 }
 216
 217 static void nvdimm_account_cleared_poison(struct nvdimm_bus *nvdimm_bus,
 218                 phys_addr_t phys, u64 cleared)
 219 {
 220         if (cleared > 0)
 221                 badrange_forget(&nvdimm_bus->badrange, phys, cleared);
 222
 223         if (cleared > 0 && cleared / 512)
 224                 nvdimm_clear_badblocks_regions(nvdimm_bus, phys, cleared);
 225 }
 226
 227 long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
 228                 unsigned int len)
 229 {
 230         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 231         struct nvdimm_bus_descriptor *nd_desc;
 232         struct nd_cmd_clear_error clear_err;
 233         struct nd_cmd_ars_cap ars_cap;
 234         u32 clear_err_unit, mask;
 235         unsigned int noio_flag;
 236         int cmd_rc, rc;
 237
 238         if (!nvdimm_bus)
 239                 return -ENXIO;
 240
 241         nd_desc = nvdimm_bus->nd_desc;
 242         /*
 243          * if ndctl does not exist, it's PMEM_LEGACY and
 244          * we want to just pretend everything is handled.
 245          */
 246         if (!nd_desc->ndctl)
 247                 return len;
 248
 249         memset(&ars_cap, 0, sizeof(ars_cap));
 250         ars_cap.address = phys;
 251         ars_cap.length = len;
 252         noio_flag = memalloc_noio_save();
 253         rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_CAP, &ars_cap,
 254                         sizeof(ars_cap), &cmd_rc);
 255         memalloc_noio_restore(noio_flag);
 256         if (rc < 0)
 257                 return rc;
 258         if (cmd_rc < 0)
 259                 return cmd_rc;
 260         clear_err_unit = ars_cap.clear_err_unit;
 261         if (!clear_err_unit || !is_power_of_2(clear_err_unit))
 262                 return -ENXIO;
 263
 264         mask = clear_err_unit - 1;
 265         if ((phys | len) & mask)
 266                 return -ENXIO;
 267         memset(&clear_err, 0, sizeof(clear_err));
 268         clear_err.address = phys;
 269         clear_err.length = len;
 270         noio_flag = memalloc_noio_save();
 271         rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_CLEAR_ERROR, &clear_err,
 272                         sizeof(clear_err), &cmd_rc);
 273         memalloc_noio_restore(noio_flag);
 274         if (rc < 0)
 275                 return rc;
 276         if (cmd_rc < 0)
 277                 return cmd_rc;
 278
 279         nvdimm_account_cleared_poison(nvdimm_bus, phys, clear_err.cleared);
 280
 281         return clear_err.cleared;
 282 }
 283 EXPORT_SYMBOL_GPL(nvdimm_clear_poison);
 284
 285 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv);
 286
 287 static struct bus_type nvdimm_bus_type = {
 288         .name = "nd",
 289         .uevent = nvdimm_bus_uevent,
 290         .match = nvdimm_bus_match,
 291         .probe = nvdimm_bus_probe,
 292         .remove = nvdimm_bus_remove,
 293         .shutdown = nvdimm_bus_shutdown,
 294 };
 295
 296 static void nvdimm_bus_release(struct device *dev)
 297 {
 298         struct nvdimm_bus *nvdimm_bus;
 299
 300         nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
 301         ida_simple_remove(&nd_ida, nvdimm_bus->id);
 302         kfree(nvdimm_bus);
 303 }
 304
 305 bool is_nvdimm_bus(struct device *dev)
 306 {
 307         return dev->release == nvdimm_bus_release;
 308 }
 309
 310 struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
 311 {
 312         struct device *dev;
 313
 314         for (dev = nd_dev; dev; dev = dev->parent)
 315                 if (is_nvdimm_bus(dev))
 316                         break;
 317         dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
 318         if (dev)
 319                 return to_nvdimm_bus(dev);
 320         return NULL;
 321 }
 322
 323 struct nvdimm_bus *to_nvdimm_bus(struct device *dev)
 324 {
 325         struct nvdimm_bus *nvdimm_bus;
 326
 327         nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
 328         WARN_ON(!is_nvdimm_bus(dev));
 329         return nvdimm_bus;
 330 }
 331 EXPORT_SYMBOL_GPL(to_nvdimm_bus);
 332
 333 struct nvdimm_bus *nvdimm_to_bus(struct nvdimm *nvdimm)
 334 {
 335         return to_nvdimm_bus(nvdimm->dev.parent);
 336 }
 337 EXPORT_SYMBOL_GPL(nvdimm_to_bus);
 338
 339 struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
 340                 struct nvdimm_bus_descriptor *nd_desc)
 341 {
 342         struct nvdimm_bus *nvdimm_bus;
 343         int rc;
 344
 345         nvdimm_bus = kzalloc(sizeof(*nvdimm_bus), GFP_KERNEL);
 346         if (!nvdimm_bus)
 347                 return NULL;
 348         INIT_LIST_HEAD(&nvdimm_bus->list);
 349         INIT_LIST_HEAD(&nvdimm_bus->mapping_list);
 350         init_waitqueue_head(&nvdimm_bus->wait);
 351         nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
 352         if (nvdimm_bus->id < 0) {
 353                 kfree(nvdimm_bus);
 354                 return NULL;
 355         }
 356         mutex_init(&nvdimm_bus->reconfig_mutex);
 357         badrange_init(&nvdimm_bus->badrange);
 358         nvdimm_bus->nd_desc = nd_desc;
 359         nvdimm_bus->dev.parent = parent;
 360         nvdimm_bus->dev.release = nvdimm_bus_release;
 361         nvdimm_bus->dev.groups = nd_desc->attr_groups;
 362         nvdimm_bus->dev.bus = &nvdimm_bus_type;
 363         nvdimm_bus->dev.of_node = nd_desc->of_node;
 364         dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
 365         rc = device_register(&nvdimm_bus->dev);
 366         if (rc) {
 367                 dev_dbg(&nvdimm_bus->dev, "registration failed: %d\n", rc);
 368                 goto err;
 369         }
 370
 371         return nvdimm_bus;
 372  err:
 373         put_device(&nvdimm_bus->dev);
 374         return NULL;
 375 }
 376 EXPORT_SYMBOL_GPL(nvdimm_bus_register);
 377
 378 void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
 379 {
 380         if (!nvdimm_bus)
 381                 return;
 382         device_unregister(&nvdimm_bus->dev);
 383 }
 384 EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);
 385
 386 static int child_unregister(struct device *dev, void *data)
 387 {
 388         /*
 389          * the singular ndctl class device per bus needs to be
 390          * "device_destroy"ed, so skip it here
 391          *
 392          * i.e. remove classless children
 393          */
 394         if (dev->class)
 395                 return 0;
 396
 397         if (is_nvdimm(dev)) {
 398                 struct nvdimm *nvdimm = to_nvdimm(dev);
 399                 bool dev_put = false;
 400
 401                 /* We are shutting down. Make state frozen artificially. */
 402                 nvdimm_bus_lock(dev);
 403                 nvdimm->sec.state = NVDIMM_SECURITY_FROZEN;
 404                 if (test_and_clear_bit(NDD_WORK_PENDING, &nvdimm->flags))
 405                         dev_put = true;
 406                 nvdimm_bus_unlock(dev);
 407                 cancel_delayed_work_sync(&nvdimm->dwork);
 408                 if (dev_put)
 409                         put_device(dev);
 410         }
 411         nd_device_unregister(dev, ND_SYNC);
 412
 413         return 0;
 414 }
 415
 416 static void free_badrange_list(struct list_head *badrange_list)
 417 {
 418         struct badrange_entry *bre, *next;
 419
 420         list_for_each_entry_safe(bre, next, badrange_list, list) {
 421                 list_del(&bre->list);
 422                 kfree(bre);
 423         }
 424         list_del_init(badrange_list);
 425 }
 426
 427 static int nd_bus_remove(struct device *dev)
 428 {
 429         struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 430
 431         mutex_lock(&nvdimm_bus_list_mutex);
 432         list_del_init(&nvdimm_bus->list);
 433         mutex_unlock(&nvdimm_bus_list_mutex);
 434
 435         wait_event(nvdimm_bus->wait,
 436                         atomic_read(&nvdimm_bus->ioctl_active) == 0);
 437
 438         nd_synchronize();
 439         device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
 440
 441         spin_lock(&nvdimm_bus->badrange.lock);
 442         free_badrange_list(&nvdimm_bus->badrange.list);
 443         spin_unlock(&nvdimm_bus->badrange.lock);
 444
 445         nvdimm_bus_destroy_ndctl(nvdimm_bus);
 446
 447         return 0;
 448 }
 449
 450 static int nd_bus_probe(struct device *dev)
 451 {
 452         struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 453         int rc;
 454
 455         rc = nvdimm_bus_create_ndctl(nvdimm_bus);
 456         if (rc)
 457                 return rc;
 458
 459         mutex_lock(&nvdimm_bus_list_mutex);
 460         list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
 461         mutex_unlock(&nvdimm_bus_list_mutex);
 462
 463         /* enable bus provider attributes to look up their local context */
 464         dev_set_drvdata(dev, nvdimm_bus->nd_desc);
 465
 466         return 0;
 467 }
 468
 469 static struct nd_device_driver nd_bus_driver = {
 470         .probe = nd_bus_probe,
 471         .remove = nd_bus_remove,
 472         .drv = {
 473                 .name = "nd_bus",
 474                 .suppress_bind_attrs = true,
 475                 .bus = &nvdimm_bus_type,
 476                 .owner = THIS_MODULE,
 477                 .mod_name = KBUILD_MODNAME,
 478         },
 479 };
 480
 481 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
 482 {
 483         struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
 484
 485         if (is_nvdimm_bus(dev) && nd_drv == &nd_bus_driver)
 486                 return true;
 487
 488         return !!test_bit(to_nd_device_type(dev), &nd_drv->type);
 489 }
 490
 491 static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
 492
 493 void nd_synchronize(void)
 494 {
 495         async_synchronize_full_domain(&nd_async_domain);
 496 }
 497 EXPORT_SYMBOL_GPL(nd_synchronize);
 498
 499 static void nd_async_device_register(void *d, async_cookie_t cookie)
 500 {
 501         struct device *dev = d;
 502
 503         if (device_add(dev) != 0) {
 504                 dev_err(dev, "%s: failed\n", __func__);
 505                 put_device(dev);
 506         }
 507         put_device(dev);
 508         if (dev->parent)
 509                 put_device(dev->parent);
 510 }
 511
 512 static void nd_async_device_unregister(void *d, async_cookie_t cookie)
 513 {
 514         struct device *dev = d;
 515
 516         /* flush bus operations before delete */
 517         nvdimm_bus_lock(dev);
 518         nvdimm_bus_unlock(dev);
 519
 520         device_unregister(dev);
 521         put_device(dev);
 522 }
 523
 524 void __nd_device_register(struct device *dev)
 525 {
 526         if (!dev)
 527                 return;
 528
 529         /*
 530          * Ensure that region devices always have their NUMA node set as
 531          * early as possible. This way we are able to make certain that
 532          * any memory associated with the creation and the creation
 533          * itself of the region is associated with the correct node.
 534          */
 535         if (is_nd_region(dev))
 536                 set_dev_node(dev, to_nd_region(dev)->numa_node);
 537
 538         dev->bus = &nvdimm_bus_type;
 539         if (dev->parent) {
 540                 get_device(dev->parent);
 541                 if (dev_to_node(dev) == NUMA_NO_NODE)
 542                         set_dev_node(dev, dev_to_node(dev->parent));
 543         }
 544         get_device(dev);
 545
 546         async_schedule_dev_domain(nd_async_device_register, dev,
 547                                   &nd_async_domain);
 548 }
 549
 550 void nd_device_register(struct device *dev)
 551 {
 552         device_initialize(dev);
 553         __nd_device_register(dev);
 554 }
 555 EXPORT_SYMBOL(nd_device_register);
 556
 557 void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
 558 {
 559         bool killed;
 560
 561         switch (mode) {
 562         case ND_ASYNC:
 563                 /*
 564                  * In the async case this is being triggered with the
 565                  * device lock held and the unregistration work needs to
 566                  * be moved out of line iff this is thread has won the
 567                  * race to schedule the deletion.
 568                  */
 569                 if (!kill_device(dev))
 570                         return;
 571
 572                 get_device(dev);
 573                 async_schedule_domain(nd_async_device_unregister, dev,
 574                                 &nd_async_domain);
 575                 break;
 576         case ND_SYNC:
 577                 /*
 578                  * In the sync case the device is being unregistered due
 579                  * to a state change of the parent. Claim the kill state
 580                  * to synchronize against other unregistration requests,
 581                  * or otherwise let the async path handle it if the
 582                  * unregistration was already queued.
 583                  */
 584                 nd_device_lock(dev);
 585                 killed = kill_device(dev);
 586                 nd_device_unlock(dev);
 587
 588                 if (!killed)
 589                         return;
 590
 591                 nd_synchronize();
 592                 device_unregister(dev);
 593                 break;
 594         }
 595 }
 596 EXPORT_SYMBOL(nd_device_unregister);
 597
 598 /**
 599  * __nd_driver_register() - register a region or a namespace driver
 600  * @nd_drv: driver to register
 601  * @owner: automatically set by nd_driver_register() macro
 602  * @mod_name: automatically set by nd_driver_register() macro
 603  */
 604 int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
 605                 const char *mod_name)
 606 {
 607         struct device_driver *drv = &nd_drv->drv;
 608
 609         if (!nd_drv->type) {
 610                 pr_debug("driver type bitmask not set (%ps)\n",
 611                                 __builtin_return_address(0));
 612                 return -EINVAL;
 613         }
 614
 615         if (!nd_drv->probe) {
 616                 pr_debug("%s ->probe() must be specified\n", mod_name);
 617                 return -EINVAL;
 618         }
 619
 620         drv->bus = &nvdimm_bus_type;
 621         drv->owner = owner;
 622         drv->mod_name = mod_name;
 623
 624         return driver_register(drv);
 625 }
 626 EXPORT_SYMBOL(__nd_driver_register);
 627
 628 int nvdimm_revalidate_disk(struct gendisk *disk)
 629 {
 630         struct device *dev = disk_to_dev(disk)->parent;
 631         struct nd_region *nd_region = to_nd_region(dev->parent);
 632         int disk_ro = get_disk_ro(disk);
 633
 634         /*
 635          * Upgrade to read-only if the region is read-only preserve as
 636          * read-only if the disk is already read-only.
 637          */
 638         if (disk_ro || nd_region->ro == disk_ro)
 639                 return 0;
 640
 641         dev_info(dev, "%s read-only, marking %s read-only\n",
 642                         dev_name(&nd_region->dev), disk->disk_name);
 643         set_disk_ro(disk, 1);
 644
 645         return 0;
 646
 647 }
 648 EXPORT_SYMBOL(nvdimm_revalidate_disk);
 649
 650 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 651                 char *buf)
 652 {
 653         return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
 654                         to_nd_device_type(dev));
 655 }
 656 static DEVICE_ATTR_RO(modalias);
 657
 658 static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
 659                 char *buf)
 660 {
 661         return sprintf(buf, "%s\n", dev->type->name);
 662 }
 663 static DEVICE_ATTR_RO(devtype);
 664
 665 static struct attribute *nd_device_attributes[] = {
 666         &dev_attr_modalias.attr,
 667         &dev_attr_devtype.attr,
 668         NULL,
 669 };
 670
 671 /*
 672  * nd_device_attribute_group - generic attributes for all devices on an nd bus
 673  */
 674 struct attribute_group nd_device_attribute_group = {
 675         .attrs = nd_device_attributes,
 676 };
 677 EXPORT_SYMBOL_GPL(nd_device_attribute_group);
 678
 679 static ssize_t numa_node_show(struct device *dev,
 680                 struct device_attribute *attr, char *buf)
 681 {
 682         return sprintf(buf, "%d\n", dev_to_node(dev));
 683 }
 684 static DEVICE_ATTR_RO(numa_node);
 685
 686 static struct attribute *nd_numa_attributes[] = {
 687         &dev_attr_numa_node.attr,
 688         NULL,
 689 };
 690
 691 static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
 692                 int n)
 693 {
 694         if (!IS_ENABLED(CONFIG_NUMA))
 695                 return 0;
 696
 697         return a->mode;
 698 }
 699
 700 /*
 701  * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
 702  */
 703 struct attribute_group nd_numa_attribute_group = {
 704         .attrs = nd_numa_attributes,
 705         .is_visible = nd_numa_attr_visible,
 706 };
 707 EXPORT_SYMBOL_GPL(nd_numa_attribute_group);
 708
 709 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
 710 {
 711         dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
 712         struct device *dev;
 713
 714         dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
 715                         "ndctl%d", nvdimm_bus->id);
 716
 717         if (IS_ERR(dev))
 718                 dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld\n",
 719                                 nvdimm_bus->id, PTR_ERR(dev));
 720         return PTR_ERR_OR_ZERO(dev);
 721 }
 722
 723 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
 724 {
 725         device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
 726 }
 727
 728 static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
 729         [ND_CMD_IMPLEMENTED] = { },
 730         [ND_CMD_SMART] = {
 731                 .out_num = 2,
 732                 .out_sizes = { 4, 128, },
 733         },
 734         [ND_CMD_SMART_THRESHOLD] = {
 735                 .out_num = 2,
 736                 .out_sizes = { 4, 8, },
 737         },
 738         [ND_CMD_DIMM_FLAGS] = {
 739                 .out_num = 2,
 740                 .out_sizes = { 4, 4 },
 741         },
 742         [ND_CMD_GET_CONFIG_SIZE] = {
 743                 .out_num = 3,
 744                 .out_sizes = { 4, 4, 4, },
 745         },
 746         [ND_CMD_GET_CONFIG_DATA] = {
 747                 .in_num = 2,
 748                 .in_sizes = { 4, 4, },
 749                 .out_num = 2,
 750                 .out_sizes = { 4, UINT_MAX, },
 751         },
 752         [ND_CMD_SET_CONFIG_DATA] = {
 753                 .in_num = 3,
 754                 .in_sizes = { 4, 4, UINT_MAX, },
 755                 .out_num = 1,
 756                 .out_sizes = { 4, },
 757         },
 758         [ND_CMD_VENDOR] = {
 759                 .in_num = 3,
 760                 .in_sizes = { 4, 4, UINT_MAX, },
 761                 .out_num = 3,
 762                 .out_sizes = { 4, 4, UINT_MAX, },
 763         },
 764         [ND_CMD_CALL] = {
 765                 .in_num = 2,
 766                 .in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
 767                 .out_num = 1,
 768                 .out_sizes = { UINT_MAX, },
 769         },
 770 };
 771
 772 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
 773 {
 774         if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
 775                 return &__nd_cmd_dimm_descs[cmd];
 776         return NULL;
 777 }
 778 EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
 779
 780 static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
 781         [ND_CMD_IMPLEMENTED] = { },
 782         [ND_CMD_ARS_CAP] = {
 783                 .in_num = 2,
 784                 .in_sizes = { 8, 8, },
 785                 .out_num = 4,
 786                 .out_sizes = { 4, 4, 4, 4, },
 787         },
 788         [ND_CMD_ARS_START] = {
 789                 .in_num = 5,
 790                 .in_sizes = { 8, 8, 2, 1, 5, },
 791                 .out_num = 2,
 792                 .out_sizes = { 4, 4, },
 793         },
 794         [ND_CMD_ARS_STATUS] = {
 795                 .out_num = 3,
 796                 .out_sizes = { 4, 4, UINT_MAX, },
 797         },
 798         [ND_CMD_CLEAR_ERROR] = {
 799                 .in_num = 2,
 800                 .in_sizes = { 8, 8, },
 801                 .out_num = 3,
 802                 .out_sizes = { 4, 4, 8, },
 803         },
 804         [ND_CMD_CALL] = {
 805                 .in_num = 2,
 806                 .in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
 807                 .out_num = 1,
 808                 .out_sizes = { UINT_MAX, },
 809         },
 810 };
 811
 812 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
 813 {
 814         if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
 815                 return &__nd_cmd_bus_descs[cmd];
 816         return NULL;
 817 }
 818 EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
 819
 820 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
 821                 const struct nd_cmd_desc *desc, int idx, void *buf)
 822 {
 823         if (idx >= desc->in_num)
 824                 return UINT_MAX;
 825
 826         if (desc->in_sizes[idx] < UINT_MAX)
 827                 return desc->in_sizes[idx];
 828
 829         if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
 830                 struct nd_cmd_set_config_hdr *hdr = buf;
 831
 832                 return hdr->in_length;
 833         } else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
 834                 struct nd_cmd_vendor_hdr *hdr = buf;
 835
 836                 return hdr->in_length;
 837         } else if (cmd == ND_CMD_CALL) {
 838                 struct nd_cmd_pkg *pkg = buf;
 839
 840                 return pkg->nd_size_in;
 841         }
 842
 843         return UINT_MAX;
 844 }
 845 EXPORT_SYMBOL_GPL(nd_cmd_in_size);
 846
 847 u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
 848                 const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
 849                 const u32 *out_field, unsigned long remainder)
 850 {
 851         if (idx >= desc->out_num)
 852                 return UINT_MAX;
 853
 854         if (desc->out_sizes[idx] < UINT_MAX)
 855                 return desc->out_sizes[idx];
 856
 857         if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
 858                 return in_field[1];
 859         else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
 860                 return out_field[1];
 861         else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 2) {
 862                 /*
 863                  * Per table 9-276 ARS Data in ACPI 6.1, out_field[1] is
 864                  * "Size of Output Buffer in bytes, including this
 865                  * field."
 866                  */
 867                 if (out_field[1] < 4)
 868                         return 0;
 869                 /*
 870                  * ACPI 6.1 is ambiguous if 'status' is included in the
 871                  * output size. If we encounter an output size that
 872                  * overshoots the remainder by 4 bytes, assume it was
 873                  * including 'status'.
 874                  */
 875                 if (out_field[1] - 4 == remainder)
 876                         return remainder;
 877                 return out_field[1] - 8;
 878         } else if (cmd == ND_CMD_CALL) {
 879                 struct nd_cmd_pkg *pkg = (struct nd_cmd_pkg *) in_field;
 880
 881                 return pkg->nd_size_out;
 882         }
 883
 884
 885         return UINT_MAX;
 886 }
 887 EXPORT_SYMBOL_GPL(nd_cmd_out_size);
 888
 889 void wait_nvdimm_bus_probe_idle(struct device *dev)
 890 {
 891         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 892
 893         do {
 894                 if (nvdimm_bus->probe_active == 0)
 895                         break;
 896                 nvdimm_bus_unlock(dev);
 897                 nd_device_unlock(dev);
 898                 wait_event(nvdimm_bus->wait,
 899                                 nvdimm_bus->probe_active == 0);
 900                 nd_device_lock(dev);
 901                 nvdimm_bus_lock(dev);
 902         } while (true);
 903 }
 904
 905 static int nd_pmem_forget_poison_check(struct device *dev, void *data)
 906 {
 907         struct nd_cmd_clear_error *clear_err =
 908                 (struct nd_cmd_clear_error *)data;
 909         struct nd_btt *nd_btt = is_nd_btt(dev) ? to_nd_btt(dev) : NULL;
 910         struct nd_pfn *nd_pfn = is_nd_pfn(dev) ? to_nd_pfn(dev) : NULL;
 911         struct nd_dax *nd_dax = is_nd_dax(dev) ? to_nd_dax(dev) : NULL;
 912         struct nd_namespace_common *ndns = NULL;
 913         struct nd_namespace_io *nsio;
 914         resource_size_t offset = 0, end_trunc = 0, start, end, pstart, pend;
 915
 916         if (nd_dax || !dev->driver)
 917                 return 0;
 918
 919         start = clear_err->address;
 920         end = clear_err->address + clear_err->cleared - 1;
 921
 922         if (nd_btt || nd_pfn || nd_dax) {
 923                 if (nd_btt)
 924                         ndns = nd_btt->ndns;
 925                 else if (nd_pfn)
 926                         ndns = nd_pfn->ndns;
 927                 else if (nd_dax)
 928                         ndns = nd_dax->nd_pfn.ndns;
 929
 930                 if (!ndns)
 931                         return 0;
 932         } else
 933                 ndns = to_ndns(dev);
 934
 935         nsio = to_nd_namespace_io(&ndns->dev);
 936         pstart = nsio->res.start + offset;
 937         pend = nsio->res.end - end_trunc;
 938
 939         if ((pstart >= start) && (pend <= end))
 940                 return -EBUSY;
 941
 942         return 0;
 943
 944 }
 945
 946 static int nd_ns_forget_poison_check(struct device *dev, void *data)
 947 {
 948         return device_for_each_child(dev, data, nd_pmem_forget_poison_check);
 949 }
 950
 951 /* set_config requires an idle interleave set */
 952 static int nd_cmd_clear_to_send(struct nvdimm_bus *nvdimm_bus,
 953                 struct nvdimm *nvdimm, unsigned int cmd, void *data)
 954 {
 955         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 956
 957         /* ask the bus provider if it would like to block this request */
 958         if (nd_desc->clear_to_send) {
 959                 int rc = nd_desc->clear_to_send(nd_desc, nvdimm, cmd, data);
 960
 961                 if (rc)
 962                         return rc;
 963         }
 964
 965         /* require clear error to go through the pmem driver */
 966         if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR)
 967                 return device_for_each_child(&nvdimm_bus->dev, data,
 968                                 nd_ns_forget_poison_check);
 969
 970         if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
 971                 return 0;
 972
 973         /* prevent label manipulation while the kernel owns label updates */
 974         wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);
 975         if (atomic_read(&nvdimm->busy))
 976                 return -EBUSY;
 977         return 0;
 978 }
 979
 980 static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
 981                 int read_only, unsigned int ioctl_cmd, unsigned long arg)
 982 {
 983         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 984         const struct nd_cmd_desc *desc = NULL;
 985         unsigned int cmd = _IOC_NR(ioctl_cmd);
 986         struct device *dev = &nvdimm_bus->dev;
 987         void __user *p = (void __user *) arg;
 988         char *out_env = NULL, *in_env = NULL;
 989         const char *cmd_name, *dimm_name;
 990         u32 in_len = 0, out_len = 0;
 991         unsigned int func = cmd;
 992         unsigned long cmd_mask;
 993         struct nd_cmd_pkg pkg;
 994         int rc, i, cmd_rc;
 995         void *buf = NULL;
 996         u64 buf_len = 0;
 997
 998         if (nvdimm) {
 999                 desc = nd_cmd_dimm_desc(cmd);
1000                 cmd_name = nvdimm_cmd_name(cmd);
1001                 cmd_mask = nvdimm->cmd_mask;
1002                 dimm_name = dev_name(&nvdimm->dev);
1003         } else {
1004                 desc = nd_cmd_bus_desc(cmd);
1005                 cmd_name = nvdimm_bus_cmd_name(cmd);
1006                 cmd_mask = nd_desc->cmd_mask;
1007                 dimm_name = "bus";
1008         }
1009
1010         if (cmd == ND_CMD_CALL) {
1011                 if (copy_from_user(&pkg, p, sizeof(pkg)))
1012                         return -EFAULT;
1013         }
1014
1015         if (!desc || (desc->out_num + desc->in_num == 0) ||
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 }