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   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
  27int nvdimm_major;
  28static int nvdimm_bus_major;
  29struct class *nd_class;
  30static DEFINE_IDA(nd_ida);
  31
  32static 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
  48static 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
  54static 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
  65static 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
  72static 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
  80static 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
 111static 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
 130static 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
 145void 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}
 157EXPORT_SYMBOL(nd_device_notify);
 158
 159void 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}
 169EXPORT_SYMBOL_GPL(nvdimm_region_notify);
 170
 171struct clear_badblocks_context {
 172	resource_size_t phys, cleared;
 173};
 174
 175static 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
 203static 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
 215static 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
 225long 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}
 281EXPORT_SYMBOL_GPL(nvdimm_clear_poison);
 282
 283static int nvdimm_bus_match(struct device *dev, struct device_driver *drv);
 284
 285static 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
 294static 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
 303static const struct device_type nvdimm_bus_dev_type = {
 304	.release = nvdimm_bus_release,
 305	.groups = nvdimm_bus_attribute_groups,
 306};
 307
 308bool is_nvdimm_bus(struct device *dev)
 309{
 310	return dev->type == &nvdimm_bus_dev_type;
 311}
 312
 313struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
 314{
 315	struct device *dev;
 316
 317	for (dev = nd_dev; dev; dev = dev->parent)
 318		if (is_nvdimm_bus(dev))
 319			break;
 320	dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
 321	if (dev)
 322		return to_nvdimm_bus(dev);
 323	return NULL;
 324}
 325
 326struct nvdimm_bus *to_nvdimm_bus(struct device *dev)
 327{
 328	struct nvdimm_bus *nvdimm_bus;
 329
 330	nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
 331	WARN_ON(!is_nvdimm_bus(dev));
 332	return nvdimm_bus;
 333}
 334EXPORT_SYMBOL_GPL(to_nvdimm_bus);
 335
 336struct nvdimm_bus *nvdimm_to_bus(struct nvdimm *nvdimm)
 337{
 338	return to_nvdimm_bus(nvdimm->dev.parent);
 339}
 340EXPORT_SYMBOL_GPL(nvdimm_to_bus);
 341
 342struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
 343		struct nvdimm_bus_descriptor *nd_desc)
 344{
 345	struct nvdimm_bus *nvdimm_bus;
 346	int rc;
 347
 348	nvdimm_bus = kzalloc(sizeof(*nvdimm_bus), GFP_KERNEL);
 349	if (!nvdimm_bus)
 350		return NULL;
 351	INIT_LIST_HEAD(&nvdimm_bus->list);
 352	INIT_LIST_HEAD(&nvdimm_bus->mapping_list);
 353	init_waitqueue_head(&nvdimm_bus->wait);
 354	nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
 355	if (nvdimm_bus->id < 0) {
 356		kfree(nvdimm_bus);
 357		return NULL;
 358	}
 359	mutex_init(&nvdimm_bus->reconfig_mutex);
 360	badrange_init(&nvdimm_bus->badrange);
 361	nvdimm_bus->nd_desc = nd_desc;
 362	nvdimm_bus->dev.parent = parent;
 363	nvdimm_bus->dev.type = &nvdimm_bus_dev_type;
 364	nvdimm_bus->dev.groups = nd_desc->attr_groups;
 365	nvdimm_bus->dev.bus = &nvdimm_bus_type;
 366	nvdimm_bus->dev.of_node = nd_desc->of_node;
 367	dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
 368	rc = device_register(&nvdimm_bus->dev);
 369	if (rc) {
 370		dev_dbg(&nvdimm_bus->dev, "registration failed: %d\n", rc);
 371		goto err;
 372	}
 373
 374	return nvdimm_bus;
 375 err:
 376	put_device(&nvdimm_bus->dev);
 377	return NULL;
 378}
 379EXPORT_SYMBOL_GPL(nvdimm_bus_register);
 380
 381void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
 382{
 383	if (!nvdimm_bus)
 384		return;
 385	device_unregister(&nvdimm_bus->dev);
 386}
 387EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);
 388
 389static int child_unregister(struct device *dev, void *data)
 390{
 391	/*
 392	 * the singular ndctl class device per bus needs to be
 393	 * "device_destroy"ed, so skip it here
 394	 *
 395	 * i.e. remove classless children
 396	 */
 397	if (dev->class)
 398		return 0;
 399
 400	if (is_nvdimm(dev)) {
 401		struct nvdimm *nvdimm = to_nvdimm(dev);
 402		bool dev_put = false;
 403
 404		/* We are shutting down. Make state frozen artificially. */
 405		nvdimm_bus_lock(dev);
 406		set_bit(NVDIMM_SECURITY_FROZEN, &nvdimm->sec.flags);
 407		if (test_and_clear_bit(NDD_WORK_PENDING, &nvdimm->flags))
 408			dev_put = true;
 409		nvdimm_bus_unlock(dev);
 410		cancel_delayed_work_sync(&nvdimm->dwork);
 411		if (dev_put)
 412			put_device(dev);
 413	}
 414	nd_device_unregister(dev, ND_SYNC);
 415
 416	return 0;
 417}
 418
 419static void free_badrange_list(struct list_head *badrange_list)
 420{
 421	struct badrange_entry *bre, *next;
 422
 423	list_for_each_entry_safe(bre, next, badrange_list, list) {
 424		list_del(&bre->list);
 425		kfree(bre);
 426	}
 427	list_del_init(badrange_list);
 428}
 429
 430static int nd_bus_remove(struct device *dev)
 431{
 432	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 433
 434	mutex_lock(&nvdimm_bus_list_mutex);
 435	list_del_init(&nvdimm_bus->list);
 436	mutex_unlock(&nvdimm_bus_list_mutex);
 437
 438	wait_event(nvdimm_bus->wait,
 439			atomic_read(&nvdimm_bus->ioctl_active) == 0);
 440
 441	nd_synchronize();
 442	device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
 443
 444	spin_lock(&nvdimm_bus->badrange.lock);
 445	free_badrange_list(&nvdimm_bus->badrange.list);
 446	spin_unlock(&nvdimm_bus->badrange.lock);
 447
 448	nvdimm_bus_destroy_ndctl(nvdimm_bus);
 449
 450	return 0;
 451}
 452
 453static int nd_bus_probe(struct device *dev)
 454{
 455	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 456	int rc;
 457
 458	rc = nvdimm_bus_create_ndctl(nvdimm_bus);
 459	if (rc)
 460		return rc;
 461
 462	mutex_lock(&nvdimm_bus_list_mutex);
 463	list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
 464	mutex_unlock(&nvdimm_bus_list_mutex);
 465
 466	/* enable bus provider attributes to look up their local context */
 467	dev_set_drvdata(dev, nvdimm_bus->nd_desc);
 468
 469	return 0;
 470}
 471
 472static struct nd_device_driver nd_bus_driver = {
 473	.probe = nd_bus_probe,
 474	.remove = nd_bus_remove,
 475	.drv = {
 476		.name = "nd_bus",
 477		.suppress_bind_attrs = true,
 478		.bus = &nvdimm_bus_type,
 479		.owner = THIS_MODULE,
 480		.mod_name = KBUILD_MODNAME,
 481	},
 482};
 483
 484static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
 485{
 486	struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
 487
 488	if (is_nvdimm_bus(dev) && nd_drv == &nd_bus_driver)
 489		return true;
 490
 491	return !!test_bit(to_nd_device_type(dev), &nd_drv->type);
 492}
 493
 494static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
 495
 496void nd_synchronize(void)
 497{
 498	async_synchronize_full_domain(&nd_async_domain);
 499}
 500EXPORT_SYMBOL_GPL(nd_synchronize);
 501
 502static void nd_async_device_register(void *d, async_cookie_t cookie)
 503{
 504	struct device *dev = d;
 505
 506	if (device_add(dev) != 0) {
 507		dev_err(dev, "%s: failed\n", __func__);
 508		put_device(dev);
 509	}
 510	put_device(dev);
 511	if (dev->parent)
 512		put_device(dev->parent);
 513}
 514
 515static void nd_async_device_unregister(void *d, async_cookie_t cookie)
 516{
 517	struct device *dev = d;
 518
 519	/* flush bus operations before delete */
 520	nvdimm_bus_lock(dev);
 521	nvdimm_bus_unlock(dev);
 522
 523	device_unregister(dev);
 524	put_device(dev);
 525}
 526
 527void __nd_device_register(struct device *dev)
 528{
 529	if (!dev)
 530		return;
 531
 532	/*
 533	 * Ensure that region devices always have their NUMA node set as
 534	 * early as possible. This way we are able to make certain that
 535	 * any memory associated with the creation and the creation
 536	 * itself of the region is associated with the correct node.
 537	 */
 538	if (is_nd_region(dev))
 539		set_dev_node(dev, to_nd_region(dev)->numa_node);
 540
 541	dev->bus = &nvdimm_bus_type;
 542	if (dev->parent) {
 543		get_device(dev->parent);
 544		if (dev_to_node(dev) == NUMA_NO_NODE)
 545			set_dev_node(dev, dev_to_node(dev->parent));
 546	}
 547	get_device(dev);
 548
 549	async_schedule_dev_domain(nd_async_device_register, dev,
 550				  &nd_async_domain);
 551}
 552
 553void nd_device_register(struct device *dev)
 554{
 555	device_initialize(dev);
 556	__nd_device_register(dev);
 557}
 558EXPORT_SYMBOL(nd_device_register);
 559
 560void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
 561{
 562	bool killed;
 563
 564	switch (mode) {
 565	case ND_ASYNC:
 566		/*
 567		 * In the async case this is being triggered with the
 568		 * device lock held and the unregistration work needs to
 569		 * be moved out of line iff this is thread has won the
 570		 * race to schedule the deletion.
 571		 */
 572		if (!kill_device(dev))
 573			return;
 574
 575		get_device(dev);
 576		async_schedule_domain(nd_async_device_unregister, dev,
 577				&nd_async_domain);
 578		break;
 579	case ND_SYNC:
 580		/*
 581		 * In the sync case the device is being unregistered due
 582		 * to a state change of the parent. Claim the kill state
 583		 * to synchronize against other unregistration requests,
 584		 * or otherwise let the async path handle it if the
 585		 * unregistration was already queued.
 586		 */
 587		nd_device_lock(dev);
 588		killed = kill_device(dev);
 589		nd_device_unlock(dev);
 590
 591		if (!killed)
 592			return;
 593
 594		nd_synchronize();
 595		device_unregister(dev);
 596		break;
 597	}
 598}
 599EXPORT_SYMBOL(nd_device_unregister);
 600
 601/**
 602 * __nd_driver_register() - register a region or a namespace driver
 603 * @nd_drv: driver to register
 604 * @owner: automatically set by nd_driver_register() macro
 605 * @mod_name: automatically set by nd_driver_register() macro
 606 */
 607int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
 608		const char *mod_name)
 609{
 610	struct device_driver *drv = &nd_drv->drv;
 611
 612	if (!nd_drv->type) {
 613		pr_debug("driver type bitmask not set (%ps)\n",
 614				__builtin_return_address(0));
 615		return -EINVAL;
 616	}
 617
 618	if (!nd_drv->probe) {
 619		pr_debug("%s ->probe() must be specified\n", mod_name);
 620		return -EINVAL;
 621	}
 622
 623	drv->bus = &nvdimm_bus_type;
 624	drv->owner = owner;
 625	drv->mod_name = mod_name;
 626
 627	return driver_register(drv);
 628}
 629EXPORT_SYMBOL(__nd_driver_register);
 630
 631int nvdimm_revalidate_disk(struct gendisk *disk)
 632{
 633	struct device *dev = disk_to_dev(disk)->parent;
 634	struct nd_region *nd_region = to_nd_region(dev->parent);
 635	int disk_ro = get_disk_ro(disk);
 636
 637	/*
 638	 * Upgrade to read-only if the region is read-only preserve as
 639	 * read-only if the disk is already read-only.
 640	 */
 641	if (disk_ro || nd_region->ro == disk_ro)
 642		return 0;
 643
 644	dev_info(dev, "%s read-only, marking %s read-only\n",
 645			dev_name(&nd_region->dev), disk->disk_name);
 646	set_disk_ro(disk, 1);
 647
 648	return 0;
 649
 650}
 651EXPORT_SYMBOL(nvdimm_revalidate_disk);
 652
 653static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 654		char *buf)
 655{
 656	return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
 657			to_nd_device_type(dev));
 658}
 659static DEVICE_ATTR_RO(modalias);
 660
 661static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
 662		char *buf)
 663{
 664	return sprintf(buf, "%s\n", dev->type->name);
 665}
 666static DEVICE_ATTR_RO(devtype);
 667
 668static struct attribute *nd_device_attributes[] = {
 669	&dev_attr_modalias.attr,
 670	&dev_attr_devtype.attr,
 671	NULL,
 672};
 673
 674/*
 675 * nd_device_attribute_group - generic attributes for all devices on an nd bus
 676 */
 677const struct attribute_group nd_device_attribute_group = {
 678	.attrs = nd_device_attributes,
 679};
 680
 681static ssize_t numa_node_show(struct device *dev,
 682		struct device_attribute *attr, char *buf)
 683{
 684	return sprintf(buf, "%d\n", dev_to_node(dev));
 685}
 686static DEVICE_ATTR_RO(numa_node);
 687
 688static int nvdimm_dev_to_target_node(struct device *dev)
 689{
 690	struct device *parent = dev->parent;
 691	struct nd_region *nd_region = NULL;
 692
 693	if (is_nd_region(dev))
 694		nd_region = to_nd_region(dev);
 695	else if (parent && is_nd_region(parent))
 696		nd_region = to_nd_region(parent);
 697
 698	if (!nd_region)
 699		return NUMA_NO_NODE;
 700	return nd_region->target_node;
 701}
 702
 703static ssize_t target_node_show(struct device *dev,
 704		struct device_attribute *attr, char *buf)
 705{
 706	return sprintf(buf, "%d\n", nvdimm_dev_to_target_node(dev));
 707}
 708static DEVICE_ATTR_RO(target_node);
 709
 710static struct attribute *nd_numa_attributes[] = {
 711	&dev_attr_numa_node.attr,
 712	&dev_attr_target_node.attr,
 713	NULL,
 714};
 715
 716static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
 717		int n)
 718{
 719	struct device *dev = container_of(kobj, typeof(*dev), kobj);
 720
 721	if (!IS_ENABLED(CONFIG_NUMA))
 722		return 0;
 723
 724	if (a == &dev_attr_target_node.attr &&
 725			nvdimm_dev_to_target_node(dev) == NUMA_NO_NODE)
 726		return 0;
 727
 728	return a->mode;
 729}
 730
 731/*
 732 * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
 733 */
 734const struct attribute_group nd_numa_attribute_group = {
 735	.attrs = nd_numa_attributes,
 736	.is_visible = nd_numa_attr_visible,
 737};
 738
 739int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
 740{
 741	dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
 742	struct device *dev;
 743
 744	dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
 745			"ndctl%d", nvdimm_bus->id);
 746
 747	if (IS_ERR(dev))
 748		dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld\n",
 749				nvdimm_bus->id, PTR_ERR(dev));
 750	return PTR_ERR_OR_ZERO(dev);
 751}
 752
 753void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
 754{
 755	device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
 756}
 757
 758static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
 759	[ND_CMD_IMPLEMENTED] = { },
 760	[ND_CMD_SMART] = {
 761		.out_num = 2,
 762		.out_sizes = { 4, 128, },
 763	},
 764	[ND_CMD_SMART_THRESHOLD] = {
 765		.out_num = 2,
 766		.out_sizes = { 4, 8, },
 767	},
 768	[ND_CMD_DIMM_FLAGS] = {
 769		.out_num = 2,
 770		.out_sizes = { 4, 4 },
 771	},
 772	[ND_CMD_GET_CONFIG_SIZE] = {
 773		.out_num = 3,
 774		.out_sizes = { 4, 4, 4, },
 775	},
 776	[ND_CMD_GET_CONFIG_DATA] = {
 777		.in_num = 2,
 778		.in_sizes = { 4, 4, },
 779		.out_num = 2,
 780		.out_sizes = { 4, UINT_MAX, },
 781	},
 782	[ND_CMD_SET_CONFIG_DATA] = {
 783		.in_num = 3,
 784		.in_sizes = { 4, 4, UINT_MAX, },
 785		.out_num = 1,
 786		.out_sizes = { 4, },
 787	},
 788	[ND_CMD_VENDOR] = {
 789		.in_num = 3,
 790		.in_sizes = { 4, 4, UINT_MAX, },
 791		.out_num = 3,
 792		.out_sizes = { 4, 4, UINT_MAX, },
 793	},
 794	[ND_CMD_CALL] = {
 795		.in_num = 2,
 796		.in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
 797		.out_num = 1,
 798		.out_sizes = { UINT_MAX, },
 799	},
 800};
 801
 802const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
 803{
 804	if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
 805		return &__nd_cmd_dimm_descs[cmd];
 806	return NULL;
 807}
 808EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
 809
 810static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
 811	[ND_CMD_IMPLEMENTED] = { },
 812	[ND_CMD_ARS_CAP] = {
 813		.in_num = 2,
 814		.in_sizes = { 8, 8, },
 815		.out_num = 4,
 816		.out_sizes = { 4, 4, 4, 4, },
 817	},
 818	[ND_CMD_ARS_START] = {
 819		.in_num = 5,
 820		.in_sizes = { 8, 8, 2, 1, 5, },
 821		.out_num = 2,
 822		.out_sizes = { 4, 4, },
 823	},
 824	[ND_CMD_ARS_STATUS] = {
 825		.out_num = 3,
 826		.out_sizes = { 4, 4, UINT_MAX, },
 827	},
 828	[ND_CMD_CLEAR_ERROR] = {
 829		.in_num = 2,
 830		.in_sizes = { 8, 8, },
 831		.out_num = 3,
 832		.out_sizes = { 4, 4, 8, },
 833	},
 834	[ND_CMD_CALL] = {
 835		.in_num = 2,
 836		.in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
 837		.out_num = 1,
 838		.out_sizes = { UINT_MAX, },
 839	},
 840};
 841
 842const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
 843{
 844	if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
 845		return &__nd_cmd_bus_descs[cmd];
 846	return NULL;
 847}
 848EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
 849
 850u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
 851		const struct nd_cmd_desc *desc, int idx, void *buf)
 852{
 853	if (idx >= desc->in_num)
 854		return UINT_MAX;
 855
 856	if (desc->in_sizes[idx] < UINT_MAX)
 857		return desc->in_sizes[idx];
 858
 859	if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
 860		struct nd_cmd_set_config_hdr *hdr = buf;
 861
 862		return hdr->in_length;
 863	} else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
 864		struct nd_cmd_vendor_hdr *hdr = buf;
 865
 866		return hdr->in_length;
 867	} else if (cmd == ND_CMD_CALL) {
 868		struct nd_cmd_pkg *pkg = buf;
 869
 870		return pkg->nd_size_in;
 871	}
 872
 873	return UINT_MAX;
 874}
 875EXPORT_SYMBOL_GPL(nd_cmd_in_size);
 876
 877u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
 878		const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
 879		const u32 *out_field, unsigned long remainder)
 880{
 881	if (idx >= desc->out_num)
 882		return UINT_MAX;
 883
 884	if (desc->out_sizes[idx] < UINT_MAX)
 885		return desc->out_sizes[idx];
 886
 887	if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
 888		return in_field[1];
 889	else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
 890		return out_field[1];
 891	else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 2) {
 892		/*
 893		 * Per table 9-276 ARS Data in ACPI 6.1, out_field[1] is
 894		 * "Size of Output Buffer in bytes, including this
 895		 * field."
 896		 */
 897		if (out_field[1] < 4)
 898			return 0;
 899		/*
 900		 * ACPI 6.1 is ambiguous if 'status' is included in the
 901		 * output size. If we encounter an output size that
 902		 * overshoots the remainder by 4 bytes, assume it was
 903		 * including 'status'.
 904		 */
 905		if (out_field[1] - 4 == remainder)
 906			return remainder;
 907		return out_field[1] - 8;
 908	} else if (cmd == ND_CMD_CALL) {
 909		struct nd_cmd_pkg *pkg = (struct nd_cmd_pkg *) in_field;
 910
 911		return pkg->nd_size_out;
 912	}
 913
 914
 915	return UINT_MAX;
 916}
 917EXPORT_SYMBOL_GPL(nd_cmd_out_size);
 918
 919void wait_nvdimm_bus_probe_idle(struct device *dev)
 920{
 921	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 922
 923	do {
 924		if (nvdimm_bus->probe_active == 0)
 925			break;
 926		nvdimm_bus_unlock(dev);
 927		nd_device_unlock(dev);
 928		wait_event(nvdimm_bus->wait,
 929				nvdimm_bus->probe_active == 0);
 930		nd_device_lock(dev);
 931		nvdimm_bus_lock(dev);
 932	} while (true);
 933}
 934
 935static int nd_pmem_forget_poison_check(struct device *dev, void *data)
 936{
 937	struct nd_cmd_clear_error *clear_err =
 938		(struct nd_cmd_clear_error *)data;
 939	struct nd_btt *nd_btt = is_nd_btt(dev) ? to_nd_btt(dev) : NULL;
 940	struct nd_pfn *nd_pfn = is_nd_pfn(dev) ? to_nd_pfn(dev) : NULL;
 941	struct nd_dax *nd_dax = is_nd_dax(dev) ? to_nd_dax(dev) : NULL;
 942	struct nd_namespace_common *ndns = NULL;
 943	struct nd_namespace_io *nsio;
 944	resource_size_t offset = 0, end_trunc = 0, start, end, pstart, pend;
 945
 946	if (nd_dax || !dev->driver)
 947		return 0;
 948
 949	start = clear_err->address;
 950	end = clear_err->address + clear_err->cleared - 1;
 951
 952	if (nd_btt || nd_pfn || nd_dax) {
 953		if (nd_btt)
 954			ndns = nd_btt->ndns;
 955		else if (nd_pfn)
 956			ndns = nd_pfn->ndns;
 957		else if (nd_dax)
 958			ndns = nd_dax->nd_pfn.ndns;
 959
 960		if (!ndns)
 961			return 0;
 962	} else
 963		ndns = to_ndns(dev);
 964
 965	nsio = to_nd_namespace_io(&ndns->dev);
 966	pstart = nsio->res.start + offset;
 967	pend = nsio->res.end - end_trunc;
 968
 969	if ((pstart >= start) && (pend <= end))
 970		return -EBUSY;
 971
 972	return 0;
 973
 974}
 975
 976static int nd_ns_forget_poison_check(struct device *dev, void *data)
 977{
 978	return device_for_each_child(dev, data, nd_pmem_forget_poison_check);
 979}
 980
 981/* set_config requires an idle interleave set */
 982static int nd_cmd_clear_to_send(struct nvdimm_bus *nvdimm_bus,
 983		struct nvdimm *nvdimm, unsigned int cmd, void *data)
 984{
 985	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 986
 987	/* ask the bus provider if it would like to block this request */
 988	if (nd_desc->clear_to_send) {
 989		int rc = nd_desc->clear_to_send(nd_desc, nvdimm, cmd, data);
 990
 991		if (rc)
 992			return rc;
 993	}
 994
 995	/* require clear error to go through the pmem driver */
 996	if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR)
 997		return device_for_each_child(&nvdimm_bus->dev, data,
 998				nd_ns_forget_poison_check);
 999
1000	if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
1001		return 0;
1002
1003	/* prevent label manipulation while the kernel owns label updates */
1004	wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);
1005	if (atomic_read(&nvdimm->busy))
1006		return -EBUSY;
1007	return 0;
1008}
1009
1010static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
1011		int read_only, unsigned int ioctl_cmd, unsigned long arg)
1012{
1013	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
1014	const struct nd_cmd_desc *desc = NULL;
1015	unsigned int cmd = _IOC_NR(ioctl_cmd);
1016	struct device *dev = &nvdimm_bus->dev;
1017	void __user *p = (void __user *) arg;
1018	char *out_env = NULL, *in_env = NULL;
1019	const char *cmd_name, *dimm_name;
1020	u32 in_len = 0, out_len = 0;
1021	unsigned int func = cmd;
1022	unsigned long cmd_mask;
1023	struct nd_cmd_pkg pkg;
1024	int rc, i, cmd_rc;
1025	void *buf = NULL;
1026	u64 buf_len = 0;
1027
1028	if (nvdimm) {
1029		desc = nd_cmd_dimm_desc(cmd);
1030		cmd_name = nvdimm_cmd_name(cmd);
1031		cmd_mask = nvdimm->cmd_mask;
1032		dimm_name = dev_name(&nvdimm->dev);
1033	} else {
1034		desc = nd_cmd_bus_desc(cmd);
1035		cmd_name = nvdimm_bus_cmd_name(cmd);
1036		cmd_mask = nd_desc->cmd_mask;
1037		dimm_name = "bus";
1038	}
1039
1040	/* Validate command family support against bus declared support */
1041	if (cmd == ND_CMD_CALL) {
1042		unsigned long *mask;
1043
1044		if (copy_from_user(&pkg, p, sizeof(pkg)))
1045			return -EFAULT;
1046
1047		if (nvdimm) {
1048			if (pkg.nd_family > NVDIMM_FAMILY_MAX)
1049				return -EINVAL;
1050			mask = &nd_desc->dimm_family_mask;
1051		} else {
1052			if (pkg.nd_family > NVDIMM_BUS_FAMILY_MAX)
1053				return -EINVAL;
1054			mask = &nd_desc->bus_family_mask;
1055		}
1056
1057		if (!test_bit(pkg.nd_family, mask))
1058			return -EINVAL;
1059	}
1060
1061	if (!desc ||
1062	    (desc->out_num + desc->in_num == 0) ||
1063	    cmd > ND_CMD_CALL ||
1064	    !test_bit(cmd, &cmd_mask))
1065		return -ENOTTY;
1066
1067	/* fail write commands (when read-only) */
1068	if (read_only)
1069		switch (cmd) {
1070		case ND_CMD_VENDOR:
1071		case ND_CMD_SET_CONFIG_DATA:
1072		case ND_CMD_ARS_START:
1073		case ND_CMD_CLEAR_ERROR:
1074		case ND_CMD_CALL:
1075			dev_dbg(dev, "'%s' command while read-only.\n",
1076					nvdimm ? nvdimm_cmd_name(cmd)
1077					: nvdimm_bus_cmd_name(cmd));
1078			return -EPERM;
1079		default:
1080			break;
1081		}
1082
1083	/* process an input envelope */
1084	in_env = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
1085	if (!in_env)
1086		return -ENOMEM;
1087	for (i = 0; i < desc->in_num; i++) {
1088		u32 in_size, copy;
1089
1090		in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
1091		if (in_size == UINT_MAX) {
1092			dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
1093					__func__, dimm_name, cmd_name, i);
1094			rc = -ENXIO;
1095			goto out;
1096		}
1097		if (in_len < ND_CMD_MAX_ENVELOPE)
1098			copy = min_t(u32, ND_CMD_MAX_ENVELOPE - in_len, in_size);
1099		else
1100			copy = 0;
1101		if (copy && copy_from_user(&in_env[in_len], p + in_len, copy)) {
1102			rc = -EFAULT;
1103			goto out;
1104		}
1105		in_len += in_size;
1106	}
1107
1108	if (cmd == ND_CMD_CALL) {
1109		func = pkg.nd_command;
1110		dev_dbg(dev, "%s, idx: %llu, in: %u, out: %u, len %llu\n",
1111				dimm_name, pkg.nd_command,
1112				in_len, out_len, buf_len);
1113	}
1114
1115	/* process an output envelope */
1116	out_env = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
1117	if (!out_env) {
1118		rc = -ENOMEM;
1119		goto out;
1120	}
1121
1122	for (i = 0; i < desc->out_num; i++) {
1123		u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
1124				(u32 *) in_env, (u32 *) out_env, 0);
1125		u32 copy;
1126
1127		if (out_size == UINT_MAX) {
1128			dev_dbg(dev, "%s unknown output size cmd: %s field: %d\n",
1129					dimm_name, cmd_name, i);
1130			rc = -EFAULT;
1131			goto out;
1132		}
1133		if (out_len < ND_CMD_MAX_ENVELOPE)
1134			copy = min_t(u32, ND_CMD_MAX_ENVELOPE - out_len, out_size);
1135		else
1136			copy = 0;
1137		if (copy && copy_from_user(&out_env[out_len],
1138					p + in_len + out_len, copy)) {
1139			rc = -EFAULT;
1140			goto out;
1141		}
1142		out_len += out_size;
1143	}
1144
1145	buf_len = (u64) out_len + (u64) in_len;
1146	if (buf_len > ND_IOCTL_MAX_BUFLEN) {
1147		dev_dbg(dev, "%s cmd: %s buf_len: %llu > %d\n", dimm_name,
1148				cmd_name, buf_len, ND_IOCTL_MAX_BUFLEN);
1149		rc = -EINVAL;
1150		goto out;
1151	}
1152
1153	buf = vmalloc(buf_len);
1154	if (!buf) {
1155		rc = -ENOMEM;
1156		goto out;
1157	}
1158
1159	if (copy_from_user(buf, p, buf_len)) {
1160		rc = -EFAULT;
1161		goto out;
1162	}
1163
1164	nd_device_lock(dev);
1165	nvdimm_bus_lock(dev);
1166	rc = nd_cmd_clear_to_send(nvdimm_bus, nvdimm, func, buf);
1167	if (rc)
1168		goto out_unlock;
1169
1170	rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len, &cmd_rc);
1171	if (rc < 0)
1172		goto out_unlock;
1173
1174	if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR && cmd_rc >= 0) {
1175		struct nd_cmd_clear_error *clear_err = buf;
1176
1177		nvdimm_account_cleared_poison(nvdimm_bus, clear_err->address,
1178				clear_err->cleared);
1179	}
1180
1181	if (copy_to_user(p, buf, buf_len))
1182		rc = -EFAULT;
1183
1184out_unlock:
1185	nvdimm_bus_unlock(dev);
1186	nd_device_unlock(dev);
1187out:
1188	kfree(in_env);
1189	kfree(out_env);
1190	vfree(buf);
1191	return rc;
1192}
1193
1194enum nd_ioctl_mode {
1195	BUS_IOCTL,
1196	DIMM_IOCTL,
1197};
1198
1199static int match_dimm(struct device *dev, void *data)
1200{
1201	long id = (long) data;
1202
1203	if (is_nvdimm(dev)) {
1204		struct nvdimm *nvdimm = to_nvdimm(dev);
1205
1206		return nvdimm->id == id;
1207	}
1208
1209	return 0;
1210}
1211
1212static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1213		enum nd_ioctl_mode mode)
1214
1215{
1216	struct nvdimm_bus *nvdimm_bus, *found = NULL;
1217	long id = (long) file->private_data;
1218	struct nvdimm *nvdimm = NULL;
1219	int rc, ro;
1220
1221	ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);
1222	mutex_lock(&nvdimm_bus_list_mutex);
1223	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
1224		if (mode == DIMM_IOCTL) {
1225			struct device *dev;
1226
1227			dev = device_find_child(&nvdimm_bus->dev,
1228					file->private_data, match_dimm);
1229			if (!dev)
1230				continue;
1231			nvdimm = to_nvdimm(dev);
1232			found = nvdimm_bus;
1233		} else if (nvdimm_bus->id == id) {
1234			found = nvdimm_bus;
1235		}
1236
1237		if (found) {
1238			atomic_inc(&nvdimm_bus->ioctl_active);
1239			break;
1240		}
1241	}
1242	mutex_unlock(&nvdimm_bus_list_mutex);
1243
1244	if (!found)
1245		return -ENXIO;
1246
1247	nvdimm_bus = found;
1248	rc = __nd_ioctl(nvdimm_bus, nvdimm, ro, cmd, arg);
1249
1250	if (nvdimm)
1251		put_device(&nvdimm->dev);
1252	if (atomic_dec_and_test(&nvdimm_bus->ioctl_active))
1253		wake_up(&nvdimm_bus->wait);
1254
1255	return rc;
1256}
1257
1258static long bus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1259{
1260	return nd_ioctl(file, cmd, arg, BUS_IOCTL);
1261}
1262
1263static long dimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1264{
1265	return nd_ioctl(file, cmd, arg, DIMM_IOCTL);
1266}
1267
1268static int nd_open(struct inode *inode, struct file *file)
1269{
1270	long minor = iminor(inode);
1271
1272	file->private_data = (void *) minor;
1273	return 0;
1274}
1275
1276static const struct file_operations nvdimm_bus_fops = {
1277	.owner = THIS_MODULE,
1278	.open = nd_open,
1279	.unlocked_ioctl = bus_ioctl,
1280	.compat_ioctl = compat_ptr_ioctl,
1281	.llseek = noop_llseek,
1282};
1283
1284static const struct file_operations nvdimm_fops = {
1285	.owner = THIS_MODULE,
1286	.open = nd_open,
1287	.unlocked_ioctl = dimm_ioctl,
1288	.compat_ioctl = compat_ptr_ioctl,
1289	.llseek = noop_llseek,
1290};
1291
1292int __init nvdimm_bus_init(void)
1293{
1294	int rc;
1295
1296	rc = bus_register(&nvdimm_bus_type);
1297	if (rc)
1298		return rc;
1299
1300	rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
1301	if (rc < 0)
1302		goto err_bus_chrdev;
1303	nvdimm_bus_major = rc;
1304
1305	rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
1306	if (rc < 0)
1307		goto err_dimm_chrdev;
1308	nvdimm_major = rc;
1309
1310	nd_class = class_create(THIS_MODULE, "nd");
1311	if (IS_ERR(nd_class)) {
1312		rc = PTR_ERR(nd_class);
1313		goto err_class;
1314	}
1315
1316	rc = driver_register(&nd_bus_driver.drv);
1317	if (rc)
1318		goto err_nd_bus;
1319
1320	return 0;
1321
1322 err_nd_bus:
1323	class_destroy(nd_class);
1324 err_class:
1325	unregister_chrdev(nvdimm_major, "dimmctl");
1326 err_dimm_chrdev:
1327	unregister_chrdev(nvdimm_bus_major, "ndctl");
1328 err_bus_chrdev:
1329	bus_unregister(&nvdimm_bus_type);
1330
1331	return rc;
1332}
1333
1334void nvdimm_bus_exit(void)
1335{
1336	driver_unregister(&nd_bus_driver.drv);
1337	class_destroy(nd_class);
1338	unregister_chrdev(nvdimm_bus_major, "ndctl");
1339	unregister_chrdev(nvdimm_major, "dimmctl");
1340	bus_unregister(&nvdimm_bus_type);
1341	ida_destroy(&nd_ida);
1342}