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/slab.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/ndctl.h>
  15#include <linux/sched.h>
  16#include <linux/cpu.h>
  17#include <linux/fs.h>
  18#include <linux/io.h>
  19#include <linux/mm.h>
  20#include <linux/nd.h>
  21#include "nd-core.h"
  22#include "nd.h"
  23#include "pfn.h"
  24
  25int nvdimm_major;
  26static int nvdimm_bus_major;
  27static DEFINE_IDA(nd_ida);
  28
  29static const struct class nd_class = {
  30	.name = "nd",
  31};
  32
  33static int to_nd_device_type(const struct device *dev)
  34{
  35	if (is_nvdimm(dev))
  36		return ND_DEVICE_DIMM;
  37	else if (is_memory(dev))
  38		return ND_DEVICE_REGION_PMEM;
  39	else if (is_nd_dax(dev))
  40		return ND_DEVICE_DAX_PMEM;
  41	else if (is_nd_region(dev->parent))
  42		return nd_region_to_nstype(to_nd_region(dev->parent));
  43
  44	return 0;
  45}
  46
  47static int nvdimm_bus_uevent(const struct device *dev, struct kobj_uevent_env *env)
  48{
  49	return add_uevent_var(env, "MODALIAS=" ND_DEVICE_MODALIAS_FMT,
  50			to_nd_device_type(dev));
  51}
  52
  53static struct module *to_bus_provider(struct device *dev)
  54{
  55	/* pin bus providers while regions are enabled */
  56	if (is_nd_region(dev)) {
  57		struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  58
  59		return nvdimm_bus->nd_desc->module;
  60	}
  61	return NULL;
  62}
  63
  64static void nvdimm_bus_probe_start(struct nvdimm_bus *nvdimm_bus)
  65{
  66	guard(nvdimm_bus)(&nvdimm_bus->dev);
  67	nvdimm_bus->probe_active++;
  68}
  69
  70static void nvdimm_bus_probe_end(struct nvdimm_bus *nvdimm_bus)
  71{
  72	guard(nvdimm_bus)(&nvdimm_bus->dev);
  73	if (--nvdimm_bus->probe_active == 0)
  74		wake_up(&nvdimm_bus->wait);
  75}
  76
  77static int nvdimm_bus_probe(struct device *dev)
  78{
  79	struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
  80	struct module *provider = to_bus_provider(dev);
  81	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  82	int rc;
  83
  84	if (!try_module_get(provider))
  85		return -ENXIO;
  86
  87	dev_dbg(&nvdimm_bus->dev, "START: %s.probe(%s)\n",
  88			dev->driver->name, dev_name(dev));
  89
  90	nvdimm_bus_probe_start(nvdimm_bus);
  91	rc = nd_drv->probe(dev);
  92	if ((rc == 0 || rc == -EOPNOTSUPP) &&
  93			dev->parent && is_nd_region(dev->parent))
  94		nd_region_advance_seeds(to_nd_region(dev->parent), dev);
  95	nvdimm_bus_probe_end(nvdimm_bus);
  96
  97	dev_dbg(&nvdimm_bus->dev, "END: %s.probe(%s) = %d\n", dev->driver->name,
  98			dev_name(dev), rc);
  99
 100	if (rc != 0)
 101		module_put(provider);
 102	return rc;
 103}
 104
 105static void nvdimm_bus_remove(struct device *dev)
 106{
 107	struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
 108	struct module *provider = to_bus_provider(dev);
 109	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 110
 111	if (nd_drv->remove)
 112		nd_drv->remove(dev);
 113
 114	dev_dbg(&nvdimm_bus->dev, "%s.remove(%s)\n", dev->driver->name,
 115			dev_name(dev));
 116	module_put(provider);
 117}
 118
 119static void nvdimm_bus_shutdown(struct device *dev)
 120{
 121	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 122	struct nd_device_driver *nd_drv = NULL;
 123
 124	if (dev->driver)
 125		nd_drv = to_nd_device_driver(dev->driver);
 126
 127	if (nd_drv && nd_drv->shutdown) {
 128		nd_drv->shutdown(dev);
 129		dev_dbg(&nvdimm_bus->dev, "%s.shutdown(%s)\n",
 130				dev->driver->name, dev_name(dev));
 131	}
 132}
 133
 134void nd_device_notify(struct device *dev, enum nvdimm_event event)
 135{
 136	device_lock(dev);
 137	if (dev->driver) {
 138		struct nd_device_driver *nd_drv;
 139
 140		nd_drv = to_nd_device_driver(dev->driver);
 141		if (nd_drv->notify)
 142			nd_drv->notify(dev, event);
 143	}
 144	device_unlock(dev);
 145}
 146EXPORT_SYMBOL(nd_device_notify);
 147
 148void nvdimm_region_notify(struct nd_region *nd_region, enum nvdimm_event event)
 149{
 150	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
 151
 152	if (!nvdimm_bus)
 153		return;
 154
 155	/* caller is responsible for holding a reference on the device */
 156	nd_device_notify(&nd_region->dev, event);
 157}
 158EXPORT_SYMBOL_GPL(nvdimm_region_notify);
 159
 160struct clear_badblocks_context {
 161	resource_size_t phys, cleared;
 162};
 163
 164static int nvdimm_clear_badblocks_region(struct device *dev, void *data)
 165{
 166	struct clear_badblocks_context *ctx = data;
 167	struct nd_region *nd_region;
 168	resource_size_t ndr_end;
 169	sector_t sector;
 170
 171	/* make sure device is a region */
 172	if (!is_memory(dev))
 173		return 0;
 174
 175	nd_region = to_nd_region(dev);
 176	ndr_end = nd_region->ndr_start + nd_region->ndr_size - 1;
 177
 178	/* make sure we are in the region */
 179	if (ctx->phys < nd_region->ndr_start ||
 180	    (ctx->phys + ctx->cleared - 1) > ndr_end)
 181		return 0;
 182
 183	sector = (ctx->phys - nd_region->ndr_start) / 512;
 184	badblocks_clear(&nd_region->bb, sector, ctx->cleared / 512);
 185
 186	if (nd_region->bb_state)
 187		sysfs_notify_dirent(nd_region->bb_state);
 188
 189	return 0;
 190}
 191
 192static void nvdimm_clear_badblocks_regions(struct nvdimm_bus *nvdimm_bus,
 193		phys_addr_t phys, u64 cleared)
 194{
 195	struct clear_badblocks_context ctx = {
 196		.phys = phys,
 197		.cleared = cleared,
 198	};
 199
 200	device_for_each_child(&nvdimm_bus->dev, &ctx,
 201			nvdimm_clear_badblocks_region);
 202}
 203
 204static void nvdimm_account_cleared_poison(struct nvdimm_bus *nvdimm_bus,
 205		phys_addr_t phys, u64 cleared)
 206{
 207	if (cleared > 0)
 208		badrange_forget(&nvdimm_bus->badrange, phys, cleared);
 209
 210	if (cleared > 0 && cleared / 512)
 211		nvdimm_clear_badblocks_regions(nvdimm_bus, phys, cleared);
 212}
 213
 214long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
 215		unsigned int len)
 216{
 217	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 218	struct nvdimm_bus_descriptor *nd_desc;
 219	struct nd_cmd_clear_error clear_err;
 220	struct nd_cmd_ars_cap ars_cap;
 221	u32 clear_err_unit, mask;
 222	unsigned int noio_flag;
 223	int cmd_rc, rc;
 224
 225	if (!nvdimm_bus)
 226		return -ENXIO;
 227
 228	nd_desc = nvdimm_bus->nd_desc;
 229	/*
 230	 * if ndctl does not exist, it's PMEM_LEGACY and
 231	 * we want to just pretend everything is handled.
 232	 */
 233	if (!nd_desc->ndctl)
 234		return len;
 235
 236	memset(&ars_cap, 0, sizeof(ars_cap));
 237	ars_cap.address = phys;
 238	ars_cap.length = len;
 239	noio_flag = memalloc_noio_save();
 240	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_CAP, &ars_cap,
 241			sizeof(ars_cap), &cmd_rc);
 242	memalloc_noio_restore(noio_flag);
 243	if (rc < 0)
 244		return rc;
 245	if (cmd_rc < 0)
 246		return cmd_rc;
 247	clear_err_unit = ars_cap.clear_err_unit;
 248	if (!clear_err_unit || !is_power_of_2(clear_err_unit))
 249		return -ENXIO;
 250
 251	mask = clear_err_unit - 1;
 252	if ((phys | len) & mask)
 253		return -ENXIO;
 254	memset(&clear_err, 0, sizeof(clear_err));
 255	clear_err.address = phys;
 256	clear_err.length = len;
 257	noio_flag = memalloc_noio_save();
 258	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_CLEAR_ERROR, &clear_err,
 259			sizeof(clear_err), &cmd_rc);
 260	memalloc_noio_restore(noio_flag);
 261	if (rc < 0)
 262		return rc;
 263	if (cmd_rc < 0)
 264		return cmd_rc;
 265
 266	nvdimm_account_cleared_poison(nvdimm_bus, phys, clear_err.cleared);
 267
 268	return clear_err.cleared;
 269}
 270EXPORT_SYMBOL_GPL(nvdimm_clear_poison);
 271
 272static int nvdimm_bus_match(struct device *dev, const struct device_driver *drv);
 273
 274static const struct bus_type nvdimm_bus_type = {
 275	.name = "nd",
 276	.uevent = nvdimm_bus_uevent,
 277	.match = nvdimm_bus_match,
 278	.probe = nvdimm_bus_probe,
 279	.remove = nvdimm_bus_remove,
 280	.shutdown = nvdimm_bus_shutdown,
 281};
 282
 283static void nvdimm_bus_release(struct device *dev)
 284{
 285	struct nvdimm_bus *nvdimm_bus;
 286
 287	nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
 288	ida_free(&nd_ida, nvdimm_bus->id);
 289	kfree(nvdimm_bus);
 290}
 291
 292static const struct device_type nvdimm_bus_dev_type = {
 293	.release = nvdimm_bus_release,
 294	.groups = nvdimm_bus_attribute_groups,
 295};
 296
 297bool is_nvdimm_bus(struct device *dev)
 298{
 299	return dev->type == &nvdimm_bus_dev_type;
 300}
 301
 302struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
 303{
 304	struct device *dev;
 305
 306	for (dev = nd_dev; dev; dev = dev->parent)
 307		if (is_nvdimm_bus(dev))
 308			break;
 309	dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
 310	if (dev)
 311		return to_nvdimm_bus(dev);
 312	return NULL;
 313}
 314
 315struct nvdimm_bus *to_nvdimm_bus(struct device *dev)
 316{
 317	struct nvdimm_bus *nvdimm_bus;
 318
 319	nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
 320	WARN_ON(!is_nvdimm_bus(dev));
 321	return nvdimm_bus;
 322}
 323EXPORT_SYMBOL_GPL(to_nvdimm_bus);
 324
 325struct nvdimm_bus *nvdimm_to_bus(struct nvdimm *nvdimm)
 326{
 327	return to_nvdimm_bus(nvdimm->dev.parent);
 328}
 329EXPORT_SYMBOL_GPL(nvdimm_to_bus);
 330
 331static struct lock_class_key nvdimm_bus_key;
 332
 333struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
 334		struct nvdimm_bus_descriptor *nd_desc)
 335{
 336	struct nvdimm_bus *nvdimm_bus;
 337	int rc;
 338
 339	nvdimm_bus = kzalloc(sizeof(*nvdimm_bus), GFP_KERNEL);
 340	if (!nvdimm_bus)
 341		return NULL;
 342	INIT_LIST_HEAD(&nvdimm_bus->list);
 343	INIT_LIST_HEAD(&nvdimm_bus->mapping_list);
 344	init_waitqueue_head(&nvdimm_bus->wait);
 345	nvdimm_bus->id = ida_alloc(&nd_ida, GFP_KERNEL);
 346	if (nvdimm_bus->id < 0) {
 347		kfree(nvdimm_bus);
 348		return NULL;
 349	}
 350	mutex_init(&nvdimm_bus->reconfig_mutex);
 351	badrange_init(&nvdimm_bus->badrange);
 352	nvdimm_bus->nd_desc = nd_desc;
 353	nvdimm_bus->dev.parent = parent;
 354	nvdimm_bus->dev.type = &nvdimm_bus_dev_type;
 355	nvdimm_bus->dev.groups = nd_desc->attr_groups;
 356	nvdimm_bus->dev.bus = &nvdimm_bus_type;
 357	nvdimm_bus->dev.of_node = nd_desc->of_node;
 358	device_initialize(&nvdimm_bus->dev);
 359	lockdep_set_class(&nvdimm_bus->dev.mutex, &nvdimm_bus_key);
 360	device_set_pm_not_required(&nvdimm_bus->dev);
 361	rc = dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
 362	if (rc)
 363		goto err;
 364
 365	rc = device_add(&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}
 376EXPORT_SYMBOL_GPL(nvdimm_bus_register);
 377
 378void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
 379{
 380	if (!nvdimm_bus)
 381		return;
 382	device_unregister(&nvdimm_bus->dev);
 383}
 384EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);
 385
 386static 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		nvdimm_delete(to_nvdimm(dev));
 399	else
 400		nd_device_unregister(dev, ND_SYNC);
 401
 402	return 0;
 403}
 404
 405static void free_badrange_list(struct list_head *badrange_list)
 406{
 407	struct badrange_entry *bre, *next;
 408
 409	list_for_each_entry_safe(bre, next, badrange_list, list) {
 410		list_del(&bre->list);
 411		kfree(bre);
 412	}
 413	list_del_init(badrange_list);
 414}
 415
 416static void nd_bus_remove(struct device *dev)
 417{
 418	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 419
 420	mutex_lock(&nvdimm_bus_list_mutex);
 421	list_del_init(&nvdimm_bus->list);
 422	mutex_unlock(&nvdimm_bus_list_mutex);
 423
 424	wait_event(nvdimm_bus->wait,
 425			atomic_read(&nvdimm_bus->ioctl_active) == 0);
 426
 427	nd_synchronize();
 428	device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
 429
 430	spin_lock(&nvdimm_bus->badrange.lock);
 431	free_badrange_list(&nvdimm_bus->badrange.list);
 432	spin_unlock(&nvdimm_bus->badrange.lock);
 433
 434	nvdimm_bus_destroy_ndctl(nvdimm_bus);
 435}
 436
 437static int nd_bus_probe(struct device *dev)
 438{
 439	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 440	int rc;
 441
 442	rc = nvdimm_bus_create_ndctl(nvdimm_bus);
 443	if (rc)
 444		return rc;
 445
 446	mutex_lock(&nvdimm_bus_list_mutex);
 447	list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
 448	mutex_unlock(&nvdimm_bus_list_mutex);
 449
 450	/* enable bus provider attributes to look up their local context */
 451	dev_set_drvdata(dev, nvdimm_bus->nd_desc);
 452
 453	return 0;
 454}
 455
 456static struct nd_device_driver nd_bus_driver = {
 457	.probe = nd_bus_probe,
 458	.remove = nd_bus_remove,
 459	.drv = {
 460		.name = "nd_bus",
 461		.suppress_bind_attrs = true,
 462		.bus = &nvdimm_bus_type,
 463		.owner = THIS_MODULE,
 464		.mod_name = KBUILD_MODNAME,
 465	},
 466};
 467
 468static int nvdimm_bus_match(struct device *dev, const struct device_driver *drv)
 469{
 470	const struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
 471
 472	if (is_nvdimm_bus(dev) && nd_drv == &nd_bus_driver)
 473		return true;
 474
 475	return !!test_bit(to_nd_device_type(dev), &nd_drv->type);
 476}
 477
 478static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
 479
 480void nd_synchronize(void)
 481{
 482	async_synchronize_full_domain(&nd_async_domain);
 483}
 484EXPORT_SYMBOL_GPL(nd_synchronize);
 485
 486static void nd_async_device_register(void *d, async_cookie_t cookie)
 487{
 488	struct device *dev = d;
 489	struct device *parent = dev->parent;
 490
 491	if (device_add(dev) != 0) {
 492		dev_err(dev, "%s: failed\n", __func__);
 493		put_device(dev);
 494	}
 495	put_device(dev);
 496	if (parent)
 497		put_device(parent);
 498}
 499
 500static void nd_async_device_unregister(void *d, async_cookie_t cookie)
 501{
 502	struct device *dev = d;
 503
 504	/* flush bus operations before delete */
 505	nvdimm_bus_lock(dev);
 506	nvdimm_bus_unlock(dev);
 507
 508	device_unregister(dev);
 509	put_device(dev);
 510}
 511
 512static void __nd_device_register(struct device *dev, bool sync)
 513{
 514	if (!dev)
 515		return;
 516
 517	/*
 518	 * Ensure that region devices always have their NUMA node set as
 519	 * early as possible. This way we are able to make certain that
 520	 * any memory associated with the creation and the creation
 521	 * itself of the region is associated with the correct node.
 522	 */
 523	if (is_nd_region(dev))
 524		set_dev_node(dev, to_nd_region(dev)->numa_node);
 525
 526	dev->bus = &nvdimm_bus_type;
 527	device_set_pm_not_required(dev);
 528	if (dev->parent) {
 529		get_device(dev->parent);
 530		if (dev_to_node(dev) == NUMA_NO_NODE)
 531			set_dev_node(dev, dev_to_node(dev->parent));
 532	}
 533	get_device(dev);
 534
 535	if (sync)
 536		nd_async_device_register(dev, 0);
 537	else
 538		async_schedule_dev_domain(nd_async_device_register, dev,
 539					  &nd_async_domain);
 540}
 541
 542void nd_device_register(struct device *dev)
 543{
 544	__nd_device_register(dev, false);
 545}
 546EXPORT_SYMBOL(nd_device_register);
 547
 548void nd_device_register_sync(struct device *dev)
 549{
 550	__nd_device_register(dev, true);
 551}
 552
 553void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
 554{
 555	bool killed;
 556
 557	switch (mode) {
 558	case ND_ASYNC:
 559		/*
 560		 * In the async case this is being triggered with the
 561		 * device lock held and the unregistration work needs to
 562		 * be moved out of line iff this is thread has won the
 563		 * race to schedule the deletion.
 564		 */
 565		if (!kill_device(dev))
 566			return;
 567
 568		get_device(dev);
 569		async_schedule_domain(nd_async_device_unregister, dev,
 570				&nd_async_domain);
 571		break;
 572	case ND_SYNC:
 573		/*
 574		 * In the sync case the device is being unregistered due
 575		 * to a state change of the parent. Claim the kill state
 576		 * to synchronize against other unregistration requests,
 577		 * or otherwise let the async path handle it if the
 578		 * unregistration was already queued.
 579		 */
 580		device_lock(dev);
 581		killed = kill_device(dev);
 582		device_unlock(dev);
 583
 584		if (!killed)
 585			return;
 586
 587		nd_synchronize();
 588		device_unregister(dev);
 589		break;
 590	}
 591}
 592EXPORT_SYMBOL(nd_device_unregister);
 593
 594/**
 595 * __nd_driver_register() - register a region or a namespace driver
 596 * @nd_drv: driver to register
 597 * @owner: automatically set by nd_driver_register() macro
 598 * @mod_name: automatically set by nd_driver_register() macro
 599 */
 600int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
 601		const char *mod_name)
 602{
 603	struct device_driver *drv = &nd_drv->drv;
 604
 605	if (!nd_drv->type) {
 606		pr_debug("driver type bitmask not set (%ps)\n",
 607				__builtin_return_address(0));
 608		return -EINVAL;
 609	}
 610
 611	if (!nd_drv->probe) {
 612		pr_debug("%s ->probe() must be specified\n", mod_name);
 613		return -EINVAL;
 614	}
 615
 616	drv->bus = &nvdimm_bus_type;
 617	drv->owner = owner;
 618	drv->mod_name = mod_name;
 619
 620	return driver_register(drv);
 621}
 622EXPORT_SYMBOL(__nd_driver_register);
 623
 624void nvdimm_check_and_set_ro(struct gendisk *disk)
 625{
 626	struct device *dev = disk_to_dev(disk)->parent;
 627	struct nd_region *nd_region = to_nd_region(dev->parent);
 628	int disk_ro = get_disk_ro(disk);
 629
 630	/* catch the disk up with the region ro state */
 631	if (disk_ro == nd_region->ro)
 632		return;
 633
 634	dev_info(dev, "%s read-%s, marking %s read-%s\n",
 635		 dev_name(&nd_region->dev), nd_region->ro ? "only" : "write",
 636		 disk->disk_name, nd_region->ro ? "only" : "write");
 637	set_disk_ro(disk, nd_region->ro);
 638}
 639EXPORT_SYMBOL(nvdimm_check_and_set_ro);
 640
 641static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 642		char *buf)
 643{
 644	return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
 645			to_nd_device_type(dev));
 646}
 647static DEVICE_ATTR_RO(modalias);
 648
 649static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
 650		char *buf)
 651{
 652	return sprintf(buf, "%s\n", dev->type->name);
 653}
 654static DEVICE_ATTR_RO(devtype);
 655
 656static struct attribute *nd_device_attributes[] = {
 657	&dev_attr_modalias.attr,
 658	&dev_attr_devtype.attr,
 659	NULL,
 660};
 661
 662/*
 663 * nd_device_attribute_group - generic attributes for all devices on an nd bus
 664 */
 665const struct attribute_group nd_device_attribute_group = {
 666	.attrs = nd_device_attributes,
 667};
 668
 669static ssize_t numa_node_show(struct device *dev,
 670		struct device_attribute *attr, char *buf)
 671{
 672	return sprintf(buf, "%d\n", dev_to_node(dev));
 673}
 674static DEVICE_ATTR_RO(numa_node);
 675
 676static int nvdimm_dev_to_target_node(struct device *dev)
 677{
 678	struct device *parent = dev->parent;
 679	struct nd_region *nd_region = NULL;
 680
 681	if (is_nd_region(dev))
 682		nd_region = to_nd_region(dev);
 683	else if (parent && is_nd_region(parent))
 684		nd_region = to_nd_region(parent);
 685
 686	if (!nd_region)
 687		return NUMA_NO_NODE;
 688	return nd_region->target_node;
 689}
 690
 691static ssize_t target_node_show(struct device *dev,
 692		struct device_attribute *attr, char *buf)
 693{
 694	return sprintf(buf, "%d\n", nvdimm_dev_to_target_node(dev));
 695}
 696static DEVICE_ATTR_RO(target_node);
 697
 698static struct attribute *nd_numa_attributes[] = {
 699	&dev_attr_numa_node.attr,
 700	&dev_attr_target_node.attr,
 701	NULL,
 702};
 703
 704static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
 705		int n)
 706{
 707	struct device *dev = container_of(kobj, typeof(*dev), kobj);
 708
 709	if (!IS_ENABLED(CONFIG_NUMA))
 710		return 0;
 711
 712	if (a == &dev_attr_target_node.attr &&
 713			nvdimm_dev_to_target_node(dev) == NUMA_NO_NODE)
 714		return 0;
 715
 716	return a->mode;
 717}
 718
 719/*
 720 * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
 721 */
 722const struct attribute_group nd_numa_attribute_group = {
 723	.attrs = nd_numa_attributes,
 724	.is_visible = nd_numa_attr_visible,
 725};
 726
 727static void ndctl_release(struct device *dev)
 728{
 729	kfree(dev);
 730}
 731
 732static struct lock_class_key nvdimm_ndctl_key;
 733
 734int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
 735{
 736	dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
 737	struct device *dev;
 738	int rc;
 739
 740	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 741	if (!dev)
 742		return -ENOMEM;
 743	device_initialize(dev);
 744	lockdep_set_class(&dev->mutex, &nvdimm_ndctl_key);
 745	device_set_pm_not_required(dev);
 746	dev->class = &nd_class;
 747	dev->parent = &nvdimm_bus->dev;
 748	dev->devt = devt;
 749	dev->release = ndctl_release;
 750	rc = dev_set_name(dev, "ndctl%d", nvdimm_bus->id);
 751	if (rc)
 752		goto err;
 753
 754	rc = device_add(dev);
 755	if (rc) {
 756		dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %d\n",
 757				nvdimm_bus->id, rc);
 758		goto err;
 759	}
 760	return 0;
 761
 762err:
 763	put_device(dev);
 764	return rc;
 765}
 766
 767void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
 768{
 769	device_destroy(&nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
 770}
 771
 772static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
 773	[ND_CMD_IMPLEMENTED] = { },
 774	[ND_CMD_SMART] = {
 775		.out_num = 2,
 776		.out_sizes = { 4, 128, },
 777	},
 778	[ND_CMD_SMART_THRESHOLD] = {
 779		.out_num = 2,
 780		.out_sizes = { 4, 8, },
 781	},
 782	[ND_CMD_DIMM_FLAGS] = {
 783		.out_num = 2,
 784		.out_sizes = { 4, 4 },
 785	},
 786	[ND_CMD_GET_CONFIG_SIZE] = {
 787		.out_num = 3,
 788		.out_sizes = { 4, 4, 4, },
 789	},
 790	[ND_CMD_GET_CONFIG_DATA] = {
 791		.in_num = 2,
 792		.in_sizes = { 4, 4, },
 793		.out_num = 2,
 794		.out_sizes = { 4, UINT_MAX, },
 795	},
 796	[ND_CMD_SET_CONFIG_DATA] = {
 797		.in_num = 3,
 798		.in_sizes = { 4, 4, UINT_MAX, },
 799		.out_num = 1,
 800		.out_sizes = { 4, },
 801	},
 802	[ND_CMD_VENDOR] = {
 803		.in_num = 3,
 804		.in_sizes = { 4, 4, UINT_MAX, },
 805		.out_num = 3,
 806		.out_sizes = { 4, 4, UINT_MAX, },
 807	},
 808	[ND_CMD_CALL] = {
 809		.in_num = 2,
 810		.in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
 811		.out_num = 1,
 812		.out_sizes = { UINT_MAX, },
 813	},
 814};
 815
 816const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
 817{
 818	if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
 819		return &__nd_cmd_dimm_descs[cmd];
 820	return NULL;
 821}
 822EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
 823
 824static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
 825	[ND_CMD_IMPLEMENTED] = { },
 826	[ND_CMD_ARS_CAP] = {
 827		.in_num = 2,
 828		.in_sizes = { 8, 8, },
 829		.out_num = 4,
 830		.out_sizes = { 4, 4, 4, 4, },
 831	},
 832	[ND_CMD_ARS_START] = {
 833		.in_num = 5,
 834		.in_sizes = { 8, 8, 2, 1, 5, },
 835		.out_num = 2,
 836		.out_sizes = { 4, 4, },
 837	},
 838	[ND_CMD_ARS_STATUS] = {
 839		.out_num = 3,
 840		.out_sizes = { 4, 4, UINT_MAX, },
 841	},
 842	[ND_CMD_CLEAR_ERROR] = {
 843		.in_num = 2,
 844		.in_sizes = { 8, 8, },
 845		.out_num = 3,
 846		.out_sizes = { 4, 4, 8, },
 847	},
 848	[ND_CMD_CALL] = {
 849		.in_num = 2,
 850		.in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
 851		.out_num = 1,
 852		.out_sizes = { UINT_MAX, },
 853	},
 854};
 855
 856const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
 857{
 858	if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
 859		return &__nd_cmd_bus_descs[cmd];
 860	return NULL;
 861}
 862EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
 863
 864u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
 865		const struct nd_cmd_desc *desc, int idx, void *buf)
 866{
 867	if (idx >= desc->in_num)
 868		return UINT_MAX;
 869
 870	if (desc->in_sizes[idx] < UINT_MAX)
 871		return desc->in_sizes[idx];
 872
 873	if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
 874		struct nd_cmd_set_config_hdr *hdr = buf;
 875
 876		return hdr->in_length;
 877	} else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
 878		struct nd_cmd_vendor_hdr *hdr = buf;
 879
 880		return hdr->in_length;
 881	} else if (cmd == ND_CMD_CALL) {
 882		struct nd_cmd_pkg *pkg = buf;
 883
 884		return pkg->nd_size_in;
 885	}
 886
 887	return UINT_MAX;
 888}
 889EXPORT_SYMBOL_GPL(nd_cmd_in_size);
 890
 891u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
 892		const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
 893		const u32 *out_field, unsigned long remainder)
 894{
 895	if (idx >= desc->out_num)
 896		return UINT_MAX;
 897
 898	if (desc->out_sizes[idx] < UINT_MAX)
 899		return desc->out_sizes[idx];
 900
 901	if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
 902		return in_field[1];
 903	else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
 904		return out_field[1];
 905	else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 2) {
 906		/*
 907		 * Per table 9-276 ARS Data in ACPI 6.1, out_field[1] is
 908		 * "Size of Output Buffer in bytes, including this
 909		 * field."
 910		 */
 911		if (out_field[1] < 4)
 912			return 0;
 913		/*
 914		 * ACPI 6.1 is ambiguous if 'status' is included in the
 915		 * output size. If we encounter an output size that
 916		 * overshoots the remainder by 4 bytes, assume it was
 917		 * including 'status'.
 918		 */
 919		if (out_field[1] - 4 == remainder)
 920			return remainder;
 921		return out_field[1] - 8;
 922	} else if (cmd == ND_CMD_CALL) {
 923		struct nd_cmd_pkg *pkg = (struct nd_cmd_pkg *) in_field;
 924
 925		return pkg->nd_size_out;
 926	}
 927
 928
 929	return UINT_MAX;
 930}
 931EXPORT_SYMBOL_GPL(nd_cmd_out_size);
 932
 933void wait_nvdimm_bus_probe_idle(struct device *dev)
 934{
 935	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 936
 937	do {
 938		if (nvdimm_bus->probe_active == 0)
 939			break;
 940		nvdimm_bus_unlock(dev);
 941		device_unlock(dev);
 942		wait_event(nvdimm_bus->wait,
 943				nvdimm_bus->probe_active == 0);
 944		device_lock(dev);
 945		nvdimm_bus_lock(dev);
 946	} while (true);
 947}
 948
 949static int nd_pmem_forget_poison_check(struct device *dev, void *data)
 950{
 951	struct nd_cmd_clear_error *clear_err =
 952		(struct nd_cmd_clear_error *)data;
 953	struct nd_btt *nd_btt = is_nd_btt(dev) ? to_nd_btt(dev) : NULL;
 954	struct nd_pfn *nd_pfn = is_nd_pfn(dev) ? to_nd_pfn(dev) : NULL;
 955	struct nd_dax *nd_dax = is_nd_dax(dev) ? to_nd_dax(dev) : NULL;
 956	struct nd_namespace_common *ndns = NULL;
 957	struct nd_namespace_io *nsio;
 958	resource_size_t offset = 0, end_trunc = 0, start, end, pstart, pend;
 959
 960	if (nd_dax || !dev->driver)
 961		return 0;
 962
 963	start = clear_err->address;
 964	end = clear_err->address + clear_err->cleared - 1;
 965
 966	if (nd_btt || nd_pfn || nd_dax) {
 967		if (nd_btt)
 968			ndns = nd_btt->ndns;
 969		else if (nd_pfn)
 970			ndns = nd_pfn->ndns;
 971		else if (nd_dax)
 972			ndns = nd_dax->nd_pfn.ndns;
 973
 974		if (!ndns)
 975			return 0;
 976	} else
 977		ndns = to_ndns(dev);
 978
 979	nsio = to_nd_namespace_io(&ndns->dev);
 980	pstart = nsio->res.start + offset;
 981	pend = nsio->res.end - end_trunc;
 982
 983	if ((pstart >= start) && (pend <= end))
 984		return -EBUSY;
 985
 986	return 0;
 987
 988}
 989
 990static int nd_ns_forget_poison_check(struct device *dev, void *data)
 991{
 992	return device_for_each_child(dev, data, nd_pmem_forget_poison_check);
 993}
 994
 995/* set_config requires an idle interleave set */
 996static int nd_cmd_clear_to_send(struct nvdimm_bus *nvdimm_bus,
 997		struct nvdimm *nvdimm, unsigned int cmd, void *data)
 998{
 999	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
1000
1001	/* ask the bus provider if it would like to block this request */
1002	if (nd_desc->clear_to_send) {
1003		int rc = nd_desc->clear_to_send(nd_desc, nvdimm, cmd, data);
1004
1005		if (rc)
1006			return rc;
1007	}
1008
1009	/* require clear error to go through the pmem driver */
1010	if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR)
1011		return device_for_each_child(&nvdimm_bus->dev, data,
1012				nd_ns_forget_poison_check);
1013
1014	if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
1015		return 0;
1016
1017	/* prevent label manipulation while the kernel owns label updates */
1018	wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);
1019	if (atomic_read(&nvdimm->busy))
1020		return -EBUSY;
1021	return 0;
1022}
1023
1024static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
1025		int read_only, unsigned int ioctl_cmd, unsigned long arg)
1026{
1027	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
1028	const struct nd_cmd_desc *desc = NULL;
1029	unsigned int cmd = _IOC_NR(ioctl_cmd);
1030	struct device *dev = &nvdimm_bus->dev;
1031	void __user *p = (void __user *) arg;
1032	const char *cmd_name, *dimm_name;
1033	u32 in_len = 0, out_len = 0;
1034	unsigned int func = cmd;
1035	unsigned long cmd_mask;
1036	struct nd_cmd_pkg pkg;
1037	int rc, i, cmd_rc;
1038	u64 buf_len = 0;
1039
1040	if (nvdimm) {
1041		desc = nd_cmd_dimm_desc(cmd);
1042		cmd_name = nvdimm_cmd_name(cmd);
1043		cmd_mask = nvdimm->cmd_mask;
1044		dimm_name = dev_name(&nvdimm->dev);
1045	} else {
1046		desc = nd_cmd_bus_desc(cmd);
1047		cmd_name = nvdimm_bus_cmd_name(cmd);
1048		cmd_mask = nd_desc->cmd_mask;
1049		dimm_name = "bus";
1050	}
1051
1052	/* Validate command family support against bus declared support */
1053	if (cmd == ND_CMD_CALL) {
1054		unsigned long *mask;
1055
1056		if (copy_from_user(&pkg, p, sizeof(pkg)))
1057			return -EFAULT;
1058
1059		if (nvdimm) {
1060			if (pkg.nd_family > NVDIMM_FAMILY_MAX)
1061				return -EINVAL;
1062			mask = &nd_desc->dimm_family_mask;
1063		} else {
1064			if (pkg.nd_family > NVDIMM_BUS_FAMILY_MAX)
1065				return -EINVAL;
1066			mask = &nd_desc->bus_family_mask;
1067		}
1068
1069		if (!test_bit(pkg.nd_family, mask))
1070			return -EINVAL;
1071	}
1072
1073	if (!desc ||
1074	    (desc->out_num + desc->in_num == 0) ||
1075	    cmd > ND_CMD_CALL ||
1076	    !test_bit(cmd, &cmd_mask))
1077		return -ENOTTY;
1078
1079	/* fail write commands (when read-only) */
1080	if (read_only)
1081		switch (cmd) {
1082		case ND_CMD_VENDOR:
1083		case ND_CMD_SET_CONFIG_DATA:
1084		case ND_CMD_ARS_START:
1085		case ND_CMD_CLEAR_ERROR:
1086		case ND_CMD_CALL:
1087			dev_dbg(dev, "'%s' command while read-only.\n",
1088					nvdimm ? nvdimm_cmd_name(cmd)
1089					: nvdimm_bus_cmd_name(cmd));
1090			return -EPERM;
1091		default:
1092			break;
1093		}
1094
1095	/* process an input envelope */
1096	char *in_env __free(kfree) = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
1097	if (!in_env)
1098		return -ENOMEM;
1099	for (i = 0; i < desc->in_num; i++) {
1100		u32 in_size, copy;
1101
1102		in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
1103		if (in_size == UINT_MAX) {
1104			dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
1105					__func__, dimm_name, cmd_name, i);
1106			return -ENXIO;
1107		}
1108		if (in_len < ND_CMD_MAX_ENVELOPE)
1109			copy = min_t(u32, ND_CMD_MAX_ENVELOPE - in_len, in_size);
1110		else
1111			copy = 0;
1112		if (copy && copy_from_user(&in_env[in_len], p + in_len, copy))
1113			return -EFAULT;
1114		in_len += in_size;
1115	}
1116
1117	if (cmd == ND_CMD_CALL) {
1118		func = pkg.nd_command;
1119		dev_dbg(dev, "%s, idx: %llu, in: %u, out: %u, len %llu\n",
1120				dimm_name, pkg.nd_command,
1121				in_len, out_len, buf_len);
1122	}
1123
1124	/* process an output envelope */
1125	char *out_env __free(kfree) = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
1126	if (!out_env)
1127		return -ENOMEM;
1128
1129	for (i = 0; i < desc->out_num; i++) {
1130		u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
1131				(u32 *) in_env, (u32 *) out_env, 0);
1132		u32 copy;
1133
1134		if (out_size == UINT_MAX) {
1135			dev_dbg(dev, "%s unknown output size cmd: %s field: %d\n",
1136					dimm_name, cmd_name, i);
1137			return -EFAULT;
1138		}
1139		if (out_len < ND_CMD_MAX_ENVELOPE)
1140			copy = min_t(u32, ND_CMD_MAX_ENVELOPE - out_len, out_size);
1141		else
1142			copy = 0;
1143		if (copy && copy_from_user(&out_env[out_len],
1144					p + in_len + out_len, copy)) {
1145			return -EFAULT;
1146		}
1147		out_len += out_size;
1148	}
1149
1150	buf_len = (u64) out_len + (u64) in_len;
1151	if (buf_len > ND_IOCTL_MAX_BUFLEN) {
1152		dev_dbg(dev, "%s cmd: %s buf_len: %llu > %d\n", dimm_name,
1153				cmd_name, buf_len, ND_IOCTL_MAX_BUFLEN);
1154		return -EINVAL;
1155	}
1156
1157	void *buf __free(kvfree) = kvzalloc(buf_len, GFP_KERNEL);
1158	if (!buf)
1159		return -ENOMEM;
1160
1161	if (copy_from_user(buf, p, buf_len))
1162		return -EFAULT;
1163
1164	guard(device)(dev);
1165	guard(nvdimm_bus)(dev);
1166	rc = nd_cmd_clear_to_send(nvdimm_bus, nvdimm, func, buf);
1167	if (rc)
1168		return rc;
1169
1170	rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len, &cmd_rc);
1171	if (rc < 0)
1172		return rc;
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		return -EFAULT;
1183
1184	return 0;
1185}
1186
1187enum nd_ioctl_mode {
1188	BUS_IOCTL,
1189	DIMM_IOCTL,
1190};
1191
1192static int match_dimm(struct device *dev, const void *data)
1193{
1194	long id = (long) data;
1195
1196	if (is_nvdimm(dev)) {
1197		struct nvdimm *nvdimm = to_nvdimm(dev);
1198
1199		return nvdimm->id == id;
1200	}
1201
1202	return 0;
1203}
1204
1205static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1206		enum nd_ioctl_mode mode)
1207
1208{
1209	struct nvdimm_bus *nvdimm_bus, *found = NULL;
1210	long id = (long) file->private_data;
1211	struct nvdimm *nvdimm = NULL;
1212	int rc, ro;
1213
1214	ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);
1215	mutex_lock(&nvdimm_bus_list_mutex);
1216	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
1217		if (mode == DIMM_IOCTL) {
1218			struct device *dev;
1219
1220			dev = device_find_child(&nvdimm_bus->dev,
1221					file->private_data, match_dimm);
1222			if (!dev)
1223				continue;
1224			nvdimm = to_nvdimm(dev);
1225			found = nvdimm_bus;
1226		} else if (nvdimm_bus->id == id) {
1227			found = nvdimm_bus;
1228		}
1229
1230		if (found) {
1231			atomic_inc(&nvdimm_bus->ioctl_active);
1232			break;
1233		}
1234	}
1235	mutex_unlock(&nvdimm_bus_list_mutex);
1236
1237	if (!found)
1238		return -ENXIO;
1239
1240	nvdimm_bus = found;
1241	rc = __nd_ioctl(nvdimm_bus, nvdimm, ro, cmd, arg);
1242
1243	if (nvdimm)
1244		put_device(&nvdimm->dev);
1245	if (atomic_dec_and_test(&nvdimm_bus->ioctl_active))
1246		wake_up(&nvdimm_bus->wait);
1247
1248	return rc;
1249}
1250
1251static long bus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1252{
1253	return nd_ioctl(file, cmd, arg, BUS_IOCTL);
1254}
1255
1256static long dimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1257{
1258	return nd_ioctl(file, cmd, arg, DIMM_IOCTL);
1259}
1260
1261static int nd_open(struct inode *inode, struct file *file)
1262{
1263	long minor = iminor(inode);
1264
1265	file->private_data = (void *) minor;
1266	return 0;
1267}
1268
1269static const struct file_operations nvdimm_bus_fops = {
1270	.owner = THIS_MODULE,
1271	.open = nd_open,
1272	.unlocked_ioctl = bus_ioctl,
1273	.compat_ioctl = compat_ptr_ioctl,
1274	.llseek = noop_llseek,
1275};
1276
1277static const struct file_operations nvdimm_fops = {
1278	.owner = THIS_MODULE,
1279	.open = nd_open,
1280	.unlocked_ioctl = dimm_ioctl,
1281	.compat_ioctl = compat_ptr_ioctl,
1282	.llseek = noop_llseek,
1283};
1284
1285int __init nvdimm_bus_init(void)
1286{
1287	int rc;
1288
1289	rc = bus_register(&nvdimm_bus_type);
1290	if (rc)
1291		return rc;
1292
1293	rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
1294	if (rc < 0)
1295		goto err_bus_chrdev;
1296	nvdimm_bus_major = rc;
1297
1298	rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
1299	if (rc < 0)
1300		goto err_dimm_chrdev;
1301	nvdimm_major = rc;
1302
1303	rc = class_register(&nd_class);
1304	if (rc)
1305		goto err_class;
1306
1307	rc = driver_register(&nd_bus_driver.drv);
1308	if (rc)
1309		goto err_nd_bus;
1310
1311	return 0;
1312
1313 err_nd_bus:
1314	class_unregister(&nd_class);
1315 err_class:
1316	unregister_chrdev(nvdimm_major, "dimmctl");
1317 err_dimm_chrdev:
1318	unregister_chrdev(nvdimm_bus_major, "ndctl");
1319 err_bus_chrdev:
1320	bus_unregister(&nvdimm_bus_type);
1321
1322	return rc;
1323}
1324
1325void nvdimm_bus_exit(void)
1326{
1327	driver_unregister(&nd_bus_driver.drv);
1328	class_unregister(&nd_class);
1329	unregister_chrdev(nvdimm_bus_major, "ndctl");
1330	unregister_chrdev(nvdimm_major, "dimmctl");
1331	bus_unregister(&nvdimm_bus_type);
1332	ida_destroy(&nd_ida);
1333}