xref: /linux/drivers/nvdimm/bus.c (revision 42466b9f29b415c254dc4c2f4618e2a96951a406)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
4  */
5 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
6 #include <linux/libnvdimm.h>
7 #include <linux/sched/mm.h>
8 #include <linux/vmalloc.h>
9 #include <linux/uaccess.h>
10 #include <linux/module.h>
11 #include <linux/blkdev.h>
12 #include <linux/fcntl.h>
13 #include <linux/async.h>
14 #include <linux/genhd.h>
15 #include <linux/ndctl.h>
16 #include <linux/sched.h>
17 #include <linux/slab.h>
18 #include <linux/cpu.h>
19 #include <linux/fs.h>
20 #include <linux/io.h>
21 #include <linux/mm.h>
22 #include <linux/nd.h>
23 #include "nd-core.h"
24 #include "nd.h"
25 #include "pfn.h"
26 
27 int nvdimm_major;
28 static int nvdimm_bus_major;
29 struct class *nd_class;
30 static DEFINE_IDA(nd_ida);
31 
32 static int to_nd_device_type(struct device *dev)
33 {
34 	if (is_nvdimm(dev))
35 		return ND_DEVICE_DIMM;
36 	else if (is_memory(dev))
37 		return ND_DEVICE_REGION_PMEM;
38 	else if (is_nd_blk(dev))
39 		return ND_DEVICE_REGION_BLK;
40 	else if (is_nd_dax(dev))
41 		return ND_DEVICE_DAX_PMEM;
42 	else if (is_nd_region(dev->parent))
43 		return nd_region_to_nstype(to_nd_region(dev->parent));
44 
45 	return 0;
46 }
47 
48 static int nvdimm_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
49 {
50 	return add_uevent_var(env, "MODALIAS=" ND_DEVICE_MODALIAS_FMT,
51 			to_nd_device_type(dev));
52 }
53 
54 static struct module *to_bus_provider(struct device *dev)
55 {
56 	/* pin bus providers while regions are enabled */
57 	if (is_nd_region(dev)) {
58 		struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
59 
60 		return nvdimm_bus->nd_desc->module;
61 	}
62 	return NULL;
63 }
64 
65 static void nvdimm_bus_probe_start(struct nvdimm_bus *nvdimm_bus)
66 {
67 	nvdimm_bus_lock(&nvdimm_bus->dev);
68 	nvdimm_bus->probe_active++;
69 	nvdimm_bus_unlock(&nvdimm_bus->dev);
70 }
71 
72 static void nvdimm_bus_probe_end(struct nvdimm_bus *nvdimm_bus)
73 {
74 	nvdimm_bus_lock(&nvdimm_bus->dev);
75 	if (--nvdimm_bus->probe_active == 0)
76 		wake_up(&nvdimm_bus->wait);
77 	nvdimm_bus_unlock(&nvdimm_bus->dev);
78 }
79 
80 static int nvdimm_bus_probe(struct device *dev)
81 {
82 	struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
83 	struct module *provider = to_bus_provider(dev);
84 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
85 	int rc;
86 
87 	if (!try_module_get(provider))
88 		return -ENXIO;
89 
90 	dev_dbg(&nvdimm_bus->dev, "START: %s.probe(%s)\n",
91 			dev->driver->name, dev_name(dev));
92 
93 	nvdimm_bus_probe_start(nvdimm_bus);
94 	debug_nvdimm_lock(dev);
95 	rc = nd_drv->probe(dev);
96 	debug_nvdimm_unlock(dev);
97 
98 	if ((rc == 0 || rc == -EOPNOTSUPP) &&
99 			dev->parent && is_nd_region(dev->parent))
100 		nd_region_advance_seeds(to_nd_region(dev->parent), dev);
101 	nvdimm_bus_probe_end(nvdimm_bus);
102 
103 	dev_dbg(&nvdimm_bus->dev, "END: %s.probe(%s) = %d\n", dev->driver->name,
104 			dev_name(dev), rc);
105 
106 	if (rc != 0)
107 		module_put(provider);
108 	return rc;
109 }
110 
111 static int nvdimm_bus_remove(struct device *dev)
112 {
113 	struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
114 	struct module *provider = to_bus_provider(dev);
115 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
116 	int rc = 0;
117 
118 	if (nd_drv->remove) {
119 		debug_nvdimm_lock(dev);
120 		rc = nd_drv->remove(dev);
121 		debug_nvdimm_unlock(dev);
122 	}
123 
124 	dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d\n", dev->driver->name,
125 			dev_name(dev), rc);
126 	module_put(provider);
127 	return rc;
128 }
129 
130 static void nvdimm_bus_shutdown(struct device *dev)
131 {
132 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
133 	struct nd_device_driver *nd_drv = NULL;
134 
135 	if (dev->driver)
136 		nd_drv = to_nd_device_driver(dev->driver);
137 
138 	if (nd_drv && nd_drv->shutdown) {
139 		nd_drv->shutdown(dev);
140 		dev_dbg(&nvdimm_bus->dev, "%s.shutdown(%s)\n",
141 				dev->driver->name, dev_name(dev));
142 	}
143 }
144 
145 void nd_device_notify(struct device *dev, enum nvdimm_event event)
146 {
147 	nd_device_lock(dev);
148 	if (dev->driver) {
149 		struct nd_device_driver *nd_drv;
150 
151 		nd_drv = to_nd_device_driver(dev->driver);
152 		if (nd_drv->notify)
153 			nd_drv->notify(dev, event);
154 	}
155 	nd_device_unlock(dev);
156 }
157 EXPORT_SYMBOL(nd_device_notify);
158 
159 void nvdimm_region_notify(struct nd_region *nd_region, enum nvdimm_event event)
160 {
161 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
162 
163 	if (!nvdimm_bus)
164 		return;
165 
166 	/* caller is responsible for holding a reference on the device */
167 	nd_device_notify(&nd_region->dev, event);
168 }
169 EXPORT_SYMBOL_GPL(nvdimm_region_notify);
170 
171 struct clear_badblocks_context {
172 	resource_size_t phys, cleared;
173 };
174 
175 static int nvdimm_clear_badblocks_region(struct device *dev, void *data)
176 {
177 	struct clear_badblocks_context *ctx = data;
178 	struct nd_region *nd_region;
179 	resource_size_t ndr_end;
180 	sector_t sector;
181 
182 	/* make sure device is a region */
183 	if (!is_memory(dev))
184 		return 0;
185 
186 	nd_region = to_nd_region(dev);
187 	ndr_end = nd_region->ndr_start + nd_region->ndr_size - 1;
188 
189 	/* make sure we are in the region */
190 	if (ctx->phys < nd_region->ndr_start
191 			|| (ctx->phys + ctx->cleared) > ndr_end)
192 		return 0;
193 
194 	sector = (ctx->phys - nd_region->ndr_start) / 512;
195 	badblocks_clear(&nd_region->bb, sector, ctx->cleared / 512);
196 
197 	if (nd_region->bb_state)
198 		sysfs_notify_dirent(nd_region->bb_state);
199 
200 	return 0;
201 }
202 
203 static void nvdimm_clear_badblocks_regions(struct nvdimm_bus *nvdimm_bus,
204 		phys_addr_t phys, u64 cleared)
205 {
206 	struct clear_badblocks_context ctx = {
207 		.phys = phys,
208 		.cleared = cleared,
209 	};
210 
211 	device_for_each_child(&nvdimm_bus->dev, &ctx,
212 			nvdimm_clear_badblocks_region);
213 }
214 
215 static void nvdimm_account_cleared_poison(struct nvdimm_bus *nvdimm_bus,
216 		phys_addr_t phys, u64 cleared)
217 {
218 	if (cleared > 0)
219 		badrange_forget(&nvdimm_bus->badrange, phys, cleared);
220 
221 	if (cleared > 0 && cleared / 512)
222 		nvdimm_clear_badblocks_regions(nvdimm_bus, phys, cleared);
223 }
224 
225 long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
226 		unsigned int len)
227 {
228 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
229 	struct nvdimm_bus_descriptor *nd_desc;
230 	struct nd_cmd_clear_error clear_err;
231 	struct nd_cmd_ars_cap ars_cap;
232 	u32 clear_err_unit, mask;
233 	unsigned int noio_flag;
234 	int cmd_rc, rc;
235 
236 	if (!nvdimm_bus)
237 		return -ENXIO;
238 
239 	nd_desc = nvdimm_bus->nd_desc;
240 	/*
241 	 * if ndctl does not exist, it's PMEM_LEGACY and
242 	 * we want to just pretend everything is handled.
243 	 */
244 	if (!nd_desc->ndctl)
245 		return len;
246 
247 	memset(&ars_cap, 0, sizeof(ars_cap));
248 	ars_cap.address = phys;
249 	ars_cap.length = len;
250 	noio_flag = memalloc_noio_save();
251 	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_CAP, &ars_cap,
252 			sizeof(ars_cap), &cmd_rc);
253 	memalloc_noio_restore(noio_flag);
254 	if (rc < 0)
255 		return rc;
256 	if (cmd_rc < 0)
257 		return cmd_rc;
258 	clear_err_unit = ars_cap.clear_err_unit;
259 	if (!clear_err_unit || !is_power_of_2(clear_err_unit))
260 		return -ENXIO;
261 
262 	mask = clear_err_unit - 1;
263 	if ((phys | len) & mask)
264 		return -ENXIO;
265 	memset(&clear_err, 0, sizeof(clear_err));
266 	clear_err.address = phys;
267 	clear_err.length = len;
268 	noio_flag = memalloc_noio_save();
269 	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_CLEAR_ERROR, &clear_err,
270 			sizeof(clear_err), &cmd_rc);
271 	memalloc_noio_restore(noio_flag);
272 	if (rc < 0)
273 		return rc;
274 	if (cmd_rc < 0)
275 		return cmd_rc;
276 
277 	nvdimm_account_cleared_poison(nvdimm_bus, phys, clear_err.cleared);
278 
279 	return clear_err.cleared;
280 }
281 EXPORT_SYMBOL_GPL(nvdimm_clear_poison);
282 
283 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv);
284 
285 static struct bus_type nvdimm_bus_type = {
286 	.name = "nd",
287 	.uevent = nvdimm_bus_uevent,
288 	.match = nvdimm_bus_match,
289 	.probe = nvdimm_bus_probe,
290 	.remove = nvdimm_bus_remove,
291 	.shutdown = nvdimm_bus_shutdown,
292 };
293 
294 static void nvdimm_bus_release(struct device *dev)
295 {
296 	struct nvdimm_bus *nvdimm_bus;
297 
298 	nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
299 	ida_simple_remove(&nd_ida, nvdimm_bus->id);
300 	kfree(nvdimm_bus);
301 }
302 
303 bool is_nvdimm_bus(struct device *dev)
304 {
305 	return dev->release == nvdimm_bus_release;
306 }
307 
308 struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
309 {
310 	struct device *dev;
311 
312 	for (dev = nd_dev; dev; dev = dev->parent)
313 		if (is_nvdimm_bus(dev))
314 			break;
315 	dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
316 	if (dev)
317 		return to_nvdimm_bus(dev);
318 	return NULL;
319 }
320 
321 struct nvdimm_bus *to_nvdimm_bus(struct device *dev)
322 {
323 	struct nvdimm_bus *nvdimm_bus;
324 
325 	nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
326 	WARN_ON(!is_nvdimm_bus(dev));
327 	return nvdimm_bus;
328 }
329 EXPORT_SYMBOL_GPL(to_nvdimm_bus);
330 
331 struct nvdimm_bus *nvdimm_to_bus(struct nvdimm *nvdimm)
332 {
333 	return to_nvdimm_bus(nvdimm->dev.parent);
334 }
335 EXPORT_SYMBOL_GPL(nvdimm_to_bus);
336 
337 struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
338 		struct nvdimm_bus_descriptor *nd_desc)
339 {
340 	struct nvdimm_bus *nvdimm_bus;
341 	int rc;
342 
343 	nvdimm_bus = kzalloc(sizeof(*nvdimm_bus), GFP_KERNEL);
344 	if (!nvdimm_bus)
345 		return NULL;
346 	INIT_LIST_HEAD(&nvdimm_bus->list);
347 	INIT_LIST_HEAD(&nvdimm_bus->mapping_list);
348 	init_waitqueue_head(&nvdimm_bus->wait);
349 	nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
350 	if (nvdimm_bus->id < 0) {
351 		kfree(nvdimm_bus);
352 		return NULL;
353 	}
354 	mutex_init(&nvdimm_bus->reconfig_mutex);
355 	badrange_init(&nvdimm_bus->badrange);
356 	nvdimm_bus->nd_desc = nd_desc;
357 	nvdimm_bus->dev.parent = parent;
358 	nvdimm_bus->dev.release = nvdimm_bus_release;
359 	nvdimm_bus->dev.groups = nd_desc->attr_groups;
360 	nvdimm_bus->dev.bus = &nvdimm_bus_type;
361 	nvdimm_bus->dev.of_node = nd_desc->of_node;
362 	dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
363 	rc = device_register(&nvdimm_bus->dev);
364 	if (rc) {
365 		dev_dbg(&nvdimm_bus->dev, "registration failed: %d\n", rc);
366 		goto err;
367 	}
368 
369 	return nvdimm_bus;
370  err:
371 	put_device(&nvdimm_bus->dev);
372 	return NULL;
373 }
374 EXPORT_SYMBOL_GPL(nvdimm_bus_register);
375 
376 void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
377 {
378 	if (!nvdimm_bus)
379 		return;
380 	device_unregister(&nvdimm_bus->dev);
381 }
382 EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);
383 
384 static int child_unregister(struct device *dev, void *data)
385 {
386 	/*
387 	 * the singular ndctl class device per bus needs to be
388 	 * "device_destroy"ed, so skip it here
389 	 *
390 	 * i.e. remove classless children
391 	 */
392 	if (dev->class)
393 		return 0;
394 
395 	if (is_nvdimm(dev)) {
396 		struct nvdimm *nvdimm = to_nvdimm(dev);
397 		bool dev_put = false;
398 
399 		/* We are shutting down. Make state frozen artificially. */
400 		nvdimm_bus_lock(dev);
401 		set_bit(NVDIMM_SECURITY_FROZEN, &nvdimm->sec.flags);
402 		if (test_and_clear_bit(NDD_WORK_PENDING, &nvdimm->flags))
403 			dev_put = true;
404 		nvdimm_bus_unlock(dev);
405 		cancel_delayed_work_sync(&nvdimm->dwork);
406 		if (dev_put)
407 			put_device(dev);
408 	}
409 	nd_device_unregister(dev, ND_SYNC);
410 
411 	return 0;
412 }
413 
414 static void free_badrange_list(struct list_head *badrange_list)
415 {
416 	struct badrange_entry *bre, *next;
417 
418 	list_for_each_entry_safe(bre, next, badrange_list, list) {
419 		list_del(&bre->list);
420 		kfree(bre);
421 	}
422 	list_del_init(badrange_list);
423 }
424 
425 static int nd_bus_remove(struct device *dev)
426 {
427 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
428 
429 	mutex_lock(&nvdimm_bus_list_mutex);
430 	list_del_init(&nvdimm_bus->list);
431 	mutex_unlock(&nvdimm_bus_list_mutex);
432 
433 	wait_event(nvdimm_bus->wait,
434 			atomic_read(&nvdimm_bus->ioctl_active) == 0);
435 
436 	nd_synchronize();
437 	device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
438 
439 	spin_lock(&nvdimm_bus->badrange.lock);
440 	free_badrange_list(&nvdimm_bus->badrange.list);
441 	spin_unlock(&nvdimm_bus->badrange.lock);
442 
443 	nvdimm_bus_destroy_ndctl(nvdimm_bus);
444 
445 	return 0;
446 }
447 
448 static int nd_bus_probe(struct device *dev)
449 {
450 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
451 	int rc;
452 
453 	rc = nvdimm_bus_create_ndctl(nvdimm_bus);
454 	if (rc)
455 		return rc;
456 
457 	mutex_lock(&nvdimm_bus_list_mutex);
458 	list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
459 	mutex_unlock(&nvdimm_bus_list_mutex);
460 
461 	/* enable bus provider attributes to look up their local context */
462 	dev_set_drvdata(dev, nvdimm_bus->nd_desc);
463 
464 	return 0;
465 }
466 
467 static struct nd_device_driver nd_bus_driver = {
468 	.probe = nd_bus_probe,
469 	.remove = nd_bus_remove,
470 	.drv = {
471 		.name = "nd_bus",
472 		.suppress_bind_attrs = true,
473 		.bus = &nvdimm_bus_type,
474 		.owner = THIS_MODULE,
475 		.mod_name = KBUILD_MODNAME,
476 	},
477 };
478 
479 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
480 {
481 	struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
482 
483 	if (is_nvdimm_bus(dev) && nd_drv == &nd_bus_driver)
484 		return true;
485 
486 	return !!test_bit(to_nd_device_type(dev), &nd_drv->type);
487 }
488 
489 static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
490 
491 void nd_synchronize(void)
492 {
493 	async_synchronize_full_domain(&nd_async_domain);
494 }
495 EXPORT_SYMBOL_GPL(nd_synchronize);
496 
497 static void nd_async_device_register(void *d, async_cookie_t cookie)
498 {
499 	struct device *dev = d;
500 
501 	if (device_add(dev) != 0) {
502 		dev_err(dev, "%s: failed\n", __func__);
503 		put_device(dev);
504 	}
505 	put_device(dev);
506 	if (dev->parent)
507 		put_device(dev->parent);
508 }
509 
510 static void nd_async_device_unregister(void *d, async_cookie_t cookie)
511 {
512 	struct device *dev = d;
513 
514 	/* flush bus operations before delete */
515 	nvdimm_bus_lock(dev);
516 	nvdimm_bus_unlock(dev);
517 
518 	device_unregister(dev);
519 	put_device(dev);
520 }
521 
522 void __nd_device_register(struct device *dev)
523 {
524 	if (!dev)
525 		return;
526 
527 	/*
528 	 * Ensure that region devices always have their NUMA node set as
529 	 * early as possible. This way we are able to make certain that
530 	 * any memory associated with the creation and the creation
531 	 * itself of the region is associated with the correct node.
532 	 */
533 	if (is_nd_region(dev))
534 		set_dev_node(dev, to_nd_region(dev)->numa_node);
535 
536 	dev->bus = &nvdimm_bus_type;
537 	if (dev->parent) {
538 		get_device(dev->parent);
539 		if (dev_to_node(dev) == NUMA_NO_NODE)
540 			set_dev_node(dev, dev_to_node(dev->parent));
541 	}
542 	get_device(dev);
543 
544 	async_schedule_dev_domain(nd_async_device_register, dev,
545 				  &nd_async_domain);
546 }
547 
548 void nd_device_register(struct device *dev)
549 {
550 	device_initialize(dev);
551 	__nd_device_register(dev);
552 }
553 EXPORT_SYMBOL(nd_device_register);
554 
555 void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
556 {
557 	bool killed;
558 
559 	switch (mode) {
560 	case ND_ASYNC:
561 		/*
562 		 * In the async case this is being triggered with the
563 		 * device lock held and the unregistration work needs to
564 		 * be moved out of line iff this is thread has won the
565 		 * race to schedule the deletion.
566 		 */
567 		if (!kill_device(dev))
568 			return;
569 
570 		get_device(dev);
571 		async_schedule_domain(nd_async_device_unregister, dev,
572 				&nd_async_domain);
573 		break;
574 	case ND_SYNC:
575 		/*
576 		 * In the sync case the device is being unregistered due
577 		 * to a state change of the parent. Claim the kill state
578 		 * to synchronize against other unregistration requests,
579 		 * or otherwise let the async path handle it if the
580 		 * unregistration was already queued.
581 		 */
582 		nd_device_lock(dev);
583 		killed = kill_device(dev);
584 		nd_device_unlock(dev);
585 
586 		if (!killed)
587 			return;
588 
589 		nd_synchronize();
590 		device_unregister(dev);
591 		break;
592 	}
593 }
594 EXPORT_SYMBOL(nd_device_unregister);
595 
596 /**
597  * __nd_driver_register() - register a region or a namespace driver
598  * @nd_drv: driver to register
599  * @owner: automatically set by nd_driver_register() macro
600  * @mod_name: automatically set by nd_driver_register() macro
601  */
602 int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
603 		const char *mod_name)
604 {
605 	struct device_driver *drv = &nd_drv->drv;
606 
607 	if (!nd_drv->type) {
608 		pr_debug("driver type bitmask not set (%ps)\n",
609 				__builtin_return_address(0));
610 		return -EINVAL;
611 	}
612 
613 	if (!nd_drv->probe) {
614 		pr_debug("%s ->probe() must be specified\n", mod_name);
615 		return -EINVAL;
616 	}
617 
618 	drv->bus = &nvdimm_bus_type;
619 	drv->owner = owner;
620 	drv->mod_name = mod_name;
621 
622 	return driver_register(drv);
623 }
624 EXPORT_SYMBOL(__nd_driver_register);
625 
626 int nvdimm_revalidate_disk(struct gendisk *disk)
627 {
628 	struct device *dev = disk_to_dev(disk)->parent;
629 	struct nd_region *nd_region = to_nd_region(dev->parent);
630 	int disk_ro = get_disk_ro(disk);
631 
632 	/*
633 	 * Upgrade to read-only if the region is read-only preserve as
634 	 * read-only if the disk is already read-only.
635 	 */
636 	if (disk_ro || nd_region->ro == disk_ro)
637 		return 0;
638 
639 	dev_info(dev, "%s read-only, marking %s read-only\n",
640 			dev_name(&nd_region->dev), disk->disk_name);
641 	set_disk_ro(disk, 1);
642 
643 	return 0;
644 
645 }
646 EXPORT_SYMBOL(nvdimm_revalidate_disk);
647 
648 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
649 		char *buf)
650 {
651 	return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
652 			to_nd_device_type(dev));
653 }
654 static DEVICE_ATTR_RO(modalias);
655 
656 static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
657 		char *buf)
658 {
659 	return sprintf(buf, "%s\n", dev->type->name);
660 }
661 static DEVICE_ATTR_RO(devtype);
662 
663 static struct attribute *nd_device_attributes[] = {
664 	&dev_attr_modalias.attr,
665 	&dev_attr_devtype.attr,
666 	NULL,
667 };
668 
669 /*
670  * nd_device_attribute_group - generic attributes for all devices on an nd bus
671  */
672 struct attribute_group nd_device_attribute_group = {
673 	.attrs = nd_device_attributes,
674 };
675 EXPORT_SYMBOL_GPL(nd_device_attribute_group);
676 
677 static ssize_t numa_node_show(struct device *dev,
678 		struct device_attribute *attr, char *buf)
679 {
680 	return sprintf(buf, "%d\n", dev_to_node(dev));
681 }
682 static DEVICE_ATTR_RO(numa_node);
683 
684 static struct attribute *nd_numa_attributes[] = {
685 	&dev_attr_numa_node.attr,
686 	NULL,
687 };
688 
689 static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
690 		int n)
691 {
692 	if (!IS_ENABLED(CONFIG_NUMA))
693 		return 0;
694 
695 	return a->mode;
696 }
697 
698 /*
699  * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
700  */
701 struct attribute_group nd_numa_attribute_group = {
702 	.attrs = nd_numa_attributes,
703 	.is_visible = nd_numa_attr_visible,
704 };
705 EXPORT_SYMBOL_GPL(nd_numa_attribute_group);
706 
707 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
708 {
709 	dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
710 	struct device *dev;
711 
712 	dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
713 			"ndctl%d", nvdimm_bus->id);
714 
715 	if (IS_ERR(dev))
716 		dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld\n",
717 				nvdimm_bus->id, PTR_ERR(dev));
718 	return PTR_ERR_OR_ZERO(dev);
719 }
720 
721 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
722 {
723 	device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
724 }
725 
726 static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
727 	[ND_CMD_IMPLEMENTED] = { },
728 	[ND_CMD_SMART] = {
729 		.out_num = 2,
730 		.out_sizes = { 4, 128, },
731 	},
732 	[ND_CMD_SMART_THRESHOLD] = {
733 		.out_num = 2,
734 		.out_sizes = { 4, 8, },
735 	},
736 	[ND_CMD_DIMM_FLAGS] = {
737 		.out_num = 2,
738 		.out_sizes = { 4, 4 },
739 	},
740 	[ND_CMD_GET_CONFIG_SIZE] = {
741 		.out_num = 3,
742 		.out_sizes = { 4, 4, 4, },
743 	},
744 	[ND_CMD_GET_CONFIG_DATA] = {
745 		.in_num = 2,
746 		.in_sizes = { 4, 4, },
747 		.out_num = 2,
748 		.out_sizes = { 4, UINT_MAX, },
749 	},
750 	[ND_CMD_SET_CONFIG_DATA] = {
751 		.in_num = 3,
752 		.in_sizes = { 4, 4, UINT_MAX, },
753 		.out_num = 1,
754 		.out_sizes = { 4, },
755 	},
756 	[ND_CMD_VENDOR] = {
757 		.in_num = 3,
758 		.in_sizes = { 4, 4, UINT_MAX, },
759 		.out_num = 3,
760 		.out_sizes = { 4, 4, UINT_MAX, },
761 	},
762 	[ND_CMD_CALL] = {
763 		.in_num = 2,
764 		.in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
765 		.out_num = 1,
766 		.out_sizes = { UINT_MAX, },
767 	},
768 };
769 
770 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
771 {
772 	if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
773 		return &__nd_cmd_dimm_descs[cmd];
774 	return NULL;
775 }
776 EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
777 
778 static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
779 	[ND_CMD_IMPLEMENTED] = { },
780 	[ND_CMD_ARS_CAP] = {
781 		.in_num = 2,
782 		.in_sizes = { 8, 8, },
783 		.out_num = 4,
784 		.out_sizes = { 4, 4, 4, 4, },
785 	},
786 	[ND_CMD_ARS_START] = {
787 		.in_num = 5,
788 		.in_sizes = { 8, 8, 2, 1, 5, },
789 		.out_num = 2,
790 		.out_sizes = { 4, 4, },
791 	},
792 	[ND_CMD_ARS_STATUS] = {
793 		.out_num = 3,
794 		.out_sizes = { 4, 4, UINT_MAX, },
795 	},
796 	[ND_CMD_CLEAR_ERROR] = {
797 		.in_num = 2,
798 		.in_sizes = { 8, 8, },
799 		.out_num = 3,
800 		.out_sizes = { 4, 4, 8, },
801 	},
802 	[ND_CMD_CALL] = {
803 		.in_num = 2,
804 		.in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
805 		.out_num = 1,
806 		.out_sizes = { UINT_MAX, },
807 	},
808 };
809 
810 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
811 {
812 	if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
813 		return &__nd_cmd_bus_descs[cmd];
814 	return NULL;
815 }
816 EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
817 
818 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
819 		const struct nd_cmd_desc *desc, int idx, void *buf)
820 {
821 	if (idx >= desc->in_num)
822 		return UINT_MAX;
823 
824 	if (desc->in_sizes[idx] < UINT_MAX)
825 		return desc->in_sizes[idx];
826 
827 	if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
828 		struct nd_cmd_set_config_hdr *hdr = buf;
829 
830 		return hdr->in_length;
831 	} else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
832 		struct nd_cmd_vendor_hdr *hdr = buf;
833 
834 		return hdr->in_length;
835 	} else if (cmd == ND_CMD_CALL) {
836 		struct nd_cmd_pkg *pkg = buf;
837 
838 		return pkg->nd_size_in;
839 	}
840 
841 	return UINT_MAX;
842 }
843 EXPORT_SYMBOL_GPL(nd_cmd_in_size);
844 
845 u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
846 		const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
847 		const u32 *out_field, unsigned long remainder)
848 {
849 	if (idx >= desc->out_num)
850 		return UINT_MAX;
851 
852 	if (desc->out_sizes[idx] < UINT_MAX)
853 		return desc->out_sizes[idx];
854 
855 	if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
856 		return in_field[1];
857 	else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
858 		return out_field[1];
859 	else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 2) {
860 		/*
861 		 * Per table 9-276 ARS Data in ACPI 6.1, out_field[1] is
862 		 * "Size of Output Buffer in bytes, including this
863 		 * field."
864 		 */
865 		if (out_field[1] < 4)
866 			return 0;
867 		/*
868 		 * ACPI 6.1 is ambiguous if 'status' is included in the
869 		 * output size. If we encounter an output size that
870 		 * overshoots the remainder by 4 bytes, assume it was
871 		 * including 'status'.
872 		 */
873 		if (out_field[1] - 4 == remainder)
874 			return remainder;
875 		return out_field[1] - 8;
876 	} else if (cmd == ND_CMD_CALL) {
877 		struct nd_cmd_pkg *pkg = (struct nd_cmd_pkg *) in_field;
878 
879 		return pkg->nd_size_out;
880 	}
881 
882 
883 	return UINT_MAX;
884 }
885 EXPORT_SYMBOL_GPL(nd_cmd_out_size);
886 
887 void wait_nvdimm_bus_probe_idle(struct device *dev)
888 {
889 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
890 
891 	do {
892 		if (nvdimm_bus->probe_active == 0)
893 			break;
894 		nvdimm_bus_unlock(dev);
895 		nd_device_unlock(dev);
896 		wait_event(nvdimm_bus->wait,
897 				nvdimm_bus->probe_active == 0);
898 		nd_device_lock(dev);
899 		nvdimm_bus_lock(dev);
900 	} while (true);
901 }
902 
903 static int nd_pmem_forget_poison_check(struct device *dev, void *data)
904 {
905 	struct nd_cmd_clear_error *clear_err =
906 		(struct nd_cmd_clear_error *)data;
907 	struct nd_btt *nd_btt = is_nd_btt(dev) ? to_nd_btt(dev) : NULL;
908 	struct nd_pfn *nd_pfn = is_nd_pfn(dev) ? to_nd_pfn(dev) : NULL;
909 	struct nd_dax *nd_dax = is_nd_dax(dev) ? to_nd_dax(dev) : NULL;
910 	struct nd_namespace_common *ndns = NULL;
911 	struct nd_namespace_io *nsio;
912 	resource_size_t offset = 0, end_trunc = 0, start, end, pstart, pend;
913 
914 	if (nd_dax || !dev->driver)
915 		return 0;
916 
917 	start = clear_err->address;
918 	end = clear_err->address + clear_err->cleared - 1;
919 
920 	if (nd_btt || nd_pfn || nd_dax) {
921 		if (nd_btt)
922 			ndns = nd_btt->ndns;
923 		else if (nd_pfn)
924 			ndns = nd_pfn->ndns;
925 		else if (nd_dax)
926 			ndns = nd_dax->nd_pfn.ndns;
927 
928 		if (!ndns)
929 			return 0;
930 	} else
931 		ndns = to_ndns(dev);
932 
933 	nsio = to_nd_namespace_io(&ndns->dev);
934 	pstart = nsio->res.start + offset;
935 	pend = nsio->res.end - end_trunc;
936 
937 	if ((pstart >= start) && (pend <= end))
938 		return -EBUSY;
939 
940 	return 0;
941 
942 }
943 
944 static int nd_ns_forget_poison_check(struct device *dev, void *data)
945 {
946 	return device_for_each_child(dev, data, nd_pmem_forget_poison_check);
947 }
948 
949 /* set_config requires an idle interleave set */
950 static int nd_cmd_clear_to_send(struct nvdimm_bus *nvdimm_bus,
951 		struct nvdimm *nvdimm, unsigned int cmd, void *data)
952 {
953 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
954 
955 	/* ask the bus provider if it would like to block this request */
956 	if (nd_desc->clear_to_send) {
957 		int rc = nd_desc->clear_to_send(nd_desc, nvdimm, cmd, data);
958 
959 		if (rc)
960 			return rc;
961 	}
962 
963 	/* require clear error to go through the pmem driver */
964 	if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR)
965 		return device_for_each_child(&nvdimm_bus->dev, data,
966 				nd_ns_forget_poison_check);
967 
968 	if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
969 		return 0;
970 
971 	/* prevent label manipulation while the kernel owns label updates */
972 	wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);
973 	if (atomic_read(&nvdimm->busy))
974 		return -EBUSY;
975 	return 0;
976 }
977 
978 static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
979 		int read_only, unsigned int ioctl_cmd, unsigned long arg)
980 {
981 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
982 	const struct nd_cmd_desc *desc = NULL;
983 	unsigned int cmd = _IOC_NR(ioctl_cmd);
984 	struct device *dev = &nvdimm_bus->dev;
985 	void __user *p = (void __user *) arg;
986 	char *out_env = NULL, *in_env = NULL;
987 	const char *cmd_name, *dimm_name;
988 	u32 in_len = 0, out_len = 0;
989 	unsigned int func = cmd;
990 	unsigned long cmd_mask;
991 	struct nd_cmd_pkg pkg;
992 	int rc, i, cmd_rc;
993 	void *buf = NULL;
994 	u64 buf_len = 0;
995 
996 	if (nvdimm) {
997 		desc = nd_cmd_dimm_desc(cmd);
998 		cmd_name = nvdimm_cmd_name(cmd);
999 		cmd_mask = nvdimm->cmd_mask;
1000 		dimm_name = dev_name(&nvdimm->dev);
1001 	} else {
1002 		desc = nd_cmd_bus_desc(cmd);
1003 		cmd_name = nvdimm_bus_cmd_name(cmd);
1004 		cmd_mask = nd_desc->cmd_mask;
1005 		dimm_name = "bus";
1006 	}
1007 
1008 	if (cmd == ND_CMD_CALL) {
1009 		if (copy_from_user(&pkg, p, sizeof(pkg)))
1010 			return -EFAULT;
1011 	}
1012 
1013 	if (!desc || (desc->out_num + desc->in_num == 0) ||
1014 			!test_bit(cmd, &cmd_mask))
1015 		return -ENOTTY;
1016 
1017 	/* fail write commands (when read-only) */
1018 	if (read_only)
1019 		switch (cmd) {
1020 		case ND_CMD_VENDOR:
1021 		case ND_CMD_SET_CONFIG_DATA:
1022 		case ND_CMD_ARS_START:
1023 		case ND_CMD_CLEAR_ERROR:
1024 		case ND_CMD_CALL:
1025 			dev_dbg(dev, "'%s' command while read-only.\n",
1026 					nvdimm ? nvdimm_cmd_name(cmd)
1027 					: nvdimm_bus_cmd_name(cmd));
1028 			return -EPERM;
1029 		default:
1030 			break;
1031 		}
1032 
1033 	/* process an input envelope */
1034 	in_env = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
1035 	if (!in_env)
1036 		return -ENOMEM;
1037 	for (i = 0; i < desc->in_num; i++) {
1038 		u32 in_size, copy;
1039 
1040 		in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
1041 		if (in_size == UINT_MAX) {
1042 			dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
1043 					__func__, dimm_name, cmd_name, i);
1044 			rc = -ENXIO;
1045 			goto out;
1046 		}
1047 		if (in_len < ND_CMD_MAX_ENVELOPE)
1048 			copy = min_t(u32, ND_CMD_MAX_ENVELOPE - in_len, in_size);
1049 		else
1050 			copy = 0;
1051 		if (copy && copy_from_user(&in_env[in_len], p + in_len, copy)) {
1052 			rc = -EFAULT;
1053 			goto out;
1054 		}
1055 		in_len += in_size;
1056 	}
1057 
1058 	if (cmd == ND_CMD_CALL) {
1059 		func = pkg.nd_command;
1060 		dev_dbg(dev, "%s, idx: %llu, in: %u, out: %u, len %llu\n",
1061 				dimm_name, pkg.nd_command,
1062 				in_len, out_len, buf_len);
1063 	}
1064 
1065 	/* process an output envelope */
1066 	out_env = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
1067 	if (!out_env) {
1068 		rc = -ENOMEM;
1069 		goto out;
1070 	}
1071 
1072 	for (i = 0; i < desc->out_num; i++) {
1073 		u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
1074 				(u32 *) in_env, (u32 *) out_env, 0);
1075 		u32 copy;
1076 
1077 		if (out_size == UINT_MAX) {
1078 			dev_dbg(dev, "%s unknown output size cmd: %s field: %d\n",
1079 					dimm_name, cmd_name, i);
1080 			rc = -EFAULT;
1081 			goto out;
1082 		}
1083 		if (out_len < ND_CMD_MAX_ENVELOPE)
1084 			copy = min_t(u32, ND_CMD_MAX_ENVELOPE - out_len, out_size);
1085 		else
1086 			copy = 0;
1087 		if (copy && copy_from_user(&out_env[out_len],
1088 					p + in_len + out_len, copy)) {
1089 			rc = -EFAULT;
1090 			goto out;
1091 		}
1092 		out_len += out_size;
1093 	}
1094 
1095 	buf_len = (u64) out_len + (u64) in_len;
1096 	if (buf_len > ND_IOCTL_MAX_BUFLEN) {
1097 		dev_dbg(dev, "%s cmd: %s buf_len: %llu > %d\n", dimm_name,
1098 				cmd_name, buf_len, ND_IOCTL_MAX_BUFLEN);
1099 		rc = -EINVAL;
1100 		goto out;
1101 	}
1102 
1103 	buf = vmalloc(buf_len);
1104 	if (!buf) {
1105 		rc = -ENOMEM;
1106 		goto out;
1107 	}
1108 
1109 	if (copy_from_user(buf, p, buf_len)) {
1110 		rc = -EFAULT;
1111 		goto out;
1112 	}
1113 
1114 	nd_device_lock(dev);
1115 	nvdimm_bus_lock(dev);
1116 	rc = nd_cmd_clear_to_send(nvdimm_bus, nvdimm, func, buf);
1117 	if (rc)
1118 		goto out_unlock;
1119 
1120 	rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len, &cmd_rc);
1121 	if (rc < 0)
1122 		goto out_unlock;
1123 
1124 	if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR && cmd_rc >= 0) {
1125 		struct nd_cmd_clear_error *clear_err = buf;
1126 
1127 		nvdimm_account_cleared_poison(nvdimm_bus, clear_err->address,
1128 				clear_err->cleared);
1129 	}
1130 
1131 	if (copy_to_user(p, buf, buf_len))
1132 		rc = -EFAULT;
1133 
1134 out_unlock:
1135 	nvdimm_bus_unlock(dev);
1136 	nd_device_unlock(dev);
1137 out:
1138 	kfree(in_env);
1139 	kfree(out_env);
1140 	vfree(buf);
1141 	return rc;
1142 }
1143 
1144 enum nd_ioctl_mode {
1145 	BUS_IOCTL,
1146 	DIMM_IOCTL,
1147 };
1148 
1149 static int match_dimm(struct device *dev, void *data)
1150 {
1151 	long id = (long) data;
1152 
1153 	if (is_nvdimm(dev)) {
1154 		struct nvdimm *nvdimm = to_nvdimm(dev);
1155 
1156 		return nvdimm->id == id;
1157 	}
1158 
1159 	return 0;
1160 }
1161 
1162 static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1163 		enum nd_ioctl_mode mode)
1164 
1165 {
1166 	struct nvdimm_bus *nvdimm_bus, *found = NULL;
1167 	long id = (long) file->private_data;
1168 	struct nvdimm *nvdimm = NULL;
1169 	int rc, ro;
1170 
1171 	ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);
1172 	mutex_lock(&nvdimm_bus_list_mutex);
1173 	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
1174 		if (mode == DIMM_IOCTL) {
1175 			struct device *dev;
1176 
1177 			dev = device_find_child(&nvdimm_bus->dev,
1178 					file->private_data, match_dimm);
1179 			if (!dev)
1180 				continue;
1181 			nvdimm = to_nvdimm(dev);
1182 			found = nvdimm_bus;
1183 		} else if (nvdimm_bus->id == id) {
1184 			found = nvdimm_bus;
1185 		}
1186 
1187 		if (found) {
1188 			atomic_inc(&nvdimm_bus->ioctl_active);
1189 			break;
1190 		}
1191 	}
1192 	mutex_unlock(&nvdimm_bus_list_mutex);
1193 
1194 	if (!found)
1195 		return -ENXIO;
1196 
1197 	nvdimm_bus = found;
1198 	rc = __nd_ioctl(nvdimm_bus, nvdimm, ro, cmd, arg);
1199 
1200 	if (nvdimm)
1201 		put_device(&nvdimm->dev);
1202 	if (atomic_dec_and_test(&nvdimm_bus->ioctl_active))
1203 		wake_up(&nvdimm_bus->wait);
1204 
1205 	return rc;
1206 }
1207 
1208 static long bus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1209 {
1210 	return nd_ioctl(file, cmd, arg, BUS_IOCTL);
1211 }
1212 
1213 static long dimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1214 {
1215 	return nd_ioctl(file, cmd, arg, DIMM_IOCTL);
1216 }
1217 
1218 static int nd_open(struct inode *inode, struct file *file)
1219 {
1220 	long minor = iminor(inode);
1221 
1222 	file->private_data = (void *) minor;
1223 	return 0;
1224 }
1225 
1226 static const struct file_operations nvdimm_bus_fops = {
1227 	.owner = THIS_MODULE,
1228 	.open = nd_open,
1229 	.unlocked_ioctl = bus_ioctl,
1230 	.compat_ioctl = bus_ioctl,
1231 	.llseek = noop_llseek,
1232 };
1233 
1234 static const struct file_operations nvdimm_fops = {
1235 	.owner = THIS_MODULE,
1236 	.open = nd_open,
1237 	.unlocked_ioctl = dimm_ioctl,
1238 	.compat_ioctl = dimm_ioctl,
1239 	.llseek = noop_llseek,
1240 };
1241 
1242 int __init nvdimm_bus_init(void)
1243 {
1244 	int rc;
1245 
1246 	rc = bus_register(&nvdimm_bus_type);
1247 	if (rc)
1248 		return rc;
1249 
1250 	rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
1251 	if (rc < 0)
1252 		goto err_bus_chrdev;
1253 	nvdimm_bus_major = rc;
1254 
1255 	rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
1256 	if (rc < 0)
1257 		goto err_dimm_chrdev;
1258 	nvdimm_major = rc;
1259 
1260 	nd_class = class_create(THIS_MODULE, "nd");
1261 	if (IS_ERR(nd_class)) {
1262 		rc = PTR_ERR(nd_class);
1263 		goto err_class;
1264 	}
1265 
1266 	rc = driver_register(&nd_bus_driver.drv);
1267 	if (rc)
1268 		goto err_nd_bus;
1269 
1270 	return 0;
1271 
1272  err_nd_bus:
1273 	class_destroy(nd_class);
1274  err_class:
1275 	unregister_chrdev(nvdimm_major, "dimmctl");
1276  err_dimm_chrdev:
1277 	unregister_chrdev(nvdimm_bus_major, "ndctl");
1278  err_bus_chrdev:
1279 	bus_unregister(&nvdimm_bus_type);
1280 
1281 	return rc;
1282 }
1283 
1284 void nvdimm_bus_exit(void)
1285 {
1286 	driver_unregister(&nd_bus_driver.drv);
1287 	class_destroy(nd_class);
1288 	unregister_chrdev(nvdimm_bus_major, "ndctl");
1289 	unregister_chrdev(nvdimm_major, "dimmctl");
1290 	bus_unregister(&nvdimm_bus_type);
1291 	ida_destroy(&nd_ida);
1292 }
1293