xref: /linux/drivers/nvdimm/bus.c (revision cbafa54aa2ae23939846e150ad4ba98c784f6395)
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 
117 	if (nd_drv->remove) {
118 		debug_nvdimm_lock(dev);
119 		nd_drv->remove(dev);
120 		debug_nvdimm_unlock(dev);
121 	}
122 
123 	dev_dbg(&nvdimm_bus->dev, "%s.remove(%s)\n", dev->driver->name,
124 			dev_name(dev));
125 	module_put(provider);
126 	return 0;
127 }
128 
129 static void nvdimm_bus_shutdown(struct device *dev)
130 {
131 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
132 	struct nd_device_driver *nd_drv = NULL;
133 
134 	if (dev->driver)
135 		nd_drv = to_nd_device_driver(dev->driver);
136 
137 	if (nd_drv && nd_drv->shutdown) {
138 		nd_drv->shutdown(dev);
139 		dev_dbg(&nvdimm_bus->dev, "%s.shutdown(%s)\n",
140 				dev->driver->name, dev_name(dev));
141 	}
142 }
143 
144 void nd_device_notify(struct device *dev, enum nvdimm_event event)
145 {
146 	nd_device_lock(dev);
147 	if (dev->driver) {
148 		struct nd_device_driver *nd_drv;
149 
150 		nd_drv = to_nd_device_driver(dev->driver);
151 		if (nd_drv->notify)
152 			nd_drv->notify(dev, event);
153 	}
154 	nd_device_unlock(dev);
155 }
156 EXPORT_SYMBOL(nd_device_notify);
157 
158 void nvdimm_region_notify(struct nd_region *nd_region, enum nvdimm_event event)
159 {
160 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
161 
162 	if (!nvdimm_bus)
163 		return;
164 
165 	/* caller is responsible for holding a reference on the device */
166 	nd_device_notify(&nd_region->dev, event);
167 }
168 EXPORT_SYMBOL_GPL(nvdimm_region_notify);
169 
170 struct clear_badblocks_context {
171 	resource_size_t phys, cleared;
172 };
173 
174 static int nvdimm_clear_badblocks_region(struct device *dev, void *data)
175 {
176 	struct clear_badblocks_context *ctx = data;
177 	struct nd_region *nd_region;
178 	resource_size_t ndr_end;
179 	sector_t sector;
180 
181 	/* make sure device is a region */
182 	if (!is_memory(dev))
183 		return 0;
184 
185 	nd_region = to_nd_region(dev);
186 	ndr_end = nd_region->ndr_start + nd_region->ndr_size - 1;
187 
188 	/* make sure we are in the region */
189 	if (ctx->phys < nd_region->ndr_start
190 			|| (ctx->phys + ctx->cleared) > ndr_end)
191 		return 0;
192 
193 	sector = (ctx->phys - nd_region->ndr_start) / 512;
194 	badblocks_clear(&nd_region->bb, sector, ctx->cleared / 512);
195 
196 	if (nd_region->bb_state)
197 		sysfs_notify_dirent(nd_region->bb_state);
198 
199 	return 0;
200 }
201 
202 static void nvdimm_clear_badblocks_regions(struct nvdimm_bus *nvdimm_bus,
203 		phys_addr_t phys, u64 cleared)
204 {
205 	struct clear_badblocks_context ctx = {
206 		.phys = phys,
207 		.cleared = cleared,
208 	};
209 
210 	device_for_each_child(&nvdimm_bus->dev, &ctx,
211 			nvdimm_clear_badblocks_region);
212 }
213 
214 static void nvdimm_account_cleared_poison(struct nvdimm_bus *nvdimm_bus,
215 		phys_addr_t phys, u64 cleared)
216 {
217 	if (cleared > 0)
218 		badrange_forget(&nvdimm_bus->badrange, phys, cleared);
219 
220 	if (cleared > 0 && cleared / 512)
221 		nvdimm_clear_badblocks_regions(nvdimm_bus, phys, cleared);
222 }
223 
224 long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
225 		unsigned int len)
226 {
227 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
228 	struct nvdimm_bus_descriptor *nd_desc;
229 	struct nd_cmd_clear_error clear_err;
230 	struct nd_cmd_ars_cap ars_cap;
231 	u32 clear_err_unit, mask;
232 	unsigned int noio_flag;
233 	int cmd_rc, rc;
234 
235 	if (!nvdimm_bus)
236 		return -ENXIO;
237 
238 	nd_desc = nvdimm_bus->nd_desc;
239 	/*
240 	 * if ndctl does not exist, it's PMEM_LEGACY and
241 	 * we want to just pretend everything is handled.
242 	 */
243 	if (!nd_desc->ndctl)
244 		return len;
245 
246 	memset(&ars_cap, 0, sizeof(ars_cap));
247 	ars_cap.address = phys;
248 	ars_cap.length = len;
249 	noio_flag = memalloc_noio_save();
250 	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_CAP, &ars_cap,
251 			sizeof(ars_cap), &cmd_rc);
252 	memalloc_noio_restore(noio_flag);
253 	if (rc < 0)
254 		return rc;
255 	if (cmd_rc < 0)
256 		return cmd_rc;
257 	clear_err_unit = ars_cap.clear_err_unit;
258 	if (!clear_err_unit || !is_power_of_2(clear_err_unit))
259 		return -ENXIO;
260 
261 	mask = clear_err_unit - 1;
262 	if ((phys | len) & mask)
263 		return -ENXIO;
264 	memset(&clear_err, 0, sizeof(clear_err));
265 	clear_err.address = phys;
266 	clear_err.length = len;
267 	noio_flag = memalloc_noio_save();
268 	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_CLEAR_ERROR, &clear_err,
269 			sizeof(clear_err), &cmd_rc);
270 	memalloc_noio_restore(noio_flag);
271 	if (rc < 0)
272 		return rc;
273 	if (cmd_rc < 0)
274 		return cmd_rc;
275 
276 	nvdimm_account_cleared_poison(nvdimm_bus, phys, clear_err.cleared);
277 
278 	return clear_err.cleared;
279 }
280 EXPORT_SYMBOL_GPL(nvdimm_clear_poison);
281 
282 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv);
283 
284 static struct bus_type nvdimm_bus_type = {
285 	.name = "nd",
286 	.uevent = nvdimm_bus_uevent,
287 	.match = nvdimm_bus_match,
288 	.probe = nvdimm_bus_probe,
289 	.remove = nvdimm_bus_remove,
290 	.shutdown = nvdimm_bus_shutdown,
291 };
292 
293 static void nvdimm_bus_release(struct device *dev)
294 {
295 	struct nvdimm_bus *nvdimm_bus;
296 
297 	nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
298 	ida_simple_remove(&nd_ida, nvdimm_bus->id);
299 	kfree(nvdimm_bus);
300 }
301 
302 static const struct device_type nvdimm_bus_dev_type = {
303 	.release = nvdimm_bus_release,
304 	.groups = nvdimm_bus_attribute_groups,
305 };
306 
307 bool is_nvdimm_bus(struct device *dev)
308 {
309 	return dev->type == &nvdimm_bus_dev_type;
310 }
311 
312 struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
313 {
314 	struct device *dev;
315 
316 	for (dev = nd_dev; dev; dev = dev->parent)
317 		if (is_nvdimm_bus(dev))
318 			break;
319 	dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
320 	if (dev)
321 		return to_nvdimm_bus(dev);
322 	return NULL;
323 }
324 
325 struct nvdimm_bus *to_nvdimm_bus(struct device *dev)
326 {
327 	struct nvdimm_bus *nvdimm_bus;
328 
329 	nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
330 	WARN_ON(!is_nvdimm_bus(dev));
331 	return nvdimm_bus;
332 }
333 EXPORT_SYMBOL_GPL(to_nvdimm_bus);
334 
335 struct nvdimm_bus *nvdimm_to_bus(struct nvdimm *nvdimm)
336 {
337 	return to_nvdimm_bus(nvdimm->dev.parent);
338 }
339 EXPORT_SYMBOL_GPL(nvdimm_to_bus);
340 
341 struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
342 		struct nvdimm_bus_descriptor *nd_desc)
343 {
344 	struct nvdimm_bus *nvdimm_bus;
345 	int rc;
346 
347 	nvdimm_bus = kzalloc(sizeof(*nvdimm_bus), GFP_KERNEL);
348 	if (!nvdimm_bus)
349 		return NULL;
350 	INIT_LIST_HEAD(&nvdimm_bus->list);
351 	INIT_LIST_HEAD(&nvdimm_bus->mapping_list);
352 	init_waitqueue_head(&nvdimm_bus->wait);
353 	nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
354 	if (nvdimm_bus->id < 0) {
355 		kfree(nvdimm_bus);
356 		return NULL;
357 	}
358 	mutex_init(&nvdimm_bus->reconfig_mutex);
359 	badrange_init(&nvdimm_bus->badrange);
360 	nvdimm_bus->nd_desc = nd_desc;
361 	nvdimm_bus->dev.parent = parent;
362 	nvdimm_bus->dev.type = &nvdimm_bus_dev_type;
363 	nvdimm_bus->dev.groups = nd_desc->attr_groups;
364 	nvdimm_bus->dev.bus = &nvdimm_bus_type;
365 	nvdimm_bus->dev.of_node = nd_desc->of_node;
366 	dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
367 	rc = device_register(&nvdimm_bus->dev);
368 	if (rc) {
369 		dev_dbg(&nvdimm_bus->dev, "registration failed: %d\n", rc);
370 		goto err;
371 	}
372 
373 	return nvdimm_bus;
374  err:
375 	put_device(&nvdimm_bus->dev);
376 	return NULL;
377 }
378 EXPORT_SYMBOL_GPL(nvdimm_bus_register);
379 
380 void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
381 {
382 	if (!nvdimm_bus)
383 		return;
384 	device_unregister(&nvdimm_bus->dev);
385 }
386 EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);
387 
388 static int child_unregister(struct device *dev, void *data)
389 {
390 	/*
391 	 * the singular ndctl class device per bus needs to be
392 	 * "device_destroy"ed, so skip it here
393 	 *
394 	 * i.e. remove classless children
395 	 */
396 	if (dev->class)
397 		return 0;
398 
399 	if (is_nvdimm(dev)) {
400 		struct nvdimm *nvdimm = to_nvdimm(dev);
401 		bool dev_put = false;
402 
403 		/* We are shutting down. Make state frozen artificially. */
404 		nvdimm_bus_lock(dev);
405 		set_bit(NVDIMM_SECURITY_FROZEN, &nvdimm->sec.flags);
406 		if (test_and_clear_bit(NDD_WORK_PENDING, &nvdimm->flags))
407 			dev_put = true;
408 		nvdimm_bus_unlock(dev);
409 		cancel_delayed_work_sync(&nvdimm->dwork);
410 		if (dev_put)
411 			put_device(dev);
412 	}
413 	nd_device_unregister(dev, ND_SYNC);
414 
415 	return 0;
416 }
417 
418 static void free_badrange_list(struct list_head *badrange_list)
419 {
420 	struct badrange_entry *bre, *next;
421 
422 	list_for_each_entry_safe(bre, next, badrange_list, list) {
423 		list_del(&bre->list);
424 		kfree(bre);
425 	}
426 	list_del_init(badrange_list);
427 }
428 
429 static void nd_bus_remove(struct device *dev)
430 {
431 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
432 
433 	mutex_lock(&nvdimm_bus_list_mutex);
434 	list_del_init(&nvdimm_bus->list);
435 	mutex_unlock(&nvdimm_bus_list_mutex);
436 
437 	wait_event(nvdimm_bus->wait,
438 			atomic_read(&nvdimm_bus->ioctl_active) == 0);
439 
440 	nd_synchronize();
441 	device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
442 
443 	spin_lock(&nvdimm_bus->badrange.lock);
444 	free_badrange_list(&nvdimm_bus->badrange.list);
445 	spin_unlock(&nvdimm_bus->badrange.lock);
446 
447 	nvdimm_bus_destroy_ndctl(nvdimm_bus);
448 }
449 
450 static int nd_bus_probe(struct device *dev)
451 {
452 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
453 	int rc;
454 
455 	rc = nvdimm_bus_create_ndctl(nvdimm_bus);
456 	if (rc)
457 		return rc;
458 
459 	mutex_lock(&nvdimm_bus_list_mutex);
460 	list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
461 	mutex_unlock(&nvdimm_bus_list_mutex);
462 
463 	/* enable bus provider attributes to look up their local context */
464 	dev_set_drvdata(dev, nvdimm_bus->nd_desc);
465 
466 	return 0;
467 }
468 
469 static struct nd_device_driver nd_bus_driver = {
470 	.probe = nd_bus_probe,
471 	.remove = nd_bus_remove,
472 	.drv = {
473 		.name = "nd_bus",
474 		.suppress_bind_attrs = true,
475 		.bus = &nvdimm_bus_type,
476 		.owner = THIS_MODULE,
477 		.mod_name = KBUILD_MODNAME,
478 	},
479 };
480 
481 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
482 {
483 	struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
484 
485 	if (is_nvdimm_bus(dev) && nd_drv == &nd_bus_driver)
486 		return true;
487 
488 	return !!test_bit(to_nd_device_type(dev), &nd_drv->type);
489 }
490 
491 static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
492 
493 void nd_synchronize(void)
494 {
495 	async_synchronize_full_domain(&nd_async_domain);
496 }
497 EXPORT_SYMBOL_GPL(nd_synchronize);
498 
499 static void nd_async_device_register(void *d, async_cookie_t cookie)
500 {
501 	struct device *dev = d;
502 
503 	if (device_add(dev) != 0) {
504 		dev_err(dev, "%s: failed\n", __func__);
505 		put_device(dev);
506 	}
507 	put_device(dev);
508 	if (dev->parent)
509 		put_device(dev->parent);
510 }
511 
512 static void nd_async_device_unregister(void *d, async_cookie_t cookie)
513 {
514 	struct device *dev = d;
515 
516 	/* flush bus operations before delete */
517 	nvdimm_bus_lock(dev);
518 	nvdimm_bus_unlock(dev);
519 
520 	device_unregister(dev);
521 	put_device(dev);
522 }
523 
524 void __nd_device_register(struct device *dev)
525 {
526 	if (!dev)
527 		return;
528 
529 	/*
530 	 * Ensure that region devices always have their NUMA node set as
531 	 * early as possible. This way we are able to make certain that
532 	 * any memory associated with the creation and the creation
533 	 * itself of the region is associated with the correct node.
534 	 */
535 	if (is_nd_region(dev))
536 		set_dev_node(dev, to_nd_region(dev)->numa_node);
537 
538 	dev->bus = &nvdimm_bus_type;
539 	if (dev->parent) {
540 		get_device(dev->parent);
541 		if (dev_to_node(dev) == NUMA_NO_NODE)
542 			set_dev_node(dev, dev_to_node(dev->parent));
543 	}
544 	get_device(dev);
545 
546 	async_schedule_dev_domain(nd_async_device_register, dev,
547 				  &nd_async_domain);
548 }
549 
550 void nd_device_register(struct device *dev)
551 {
552 	device_initialize(dev);
553 	__nd_device_register(dev);
554 }
555 EXPORT_SYMBOL(nd_device_register);
556 
557 void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
558 {
559 	bool killed;
560 
561 	switch (mode) {
562 	case ND_ASYNC:
563 		/*
564 		 * In the async case this is being triggered with the
565 		 * device lock held and the unregistration work needs to
566 		 * be moved out of line iff this is thread has won the
567 		 * race to schedule the deletion.
568 		 */
569 		if (!kill_device(dev))
570 			return;
571 
572 		get_device(dev);
573 		async_schedule_domain(nd_async_device_unregister, dev,
574 				&nd_async_domain);
575 		break;
576 	case ND_SYNC:
577 		/*
578 		 * In the sync case the device is being unregistered due
579 		 * to a state change of the parent. Claim the kill state
580 		 * to synchronize against other unregistration requests,
581 		 * or otherwise let the async path handle it if the
582 		 * unregistration was already queued.
583 		 */
584 		nd_device_lock(dev);
585 		killed = kill_device(dev);
586 		nd_device_unlock(dev);
587 
588 		if (!killed)
589 			return;
590 
591 		nd_synchronize();
592 		device_unregister(dev);
593 		break;
594 	}
595 }
596 EXPORT_SYMBOL(nd_device_unregister);
597 
598 /**
599  * __nd_driver_register() - register a region or a namespace driver
600  * @nd_drv: driver to register
601  * @owner: automatically set by nd_driver_register() macro
602  * @mod_name: automatically set by nd_driver_register() macro
603  */
604 int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
605 		const char *mod_name)
606 {
607 	struct device_driver *drv = &nd_drv->drv;
608 
609 	if (!nd_drv->type) {
610 		pr_debug("driver type bitmask not set (%ps)\n",
611 				__builtin_return_address(0));
612 		return -EINVAL;
613 	}
614 
615 	if (!nd_drv->probe) {
616 		pr_debug("%s ->probe() must be specified\n", mod_name);
617 		return -EINVAL;
618 	}
619 
620 	drv->bus = &nvdimm_bus_type;
621 	drv->owner = owner;
622 	drv->mod_name = mod_name;
623 
624 	return driver_register(drv);
625 }
626 EXPORT_SYMBOL(__nd_driver_register);
627 
628 void nvdimm_check_and_set_ro(struct gendisk *disk)
629 {
630 	struct device *dev = disk_to_dev(disk)->parent;
631 	struct nd_region *nd_region = to_nd_region(dev->parent);
632 	int disk_ro = get_disk_ro(disk);
633 
634 	/* catch the disk up with the region ro state */
635 	if (disk_ro == nd_region->ro)
636 		return;
637 
638 	dev_info(dev, "%s read-%s, marking %s read-%s\n",
639 		 dev_name(&nd_region->dev), nd_region->ro ? "only" : "write",
640 		 disk->disk_name, nd_region->ro ? "only" : "write");
641 	set_disk_ro(disk, nd_region->ro);
642 }
643 EXPORT_SYMBOL(nvdimm_check_and_set_ro);
644 
645 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
646 		char *buf)
647 {
648 	return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
649 			to_nd_device_type(dev));
650 }
651 static DEVICE_ATTR_RO(modalias);
652 
653 static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
654 		char *buf)
655 {
656 	return sprintf(buf, "%s\n", dev->type->name);
657 }
658 static DEVICE_ATTR_RO(devtype);
659 
660 static struct attribute *nd_device_attributes[] = {
661 	&dev_attr_modalias.attr,
662 	&dev_attr_devtype.attr,
663 	NULL,
664 };
665 
666 /*
667  * nd_device_attribute_group - generic attributes for all devices on an nd bus
668  */
669 const struct attribute_group nd_device_attribute_group = {
670 	.attrs = nd_device_attributes,
671 };
672 
673 static ssize_t numa_node_show(struct device *dev,
674 		struct device_attribute *attr, char *buf)
675 {
676 	return sprintf(buf, "%d\n", dev_to_node(dev));
677 }
678 static DEVICE_ATTR_RO(numa_node);
679 
680 static int nvdimm_dev_to_target_node(struct device *dev)
681 {
682 	struct device *parent = dev->parent;
683 	struct nd_region *nd_region = NULL;
684 
685 	if (is_nd_region(dev))
686 		nd_region = to_nd_region(dev);
687 	else if (parent && is_nd_region(parent))
688 		nd_region = to_nd_region(parent);
689 
690 	if (!nd_region)
691 		return NUMA_NO_NODE;
692 	return nd_region->target_node;
693 }
694 
695 static ssize_t target_node_show(struct device *dev,
696 		struct device_attribute *attr, char *buf)
697 {
698 	return sprintf(buf, "%d\n", nvdimm_dev_to_target_node(dev));
699 }
700 static DEVICE_ATTR_RO(target_node);
701 
702 static struct attribute *nd_numa_attributes[] = {
703 	&dev_attr_numa_node.attr,
704 	&dev_attr_target_node.attr,
705 	NULL,
706 };
707 
708 static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
709 		int n)
710 {
711 	struct device *dev = container_of(kobj, typeof(*dev), kobj);
712 
713 	if (!IS_ENABLED(CONFIG_NUMA))
714 		return 0;
715 
716 	if (a == &dev_attr_target_node.attr &&
717 			nvdimm_dev_to_target_node(dev) == NUMA_NO_NODE)
718 		return 0;
719 
720 	return a->mode;
721 }
722 
723 /*
724  * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
725  */
726 const struct attribute_group nd_numa_attribute_group = {
727 	.attrs = nd_numa_attributes,
728 	.is_visible = nd_numa_attr_visible,
729 };
730 
731 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
732 {
733 	dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
734 	struct device *dev;
735 
736 	dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
737 			"ndctl%d", nvdimm_bus->id);
738 
739 	if (IS_ERR(dev))
740 		dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld\n",
741 				nvdimm_bus->id, PTR_ERR(dev));
742 	return PTR_ERR_OR_ZERO(dev);
743 }
744 
745 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
746 {
747 	device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
748 }
749 
750 static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
751 	[ND_CMD_IMPLEMENTED] = { },
752 	[ND_CMD_SMART] = {
753 		.out_num = 2,
754 		.out_sizes = { 4, 128, },
755 	},
756 	[ND_CMD_SMART_THRESHOLD] = {
757 		.out_num = 2,
758 		.out_sizes = { 4, 8, },
759 	},
760 	[ND_CMD_DIMM_FLAGS] = {
761 		.out_num = 2,
762 		.out_sizes = { 4, 4 },
763 	},
764 	[ND_CMD_GET_CONFIG_SIZE] = {
765 		.out_num = 3,
766 		.out_sizes = { 4, 4, 4, },
767 	},
768 	[ND_CMD_GET_CONFIG_DATA] = {
769 		.in_num = 2,
770 		.in_sizes = { 4, 4, },
771 		.out_num = 2,
772 		.out_sizes = { 4, UINT_MAX, },
773 	},
774 	[ND_CMD_SET_CONFIG_DATA] = {
775 		.in_num = 3,
776 		.in_sizes = { 4, 4, UINT_MAX, },
777 		.out_num = 1,
778 		.out_sizes = { 4, },
779 	},
780 	[ND_CMD_VENDOR] = {
781 		.in_num = 3,
782 		.in_sizes = { 4, 4, UINT_MAX, },
783 		.out_num = 3,
784 		.out_sizes = { 4, 4, UINT_MAX, },
785 	},
786 	[ND_CMD_CALL] = {
787 		.in_num = 2,
788 		.in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
789 		.out_num = 1,
790 		.out_sizes = { UINT_MAX, },
791 	},
792 };
793 
794 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
795 {
796 	if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
797 		return &__nd_cmd_dimm_descs[cmd];
798 	return NULL;
799 }
800 EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
801 
802 static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
803 	[ND_CMD_IMPLEMENTED] = { },
804 	[ND_CMD_ARS_CAP] = {
805 		.in_num = 2,
806 		.in_sizes = { 8, 8, },
807 		.out_num = 4,
808 		.out_sizes = { 4, 4, 4, 4, },
809 	},
810 	[ND_CMD_ARS_START] = {
811 		.in_num = 5,
812 		.in_sizes = { 8, 8, 2, 1, 5, },
813 		.out_num = 2,
814 		.out_sizes = { 4, 4, },
815 	},
816 	[ND_CMD_ARS_STATUS] = {
817 		.out_num = 3,
818 		.out_sizes = { 4, 4, UINT_MAX, },
819 	},
820 	[ND_CMD_CLEAR_ERROR] = {
821 		.in_num = 2,
822 		.in_sizes = { 8, 8, },
823 		.out_num = 3,
824 		.out_sizes = { 4, 4, 8, },
825 	},
826 	[ND_CMD_CALL] = {
827 		.in_num = 2,
828 		.in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
829 		.out_num = 1,
830 		.out_sizes = { UINT_MAX, },
831 	},
832 };
833 
834 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
835 {
836 	if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
837 		return &__nd_cmd_bus_descs[cmd];
838 	return NULL;
839 }
840 EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
841 
842 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
843 		const struct nd_cmd_desc *desc, int idx, void *buf)
844 {
845 	if (idx >= desc->in_num)
846 		return UINT_MAX;
847 
848 	if (desc->in_sizes[idx] < UINT_MAX)
849 		return desc->in_sizes[idx];
850 
851 	if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
852 		struct nd_cmd_set_config_hdr *hdr = buf;
853 
854 		return hdr->in_length;
855 	} else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
856 		struct nd_cmd_vendor_hdr *hdr = buf;
857 
858 		return hdr->in_length;
859 	} else if (cmd == ND_CMD_CALL) {
860 		struct nd_cmd_pkg *pkg = buf;
861 
862 		return pkg->nd_size_in;
863 	}
864 
865 	return UINT_MAX;
866 }
867 EXPORT_SYMBOL_GPL(nd_cmd_in_size);
868 
869 u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
870 		const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
871 		const u32 *out_field, unsigned long remainder)
872 {
873 	if (idx >= desc->out_num)
874 		return UINT_MAX;
875 
876 	if (desc->out_sizes[idx] < UINT_MAX)
877 		return desc->out_sizes[idx];
878 
879 	if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
880 		return in_field[1];
881 	else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
882 		return out_field[1];
883 	else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 2) {
884 		/*
885 		 * Per table 9-276 ARS Data in ACPI 6.1, out_field[1] is
886 		 * "Size of Output Buffer in bytes, including this
887 		 * field."
888 		 */
889 		if (out_field[1] < 4)
890 			return 0;
891 		/*
892 		 * ACPI 6.1 is ambiguous if 'status' is included in the
893 		 * output size. If we encounter an output size that
894 		 * overshoots the remainder by 4 bytes, assume it was
895 		 * including 'status'.
896 		 */
897 		if (out_field[1] - 4 == remainder)
898 			return remainder;
899 		return out_field[1] - 8;
900 	} else if (cmd == ND_CMD_CALL) {
901 		struct nd_cmd_pkg *pkg = (struct nd_cmd_pkg *) in_field;
902 
903 		return pkg->nd_size_out;
904 	}
905 
906 
907 	return UINT_MAX;
908 }
909 EXPORT_SYMBOL_GPL(nd_cmd_out_size);
910 
911 void wait_nvdimm_bus_probe_idle(struct device *dev)
912 {
913 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
914 
915 	do {
916 		if (nvdimm_bus->probe_active == 0)
917 			break;
918 		nvdimm_bus_unlock(dev);
919 		nd_device_unlock(dev);
920 		wait_event(nvdimm_bus->wait,
921 				nvdimm_bus->probe_active == 0);
922 		nd_device_lock(dev);
923 		nvdimm_bus_lock(dev);
924 	} while (true);
925 }
926 
927 static int nd_pmem_forget_poison_check(struct device *dev, void *data)
928 {
929 	struct nd_cmd_clear_error *clear_err =
930 		(struct nd_cmd_clear_error *)data;
931 	struct nd_btt *nd_btt = is_nd_btt(dev) ? to_nd_btt(dev) : NULL;
932 	struct nd_pfn *nd_pfn = is_nd_pfn(dev) ? to_nd_pfn(dev) : NULL;
933 	struct nd_dax *nd_dax = is_nd_dax(dev) ? to_nd_dax(dev) : NULL;
934 	struct nd_namespace_common *ndns = NULL;
935 	struct nd_namespace_io *nsio;
936 	resource_size_t offset = 0, end_trunc = 0, start, end, pstart, pend;
937 
938 	if (nd_dax || !dev->driver)
939 		return 0;
940 
941 	start = clear_err->address;
942 	end = clear_err->address + clear_err->cleared - 1;
943 
944 	if (nd_btt || nd_pfn || nd_dax) {
945 		if (nd_btt)
946 			ndns = nd_btt->ndns;
947 		else if (nd_pfn)
948 			ndns = nd_pfn->ndns;
949 		else if (nd_dax)
950 			ndns = nd_dax->nd_pfn.ndns;
951 
952 		if (!ndns)
953 			return 0;
954 	} else
955 		ndns = to_ndns(dev);
956 
957 	nsio = to_nd_namespace_io(&ndns->dev);
958 	pstart = nsio->res.start + offset;
959 	pend = nsio->res.end - end_trunc;
960 
961 	if ((pstart >= start) && (pend <= end))
962 		return -EBUSY;
963 
964 	return 0;
965 
966 }
967 
968 static int nd_ns_forget_poison_check(struct device *dev, void *data)
969 {
970 	return device_for_each_child(dev, data, nd_pmem_forget_poison_check);
971 }
972 
973 /* set_config requires an idle interleave set */
974 static int nd_cmd_clear_to_send(struct nvdimm_bus *nvdimm_bus,
975 		struct nvdimm *nvdimm, unsigned int cmd, void *data)
976 {
977 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
978 
979 	/* ask the bus provider if it would like to block this request */
980 	if (nd_desc->clear_to_send) {
981 		int rc = nd_desc->clear_to_send(nd_desc, nvdimm, cmd, data);
982 
983 		if (rc)
984 			return rc;
985 	}
986 
987 	/* require clear error to go through the pmem driver */
988 	if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR)
989 		return device_for_each_child(&nvdimm_bus->dev, data,
990 				nd_ns_forget_poison_check);
991 
992 	if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
993 		return 0;
994 
995 	/* prevent label manipulation while the kernel owns label updates */
996 	wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);
997 	if (atomic_read(&nvdimm->busy))
998 		return -EBUSY;
999 	return 0;
1000 }
1001 
1002 static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
1003 		int read_only, unsigned int ioctl_cmd, unsigned long arg)
1004 {
1005 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
1006 	const struct nd_cmd_desc *desc = NULL;
1007 	unsigned int cmd = _IOC_NR(ioctl_cmd);
1008 	struct device *dev = &nvdimm_bus->dev;
1009 	void __user *p = (void __user *) arg;
1010 	char *out_env = NULL, *in_env = NULL;
1011 	const char *cmd_name, *dimm_name;
1012 	u32 in_len = 0, out_len = 0;
1013 	unsigned int func = cmd;
1014 	unsigned long cmd_mask;
1015 	struct nd_cmd_pkg pkg;
1016 	int rc, i, cmd_rc;
1017 	void *buf = NULL;
1018 	u64 buf_len = 0;
1019 
1020 	if (nvdimm) {
1021 		desc = nd_cmd_dimm_desc(cmd);
1022 		cmd_name = nvdimm_cmd_name(cmd);
1023 		cmd_mask = nvdimm->cmd_mask;
1024 		dimm_name = dev_name(&nvdimm->dev);
1025 	} else {
1026 		desc = nd_cmd_bus_desc(cmd);
1027 		cmd_name = nvdimm_bus_cmd_name(cmd);
1028 		cmd_mask = nd_desc->cmd_mask;
1029 		dimm_name = "bus";
1030 	}
1031 
1032 	/* Validate command family support against bus declared support */
1033 	if (cmd == ND_CMD_CALL) {
1034 		unsigned long *mask;
1035 
1036 		if (copy_from_user(&pkg, p, sizeof(pkg)))
1037 			return -EFAULT;
1038 
1039 		if (nvdimm) {
1040 			if (pkg.nd_family > NVDIMM_FAMILY_MAX)
1041 				return -EINVAL;
1042 			mask = &nd_desc->dimm_family_mask;
1043 		} else {
1044 			if (pkg.nd_family > NVDIMM_BUS_FAMILY_MAX)
1045 				return -EINVAL;
1046 			mask = &nd_desc->bus_family_mask;
1047 		}
1048 
1049 		if (!test_bit(pkg.nd_family, mask))
1050 			return -EINVAL;
1051 	}
1052 
1053 	if (!desc ||
1054 	    (desc->out_num + desc->in_num == 0) ||
1055 	    cmd > ND_CMD_CALL ||
1056 	    !test_bit(cmd, &cmd_mask))
1057 		return -ENOTTY;
1058 
1059 	/* fail write commands (when read-only) */
1060 	if (read_only)
1061 		switch (cmd) {
1062 		case ND_CMD_VENDOR:
1063 		case ND_CMD_SET_CONFIG_DATA:
1064 		case ND_CMD_ARS_START:
1065 		case ND_CMD_CLEAR_ERROR:
1066 		case ND_CMD_CALL:
1067 			dev_dbg(dev, "'%s' command while read-only.\n",
1068 					nvdimm ? nvdimm_cmd_name(cmd)
1069 					: nvdimm_bus_cmd_name(cmd));
1070 			return -EPERM;
1071 		default:
1072 			break;
1073 		}
1074 
1075 	/* process an input envelope */
1076 	in_env = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
1077 	if (!in_env)
1078 		return -ENOMEM;
1079 	for (i = 0; i < desc->in_num; i++) {
1080 		u32 in_size, copy;
1081 
1082 		in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
1083 		if (in_size == UINT_MAX) {
1084 			dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
1085 					__func__, dimm_name, cmd_name, i);
1086 			rc = -ENXIO;
1087 			goto out;
1088 		}
1089 		if (in_len < ND_CMD_MAX_ENVELOPE)
1090 			copy = min_t(u32, ND_CMD_MAX_ENVELOPE - in_len, in_size);
1091 		else
1092 			copy = 0;
1093 		if (copy && copy_from_user(&in_env[in_len], p + in_len, copy)) {
1094 			rc = -EFAULT;
1095 			goto out;
1096 		}
1097 		in_len += in_size;
1098 	}
1099 
1100 	if (cmd == ND_CMD_CALL) {
1101 		func = pkg.nd_command;
1102 		dev_dbg(dev, "%s, idx: %llu, in: %u, out: %u, len %llu\n",
1103 				dimm_name, pkg.nd_command,
1104 				in_len, out_len, buf_len);
1105 	}
1106 
1107 	/* process an output envelope */
1108 	out_env = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
1109 	if (!out_env) {
1110 		rc = -ENOMEM;
1111 		goto out;
1112 	}
1113 
1114 	for (i = 0; i < desc->out_num; i++) {
1115 		u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
1116 				(u32 *) in_env, (u32 *) out_env, 0);
1117 		u32 copy;
1118 
1119 		if (out_size == UINT_MAX) {
1120 			dev_dbg(dev, "%s unknown output size cmd: %s field: %d\n",
1121 					dimm_name, cmd_name, i);
1122 			rc = -EFAULT;
1123 			goto out;
1124 		}
1125 		if (out_len < ND_CMD_MAX_ENVELOPE)
1126 			copy = min_t(u32, ND_CMD_MAX_ENVELOPE - out_len, out_size);
1127 		else
1128 			copy = 0;
1129 		if (copy && copy_from_user(&out_env[out_len],
1130 					p + in_len + out_len, copy)) {
1131 			rc = -EFAULT;
1132 			goto out;
1133 		}
1134 		out_len += out_size;
1135 	}
1136 
1137 	buf_len = (u64) out_len + (u64) in_len;
1138 	if (buf_len > ND_IOCTL_MAX_BUFLEN) {
1139 		dev_dbg(dev, "%s cmd: %s buf_len: %llu > %d\n", dimm_name,
1140 				cmd_name, buf_len, ND_IOCTL_MAX_BUFLEN);
1141 		rc = -EINVAL;
1142 		goto out;
1143 	}
1144 
1145 	buf = vmalloc(buf_len);
1146 	if (!buf) {
1147 		rc = -ENOMEM;
1148 		goto out;
1149 	}
1150 
1151 	if (copy_from_user(buf, p, buf_len)) {
1152 		rc = -EFAULT;
1153 		goto out;
1154 	}
1155 
1156 	nd_device_lock(dev);
1157 	nvdimm_bus_lock(dev);
1158 	rc = nd_cmd_clear_to_send(nvdimm_bus, nvdimm, func, buf);
1159 	if (rc)
1160 		goto out_unlock;
1161 
1162 	rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len, &cmd_rc);
1163 	if (rc < 0)
1164 		goto out_unlock;
1165 
1166 	if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR && cmd_rc >= 0) {
1167 		struct nd_cmd_clear_error *clear_err = buf;
1168 
1169 		nvdimm_account_cleared_poison(nvdimm_bus, clear_err->address,
1170 				clear_err->cleared);
1171 	}
1172 
1173 	if (copy_to_user(p, buf, buf_len))
1174 		rc = -EFAULT;
1175 
1176 out_unlock:
1177 	nvdimm_bus_unlock(dev);
1178 	nd_device_unlock(dev);
1179 out:
1180 	kfree(in_env);
1181 	kfree(out_env);
1182 	vfree(buf);
1183 	return rc;
1184 }
1185 
1186 enum nd_ioctl_mode {
1187 	BUS_IOCTL,
1188 	DIMM_IOCTL,
1189 };
1190 
1191 static int match_dimm(struct device *dev, void *data)
1192 {
1193 	long id = (long) data;
1194 
1195 	if (is_nvdimm(dev)) {
1196 		struct nvdimm *nvdimm = to_nvdimm(dev);
1197 
1198 		return nvdimm->id == id;
1199 	}
1200 
1201 	return 0;
1202 }
1203 
1204 static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1205 		enum nd_ioctl_mode mode)
1206 
1207 {
1208 	struct nvdimm_bus *nvdimm_bus, *found = NULL;
1209 	long id = (long) file->private_data;
1210 	struct nvdimm *nvdimm = NULL;
1211 	int rc, ro;
1212 
1213 	ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);
1214 	mutex_lock(&nvdimm_bus_list_mutex);
1215 	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
1216 		if (mode == DIMM_IOCTL) {
1217 			struct device *dev;
1218 
1219 			dev = device_find_child(&nvdimm_bus->dev,
1220 					file->private_data, match_dimm);
1221 			if (!dev)
1222 				continue;
1223 			nvdimm = to_nvdimm(dev);
1224 			found = nvdimm_bus;
1225 		} else if (nvdimm_bus->id == id) {
1226 			found = nvdimm_bus;
1227 		}
1228 
1229 		if (found) {
1230 			atomic_inc(&nvdimm_bus->ioctl_active);
1231 			break;
1232 		}
1233 	}
1234 	mutex_unlock(&nvdimm_bus_list_mutex);
1235 
1236 	if (!found)
1237 		return -ENXIO;
1238 
1239 	nvdimm_bus = found;
1240 	rc = __nd_ioctl(nvdimm_bus, nvdimm, ro, cmd, arg);
1241 
1242 	if (nvdimm)
1243 		put_device(&nvdimm->dev);
1244 	if (atomic_dec_and_test(&nvdimm_bus->ioctl_active))
1245 		wake_up(&nvdimm_bus->wait);
1246 
1247 	return rc;
1248 }
1249 
1250 static long bus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1251 {
1252 	return nd_ioctl(file, cmd, arg, BUS_IOCTL);
1253 }
1254 
1255 static long dimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1256 {
1257 	return nd_ioctl(file, cmd, arg, DIMM_IOCTL);
1258 }
1259 
1260 static int nd_open(struct inode *inode, struct file *file)
1261 {
1262 	long minor = iminor(inode);
1263 
1264 	file->private_data = (void *) minor;
1265 	return 0;
1266 }
1267 
1268 static const struct file_operations nvdimm_bus_fops = {
1269 	.owner = THIS_MODULE,
1270 	.open = nd_open,
1271 	.unlocked_ioctl = bus_ioctl,
1272 	.compat_ioctl = compat_ptr_ioctl,
1273 	.llseek = noop_llseek,
1274 };
1275 
1276 static const struct file_operations nvdimm_fops = {
1277 	.owner = THIS_MODULE,
1278 	.open = nd_open,
1279 	.unlocked_ioctl = dimm_ioctl,
1280 	.compat_ioctl = compat_ptr_ioctl,
1281 	.llseek = noop_llseek,
1282 };
1283 
1284 int __init nvdimm_bus_init(void)
1285 {
1286 	int rc;
1287 
1288 	rc = bus_register(&nvdimm_bus_type);
1289 	if (rc)
1290 		return rc;
1291 
1292 	rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
1293 	if (rc < 0)
1294 		goto err_bus_chrdev;
1295 	nvdimm_bus_major = rc;
1296 
1297 	rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
1298 	if (rc < 0)
1299 		goto err_dimm_chrdev;
1300 	nvdimm_major = rc;
1301 
1302 	nd_class = class_create(THIS_MODULE, "nd");
1303 	if (IS_ERR(nd_class)) {
1304 		rc = PTR_ERR(nd_class);
1305 		goto err_class;
1306 	}
1307 
1308 	rc = driver_register(&nd_bus_driver.drv);
1309 	if (rc)
1310 		goto err_nd_bus;
1311 
1312 	return 0;
1313 
1314  err_nd_bus:
1315 	class_destroy(nd_class);
1316  err_class:
1317 	unregister_chrdev(nvdimm_major, "dimmctl");
1318  err_dimm_chrdev:
1319 	unregister_chrdev(nvdimm_bus_major, "ndctl");
1320  err_bus_chrdev:
1321 	bus_unregister(&nvdimm_bus_type);
1322 
1323 	return rc;
1324 }
1325 
1326 void nvdimm_bus_exit(void)
1327 {
1328 	driver_unregister(&nd_bus_driver.drv);
1329 	class_destroy(nd_class);
1330 	unregister_chrdev(nvdimm_bus_major, "ndctl");
1331 	unregister_chrdev(nvdimm_major, "dimmctl");
1332 	bus_unregister(&nvdimm_bus_type);
1333 	ida_destroy(&nd_ida);
1334 }
1335