xref: /linux/drivers/nvdimm/bus.c (revision 9052e9c95d908d6c3d7570aadc8898e1d871c8bb)
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 void 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 }
127 
128 static void nvdimm_bus_shutdown(struct device *dev)
129 {
130 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
131 	struct nd_device_driver *nd_drv = NULL;
132 
133 	if (dev->driver)
134 		nd_drv = to_nd_device_driver(dev->driver);
135 
136 	if (nd_drv && nd_drv->shutdown) {
137 		nd_drv->shutdown(dev);
138 		dev_dbg(&nvdimm_bus->dev, "%s.shutdown(%s)\n",
139 				dev->driver->name, dev_name(dev));
140 	}
141 }
142 
143 void nd_device_notify(struct device *dev, enum nvdimm_event event)
144 {
145 	nd_device_lock(dev);
146 	if (dev->driver) {
147 		struct nd_device_driver *nd_drv;
148 
149 		nd_drv = to_nd_device_driver(dev->driver);
150 		if (nd_drv->notify)
151 			nd_drv->notify(dev, event);
152 	}
153 	nd_device_unlock(dev);
154 }
155 EXPORT_SYMBOL(nd_device_notify);
156 
157 void nvdimm_region_notify(struct nd_region *nd_region, enum nvdimm_event event)
158 {
159 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
160 
161 	if (!nvdimm_bus)
162 		return;
163 
164 	/* caller is responsible for holding a reference on the device */
165 	nd_device_notify(&nd_region->dev, event);
166 }
167 EXPORT_SYMBOL_GPL(nvdimm_region_notify);
168 
169 struct clear_badblocks_context {
170 	resource_size_t phys, cleared;
171 };
172 
173 static int nvdimm_clear_badblocks_region(struct device *dev, void *data)
174 {
175 	struct clear_badblocks_context *ctx = data;
176 	struct nd_region *nd_region;
177 	resource_size_t ndr_end;
178 	sector_t sector;
179 
180 	/* make sure device is a region */
181 	if (!is_memory(dev))
182 		return 0;
183 
184 	nd_region = to_nd_region(dev);
185 	ndr_end = nd_region->ndr_start + nd_region->ndr_size - 1;
186 
187 	/* make sure we are in the region */
188 	if (ctx->phys < nd_region->ndr_start
189 			|| (ctx->phys + ctx->cleared) > ndr_end)
190 		return 0;
191 
192 	sector = (ctx->phys - nd_region->ndr_start) / 512;
193 	badblocks_clear(&nd_region->bb, sector, ctx->cleared / 512);
194 
195 	if (nd_region->bb_state)
196 		sysfs_notify_dirent(nd_region->bb_state);
197 
198 	return 0;
199 }
200 
201 static void nvdimm_clear_badblocks_regions(struct nvdimm_bus *nvdimm_bus,
202 		phys_addr_t phys, u64 cleared)
203 {
204 	struct clear_badblocks_context ctx = {
205 		.phys = phys,
206 		.cleared = cleared,
207 	};
208 
209 	device_for_each_child(&nvdimm_bus->dev, &ctx,
210 			nvdimm_clear_badblocks_region);
211 }
212 
213 static void nvdimm_account_cleared_poison(struct nvdimm_bus *nvdimm_bus,
214 		phys_addr_t phys, u64 cleared)
215 {
216 	if (cleared > 0)
217 		badrange_forget(&nvdimm_bus->badrange, phys, cleared);
218 
219 	if (cleared > 0 && cleared / 512)
220 		nvdimm_clear_badblocks_regions(nvdimm_bus, phys, cleared);
221 }
222 
223 long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
224 		unsigned int len)
225 {
226 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
227 	struct nvdimm_bus_descriptor *nd_desc;
228 	struct nd_cmd_clear_error clear_err;
229 	struct nd_cmd_ars_cap ars_cap;
230 	u32 clear_err_unit, mask;
231 	unsigned int noio_flag;
232 	int cmd_rc, rc;
233 
234 	if (!nvdimm_bus)
235 		return -ENXIO;
236 
237 	nd_desc = nvdimm_bus->nd_desc;
238 	/*
239 	 * if ndctl does not exist, it's PMEM_LEGACY and
240 	 * we want to just pretend everything is handled.
241 	 */
242 	if (!nd_desc->ndctl)
243 		return len;
244 
245 	memset(&ars_cap, 0, sizeof(ars_cap));
246 	ars_cap.address = phys;
247 	ars_cap.length = len;
248 	noio_flag = memalloc_noio_save();
249 	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_CAP, &ars_cap,
250 			sizeof(ars_cap), &cmd_rc);
251 	memalloc_noio_restore(noio_flag);
252 	if (rc < 0)
253 		return rc;
254 	if (cmd_rc < 0)
255 		return cmd_rc;
256 	clear_err_unit = ars_cap.clear_err_unit;
257 	if (!clear_err_unit || !is_power_of_2(clear_err_unit))
258 		return -ENXIO;
259 
260 	mask = clear_err_unit - 1;
261 	if ((phys | len) & mask)
262 		return -ENXIO;
263 	memset(&clear_err, 0, sizeof(clear_err));
264 	clear_err.address = phys;
265 	clear_err.length = len;
266 	noio_flag = memalloc_noio_save();
267 	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_CLEAR_ERROR, &clear_err,
268 			sizeof(clear_err), &cmd_rc);
269 	memalloc_noio_restore(noio_flag);
270 	if (rc < 0)
271 		return rc;
272 	if (cmd_rc < 0)
273 		return cmd_rc;
274 
275 	nvdimm_account_cleared_poison(nvdimm_bus, phys, clear_err.cleared);
276 
277 	return clear_err.cleared;
278 }
279 EXPORT_SYMBOL_GPL(nvdimm_clear_poison);
280 
281 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv);
282 
283 static struct bus_type nvdimm_bus_type = {
284 	.name = "nd",
285 	.uevent = nvdimm_bus_uevent,
286 	.match = nvdimm_bus_match,
287 	.probe = nvdimm_bus_probe,
288 	.remove = nvdimm_bus_remove,
289 	.shutdown = nvdimm_bus_shutdown,
290 };
291 
292 static void nvdimm_bus_release(struct device *dev)
293 {
294 	struct nvdimm_bus *nvdimm_bus;
295 
296 	nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
297 	ida_simple_remove(&nd_ida, nvdimm_bus->id);
298 	kfree(nvdimm_bus);
299 }
300 
301 static const struct device_type nvdimm_bus_dev_type = {
302 	.release = nvdimm_bus_release,
303 	.groups = nvdimm_bus_attribute_groups,
304 };
305 
306 bool is_nvdimm_bus(struct device *dev)
307 {
308 	return dev->type == &nvdimm_bus_dev_type;
309 }
310 
311 struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
312 {
313 	struct device *dev;
314 
315 	for (dev = nd_dev; dev; dev = dev->parent)
316 		if (is_nvdimm_bus(dev))
317 			break;
318 	dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
319 	if (dev)
320 		return to_nvdimm_bus(dev);
321 	return NULL;
322 }
323 
324 struct nvdimm_bus *to_nvdimm_bus(struct device *dev)
325 {
326 	struct nvdimm_bus *nvdimm_bus;
327 
328 	nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
329 	WARN_ON(!is_nvdimm_bus(dev));
330 	return nvdimm_bus;
331 }
332 EXPORT_SYMBOL_GPL(to_nvdimm_bus);
333 
334 struct nvdimm_bus *nvdimm_to_bus(struct nvdimm *nvdimm)
335 {
336 	return to_nvdimm_bus(nvdimm->dev.parent);
337 }
338 EXPORT_SYMBOL_GPL(nvdimm_to_bus);
339 
340 struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
341 		struct nvdimm_bus_descriptor *nd_desc)
342 {
343 	struct nvdimm_bus *nvdimm_bus;
344 	int rc;
345 
346 	nvdimm_bus = kzalloc(sizeof(*nvdimm_bus), GFP_KERNEL);
347 	if (!nvdimm_bus)
348 		return NULL;
349 	INIT_LIST_HEAD(&nvdimm_bus->list);
350 	INIT_LIST_HEAD(&nvdimm_bus->mapping_list);
351 	init_waitqueue_head(&nvdimm_bus->wait);
352 	nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
353 	if (nvdimm_bus->id < 0) {
354 		kfree(nvdimm_bus);
355 		return NULL;
356 	}
357 	mutex_init(&nvdimm_bus->reconfig_mutex);
358 	badrange_init(&nvdimm_bus->badrange);
359 	nvdimm_bus->nd_desc = nd_desc;
360 	nvdimm_bus->dev.parent = parent;
361 	nvdimm_bus->dev.type = &nvdimm_bus_dev_type;
362 	nvdimm_bus->dev.groups = nd_desc->attr_groups;
363 	nvdimm_bus->dev.bus = &nvdimm_bus_type;
364 	nvdimm_bus->dev.of_node = nd_desc->of_node;
365 	device_initialize(&nvdimm_bus->dev);
366 	device_set_pm_not_required(&nvdimm_bus->dev);
367 	rc = dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
368 	if (rc)
369 		goto err;
370 
371 	rc = device_add(&nvdimm_bus->dev);
372 	if (rc) {
373 		dev_dbg(&nvdimm_bus->dev, "registration failed: %d\n", rc);
374 		goto err;
375 	}
376 
377 	return nvdimm_bus;
378  err:
379 	put_device(&nvdimm_bus->dev);
380 	return NULL;
381 }
382 EXPORT_SYMBOL_GPL(nvdimm_bus_register);
383 
384 void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
385 {
386 	if (!nvdimm_bus)
387 		return;
388 	device_unregister(&nvdimm_bus->dev);
389 }
390 EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);
391 
392 static int child_unregister(struct device *dev, void *data)
393 {
394 	/*
395 	 * the singular ndctl class device per bus needs to be
396 	 * "device_destroy"ed, so skip it here
397 	 *
398 	 * i.e. remove classless children
399 	 */
400 	if (dev->class)
401 		return 0;
402 
403 	if (is_nvdimm(dev))
404 		nvdimm_delete(to_nvdimm(dev));
405 	else
406 		nd_device_unregister(dev, ND_SYNC);
407 
408 	return 0;
409 }
410 
411 static void free_badrange_list(struct list_head *badrange_list)
412 {
413 	struct badrange_entry *bre, *next;
414 
415 	list_for_each_entry_safe(bre, next, badrange_list, list) {
416 		list_del(&bre->list);
417 		kfree(bre);
418 	}
419 	list_del_init(badrange_list);
420 }
421 
422 static void nd_bus_remove(struct device *dev)
423 {
424 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
425 
426 	mutex_lock(&nvdimm_bus_list_mutex);
427 	list_del_init(&nvdimm_bus->list);
428 	mutex_unlock(&nvdimm_bus_list_mutex);
429 
430 	wait_event(nvdimm_bus->wait,
431 			atomic_read(&nvdimm_bus->ioctl_active) == 0);
432 
433 	nd_synchronize();
434 	device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
435 
436 	spin_lock(&nvdimm_bus->badrange.lock);
437 	free_badrange_list(&nvdimm_bus->badrange.list);
438 	spin_unlock(&nvdimm_bus->badrange.lock);
439 
440 	nvdimm_bus_destroy_ndctl(nvdimm_bus);
441 }
442 
443 static int nd_bus_probe(struct device *dev)
444 {
445 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
446 	int rc;
447 
448 	rc = nvdimm_bus_create_ndctl(nvdimm_bus);
449 	if (rc)
450 		return rc;
451 
452 	mutex_lock(&nvdimm_bus_list_mutex);
453 	list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
454 	mutex_unlock(&nvdimm_bus_list_mutex);
455 
456 	/* enable bus provider attributes to look up their local context */
457 	dev_set_drvdata(dev, nvdimm_bus->nd_desc);
458 
459 	return 0;
460 }
461 
462 static struct nd_device_driver nd_bus_driver = {
463 	.probe = nd_bus_probe,
464 	.remove = nd_bus_remove,
465 	.drv = {
466 		.name = "nd_bus",
467 		.suppress_bind_attrs = true,
468 		.bus = &nvdimm_bus_type,
469 		.owner = THIS_MODULE,
470 		.mod_name = KBUILD_MODNAME,
471 	},
472 };
473 
474 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
475 {
476 	struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
477 
478 	if (is_nvdimm_bus(dev) && nd_drv == &nd_bus_driver)
479 		return true;
480 
481 	return !!test_bit(to_nd_device_type(dev), &nd_drv->type);
482 }
483 
484 static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
485 
486 void nd_synchronize(void)
487 {
488 	async_synchronize_full_domain(&nd_async_domain);
489 }
490 EXPORT_SYMBOL_GPL(nd_synchronize);
491 
492 static void nd_async_device_register(void *d, async_cookie_t cookie)
493 {
494 	struct device *dev = d;
495 
496 	if (device_add(dev) != 0) {
497 		dev_err(dev, "%s: failed\n", __func__);
498 		put_device(dev);
499 	}
500 	put_device(dev);
501 	if (dev->parent)
502 		put_device(dev->parent);
503 }
504 
505 static void nd_async_device_unregister(void *d, async_cookie_t cookie)
506 {
507 	struct device *dev = d;
508 
509 	/* flush bus operations before delete */
510 	nvdimm_bus_lock(dev);
511 	nvdimm_bus_unlock(dev);
512 
513 	device_unregister(dev);
514 	put_device(dev);
515 }
516 
517 void __nd_device_register(struct device *dev)
518 {
519 	if (!dev)
520 		return;
521 
522 	/*
523 	 * Ensure that region devices always have their NUMA node set as
524 	 * early as possible. This way we are able to make certain that
525 	 * any memory associated with the creation and the creation
526 	 * itself of the region is associated with the correct node.
527 	 */
528 	if (is_nd_region(dev))
529 		set_dev_node(dev, to_nd_region(dev)->numa_node);
530 
531 	dev->bus = &nvdimm_bus_type;
532 	device_set_pm_not_required(dev);
533 	if (dev->parent) {
534 		get_device(dev->parent);
535 		if (dev_to_node(dev) == NUMA_NO_NODE)
536 			set_dev_node(dev, dev_to_node(dev->parent));
537 	}
538 	get_device(dev);
539 
540 	async_schedule_dev_domain(nd_async_device_register, dev,
541 				  &nd_async_domain);
542 }
543 
544 void nd_device_register(struct device *dev)
545 {
546 	device_initialize(dev);
547 	__nd_device_register(dev);
548 }
549 EXPORT_SYMBOL(nd_device_register);
550 
551 void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
552 {
553 	bool killed;
554 
555 	switch (mode) {
556 	case ND_ASYNC:
557 		/*
558 		 * In the async case this is being triggered with the
559 		 * device lock held and the unregistration work needs to
560 		 * be moved out of line iff this is thread has won the
561 		 * race to schedule the deletion.
562 		 */
563 		if (!kill_device(dev))
564 			return;
565 
566 		get_device(dev);
567 		async_schedule_domain(nd_async_device_unregister, dev,
568 				&nd_async_domain);
569 		break;
570 	case ND_SYNC:
571 		/*
572 		 * In the sync case the device is being unregistered due
573 		 * to a state change of the parent. Claim the kill state
574 		 * to synchronize against other unregistration requests,
575 		 * or otherwise let the async path handle it if the
576 		 * unregistration was already queued.
577 		 */
578 		nd_device_lock(dev);
579 		killed = kill_device(dev);
580 		nd_device_unlock(dev);
581 
582 		if (!killed)
583 			return;
584 
585 		nd_synchronize();
586 		device_unregister(dev);
587 		break;
588 	}
589 }
590 EXPORT_SYMBOL(nd_device_unregister);
591 
592 /**
593  * __nd_driver_register() - register a region or a namespace driver
594  * @nd_drv: driver to register
595  * @owner: automatically set by nd_driver_register() macro
596  * @mod_name: automatically set by nd_driver_register() macro
597  */
598 int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
599 		const char *mod_name)
600 {
601 	struct device_driver *drv = &nd_drv->drv;
602 
603 	if (!nd_drv->type) {
604 		pr_debug("driver type bitmask not set (%ps)\n",
605 				__builtin_return_address(0));
606 		return -EINVAL;
607 	}
608 
609 	if (!nd_drv->probe) {
610 		pr_debug("%s ->probe() must be specified\n", mod_name);
611 		return -EINVAL;
612 	}
613 
614 	drv->bus = &nvdimm_bus_type;
615 	drv->owner = owner;
616 	drv->mod_name = mod_name;
617 
618 	return driver_register(drv);
619 }
620 EXPORT_SYMBOL(__nd_driver_register);
621 
622 void nvdimm_check_and_set_ro(struct gendisk *disk)
623 {
624 	struct device *dev = disk_to_dev(disk)->parent;
625 	struct nd_region *nd_region = to_nd_region(dev->parent);
626 	int disk_ro = get_disk_ro(disk);
627 
628 	/* catch the disk up with the region ro state */
629 	if (disk_ro == nd_region->ro)
630 		return;
631 
632 	dev_info(dev, "%s read-%s, marking %s read-%s\n",
633 		 dev_name(&nd_region->dev), nd_region->ro ? "only" : "write",
634 		 disk->disk_name, nd_region->ro ? "only" : "write");
635 	set_disk_ro(disk, nd_region->ro);
636 }
637 EXPORT_SYMBOL(nvdimm_check_and_set_ro);
638 
639 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
640 		char *buf)
641 {
642 	return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
643 			to_nd_device_type(dev));
644 }
645 static DEVICE_ATTR_RO(modalias);
646 
647 static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
648 		char *buf)
649 {
650 	return sprintf(buf, "%s\n", dev->type->name);
651 }
652 static DEVICE_ATTR_RO(devtype);
653 
654 static struct attribute *nd_device_attributes[] = {
655 	&dev_attr_modalias.attr,
656 	&dev_attr_devtype.attr,
657 	NULL,
658 };
659 
660 /*
661  * nd_device_attribute_group - generic attributes for all devices on an nd bus
662  */
663 const struct attribute_group nd_device_attribute_group = {
664 	.attrs = nd_device_attributes,
665 };
666 
667 static ssize_t numa_node_show(struct device *dev,
668 		struct device_attribute *attr, char *buf)
669 {
670 	return sprintf(buf, "%d\n", dev_to_node(dev));
671 }
672 static DEVICE_ATTR_RO(numa_node);
673 
674 static int nvdimm_dev_to_target_node(struct device *dev)
675 {
676 	struct device *parent = dev->parent;
677 	struct nd_region *nd_region = NULL;
678 
679 	if (is_nd_region(dev))
680 		nd_region = to_nd_region(dev);
681 	else if (parent && is_nd_region(parent))
682 		nd_region = to_nd_region(parent);
683 
684 	if (!nd_region)
685 		return NUMA_NO_NODE;
686 	return nd_region->target_node;
687 }
688 
689 static ssize_t target_node_show(struct device *dev,
690 		struct device_attribute *attr, char *buf)
691 {
692 	return sprintf(buf, "%d\n", nvdimm_dev_to_target_node(dev));
693 }
694 static DEVICE_ATTR_RO(target_node);
695 
696 static struct attribute *nd_numa_attributes[] = {
697 	&dev_attr_numa_node.attr,
698 	&dev_attr_target_node.attr,
699 	NULL,
700 };
701 
702 static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
703 		int n)
704 {
705 	struct device *dev = container_of(kobj, typeof(*dev), kobj);
706 
707 	if (!IS_ENABLED(CONFIG_NUMA))
708 		return 0;
709 
710 	if (a == &dev_attr_target_node.attr &&
711 			nvdimm_dev_to_target_node(dev) == NUMA_NO_NODE)
712 		return 0;
713 
714 	return a->mode;
715 }
716 
717 /*
718  * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
719  */
720 const struct attribute_group nd_numa_attribute_group = {
721 	.attrs = nd_numa_attributes,
722 	.is_visible = nd_numa_attr_visible,
723 };
724 
725 static void ndctl_release(struct device *dev)
726 {
727 	kfree(dev);
728 }
729 
730 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
731 {
732 	dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
733 	struct device *dev;
734 	int rc;
735 
736 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
737 	if (!dev)
738 		return -ENOMEM;
739 	device_initialize(dev);
740 	device_set_pm_not_required(dev);
741 	dev->class = nd_class;
742 	dev->parent = &nvdimm_bus->dev;
743 	dev->devt = devt;
744 	dev->release = ndctl_release;
745 	rc = dev_set_name(dev, "ndctl%d", nvdimm_bus->id);
746 	if (rc)
747 		goto err;
748 
749 	rc = device_add(dev);
750 	if (rc) {
751 		dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %d\n",
752 				nvdimm_bus->id, rc);
753 		goto err;
754 	}
755 	return 0;
756 
757 err:
758 	put_device(dev);
759 	return rc;
760 }
761 
762 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
763 {
764 	device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
765 }
766 
767 static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
768 	[ND_CMD_IMPLEMENTED] = { },
769 	[ND_CMD_SMART] = {
770 		.out_num = 2,
771 		.out_sizes = { 4, 128, },
772 	},
773 	[ND_CMD_SMART_THRESHOLD] = {
774 		.out_num = 2,
775 		.out_sizes = { 4, 8, },
776 	},
777 	[ND_CMD_DIMM_FLAGS] = {
778 		.out_num = 2,
779 		.out_sizes = { 4, 4 },
780 	},
781 	[ND_CMD_GET_CONFIG_SIZE] = {
782 		.out_num = 3,
783 		.out_sizes = { 4, 4, 4, },
784 	},
785 	[ND_CMD_GET_CONFIG_DATA] = {
786 		.in_num = 2,
787 		.in_sizes = { 4, 4, },
788 		.out_num = 2,
789 		.out_sizes = { 4, UINT_MAX, },
790 	},
791 	[ND_CMD_SET_CONFIG_DATA] = {
792 		.in_num = 3,
793 		.in_sizes = { 4, 4, UINT_MAX, },
794 		.out_num = 1,
795 		.out_sizes = { 4, },
796 	},
797 	[ND_CMD_VENDOR] = {
798 		.in_num = 3,
799 		.in_sizes = { 4, 4, UINT_MAX, },
800 		.out_num = 3,
801 		.out_sizes = { 4, 4, UINT_MAX, },
802 	},
803 	[ND_CMD_CALL] = {
804 		.in_num = 2,
805 		.in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
806 		.out_num = 1,
807 		.out_sizes = { UINT_MAX, },
808 	},
809 };
810 
811 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
812 {
813 	if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
814 		return &__nd_cmd_dimm_descs[cmd];
815 	return NULL;
816 }
817 EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
818 
819 static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
820 	[ND_CMD_IMPLEMENTED] = { },
821 	[ND_CMD_ARS_CAP] = {
822 		.in_num = 2,
823 		.in_sizes = { 8, 8, },
824 		.out_num = 4,
825 		.out_sizes = { 4, 4, 4, 4, },
826 	},
827 	[ND_CMD_ARS_START] = {
828 		.in_num = 5,
829 		.in_sizes = { 8, 8, 2, 1, 5, },
830 		.out_num = 2,
831 		.out_sizes = { 4, 4, },
832 	},
833 	[ND_CMD_ARS_STATUS] = {
834 		.out_num = 3,
835 		.out_sizes = { 4, 4, UINT_MAX, },
836 	},
837 	[ND_CMD_CLEAR_ERROR] = {
838 		.in_num = 2,
839 		.in_sizes = { 8, 8, },
840 		.out_num = 3,
841 		.out_sizes = { 4, 4, 8, },
842 	},
843 	[ND_CMD_CALL] = {
844 		.in_num = 2,
845 		.in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
846 		.out_num = 1,
847 		.out_sizes = { UINT_MAX, },
848 	},
849 };
850 
851 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
852 {
853 	if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
854 		return &__nd_cmd_bus_descs[cmd];
855 	return NULL;
856 }
857 EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
858 
859 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
860 		const struct nd_cmd_desc *desc, int idx, void *buf)
861 {
862 	if (idx >= desc->in_num)
863 		return UINT_MAX;
864 
865 	if (desc->in_sizes[idx] < UINT_MAX)
866 		return desc->in_sizes[idx];
867 
868 	if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
869 		struct nd_cmd_set_config_hdr *hdr = buf;
870 
871 		return hdr->in_length;
872 	} else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
873 		struct nd_cmd_vendor_hdr *hdr = buf;
874 
875 		return hdr->in_length;
876 	} else if (cmd == ND_CMD_CALL) {
877 		struct nd_cmd_pkg *pkg = buf;
878 
879 		return pkg->nd_size_in;
880 	}
881 
882 	return UINT_MAX;
883 }
884 EXPORT_SYMBOL_GPL(nd_cmd_in_size);
885 
886 u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
887 		const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
888 		const u32 *out_field, unsigned long remainder)
889 {
890 	if (idx >= desc->out_num)
891 		return UINT_MAX;
892 
893 	if (desc->out_sizes[idx] < UINT_MAX)
894 		return desc->out_sizes[idx];
895 
896 	if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
897 		return in_field[1];
898 	else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
899 		return out_field[1];
900 	else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 2) {
901 		/*
902 		 * Per table 9-276 ARS Data in ACPI 6.1, out_field[1] is
903 		 * "Size of Output Buffer in bytes, including this
904 		 * field."
905 		 */
906 		if (out_field[1] < 4)
907 			return 0;
908 		/*
909 		 * ACPI 6.1 is ambiguous if 'status' is included in the
910 		 * output size. If we encounter an output size that
911 		 * overshoots the remainder by 4 bytes, assume it was
912 		 * including 'status'.
913 		 */
914 		if (out_field[1] - 4 == remainder)
915 			return remainder;
916 		return out_field[1] - 8;
917 	} else if (cmd == ND_CMD_CALL) {
918 		struct nd_cmd_pkg *pkg = (struct nd_cmd_pkg *) in_field;
919 
920 		return pkg->nd_size_out;
921 	}
922 
923 
924 	return UINT_MAX;
925 }
926 EXPORT_SYMBOL_GPL(nd_cmd_out_size);
927 
928 void wait_nvdimm_bus_probe_idle(struct device *dev)
929 {
930 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
931 
932 	do {
933 		if (nvdimm_bus->probe_active == 0)
934 			break;
935 		nvdimm_bus_unlock(dev);
936 		nd_device_unlock(dev);
937 		wait_event(nvdimm_bus->wait,
938 				nvdimm_bus->probe_active == 0);
939 		nd_device_lock(dev);
940 		nvdimm_bus_lock(dev);
941 	} while (true);
942 }
943 
944 static int nd_pmem_forget_poison_check(struct device *dev, void *data)
945 {
946 	struct nd_cmd_clear_error *clear_err =
947 		(struct nd_cmd_clear_error *)data;
948 	struct nd_btt *nd_btt = is_nd_btt(dev) ? to_nd_btt(dev) : NULL;
949 	struct nd_pfn *nd_pfn = is_nd_pfn(dev) ? to_nd_pfn(dev) : NULL;
950 	struct nd_dax *nd_dax = is_nd_dax(dev) ? to_nd_dax(dev) : NULL;
951 	struct nd_namespace_common *ndns = NULL;
952 	struct nd_namespace_io *nsio;
953 	resource_size_t offset = 0, end_trunc = 0, start, end, pstart, pend;
954 
955 	if (nd_dax || !dev->driver)
956 		return 0;
957 
958 	start = clear_err->address;
959 	end = clear_err->address + clear_err->cleared - 1;
960 
961 	if (nd_btt || nd_pfn || nd_dax) {
962 		if (nd_btt)
963 			ndns = nd_btt->ndns;
964 		else if (nd_pfn)
965 			ndns = nd_pfn->ndns;
966 		else if (nd_dax)
967 			ndns = nd_dax->nd_pfn.ndns;
968 
969 		if (!ndns)
970 			return 0;
971 	} else
972 		ndns = to_ndns(dev);
973 
974 	nsio = to_nd_namespace_io(&ndns->dev);
975 	pstart = nsio->res.start + offset;
976 	pend = nsio->res.end - end_trunc;
977 
978 	if ((pstart >= start) && (pend <= end))
979 		return -EBUSY;
980 
981 	return 0;
982 
983 }
984 
985 static int nd_ns_forget_poison_check(struct device *dev, void *data)
986 {
987 	return device_for_each_child(dev, data, nd_pmem_forget_poison_check);
988 }
989 
990 /* set_config requires an idle interleave set */
991 static int nd_cmd_clear_to_send(struct nvdimm_bus *nvdimm_bus,
992 		struct nvdimm *nvdimm, unsigned int cmd, void *data)
993 {
994 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
995 
996 	/* ask the bus provider if it would like to block this request */
997 	if (nd_desc->clear_to_send) {
998 		int rc = nd_desc->clear_to_send(nd_desc, nvdimm, cmd, data);
999 
1000 		if (rc)
1001 			return rc;
1002 	}
1003 
1004 	/* require clear error to go through the pmem driver */
1005 	if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR)
1006 		return device_for_each_child(&nvdimm_bus->dev, data,
1007 				nd_ns_forget_poison_check);
1008 
1009 	if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
1010 		return 0;
1011 
1012 	/* prevent label manipulation while the kernel owns label updates */
1013 	wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);
1014 	if (atomic_read(&nvdimm->busy))
1015 		return -EBUSY;
1016 	return 0;
1017 }
1018 
1019 static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
1020 		int read_only, unsigned int ioctl_cmd, unsigned long arg)
1021 {
1022 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
1023 	const struct nd_cmd_desc *desc = NULL;
1024 	unsigned int cmd = _IOC_NR(ioctl_cmd);
1025 	struct device *dev = &nvdimm_bus->dev;
1026 	void __user *p = (void __user *) arg;
1027 	char *out_env = NULL, *in_env = NULL;
1028 	const char *cmd_name, *dimm_name;
1029 	u32 in_len = 0, out_len = 0;
1030 	unsigned int func = cmd;
1031 	unsigned long cmd_mask;
1032 	struct nd_cmd_pkg pkg;
1033 	int rc, i, cmd_rc;
1034 	void *buf = NULL;
1035 	u64 buf_len = 0;
1036 
1037 	if (nvdimm) {
1038 		desc = nd_cmd_dimm_desc(cmd);
1039 		cmd_name = nvdimm_cmd_name(cmd);
1040 		cmd_mask = nvdimm->cmd_mask;
1041 		dimm_name = dev_name(&nvdimm->dev);
1042 	} else {
1043 		desc = nd_cmd_bus_desc(cmd);
1044 		cmd_name = nvdimm_bus_cmd_name(cmd);
1045 		cmd_mask = nd_desc->cmd_mask;
1046 		dimm_name = "bus";
1047 	}
1048 
1049 	/* Validate command family support against bus declared support */
1050 	if (cmd == ND_CMD_CALL) {
1051 		unsigned long *mask;
1052 
1053 		if (copy_from_user(&pkg, p, sizeof(pkg)))
1054 			return -EFAULT;
1055 
1056 		if (nvdimm) {
1057 			if (pkg.nd_family > NVDIMM_FAMILY_MAX)
1058 				return -EINVAL;
1059 			mask = &nd_desc->dimm_family_mask;
1060 		} else {
1061 			if (pkg.nd_family > NVDIMM_BUS_FAMILY_MAX)
1062 				return -EINVAL;
1063 			mask = &nd_desc->bus_family_mask;
1064 		}
1065 
1066 		if (!test_bit(pkg.nd_family, mask))
1067 			return -EINVAL;
1068 	}
1069 
1070 	if (!desc ||
1071 	    (desc->out_num + desc->in_num == 0) ||
1072 	    cmd > ND_CMD_CALL ||
1073 	    !test_bit(cmd, &cmd_mask))
1074 		return -ENOTTY;
1075 
1076 	/* fail write commands (when read-only) */
1077 	if (read_only)
1078 		switch (cmd) {
1079 		case ND_CMD_VENDOR:
1080 		case ND_CMD_SET_CONFIG_DATA:
1081 		case ND_CMD_ARS_START:
1082 		case ND_CMD_CLEAR_ERROR:
1083 		case ND_CMD_CALL:
1084 			dev_dbg(dev, "'%s' command while read-only.\n",
1085 					nvdimm ? nvdimm_cmd_name(cmd)
1086 					: nvdimm_bus_cmd_name(cmd));
1087 			return -EPERM;
1088 		default:
1089 			break;
1090 		}
1091 
1092 	/* process an input envelope */
1093 	in_env = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
1094 	if (!in_env)
1095 		return -ENOMEM;
1096 	for (i = 0; i < desc->in_num; i++) {
1097 		u32 in_size, copy;
1098 
1099 		in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
1100 		if (in_size == UINT_MAX) {
1101 			dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
1102 					__func__, dimm_name, cmd_name, i);
1103 			rc = -ENXIO;
1104 			goto out;
1105 		}
1106 		if (in_len < ND_CMD_MAX_ENVELOPE)
1107 			copy = min_t(u32, ND_CMD_MAX_ENVELOPE - in_len, in_size);
1108 		else
1109 			copy = 0;
1110 		if (copy && copy_from_user(&in_env[in_len], p + in_len, copy)) {
1111 			rc = -EFAULT;
1112 			goto out;
1113 		}
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 	out_env = kzalloc(ND_CMD_MAX_ENVELOPE, GFP_KERNEL);
1126 	if (!out_env) {
1127 		rc = -ENOMEM;
1128 		goto out;
1129 	}
1130 
1131 	for (i = 0; i < desc->out_num; i++) {
1132 		u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
1133 				(u32 *) in_env, (u32 *) out_env, 0);
1134 		u32 copy;
1135 
1136 		if (out_size == UINT_MAX) {
1137 			dev_dbg(dev, "%s unknown output size cmd: %s field: %d\n",
1138 					dimm_name, cmd_name, i);
1139 			rc = -EFAULT;
1140 			goto out;
1141 		}
1142 		if (out_len < ND_CMD_MAX_ENVELOPE)
1143 			copy = min_t(u32, ND_CMD_MAX_ENVELOPE - out_len, out_size);
1144 		else
1145 			copy = 0;
1146 		if (copy && copy_from_user(&out_env[out_len],
1147 					p + in_len + out_len, copy)) {
1148 			rc = -EFAULT;
1149 			goto out;
1150 		}
1151 		out_len += out_size;
1152 	}
1153 
1154 	buf_len = (u64) out_len + (u64) in_len;
1155 	if (buf_len > ND_IOCTL_MAX_BUFLEN) {
1156 		dev_dbg(dev, "%s cmd: %s buf_len: %llu > %d\n", dimm_name,
1157 				cmd_name, buf_len, ND_IOCTL_MAX_BUFLEN);
1158 		rc = -EINVAL;
1159 		goto out;
1160 	}
1161 
1162 	buf = vmalloc(buf_len);
1163 	if (!buf) {
1164 		rc = -ENOMEM;
1165 		goto out;
1166 	}
1167 
1168 	if (copy_from_user(buf, p, buf_len)) {
1169 		rc = -EFAULT;
1170 		goto out;
1171 	}
1172 
1173 	nd_device_lock(dev);
1174 	nvdimm_bus_lock(dev);
1175 	rc = nd_cmd_clear_to_send(nvdimm_bus, nvdimm, func, buf);
1176 	if (rc)
1177 		goto out_unlock;
1178 
1179 	rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len, &cmd_rc);
1180 	if (rc < 0)
1181 		goto out_unlock;
1182 
1183 	if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR && cmd_rc >= 0) {
1184 		struct nd_cmd_clear_error *clear_err = buf;
1185 
1186 		nvdimm_account_cleared_poison(nvdimm_bus, clear_err->address,
1187 				clear_err->cleared);
1188 	}
1189 
1190 	if (copy_to_user(p, buf, buf_len))
1191 		rc = -EFAULT;
1192 
1193 out_unlock:
1194 	nvdimm_bus_unlock(dev);
1195 	nd_device_unlock(dev);
1196 out:
1197 	kfree(in_env);
1198 	kfree(out_env);
1199 	vfree(buf);
1200 	return rc;
1201 }
1202 
1203 enum nd_ioctl_mode {
1204 	BUS_IOCTL,
1205 	DIMM_IOCTL,
1206 };
1207 
1208 static int match_dimm(struct device *dev, void *data)
1209 {
1210 	long id = (long) data;
1211 
1212 	if (is_nvdimm(dev)) {
1213 		struct nvdimm *nvdimm = to_nvdimm(dev);
1214 
1215 		return nvdimm->id == id;
1216 	}
1217 
1218 	return 0;
1219 }
1220 
1221 static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1222 		enum nd_ioctl_mode mode)
1223 
1224 {
1225 	struct nvdimm_bus *nvdimm_bus, *found = NULL;
1226 	long id = (long) file->private_data;
1227 	struct nvdimm *nvdimm = NULL;
1228 	int rc, ro;
1229 
1230 	ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);
1231 	mutex_lock(&nvdimm_bus_list_mutex);
1232 	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
1233 		if (mode == DIMM_IOCTL) {
1234 			struct device *dev;
1235 
1236 			dev = device_find_child(&nvdimm_bus->dev,
1237 					file->private_data, match_dimm);
1238 			if (!dev)
1239 				continue;
1240 			nvdimm = to_nvdimm(dev);
1241 			found = nvdimm_bus;
1242 		} else if (nvdimm_bus->id == id) {
1243 			found = nvdimm_bus;
1244 		}
1245 
1246 		if (found) {
1247 			atomic_inc(&nvdimm_bus->ioctl_active);
1248 			break;
1249 		}
1250 	}
1251 	mutex_unlock(&nvdimm_bus_list_mutex);
1252 
1253 	if (!found)
1254 		return -ENXIO;
1255 
1256 	nvdimm_bus = found;
1257 	rc = __nd_ioctl(nvdimm_bus, nvdimm, ro, cmd, arg);
1258 
1259 	if (nvdimm)
1260 		put_device(&nvdimm->dev);
1261 	if (atomic_dec_and_test(&nvdimm_bus->ioctl_active))
1262 		wake_up(&nvdimm_bus->wait);
1263 
1264 	return rc;
1265 }
1266 
1267 static long bus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1268 {
1269 	return nd_ioctl(file, cmd, arg, BUS_IOCTL);
1270 }
1271 
1272 static long dimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1273 {
1274 	return nd_ioctl(file, cmd, arg, DIMM_IOCTL);
1275 }
1276 
1277 static int nd_open(struct inode *inode, struct file *file)
1278 {
1279 	long minor = iminor(inode);
1280 
1281 	file->private_data = (void *) minor;
1282 	return 0;
1283 }
1284 
1285 static const struct file_operations nvdimm_bus_fops = {
1286 	.owner = THIS_MODULE,
1287 	.open = nd_open,
1288 	.unlocked_ioctl = bus_ioctl,
1289 	.compat_ioctl = compat_ptr_ioctl,
1290 	.llseek = noop_llseek,
1291 };
1292 
1293 static const struct file_operations nvdimm_fops = {
1294 	.owner = THIS_MODULE,
1295 	.open = nd_open,
1296 	.unlocked_ioctl = dimm_ioctl,
1297 	.compat_ioctl = compat_ptr_ioctl,
1298 	.llseek = noop_llseek,
1299 };
1300 
1301 int __init nvdimm_bus_init(void)
1302 {
1303 	int rc;
1304 
1305 	rc = bus_register(&nvdimm_bus_type);
1306 	if (rc)
1307 		return rc;
1308 
1309 	rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
1310 	if (rc < 0)
1311 		goto err_bus_chrdev;
1312 	nvdimm_bus_major = rc;
1313 
1314 	rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
1315 	if (rc < 0)
1316 		goto err_dimm_chrdev;
1317 	nvdimm_major = rc;
1318 
1319 	nd_class = class_create(THIS_MODULE, "nd");
1320 	if (IS_ERR(nd_class)) {
1321 		rc = PTR_ERR(nd_class);
1322 		goto err_class;
1323 	}
1324 
1325 	rc = driver_register(&nd_bus_driver.drv);
1326 	if (rc)
1327 		goto err_nd_bus;
1328 
1329 	return 0;
1330 
1331  err_nd_bus:
1332 	class_destroy(nd_class);
1333  err_class:
1334 	unregister_chrdev(nvdimm_major, "dimmctl");
1335  err_dimm_chrdev:
1336 	unregister_chrdev(nvdimm_bus_major, "ndctl");
1337  err_bus_chrdev:
1338 	bus_unregister(&nvdimm_bus_type);
1339 
1340 	return rc;
1341 }
1342 
1343 void nvdimm_bus_exit(void)
1344 {
1345 	driver_unregister(&nd_bus_driver.drv);
1346 	class_destroy(nd_class);
1347 	unregister_chrdev(nvdimm_bus_major, "ndctl");
1348 	unregister_chrdev(nvdimm_major, "dimmctl");
1349 	bus_unregister(&nvdimm_bus_type);
1350 	ida_destroy(&nd_ida);
1351 }
1352