xref: /linux/drivers/nvdimm/bus.c (revision 59024954a1e7e26b62680e1f2b5725249a6c09f7)
1 /*
2  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of version 2 of the GNU General Public License as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  */
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/vmalloc.h>
15 #include <linux/uaccess.h>
16 #include <linux/module.h>
17 #include <linux/blkdev.h>
18 #include <linux/fcntl.h>
19 #include <linux/async.h>
20 #include <linux/genhd.h>
21 #include <linux/ndctl.h>
22 #include <linux/sched.h>
23 #include <linux/slab.h>
24 #include <linux/fs.h>
25 #include <linux/io.h>
26 #include <linux/mm.h>
27 #include <linux/nd.h>
28 #include "nd-core.h"
29 #include "nd.h"
30 
31 int nvdimm_major;
32 static int nvdimm_bus_major;
33 static struct class *nd_class;
34 static DEFINE_IDA(nd_ida);
35 
36 static int to_nd_device_type(struct device *dev)
37 {
38 	if (is_nvdimm(dev))
39 		return ND_DEVICE_DIMM;
40 	else if (is_nd_pmem(dev))
41 		return ND_DEVICE_REGION_PMEM;
42 	else if (is_nd_blk(dev))
43 		return ND_DEVICE_REGION_BLK;
44 	else if (is_nd_dax(dev))
45 		return ND_DEVICE_DAX_PMEM;
46 	else if (is_nd_pmem(dev->parent) || is_nd_blk(dev->parent))
47 		return nd_region_to_nstype(to_nd_region(dev->parent));
48 
49 	return 0;
50 }
51 
52 static int nvdimm_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
53 {
54 	/*
55 	 * Ensure that region devices always have their numa node set as
56 	 * early as possible.
57 	 */
58 	if (is_nd_pmem(dev) || is_nd_blk(dev))
59 		set_dev_node(dev, to_nd_region(dev)->numa_node);
60 	return add_uevent_var(env, "MODALIAS=" ND_DEVICE_MODALIAS_FMT,
61 			to_nd_device_type(dev));
62 }
63 
64 static struct module *to_bus_provider(struct device *dev)
65 {
66 	/* pin bus providers while regions are enabled */
67 	if (is_nd_pmem(dev) || is_nd_blk(dev)) {
68 		struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
69 
70 		return nvdimm_bus->nd_desc->module;
71 	}
72 	return NULL;
73 }
74 
75 static void nvdimm_bus_probe_start(struct nvdimm_bus *nvdimm_bus)
76 {
77 	nvdimm_bus_lock(&nvdimm_bus->dev);
78 	nvdimm_bus->probe_active++;
79 	nvdimm_bus_unlock(&nvdimm_bus->dev);
80 }
81 
82 static void nvdimm_bus_probe_end(struct nvdimm_bus *nvdimm_bus)
83 {
84 	nvdimm_bus_lock(&nvdimm_bus->dev);
85 	if (--nvdimm_bus->probe_active == 0)
86 		wake_up(&nvdimm_bus->probe_wait);
87 	nvdimm_bus_unlock(&nvdimm_bus->dev);
88 }
89 
90 static int nvdimm_bus_probe(struct device *dev)
91 {
92 	struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
93 	struct module *provider = to_bus_provider(dev);
94 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
95 	int rc;
96 
97 	if (!try_module_get(provider))
98 		return -ENXIO;
99 
100 	nvdimm_bus_probe_start(nvdimm_bus);
101 	rc = nd_drv->probe(dev);
102 	if (rc == 0)
103 		nd_region_probe_success(nvdimm_bus, dev);
104 	else
105 		nd_region_disable(nvdimm_bus, dev);
106 	nvdimm_bus_probe_end(nvdimm_bus);
107 
108 	dev_dbg(&nvdimm_bus->dev, "%s.probe(%s) = %d\n", dev->driver->name,
109 			dev_name(dev), rc);
110 
111 	if (rc != 0)
112 		module_put(provider);
113 	return rc;
114 }
115 
116 static int nvdimm_bus_remove(struct device *dev)
117 {
118 	struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
119 	struct module *provider = to_bus_provider(dev);
120 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
121 	int rc = 0;
122 
123 	if (nd_drv->remove)
124 		rc = nd_drv->remove(dev);
125 	nd_region_disable(nvdimm_bus, dev);
126 
127 	dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d\n", dev->driver->name,
128 			dev_name(dev), rc);
129 	module_put(provider);
130 	return rc;
131 }
132 
133 static void nvdimm_bus_shutdown(struct device *dev)
134 {
135 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
136 	struct nd_device_driver *nd_drv = NULL;
137 
138 	if (dev->driver)
139 		nd_drv = to_nd_device_driver(dev->driver);
140 
141 	if (nd_drv && nd_drv->shutdown) {
142 		nd_drv->shutdown(dev);
143 		dev_dbg(&nvdimm_bus->dev, "%s.shutdown(%s)\n",
144 				dev->driver->name, dev_name(dev));
145 	}
146 }
147 
148 void nd_device_notify(struct device *dev, enum nvdimm_event event)
149 {
150 	device_lock(dev);
151 	if (dev->driver) {
152 		struct nd_device_driver *nd_drv;
153 
154 		nd_drv = to_nd_device_driver(dev->driver);
155 		if (nd_drv->notify)
156 			nd_drv->notify(dev, event);
157 	}
158 	device_unlock(dev);
159 }
160 EXPORT_SYMBOL(nd_device_notify);
161 
162 void nvdimm_region_notify(struct nd_region *nd_region, enum nvdimm_event event)
163 {
164 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
165 
166 	if (!nvdimm_bus)
167 		return;
168 
169 	/* caller is responsible for holding a reference on the device */
170 	nd_device_notify(&nd_region->dev, event);
171 }
172 EXPORT_SYMBOL_GPL(nvdimm_region_notify);
173 
174 long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
175 		unsigned int len)
176 {
177 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
178 	struct nvdimm_bus_descriptor *nd_desc;
179 	struct nd_cmd_clear_error clear_err;
180 	struct nd_cmd_ars_cap ars_cap;
181 	u32 clear_err_unit, mask;
182 	int cmd_rc, rc;
183 
184 	if (!nvdimm_bus)
185 		return -ENXIO;
186 
187 	nd_desc = nvdimm_bus->nd_desc;
188 	/*
189 	 * if ndctl does not exist, it's PMEM_LEGACY and
190 	 * we want to just pretend everything is handled.
191 	 */
192 	if (!nd_desc->ndctl)
193 		return len;
194 
195 	memset(&ars_cap, 0, sizeof(ars_cap));
196 	ars_cap.address = phys;
197 	ars_cap.length = len;
198 	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_CAP, &ars_cap,
199 			sizeof(ars_cap), &cmd_rc);
200 	if (rc < 0)
201 		return rc;
202 	if (cmd_rc < 0)
203 		return cmd_rc;
204 	clear_err_unit = ars_cap.clear_err_unit;
205 	if (!clear_err_unit || !is_power_of_2(clear_err_unit))
206 		return -ENXIO;
207 
208 	mask = clear_err_unit - 1;
209 	if ((phys | len) & mask)
210 		return -ENXIO;
211 	memset(&clear_err, 0, sizeof(clear_err));
212 	clear_err.address = phys;
213 	clear_err.length = len;
214 	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_CLEAR_ERROR, &clear_err,
215 			sizeof(clear_err), &cmd_rc);
216 	if (rc < 0)
217 		return rc;
218 	if (cmd_rc < 0)
219 		return cmd_rc;
220 	return clear_err.cleared;
221 }
222 EXPORT_SYMBOL_GPL(nvdimm_clear_poison);
223 
224 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv);
225 
226 static struct bus_type nvdimm_bus_type = {
227 	.name = "nd",
228 	.uevent = nvdimm_bus_uevent,
229 	.match = nvdimm_bus_match,
230 	.probe = nvdimm_bus_probe,
231 	.remove = nvdimm_bus_remove,
232 	.shutdown = nvdimm_bus_shutdown,
233 };
234 
235 static void nvdimm_bus_release(struct device *dev)
236 {
237 	struct nvdimm_bus *nvdimm_bus;
238 
239 	nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
240 	ida_simple_remove(&nd_ida, nvdimm_bus->id);
241 	kfree(nvdimm_bus);
242 }
243 
244 static bool is_nvdimm_bus(struct device *dev)
245 {
246 	return dev->release == nvdimm_bus_release;
247 }
248 
249 struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
250 {
251 	struct device *dev;
252 
253 	for (dev = nd_dev; dev; dev = dev->parent)
254 		if (is_nvdimm_bus(dev))
255 			break;
256 	dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
257 	if (dev)
258 		return to_nvdimm_bus(dev);
259 	return NULL;
260 }
261 
262 struct nvdimm_bus *to_nvdimm_bus(struct device *dev)
263 {
264 	struct nvdimm_bus *nvdimm_bus;
265 
266 	nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
267 	WARN_ON(!is_nvdimm_bus(dev));
268 	return nvdimm_bus;
269 }
270 EXPORT_SYMBOL_GPL(to_nvdimm_bus);
271 
272 struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
273 		struct nvdimm_bus_descriptor *nd_desc)
274 {
275 	struct nvdimm_bus *nvdimm_bus;
276 	int rc;
277 
278 	nvdimm_bus = kzalloc(sizeof(*nvdimm_bus), GFP_KERNEL);
279 	if (!nvdimm_bus)
280 		return NULL;
281 	INIT_LIST_HEAD(&nvdimm_bus->list);
282 	INIT_LIST_HEAD(&nvdimm_bus->mapping_list);
283 	INIT_LIST_HEAD(&nvdimm_bus->poison_list);
284 	init_waitqueue_head(&nvdimm_bus->probe_wait);
285 	nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
286 	mutex_init(&nvdimm_bus->reconfig_mutex);
287 	if (nvdimm_bus->id < 0) {
288 		kfree(nvdimm_bus);
289 		return NULL;
290 	}
291 	nvdimm_bus->nd_desc = nd_desc;
292 	nvdimm_bus->dev.parent = parent;
293 	nvdimm_bus->dev.release = nvdimm_bus_release;
294 	nvdimm_bus->dev.groups = nd_desc->attr_groups;
295 	nvdimm_bus->dev.bus = &nvdimm_bus_type;
296 	dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
297 	rc = device_register(&nvdimm_bus->dev);
298 	if (rc) {
299 		dev_dbg(&nvdimm_bus->dev, "registration failed: %d\n", rc);
300 		goto err;
301 	}
302 
303 	return nvdimm_bus;
304  err:
305 	put_device(&nvdimm_bus->dev);
306 	return NULL;
307 }
308 EXPORT_SYMBOL_GPL(nvdimm_bus_register);
309 
310 void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
311 {
312 	if (!nvdimm_bus)
313 		return;
314 	device_unregister(&nvdimm_bus->dev);
315 }
316 EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);
317 
318 static int child_unregister(struct device *dev, void *data)
319 {
320 	/*
321 	 * the singular ndctl class device per bus needs to be
322 	 * "device_destroy"ed, so skip it here
323 	 *
324 	 * i.e. remove classless children
325 	 */
326 	if (dev->class)
327 		/* pass */;
328 	else
329 		nd_device_unregister(dev, ND_SYNC);
330 	return 0;
331 }
332 
333 static void free_poison_list(struct list_head *poison_list)
334 {
335 	struct nd_poison *pl, *next;
336 
337 	list_for_each_entry_safe(pl, next, poison_list, list) {
338 		list_del(&pl->list);
339 		kfree(pl);
340 	}
341 	list_del_init(poison_list);
342 }
343 
344 static int nd_bus_remove(struct device *dev)
345 {
346 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
347 
348 	mutex_lock(&nvdimm_bus_list_mutex);
349 	list_del_init(&nvdimm_bus->list);
350 	mutex_unlock(&nvdimm_bus_list_mutex);
351 
352 	nd_synchronize();
353 	device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
354 
355 	nvdimm_bus_lock(&nvdimm_bus->dev);
356 	free_poison_list(&nvdimm_bus->poison_list);
357 	nvdimm_bus_unlock(&nvdimm_bus->dev);
358 
359 	nvdimm_bus_destroy_ndctl(nvdimm_bus);
360 
361 	return 0;
362 }
363 
364 static int nd_bus_probe(struct device *dev)
365 {
366 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
367 	int rc;
368 
369 	rc = nvdimm_bus_create_ndctl(nvdimm_bus);
370 	if (rc)
371 		return rc;
372 
373 	mutex_lock(&nvdimm_bus_list_mutex);
374 	list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
375 	mutex_unlock(&nvdimm_bus_list_mutex);
376 
377 	/* enable bus provider attributes to look up their local context */
378 	dev_set_drvdata(dev, nvdimm_bus->nd_desc);
379 
380 	return 0;
381 }
382 
383 static struct nd_device_driver nd_bus_driver = {
384 	.probe = nd_bus_probe,
385 	.remove = nd_bus_remove,
386 	.drv = {
387 		.name = "nd_bus",
388 		.suppress_bind_attrs = true,
389 		.bus = &nvdimm_bus_type,
390 		.owner = THIS_MODULE,
391 		.mod_name = KBUILD_MODNAME,
392 	},
393 };
394 
395 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
396 {
397 	struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
398 
399 	if (is_nvdimm_bus(dev) && nd_drv == &nd_bus_driver)
400 		return true;
401 
402 	return !!test_bit(to_nd_device_type(dev), &nd_drv->type);
403 }
404 
405 static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
406 
407 void nd_synchronize(void)
408 {
409 	async_synchronize_full_domain(&nd_async_domain);
410 }
411 EXPORT_SYMBOL_GPL(nd_synchronize);
412 
413 static void nd_async_device_register(void *d, async_cookie_t cookie)
414 {
415 	struct device *dev = d;
416 
417 	if (device_add(dev) != 0) {
418 		dev_err(dev, "%s: failed\n", __func__);
419 		put_device(dev);
420 	}
421 	put_device(dev);
422 }
423 
424 static void nd_async_device_unregister(void *d, async_cookie_t cookie)
425 {
426 	struct device *dev = d;
427 
428 	/* flush bus operations before delete */
429 	nvdimm_bus_lock(dev);
430 	nvdimm_bus_unlock(dev);
431 
432 	device_unregister(dev);
433 	put_device(dev);
434 }
435 
436 void __nd_device_register(struct device *dev)
437 {
438 	if (!dev)
439 		return;
440 	dev->bus = &nvdimm_bus_type;
441 	get_device(dev);
442 	async_schedule_domain(nd_async_device_register, dev,
443 			&nd_async_domain);
444 }
445 
446 void nd_device_register(struct device *dev)
447 {
448 	device_initialize(dev);
449 	__nd_device_register(dev);
450 }
451 EXPORT_SYMBOL(nd_device_register);
452 
453 void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
454 {
455 	switch (mode) {
456 	case ND_ASYNC:
457 		get_device(dev);
458 		async_schedule_domain(nd_async_device_unregister, dev,
459 				&nd_async_domain);
460 		break;
461 	case ND_SYNC:
462 		nd_synchronize();
463 		device_unregister(dev);
464 		break;
465 	}
466 }
467 EXPORT_SYMBOL(nd_device_unregister);
468 
469 /**
470  * __nd_driver_register() - register a region or a namespace driver
471  * @nd_drv: driver to register
472  * @owner: automatically set by nd_driver_register() macro
473  * @mod_name: automatically set by nd_driver_register() macro
474  */
475 int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
476 		const char *mod_name)
477 {
478 	struct device_driver *drv = &nd_drv->drv;
479 
480 	if (!nd_drv->type) {
481 		pr_debug("driver type bitmask not set (%pf)\n",
482 				__builtin_return_address(0));
483 		return -EINVAL;
484 	}
485 
486 	if (!nd_drv->probe) {
487 		pr_debug("%s ->probe() must be specified\n", mod_name);
488 		return -EINVAL;
489 	}
490 
491 	drv->bus = &nvdimm_bus_type;
492 	drv->owner = owner;
493 	drv->mod_name = mod_name;
494 
495 	return driver_register(drv);
496 }
497 EXPORT_SYMBOL(__nd_driver_register);
498 
499 int nvdimm_revalidate_disk(struct gendisk *disk)
500 {
501 	struct device *dev = disk_to_dev(disk)->parent;
502 	struct nd_region *nd_region = to_nd_region(dev->parent);
503 	const char *pol = nd_region->ro ? "only" : "write";
504 
505 	if (nd_region->ro == get_disk_ro(disk))
506 		return 0;
507 
508 	dev_info(dev, "%s read-%s, marking %s read-%s\n",
509 			dev_name(&nd_region->dev), pol, disk->disk_name, pol);
510 	set_disk_ro(disk, nd_region->ro);
511 
512 	return 0;
513 
514 }
515 EXPORT_SYMBOL(nvdimm_revalidate_disk);
516 
517 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
518 		char *buf)
519 {
520 	return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
521 			to_nd_device_type(dev));
522 }
523 static DEVICE_ATTR_RO(modalias);
524 
525 static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
526 		char *buf)
527 {
528 	return sprintf(buf, "%s\n", dev->type->name);
529 }
530 static DEVICE_ATTR_RO(devtype);
531 
532 static struct attribute *nd_device_attributes[] = {
533 	&dev_attr_modalias.attr,
534 	&dev_attr_devtype.attr,
535 	NULL,
536 };
537 
538 /**
539  * nd_device_attribute_group - generic attributes for all devices on an nd bus
540  */
541 struct attribute_group nd_device_attribute_group = {
542 	.attrs = nd_device_attributes,
543 };
544 EXPORT_SYMBOL_GPL(nd_device_attribute_group);
545 
546 static ssize_t numa_node_show(struct device *dev,
547 		struct device_attribute *attr, char *buf)
548 {
549 	return sprintf(buf, "%d\n", dev_to_node(dev));
550 }
551 static DEVICE_ATTR_RO(numa_node);
552 
553 static struct attribute *nd_numa_attributes[] = {
554 	&dev_attr_numa_node.attr,
555 	NULL,
556 };
557 
558 static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
559 		int n)
560 {
561 	if (!IS_ENABLED(CONFIG_NUMA))
562 		return 0;
563 
564 	return a->mode;
565 }
566 
567 /**
568  * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
569  */
570 struct attribute_group nd_numa_attribute_group = {
571 	.attrs = nd_numa_attributes,
572 	.is_visible = nd_numa_attr_visible,
573 };
574 EXPORT_SYMBOL_GPL(nd_numa_attribute_group);
575 
576 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
577 {
578 	dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
579 	struct device *dev;
580 
581 	dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
582 			"ndctl%d", nvdimm_bus->id);
583 
584 	if (IS_ERR(dev))
585 		dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld\n",
586 				nvdimm_bus->id, PTR_ERR(dev));
587 	return PTR_ERR_OR_ZERO(dev);
588 }
589 
590 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
591 {
592 	device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
593 }
594 
595 static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
596 	[ND_CMD_IMPLEMENTED] = { },
597 	[ND_CMD_SMART] = {
598 		.out_num = 2,
599 		.out_sizes = { 4, 128, },
600 	},
601 	[ND_CMD_SMART_THRESHOLD] = {
602 		.out_num = 2,
603 		.out_sizes = { 4, 8, },
604 	},
605 	[ND_CMD_DIMM_FLAGS] = {
606 		.out_num = 2,
607 		.out_sizes = { 4, 4 },
608 	},
609 	[ND_CMD_GET_CONFIG_SIZE] = {
610 		.out_num = 3,
611 		.out_sizes = { 4, 4, 4, },
612 	},
613 	[ND_CMD_GET_CONFIG_DATA] = {
614 		.in_num = 2,
615 		.in_sizes = { 4, 4, },
616 		.out_num = 2,
617 		.out_sizes = { 4, UINT_MAX, },
618 	},
619 	[ND_CMD_SET_CONFIG_DATA] = {
620 		.in_num = 3,
621 		.in_sizes = { 4, 4, UINT_MAX, },
622 		.out_num = 1,
623 		.out_sizes = { 4, },
624 	},
625 	[ND_CMD_VENDOR] = {
626 		.in_num = 3,
627 		.in_sizes = { 4, 4, UINT_MAX, },
628 		.out_num = 3,
629 		.out_sizes = { 4, 4, UINT_MAX, },
630 	},
631 	[ND_CMD_CALL] = {
632 		.in_num = 2,
633 		.in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
634 		.out_num = 1,
635 		.out_sizes = { UINT_MAX, },
636 	},
637 };
638 
639 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
640 {
641 	if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
642 		return &__nd_cmd_dimm_descs[cmd];
643 	return NULL;
644 }
645 EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
646 
647 static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
648 	[ND_CMD_IMPLEMENTED] = { },
649 	[ND_CMD_ARS_CAP] = {
650 		.in_num = 2,
651 		.in_sizes = { 8, 8, },
652 		.out_num = 4,
653 		.out_sizes = { 4, 4, 4, 4, },
654 	},
655 	[ND_CMD_ARS_START] = {
656 		.in_num = 5,
657 		.in_sizes = { 8, 8, 2, 1, 5, },
658 		.out_num = 2,
659 		.out_sizes = { 4, 4, },
660 	},
661 	[ND_CMD_ARS_STATUS] = {
662 		.out_num = 3,
663 		.out_sizes = { 4, 4, UINT_MAX, },
664 	},
665 	[ND_CMD_CLEAR_ERROR] = {
666 		.in_num = 2,
667 		.in_sizes = { 8, 8, },
668 		.out_num = 3,
669 		.out_sizes = { 4, 4, 8, },
670 	},
671 	[ND_CMD_CALL] = {
672 		.in_num = 2,
673 		.in_sizes = { sizeof(struct nd_cmd_pkg), UINT_MAX, },
674 		.out_num = 1,
675 		.out_sizes = { UINT_MAX, },
676 	},
677 };
678 
679 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
680 {
681 	if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
682 		return &__nd_cmd_bus_descs[cmd];
683 	return NULL;
684 }
685 EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
686 
687 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
688 		const struct nd_cmd_desc *desc, int idx, void *buf)
689 {
690 	if (idx >= desc->in_num)
691 		return UINT_MAX;
692 
693 	if (desc->in_sizes[idx] < UINT_MAX)
694 		return desc->in_sizes[idx];
695 
696 	if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
697 		struct nd_cmd_set_config_hdr *hdr = buf;
698 
699 		return hdr->in_length;
700 	} else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
701 		struct nd_cmd_vendor_hdr *hdr = buf;
702 
703 		return hdr->in_length;
704 	} else if (cmd == ND_CMD_CALL) {
705 		struct nd_cmd_pkg *pkg = buf;
706 
707 		return pkg->nd_size_in;
708 	}
709 
710 	return UINT_MAX;
711 }
712 EXPORT_SYMBOL_GPL(nd_cmd_in_size);
713 
714 u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
715 		const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
716 		const u32 *out_field)
717 {
718 	if (idx >= desc->out_num)
719 		return UINT_MAX;
720 
721 	if (desc->out_sizes[idx] < UINT_MAX)
722 		return desc->out_sizes[idx];
723 
724 	if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
725 		return in_field[1];
726 	else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
727 		return out_field[1];
728 	else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 2)
729 		return out_field[1] - 8;
730 	else if (cmd == ND_CMD_CALL) {
731 		struct nd_cmd_pkg *pkg = (struct nd_cmd_pkg *) in_field;
732 
733 		return pkg->nd_size_out;
734 	}
735 
736 
737 	return UINT_MAX;
738 }
739 EXPORT_SYMBOL_GPL(nd_cmd_out_size);
740 
741 void wait_nvdimm_bus_probe_idle(struct device *dev)
742 {
743 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
744 
745 	do {
746 		if (nvdimm_bus->probe_active == 0)
747 			break;
748 		nvdimm_bus_unlock(&nvdimm_bus->dev);
749 		wait_event(nvdimm_bus->probe_wait,
750 				nvdimm_bus->probe_active == 0);
751 		nvdimm_bus_lock(&nvdimm_bus->dev);
752 	} while (true);
753 }
754 
755 static int pmem_active(struct device *dev, void *data)
756 {
757 	if (is_nd_pmem(dev) && dev->driver)
758 		return -EBUSY;
759 	return 0;
760 }
761 
762 /* set_config requires an idle interleave set */
763 static int nd_cmd_clear_to_send(struct nvdimm_bus *nvdimm_bus,
764 		struct nvdimm *nvdimm, unsigned int cmd)
765 {
766 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
767 
768 	/* ask the bus provider if it would like to block this request */
769 	if (nd_desc->clear_to_send) {
770 		int rc = nd_desc->clear_to_send(nd_desc, nvdimm, cmd);
771 
772 		if (rc)
773 			return rc;
774 	}
775 
776 	/* require clear error to go through the pmem driver */
777 	if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR)
778 		return device_for_each_child(&nvdimm_bus->dev, NULL,
779 				pmem_active);
780 
781 	if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
782 		return 0;
783 
784 	/* prevent label manipulation while the kernel owns label updates */
785 	wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);
786 	if (atomic_read(&nvdimm->busy))
787 		return -EBUSY;
788 	return 0;
789 }
790 
791 static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
792 		int read_only, unsigned int ioctl_cmd, unsigned long arg)
793 {
794 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
795 	size_t buf_len = 0, in_len = 0, out_len = 0;
796 	static char out_env[ND_CMD_MAX_ENVELOPE];
797 	static char in_env[ND_CMD_MAX_ENVELOPE];
798 	const struct nd_cmd_desc *desc = NULL;
799 	unsigned int cmd = _IOC_NR(ioctl_cmd);
800 	void __user *p = (void __user *) arg;
801 	struct device *dev = &nvdimm_bus->dev;
802 	struct nd_cmd_pkg pkg;
803 	const char *cmd_name, *dimm_name;
804 	unsigned long cmd_mask;
805 	void *buf;
806 	int rc, i;
807 
808 	if (nvdimm) {
809 		desc = nd_cmd_dimm_desc(cmd);
810 		cmd_name = nvdimm_cmd_name(cmd);
811 		cmd_mask = nvdimm->cmd_mask;
812 		dimm_name = dev_name(&nvdimm->dev);
813 	} else {
814 		desc = nd_cmd_bus_desc(cmd);
815 		cmd_name = nvdimm_bus_cmd_name(cmd);
816 		cmd_mask = nd_desc->cmd_mask;
817 		dimm_name = "bus";
818 	}
819 
820 	if (cmd == ND_CMD_CALL) {
821 		if (copy_from_user(&pkg, p, sizeof(pkg)))
822 			return -EFAULT;
823 	}
824 
825 	if (!desc || (desc->out_num + desc->in_num == 0) ||
826 			!test_bit(cmd, &cmd_mask))
827 		return -ENOTTY;
828 
829 	/* fail write commands (when read-only) */
830 	if (read_only)
831 		switch (cmd) {
832 		case ND_CMD_VENDOR:
833 		case ND_CMD_SET_CONFIG_DATA:
834 		case ND_CMD_ARS_START:
835 		case ND_CMD_CLEAR_ERROR:
836 		case ND_CMD_CALL:
837 			dev_dbg(&nvdimm_bus->dev, "'%s' command while read-only.\n",
838 					nvdimm ? nvdimm_cmd_name(cmd)
839 					: nvdimm_bus_cmd_name(cmd));
840 			return -EPERM;
841 		default:
842 			break;
843 		}
844 
845 	/* process an input envelope */
846 	for (i = 0; i < desc->in_num; i++) {
847 		u32 in_size, copy;
848 
849 		in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
850 		if (in_size == UINT_MAX) {
851 			dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
852 					__func__, dimm_name, cmd_name, i);
853 			return -ENXIO;
854 		}
855 		if (in_len < sizeof(in_env))
856 			copy = min_t(u32, sizeof(in_env) - in_len, in_size);
857 		else
858 			copy = 0;
859 		if (copy && copy_from_user(&in_env[in_len], p + in_len, copy))
860 			return -EFAULT;
861 		in_len += in_size;
862 	}
863 
864 	if (cmd == ND_CMD_CALL) {
865 		dev_dbg(dev, "%s:%s, idx: %llu, in: %zu, out: %zu, len %zu\n",
866 				__func__, dimm_name, pkg.nd_command,
867 				in_len, out_len, buf_len);
868 
869 		for (i = 0; i < ARRAY_SIZE(pkg.nd_reserved2); i++)
870 			if (pkg.nd_reserved2[i])
871 				return -EINVAL;
872 	}
873 
874 	/* process an output envelope */
875 	for (i = 0; i < desc->out_num; i++) {
876 		u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
877 				(u32 *) in_env, (u32 *) out_env);
878 		u32 copy;
879 
880 		if (out_size == UINT_MAX) {
881 			dev_dbg(dev, "%s:%s unknown output size cmd: %s field: %d\n",
882 					__func__, dimm_name, cmd_name, i);
883 			return -EFAULT;
884 		}
885 		if (out_len < sizeof(out_env))
886 			copy = min_t(u32, sizeof(out_env) - out_len, out_size);
887 		else
888 			copy = 0;
889 		if (copy && copy_from_user(&out_env[out_len],
890 					p + in_len + out_len, copy))
891 			return -EFAULT;
892 		out_len += out_size;
893 	}
894 
895 	buf_len = out_len + in_len;
896 	if (buf_len > ND_IOCTL_MAX_BUFLEN) {
897 		dev_dbg(dev, "%s:%s cmd: %s buf_len: %zu > %d\n", __func__,
898 				dimm_name, cmd_name, buf_len,
899 				ND_IOCTL_MAX_BUFLEN);
900 		return -EINVAL;
901 	}
902 
903 	buf = vmalloc(buf_len);
904 	if (!buf)
905 		return -ENOMEM;
906 
907 	if (copy_from_user(buf, p, buf_len)) {
908 		rc = -EFAULT;
909 		goto out;
910 	}
911 
912 	nvdimm_bus_lock(&nvdimm_bus->dev);
913 	rc = nd_cmd_clear_to_send(nvdimm_bus, nvdimm, cmd);
914 	if (rc)
915 		goto out_unlock;
916 
917 	rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len, NULL);
918 	if (rc < 0)
919 		goto out_unlock;
920 	if (copy_to_user(p, buf, buf_len))
921 		rc = -EFAULT;
922  out_unlock:
923 	nvdimm_bus_unlock(&nvdimm_bus->dev);
924  out:
925 	vfree(buf);
926 	return rc;
927 }
928 
929 static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
930 {
931 	long id = (long) file->private_data;
932 	int rc = -ENXIO, ro;
933 	struct nvdimm_bus *nvdimm_bus;
934 
935 	ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);
936 	mutex_lock(&nvdimm_bus_list_mutex);
937 	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
938 		if (nvdimm_bus->id == id) {
939 			rc = __nd_ioctl(nvdimm_bus, NULL, ro, cmd, arg);
940 			break;
941 		}
942 	}
943 	mutex_unlock(&nvdimm_bus_list_mutex);
944 
945 	return rc;
946 }
947 
948 static int match_dimm(struct device *dev, void *data)
949 {
950 	long id = (long) data;
951 
952 	if (is_nvdimm(dev)) {
953 		struct nvdimm *nvdimm = to_nvdimm(dev);
954 
955 		return nvdimm->id == id;
956 	}
957 
958 	return 0;
959 }
960 
961 static long nvdimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
962 {
963 	int rc = -ENXIO, ro;
964 	struct nvdimm_bus *nvdimm_bus;
965 
966 	ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);
967 	mutex_lock(&nvdimm_bus_list_mutex);
968 	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
969 		struct device *dev = device_find_child(&nvdimm_bus->dev,
970 				file->private_data, match_dimm);
971 		struct nvdimm *nvdimm;
972 
973 		if (!dev)
974 			continue;
975 
976 		nvdimm = to_nvdimm(dev);
977 		rc = __nd_ioctl(nvdimm_bus, nvdimm, ro, cmd, arg);
978 		put_device(dev);
979 		break;
980 	}
981 	mutex_unlock(&nvdimm_bus_list_mutex);
982 
983 	return rc;
984 }
985 
986 static int nd_open(struct inode *inode, struct file *file)
987 {
988 	long minor = iminor(inode);
989 
990 	file->private_data = (void *) minor;
991 	return 0;
992 }
993 
994 static const struct file_operations nvdimm_bus_fops = {
995 	.owner = THIS_MODULE,
996 	.open = nd_open,
997 	.unlocked_ioctl = nd_ioctl,
998 	.compat_ioctl = nd_ioctl,
999 	.llseek = noop_llseek,
1000 };
1001 
1002 static const struct file_operations nvdimm_fops = {
1003 	.owner = THIS_MODULE,
1004 	.open = nd_open,
1005 	.unlocked_ioctl = nvdimm_ioctl,
1006 	.compat_ioctl = nvdimm_ioctl,
1007 	.llseek = noop_llseek,
1008 };
1009 
1010 int __init nvdimm_bus_init(void)
1011 {
1012 	int rc;
1013 
1014 	BUILD_BUG_ON(sizeof(struct nd_smart_payload) != 128);
1015 	BUILD_BUG_ON(sizeof(struct nd_smart_threshold_payload) != 8);
1016 
1017 	rc = bus_register(&nvdimm_bus_type);
1018 	if (rc)
1019 		return rc;
1020 
1021 	rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
1022 	if (rc < 0)
1023 		goto err_bus_chrdev;
1024 	nvdimm_bus_major = rc;
1025 
1026 	rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
1027 	if (rc < 0)
1028 		goto err_dimm_chrdev;
1029 	nvdimm_major = rc;
1030 
1031 	nd_class = class_create(THIS_MODULE, "nd");
1032 	if (IS_ERR(nd_class)) {
1033 		rc = PTR_ERR(nd_class);
1034 		goto err_class;
1035 	}
1036 
1037 	rc = driver_register(&nd_bus_driver.drv);
1038 	if (rc)
1039 		goto err_nd_bus;
1040 
1041 	return 0;
1042 
1043  err_nd_bus:
1044 	class_destroy(nd_class);
1045  err_class:
1046 	unregister_chrdev(nvdimm_major, "dimmctl");
1047  err_dimm_chrdev:
1048 	unregister_chrdev(nvdimm_bus_major, "ndctl");
1049  err_bus_chrdev:
1050 	bus_unregister(&nvdimm_bus_type);
1051 
1052 	return rc;
1053 }
1054 
1055 void nvdimm_bus_exit(void)
1056 {
1057 	driver_unregister(&nd_bus_driver.drv);
1058 	class_destroy(nd_class);
1059 	unregister_chrdev(nvdimm_bus_major, "ndctl");
1060 	unregister_chrdev(nvdimm_major, "dimmctl");
1061 	bus_unregister(&nvdimm_bus_type);
1062 	ida_destroy(&nd_ida);
1063 }
1064