xref: /linux/drivers/nvdimm/region_devs.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 #include <linux/scatterlist.h>
14 #include <linux/highmem.h>
15 #include <linux/sched.h>
16 #include <linux/slab.h>
17 #include <linux/sort.h>
18 #include <linux/io.h>
19 #include <linux/nd.h>
20 #include "nd-core.h"
21 #include "nd.h"
22 
23 static DEFINE_IDA(region_ida);
24 
25 static void nd_region_release(struct device *dev)
26 {
27 	struct nd_region *nd_region = to_nd_region(dev);
28 	u16 i;
29 
30 	for (i = 0; i < nd_region->ndr_mappings; i++) {
31 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
32 		struct nvdimm *nvdimm = nd_mapping->nvdimm;
33 
34 		put_device(&nvdimm->dev);
35 	}
36 	free_percpu(nd_region->lane);
37 	ida_simple_remove(&region_ida, nd_region->id);
38 	if (is_nd_blk(dev))
39 		kfree(to_nd_blk_region(dev));
40 	else
41 		kfree(nd_region);
42 }
43 
44 static struct device_type nd_blk_device_type = {
45 	.name = "nd_blk",
46 	.release = nd_region_release,
47 };
48 
49 static struct device_type nd_pmem_device_type = {
50 	.name = "nd_pmem",
51 	.release = nd_region_release,
52 };
53 
54 static struct device_type nd_volatile_device_type = {
55 	.name = "nd_volatile",
56 	.release = nd_region_release,
57 };
58 
59 bool is_nd_pmem(struct device *dev)
60 {
61 	return dev ? dev->type == &nd_pmem_device_type : false;
62 }
63 
64 bool is_nd_blk(struct device *dev)
65 {
66 	return dev ? dev->type == &nd_blk_device_type : false;
67 }
68 
69 struct nd_region *to_nd_region(struct device *dev)
70 {
71 	struct nd_region *nd_region = container_of(dev, struct nd_region, dev);
72 
73 	WARN_ON(dev->type->release != nd_region_release);
74 	return nd_region;
75 }
76 EXPORT_SYMBOL_GPL(to_nd_region);
77 
78 struct nd_blk_region *to_nd_blk_region(struct device *dev)
79 {
80 	struct nd_region *nd_region = to_nd_region(dev);
81 
82 	WARN_ON(!is_nd_blk(dev));
83 	return container_of(nd_region, struct nd_blk_region, nd_region);
84 }
85 EXPORT_SYMBOL_GPL(to_nd_blk_region);
86 
87 void *nd_region_provider_data(struct nd_region *nd_region)
88 {
89 	return nd_region->provider_data;
90 }
91 EXPORT_SYMBOL_GPL(nd_region_provider_data);
92 
93 void *nd_blk_region_provider_data(struct nd_blk_region *ndbr)
94 {
95 	return ndbr->blk_provider_data;
96 }
97 EXPORT_SYMBOL_GPL(nd_blk_region_provider_data);
98 
99 void nd_blk_region_set_provider_data(struct nd_blk_region *ndbr, void *data)
100 {
101 	ndbr->blk_provider_data = data;
102 }
103 EXPORT_SYMBOL_GPL(nd_blk_region_set_provider_data);
104 
105 /**
106  * nd_region_to_nstype() - region to an integer namespace type
107  * @nd_region: region-device to interrogate
108  *
109  * This is the 'nstype' attribute of a region as well, an input to the
110  * MODALIAS for namespace devices, and bit number for a nvdimm_bus to match
111  * namespace devices with namespace drivers.
112  */
113 int nd_region_to_nstype(struct nd_region *nd_region)
114 {
115 	if (is_nd_pmem(&nd_region->dev)) {
116 		u16 i, alias;
117 
118 		for (i = 0, alias = 0; i < nd_region->ndr_mappings; i++) {
119 			struct nd_mapping *nd_mapping = &nd_region->mapping[i];
120 			struct nvdimm *nvdimm = nd_mapping->nvdimm;
121 
122 			if (nvdimm->flags & NDD_ALIASING)
123 				alias++;
124 		}
125 		if (alias)
126 			return ND_DEVICE_NAMESPACE_PMEM;
127 		else
128 			return ND_DEVICE_NAMESPACE_IO;
129 	} else if (is_nd_blk(&nd_region->dev)) {
130 		return ND_DEVICE_NAMESPACE_BLK;
131 	}
132 
133 	return 0;
134 }
135 EXPORT_SYMBOL(nd_region_to_nstype);
136 
137 static int is_uuid_busy(struct device *dev, void *data)
138 {
139 	struct nd_region *nd_region = to_nd_region(dev->parent);
140 	u8 *uuid = data;
141 
142 	switch (nd_region_to_nstype(nd_region)) {
143 	case ND_DEVICE_NAMESPACE_PMEM: {
144 		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);
145 
146 		if (!nspm->uuid)
147 			break;
148 		if (memcmp(uuid, nspm->uuid, NSLABEL_UUID_LEN) == 0)
149 			return -EBUSY;
150 		break;
151 	}
152 	case ND_DEVICE_NAMESPACE_BLK: {
153 		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);
154 
155 		if (!nsblk->uuid)
156 			break;
157 		if (memcmp(uuid, nsblk->uuid, NSLABEL_UUID_LEN) == 0)
158 			return -EBUSY;
159 		break;
160 	}
161 	default:
162 		break;
163 	}
164 
165 	return 0;
166 }
167 
168 static int is_namespace_uuid_busy(struct device *dev, void *data)
169 {
170 	if (is_nd_pmem(dev) || is_nd_blk(dev))
171 		return device_for_each_child(dev, data, is_uuid_busy);
172 	return 0;
173 }
174 
175 /**
176  * nd_is_uuid_unique - verify that no other namespace has @uuid
177  * @dev: any device on a nvdimm_bus
178  * @uuid: uuid to check
179  */
180 bool nd_is_uuid_unique(struct device *dev, u8 *uuid)
181 {
182 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
183 
184 	if (!nvdimm_bus)
185 		return false;
186 	WARN_ON_ONCE(!is_nvdimm_bus_locked(&nvdimm_bus->dev));
187 	if (device_for_each_child(&nvdimm_bus->dev, uuid,
188 				is_namespace_uuid_busy) != 0)
189 		return false;
190 	return true;
191 }
192 
193 static ssize_t size_show(struct device *dev,
194 		struct device_attribute *attr, char *buf)
195 {
196 	struct nd_region *nd_region = to_nd_region(dev);
197 	unsigned long long size = 0;
198 
199 	if (is_nd_pmem(dev)) {
200 		size = nd_region->ndr_size;
201 	} else if (nd_region->ndr_mappings == 1) {
202 		struct nd_mapping *nd_mapping = &nd_region->mapping[0];
203 
204 		size = nd_mapping->size;
205 	}
206 
207 	return sprintf(buf, "%llu\n", size);
208 }
209 static DEVICE_ATTR_RO(size);
210 
211 static ssize_t mappings_show(struct device *dev,
212 		struct device_attribute *attr, char *buf)
213 {
214 	struct nd_region *nd_region = to_nd_region(dev);
215 
216 	return sprintf(buf, "%d\n", nd_region->ndr_mappings);
217 }
218 static DEVICE_ATTR_RO(mappings);
219 
220 static ssize_t nstype_show(struct device *dev,
221 		struct device_attribute *attr, char *buf)
222 {
223 	struct nd_region *nd_region = to_nd_region(dev);
224 
225 	return sprintf(buf, "%d\n", nd_region_to_nstype(nd_region));
226 }
227 static DEVICE_ATTR_RO(nstype);
228 
229 static ssize_t set_cookie_show(struct device *dev,
230 		struct device_attribute *attr, char *buf)
231 {
232 	struct nd_region *nd_region = to_nd_region(dev);
233 	struct nd_interleave_set *nd_set = nd_region->nd_set;
234 
235 	if (is_nd_pmem(dev) && nd_set)
236 		/* pass, should be precluded by region_visible */;
237 	else
238 		return -ENXIO;
239 
240 	return sprintf(buf, "%#llx\n", nd_set->cookie);
241 }
242 static DEVICE_ATTR_RO(set_cookie);
243 
244 resource_size_t nd_region_available_dpa(struct nd_region *nd_region)
245 {
246 	resource_size_t blk_max_overlap = 0, available, overlap;
247 	int i;
248 
249 	WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
250 
251  retry:
252 	available = 0;
253 	overlap = blk_max_overlap;
254 	for (i = 0; i < nd_region->ndr_mappings; i++) {
255 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
256 		struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
257 
258 		/* if a dimm is disabled the available capacity is zero */
259 		if (!ndd)
260 			return 0;
261 
262 		if (is_nd_pmem(&nd_region->dev)) {
263 			available += nd_pmem_available_dpa(nd_region,
264 					nd_mapping, &overlap);
265 			if (overlap > blk_max_overlap) {
266 				blk_max_overlap = overlap;
267 				goto retry;
268 			}
269 		} else if (is_nd_blk(&nd_region->dev)) {
270 			available += nd_blk_available_dpa(nd_mapping);
271 		}
272 	}
273 
274 	return available;
275 }
276 
277 static ssize_t available_size_show(struct device *dev,
278 		struct device_attribute *attr, char *buf)
279 {
280 	struct nd_region *nd_region = to_nd_region(dev);
281 	unsigned long long available = 0;
282 
283 	/*
284 	 * Flush in-flight updates and grab a snapshot of the available
285 	 * size.  Of course, this value is potentially invalidated the
286 	 * memory nvdimm_bus_lock() is dropped, but that's userspace's
287 	 * problem to not race itself.
288 	 */
289 	nvdimm_bus_lock(dev);
290 	wait_nvdimm_bus_probe_idle(dev);
291 	available = nd_region_available_dpa(nd_region);
292 	nvdimm_bus_unlock(dev);
293 
294 	return sprintf(buf, "%llu\n", available);
295 }
296 static DEVICE_ATTR_RO(available_size);
297 
298 static ssize_t init_namespaces_show(struct device *dev,
299 		struct device_attribute *attr, char *buf)
300 {
301 	struct nd_region_namespaces *num_ns = dev_get_drvdata(dev);
302 	ssize_t rc;
303 
304 	nvdimm_bus_lock(dev);
305 	if (num_ns)
306 		rc = sprintf(buf, "%d/%d\n", num_ns->active, num_ns->count);
307 	else
308 		rc = -ENXIO;
309 	nvdimm_bus_unlock(dev);
310 
311 	return rc;
312 }
313 static DEVICE_ATTR_RO(init_namespaces);
314 
315 static ssize_t namespace_seed_show(struct device *dev,
316 		struct device_attribute *attr, char *buf)
317 {
318 	struct nd_region *nd_region = to_nd_region(dev);
319 	ssize_t rc;
320 
321 	nvdimm_bus_lock(dev);
322 	if (nd_region->ns_seed)
323 		rc = sprintf(buf, "%s\n", dev_name(nd_region->ns_seed));
324 	else
325 		rc = sprintf(buf, "\n");
326 	nvdimm_bus_unlock(dev);
327 	return rc;
328 }
329 static DEVICE_ATTR_RO(namespace_seed);
330 
331 static ssize_t btt_seed_show(struct device *dev,
332 		struct device_attribute *attr, char *buf)
333 {
334 	struct nd_region *nd_region = to_nd_region(dev);
335 	ssize_t rc;
336 
337 	nvdimm_bus_lock(dev);
338 	if (nd_region->btt_seed)
339 		rc = sprintf(buf, "%s\n", dev_name(nd_region->btt_seed));
340 	else
341 		rc = sprintf(buf, "\n");
342 	nvdimm_bus_unlock(dev);
343 
344 	return rc;
345 }
346 static DEVICE_ATTR_RO(btt_seed);
347 
348 static ssize_t pfn_seed_show(struct device *dev,
349 		struct device_attribute *attr, char *buf)
350 {
351 	struct nd_region *nd_region = to_nd_region(dev);
352 	ssize_t rc;
353 
354 	nvdimm_bus_lock(dev);
355 	if (nd_region->pfn_seed)
356 		rc = sprintf(buf, "%s\n", dev_name(nd_region->pfn_seed));
357 	else
358 		rc = sprintf(buf, "\n");
359 	nvdimm_bus_unlock(dev);
360 
361 	return rc;
362 }
363 static DEVICE_ATTR_RO(pfn_seed);
364 
365 static ssize_t read_only_show(struct device *dev,
366 		struct device_attribute *attr, char *buf)
367 {
368 	struct nd_region *nd_region = to_nd_region(dev);
369 
370 	return sprintf(buf, "%d\n", nd_region->ro);
371 }
372 
373 static ssize_t read_only_store(struct device *dev,
374 		struct device_attribute *attr, const char *buf, size_t len)
375 {
376 	bool ro;
377 	int rc = strtobool(buf, &ro);
378 	struct nd_region *nd_region = to_nd_region(dev);
379 
380 	if (rc)
381 		return rc;
382 
383 	nd_region->ro = ro;
384 	return len;
385 }
386 static DEVICE_ATTR_RW(read_only);
387 
388 static struct attribute *nd_region_attributes[] = {
389 	&dev_attr_size.attr,
390 	&dev_attr_nstype.attr,
391 	&dev_attr_mappings.attr,
392 	&dev_attr_btt_seed.attr,
393 	&dev_attr_pfn_seed.attr,
394 	&dev_attr_read_only.attr,
395 	&dev_attr_set_cookie.attr,
396 	&dev_attr_available_size.attr,
397 	&dev_attr_namespace_seed.attr,
398 	&dev_attr_init_namespaces.attr,
399 	NULL,
400 };
401 
402 static umode_t region_visible(struct kobject *kobj, struct attribute *a, int n)
403 {
404 	struct device *dev = container_of(kobj, typeof(*dev), kobj);
405 	struct nd_region *nd_region = to_nd_region(dev);
406 	struct nd_interleave_set *nd_set = nd_region->nd_set;
407 	int type = nd_region_to_nstype(nd_region);
408 
409 	if (a != &dev_attr_set_cookie.attr
410 			&& a != &dev_attr_available_size.attr)
411 		return a->mode;
412 
413 	if ((type == ND_DEVICE_NAMESPACE_PMEM
414 				|| type == ND_DEVICE_NAMESPACE_BLK)
415 			&& a == &dev_attr_available_size.attr)
416 		return a->mode;
417 	else if (is_nd_pmem(dev) && nd_set)
418 		return a->mode;
419 
420 	return 0;
421 }
422 
423 struct attribute_group nd_region_attribute_group = {
424 	.attrs = nd_region_attributes,
425 	.is_visible = region_visible,
426 };
427 EXPORT_SYMBOL_GPL(nd_region_attribute_group);
428 
429 u64 nd_region_interleave_set_cookie(struct nd_region *nd_region)
430 {
431 	struct nd_interleave_set *nd_set = nd_region->nd_set;
432 
433 	if (nd_set)
434 		return nd_set->cookie;
435 	return 0;
436 }
437 
438 /*
439  * Upon successful probe/remove, take/release a reference on the
440  * associated interleave set (if present), and plant new btt + namespace
441  * seeds.  Also, on the removal of a BLK region, notify the provider to
442  * disable the region.
443  */
444 static void nd_region_notify_driver_action(struct nvdimm_bus *nvdimm_bus,
445 		struct device *dev, bool probe)
446 {
447 	struct nd_region *nd_region;
448 
449 	if (!probe && (is_nd_pmem(dev) || is_nd_blk(dev))) {
450 		int i;
451 
452 		nd_region = to_nd_region(dev);
453 		for (i = 0; i < nd_region->ndr_mappings; i++) {
454 			struct nd_mapping *nd_mapping = &nd_region->mapping[i];
455 			struct nvdimm_drvdata *ndd = nd_mapping->ndd;
456 			struct nvdimm *nvdimm = nd_mapping->nvdimm;
457 
458 			kfree(nd_mapping->labels);
459 			nd_mapping->labels = NULL;
460 			put_ndd(ndd);
461 			nd_mapping->ndd = NULL;
462 			if (ndd)
463 				atomic_dec(&nvdimm->busy);
464 		}
465 
466 		if (is_nd_pmem(dev))
467 			return;
468 
469 		to_nd_blk_region(dev)->disable(nvdimm_bus, dev);
470 	}
471 	if (dev->parent && is_nd_blk(dev->parent) && probe) {
472 		nd_region = to_nd_region(dev->parent);
473 		nvdimm_bus_lock(dev);
474 		if (nd_region->ns_seed == dev)
475 			nd_region_create_blk_seed(nd_region);
476 		nvdimm_bus_unlock(dev);
477 	}
478 	if (is_nd_btt(dev) && probe) {
479 		struct nd_btt *nd_btt = to_nd_btt(dev);
480 
481 		nd_region = to_nd_region(dev->parent);
482 		nvdimm_bus_lock(dev);
483 		if (nd_region->btt_seed == dev)
484 			nd_region_create_btt_seed(nd_region);
485 		if (nd_region->ns_seed == &nd_btt->ndns->dev &&
486 				is_nd_blk(dev->parent))
487 			nd_region_create_blk_seed(nd_region);
488 		nvdimm_bus_unlock(dev);
489 	}
490 }
491 
492 void nd_region_probe_success(struct nvdimm_bus *nvdimm_bus, struct device *dev)
493 {
494 	nd_region_notify_driver_action(nvdimm_bus, dev, true);
495 }
496 
497 void nd_region_disable(struct nvdimm_bus *nvdimm_bus, struct device *dev)
498 {
499 	nd_region_notify_driver_action(nvdimm_bus, dev, false);
500 }
501 
502 static ssize_t mappingN(struct device *dev, char *buf, int n)
503 {
504 	struct nd_region *nd_region = to_nd_region(dev);
505 	struct nd_mapping *nd_mapping;
506 	struct nvdimm *nvdimm;
507 
508 	if (n >= nd_region->ndr_mappings)
509 		return -ENXIO;
510 	nd_mapping = &nd_region->mapping[n];
511 	nvdimm = nd_mapping->nvdimm;
512 
513 	return sprintf(buf, "%s,%llu,%llu\n", dev_name(&nvdimm->dev),
514 			nd_mapping->start, nd_mapping->size);
515 }
516 
517 #define REGION_MAPPING(idx) \
518 static ssize_t mapping##idx##_show(struct device *dev,		\
519 		struct device_attribute *attr, char *buf)	\
520 {								\
521 	return mappingN(dev, buf, idx);				\
522 }								\
523 static DEVICE_ATTR_RO(mapping##idx)
524 
525 /*
526  * 32 should be enough for a while, even in the presence of socket
527  * interleave a 32-way interleave set is a degenerate case.
528  */
529 REGION_MAPPING(0);
530 REGION_MAPPING(1);
531 REGION_MAPPING(2);
532 REGION_MAPPING(3);
533 REGION_MAPPING(4);
534 REGION_MAPPING(5);
535 REGION_MAPPING(6);
536 REGION_MAPPING(7);
537 REGION_MAPPING(8);
538 REGION_MAPPING(9);
539 REGION_MAPPING(10);
540 REGION_MAPPING(11);
541 REGION_MAPPING(12);
542 REGION_MAPPING(13);
543 REGION_MAPPING(14);
544 REGION_MAPPING(15);
545 REGION_MAPPING(16);
546 REGION_MAPPING(17);
547 REGION_MAPPING(18);
548 REGION_MAPPING(19);
549 REGION_MAPPING(20);
550 REGION_MAPPING(21);
551 REGION_MAPPING(22);
552 REGION_MAPPING(23);
553 REGION_MAPPING(24);
554 REGION_MAPPING(25);
555 REGION_MAPPING(26);
556 REGION_MAPPING(27);
557 REGION_MAPPING(28);
558 REGION_MAPPING(29);
559 REGION_MAPPING(30);
560 REGION_MAPPING(31);
561 
562 static umode_t mapping_visible(struct kobject *kobj, struct attribute *a, int n)
563 {
564 	struct device *dev = container_of(kobj, struct device, kobj);
565 	struct nd_region *nd_region = to_nd_region(dev);
566 
567 	if (n < nd_region->ndr_mappings)
568 		return a->mode;
569 	return 0;
570 }
571 
572 static struct attribute *mapping_attributes[] = {
573 	&dev_attr_mapping0.attr,
574 	&dev_attr_mapping1.attr,
575 	&dev_attr_mapping2.attr,
576 	&dev_attr_mapping3.attr,
577 	&dev_attr_mapping4.attr,
578 	&dev_attr_mapping5.attr,
579 	&dev_attr_mapping6.attr,
580 	&dev_attr_mapping7.attr,
581 	&dev_attr_mapping8.attr,
582 	&dev_attr_mapping9.attr,
583 	&dev_attr_mapping10.attr,
584 	&dev_attr_mapping11.attr,
585 	&dev_attr_mapping12.attr,
586 	&dev_attr_mapping13.attr,
587 	&dev_attr_mapping14.attr,
588 	&dev_attr_mapping15.attr,
589 	&dev_attr_mapping16.attr,
590 	&dev_attr_mapping17.attr,
591 	&dev_attr_mapping18.attr,
592 	&dev_attr_mapping19.attr,
593 	&dev_attr_mapping20.attr,
594 	&dev_attr_mapping21.attr,
595 	&dev_attr_mapping22.attr,
596 	&dev_attr_mapping23.attr,
597 	&dev_attr_mapping24.attr,
598 	&dev_attr_mapping25.attr,
599 	&dev_attr_mapping26.attr,
600 	&dev_attr_mapping27.attr,
601 	&dev_attr_mapping28.attr,
602 	&dev_attr_mapping29.attr,
603 	&dev_attr_mapping30.attr,
604 	&dev_attr_mapping31.attr,
605 	NULL,
606 };
607 
608 struct attribute_group nd_mapping_attribute_group = {
609 	.is_visible = mapping_visible,
610 	.attrs = mapping_attributes,
611 };
612 EXPORT_SYMBOL_GPL(nd_mapping_attribute_group);
613 
614 int nd_blk_region_init(struct nd_region *nd_region)
615 {
616 	struct device *dev = &nd_region->dev;
617 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
618 
619 	if (!is_nd_blk(dev))
620 		return 0;
621 
622 	if (nd_region->ndr_mappings < 1) {
623 		dev_err(dev, "invalid BLK region\n");
624 		return -ENXIO;
625 	}
626 
627 	return to_nd_blk_region(dev)->enable(nvdimm_bus, dev);
628 }
629 
630 /**
631  * nd_region_acquire_lane - allocate and lock a lane
632  * @nd_region: region id and number of lanes possible
633  *
634  * A lane correlates to a BLK-data-window and/or a log slot in the BTT.
635  * We optimize for the common case where there are 256 lanes, one
636  * per-cpu.  For larger systems we need to lock to share lanes.  For now
637  * this implementation assumes the cost of maintaining an allocator for
638  * free lanes is on the order of the lock hold time, so it implements a
639  * static lane = cpu % num_lanes mapping.
640  *
641  * In the case of a BTT instance on top of a BLK namespace a lane may be
642  * acquired recursively.  We lock on the first instance.
643  *
644  * In the case of a BTT instance on top of PMEM, we only acquire a lane
645  * for the BTT metadata updates.
646  */
647 unsigned int nd_region_acquire_lane(struct nd_region *nd_region)
648 {
649 	unsigned int cpu, lane;
650 
651 	cpu = get_cpu();
652 	if (nd_region->num_lanes < nr_cpu_ids) {
653 		struct nd_percpu_lane *ndl_lock, *ndl_count;
654 
655 		lane = cpu % nd_region->num_lanes;
656 		ndl_count = per_cpu_ptr(nd_region->lane, cpu);
657 		ndl_lock = per_cpu_ptr(nd_region->lane, lane);
658 		if (ndl_count->count++ == 0)
659 			spin_lock(&ndl_lock->lock);
660 	} else
661 		lane = cpu;
662 
663 	return lane;
664 }
665 EXPORT_SYMBOL(nd_region_acquire_lane);
666 
667 void nd_region_release_lane(struct nd_region *nd_region, unsigned int lane)
668 {
669 	if (nd_region->num_lanes < nr_cpu_ids) {
670 		unsigned int cpu = get_cpu();
671 		struct nd_percpu_lane *ndl_lock, *ndl_count;
672 
673 		ndl_count = per_cpu_ptr(nd_region->lane, cpu);
674 		ndl_lock = per_cpu_ptr(nd_region->lane, lane);
675 		if (--ndl_count->count == 0)
676 			spin_unlock(&ndl_lock->lock);
677 		put_cpu();
678 	}
679 	put_cpu();
680 }
681 EXPORT_SYMBOL(nd_region_release_lane);
682 
683 static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
684 		struct nd_region_desc *ndr_desc, struct device_type *dev_type,
685 		const char *caller)
686 {
687 	struct nd_region *nd_region;
688 	struct device *dev;
689 	void *region_buf;
690 	unsigned int i;
691 	int ro = 0;
692 
693 	for (i = 0; i < ndr_desc->num_mappings; i++) {
694 		struct nd_mapping *nd_mapping = &ndr_desc->nd_mapping[i];
695 		struct nvdimm *nvdimm = nd_mapping->nvdimm;
696 
697 		if ((nd_mapping->start | nd_mapping->size) % SZ_4K) {
698 			dev_err(&nvdimm_bus->dev, "%s: %s mapping%d is not 4K aligned\n",
699 					caller, dev_name(&nvdimm->dev), i);
700 
701 			return NULL;
702 		}
703 
704 		if (nvdimm->flags & NDD_UNARMED)
705 			ro = 1;
706 	}
707 
708 	if (dev_type == &nd_blk_device_type) {
709 		struct nd_blk_region_desc *ndbr_desc;
710 		struct nd_blk_region *ndbr;
711 
712 		ndbr_desc = to_blk_region_desc(ndr_desc);
713 		ndbr = kzalloc(sizeof(*ndbr) + sizeof(struct nd_mapping)
714 				* ndr_desc->num_mappings,
715 				GFP_KERNEL);
716 		if (ndbr) {
717 			nd_region = &ndbr->nd_region;
718 			ndbr->enable = ndbr_desc->enable;
719 			ndbr->disable = ndbr_desc->disable;
720 			ndbr->do_io = ndbr_desc->do_io;
721 		}
722 		region_buf = ndbr;
723 	} else {
724 		nd_region = kzalloc(sizeof(struct nd_region)
725 				+ sizeof(struct nd_mapping)
726 				* ndr_desc->num_mappings,
727 				GFP_KERNEL);
728 		region_buf = nd_region;
729 	}
730 
731 	if (!region_buf)
732 		return NULL;
733 	nd_region->id = ida_simple_get(&region_ida, 0, 0, GFP_KERNEL);
734 	if (nd_region->id < 0)
735 		goto err_id;
736 
737 	nd_region->lane = alloc_percpu(struct nd_percpu_lane);
738 	if (!nd_region->lane)
739 		goto err_percpu;
740 
741         for (i = 0; i < nr_cpu_ids; i++) {
742 		struct nd_percpu_lane *ndl;
743 
744 		ndl = per_cpu_ptr(nd_region->lane, i);
745 		spin_lock_init(&ndl->lock);
746 		ndl->count = 0;
747 	}
748 
749 	memcpy(nd_region->mapping, ndr_desc->nd_mapping,
750 			sizeof(struct nd_mapping) * ndr_desc->num_mappings);
751 	for (i = 0; i < ndr_desc->num_mappings; i++) {
752 		struct nd_mapping *nd_mapping = &ndr_desc->nd_mapping[i];
753 		struct nvdimm *nvdimm = nd_mapping->nvdimm;
754 
755 		get_device(&nvdimm->dev);
756 	}
757 	nd_region->ndr_mappings = ndr_desc->num_mappings;
758 	nd_region->provider_data = ndr_desc->provider_data;
759 	nd_region->nd_set = ndr_desc->nd_set;
760 	nd_region->num_lanes = ndr_desc->num_lanes;
761 	nd_region->flags = ndr_desc->flags;
762 	nd_region->ro = ro;
763 	nd_region->numa_node = ndr_desc->numa_node;
764 	ida_init(&nd_region->ns_ida);
765 	ida_init(&nd_region->btt_ida);
766 	ida_init(&nd_region->pfn_ida);
767 	dev = &nd_region->dev;
768 	dev_set_name(dev, "region%d", nd_region->id);
769 	dev->parent = &nvdimm_bus->dev;
770 	dev->type = dev_type;
771 	dev->groups = ndr_desc->attr_groups;
772 	nd_region->ndr_size = resource_size(ndr_desc->res);
773 	nd_region->ndr_start = ndr_desc->res->start;
774 	nd_device_register(dev);
775 
776 	return nd_region;
777 
778  err_percpu:
779 	ida_simple_remove(&region_ida, nd_region->id);
780  err_id:
781 	kfree(region_buf);
782 	return NULL;
783 }
784 
785 struct nd_region *nvdimm_pmem_region_create(struct nvdimm_bus *nvdimm_bus,
786 		struct nd_region_desc *ndr_desc)
787 {
788 	ndr_desc->num_lanes = ND_MAX_LANES;
789 	return nd_region_create(nvdimm_bus, ndr_desc, &nd_pmem_device_type,
790 			__func__);
791 }
792 EXPORT_SYMBOL_GPL(nvdimm_pmem_region_create);
793 
794 struct nd_region *nvdimm_blk_region_create(struct nvdimm_bus *nvdimm_bus,
795 		struct nd_region_desc *ndr_desc)
796 {
797 	if (ndr_desc->num_mappings > 1)
798 		return NULL;
799 	ndr_desc->num_lanes = min(ndr_desc->num_lanes, ND_MAX_LANES);
800 	return nd_region_create(nvdimm_bus, ndr_desc, &nd_blk_device_type,
801 			__func__);
802 }
803 EXPORT_SYMBOL_GPL(nvdimm_blk_region_create);
804 
805 struct nd_region *nvdimm_volatile_region_create(struct nvdimm_bus *nvdimm_bus,
806 		struct nd_region_desc *ndr_desc)
807 {
808 	ndr_desc->num_lanes = ND_MAX_LANES;
809 	return nd_region_create(nvdimm_bus, ndr_desc, &nd_volatile_device_type,
810 			__func__);
811 }
812 EXPORT_SYMBOL_GPL(nvdimm_volatile_region_create);
813