xref: /openbmc/linux/drivers/nvdimm/region_devs.c (revision 0883c2c0)
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 ssize_t size_show(struct device *dev,
138 		struct device_attribute *attr, char *buf)
139 {
140 	struct nd_region *nd_region = to_nd_region(dev);
141 	unsigned long long size = 0;
142 
143 	if (is_nd_pmem(dev)) {
144 		size = nd_region->ndr_size;
145 	} else if (nd_region->ndr_mappings == 1) {
146 		struct nd_mapping *nd_mapping = &nd_region->mapping[0];
147 
148 		size = nd_mapping->size;
149 	}
150 
151 	return sprintf(buf, "%llu\n", size);
152 }
153 static DEVICE_ATTR_RO(size);
154 
155 static ssize_t mappings_show(struct device *dev,
156 		struct device_attribute *attr, char *buf)
157 {
158 	struct nd_region *nd_region = to_nd_region(dev);
159 
160 	return sprintf(buf, "%d\n", nd_region->ndr_mappings);
161 }
162 static DEVICE_ATTR_RO(mappings);
163 
164 static ssize_t nstype_show(struct device *dev,
165 		struct device_attribute *attr, char *buf)
166 {
167 	struct nd_region *nd_region = to_nd_region(dev);
168 
169 	return sprintf(buf, "%d\n", nd_region_to_nstype(nd_region));
170 }
171 static DEVICE_ATTR_RO(nstype);
172 
173 static ssize_t set_cookie_show(struct device *dev,
174 		struct device_attribute *attr, char *buf)
175 {
176 	struct nd_region *nd_region = to_nd_region(dev);
177 	struct nd_interleave_set *nd_set = nd_region->nd_set;
178 
179 	if (is_nd_pmem(dev) && nd_set)
180 		/* pass, should be precluded by region_visible */;
181 	else
182 		return -ENXIO;
183 
184 	return sprintf(buf, "%#llx\n", nd_set->cookie);
185 }
186 static DEVICE_ATTR_RO(set_cookie);
187 
188 resource_size_t nd_region_available_dpa(struct nd_region *nd_region)
189 {
190 	resource_size_t blk_max_overlap = 0, available, overlap;
191 	int i;
192 
193 	WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
194 
195  retry:
196 	available = 0;
197 	overlap = blk_max_overlap;
198 	for (i = 0; i < nd_region->ndr_mappings; i++) {
199 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
200 		struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
201 
202 		/* if a dimm is disabled the available capacity is zero */
203 		if (!ndd)
204 			return 0;
205 
206 		if (is_nd_pmem(&nd_region->dev)) {
207 			available += nd_pmem_available_dpa(nd_region,
208 					nd_mapping, &overlap);
209 			if (overlap > blk_max_overlap) {
210 				blk_max_overlap = overlap;
211 				goto retry;
212 			}
213 		} else if (is_nd_blk(&nd_region->dev)) {
214 			available += nd_blk_available_dpa(nd_mapping);
215 		}
216 	}
217 
218 	return available;
219 }
220 
221 static ssize_t available_size_show(struct device *dev,
222 		struct device_attribute *attr, char *buf)
223 {
224 	struct nd_region *nd_region = to_nd_region(dev);
225 	unsigned long long available = 0;
226 
227 	/*
228 	 * Flush in-flight updates and grab a snapshot of the available
229 	 * size.  Of course, this value is potentially invalidated the
230 	 * memory nvdimm_bus_lock() is dropped, but that's userspace's
231 	 * problem to not race itself.
232 	 */
233 	nvdimm_bus_lock(dev);
234 	wait_nvdimm_bus_probe_idle(dev);
235 	available = nd_region_available_dpa(nd_region);
236 	nvdimm_bus_unlock(dev);
237 
238 	return sprintf(buf, "%llu\n", available);
239 }
240 static DEVICE_ATTR_RO(available_size);
241 
242 static ssize_t init_namespaces_show(struct device *dev,
243 		struct device_attribute *attr, char *buf)
244 {
245 	struct nd_region_namespaces *num_ns = dev_get_drvdata(dev);
246 	ssize_t rc;
247 
248 	nvdimm_bus_lock(dev);
249 	if (num_ns)
250 		rc = sprintf(buf, "%d/%d\n", num_ns->active, num_ns->count);
251 	else
252 		rc = -ENXIO;
253 	nvdimm_bus_unlock(dev);
254 
255 	return rc;
256 }
257 static DEVICE_ATTR_RO(init_namespaces);
258 
259 static ssize_t namespace_seed_show(struct device *dev,
260 		struct device_attribute *attr, char *buf)
261 {
262 	struct nd_region *nd_region = to_nd_region(dev);
263 	ssize_t rc;
264 
265 	nvdimm_bus_lock(dev);
266 	if (nd_region->ns_seed)
267 		rc = sprintf(buf, "%s\n", dev_name(nd_region->ns_seed));
268 	else
269 		rc = sprintf(buf, "\n");
270 	nvdimm_bus_unlock(dev);
271 	return rc;
272 }
273 static DEVICE_ATTR_RO(namespace_seed);
274 
275 static ssize_t btt_seed_show(struct device *dev,
276 		struct device_attribute *attr, char *buf)
277 {
278 	struct nd_region *nd_region = to_nd_region(dev);
279 	ssize_t rc;
280 
281 	nvdimm_bus_lock(dev);
282 	if (nd_region->btt_seed)
283 		rc = sprintf(buf, "%s\n", dev_name(nd_region->btt_seed));
284 	else
285 		rc = sprintf(buf, "\n");
286 	nvdimm_bus_unlock(dev);
287 
288 	return rc;
289 }
290 static DEVICE_ATTR_RO(btt_seed);
291 
292 static ssize_t pfn_seed_show(struct device *dev,
293 		struct device_attribute *attr, char *buf)
294 {
295 	struct nd_region *nd_region = to_nd_region(dev);
296 	ssize_t rc;
297 
298 	nvdimm_bus_lock(dev);
299 	if (nd_region->pfn_seed)
300 		rc = sprintf(buf, "%s\n", dev_name(nd_region->pfn_seed));
301 	else
302 		rc = sprintf(buf, "\n");
303 	nvdimm_bus_unlock(dev);
304 
305 	return rc;
306 }
307 static DEVICE_ATTR_RO(pfn_seed);
308 
309 static ssize_t dax_seed_show(struct device *dev,
310 		struct device_attribute *attr, char *buf)
311 {
312 	struct nd_region *nd_region = to_nd_region(dev);
313 	ssize_t rc;
314 
315 	nvdimm_bus_lock(dev);
316 	if (nd_region->dax_seed)
317 		rc = sprintf(buf, "%s\n", dev_name(nd_region->dax_seed));
318 	else
319 		rc = sprintf(buf, "\n");
320 	nvdimm_bus_unlock(dev);
321 
322 	return rc;
323 }
324 static DEVICE_ATTR_RO(dax_seed);
325 
326 static ssize_t read_only_show(struct device *dev,
327 		struct device_attribute *attr, char *buf)
328 {
329 	struct nd_region *nd_region = to_nd_region(dev);
330 
331 	return sprintf(buf, "%d\n", nd_region->ro);
332 }
333 
334 static ssize_t read_only_store(struct device *dev,
335 		struct device_attribute *attr, const char *buf, size_t len)
336 {
337 	bool ro;
338 	int rc = strtobool(buf, &ro);
339 	struct nd_region *nd_region = to_nd_region(dev);
340 
341 	if (rc)
342 		return rc;
343 
344 	nd_region->ro = ro;
345 	return len;
346 }
347 static DEVICE_ATTR_RW(read_only);
348 
349 static struct attribute *nd_region_attributes[] = {
350 	&dev_attr_size.attr,
351 	&dev_attr_nstype.attr,
352 	&dev_attr_mappings.attr,
353 	&dev_attr_btt_seed.attr,
354 	&dev_attr_pfn_seed.attr,
355 	&dev_attr_dax_seed.attr,
356 	&dev_attr_read_only.attr,
357 	&dev_attr_set_cookie.attr,
358 	&dev_attr_available_size.attr,
359 	&dev_attr_namespace_seed.attr,
360 	&dev_attr_init_namespaces.attr,
361 	NULL,
362 };
363 
364 static umode_t region_visible(struct kobject *kobj, struct attribute *a, int n)
365 {
366 	struct device *dev = container_of(kobj, typeof(*dev), kobj);
367 	struct nd_region *nd_region = to_nd_region(dev);
368 	struct nd_interleave_set *nd_set = nd_region->nd_set;
369 	int type = nd_region_to_nstype(nd_region);
370 
371 	if (!is_nd_pmem(dev) && a == &dev_attr_pfn_seed.attr)
372 		return 0;
373 
374 	if (!is_nd_pmem(dev) && a == &dev_attr_dax_seed.attr)
375 		return 0;
376 
377 	if (a != &dev_attr_set_cookie.attr
378 			&& a != &dev_attr_available_size.attr)
379 		return a->mode;
380 
381 	if ((type == ND_DEVICE_NAMESPACE_PMEM
382 				|| type == ND_DEVICE_NAMESPACE_BLK)
383 			&& a == &dev_attr_available_size.attr)
384 		return a->mode;
385 	else if (is_nd_pmem(dev) && nd_set)
386 		return a->mode;
387 
388 	return 0;
389 }
390 
391 struct attribute_group nd_region_attribute_group = {
392 	.attrs = nd_region_attributes,
393 	.is_visible = region_visible,
394 };
395 EXPORT_SYMBOL_GPL(nd_region_attribute_group);
396 
397 u64 nd_region_interleave_set_cookie(struct nd_region *nd_region)
398 {
399 	struct nd_interleave_set *nd_set = nd_region->nd_set;
400 
401 	if (nd_set)
402 		return nd_set->cookie;
403 	return 0;
404 }
405 
406 /*
407  * Upon successful probe/remove, take/release a reference on the
408  * associated interleave set (if present), and plant new btt + namespace
409  * seeds.  Also, on the removal of a BLK region, notify the provider to
410  * disable the region.
411  */
412 static void nd_region_notify_driver_action(struct nvdimm_bus *nvdimm_bus,
413 		struct device *dev, bool probe)
414 {
415 	struct nd_region *nd_region;
416 
417 	if (!probe && (is_nd_pmem(dev) || is_nd_blk(dev))) {
418 		int i;
419 
420 		nd_region = to_nd_region(dev);
421 		for (i = 0; i < nd_region->ndr_mappings; i++) {
422 			struct nd_mapping *nd_mapping = &nd_region->mapping[i];
423 			struct nvdimm_drvdata *ndd = nd_mapping->ndd;
424 			struct nvdimm *nvdimm = nd_mapping->nvdimm;
425 
426 			kfree(nd_mapping->labels);
427 			nd_mapping->labels = NULL;
428 			put_ndd(ndd);
429 			nd_mapping->ndd = NULL;
430 			if (ndd)
431 				atomic_dec(&nvdimm->busy);
432 		}
433 
434 		if (is_nd_pmem(dev))
435 			return;
436 
437 		to_nd_blk_region(dev)->disable(nvdimm_bus, dev);
438 	}
439 	if (dev->parent && is_nd_blk(dev->parent) && probe) {
440 		nd_region = to_nd_region(dev->parent);
441 		nvdimm_bus_lock(dev);
442 		if (nd_region->ns_seed == dev)
443 			nd_region_create_blk_seed(nd_region);
444 		nvdimm_bus_unlock(dev);
445 	}
446 	if (is_nd_btt(dev) && probe) {
447 		struct nd_btt *nd_btt = to_nd_btt(dev);
448 
449 		nd_region = to_nd_region(dev->parent);
450 		nvdimm_bus_lock(dev);
451 		if (nd_region->btt_seed == dev)
452 			nd_region_create_btt_seed(nd_region);
453 		if (nd_region->ns_seed == &nd_btt->ndns->dev &&
454 				is_nd_blk(dev->parent))
455 			nd_region_create_blk_seed(nd_region);
456 		nvdimm_bus_unlock(dev);
457 	}
458 	if (is_nd_pfn(dev) && probe) {
459 		nd_region = to_nd_region(dev->parent);
460 		nvdimm_bus_lock(dev);
461 		if (nd_region->pfn_seed == dev)
462 			nd_region_create_pfn_seed(nd_region);
463 		nvdimm_bus_unlock(dev);
464 	}
465 	if (is_nd_dax(dev) && probe) {
466 		nd_region = to_nd_region(dev->parent);
467 		nvdimm_bus_lock(dev);
468 		if (nd_region->dax_seed == dev)
469 			nd_region_create_dax_seed(nd_region);
470 		nvdimm_bus_unlock(dev);
471 	}
472 }
473 
474 void nd_region_probe_success(struct nvdimm_bus *nvdimm_bus, struct device *dev)
475 {
476 	nd_region_notify_driver_action(nvdimm_bus, dev, true);
477 }
478 
479 void nd_region_disable(struct nvdimm_bus *nvdimm_bus, struct device *dev)
480 {
481 	nd_region_notify_driver_action(nvdimm_bus, dev, false);
482 }
483 
484 static ssize_t mappingN(struct device *dev, char *buf, int n)
485 {
486 	struct nd_region *nd_region = to_nd_region(dev);
487 	struct nd_mapping *nd_mapping;
488 	struct nvdimm *nvdimm;
489 
490 	if (n >= nd_region->ndr_mappings)
491 		return -ENXIO;
492 	nd_mapping = &nd_region->mapping[n];
493 	nvdimm = nd_mapping->nvdimm;
494 
495 	return sprintf(buf, "%s,%llu,%llu\n", dev_name(&nvdimm->dev),
496 			nd_mapping->start, nd_mapping->size);
497 }
498 
499 #define REGION_MAPPING(idx) \
500 static ssize_t mapping##idx##_show(struct device *dev,		\
501 		struct device_attribute *attr, char *buf)	\
502 {								\
503 	return mappingN(dev, buf, idx);				\
504 }								\
505 static DEVICE_ATTR_RO(mapping##idx)
506 
507 /*
508  * 32 should be enough for a while, even in the presence of socket
509  * interleave a 32-way interleave set is a degenerate case.
510  */
511 REGION_MAPPING(0);
512 REGION_MAPPING(1);
513 REGION_MAPPING(2);
514 REGION_MAPPING(3);
515 REGION_MAPPING(4);
516 REGION_MAPPING(5);
517 REGION_MAPPING(6);
518 REGION_MAPPING(7);
519 REGION_MAPPING(8);
520 REGION_MAPPING(9);
521 REGION_MAPPING(10);
522 REGION_MAPPING(11);
523 REGION_MAPPING(12);
524 REGION_MAPPING(13);
525 REGION_MAPPING(14);
526 REGION_MAPPING(15);
527 REGION_MAPPING(16);
528 REGION_MAPPING(17);
529 REGION_MAPPING(18);
530 REGION_MAPPING(19);
531 REGION_MAPPING(20);
532 REGION_MAPPING(21);
533 REGION_MAPPING(22);
534 REGION_MAPPING(23);
535 REGION_MAPPING(24);
536 REGION_MAPPING(25);
537 REGION_MAPPING(26);
538 REGION_MAPPING(27);
539 REGION_MAPPING(28);
540 REGION_MAPPING(29);
541 REGION_MAPPING(30);
542 REGION_MAPPING(31);
543 
544 static umode_t mapping_visible(struct kobject *kobj, struct attribute *a, int n)
545 {
546 	struct device *dev = container_of(kobj, struct device, kobj);
547 	struct nd_region *nd_region = to_nd_region(dev);
548 
549 	if (n < nd_region->ndr_mappings)
550 		return a->mode;
551 	return 0;
552 }
553 
554 static struct attribute *mapping_attributes[] = {
555 	&dev_attr_mapping0.attr,
556 	&dev_attr_mapping1.attr,
557 	&dev_attr_mapping2.attr,
558 	&dev_attr_mapping3.attr,
559 	&dev_attr_mapping4.attr,
560 	&dev_attr_mapping5.attr,
561 	&dev_attr_mapping6.attr,
562 	&dev_attr_mapping7.attr,
563 	&dev_attr_mapping8.attr,
564 	&dev_attr_mapping9.attr,
565 	&dev_attr_mapping10.attr,
566 	&dev_attr_mapping11.attr,
567 	&dev_attr_mapping12.attr,
568 	&dev_attr_mapping13.attr,
569 	&dev_attr_mapping14.attr,
570 	&dev_attr_mapping15.attr,
571 	&dev_attr_mapping16.attr,
572 	&dev_attr_mapping17.attr,
573 	&dev_attr_mapping18.attr,
574 	&dev_attr_mapping19.attr,
575 	&dev_attr_mapping20.attr,
576 	&dev_attr_mapping21.attr,
577 	&dev_attr_mapping22.attr,
578 	&dev_attr_mapping23.attr,
579 	&dev_attr_mapping24.attr,
580 	&dev_attr_mapping25.attr,
581 	&dev_attr_mapping26.attr,
582 	&dev_attr_mapping27.attr,
583 	&dev_attr_mapping28.attr,
584 	&dev_attr_mapping29.attr,
585 	&dev_attr_mapping30.attr,
586 	&dev_attr_mapping31.attr,
587 	NULL,
588 };
589 
590 struct attribute_group nd_mapping_attribute_group = {
591 	.is_visible = mapping_visible,
592 	.attrs = mapping_attributes,
593 };
594 EXPORT_SYMBOL_GPL(nd_mapping_attribute_group);
595 
596 int nd_blk_region_init(struct nd_region *nd_region)
597 {
598 	struct device *dev = &nd_region->dev;
599 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
600 
601 	if (!is_nd_blk(dev))
602 		return 0;
603 
604 	if (nd_region->ndr_mappings < 1) {
605 		dev_err(dev, "invalid BLK region\n");
606 		return -ENXIO;
607 	}
608 
609 	return to_nd_blk_region(dev)->enable(nvdimm_bus, dev);
610 }
611 
612 /**
613  * nd_region_acquire_lane - allocate and lock a lane
614  * @nd_region: region id and number of lanes possible
615  *
616  * A lane correlates to a BLK-data-window and/or a log slot in the BTT.
617  * We optimize for the common case where there are 256 lanes, one
618  * per-cpu.  For larger systems we need to lock to share lanes.  For now
619  * this implementation assumes the cost of maintaining an allocator for
620  * free lanes is on the order of the lock hold time, so it implements a
621  * static lane = cpu % num_lanes mapping.
622  *
623  * In the case of a BTT instance on top of a BLK namespace a lane may be
624  * acquired recursively.  We lock on the first instance.
625  *
626  * In the case of a BTT instance on top of PMEM, we only acquire a lane
627  * for the BTT metadata updates.
628  */
629 unsigned int nd_region_acquire_lane(struct nd_region *nd_region)
630 {
631 	unsigned int cpu, lane;
632 
633 	cpu = get_cpu();
634 	if (nd_region->num_lanes < nr_cpu_ids) {
635 		struct nd_percpu_lane *ndl_lock, *ndl_count;
636 
637 		lane = cpu % nd_region->num_lanes;
638 		ndl_count = per_cpu_ptr(nd_region->lane, cpu);
639 		ndl_lock = per_cpu_ptr(nd_region->lane, lane);
640 		if (ndl_count->count++ == 0)
641 			spin_lock(&ndl_lock->lock);
642 	} else
643 		lane = cpu;
644 
645 	return lane;
646 }
647 EXPORT_SYMBOL(nd_region_acquire_lane);
648 
649 void nd_region_release_lane(struct nd_region *nd_region, unsigned int lane)
650 {
651 	if (nd_region->num_lanes < nr_cpu_ids) {
652 		unsigned int cpu = get_cpu();
653 		struct nd_percpu_lane *ndl_lock, *ndl_count;
654 
655 		ndl_count = per_cpu_ptr(nd_region->lane, cpu);
656 		ndl_lock = per_cpu_ptr(nd_region->lane, lane);
657 		if (--ndl_count->count == 0)
658 			spin_unlock(&ndl_lock->lock);
659 		put_cpu();
660 	}
661 	put_cpu();
662 }
663 EXPORT_SYMBOL(nd_region_release_lane);
664 
665 static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
666 		struct nd_region_desc *ndr_desc, struct device_type *dev_type,
667 		const char *caller)
668 {
669 	struct nd_region *nd_region;
670 	struct device *dev;
671 	void *region_buf;
672 	unsigned int i;
673 	int ro = 0;
674 
675 	for (i = 0; i < ndr_desc->num_mappings; i++) {
676 		struct nd_mapping *nd_mapping = &ndr_desc->nd_mapping[i];
677 		struct nvdimm *nvdimm = nd_mapping->nvdimm;
678 
679 		if ((nd_mapping->start | nd_mapping->size) % SZ_4K) {
680 			dev_err(&nvdimm_bus->dev, "%s: %s mapping%d is not 4K aligned\n",
681 					caller, dev_name(&nvdimm->dev), i);
682 
683 			return NULL;
684 		}
685 
686 		if (nvdimm->flags & NDD_UNARMED)
687 			ro = 1;
688 	}
689 
690 	if (dev_type == &nd_blk_device_type) {
691 		struct nd_blk_region_desc *ndbr_desc;
692 		struct nd_blk_region *ndbr;
693 
694 		ndbr_desc = to_blk_region_desc(ndr_desc);
695 		ndbr = kzalloc(sizeof(*ndbr) + sizeof(struct nd_mapping)
696 				* ndr_desc->num_mappings,
697 				GFP_KERNEL);
698 		if (ndbr) {
699 			nd_region = &ndbr->nd_region;
700 			ndbr->enable = ndbr_desc->enable;
701 			ndbr->disable = ndbr_desc->disable;
702 			ndbr->do_io = ndbr_desc->do_io;
703 		}
704 		region_buf = ndbr;
705 	} else {
706 		nd_region = kzalloc(sizeof(struct nd_region)
707 				+ sizeof(struct nd_mapping)
708 				* ndr_desc->num_mappings,
709 				GFP_KERNEL);
710 		region_buf = nd_region;
711 	}
712 
713 	if (!region_buf)
714 		return NULL;
715 	nd_region->id = ida_simple_get(&region_ida, 0, 0, GFP_KERNEL);
716 	if (nd_region->id < 0)
717 		goto err_id;
718 
719 	nd_region->lane = alloc_percpu(struct nd_percpu_lane);
720 	if (!nd_region->lane)
721 		goto err_percpu;
722 
723         for (i = 0; i < nr_cpu_ids; i++) {
724 		struct nd_percpu_lane *ndl;
725 
726 		ndl = per_cpu_ptr(nd_region->lane, i);
727 		spin_lock_init(&ndl->lock);
728 		ndl->count = 0;
729 	}
730 
731 	memcpy(nd_region->mapping, ndr_desc->nd_mapping,
732 			sizeof(struct nd_mapping) * ndr_desc->num_mappings);
733 	for (i = 0; i < ndr_desc->num_mappings; i++) {
734 		struct nd_mapping *nd_mapping = &ndr_desc->nd_mapping[i];
735 		struct nvdimm *nvdimm = nd_mapping->nvdimm;
736 
737 		get_device(&nvdimm->dev);
738 	}
739 	nd_region->ndr_mappings = ndr_desc->num_mappings;
740 	nd_region->provider_data = ndr_desc->provider_data;
741 	nd_region->nd_set = ndr_desc->nd_set;
742 	nd_region->num_lanes = ndr_desc->num_lanes;
743 	nd_region->flags = ndr_desc->flags;
744 	nd_region->ro = ro;
745 	nd_region->numa_node = ndr_desc->numa_node;
746 	ida_init(&nd_region->ns_ida);
747 	ida_init(&nd_region->btt_ida);
748 	ida_init(&nd_region->pfn_ida);
749 	ida_init(&nd_region->dax_ida);
750 	dev = &nd_region->dev;
751 	dev_set_name(dev, "region%d", nd_region->id);
752 	dev->parent = &nvdimm_bus->dev;
753 	dev->type = dev_type;
754 	dev->groups = ndr_desc->attr_groups;
755 	nd_region->ndr_size = resource_size(ndr_desc->res);
756 	nd_region->ndr_start = ndr_desc->res->start;
757 	nd_device_register(dev);
758 
759 	return nd_region;
760 
761  err_percpu:
762 	ida_simple_remove(&region_ida, nd_region->id);
763  err_id:
764 	kfree(region_buf);
765 	return NULL;
766 }
767 
768 struct nd_region *nvdimm_pmem_region_create(struct nvdimm_bus *nvdimm_bus,
769 		struct nd_region_desc *ndr_desc)
770 {
771 	ndr_desc->num_lanes = ND_MAX_LANES;
772 	return nd_region_create(nvdimm_bus, ndr_desc, &nd_pmem_device_type,
773 			__func__);
774 }
775 EXPORT_SYMBOL_GPL(nvdimm_pmem_region_create);
776 
777 struct nd_region *nvdimm_blk_region_create(struct nvdimm_bus *nvdimm_bus,
778 		struct nd_region_desc *ndr_desc)
779 {
780 	if (ndr_desc->num_mappings > 1)
781 		return NULL;
782 	ndr_desc->num_lanes = min(ndr_desc->num_lanes, ND_MAX_LANES);
783 	return nd_region_create(nvdimm_bus, ndr_desc, &nd_blk_device_type,
784 			__func__);
785 }
786 EXPORT_SYMBOL_GPL(nvdimm_blk_region_create);
787 
788 struct nd_region *nvdimm_volatile_region_create(struct nvdimm_bus *nvdimm_bus,
789 		struct nd_region_desc *ndr_desc)
790 {
791 	ndr_desc->num_lanes = ND_MAX_LANES;
792 	return nd_region_create(nvdimm_bus, ndr_desc, &nd_volatile_device_type,
793 			__func__);
794 }
795 EXPORT_SYMBOL_GPL(nvdimm_volatile_region_create);
796 
797 void __exit nd_region_devs_exit(void)
798 {
799 	ida_destroy(&region_ida);
800 }
801