xref: /openbmc/linux/drivers/nvdimm/region_devs.c (revision 6db6b729)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
4  */
5 #include <linux/scatterlist.h>
6 #include <linux/memregion.h>
7 #include <linux/highmem.h>
8 #include <linux/kstrtox.h>
9 #include <linux/sched.h>
10 #include <linux/slab.h>
11 #include <linux/hash.h>
12 #include <linux/sort.h>
13 #include <linux/io.h>
14 #include <linux/nd.h>
15 #include "nd-core.h"
16 #include "nd.h"
17 
18 /*
19  * For readq() and writeq() on 32-bit builds, the hi-lo, lo-hi order is
20  * irrelevant.
21  */
22 #include <linux/io-64-nonatomic-hi-lo.h>
23 
24 static DEFINE_PER_CPU(int, flush_idx);
25 
26 static int nvdimm_map_flush(struct device *dev, struct nvdimm *nvdimm, int dimm,
27 		struct nd_region_data *ndrd)
28 {
29 	int i, j;
30 
31 	dev_dbg(dev, "%s: map %d flush address%s\n", nvdimm_name(nvdimm),
32 			nvdimm->num_flush, nvdimm->num_flush == 1 ? "" : "es");
33 	for (i = 0; i < (1 << ndrd->hints_shift); i++) {
34 		struct resource *res = &nvdimm->flush_wpq[i];
35 		unsigned long pfn = PHYS_PFN(res->start);
36 		void __iomem *flush_page;
37 
38 		/* check if flush hints share a page */
39 		for (j = 0; j < i; j++) {
40 			struct resource *res_j = &nvdimm->flush_wpq[j];
41 			unsigned long pfn_j = PHYS_PFN(res_j->start);
42 
43 			if (pfn == pfn_j)
44 				break;
45 		}
46 
47 		if (j < i)
48 			flush_page = (void __iomem *) ((unsigned long)
49 					ndrd_get_flush_wpq(ndrd, dimm, j)
50 					& PAGE_MASK);
51 		else
52 			flush_page = devm_nvdimm_ioremap(dev,
53 					PFN_PHYS(pfn), PAGE_SIZE);
54 		if (!flush_page)
55 			return -ENXIO;
56 		ndrd_set_flush_wpq(ndrd, dimm, i, flush_page
57 				+ (res->start & ~PAGE_MASK));
58 	}
59 
60 	return 0;
61 }
62 
63 static int nd_region_invalidate_memregion(struct nd_region *nd_region)
64 {
65 	int i, incoherent = 0;
66 
67 	for (i = 0; i < nd_region->ndr_mappings; i++) {
68 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
69 		struct nvdimm *nvdimm = nd_mapping->nvdimm;
70 
71 		if (test_bit(NDD_INCOHERENT, &nvdimm->flags)) {
72 			incoherent++;
73 			break;
74 		}
75 	}
76 
77 	if (!incoherent)
78 		return 0;
79 
80 	if (!cpu_cache_has_invalidate_memregion()) {
81 		if (IS_ENABLED(CONFIG_NVDIMM_SECURITY_TEST)) {
82 			dev_warn(
83 				&nd_region->dev,
84 				"Bypassing cpu_cache_invalidate_memergion() for testing!\n");
85 			goto out;
86 		} else {
87 			dev_err(&nd_region->dev,
88 				"Failed to synchronize CPU cache state\n");
89 			return -ENXIO;
90 		}
91 	}
92 
93 	cpu_cache_invalidate_memregion(IORES_DESC_PERSISTENT_MEMORY);
94 out:
95 	for (i = 0; i < nd_region->ndr_mappings; i++) {
96 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
97 		struct nvdimm *nvdimm = nd_mapping->nvdimm;
98 
99 		clear_bit(NDD_INCOHERENT, &nvdimm->flags);
100 	}
101 
102 	return 0;
103 }
104 
105 int nd_region_activate(struct nd_region *nd_region)
106 {
107 	int i, j, rc, num_flush = 0;
108 	struct nd_region_data *ndrd;
109 	struct device *dev = &nd_region->dev;
110 	size_t flush_data_size = sizeof(void *);
111 
112 	nvdimm_bus_lock(&nd_region->dev);
113 	for (i = 0; i < nd_region->ndr_mappings; i++) {
114 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
115 		struct nvdimm *nvdimm = nd_mapping->nvdimm;
116 
117 		if (test_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags)) {
118 			nvdimm_bus_unlock(&nd_region->dev);
119 			return -EBUSY;
120 		}
121 
122 		/* at least one null hint slot per-dimm for the "no-hint" case */
123 		flush_data_size += sizeof(void *);
124 		num_flush = min_not_zero(num_flush, nvdimm->num_flush);
125 		if (!nvdimm->num_flush)
126 			continue;
127 		flush_data_size += nvdimm->num_flush * sizeof(void *);
128 	}
129 	nvdimm_bus_unlock(&nd_region->dev);
130 
131 	rc = nd_region_invalidate_memregion(nd_region);
132 	if (rc)
133 		return rc;
134 
135 	ndrd = devm_kzalloc(dev, sizeof(*ndrd) + flush_data_size, GFP_KERNEL);
136 	if (!ndrd)
137 		return -ENOMEM;
138 	dev_set_drvdata(dev, ndrd);
139 
140 	if (!num_flush)
141 		return 0;
142 
143 	ndrd->hints_shift = ilog2(num_flush);
144 	for (i = 0; i < nd_region->ndr_mappings; i++) {
145 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
146 		struct nvdimm *nvdimm = nd_mapping->nvdimm;
147 		int rc = nvdimm_map_flush(&nd_region->dev, nvdimm, i, ndrd);
148 
149 		if (rc)
150 			return rc;
151 	}
152 
153 	/*
154 	 * Clear out entries that are duplicates. This should prevent the
155 	 * extra flushings.
156 	 */
157 	for (i = 0; i < nd_region->ndr_mappings - 1; i++) {
158 		/* ignore if NULL already */
159 		if (!ndrd_get_flush_wpq(ndrd, i, 0))
160 			continue;
161 
162 		for (j = i + 1; j < nd_region->ndr_mappings; j++)
163 			if (ndrd_get_flush_wpq(ndrd, i, 0) ==
164 			    ndrd_get_flush_wpq(ndrd, j, 0))
165 				ndrd_set_flush_wpq(ndrd, j, 0, NULL);
166 	}
167 
168 	return 0;
169 }
170 
171 static void nd_region_release(struct device *dev)
172 {
173 	struct nd_region *nd_region = to_nd_region(dev);
174 	u16 i;
175 
176 	for (i = 0; i < nd_region->ndr_mappings; i++) {
177 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
178 		struct nvdimm *nvdimm = nd_mapping->nvdimm;
179 
180 		put_device(&nvdimm->dev);
181 	}
182 	free_percpu(nd_region->lane);
183 	if (!test_bit(ND_REGION_CXL, &nd_region->flags))
184 		memregion_free(nd_region->id);
185 	kfree(nd_region);
186 }
187 
188 struct nd_region *to_nd_region(struct device *dev)
189 {
190 	struct nd_region *nd_region = container_of(dev, struct nd_region, dev);
191 
192 	WARN_ON(dev->type->release != nd_region_release);
193 	return nd_region;
194 }
195 EXPORT_SYMBOL_GPL(to_nd_region);
196 
197 struct device *nd_region_dev(struct nd_region *nd_region)
198 {
199 	if (!nd_region)
200 		return NULL;
201 	return &nd_region->dev;
202 }
203 EXPORT_SYMBOL_GPL(nd_region_dev);
204 
205 void *nd_region_provider_data(struct nd_region *nd_region)
206 {
207 	return nd_region->provider_data;
208 }
209 EXPORT_SYMBOL_GPL(nd_region_provider_data);
210 
211 /**
212  * nd_region_to_nstype() - region to an integer namespace type
213  * @nd_region: region-device to interrogate
214  *
215  * This is the 'nstype' attribute of a region as well, an input to the
216  * MODALIAS for namespace devices, and bit number for a nvdimm_bus to match
217  * namespace devices with namespace drivers.
218  */
219 int nd_region_to_nstype(struct nd_region *nd_region)
220 {
221 	if (is_memory(&nd_region->dev)) {
222 		u16 i, label;
223 
224 		for (i = 0, label = 0; i < nd_region->ndr_mappings; i++) {
225 			struct nd_mapping *nd_mapping = &nd_region->mapping[i];
226 			struct nvdimm *nvdimm = nd_mapping->nvdimm;
227 
228 			if (test_bit(NDD_LABELING, &nvdimm->flags))
229 				label++;
230 		}
231 		if (label)
232 			return ND_DEVICE_NAMESPACE_PMEM;
233 		else
234 			return ND_DEVICE_NAMESPACE_IO;
235 	}
236 
237 	return 0;
238 }
239 EXPORT_SYMBOL(nd_region_to_nstype);
240 
241 static unsigned long long region_size(struct nd_region *nd_region)
242 {
243 	if (is_memory(&nd_region->dev)) {
244 		return nd_region->ndr_size;
245 	} else if (nd_region->ndr_mappings == 1) {
246 		struct nd_mapping *nd_mapping = &nd_region->mapping[0];
247 
248 		return nd_mapping->size;
249 	}
250 
251 	return 0;
252 }
253 
254 static ssize_t size_show(struct device *dev,
255 		struct device_attribute *attr, char *buf)
256 {
257 	struct nd_region *nd_region = to_nd_region(dev);
258 
259 	return sprintf(buf, "%llu\n", region_size(nd_region));
260 }
261 static DEVICE_ATTR_RO(size);
262 
263 static ssize_t deep_flush_show(struct device *dev,
264 		struct device_attribute *attr, char *buf)
265 {
266 	struct nd_region *nd_region = to_nd_region(dev);
267 
268 	/*
269 	 * NOTE: in the nvdimm_has_flush() error case this attribute is
270 	 * not visible.
271 	 */
272 	return sprintf(buf, "%d\n", nvdimm_has_flush(nd_region));
273 }
274 
275 static ssize_t deep_flush_store(struct device *dev, struct device_attribute *attr,
276 		const char *buf, size_t len)
277 {
278 	bool flush;
279 	int rc = kstrtobool(buf, &flush);
280 	struct nd_region *nd_region = to_nd_region(dev);
281 
282 	if (rc)
283 		return rc;
284 	if (!flush)
285 		return -EINVAL;
286 	rc = nvdimm_flush(nd_region, NULL);
287 	if (rc)
288 		return rc;
289 
290 	return len;
291 }
292 static DEVICE_ATTR_RW(deep_flush);
293 
294 static ssize_t mappings_show(struct device *dev,
295 		struct device_attribute *attr, char *buf)
296 {
297 	struct nd_region *nd_region = to_nd_region(dev);
298 
299 	return sprintf(buf, "%d\n", nd_region->ndr_mappings);
300 }
301 static DEVICE_ATTR_RO(mappings);
302 
303 static ssize_t nstype_show(struct device *dev,
304 		struct device_attribute *attr, char *buf)
305 {
306 	struct nd_region *nd_region = to_nd_region(dev);
307 
308 	return sprintf(buf, "%d\n", nd_region_to_nstype(nd_region));
309 }
310 static DEVICE_ATTR_RO(nstype);
311 
312 static ssize_t set_cookie_show(struct device *dev,
313 		struct device_attribute *attr, char *buf)
314 {
315 	struct nd_region *nd_region = to_nd_region(dev);
316 	struct nd_interleave_set *nd_set = nd_region->nd_set;
317 	ssize_t rc = 0;
318 
319 	if (is_memory(dev) && nd_set)
320 		/* pass, should be precluded by region_visible */;
321 	else
322 		return -ENXIO;
323 
324 	/*
325 	 * The cookie to show depends on which specification of the
326 	 * labels we are using. If there are not labels then default to
327 	 * the v1.1 namespace label cookie definition. To read all this
328 	 * data we need to wait for probing to settle.
329 	 */
330 	device_lock(dev);
331 	nvdimm_bus_lock(dev);
332 	wait_nvdimm_bus_probe_idle(dev);
333 	if (nd_region->ndr_mappings) {
334 		struct nd_mapping *nd_mapping = &nd_region->mapping[0];
335 		struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
336 
337 		if (ndd) {
338 			struct nd_namespace_index *nsindex;
339 
340 			nsindex = to_namespace_index(ndd, ndd->ns_current);
341 			rc = sprintf(buf, "%#llx\n",
342 					nd_region_interleave_set_cookie(nd_region,
343 						nsindex));
344 		}
345 	}
346 	nvdimm_bus_unlock(dev);
347 	device_unlock(dev);
348 
349 	if (rc)
350 		return rc;
351 	return sprintf(buf, "%#llx\n", nd_set->cookie1);
352 }
353 static DEVICE_ATTR_RO(set_cookie);
354 
355 resource_size_t nd_region_available_dpa(struct nd_region *nd_region)
356 {
357 	resource_size_t available;
358 	int i;
359 
360 	WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
361 
362 	available = 0;
363 	for (i = 0; i < nd_region->ndr_mappings; i++) {
364 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
365 		struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
366 
367 		/* if a dimm is disabled the available capacity is zero */
368 		if (!ndd)
369 			return 0;
370 
371 		available += nd_pmem_available_dpa(nd_region, nd_mapping);
372 	}
373 
374 	return available;
375 }
376 
377 resource_size_t nd_region_allocatable_dpa(struct nd_region *nd_region)
378 {
379 	resource_size_t avail = 0;
380 	int i;
381 
382 	WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
383 	for (i = 0; i < nd_region->ndr_mappings; i++) {
384 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
385 
386 		avail = min_not_zero(avail, nd_pmem_max_contiguous_dpa(
387 						    nd_region, nd_mapping));
388 	}
389 	return avail * nd_region->ndr_mappings;
390 }
391 
392 static ssize_t available_size_show(struct device *dev,
393 		struct device_attribute *attr, char *buf)
394 {
395 	struct nd_region *nd_region = to_nd_region(dev);
396 	unsigned long long available = 0;
397 
398 	/*
399 	 * Flush in-flight updates and grab a snapshot of the available
400 	 * size.  Of course, this value is potentially invalidated the
401 	 * memory nvdimm_bus_lock() is dropped, but that's userspace's
402 	 * problem to not race itself.
403 	 */
404 	device_lock(dev);
405 	nvdimm_bus_lock(dev);
406 	wait_nvdimm_bus_probe_idle(dev);
407 	available = nd_region_available_dpa(nd_region);
408 	nvdimm_bus_unlock(dev);
409 	device_unlock(dev);
410 
411 	return sprintf(buf, "%llu\n", available);
412 }
413 static DEVICE_ATTR_RO(available_size);
414 
415 static ssize_t max_available_extent_show(struct device *dev,
416 		struct device_attribute *attr, char *buf)
417 {
418 	struct nd_region *nd_region = to_nd_region(dev);
419 	unsigned long long available = 0;
420 
421 	device_lock(dev);
422 	nvdimm_bus_lock(dev);
423 	wait_nvdimm_bus_probe_idle(dev);
424 	available = nd_region_allocatable_dpa(nd_region);
425 	nvdimm_bus_unlock(dev);
426 	device_unlock(dev);
427 
428 	return sprintf(buf, "%llu\n", available);
429 }
430 static DEVICE_ATTR_RO(max_available_extent);
431 
432 static ssize_t init_namespaces_show(struct device *dev,
433 		struct device_attribute *attr, char *buf)
434 {
435 	struct nd_region_data *ndrd = dev_get_drvdata(dev);
436 	ssize_t rc;
437 
438 	nvdimm_bus_lock(dev);
439 	if (ndrd)
440 		rc = sprintf(buf, "%d/%d\n", ndrd->ns_active, ndrd->ns_count);
441 	else
442 		rc = -ENXIO;
443 	nvdimm_bus_unlock(dev);
444 
445 	return rc;
446 }
447 static DEVICE_ATTR_RO(init_namespaces);
448 
449 static ssize_t namespace_seed_show(struct device *dev,
450 		struct device_attribute *attr, char *buf)
451 {
452 	struct nd_region *nd_region = to_nd_region(dev);
453 	ssize_t rc;
454 
455 	nvdimm_bus_lock(dev);
456 	if (nd_region->ns_seed)
457 		rc = sprintf(buf, "%s\n", dev_name(nd_region->ns_seed));
458 	else
459 		rc = sprintf(buf, "\n");
460 	nvdimm_bus_unlock(dev);
461 	return rc;
462 }
463 static DEVICE_ATTR_RO(namespace_seed);
464 
465 static ssize_t btt_seed_show(struct device *dev,
466 		struct device_attribute *attr, char *buf)
467 {
468 	struct nd_region *nd_region = to_nd_region(dev);
469 	ssize_t rc;
470 
471 	nvdimm_bus_lock(dev);
472 	if (nd_region->btt_seed)
473 		rc = sprintf(buf, "%s\n", dev_name(nd_region->btt_seed));
474 	else
475 		rc = sprintf(buf, "\n");
476 	nvdimm_bus_unlock(dev);
477 
478 	return rc;
479 }
480 static DEVICE_ATTR_RO(btt_seed);
481 
482 static ssize_t pfn_seed_show(struct device *dev,
483 		struct device_attribute *attr, char *buf)
484 {
485 	struct nd_region *nd_region = to_nd_region(dev);
486 	ssize_t rc;
487 
488 	nvdimm_bus_lock(dev);
489 	if (nd_region->pfn_seed)
490 		rc = sprintf(buf, "%s\n", dev_name(nd_region->pfn_seed));
491 	else
492 		rc = sprintf(buf, "\n");
493 	nvdimm_bus_unlock(dev);
494 
495 	return rc;
496 }
497 static DEVICE_ATTR_RO(pfn_seed);
498 
499 static ssize_t dax_seed_show(struct device *dev,
500 		struct device_attribute *attr, char *buf)
501 {
502 	struct nd_region *nd_region = to_nd_region(dev);
503 	ssize_t rc;
504 
505 	nvdimm_bus_lock(dev);
506 	if (nd_region->dax_seed)
507 		rc = sprintf(buf, "%s\n", dev_name(nd_region->dax_seed));
508 	else
509 		rc = sprintf(buf, "\n");
510 	nvdimm_bus_unlock(dev);
511 
512 	return rc;
513 }
514 static DEVICE_ATTR_RO(dax_seed);
515 
516 static ssize_t read_only_show(struct device *dev,
517 		struct device_attribute *attr, char *buf)
518 {
519 	struct nd_region *nd_region = to_nd_region(dev);
520 
521 	return sprintf(buf, "%d\n", nd_region->ro);
522 }
523 
524 static int revalidate_read_only(struct device *dev, void *data)
525 {
526 	nd_device_notify(dev, NVDIMM_REVALIDATE_REGION);
527 	return 0;
528 }
529 
530 static ssize_t read_only_store(struct device *dev,
531 		struct device_attribute *attr, const char *buf, size_t len)
532 {
533 	bool ro;
534 	int rc = kstrtobool(buf, &ro);
535 	struct nd_region *nd_region = to_nd_region(dev);
536 
537 	if (rc)
538 		return rc;
539 
540 	nd_region->ro = ro;
541 	device_for_each_child(dev, NULL, revalidate_read_only);
542 	return len;
543 }
544 static DEVICE_ATTR_RW(read_only);
545 
546 static ssize_t align_show(struct device *dev,
547 		struct device_attribute *attr, char *buf)
548 {
549 	struct nd_region *nd_region = to_nd_region(dev);
550 
551 	return sprintf(buf, "%#lx\n", nd_region->align);
552 }
553 
554 static ssize_t align_store(struct device *dev,
555 		struct device_attribute *attr, const char *buf, size_t len)
556 {
557 	struct nd_region *nd_region = to_nd_region(dev);
558 	unsigned long val, dpa;
559 	u32 mappings, remainder;
560 	int rc;
561 
562 	rc = kstrtoul(buf, 0, &val);
563 	if (rc)
564 		return rc;
565 
566 	/*
567 	 * Ensure space-align is evenly divisible by the region
568 	 * interleave-width because the kernel typically has no facility
569 	 * to determine which DIMM(s), dimm-physical-addresses, would
570 	 * contribute to the tail capacity in system-physical-address
571 	 * space for the namespace.
572 	 */
573 	mappings = max_t(u32, 1, nd_region->ndr_mappings);
574 	dpa = div_u64_rem(val, mappings, &remainder);
575 	if (!is_power_of_2(dpa) || dpa < PAGE_SIZE
576 			|| val > region_size(nd_region) || remainder)
577 		return -EINVAL;
578 
579 	/*
580 	 * Given that space allocation consults this value multiple
581 	 * times ensure it does not change for the duration of the
582 	 * allocation.
583 	 */
584 	nvdimm_bus_lock(dev);
585 	nd_region->align = val;
586 	nvdimm_bus_unlock(dev);
587 
588 	return len;
589 }
590 static DEVICE_ATTR_RW(align);
591 
592 static ssize_t region_badblocks_show(struct device *dev,
593 		struct device_attribute *attr, char *buf)
594 {
595 	struct nd_region *nd_region = to_nd_region(dev);
596 	ssize_t rc;
597 
598 	device_lock(dev);
599 	if (dev->driver)
600 		rc = badblocks_show(&nd_region->bb, buf, 0);
601 	else
602 		rc = -ENXIO;
603 	device_unlock(dev);
604 
605 	return rc;
606 }
607 static DEVICE_ATTR(badblocks, 0444, region_badblocks_show, NULL);
608 
609 static ssize_t resource_show(struct device *dev,
610 		struct device_attribute *attr, char *buf)
611 {
612 	struct nd_region *nd_region = to_nd_region(dev);
613 
614 	return sprintf(buf, "%#llx\n", nd_region->ndr_start);
615 }
616 static DEVICE_ATTR_ADMIN_RO(resource);
617 
618 static ssize_t persistence_domain_show(struct device *dev,
619 		struct device_attribute *attr, char *buf)
620 {
621 	struct nd_region *nd_region = to_nd_region(dev);
622 
623 	if (test_bit(ND_REGION_PERSIST_CACHE, &nd_region->flags))
624 		return sprintf(buf, "cpu_cache\n");
625 	else if (test_bit(ND_REGION_PERSIST_MEMCTRL, &nd_region->flags))
626 		return sprintf(buf, "memory_controller\n");
627 	else
628 		return sprintf(buf, "\n");
629 }
630 static DEVICE_ATTR_RO(persistence_domain);
631 
632 static struct attribute *nd_region_attributes[] = {
633 	&dev_attr_size.attr,
634 	&dev_attr_align.attr,
635 	&dev_attr_nstype.attr,
636 	&dev_attr_mappings.attr,
637 	&dev_attr_btt_seed.attr,
638 	&dev_attr_pfn_seed.attr,
639 	&dev_attr_dax_seed.attr,
640 	&dev_attr_deep_flush.attr,
641 	&dev_attr_read_only.attr,
642 	&dev_attr_set_cookie.attr,
643 	&dev_attr_available_size.attr,
644 	&dev_attr_max_available_extent.attr,
645 	&dev_attr_namespace_seed.attr,
646 	&dev_attr_init_namespaces.attr,
647 	&dev_attr_badblocks.attr,
648 	&dev_attr_resource.attr,
649 	&dev_attr_persistence_domain.attr,
650 	NULL,
651 };
652 
653 static umode_t region_visible(struct kobject *kobj, struct attribute *a, int n)
654 {
655 	struct device *dev = container_of(kobj, typeof(*dev), kobj);
656 	struct nd_region *nd_region = to_nd_region(dev);
657 	struct nd_interleave_set *nd_set = nd_region->nd_set;
658 	int type = nd_region_to_nstype(nd_region);
659 
660 	if (!is_memory(dev) && a == &dev_attr_pfn_seed.attr)
661 		return 0;
662 
663 	if (!is_memory(dev) && a == &dev_attr_dax_seed.attr)
664 		return 0;
665 
666 	if (!is_memory(dev) && a == &dev_attr_badblocks.attr)
667 		return 0;
668 
669 	if (a == &dev_attr_resource.attr && !is_memory(dev))
670 		return 0;
671 
672 	if (a == &dev_attr_deep_flush.attr) {
673 		int has_flush = nvdimm_has_flush(nd_region);
674 
675 		if (has_flush == 1)
676 			return a->mode;
677 		else if (has_flush == 0)
678 			return 0444;
679 		else
680 			return 0;
681 	}
682 
683 	if (a == &dev_attr_persistence_domain.attr) {
684 		if ((nd_region->flags & (BIT(ND_REGION_PERSIST_CACHE)
685 					| BIT(ND_REGION_PERSIST_MEMCTRL))) == 0)
686 			return 0;
687 		return a->mode;
688 	}
689 
690 	if (a == &dev_attr_align.attr)
691 		return a->mode;
692 
693 	if (a != &dev_attr_set_cookie.attr
694 			&& a != &dev_attr_available_size.attr)
695 		return a->mode;
696 
697 	if (type == ND_DEVICE_NAMESPACE_PMEM &&
698 	    a == &dev_attr_available_size.attr)
699 		return a->mode;
700 	else if (is_memory(dev) && nd_set)
701 		return a->mode;
702 
703 	return 0;
704 }
705 
706 static ssize_t mappingN(struct device *dev, char *buf, int n)
707 {
708 	struct nd_region *nd_region = to_nd_region(dev);
709 	struct nd_mapping *nd_mapping;
710 	struct nvdimm *nvdimm;
711 
712 	if (n >= nd_region->ndr_mappings)
713 		return -ENXIO;
714 	nd_mapping = &nd_region->mapping[n];
715 	nvdimm = nd_mapping->nvdimm;
716 
717 	return sprintf(buf, "%s,%llu,%llu,%d\n", dev_name(&nvdimm->dev),
718 			nd_mapping->start, nd_mapping->size,
719 			nd_mapping->position);
720 }
721 
722 #define REGION_MAPPING(idx) \
723 static ssize_t mapping##idx##_show(struct device *dev,		\
724 		struct device_attribute *attr, char *buf)	\
725 {								\
726 	return mappingN(dev, buf, idx);				\
727 }								\
728 static DEVICE_ATTR_RO(mapping##idx)
729 
730 /*
731  * 32 should be enough for a while, even in the presence of socket
732  * interleave a 32-way interleave set is a degenerate case.
733  */
734 REGION_MAPPING(0);
735 REGION_MAPPING(1);
736 REGION_MAPPING(2);
737 REGION_MAPPING(3);
738 REGION_MAPPING(4);
739 REGION_MAPPING(5);
740 REGION_MAPPING(6);
741 REGION_MAPPING(7);
742 REGION_MAPPING(8);
743 REGION_MAPPING(9);
744 REGION_MAPPING(10);
745 REGION_MAPPING(11);
746 REGION_MAPPING(12);
747 REGION_MAPPING(13);
748 REGION_MAPPING(14);
749 REGION_MAPPING(15);
750 REGION_MAPPING(16);
751 REGION_MAPPING(17);
752 REGION_MAPPING(18);
753 REGION_MAPPING(19);
754 REGION_MAPPING(20);
755 REGION_MAPPING(21);
756 REGION_MAPPING(22);
757 REGION_MAPPING(23);
758 REGION_MAPPING(24);
759 REGION_MAPPING(25);
760 REGION_MAPPING(26);
761 REGION_MAPPING(27);
762 REGION_MAPPING(28);
763 REGION_MAPPING(29);
764 REGION_MAPPING(30);
765 REGION_MAPPING(31);
766 
767 static umode_t mapping_visible(struct kobject *kobj, struct attribute *a, int n)
768 {
769 	struct device *dev = container_of(kobj, struct device, kobj);
770 	struct nd_region *nd_region = to_nd_region(dev);
771 
772 	if (n < nd_region->ndr_mappings)
773 		return a->mode;
774 	return 0;
775 }
776 
777 static struct attribute *mapping_attributes[] = {
778 	&dev_attr_mapping0.attr,
779 	&dev_attr_mapping1.attr,
780 	&dev_attr_mapping2.attr,
781 	&dev_attr_mapping3.attr,
782 	&dev_attr_mapping4.attr,
783 	&dev_attr_mapping5.attr,
784 	&dev_attr_mapping6.attr,
785 	&dev_attr_mapping7.attr,
786 	&dev_attr_mapping8.attr,
787 	&dev_attr_mapping9.attr,
788 	&dev_attr_mapping10.attr,
789 	&dev_attr_mapping11.attr,
790 	&dev_attr_mapping12.attr,
791 	&dev_attr_mapping13.attr,
792 	&dev_attr_mapping14.attr,
793 	&dev_attr_mapping15.attr,
794 	&dev_attr_mapping16.attr,
795 	&dev_attr_mapping17.attr,
796 	&dev_attr_mapping18.attr,
797 	&dev_attr_mapping19.attr,
798 	&dev_attr_mapping20.attr,
799 	&dev_attr_mapping21.attr,
800 	&dev_attr_mapping22.attr,
801 	&dev_attr_mapping23.attr,
802 	&dev_attr_mapping24.attr,
803 	&dev_attr_mapping25.attr,
804 	&dev_attr_mapping26.attr,
805 	&dev_attr_mapping27.attr,
806 	&dev_attr_mapping28.attr,
807 	&dev_attr_mapping29.attr,
808 	&dev_attr_mapping30.attr,
809 	&dev_attr_mapping31.attr,
810 	NULL,
811 };
812 
813 static const struct attribute_group nd_mapping_attribute_group = {
814 	.is_visible = mapping_visible,
815 	.attrs = mapping_attributes,
816 };
817 
818 static const struct attribute_group nd_region_attribute_group = {
819 	.attrs = nd_region_attributes,
820 	.is_visible = region_visible,
821 };
822 
823 static const struct attribute_group *nd_region_attribute_groups[] = {
824 	&nd_device_attribute_group,
825 	&nd_region_attribute_group,
826 	&nd_numa_attribute_group,
827 	&nd_mapping_attribute_group,
828 	NULL,
829 };
830 
831 static const struct device_type nd_pmem_device_type = {
832 	.name = "nd_pmem",
833 	.release = nd_region_release,
834 	.groups = nd_region_attribute_groups,
835 };
836 
837 static const struct device_type nd_volatile_device_type = {
838 	.name = "nd_volatile",
839 	.release = nd_region_release,
840 	.groups = nd_region_attribute_groups,
841 };
842 
843 bool is_nd_pmem(const struct device *dev)
844 {
845 	return dev ? dev->type == &nd_pmem_device_type : false;
846 }
847 
848 bool is_nd_volatile(const struct device *dev)
849 {
850 	return dev ? dev->type == &nd_volatile_device_type : false;
851 }
852 
853 u64 nd_region_interleave_set_cookie(struct nd_region *nd_region,
854 		struct nd_namespace_index *nsindex)
855 {
856 	struct nd_interleave_set *nd_set = nd_region->nd_set;
857 
858 	if (!nd_set)
859 		return 0;
860 
861 	if (nsindex && __le16_to_cpu(nsindex->major) == 1
862 			&& __le16_to_cpu(nsindex->minor) == 1)
863 		return nd_set->cookie1;
864 	return nd_set->cookie2;
865 }
866 
867 u64 nd_region_interleave_set_altcookie(struct nd_region *nd_region)
868 {
869 	struct nd_interleave_set *nd_set = nd_region->nd_set;
870 
871 	if (nd_set)
872 		return nd_set->altcookie;
873 	return 0;
874 }
875 
876 void nd_mapping_free_labels(struct nd_mapping *nd_mapping)
877 {
878 	struct nd_label_ent *label_ent, *e;
879 
880 	lockdep_assert_held(&nd_mapping->lock);
881 	list_for_each_entry_safe(label_ent, e, &nd_mapping->labels, list) {
882 		list_del(&label_ent->list);
883 		kfree(label_ent);
884 	}
885 }
886 
887 /*
888  * When a namespace is activated create new seeds for the next
889  * namespace, or namespace-personality to be configured.
890  */
891 void nd_region_advance_seeds(struct nd_region *nd_region, struct device *dev)
892 {
893 	nvdimm_bus_lock(dev);
894 	if (nd_region->ns_seed == dev) {
895 		nd_region_create_ns_seed(nd_region);
896 	} else if (is_nd_btt(dev)) {
897 		struct nd_btt *nd_btt = to_nd_btt(dev);
898 
899 		if (nd_region->btt_seed == dev)
900 			nd_region_create_btt_seed(nd_region);
901 		if (nd_region->ns_seed == &nd_btt->ndns->dev)
902 			nd_region_create_ns_seed(nd_region);
903 	} else if (is_nd_pfn(dev)) {
904 		struct nd_pfn *nd_pfn = to_nd_pfn(dev);
905 
906 		if (nd_region->pfn_seed == dev)
907 			nd_region_create_pfn_seed(nd_region);
908 		if (nd_region->ns_seed == &nd_pfn->ndns->dev)
909 			nd_region_create_ns_seed(nd_region);
910 	} else if (is_nd_dax(dev)) {
911 		struct nd_dax *nd_dax = to_nd_dax(dev);
912 
913 		if (nd_region->dax_seed == dev)
914 			nd_region_create_dax_seed(nd_region);
915 		if (nd_region->ns_seed == &nd_dax->nd_pfn.ndns->dev)
916 			nd_region_create_ns_seed(nd_region);
917 	}
918 	nvdimm_bus_unlock(dev);
919 }
920 
921 /**
922  * nd_region_acquire_lane - allocate and lock a lane
923  * @nd_region: region id and number of lanes possible
924  *
925  * A lane correlates to a BLK-data-window and/or a log slot in the BTT.
926  * We optimize for the common case where there are 256 lanes, one
927  * per-cpu.  For larger systems we need to lock to share lanes.  For now
928  * this implementation assumes the cost of maintaining an allocator for
929  * free lanes is on the order of the lock hold time, so it implements a
930  * static lane = cpu % num_lanes mapping.
931  *
932  * In the case of a BTT instance on top of a BLK namespace a lane may be
933  * acquired recursively.  We lock on the first instance.
934  *
935  * In the case of a BTT instance on top of PMEM, we only acquire a lane
936  * for the BTT metadata updates.
937  */
938 unsigned int nd_region_acquire_lane(struct nd_region *nd_region)
939 {
940 	unsigned int cpu, lane;
941 
942 	cpu = get_cpu();
943 	if (nd_region->num_lanes < nr_cpu_ids) {
944 		struct nd_percpu_lane *ndl_lock, *ndl_count;
945 
946 		lane = cpu % nd_region->num_lanes;
947 		ndl_count = per_cpu_ptr(nd_region->lane, cpu);
948 		ndl_lock = per_cpu_ptr(nd_region->lane, lane);
949 		if (ndl_count->count++ == 0)
950 			spin_lock(&ndl_lock->lock);
951 	} else
952 		lane = cpu;
953 
954 	return lane;
955 }
956 EXPORT_SYMBOL(nd_region_acquire_lane);
957 
958 void nd_region_release_lane(struct nd_region *nd_region, unsigned int lane)
959 {
960 	if (nd_region->num_lanes < nr_cpu_ids) {
961 		unsigned int cpu = get_cpu();
962 		struct nd_percpu_lane *ndl_lock, *ndl_count;
963 
964 		ndl_count = per_cpu_ptr(nd_region->lane, cpu);
965 		ndl_lock = per_cpu_ptr(nd_region->lane, lane);
966 		if (--ndl_count->count == 0)
967 			spin_unlock(&ndl_lock->lock);
968 		put_cpu();
969 	}
970 	put_cpu();
971 }
972 EXPORT_SYMBOL(nd_region_release_lane);
973 
974 /*
975  * PowerPC requires this alignment for memremap_pages(). All other archs
976  * should be ok with SUBSECTION_SIZE (see memremap_compat_align()).
977  */
978 #define MEMREMAP_COMPAT_ALIGN_MAX SZ_16M
979 
980 static unsigned long default_align(struct nd_region *nd_region)
981 {
982 	unsigned long align;
983 	u32 remainder;
984 	int mappings;
985 
986 	align = MEMREMAP_COMPAT_ALIGN_MAX;
987 	if (nd_region->ndr_size < MEMREMAP_COMPAT_ALIGN_MAX)
988 		align = PAGE_SIZE;
989 
990 	mappings = max_t(u16, 1, nd_region->ndr_mappings);
991 	div_u64_rem(align, mappings, &remainder);
992 	if (remainder)
993 		align *= mappings;
994 
995 	return align;
996 }
997 
998 static struct lock_class_key nvdimm_region_key;
999 
1000 static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
1001 		struct nd_region_desc *ndr_desc,
1002 		const struct device_type *dev_type, const char *caller)
1003 {
1004 	struct nd_region *nd_region;
1005 	struct device *dev;
1006 	unsigned int i;
1007 	int ro = 0;
1008 
1009 	for (i = 0; i < ndr_desc->num_mappings; i++) {
1010 		struct nd_mapping_desc *mapping = &ndr_desc->mapping[i];
1011 		struct nvdimm *nvdimm = mapping->nvdimm;
1012 
1013 		if ((mapping->start | mapping->size) % PAGE_SIZE) {
1014 			dev_err(&nvdimm_bus->dev,
1015 				"%s: %s mapping%d is not %ld aligned\n",
1016 				caller, dev_name(&nvdimm->dev), i, PAGE_SIZE);
1017 			return NULL;
1018 		}
1019 
1020 		if (test_bit(NDD_UNARMED, &nvdimm->flags))
1021 			ro = 1;
1022 
1023 	}
1024 
1025 	nd_region =
1026 		kzalloc(struct_size(nd_region, mapping, ndr_desc->num_mappings),
1027 			GFP_KERNEL);
1028 
1029 	if (!nd_region)
1030 		return NULL;
1031 	/* CXL pre-assigns memregion ids before creating nvdimm regions */
1032 	if (test_bit(ND_REGION_CXL, &ndr_desc->flags)) {
1033 		nd_region->id = ndr_desc->memregion;
1034 	} else {
1035 		nd_region->id = memregion_alloc(GFP_KERNEL);
1036 		if (nd_region->id < 0)
1037 			goto err_id;
1038 	}
1039 
1040 	nd_region->lane = alloc_percpu(struct nd_percpu_lane);
1041 	if (!nd_region->lane)
1042 		goto err_percpu;
1043 
1044         for (i = 0; i < nr_cpu_ids; i++) {
1045 		struct nd_percpu_lane *ndl;
1046 
1047 		ndl = per_cpu_ptr(nd_region->lane, i);
1048 		spin_lock_init(&ndl->lock);
1049 		ndl->count = 0;
1050 	}
1051 
1052 	for (i = 0; i < ndr_desc->num_mappings; i++) {
1053 		struct nd_mapping_desc *mapping = &ndr_desc->mapping[i];
1054 		struct nvdimm *nvdimm = mapping->nvdimm;
1055 
1056 		nd_region->mapping[i].nvdimm = nvdimm;
1057 		nd_region->mapping[i].start = mapping->start;
1058 		nd_region->mapping[i].size = mapping->size;
1059 		nd_region->mapping[i].position = mapping->position;
1060 		INIT_LIST_HEAD(&nd_region->mapping[i].labels);
1061 		mutex_init(&nd_region->mapping[i].lock);
1062 
1063 		get_device(&nvdimm->dev);
1064 	}
1065 	nd_region->ndr_mappings = ndr_desc->num_mappings;
1066 	nd_region->provider_data = ndr_desc->provider_data;
1067 	nd_region->nd_set = ndr_desc->nd_set;
1068 	nd_region->num_lanes = ndr_desc->num_lanes;
1069 	nd_region->flags = ndr_desc->flags;
1070 	nd_region->ro = ro;
1071 	nd_region->numa_node = ndr_desc->numa_node;
1072 	nd_region->target_node = ndr_desc->target_node;
1073 	ida_init(&nd_region->ns_ida);
1074 	ida_init(&nd_region->btt_ida);
1075 	ida_init(&nd_region->pfn_ida);
1076 	ida_init(&nd_region->dax_ida);
1077 	dev = &nd_region->dev;
1078 	dev_set_name(dev, "region%d", nd_region->id);
1079 	dev->parent = &nvdimm_bus->dev;
1080 	dev->type = dev_type;
1081 	dev->groups = ndr_desc->attr_groups;
1082 	dev->of_node = ndr_desc->of_node;
1083 	nd_region->ndr_size = resource_size(ndr_desc->res);
1084 	nd_region->ndr_start = ndr_desc->res->start;
1085 	nd_region->align = default_align(nd_region);
1086 	if (ndr_desc->flush)
1087 		nd_region->flush = ndr_desc->flush;
1088 	else
1089 		nd_region->flush = NULL;
1090 
1091 	device_initialize(dev);
1092 	lockdep_set_class(&dev->mutex, &nvdimm_region_key);
1093 	nd_device_register(dev);
1094 
1095 	return nd_region;
1096 
1097 err_percpu:
1098 	if (!test_bit(ND_REGION_CXL, &ndr_desc->flags))
1099 		memregion_free(nd_region->id);
1100 err_id:
1101 	kfree(nd_region);
1102 	return NULL;
1103 }
1104 
1105 struct nd_region *nvdimm_pmem_region_create(struct nvdimm_bus *nvdimm_bus,
1106 		struct nd_region_desc *ndr_desc)
1107 {
1108 	ndr_desc->num_lanes = ND_MAX_LANES;
1109 	return nd_region_create(nvdimm_bus, ndr_desc, &nd_pmem_device_type,
1110 			__func__);
1111 }
1112 EXPORT_SYMBOL_GPL(nvdimm_pmem_region_create);
1113 
1114 struct nd_region *nvdimm_volatile_region_create(struct nvdimm_bus *nvdimm_bus,
1115 		struct nd_region_desc *ndr_desc)
1116 {
1117 	ndr_desc->num_lanes = ND_MAX_LANES;
1118 	return nd_region_create(nvdimm_bus, ndr_desc, &nd_volatile_device_type,
1119 			__func__);
1120 }
1121 EXPORT_SYMBOL_GPL(nvdimm_volatile_region_create);
1122 
1123 void nvdimm_region_delete(struct nd_region *nd_region)
1124 {
1125 	if (nd_region)
1126 		nd_device_unregister(&nd_region->dev, ND_SYNC);
1127 }
1128 EXPORT_SYMBOL_GPL(nvdimm_region_delete);
1129 
1130 int nvdimm_flush(struct nd_region *nd_region, struct bio *bio)
1131 {
1132 	int rc = 0;
1133 
1134 	if (!nd_region->flush)
1135 		rc = generic_nvdimm_flush(nd_region);
1136 	else {
1137 		if (nd_region->flush(nd_region, bio))
1138 			rc = -EIO;
1139 	}
1140 
1141 	return rc;
1142 }
1143 /**
1144  * generic_nvdimm_flush() - flush any posted write queues between the cpu and pmem media
1145  * @nd_region: interleaved pmem region
1146  */
1147 int generic_nvdimm_flush(struct nd_region *nd_region)
1148 {
1149 	struct nd_region_data *ndrd = dev_get_drvdata(&nd_region->dev);
1150 	int i, idx;
1151 
1152 	/*
1153 	 * Try to encourage some diversity in flush hint addresses
1154 	 * across cpus assuming a limited number of flush hints.
1155 	 */
1156 	idx = this_cpu_read(flush_idx);
1157 	idx = this_cpu_add_return(flush_idx, hash_32(current->pid + idx, 8));
1158 
1159 	/*
1160 	 * The pmem_wmb() is needed to 'sfence' all
1161 	 * previous writes such that they are architecturally visible for
1162 	 * the platform buffer flush. Note that we've already arranged for pmem
1163 	 * writes to avoid the cache via memcpy_flushcache().  The final
1164 	 * wmb() ensures ordering for the NVDIMM flush write.
1165 	 */
1166 	pmem_wmb();
1167 	for (i = 0; i < nd_region->ndr_mappings; i++)
1168 		if (ndrd_get_flush_wpq(ndrd, i, 0))
1169 			writeq(1, ndrd_get_flush_wpq(ndrd, i, idx));
1170 	wmb();
1171 
1172 	return 0;
1173 }
1174 EXPORT_SYMBOL_GPL(nvdimm_flush);
1175 
1176 /**
1177  * nvdimm_has_flush - determine write flushing requirements
1178  * @nd_region: interleaved pmem region
1179  *
1180  * Returns 1 if writes require flushing
1181  * Returns 0 if writes do not require flushing
1182  * Returns -ENXIO if flushing capability can not be determined
1183  */
1184 int nvdimm_has_flush(struct nd_region *nd_region)
1185 {
1186 	int i;
1187 
1188 	/* no nvdimm or pmem api == flushing capability unknown */
1189 	if (nd_region->ndr_mappings == 0
1190 			|| !IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API))
1191 		return -ENXIO;
1192 
1193 	/* Test if an explicit flush function is defined */
1194 	if (test_bit(ND_REGION_ASYNC, &nd_region->flags) && nd_region->flush)
1195 		return 1;
1196 
1197 	/* Test if any flush hints for the region are available */
1198 	for (i = 0; i < nd_region->ndr_mappings; i++) {
1199 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
1200 		struct nvdimm *nvdimm = nd_mapping->nvdimm;
1201 
1202 		/* flush hints present / available */
1203 		if (nvdimm->num_flush)
1204 			return 1;
1205 	}
1206 
1207 	/*
1208 	 * The platform defines dimm devices without hints nor explicit flush,
1209 	 * assume platform persistence mechanism like ADR
1210 	 */
1211 	return 0;
1212 }
1213 EXPORT_SYMBOL_GPL(nvdimm_has_flush);
1214 
1215 int nvdimm_has_cache(struct nd_region *nd_region)
1216 {
1217 	return is_nd_pmem(&nd_region->dev) &&
1218 		!test_bit(ND_REGION_PERSIST_CACHE, &nd_region->flags);
1219 }
1220 EXPORT_SYMBOL_GPL(nvdimm_has_cache);
1221 
1222 bool is_nvdimm_sync(struct nd_region *nd_region)
1223 {
1224 	if (is_nd_volatile(&nd_region->dev))
1225 		return true;
1226 
1227 	return is_nd_pmem(&nd_region->dev) &&
1228 		!test_bit(ND_REGION_ASYNC, &nd_region->flags);
1229 }
1230 EXPORT_SYMBOL_GPL(is_nvdimm_sync);
1231 
1232 struct conflict_context {
1233 	struct nd_region *nd_region;
1234 	resource_size_t start, size;
1235 };
1236 
1237 static int region_conflict(struct device *dev, void *data)
1238 {
1239 	struct nd_region *nd_region;
1240 	struct conflict_context *ctx = data;
1241 	resource_size_t res_end, region_end, region_start;
1242 
1243 	if (!is_memory(dev))
1244 		return 0;
1245 
1246 	nd_region = to_nd_region(dev);
1247 	if (nd_region == ctx->nd_region)
1248 		return 0;
1249 
1250 	res_end = ctx->start + ctx->size;
1251 	region_start = nd_region->ndr_start;
1252 	region_end = region_start + nd_region->ndr_size;
1253 	if (ctx->start >= region_start && ctx->start < region_end)
1254 		return -EBUSY;
1255 	if (res_end > region_start && res_end <= region_end)
1256 		return -EBUSY;
1257 	return 0;
1258 }
1259 
1260 int nd_region_conflict(struct nd_region *nd_region, resource_size_t start,
1261 		resource_size_t size)
1262 {
1263 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
1264 	struct conflict_context ctx = {
1265 		.nd_region = nd_region,
1266 		.start = start,
1267 		.size = size,
1268 	};
1269 
1270 	return device_for_each_child(&nvdimm_bus->dev, &ctx, region_conflict);
1271 }
1272 
1273 MODULE_IMPORT_NS(DEVMEM);
1274