drivers/nvdimm/region_devs.c

   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/highmem.h>
   7 #include <linux/sched.h>
   8 #include <linux/slab.h>
   9 #include <linux/hash.h>
  10 #include <linux/sort.h>
  11 #include <linux/io.h>
  12 #include <linux/nd.h>
  13 #include "nd-core.h"
  14 #include "nd.h"
  15
  16 /*
  17  * For readq() and writeq() on 32-bit builds, the hi-lo, lo-hi order is
  18  * irrelevant.
  19  */
  20 #include <linux/io-64-nonatomic-hi-lo.h>
  21
  22 static DEFINE_IDA(region_ida);
  23 static DEFINE_PER_CPU(int, flush_idx);
  24
  25 static int nvdimm_map_flush(struct device *dev, struct nvdimm *nvdimm, int dimm,
  26                 struct nd_region_data *ndrd)
  27 {
  28         int i, j;
  29
  30         dev_dbg(dev, "%s: map %d flush address%s\n", nvdimm_name(nvdimm),
  31                         nvdimm->num_flush, nvdimm->num_flush == 1 ? "" : "es");
  32         for (i = 0; i < (1 << ndrd->hints_shift); i++) {
  33                 struct resource *res = &nvdimm->flush_wpq[i];
  34                 unsigned long pfn = PHYS_PFN(res->start);
  35                 void __iomem *flush_page;
  36
  37                 /* check if flush hints share a page */
  38                 for (j = 0; j < i; j++) {
  39                         struct resource *res_j = &nvdimm->flush_wpq[j];
  40                         unsigned long pfn_j = PHYS_PFN(res_j->start);
  41
  42                         if (pfn == pfn_j)
  43                                 break;
  44                 }
  45
  46                 if (j < i)
  47                         flush_page = (void __iomem *) ((unsigned long)
  48                                         ndrd_get_flush_wpq(ndrd, dimm, j)
  49                                         & PAGE_MASK);
  50                 else
  51                         flush_page = devm_nvdimm_ioremap(dev,
  52                                         PFN_PHYS(pfn), PAGE_SIZE);
  53                 if (!flush_page)
  54                         return -ENXIO;
  55                 ndrd_set_flush_wpq(ndrd, dimm, i, flush_page
  56                                 + (res->start & ~PAGE_MASK));
  57         }
  58
  59         return 0;
  60 }
  61
  62 int nd_region_activate(struct nd_region *nd_region)
  63 {
  64         int i, j, num_flush = 0;
  65         struct nd_region_data *ndrd;
  66         struct device *dev = &nd_region->dev;
  67         size_t flush_data_size = sizeof(void *);
  68
  69         nvdimm_bus_lock(&nd_region->dev);
  70         for (i = 0; i < nd_region->ndr_mappings; i++) {
  71                 struct nd_mapping *nd_mapping = &nd_region->mapping[i];
  72                 struct nvdimm *nvdimm = nd_mapping->nvdimm;
  73
  74                 if (test_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags)) {
  75                         nvdimm_bus_unlock(&nd_region->dev);
  76                         return -EBUSY;
  77                 }
  78
  79                 /* at least one null hint slot per-dimm for the "no-hint" case */
  80                 flush_data_size += sizeof(void *);
  81                 num_flush = min_not_zero(num_flush, nvdimm->num_flush);
  82                 if (!nvdimm->num_flush)
  83                         continue;
  84                 flush_data_size += nvdimm->num_flush * sizeof(void *);
  85         }
  86         nvdimm_bus_unlock(&nd_region->dev);
  87
  88         ndrd = devm_kzalloc(dev, sizeof(*ndrd) + flush_data_size, GFP_KERNEL);
  89         if (!ndrd)
  90                 return -ENOMEM;
  91         dev_set_drvdata(dev, ndrd);
  92
  93         if (!num_flush)
  94                 return 0;
  95
  96         ndrd->hints_shift = ilog2(num_flush);
  97         for (i = 0; i < nd_region->ndr_mappings; i++) {
  98                 struct nd_mapping *nd_mapping = &nd_region->mapping[i];
  99                 struct nvdimm *nvdimm = nd_mapping->nvdimm;
 100                 int rc = nvdimm_map_flush(&nd_region->dev, nvdimm, i, ndrd);
 101
 102                 if (rc)
 103                         return rc;
 104         }
 105
 106         /*
 107          * Clear out entries that are duplicates. This should prevent the
 108          * extra flushings.
 109          */
 110         for (i = 0; i < nd_region->ndr_mappings - 1; i++) {
 111                 /* ignore if NULL already */
 112                 if (!ndrd_get_flush_wpq(ndrd, i, 0))
 113                         continue;
 114
 115                 for (j = i + 1; j < nd_region->ndr_mappings; j++)
 116                         if (ndrd_get_flush_wpq(ndrd, i, 0) ==
 117                             ndrd_get_flush_wpq(ndrd, j, 0))
 118                                 ndrd_set_flush_wpq(ndrd, j, 0, NULL);
 119         }
 120
 121         return 0;
 122 }
 123
 124 static void nd_region_release(struct device *dev)
 125 {
 126         struct nd_region *nd_region = to_nd_region(dev);
 127         u16 i;
 128
 129         for (i = 0; i < nd_region->ndr_mappings; i++) {
 130                 struct nd_mapping *nd_mapping = &nd_region->mapping[i];
 131                 struct nvdimm *nvdimm = nd_mapping->nvdimm;
 132
 133                 put_device(&nvdimm->dev);
 134         }
 135         free_percpu(nd_region->lane);
 136         ida_simple_remove(&region_ida, nd_region->id);
 137         if (is_nd_blk(dev))
 138                 kfree(to_nd_blk_region(dev));
 139         else
 140                 kfree(nd_region);
 141 }
 142
 143 static struct device_type nd_blk_device_type = {
 144         .name = "nd_blk",
 145         .release = nd_region_release,
 146 };
 147
 148 static struct device_type nd_pmem_device_type = {
 149         .name = "nd_pmem",
 150         .release = nd_region_release,
 151 };
 152
 153 static struct device_type nd_volatile_device_type = {
 154         .name = "nd_volatile",
 155         .release = nd_region_release,
 156 };
 157
 158 bool is_nd_pmem(struct device *dev)
 159 {
 160         return dev ? dev->type == &nd_pmem_device_type : false;
 161 }
 162
 163 bool is_nd_blk(struct device *dev)
 164 {
 165         return dev ? dev->type == &nd_blk_device_type : false;
 166 }
 167
 168 bool is_nd_volatile(struct device *dev)
 169 {
 170         return dev ? dev->type == &nd_volatile_device_type : false;
 171 }
 172
 173 struct nd_region *to_nd_region(struct device *dev)
 174 {
 175         struct nd_region *nd_region = container_of(dev, struct nd_region, dev);
 176
 177         WARN_ON(dev->type->release != nd_region_release);
 178         return nd_region;
 179 }
 180 EXPORT_SYMBOL_GPL(to_nd_region);
 181
 182 struct device *nd_region_dev(struct nd_region *nd_region)
 183 {
 184         if (!nd_region)
 185                 return NULL;
 186         return &nd_region->dev;
 187 }
 188 EXPORT_SYMBOL_GPL(nd_region_dev);
 189
 190 struct nd_blk_region *to_nd_blk_region(struct device *dev)
 191 {
 192         struct nd_region *nd_region = to_nd_region(dev);
 193
 194         WARN_ON(!is_nd_blk(dev));
 195         return container_of(nd_region, struct nd_blk_region, nd_region);
 196 }
 197 EXPORT_SYMBOL_GPL(to_nd_blk_region);
 198
 199 void *nd_region_provider_data(struct nd_region *nd_region)
 200 {
 201         return nd_region->provider_data;
 202 }
 203 EXPORT_SYMBOL_GPL(nd_region_provider_data);
 204
 205 void *nd_blk_region_provider_data(struct nd_blk_region *ndbr)
 206 {
 207         return ndbr->blk_provider_data;
 208 }
 209 EXPORT_SYMBOL_GPL(nd_blk_region_provider_data);
 210
 211 void nd_blk_region_set_provider_data(struct nd_blk_region *ndbr, void *data)
 212 {
 213         ndbr->blk_provider_data = data;
 214 }
 215 EXPORT_SYMBOL_GPL(nd_blk_region_set_provider_data);
 216
 217 /**
 218  * nd_region_to_nstype() - region to an integer namespace type
 219  * @nd_region: region-device to interrogate
 220  *
 221  * This is the 'nstype' attribute of a region as well, an input to the
 222  * MODALIAS for namespace devices, and bit number for a nvdimm_bus to match
 223  * namespace devices with namespace drivers.
 224  */
 225 int nd_region_to_nstype(struct nd_region *nd_region)
 226 {
 227         if (is_memory(&nd_region->dev)) {
 228                 u16 i, alias;
 229
 230                 for (i = 0, alias = 0; i < nd_region->ndr_mappings; i++) {
 231                         struct nd_mapping *nd_mapping = &nd_region->mapping[i];
 232                         struct nvdimm *nvdimm = nd_mapping->nvdimm;
 233
 234                         if (test_bit(NDD_ALIASING, &nvdimm->flags))
 235                                 alias++;
 236                 }
 237                 if (alias)
 238                         return ND_DEVICE_NAMESPACE_PMEM;
 239                 else
 240                         return ND_DEVICE_NAMESPACE_IO;
 241         } else if (is_nd_blk(&nd_region->dev)) {
 242                 return ND_DEVICE_NAMESPACE_BLK;
 243         }
 244
 245         return 0;
 246 }
 247 EXPORT_SYMBOL(nd_region_to_nstype);
 248
 249 static ssize_t size_show(struct device *dev,
 250                 struct device_attribute *attr, char *buf)
 251 {
 252         struct nd_region *nd_region = to_nd_region(dev);
 253         unsigned long long size = 0;
 254
 255         if (is_memory(dev)) {
 256                 size = nd_region->ndr_size;
 257         } else if (nd_region->ndr_mappings == 1) {
 258                 struct nd_mapping *nd_mapping = &nd_region->mapping[0];
 259
 260                 size = nd_mapping->size;
 261         }
 262
 263         return sprintf(buf, "%llu\n", size);
 264 }
 265 static DEVICE_ATTR_RO(size);
 266
 267 static ssize_t deep_flush_show(struct device *dev,
 268                 struct device_attribute *attr, char *buf)
 269 {
 270         struct nd_region *nd_region = to_nd_region(dev);
 271
 272         /*
 273          * NOTE: in the nvdimm_has_flush() error case this attribute is
 274          * not visible.
 275          */
 276         return sprintf(buf, "%d\n", nvdimm_has_flush(nd_region));
 277 }
 278
 279 static ssize_t deep_flush_store(struct device *dev, struct device_attribute *attr,
 280                 const char *buf, size_t len)
 281 {
 282         bool flush;
 283         int rc = strtobool(buf, &flush);
 284         struct nd_region *nd_region = to_nd_region(dev);
 285
 286         if (rc)
 287                 return rc;
 288         if (!flush)
 289                 return -EINVAL;
 290         rc = nvdimm_flush(nd_region, NULL);
 291         if (rc)
 292                 return rc;
 293
 294         return len;
 295 }
 296 static DEVICE_ATTR_RW(deep_flush);
 297
 298 static ssize_t mappings_show(struct device *dev,
 299                 struct device_attribute *attr, char *buf)
 300 {
 301         struct nd_region *nd_region = to_nd_region(dev);
 302
 303         return sprintf(buf, "%d\n", nd_region->ndr_mappings);
 304 }
 305 static DEVICE_ATTR_RO(mappings);
 306
 307 static ssize_t nstype_show(struct device *dev,
 308                 struct device_attribute *attr, char *buf)
 309 {
 310         struct nd_region *nd_region = to_nd_region(dev);
 311
 312         return sprintf(buf, "%d\n", nd_region_to_nstype(nd_region));
 313 }
 314 static DEVICE_ATTR_RO(nstype);
 315
 316 static ssize_t set_cookie_show(struct device *dev,
 317                 struct device_attribute *attr, char *buf)
 318 {
 319         struct nd_region *nd_region = to_nd_region(dev);
 320         struct nd_interleave_set *nd_set = nd_region->nd_set;
 321         ssize_t rc = 0;
 322
 323         if (is_memory(dev) && nd_set)
 324                 /* pass, should be precluded by region_visible */;
 325         else
 326                 return -ENXIO;
 327
 328         /*
 329          * The cookie to show depends on which specification of the
 330          * labels we are using. If there are not labels then default to
 331          * the v1.1 namespace label cookie definition. To read all this
 332          * data we need to wait for probing to settle.
 333          */
 334         device_lock(dev);
 335         nvdimm_bus_lock(dev);
 336         wait_nvdimm_bus_probe_idle(dev);
 337         if (nd_region->ndr_mappings) {
 338                 struct nd_mapping *nd_mapping = &nd_region->mapping[0];
 339                 struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
 340
 341                 if (ndd) {
 342                         struct nd_namespace_index *nsindex;
 343
 344                         nsindex = to_namespace_index(ndd, ndd->ns_current);
 345                         rc = sprintf(buf, "%#llx\n",
 346                                         nd_region_interleave_set_cookie(nd_region,
 347                                                 nsindex));
 348                 }
 349         }
 350         nvdimm_bus_unlock(dev);
 351         device_unlock(dev);
 352
 353         if (rc)
 354                 return rc;
 355         return sprintf(buf, "%#llx\n", nd_set->cookie1);
 356 }
 357 static DEVICE_ATTR_RO(set_cookie);
 358
 359 resource_size_t nd_region_available_dpa(struct nd_region *nd_region)
 360 {
 361         resource_size_t blk_max_overlap = 0, available, overlap;
 362         int i;
 363
 364         WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
 365
 366  retry:
 367         available = 0;
 368         overlap = blk_max_overlap;
 369         for (i = 0; i < nd_region->ndr_mappings; i++) {
 370                 struct nd_mapping *nd_mapping = &nd_region->mapping[i];
 371                 struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
 372
 373                 /* if a dimm is disabled the available capacity is zero */
 374                 if (!ndd)
 375                         return 0;
 376
 377                 if (is_memory(&nd_region->dev)) {
 378                         available += nd_pmem_available_dpa(nd_region,
 379                                         nd_mapping, &overlap);
 380                         if (overlap > blk_max_overlap) {
 381                                 blk_max_overlap = overlap;
 382                                 goto retry;
 383                         }
 384                 } else if (is_nd_blk(&nd_region->dev))
 385                         available += nd_blk_available_dpa(nd_region);
 386         }
 387
 388         return available;
 389 }
 390
 391 resource_size_t nd_region_allocatable_dpa(struct nd_region *nd_region)
 392 {
 393         resource_size_t available = 0;
 394         int i;
 395
 396         if (is_memory(&nd_region->dev))
 397                 available = PHYS_ADDR_MAX;
 398
 399         WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
 400         for (i = 0; i < nd_region->ndr_mappings; i++) {
 401                 struct nd_mapping *nd_mapping = &nd_region->mapping[i];
 402
 403                 if (is_memory(&nd_region->dev))
 404                         available = min(available,
 405                                         nd_pmem_max_contiguous_dpa(nd_region,
 406                                                                    nd_mapping));
 407                 else if (is_nd_blk(&nd_region->dev))
 408                         available += nd_blk_available_dpa(nd_region);
 409         }
 410         if (is_memory(&nd_region->dev))
 411                 return available * nd_region->ndr_mappings;
 412         return available;
 413 }
 414
 415 static ssize_t available_size_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         /*
 422          * Flush in-flight updates and grab a snapshot of the available
 423          * size.  Of course, this value is potentially invalidated the
 424          * memory nvdimm_bus_lock() is dropped, but that's userspace's
 425          * problem to not race itself.
 426          */
 427         nvdimm_bus_lock(dev);
 428         wait_nvdimm_bus_probe_idle(dev);
 429         available = nd_region_available_dpa(nd_region);
 430         nvdimm_bus_unlock(dev);
 431
 432         return sprintf(buf, "%llu\n", available);
 433 }
 434 static DEVICE_ATTR_RO(available_size);
 435
 436 static ssize_t max_available_extent_show(struct device *dev,
 437                 struct device_attribute *attr, char *buf)
 438 {
 439         struct nd_region *nd_region = to_nd_region(dev);
 440         unsigned long long available = 0;
 441
 442         nvdimm_bus_lock(dev);
 443         wait_nvdimm_bus_probe_idle(dev);
 444         available = nd_region_allocatable_dpa(nd_region);
 445         nvdimm_bus_unlock(dev);
 446
 447         return sprintf(buf, "%llu\n", available);
 448 }
 449 static DEVICE_ATTR_RO(max_available_extent);
 450
 451 static ssize_t init_namespaces_show(struct device *dev,
 452                 struct device_attribute *attr, char *buf)
 453 {
 454         struct nd_region_data *ndrd = dev_get_drvdata(dev);
 455         ssize_t rc;
 456
 457         nvdimm_bus_lock(dev);
 458         if (ndrd)
 459                 rc = sprintf(buf, "%d/%d\n", ndrd->ns_active, ndrd->ns_count);
 460         else
 461                 rc = -ENXIO;
 462         nvdimm_bus_unlock(dev);
 463
 464         return rc;
 465 }
 466 static DEVICE_ATTR_RO(init_namespaces);
 467
 468 static ssize_t namespace_seed_show(struct device *dev,
 469                 struct device_attribute *attr, char *buf)
 470 {
 471         struct nd_region *nd_region = to_nd_region(dev);
 472         ssize_t rc;
 473
 474         nvdimm_bus_lock(dev);
 475         if (nd_region->ns_seed)
 476                 rc = sprintf(buf, "%s\n", dev_name(nd_region->ns_seed));
 477         else
 478                 rc = sprintf(buf, "\n");
 479         nvdimm_bus_unlock(dev);
 480         return rc;
 481 }
 482 static DEVICE_ATTR_RO(namespace_seed);
 483
 484 static ssize_t btt_seed_show(struct device *dev,
 485                 struct device_attribute *attr, char *buf)
 486 {
 487         struct nd_region *nd_region = to_nd_region(dev);
 488         ssize_t rc;
 489
 490         nvdimm_bus_lock(dev);
 491         if (nd_region->btt_seed)
 492                 rc = sprintf(buf, "%s\n", dev_name(nd_region->btt_seed));
 493         else
 494                 rc = sprintf(buf, "\n");
 495         nvdimm_bus_unlock(dev);
 496
 497         return rc;
 498 }
 499 static DEVICE_ATTR_RO(btt_seed);
 500
 501 static ssize_t pfn_seed_show(struct device *dev,
 502                 struct device_attribute *attr, char *buf)
 503 {
 504         struct nd_region *nd_region = to_nd_region(dev);
 505         ssize_t rc;
 506
 507         nvdimm_bus_lock(dev);
 508         if (nd_region->pfn_seed)
 509                 rc = sprintf(buf, "%s\n", dev_name(nd_region->pfn_seed));
 510         else
 511                 rc = sprintf(buf, "\n");
 512         nvdimm_bus_unlock(dev);
 513
 514         return rc;
 515 }
 516 static DEVICE_ATTR_RO(pfn_seed);
 517
 518 static ssize_t dax_seed_show(struct device *dev,
 519                 struct device_attribute *attr, char *buf)
 520 {
 521         struct nd_region *nd_region = to_nd_region(dev);
 522         ssize_t rc;
 523
 524         nvdimm_bus_lock(dev);
 525         if (nd_region->dax_seed)
 526                 rc = sprintf(buf, "%s\n", dev_name(nd_region->dax_seed));
 527         else
 528                 rc = sprintf(buf, "\n");
 529         nvdimm_bus_unlock(dev);
 530
 531         return rc;
 532 }
 533 static DEVICE_ATTR_RO(dax_seed);
 534
 535 static ssize_t read_only_show(struct device *dev,
 536                 struct device_attribute *attr, char *buf)
 537 {
 538         struct nd_region *nd_region = to_nd_region(dev);
 539
 540         return sprintf(buf, "%d\n", nd_region->ro);
 541 }
 542
 543 static ssize_t read_only_store(struct device *dev,
 544                 struct device_attribute *attr, const char *buf, size_t len)
 545 {
 546         bool ro;
 547         int rc = strtobool(buf, &ro);
 548         struct nd_region *nd_region = to_nd_region(dev);
 549
 550         if (rc)
 551                 return rc;
 552
 553         nd_region->ro = ro;
 554         return len;
 555 }
 556 static DEVICE_ATTR_RW(read_only);
 557
 558 static ssize_t region_badblocks_show(struct device *dev,
 559                 struct device_attribute *attr, char *buf)
 560 {
 561         struct nd_region *nd_region = to_nd_region(dev);
 562         ssize_t rc;
 563
 564         device_lock(dev);
 565         if (dev->driver)
 566                 rc = badblocks_show(&nd_region->bb, buf, 0);
 567         else
 568                 rc = -ENXIO;
 569         device_unlock(dev);
 570
 571         return rc;
 572 }
 573 static DEVICE_ATTR(badblocks, 0444, region_badblocks_show, NULL);
 574
 575 static ssize_t resource_show(struct device *dev,
 576                 struct device_attribute *attr, char *buf)
 577 {
 578         struct nd_region *nd_region = to_nd_region(dev);
 579
 580         return sprintf(buf, "%#llx\n", nd_region->ndr_start);
 581 }
 582 static DEVICE_ATTR_RO(resource);
 583
 584 static ssize_t persistence_domain_show(struct device *dev,
 585                 struct device_attribute *attr, char *buf)
 586 {
 587         struct nd_region *nd_region = to_nd_region(dev);
 588
 589         if (test_bit(ND_REGION_PERSIST_CACHE, &nd_region->flags))
 590                 return sprintf(buf, "cpu_cache\n");
 591         else if (test_bit(ND_REGION_PERSIST_MEMCTRL, &nd_region->flags))
 592                 return sprintf(buf, "memory_controller\n");
 593         else
 594                 return sprintf(buf, "\n");
 595 }
 596 static DEVICE_ATTR_RO(persistence_domain);
 597
 598 static struct attribute *nd_region_attributes[] = {
 599         &dev_attr_size.attr,
 600         &dev_attr_nstype.attr,
 601         &dev_attr_mappings.attr,
 602         &dev_attr_btt_seed.attr,
 603         &dev_attr_pfn_seed.attr,
 604         &dev_attr_dax_seed.attr,
 605         &dev_attr_deep_flush.attr,
 606         &dev_attr_read_only.attr,
 607         &dev_attr_set_cookie.attr,
 608         &dev_attr_available_size.attr,
 609         &dev_attr_max_available_extent.attr,
 610         &dev_attr_namespace_seed.attr,
 611         &dev_attr_init_namespaces.attr,
 612         &dev_attr_badblocks.attr,
 613         &dev_attr_resource.attr,
 614         &dev_attr_persistence_domain.attr,
 615         NULL,
 616 };
 617
 618 static umode_t region_visible(struct kobject *kobj, struct attribute *a, int n)
 619 {
 620         struct device *dev = container_of(kobj, typeof(*dev), kobj);
 621         struct nd_region *nd_region = to_nd_region(dev);
 622         struct nd_interleave_set *nd_set = nd_region->nd_set;
 623         int type = nd_region_to_nstype(nd_region);
 624
 625         if (!is_memory(dev) && a == &dev_attr_pfn_seed.attr)
 626                 return 0;
 627
 628         if (!is_memory(dev) && a == &dev_attr_dax_seed.attr)
 629                 return 0;
 630
 631         if (!is_nd_pmem(dev) && a == &dev_attr_badblocks.attr)
 632                 return 0;
 633
 634         if (a == &dev_attr_resource.attr) {
 635                 if (is_nd_pmem(dev))
 636                         return 0400;
 637                 else
 638                         return 0;
 639         }
 640
 641         if (a == &dev_attr_deep_flush.attr) {
 642                 int has_flush = nvdimm_has_flush(nd_region);
 643
 644                 if (has_flush == 1)
 645                         return a->mode;
 646                 else if (has_flush == 0)
 647                         return 0444;
 648                 else
 649                         return 0;
 650         }
 651
 652         if (a == &dev_attr_persistence_domain.attr) {
 653                 if ((nd_region->flags & (BIT(ND_REGION_PERSIST_CACHE)
 654                                         | BIT(ND_REGION_PERSIST_MEMCTRL))) == 0)
 655                         return 0;
 656                 return a->mode;
 657         }
 658
 659         if (a != &dev_attr_set_cookie.attr
 660                         && a != &dev_attr_available_size.attr)
 661                 return a->mode;
 662
 663         if ((type == ND_DEVICE_NAMESPACE_PMEM
 664                                 || type == ND_DEVICE_NAMESPACE_BLK)
 665                         && a == &dev_attr_available_size.attr)
 666                 return a->mode;
 667         else if (is_memory(dev) && nd_set)
 668                 return a->mode;
 669
 670         return 0;
 671 }
 672
 673 struct attribute_group nd_region_attribute_group = {
 674         .attrs = nd_region_attributes,
 675         .is_visible = region_visible,
 676 };
 677 EXPORT_SYMBOL_GPL(nd_region_attribute_group);
 678
 679 u64 nd_region_interleave_set_cookie(struct nd_region *nd_region,
 680                 struct nd_namespace_index *nsindex)
 681 {
 682         struct nd_interleave_set *nd_set = nd_region->nd_set;
 683
 684         if (!nd_set)
 685                 return 0;
 686
 687         if (nsindex && __le16_to_cpu(nsindex->major) == 1
 688                         && __le16_to_cpu(nsindex->minor) == 1)
 689                 return nd_set->cookie1;
 690         return nd_set->cookie2;
 691 }
 692
 693 u64 nd_region_interleave_set_altcookie(struct nd_region *nd_region)
 694 {
 695         struct nd_interleave_set *nd_set = nd_region->nd_set;
 696
 697         if (nd_set)
 698                 return nd_set->altcookie;
 699         return 0;
 700 }
 701
 702 void nd_mapping_free_labels(struct nd_mapping *nd_mapping)
 703 {
 704         struct nd_label_ent *label_ent, *e;
 705
 706         lockdep_assert_held(&nd_mapping->lock);
 707         list_for_each_entry_safe(label_ent, e, &nd_mapping->labels, list) {
 708                 list_del(&label_ent->list);
 709                 kfree(label_ent);
 710         }
 711 }
 712
 713 /*
 714  * Upon successful probe/remove, take/release a reference on the
 715  * associated interleave set (if present), and plant new btt + namespace
 716  * seeds.  Also, on the removal of a BLK region, notify the provider to
 717  * disable the region.
 718  */
 719 static void nd_region_notify_driver_action(struct nvdimm_bus *nvdimm_bus,
 720                 struct device *dev, bool probe)
 721 {
 722         struct nd_region *nd_region;
 723
 724         if (!probe && is_nd_region(dev)) {
 725                 int i;
 726
 727                 nd_region = to_nd_region(dev);
 728                 for (i = 0; i < nd_region->ndr_mappings; i++) {
 729                         struct nd_mapping *nd_mapping = &nd_region->mapping[i];
 730                         struct nvdimm_drvdata *ndd = nd_mapping->ndd;
 731                         struct nvdimm *nvdimm = nd_mapping->nvdimm;
 732
 733                         mutex_lock(&nd_mapping->lock);
 734                         nd_mapping_free_labels(nd_mapping);
 735                         mutex_unlock(&nd_mapping->lock);
 736
 737                         put_ndd(ndd);
 738                         nd_mapping->ndd = NULL;
 739                         if (ndd)
 740                                 atomic_dec(&nvdimm->busy);
 741                 }
 742         }
 743         if (dev->parent && is_nd_region(dev->parent) && probe) {
 744                 nd_region = to_nd_region(dev->parent);
 745                 nvdimm_bus_lock(dev);
 746                 if (nd_region->ns_seed == dev)
 747                         nd_region_create_ns_seed(nd_region);
 748                 nvdimm_bus_unlock(dev);
 749         }
 750         if (is_nd_btt(dev) && probe) {
 751                 struct nd_btt *nd_btt = to_nd_btt(dev);
 752
 753                 nd_region = to_nd_region(dev->parent);
 754                 nvdimm_bus_lock(dev);
 755                 if (nd_region->btt_seed == dev)
 756                         nd_region_create_btt_seed(nd_region);
 757                 if (nd_region->ns_seed == &nd_btt->ndns->dev)
 758                         nd_region_create_ns_seed(nd_region);
 759                 nvdimm_bus_unlock(dev);
 760         }
 761         if (is_nd_pfn(dev) && probe) {
 762                 struct nd_pfn *nd_pfn = to_nd_pfn(dev);
 763
 764                 nd_region = to_nd_region(dev->parent);
 765                 nvdimm_bus_lock(dev);
 766                 if (nd_region->pfn_seed == dev)
 767                         nd_region_create_pfn_seed(nd_region);
 768                 if (nd_region->ns_seed == &nd_pfn->ndns->dev)
 769                         nd_region_create_ns_seed(nd_region);
 770                 nvdimm_bus_unlock(dev);
 771         }
 772         if (is_nd_dax(dev) && probe) {
 773                 struct nd_dax *nd_dax = to_nd_dax(dev);
 774
 775                 nd_region = to_nd_region(dev->parent);
 776                 nvdimm_bus_lock(dev);
 777                 if (nd_region->dax_seed == dev)
 778                         nd_region_create_dax_seed(nd_region);
 779                 if (nd_region->ns_seed == &nd_dax->nd_pfn.ndns->dev)
 780                         nd_region_create_ns_seed(nd_region);
 781                 nvdimm_bus_unlock(dev);
 782         }
 783 }
 784
 785 void nd_region_probe_success(struct nvdimm_bus *nvdimm_bus, struct device *dev)
 786 {
 787         nd_region_notify_driver_action(nvdimm_bus, dev, true);
 788 }
 789
 790 void nd_region_disable(struct nvdimm_bus *nvdimm_bus, struct device *dev)
 791 {
 792         nd_region_notify_driver_action(nvdimm_bus, dev, false);
 793 }
 794
 795 static ssize_t mappingN(struct device *dev, char *buf, int n)
 796 {
 797         struct nd_region *nd_region = to_nd_region(dev);
 798         struct nd_mapping *nd_mapping;
 799         struct nvdimm *nvdimm;
 800
 801         if (n >= nd_region->ndr_mappings)
 802                 return -ENXIO;
 803         nd_mapping = &nd_region->mapping[n];
 804         nvdimm = nd_mapping->nvdimm;
 805
 806         return sprintf(buf, "%s,%llu,%llu,%d\n", dev_name(&nvdimm->dev),
 807                         nd_mapping->start, nd_mapping->size,
 808                         nd_mapping->position);
 809 }
 810
 811 #define REGION_MAPPING(idx) \
 812 static ssize_t mapping##idx##_show(struct device *dev,          \
 813                 struct device_attribute *attr, char *buf)       \
 814 {                                                               \
 815         return mappingN(dev, buf, idx);                         \
 816 }                                                               \
 817 static DEVICE_ATTR_RO(mapping##idx)
 818
 819 /*
 820  * 32 should be enough for a while, even in the presence of socket
 821  * interleave a 32-way interleave set is a degenerate case.
 822  */
 823 REGION_MAPPING(0);
 824 REGION_MAPPING(1);
 825 REGION_MAPPING(2);
 826 REGION_MAPPING(3);
 827 REGION_MAPPING(4);
 828 REGION_MAPPING(5);
 829 REGION_MAPPING(6);
 830 REGION_MAPPING(7);
 831 REGION_MAPPING(8);
 832 REGION_MAPPING(9);
 833 REGION_MAPPING(10);
 834 REGION_MAPPING(11);
 835 REGION_MAPPING(12);
 836 REGION_MAPPING(13);
 837 REGION_MAPPING(14);
 838 REGION_MAPPING(15);
 839 REGION_MAPPING(16);
 840 REGION_MAPPING(17);
 841 REGION_MAPPING(18);
 842 REGION_MAPPING(19);
 843 REGION_MAPPING(20);
 844 REGION_MAPPING(21);
 845 REGION_MAPPING(22);
 846 REGION_MAPPING(23);
 847 REGION_MAPPING(24);
 848 REGION_MAPPING(25);
 849 REGION_MAPPING(26);
 850 REGION_MAPPING(27);
 851 REGION_MAPPING(28);
 852 REGION_MAPPING(29);
 853 REGION_MAPPING(30);
 854 REGION_MAPPING(31);
 855
 856 static umode_t mapping_visible(struct kobject *kobj, struct attribute *a, int n)
 857 {
 858         struct device *dev = container_of(kobj, struct device, kobj);
 859         struct nd_region *nd_region = to_nd_region(dev);
 860
 861         if (n < nd_region->ndr_mappings)
 862                 return a->mode;
 863         return 0;
 864 }
 865
 866 static struct attribute *mapping_attributes[] = {
 867         &dev_attr_mapping0.attr,
 868         &dev_attr_mapping1.attr,
 869         &dev_attr_mapping2.attr,
 870         &dev_attr_mapping3.attr,
 871         &dev_attr_mapping4.attr,
 872         &dev_attr_mapping5.attr,
 873         &dev_attr_mapping6.attr,
 874         &dev_attr_mapping7.attr,
 875         &dev_attr_mapping8.attr,
 876         &dev_attr_mapping9.attr,
 877         &dev_attr_mapping10.attr,
 878         &dev_attr_mapping11.attr,
 879         &dev_attr_mapping12.attr,
 880         &dev_attr_mapping13.attr,
 881         &dev_attr_mapping14.attr,
 882         &dev_attr_mapping15.attr,
 883         &dev_attr_mapping16.attr,
 884         &dev_attr_mapping17.attr,
 885         &dev_attr_mapping18.attr,
 886         &dev_attr_mapping19.attr,
 887         &dev_attr_mapping20.attr,
 888         &dev_attr_mapping21.attr,
 889         &dev_attr_mapping22.attr,
 890         &dev_attr_mapping23.attr,
 891         &dev_attr_mapping24.attr,
 892         &dev_attr_mapping25.attr,
 893         &dev_attr_mapping26.attr,
 894         &dev_attr_mapping27.attr,
 895         &dev_attr_mapping28.attr,
 896         &dev_attr_mapping29.attr,
 897         &dev_attr_mapping30.attr,
 898         &dev_attr_mapping31.attr,
 899         NULL,
 900 };
 901
 902 struct attribute_group nd_mapping_attribute_group = {
 903         .is_visible = mapping_visible,
 904         .attrs = mapping_attributes,
 905 };
 906 EXPORT_SYMBOL_GPL(nd_mapping_attribute_group);
 907
 908 int nd_blk_region_init(struct nd_region *nd_region)
 909 {
 910         struct device *dev = &nd_region->dev;
 911         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 912
 913         if (!is_nd_blk(dev))
 914                 return 0;
 915
 916         if (nd_region->ndr_mappings < 1) {
 917                 dev_dbg(dev, "invalid BLK region\n");
 918                 return -ENXIO;
 919         }
 920
 921         return to_nd_blk_region(dev)->enable(nvdimm_bus, dev);
 922 }
 923
 924 /**
 925  * nd_region_acquire_lane - allocate and lock a lane
 926  * @nd_region: region id and number of lanes possible
 927  *
 928  * A lane correlates to a BLK-data-window and/or a log slot in the BTT.
 929  * We optimize for the common case where there are 256 lanes, one
 930  * per-cpu.  For larger systems we need to lock to share lanes.  For now
 931  * this implementation assumes the cost of maintaining an allocator for
 932  * free lanes is on the order of the lock hold time, so it implements a
 933  * static lane = cpu % num_lanes mapping.
 934  *
 935  * In the case of a BTT instance on top of a BLK namespace a lane may be
 936  * acquired recursively.  We lock on the first instance.
 937  *
 938  * In the case of a BTT instance on top of PMEM, we only acquire a lane
 939  * for the BTT metadata updates.
 940  */
 941 unsigned int nd_region_acquire_lane(struct nd_region *nd_region)
 942 {
 943         unsigned int cpu, lane;
 944
 945         cpu = get_cpu();
 946         if (nd_region->num_lanes < nr_cpu_ids) {
 947                 struct nd_percpu_lane *ndl_lock, *ndl_count;
 948
 949                 lane = cpu % nd_region->num_lanes;
 950                 ndl_count = per_cpu_ptr(nd_region->lane, cpu);
 951                 ndl_lock = per_cpu_ptr(nd_region->lane, lane);
 952                 if (ndl_count->count++ == 0)
 953                         spin_lock(&ndl_lock->lock);
 954         } else
 955                 lane = cpu;
 956
 957         return lane;
 958 }
 959 EXPORT_SYMBOL(nd_region_acquire_lane);
 960
 961 void nd_region_release_lane(struct nd_region *nd_region, unsigned int lane)
 962 {
 963         if (nd_region->num_lanes < nr_cpu_ids) {
 964                 unsigned int cpu = get_cpu();
 965                 struct nd_percpu_lane *ndl_lock, *ndl_count;
 966
 967                 ndl_count = per_cpu_ptr(nd_region->lane, cpu);
 968                 ndl_lock = per_cpu_ptr(nd_region->lane, lane);
 969                 if (--ndl_count->count == 0)
 970                         spin_unlock(&ndl_lock->lock);
 971                 put_cpu();
 972         }
 973         put_cpu();
 974 }
 975 EXPORT_SYMBOL(nd_region_release_lane);
 976
 977 static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
 978                 struct nd_region_desc *ndr_desc, struct device_type *dev_type,
 979                 const char *caller)
 980 {
 981         struct nd_region *nd_region;
 982         struct device *dev;
 983         void *region_buf;
 984         unsigned int i;
 985         int ro = 0;
 986
 987         for (i = 0; i < ndr_desc->num_mappings; i++) {
 988                 struct nd_mapping_desc *mapping = &ndr_desc->mapping[i];
 989                 struct nvdimm *nvdimm = mapping->nvdimm;
 990
 991                 if ((mapping->start | mapping->size) % SZ_4K) {
 992                         dev_err(&nvdimm_bus->dev, "%s: %s mapping%d is not 4K aligned\n",
 993                                         caller, dev_name(&nvdimm->dev), i);
 994
 995                         return NULL;
 996                 }
 997
 998                 if (test_bit(NDD_UNARMED, &nvdimm->flags))
 999                         ro = 1;
1000
1001                 if (test_bit(NDD_NOBLK, &nvdimm->flags)
1002                                 && dev_type == &nd_blk_device_type) {
1003                         dev_err(&nvdimm_bus->dev, "%s: %s mapping%d is not BLK capable\n",
1004                                         caller, dev_name(&nvdimm->dev), i);
1005                         return NULL;
1006                 }
1007         }
1008
1009         if (dev_type == &nd_blk_device_type) {
1010                 struct nd_blk_region_desc *ndbr_desc;
1011                 struct nd_blk_region *ndbr;
1012
1013                 ndbr_desc = to_blk_region_desc(ndr_desc);
1014                 ndbr = kzalloc(sizeof(*ndbr) + sizeof(struct nd_mapping)
1015                                 * ndr_desc->num_mappings,
1016                                 GFP_KERNEL);
1017                 if (ndbr) {
1018                         nd_region = &ndbr->nd_region;
1019                         ndbr->enable = ndbr_desc->enable;
1020                         ndbr->do_io = ndbr_desc->do_io;
1021                 }
1022                 region_buf = ndbr;
1023         } else {
1024                 nd_region = kzalloc(sizeof(struct nd_region)
1025                                 + sizeof(struct nd_mapping)
1026                                 * ndr_desc->num_mappings,
1027                                 GFP_KERNEL);
1028                 region_buf = nd_region;
1029         }
1030
1031         if (!region_buf)
1032                 return NULL;
1033         nd_region->id = ida_simple_get(&region_ida, 0, 0, GFP_KERNEL);
1034         if (nd_region->id < 0)
1035                 goto err_id;
1036
1037         nd_region->lane = alloc_percpu(struct nd_percpu_lane);
1038         if (!nd_region->lane)
1039                 goto err_percpu;
1040
1041         for (i = 0; i < nr_cpu_ids; i++) {
1042                 struct nd_percpu_lane *ndl;
1043
1044                 ndl = per_cpu_ptr(nd_region->lane, i);
1045                 spin_lock_init(&ndl->lock);
1046                 ndl->count = 0;
1047         }
1048
1049         for (i = 0; i < ndr_desc->num_mappings; i++) {
1050                 struct nd_mapping_desc *mapping = &ndr_desc->mapping[i];
1051                 struct nvdimm *nvdimm = mapping->nvdimm;
1052
1053                 nd_region->mapping[i].nvdimm = nvdimm;
1054                 nd_region->mapping[i].start = mapping->start;
1055                 nd_region->mapping[i].size = mapping->size;
1056                 nd_region->mapping[i].position = mapping->position;
1057                 INIT_LIST_HEAD(&nd_region->mapping[i].labels);
1058                 mutex_init(&nd_region->mapping[i].lock);
1059
1060                 get_device(&nvdimm->dev);
1061         }
1062         nd_region->ndr_mappings = ndr_desc->num_mappings;
1063         nd_region->provider_data = ndr_desc->provider_data;
1064         nd_region->nd_set = ndr_desc->nd_set;
1065         nd_region->num_lanes = ndr_desc->num_lanes;
1066         nd_region->flags = ndr_desc->flags;
1067         nd_region->ro = ro;
1068         nd_region->numa_node = ndr_desc->numa_node;
1069         nd_region->target_node = ndr_desc->target_node;
1070         ida_init(&nd_region->ns_ida);
1071         ida_init(&nd_region->btt_ida);
1072         ida_init(&nd_region->pfn_ida);
1073         ida_init(&nd_region->dax_ida);
1074         dev = &nd_region->dev;
1075         dev_set_name(dev, "region%d", nd_region->id);
1076         dev->parent = &nvdimm_bus->dev;
1077         dev->type = dev_type;
1078         dev->groups = ndr_desc->attr_groups;
1079         dev->of_node = ndr_desc->of_node;
1080         nd_region->ndr_size = resource_size(ndr_desc->res);
1081         nd_region->ndr_start = ndr_desc->res->start;
1082         if (ndr_desc->flush)
1083                 nd_region->flush = ndr_desc->flush;
1084         else
1085                 nd_region->flush = NULL;
1086
1087         nd_device_register(dev);
1088
1089         return nd_region;
1090
1091  err_percpu:
1092         ida_simple_remove(&region_ida, nd_region->id);
1093  err_id:
1094         kfree(region_buf);
1095         return NULL;
1096 }
1097
1098 struct nd_region *nvdimm_pmem_region_create(struct nvdimm_bus *nvdimm_bus,
1099                 struct nd_region_desc *ndr_desc)
1100 {
1101         ndr_desc->num_lanes = ND_MAX_LANES;
1102         return nd_region_create(nvdimm_bus, ndr_desc, &nd_pmem_device_type,
1103                         __func__);
1104 }
1105 EXPORT_SYMBOL_GPL(nvdimm_pmem_region_create);
1106
1107 struct nd_region *nvdimm_blk_region_create(struct nvdimm_bus *nvdimm_bus,
1108                 struct nd_region_desc *ndr_desc)
1109 {
1110         if (ndr_desc->num_mappings > 1)
1111                 return NULL;
1112         ndr_desc->num_lanes = min(ndr_desc->num_lanes, ND_MAX_LANES);
1113         return nd_region_create(nvdimm_bus, ndr_desc, &nd_blk_device_type,
1114                         __func__);
1115 }
1116 EXPORT_SYMBOL_GPL(nvdimm_blk_region_create);
1117
1118 struct nd_region *nvdimm_volatile_region_create(struct nvdimm_bus *nvdimm_bus,
1119                 struct nd_region_desc *ndr_desc)
1120 {
1121         ndr_desc->num_lanes = ND_MAX_LANES;
1122         return nd_region_create(nvdimm_bus, ndr_desc, &nd_volatile_device_type,
1123                         __func__);
1124 }
1125 EXPORT_SYMBOL_GPL(nvdimm_volatile_region_create);
1126
1127 int nvdimm_flush(struct nd_region *nd_region, struct bio *bio)
1128 {
1129         int rc = 0;
1130
1131         if (!nd_region->flush)
1132                 rc = generic_nvdimm_flush(nd_region);
1133         else {
1134                 if (nd_region->flush(nd_region, bio))
1135                         rc = -EIO;
1136         }
1137
1138         return rc;
1139 }
1140 /**
1141  * nvdimm_flush - flush any posted write queues between the cpu and pmem media
1142  * @nd_region: blk or interleaved pmem region
1143  */
1144 int generic_nvdimm_flush(struct nd_region *nd_region)
1145 {
1146         struct nd_region_data *ndrd = dev_get_drvdata(&nd_region->dev);
1147         int i, idx;
1148
1149         /*
1150          * Try to encourage some diversity in flush hint addresses
1151          * across cpus assuming a limited number of flush hints.
1152          */
1153         idx = this_cpu_read(flush_idx);
1154         idx = this_cpu_add_return(flush_idx, hash_32(current->pid + idx, 8));
1155
1156         /*
1157          * The first wmb() is needed to 'sfence' all previous writes
1158          * such that they are architecturally visible for the platform
1159          * buffer flush.  Note that we've already arranged for pmem
1160          * writes to avoid the cache via memcpy_flushcache().  The final
1161          * wmb() ensures ordering for the NVDIMM flush write.
1162          */
1163         wmb();
1164         for (i = 0; i < nd_region->ndr_mappings; i++)
1165                 if (ndrd_get_flush_wpq(ndrd, i, 0))
1166                         writeq(1, ndrd_get_flush_wpq(ndrd, i, idx));
1167         wmb();
1168
1169         return 0;
1170 }
1171 EXPORT_SYMBOL_GPL(nvdimm_flush);
1172
1173 /**
1174  * nvdimm_has_flush - determine write flushing requirements
1175  * @nd_region: blk or interleaved pmem region
1176  *
1177  * Returns 1 if writes require flushing
1178  * Returns 0 if writes do not require flushing
1179  * Returns -ENXIO if flushing capability can not be determined
1180  */
1181 int nvdimm_has_flush(struct nd_region *nd_region)
1182 {
1183         int i;
1184
1185         /* no nvdimm or pmem api == flushing capability unknown */
1186         if (nd_region->ndr_mappings == 0
1187                         || !IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API))
1188                 return -ENXIO;
1189
1190         for (i = 0; i < nd_region->ndr_mappings; i++) {
1191                 struct nd_mapping *nd_mapping = &nd_region->mapping[i];
1192                 struct nvdimm *nvdimm = nd_mapping->nvdimm;
1193
1194                 /* flush hints present / available */
1195                 if (nvdimm->num_flush)
1196                         return 1;
1197         }
1198
1199         /*
1200          * The platform defines dimm devices without hints, assume
1201          * platform persistence mechanism like ADR
1202          */
1203         return 0;
1204 }
1205 EXPORT_SYMBOL_GPL(nvdimm_has_flush);
1206
1207 int nvdimm_has_cache(struct nd_region *nd_region)
1208 {
1209         return is_nd_pmem(&nd_region->dev) &&
1210                 !test_bit(ND_REGION_PERSIST_CACHE, &nd_region->flags);
1211 }
1212 EXPORT_SYMBOL_GPL(nvdimm_has_cache);
1213
1214 bool is_nvdimm_sync(struct nd_region *nd_region)
1215 {
1216         return is_nd_pmem(&nd_region->dev) &&
1217                 !test_bit(ND_REGION_ASYNC, &nd_region->flags);
1218 }
1219 EXPORT_SYMBOL_GPL(is_nvdimm_sync);
1220
1221 struct conflict_context {
1222         struct nd_region *nd_region;
1223         resource_size_t start, size;
1224 };
1225
1226 static int region_conflict(struct device *dev, void *data)
1227 {
1228         struct nd_region *nd_region;
1229         struct conflict_context *ctx = data;
1230         resource_size_t res_end, region_end, region_start;
1231
1232         if (!is_memory(dev))
1233                 return 0;
1234
1235         nd_region = to_nd_region(dev);
1236         if (nd_region == ctx->nd_region)
1237                 return 0;
1238
1239         res_end = ctx->start + ctx->size;
1240         region_start = nd_region->ndr_start;
1241         region_end = region_start + nd_region->ndr_size;
1242         if (ctx->start >= region_start && ctx->start < region_end)
1243                 return -EBUSY;
1244         if (res_end > region_start && res_end <= region_end)
1245                 return -EBUSY;
1246         return 0;
1247 }
1248
1249 int nd_region_conflict(struct nd_region *nd_region, resource_size_t start,
1250                 resource_size_t size)
1251 {
1252         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
1253         struct conflict_context ctx = {
1254                 .nd_region = nd_region,
1255                 .start = start,
1256                 .size = size,
1257         };
1258
1259         return device_for_each_child(&nvdimm_bus->dev, &ctx, region_conflict);
1260 }
1261
1262 void __exit nd_region_devs_exit(void)
1263 {
1264         ida_destroy(&region_ida);
1265 }