drivers/nvdimm/region_devs.c

   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 }