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/memregion.h>
   7 #include <linux/highmem.h>
   8 #include <linux/sched.h>
   9 #include <linux/slab.h>
  10 #include <linux/hash.h>
  11 #include <linux/sort.h>
  12 #include <linux/io.h>
  13 #include <linux/nd.h>
  14 #include "nd-core.h"
  15 #include "nd.h"
  16
  17 /*
  18  * For readq() and writeq() on 32-bit builds, the hi-lo, lo-hi order is
  19  * irrelevant.
  20  */
  21 #include <linux/io-64-nonatomic-hi-lo.h>
  22
  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         memregion_free(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 struct nd_region *to_nd_region(struct device *dev)
 144 {
 145         struct nd_region *nd_region = container_of(dev, struct nd_region, dev);
 146
 147         WARN_ON(dev->type->release != nd_region_release);
 148         return nd_region;
 149 }
 150 EXPORT_SYMBOL_GPL(to_nd_region);
 151
 152 struct device *nd_region_dev(struct nd_region *nd_region)
 153 {
 154         if (!nd_region)
 155                 return NULL;
 156         return &nd_region->dev;
 157 }
 158 EXPORT_SYMBOL_GPL(nd_region_dev);
 159
 160 struct nd_blk_region *to_nd_blk_region(struct device *dev)
 161 {
 162         struct nd_region *nd_region = to_nd_region(dev);
 163
 164         WARN_ON(!is_nd_blk(dev));
 165         return container_of(nd_region, struct nd_blk_region, nd_region);
 166 }
 167 EXPORT_SYMBOL_GPL(to_nd_blk_region);
 168
 169 void *nd_region_provider_data(struct nd_region *nd_region)
 170 {
 171         return nd_region->provider_data;
 172 }
 173 EXPORT_SYMBOL_GPL(nd_region_provider_data);
 174
 175 void *nd_blk_region_provider_data(struct nd_blk_region *ndbr)
 176 {
 177         return ndbr->blk_provider_data;
 178 }
 179 EXPORT_SYMBOL_GPL(nd_blk_region_provider_data);
 180
 181 void nd_blk_region_set_provider_data(struct nd_blk_region *ndbr, void *data)
 182 {
 183         ndbr->blk_provider_data = data;
 184 }
 185 EXPORT_SYMBOL_GPL(nd_blk_region_set_provider_data);
 186
 187 /**
 188  * nd_region_to_nstype() - region to an integer namespace type
 189  * @nd_region: region-device to interrogate
 190  *
 191  * This is the 'nstype' attribute of a region as well, an input to the
 192  * MODALIAS for namespace devices, and bit number for a nvdimm_bus to match
 193  * namespace devices with namespace drivers.
 194  */
 195 int nd_region_to_nstype(struct nd_region *nd_region)
 196 {
 197         if (is_memory(&nd_region->dev)) {
 198                 u16 i, label;
 199
 200                 for (i = 0, label = 0; i < nd_region->ndr_mappings; i++) {
 201                         struct nd_mapping *nd_mapping = &nd_region->mapping[i];
 202                         struct nvdimm *nvdimm = nd_mapping->nvdimm;
 203
 204                         if (test_bit(NDD_LABELING, &nvdimm->flags))
 205                                 label++;
 206                 }
 207                 if (label)
 208                         return ND_DEVICE_NAMESPACE_PMEM;
 209                 else
 210                         return ND_DEVICE_NAMESPACE_IO;
 211         } else if (is_nd_blk(&nd_region->dev)) {
 212                 return ND_DEVICE_NAMESPACE_BLK;
 213         }
 214
 215         return 0;
 216 }
 217 EXPORT_SYMBOL(nd_region_to_nstype);
 218
 219 static unsigned long long region_size(struct nd_region *nd_region)
 220 {
 221         if (is_memory(&nd_region->dev)) {
 222                 return nd_region->ndr_size;
 223         } else if (nd_region->ndr_mappings == 1) {
 224                 struct nd_mapping *nd_mapping = &nd_region->mapping[0];
 225
 226                 return nd_mapping->size;
 227         }
 228
 229         return 0;
 230 }
 231
 232 static ssize_t size_show(struct device *dev,
 233                 struct device_attribute *attr, char *buf)
 234 {
 235         struct nd_region *nd_region = to_nd_region(dev);
 236
 237         return sprintf(buf, "%llu\n", region_size(nd_region));
 238 }
 239 static DEVICE_ATTR_RO(size);
 240
 241 static ssize_t deep_flush_show(struct device *dev,
 242                 struct device_attribute *attr, char *buf)
 243 {
 244         struct nd_region *nd_region = to_nd_region(dev);
 245
 246         /*
 247          * NOTE: in the nvdimm_has_flush() error case this attribute is
 248          * not visible.
 249          */
 250         return sprintf(buf, "%d\n", nvdimm_has_flush(nd_region));
 251 }
 252
 253 static ssize_t deep_flush_store(struct device *dev, struct device_attribute *attr,
 254                 const char *buf, size_t len)
 255 {
 256         bool flush;
 257         int rc = strtobool(buf, &flush);
 258         struct nd_region *nd_region = to_nd_region(dev);
 259
 260         if (rc)
 261                 return rc;
 262         if (!flush)
 263                 return -EINVAL;
 264         rc = nvdimm_flush(nd_region, NULL);
 265         if (rc)
 266                 return rc;
 267
 268         return len;
 269 }
 270 static DEVICE_ATTR_RW(deep_flush);
 271
 272 static ssize_t mappings_show(struct device *dev,
 273                 struct device_attribute *attr, char *buf)
 274 {
 275         struct nd_region *nd_region = to_nd_region(dev);
 276
 277         return sprintf(buf, "%d\n", nd_region->ndr_mappings);
 278 }
 279 static DEVICE_ATTR_RO(mappings);
 280
 281 static ssize_t nstype_show(struct device *dev,
 282                 struct device_attribute *attr, char *buf)
 283 {
 284         struct nd_region *nd_region = to_nd_region(dev);
 285
 286         return sprintf(buf, "%d\n", nd_region_to_nstype(nd_region));
 287 }
 288 static DEVICE_ATTR_RO(nstype);
 289
 290 static ssize_t set_cookie_show(struct device *dev,
 291                 struct device_attribute *attr, char *buf)
 292 {
 293         struct nd_region *nd_region = to_nd_region(dev);
 294         struct nd_interleave_set *nd_set = nd_region->nd_set;
 295         ssize_t rc = 0;
 296
 297         if (is_memory(dev) && nd_set)
 298                 /* pass, should be precluded by region_visible */;
 299         else
 300                 return -ENXIO;
 301
 302         /*
 303          * The cookie to show depends on which specification of the
 304          * labels we are using. If there are not labels then default to
 305          * the v1.1 namespace label cookie definition. To read all this
 306          * data we need to wait for probing to settle.
 307          */
 308         nd_device_lock(dev);
 309         nvdimm_bus_lock(dev);
 310         wait_nvdimm_bus_probe_idle(dev);
 311         if (nd_region->ndr_mappings) {
 312                 struct nd_mapping *nd_mapping = &nd_region->mapping[0];
 313                 struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
 314
 315                 if (ndd) {
 316                         struct nd_namespace_index *nsindex;
 317
 318                         nsindex = to_namespace_index(ndd, ndd->ns_current);
 319                         rc = sprintf(buf, "%#llx\n",
 320                                         nd_region_interleave_set_cookie(nd_region,
 321                                                 nsindex));
 322                 }
 323         }
 324         nvdimm_bus_unlock(dev);
 325         nd_device_unlock(dev);
 326
 327         if (rc)
 328                 return rc;
 329         return sprintf(buf, "%#llx\n", nd_set->cookie1);
 330 }
 331 static DEVICE_ATTR_RO(set_cookie);
 332
 333 resource_size_t nd_region_available_dpa(struct nd_region *nd_region)
 334 {
 335         resource_size_t blk_max_overlap = 0, available, overlap;
 336         int i;
 337
 338         WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
 339
 340  retry:
 341         available = 0;
 342         overlap = blk_max_overlap;
 343         for (i = 0; i < nd_region->ndr_mappings; i++) {
 344                 struct nd_mapping *nd_mapping = &nd_region->mapping[i];
 345                 struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
 346
 347                 /* if a dimm is disabled the available capacity is zero */
 348                 if (!ndd)
 349                         return 0;
 350
 351                 if (is_memory(&nd_region->dev)) {
 352                         available += nd_pmem_available_dpa(nd_region,
 353                                         nd_mapping, &overlap);
 354                         if (overlap > blk_max_overlap) {
 355                                 blk_max_overlap = overlap;
 356                                 goto retry;
 357                         }
 358                 } else if (is_nd_blk(&nd_region->dev))
 359                         available += nd_blk_available_dpa(nd_region);
 360         }
 361
 362         return available;
 363 }
 364
 365 resource_size_t nd_region_allocatable_dpa(struct nd_region *nd_region)
 366 {
 367         resource_size_t available = 0;
 368         int i;
 369
 370         if (is_memory(&nd_region->dev))
 371                 available = PHYS_ADDR_MAX;
 372
 373         WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
 374         for (i = 0; i < nd_region->ndr_mappings; i++) {
 375                 struct nd_mapping *nd_mapping = &nd_region->mapping[i];
 376
 377                 if (is_memory(&nd_region->dev))
 378                         available = min(available,
 379                                         nd_pmem_max_contiguous_dpa(nd_region,
 380                                                                    nd_mapping));
 381                 else if (is_nd_blk(&nd_region->dev))
 382                         available += nd_blk_available_dpa(nd_region);
 383         }
 384         if (is_memory(&nd_region->dev))
 385                 return available * nd_region->ndr_mappings;
 386         return available;
 387 }
 388
 389 static ssize_t available_size_show(struct device *dev,
 390                 struct device_attribute *attr, char *buf)
 391 {
 392         struct nd_region *nd_region = to_nd_region(dev);
 393         unsigned long long available = 0;
 394
 395         /*
 396          * Flush in-flight updates and grab a snapshot of the available
 397          * size.  Of course, this value is potentially invalidated the
 398          * memory nvdimm_bus_lock() is dropped, but that's userspace's
 399          * problem to not race itself.
 400          */
 401         nd_device_lock(dev);
 402         nvdimm_bus_lock(dev);
 403         wait_nvdimm_bus_probe_idle(dev);
 404         available = nd_region_available_dpa(nd_region);
 405         nvdimm_bus_unlock(dev);
 406         nd_device_unlock(dev);
 407
 408         return sprintf(buf, "%llu\n", available);
 409 }
 410 static DEVICE_ATTR_RO(available_size);
 411
 412 static ssize_t max_available_extent_show(struct device *dev,
 413                 struct device_attribute *attr, char *buf)
 414 {
 415         struct nd_region *nd_region = to_nd_region(dev);
 416         unsigned long long available = 0;
 417
 418         nd_device_lock(dev);
 419         nvdimm_bus_lock(dev);
 420         wait_nvdimm_bus_probe_idle(dev);
 421         available = nd_region_allocatable_dpa(nd_region);
 422         nvdimm_bus_unlock(dev);
 423         nd_device_unlock(dev);
 424
 425         return sprintf(buf, "%llu\n", available);
 426 }
 427 static DEVICE_ATTR_RO(max_available_extent);
 428
 429 static ssize_t init_namespaces_show(struct device *dev,
 430                 struct device_attribute *attr, char *buf)
 431 {
 432         struct nd_region_data *ndrd = dev_get_drvdata(dev);
 433         ssize_t rc;
 434
 435         nvdimm_bus_lock(dev);
 436         if (ndrd)
 437                 rc = sprintf(buf, "%d/%d\n", ndrd->ns_active, ndrd->ns_count);
 438         else
 439                 rc = -ENXIO;
 440         nvdimm_bus_unlock(dev);
 441
 442         return rc;
 443 }
 444 static DEVICE_ATTR_RO(init_namespaces);
 445
 446 static ssize_t namespace_seed_show(struct device *dev,
 447                 struct device_attribute *attr, char *buf)
 448 {
 449         struct nd_region *nd_region = to_nd_region(dev);
 450         ssize_t rc;
 451
 452         nvdimm_bus_lock(dev);
 453         if (nd_region->ns_seed)
 454                 rc = sprintf(buf, "%s\n", dev_name(nd_region->ns_seed));
 455         else
 456                 rc = sprintf(buf, "\n");
 457         nvdimm_bus_unlock(dev);
 458         return rc;
 459 }
 460 static DEVICE_ATTR_RO(namespace_seed);
 461
 462 static ssize_t btt_seed_show(struct device *dev,
 463                 struct device_attribute *attr, char *buf)
 464 {
 465         struct nd_region *nd_region = to_nd_region(dev);
 466         ssize_t rc;
 467
 468         nvdimm_bus_lock(dev);
 469         if (nd_region->btt_seed)
 470                 rc = sprintf(buf, "%s\n", dev_name(nd_region->btt_seed));
 471         else
 472                 rc = sprintf(buf, "\n");
 473         nvdimm_bus_unlock(dev);
 474
 475         return rc;
 476 }
 477 static DEVICE_ATTR_RO(btt_seed);
 478
 479 static ssize_t pfn_seed_show(struct device *dev,
 480                 struct device_attribute *attr, char *buf)
 481 {
 482         struct nd_region *nd_region = to_nd_region(dev);
 483         ssize_t rc;
 484
 485         nvdimm_bus_lock(dev);
 486         if (nd_region->pfn_seed)
 487                 rc = sprintf(buf, "%s\n", dev_name(nd_region->pfn_seed));
 488         else
 489                 rc = sprintf(buf, "\n");
 490         nvdimm_bus_unlock(dev);
 491
 492         return rc;
 493 }
 494 static DEVICE_ATTR_RO(pfn_seed);
 495
 496 static ssize_t dax_seed_show(struct device *dev,
 497                 struct device_attribute *attr, char *buf)
 498 {
 499         struct nd_region *nd_region = to_nd_region(dev);
 500         ssize_t rc;
 501
 502         nvdimm_bus_lock(dev);
 503         if (nd_region->dax_seed)
 504                 rc = sprintf(buf, "%s\n", dev_name(nd_region->dax_seed));
 505         else
 506                 rc = sprintf(buf, "\n");
 507         nvdimm_bus_unlock(dev);
 508
 509         return rc;
 510 }
 511 static DEVICE_ATTR_RO(dax_seed);
 512
 513 static ssize_t read_only_show(struct device *dev,
 514                 struct device_attribute *attr, char *buf)
 515 {
 516         struct nd_region *nd_region = to_nd_region(dev);
 517
 518         return sprintf(buf, "%d\n", nd_region->ro);
 519 }
 520
 521 static int revalidate_read_only(struct device *dev, void *data)
 522 {
 523         nd_device_notify(dev, NVDIMM_REVALIDATE_REGION);
 524         return 0;
 525 }
 526
 527 static ssize_t read_only_store(struct device *dev,
 528                 struct device_attribute *attr, const char *buf, size_t len)
 529 {
 530         bool ro;
 531         int rc = strtobool(buf, &ro);
 532         struct nd_region *nd_region = to_nd_region(dev);
 533
 534         if (rc)
 535                 return rc;
 536
 537         nd_region->ro = ro;
 538         device_for_each_child(dev, NULL, revalidate_read_only);
 539         return len;
 540 }
 541 static DEVICE_ATTR_RW(read_only);
 542
 543 static ssize_t align_show(struct device *dev,
 544                 struct device_attribute *attr, char *buf)
 545 {
 546         struct nd_region *nd_region = to_nd_region(dev);
 547
 548         return sprintf(buf, "%#lx\n", nd_region->align);
 549 }
 550
 551 static ssize_t align_store(struct device *dev,
 552                 struct device_attribute *attr, const char *buf, size_t len)
 553 {
 554         struct nd_region *nd_region = to_nd_region(dev);
 555         unsigned long val, dpa;
 556         u32 remainder;
 557         int rc;
 558
 559         rc = kstrtoul(buf, 0, &val);
 560         if (rc)
 561                 return rc;
 562
 563         if (!nd_region->ndr_mappings)
 564                 return -ENXIO;
 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         dpa = div_u64_rem(val, nd_region->ndr_mappings, &remainder);
 574         if (!is_power_of_2(dpa) || dpa < PAGE_SIZE
 575                         || val > region_size(nd_region) || remainder)
 576                 return -EINVAL;
 577
 578         /*
 579          * Given that space allocation consults this value multiple
 580          * times ensure it does not change for the duration of the
 581          * allocation.
 582          */
 583         nvdimm_bus_lock(dev);
 584         nd_region->align = val;
 585         nvdimm_bus_unlock(dev);
 586
 587         return len;
 588 }
 589 static DEVICE_ATTR_RW(align);
 590
 591 static ssize_t region_badblocks_show(struct device *dev,
 592                 struct device_attribute *attr, char *buf)
 593 {
 594         struct nd_region *nd_region = to_nd_region(dev);
 595         ssize_t rc;
 596
 597         nd_device_lock(dev);
 598         if (dev->driver)
 599                 rc = badblocks_show(&nd_region->bb, buf, 0);
 600         else
 601                 rc = -ENXIO;
 602         nd_device_unlock(dev);
 603
 604         return rc;
 605 }
 606 static DEVICE_ATTR(badblocks, 0444, region_badblocks_show, NULL);
 607
 608 static ssize_t resource_show(struct device *dev,
 609                 struct device_attribute *attr, char *buf)
 610 {
 611         struct nd_region *nd_region = to_nd_region(dev);
 612
 613         return sprintf(buf, "%#llx\n", nd_region->ndr_start);
 614 }
 615 static DEVICE_ATTR_ADMIN_RO(resource);
 616
 617 static ssize_t persistence_domain_show(struct device *dev,
 618                 struct device_attribute *attr, char *buf)
 619 {
 620         struct nd_region *nd_region = to_nd_region(dev);
 621
 622         if (test_bit(ND_REGION_PERSIST_CACHE, &nd_region->flags))
 623                 return sprintf(buf, "cpu_cache\n");
 624         else if (test_bit(ND_REGION_PERSIST_MEMCTRL, &nd_region->flags))
 625                 return sprintf(buf, "memory_controller\n");
 626         else
 627                 return sprintf(buf, "\n");
 628 }
 629 static DEVICE_ATTR_RO(persistence_domain);
 630
 631 static struct attribute *nd_region_attributes[] = {
 632         &dev_attr_size.attr,
 633         &dev_attr_align.attr,
 634         &dev_attr_nstype.attr,
 635         &dev_attr_mappings.attr,
 636         &dev_attr_btt_seed.attr,
 637         &dev_attr_pfn_seed.attr,
 638         &dev_attr_dax_seed.attr,
 639         &dev_attr_deep_flush.attr,
 640         &dev_attr_read_only.attr,
 641         &dev_attr_set_cookie.attr,
 642         &dev_attr_available_size.attr,
 643         &dev_attr_max_available_extent.attr,
 644         &dev_attr_namespace_seed.attr,
 645         &dev_attr_init_namespaces.attr,
 646         &dev_attr_badblocks.attr,
 647         &dev_attr_resource.attr,
 648         &dev_attr_persistence_domain.attr,
 649         NULL,
 650 };
 651
 652 static umode_t region_visible(struct kobject *kobj, struct attribute *a, int n)
 653 {
 654         struct device *dev = container_of(kobj, typeof(*dev), kobj);
 655         struct nd_region *nd_region = to_nd_region(dev);
 656         struct nd_interleave_set *nd_set = nd_region->nd_set;
 657         int type = nd_region_to_nstype(nd_region);
 658
 659         if (!is_memory(dev) && a == &dev_attr_pfn_seed.attr)
 660                 return 0;
 661
 662         if (!is_memory(dev) && a == &dev_attr_dax_seed.attr)
 663                 return 0;
 664
 665         if (!is_memory(dev) && a == &dev_attr_badblocks.attr)
 666                 return 0;
 667
 668         if (a == &dev_attr_resource.attr && !is_memory(dev))
 669                 return 0;
 670
 671         if (a == &dev_attr_deep_flush.attr) {
 672                 int has_flush = nvdimm_has_flush(nd_region);
 673
 674                 if (has_flush == 1)
 675                         return a->mode;
 676                 else if (has_flush == 0)
 677                         return 0444;
 678                 else
 679                         return 0;
 680         }
 681
 682         if (a == &dev_attr_persistence_domain.attr) {
 683                 if ((nd_region->flags & (BIT(ND_REGION_PERSIST_CACHE)
 684                                         | BIT(ND_REGION_PERSIST_MEMCTRL))) == 0)
 685                         return 0;
 686                 return a->mode;
 687         }
 688
 689         if (a == &dev_attr_align.attr)
 690                 return a->mode;
 691
 692         if (a != &dev_attr_set_cookie.attr
 693                         && a != &dev_attr_available_size.attr)
 694                 return a->mode;
 695
 696         if ((type == ND_DEVICE_NAMESPACE_PMEM
 697                                 || type == ND_DEVICE_NAMESPACE_BLK)
 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_blk_device_type = {
 832         .name = "nd_blk",
 833         .release = nd_region_release,
 834         .groups = nd_region_attribute_groups,
 835 };
 836
 837 static const struct device_type nd_pmem_device_type = {
 838         .name = "nd_pmem",
 839         .release = nd_region_release,
 840         .groups = nd_region_attribute_groups,
 841 };
 842
 843 static const struct device_type nd_volatile_device_type = {
 844         .name = "nd_volatile",
 845         .release = nd_region_release,
 846         .groups = nd_region_attribute_groups,
 847 };
 848
 849 bool is_nd_pmem(struct device *dev)
 850 {
 851         return dev ? dev->type == &nd_pmem_device_type : false;
 852 }
 853
 854 bool is_nd_blk(struct device *dev)
 855 {
 856         return dev ? dev->type == &nd_blk_device_type : false;
 857 }
 858
 859 bool is_nd_volatile(struct device *dev)
 860 {
 861         return dev ? dev->type == &nd_volatile_device_type : false;
 862 }
 863
 864 u64 nd_region_interleave_set_cookie(struct nd_region *nd_region,
 865                 struct nd_namespace_index *nsindex)
 866 {
 867         struct nd_interleave_set *nd_set = nd_region->nd_set;
 868
 869         if (!nd_set)
 870                 return 0;
 871
 872         if (nsindex && __le16_to_cpu(nsindex->major) == 1
 873                         && __le16_to_cpu(nsindex->minor) == 1)
 874                 return nd_set->cookie1;
 875         return nd_set->cookie2;
 876 }
 877
 878 u64 nd_region_interleave_set_altcookie(struct nd_region *nd_region)
 879 {
 880         struct nd_interleave_set *nd_set = nd_region->nd_set;
 881
 882         if (nd_set)
 883                 return nd_set->altcookie;
 884         return 0;
 885 }
 886
 887 void nd_mapping_free_labels(struct nd_mapping *nd_mapping)
 888 {
 889         struct nd_label_ent *label_ent, *e;
 890
 891         lockdep_assert_held(&nd_mapping->lock);
 892         list_for_each_entry_safe(label_ent, e, &nd_mapping->labels, list) {
 893                 list_del(&label_ent->list);
 894                 kfree(label_ent);
 895         }
 896 }
 897
 898 /*
 899  * When a namespace is activated create new seeds for the next
 900  * namespace, or namespace-personality to be configured.
 901  */
 902 void nd_region_advance_seeds(struct nd_region *nd_region, struct device *dev)
 903 {
 904         nvdimm_bus_lock(dev);
 905         if (nd_region->ns_seed == dev) {
 906                 nd_region_create_ns_seed(nd_region);
 907         } else if (is_nd_btt(dev)) {
 908                 struct nd_btt *nd_btt = to_nd_btt(dev);
 909
 910                 if (nd_region->btt_seed == dev)
 911                         nd_region_create_btt_seed(nd_region);
 912                 if (nd_region->ns_seed == &nd_btt->ndns->dev)
 913                         nd_region_create_ns_seed(nd_region);
 914         } else if (is_nd_pfn(dev)) {
 915                 struct nd_pfn *nd_pfn = to_nd_pfn(dev);
 916
 917                 if (nd_region->pfn_seed == dev)
 918                         nd_region_create_pfn_seed(nd_region);
 919                 if (nd_region->ns_seed == &nd_pfn->ndns->dev)
 920                         nd_region_create_ns_seed(nd_region);
 921         } else if (is_nd_dax(dev)) {
 922                 struct nd_dax *nd_dax = to_nd_dax(dev);
 923
 924                 if (nd_region->dax_seed == dev)
 925                         nd_region_create_dax_seed(nd_region);
 926                 if (nd_region->ns_seed == &nd_dax->nd_pfn.ndns->dev)
 927                         nd_region_create_ns_seed(nd_region);
 928         }
 929         nvdimm_bus_unlock(dev);
 930 }
 931
 932 int nd_blk_region_init(struct nd_region *nd_region)
 933 {
 934         struct device *dev = &nd_region->dev;
 935         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 936
 937         if (!is_nd_blk(dev))
 938                 return 0;
 939
 940         if (nd_region->ndr_mappings < 1) {
 941                 dev_dbg(dev, "invalid BLK region\n");
 942                 return -ENXIO;
 943         }
 944
 945         return to_nd_blk_region(dev)->enable(nvdimm_bus, dev);
 946 }
 947
 948 /**
 949  * nd_region_acquire_lane - allocate and lock a lane
 950  * @nd_region: region id and number of lanes possible
 951  *
 952  * A lane correlates to a BLK-data-window and/or a log slot in the BTT.
 953  * We optimize for the common case where there are 256 lanes, one
 954  * per-cpu.  For larger systems we need to lock to share lanes.  For now
 955  * this implementation assumes the cost of maintaining an allocator for
 956  * free lanes is on the order of the lock hold time, so it implements a
 957  * static lane = cpu % num_lanes mapping.
 958  *
 959  * In the case of a BTT instance on top of a BLK namespace a lane may be
 960  * acquired recursively.  We lock on the first instance.
 961  *
 962  * In the case of a BTT instance on top of PMEM, we only acquire a lane
 963  * for the BTT metadata updates.
 964  */
 965 unsigned int nd_region_acquire_lane(struct nd_region *nd_region)
 966 {
 967         unsigned int cpu, lane;
 968
 969         cpu = get_cpu();
 970         if (nd_region->num_lanes < nr_cpu_ids) {
 971                 struct nd_percpu_lane *ndl_lock, *ndl_count;
 972
 973                 lane = cpu % nd_region->num_lanes;
 974                 ndl_count = per_cpu_ptr(nd_region->lane, cpu);
 975                 ndl_lock = per_cpu_ptr(nd_region->lane, lane);
 976                 if (ndl_count->count++ == 0)
 977                         spin_lock(&ndl_lock->lock);
 978         } else
 979                 lane = cpu;
 980
 981         return lane;
 982 }
 983 EXPORT_SYMBOL(nd_region_acquire_lane);
 984
 985 void nd_region_release_lane(struct nd_region *nd_region, unsigned int lane)
 986 {
 987         if (nd_region->num_lanes < nr_cpu_ids) {
 988                 unsigned int cpu = get_cpu();
 989                 struct nd_percpu_lane *ndl_lock, *ndl_count;
 990
 991                 ndl_count = per_cpu_ptr(nd_region->lane, cpu);
 992                 ndl_lock = per_cpu_ptr(nd_region->lane, lane);
 993                 if (--ndl_count->count == 0)
 994                         spin_unlock(&ndl_lock->lock);
 995                 put_cpu();
 996         }
 997         put_cpu();
 998 }
 999 EXPORT_SYMBOL(nd_region_release_lane);
1000
1001 /*
1002  * PowerPC requires this alignment for memremap_pages(). All other archs
1003  * should be ok with SUBSECTION_SIZE (see memremap_compat_align()).
1004  */
1005 #define MEMREMAP_COMPAT_ALIGN_MAX SZ_16M
1006
1007 static unsigned long default_align(struct nd_region *nd_region)
1008 {
1009         unsigned long align;
1010         int i, mappings;
1011         u32 remainder;
1012
1013         if (is_nd_blk(&nd_region->dev))
1014                 align = PAGE_SIZE;
1015         else
1016                 align = MEMREMAP_COMPAT_ALIGN_MAX;
1017
1018         for (i = 0; i < nd_region->ndr_mappings; i++) {
1019                 struct nd_mapping *nd_mapping = &nd_region->mapping[i];
1020                 struct nvdimm *nvdimm = nd_mapping->nvdimm;
1021
1022                 if (test_bit(NDD_ALIASING, &nvdimm->flags)) {
1023                         align = MEMREMAP_COMPAT_ALIGN_MAX;
1024                         break;
1025                 }
1026         }
1027
1028         mappings = max_t(u16, 1, nd_region->ndr_mappings);
1029         div_u64_rem(align, mappings, &remainder);
1030         if (remainder)
1031                 align *= mappings;
1032
1033         return align;
1034 }
1035
1036 static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
1037                 struct nd_region_desc *ndr_desc,
1038                 const struct device_type *dev_type, const char *caller)
1039 {
1040         struct nd_region *nd_region;
1041         struct device *dev;
1042         void *region_buf;
1043         unsigned int i;
1044         int ro = 0;
1045
1046         for (i = 0; i < ndr_desc->num_mappings; i++) {
1047                 struct nd_mapping_desc *mapping = &ndr_desc->mapping[i];
1048                 struct nvdimm *nvdimm = mapping->nvdimm;
1049
1050                 if ((mapping->start | mapping->size) % PAGE_SIZE) {
1051                         dev_err(&nvdimm_bus->dev,
1052                                 "%s: %s mapping%d is not %ld aligned\n",
1053                                 caller, dev_name(&nvdimm->dev), i, PAGE_SIZE);
1054                         return NULL;
1055                 }
1056
1057                 if (test_bit(NDD_UNARMED, &nvdimm->flags))
1058                         ro = 1;
1059
1060                 if (test_bit(NDD_NOBLK, &nvdimm->flags)
1061                                 && dev_type == &nd_blk_device_type) {
1062                         dev_err(&nvdimm_bus->dev, "%s: %s mapping%d is not BLK capable\n",
1063                                         caller, dev_name(&nvdimm->dev), i);
1064                         return NULL;
1065                 }
1066         }
1067
1068         if (dev_type == &nd_blk_device_type) {
1069                 struct nd_blk_region_desc *ndbr_desc;
1070                 struct nd_blk_region *ndbr;
1071
1072                 ndbr_desc = to_blk_region_desc(ndr_desc);
1073                 ndbr = kzalloc(sizeof(*ndbr) + sizeof(struct nd_mapping)
1074                                 * ndr_desc->num_mappings,
1075                                 GFP_KERNEL);
1076                 if (ndbr) {
1077                         nd_region = &ndbr->nd_region;
1078                         ndbr->enable = ndbr_desc->enable;
1079                         ndbr->do_io = ndbr_desc->do_io;
1080                 }
1081                 region_buf = ndbr;
1082         } else {
1083                 nd_region = kzalloc(struct_size(nd_region, mapping,
1084                                                 ndr_desc->num_mappings),
1085                                     GFP_KERNEL);
1086                 region_buf = nd_region;
1087         }
1088
1089         if (!region_buf)
1090                 return NULL;
1091         nd_region->id = memregion_alloc(GFP_KERNEL);
1092         if (nd_region->id < 0)
1093                 goto err_id;
1094
1095         nd_region->lane = alloc_percpu(struct nd_percpu_lane);
1096         if (!nd_region->lane)
1097                 goto err_percpu;
1098
1099         for (i = 0; i < nr_cpu_ids; i++) {
1100                 struct nd_percpu_lane *ndl;
1101
1102                 ndl = per_cpu_ptr(nd_region->lane, i);
1103                 spin_lock_init(&ndl->lock);
1104                 ndl->count = 0;
1105         }
1106
1107         for (i = 0; i < ndr_desc->num_mappings; i++) {
1108                 struct nd_mapping_desc *mapping = &ndr_desc->mapping[i];
1109                 struct nvdimm *nvdimm = mapping->nvdimm;
1110
1111                 nd_region->mapping[i].nvdimm = nvdimm;
1112                 nd_region->mapping[i].start = mapping->start;
1113                 nd_region->mapping[i].size = mapping->size;
1114                 nd_region->mapping[i].position = mapping->position;
1115                 INIT_LIST_HEAD(&nd_region->mapping[i].labels);
1116                 mutex_init(&nd_region->mapping[i].lock);
1117
1118                 get_device(&nvdimm->dev);
1119         }
1120         nd_region->ndr_mappings = ndr_desc->num_mappings;
1121         nd_region->provider_data = ndr_desc->provider_data;
1122         nd_region->nd_set = ndr_desc->nd_set;
1123         nd_region->num_lanes = ndr_desc->num_lanes;
1124         nd_region->flags = ndr_desc->flags;
1125         nd_region->ro = ro;
1126         nd_region->numa_node = ndr_desc->numa_node;
1127         nd_region->target_node = ndr_desc->target_node;
1128         ida_init(&nd_region->ns_ida);
1129         ida_init(&nd_region->btt_ida);
1130         ida_init(&nd_region->pfn_ida);
1131         ida_init(&nd_region->dax_ida);
1132         dev = &nd_region->dev;
1133         dev_set_name(dev, "region%d", nd_region->id);
1134         dev->parent = &nvdimm_bus->dev;
1135         dev->type = dev_type;
1136         dev->groups = ndr_desc->attr_groups;
1137         dev->of_node = ndr_desc->of_node;
1138         nd_region->ndr_size = resource_size(ndr_desc->res);
1139         nd_region->ndr_start = ndr_desc->res->start;
1140         nd_region->align = default_align(nd_region);
1141         if (ndr_desc->flush)
1142                 nd_region->flush = ndr_desc->flush;
1143         else
1144                 nd_region->flush = NULL;
1145
1146         nd_device_register(dev);
1147
1148         return nd_region;
1149
1150  err_percpu:
1151         memregion_free(nd_region->id);
1152  err_id:
1153         kfree(region_buf);
1154         return NULL;
1155 }
1156
1157 struct nd_region *nvdimm_pmem_region_create(struct nvdimm_bus *nvdimm_bus,
1158                 struct nd_region_desc *ndr_desc)
1159 {
1160         ndr_desc->num_lanes = ND_MAX_LANES;
1161         return nd_region_create(nvdimm_bus, ndr_desc, &nd_pmem_device_type,
1162                         __func__);
1163 }
1164 EXPORT_SYMBOL_GPL(nvdimm_pmem_region_create);
1165
1166 struct nd_region *nvdimm_blk_region_create(struct nvdimm_bus *nvdimm_bus,
1167                 struct nd_region_desc *ndr_desc)
1168 {
1169         if (ndr_desc->num_mappings > 1)
1170                 return NULL;
1171         ndr_desc->num_lanes = min(ndr_desc->num_lanes, ND_MAX_LANES);
1172         return nd_region_create(nvdimm_bus, ndr_desc, &nd_blk_device_type,
1173                         __func__);
1174 }
1175 EXPORT_SYMBOL_GPL(nvdimm_blk_region_create);
1176
1177 struct nd_region *nvdimm_volatile_region_create(struct nvdimm_bus *nvdimm_bus,
1178                 struct nd_region_desc *ndr_desc)
1179 {
1180         ndr_desc->num_lanes = ND_MAX_LANES;
1181         return nd_region_create(nvdimm_bus, ndr_desc, &nd_volatile_device_type,
1182                         __func__);
1183 }
1184 EXPORT_SYMBOL_GPL(nvdimm_volatile_region_create);
1185
1186 int nvdimm_flush(struct nd_region *nd_region, struct bio *bio)
1187 {
1188         int rc = 0;
1189
1190         if (!nd_region->flush)
1191                 rc = generic_nvdimm_flush(nd_region);
1192         else {
1193                 if (nd_region->flush(nd_region, bio))
1194                         rc = -EIO;
1195         }
1196
1197         return rc;
1198 }
1199 /**
1200  * nvdimm_flush - flush any posted write queues between the cpu and pmem media
1201  * @nd_region: blk or interleaved pmem region
1202  */
1203 int generic_nvdimm_flush(struct nd_region *nd_region)
1204 {
1205         struct nd_region_data *ndrd = dev_get_drvdata(&nd_region->dev);
1206         int i, idx;
1207
1208         /*
1209          * Try to encourage some diversity in flush hint addresses
1210          * across cpus assuming a limited number of flush hints.
1211          */
1212         idx = this_cpu_read(flush_idx);
1213         idx = this_cpu_add_return(flush_idx, hash_32(current->pid + idx, 8));
1214
1215         /*
1216          * The pmem_wmb() is needed to 'sfence' all
1217          * previous writes such that they are architecturally visible for
1218          * the platform buffer flush. Note that we've already arranged for pmem
1219          * writes to avoid the cache via memcpy_flushcache().  The final
1220          * wmb() ensures ordering for the NVDIMM flush write.
1221          */
1222         pmem_wmb();
1223         for (i = 0; i < nd_region->ndr_mappings; i++)
1224                 if (ndrd_get_flush_wpq(ndrd, i, 0))
1225                         writeq(1, ndrd_get_flush_wpq(ndrd, i, idx));
1226         wmb();
1227
1228         return 0;
1229 }
1230 EXPORT_SYMBOL_GPL(nvdimm_flush);
1231
1232 /**
1233  * nvdimm_has_flush - determine write flushing requirements
1234  * @nd_region: blk or interleaved pmem region
1235  *
1236  * Returns 1 if writes require flushing
1237  * Returns 0 if writes do not require flushing
1238  * Returns -ENXIO if flushing capability can not be determined
1239  */
1240 int nvdimm_has_flush(struct nd_region *nd_region)
1241 {
1242         int i;
1243
1244         /* no nvdimm or pmem api == flushing capability unknown */
1245         if (nd_region->ndr_mappings == 0
1246                         || !IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API))
1247                 return -ENXIO;
1248
1249         /* Test if an explicit flush function is defined */
1250         if (test_bit(ND_REGION_ASYNC, &nd_region->flags) && nd_region->flush)
1251                 return 1;
1252
1253         /* Test if any flush hints for the region are available */
1254         for (i = 0; i < nd_region->ndr_mappings; i++) {
1255                 struct nd_mapping *nd_mapping = &nd_region->mapping[i];
1256                 struct nvdimm *nvdimm = nd_mapping->nvdimm;
1257
1258                 /* flush hints present / available */
1259                 if (nvdimm->num_flush)
1260                         return 1;
1261         }
1262
1263         /*
1264          * The platform defines dimm devices without hints nor explicit flush,
1265          * assume platform persistence mechanism like ADR
1266          */
1267         return 0;
1268 }
1269 EXPORT_SYMBOL_GPL(nvdimm_has_flush);
1270
1271 int nvdimm_has_cache(struct nd_region *nd_region)
1272 {
1273         return is_nd_pmem(&nd_region->dev) &&
1274                 !test_bit(ND_REGION_PERSIST_CACHE, &nd_region->flags);
1275 }
1276 EXPORT_SYMBOL_GPL(nvdimm_has_cache);
1277
1278 bool is_nvdimm_sync(struct nd_region *nd_region)
1279 {
1280         if (is_nd_volatile(&nd_region->dev))
1281                 return true;
1282
1283         return is_nd_pmem(&nd_region->dev) &&
1284                 !test_bit(ND_REGION_ASYNC, &nd_region->flags);
1285 }
1286 EXPORT_SYMBOL_GPL(is_nvdimm_sync);
1287
1288 struct conflict_context {
1289         struct nd_region *nd_region;
1290         resource_size_t start, size;
1291 };
1292
1293 static int region_conflict(struct device *dev, void *data)
1294 {
1295         struct nd_region *nd_region;
1296         struct conflict_context *ctx = data;
1297         resource_size_t res_end, region_end, region_start;
1298
1299         if (!is_memory(dev))
1300                 return 0;
1301
1302         nd_region = to_nd_region(dev);
1303         if (nd_region == ctx->nd_region)
1304                 return 0;
1305
1306         res_end = ctx->start + ctx->size;
1307         region_start = nd_region->ndr_start;
1308         region_end = region_start + nd_region->ndr_size;
1309         if (ctx->start >= region_start && ctx->start < region_end)
1310                 return -EBUSY;
1311         if (res_end > region_start && res_end <= region_end)
1312                 return -EBUSY;
1313         return 0;
1314 }
1315
1316 int nd_region_conflict(struct nd_region *nd_region, resource_size_t start,
1317                 resource_size_t size)
1318 {
1319         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
1320         struct conflict_context ctx = {
1321                 .nd_region = nd_region,
1322                 .start = start,
1323                 .size = size,
1324         };
1325
1326         return device_for_each_child(&nvdimm_bus->dev, &ctx, region_conflict);
1327 }