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/hash.h>
  18 #include <linux/pmem.h>
  19 #include <linux/sort.h>
  20 #include <linux/io.h>
  21 #include <linux/nd.h>
  22 #include "nd-core.h"
  23 #include "nd.h"
  24
  25 /*
  26  * For readq() and writeq() on 32-bit builds, the hi-lo, lo-hi order is
  27  * irrelevant.
  28  */
  29 #include <linux/io-64-nonatomic-hi-lo.h>
  30
  31 static DEFINE_IDA(region_ida);
  32 static DEFINE_PER_CPU(int, flush_idx);
  33
  34 static int nvdimm_map_flush(struct device *dev, struct nvdimm *nvdimm, int dimm,
  35                 struct nd_region_data *ndrd)
  36 {
  37         int i, j;
  38
  39         dev_dbg(dev, "%s: map %d flush address%s\n", nvdimm_name(nvdimm),
  40                         nvdimm->num_flush, nvdimm->num_flush == 1 ? "" : "es");
  41         for (i = 0; i < nvdimm->num_flush; i++) {
  42                 struct resource *res = &nvdimm->flush_wpq[i];
  43                 unsigned long pfn = PHYS_PFN(res->start);
  44                 void __iomem *flush_page;
  45
  46                 /* check if flush hints share a page */
  47                 for (j = 0; j < i; j++) {
  48                         struct resource *res_j = &nvdimm->flush_wpq[j];
  49                         unsigned long pfn_j = PHYS_PFN(res_j->start);
  50
  51                         if (pfn == pfn_j)
  52                                 break;
  53                 }
  54
  55                 if (j < i)
  56                         flush_page = (void __iomem *) ((unsigned long)
  57                                         ndrd->flush_wpq[dimm][j] & PAGE_MASK);
  58                 else
  59                         flush_page = devm_nvdimm_ioremap(dev,
  60                                         PHYS_PFN(pfn), PAGE_SIZE);
  61                 if (!flush_page)
  62                         return -ENXIO;
  63                 ndrd->flush_wpq[dimm][i] = flush_page
  64                         + (res->start & ~PAGE_MASK);
  65         }
  66
  67         return 0;
  68 }
  69
  70 int nd_region_activate(struct nd_region *nd_region)
  71 {
  72         int i, num_flush = 0;
  73         struct nd_region_data *ndrd;
  74         struct device *dev = &nd_region->dev;
  75         size_t flush_data_size = sizeof(void *);
  76
  77         nvdimm_bus_lock(&nd_region->dev);
  78         for (i = 0; i < nd_region->ndr_mappings; i++) {
  79                 struct nd_mapping *nd_mapping = &nd_region->mapping[i];
  80                 struct nvdimm *nvdimm = nd_mapping->nvdimm;
  81
  82                 /* at least one null hint slot per-dimm for the "no-hint" case */
  83                 flush_data_size += sizeof(void *);
  84                 num_flush = min_not_zero(num_flush, nvdimm->num_flush);
  85                 if (!nvdimm->num_flush)
  86                         continue;
  87                 flush_data_size += nvdimm->num_flush * sizeof(void *);
  88         }
  89         nvdimm_bus_unlock(&nd_region->dev);
  90
  91         ndrd = devm_kzalloc(dev, sizeof(*ndrd) + flush_data_size, GFP_KERNEL);
  92         if (!ndrd)
  93                 return -ENOMEM;
  94         dev_set_drvdata(dev, ndrd);
  95
  96         ndrd->flush_mask = (1 << ilog2(num_flush)) - 1;
  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         return 0;
 107 }
 108
 109 static void nd_region_release(struct device *dev)
 110 {
 111         struct nd_region *nd_region = to_nd_region(dev);
 112         u16 i;
 113
 114         for (i = 0; i < nd_region->ndr_mappings; i++) {
 115                 struct nd_mapping *nd_mapping = &nd_region->mapping[i];
 116                 struct nvdimm *nvdimm = nd_mapping->nvdimm;
 117
 118                 put_device(&nvdimm->dev);
 119         }
 120         free_percpu(nd_region->lane);
 121         ida_simple_remove(&region_ida, nd_region->id);
 122         if (is_nd_blk(dev))
 123                 kfree(to_nd_blk_region(dev));
 124         else
 125                 kfree(nd_region);
 126 }
 127
 128 static struct device_type nd_blk_device_type = {
 129         .name = "nd_blk",
 130         .release = nd_region_release,
 131 };
 132
 133 static struct device_type nd_pmem_device_type = {
 134         .name = "nd_pmem",
 135         .release = nd_region_release,
 136 };
 137
 138 static struct device_type nd_volatile_device_type = {
 139         .name = "nd_volatile",
 140         .release = nd_region_release,
 141 };
 142
 143 bool is_nd_pmem(struct device *dev)
 144 {
 145         return dev ? dev->type == &nd_pmem_device_type : false;
 146 }
 147
 148 bool is_nd_blk(struct device *dev)
 149 {
 150         return dev ? dev->type == &nd_blk_device_type : false;
 151 }
 152
 153 struct nd_region *to_nd_region(struct device *dev)
 154 {
 155         struct nd_region *nd_region = container_of(dev, struct nd_region, dev);
 156
 157         WARN_ON(dev->type->release != nd_region_release);
 158         return nd_region;
 159 }
 160 EXPORT_SYMBOL_GPL(to_nd_region);
 161
 162 struct nd_blk_region *to_nd_blk_region(struct device *dev)
 163 {
 164         struct nd_region *nd_region = to_nd_region(dev);
 165
 166         WARN_ON(!is_nd_blk(dev));
 167         return container_of(nd_region, struct nd_blk_region, nd_region);
 168 }
 169 EXPORT_SYMBOL_GPL(to_nd_blk_region);
 170
 171 void *nd_region_provider_data(struct nd_region *nd_region)
 172 {
 173         return nd_region->provider_data;
 174 }
 175 EXPORT_SYMBOL_GPL(nd_region_provider_data);
 176
 177 void *nd_blk_region_provider_data(struct nd_blk_region *ndbr)
 178 {
 179         return ndbr->blk_provider_data;
 180 }
 181 EXPORT_SYMBOL_GPL(nd_blk_region_provider_data);
 182
 183 void nd_blk_region_set_provider_data(struct nd_blk_region *ndbr, void *data)
 184 {
 185         ndbr->blk_provider_data = data;
 186 }
 187 EXPORT_SYMBOL_GPL(nd_blk_region_set_provider_data);
 188
 189 /**
 190  * nd_region_to_nstype() - region to an integer namespace type
 191  * @nd_region: region-device to interrogate
 192  *
 193  * This is the 'nstype' attribute of a region as well, an input to the
 194  * MODALIAS for namespace devices, and bit number for a nvdimm_bus to match
 195  * namespace devices with namespace drivers.
 196  */
 197 int nd_region_to_nstype(struct nd_region *nd_region)
 198 {
 199         if (is_nd_pmem(&nd_region->dev)) {
 200                 u16 i, alias;
 201
 202                 for (i = 0, alias = 0; i < nd_region->ndr_mappings; i++) {
 203                         struct nd_mapping *nd_mapping = &nd_region->mapping[i];
 204                         struct nvdimm *nvdimm = nd_mapping->nvdimm;
 205
 206                         if (nvdimm->flags & NDD_ALIASING)
 207                                 alias++;
 208                 }
 209                 if (alias)
 210                         return ND_DEVICE_NAMESPACE_PMEM;
 211                 else
 212                         return ND_DEVICE_NAMESPACE_IO;
 213         } else if (is_nd_blk(&nd_region->dev)) {
 214                 return ND_DEVICE_NAMESPACE_BLK;
 215         }
 216
 217         return 0;
 218 }
 219 EXPORT_SYMBOL(nd_region_to_nstype);
 220
 221 static ssize_t 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 size = 0;
 226
 227         if (is_nd_pmem(dev)) {
 228                 size = nd_region->ndr_size;
 229         } else if (nd_region->ndr_mappings == 1) {
 230                 struct nd_mapping *nd_mapping = &nd_region->mapping[0];
 231
 232                 size = nd_mapping->size;
 233         }
 234
 235         return sprintf(buf, "%llu\n", size);
 236 }
 237 static DEVICE_ATTR_RO(size);
 238
 239 static ssize_t mappings_show(struct device *dev,
 240                 struct device_attribute *attr, char *buf)
 241 {
 242         struct nd_region *nd_region = to_nd_region(dev);
 243
 244         return sprintf(buf, "%d\n", nd_region->ndr_mappings);
 245 }
 246 static DEVICE_ATTR_RO(mappings);
 247
 248 static ssize_t nstype_show(struct device *dev,
 249                 struct device_attribute *attr, char *buf)
 250 {
 251         struct nd_region *nd_region = to_nd_region(dev);
 252
 253         return sprintf(buf, "%d\n", nd_region_to_nstype(nd_region));
 254 }
 255 static DEVICE_ATTR_RO(nstype);
 256
 257 static ssize_t set_cookie_show(struct device *dev,
 258                 struct device_attribute *attr, char *buf)
 259 {
 260         struct nd_region *nd_region = to_nd_region(dev);
 261         struct nd_interleave_set *nd_set = nd_region->nd_set;
 262
 263         if (is_nd_pmem(dev) && nd_set)
 264                 /* pass, should be precluded by region_visible */;
 265         else
 266                 return -ENXIO;
 267
 268         return sprintf(buf, "%#llx\n", nd_set->cookie);
 269 }
 270 static DEVICE_ATTR_RO(set_cookie);
 271
 272 resource_size_t nd_region_available_dpa(struct nd_region *nd_region)
 273 {
 274         resource_size_t blk_max_overlap = 0, available, overlap;
 275         int i;
 276
 277         WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
 278
 279  retry:
 280         available = 0;
 281         overlap = blk_max_overlap;
 282         for (i = 0; i < nd_region->ndr_mappings; i++) {
 283                 struct nd_mapping *nd_mapping = &nd_region->mapping[i];
 284                 struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
 285
 286                 /* if a dimm is disabled the available capacity is zero */
 287                 if (!ndd)
 288                         return 0;
 289
 290                 if (is_nd_pmem(&nd_region->dev)) {
 291                         available += nd_pmem_available_dpa(nd_region,
 292                                         nd_mapping, &overlap);
 293                         if (overlap > blk_max_overlap) {
 294                                 blk_max_overlap = overlap;
 295                                 goto retry;
 296                         }
 297                 } else if (is_nd_blk(&nd_region->dev)) {
 298                         available += nd_blk_available_dpa(nd_mapping);
 299                 }
 300         }
 301
 302         return available;
 303 }
 304
 305 static ssize_t available_size_show(struct device *dev,
 306                 struct device_attribute *attr, char *buf)
 307 {
 308         struct nd_region *nd_region = to_nd_region(dev);
 309         unsigned long long available = 0;
 310
 311         /*
 312          * Flush in-flight updates and grab a snapshot of the available
 313          * size.  Of course, this value is potentially invalidated the
 314          * memory nvdimm_bus_lock() is dropped, but that's userspace's
 315          * problem to not race itself.
 316          */
 317         nvdimm_bus_lock(dev);
 318         wait_nvdimm_bus_probe_idle(dev);
 319         available = nd_region_available_dpa(nd_region);
 320         nvdimm_bus_unlock(dev);
 321
 322         return sprintf(buf, "%llu\n", available);
 323 }
 324 static DEVICE_ATTR_RO(available_size);
 325
 326 static ssize_t init_namespaces_show(struct device *dev,
 327                 struct device_attribute *attr, char *buf)
 328 {
 329         struct nd_region_data *ndrd = dev_get_drvdata(dev);
 330         ssize_t rc;
 331
 332         nvdimm_bus_lock(dev);
 333         if (ndrd)
 334                 rc = sprintf(buf, "%d/%d\n", ndrd->ns_active, ndrd->ns_count);
 335         else
 336                 rc = -ENXIO;
 337         nvdimm_bus_unlock(dev);
 338
 339         return rc;
 340 }
 341 static DEVICE_ATTR_RO(init_namespaces);
 342
 343 static ssize_t namespace_seed_show(struct device *dev,
 344                 struct device_attribute *attr, char *buf)
 345 {
 346         struct nd_region *nd_region = to_nd_region(dev);
 347         ssize_t rc;
 348
 349         nvdimm_bus_lock(dev);
 350         if (nd_region->ns_seed)
 351                 rc = sprintf(buf, "%s\n", dev_name(nd_region->ns_seed));
 352         else
 353                 rc = sprintf(buf, "\n");
 354         nvdimm_bus_unlock(dev);
 355         return rc;
 356 }
 357 static DEVICE_ATTR_RO(namespace_seed);
 358
 359 static ssize_t btt_seed_show(struct device *dev,
 360                 struct device_attribute *attr, char *buf)
 361 {
 362         struct nd_region *nd_region = to_nd_region(dev);
 363         ssize_t rc;
 364
 365         nvdimm_bus_lock(dev);
 366         if (nd_region->btt_seed)
 367                 rc = sprintf(buf, "%s\n", dev_name(nd_region->btt_seed));
 368         else
 369                 rc = sprintf(buf, "\n");
 370         nvdimm_bus_unlock(dev);
 371
 372         return rc;
 373 }
 374 static DEVICE_ATTR_RO(btt_seed);
 375
 376 static ssize_t pfn_seed_show(struct device *dev,
 377                 struct device_attribute *attr, char *buf)
 378 {
 379         struct nd_region *nd_region = to_nd_region(dev);
 380         ssize_t rc;
 381
 382         nvdimm_bus_lock(dev);
 383         if (nd_region->pfn_seed)
 384                 rc = sprintf(buf, "%s\n", dev_name(nd_region->pfn_seed));
 385         else
 386                 rc = sprintf(buf, "\n");
 387         nvdimm_bus_unlock(dev);
 388
 389         return rc;
 390 }
 391 static DEVICE_ATTR_RO(pfn_seed);
 392
 393 static ssize_t dax_seed_show(struct device *dev,
 394                 struct device_attribute *attr, char *buf)
 395 {
 396         struct nd_region *nd_region = to_nd_region(dev);
 397         ssize_t rc;
 398
 399         nvdimm_bus_lock(dev);
 400         if (nd_region->dax_seed)
 401                 rc = sprintf(buf, "%s\n", dev_name(nd_region->dax_seed));
 402         else
 403                 rc = sprintf(buf, "\n");
 404         nvdimm_bus_unlock(dev);
 405
 406         return rc;
 407 }
 408 static DEVICE_ATTR_RO(dax_seed);
 409
 410 static ssize_t read_only_show(struct device *dev,
 411                 struct device_attribute *attr, char *buf)
 412 {
 413         struct nd_region *nd_region = to_nd_region(dev);
 414
 415         return sprintf(buf, "%d\n", nd_region->ro);
 416 }
 417
 418 static ssize_t read_only_store(struct device *dev,
 419                 struct device_attribute *attr, const char *buf, size_t len)
 420 {
 421         bool ro;
 422         int rc = strtobool(buf, &ro);
 423         struct nd_region *nd_region = to_nd_region(dev);
 424
 425         if (rc)
 426                 return rc;
 427
 428         nd_region->ro = ro;
 429         return len;
 430 }
 431 static DEVICE_ATTR_RW(read_only);
 432
 433 static struct attribute *nd_region_attributes[] = {
 434         &dev_attr_size.attr,
 435         &dev_attr_nstype.attr,
 436         &dev_attr_mappings.attr,
 437         &dev_attr_btt_seed.attr,
 438         &dev_attr_pfn_seed.attr,
 439         &dev_attr_dax_seed.attr,
 440         &dev_attr_read_only.attr,
 441         &dev_attr_set_cookie.attr,
 442         &dev_attr_available_size.attr,
 443         &dev_attr_namespace_seed.attr,
 444         &dev_attr_init_namespaces.attr,
 445         NULL,
 446 };
 447
 448 static umode_t region_visible(struct kobject *kobj, struct attribute *a, int n)
 449 {
 450         struct device *dev = container_of(kobj, typeof(*dev), kobj);
 451         struct nd_region *nd_region = to_nd_region(dev);
 452         struct nd_interleave_set *nd_set = nd_region->nd_set;
 453         int type = nd_region_to_nstype(nd_region);
 454
 455         if (!is_nd_pmem(dev) && a == &dev_attr_pfn_seed.attr)
 456                 return 0;
 457
 458         if (!is_nd_pmem(dev) && a == &dev_attr_dax_seed.attr)
 459                 return 0;
 460
 461         if (a != &dev_attr_set_cookie.attr
 462                         && a != &dev_attr_available_size.attr)
 463                 return a->mode;
 464
 465         if ((type == ND_DEVICE_NAMESPACE_PMEM
 466                                 || type == ND_DEVICE_NAMESPACE_BLK)
 467                         && a == &dev_attr_available_size.attr)
 468                 return a->mode;
 469         else if (is_nd_pmem(dev) && nd_set)
 470                 return a->mode;
 471
 472         return 0;
 473 }
 474
 475 struct attribute_group nd_region_attribute_group = {
 476         .attrs = nd_region_attributes,
 477         .is_visible = region_visible,
 478 };
 479 EXPORT_SYMBOL_GPL(nd_region_attribute_group);
 480
 481 u64 nd_region_interleave_set_cookie(struct nd_region *nd_region)
 482 {
 483         struct nd_interleave_set *nd_set = nd_region->nd_set;
 484
 485         if (nd_set)
 486                 return nd_set->cookie;
 487         return 0;
 488 }
 489
 490 /*
 491  * Upon successful probe/remove, take/release a reference on the
 492  * associated interleave set (if present), and plant new btt + namespace
 493  * seeds.  Also, on the removal of a BLK region, notify the provider to
 494  * disable the region.
 495  */
 496 static void nd_region_notify_driver_action(struct nvdimm_bus *nvdimm_bus,
 497                 struct device *dev, bool probe)
 498 {
 499         struct nd_region *nd_region;
 500
 501         if (!probe && (is_nd_pmem(dev) || is_nd_blk(dev))) {
 502                 int i;
 503
 504                 nd_region = to_nd_region(dev);
 505                 for (i = 0; i < nd_region->ndr_mappings; i++) {
 506                         struct nd_mapping *nd_mapping = &nd_region->mapping[i];
 507                         struct nvdimm_drvdata *ndd = nd_mapping->ndd;
 508                         struct nvdimm *nvdimm = nd_mapping->nvdimm;
 509
 510                         kfree(nd_mapping->labels);
 511                         nd_mapping->labels = NULL;
 512                         put_ndd(ndd);
 513                         nd_mapping->ndd = NULL;
 514                         if (ndd)
 515                                 atomic_dec(&nvdimm->busy);
 516                 }
 517
 518                 if (is_nd_pmem(dev))
 519                         return;
 520         }
 521         if (dev->parent && is_nd_blk(dev->parent) && probe) {
 522                 nd_region = to_nd_region(dev->parent);
 523                 nvdimm_bus_lock(dev);
 524                 if (nd_region->ns_seed == dev)
 525                         nd_region_create_blk_seed(nd_region);
 526                 nvdimm_bus_unlock(dev);
 527         }
 528         if (is_nd_btt(dev) && probe) {
 529                 struct nd_btt *nd_btt = to_nd_btt(dev);
 530
 531                 nd_region = to_nd_region(dev->parent);
 532                 nvdimm_bus_lock(dev);
 533                 if (nd_region->btt_seed == dev)
 534                         nd_region_create_btt_seed(nd_region);
 535                 if (nd_region->ns_seed == &nd_btt->ndns->dev &&
 536                                 is_nd_blk(dev->parent))
 537                         nd_region_create_blk_seed(nd_region);
 538                 nvdimm_bus_unlock(dev);
 539         }
 540         if (is_nd_pfn(dev) && probe) {
 541                 nd_region = to_nd_region(dev->parent);
 542                 nvdimm_bus_lock(dev);
 543                 if (nd_region->pfn_seed == dev)
 544                         nd_region_create_pfn_seed(nd_region);
 545                 nvdimm_bus_unlock(dev);
 546         }
 547         if (is_nd_dax(dev) && probe) {
 548                 nd_region = to_nd_region(dev->parent);
 549                 nvdimm_bus_lock(dev);
 550                 if (nd_region->dax_seed == dev)
 551                         nd_region_create_dax_seed(nd_region);
 552                 nvdimm_bus_unlock(dev);
 553         }
 554 }
 555
 556 void nd_region_probe_success(struct nvdimm_bus *nvdimm_bus, struct device *dev)
 557 {
 558         nd_region_notify_driver_action(nvdimm_bus, dev, true);
 559 }
 560
 561 void nd_region_disable(struct nvdimm_bus *nvdimm_bus, struct device *dev)
 562 {
 563         nd_region_notify_driver_action(nvdimm_bus, dev, false);
 564 }
 565
 566 static ssize_t mappingN(struct device *dev, char *buf, int n)
 567 {
 568         struct nd_region *nd_region = to_nd_region(dev);
 569         struct nd_mapping *nd_mapping;
 570         struct nvdimm *nvdimm;
 571
 572         if (n >= nd_region->ndr_mappings)
 573                 return -ENXIO;
 574         nd_mapping = &nd_region->mapping[n];
 575         nvdimm = nd_mapping->nvdimm;
 576
 577         return sprintf(buf, "%s,%llu,%llu\n", dev_name(&nvdimm->dev),
 578                         nd_mapping->start, nd_mapping->size);
 579 }
 580
 581 #define REGION_MAPPING(idx) \
 582 static ssize_t mapping##idx##_show(struct device *dev,          \
 583                 struct device_attribute *attr, char *buf)       \
 584 {                                                               \
 585         return mappingN(dev, buf, idx);                         \
 586 }                                                               \
 587 static DEVICE_ATTR_RO(mapping##idx)
 588
 589 /*
 590  * 32 should be enough for a while, even in the presence of socket
 591  * interleave a 32-way interleave set is a degenerate case.
 592  */
 593 REGION_MAPPING(0);
 594 REGION_MAPPING(1);
 595 REGION_MAPPING(2);
 596 REGION_MAPPING(3);
 597 REGION_MAPPING(4);
 598 REGION_MAPPING(5);
 599 REGION_MAPPING(6);
 600 REGION_MAPPING(7);
 601 REGION_MAPPING(8);
 602 REGION_MAPPING(9);
 603 REGION_MAPPING(10);
 604 REGION_MAPPING(11);
 605 REGION_MAPPING(12);
 606 REGION_MAPPING(13);
 607 REGION_MAPPING(14);
 608 REGION_MAPPING(15);
 609 REGION_MAPPING(16);
 610 REGION_MAPPING(17);
 611 REGION_MAPPING(18);
 612 REGION_MAPPING(19);
 613 REGION_MAPPING(20);
 614 REGION_MAPPING(21);
 615 REGION_MAPPING(22);
 616 REGION_MAPPING(23);
 617 REGION_MAPPING(24);
 618 REGION_MAPPING(25);
 619 REGION_MAPPING(26);
 620 REGION_MAPPING(27);
 621 REGION_MAPPING(28);
 622 REGION_MAPPING(29);
 623 REGION_MAPPING(30);
 624 REGION_MAPPING(31);
 625
 626 static umode_t mapping_visible(struct kobject *kobj, struct attribute *a, int n)
 627 {
 628         struct device *dev = container_of(kobj, struct device, kobj);
 629         struct nd_region *nd_region = to_nd_region(dev);
 630
 631         if (n < nd_region->ndr_mappings)
 632                 return a->mode;
 633         return 0;
 634 }
 635
 636 static struct attribute *mapping_attributes[] = {
 637         &dev_attr_mapping0.attr,
 638         &dev_attr_mapping1.attr,
 639         &dev_attr_mapping2.attr,
 640         &dev_attr_mapping3.attr,
 641         &dev_attr_mapping4.attr,
 642         &dev_attr_mapping5.attr,
 643         &dev_attr_mapping6.attr,
 644         &dev_attr_mapping7.attr,
 645         &dev_attr_mapping8.attr,
 646         &dev_attr_mapping9.attr,
 647         &dev_attr_mapping10.attr,
 648         &dev_attr_mapping11.attr,
 649         &dev_attr_mapping12.attr,
 650         &dev_attr_mapping13.attr,
 651         &dev_attr_mapping14.attr,
 652         &dev_attr_mapping15.attr,
 653         &dev_attr_mapping16.attr,
 654         &dev_attr_mapping17.attr,
 655         &dev_attr_mapping18.attr,
 656         &dev_attr_mapping19.attr,
 657         &dev_attr_mapping20.attr,
 658         &dev_attr_mapping21.attr,
 659         &dev_attr_mapping22.attr,
 660         &dev_attr_mapping23.attr,
 661         &dev_attr_mapping24.attr,
 662         &dev_attr_mapping25.attr,
 663         &dev_attr_mapping26.attr,
 664         &dev_attr_mapping27.attr,
 665         &dev_attr_mapping28.attr,
 666         &dev_attr_mapping29.attr,
 667         &dev_attr_mapping30.attr,
 668         &dev_attr_mapping31.attr,
 669         NULL,
 670 };
 671
 672 struct attribute_group nd_mapping_attribute_group = {
 673         .is_visible = mapping_visible,
 674         .attrs = mapping_attributes,
 675 };
 676 EXPORT_SYMBOL_GPL(nd_mapping_attribute_group);
 677
 678 int nd_blk_region_init(struct nd_region *nd_region)
 679 {
 680         struct device *dev = &nd_region->dev;
 681         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 682
 683         if (!is_nd_blk(dev))
 684                 return 0;
 685
 686         if (nd_region->ndr_mappings < 1) {
 687                 dev_err(dev, "invalid BLK region\n");
 688                 return -ENXIO;
 689         }
 690
 691         return to_nd_blk_region(dev)->enable(nvdimm_bus, dev);
 692 }
 693
 694 /**
 695  * nd_region_acquire_lane - allocate and lock a lane
 696  * @nd_region: region id and number of lanes possible
 697  *
 698  * A lane correlates to a BLK-data-window and/or a log slot in the BTT.
 699  * We optimize for the common case where there are 256 lanes, one
 700  * per-cpu.  For larger systems we need to lock to share lanes.  For now
 701  * this implementation assumes the cost of maintaining an allocator for
 702  * free lanes is on the order of the lock hold time, so it implements a
 703  * static lane = cpu % num_lanes mapping.
 704  *
 705  * In the case of a BTT instance on top of a BLK namespace a lane may be
 706  * acquired recursively.  We lock on the first instance.
 707  *
 708  * In the case of a BTT instance on top of PMEM, we only acquire a lane
 709  * for the BTT metadata updates.
 710  */
 711 unsigned int nd_region_acquire_lane(struct nd_region *nd_region)
 712 {
 713         unsigned int cpu, lane;
 714
 715         cpu = get_cpu();
 716         if (nd_region->num_lanes < nr_cpu_ids) {
 717                 struct nd_percpu_lane *ndl_lock, *ndl_count;
 718
 719                 lane = cpu % nd_region->num_lanes;
 720                 ndl_count = per_cpu_ptr(nd_region->lane, cpu);
 721                 ndl_lock = per_cpu_ptr(nd_region->lane, lane);
 722                 if (ndl_count->count++ == 0)
 723                         spin_lock(&ndl_lock->lock);
 724         } else
 725                 lane = cpu;
 726
 727         return lane;
 728 }
 729 EXPORT_SYMBOL(nd_region_acquire_lane);
 730
 731 void nd_region_release_lane(struct nd_region *nd_region, unsigned int lane)
 732 {
 733         if (nd_region->num_lanes < nr_cpu_ids) {
 734                 unsigned int cpu = get_cpu();
 735                 struct nd_percpu_lane *ndl_lock, *ndl_count;
 736
 737                 ndl_count = per_cpu_ptr(nd_region->lane, cpu);
 738                 ndl_lock = per_cpu_ptr(nd_region->lane, lane);
 739                 if (--ndl_count->count == 0)
 740                         spin_unlock(&ndl_lock->lock);
 741                 put_cpu();
 742         }
 743         put_cpu();
 744 }
 745 EXPORT_SYMBOL(nd_region_release_lane);
 746
 747 static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
 748                 struct nd_region_desc *ndr_desc, struct device_type *dev_type,
 749                 const char *caller)
 750 {
 751         struct nd_region *nd_region;
 752         struct device *dev;
 753         void *region_buf;
 754         unsigned int i;
 755         int ro = 0;
 756
 757         for (i = 0; i < ndr_desc->num_mappings; i++) {
 758                 struct nd_mapping *nd_mapping = &ndr_desc->nd_mapping[i];
 759                 struct nvdimm *nvdimm = nd_mapping->nvdimm;
 760
 761                 if ((nd_mapping->start | nd_mapping->size) % SZ_4K) {
 762                         dev_err(&nvdimm_bus->dev, "%s: %s mapping%d is not 4K aligned\n",
 763                                         caller, dev_name(&nvdimm->dev), i);
 764
 765                         return NULL;
 766                 }
 767
 768                 if (nvdimm->flags & NDD_UNARMED)
 769                         ro = 1;
 770         }
 771
 772         if (dev_type == &nd_blk_device_type) {
 773                 struct nd_blk_region_desc *ndbr_desc;
 774                 struct nd_blk_region *ndbr;
 775
 776                 ndbr_desc = to_blk_region_desc(ndr_desc);
 777                 ndbr = kzalloc(sizeof(*ndbr) + sizeof(struct nd_mapping)
 778                                 * ndr_desc->num_mappings,
 779                                 GFP_KERNEL);
 780                 if (ndbr) {
 781                         nd_region = &ndbr->nd_region;
 782                         ndbr->enable = ndbr_desc->enable;
 783                         ndbr->do_io = ndbr_desc->do_io;
 784                 }
 785                 region_buf = ndbr;
 786         } else {
 787                 nd_region = kzalloc(sizeof(struct nd_region)
 788                                 + sizeof(struct nd_mapping)
 789                                 * ndr_desc->num_mappings,
 790                                 GFP_KERNEL);
 791                 region_buf = nd_region;
 792         }
 793
 794         if (!region_buf)
 795                 return NULL;
 796         nd_region->id = ida_simple_get(&region_ida, 0, 0, GFP_KERNEL);
 797         if (nd_region->id < 0)
 798                 goto err_id;
 799
 800         nd_region->lane = alloc_percpu(struct nd_percpu_lane);
 801         if (!nd_region->lane)
 802                 goto err_percpu;
 803
 804         for (i = 0; i < nr_cpu_ids; i++) {
 805                 struct nd_percpu_lane *ndl;
 806
 807                 ndl = per_cpu_ptr(nd_region->lane, i);
 808                 spin_lock_init(&ndl->lock);
 809                 ndl->count = 0;
 810         }
 811
 812         memcpy(nd_region->mapping, ndr_desc->nd_mapping,
 813                         sizeof(struct nd_mapping) * ndr_desc->num_mappings);
 814         for (i = 0; i < ndr_desc->num_mappings; i++) {
 815                 struct nd_mapping *nd_mapping = &ndr_desc->nd_mapping[i];
 816                 struct nvdimm *nvdimm = nd_mapping->nvdimm;
 817
 818                 get_device(&nvdimm->dev);
 819         }
 820         nd_region->ndr_mappings = ndr_desc->num_mappings;
 821         nd_region->provider_data = ndr_desc->provider_data;
 822         nd_region->nd_set = ndr_desc->nd_set;
 823         nd_region->num_lanes = ndr_desc->num_lanes;
 824         nd_region->flags = ndr_desc->flags;
 825         nd_region->ro = ro;
 826         nd_region->numa_node = ndr_desc->numa_node;
 827         ida_init(&nd_region->ns_ida);
 828         ida_init(&nd_region->btt_ida);
 829         ida_init(&nd_region->pfn_ida);
 830         ida_init(&nd_region->dax_ida);
 831         dev = &nd_region->dev;
 832         dev_set_name(dev, "region%d", nd_region->id);
 833         dev->parent = &nvdimm_bus->dev;
 834         dev->type = dev_type;
 835         dev->groups = ndr_desc->attr_groups;
 836         nd_region->ndr_size = resource_size(ndr_desc->res);
 837         nd_region->ndr_start = ndr_desc->res->start;
 838         nd_device_register(dev);
 839
 840         return nd_region;
 841
 842  err_percpu:
 843         ida_simple_remove(&region_ida, nd_region->id);
 844  err_id:
 845         kfree(region_buf);
 846         return NULL;
 847 }
 848
 849 struct nd_region *nvdimm_pmem_region_create(struct nvdimm_bus *nvdimm_bus,
 850                 struct nd_region_desc *ndr_desc)
 851 {
 852         ndr_desc->num_lanes = ND_MAX_LANES;
 853         return nd_region_create(nvdimm_bus, ndr_desc, &nd_pmem_device_type,
 854                         __func__);
 855 }
 856 EXPORT_SYMBOL_GPL(nvdimm_pmem_region_create);
 857
 858 struct nd_region *nvdimm_blk_region_create(struct nvdimm_bus *nvdimm_bus,
 859                 struct nd_region_desc *ndr_desc)
 860 {
 861         if (ndr_desc->num_mappings > 1)
 862                 return NULL;
 863         ndr_desc->num_lanes = min(ndr_desc->num_lanes, ND_MAX_LANES);
 864         return nd_region_create(nvdimm_bus, ndr_desc, &nd_blk_device_type,
 865                         __func__);
 866 }
 867 EXPORT_SYMBOL_GPL(nvdimm_blk_region_create);
 868
 869 struct nd_region *nvdimm_volatile_region_create(struct nvdimm_bus *nvdimm_bus,
 870                 struct nd_region_desc *ndr_desc)
 871 {
 872         ndr_desc->num_lanes = ND_MAX_LANES;
 873         return nd_region_create(nvdimm_bus, ndr_desc, &nd_volatile_device_type,
 874                         __func__);
 875 }
 876 EXPORT_SYMBOL_GPL(nvdimm_volatile_region_create);
 877
 878 /**
 879  * nvdimm_flush - flush any posted write queues between the cpu and pmem media
 880  * @nd_region: blk or interleaved pmem region
 881  */
 882 void nvdimm_flush(struct nd_region *nd_region)
 883 {
 884         struct nd_region_data *ndrd = dev_get_drvdata(&nd_region->dev);
 885         int i, idx;
 886
 887         /*
 888          * Try to encourage some diversity in flush hint addresses
 889          * across cpus assuming a limited number of flush hints.
 890          */
 891         idx = this_cpu_read(flush_idx);
 892         idx = this_cpu_add_return(flush_idx, hash_32(current->pid + idx, 8));
 893
 894         /*
 895          * The first wmb() is needed to 'sfence' all previous writes
 896          * such that they are architecturally visible for the platform
 897          * buffer flush.  Note that we've already arranged for pmem
 898          * writes to avoid the cache via arch_memcpy_to_pmem().  The
 899          * final wmb() ensures ordering for the NVDIMM flush write.
 900          */
 901         wmb();
 902         for (i = 0; i < nd_region->ndr_mappings; i++)
 903                 if (ndrd->flush_wpq[i][0])
 904                         writeq(1, ndrd->flush_wpq[i][idx & ndrd->flush_mask]);
 905         wmb();
 906 }
 907 EXPORT_SYMBOL_GPL(nvdimm_flush);
 908
 909 /**
 910  * nvdimm_has_flush - determine write flushing requirements
 911  * @nd_region: blk or interleaved pmem region
 912  *
 913  * Returns 1 if writes require flushing
 914  * Returns 0 if writes do not require flushing
 915  * Returns -ENXIO if flushing capability can not be determined
 916  */
 917 int nvdimm_has_flush(struct nd_region *nd_region)
 918 {
 919         struct nd_region_data *ndrd = dev_get_drvdata(&nd_region->dev);
 920         int i;
 921
 922         /* no nvdimm == flushing capability unknown */
 923         if (nd_region->ndr_mappings == 0)
 924                 return -ENXIO;
 925
 926         for (i = 0; i < nd_region->ndr_mappings; i++)
 927                 /* flush hints present, flushing required */
 928                 if (ndrd->flush_wpq[i][0])
 929                         return 1;
 930
 931         /*
 932          * The platform defines dimm devices without hints, assume
 933          * platform persistence mechanism like ADR
 934          */
 935         return 0;
 936 }
 937 EXPORT_SYMBOL_GPL(nvdimm_has_flush);
 938
 939 void __exit nd_region_devs_exit(void)
 940 {
 941         ida_destroy(&region_ida);
 942 }