drivers/nvdimm/dimm_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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14 #include <linux/vmalloc.h>
  15 #include <linux/device.h>
  16 #include <linux/ndctl.h>
  17 #include <linux/slab.h>
  18 #include <linux/io.h>
  19 #include <linux/fs.h>
  20 #include <linux/mm.h>
  21 #include "nd-core.h"
  22 #include "label.h"
  23 #include "nd.h"
  24
  25 static DEFINE_IDA(dimm_ida);
  26
  27 /*
  28  * Retrieve bus and dimm handle and return if this bus supports
  29  * get_config_data commands
  30  */
  31 int nvdimm_check_config_data(struct device *dev)
  32 {
  33         struct nvdimm *nvdimm = to_nvdimm(dev);
  34
  35         if (!nvdimm->cmd_mask ||
  36             !test_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm->cmd_mask)) {
  37                 if (nvdimm->flags & NDD_ALIASING)
  38                         return -ENXIO;
  39                 else
  40                         return -ENOTTY;
  41         }
  42
  43         return 0;
  44 }
  45
  46 static int validate_dimm(struct nvdimm_drvdata *ndd)
  47 {
  48         int rc;
  49
  50         if (!ndd)
  51                 return -EINVAL;
  52
  53         rc = nvdimm_check_config_data(ndd->dev);
  54         if (rc)
  55                 dev_dbg(ndd->dev, "%pf: %s error: %d\n",
  56                                 __builtin_return_address(0), __func__, rc);
  57         return rc;
  58 }
  59
  60 /**
  61  * nvdimm_init_nsarea - determine the geometry of a dimm's namespace area
  62  * @nvdimm: dimm to initialize
  63  */
  64 int nvdimm_init_nsarea(struct nvdimm_drvdata *ndd)
  65 {
  66         struct nd_cmd_get_config_size *cmd = &ndd->nsarea;
  67         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
  68         struct nvdimm_bus_descriptor *nd_desc;
  69         int rc = validate_dimm(ndd);
  70
  71         if (rc)
  72                 return rc;
  73
  74         if (cmd->config_size)
  75                 return 0; /* already valid */
  76
  77         memset(cmd, 0, sizeof(*cmd));
  78         nd_desc = nvdimm_bus->nd_desc;
  79         return nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
  80                         ND_CMD_GET_CONFIG_SIZE, cmd, sizeof(*cmd), NULL);
  81 }
  82
  83 int nvdimm_init_config_data(struct nvdimm_drvdata *ndd)
  84 {
  85         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
  86         struct nd_cmd_get_config_data_hdr *cmd;
  87         struct nvdimm_bus_descriptor *nd_desc;
  88         int rc = validate_dimm(ndd);
  89         u32 max_cmd_size, config_size;
  90         size_t offset;
  91
  92         if (rc)
  93                 return rc;
  94
  95         if (ndd->data)
  96                 return 0;
  97
  98         if (ndd->nsarea.status || ndd->nsarea.max_xfer == 0
  99                         || ndd->nsarea.config_size < ND_LABEL_MIN_SIZE) {
 100                 dev_dbg(ndd->dev, "failed to init config data area: (%d:%d)\n",
 101                                 ndd->nsarea.max_xfer, ndd->nsarea.config_size);
 102                 return -ENXIO;
 103         }
 104
 105         ndd->data = kmalloc(ndd->nsarea.config_size, GFP_KERNEL);
 106         if (!ndd->data)
 107                 ndd->data = vmalloc(ndd->nsarea.config_size);
 108
 109         if (!ndd->data)
 110                 return -ENOMEM;
 111
 112         max_cmd_size = min_t(u32, PAGE_SIZE, ndd->nsarea.max_xfer);
 113         cmd = kzalloc(max_cmd_size + sizeof(*cmd), GFP_KERNEL);
 114         if (!cmd)
 115                 return -ENOMEM;
 116
 117         nd_desc = nvdimm_bus->nd_desc;
 118         for (config_size = ndd->nsarea.config_size, offset = 0;
 119                         config_size; config_size -= cmd->in_length,
 120                         offset += cmd->in_length) {
 121                 cmd->in_length = min(config_size, max_cmd_size);
 122                 cmd->in_offset = offset;
 123                 rc = nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
 124                                 ND_CMD_GET_CONFIG_DATA, cmd,
 125                                 cmd->in_length + sizeof(*cmd), NULL);
 126                 if (rc || cmd->status) {
 127                         rc = -ENXIO;
 128                         break;
 129                 }
 130                 memcpy(ndd->data + offset, cmd->out_buf, cmd->in_length);
 131         }
 132         dev_dbg(ndd->dev, "%s: len: %zu rc: %d\n", __func__, offset, rc);
 133         kfree(cmd);
 134
 135         return rc;
 136 }
 137
 138 int nvdimm_set_config_data(struct nvdimm_drvdata *ndd, size_t offset,
 139                 void *buf, size_t len)
 140 {
 141         int rc = validate_dimm(ndd);
 142         size_t max_cmd_size, buf_offset;
 143         struct nd_cmd_set_config_hdr *cmd;
 144         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
 145         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 146
 147         if (rc)
 148                 return rc;
 149
 150         if (!ndd->data)
 151                 return -ENXIO;
 152
 153         if (offset + len > ndd->nsarea.config_size)
 154                 return -ENXIO;
 155
 156         max_cmd_size = min_t(u32, PAGE_SIZE, len);
 157         max_cmd_size = min_t(u32, max_cmd_size, ndd->nsarea.max_xfer);
 158         cmd = kzalloc(max_cmd_size + sizeof(*cmd) + sizeof(u32), GFP_KERNEL);
 159         if (!cmd)
 160                 return -ENOMEM;
 161
 162         for (buf_offset = 0; len; len -= cmd->in_length,
 163                         buf_offset += cmd->in_length) {
 164                 size_t cmd_size;
 165                 u32 *status;
 166
 167                 cmd->in_offset = offset + buf_offset;
 168                 cmd->in_length = min(max_cmd_size, len);
 169                 memcpy(cmd->in_buf, buf + buf_offset, cmd->in_length);
 170
 171                 /* status is output in the last 4-bytes of the command buffer */
 172                 cmd_size = sizeof(*cmd) + cmd->in_length + sizeof(u32);
 173                 status = ((void *) cmd) + cmd_size - sizeof(u32);
 174
 175                 rc = nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
 176                                 ND_CMD_SET_CONFIG_DATA, cmd, cmd_size, NULL);
 177                 if (rc || *status) {
 178                         rc = rc ? rc : -ENXIO;
 179                         break;
 180                 }
 181         }
 182         kfree(cmd);
 183
 184         return rc;
 185 }
 186
 187 void nvdimm_set_aliasing(struct device *dev)
 188 {
 189         struct nvdimm *nvdimm = to_nvdimm(dev);
 190
 191         nvdimm->flags |= NDD_ALIASING;
 192 }
 193
 194 static void nvdimm_release(struct device *dev)
 195 {
 196         struct nvdimm *nvdimm = to_nvdimm(dev);
 197
 198         ida_simple_remove(&dimm_ida, nvdimm->id);
 199         kfree(nvdimm);
 200 }
 201
 202 static struct device_type nvdimm_device_type = {
 203         .name = "nvdimm",
 204         .release = nvdimm_release,
 205 };
 206
 207 bool is_nvdimm(struct device *dev)
 208 {
 209         return dev->type == &nvdimm_device_type;
 210 }
 211
 212 struct nvdimm *to_nvdimm(struct device *dev)
 213 {
 214         struct nvdimm *nvdimm = container_of(dev, struct nvdimm, dev);
 215
 216         WARN_ON(!is_nvdimm(dev));
 217         return nvdimm;
 218 }
 219 EXPORT_SYMBOL_GPL(to_nvdimm);
 220
 221 struct nvdimm *nd_blk_region_to_dimm(struct nd_blk_region *ndbr)
 222 {
 223         struct nd_region *nd_region = &ndbr->nd_region;
 224         struct nd_mapping *nd_mapping = &nd_region->mapping[0];
 225
 226         return nd_mapping->nvdimm;
 227 }
 228 EXPORT_SYMBOL_GPL(nd_blk_region_to_dimm);
 229
 230 struct nvdimm_drvdata *to_ndd(struct nd_mapping *nd_mapping)
 231 {
 232         struct nvdimm *nvdimm = nd_mapping->nvdimm;
 233
 234         WARN_ON_ONCE(!is_nvdimm_bus_locked(&nvdimm->dev));
 235
 236         return dev_get_drvdata(&nvdimm->dev);
 237 }
 238 EXPORT_SYMBOL(to_ndd);
 239
 240 void nvdimm_drvdata_release(struct kref *kref)
 241 {
 242         struct nvdimm_drvdata *ndd = container_of(kref, typeof(*ndd), kref);
 243         struct device *dev = ndd->dev;
 244         struct resource *res, *_r;
 245
 246         dev_dbg(dev, "%s\n", __func__);
 247
 248         nvdimm_bus_lock(dev);
 249         for_each_dpa_resource_safe(ndd, res, _r)
 250                 nvdimm_free_dpa(ndd, res);
 251         nvdimm_bus_unlock(dev);
 252
 253         kvfree(ndd->data);
 254         kfree(ndd);
 255         put_device(dev);
 256 }
 257
 258 void get_ndd(struct nvdimm_drvdata *ndd)
 259 {
 260         kref_get(&ndd->kref);
 261 }
 262
 263 void put_ndd(struct nvdimm_drvdata *ndd)
 264 {
 265         if (ndd)
 266                 kref_put(&ndd->kref, nvdimm_drvdata_release);
 267 }
 268
 269 const char *nvdimm_name(struct nvdimm *nvdimm)
 270 {
 271         return dev_name(&nvdimm->dev);
 272 }
 273 EXPORT_SYMBOL_GPL(nvdimm_name);
 274
 275 struct kobject *nvdimm_kobj(struct nvdimm *nvdimm)
 276 {
 277         return &nvdimm->dev.kobj;
 278 }
 279 EXPORT_SYMBOL_GPL(nvdimm_kobj);
 280
 281 unsigned long nvdimm_cmd_mask(struct nvdimm *nvdimm)
 282 {
 283         return nvdimm->cmd_mask;
 284 }
 285 EXPORT_SYMBOL_GPL(nvdimm_cmd_mask);
 286
 287 void *nvdimm_provider_data(struct nvdimm *nvdimm)
 288 {
 289         if (nvdimm)
 290                 return nvdimm->provider_data;
 291         return NULL;
 292 }
 293 EXPORT_SYMBOL_GPL(nvdimm_provider_data);
 294
 295 static ssize_t commands_show(struct device *dev,
 296                 struct device_attribute *attr, char *buf)
 297 {
 298         struct nvdimm *nvdimm = to_nvdimm(dev);
 299         int cmd, len = 0;
 300
 301         if (!nvdimm->cmd_mask)
 302                 return sprintf(buf, "\n");
 303
 304         for_each_set_bit(cmd, &nvdimm->cmd_mask, BITS_PER_LONG)
 305                 len += sprintf(buf + len, "%s ", nvdimm_cmd_name(cmd));
 306         len += sprintf(buf + len, "\n");
 307         return len;
 308 }
 309 static DEVICE_ATTR_RO(commands);
 310
 311 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 312                 char *buf)
 313 {
 314         struct nvdimm *nvdimm = to_nvdimm(dev);
 315
 316         /*
 317          * The state may be in the process of changing, userspace should
 318          * quiesce probing if it wants a static answer
 319          */
 320         nvdimm_bus_lock(dev);
 321         nvdimm_bus_unlock(dev);
 322         return sprintf(buf, "%s\n", atomic_read(&nvdimm->busy)
 323                         ? "active" : "idle");
 324 }
 325 static DEVICE_ATTR_RO(state);
 326
 327 static ssize_t available_slots_show(struct device *dev,
 328                 struct device_attribute *attr, char *buf)
 329 {
 330         struct nvdimm_drvdata *ndd = dev_get_drvdata(dev);
 331         ssize_t rc;
 332         u32 nfree;
 333
 334         if (!ndd)
 335                 return -ENXIO;
 336
 337         nvdimm_bus_lock(dev);
 338         nfree = nd_label_nfree(ndd);
 339         if (nfree - 1 > nfree) {
 340                 dev_WARN_ONCE(dev, 1, "we ate our last label?\n");
 341                 nfree = 0;
 342         } else
 343                 nfree--;
 344         rc = sprintf(buf, "%d\n", nfree);
 345         nvdimm_bus_unlock(dev);
 346         return rc;
 347 }
 348 static DEVICE_ATTR_RO(available_slots);
 349
 350 static struct attribute *nvdimm_attributes[] = {
 351         &dev_attr_state.attr,
 352         &dev_attr_commands.attr,
 353         &dev_attr_available_slots.attr,
 354         NULL,
 355 };
 356
 357 struct attribute_group nvdimm_attribute_group = {
 358         .attrs = nvdimm_attributes,
 359 };
 360 EXPORT_SYMBOL_GPL(nvdimm_attribute_group);
 361
 362 struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus, void *provider_data,
 363                 const struct attribute_group **groups, unsigned long flags,
 364                 unsigned long cmd_mask, int num_flush,
 365                 struct resource *flush_wpq)
 366 {
 367         struct nvdimm *nvdimm = kzalloc(sizeof(*nvdimm), GFP_KERNEL);
 368         struct device *dev;
 369
 370         if (!nvdimm)
 371                 return NULL;
 372
 373         nvdimm->id = ida_simple_get(&dimm_ida, 0, 0, GFP_KERNEL);
 374         if (nvdimm->id < 0) {
 375                 kfree(nvdimm);
 376                 return NULL;
 377         }
 378         nvdimm->provider_data = provider_data;
 379         nvdimm->flags = flags;
 380         nvdimm->cmd_mask = cmd_mask;
 381         nvdimm->num_flush = num_flush;
 382         nvdimm->flush_wpq = flush_wpq;
 383         atomic_set(&nvdimm->busy, 0);
 384         dev = &nvdimm->dev;
 385         dev_set_name(dev, "nmem%d", nvdimm->id);
 386         dev->parent = &nvdimm_bus->dev;
 387         dev->type = &nvdimm_device_type;
 388         dev->devt = MKDEV(nvdimm_major, nvdimm->id);
 389         dev->groups = groups;
 390         nd_device_register(dev);
 391
 392         return nvdimm;
 393 }
 394 EXPORT_SYMBOL_GPL(nvdimm_create);
 395
 396 int alias_dpa_busy(struct device *dev, void *data)
 397 {
 398         resource_size_t map_end, blk_start, new, busy;
 399         struct blk_alloc_info *info = data;
 400         struct nd_mapping *nd_mapping;
 401         struct nd_region *nd_region;
 402         struct nvdimm_drvdata *ndd;
 403         struct resource *res;
 404         int i;
 405
 406         if (!is_nd_pmem(dev))
 407                 return 0;
 408
 409         nd_region = to_nd_region(dev);
 410         for (i = 0; i < nd_region->ndr_mappings; i++) {
 411                 nd_mapping  = &nd_region->mapping[i];
 412                 if (nd_mapping->nvdimm == info->nd_mapping->nvdimm)
 413                         break;
 414         }
 415
 416         if (i >= nd_region->ndr_mappings)
 417                 return 0;
 418
 419         ndd = to_ndd(nd_mapping);
 420         map_end = nd_mapping->start + nd_mapping->size - 1;
 421         blk_start = nd_mapping->start;
 422
 423         /*
 424          * In the allocation case ->res is set to free space that we are
 425          * looking to validate against PMEM aliasing collision rules
 426          * (i.e. BLK is allocated after all aliased PMEM).
 427          */
 428         if (info->res) {
 429                 if (info->res->start >= nd_mapping->start
 430                                 && info->res->start < map_end)
 431                         /* pass */;
 432                 else
 433                         return 0;
 434         }
 435
 436  retry:
 437         /*
 438          * Find the free dpa from the end of the last pmem allocation to
 439          * the end of the interleave-set mapping that is not already
 440          * covered by a blk allocation.
 441          */
 442         busy = 0;
 443         for_each_dpa_resource(ndd, res) {
 444                 if ((res->start >= blk_start && res->start < map_end)
 445                                 || (res->end >= blk_start
 446                                         && res->end <= map_end)) {
 447                         if (strncmp(res->name, "pmem", 4) == 0) {
 448                                 new = max(blk_start, min(map_end + 1,
 449                                                         res->end + 1));
 450                                 if (new != blk_start) {
 451                                         blk_start = new;
 452                                         goto retry;
 453                                 }
 454                         } else
 455                                 busy += min(map_end, res->end)
 456                                         - max(nd_mapping->start, res->start) + 1;
 457                 } else if (nd_mapping->start > res->start
 458                                 && map_end < res->end) {
 459                         /* total eclipse of the PMEM region mapping */
 460                         busy += nd_mapping->size;
 461                         break;
 462                 }
 463         }
 464
 465         /* update the free space range with the probed blk_start */
 466         if (info->res && blk_start > info->res->start) {
 467                 info->res->start = max(info->res->start, blk_start);
 468                 if (info->res->start > info->res->end)
 469                         info->res->end = info->res->start - 1;
 470                 return 1;
 471         }
 472
 473         info->available -= blk_start - nd_mapping->start + busy;
 474
 475         return 0;
 476 }
 477
 478 static int blk_dpa_busy(struct device *dev, void *data)
 479 {
 480         struct blk_alloc_info *info = data;
 481         struct nd_mapping *nd_mapping;
 482         struct nd_region *nd_region;
 483         resource_size_t map_end;
 484         int i;
 485
 486         if (!is_nd_pmem(dev))
 487                 return 0;
 488
 489         nd_region = to_nd_region(dev);
 490         for (i = 0; i < nd_region->ndr_mappings; i++) {
 491                 nd_mapping  = &nd_region->mapping[i];
 492                 if (nd_mapping->nvdimm == info->nd_mapping->nvdimm)
 493                         break;
 494         }
 495
 496         if (i >= nd_region->ndr_mappings)
 497                 return 0;
 498
 499         map_end = nd_mapping->start + nd_mapping->size - 1;
 500         if (info->res->start >= nd_mapping->start
 501                         && info->res->start < map_end) {
 502                 if (info->res->end <= map_end) {
 503                         info->busy = 0;
 504                         return 1;
 505                 } else {
 506                         info->busy -= info->res->end - map_end;
 507                         return 0;
 508                 }
 509         } else if (info->res->end >= nd_mapping->start
 510                         && info->res->end <= map_end) {
 511                 info->busy -= nd_mapping->start - info->res->start;
 512                 return 0;
 513         } else {
 514                 info->busy -= nd_mapping->size;
 515                 return 0;
 516         }
 517 }
 518
 519 /**
 520  * nd_blk_available_dpa - account the unused dpa of BLK region
 521  * @nd_mapping: container of dpa-resource-root + labels
 522  *
 523  * Unlike PMEM, BLK namespaces can occupy discontiguous DPA ranges, but
 524  * we arrange for them to never start at an lower dpa than the last
 525  * PMEM allocation in an aliased region.
 526  */
 527 resource_size_t nd_blk_available_dpa(struct nd_region *nd_region)
 528 {
 529         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
 530         struct nd_mapping *nd_mapping = &nd_region->mapping[0];
 531         struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
 532         struct blk_alloc_info info = {
 533                 .nd_mapping = nd_mapping,
 534                 .available = nd_mapping->size,
 535                 .res = NULL,
 536         };
 537         struct resource *res;
 538
 539         if (!ndd)
 540                 return 0;
 541
 542         device_for_each_child(&nvdimm_bus->dev, &info, alias_dpa_busy);
 543
 544         /* now account for busy blk allocations in unaliased dpa */
 545         for_each_dpa_resource(ndd, res) {
 546                 if (strncmp(res->name, "blk", 3) != 0)
 547                         continue;
 548
 549                 info.res = res;
 550                 info.busy = resource_size(res);
 551                 device_for_each_child(&nvdimm_bus->dev, &info, blk_dpa_busy);
 552                 info.available -= info.busy;
 553         }
 554
 555         return info.available;
 556 }
 557
 558 /**
 559  * nd_pmem_available_dpa - for the given dimm+region account unallocated dpa
 560  * @nd_mapping: container of dpa-resource-root + labels
 561  * @nd_region: constrain available space check to this reference region
 562  * @overlap: calculate available space assuming this level of overlap
 563  *
 564  * Validate that a PMEM label, if present, aligns with the start of an
 565  * interleave set and truncate the available size at the lowest BLK
 566  * overlap point.
 567  *
 568  * The expectation is that this routine is called multiple times as it
 569  * probes for the largest BLK encroachment for any single member DIMM of
 570  * the interleave set.  Once that value is determined the PMEM-limit for
 571  * the set can be established.
 572  */
 573 resource_size_t nd_pmem_available_dpa(struct nd_region *nd_region,
 574                 struct nd_mapping *nd_mapping, resource_size_t *overlap)
 575 {
 576         resource_size_t map_start, map_end, busy = 0, available, blk_start;
 577         struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
 578         struct resource *res;
 579         const char *reason;
 580
 581         if (!ndd)
 582                 return 0;
 583
 584         map_start = nd_mapping->start;
 585         map_end = map_start + nd_mapping->size - 1;
 586         blk_start = max(map_start, map_end + 1 - *overlap);
 587         for_each_dpa_resource(ndd, res) {
 588                 if (res->start >= map_start && res->start < map_end) {
 589                         if (strncmp(res->name, "blk", 3) == 0)
 590                                 blk_start = min(blk_start,
 591                                                 max(map_start, res->start));
 592                         else if (res->end > map_end) {
 593                                 reason = "misaligned to iset";
 594                                 goto err;
 595                         } else
 596                                 busy += resource_size(res);
 597                 } else if (res->end >= map_start && res->end <= map_end) {
 598                         if (strncmp(res->name, "blk", 3) == 0) {
 599                                 /*
 600                                  * If a BLK allocation overlaps the start of
 601                                  * PMEM the entire interleave set may now only
 602                                  * be used for BLK.
 603                                  */
 604                                 blk_start = map_start;
 605                         } else
 606                                 busy += resource_size(res);
 607                 } else if (map_start > res->start && map_start < res->end) {
 608                         /* total eclipse of the mapping */
 609                         busy += nd_mapping->size;
 610                         blk_start = map_start;
 611                 }
 612         }
 613
 614         *overlap = map_end + 1 - blk_start;
 615         available = blk_start - map_start;
 616         if (busy < available)
 617                 return available - busy;
 618         return 0;
 619
 620  err:
 621         nd_dbg_dpa(nd_region, ndd, res, "%s\n", reason);
 622         return 0;
 623 }
 624
 625 void nvdimm_free_dpa(struct nvdimm_drvdata *ndd, struct resource *res)
 626 {
 627         WARN_ON_ONCE(!is_nvdimm_bus_locked(ndd->dev));
 628         kfree(res->name);
 629         __release_region(&ndd->dpa, res->start, resource_size(res));
 630 }
 631
 632 struct resource *nvdimm_allocate_dpa(struct nvdimm_drvdata *ndd,
 633                 struct nd_label_id *label_id, resource_size_t start,
 634                 resource_size_t n)
 635 {
 636         char *name = kmemdup(label_id, sizeof(*label_id), GFP_KERNEL);
 637         struct resource *res;
 638
 639         if (!name)
 640                 return NULL;
 641
 642         WARN_ON_ONCE(!is_nvdimm_bus_locked(ndd->dev));
 643         res = __request_region(&ndd->dpa, start, n, name, 0);
 644         if (!res)
 645                 kfree(name);
 646         return res;
 647 }
 648
 649 /**
 650  * nvdimm_allocated_dpa - sum up the dpa currently allocated to this label_id
 651  * @nvdimm: container of dpa-resource-root + labels
 652  * @label_id: dpa resource name of the form {pmem|blk}-<human readable uuid>
 653  */
 654 resource_size_t nvdimm_allocated_dpa(struct nvdimm_drvdata *ndd,
 655                 struct nd_label_id *label_id)
 656 {
 657         resource_size_t allocated = 0;
 658         struct resource *res;
 659
 660         for_each_dpa_resource(ndd, res)
 661                 if (strcmp(res->name, label_id->id) == 0)
 662                         allocated += resource_size(res);
 663
 664         return allocated;
 665 }
 666
 667 static int count_dimms(struct device *dev, void *c)
 668 {
 669         int *count = c;
 670
 671         if (is_nvdimm(dev))
 672                 (*count)++;
 673         return 0;
 674 }
 675
 676 int nvdimm_bus_check_dimm_count(struct nvdimm_bus *nvdimm_bus, int dimm_count)
 677 {
 678         int count = 0;
 679         /* Flush any possible dimm registration failures */
 680         nd_synchronize();
 681
 682         device_for_each_child(&nvdimm_bus->dev, &count, count_dimms);
 683         dev_dbg(&nvdimm_bus->dev, "%s: count: %d\n", __func__, count);
 684         if (count != dimm_count)
 685                 return -ENXIO;
 686         return 0;
 687 }
 688 EXPORT_SYMBOL_GPL(nvdimm_bus_check_dimm_count);
 689
 690 void __exit nvdimm_devs_exit(void)
 691 {
 692         ida_destroy(&dimm_ida);
 693 }