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 "pmem.h"
  24 #include "nd.h"
  25
  26 static DEFINE_IDA(dimm_ida);
  27
  28 /*
  29  * Retrieve bus and dimm handle and return if this bus supports
  30  * get_config_data commands
  31  */
  32 int nvdimm_check_config_data(struct device *dev)
  33 {
  34         struct nvdimm *nvdimm = to_nvdimm(dev);
  35
  36         if (!nvdimm->cmd_mask ||
  37             !test_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm->cmd_mask)) {
  38                 if (test_bit(NDD_ALIASING, &nvdimm->flags))
  39                         return -ENXIO;
  40                 else
  41                         return -ENOTTY;
  42         }
  43
  44         return 0;
  45 }
  46
  47 static int validate_dimm(struct nvdimm_drvdata *ndd)
  48 {
  49         int rc;
  50
  51         if (!ndd)
  52                 return -EINVAL;
  53
  54         rc = nvdimm_check_config_data(ndd->dev);
  55         if (rc)
  56                 dev_dbg(ndd->dev, "%pf: %s error: %d\n",
  57                                 __builtin_return_address(0), __func__, rc);
  58         return rc;
  59 }
  60
  61 /**
  62  * nvdimm_init_nsarea - determine the geometry of a dimm's namespace area
  63  * @nvdimm: dimm to initialize
  64  */
  65 int nvdimm_init_nsarea(struct nvdimm_drvdata *ndd)
  66 {
  67         struct nd_cmd_get_config_size *cmd = &ndd->nsarea;
  68         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
  69         struct nvdimm_bus_descriptor *nd_desc;
  70         int rc = validate_dimm(ndd);
  71         int cmd_rc = 0;
  72
  73         if (rc)
  74                 return rc;
  75
  76         if (cmd->config_size)
  77                 return 0; /* already valid */
  78
  79         memset(cmd, 0, sizeof(*cmd));
  80         nd_desc = nvdimm_bus->nd_desc;
  81         rc = nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
  82                         ND_CMD_GET_CONFIG_SIZE, cmd, sizeof(*cmd), &cmd_rc);
  83         if (rc < 0)
  84                 return rc;
  85         return cmd_rc;
  86 }
  87
  88 int nvdimm_get_config_data(struct nvdimm_drvdata *ndd, void *buf,
  89                            size_t offset, size_t len)
  90 {
  91         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
  92         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
  93         int rc = validate_dimm(ndd), cmd_rc = 0;
  94         struct nd_cmd_get_config_data_hdr *cmd;
  95         size_t max_cmd_size, buf_offset;
  96
  97         if (rc)
  98                 return rc;
  99
 100         if (offset + len > ndd->nsarea.config_size)
 101                 return -ENXIO;
 102
 103         max_cmd_size = min_t(u32, len, ndd->nsarea.max_xfer);
 104         cmd = kvzalloc(max_cmd_size + sizeof(*cmd), GFP_KERNEL);
 105         if (!cmd)
 106                 return -ENOMEM;
 107
 108         for (buf_offset = 0; len;
 109              len -= cmd->in_length, buf_offset += cmd->in_length) {
 110                 size_t cmd_size;
 111
 112                 cmd->in_offset = offset + buf_offset;
 113                 cmd->in_length = min(max_cmd_size, len);
 114
 115                 cmd_size = sizeof(*cmd) + cmd->in_length;
 116
 117                 rc = nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
 118                                 ND_CMD_GET_CONFIG_DATA, cmd, cmd_size, &cmd_rc);
 119                 if (rc < 0)
 120                         break;
 121                 if (cmd_rc < 0) {
 122                         rc = cmd_rc;
 123                         break;
 124                 }
 125
 126                 /* out_buf should be valid, copy it into our output buffer */
 127                 memcpy(buf + buf_offset, cmd->out_buf, cmd->in_length);
 128         }
 129         kvfree(cmd);
 130
 131         return rc;
 132 }
 133
 134 int nvdimm_set_config_data(struct nvdimm_drvdata *ndd, size_t offset,
 135                 void *buf, size_t len)
 136 {
 137         size_t max_cmd_size, buf_offset;
 138         struct nd_cmd_set_config_hdr *cmd;
 139         int rc = validate_dimm(ndd), cmd_rc = 0;
 140         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
 141         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 142
 143         if (rc)
 144                 return rc;
 145
 146         if (offset + len > ndd->nsarea.config_size)
 147                 return -ENXIO;
 148
 149         max_cmd_size = min_t(u32, len, ndd->nsarea.max_xfer);
 150         cmd = kvzalloc(max_cmd_size + sizeof(*cmd) + sizeof(u32), GFP_KERNEL);
 151         if (!cmd)
 152                 return -ENOMEM;
 153
 154         for (buf_offset = 0; len; len -= cmd->in_length,
 155                         buf_offset += cmd->in_length) {
 156                 size_t cmd_size;
 157
 158                 cmd->in_offset = offset + buf_offset;
 159                 cmd->in_length = min(max_cmd_size, len);
 160                 memcpy(cmd->in_buf, buf + buf_offset, cmd->in_length);
 161
 162                 /* status is output in the last 4-bytes of the command buffer */
 163                 cmd_size = sizeof(*cmd) + cmd->in_length + sizeof(u32);
 164
 165                 rc = nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
 166                                 ND_CMD_SET_CONFIG_DATA, cmd, cmd_size, &cmd_rc);
 167                 if (rc < 0)
 168                         break;
 169                 if (cmd_rc < 0) {
 170                         rc = cmd_rc;
 171                         break;
 172                 }
 173         }
 174         kvfree(cmd);
 175
 176         return rc;
 177 }
 178
 179 void nvdimm_set_aliasing(struct device *dev)
 180 {
 181         struct nvdimm *nvdimm = to_nvdimm(dev);
 182
 183         set_bit(NDD_ALIASING, &nvdimm->flags);
 184 }
 185
 186 void nvdimm_set_locked(struct device *dev)
 187 {
 188         struct nvdimm *nvdimm = to_nvdimm(dev);
 189
 190         set_bit(NDD_LOCKED, &nvdimm->flags);
 191 }
 192
 193 void nvdimm_clear_locked(struct device *dev)
 194 {
 195         struct nvdimm *nvdimm = to_nvdimm(dev);
 196
 197         clear_bit(NDD_LOCKED, &nvdimm->flags);
 198 }
 199
 200 static void nvdimm_release(struct device *dev)
 201 {
 202         struct nvdimm *nvdimm = to_nvdimm(dev);
 203
 204         ida_simple_remove(&dimm_ida, nvdimm->id);
 205         kfree(nvdimm);
 206 }
 207
 208 static struct device_type nvdimm_device_type = {
 209         .name = "nvdimm",
 210         .release = nvdimm_release,
 211 };
 212
 213 bool is_nvdimm(struct device *dev)
 214 {
 215         return dev->type == &nvdimm_device_type;
 216 }
 217
 218 struct nvdimm *to_nvdimm(struct device *dev)
 219 {
 220         struct nvdimm *nvdimm = container_of(dev, struct nvdimm, dev);
 221
 222         WARN_ON(!is_nvdimm(dev));
 223         return nvdimm;
 224 }
 225 EXPORT_SYMBOL_GPL(to_nvdimm);
 226
 227 struct nvdimm *nd_blk_region_to_dimm(struct nd_blk_region *ndbr)
 228 {
 229         struct nd_region *nd_region = &ndbr->nd_region;
 230         struct nd_mapping *nd_mapping = &nd_region->mapping[0];
 231
 232         return nd_mapping->nvdimm;
 233 }
 234 EXPORT_SYMBOL_GPL(nd_blk_region_to_dimm);
 235
 236 unsigned long nd_blk_memremap_flags(struct nd_blk_region *ndbr)
 237 {
 238         /* pmem mapping properties are private to libnvdimm */
 239         return ARCH_MEMREMAP_PMEM;
 240 }
 241 EXPORT_SYMBOL_GPL(nd_blk_memremap_flags);
 242
 243 struct nvdimm_drvdata *to_ndd(struct nd_mapping *nd_mapping)
 244 {
 245         struct nvdimm *nvdimm = nd_mapping->nvdimm;
 246
 247         WARN_ON_ONCE(!is_nvdimm_bus_locked(&nvdimm->dev));
 248
 249         return dev_get_drvdata(&nvdimm->dev);
 250 }
 251 EXPORT_SYMBOL(to_ndd);
 252
 253 void nvdimm_drvdata_release(struct kref *kref)
 254 {
 255         struct nvdimm_drvdata *ndd = container_of(kref, typeof(*ndd), kref);
 256         struct device *dev = ndd->dev;
 257         struct resource *res, *_r;
 258
 259         dev_dbg(dev, "trace\n");
 260         nvdimm_bus_lock(dev);
 261         for_each_dpa_resource_safe(ndd, res, _r)
 262                 nvdimm_free_dpa(ndd, res);
 263         nvdimm_bus_unlock(dev);
 264
 265         kvfree(ndd->data);
 266         kfree(ndd);
 267         put_device(dev);
 268 }
 269
 270 void get_ndd(struct nvdimm_drvdata *ndd)
 271 {
 272         kref_get(&ndd->kref);
 273 }
 274
 275 void put_ndd(struct nvdimm_drvdata *ndd)
 276 {
 277         if (ndd)
 278                 kref_put(&ndd->kref, nvdimm_drvdata_release);
 279 }
 280
 281 const char *nvdimm_name(struct nvdimm *nvdimm)
 282 {
 283         return dev_name(&nvdimm->dev);
 284 }
 285 EXPORT_SYMBOL_GPL(nvdimm_name);
 286
 287 struct kobject *nvdimm_kobj(struct nvdimm *nvdimm)
 288 {
 289         return &nvdimm->dev.kobj;
 290 }
 291 EXPORT_SYMBOL_GPL(nvdimm_kobj);
 292
 293 unsigned long nvdimm_cmd_mask(struct nvdimm *nvdimm)
 294 {
 295         return nvdimm->cmd_mask;
 296 }
 297 EXPORT_SYMBOL_GPL(nvdimm_cmd_mask);
 298
 299 void *nvdimm_provider_data(struct nvdimm *nvdimm)
 300 {
 301         if (nvdimm)
 302                 return nvdimm->provider_data;
 303         return NULL;
 304 }
 305 EXPORT_SYMBOL_GPL(nvdimm_provider_data);
 306
 307 static ssize_t commands_show(struct device *dev,
 308                 struct device_attribute *attr, char *buf)
 309 {
 310         struct nvdimm *nvdimm = to_nvdimm(dev);
 311         int cmd, len = 0;
 312
 313         if (!nvdimm->cmd_mask)
 314                 return sprintf(buf, "\n");
 315
 316         for_each_set_bit(cmd, &nvdimm->cmd_mask, BITS_PER_LONG)
 317                 len += sprintf(buf + len, "%s ", nvdimm_cmd_name(cmd));
 318         len += sprintf(buf + len, "\n");
 319         return len;
 320 }
 321 static DEVICE_ATTR_RO(commands);
 322
 323 static ssize_t flags_show(struct device *dev,
 324                 struct device_attribute *attr, char *buf)
 325 {
 326         struct nvdimm *nvdimm = to_nvdimm(dev);
 327
 328         return sprintf(buf, "%s%s\n",
 329                         test_bit(NDD_ALIASING, &nvdimm->flags) ? "alias " : "",
 330                         test_bit(NDD_LOCKED, &nvdimm->flags) ? "lock " : "");
 331 }
 332 static DEVICE_ATTR_RO(flags);
 333
 334 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 335                 char *buf)
 336 {
 337         struct nvdimm *nvdimm = to_nvdimm(dev);
 338
 339         /*
 340          * The state may be in the process of changing, userspace should
 341          * quiesce probing if it wants a static answer
 342          */
 343         nvdimm_bus_lock(dev);
 344         nvdimm_bus_unlock(dev);
 345         return sprintf(buf, "%s\n", atomic_read(&nvdimm->busy)
 346                         ? "active" : "idle");
 347 }
 348 static DEVICE_ATTR_RO(state);
 349
 350 static ssize_t available_slots_show(struct device *dev,
 351                 struct device_attribute *attr, char *buf)
 352 {
 353         struct nvdimm_drvdata *ndd = dev_get_drvdata(dev);
 354         ssize_t rc;
 355         u32 nfree;
 356
 357         if (!ndd)
 358                 return -ENXIO;
 359
 360         nvdimm_bus_lock(dev);
 361         nfree = nd_label_nfree(ndd);
 362         if (nfree - 1 > nfree) {
 363                 dev_WARN_ONCE(dev, 1, "we ate our last label?\n");
 364                 nfree = 0;
 365         } else
 366                 nfree--;
 367         rc = sprintf(buf, "%d\n", nfree);
 368         nvdimm_bus_unlock(dev);
 369         return rc;
 370 }
 371 static DEVICE_ATTR_RO(available_slots);
 372
 373 static struct attribute *nvdimm_attributes[] = {
 374         &dev_attr_state.attr,
 375         &dev_attr_flags.attr,
 376         &dev_attr_commands.attr,
 377         &dev_attr_available_slots.attr,
 378         NULL,
 379 };
 380
 381 struct attribute_group nvdimm_attribute_group = {
 382         .attrs = nvdimm_attributes,
 383 };
 384 EXPORT_SYMBOL_GPL(nvdimm_attribute_group);
 385
 386 struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus, void *provider_data,
 387                 const struct attribute_group **groups, unsigned long flags,
 388                 unsigned long cmd_mask, int num_flush,
 389                 struct resource *flush_wpq)
 390 {
 391         struct nvdimm *nvdimm = kzalloc(sizeof(*nvdimm), GFP_KERNEL);
 392         struct device *dev;
 393
 394         if (!nvdimm)
 395                 return NULL;
 396
 397         nvdimm->id = ida_simple_get(&dimm_ida, 0, 0, GFP_KERNEL);
 398         if (nvdimm->id < 0) {
 399                 kfree(nvdimm);
 400                 return NULL;
 401         }
 402         nvdimm->provider_data = provider_data;
 403         nvdimm->flags = flags;
 404         nvdimm->cmd_mask = cmd_mask;
 405         nvdimm->num_flush = num_flush;
 406         nvdimm->flush_wpq = flush_wpq;
 407         atomic_set(&nvdimm->busy, 0);
 408         dev = &nvdimm->dev;
 409         dev_set_name(dev, "nmem%d", nvdimm->id);
 410         dev->parent = &nvdimm_bus->dev;
 411         dev->type = &nvdimm_device_type;
 412         dev->devt = MKDEV(nvdimm_major, nvdimm->id);
 413         dev->groups = groups;
 414         nd_device_register(dev);
 415
 416         return nvdimm;
 417 }
 418 EXPORT_SYMBOL_GPL(nvdimm_create);
 419
 420 int alias_dpa_busy(struct device *dev, void *data)
 421 {
 422         resource_size_t map_end, blk_start, new;
 423         struct blk_alloc_info *info = data;
 424         struct nd_mapping *nd_mapping;
 425         struct nd_region *nd_region;
 426         struct nvdimm_drvdata *ndd;
 427         struct resource *res;
 428         int i;
 429
 430         if (!is_memory(dev))
 431                 return 0;
 432
 433         nd_region = to_nd_region(dev);
 434         for (i = 0; i < nd_region->ndr_mappings; i++) {
 435                 nd_mapping  = &nd_region->mapping[i];
 436                 if (nd_mapping->nvdimm == info->nd_mapping->nvdimm)
 437                         break;
 438         }
 439
 440         if (i >= nd_region->ndr_mappings)
 441                 return 0;
 442
 443         ndd = to_ndd(nd_mapping);
 444         map_end = nd_mapping->start + nd_mapping->size - 1;
 445         blk_start = nd_mapping->start;
 446
 447         /*
 448          * In the allocation case ->res is set to free space that we are
 449          * looking to validate against PMEM aliasing collision rules
 450          * (i.e. BLK is allocated after all aliased PMEM).
 451          */
 452         if (info->res) {
 453                 if (info->res->start >= nd_mapping->start
 454                                 && info->res->start < map_end)
 455                         /* pass */;
 456                 else
 457                         return 0;
 458         }
 459
 460  retry:
 461         /*
 462          * Find the free dpa from the end of the last pmem allocation to
 463          * the end of the interleave-set mapping.
 464          */
 465         for_each_dpa_resource(ndd, res) {
 466                 if (strncmp(res->name, "pmem", 4) != 0)
 467                         continue;
 468                 if ((res->start >= blk_start && res->start < map_end)
 469                                 || (res->end >= blk_start
 470                                         && res->end <= map_end)) {
 471                         new = max(blk_start, min(map_end + 1, res->end + 1));
 472                         if (new != blk_start) {
 473                                 blk_start = new;
 474                                 goto retry;
 475                         }
 476                 }
 477         }
 478
 479         /* update the free space range with the probed blk_start */
 480         if (info->res && blk_start > info->res->start) {
 481                 info->res->start = max(info->res->start, blk_start);
 482                 if (info->res->start > info->res->end)
 483                         info->res->end = info->res->start - 1;
 484                 return 1;
 485         }
 486
 487         info->available -= blk_start - nd_mapping->start;
 488
 489         return 0;
 490 }
 491
 492 /**
 493  * nd_blk_available_dpa - account the unused dpa of BLK region
 494  * @nd_mapping: container of dpa-resource-root + labels
 495  *
 496  * Unlike PMEM, BLK namespaces can occupy discontiguous DPA ranges, but
 497  * we arrange for them to never start at an lower dpa than the last
 498  * PMEM allocation in an aliased region.
 499  */
 500 resource_size_t nd_blk_available_dpa(struct nd_region *nd_region)
 501 {
 502         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
 503         struct nd_mapping *nd_mapping = &nd_region->mapping[0];
 504         struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
 505         struct blk_alloc_info info = {
 506                 .nd_mapping = nd_mapping,
 507                 .available = nd_mapping->size,
 508                 .res = NULL,
 509         };
 510         struct resource *res;
 511
 512         if (!ndd)
 513                 return 0;
 514
 515         device_for_each_child(&nvdimm_bus->dev, &info, alias_dpa_busy);
 516
 517         /* now account for busy blk allocations in unaliased dpa */
 518         for_each_dpa_resource(ndd, res) {
 519                 if (strncmp(res->name, "blk", 3) != 0)
 520                         continue;
 521                 info.available -= resource_size(res);
 522         }
 523
 524         return info.available;
 525 }
 526
 527 /**
 528  * nd_pmem_max_contiguous_dpa - For the given dimm+region, return the max
 529  *                         contiguous unallocated dpa range.
 530  * @nd_region: constrain available space check to this reference region
 531  * @nd_mapping: container of dpa-resource-root + labels
 532  */
 533 resource_size_t nd_pmem_max_contiguous_dpa(struct nd_region *nd_region,
 534                                            struct nd_mapping *nd_mapping)
 535 {
 536         struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
 537         struct nvdimm_bus *nvdimm_bus;
 538         resource_size_t max = 0;
 539         struct resource *res;
 540
 541         /* if a dimm is disabled the available capacity is zero */
 542         if (!ndd)
 543                 return 0;
 544
 545         nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
 546         if (__reserve_free_pmem(&nd_region->dev, nd_mapping->nvdimm))
 547                 return 0;
 548         for_each_dpa_resource(ndd, res) {
 549                 if (strcmp(res->name, "pmem-reserve") != 0)
 550                         continue;
 551                 if (resource_size(res) > max)
 552                         max = resource_size(res);
 553         }
 554         release_free_pmem(nvdimm_bus, nd_mapping);
 555         return max;
 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, "count: %d\n", 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 }