drivers/nvdimm/core.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/libnvdimm.h>
  14 #include <linux/badblocks.h>
  15 #include <linux/export.h>
  16 #include <linux/module.h>
  17 #include <linux/blkdev.h>
  18 #include <linux/device.h>
  19 #include <linux/ctype.h>
  20 #include <linux/ndctl.h>
  21 #include <linux/mutex.h>
  22 #include <linux/slab.h>
  23 #include <linux/io.h>
  24 #include "nd-core.h"
  25 #include "nd.h"
  26
  27 LIST_HEAD(nvdimm_bus_list);
  28 DEFINE_MUTEX(nvdimm_bus_list_mutex);
  29
  30 void nvdimm_bus_lock(struct device *dev)
  31 {
  32         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  33
  34         if (!nvdimm_bus)
  35                 return;
  36         mutex_lock(&nvdimm_bus->reconfig_mutex);
  37 }
  38 EXPORT_SYMBOL(nvdimm_bus_lock);
  39
  40 void nvdimm_bus_unlock(struct device *dev)
  41 {
  42         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  43
  44         if (!nvdimm_bus)
  45                 return;
  46         mutex_unlock(&nvdimm_bus->reconfig_mutex);
  47 }
  48 EXPORT_SYMBOL(nvdimm_bus_unlock);
  49
  50 bool is_nvdimm_bus_locked(struct device *dev)
  51 {
  52         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  53
  54         if (!nvdimm_bus)
  55                 return false;
  56         return mutex_is_locked(&nvdimm_bus->reconfig_mutex);
  57 }
  58 EXPORT_SYMBOL(is_nvdimm_bus_locked);
  59
  60 struct nvdimm_map {
  61         struct nvdimm_bus *nvdimm_bus;
  62         struct list_head list;
  63         resource_size_t offset;
  64         unsigned long flags;
  65         size_t size;
  66         union {
  67                 void *mem;
  68                 void __iomem *iomem;
  69         };
  70         struct kref kref;
  71 };
  72
  73 static struct nvdimm_map *find_nvdimm_map(struct device *dev,
  74                 resource_size_t offset)
  75 {
  76         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  77         struct nvdimm_map *nvdimm_map;
  78
  79         list_for_each_entry(nvdimm_map, &nvdimm_bus->mapping_list, list)
  80                 if (nvdimm_map->offset == offset)
  81                         return nvdimm_map;
  82         return NULL;
  83 }
  84
  85 static struct nvdimm_map *alloc_nvdimm_map(struct device *dev,
  86                 resource_size_t offset, size_t size, unsigned long flags)
  87 {
  88         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
  89         struct nvdimm_map *nvdimm_map;
  90
  91         nvdimm_map = kzalloc(sizeof(*nvdimm_map), GFP_KERNEL);
  92         if (!nvdimm_map)
  93                 return NULL;
  94
  95         INIT_LIST_HEAD(&nvdimm_map->list);
  96         nvdimm_map->nvdimm_bus = nvdimm_bus;
  97         nvdimm_map->offset = offset;
  98         nvdimm_map->flags = flags;
  99         nvdimm_map->size = size;
 100         kref_init(&nvdimm_map->kref);
 101
 102         if (!request_mem_region(offset, size, dev_name(&nvdimm_bus->dev))) {
 103                 dev_err(&nvdimm_bus->dev, "failed to request %pa + %zd for %s\n",
 104                                 &offset, size, dev_name(dev));
 105                 goto err_request_region;
 106         }
 107
 108         if (flags)
 109                 nvdimm_map->mem = memremap(offset, size, flags);
 110         else
 111                 nvdimm_map->iomem = ioremap(offset, size);
 112
 113         if (!nvdimm_map->mem)
 114                 goto err_map;
 115
 116         dev_WARN_ONCE(dev, !is_nvdimm_bus_locked(dev), "%s: bus unlocked!",
 117                         __func__);
 118         list_add(&nvdimm_map->list, &nvdimm_bus->mapping_list);
 119
 120         return nvdimm_map;
 121
 122  err_map:
 123         release_mem_region(offset, size);
 124  err_request_region:
 125         kfree(nvdimm_map);
 126         return NULL;
 127 }
 128
 129 static void nvdimm_map_release(struct kref *kref)
 130 {
 131         struct nvdimm_bus *nvdimm_bus;
 132         struct nvdimm_map *nvdimm_map;
 133
 134         nvdimm_map = container_of(kref, struct nvdimm_map, kref);
 135         nvdimm_bus = nvdimm_map->nvdimm_bus;
 136
 137         dev_dbg(&nvdimm_bus->dev, "%s: %pa\n", __func__, &nvdimm_map->offset);
 138         list_del(&nvdimm_map->list);
 139         if (nvdimm_map->flags)
 140                 memunmap(nvdimm_map->mem);
 141         else
 142                 iounmap(nvdimm_map->iomem);
 143         release_mem_region(nvdimm_map->offset, nvdimm_map->size);
 144         kfree(nvdimm_map);
 145 }
 146
 147 static void nvdimm_map_put(void *data)
 148 {
 149         struct nvdimm_map *nvdimm_map = data;
 150         struct nvdimm_bus *nvdimm_bus = nvdimm_map->nvdimm_bus;
 151
 152         nvdimm_bus_lock(&nvdimm_bus->dev);
 153         kref_put(&nvdimm_map->kref, nvdimm_map_release);
 154         nvdimm_bus_unlock(&nvdimm_bus->dev);
 155 }
 156
 157 /**
 158  * devm_nvdimm_memremap - map a resource that is shared across regions
 159  * @dev: device that will own a reference to the shared mapping
 160  * @offset: physical base address of the mapping
 161  * @size: mapping size
 162  * @flags: memremap flags, or, if zero, perform an ioremap instead
 163  */
 164 void *devm_nvdimm_memremap(struct device *dev, resource_size_t offset,
 165                 size_t size, unsigned long flags)
 166 {
 167         struct nvdimm_map *nvdimm_map;
 168
 169         nvdimm_bus_lock(dev);
 170         nvdimm_map = find_nvdimm_map(dev, offset);
 171         if (!nvdimm_map)
 172                 nvdimm_map = alloc_nvdimm_map(dev, offset, size, flags);
 173         else
 174                 kref_get(&nvdimm_map->kref);
 175         nvdimm_bus_unlock(dev);
 176
 177         if (!nvdimm_map)
 178                 return NULL;
 179
 180         if (devm_add_action_or_reset(dev, nvdimm_map_put, nvdimm_map))
 181                 return NULL;
 182
 183         return nvdimm_map->mem;
 184 }
 185 EXPORT_SYMBOL_GPL(devm_nvdimm_memremap);
 186
 187 u64 nd_fletcher64(void *addr, size_t len, bool le)
 188 {
 189         u32 *buf = addr;
 190         u32 lo32 = 0;
 191         u64 hi32 = 0;
 192         int i;
 193
 194         for (i = 0; i < len / sizeof(u32); i++) {
 195                 lo32 += le ? le32_to_cpu((__le32) buf[i]) : buf[i];
 196                 hi32 += lo32;
 197         }
 198
 199         return hi32 << 32 | lo32;
 200 }
 201 EXPORT_SYMBOL_GPL(nd_fletcher64);
 202
 203 struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus)
 204 {
 205         /* struct nvdimm_bus definition is private to libnvdimm */
 206         return nvdimm_bus->nd_desc;
 207 }
 208 EXPORT_SYMBOL_GPL(to_nd_desc);
 209
 210 struct device *to_nvdimm_bus_dev(struct nvdimm_bus *nvdimm_bus)
 211 {
 212         /* struct nvdimm_bus definition is private to libnvdimm */
 213         return &nvdimm_bus->dev;
 214 }
 215 EXPORT_SYMBOL_GPL(to_nvdimm_bus_dev);
 216
 217 static bool is_uuid_sep(char sep)
 218 {
 219         if (sep == '\n' || sep == '-' || sep == ':' || sep == '\0')
 220                 return true;
 221         return false;
 222 }
 223
 224 static int nd_uuid_parse(struct device *dev, u8 *uuid_out, const char *buf,
 225                 size_t len)
 226 {
 227         const char *str = buf;
 228         u8 uuid[16];
 229         int i;
 230
 231         for (i = 0; i < 16; i++) {
 232                 if (!isxdigit(str[0]) || !isxdigit(str[1])) {
 233                         dev_dbg(dev, "%s: pos: %d buf[%zd]: %c buf[%zd]: %c\n",
 234                                         __func__, i, str - buf, str[0],
 235                                         str + 1 - buf, str[1]);
 236                         return -EINVAL;
 237                 }
 238
 239                 uuid[i] = (hex_to_bin(str[0]) << 4) | hex_to_bin(str[1]);
 240                 str += 2;
 241                 if (is_uuid_sep(*str))
 242                         str++;
 243         }
 244
 245         memcpy(uuid_out, uuid, sizeof(uuid));
 246         return 0;
 247 }
 248
 249 /**
 250  * nd_uuid_store: common implementation for writing 'uuid' sysfs attributes
 251  * @dev: container device for the uuid property
 252  * @uuid_out: uuid buffer to replace
 253  * @buf: raw sysfs buffer to parse
 254  *
 255  * Enforce that uuids can only be changed while the device is disabled
 256  * (driver detached)
 257  * LOCKING: expects device_lock() is held on entry
 258  */
 259 int nd_uuid_store(struct device *dev, u8 **uuid_out, const char *buf,
 260                 size_t len)
 261 {
 262         u8 uuid[16];
 263         int rc;
 264
 265         if (dev->driver)
 266                 return -EBUSY;
 267
 268         rc = nd_uuid_parse(dev, uuid, buf, len);
 269         if (rc)
 270                 return rc;
 271
 272         kfree(*uuid_out);
 273         *uuid_out = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);
 274         if (!(*uuid_out))
 275                 return -ENOMEM;
 276
 277         return 0;
 278 }
 279
 280 ssize_t nd_sector_size_show(unsigned long current_lbasize,
 281                 const unsigned long *supported, char *buf)
 282 {
 283         ssize_t len = 0;
 284         int i;
 285
 286         for (i = 0; supported[i]; i++)
 287                 if (current_lbasize == supported[i])
 288                         len += sprintf(buf + len, "[%ld] ", supported[i]);
 289                 else
 290                         len += sprintf(buf + len, "%ld ", supported[i]);
 291         len += sprintf(buf + len, "\n");
 292         return len;
 293 }
 294
 295 ssize_t nd_sector_size_store(struct device *dev, const char *buf,
 296                 unsigned long *current_lbasize, const unsigned long *supported)
 297 {
 298         unsigned long lbasize;
 299         int rc, i;
 300
 301         if (dev->driver)
 302                 return -EBUSY;
 303
 304         rc = kstrtoul(buf, 0, &lbasize);
 305         if (rc)
 306                 return rc;
 307
 308         for (i = 0; supported[i]; i++)
 309                 if (lbasize == supported[i])
 310                         break;
 311
 312         if (supported[i]) {
 313                 *current_lbasize = lbasize;
 314                 return 0;
 315         } else {
 316                 return -EINVAL;
 317         }
 318 }
 319
 320 void __nd_iostat_start(struct bio *bio, unsigned long *start)
 321 {
 322         struct gendisk *disk = bio->bi_bdev->bd_disk;
 323         const int rw = bio_data_dir(bio);
 324         int cpu = part_stat_lock();
 325
 326         *start = jiffies;
 327         part_round_stats(cpu, &disk->part0);
 328         part_stat_inc(cpu, &disk->part0, ios[rw]);
 329         part_stat_add(cpu, &disk->part0, sectors[rw], bio_sectors(bio));
 330         part_inc_in_flight(&disk->part0, rw);
 331         part_stat_unlock();
 332 }
 333 EXPORT_SYMBOL(__nd_iostat_start);
 334
 335 void nd_iostat_end(struct bio *bio, unsigned long start)
 336 {
 337         struct gendisk *disk = bio->bi_bdev->bd_disk;
 338         unsigned long duration = jiffies - start;
 339         const int rw = bio_data_dir(bio);
 340         int cpu = part_stat_lock();
 341
 342         part_stat_add(cpu, &disk->part0, ticks[rw], duration);
 343         part_round_stats(cpu, &disk->part0);
 344         part_dec_in_flight(&disk->part0, rw);
 345         part_stat_unlock();
 346 }
 347 EXPORT_SYMBOL(nd_iostat_end);
 348
 349 static ssize_t commands_show(struct device *dev,
 350                 struct device_attribute *attr, char *buf)
 351 {
 352         int cmd, len = 0;
 353         struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 354         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 355
 356         for_each_set_bit(cmd, &nd_desc->cmd_mask, BITS_PER_LONG)
 357                 len += sprintf(buf + len, "%s ", nvdimm_bus_cmd_name(cmd));
 358         len += sprintf(buf + len, "\n");
 359         return len;
 360 }
 361 static DEVICE_ATTR_RO(commands);
 362
 363 static const char *nvdimm_bus_provider(struct nvdimm_bus *nvdimm_bus)
 364 {
 365         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 366         struct device *parent = nvdimm_bus->dev.parent;
 367
 368         if (nd_desc->provider_name)
 369                 return nd_desc->provider_name;
 370         else if (parent)
 371                 return dev_name(parent);
 372         else
 373                 return "unknown";
 374 }
 375
 376 static ssize_t provider_show(struct device *dev,
 377                 struct device_attribute *attr, char *buf)
 378 {
 379         struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 380
 381         return sprintf(buf, "%s\n", nvdimm_bus_provider(nvdimm_bus));
 382 }
 383 static DEVICE_ATTR_RO(provider);
 384
 385 static int flush_namespaces(struct device *dev, void *data)
 386 {
 387         device_lock(dev);
 388         device_unlock(dev);
 389         return 0;
 390 }
 391
 392 static int flush_regions_dimms(struct device *dev, void *data)
 393 {
 394         device_lock(dev);
 395         device_unlock(dev);
 396         device_for_each_child(dev, NULL, flush_namespaces);
 397         return 0;
 398 }
 399
 400 static ssize_t wait_probe_show(struct device *dev,
 401                 struct device_attribute *attr, char *buf)
 402 {
 403         struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 404         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 405         int rc;
 406
 407         if (nd_desc->flush_probe) {
 408                 rc = nd_desc->flush_probe(nd_desc);
 409                 if (rc)
 410                         return rc;
 411         }
 412         nd_synchronize();
 413         device_for_each_child(dev, NULL, flush_regions_dimms);
 414         return sprintf(buf, "1\n");
 415 }
 416 static DEVICE_ATTR_RO(wait_probe);
 417
 418 static struct attribute *nvdimm_bus_attributes[] = {
 419         &dev_attr_commands.attr,
 420         &dev_attr_wait_probe.attr,
 421         &dev_attr_provider.attr,
 422         NULL,
 423 };
 424
 425 struct attribute_group nvdimm_bus_attribute_group = {
 426         .attrs = nvdimm_bus_attributes,
 427 };
 428 EXPORT_SYMBOL_GPL(nvdimm_bus_attribute_group);
 429
 430 static void set_badblock(struct badblocks *bb, sector_t s, int num)
 431 {
 432         dev_dbg(bb->dev, "Found a poison range (0x%llx, 0x%llx)\n",
 433                         (u64) s * 512, (u64) num * 512);
 434         /* this isn't an error as the hardware will still throw an exception */
 435         if (badblocks_set(bb, s, num, 1))
 436                 dev_info_once(bb->dev, "%s: failed for sector %llx\n",
 437                                 __func__, (u64) s);
 438 }
 439
 440 /**
 441  * __add_badblock_range() - Convert a physical address range to bad sectors
 442  * @bb:         badblocks instance to populate
 443  * @ns_offset:  namespace offset where the error range begins (in bytes)
 444  * @len:        number of bytes of poison to be added
 445  *
 446  * This assumes that the range provided with (ns_offset, len) is within
 447  * the bounds of physical addresses for this namespace, i.e. lies in the
 448  * interval [ns_start, ns_start + ns_size)
 449  */
 450 static void __add_badblock_range(struct badblocks *bb, u64 ns_offset, u64 len)
 451 {
 452         const unsigned int sector_size = 512;
 453         sector_t start_sector, end_sector;
 454         u64 num_sectors;
 455         u32 rem;
 456
 457         start_sector = div_u64(ns_offset, sector_size);
 458         end_sector = div_u64_rem(ns_offset + len, sector_size, &rem);
 459         if (rem)
 460                 end_sector++;
 461         num_sectors = end_sector - start_sector;
 462
 463         if (unlikely(num_sectors > (u64)INT_MAX)) {
 464                 u64 remaining = num_sectors;
 465                 sector_t s = start_sector;
 466
 467                 while (remaining) {
 468                         int done = min_t(u64, remaining, INT_MAX);
 469
 470                         set_badblock(bb, s, done);
 471                         remaining -= done;
 472                         s += done;
 473                 }
 474         } else
 475                 set_badblock(bb, start_sector, num_sectors);
 476 }
 477
 478 static void badblocks_populate(struct list_head *poison_list,
 479                 struct badblocks *bb, const struct resource *res)
 480 {
 481         struct nd_poison *pl;
 482
 483         if (list_empty(poison_list))
 484                 return;
 485
 486         list_for_each_entry(pl, poison_list, list) {
 487                 u64 pl_end = pl->start + pl->length - 1;
 488
 489                 /* Discard intervals with no intersection */
 490                 if (pl_end < res->start)
 491                         continue;
 492                 if (pl->start >  res->end)
 493                         continue;
 494                 /* Deal with any overlap after start of the namespace */
 495                 if (pl->start >= res->start) {
 496                         u64 start = pl->start;
 497                         u64 len;
 498
 499                         if (pl_end <= res->end)
 500                                 len = pl->length;
 501                         else
 502                                 len = res->start + resource_size(res)
 503                                         - pl->start;
 504                         __add_badblock_range(bb, start - res->start, len);
 505                         continue;
 506                 }
 507                 /* Deal with overlap for poison starting before the namespace */
 508                 if (pl->start < res->start) {
 509                         u64 len;
 510
 511                         if (pl_end < res->end)
 512                                 len = pl->start + pl->length - res->start;
 513                         else
 514                                 len = resource_size(res);
 515                         __add_badblock_range(bb, 0, len);
 516                 }
 517         }
 518 }
 519
 520 /**
 521  * nvdimm_badblocks_populate() - Convert a list of poison ranges to badblocks
 522  * @region: parent region of the range to interrogate
 523  * @bb: badblocks instance to populate
 524  * @res: resource range to consider
 525  *
 526  * The poison list generated during bus initialization may contain
 527  * multiple, possibly overlapping physical address ranges.  Compare each
 528  * of these ranges to the resource range currently being initialized,
 529  * and add badblocks entries for all matching sub-ranges
 530  */
 531 void nvdimm_badblocks_populate(struct nd_region *nd_region,
 532                 struct badblocks *bb, const struct resource *res)
 533 {
 534         struct nvdimm_bus *nvdimm_bus;
 535         struct list_head *poison_list;
 536
 537         if (!is_nd_pmem(&nd_region->dev)) {
 538                 dev_WARN_ONCE(&nd_region->dev, 1,
 539                                 "%s only valid for pmem regions\n", __func__);
 540                 return;
 541         }
 542         nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
 543         poison_list = &nvdimm_bus->poison_list;
 544
 545         nvdimm_bus_lock(&nvdimm_bus->dev);
 546         badblocks_populate(poison_list, bb, res);
 547         nvdimm_bus_unlock(&nvdimm_bus->dev);
 548 }
 549 EXPORT_SYMBOL_GPL(nvdimm_badblocks_populate);
 550
 551 static int add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length,
 552                         gfp_t flags)
 553 {
 554         struct nd_poison *pl;
 555
 556         pl = kzalloc(sizeof(*pl), flags);
 557         if (!pl)
 558                 return -ENOMEM;
 559
 560         pl->start = addr;
 561         pl->length = length;
 562         list_add_tail(&pl->list, &nvdimm_bus->poison_list);
 563
 564         return 0;
 565 }
 566
 567 static int bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
 568 {
 569         struct nd_poison *pl;
 570
 571         if (list_empty(&nvdimm_bus->poison_list))
 572                 return add_poison(nvdimm_bus, addr, length, GFP_KERNEL);
 573
 574         /*
 575          * There is a chance this is a duplicate, check for those first.
 576          * This will be the common case as ARS_STATUS returns all known
 577          * errors in the SPA space, and we can't query it per region
 578          */
 579         list_for_each_entry(pl, &nvdimm_bus->poison_list, list)
 580                 if (pl->start == addr) {
 581                         /* If length has changed, update this list entry */
 582                         if (pl->length != length)
 583                                 pl->length = length;
 584                         return 0;
 585                 }
 586
 587         /*
 588          * If not a duplicate or a simple length update, add the entry as is,
 589          * as any overlapping ranges will get resolved when the list is consumed
 590          * and converted to badblocks
 591          */
 592         return add_poison(nvdimm_bus, addr, length, GFP_KERNEL);
 593 }
 594
 595 int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
 596 {
 597         int rc;
 598
 599         nvdimm_bus_lock(&nvdimm_bus->dev);
 600         rc = bus_add_poison(nvdimm_bus, addr, length);
 601         nvdimm_bus_unlock(&nvdimm_bus->dev);
 602
 603         return rc;
 604 }
 605 EXPORT_SYMBOL_GPL(nvdimm_bus_add_poison);
 606
 607 void nvdimm_clear_from_poison_list(struct nvdimm_bus *nvdimm_bus,
 608                 phys_addr_t start, unsigned int len)
 609 {
 610         struct list_head *poison_list = &nvdimm_bus->poison_list;
 611         u64 clr_end = start + len - 1;
 612         struct nd_poison *pl, *next;
 613
 614         nvdimm_bus_lock(&nvdimm_bus->dev);
 615         WARN_ON_ONCE(list_empty(poison_list));
 616
 617         /*
 618          * [start, clr_end] is the poison interval being cleared.
 619          * [pl->start, pl_end] is the poison_list entry we're comparing
 620          * the above interval against. The poison list entry may need
 621          * to be modified (update either start or length), deleted, or
 622          * split into two based on the overlap characteristics
 623          */
 624
 625         list_for_each_entry_safe(pl, next, poison_list, list) {
 626                 u64 pl_end = pl->start + pl->length - 1;
 627
 628                 /* Skip intervals with no intersection */
 629                 if (pl_end < start)
 630                         continue;
 631                 if (pl->start >  clr_end)
 632                         continue;
 633                 /* Delete completely overlapped poison entries */
 634                 if ((pl->start >= start) && (pl_end <= clr_end)) {
 635                         list_del(&pl->list);
 636                         kfree(pl);
 637                         continue;
 638                 }
 639                 /* Adjust start point of partially cleared entries */
 640                 if ((start <= pl->start) && (clr_end > pl->start)) {
 641                         pl->length -= clr_end - pl->start + 1;
 642                         pl->start = clr_end + 1;
 643                         continue;
 644                 }
 645                 /* Adjust pl->length for partial clearing at the tail end */
 646                 if ((pl->start < start) && (pl_end <= clr_end)) {
 647                         /* pl->start remains the same */
 648                         pl->length = start - pl->start;
 649                         continue;
 650                 }
 651                 /*
 652                  * If clearing in the middle of an entry, we split it into
 653                  * two by modifying the current entry to represent one half of
 654                  * the split, and adding a new entry for the second half.
 655                  */
 656                 if ((pl->start < start) && (pl_end > clr_end)) {
 657                         u64 new_start = clr_end + 1;
 658                         u64 new_len = pl_end - new_start + 1;
 659
 660                         /* Add new entry covering the right half */
 661                         add_poison(nvdimm_bus, new_start, new_len, GFP_NOIO);
 662                         /* Adjust this entry to cover the left half */
 663                         pl->length = start - pl->start;
 664                         continue;
 665                 }
 666         }
 667         nvdimm_bus_unlock(&nvdimm_bus->dev);
 668 }
 669 EXPORT_SYMBOL_GPL(nvdimm_clear_from_poison_list);
 670
 671 #ifdef CONFIG_BLK_DEV_INTEGRITY
 672 int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
 673 {
 674         struct blk_integrity bi;
 675
 676         if (meta_size == 0)
 677                 return 0;
 678
 679         memset(&bi, 0, sizeof(bi));
 680
 681         bi.tuple_size = meta_size;
 682         bi.tag_size = meta_size;
 683
 684         blk_integrity_register(disk, &bi);
 685         blk_queue_max_integrity_segments(disk->queue, 1);
 686
 687         return 0;
 688 }
 689 EXPORT_SYMBOL(nd_integrity_init);
 690
 691 #else /* CONFIG_BLK_DEV_INTEGRITY */
 692 int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
 693 {
 694         return 0;
 695 }
 696 EXPORT_SYMBOL(nd_integrity_init);
 697
 698 #endif
 699
 700 static __init int libnvdimm_init(void)
 701 {
 702         int rc;
 703
 704         rc = nvdimm_bus_init();
 705         if (rc)
 706                 return rc;
 707         rc = nvdimm_init();
 708         if (rc)
 709                 goto err_dimm;
 710         rc = nd_region_init();
 711         if (rc)
 712                 goto err_region;
 713         return 0;
 714  err_region:
 715         nvdimm_exit();
 716  err_dimm:
 717         nvdimm_bus_exit();
 718         return rc;
 719 }
 720
 721 static __exit void libnvdimm_exit(void)
 722 {
 723         WARN_ON(!list_empty(&nvdimm_bus_list));
 724         nd_region_exit();
 725         nvdimm_exit();
 726         nvdimm_bus_exit();
 727         nd_region_devs_exit();
 728         nvdimm_devs_exit();
 729 }
 730
 731 MODULE_LICENSE("GPL v2");
 732 MODULE_AUTHOR("Intel Corporation");
 733 subsys_initcall(libnvdimm_init);
 734 module_exit(libnvdimm_exit);