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;
 454         u64 num_sectors;
 455         u32 rem;
 456
 457         start_sector = div_u64(ns_offset, sector_size);
 458         num_sectors = div_u64_rem(len, sector_size, &rem);
 459         if (rem)
 460                 num_sectors++;
 461
 462         if (unlikely(num_sectors > (u64)INT_MAX)) {
 463                 u64 remaining = num_sectors;
 464                 sector_t s = start_sector;
 465
 466                 while (remaining) {
 467                         int done = min_t(u64, remaining, INT_MAX);
 468
 469                         set_badblock(bb, s, done);
 470                         remaining -= done;
 471                         s += done;
 472                 }
 473         } else
 474                 set_badblock(bb, start_sector, num_sectors);
 475 }
 476
 477 static void badblocks_populate(struct list_head *poison_list,
 478                 struct badblocks *bb, const struct resource *res)
 479 {
 480         struct nd_poison *pl;
 481
 482         if (list_empty(poison_list))
 483                 return;
 484
 485         list_for_each_entry(pl, poison_list, list) {
 486                 u64 pl_end = pl->start + pl->length - 1;
 487
 488                 /* Discard intervals with no intersection */
 489                 if (pl_end < res->start)
 490                         continue;
 491                 if (pl->start >  res->end)
 492                         continue;
 493                 /* Deal with any overlap after start of the namespace */
 494                 if (pl->start >= res->start) {
 495                         u64 start = pl->start;
 496                         u64 len;
 497
 498                         if (pl_end <= res->end)
 499                                 len = pl->length;
 500                         else
 501                                 len = res->start + resource_size(res)
 502                                         - pl->start;
 503                         __add_badblock_range(bb, start - res->start, len);
 504                         continue;
 505                 }
 506                 /* Deal with overlap for poison starting before the namespace */
 507                 if (pl->start < res->start) {
 508                         u64 len;
 509
 510                         if (pl_end < res->end)
 511                                 len = pl->start + pl->length - res->start;
 512                         else
 513                                 len = resource_size(res);
 514                         __add_badblock_range(bb, 0, len);
 515                 }
 516         }
 517 }
 518
 519 /**
 520  * nvdimm_badblocks_populate() - Convert a list of poison ranges to badblocks
 521  * @region: parent region of the range to interrogate
 522  * @bb: badblocks instance to populate
 523  * @res: resource range to consider
 524  *
 525  * The poison list generated during bus initialization may contain
 526  * multiple, possibly overlapping physical address ranges.  Compare each
 527  * of these ranges to the resource range currently being initialized,
 528  * and add badblocks entries for all matching sub-ranges
 529  */
 530 void nvdimm_badblocks_populate(struct nd_region *nd_region,
 531                 struct badblocks *bb, const struct resource *res)
 532 {
 533         struct nvdimm_bus *nvdimm_bus;
 534         struct list_head *poison_list;
 535
 536         if (!is_nd_pmem(&nd_region->dev)) {
 537                 dev_WARN_ONCE(&nd_region->dev, 1,
 538                                 "%s only valid for pmem regions\n", __func__);
 539                 return;
 540         }
 541         nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
 542         poison_list = &nvdimm_bus->poison_list;
 543
 544         nvdimm_bus_lock(&nvdimm_bus->dev);
 545         badblocks_populate(poison_list, bb, res);
 546         nvdimm_bus_unlock(&nvdimm_bus->dev);
 547 }
 548 EXPORT_SYMBOL_GPL(nvdimm_badblocks_populate);
 549
 550 static int add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length,
 551                         gfp_t flags)
 552 {
 553         struct nd_poison *pl;
 554
 555         pl = kzalloc(sizeof(*pl), flags);
 556         if (!pl)
 557                 return -ENOMEM;
 558
 559         pl->start = addr;
 560         pl->length = length;
 561         list_add_tail(&pl->list, &nvdimm_bus->poison_list);
 562
 563         return 0;
 564 }
 565
 566 static int bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
 567 {
 568         struct nd_poison *pl;
 569
 570         if (list_empty(&nvdimm_bus->poison_list))
 571                 return add_poison(nvdimm_bus, addr, length, GFP_KERNEL);
 572
 573         /*
 574          * There is a chance this is a duplicate, check for those first.
 575          * This will be the common case as ARS_STATUS returns all known
 576          * errors in the SPA space, and we can't query it per region
 577          */
 578         list_for_each_entry(pl, &nvdimm_bus->poison_list, list)
 579                 if (pl->start == addr) {
 580                         /* If length has changed, update this list entry */
 581                         if (pl->length != length)
 582                                 pl->length = length;
 583                         return 0;
 584                 }
 585
 586         /*
 587          * If not a duplicate or a simple length update, add the entry as is,
 588          * as any overlapping ranges will get resolved when the list is consumed
 589          * and converted to badblocks
 590          */
 591         return add_poison(nvdimm_bus, addr, length, GFP_KERNEL);
 592 }
 593
 594 int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
 595 {
 596         int rc;
 597
 598         nvdimm_bus_lock(&nvdimm_bus->dev);
 599         rc = bus_add_poison(nvdimm_bus, addr, length);
 600         nvdimm_bus_unlock(&nvdimm_bus->dev);
 601
 602         return rc;
 603 }
 604 EXPORT_SYMBOL_GPL(nvdimm_bus_add_poison);
 605
 606 void nvdimm_clear_from_poison_list(struct nvdimm_bus *nvdimm_bus,
 607                 phys_addr_t start, unsigned int len)
 608 {
 609         struct list_head *poison_list = &nvdimm_bus->poison_list;
 610         u64 clr_end = start + len - 1;
 611         struct nd_poison *pl, *next;
 612
 613         nvdimm_bus_lock(&nvdimm_bus->dev);
 614         WARN_ON_ONCE(list_empty(poison_list));
 615
 616         /*
 617          * [start, clr_end] is the poison interval being cleared.
 618          * [pl->start, pl_end] is the poison_list entry we're comparing
 619          * the above interval against. The poison list entry may need
 620          * to be modified (update either start or length), deleted, or
 621          * split into two based on the overlap characteristics
 622          */
 623
 624         list_for_each_entry_safe(pl, next, poison_list, list) {
 625                 u64 pl_end = pl->start + pl->length - 1;
 626
 627                 /* Skip intervals with no intersection */
 628                 if (pl_end < start)
 629                         continue;
 630                 if (pl->start >  clr_end)
 631                         continue;
 632                 /* Delete completely overlapped poison entries */
 633                 if ((pl->start >= start) && (pl_end <= clr_end)) {
 634                         list_del(&pl->list);
 635                         kfree(pl);
 636                         continue;
 637                 }
 638                 /* Adjust start point of partially cleared entries */
 639                 if ((start <= pl->start) && (clr_end > pl->start)) {
 640                         pl->length -= clr_end - pl->start + 1;
 641                         pl->start = clr_end + 1;
 642                         continue;
 643                 }
 644                 /* Adjust pl->length for partial clearing at the tail end */
 645                 if ((pl->start < start) && (pl_end <= clr_end)) {
 646                         /* pl->start remains the same */
 647                         pl->length = start - pl->start;
 648                         continue;
 649                 }
 650                 /*
 651                  * If clearing in the middle of an entry, we split it into
 652                  * two by modifying the current entry to represent one half of
 653                  * the split, and adding a new entry for the second half.
 654                  */
 655                 if ((pl->start < start) && (pl_end > clr_end)) {
 656                         u64 new_start = clr_end + 1;
 657                         u64 new_len = pl_end - new_start + 1;
 658
 659                         /* Add new entry covering the right half */
 660                         add_poison(nvdimm_bus, new_start, new_len, GFP_NOIO);
 661                         /* Adjust this entry to cover the left half */
 662                         pl->length = start - pl->start;
 663                         continue;
 664                 }
 665         }
 666         nvdimm_bus_unlock(&nvdimm_bus->dev);
 667 }
 668 EXPORT_SYMBOL_GPL(nvdimm_clear_from_poison_list);
 669
 670 #ifdef CONFIG_BLK_DEV_INTEGRITY
 671 int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
 672 {
 673         struct blk_integrity bi;
 674
 675         if (meta_size == 0)
 676                 return 0;
 677
 678         memset(&bi, 0, sizeof(bi));
 679
 680         bi.tuple_size = meta_size;
 681         bi.tag_size = meta_size;
 682
 683         blk_integrity_register(disk, &bi);
 684         blk_queue_max_integrity_segments(disk->queue, 1);
 685
 686         return 0;
 687 }
 688 EXPORT_SYMBOL(nd_integrity_init);
 689
 690 #else /* CONFIG_BLK_DEV_INTEGRITY */
 691 int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
 692 {
 693         return 0;
 694 }
 695 EXPORT_SYMBOL(nd_integrity_init);
 696
 697 #endif
 698
 699 static __init int libnvdimm_init(void)
 700 {
 701         int rc;
 702
 703         rc = nvdimm_bus_init();
 704         if (rc)
 705                 return rc;
 706         rc = nvdimm_init();
 707         if (rc)
 708                 goto err_dimm;
 709         rc = nd_region_init();
 710         if (rc)
 711                 goto err_region;
 712         return 0;
 713  err_region:
 714         nvdimm_exit();
 715  err_dimm:
 716         nvdimm_bus_exit();
 717         return rc;
 718 }
 719
 720 static __exit void libnvdimm_exit(void)
 721 {
 722         WARN_ON(!list_empty(&nvdimm_bus_list));
 723         nd_region_exit();
 724         nvdimm_exit();
 725         nvdimm_bus_exit();
 726         nd_region_devs_exit();
 727         nvdimm_devs_exit();
 728 }
 729
 730 MODULE_LICENSE("GPL v2");
 731 MODULE_AUTHOR("Intel Corporation");
 732 subsys_initcall(libnvdimm_init);
 733 module_exit(libnvdimm_exit);