drivers/nvdimm/pmem.c

   1 /*
   2  * Persistent Memory Driver
   3  *
   4  * Copyright (c) 2014-2015, Intel Corporation.
   5  * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
   6  * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms and conditions of the GNU General Public License,
  10  * version 2, as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15  * more details.
  16  */
  17
  18 #include <asm/cacheflush.h>
  19 #include <linux/blkdev.h>
  20 #include <linux/hdreg.h>
  21 #include <linux/init.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/module.h>
  24 #include <linux/moduleparam.h>
  25 #include <linux/badblocks.h>
  26 #include <linux/memremap.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/pfn_t.h>
  29 #include <linux/slab.h>
  30 #include <linux/pmem.h>
  31 #include <linux/nd.h>
  32 #include "pfn.h"
  33 #include "nd.h"
  34
  35 struct pmem_device {
  36         struct request_queue    *pmem_queue;
  37         struct gendisk          *pmem_disk;
  38         struct nd_namespace_common *ndns;
  39
  40         /* One contiguous memory region per device */
  41         phys_addr_t             phys_addr;
  42         /* when non-zero this device is hosting a 'pfn' instance */
  43         phys_addr_t             data_offset;
  44         u64                     pfn_flags;
  45         void __pmem             *virt_addr;
  46         /* immutable base size of the namespace */
  47         size_t                  size;
  48         /* trim size when namespace capacity has been section aligned */
  49         u32                     pfn_pad;
  50         struct badblocks        bb;
  51 };
  52
  53 static bool is_bad_pmem(struct badblocks *bb, sector_t sector, unsigned int len)
  54 {
  55         if (bb->count) {
  56                 sector_t first_bad;
  57                 int num_bad;
  58
  59                 return !!badblocks_check(bb, sector, len / 512, &first_bad,
  60                                 &num_bad);
  61         }
  62
  63         return false;
  64 }
  65
  66 static void pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
  67                 unsigned int len)
  68 {
  69         struct device *dev = disk_to_dev(pmem->pmem_disk);
  70         sector_t sector;
  71         long cleared;
  72
  73         sector = (offset - pmem->data_offset) / 512;
  74         cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
  75
  76         if (cleared > 0 && cleared / 512) {
  77                 dev_dbg(dev, "%s: %llx clear %ld sector%s\n",
  78                                 __func__, (unsigned long long) sector,
  79                                 cleared / 512, cleared / 512 > 1 ? "s" : "");
  80                 badblocks_clear(&pmem->bb, sector, cleared / 512);
  81         }
  82         invalidate_pmem(pmem->virt_addr + offset, len);
  83 }
  84
  85 static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
  86                         unsigned int len, unsigned int off, int rw,
  87                         sector_t sector)
  88 {
  89         int rc = 0;
  90         bool bad_pmem = false;
  91         void *mem = kmap_atomic(page);
  92         phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
  93         void __pmem *pmem_addr = pmem->virt_addr + pmem_off;
  94
  95         if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
  96                 bad_pmem = true;
  97
  98         if (rw == READ) {
  99                 if (unlikely(bad_pmem))
 100                         rc = -EIO;
 101                 else {
 102                         rc = memcpy_from_pmem(mem + off, pmem_addr, len);
 103                         flush_dcache_page(page);
 104                 }
 105         } else {
 106                 flush_dcache_page(page);
 107                 memcpy_to_pmem(pmem_addr, mem + off, len);
 108                 if (unlikely(bad_pmem)) {
 109                         pmem_clear_poison(pmem, pmem_off, len);
 110                         memcpy_to_pmem(pmem_addr, mem + off, len);
 111                 }
 112         }
 113
 114         kunmap_atomic(mem);
 115         return rc;
 116 }
 117
 118 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
 119 {
 120         int rc = 0;
 121         bool do_acct;
 122         unsigned long start;
 123         struct bio_vec bvec;
 124         struct bvec_iter iter;
 125         struct block_device *bdev = bio->bi_bdev;
 126         struct pmem_device *pmem = bdev->bd_disk->private_data;
 127
 128         do_acct = nd_iostat_start(bio, &start);
 129         bio_for_each_segment(bvec, bio, iter) {
 130                 rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
 131                                 bvec.bv_offset, bio_data_dir(bio),
 132                                 iter.bi_sector);
 133                 if (rc) {
 134                         bio->bi_error = rc;
 135                         break;
 136                 }
 137         }
 138         if (do_acct)
 139                 nd_iostat_end(bio, start);
 140
 141         if (bio_data_dir(bio))
 142                 wmb_pmem();
 143
 144         bio_endio(bio);
 145         return BLK_QC_T_NONE;
 146 }
 147
 148 static int pmem_rw_page(struct block_device *bdev, sector_t sector,
 149                        struct page *page, int rw)
 150 {
 151         struct pmem_device *pmem = bdev->bd_disk->private_data;
 152         int rc;
 153
 154         rc = pmem_do_bvec(pmem, page, PAGE_CACHE_SIZE, 0, rw, sector);
 155         if (rw & WRITE)
 156                 wmb_pmem();
 157
 158         /*
 159          * The ->rw_page interface is subtle and tricky.  The core
 160          * retries on any error, so we can only invoke page_endio() in
 161          * the successful completion case.  Otherwise, we'll see crashes
 162          * caused by double completion.
 163          */
 164         if (rc == 0)
 165                 page_endio(page, rw & WRITE, 0);
 166
 167         return rc;
 168 }
 169
 170 static long pmem_direct_access(struct block_device *bdev, sector_t sector,
 171                       void __pmem **kaddr, pfn_t *pfn)
 172 {
 173         struct pmem_device *pmem = bdev->bd_disk->private_data;
 174         resource_size_t offset = sector * 512 + pmem->data_offset;
 175
 176         *kaddr = pmem->virt_addr + offset;
 177         *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
 178
 179         return pmem->size - pmem->pfn_pad - offset;
 180 }
 181
 182 static const struct block_device_operations pmem_fops = {
 183         .owner =                THIS_MODULE,
 184         .rw_page =              pmem_rw_page,
 185         .direct_access =        pmem_direct_access,
 186         .revalidate_disk =      nvdimm_revalidate_disk,
 187 };
 188
 189 static struct pmem_device *pmem_alloc(struct device *dev,
 190                 struct resource *res, int id)
 191 {
 192         struct pmem_device *pmem;
 193         struct request_queue *q;
 194
 195         pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
 196         if (!pmem)
 197                 return ERR_PTR(-ENOMEM);
 198
 199         pmem->phys_addr = res->start;
 200         pmem->size = resource_size(res);
 201         if (!arch_has_wmb_pmem())
 202                 dev_warn(dev, "unable to guarantee persistence of writes\n");
 203
 204         if (!devm_request_mem_region(dev, pmem->phys_addr, pmem->size,
 205                         dev_name(dev))) {
 206                 dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n",
 207                                 &pmem->phys_addr, pmem->size);
 208                 return ERR_PTR(-EBUSY);
 209         }
 210
 211         q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
 212         if (!q)
 213                 return ERR_PTR(-ENOMEM);
 214
 215         pmem->pfn_flags = PFN_DEV;
 216         if (pmem_should_map_pages(dev)) {
 217                 pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, res,
 218                                 &q->q_usage_counter, NULL);
 219                 pmem->pfn_flags |= PFN_MAP;
 220         } else
 221                 pmem->virt_addr = (void __pmem *) devm_memremap(dev,
 222                                 pmem->phys_addr, pmem->size,
 223                                 ARCH_MEMREMAP_PMEM);
 224
 225         if (IS_ERR(pmem->virt_addr)) {
 226                 blk_cleanup_queue(q);
 227                 return (void __force *) pmem->virt_addr;
 228         }
 229
 230         pmem->pmem_queue = q;
 231         return pmem;
 232 }
 233
 234 static void pmem_detach_disk(struct pmem_device *pmem)
 235 {
 236         if (!pmem->pmem_disk)
 237                 return;
 238
 239         del_gendisk(pmem->pmem_disk);
 240         put_disk(pmem->pmem_disk);
 241         blk_cleanup_queue(pmem->pmem_queue);
 242 }
 243
 244 static int pmem_attach_disk(struct device *dev,
 245                 struct nd_namespace_common *ndns, struct pmem_device *pmem)
 246 {
 247         int nid = dev_to_node(dev);
 248         struct gendisk *disk;
 249
 250         blk_queue_make_request(pmem->pmem_queue, pmem_make_request);
 251         blk_queue_physical_block_size(pmem->pmem_queue, PAGE_SIZE);
 252         blk_queue_max_hw_sectors(pmem->pmem_queue, UINT_MAX);
 253         blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY);
 254         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, pmem->pmem_queue);
 255
 256         disk = alloc_disk_node(0, nid);
 257         if (!disk) {
 258                 blk_cleanup_queue(pmem->pmem_queue);
 259                 return -ENOMEM;
 260         }
 261
 262         disk->fops              = &pmem_fops;
 263         disk->private_data      = pmem;
 264         disk->queue             = pmem->pmem_queue;
 265         disk->flags             = GENHD_FL_EXT_DEVT;
 266         nvdimm_namespace_disk_name(ndns, disk->disk_name);
 267         disk->driverfs_dev = dev;
 268         set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
 269                         / 512);
 270         pmem->pmem_disk = disk;
 271         devm_exit_badblocks(dev, &pmem->bb);
 272         if (devm_init_badblocks(dev, &pmem->bb))
 273                 return -ENOMEM;
 274         nvdimm_namespace_add_poison(ndns, &pmem->bb, pmem->data_offset);
 275
 276         disk->bb = &pmem->bb;
 277         add_disk(disk);
 278         revalidate_disk(disk);
 279
 280         return 0;
 281 }
 282
 283 static int pmem_rw_bytes(struct nd_namespace_common *ndns,
 284                 resource_size_t offset, void *buf, size_t size, int rw)
 285 {
 286         struct pmem_device *pmem = dev_get_drvdata(ndns->claim);
 287
 288         if (unlikely(offset + size > pmem->size)) {
 289                 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
 290                 return -EFAULT;
 291         }
 292
 293         if (rw == READ) {
 294                 unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
 295
 296                 if (unlikely(is_bad_pmem(&pmem->bb, offset / 512, sz_align)))
 297                         return -EIO;
 298                 return memcpy_from_pmem(buf, pmem->virt_addr + offset, size);
 299         } else {
 300                 memcpy_to_pmem(pmem->virt_addr + offset, buf, size);
 301                 wmb_pmem();
 302         }
 303
 304         return 0;
 305 }
 306
 307 static int nd_pfn_init(struct nd_pfn *nd_pfn)
 308 {
 309         struct nd_pfn_sb *pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
 310         struct pmem_device *pmem = dev_get_drvdata(&nd_pfn->dev);
 311         struct nd_namespace_common *ndns = nd_pfn->ndns;
 312         u32 start_pad = 0, end_trunc = 0;
 313         resource_size_t start, size;
 314         struct nd_namespace_io *nsio;
 315         struct nd_region *nd_region;
 316         unsigned long npfns;
 317         phys_addr_t offset;
 318         u64 checksum;
 319         int rc;
 320
 321         if (!pfn_sb)
 322                 return -ENOMEM;
 323
 324         nd_pfn->pfn_sb = pfn_sb;
 325         rc = nd_pfn_validate(nd_pfn);
 326         if (rc == -ENODEV)
 327                 /* no info block, do init */;
 328         else
 329                 return rc;
 330
 331         nd_region = to_nd_region(nd_pfn->dev.parent);
 332         if (nd_region->ro) {
 333                 dev_info(&nd_pfn->dev,
 334                                 "%s is read-only, unable to init metadata\n",
 335                                 dev_name(&nd_region->dev));
 336                 goto err;
 337         }
 338
 339         memset(pfn_sb, 0, sizeof(*pfn_sb));
 340
 341         /*
 342          * Check if pmem collides with 'System RAM' when section aligned and
 343          * trim it accordingly
 344          */
 345         nsio = to_nd_namespace_io(&ndns->dev);
 346         start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start);
 347         size = resource_size(&nsio->res);
 348         if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
 349                                 IORES_DESC_NONE) == REGION_MIXED) {
 350
 351                 start = nsio->res.start;
 352                 start_pad = PHYS_SECTION_ALIGN_UP(start) - start;
 353         }
 354
 355         start = nsio->res.start;
 356         size = PHYS_SECTION_ALIGN_UP(start + size) - start;
 357         if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
 358                                 IORES_DESC_NONE) == REGION_MIXED) {
 359                 size = resource_size(&nsio->res);
 360                 end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size);
 361         }
 362
 363         if (start_pad + end_trunc)
 364                 dev_info(&nd_pfn->dev, "%s section collision, truncate %d bytes\n",
 365                                 dev_name(&ndns->dev), start_pad + end_trunc);
 366
 367         /*
 368          * Note, we use 64 here for the standard size of struct page,
 369          * debugging options may cause it to be larger in which case the
 370          * implementation will limit the pfns advertised through
 371          * ->direct_access() to those that are included in the memmap.
 372          */
 373         start += start_pad;
 374         npfns = (pmem->size - start_pad - end_trunc - SZ_8K) / SZ_4K;
 375         if (nd_pfn->mode == PFN_MODE_PMEM)
 376                 offset = ALIGN(start + SZ_8K + 64 * npfns, nd_pfn->align)
 377                         - start;
 378         else if (nd_pfn->mode == PFN_MODE_RAM)
 379                 offset = ALIGN(start + SZ_8K, nd_pfn->align) - start;
 380         else
 381                 goto err;
 382
 383         if (offset + start_pad + end_trunc >= pmem->size) {
 384                 dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
 385                                 dev_name(&ndns->dev));
 386                 goto err;
 387         }
 388
 389         npfns = (pmem->size - offset - start_pad - end_trunc) / SZ_4K;
 390         pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
 391         pfn_sb->dataoff = cpu_to_le64(offset);
 392         pfn_sb->npfns = cpu_to_le64(npfns);
 393         memcpy(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN);
 394         memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
 395         memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
 396         pfn_sb->version_major = cpu_to_le16(1);
 397         pfn_sb->version_minor = cpu_to_le16(1);
 398         pfn_sb->start_pad = cpu_to_le32(start_pad);
 399         pfn_sb->end_trunc = cpu_to_le32(end_trunc);
 400         checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
 401         pfn_sb->checksum = cpu_to_le64(checksum);
 402
 403         rc = nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb));
 404         if (rc)
 405                 goto err;
 406
 407         return 0;
 408  err:
 409         nd_pfn->pfn_sb = NULL;
 410         kfree(pfn_sb);
 411         return -ENXIO;
 412 }
 413
 414 static int nvdimm_namespace_detach_pfn(struct nd_namespace_common *ndns)
 415 {
 416         struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
 417         struct pmem_device *pmem;
 418
 419         /* free pmem disk */
 420         pmem = dev_get_drvdata(&nd_pfn->dev);
 421         pmem_detach_disk(pmem);
 422
 423         /* release nd_pfn resources */
 424         kfree(nd_pfn->pfn_sb);
 425         nd_pfn->pfn_sb = NULL;
 426
 427         return 0;
 428 }
 429
 430 /*
 431  * We hotplug memory at section granularity, pad the reserved area from
 432  * the previous section base to the namespace base address.
 433  */
 434 static unsigned long init_altmap_base(resource_size_t base)
 435 {
 436         unsigned long base_pfn = PHYS_PFN(base);
 437
 438         return PFN_SECTION_ALIGN_DOWN(base_pfn);
 439 }
 440
 441 static unsigned long init_altmap_reserve(resource_size_t base)
 442 {
 443         unsigned long reserve = PHYS_PFN(SZ_8K);
 444         unsigned long base_pfn = PHYS_PFN(base);
 445
 446         reserve += base_pfn - PFN_SECTION_ALIGN_DOWN(base_pfn);
 447         return reserve;
 448 }
 449
 450 static int __nvdimm_namespace_attach_pfn(struct nd_pfn *nd_pfn)
 451 {
 452         int rc;
 453         struct resource res;
 454         struct request_queue *q;
 455         struct pmem_device *pmem;
 456         struct vmem_altmap *altmap;
 457         struct device *dev = &nd_pfn->dev;
 458         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 459         struct nd_namespace_common *ndns = nd_pfn->ndns;
 460         u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
 461         u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
 462         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 463         resource_size_t base = nsio->res.start + start_pad;
 464         struct vmem_altmap __altmap = {
 465                 .base_pfn = init_altmap_base(base),
 466                 .reserve = init_altmap_reserve(base),
 467         };
 468
 469         pmem = dev_get_drvdata(dev);
 470         pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
 471         pmem->pfn_pad = start_pad + end_trunc;
 472         nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
 473         if (nd_pfn->mode == PFN_MODE_RAM) {
 474                 if (pmem->data_offset < SZ_8K)
 475                         return -EINVAL;
 476                 nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
 477                 altmap = NULL;
 478         } else if (nd_pfn->mode == PFN_MODE_PMEM) {
 479                 nd_pfn->npfns = (pmem->size - pmem->pfn_pad - pmem->data_offset)
 480                         / PAGE_SIZE;
 481                 if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
 482                         dev_info(&nd_pfn->dev,
 483                                         "number of pfns truncated from %lld to %ld\n",
 484                                         le64_to_cpu(nd_pfn->pfn_sb->npfns),
 485                                         nd_pfn->npfns);
 486                 altmap = & __altmap;
 487                 altmap->free = PHYS_PFN(pmem->data_offset - SZ_8K);
 488                 altmap->alloc = 0;
 489         } else {
 490                 rc = -ENXIO;
 491                 goto err;
 492         }
 493
 494         /* establish pfn range for lookup, and switch to direct map */
 495         q = pmem->pmem_queue;
 496         memcpy(&res, &nsio->res, sizeof(res));
 497         res.start += start_pad;
 498         res.end -= end_trunc;
 499         devm_memunmap(dev, (void __force *) pmem->virt_addr);
 500         pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, &res,
 501                         &q->q_usage_counter, altmap);
 502         pmem->pfn_flags |= PFN_MAP;
 503         if (IS_ERR(pmem->virt_addr)) {
 504                 rc = PTR_ERR(pmem->virt_addr);
 505                 goto err;
 506         }
 507
 508         /* attach pmem disk in "pfn-mode" */
 509         rc = pmem_attach_disk(dev, ndns, pmem);
 510         if (rc)
 511                 goto err;
 512
 513         return rc;
 514  err:
 515         nvdimm_namespace_detach_pfn(ndns);
 516         return rc;
 517
 518 }
 519
 520 static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
 521 {
 522         struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
 523         int rc;
 524
 525         if (!nd_pfn->uuid || !nd_pfn->ndns)
 526                 return -ENODEV;
 527
 528         rc = nd_pfn_init(nd_pfn);
 529         if (rc)
 530                 return rc;
 531         /* we need a valid pfn_sb before we can init a vmem_altmap */
 532         return __nvdimm_namespace_attach_pfn(nd_pfn);
 533 }
 534
 535 static int nd_pmem_probe(struct device *dev)
 536 {
 537         struct nd_region *nd_region = to_nd_region(dev->parent);
 538         struct nd_namespace_common *ndns;
 539         struct nd_namespace_io *nsio;
 540         struct pmem_device *pmem;
 541
 542         ndns = nvdimm_namespace_common_probe(dev);
 543         if (IS_ERR(ndns))
 544                 return PTR_ERR(ndns);
 545
 546         nsio = to_nd_namespace_io(&ndns->dev);
 547         pmem = pmem_alloc(dev, &nsio->res, nd_region->id);
 548         if (IS_ERR(pmem))
 549                 return PTR_ERR(pmem);
 550
 551         pmem->ndns = ndns;
 552         dev_set_drvdata(dev, pmem);
 553         ndns->rw_bytes = pmem_rw_bytes;
 554         if (devm_init_badblocks(dev, &pmem->bb))
 555                 return -ENOMEM;
 556         nvdimm_namespace_add_poison(ndns, &pmem->bb, 0);
 557
 558         if (is_nd_btt(dev)) {
 559                 /* btt allocates its own request_queue */
 560                 blk_cleanup_queue(pmem->pmem_queue);
 561                 pmem->pmem_queue = NULL;
 562                 return nvdimm_namespace_attach_btt(ndns);
 563         }
 564
 565         if (is_nd_pfn(dev))
 566                 return nvdimm_namespace_attach_pfn(ndns);
 567
 568         if (nd_btt_probe(ndns, pmem) == 0 || nd_pfn_probe(ndns, pmem) == 0) {
 569                 /*
 570                  * We'll come back as either btt-pmem, or pfn-pmem, so
 571                  * drop the queue allocation for now.
 572                  */
 573                 blk_cleanup_queue(pmem->pmem_queue);
 574                 return -ENXIO;
 575         }
 576
 577         return pmem_attach_disk(dev, ndns, pmem);
 578 }
 579
 580 static int nd_pmem_remove(struct device *dev)
 581 {
 582         struct pmem_device *pmem = dev_get_drvdata(dev);
 583
 584         if (is_nd_btt(dev))
 585                 nvdimm_namespace_detach_btt(pmem->ndns);
 586         else if (is_nd_pfn(dev))
 587                 nvdimm_namespace_detach_pfn(pmem->ndns);
 588         else
 589                 pmem_detach_disk(pmem);
 590
 591         return 0;
 592 }
 593
 594 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
 595 {
 596         struct pmem_device *pmem = dev_get_drvdata(dev);
 597         struct nd_namespace_common *ndns = pmem->ndns;
 598
 599         if (event != NVDIMM_REVALIDATE_POISON)
 600                 return;
 601
 602         if (is_nd_btt(dev))
 603                 nvdimm_namespace_add_poison(ndns, &pmem->bb, 0);
 604         else
 605                 nvdimm_namespace_add_poison(ndns, &pmem->bb, pmem->data_offset);
 606 }
 607
 608 MODULE_ALIAS("pmem");
 609 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
 610 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
 611 static struct nd_device_driver nd_pmem_driver = {
 612         .probe = nd_pmem_probe,
 613         .remove = nd_pmem_remove,
 614         .notify = nd_pmem_notify,
 615         .drv = {
 616                 .name = "nd_pmem",
 617         },
 618         .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
 619 };
 620
 621 static int __init pmem_init(void)
 622 {
 623         return nd_driver_register(&nd_pmem_driver);
 624 }
 625 module_init(pmem_init);
 626
 627 static void pmem_exit(void)
 628 {
 629         driver_unregister(&nd_pmem_driver.drv);
 630 }
 631 module_exit(pmem_exit);
 632
 633 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
 634 MODULE_LICENSE("GPL v2");