drivers/nvdimm/pmem.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Persistent Memory Driver
   4  *
   5  * Copyright (c) 2014-2015, Intel Corporation.
   6  * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
   7  * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
   8  */
   9
  10 #include <asm/cacheflush.h>
  11 #include <linux/blkdev.h>
  12 #include <linux/hdreg.h>
  13 #include <linux/init.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/set_memory.h>
  16 #include <linux/module.h>
  17 #include <linux/moduleparam.h>
  18 #include <linux/badblocks.h>
  19 #include <linux/memremap.h>
  20 #include <linux/vmalloc.h>
  21 #include <linux/blk-mq.h>
  22 #include <linux/pfn_t.h>
  23 #include <linux/slab.h>
  24 #include <linux/uio.h>
  25 #include <linux/dax.h>
  26 #include <linux/nd.h>
  27 #include <linux/backing-dev.h>
  28 #include "pmem.h"
  29 #include "pfn.h"
  30 #include "nd.h"
  31
  32 static struct device *to_dev(struct pmem_device *pmem)
  33 {
  34         /*
  35          * nvdimm bus services need a 'dev' parameter, and we record the device
  36          * at init in bb.dev.
  37          */
  38         return pmem->bb.dev;
  39 }
  40
  41 static struct nd_region *to_region(struct pmem_device *pmem)
  42 {
  43         return to_nd_region(to_dev(pmem)->parent);
  44 }
  45
  46 static void hwpoison_clear(struct pmem_device *pmem,
  47                 phys_addr_t phys, unsigned int len)
  48 {
  49         unsigned long pfn_start, pfn_end, pfn;
  50
  51         /* only pmem in the linear map supports HWPoison */
  52         if (is_vmalloc_addr(pmem->virt_addr))
  53                 return;
  54
  55         pfn_start = PHYS_PFN(phys);
  56         pfn_end = pfn_start + PHYS_PFN(len);
  57         for (pfn = pfn_start; pfn < pfn_end; pfn++) {
  58                 struct page *page = pfn_to_page(pfn);
  59
  60                 /*
  61                  * Note, no need to hold a get_dev_pagemap() reference
  62                  * here since we're in the driver I/O path and
  63                  * outstanding I/O requests pin the dev_pagemap.
  64                  */
  65                 if (test_and_clear_pmem_poison(page))
  66                         clear_mce_nospec(pfn);
  67         }
  68 }
  69
  70 static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
  71                 phys_addr_t offset, unsigned int len)
  72 {
  73         struct device *dev = to_dev(pmem);
  74         sector_t sector;
  75         long cleared;
  76         blk_status_t rc = BLK_STS_OK;
  77
  78         sector = (offset - pmem->data_offset) / 512;
  79
  80         cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
  81         if (cleared < len)
  82                 rc = BLK_STS_IOERR;
  83         if (cleared > 0 && cleared / 512) {
  84                 hwpoison_clear(pmem, pmem->phys_addr + offset, cleared);
  85                 cleared /= 512;
  86                 dev_dbg(dev, "%#llx clear %ld sector%s\n",
  87                                 (unsigned long long) sector, cleared,
  88                                 cleared > 1 ? "s" : "");
  89                 badblocks_clear(&pmem->bb, sector, cleared);
  90                 if (pmem->bb_state)
  91                         sysfs_notify_dirent(pmem->bb_state);
  92         }
  93
  94         arch_invalidate_pmem(pmem->virt_addr + offset, len);
  95
  96         return rc;
  97 }
  98
  99 static void write_pmem(void *pmem_addr, struct page *page,
 100                 unsigned int off, unsigned int len)
 101 {
 102         unsigned int chunk;
 103         void *mem;
 104
 105         while (len) {
 106                 mem = kmap_atomic(page);
 107                 chunk = min_t(unsigned int, len, PAGE_SIZE - off);
 108                 memcpy_flushcache(pmem_addr, mem + off, chunk);
 109                 kunmap_atomic(mem);
 110                 len -= chunk;
 111                 off = 0;
 112                 page++;
 113                 pmem_addr += chunk;
 114         }
 115 }
 116
 117 static blk_status_t read_pmem(struct page *page, unsigned int off,
 118                 void *pmem_addr, unsigned int len)
 119 {
 120         unsigned int chunk;
 121         unsigned long rem;
 122         void *mem;
 123
 124         while (len) {
 125                 mem = kmap_atomic(page);
 126                 chunk = min_t(unsigned int, len, PAGE_SIZE - off);
 127                 rem = memcpy_mcsafe(mem + off, pmem_addr, chunk);
 128                 kunmap_atomic(mem);
 129                 if (rem)
 130                         return BLK_STS_IOERR;
 131                 len -= chunk;
 132                 off = 0;
 133                 page++;
 134                 pmem_addr += chunk;
 135         }
 136         return BLK_STS_OK;
 137 }
 138
 139 static blk_status_t pmem_do_bvec(struct pmem_device *pmem, struct page *page,
 140                         unsigned int len, unsigned int off, unsigned int op,
 141                         sector_t sector)
 142 {
 143         blk_status_t rc = BLK_STS_OK;
 144         bool bad_pmem = false;
 145         phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
 146         void *pmem_addr = pmem->virt_addr + pmem_off;
 147
 148         if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
 149                 bad_pmem = true;
 150
 151         if (!op_is_write(op)) {
 152                 if (unlikely(bad_pmem))
 153                         rc = BLK_STS_IOERR;
 154                 else {
 155                         rc = read_pmem(page, off, pmem_addr, len);
 156                         flush_dcache_page(page);
 157                 }
 158         } else {
 159                 /*
 160                  * Note that we write the data both before and after
 161                  * clearing poison.  The write before clear poison
 162                  * handles situations where the latest written data is
 163                  * preserved and the clear poison operation simply marks
 164                  * the address range as valid without changing the data.
 165                  * In this case application software can assume that an
 166                  * interrupted write will either return the new good
 167                  * data or an error.
 168                  *
 169                  * However, if pmem_clear_poison() leaves the data in an
 170                  * indeterminate state we need to perform the write
 171                  * after clear poison.
 172                  */
 173                 flush_dcache_page(page);
 174                 write_pmem(pmem_addr, page, off, len);
 175                 if (unlikely(bad_pmem)) {
 176                         rc = pmem_clear_poison(pmem, pmem_off, len);
 177                         write_pmem(pmem_addr, page, off, len);
 178                 }
 179         }
 180
 181         return rc;
 182 }
 183
 184 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
 185 {
 186         int ret = 0;
 187         blk_status_t rc = 0;
 188         bool do_acct;
 189         unsigned long start;
 190         struct bio_vec bvec;
 191         struct bvec_iter iter;
 192         struct pmem_device *pmem = q->queuedata;
 193         struct nd_region *nd_region = to_region(pmem);
 194
 195         if (bio->bi_opf & REQ_PREFLUSH)
 196                 ret = nvdimm_flush(nd_region, bio);
 197
 198         do_acct = nd_iostat_start(bio, &start);
 199         bio_for_each_segment(bvec, bio, iter) {
 200                 rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
 201                                 bvec.bv_offset, bio_op(bio), iter.bi_sector);
 202                 if (rc) {
 203                         bio->bi_status = rc;
 204                         break;
 205                 }
 206         }
 207         if (do_acct)
 208                 nd_iostat_end(bio, start);
 209
 210         if (bio->bi_opf & REQ_FUA)
 211                 ret = nvdimm_flush(nd_region, bio);
 212
 213         if (ret)
 214                 bio->bi_status = errno_to_blk_status(ret);
 215
 216         bio_endio(bio);
 217         return BLK_QC_T_NONE;
 218 }
 219
 220 static int pmem_rw_page(struct block_device *bdev, sector_t sector,
 221                        struct page *page, unsigned int op)
 222 {
 223         struct pmem_device *pmem = bdev->bd_queue->queuedata;
 224         blk_status_t rc;
 225
 226         rc = pmem_do_bvec(pmem, page, hpage_nr_pages(page) * PAGE_SIZE,
 227                           0, op, sector);
 228
 229         /*
 230          * The ->rw_page interface is subtle and tricky.  The core
 231          * retries on any error, so we can only invoke page_endio() in
 232          * the successful completion case.  Otherwise, we'll see crashes
 233          * caused by double completion.
 234          */
 235         if (rc == 0)
 236                 page_endio(page, op_is_write(op), 0);
 237
 238         return blk_status_to_errno(rc);
 239 }
 240
 241 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
 242 __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
 243                 long nr_pages, void **kaddr, pfn_t *pfn)
 244 {
 245         resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
 246
 247         if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
 248                                         PFN_PHYS(nr_pages))))
 249                 return -EIO;
 250
 251         if (kaddr)
 252                 *kaddr = pmem->virt_addr + offset;
 253         if (pfn)
 254                 *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
 255
 256         /*
 257          * If badblocks are present, limit known good range to the
 258          * requested range.
 259          */
 260         if (unlikely(pmem->bb.count))
 261                 return nr_pages;
 262         return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
 263 }
 264
 265 static const struct block_device_operations pmem_fops = {
 266         .owner =                THIS_MODULE,
 267         .rw_page =              pmem_rw_page,
 268         .revalidate_disk =      nvdimm_revalidate_disk,
 269 };
 270
 271 static long pmem_dax_direct_access(struct dax_device *dax_dev,
 272                 pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn)
 273 {
 274         struct pmem_device *pmem = dax_get_private(dax_dev);
 275
 276         return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn);
 277 }
 278
 279 /*
 280  * Use the 'no check' versions of copy_from_iter_flushcache() and
 281  * copy_to_iter_mcsafe() to bypass HARDENED_USERCOPY overhead. Bounds
 282  * checking, both file offset and device offset, is handled by
 283  * dax_iomap_actor()
 284  */
 285 static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
 286                 void *addr, size_t bytes, struct iov_iter *i)
 287 {
 288         return _copy_from_iter_flushcache(addr, bytes, i);
 289 }
 290
 291 static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
 292                 void *addr, size_t bytes, struct iov_iter *i)
 293 {
 294         return _copy_to_iter_mcsafe(addr, bytes, i);
 295 }
 296
 297 static const struct dax_operations pmem_dax_ops = {
 298         .direct_access = pmem_dax_direct_access,
 299         .dax_supported = generic_fsdax_supported,
 300         .copy_from_iter = pmem_copy_from_iter,
 301         .copy_to_iter = pmem_copy_to_iter,
 302 };
 303
 304 static const struct attribute_group *pmem_attribute_groups[] = {
 305         &dax_attribute_group,
 306         NULL,
 307 };
 308
 309 static void pmem_pagemap_cleanup(struct dev_pagemap *pgmap)
 310 {
 311         struct request_queue *q =
 312                 container_of(pgmap->ref, struct request_queue, q_usage_counter);
 313
 314         blk_cleanup_queue(q);
 315 }
 316
 317 static void pmem_release_queue(void *pgmap)
 318 {
 319         pmem_pagemap_cleanup(pgmap);
 320 }
 321
 322 static void pmem_pagemap_kill(struct dev_pagemap *pgmap)
 323 {
 324         struct request_queue *q =
 325                 container_of(pgmap->ref, struct request_queue, q_usage_counter);
 326
 327         blk_freeze_queue_start(q);
 328 }
 329
 330 static void pmem_release_disk(void *__pmem)
 331 {
 332         struct pmem_device *pmem = __pmem;
 333
 334         kill_dax(pmem->dax_dev);
 335         put_dax(pmem->dax_dev);
 336         del_gendisk(pmem->disk);
 337         put_disk(pmem->disk);
 338 }
 339
 340 static void pmem_pagemap_page_free(struct page *page)
 341 {
 342         wake_up_var(&page->_refcount);
 343 }
 344
 345 static const struct dev_pagemap_ops fsdax_pagemap_ops = {
 346         .page_free              = pmem_pagemap_page_free,
 347         .kill                   = pmem_pagemap_kill,
 348         .cleanup                = pmem_pagemap_cleanup,
 349 };
 350
 351 static int pmem_attach_disk(struct device *dev,
 352                 struct nd_namespace_common *ndns)
 353 {
 354         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 355         struct nd_region *nd_region = to_nd_region(dev->parent);
 356         int nid = dev_to_node(dev), fua;
 357         struct resource *res = &nsio->res;
 358         struct resource bb_res;
 359         struct nd_pfn *nd_pfn = NULL;
 360         struct dax_device *dax_dev;
 361         struct nd_pfn_sb *pfn_sb;
 362         struct pmem_device *pmem;
 363         struct request_queue *q;
 364         struct device *gendev;
 365         struct gendisk *disk;
 366         void *addr;
 367         int rc;
 368         unsigned long flags = 0UL;
 369
 370         pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
 371         if (!pmem)
 372                 return -ENOMEM;
 373
 374         rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
 375         if (rc)
 376                 return rc;
 377
 378         /* while nsio_rw_bytes is active, parse a pfn info block if present */
 379         if (is_nd_pfn(dev)) {
 380                 nd_pfn = to_nd_pfn(dev);
 381                 rc = nvdimm_setup_pfn(nd_pfn, &pmem->pgmap);
 382                 if (rc)
 383                         return rc;
 384         }
 385
 386         /* we're attaching a block device, disable raw namespace access */
 387         devm_namespace_disable(dev, ndns);
 388
 389         dev_set_drvdata(dev, pmem);
 390         pmem->phys_addr = res->start;
 391         pmem->size = resource_size(res);
 392         fua = nvdimm_has_flush(nd_region);
 393         if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) {
 394                 dev_warn(dev, "unable to guarantee persistence of writes\n");
 395                 fua = 0;
 396         }
 397
 398         if (!devm_request_mem_region(dev, res->start, resource_size(res),
 399                                 dev_name(&ndns->dev))) {
 400                 dev_warn(dev, "could not reserve region %pR\n", res);
 401                 return -EBUSY;
 402         }
 403
 404         q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
 405         if (!q)
 406                 return -ENOMEM;
 407
 408         pmem->pfn_flags = PFN_DEV;
 409         pmem->pgmap.ref = &q->q_usage_counter;
 410         if (is_nd_pfn(dev)) {
 411                 pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
 412                 pmem->pgmap.ops = &fsdax_pagemap_ops;
 413                 addr = devm_memremap_pages(dev, &pmem->pgmap);
 414                 pfn_sb = nd_pfn->pfn_sb;
 415                 pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
 416                 pmem->pfn_pad = resource_size(res) -
 417                         resource_size(&pmem->pgmap.res);
 418                 pmem->pfn_flags |= PFN_MAP;
 419                 memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
 420                 bb_res.start += pmem->data_offset;
 421         } else if (pmem_should_map_pages(dev)) {
 422                 memcpy(&pmem->pgmap.res, &nsio->res, sizeof(pmem->pgmap.res));
 423                 pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
 424                 pmem->pgmap.ops = &fsdax_pagemap_ops;
 425                 addr = devm_memremap_pages(dev, &pmem->pgmap);
 426                 pmem->pfn_flags |= PFN_MAP;
 427                 memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
 428         } else {
 429                 if (devm_add_action_or_reset(dev, pmem_release_queue,
 430                                         &pmem->pgmap))
 431                         return -ENOMEM;
 432                 addr = devm_memremap(dev, pmem->phys_addr,
 433                                 pmem->size, ARCH_MEMREMAP_PMEM);
 434                 memcpy(&bb_res, &nsio->res, sizeof(bb_res));
 435         }
 436
 437         if (IS_ERR(addr))
 438                 return PTR_ERR(addr);
 439         pmem->virt_addr = addr;
 440
 441         blk_queue_write_cache(q, true, fua);
 442         blk_queue_make_request(q, pmem_make_request);
 443         blk_queue_physical_block_size(q, PAGE_SIZE);
 444         blk_queue_logical_block_size(q, pmem_sector_size(ndns));
 445         blk_queue_max_hw_sectors(q, UINT_MAX);
 446         blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
 447         if (pmem->pfn_flags & PFN_MAP)
 448                 blk_queue_flag_set(QUEUE_FLAG_DAX, q);
 449         q->queuedata = pmem;
 450
 451         disk = alloc_disk_node(0, nid);
 452         if (!disk)
 453                 return -ENOMEM;
 454         pmem->disk = disk;
 455
 456         disk->fops              = &pmem_fops;
 457         disk->queue             = q;
 458         disk->flags             = GENHD_FL_EXT_DEVT;
 459         disk->queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO;
 460         nvdimm_namespace_disk_name(ndns, disk->disk_name);
 461         set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
 462                         / 512);
 463         if (devm_init_badblocks(dev, &pmem->bb))
 464                 return -ENOMEM;
 465         nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_res);
 466         disk->bb = &pmem->bb;
 467
 468         if (is_nvdimm_sync(nd_region))
 469                 flags = DAXDEV_F_SYNC;
 470         dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops, flags);
 471         if (!dax_dev) {
 472                 put_disk(disk);
 473                 return -ENOMEM;
 474         }
 475         dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
 476         pmem->dax_dev = dax_dev;
 477         gendev = disk_to_dev(disk);
 478         gendev->groups = pmem_attribute_groups;
 479
 480         device_add_disk(dev, disk, NULL);
 481         if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
 482                 return -ENOMEM;
 483
 484         revalidate_disk(disk);
 485
 486         pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd,
 487                                           "badblocks");
 488         if (!pmem->bb_state)
 489                 dev_warn(dev, "'badblocks' notification disabled\n");
 490
 491         return 0;
 492 }
 493
 494 static int nd_pmem_probe(struct device *dev)
 495 {
 496         int ret;
 497         struct nd_namespace_common *ndns;
 498
 499         ndns = nvdimm_namespace_common_probe(dev);
 500         if (IS_ERR(ndns))
 501                 return PTR_ERR(ndns);
 502
 503         if (is_nd_btt(dev))
 504                 return nvdimm_namespace_attach_btt(ndns);
 505
 506         if (is_nd_pfn(dev))
 507                 return pmem_attach_disk(dev, ndns);
 508
 509         ret = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
 510         if (ret)
 511                 return ret;
 512
 513         ret = nd_btt_probe(dev, ndns);
 514         if (ret == 0)
 515                 return -ENXIO;
 516
 517         /*
 518          * We have two failure conditions here, there is no
 519          * info reserver block or we found a valid info reserve block
 520          * but failed to initialize the pfn superblock.
 521          *
 522          * For the first case consider namespace as a raw pmem namespace
 523          * and attach a disk.
 524          *
 525          * For the latter, consider this a success and advance the namespace
 526          * seed.
 527          */
 528         ret = nd_pfn_probe(dev, ndns);
 529         if (ret == 0)
 530                 return -ENXIO;
 531         else if (ret == -EOPNOTSUPP)
 532                 return ret;
 533
 534         ret = nd_dax_probe(dev, ndns);
 535         if (ret == 0)
 536                 return -ENXIO;
 537         else if (ret == -EOPNOTSUPP)
 538                 return ret;
 539
 540         /* probe complete, attach handles namespace enabling */
 541         devm_namespace_disable(dev, ndns);
 542
 543         return pmem_attach_disk(dev, ndns);
 544 }
 545
 546 static int nd_pmem_remove(struct device *dev)
 547 {
 548         struct pmem_device *pmem = dev_get_drvdata(dev);
 549
 550         if (is_nd_btt(dev))
 551                 nvdimm_namespace_detach_btt(to_nd_btt(dev));
 552         else {
 553                 /*
 554                  * Note, this assumes nd_device_lock() context to not
 555                  * race nd_pmem_notify()
 556                  */
 557                 sysfs_put(pmem->bb_state);
 558                 pmem->bb_state = NULL;
 559         }
 560         nvdimm_flush(to_nd_region(dev->parent), NULL);
 561
 562         return 0;
 563 }
 564
 565 static void nd_pmem_shutdown(struct device *dev)
 566 {
 567         nvdimm_flush(to_nd_region(dev->parent), NULL);
 568 }
 569
 570 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
 571 {
 572         struct nd_region *nd_region;
 573         resource_size_t offset = 0, end_trunc = 0;
 574         struct nd_namespace_common *ndns;
 575         struct nd_namespace_io *nsio;
 576         struct resource res;
 577         struct badblocks *bb;
 578         struct kernfs_node *bb_state;
 579
 580         if (event != NVDIMM_REVALIDATE_POISON)
 581                 return;
 582
 583         if (is_nd_btt(dev)) {
 584                 struct nd_btt *nd_btt = to_nd_btt(dev);
 585
 586                 ndns = nd_btt->ndns;
 587                 nd_region = to_nd_region(ndns->dev.parent);
 588                 nsio = to_nd_namespace_io(&ndns->dev);
 589                 bb = &nsio->bb;
 590                 bb_state = NULL;
 591         } else {
 592                 struct pmem_device *pmem = dev_get_drvdata(dev);
 593
 594                 nd_region = to_region(pmem);
 595                 bb = &pmem->bb;
 596                 bb_state = pmem->bb_state;
 597
 598                 if (is_nd_pfn(dev)) {
 599                         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
 600                         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 601
 602                         ndns = nd_pfn->ndns;
 603                         offset = pmem->data_offset +
 604                                         __le32_to_cpu(pfn_sb->start_pad);
 605                         end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
 606                 } else {
 607                         ndns = to_ndns(dev);
 608                 }
 609
 610                 nsio = to_nd_namespace_io(&ndns->dev);
 611         }
 612
 613         res.start = nsio->res.start + offset;
 614         res.end = nsio->res.end - end_trunc;
 615         nvdimm_badblocks_populate(nd_region, bb, &res);
 616         if (bb_state)
 617                 sysfs_notify_dirent(bb_state);
 618 }
 619
 620 MODULE_ALIAS("pmem");
 621 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
 622 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
 623 static struct nd_device_driver nd_pmem_driver = {
 624         .probe = nd_pmem_probe,
 625         .remove = nd_pmem_remove,
 626         .notify = nd_pmem_notify,
 627         .shutdown = nd_pmem_shutdown,
 628         .drv = {
 629                 .name = "nd_pmem",
 630         },
 631         .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
 632 };
 633
 634 module_nd_driver(nd_pmem_driver);
 635
 636 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
 637 MODULE_LICENSE("GPL v2");