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 <linux/blkdev.h>
  11 #include <linux/pagemap.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/kstrtox.h>
  21 #include <linux/vmalloc.h>
  22 #include <linux/blk-mq.h>
  23 #include <linux/pfn_t.h>
  24 #include <linux/slab.h>
  25 #include <linux/uio.h>
  26 #include <linux/dax.h>
  27 #include <linux/nd.h>
  28 #include <linux/mm.h>
  29 #include <asm/cacheflush.h>
  30 #include "pmem.h"
  31 #include "btt.h"
  32 #include "pfn.h"
  33 #include "nd.h"
  34
  35 static struct device *to_dev(struct pmem_device *pmem)
  36 {
  37         /*
  38          * nvdimm bus services need a 'dev' parameter, and we record the device
  39          * at init in bb.dev.
  40          */
  41         return pmem->bb.dev;
  42 }
  43
  44 static struct nd_region *to_region(struct pmem_device *pmem)
  45 {
  46         return to_nd_region(to_dev(pmem)->parent);
  47 }
  48
  49 static phys_addr_t pmem_to_phys(struct pmem_device *pmem, phys_addr_t offset)
  50 {
  51         return pmem->phys_addr + offset;
  52 }
  53
  54 static sector_t to_sect(struct pmem_device *pmem, phys_addr_t offset)
  55 {
  56         return (offset - pmem->data_offset) >> SECTOR_SHIFT;
  57 }
  58
  59 static phys_addr_t to_offset(struct pmem_device *pmem, sector_t sector)
  60 {
  61         return (sector << SECTOR_SHIFT) + pmem->data_offset;
  62 }
  63
  64 static void pmem_mkpage_present(struct pmem_device *pmem, phys_addr_t offset,
  65                 unsigned int len)
  66 {
  67         phys_addr_t phys = pmem_to_phys(pmem, offset);
  68         unsigned long pfn_start, pfn_end, pfn;
  69
  70         /* only pmem in the linear map supports HWPoison */
  71         if (is_vmalloc_addr(pmem->virt_addr))
  72                 return;
  73
  74         pfn_start = PHYS_PFN(phys);
  75         pfn_end = pfn_start + PHYS_PFN(len);
  76         for (pfn = pfn_start; pfn < pfn_end; pfn++) {
  77                 struct page *page = pfn_to_page(pfn);
  78
  79                 /*
  80                  * Note, no need to hold a get_dev_pagemap() reference
  81                  * here since we're in the driver I/O path and
  82                  * outstanding I/O requests pin the dev_pagemap.
  83                  */
  84                 if (test_and_clear_pmem_poison(page))
  85                         clear_mce_nospec(pfn);
  86         }
  87 }
  88
  89 static void pmem_clear_bb(struct pmem_device *pmem, sector_t sector, long blks)
  90 {
  91         if (blks == 0)
  92                 return;
  93         badblocks_clear(&pmem->bb, sector, blks);
  94         if (pmem->bb_state)
  95                 sysfs_notify_dirent(pmem->bb_state);
  96 }
  97
  98 static long __pmem_clear_poison(struct pmem_device *pmem,
  99                 phys_addr_t offset, unsigned int len)
 100 {
 101         phys_addr_t phys = pmem_to_phys(pmem, offset);
 102         long cleared = nvdimm_clear_poison(to_dev(pmem), phys, len);
 103
 104         if (cleared > 0) {
 105                 pmem_mkpage_present(pmem, offset, cleared);
 106                 arch_invalidate_pmem(pmem->virt_addr + offset, len);
 107         }
 108         return cleared;
 109 }
 110
 111 static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
 112                 phys_addr_t offset, unsigned int len)
 113 {
 114         long cleared = __pmem_clear_poison(pmem, offset, len);
 115
 116         if (cleared < 0)
 117                 return BLK_STS_IOERR;
 118
 119         pmem_clear_bb(pmem, to_sect(pmem, offset), cleared >> SECTOR_SHIFT);
 120         if (cleared < len)
 121                 return BLK_STS_IOERR;
 122         return BLK_STS_OK;
 123 }
 124
 125 static void write_pmem(void *pmem_addr, struct page *page,
 126                 unsigned int off, unsigned int len)
 127 {
 128         unsigned int chunk;
 129         void *mem;
 130
 131         while (len) {
 132                 mem = kmap_atomic(page);
 133                 chunk = min_t(unsigned int, len, PAGE_SIZE - off);
 134                 memcpy_flushcache(pmem_addr, mem + off, chunk);
 135                 kunmap_atomic(mem);
 136                 len -= chunk;
 137                 off = 0;
 138                 page++;
 139                 pmem_addr += chunk;
 140         }
 141 }
 142
 143 static blk_status_t read_pmem(struct page *page, unsigned int off,
 144                 void *pmem_addr, unsigned int len)
 145 {
 146         unsigned int chunk;
 147         unsigned long rem;
 148         void *mem;
 149
 150         while (len) {
 151                 mem = kmap_atomic(page);
 152                 chunk = min_t(unsigned int, len, PAGE_SIZE - off);
 153                 rem = copy_mc_to_kernel(mem + off, pmem_addr, chunk);
 154                 kunmap_atomic(mem);
 155                 if (rem)
 156                         return BLK_STS_IOERR;
 157                 len -= chunk;
 158                 off = 0;
 159                 page++;
 160                 pmem_addr += chunk;
 161         }
 162         return BLK_STS_OK;
 163 }
 164
 165 static blk_status_t pmem_do_read(struct pmem_device *pmem,
 166                         struct page *page, unsigned int page_off,
 167                         sector_t sector, unsigned int len)
 168 {
 169         blk_status_t rc;
 170         phys_addr_t pmem_off = to_offset(pmem, sector);
 171         void *pmem_addr = pmem->virt_addr + pmem_off;
 172
 173         if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
 174                 return BLK_STS_IOERR;
 175
 176         rc = read_pmem(page, page_off, pmem_addr, len);
 177         flush_dcache_page(page);
 178         return rc;
 179 }
 180
 181 static blk_status_t pmem_do_write(struct pmem_device *pmem,
 182                         struct page *page, unsigned int page_off,
 183                         sector_t sector, unsigned int len)
 184 {
 185         phys_addr_t pmem_off = to_offset(pmem, sector);
 186         void *pmem_addr = pmem->virt_addr + pmem_off;
 187
 188         if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) {
 189                 blk_status_t rc = pmem_clear_poison(pmem, pmem_off, len);
 190
 191                 if (rc != BLK_STS_OK)
 192                         return rc;
 193         }
 194
 195         flush_dcache_page(page);
 196         write_pmem(pmem_addr, page, page_off, len);
 197
 198         return BLK_STS_OK;
 199 }
 200
 201 static void pmem_submit_bio(struct bio *bio)
 202 {
 203         int ret = 0;
 204         blk_status_t rc = 0;
 205         bool do_acct;
 206         unsigned long start;
 207         struct bio_vec bvec;
 208         struct bvec_iter iter;
 209         struct pmem_device *pmem = bio->bi_bdev->bd_disk->private_data;
 210         struct nd_region *nd_region = to_region(pmem);
 211
 212         if (bio->bi_opf & REQ_PREFLUSH)
 213                 ret = nvdimm_flush(nd_region, bio);
 214
 215         do_acct = blk_queue_io_stat(bio->bi_bdev->bd_disk->queue);
 216         if (do_acct)
 217                 start = bio_start_io_acct(bio);
 218         bio_for_each_segment(bvec, bio, iter) {
 219                 if (op_is_write(bio_op(bio)))
 220                         rc = pmem_do_write(pmem, bvec.bv_page, bvec.bv_offset,
 221                                 iter.bi_sector, bvec.bv_len);
 222                 else
 223                         rc = pmem_do_read(pmem, bvec.bv_page, bvec.bv_offset,
 224                                 iter.bi_sector, bvec.bv_len);
 225                 if (rc) {
 226                         bio->bi_status = rc;
 227                         break;
 228                 }
 229         }
 230         if (do_acct)
 231                 bio_end_io_acct(bio, start);
 232
 233         if (bio->bi_opf & REQ_FUA)
 234                 ret = nvdimm_flush(nd_region, bio);
 235
 236         if (ret)
 237                 bio->bi_status = errno_to_blk_status(ret);
 238
 239         bio_endio(bio);
 240 }
 241
 242 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
 243 __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
 244                 long nr_pages, enum dax_access_mode mode, void **kaddr,
 245                 pfn_t *pfn)
 246 {
 247         resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
 248         sector_t sector = PFN_PHYS(pgoff) >> SECTOR_SHIFT;
 249         unsigned int num = PFN_PHYS(nr_pages) >> SECTOR_SHIFT;
 250         struct badblocks *bb = &pmem->bb;
 251         sector_t first_bad;
 252         int num_bad;
 253
 254         if (kaddr)
 255                 *kaddr = pmem->virt_addr + offset;
 256         if (pfn)
 257                 *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
 258
 259         if (bb->count &&
 260             badblocks_check(bb, sector, num, &first_bad, &num_bad)) {
 261                 long actual_nr;
 262
 263                 if (mode != DAX_RECOVERY_WRITE)
 264                         return -EHWPOISON;
 265
 266                 /*
 267                  * Set the recovery stride is set to kernel page size because
 268                  * the underlying driver and firmware clear poison functions
 269                  * don't appear to handle large chunk(such as 2MiB) reliably.
 270                  */
 271                 actual_nr = PHYS_PFN(
 272                         PAGE_ALIGN((first_bad - sector) << SECTOR_SHIFT));
 273                 dev_dbg(pmem->bb.dev, "start sector(%llu), nr_pages(%ld), first_bad(%llu), actual_nr(%ld)\n",
 274                                 sector, nr_pages, first_bad, actual_nr);
 275                 if (actual_nr)
 276                         return actual_nr;
 277                 return 1;
 278         }
 279
 280         /*
 281          * If badblocks are present but not in the range, limit known good range
 282          * to the requested range.
 283          */
 284         if (bb->count)
 285                 return nr_pages;
 286         return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
 287 }
 288
 289 static const struct block_device_operations pmem_fops = {
 290         .owner =                THIS_MODULE,
 291         .submit_bio =           pmem_submit_bio,
 292 };
 293
 294 static int pmem_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
 295                                     size_t nr_pages)
 296 {
 297         struct pmem_device *pmem = dax_get_private(dax_dev);
 298
 299         return blk_status_to_errno(pmem_do_write(pmem, ZERO_PAGE(0), 0,
 300                                    PFN_PHYS(pgoff) >> SECTOR_SHIFT,
 301                                    PAGE_SIZE));
 302 }
 303
 304 static long pmem_dax_direct_access(struct dax_device *dax_dev,
 305                 pgoff_t pgoff, long nr_pages, enum dax_access_mode mode,
 306                 void **kaddr, pfn_t *pfn)
 307 {
 308         struct pmem_device *pmem = dax_get_private(dax_dev);
 309
 310         return __pmem_direct_access(pmem, pgoff, nr_pages, mode, kaddr, pfn);
 311 }
 312
 313 /*
 314  * The recovery write thread started out as a normal pwrite thread and
 315  * when the filesystem was told about potential media error in the
 316  * range, filesystem turns the normal pwrite to a dax_recovery_write.
 317  *
 318  * The recovery write consists of clearing media poison, clearing page
 319  * HWPoison bit, reenable page-wide read-write permission, flush the
 320  * caches and finally write.  A competing pread thread will be held
 321  * off during the recovery process since data read back might not be
 322  * valid, and this is achieved by clearing the badblock records after
 323  * the recovery write is complete. Competing recovery write threads
 324  * are already serialized by writer lock held by dax_iomap_rw().
 325  */
 326 static size_t pmem_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff,
 327                 void *addr, size_t bytes, struct iov_iter *i)
 328 {
 329         struct pmem_device *pmem = dax_get_private(dax_dev);
 330         size_t olen, len, off;
 331         phys_addr_t pmem_off;
 332         struct device *dev = pmem->bb.dev;
 333         long cleared;
 334
 335         off = offset_in_page(addr);
 336         len = PFN_PHYS(PFN_UP(off + bytes));
 337         if (!is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) >> SECTOR_SHIFT, len))
 338                 return _copy_from_iter_flushcache(addr, bytes, i);
 339
 340         /*
 341          * Not page-aligned range cannot be recovered. This should not
 342          * happen unless something else went wrong.
 343          */
 344         if (off || !PAGE_ALIGNED(bytes)) {
 345                 dev_dbg(dev, "Found poison, but addr(%p) or bytes(%#zx) not page aligned\n",
 346                         addr, bytes);
 347                 return 0;
 348         }
 349
 350         pmem_off = PFN_PHYS(pgoff) + pmem->data_offset;
 351         cleared = __pmem_clear_poison(pmem, pmem_off, len);
 352         if (cleared > 0 && cleared < len) {
 353                 dev_dbg(dev, "poison cleared only %ld out of %zu bytes\n",
 354                         cleared, len);
 355                 return 0;
 356         }
 357         if (cleared < 0) {
 358                 dev_dbg(dev, "poison clear failed: %ld\n", cleared);
 359                 return 0;
 360         }
 361
 362         olen = _copy_from_iter_flushcache(addr, bytes, i);
 363         pmem_clear_bb(pmem, to_sect(pmem, pmem_off), cleared >> SECTOR_SHIFT);
 364
 365         return olen;
 366 }
 367
 368 static const struct dax_operations pmem_dax_ops = {
 369         .direct_access = pmem_dax_direct_access,
 370         .zero_page_range = pmem_dax_zero_page_range,
 371         .recovery_write = pmem_recovery_write,
 372 };
 373
 374 static ssize_t write_cache_show(struct device *dev,
 375                 struct device_attribute *attr, char *buf)
 376 {
 377         struct pmem_device *pmem = dev_to_disk(dev)->private_data;
 378
 379         return sprintf(buf, "%d\n", !!dax_write_cache_enabled(pmem->dax_dev));
 380 }
 381
 382 static ssize_t write_cache_store(struct device *dev,
 383                 struct device_attribute *attr, const char *buf, size_t len)
 384 {
 385         struct pmem_device *pmem = dev_to_disk(dev)->private_data;
 386         bool write_cache;
 387         int rc;
 388
 389         rc = kstrtobool(buf, &write_cache);
 390         if (rc)
 391                 return rc;
 392         dax_write_cache(pmem->dax_dev, write_cache);
 393         return len;
 394 }
 395 static DEVICE_ATTR_RW(write_cache);
 396
 397 static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n)
 398 {
 399 #ifndef CONFIG_ARCH_HAS_PMEM_API
 400         if (a == &dev_attr_write_cache.attr)
 401                 return 0;
 402 #endif
 403         return a->mode;
 404 }
 405
 406 static struct attribute *dax_attributes[] = {
 407         &dev_attr_write_cache.attr,
 408         NULL,
 409 };
 410
 411 static const struct attribute_group dax_attribute_group = {
 412         .name           = "dax",
 413         .attrs          = dax_attributes,
 414         .is_visible     = dax_visible,
 415 };
 416
 417 static const struct attribute_group *pmem_attribute_groups[] = {
 418         &dax_attribute_group,
 419         NULL,
 420 };
 421
 422 static void pmem_release_disk(void *__pmem)
 423 {
 424         struct pmem_device *pmem = __pmem;
 425
 426         dax_remove_host(pmem->disk);
 427         kill_dax(pmem->dax_dev);
 428         put_dax(pmem->dax_dev);
 429         del_gendisk(pmem->disk);
 430
 431         put_disk(pmem->disk);
 432 }
 433
 434 static int pmem_pagemap_memory_failure(struct dev_pagemap *pgmap,
 435                 unsigned long pfn, unsigned long nr_pages, int mf_flags)
 436 {
 437         struct pmem_device *pmem =
 438                         container_of(pgmap, struct pmem_device, pgmap);
 439         u64 offset = PFN_PHYS(pfn) - pmem->phys_addr - pmem->data_offset;
 440         u64 len = nr_pages << PAGE_SHIFT;
 441
 442         return dax_holder_notify_failure(pmem->dax_dev, offset, len, mf_flags);
 443 }
 444
 445 static const struct dev_pagemap_ops fsdax_pagemap_ops = {
 446         .memory_failure         = pmem_pagemap_memory_failure,
 447 };
 448
 449 static int pmem_attach_disk(struct device *dev,
 450                 struct nd_namespace_common *ndns)
 451 {
 452         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 453         struct nd_region *nd_region = to_nd_region(dev->parent);
 454         int nid = dev_to_node(dev), fua;
 455         struct resource *res = &nsio->res;
 456         struct range bb_range;
 457         struct nd_pfn *nd_pfn = NULL;
 458         struct dax_device *dax_dev;
 459         struct nd_pfn_sb *pfn_sb;
 460         struct pmem_device *pmem;
 461         struct request_queue *q;
 462         struct gendisk *disk;
 463         void *addr;
 464         int rc;
 465
 466         pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
 467         if (!pmem)
 468                 return -ENOMEM;
 469
 470         rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
 471         if (rc)
 472                 return rc;
 473
 474         /* while nsio_rw_bytes is active, parse a pfn info block if present */
 475         if (is_nd_pfn(dev)) {
 476                 nd_pfn = to_nd_pfn(dev);
 477                 rc = nvdimm_setup_pfn(nd_pfn, &pmem->pgmap);
 478                 if (rc)
 479                         return rc;
 480         }
 481
 482         /* we're attaching a block device, disable raw namespace access */
 483         devm_namespace_disable(dev, ndns);
 484
 485         dev_set_drvdata(dev, pmem);
 486         pmem->phys_addr = res->start;
 487         pmem->size = resource_size(res);
 488         fua = nvdimm_has_flush(nd_region);
 489         if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) {
 490                 dev_warn(dev, "unable to guarantee persistence of writes\n");
 491                 fua = 0;
 492         }
 493
 494         if (!devm_request_mem_region(dev, res->start, resource_size(res),
 495                                 dev_name(&ndns->dev))) {
 496                 dev_warn(dev, "could not reserve region %pR\n", res);
 497                 return -EBUSY;
 498         }
 499
 500         disk = blk_alloc_disk(nid);
 501         if (!disk)
 502                 return -ENOMEM;
 503         q = disk->queue;
 504
 505         pmem->disk = disk;
 506         pmem->pgmap.owner = pmem;
 507         pmem->pfn_flags = PFN_DEV;
 508         if (is_nd_pfn(dev)) {
 509                 pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
 510                 pmem->pgmap.ops = &fsdax_pagemap_ops;
 511                 addr = devm_memremap_pages(dev, &pmem->pgmap);
 512                 pfn_sb = nd_pfn->pfn_sb;
 513                 pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
 514                 pmem->pfn_pad = resource_size(res) -
 515                         range_len(&pmem->pgmap.range);
 516                 pmem->pfn_flags |= PFN_MAP;
 517                 bb_range = pmem->pgmap.range;
 518                 bb_range.start += pmem->data_offset;
 519         } else if (pmem_should_map_pages(dev)) {
 520                 pmem->pgmap.range.start = res->start;
 521                 pmem->pgmap.range.end = res->end;
 522                 pmem->pgmap.nr_range = 1;
 523                 pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
 524                 pmem->pgmap.ops = &fsdax_pagemap_ops;
 525                 addr = devm_memremap_pages(dev, &pmem->pgmap);
 526                 pmem->pfn_flags |= PFN_MAP;
 527                 bb_range = pmem->pgmap.range;
 528         } else {
 529                 addr = devm_memremap(dev, pmem->phys_addr,
 530                                 pmem->size, ARCH_MEMREMAP_PMEM);
 531                 bb_range.start =  res->start;
 532                 bb_range.end = res->end;
 533         }
 534
 535         if (IS_ERR(addr)) {
 536                 rc = PTR_ERR(addr);
 537                 goto out;
 538         }
 539         pmem->virt_addr = addr;
 540
 541         blk_queue_write_cache(q, true, fua);
 542         blk_queue_physical_block_size(q, PAGE_SIZE);
 543         blk_queue_logical_block_size(q, pmem_sector_size(ndns));
 544         blk_queue_max_hw_sectors(q, UINT_MAX);
 545         blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
 546         blk_queue_flag_set(QUEUE_FLAG_SYNCHRONOUS, q);
 547         if (pmem->pfn_flags & PFN_MAP)
 548                 blk_queue_flag_set(QUEUE_FLAG_DAX, q);
 549
 550         disk->fops              = &pmem_fops;
 551         disk->private_data      = pmem;
 552         nvdimm_namespace_disk_name(ndns, disk->disk_name);
 553         set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
 554                         / 512);
 555         if (devm_init_badblocks(dev, &pmem->bb))
 556                 return -ENOMEM;
 557         nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_range);
 558         disk->bb = &pmem->bb;
 559
 560         dax_dev = alloc_dax(pmem, &pmem_dax_ops);
 561         if (IS_ERR(dax_dev)) {
 562                 rc = PTR_ERR(dax_dev);
 563                 goto out;
 564         }
 565         set_dax_nocache(dax_dev);
 566         set_dax_nomc(dax_dev);
 567         if (is_nvdimm_sync(nd_region))
 568                 set_dax_synchronous(dax_dev);
 569         rc = dax_add_host(dax_dev, disk);
 570         if (rc)
 571                 goto out_cleanup_dax;
 572         dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
 573         pmem->dax_dev = dax_dev;
 574
 575         rc = device_add_disk(dev, disk, pmem_attribute_groups);
 576         if (rc)
 577                 goto out_remove_host;
 578         if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
 579                 return -ENOMEM;
 580
 581         nvdimm_check_and_set_ro(disk);
 582
 583         pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd,
 584                                           "badblocks");
 585         if (!pmem->bb_state)
 586                 dev_warn(dev, "'badblocks' notification disabled\n");
 587         return 0;
 588
 589 out_remove_host:
 590         dax_remove_host(pmem->disk);
 591 out_cleanup_dax:
 592         kill_dax(pmem->dax_dev);
 593         put_dax(pmem->dax_dev);
 594 out:
 595         put_disk(pmem->disk);
 596         return rc;
 597 }
 598
 599 static int nd_pmem_probe(struct device *dev)
 600 {
 601         int ret;
 602         struct nd_namespace_common *ndns;
 603
 604         ndns = nvdimm_namespace_common_probe(dev);
 605         if (IS_ERR(ndns))
 606                 return PTR_ERR(ndns);
 607
 608         if (is_nd_btt(dev))
 609                 return nvdimm_namespace_attach_btt(ndns);
 610
 611         if (is_nd_pfn(dev))
 612                 return pmem_attach_disk(dev, ndns);
 613
 614         ret = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
 615         if (ret)
 616                 return ret;
 617
 618         ret = nd_btt_probe(dev, ndns);
 619         if (ret == 0)
 620                 return -ENXIO;
 621
 622         /*
 623          * We have two failure conditions here, there is no
 624          * info reserver block or we found a valid info reserve block
 625          * but failed to initialize the pfn superblock.
 626          *
 627          * For the first case consider namespace as a raw pmem namespace
 628          * and attach a disk.
 629          *
 630          * For the latter, consider this a success and advance the namespace
 631          * seed.
 632          */
 633         ret = nd_pfn_probe(dev, ndns);
 634         if (ret == 0)
 635                 return -ENXIO;
 636         else if (ret == -EOPNOTSUPP)
 637                 return ret;
 638
 639         ret = nd_dax_probe(dev, ndns);
 640         if (ret == 0)
 641                 return -ENXIO;
 642         else if (ret == -EOPNOTSUPP)
 643                 return ret;
 644
 645         /* probe complete, attach handles namespace enabling */
 646         devm_namespace_disable(dev, ndns);
 647
 648         return pmem_attach_disk(dev, ndns);
 649 }
 650
 651 static void nd_pmem_remove(struct device *dev)
 652 {
 653         struct pmem_device *pmem = dev_get_drvdata(dev);
 654
 655         if (is_nd_btt(dev))
 656                 nvdimm_namespace_detach_btt(to_nd_btt(dev));
 657         else {
 658                 /*
 659                  * Note, this assumes device_lock() context to not
 660                  * race nd_pmem_notify()
 661                  */
 662                 sysfs_put(pmem->bb_state);
 663                 pmem->bb_state = NULL;
 664         }
 665         nvdimm_flush(to_nd_region(dev->parent), NULL);
 666 }
 667
 668 static void nd_pmem_shutdown(struct device *dev)
 669 {
 670         nvdimm_flush(to_nd_region(dev->parent), NULL);
 671 }
 672
 673 static void pmem_revalidate_poison(struct device *dev)
 674 {
 675         struct nd_region *nd_region;
 676         resource_size_t offset = 0, end_trunc = 0;
 677         struct nd_namespace_common *ndns;
 678         struct nd_namespace_io *nsio;
 679         struct badblocks *bb;
 680         struct range range;
 681         struct kernfs_node *bb_state;
 682
 683         if (is_nd_btt(dev)) {
 684                 struct nd_btt *nd_btt = to_nd_btt(dev);
 685
 686                 ndns = nd_btt->ndns;
 687                 nd_region = to_nd_region(ndns->dev.parent);
 688                 nsio = to_nd_namespace_io(&ndns->dev);
 689                 bb = &nsio->bb;
 690                 bb_state = NULL;
 691         } else {
 692                 struct pmem_device *pmem = dev_get_drvdata(dev);
 693
 694                 nd_region = to_region(pmem);
 695                 bb = &pmem->bb;
 696                 bb_state = pmem->bb_state;
 697
 698                 if (is_nd_pfn(dev)) {
 699                         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
 700                         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 701
 702                         ndns = nd_pfn->ndns;
 703                         offset = pmem->data_offset +
 704                                         __le32_to_cpu(pfn_sb->start_pad);
 705                         end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
 706                 } else {
 707                         ndns = to_ndns(dev);
 708                 }
 709
 710                 nsio = to_nd_namespace_io(&ndns->dev);
 711         }
 712
 713         range.start = nsio->res.start + offset;
 714         range.end = nsio->res.end - end_trunc;
 715         nvdimm_badblocks_populate(nd_region, bb, &range);
 716         if (bb_state)
 717                 sysfs_notify_dirent(bb_state);
 718 }
 719
 720 static void pmem_revalidate_region(struct device *dev)
 721 {
 722         struct pmem_device *pmem;
 723
 724         if (is_nd_btt(dev)) {
 725                 struct nd_btt *nd_btt = to_nd_btt(dev);
 726                 struct btt *btt = nd_btt->btt;
 727
 728                 nvdimm_check_and_set_ro(btt->btt_disk);
 729                 return;
 730         }
 731
 732         pmem = dev_get_drvdata(dev);
 733         nvdimm_check_and_set_ro(pmem->disk);
 734 }
 735
 736 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
 737 {
 738         switch (event) {
 739         case NVDIMM_REVALIDATE_POISON:
 740                 pmem_revalidate_poison(dev);
 741                 break;
 742         case NVDIMM_REVALIDATE_REGION:
 743                 pmem_revalidate_region(dev);
 744                 break;
 745         default:
 746                 dev_WARN_ONCE(dev, 1, "notify: unknown event: %d\n", event);
 747                 break;
 748         }
 749 }
 750
 751 MODULE_ALIAS("pmem");
 752 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
 753 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
 754 static struct nd_device_driver nd_pmem_driver = {
 755         .probe = nd_pmem_probe,
 756         .remove = nd_pmem_remove,
 757         .notify = nd_pmem_notify,
 758         .shutdown = nd_pmem_shutdown,
 759         .drv = {
 760                 .name = "nd_pmem",
 761         },
 762         .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
 763 };
 764
 765 module_nd_driver(nd_pmem_driver);
 766
 767 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
 768 MODULE_LICENSE("GPL v2");