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                 /*
 107                  * Note that we write the data both before and after
 108                  * clearing poison.  The write before clear poison
 109                  * handles situations where the latest written data is
 110                  * preserved and the clear poison operation simply marks
 111                  * the address range as valid without changing the data.
 112                  * In this case application software can assume that an
 113                  * interrupted write will either return the new good
 114                  * data or an error.
 115                  *
 116                  * However, if pmem_clear_poison() leaves the data in an
 117                  * indeterminate state we need to perform the write
 118                  * after clear poison.
 119                  */
 120                 flush_dcache_page(page);
 121                 memcpy_to_pmem(pmem_addr, mem + off, len);
 122                 if (unlikely(bad_pmem)) {
 123                         pmem_clear_poison(pmem, pmem_off, len);
 124                         memcpy_to_pmem(pmem_addr, mem + off, len);
 125                 }
 126         }
 127
 128         kunmap_atomic(mem);
 129         return rc;
 130 }
 131
 132 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
 133 {
 134         int rc = 0;
 135         bool do_acct;
 136         unsigned long start;
 137         struct bio_vec bvec;
 138         struct bvec_iter iter;
 139         struct block_device *bdev = bio->bi_bdev;
 140         struct pmem_device *pmem = bdev->bd_disk->private_data;
 141
 142         do_acct = nd_iostat_start(bio, &start);
 143         bio_for_each_segment(bvec, bio, iter) {
 144                 rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
 145                                 bvec.bv_offset, bio_data_dir(bio),
 146                                 iter.bi_sector);
 147                 if (rc) {
 148                         bio->bi_error = rc;
 149                         break;
 150                 }
 151         }
 152         if (do_acct)
 153                 nd_iostat_end(bio, start);
 154
 155         if (bio_data_dir(bio))
 156                 wmb_pmem();
 157
 158         bio_endio(bio);
 159         return BLK_QC_T_NONE;
 160 }
 161
 162 static int pmem_rw_page(struct block_device *bdev, sector_t sector,
 163                        struct page *page, int rw)
 164 {
 165         struct pmem_device *pmem = bdev->bd_disk->private_data;
 166         int rc;
 167
 168         rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, rw, sector);
 169         if (rw & WRITE)
 170                 wmb_pmem();
 171
 172         /*
 173          * The ->rw_page interface is subtle and tricky.  The core
 174          * retries on any error, so we can only invoke page_endio() in
 175          * the successful completion case.  Otherwise, we'll see crashes
 176          * caused by double completion.
 177          */
 178         if (rc == 0)
 179                 page_endio(page, rw & WRITE, 0);
 180
 181         return rc;
 182 }
 183
 184 static long pmem_direct_access(struct block_device *bdev, sector_t sector,
 185                       void __pmem **kaddr, pfn_t *pfn)
 186 {
 187         struct pmem_device *pmem = bdev->bd_disk->private_data;
 188         resource_size_t offset = sector * 512 + pmem->data_offset;
 189
 190         *kaddr = pmem->virt_addr + offset;
 191         *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
 192
 193         return pmem->size - pmem->pfn_pad - offset;
 194 }
 195
 196 static const struct block_device_operations pmem_fops = {
 197         .owner =                THIS_MODULE,
 198         .rw_page =              pmem_rw_page,
 199         .direct_access =        pmem_direct_access,
 200         .revalidate_disk =      nvdimm_revalidate_disk,
 201 };
 202
 203 static struct pmem_device *pmem_alloc(struct device *dev,
 204                 struct resource *res, int id)
 205 {
 206         struct pmem_device *pmem;
 207         struct request_queue *q;
 208
 209         pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
 210         if (!pmem)
 211                 return ERR_PTR(-ENOMEM);
 212
 213         pmem->phys_addr = res->start;
 214         pmem->size = resource_size(res);
 215         if (!arch_has_wmb_pmem())
 216                 dev_warn(dev, "unable to guarantee persistence of writes\n");
 217
 218         if (!devm_request_mem_region(dev, pmem->phys_addr, pmem->size,
 219                         dev_name(dev))) {
 220                 dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n",
 221                                 &pmem->phys_addr, pmem->size);
 222                 return ERR_PTR(-EBUSY);
 223         }
 224
 225         q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
 226         if (!q)
 227                 return ERR_PTR(-ENOMEM);
 228
 229         pmem->pfn_flags = PFN_DEV;
 230         if (pmem_should_map_pages(dev)) {
 231                 pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, res,
 232                                 &q->q_usage_counter, NULL);
 233                 pmem->pfn_flags |= PFN_MAP;
 234         } else
 235                 pmem->virt_addr = (void __pmem *) devm_memremap(dev,
 236                                 pmem->phys_addr, pmem->size,
 237                                 ARCH_MEMREMAP_PMEM);
 238
 239         if (IS_ERR(pmem->virt_addr)) {
 240                 blk_cleanup_queue(q);
 241                 return (void __force *) pmem->virt_addr;
 242         }
 243
 244         pmem->pmem_queue = q;
 245         return pmem;
 246 }
 247
 248 static void pmem_detach_disk(struct pmem_device *pmem)
 249 {
 250         if (!pmem->pmem_disk)
 251                 return;
 252
 253         del_gendisk(pmem->pmem_disk);
 254         put_disk(pmem->pmem_disk);
 255         blk_cleanup_queue(pmem->pmem_queue);
 256 }
 257
 258 static int pmem_attach_disk(struct device *dev,
 259                 struct nd_namespace_common *ndns, struct pmem_device *pmem)
 260 {
 261         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 262         int nid = dev_to_node(dev);
 263         struct resource bb_res;
 264         struct gendisk *disk;
 265
 266         blk_queue_make_request(pmem->pmem_queue, pmem_make_request);
 267         blk_queue_physical_block_size(pmem->pmem_queue, PAGE_SIZE);
 268         blk_queue_max_hw_sectors(pmem->pmem_queue, UINT_MAX);
 269         blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY);
 270         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, pmem->pmem_queue);
 271
 272         disk = alloc_disk_node(0, nid);
 273         if (!disk) {
 274                 blk_cleanup_queue(pmem->pmem_queue);
 275                 return -ENOMEM;
 276         }
 277
 278         disk->fops              = &pmem_fops;
 279         disk->private_data      = pmem;
 280         disk->queue             = pmem->pmem_queue;
 281         disk->flags             = GENHD_FL_EXT_DEVT;
 282         nvdimm_namespace_disk_name(ndns, disk->disk_name);
 283         disk->driverfs_dev = dev;
 284         set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
 285                         / 512);
 286         pmem->pmem_disk = disk;
 287         devm_exit_badblocks(dev, &pmem->bb);
 288         if (devm_init_badblocks(dev, &pmem->bb))
 289                 return -ENOMEM;
 290         bb_res.start = nsio->res.start + pmem->data_offset;
 291         bb_res.end = nsio->res.end;
 292         if (is_nd_pfn(dev)) {
 293                 struct nd_pfn *nd_pfn = to_nd_pfn(dev);
 294                 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 295
 296                 bb_res.start += __le32_to_cpu(pfn_sb->start_pad);
 297                 bb_res.end -= __le32_to_cpu(pfn_sb->end_trunc);
 298         }
 299         nvdimm_badblocks_populate(to_nd_region(dev->parent), &pmem->bb,
 300                         &bb_res);
 301         disk->bb = &pmem->bb;
 302         add_disk(disk);
 303         revalidate_disk(disk);
 304
 305         return 0;
 306 }
 307
 308 static int pmem_rw_bytes(struct nd_namespace_common *ndns,
 309                 resource_size_t offset, void *buf, size_t size, int rw)
 310 {
 311         struct pmem_device *pmem = dev_get_drvdata(ndns->claim);
 312
 313         if (unlikely(offset + size > pmem->size)) {
 314                 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
 315                 return -EFAULT;
 316         }
 317
 318         if (rw == READ) {
 319                 unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
 320
 321                 if (unlikely(is_bad_pmem(&pmem->bb, offset / 512, sz_align)))
 322                         return -EIO;
 323                 return memcpy_from_pmem(buf, pmem->virt_addr + offset, size);
 324         } else {
 325                 memcpy_to_pmem(pmem->virt_addr + offset, buf, size);
 326                 wmb_pmem();
 327         }
 328
 329         return 0;
 330 }
 331
 332 static int nd_pfn_init(struct nd_pfn *nd_pfn)
 333 {
 334         struct nd_pfn_sb *pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
 335         struct pmem_device *pmem = dev_get_drvdata(&nd_pfn->dev);
 336         struct nd_namespace_common *ndns = nd_pfn->ndns;
 337         u32 start_pad = 0, end_trunc = 0;
 338         resource_size_t start, size;
 339         struct nd_namespace_io *nsio;
 340         struct nd_region *nd_region;
 341         unsigned long npfns;
 342         phys_addr_t offset;
 343         u64 checksum;
 344         int rc;
 345
 346         if (!pfn_sb)
 347                 return -ENOMEM;
 348
 349         nd_pfn->pfn_sb = pfn_sb;
 350         rc = nd_pfn_validate(nd_pfn);
 351         if (rc == -ENODEV)
 352                 /* no info block, do init */;
 353         else
 354                 return rc;
 355
 356         nd_region = to_nd_region(nd_pfn->dev.parent);
 357         if (nd_region->ro) {
 358                 dev_info(&nd_pfn->dev,
 359                                 "%s is read-only, unable to init metadata\n",
 360                                 dev_name(&nd_region->dev));
 361                 goto err;
 362         }
 363
 364         memset(pfn_sb, 0, sizeof(*pfn_sb));
 365
 366         /*
 367          * Check if pmem collides with 'System RAM' when section aligned and
 368          * trim it accordingly
 369          */
 370         nsio = to_nd_namespace_io(&ndns->dev);
 371         start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start);
 372         size = resource_size(&nsio->res);
 373         if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
 374                                 IORES_DESC_NONE) == REGION_MIXED) {
 375
 376                 start = nsio->res.start;
 377                 start_pad = PHYS_SECTION_ALIGN_UP(start) - start;
 378         }
 379
 380         start = nsio->res.start;
 381         size = PHYS_SECTION_ALIGN_UP(start + size) - start;
 382         if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
 383                                 IORES_DESC_NONE) == REGION_MIXED) {
 384                 size = resource_size(&nsio->res);
 385                 end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size);
 386         }
 387
 388         if (start_pad + end_trunc)
 389                 dev_info(&nd_pfn->dev, "%s section collision, truncate %d bytes\n",
 390                                 dev_name(&ndns->dev), start_pad + end_trunc);
 391
 392         /*
 393          * Note, we use 64 here for the standard size of struct page,
 394          * debugging options may cause it to be larger in which case the
 395          * implementation will limit the pfns advertised through
 396          * ->direct_access() to those that are included in the memmap.
 397          */
 398         start += start_pad;
 399         npfns = (pmem->size - start_pad - end_trunc - SZ_8K) / SZ_4K;
 400         if (nd_pfn->mode == PFN_MODE_PMEM) {
 401                 unsigned long memmap_size;
 402
 403                 /*
 404                  * vmemmap_populate_hugepages() allocates the memmap array in
 405                  * HPAGE_SIZE chunks.
 406                  */
 407                 memmap_size = ALIGN(64 * npfns, HPAGE_SIZE);
 408                 offset = ALIGN(start + SZ_8K + memmap_size, nd_pfn->align)
 409                         - start;
 410         } else if (nd_pfn->mode == PFN_MODE_RAM)
 411                 offset = ALIGN(start + SZ_8K, nd_pfn->align) - start;
 412         else
 413                 goto err;
 414
 415         if (offset + start_pad + end_trunc >= pmem->size) {
 416                 dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
 417                                 dev_name(&ndns->dev));
 418                 goto err;
 419         }
 420
 421         npfns = (pmem->size - offset - start_pad - end_trunc) / SZ_4K;
 422         pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
 423         pfn_sb->dataoff = cpu_to_le64(offset);
 424         pfn_sb->npfns = cpu_to_le64(npfns);
 425         memcpy(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN);
 426         memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
 427         memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
 428         pfn_sb->version_major = cpu_to_le16(1);
 429         pfn_sb->version_minor = cpu_to_le16(1);
 430         pfn_sb->start_pad = cpu_to_le32(start_pad);
 431         pfn_sb->end_trunc = cpu_to_le32(end_trunc);
 432         checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
 433         pfn_sb->checksum = cpu_to_le64(checksum);
 434
 435         rc = nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb));
 436         if (rc)
 437                 goto err;
 438
 439         return 0;
 440  err:
 441         nd_pfn->pfn_sb = NULL;
 442         kfree(pfn_sb);
 443         return -ENXIO;
 444 }
 445
 446 static int nvdimm_namespace_detach_pfn(struct nd_namespace_common *ndns)
 447 {
 448         struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
 449         struct pmem_device *pmem;
 450
 451         /* free pmem disk */
 452         pmem = dev_get_drvdata(&nd_pfn->dev);
 453         pmem_detach_disk(pmem);
 454
 455         /* release nd_pfn resources */
 456         kfree(nd_pfn->pfn_sb);
 457         nd_pfn->pfn_sb = NULL;
 458
 459         return 0;
 460 }
 461
 462 /*
 463  * We hotplug memory at section granularity, pad the reserved area from
 464  * the previous section base to the namespace base address.
 465  */
 466 static unsigned long init_altmap_base(resource_size_t base)
 467 {
 468         unsigned long base_pfn = PHYS_PFN(base);
 469
 470         return PFN_SECTION_ALIGN_DOWN(base_pfn);
 471 }
 472
 473 static unsigned long init_altmap_reserve(resource_size_t base)
 474 {
 475         unsigned long reserve = PHYS_PFN(SZ_8K);
 476         unsigned long base_pfn = PHYS_PFN(base);
 477
 478         reserve += base_pfn - PFN_SECTION_ALIGN_DOWN(base_pfn);
 479         return reserve;
 480 }
 481
 482 static int __nvdimm_namespace_attach_pfn(struct nd_pfn *nd_pfn)
 483 {
 484         int rc;
 485         struct resource res;
 486         struct request_queue *q;
 487         struct pmem_device *pmem;
 488         struct vmem_altmap *altmap;
 489         struct device *dev = &nd_pfn->dev;
 490         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 491         struct nd_namespace_common *ndns = nd_pfn->ndns;
 492         u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
 493         u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
 494         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 495         resource_size_t base = nsio->res.start + start_pad;
 496         struct vmem_altmap __altmap = {
 497                 .base_pfn = init_altmap_base(base),
 498                 .reserve = init_altmap_reserve(base),
 499         };
 500
 501         pmem = dev_get_drvdata(dev);
 502         pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
 503         pmem->pfn_pad = start_pad + end_trunc;
 504         nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
 505         if (nd_pfn->mode == PFN_MODE_RAM) {
 506                 if (pmem->data_offset < SZ_8K)
 507                         return -EINVAL;
 508                 nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
 509                 altmap = NULL;
 510         } else if (nd_pfn->mode == PFN_MODE_PMEM) {
 511                 nd_pfn->npfns = (pmem->size - pmem->pfn_pad - pmem->data_offset)
 512                         / PAGE_SIZE;
 513                 if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
 514                         dev_info(&nd_pfn->dev,
 515                                         "number of pfns truncated from %lld to %ld\n",
 516                                         le64_to_cpu(nd_pfn->pfn_sb->npfns),
 517                                         nd_pfn->npfns);
 518                 altmap = & __altmap;
 519                 altmap->free = PHYS_PFN(pmem->data_offset - SZ_8K);
 520                 altmap->alloc = 0;
 521         } else {
 522                 rc = -ENXIO;
 523                 goto err;
 524         }
 525
 526         /* establish pfn range for lookup, and switch to direct map */
 527         q = pmem->pmem_queue;
 528         memcpy(&res, &nsio->res, sizeof(res));
 529         res.start += start_pad;
 530         res.end -= end_trunc;
 531         devm_memunmap(dev, (void __force *) pmem->virt_addr);
 532         pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, &res,
 533                         &q->q_usage_counter, altmap);
 534         pmem->pfn_flags |= PFN_MAP;
 535         if (IS_ERR(pmem->virt_addr)) {
 536                 rc = PTR_ERR(pmem->virt_addr);
 537                 goto err;
 538         }
 539
 540         /* attach pmem disk in "pfn-mode" */
 541         rc = pmem_attach_disk(dev, ndns, pmem);
 542         if (rc)
 543                 goto err;
 544
 545         return rc;
 546  err:
 547         nvdimm_namespace_detach_pfn(ndns);
 548         return rc;
 549
 550 }
 551
 552 static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
 553 {
 554         struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
 555         int rc;
 556
 557         if (!nd_pfn->uuid || !nd_pfn->ndns)
 558                 return -ENODEV;
 559
 560         rc = nd_pfn_init(nd_pfn);
 561         if (rc)
 562                 return rc;
 563         /* we need a valid pfn_sb before we can init a vmem_altmap */
 564         return __nvdimm_namespace_attach_pfn(nd_pfn);
 565 }
 566
 567 static int nd_pmem_probe(struct device *dev)
 568 {
 569         struct nd_region *nd_region = to_nd_region(dev->parent);
 570         struct nd_namespace_common *ndns;
 571         struct nd_namespace_io *nsio;
 572         struct pmem_device *pmem;
 573
 574         ndns = nvdimm_namespace_common_probe(dev);
 575         if (IS_ERR(ndns))
 576                 return PTR_ERR(ndns);
 577
 578         nsio = to_nd_namespace_io(&ndns->dev);
 579         pmem = pmem_alloc(dev, &nsio->res, nd_region->id);
 580         if (IS_ERR(pmem))
 581                 return PTR_ERR(pmem);
 582
 583         pmem->ndns = ndns;
 584         dev_set_drvdata(dev, pmem);
 585         ndns->rw_bytes = pmem_rw_bytes;
 586         if (devm_init_badblocks(dev, &pmem->bb))
 587                 return -ENOMEM;
 588         nvdimm_badblocks_populate(nd_region, &pmem->bb, &nsio->res);
 589
 590         if (is_nd_btt(dev)) {
 591                 /* btt allocates its own request_queue */
 592                 blk_cleanup_queue(pmem->pmem_queue);
 593                 pmem->pmem_queue = NULL;
 594                 return nvdimm_namespace_attach_btt(ndns);
 595         }
 596
 597         if (is_nd_pfn(dev))
 598                 return nvdimm_namespace_attach_pfn(ndns);
 599
 600         if (nd_btt_probe(ndns, pmem) == 0 || nd_pfn_probe(ndns, pmem) == 0) {
 601                 /*
 602                  * We'll come back as either btt-pmem, or pfn-pmem, so
 603                  * drop the queue allocation for now.
 604                  */
 605                 blk_cleanup_queue(pmem->pmem_queue);
 606                 return -ENXIO;
 607         }
 608
 609         return pmem_attach_disk(dev, ndns, pmem);
 610 }
 611
 612 static int nd_pmem_remove(struct device *dev)
 613 {
 614         struct pmem_device *pmem = dev_get_drvdata(dev);
 615
 616         if (is_nd_btt(dev))
 617                 nvdimm_namespace_detach_btt(pmem->ndns);
 618         else if (is_nd_pfn(dev))
 619                 nvdimm_namespace_detach_pfn(pmem->ndns);
 620         else
 621                 pmem_detach_disk(pmem);
 622
 623         return 0;
 624 }
 625
 626 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
 627 {
 628         struct pmem_device *pmem = dev_get_drvdata(dev);
 629         struct nd_namespace_common *ndns = pmem->ndns;
 630         struct nd_region *nd_region = to_nd_region(dev->parent);
 631         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 632         struct resource res = {
 633                 .start = nsio->res.start + pmem->data_offset,
 634                 .end = nsio->res.end,
 635         };
 636
 637         if (event != NVDIMM_REVALIDATE_POISON)
 638                 return;
 639
 640         if (is_nd_pfn(dev)) {
 641                 struct nd_pfn *nd_pfn = to_nd_pfn(dev);
 642                 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 643
 644                 res.start += __le32_to_cpu(pfn_sb->start_pad);
 645                 res.end -= __le32_to_cpu(pfn_sb->end_trunc);
 646         }
 647
 648         nvdimm_badblocks_populate(nd_region, &pmem->bb, &res);
 649 }
 650
 651 MODULE_ALIAS("pmem");
 652 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
 653 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
 654 static struct nd_device_driver nd_pmem_driver = {
 655         .probe = nd_pmem_probe,
 656         .remove = nd_pmem_remove,
 657         .notify = nd_pmem_notify,
 658         .drv = {
 659                 .name = "nd_pmem",
 660         },
 661         .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
 662 };
 663
 664 static int __init pmem_init(void)
 665 {
 666         return nd_driver_register(&nd_pmem_driver);
 667 }
 668 module_init(pmem_init);
 669
 670 static void pmem_exit(void)
 671 {
 672         driver_unregister(&nd_pmem_driver.drv);
 673 }
 674 module_exit(pmem_exit);
 675
 676 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
 677 MODULE_LICENSE("GPL v2");