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