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