drivers/nvdimm/pfn_devs.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright(c) 2013-2016 Intel Corporation. All rights reserved.
   4  */
   5 #include <linux/memremap.h>
   6 #include <linux/blkdev.h>
   7 #include <linux/device.h>
   8 #include <linux/sizes.h>
   9 #include <linux/slab.h>
  10 #include <linux/fs.h>
  11 #include <linux/mm.h>
  12 #include "nd-core.h"
  13 #include "pfn.h"
  14 #include "nd.h"
  15
  16 static const bool page_struct_override = IS_ENABLED(CONFIG_NVDIMM_KMSAN);
  17
  18 static void nd_pfn_release(struct device *dev)
  19 {
  20         struct nd_region *nd_region = to_nd_region(dev->parent);
  21         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
  22
  23         dev_dbg(dev, "trace\n");
  24         nd_detach_ndns(&nd_pfn->dev, &nd_pfn->ndns);
  25         ida_simple_remove(&nd_region->pfn_ida, nd_pfn->id);
  26         kfree(nd_pfn->uuid);
  27         kfree(nd_pfn);
  28 }
  29
  30 struct nd_pfn *to_nd_pfn(struct device *dev)
  31 {
  32         struct nd_pfn *nd_pfn = container_of(dev, struct nd_pfn, dev);
  33
  34         WARN_ON(!is_nd_pfn(dev));
  35         return nd_pfn;
  36 }
  37 EXPORT_SYMBOL(to_nd_pfn);
  38
  39 static ssize_t mode_show(struct device *dev,
  40                 struct device_attribute *attr, char *buf)
  41 {
  42         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
  43
  44         switch (nd_pfn->mode) {
  45         case PFN_MODE_RAM:
  46                 return sprintf(buf, "ram\n");
  47         case PFN_MODE_PMEM:
  48                 return sprintf(buf, "pmem\n");
  49         default:
  50                 return sprintf(buf, "none\n");
  51         }
  52 }
  53
  54 static ssize_t mode_store(struct device *dev,
  55                 struct device_attribute *attr, const char *buf, size_t len)
  56 {
  57         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
  58         ssize_t rc = 0;
  59
  60         device_lock(dev);
  61         nvdimm_bus_lock(dev);
  62         if (dev->driver)
  63                 rc = -EBUSY;
  64         else {
  65                 size_t n = len - 1;
  66
  67                 if (strncmp(buf, "pmem\n", n) == 0
  68                                 || strncmp(buf, "pmem", n) == 0) {
  69                         nd_pfn->mode = PFN_MODE_PMEM;
  70                 } else if (strncmp(buf, "ram\n", n) == 0
  71                                 || strncmp(buf, "ram", n) == 0)
  72                         nd_pfn->mode = PFN_MODE_RAM;
  73                 else if (strncmp(buf, "none\n", n) == 0
  74                                 || strncmp(buf, "none", n) == 0)
  75                         nd_pfn->mode = PFN_MODE_NONE;
  76                 else
  77                         rc = -EINVAL;
  78         }
  79         dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
  80                         buf[len - 1] == '\n' ? "" : "\n");
  81         nvdimm_bus_unlock(dev);
  82         device_unlock(dev);
  83
  84         return rc ? rc : len;
  85 }
  86 static DEVICE_ATTR_RW(mode);
  87
  88 static ssize_t align_show(struct device *dev,
  89                 struct device_attribute *attr, char *buf)
  90 {
  91         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
  92
  93         return sprintf(buf, "%ld\n", nd_pfn->align);
  94 }
  95
  96 static unsigned long *nd_pfn_supported_alignments(unsigned long *alignments)
  97 {
  98
  99         alignments[0] = PAGE_SIZE;
 100
 101         if (has_transparent_hugepage()) {
 102                 alignments[1] = HPAGE_PMD_SIZE;
 103                 if (IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD))
 104                         alignments[2] = HPAGE_PUD_SIZE;
 105         }
 106
 107         return alignments;
 108 }
 109
 110 /*
 111  * Use pmd mapping if supported as default alignment
 112  */
 113 static unsigned long nd_pfn_default_alignment(void)
 114 {
 115
 116         if (has_transparent_hugepage())
 117                 return HPAGE_PMD_SIZE;
 118         return PAGE_SIZE;
 119 }
 120
 121 static ssize_t align_store(struct device *dev,
 122                 struct device_attribute *attr, const char *buf, size_t len)
 123 {
 124         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 125         unsigned long aligns[MAX_NVDIMM_ALIGN] = { [0] = 0, };
 126         ssize_t rc;
 127
 128         device_lock(dev);
 129         nvdimm_bus_lock(dev);
 130         rc = nd_size_select_store(dev, buf, &nd_pfn->align,
 131                         nd_pfn_supported_alignments(aligns));
 132         dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
 133                         buf[len - 1] == '\n' ? "" : "\n");
 134         nvdimm_bus_unlock(dev);
 135         device_unlock(dev);
 136
 137         return rc ? rc : len;
 138 }
 139 static DEVICE_ATTR_RW(align);
 140
 141 static ssize_t uuid_show(struct device *dev,
 142                 struct device_attribute *attr, char *buf)
 143 {
 144         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 145
 146         if (nd_pfn->uuid)
 147                 return sprintf(buf, "%pUb\n", nd_pfn->uuid);
 148         return sprintf(buf, "\n");
 149 }
 150
 151 static ssize_t uuid_store(struct device *dev,
 152                 struct device_attribute *attr, const char *buf, size_t len)
 153 {
 154         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 155         ssize_t rc;
 156
 157         device_lock(dev);
 158         rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len);
 159         dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
 160                         buf[len - 1] == '\n' ? "" : "\n");
 161         device_unlock(dev);
 162
 163         return rc ? rc : len;
 164 }
 165 static DEVICE_ATTR_RW(uuid);
 166
 167 static ssize_t namespace_show(struct device *dev,
 168                 struct device_attribute *attr, char *buf)
 169 {
 170         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 171         ssize_t rc;
 172
 173         nvdimm_bus_lock(dev);
 174         rc = sprintf(buf, "%s\n", nd_pfn->ndns
 175                         ? dev_name(&nd_pfn->ndns->dev) : "");
 176         nvdimm_bus_unlock(dev);
 177         return rc;
 178 }
 179
 180 static ssize_t namespace_store(struct device *dev,
 181                 struct device_attribute *attr, const char *buf, size_t len)
 182 {
 183         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 184         ssize_t rc;
 185
 186         device_lock(dev);
 187         nvdimm_bus_lock(dev);
 188         rc = nd_namespace_store(dev, &nd_pfn->ndns, buf, len);
 189         dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
 190                         buf[len - 1] == '\n' ? "" : "\n");
 191         nvdimm_bus_unlock(dev);
 192         device_unlock(dev);
 193
 194         return rc;
 195 }
 196 static DEVICE_ATTR_RW(namespace);
 197
 198 static ssize_t resource_show(struct device *dev,
 199                 struct device_attribute *attr, char *buf)
 200 {
 201         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 202         ssize_t rc;
 203
 204         device_lock(dev);
 205         if (dev->driver) {
 206                 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 207                 u64 offset = __le64_to_cpu(pfn_sb->dataoff);
 208                 struct nd_namespace_common *ndns = nd_pfn->ndns;
 209                 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
 210                 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 211
 212                 rc = sprintf(buf, "%#llx\n", (unsigned long long) nsio->res.start
 213                                 + start_pad + offset);
 214         } else {
 215                 /* no address to convey if the pfn instance is disabled */
 216                 rc = -ENXIO;
 217         }
 218         device_unlock(dev);
 219
 220         return rc;
 221 }
 222 static DEVICE_ATTR_ADMIN_RO(resource);
 223
 224 static ssize_t size_show(struct device *dev,
 225                 struct device_attribute *attr, char *buf)
 226 {
 227         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 228         ssize_t rc;
 229
 230         device_lock(dev);
 231         if (dev->driver) {
 232                 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 233                 u64 offset = __le64_to_cpu(pfn_sb->dataoff);
 234                 struct nd_namespace_common *ndns = nd_pfn->ndns;
 235                 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
 236                 u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
 237                 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 238
 239                 rc = sprintf(buf, "%llu\n", (unsigned long long)
 240                                 resource_size(&nsio->res) - start_pad
 241                                 - end_trunc - offset);
 242         } else {
 243                 /* no size to convey if the pfn instance is disabled */
 244                 rc = -ENXIO;
 245         }
 246         device_unlock(dev);
 247
 248         return rc;
 249 }
 250 static DEVICE_ATTR_RO(size);
 251
 252 static ssize_t supported_alignments_show(struct device *dev,
 253                 struct device_attribute *attr, char *buf)
 254 {
 255         unsigned long aligns[MAX_NVDIMM_ALIGN] = { [0] = 0, };
 256
 257         return nd_size_select_show(0,
 258                         nd_pfn_supported_alignments(aligns), buf);
 259 }
 260 static DEVICE_ATTR_RO(supported_alignments);
 261
 262 static struct attribute *nd_pfn_attributes[] = {
 263         &dev_attr_mode.attr,
 264         &dev_attr_namespace.attr,
 265         &dev_attr_uuid.attr,
 266         &dev_attr_align.attr,
 267         &dev_attr_resource.attr,
 268         &dev_attr_size.attr,
 269         &dev_attr_supported_alignments.attr,
 270         NULL,
 271 };
 272
 273 static struct attribute_group nd_pfn_attribute_group = {
 274         .attrs = nd_pfn_attributes,
 275 };
 276
 277 const struct attribute_group *nd_pfn_attribute_groups[] = {
 278         &nd_pfn_attribute_group,
 279         &nd_device_attribute_group,
 280         &nd_numa_attribute_group,
 281         NULL,
 282 };
 283
 284 static const struct device_type nd_pfn_device_type = {
 285         .name = "nd_pfn",
 286         .release = nd_pfn_release,
 287         .groups = nd_pfn_attribute_groups,
 288 };
 289
 290 bool is_nd_pfn(struct device *dev)
 291 {
 292         return dev ? dev->type == &nd_pfn_device_type : false;
 293 }
 294 EXPORT_SYMBOL(is_nd_pfn);
 295
 296 static struct lock_class_key nvdimm_pfn_key;
 297
 298 struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
 299                 struct nd_namespace_common *ndns)
 300 {
 301         struct device *dev;
 302
 303         if (!nd_pfn)
 304                 return NULL;
 305
 306         nd_pfn->mode = PFN_MODE_NONE;
 307         nd_pfn->align = nd_pfn_default_alignment();
 308         dev = &nd_pfn->dev;
 309         device_initialize(&nd_pfn->dev);
 310         lockdep_set_class(&nd_pfn->dev.mutex, &nvdimm_pfn_key);
 311         if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
 312                 dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
 313                                 dev_name(ndns->claim));
 314                 put_device(dev);
 315                 return NULL;
 316         }
 317         return dev;
 318 }
 319
 320 static struct nd_pfn *nd_pfn_alloc(struct nd_region *nd_region)
 321 {
 322         struct nd_pfn *nd_pfn;
 323         struct device *dev;
 324
 325         nd_pfn = kzalloc(sizeof(*nd_pfn), GFP_KERNEL);
 326         if (!nd_pfn)
 327                 return NULL;
 328
 329         nd_pfn->id = ida_simple_get(&nd_region->pfn_ida, 0, 0, GFP_KERNEL);
 330         if (nd_pfn->id < 0) {
 331                 kfree(nd_pfn);
 332                 return NULL;
 333         }
 334
 335         dev = &nd_pfn->dev;
 336         dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
 337         dev->type = &nd_pfn_device_type;
 338         dev->parent = &nd_region->dev;
 339
 340         return nd_pfn;
 341 }
 342
 343 struct device *nd_pfn_create(struct nd_region *nd_region)
 344 {
 345         struct nd_pfn *nd_pfn;
 346         struct device *dev;
 347
 348         if (!is_memory(&nd_region->dev))
 349                 return NULL;
 350
 351         nd_pfn = nd_pfn_alloc(nd_region);
 352         dev = nd_pfn_devinit(nd_pfn, NULL);
 353
 354         nd_device_register(dev);
 355         return dev;
 356 }
 357
 358 /*
 359  * nd_pfn_clear_memmap_errors() clears any errors in the volatile memmap
 360  * space associated with the namespace. If the memmap is set to DRAM, then
 361  * this is a no-op. Since the memmap area is freshly initialized during
 362  * probe, we have an opportunity to clear any badblocks in this area.
 363  */
 364 static int nd_pfn_clear_memmap_errors(struct nd_pfn *nd_pfn)
 365 {
 366         struct nd_region *nd_region = to_nd_region(nd_pfn->dev.parent);
 367         struct nd_namespace_common *ndns = nd_pfn->ndns;
 368         void *zero_page = page_address(ZERO_PAGE(0));
 369         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 370         int num_bad, meta_num, rc, bb_present;
 371         sector_t first_bad, meta_start;
 372         struct nd_namespace_io *nsio;
 373
 374         if (nd_pfn->mode != PFN_MODE_PMEM)
 375                 return 0;
 376
 377         nsio = to_nd_namespace_io(&ndns->dev);
 378         meta_start = (SZ_4K + sizeof(*pfn_sb)) >> 9;
 379         meta_num = (le64_to_cpu(pfn_sb->dataoff) >> 9) - meta_start;
 380
 381         /*
 382          * re-enable the namespace with correct size so that we can access
 383          * the device memmap area.
 384          */
 385         devm_namespace_disable(&nd_pfn->dev, ndns);
 386         rc = devm_namespace_enable(&nd_pfn->dev, ndns, le64_to_cpu(pfn_sb->dataoff));
 387         if (rc)
 388                 return rc;
 389
 390         do {
 391                 unsigned long zero_len;
 392                 u64 nsoff;
 393
 394                 bb_present = badblocks_check(&nd_region->bb, meta_start,
 395                                 meta_num, &first_bad, &num_bad);
 396                 if (bb_present) {
 397                         dev_dbg(&nd_pfn->dev, "meta: %x badblocks at %llx\n",
 398                                         num_bad, first_bad);
 399                         nsoff = ALIGN_DOWN((nd_region->ndr_start
 400                                         + (first_bad << 9)) - nsio->res.start,
 401                                         PAGE_SIZE);
 402                         zero_len = ALIGN(num_bad << 9, PAGE_SIZE);
 403                         while (zero_len) {
 404                                 unsigned long chunk = min(zero_len, PAGE_SIZE);
 405
 406                                 rc = nvdimm_write_bytes(ndns, nsoff, zero_page,
 407                                                         chunk, 0);
 408                                 if (rc)
 409                                         break;
 410
 411                                 zero_len -= chunk;
 412                                 nsoff += chunk;
 413                         }
 414                         if (rc) {
 415                                 dev_err(&nd_pfn->dev,
 416                                         "error clearing %x badblocks at %llx\n",
 417                                         num_bad, first_bad);
 418                                 return rc;
 419                         }
 420                 }
 421         } while (bb_present);
 422
 423         return 0;
 424 }
 425
 426 static bool nd_supported_alignment(unsigned long align)
 427 {
 428         int i;
 429         unsigned long supported[MAX_NVDIMM_ALIGN] = { [0] = 0, };
 430
 431         if (align == 0)
 432                 return false;
 433
 434         nd_pfn_supported_alignments(supported);
 435         for (i = 0; supported[i]; i++)
 436                 if (align == supported[i])
 437                         return true;
 438         return false;
 439 }
 440
 441 /**
 442  * nd_pfn_validate - read and validate info-block
 443  * @nd_pfn: fsdax namespace runtime state / properties
 444  * @sig: 'devdax' or 'fsdax' signature
 445  *
 446  * Upon return the info-block buffer contents (->pfn_sb) are
 447  * indeterminate when validation fails, and a coherent info-block
 448  * otherwise.
 449  */
 450 int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
 451 {
 452         u64 checksum, offset;
 453         struct resource *res;
 454         enum nd_pfn_mode mode;
 455         struct nd_namespace_io *nsio;
 456         unsigned long align, start_pad;
 457         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 458         struct nd_namespace_common *ndns = nd_pfn->ndns;
 459         const uuid_t *parent_uuid = nd_dev_to_uuid(&ndns->dev);
 460
 461         if (!pfn_sb || !ndns)
 462                 return -ENODEV;
 463
 464         if (!is_memory(nd_pfn->dev.parent))
 465                 return -ENODEV;
 466
 467         if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0))
 468                 return -ENXIO;
 469
 470         if (memcmp(pfn_sb->signature, sig, PFN_SIG_LEN) != 0)
 471                 return -ENODEV;
 472
 473         checksum = le64_to_cpu(pfn_sb->checksum);
 474         pfn_sb->checksum = 0;
 475         if (checksum != nd_sb_checksum((struct nd_gen_sb *) pfn_sb))
 476                 return -ENODEV;
 477         pfn_sb->checksum = cpu_to_le64(checksum);
 478
 479         if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
 480                 return -ENODEV;
 481
 482         if (__le16_to_cpu(pfn_sb->version_minor) < 1) {
 483                 pfn_sb->start_pad = 0;
 484                 pfn_sb->end_trunc = 0;
 485         }
 486
 487         if (__le16_to_cpu(pfn_sb->version_minor) < 2)
 488                 pfn_sb->align = 0;
 489
 490         if (__le16_to_cpu(pfn_sb->version_minor) < 4) {
 491                 pfn_sb->page_struct_size = cpu_to_le16(64);
 492                 pfn_sb->page_size = cpu_to_le32(PAGE_SIZE);
 493         }
 494
 495         switch (le32_to_cpu(pfn_sb->mode)) {
 496         case PFN_MODE_RAM:
 497         case PFN_MODE_PMEM:
 498                 break;
 499         default:
 500                 return -ENXIO;
 501         }
 502
 503         align = le32_to_cpu(pfn_sb->align);
 504         offset = le64_to_cpu(pfn_sb->dataoff);
 505         start_pad = le32_to_cpu(pfn_sb->start_pad);
 506         if (align == 0)
 507                 align = 1UL << ilog2(offset);
 508         mode = le32_to_cpu(pfn_sb->mode);
 509
 510         if ((le32_to_cpu(pfn_sb->page_size) > PAGE_SIZE) &&
 511                         (mode == PFN_MODE_PMEM)) {
 512                 dev_err(&nd_pfn->dev,
 513                                 "init failed, page size mismatch %d\n",
 514                                 le32_to_cpu(pfn_sb->page_size));
 515                 return -EOPNOTSUPP;
 516         }
 517
 518         if ((le16_to_cpu(pfn_sb->page_struct_size) < sizeof(struct page)) &&
 519                         (mode == PFN_MODE_PMEM)) {
 520                 dev_err(&nd_pfn->dev,
 521                                 "init failed, struct page size mismatch %d\n",
 522                                 le16_to_cpu(pfn_sb->page_struct_size));
 523                 return -EOPNOTSUPP;
 524         }
 525
 526         /*
 527          * Check whether the we support the alignment. For Dax if the
 528          * superblock alignment is not matching, we won't initialize
 529          * the device.
 530          */
 531         if (!nd_supported_alignment(align) &&
 532                         !memcmp(pfn_sb->signature, DAX_SIG, PFN_SIG_LEN)) {
 533                 dev_err(&nd_pfn->dev, "init failed, alignment mismatch: "
 534                                 "%ld:%ld\n", nd_pfn->align, align);
 535                 return -EOPNOTSUPP;
 536         }
 537
 538         if (!nd_pfn->uuid) {
 539                 /*
 540                  * When probing a namepace via nd_pfn_probe() the uuid
 541                  * is NULL (see: nd_pfn_devinit()) we init settings from
 542                  * pfn_sb
 543                  */
 544                 nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
 545                 if (!nd_pfn->uuid)
 546                         return -ENOMEM;
 547                 nd_pfn->align = align;
 548                 nd_pfn->mode = mode;
 549         } else {
 550                 /*
 551                  * When probing a pfn / dax instance we validate the
 552                  * live settings against the pfn_sb
 553                  */
 554                 if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
 555                         return -ENODEV;
 556
 557                 /*
 558                  * If the uuid validates, but other settings mismatch
 559                  * return EINVAL because userspace has managed to change
 560                  * the configuration without specifying new
 561                  * identification.
 562                  */
 563                 if (nd_pfn->align != align || nd_pfn->mode != mode) {
 564                         dev_err(&nd_pfn->dev,
 565                                         "init failed, settings mismatch\n");
 566                         dev_dbg(&nd_pfn->dev, "align: %lx:%lx mode: %d:%d\n",
 567                                         nd_pfn->align, align, nd_pfn->mode,
 568                                         mode);
 569                         return -EOPNOTSUPP;
 570                 }
 571         }
 572
 573         if (align > nvdimm_namespace_capacity(ndns)) {
 574                 dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
 575                                 align, nvdimm_namespace_capacity(ndns));
 576                 return -EOPNOTSUPP;
 577         }
 578
 579         /*
 580          * These warnings are verbose because they can only trigger in
 581          * the case where the physical address alignment of the
 582          * namespace has changed since the pfn superblock was
 583          * established.
 584          */
 585         nsio = to_nd_namespace_io(&ndns->dev);
 586         res = &nsio->res;
 587         if (offset >= resource_size(res)) {
 588                 dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
 589                                 dev_name(&ndns->dev));
 590                 return -EOPNOTSUPP;
 591         }
 592
 593         if ((align && !IS_ALIGNED(res->start + offset + start_pad, align))
 594                         || !IS_ALIGNED(offset, PAGE_SIZE)) {
 595                 dev_err(&nd_pfn->dev,
 596                                 "bad offset: %#llx dax disabled align: %#lx\n",
 597                                 offset, align);
 598                 return -EOPNOTSUPP;
 599         }
 600
 601         if (!IS_ALIGNED(res->start + le32_to_cpu(pfn_sb->start_pad),
 602                                 memremap_compat_align())) {
 603                 dev_err(&nd_pfn->dev, "resource start misaligned\n");
 604                 return -EOPNOTSUPP;
 605         }
 606
 607         if (!IS_ALIGNED(res->end + 1 - le32_to_cpu(pfn_sb->end_trunc),
 608                                 memremap_compat_align())) {
 609                 dev_err(&nd_pfn->dev, "resource end misaligned\n");
 610                 return -EOPNOTSUPP;
 611         }
 612
 613         return 0;
 614 }
 615 EXPORT_SYMBOL(nd_pfn_validate);
 616
 617 int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns)
 618 {
 619         int rc;
 620         struct nd_pfn *nd_pfn;
 621         struct device *pfn_dev;
 622         struct nd_pfn_sb *pfn_sb;
 623         struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
 624
 625         if (ndns->force_raw)
 626                 return -ENODEV;
 627
 628         switch (ndns->claim_class) {
 629         case NVDIMM_CCLASS_NONE:
 630         case NVDIMM_CCLASS_PFN:
 631                 break;
 632         default:
 633                 return -ENODEV;
 634         }
 635
 636         nvdimm_bus_lock(&ndns->dev);
 637         nd_pfn = nd_pfn_alloc(nd_region);
 638         pfn_dev = nd_pfn_devinit(nd_pfn, ndns);
 639         nvdimm_bus_unlock(&ndns->dev);
 640         if (!pfn_dev)
 641                 return -ENOMEM;
 642         pfn_sb = devm_kmalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
 643         nd_pfn = to_nd_pfn(pfn_dev);
 644         nd_pfn->pfn_sb = pfn_sb;
 645         rc = nd_pfn_validate(nd_pfn, PFN_SIG);
 646         dev_dbg(dev, "pfn: %s\n", rc == 0 ? dev_name(pfn_dev) : "<none>");
 647         if (rc < 0) {
 648                 nd_detach_ndns(pfn_dev, &nd_pfn->ndns);
 649                 put_device(pfn_dev);
 650         } else
 651                 nd_device_register(pfn_dev);
 652
 653         return rc;
 654 }
 655 EXPORT_SYMBOL(nd_pfn_probe);
 656
 657 /*
 658  * We hotplug memory at sub-section granularity, pad the reserved area
 659  * from the previous section base to the namespace base address.
 660  */
 661 static unsigned long init_altmap_base(resource_size_t base)
 662 {
 663         unsigned long base_pfn = PHYS_PFN(base);
 664
 665         return SUBSECTION_ALIGN_DOWN(base_pfn);
 666 }
 667
 668 static unsigned long init_altmap_reserve(resource_size_t base)
 669 {
 670         unsigned long reserve = nd_info_block_reserve() >> PAGE_SHIFT;
 671         unsigned long base_pfn = PHYS_PFN(base);
 672
 673         reserve += base_pfn - SUBSECTION_ALIGN_DOWN(base_pfn);
 674         return reserve;
 675 }
 676
 677 static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap)
 678 {
 679         struct range *range = &pgmap->range;
 680         struct vmem_altmap *altmap = &pgmap->altmap;
 681         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 682         u64 offset = le64_to_cpu(pfn_sb->dataoff);
 683         u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
 684         u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
 685         u32 reserve = nd_info_block_reserve();
 686         struct nd_namespace_common *ndns = nd_pfn->ndns;
 687         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 688         resource_size_t base = nsio->res.start + start_pad;
 689         resource_size_t end = nsio->res.end - end_trunc;
 690         struct vmem_altmap __altmap = {
 691                 .base_pfn = init_altmap_base(base),
 692                 .reserve = init_altmap_reserve(base),
 693                 .end_pfn = PHYS_PFN(end),
 694         };
 695
 696         *range = (struct range) {
 697                 .start = nsio->res.start + start_pad,
 698                 .end = nsio->res.end - end_trunc,
 699         };
 700         pgmap->nr_range = 1;
 701         if (nd_pfn->mode == PFN_MODE_RAM) {
 702                 if (offset < reserve)
 703                         return -EINVAL;
 704                 nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
 705         } else if (nd_pfn->mode == PFN_MODE_PMEM) {
 706                 nd_pfn->npfns = PHYS_PFN((range_len(range) - offset));
 707                 if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
 708                         dev_info(&nd_pfn->dev,
 709                                         "number of pfns truncated from %lld to %ld\n",
 710                                         le64_to_cpu(nd_pfn->pfn_sb->npfns),
 711                                         nd_pfn->npfns);
 712                 memcpy(altmap, &__altmap, sizeof(*altmap));
 713                 altmap->free = PHYS_PFN(offset - reserve);
 714                 altmap->alloc = 0;
 715                 pgmap->flags |= PGMAP_ALTMAP_VALID;
 716         } else
 717                 return -ENXIO;
 718
 719         return 0;
 720 }
 721
 722 static int nd_pfn_init(struct nd_pfn *nd_pfn)
 723 {
 724         struct nd_namespace_common *ndns = nd_pfn->ndns;
 725         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 726         resource_size_t start, size;
 727         struct nd_region *nd_region;
 728         unsigned long npfns, align;
 729         u32 end_trunc;
 730         struct nd_pfn_sb *pfn_sb;
 731         phys_addr_t offset;
 732         const char *sig;
 733         u64 checksum;
 734         int rc;
 735
 736         pfn_sb = devm_kmalloc(&nd_pfn->dev, sizeof(*pfn_sb), GFP_KERNEL);
 737         if (!pfn_sb)
 738                 return -ENOMEM;
 739
 740         nd_pfn->pfn_sb = pfn_sb;
 741         if (is_nd_dax(&nd_pfn->dev))
 742                 sig = DAX_SIG;
 743         else
 744                 sig = PFN_SIG;
 745
 746         rc = nd_pfn_validate(nd_pfn, sig);
 747         if (rc == 0)
 748                 return nd_pfn_clear_memmap_errors(nd_pfn);
 749         if (rc != -ENODEV)
 750                 return rc;
 751
 752         /* no info block, do init */;
 753         memset(pfn_sb, 0, sizeof(*pfn_sb));
 754
 755         nd_region = to_nd_region(nd_pfn->dev.parent);
 756         if (nd_region->ro) {
 757                 dev_info(&nd_pfn->dev,
 758                                 "%s is read-only, unable to init metadata\n",
 759                                 dev_name(&nd_region->dev));
 760                 return -ENXIO;
 761         }
 762
 763         start = nsio->res.start;
 764         size = resource_size(&nsio->res);
 765         npfns = PHYS_PFN(size - SZ_8K);
 766         align = max(nd_pfn->align, memremap_compat_align());
 767
 768         /*
 769          * When @start is misaligned fail namespace creation. See
 770          * the 'struct nd_pfn_sb' commentary on why ->start_pad is not
 771          * an option.
 772          */
 773         if (!IS_ALIGNED(start, memremap_compat_align())) {
 774                 dev_err(&nd_pfn->dev, "%s: start %pa misaligned to %#lx\n",
 775                                 dev_name(&ndns->dev), &start,
 776                                 memremap_compat_align());
 777                 return -EINVAL;
 778         }
 779         end_trunc = start + size - ALIGN_DOWN(start + size, align);
 780         if (nd_pfn->mode == PFN_MODE_PMEM) {
 781                 unsigned long page_map_size = MAX_STRUCT_PAGE_SIZE * npfns;
 782
 783                 /*
 784                  * The altmap should be padded out to the block size used
 785                  * when populating the vmemmap. This *should* be equal to
 786                  * PMD_SIZE for most architectures.
 787                  *
 788                  * Also make sure size of struct page is less than
 789                  * MAX_STRUCT_PAGE_SIZE. The goal here is compatibility in the
 790                  * face of production kernel configurations that reduce the
 791                  * 'struct page' size below MAX_STRUCT_PAGE_SIZE. For debug
 792                  * kernel configurations that increase the 'struct page' size
 793                  * above MAX_STRUCT_PAGE_SIZE, the page_struct_override allows
 794                  * for continuing with the capacity that will be wasted when
 795                  * reverting to a production kernel configuration. Otherwise,
 796                  * those configurations are blocked by default.
 797                  */
 798                 if (sizeof(struct page) > MAX_STRUCT_PAGE_SIZE) {
 799                         if (page_struct_override)
 800                                 page_map_size = sizeof(struct page) * npfns;
 801                         else {
 802                                 dev_err(&nd_pfn->dev,
 803                                         "Memory debug options prevent using pmem for the page map\n");
 804                                 return -EINVAL;
 805                         }
 806                 }
 807                 offset = ALIGN(start + SZ_8K + page_map_size, align) - start;
 808         } else if (nd_pfn->mode == PFN_MODE_RAM)
 809                 offset = ALIGN(start + SZ_8K, align) - start;
 810         else
 811                 return -ENXIO;
 812
 813         if (offset >= size) {
 814                 dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
 815                                 dev_name(&ndns->dev));
 816                 return -ENXIO;
 817         }
 818
 819         npfns = PHYS_PFN(size - offset - end_trunc);
 820         pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
 821         pfn_sb->dataoff = cpu_to_le64(offset);
 822         pfn_sb->npfns = cpu_to_le64(npfns);
 823         memcpy(pfn_sb->signature, sig, PFN_SIG_LEN);
 824         memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
 825         memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
 826         pfn_sb->version_major = cpu_to_le16(1);
 827         pfn_sb->version_minor = cpu_to_le16(4);
 828         pfn_sb->end_trunc = cpu_to_le32(end_trunc);
 829         pfn_sb->align = cpu_to_le32(nd_pfn->align);
 830         if (sizeof(struct page) > MAX_STRUCT_PAGE_SIZE && page_struct_override)
 831                 pfn_sb->page_struct_size = cpu_to_le16(sizeof(struct page));
 832         else
 833                 pfn_sb->page_struct_size = cpu_to_le16(MAX_STRUCT_PAGE_SIZE);
 834         pfn_sb->page_size = cpu_to_le32(PAGE_SIZE);
 835         checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
 836         pfn_sb->checksum = cpu_to_le64(checksum);
 837
 838         rc = nd_pfn_clear_memmap_errors(nd_pfn);
 839         if (rc)
 840                 return rc;
 841
 842         return nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0);
 843 }
 844
 845 /*
 846  * Determine the effective resource range and vmem_altmap from an nd_pfn
 847  * instance.
 848  */
 849 int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap)
 850 {
 851         int rc;
 852
 853         if (!nd_pfn->uuid || !nd_pfn->ndns)
 854                 return -ENODEV;
 855
 856         rc = nd_pfn_init(nd_pfn);
 857         if (rc)
 858                 return rc;
 859
 860         /* we need a valid pfn_sb before we can init a dev_pagemap */
 861         return __nvdimm_setup_pfn(nd_pfn, pgmap);
 862 }
 863 EXPORT_SYMBOL_GPL(nvdimm_setup_pfn);