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