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 (has_transparent_pud_hugepage())
 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         resource_size_t res_size;
 456         struct nd_namespace_io *nsio;
 457         unsigned long align, start_pad, end_trunc;
 458         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 459         struct nd_namespace_common *ndns = nd_pfn->ndns;
 460         const uuid_t *parent_uuid = nd_dev_to_uuid(&ndns->dev);
 461
 462         if (!pfn_sb || !ndns)
 463                 return -ENODEV;
 464
 465         if (!is_memory(nd_pfn->dev.parent))
 466                 return -ENODEV;
 467
 468         if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0))
 469                 return -ENXIO;
 470
 471         if (memcmp(pfn_sb->signature, sig, PFN_SIG_LEN) != 0)
 472                 return -ENODEV;
 473
 474         checksum = le64_to_cpu(pfn_sb->checksum);
 475         pfn_sb->checksum = 0;
 476         if (checksum != nd_sb_checksum((struct nd_gen_sb *) pfn_sb))
 477                 return -ENODEV;
 478         pfn_sb->checksum = cpu_to_le64(checksum);
 479
 480         if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
 481                 return -ENODEV;
 482
 483         if (__le16_to_cpu(pfn_sb->version_minor) < 1) {
 484                 pfn_sb->start_pad = 0;
 485                 pfn_sb->end_trunc = 0;
 486         }
 487
 488         if (__le16_to_cpu(pfn_sb->version_minor) < 2)
 489                 pfn_sb->align = 0;
 490
 491         if (__le16_to_cpu(pfn_sb->version_minor) < 4) {
 492                 pfn_sb->page_struct_size = cpu_to_le16(64);
 493                 pfn_sb->page_size = cpu_to_le32(PAGE_SIZE);
 494         }
 495
 496         switch (le32_to_cpu(pfn_sb->mode)) {
 497         case PFN_MODE_RAM:
 498         case PFN_MODE_PMEM:
 499                 break;
 500         default:
 501                 return -ENXIO;
 502         }
 503
 504         align = le32_to_cpu(pfn_sb->align);
 505         offset = le64_to_cpu(pfn_sb->dataoff);
 506         start_pad = le32_to_cpu(pfn_sb->start_pad);
 507         end_trunc = le32_to_cpu(pfn_sb->end_trunc);
 508         if (align == 0)
 509                 align = 1UL << ilog2(offset);
 510         mode = le32_to_cpu(pfn_sb->mode);
 511
 512         if ((le32_to_cpu(pfn_sb->page_size) > PAGE_SIZE) &&
 513                         (mode == PFN_MODE_PMEM)) {
 514                 dev_err(&nd_pfn->dev,
 515                                 "init failed, page size mismatch %d\n",
 516                                 le32_to_cpu(pfn_sb->page_size));
 517                 return -EOPNOTSUPP;
 518         }
 519
 520         if ((le16_to_cpu(pfn_sb->page_struct_size) < sizeof(struct page)) &&
 521                         (mode == PFN_MODE_PMEM)) {
 522                 dev_err(&nd_pfn->dev,
 523                                 "init failed, struct page size mismatch %d\n",
 524                                 le16_to_cpu(pfn_sb->page_struct_size));
 525                 return -EOPNOTSUPP;
 526         }
 527
 528         /*
 529          * Check whether the we support the alignment. For Dax if the
 530          * superblock alignment is not matching, we won't initialize
 531          * the device.
 532          */
 533         if (!nd_supported_alignment(align) &&
 534                         !memcmp(pfn_sb->signature, DAX_SIG, PFN_SIG_LEN)) {
 535                 dev_err(&nd_pfn->dev, "init failed, alignment mismatch: "
 536                                 "%ld:%ld\n", nd_pfn->align, align);
 537                 return -EOPNOTSUPP;
 538         }
 539
 540         if (!nd_pfn->uuid) {
 541                 /*
 542                  * When probing a namepace via nd_pfn_probe() the uuid
 543                  * is NULL (see: nd_pfn_devinit()) we init settings from
 544                  * pfn_sb
 545                  */
 546                 nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
 547                 if (!nd_pfn->uuid)
 548                         return -ENOMEM;
 549                 nd_pfn->align = align;
 550                 nd_pfn->mode = mode;
 551         } else {
 552                 /*
 553                  * When probing a pfn / dax instance we validate the
 554                  * live settings against the pfn_sb
 555                  */
 556                 if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
 557                         return -ENODEV;
 558
 559                 /*
 560                  * If the uuid validates, but other settings mismatch
 561                  * return EINVAL because userspace has managed to change
 562                  * the configuration without specifying new
 563                  * identification.
 564                  */
 565                 if (nd_pfn->align != align || nd_pfn->mode != mode) {
 566                         dev_err(&nd_pfn->dev,
 567                                         "init failed, settings mismatch\n");
 568                         dev_dbg(&nd_pfn->dev, "align: %lx:%lx mode: %d:%d\n",
 569                                         nd_pfn->align, align, nd_pfn->mode,
 570                                         mode);
 571                         return -EOPNOTSUPP;
 572                 }
 573         }
 574
 575         if (align > nvdimm_namespace_capacity(ndns)) {
 576                 dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
 577                                 align, nvdimm_namespace_capacity(ndns));
 578                 return -EOPNOTSUPP;
 579         }
 580
 581         /*
 582          * These warnings are verbose because they can only trigger in
 583          * the case where the physical address alignment of the
 584          * namespace has changed since the pfn superblock was
 585          * established.
 586          */
 587         nsio = to_nd_namespace_io(&ndns->dev);
 588         res = &nsio->res;
 589         res_size = resource_size(res);
 590         if (offset >= res_size) {
 591                 dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
 592                                 dev_name(&ndns->dev));
 593                 return -EOPNOTSUPP;
 594         }
 595
 596         if ((align && !IS_ALIGNED(res->start + offset + start_pad, align))
 597                         || !IS_ALIGNED(offset, PAGE_SIZE)) {
 598                 dev_err(&nd_pfn->dev,
 599                                 "bad offset: %#llx dax disabled align: %#lx\n",
 600                                 offset, align);
 601                 return -EOPNOTSUPP;
 602         }
 603
 604         if (!IS_ALIGNED(res->start + start_pad, memremap_compat_align())) {
 605                 dev_err(&nd_pfn->dev, "resource start misaligned\n");
 606                 return -EOPNOTSUPP;
 607         }
 608
 609         if (!IS_ALIGNED(res->end + 1 - end_trunc, memremap_compat_align())) {
 610                 dev_err(&nd_pfn->dev, "resource end misaligned\n");
 611                 return -EOPNOTSUPP;
 612         }
 613
 614         if (offset >= (res_size - start_pad - end_trunc)) {
 615                 dev_err(&nd_pfn->dev, "bad offset with small namespace\n");
 616                 return -EOPNOTSUPP;
 617         }
 618         return 0;
 619 }
 620 EXPORT_SYMBOL(nd_pfn_validate);
 621
 622 int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns)
 623 {
 624         int rc;
 625         struct nd_pfn *nd_pfn;
 626         struct device *pfn_dev;
 627         struct nd_pfn_sb *pfn_sb;
 628         struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
 629
 630         if (ndns->force_raw)
 631                 return -ENODEV;
 632
 633         switch (ndns->claim_class) {
 634         case NVDIMM_CCLASS_NONE:
 635         case NVDIMM_CCLASS_PFN:
 636                 break;
 637         default:
 638                 return -ENODEV;
 639         }
 640
 641         nvdimm_bus_lock(&ndns->dev);
 642         nd_pfn = nd_pfn_alloc(nd_region);
 643         pfn_dev = nd_pfn_devinit(nd_pfn, ndns);
 644         nvdimm_bus_unlock(&ndns->dev);
 645         if (!pfn_dev)
 646                 return -ENOMEM;
 647         pfn_sb = devm_kmalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
 648         nd_pfn = to_nd_pfn(pfn_dev);
 649         nd_pfn->pfn_sb = pfn_sb;
 650         rc = nd_pfn_validate(nd_pfn, PFN_SIG);
 651         dev_dbg(dev, "pfn: %s\n", rc == 0 ? dev_name(pfn_dev) : "<none>");
 652         if (rc < 0) {
 653                 nd_detach_ndns(pfn_dev, &nd_pfn->ndns);
 654                 put_device(pfn_dev);
 655         } else
 656                 nd_device_register(pfn_dev);
 657
 658         return rc;
 659 }
 660 EXPORT_SYMBOL(nd_pfn_probe);
 661
 662 /*
 663  * We hotplug memory at sub-section granularity, pad the reserved area
 664  * from the previous section base to the namespace base address.
 665  */
 666 static unsigned long init_altmap_base(resource_size_t base)
 667 {
 668         unsigned long base_pfn = PHYS_PFN(base);
 669
 670         return SUBSECTION_ALIGN_DOWN(base_pfn);
 671 }
 672
 673 static unsigned long init_altmap_reserve(resource_size_t base)
 674 {
 675         unsigned long reserve = nd_info_block_reserve() >> PAGE_SHIFT;
 676         unsigned long base_pfn = PHYS_PFN(base);
 677
 678         reserve += base_pfn - SUBSECTION_ALIGN_DOWN(base_pfn);
 679         return reserve;
 680 }
 681
 682 static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap)
 683 {
 684         struct range *range = &pgmap->range;
 685         struct vmem_altmap *altmap = &pgmap->altmap;
 686         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 687         u64 offset = le64_to_cpu(pfn_sb->dataoff);
 688         u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
 689         u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
 690         u32 reserve = nd_info_block_reserve();
 691         struct nd_namespace_common *ndns = nd_pfn->ndns;
 692         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 693         resource_size_t base = nsio->res.start + start_pad;
 694         resource_size_t end = nsio->res.end - end_trunc;
 695         struct vmem_altmap __altmap = {
 696                 .base_pfn = init_altmap_base(base),
 697                 .reserve = init_altmap_reserve(base),
 698                 .end_pfn = PHYS_PFN(end),
 699         };
 700
 701         *range = (struct range) {
 702                 .start = nsio->res.start + start_pad,
 703                 .end = nsio->res.end - end_trunc,
 704         };
 705         pgmap->nr_range = 1;
 706         if (nd_pfn->mode == PFN_MODE_RAM) {
 707                 if (offset < reserve)
 708                         return -EINVAL;
 709                 nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
 710         } else if (nd_pfn->mode == PFN_MODE_PMEM) {
 711                 nd_pfn->npfns = PHYS_PFN((range_len(range) - offset));
 712                 if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
 713                         dev_info(&nd_pfn->dev,
 714                                         "number of pfns truncated from %lld to %ld\n",
 715                                         le64_to_cpu(nd_pfn->pfn_sb->npfns),
 716                                         nd_pfn->npfns);
 717                 memcpy(altmap, &__altmap, sizeof(*altmap));
 718                 altmap->free = PHYS_PFN(offset - reserve);
 719                 altmap->alloc = 0;
 720                 pgmap->flags |= PGMAP_ALTMAP_VALID;
 721         } else
 722                 return -ENXIO;
 723
 724         return 0;
 725 }
 726
 727 static int nd_pfn_init(struct nd_pfn *nd_pfn)
 728 {
 729         struct nd_namespace_common *ndns = nd_pfn->ndns;
 730         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 731         resource_size_t start, size;
 732         struct nd_region *nd_region;
 733         unsigned long npfns, align;
 734         u32 end_trunc;
 735         struct nd_pfn_sb *pfn_sb;
 736         phys_addr_t offset;
 737         const char *sig;
 738         u64 checksum;
 739         int rc;
 740
 741         pfn_sb = devm_kmalloc(&nd_pfn->dev, sizeof(*pfn_sb), GFP_KERNEL);
 742         if (!pfn_sb)
 743                 return -ENOMEM;
 744
 745         nd_pfn->pfn_sb = pfn_sb;
 746         if (is_nd_dax(&nd_pfn->dev))
 747                 sig = DAX_SIG;
 748         else
 749                 sig = PFN_SIG;
 750
 751         rc = nd_pfn_validate(nd_pfn, sig);
 752         if (rc == 0)
 753                 return nd_pfn_clear_memmap_errors(nd_pfn);
 754         if (rc != -ENODEV)
 755                 return rc;
 756
 757         /* no info block, do init */;
 758         memset(pfn_sb, 0, sizeof(*pfn_sb));
 759
 760         nd_region = to_nd_region(nd_pfn->dev.parent);
 761         if (nd_region->ro) {
 762                 dev_info(&nd_pfn->dev,
 763                                 "%s is read-only, unable to init metadata\n",
 764                                 dev_name(&nd_region->dev));
 765                 return -ENXIO;
 766         }
 767
 768         start = nsio->res.start;
 769         size = resource_size(&nsio->res);
 770         npfns = PHYS_PFN(size - SZ_8K);
 771         align = max(nd_pfn->align, memremap_compat_align());
 772
 773         /*
 774          * When @start is misaligned fail namespace creation. See
 775          * the 'struct nd_pfn_sb' commentary on why ->start_pad is not
 776          * an option.
 777          */
 778         if (!IS_ALIGNED(start, memremap_compat_align())) {
 779                 dev_err(&nd_pfn->dev, "%s: start %pa misaligned to %#lx\n",
 780                                 dev_name(&ndns->dev), &start,
 781                                 memremap_compat_align());
 782                 return -EINVAL;
 783         }
 784         end_trunc = start + size - ALIGN_DOWN(start + size, align);
 785         if (nd_pfn->mode == PFN_MODE_PMEM) {
 786                 unsigned long page_map_size = MAX_STRUCT_PAGE_SIZE * npfns;
 787
 788                 /*
 789                  * The altmap should be padded out to the block size used
 790                  * when populating the vmemmap. This *should* be equal to
 791                  * PMD_SIZE for most architectures.
 792                  *
 793                  * Also make sure size of struct page is less than
 794                  * MAX_STRUCT_PAGE_SIZE. The goal here is compatibility in the
 795                  * face of production kernel configurations that reduce the
 796                  * 'struct page' size below MAX_STRUCT_PAGE_SIZE. For debug
 797                  * kernel configurations that increase the 'struct page' size
 798                  * above MAX_STRUCT_PAGE_SIZE, the page_struct_override allows
 799                  * for continuing with the capacity that will be wasted when
 800                  * reverting to a production kernel configuration. Otherwise,
 801                  * those configurations are blocked by default.
 802                  */
 803                 if (sizeof(struct page) > MAX_STRUCT_PAGE_SIZE) {
 804                         if (page_struct_override)
 805                                 page_map_size = sizeof(struct page) * npfns;
 806                         else {
 807                                 dev_err(&nd_pfn->dev,
 808                                         "Memory debug options prevent using pmem for the page map\n");
 809                                 return -EINVAL;
 810                         }
 811                 }
 812                 offset = ALIGN(start + SZ_8K + page_map_size, align) - start;
 813         } else if (nd_pfn->mode == PFN_MODE_RAM)
 814                 offset = ALIGN(start + SZ_8K, align) - start;
 815         else
 816                 return -ENXIO;
 817
 818         if (offset >= (size - end_trunc)) {
 819                 /* This results in zero size devices */
 820                 dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
 821                                 dev_name(&ndns->dev));
 822                 return -ENXIO;
 823         }
 824
 825         npfns = PHYS_PFN(size - offset - end_trunc);
 826         pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
 827         pfn_sb->dataoff = cpu_to_le64(offset);
 828         pfn_sb->npfns = cpu_to_le64(npfns);
 829         memcpy(pfn_sb->signature, sig, PFN_SIG_LEN);
 830         memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
 831         memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
 832         pfn_sb->version_major = cpu_to_le16(1);
 833         pfn_sb->version_minor = cpu_to_le16(4);
 834         pfn_sb->end_trunc = cpu_to_le32(end_trunc);
 835         pfn_sb->align = cpu_to_le32(nd_pfn->align);
 836         if (sizeof(struct page) > MAX_STRUCT_PAGE_SIZE && page_struct_override)
 837                 pfn_sb->page_struct_size = cpu_to_le16(sizeof(struct page));
 838         else
 839                 pfn_sb->page_struct_size = cpu_to_le16(MAX_STRUCT_PAGE_SIZE);
 840         pfn_sb->page_size = cpu_to_le32(PAGE_SIZE);
 841         checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
 842         pfn_sb->checksum = cpu_to_le64(checksum);
 843
 844         rc = nd_pfn_clear_memmap_errors(nd_pfn);
 845         if (rc)
 846                 return rc;
 847
 848         return nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0);
 849 }
 850
 851 /*
 852  * Determine the effective resource range and vmem_altmap from an nd_pfn
 853  * instance.
 854  */
 855 int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap)
 856 {
 857         int rc;
 858
 859         if (!nd_pfn->uuid || !nd_pfn->ndns)
 860                 return -ENODEV;
 861
 862         rc = nd_pfn_init(nd_pfn);
 863         if (rc)
 864                 return rc;
 865
 866         /* we need a valid pfn_sb before we can init a dev_pagemap */
 867         return __nvdimm_setup_pfn(nd_pfn, pgmap);
 868 }
 869 EXPORT_SYMBOL_GPL(nvdimm_setup_pfn);