drivers/nvdimm/pfn_devs.c

   1 /*
   2  * Copyright(c) 2013-2016 Intel Corporation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  */
  13 #include <linux/memremap.h>
  14 #include <linux/blkdev.h>
  15 #include <linux/device.h>
  16 #include <linux/genhd.h>
  17 #include <linux/sizes.h>
  18 #include <linux/slab.h>
  19 #include <linux/fs.h>
  20 #include <linux/mm.h>
  21 #include "nd-core.h"
  22 #include "pfn.h"
  23 #include "nd.h"
  24
  25 static void nd_pfn_release(struct device *dev)
  26 {
  27         struct nd_region *nd_region = to_nd_region(dev->parent);
  28         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
  29
  30         dev_dbg(dev, "%s\n", __func__);
  31         nd_detach_ndns(&nd_pfn->dev, &nd_pfn->ndns);
  32         ida_simple_remove(&nd_region->pfn_ida, nd_pfn->id);
  33         kfree(nd_pfn->uuid);
  34         kfree(nd_pfn);
  35 }
  36
  37 static struct device_type nd_pfn_device_type = {
  38         .name = "nd_pfn",
  39         .release = nd_pfn_release,
  40 };
  41
  42 bool is_nd_pfn(struct device *dev)
  43 {
  44         return dev ? dev->type == &nd_pfn_device_type : false;
  45 }
  46 EXPORT_SYMBOL(is_nd_pfn);
  47
  48 struct nd_pfn *to_nd_pfn(struct device *dev)
  49 {
  50         struct nd_pfn *nd_pfn = container_of(dev, struct nd_pfn, dev);
  51
  52         WARN_ON(!is_nd_pfn(dev));
  53         return nd_pfn;
  54 }
  55 EXPORT_SYMBOL(to_nd_pfn);
  56
  57 static ssize_t mode_show(struct device *dev,
  58                 struct device_attribute *attr, char *buf)
  59 {
  60         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
  61
  62         switch (nd_pfn->mode) {
  63         case PFN_MODE_RAM:
  64                 return sprintf(buf, "ram\n");
  65         case PFN_MODE_PMEM:
  66                 return sprintf(buf, "pmem\n");
  67         default:
  68                 return sprintf(buf, "none\n");
  69         }
  70 }
  71
  72 static ssize_t mode_store(struct device *dev,
  73                 struct device_attribute *attr, const char *buf, size_t len)
  74 {
  75         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
  76         ssize_t rc = 0;
  77
  78         device_lock(dev);
  79         nvdimm_bus_lock(dev);
  80         if (dev->driver)
  81                 rc = -EBUSY;
  82         else {
  83                 size_t n = len - 1;
  84
  85                 if (strncmp(buf, "pmem\n", n) == 0
  86                                 || strncmp(buf, "pmem", n) == 0) {
  87                         nd_pfn->mode = PFN_MODE_PMEM;
  88                 } else if (strncmp(buf, "ram\n", n) == 0
  89                                 || strncmp(buf, "ram", n) == 0)
  90                         nd_pfn->mode = PFN_MODE_RAM;
  91                 else if (strncmp(buf, "none\n", n) == 0
  92                                 || strncmp(buf, "none", n) == 0)
  93                         nd_pfn->mode = PFN_MODE_NONE;
  94                 else
  95                         rc = -EINVAL;
  96         }
  97         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
  98                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
  99         nvdimm_bus_unlock(dev);
 100         device_unlock(dev);
 101
 102         return rc ? rc : len;
 103 }
 104 static DEVICE_ATTR_RW(mode);
 105
 106 static ssize_t align_show(struct device *dev,
 107                 struct device_attribute *attr, char *buf)
 108 {
 109         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 110
 111         return sprintf(buf, "%ld\n", nd_pfn->align);
 112 }
 113
 114 static ssize_t __align_store(struct nd_pfn *nd_pfn, const char *buf)
 115 {
 116         unsigned long val;
 117         int rc;
 118
 119         rc = kstrtoul(buf, 0, &val);
 120         if (rc)
 121                 return rc;
 122
 123         if (!is_power_of_2(val) || val < PAGE_SIZE || val > SZ_1G)
 124                 return -EINVAL;
 125
 126         if (nd_pfn->dev.driver)
 127                 return -EBUSY;
 128         else
 129                 nd_pfn->align = val;
 130
 131         return 0;
 132 }
 133
 134 static ssize_t align_store(struct device *dev,
 135                 struct device_attribute *attr, const char *buf, size_t len)
 136 {
 137         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 138         ssize_t rc;
 139
 140         device_lock(dev);
 141         nvdimm_bus_lock(dev);
 142         rc = __align_store(nd_pfn, buf);
 143         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 144                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
 145         nvdimm_bus_unlock(dev);
 146         device_unlock(dev);
 147
 148         return rc ? rc : len;
 149 }
 150 static DEVICE_ATTR_RW(align);
 151
 152 static ssize_t uuid_show(struct device *dev,
 153                 struct device_attribute *attr, char *buf)
 154 {
 155         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 156
 157         if (nd_pfn->uuid)
 158                 return sprintf(buf, "%pUb\n", nd_pfn->uuid);
 159         return sprintf(buf, "\n");
 160 }
 161
 162 static ssize_t uuid_store(struct device *dev,
 163                 struct device_attribute *attr, const char *buf, size_t len)
 164 {
 165         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 166         ssize_t rc;
 167
 168         device_lock(dev);
 169         rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len);
 170         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 171                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
 172         device_unlock(dev);
 173
 174         return rc ? rc : len;
 175 }
 176 static DEVICE_ATTR_RW(uuid);
 177
 178 static ssize_t namespace_show(struct device *dev,
 179                 struct device_attribute *attr, char *buf)
 180 {
 181         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 182         ssize_t rc;
 183
 184         nvdimm_bus_lock(dev);
 185         rc = sprintf(buf, "%s\n", nd_pfn->ndns
 186                         ? dev_name(&nd_pfn->ndns->dev) : "");
 187         nvdimm_bus_unlock(dev);
 188         return rc;
 189 }
 190
 191 static ssize_t namespace_store(struct device *dev,
 192                 struct device_attribute *attr, const char *buf, size_t len)
 193 {
 194         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 195         ssize_t rc;
 196
 197         device_lock(dev);
 198         nvdimm_bus_lock(dev);
 199         rc = nd_namespace_store(dev, &nd_pfn->ndns, buf, len);
 200         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 201                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
 202         nvdimm_bus_unlock(dev);
 203         device_unlock(dev);
 204
 205         return rc;
 206 }
 207 static DEVICE_ATTR_RW(namespace);
 208
 209 static ssize_t resource_show(struct device *dev,
 210                 struct device_attribute *attr, char *buf)
 211 {
 212         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 213         ssize_t rc;
 214
 215         device_lock(dev);
 216         if (dev->driver) {
 217                 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 218                 u64 offset = __le64_to_cpu(pfn_sb->dataoff);
 219                 struct nd_namespace_common *ndns = nd_pfn->ndns;
 220                 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
 221                 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 222
 223                 rc = sprintf(buf, "%#llx\n", (unsigned long long) nsio->res.start
 224                                 + start_pad + offset);
 225         } else {
 226                 /* no address to convey if the pfn instance is disabled */
 227                 rc = -ENXIO;
 228         }
 229         device_unlock(dev);
 230
 231         return rc;
 232 }
 233 static DEVICE_ATTR_RO(resource);
 234
 235 static ssize_t size_show(struct device *dev,
 236                 struct device_attribute *attr, char *buf)
 237 {
 238         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 239         ssize_t rc;
 240
 241         device_lock(dev);
 242         if (dev->driver) {
 243                 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 244                 u64 offset = __le64_to_cpu(pfn_sb->dataoff);
 245                 struct nd_namespace_common *ndns = nd_pfn->ndns;
 246                 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
 247                 u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
 248                 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 249
 250                 rc = sprintf(buf, "%llu\n", (unsigned long long)
 251                                 resource_size(&nsio->res) - start_pad
 252                                 - end_trunc - offset);
 253         } else {
 254                 /* no size to convey if the pfn instance is disabled */
 255                 rc = -ENXIO;
 256         }
 257         device_unlock(dev);
 258
 259         return rc;
 260 }
 261 static DEVICE_ATTR_RO(size);
 262
 263 static struct attribute *nd_pfn_attributes[] = {
 264         &dev_attr_mode.attr,
 265         &dev_attr_namespace.attr,
 266         &dev_attr_uuid.attr,
 267         &dev_attr_align.attr,
 268         &dev_attr_resource.attr,
 269         &dev_attr_size.attr,
 270         NULL,
 271 };
 272
 273 static umode_t pfn_visible(struct kobject *kobj, struct attribute *a, int n)
 274 {
 275         if (a == &dev_attr_resource.attr)
 276                 return 0400;
 277         return a->mode;
 278 }
 279
 280 struct attribute_group nd_pfn_attribute_group = {
 281         .attrs = nd_pfn_attributes,
 282         .is_visible = pfn_visible,
 283 };
 284
 285 static const struct attribute_group *nd_pfn_attribute_groups[] = {
 286         &nd_pfn_attribute_group,
 287         &nd_device_attribute_group,
 288         &nd_numa_attribute_group,
 289         NULL,
 290 };
 291
 292 struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
 293                 struct nd_namespace_common *ndns)
 294 {
 295         struct device *dev = &nd_pfn->dev;
 296
 297         if (!nd_pfn)
 298                 return NULL;
 299
 300         nd_pfn->mode = PFN_MODE_NONE;
 301         nd_pfn->align = HPAGE_SIZE;
 302         dev = &nd_pfn->dev;
 303         device_initialize(&nd_pfn->dev);
 304         if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
 305                 dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
 306                                 __func__, dev_name(ndns->claim));
 307                 put_device(dev);
 308                 return NULL;
 309         }
 310         return dev;
 311 }
 312
 313 static struct nd_pfn *nd_pfn_alloc(struct nd_region *nd_region)
 314 {
 315         struct nd_pfn *nd_pfn;
 316         struct device *dev;
 317
 318         nd_pfn = kzalloc(sizeof(*nd_pfn), GFP_KERNEL);
 319         if (!nd_pfn)
 320                 return NULL;
 321
 322         nd_pfn->id = ida_simple_get(&nd_region->pfn_ida, 0, 0, GFP_KERNEL);
 323         if (nd_pfn->id < 0) {
 324                 kfree(nd_pfn);
 325                 return NULL;
 326         }
 327
 328         dev = &nd_pfn->dev;
 329         dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
 330         dev->groups = nd_pfn_attribute_groups;
 331         dev->type = &nd_pfn_device_type;
 332         dev->parent = &nd_region->dev;
 333
 334         return nd_pfn;
 335 }
 336
 337 struct device *nd_pfn_create(struct nd_region *nd_region)
 338 {
 339         struct nd_pfn *nd_pfn;
 340         struct device *dev;
 341
 342         if (!is_nd_pmem(&nd_region->dev))
 343                 return NULL;
 344
 345         nd_pfn = nd_pfn_alloc(nd_region);
 346         dev = nd_pfn_devinit(nd_pfn, NULL);
 347
 348         __nd_device_register(dev);
 349         return dev;
 350 }
 351
 352 /**
 353  * nd_pfn_validate - read and validate info-block
 354  * @nd_pfn: fsdax namespace runtime state / properties
 355  * @sig: 'devdax' or 'fsdax' signature
 356  *
 357  * Upon return the info-block buffer contents (->pfn_sb) are
 358  * indeterminate when validation fails, and a coherent info-block
 359  * otherwise.
 360  */
 361 int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
 362 {
 363         u64 checksum, offset;
 364         enum nd_pfn_mode mode;
 365         struct nd_namespace_io *nsio;
 366         unsigned long align, start_pad;
 367         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 368         struct nd_namespace_common *ndns = nd_pfn->ndns;
 369         const u8 *parent_uuid = nd_dev_to_uuid(&ndns->dev);
 370
 371         if (!pfn_sb || !ndns)
 372                 return -ENODEV;
 373
 374         if (!is_nd_pmem(nd_pfn->dev.parent))
 375                 return -ENODEV;
 376
 377         if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb)))
 378                 return -ENXIO;
 379
 380         if (memcmp(pfn_sb->signature, sig, PFN_SIG_LEN) != 0)
 381                 return -ENODEV;
 382
 383         checksum = le64_to_cpu(pfn_sb->checksum);
 384         pfn_sb->checksum = 0;
 385         if (checksum != nd_sb_checksum((struct nd_gen_sb *) pfn_sb))
 386                 return -ENODEV;
 387         pfn_sb->checksum = cpu_to_le64(checksum);
 388
 389         if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
 390                 return -ENODEV;
 391
 392         if (__le16_to_cpu(pfn_sb->version_minor) < 1) {
 393                 pfn_sb->start_pad = 0;
 394                 pfn_sb->end_trunc = 0;
 395         }
 396
 397         if (__le16_to_cpu(pfn_sb->version_minor) < 2)
 398                 pfn_sb->align = 0;
 399
 400         switch (le32_to_cpu(pfn_sb->mode)) {
 401         case PFN_MODE_RAM:
 402         case PFN_MODE_PMEM:
 403                 break;
 404         default:
 405                 return -ENXIO;
 406         }
 407
 408         align = le32_to_cpu(pfn_sb->align);
 409         offset = le64_to_cpu(pfn_sb->dataoff);
 410         start_pad = le32_to_cpu(pfn_sb->start_pad);
 411         if (align == 0)
 412                 align = 1UL << ilog2(offset);
 413         mode = le32_to_cpu(pfn_sb->mode);
 414
 415         if (!nd_pfn->uuid) {
 416                 /*
 417                  * When probing a namepace via nd_pfn_probe() the uuid
 418                  * is NULL (see: nd_pfn_devinit()) we init settings from
 419                  * pfn_sb
 420                  */
 421                 nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
 422                 if (!nd_pfn->uuid)
 423                         return -ENOMEM;
 424                 nd_pfn->align = align;
 425                 nd_pfn->mode = mode;
 426         } else {
 427                 /*
 428                  * When probing a pfn / dax instance we validate the
 429                  * live settings against the pfn_sb
 430                  */
 431                 if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
 432                         return -ENODEV;
 433
 434                 /*
 435                  * If the uuid validates, but other settings mismatch
 436                  * return EINVAL because userspace has managed to change
 437                  * the configuration without specifying new
 438                  * identification.
 439                  */
 440                 if (nd_pfn->align != align || nd_pfn->mode != mode) {
 441                         dev_err(&nd_pfn->dev,
 442                                         "init failed, settings mismatch\n");
 443                         dev_dbg(&nd_pfn->dev, "align: %lx:%lx mode: %d:%d\n",
 444                                         nd_pfn->align, align, nd_pfn->mode,
 445                                         mode);
 446                         return -EINVAL;
 447                 }
 448         }
 449
 450         if (align > nvdimm_namespace_capacity(ndns)) {
 451                 dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
 452                                 align, nvdimm_namespace_capacity(ndns));
 453                 return -EINVAL;
 454         }
 455
 456         /*
 457          * These warnings are verbose because they can only trigger in
 458          * the case where the physical address alignment of the
 459          * namespace has changed since the pfn superblock was
 460          * established.
 461          */
 462         nsio = to_nd_namespace_io(&ndns->dev);
 463         if (offset >= resource_size(&nsio->res)) {
 464                 dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
 465                                 dev_name(&ndns->dev));
 466                 return -EBUSY;
 467         }
 468
 469         if ((align && !IS_ALIGNED(nsio->res.start + offset + start_pad, align))
 470                         || !IS_ALIGNED(offset, PAGE_SIZE)) {
 471                 dev_err(&nd_pfn->dev,
 472                                 "bad offset: %#llx dax disabled align: %#lx\n",
 473                                 offset, align);
 474                 return -ENXIO;
 475         }
 476
 477         return 0;
 478 }
 479 EXPORT_SYMBOL(nd_pfn_validate);
 480
 481 int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns)
 482 {
 483         int rc;
 484         struct nd_pfn *nd_pfn;
 485         struct device *pfn_dev;
 486         struct nd_pfn_sb *pfn_sb;
 487         struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
 488
 489         if (ndns->force_raw)
 490                 return -ENODEV;
 491
 492         nvdimm_bus_lock(&ndns->dev);
 493         nd_pfn = nd_pfn_alloc(nd_region);
 494         pfn_dev = nd_pfn_devinit(nd_pfn, ndns);
 495         nvdimm_bus_unlock(&ndns->dev);
 496         if (!pfn_dev)
 497                 return -ENOMEM;
 498         pfn_sb = devm_kmalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
 499         nd_pfn = to_nd_pfn(pfn_dev);
 500         nd_pfn->pfn_sb = pfn_sb;
 501         rc = nd_pfn_validate(nd_pfn, PFN_SIG);
 502         dev_dbg(dev, "%s: pfn: %s\n", __func__,
 503                         rc == 0 ? dev_name(pfn_dev) : "<none>");
 504         if (rc < 0) {
 505                 __nd_detach_ndns(pfn_dev, &nd_pfn->ndns);
 506                 put_device(pfn_dev);
 507         } else
 508                 __nd_device_register(pfn_dev);
 509
 510         return rc;
 511 }
 512 EXPORT_SYMBOL(nd_pfn_probe);
 513
 514 /*
 515  * We hotplug memory at section granularity, pad the reserved area from
 516  * the previous section base to the namespace base address.
 517  */
 518 static unsigned long init_altmap_base(resource_size_t base)
 519 {
 520         unsigned long base_pfn = PHYS_PFN(base);
 521
 522         return PFN_SECTION_ALIGN_DOWN(base_pfn);
 523 }
 524
 525 static unsigned long init_altmap_reserve(resource_size_t base)
 526 {
 527         unsigned long reserve = PFN_UP(SZ_8K);
 528         unsigned long base_pfn = PHYS_PFN(base);
 529
 530         reserve += base_pfn - PFN_SECTION_ALIGN_DOWN(base_pfn);
 531         return reserve;
 532 }
 533
 534 static struct vmem_altmap *__nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
 535                 struct resource *res, struct vmem_altmap *altmap)
 536 {
 537         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 538         u64 offset = le64_to_cpu(pfn_sb->dataoff);
 539         u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
 540         u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
 541         struct nd_namespace_common *ndns = nd_pfn->ndns;
 542         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 543         resource_size_t base = nsio->res.start + start_pad;
 544         struct vmem_altmap __altmap = {
 545                 .base_pfn = init_altmap_base(base),
 546                 .reserve = init_altmap_reserve(base),
 547         };
 548
 549         memcpy(res, &nsio->res, sizeof(*res));
 550         res->start += start_pad;
 551         res->end -= end_trunc;
 552
 553         if (nd_pfn->mode == PFN_MODE_RAM) {
 554                 if (offset < SZ_8K)
 555                         return ERR_PTR(-EINVAL);
 556                 nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
 557                 altmap = NULL;
 558         } else if (nd_pfn->mode == PFN_MODE_PMEM) {
 559                 nd_pfn->npfns = PFN_SECTION_ALIGN_UP((resource_size(res)
 560                                         - offset) / PAGE_SIZE);
 561                 if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
 562                         dev_info(&nd_pfn->dev,
 563                                         "number of pfns truncated from %lld to %ld\n",
 564                                         le64_to_cpu(nd_pfn->pfn_sb->npfns),
 565                                         nd_pfn->npfns);
 566                 memcpy(altmap, &__altmap, sizeof(*altmap));
 567                 altmap->free = PHYS_PFN(offset - SZ_8K);
 568                 altmap->alloc = 0;
 569         } else
 570                 return ERR_PTR(-ENXIO);
 571
 572         return altmap;
 573 }
 574
 575 static u64 phys_pmem_align_down(struct nd_pfn *nd_pfn, u64 phys)
 576 {
 577         return min_t(u64, PHYS_SECTION_ALIGN_DOWN(phys),
 578                         ALIGN_DOWN(phys, nd_pfn->align));
 579 }
 580
 581 static int nd_pfn_init(struct nd_pfn *nd_pfn)
 582 {
 583         u32 dax_label_reserve = is_nd_dax(&nd_pfn->dev) ? SZ_128K : 0;
 584         struct nd_namespace_common *ndns = nd_pfn->ndns;
 585         u32 start_pad = 0, end_trunc = 0;
 586         resource_size_t start, size;
 587         struct nd_namespace_io *nsio;
 588         struct nd_region *nd_region;
 589         struct nd_pfn_sb *pfn_sb;
 590         unsigned long npfns;
 591         phys_addr_t offset;
 592         const char *sig;
 593         u64 checksum;
 594         int rc;
 595
 596         pfn_sb = devm_kmalloc(&nd_pfn->dev, sizeof(*pfn_sb), GFP_KERNEL);
 597         if (!pfn_sb)
 598                 return -ENOMEM;
 599
 600         nd_pfn->pfn_sb = pfn_sb;
 601         if (is_nd_dax(&nd_pfn->dev))
 602                 sig = DAX_SIG;
 603         else
 604                 sig = PFN_SIG;
 605
 606         rc = nd_pfn_validate(nd_pfn, sig);
 607         if (rc != -ENODEV)
 608                 return rc;
 609
 610         /* no info block, do init */;
 611         memset(pfn_sb, 0, sizeof(*pfn_sb));
 612
 613         nd_region = to_nd_region(nd_pfn->dev.parent);
 614         if (nd_region->ro) {
 615                 dev_info(&nd_pfn->dev,
 616                                 "%s is read-only, unable to init metadata\n",
 617                                 dev_name(&nd_region->dev));
 618                 return -ENXIO;
 619         }
 620
 621         memset(pfn_sb, 0, sizeof(*pfn_sb));
 622
 623         /*
 624          * Check if pmem collides with 'System RAM' when section aligned and
 625          * trim it accordingly
 626          */
 627         nsio = to_nd_namespace_io(&ndns->dev);
 628         start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start);
 629         size = resource_size(&nsio->res);
 630         if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
 631                                 IORES_DESC_NONE) == REGION_MIXED) {
 632                 start = nsio->res.start;
 633                 start_pad = PHYS_SECTION_ALIGN_UP(start) - start;
 634         }
 635
 636         start = nsio->res.start;
 637         size = PHYS_SECTION_ALIGN_UP(start + size) - start;
 638         if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
 639                                 IORES_DESC_NONE) == REGION_MIXED
 640                         || !IS_ALIGNED(start + resource_size(&nsio->res),
 641                                 nd_pfn->align)) {
 642                 size = resource_size(&nsio->res);
 643                 end_trunc = start + size - phys_pmem_align_down(nd_pfn,
 644                                 start + size);
 645         }
 646
 647         if (start_pad + end_trunc)
 648                 dev_info(&nd_pfn->dev, "%s alignment collision, truncate %d bytes\n",
 649                                 dev_name(&ndns->dev), start_pad + end_trunc);
 650
 651         /*
 652          * Note, we use 64 here for the standard size of struct page,
 653          * debugging options may cause it to be larger in which case the
 654          * implementation will limit the pfns advertised through
 655          * ->direct_access() to those that are included in the memmap.
 656          */
 657         start += start_pad;
 658         size = resource_size(&nsio->res);
 659         npfns = PFN_SECTION_ALIGN_UP((size - start_pad - end_trunc - SZ_8K)
 660                         / PAGE_SIZE);
 661         if (nd_pfn->mode == PFN_MODE_PMEM) {
 662                 /*
 663                  * vmemmap_populate_hugepages() allocates the memmap array in
 664                  * HPAGE_SIZE chunks.
 665                  */
 666                 offset = ALIGN(start + SZ_8K + 64 * npfns + dax_label_reserve,
 667                                 max(nd_pfn->align, HPAGE_SIZE)) - start;
 668         } else if (nd_pfn->mode == PFN_MODE_RAM)
 669                 offset = ALIGN(start + SZ_8K + dax_label_reserve,
 670                                 nd_pfn->align) - start;
 671         else
 672                 return -ENXIO;
 673
 674         if (offset + start_pad + end_trunc >= size) {
 675                 dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
 676                                 dev_name(&ndns->dev));
 677                 return -ENXIO;
 678         }
 679
 680         npfns = (size - offset - start_pad - end_trunc) / SZ_4K;
 681         pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
 682         pfn_sb->dataoff = cpu_to_le64(offset);
 683         pfn_sb->npfns = cpu_to_le64(npfns);
 684         memcpy(pfn_sb->signature, sig, PFN_SIG_LEN);
 685         memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
 686         memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
 687         pfn_sb->version_major = cpu_to_le16(1);
 688         pfn_sb->version_minor = cpu_to_le16(3);
 689         pfn_sb->start_pad = cpu_to_le32(start_pad);
 690         pfn_sb->end_trunc = cpu_to_le32(end_trunc);
 691         pfn_sb->align = cpu_to_le32(nd_pfn->align);
 692         checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
 693         pfn_sb->checksum = cpu_to_le64(checksum);
 694
 695         return nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb));
 696 }
 697
 698 /*
 699  * Determine the effective resource range and vmem_altmap from an nd_pfn
 700  * instance.
 701  */
 702 struct vmem_altmap *nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
 703                 struct resource *res, struct vmem_altmap *altmap)
 704 {
 705         int rc;
 706
 707         if (!nd_pfn->uuid || !nd_pfn->ndns)
 708                 return ERR_PTR(-ENODEV);
 709
 710         rc = nd_pfn_init(nd_pfn);
 711         if (rc)
 712                 return ERR_PTR(rc);
 713
 714         /* we need a valid pfn_sb before we can init a vmem_altmap */
 715         return __nvdimm_setup_pfn(nd_pfn, res, altmap);
 716 }
 717 EXPORT_SYMBOL_GPL(nvdimm_setup_pfn);