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 const unsigned long *nd_pfn_supported_alignments(void)
 115 {
 116         /*
 117          * This needs to be a non-static variable because the *_SIZE
 118          * macros aren't always constants.
 119          */
 120         const unsigned long supported_alignments[] = {
 121                 PAGE_SIZE,
 122 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 123                 HPAGE_PMD_SIZE,
 124 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
 125                 HPAGE_PUD_SIZE,
 126 #endif
 127 #endif
 128                 0,
 129         };
 130         static unsigned long data[ARRAY_SIZE(supported_alignments)];
 131
 132         memcpy(data, supported_alignments, sizeof(data));
 133
 134         return data;
 135 }
 136
 137 static ssize_t __align_store(struct nd_pfn *nd_pfn, const char *buf)
 138 {
 139         unsigned long val;
 140         int rc;
 141
 142         rc = kstrtoul(buf, 0, &val);
 143         if (rc)
 144                 return rc;
 145
 146         if (!is_power_of_2(val) || val < PAGE_SIZE || val > SZ_1G)
 147                 return -EINVAL;
 148
 149         if (nd_pfn->dev.driver)
 150                 return -EBUSY;
 151         else
 152                 nd_pfn->align = val;
 153
 154         return 0;
 155 }
 156
 157 static ssize_t align_store(struct device *dev,
 158                 struct device_attribute *attr, const char *buf, size_t len)
 159 {
 160         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 161         ssize_t rc;
 162
 163         device_lock(dev);
 164         nvdimm_bus_lock(dev);
 165         rc = __align_store(nd_pfn, buf);
 166         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 167                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
 168         nvdimm_bus_unlock(dev);
 169         device_unlock(dev);
 170
 171         return rc ? rc : len;
 172 }
 173 static DEVICE_ATTR_RW(align);
 174
 175 static ssize_t uuid_show(struct device *dev,
 176                 struct device_attribute *attr, char *buf)
 177 {
 178         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 179
 180         if (nd_pfn->uuid)
 181                 return sprintf(buf, "%pUb\n", nd_pfn->uuid);
 182         return sprintf(buf, "\n");
 183 }
 184
 185 static ssize_t uuid_store(struct device *dev,
 186                 struct device_attribute *attr, const char *buf, size_t len)
 187 {
 188         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 189         ssize_t rc;
 190
 191         device_lock(dev);
 192         rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len);
 193         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 194                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
 195         device_unlock(dev);
 196
 197         return rc ? rc : len;
 198 }
 199 static DEVICE_ATTR_RW(uuid);
 200
 201 static ssize_t namespace_show(struct device *dev,
 202                 struct device_attribute *attr, char *buf)
 203 {
 204         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 205         ssize_t rc;
 206
 207         nvdimm_bus_lock(dev);
 208         rc = sprintf(buf, "%s\n", nd_pfn->ndns
 209                         ? dev_name(&nd_pfn->ndns->dev) : "");
 210         nvdimm_bus_unlock(dev);
 211         return rc;
 212 }
 213
 214 static ssize_t namespace_store(struct device *dev,
 215                 struct device_attribute *attr, const char *buf, size_t len)
 216 {
 217         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 218         ssize_t rc;
 219
 220         device_lock(dev);
 221         nvdimm_bus_lock(dev);
 222         rc = nd_namespace_store(dev, &nd_pfn->ndns, buf, len);
 223         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 224                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
 225         nvdimm_bus_unlock(dev);
 226         device_unlock(dev);
 227
 228         return rc;
 229 }
 230 static DEVICE_ATTR_RW(namespace);
 231
 232 static ssize_t resource_show(struct device *dev,
 233                 struct device_attribute *attr, char *buf)
 234 {
 235         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 236         ssize_t rc;
 237
 238         device_lock(dev);
 239         if (dev->driver) {
 240                 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 241                 u64 offset = __le64_to_cpu(pfn_sb->dataoff);
 242                 struct nd_namespace_common *ndns = nd_pfn->ndns;
 243                 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
 244                 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 245
 246                 rc = sprintf(buf, "%#llx\n", (unsigned long long) nsio->res.start
 247                                 + start_pad + offset);
 248         } else {
 249                 /* no address to convey if the pfn instance is disabled */
 250                 rc = -ENXIO;
 251         }
 252         device_unlock(dev);
 253
 254         return rc;
 255 }
 256 static DEVICE_ATTR_RO(resource);
 257
 258 static ssize_t size_show(struct device *dev,
 259                 struct device_attribute *attr, char *buf)
 260 {
 261         struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 262         ssize_t rc;
 263
 264         device_lock(dev);
 265         if (dev->driver) {
 266                 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 267                 u64 offset = __le64_to_cpu(pfn_sb->dataoff);
 268                 struct nd_namespace_common *ndns = nd_pfn->ndns;
 269                 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
 270                 u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
 271                 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 272
 273                 rc = sprintf(buf, "%llu\n", (unsigned long long)
 274                                 resource_size(&nsio->res) - start_pad
 275                                 - end_trunc - offset);
 276         } else {
 277                 /* no size to convey if the pfn instance is disabled */
 278                 rc = -ENXIO;
 279         }
 280         device_unlock(dev);
 281
 282         return rc;
 283 }
 284 static DEVICE_ATTR_RO(size);
 285
 286 static ssize_t supported_alignments_show(struct device *dev,
 287                 struct device_attribute *attr, char *buf)
 288 {
 289         return nd_size_select_show(0, nd_pfn_supported_alignments(), buf);
 290 }
 291 static DEVICE_ATTR_RO(supported_alignments);
 292
 293 static struct attribute *nd_pfn_attributes[] = {
 294         &dev_attr_mode.attr,
 295         &dev_attr_namespace.attr,
 296         &dev_attr_uuid.attr,
 297         &dev_attr_align.attr,
 298         &dev_attr_resource.attr,
 299         &dev_attr_size.attr,
 300         &dev_attr_supported_alignments.attr,
 301         NULL,
 302 };
 303
 304 struct attribute_group nd_pfn_attribute_group = {
 305         .attrs = nd_pfn_attributes,
 306 };
 307
 308 static const struct attribute_group *nd_pfn_attribute_groups[] = {
 309         &nd_pfn_attribute_group,
 310         &nd_device_attribute_group,
 311         &nd_numa_attribute_group,
 312         NULL,
 313 };
 314
 315 struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
 316                 struct nd_namespace_common *ndns)
 317 {
 318         struct device *dev = &nd_pfn->dev;
 319
 320         if (!nd_pfn)
 321                 return NULL;
 322
 323         nd_pfn->mode = PFN_MODE_NONE;
 324         nd_pfn->align = PFN_DEFAULT_ALIGNMENT;
 325         dev = &nd_pfn->dev;
 326         device_initialize(&nd_pfn->dev);
 327         if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
 328                 dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
 329                                 __func__, dev_name(ndns->claim));
 330                 put_device(dev);
 331                 return NULL;
 332         }
 333         return dev;
 334 }
 335
 336 static struct nd_pfn *nd_pfn_alloc(struct nd_region *nd_region)
 337 {
 338         struct nd_pfn *nd_pfn;
 339         struct device *dev;
 340
 341         nd_pfn = kzalloc(sizeof(*nd_pfn), GFP_KERNEL);
 342         if (!nd_pfn)
 343                 return NULL;
 344
 345         nd_pfn->id = ida_simple_get(&nd_region->pfn_ida, 0, 0, GFP_KERNEL);
 346         if (nd_pfn->id < 0) {
 347                 kfree(nd_pfn);
 348                 return NULL;
 349         }
 350
 351         dev = &nd_pfn->dev;
 352         dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
 353         dev->groups = nd_pfn_attribute_groups;
 354         dev->type = &nd_pfn_device_type;
 355         dev->parent = &nd_region->dev;
 356
 357         return nd_pfn;
 358 }
 359
 360 struct device *nd_pfn_create(struct nd_region *nd_region)
 361 {
 362         struct nd_pfn *nd_pfn;
 363         struct device *dev;
 364
 365         if (!is_memory(&nd_region->dev))
 366                 return NULL;
 367
 368         nd_pfn = nd_pfn_alloc(nd_region);
 369         dev = nd_pfn_devinit(nd_pfn, NULL);
 370
 371         __nd_device_register(dev);
 372         return dev;
 373 }
 374
 375 int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
 376 {
 377         u64 checksum, offset;
 378         unsigned long align;
 379         enum nd_pfn_mode mode;
 380         struct nd_namespace_io *nsio;
 381         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 382         struct nd_namespace_common *ndns = nd_pfn->ndns;
 383         const u8 *parent_uuid = nd_dev_to_uuid(&ndns->dev);
 384
 385         if (!pfn_sb || !ndns)
 386                 return -ENODEV;
 387
 388         if (!is_memory(nd_pfn->dev.parent))
 389                 return -ENODEV;
 390
 391         if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0))
 392                 return -ENXIO;
 393
 394         if (memcmp(pfn_sb->signature, sig, PFN_SIG_LEN) != 0)
 395                 return -ENODEV;
 396
 397         checksum = le64_to_cpu(pfn_sb->checksum);
 398         pfn_sb->checksum = 0;
 399         if (checksum != nd_sb_checksum((struct nd_gen_sb *) pfn_sb))
 400                 return -ENODEV;
 401         pfn_sb->checksum = cpu_to_le64(checksum);
 402
 403         if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
 404                 return -ENODEV;
 405
 406         if (__le16_to_cpu(pfn_sb->version_minor) < 1) {
 407                 pfn_sb->start_pad = 0;
 408                 pfn_sb->end_trunc = 0;
 409         }
 410
 411         if (__le16_to_cpu(pfn_sb->version_minor) < 2)
 412                 pfn_sb->align = 0;
 413
 414         switch (le32_to_cpu(pfn_sb->mode)) {
 415         case PFN_MODE_RAM:
 416         case PFN_MODE_PMEM:
 417                 break;
 418         default:
 419                 return -ENXIO;
 420         }
 421
 422         align = le32_to_cpu(pfn_sb->align);
 423         offset = le64_to_cpu(pfn_sb->dataoff);
 424         if (align == 0)
 425                 align = 1UL << ilog2(offset);
 426         mode = le32_to_cpu(pfn_sb->mode);
 427
 428         if (!nd_pfn->uuid) {
 429                 /*
 430                  * When probing a namepace via nd_pfn_probe() the uuid
 431                  * is NULL (see: nd_pfn_devinit()) we init settings from
 432                  * pfn_sb
 433                  */
 434                 nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
 435                 if (!nd_pfn->uuid)
 436                         return -ENOMEM;
 437                 nd_pfn->align = align;
 438                 nd_pfn->mode = mode;
 439         } else {
 440                 /*
 441                  * When probing a pfn / dax instance we validate the
 442                  * live settings against the pfn_sb
 443                  */
 444                 if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
 445                         return -ENODEV;
 446
 447                 /*
 448                  * If the uuid validates, but other settings mismatch
 449                  * return EINVAL because userspace has managed to change
 450                  * the configuration without specifying new
 451                  * identification.
 452                  */
 453                 if (nd_pfn->align != align || nd_pfn->mode != mode) {
 454                         dev_err(&nd_pfn->dev,
 455                                         "init failed, settings mismatch\n");
 456                         dev_dbg(&nd_pfn->dev, "align: %lx:%lx mode: %d:%d\n",
 457                                         nd_pfn->align, align, nd_pfn->mode,
 458                                         mode);
 459                         return -EINVAL;
 460                 }
 461         }
 462
 463         if (align > nvdimm_namespace_capacity(ndns)) {
 464                 dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
 465                                 align, nvdimm_namespace_capacity(ndns));
 466                 return -EINVAL;
 467         }
 468
 469         /*
 470          * These warnings are verbose because they can only trigger in
 471          * the case where the physical address alignment of the
 472          * namespace has changed since the pfn superblock was
 473          * established.
 474          */
 475         nsio = to_nd_namespace_io(&ndns->dev);
 476         if (offset >= resource_size(&nsio->res)) {
 477                 dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
 478                                 dev_name(&ndns->dev));
 479                 return -EBUSY;
 480         }
 481
 482         if ((align && !IS_ALIGNED(offset, align))
 483                         || !IS_ALIGNED(offset, PAGE_SIZE)) {
 484                 dev_err(&nd_pfn->dev,
 485                                 "bad offset: %#llx dax disabled align: %#lx\n",
 486                                 offset, align);
 487                 return -ENXIO;
 488         }
 489
 490         return 0;
 491 }
 492 EXPORT_SYMBOL(nd_pfn_validate);
 493
 494 int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns)
 495 {
 496         int rc;
 497         struct nd_pfn *nd_pfn;
 498         struct device *pfn_dev;
 499         struct nd_pfn_sb *pfn_sb;
 500         struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
 501
 502         if (ndns->force_raw)
 503                 return -ENODEV;
 504
 505         switch (ndns->claim_class) {
 506         case NVDIMM_CCLASS_NONE:
 507         case NVDIMM_CCLASS_PFN:
 508                 break;
 509         default:
 510                 return -ENODEV;
 511         }
 512
 513         nvdimm_bus_lock(&ndns->dev);
 514         nd_pfn = nd_pfn_alloc(nd_region);
 515         pfn_dev = nd_pfn_devinit(nd_pfn, ndns);
 516         nvdimm_bus_unlock(&ndns->dev);
 517         if (!pfn_dev)
 518                 return -ENOMEM;
 519         pfn_sb = devm_kzalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
 520         nd_pfn = to_nd_pfn(pfn_dev);
 521         nd_pfn->pfn_sb = pfn_sb;
 522         rc = nd_pfn_validate(nd_pfn, PFN_SIG);
 523         dev_dbg(dev, "%s: pfn: %s\n", __func__,
 524                         rc == 0 ? dev_name(pfn_dev) : "<none>");
 525         if (rc < 0) {
 526                 nd_detach_ndns(pfn_dev, &nd_pfn->ndns);
 527                 put_device(pfn_dev);
 528         } else
 529                 __nd_device_register(pfn_dev);
 530
 531         return rc;
 532 }
 533 EXPORT_SYMBOL(nd_pfn_probe);
 534
 535 /*
 536  * We hotplug memory at section granularity, pad the reserved area from
 537  * the previous section base to the namespace base address.
 538  */
 539 static unsigned long init_altmap_base(resource_size_t base)
 540 {
 541         unsigned long base_pfn = PHYS_PFN(base);
 542
 543         return PFN_SECTION_ALIGN_DOWN(base_pfn);
 544 }
 545
 546 static unsigned long init_altmap_reserve(resource_size_t base)
 547 {
 548         unsigned long reserve = PHYS_PFN(SZ_8K);
 549         unsigned long base_pfn = PHYS_PFN(base);
 550
 551         reserve += base_pfn - PFN_SECTION_ALIGN_DOWN(base_pfn);
 552         return reserve;
 553 }
 554
 555 static struct vmem_altmap *__nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
 556                 struct resource *res, struct vmem_altmap *altmap)
 557 {
 558         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 559         u64 offset = le64_to_cpu(pfn_sb->dataoff);
 560         u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
 561         u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
 562         struct nd_namespace_common *ndns = nd_pfn->ndns;
 563         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 564         resource_size_t base = nsio->res.start + start_pad;
 565         struct vmem_altmap __altmap = {
 566                 .base_pfn = init_altmap_base(base),
 567                 .reserve = init_altmap_reserve(base),
 568         };
 569
 570         memcpy(res, &nsio->res, sizeof(*res));
 571         res->start += start_pad;
 572         res->end -= end_trunc;
 573
 574         if (nd_pfn->mode == PFN_MODE_RAM) {
 575                 if (offset < SZ_8K)
 576                         return ERR_PTR(-EINVAL);
 577                 nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
 578                 altmap = NULL;
 579         } else if (nd_pfn->mode == PFN_MODE_PMEM) {
 580                 nd_pfn->npfns = PFN_SECTION_ALIGN_UP((resource_size(res)
 581                                         - offset) / PAGE_SIZE);
 582                 if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
 583                         dev_info(&nd_pfn->dev,
 584                                         "number of pfns truncated from %lld to %ld\n",
 585                                         le64_to_cpu(nd_pfn->pfn_sb->npfns),
 586                                         nd_pfn->npfns);
 587                 memcpy(altmap, &__altmap, sizeof(*altmap));
 588                 altmap->free = PHYS_PFN(offset - SZ_8K);
 589                 altmap->alloc = 0;
 590         } else
 591                 return ERR_PTR(-ENXIO);
 592
 593         return altmap;
 594 }
 595
 596 static int nd_pfn_init(struct nd_pfn *nd_pfn)
 597 {
 598         u32 dax_label_reserve = is_nd_dax(&nd_pfn->dev) ? SZ_128K : 0;
 599         struct nd_namespace_common *ndns = nd_pfn->ndns;
 600         u32 start_pad = 0, end_trunc = 0;
 601         resource_size_t start, size;
 602         struct nd_namespace_io *nsio;
 603         struct nd_region *nd_region;
 604         struct nd_pfn_sb *pfn_sb;
 605         unsigned long npfns;
 606         phys_addr_t offset;
 607         const char *sig;
 608         u64 checksum;
 609         int rc;
 610
 611         pfn_sb = devm_kzalloc(&nd_pfn->dev, sizeof(*pfn_sb), GFP_KERNEL);
 612         if (!pfn_sb)
 613                 return -ENOMEM;
 614
 615         nd_pfn->pfn_sb = pfn_sb;
 616         if (is_nd_dax(&nd_pfn->dev))
 617                 sig = DAX_SIG;
 618         else
 619                 sig = PFN_SIG;
 620         rc = nd_pfn_validate(nd_pfn, sig);
 621         if (rc != -ENODEV)
 622                 return rc;
 623
 624         /* no info block, do init */;
 625         nd_region = to_nd_region(nd_pfn->dev.parent);
 626         if (nd_region->ro) {
 627                 dev_info(&nd_pfn->dev,
 628                                 "%s is read-only, unable to init metadata\n",
 629                                 dev_name(&nd_region->dev));
 630                 return -ENXIO;
 631         }
 632
 633         memset(pfn_sb, 0, sizeof(*pfn_sb));
 634
 635         /*
 636          * Check if pmem collides with 'System RAM' when section aligned and
 637          * trim it accordingly
 638          */
 639         nsio = to_nd_namespace_io(&ndns->dev);
 640         start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start);
 641         size = resource_size(&nsio->res);
 642         if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
 643                                 IORES_DESC_NONE) == REGION_MIXED) {
 644                 start = nsio->res.start;
 645                 start_pad = PHYS_SECTION_ALIGN_UP(start) - start;
 646         }
 647
 648         start = nsio->res.start;
 649         size = PHYS_SECTION_ALIGN_UP(start + size) - start;
 650         if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
 651                                 IORES_DESC_NONE) == REGION_MIXED) {
 652                 size = resource_size(&nsio->res);
 653                 end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size);
 654         }
 655
 656         if (start_pad + end_trunc)
 657                 dev_info(&nd_pfn->dev, "%s section collision, truncate %d bytes\n",
 658                                 dev_name(&ndns->dev), start_pad + end_trunc);
 659
 660         /*
 661          * Note, we use 64 here for the standard size of struct page,
 662          * debugging options may cause it to be larger in which case the
 663          * implementation will limit the pfns advertised through
 664          * ->direct_access() to those that are included in the memmap.
 665          */
 666         start += start_pad;
 667         size = resource_size(&nsio->res);
 668         npfns = PFN_SECTION_ALIGN_UP((size - start_pad - end_trunc - SZ_8K)
 669                         / PAGE_SIZE);
 670         if (nd_pfn->mode == PFN_MODE_PMEM) {
 671                 /*
 672                  * The altmap should be padded out to the block size used
 673                  * when populating the vmemmap. This *should* be equal to
 674                  * PMD_SIZE for most architectures.
 675                  */
 676                 offset = ALIGN(start + SZ_8K + 64 * npfns + dax_label_reserve,
 677                                 max(nd_pfn->align, PMD_SIZE)) - start;
 678         } else if (nd_pfn->mode == PFN_MODE_RAM)
 679                 offset = ALIGN(start + SZ_8K + dax_label_reserve,
 680                                 nd_pfn->align) - start;
 681         else
 682                 return -ENXIO;
 683
 684         if (offset + start_pad + end_trunc >= size) {
 685                 dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
 686                                 dev_name(&ndns->dev));
 687                 return -ENXIO;
 688         }
 689
 690         npfns = (size - offset - start_pad - end_trunc) / SZ_4K;
 691         pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
 692         pfn_sb->dataoff = cpu_to_le64(offset);
 693         pfn_sb->npfns = cpu_to_le64(npfns);
 694         memcpy(pfn_sb->signature, sig, PFN_SIG_LEN);
 695         memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
 696         memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
 697         pfn_sb->version_major = cpu_to_le16(1);
 698         pfn_sb->version_minor = cpu_to_le16(2);
 699         pfn_sb->start_pad = cpu_to_le32(start_pad);
 700         pfn_sb->end_trunc = cpu_to_le32(end_trunc);
 701         pfn_sb->align = cpu_to_le32(nd_pfn->align);
 702         checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
 703         pfn_sb->checksum = cpu_to_le64(checksum);
 704
 705         return nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0);
 706 }
 707
 708 /*
 709  * Determine the effective resource range and vmem_altmap from an nd_pfn
 710  * instance.
 711  */
 712 struct vmem_altmap *nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
 713                 struct resource *res, struct vmem_altmap *altmap)
 714 {
 715         int rc;
 716
 717         if (!nd_pfn->uuid || !nd_pfn->ndns)
 718                 return ERR_PTR(-ENODEV);
 719
 720         rc = nd_pfn_init(nd_pfn);
 721         if (rc)
 722                 return ERR_PTR(rc);
 723
 724         /* we need a valid pfn_sb before we can init a vmem_altmap */
 725         return __nvdimm_setup_pfn(nd_pfn, res, altmap);
 726 }
 727 EXPORT_SYMBOL_GPL(nvdimm_setup_pfn);