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/genhd.h> 9 #include <linux/sizes.h> 10 #include <linux/slab.h> 11 #include <linux/fs.h> 12 #include <linux/mm.h> 13 #include "nd-core.h" 14 #include "pfn.h" 15 #include "nd.h" 16 17 static void nd_pfn_release(struct device *dev) 18 { 19 struct nd_region *nd_region = to_nd_region(dev->parent); 20 struct nd_pfn *nd_pfn = to_nd_pfn(dev); 21 22 dev_dbg(dev, "trace\n"); 23 nd_detach_ndns(&nd_pfn->dev, &nd_pfn->ndns); 24 ida_simple_remove(&nd_region->pfn_ida, nd_pfn->id); 25 kfree(nd_pfn->uuid); 26 kfree(nd_pfn); 27 } 28 29 static struct device_type nd_pfn_device_type = { 30 .name = "nd_pfn", 31 .release = nd_pfn_release, 32 }; 33 34 bool is_nd_pfn(struct device *dev) 35 { 36 return dev ? dev->type == &nd_pfn_device_type : false; 37 } 38 EXPORT_SYMBOL(is_nd_pfn); 39 40 struct nd_pfn *to_nd_pfn(struct device *dev) 41 { 42 struct nd_pfn *nd_pfn = container_of(dev, struct nd_pfn, dev); 43 44 WARN_ON(!is_nd_pfn(dev)); 45 return nd_pfn; 46 } 47 EXPORT_SYMBOL(to_nd_pfn); 48 49 static ssize_t mode_show(struct device *dev, 50 struct device_attribute *attr, char *buf) 51 { 52 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev); 53 54 switch (nd_pfn->mode) { 55 case PFN_MODE_RAM: 56 return sprintf(buf, "ram\n"); 57 case PFN_MODE_PMEM: 58 return sprintf(buf, "pmem\n"); 59 default: 60 return sprintf(buf, "none\n"); 61 } 62 } 63 64 static ssize_t mode_store(struct device *dev, 65 struct device_attribute *attr, const char *buf, size_t len) 66 { 67 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev); 68 ssize_t rc = 0; 69 70 nd_device_lock(dev); 71 nvdimm_bus_lock(dev); 72 if (dev->driver) 73 rc = -EBUSY; 74 else { 75 size_t n = len - 1; 76 77 if (strncmp(buf, "pmem\n", n) == 0 78 || strncmp(buf, "pmem", n) == 0) { 79 nd_pfn->mode = PFN_MODE_PMEM; 80 } else if (strncmp(buf, "ram\n", n) == 0 81 || strncmp(buf, "ram", n) == 0) 82 nd_pfn->mode = PFN_MODE_RAM; 83 else if (strncmp(buf, "none\n", n) == 0 84 || strncmp(buf, "none", n) == 0) 85 nd_pfn->mode = PFN_MODE_NONE; 86 else 87 rc = -EINVAL; 88 } 89 dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf, 90 buf[len - 1] == '\n' ? "" : "\n"); 91 nvdimm_bus_unlock(dev); 92 nd_device_unlock(dev); 93 94 return rc ? rc : len; 95 } 96 static DEVICE_ATTR_RW(mode); 97 98 static ssize_t align_show(struct device *dev, 99 struct device_attribute *attr, char *buf) 100 { 101 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev); 102 103 return sprintf(buf, "%ld\n", nd_pfn->align); 104 } 105 106 static const unsigned long *nd_pfn_supported_alignments(void) 107 { 108 /* 109 * This needs to be a non-static variable because the *_SIZE 110 * macros aren't always constants. 111 */ 112 const unsigned long supported_alignments[] = { 113 PAGE_SIZE, 114 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 115 HPAGE_PMD_SIZE, 116 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD 117 HPAGE_PUD_SIZE, 118 #endif 119 #endif 120 0, 121 }; 122 static unsigned long data[ARRAY_SIZE(supported_alignments)]; 123 124 memcpy(data, supported_alignments, sizeof(data)); 125 126 return data; 127 } 128 129 static ssize_t align_store(struct device *dev, 130 struct device_attribute *attr, const char *buf, size_t len) 131 { 132 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev); 133 ssize_t rc; 134 135 nd_device_lock(dev); 136 nvdimm_bus_lock(dev); 137 rc = nd_size_select_store(dev, buf, &nd_pfn->align, 138 nd_pfn_supported_alignments()); 139 dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf, 140 buf[len - 1] == '\n' ? "" : "\n"); 141 nvdimm_bus_unlock(dev); 142 nd_device_unlock(dev); 143 144 return rc ? rc : len; 145 } 146 static DEVICE_ATTR_RW(align); 147 148 static ssize_t uuid_show(struct device *dev, 149 struct device_attribute *attr, char *buf) 150 { 151 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev); 152 153 if (nd_pfn->uuid) 154 return sprintf(buf, "%pUb\n", nd_pfn->uuid); 155 return sprintf(buf, "\n"); 156 } 157 158 static ssize_t uuid_store(struct device *dev, 159 struct device_attribute *attr, const char *buf, size_t len) 160 { 161 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev); 162 ssize_t rc; 163 164 nd_device_lock(dev); 165 rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len); 166 dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf, 167 buf[len - 1] == '\n' ? "" : "\n"); 168 nd_device_unlock(dev); 169 170 return rc ? rc : len; 171 } 172 static DEVICE_ATTR_RW(uuid); 173 174 static ssize_t namespace_show(struct device *dev, 175 struct device_attribute *attr, char *buf) 176 { 177 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev); 178 ssize_t rc; 179 180 nvdimm_bus_lock(dev); 181 rc = sprintf(buf, "%s\n", nd_pfn->ndns 182 ? dev_name(&nd_pfn->ndns->dev) : ""); 183 nvdimm_bus_unlock(dev); 184 return rc; 185 } 186 187 static ssize_t namespace_store(struct device *dev, 188 struct device_attribute *attr, const char *buf, size_t len) 189 { 190 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev); 191 ssize_t rc; 192 193 nd_device_lock(dev); 194 nvdimm_bus_lock(dev); 195 rc = nd_namespace_store(dev, &nd_pfn->ndns, buf, len); 196 dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf, 197 buf[len - 1] == '\n' ? "" : "\n"); 198 nvdimm_bus_unlock(dev); 199 nd_device_unlock(dev); 200 201 return rc; 202 } 203 static DEVICE_ATTR_RW(namespace); 204 205 static ssize_t resource_show(struct device *dev, 206 struct device_attribute *attr, char *buf) 207 { 208 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev); 209 ssize_t rc; 210 211 nd_device_lock(dev); 212 if (dev->driver) { 213 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb; 214 u64 offset = __le64_to_cpu(pfn_sb->dataoff); 215 struct nd_namespace_common *ndns = nd_pfn->ndns; 216 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad); 217 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); 218 219 rc = sprintf(buf, "%#llx\n", (unsigned long long) nsio->res.start 220 + start_pad + offset); 221 } else { 222 /* no address to convey if the pfn instance is disabled */ 223 rc = -ENXIO; 224 } 225 nd_device_unlock(dev); 226 227 return rc; 228 } 229 static DEVICE_ATTR_RO(resource); 230 231 static ssize_t size_show(struct device *dev, 232 struct device_attribute *attr, char *buf) 233 { 234 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev); 235 ssize_t rc; 236 237 nd_device_lock(dev); 238 if (dev->driver) { 239 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb; 240 u64 offset = __le64_to_cpu(pfn_sb->dataoff); 241 struct nd_namespace_common *ndns = nd_pfn->ndns; 242 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad); 243 u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc); 244 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); 245 246 rc = sprintf(buf, "%llu\n", (unsigned long long) 247 resource_size(&nsio->res) - start_pad 248 - end_trunc - offset); 249 } else { 250 /* no size to convey if the pfn instance is disabled */ 251 rc = -ENXIO; 252 } 253 nd_device_unlock(dev); 254 255 return rc; 256 } 257 static DEVICE_ATTR_RO(size); 258 259 static ssize_t supported_alignments_show(struct device *dev, 260 struct device_attribute *attr, char *buf) 261 { 262 return nd_size_select_show(0, nd_pfn_supported_alignments(), buf); 263 } 264 static DEVICE_ATTR_RO(supported_alignments); 265 266 static struct attribute *nd_pfn_attributes[] = { 267 &dev_attr_mode.attr, 268 &dev_attr_namespace.attr, 269 &dev_attr_uuid.attr, 270 &dev_attr_align.attr, 271 &dev_attr_resource.attr, 272 &dev_attr_size.attr, 273 &dev_attr_supported_alignments.attr, 274 NULL, 275 }; 276 277 static umode_t pfn_visible(struct kobject *kobj, struct attribute *a, int n) 278 { 279 if (a == &dev_attr_resource.attr) 280 return 0400; 281 return a->mode; 282 } 283 284 struct attribute_group nd_pfn_attribute_group = { 285 .attrs = nd_pfn_attributes, 286 .is_visible = pfn_visible, 287 }; 288 289 static const struct attribute_group *nd_pfn_attribute_groups[] = { 290 &nd_pfn_attribute_group, 291 &nd_device_attribute_group, 292 &nd_numa_attribute_group, 293 NULL, 294 }; 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 = PFN_DEFAULT_ALIGNMENT; 306 dev = &nd_pfn->dev; 307 device_initialize(&nd_pfn->dev); 308 if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) { 309 dev_dbg(&ndns->dev, "failed, already claimed by %s\n", 310 dev_name(ndns->claim)); 311 put_device(dev); 312 return NULL; 313 } 314 return dev; 315 } 316 317 static struct nd_pfn *nd_pfn_alloc(struct nd_region *nd_region) 318 { 319 struct nd_pfn *nd_pfn; 320 struct device *dev; 321 322 nd_pfn = kzalloc(sizeof(*nd_pfn), GFP_KERNEL); 323 if (!nd_pfn) 324 return NULL; 325 326 nd_pfn->id = ida_simple_get(&nd_region->pfn_ida, 0, 0, GFP_KERNEL); 327 if (nd_pfn->id < 0) { 328 kfree(nd_pfn); 329 return NULL; 330 } 331 332 dev = &nd_pfn->dev; 333 dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id); 334 dev->groups = nd_pfn_attribute_groups; 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 do { 380 unsigned long zero_len; 381 u64 nsoff; 382 383 bb_present = badblocks_check(&nd_region->bb, meta_start, 384 meta_num, &first_bad, &num_bad); 385 if (bb_present) { 386 dev_dbg(&nd_pfn->dev, "meta: %x badblocks at %llx\n", 387 num_bad, first_bad); 388 nsoff = ALIGN_DOWN((nd_region->ndr_start 389 + (first_bad << 9)) - nsio->res.start, 390 PAGE_SIZE); 391 zero_len = ALIGN(num_bad << 9, PAGE_SIZE); 392 while (zero_len) { 393 unsigned long chunk = min(zero_len, PAGE_SIZE); 394 395 rc = nvdimm_write_bytes(ndns, nsoff, zero_page, 396 chunk, 0); 397 if (rc) 398 break; 399 400 zero_len -= chunk; 401 nsoff += chunk; 402 } 403 if (rc) { 404 dev_err(&nd_pfn->dev, 405 "error clearing %x badblocks at %llx\n", 406 num_bad, first_bad); 407 return rc; 408 } 409 } 410 } while (bb_present); 411 412 return 0; 413 } 414 415 /** 416 * nd_pfn_validate - read and validate info-block 417 * @nd_pfn: fsdax namespace runtime state / properties 418 * @sig: 'devdax' or 'fsdax' signature 419 * 420 * Upon return the info-block buffer contents (->pfn_sb) are 421 * indeterminate when validation fails, and a coherent info-block 422 * otherwise. 423 */ 424 int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig) 425 { 426 u64 checksum, offset; 427 enum nd_pfn_mode mode; 428 struct nd_namespace_io *nsio; 429 unsigned long align, start_pad; 430 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb; 431 struct nd_namespace_common *ndns = nd_pfn->ndns; 432 const u8 *parent_uuid = nd_dev_to_uuid(&ndns->dev); 433 434 if (!pfn_sb || !ndns) 435 return -ENODEV; 436 437 if (!is_memory(nd_pfn->dev.parent)) 438 return -ENODEV; 439 440 if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0)) 441 return -ENXIO; 442 443 if (memcmp(pfn_sb->signature, sig, PFN_SIG_LEN) != 0) 444 return -ENODEV; 445 446 checksum = le64_to_cpu(pfn_sb->checksum); 447 pfn_sb->checksum = 0; 448 if (checksum != nd_sb_checksum((struct nd_gen_sb *) pfn_sb)) 449 return -ENODEV; 450 pfn_sb->checksum = cpu_to_le64(checksum); 451 452 if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0) 453 return -ENODEV; 454 455 if (__le16_to_cpu(pfn_sb->version_minor) < 1) { 456 pfn_sb->start_pad = 0; 457 pfn_sb->end_trunc = 0; 458 } 459 460 if (__le16_to_cpu(pfn_sb->version_minor) < 2) 461 pfn_sb->align = 0; 462 463 switch (le32_to_cpu(pfn_sb->mode)) { 464 case PFN_MODE_RAM: 465 case PFN_MODE_PMEM: 466 break; 467 default: 468 return -ENXIO; 469 } 470 471 align = le32_to_cpu(pfn_sb->align); 472 offset = le64_to_cpu(pfn_sb->dataoff); 473 start_pad = le32_to_cpu(pfn_sb->start_pad); 474 if (align == 0) 475 align = 1UL << ilog2(offset); 476 mode = le32_to_cpu(pfn_sb->mode); 477 478 if (!nd_pfn->uuid) { 479 /* 480 * When probing a namepace via nd_pfn_probe() the uuid 481 * is NULL (see: nd_pfn_devinit()) we init settings from 482 * pfn_sb 483 */ 484 nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL); 485 if (!nd_pfn->uuid) 486 return -ENOMEM; 487 nd_pfn->align = align; 488 nd_pfn->mode = mode; 489 } else { 490 /* 491 * When probing a pfn / dax instance we validate the 492 * live settings against the pfn_sb 493 */ 494 if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0) 495 return -ENODEV; 496 497 /* 498 * If the uuid validates, but other settings mismatch 499 * return EINVAL because userspace has managed to change 500 * the configuration without specifying new 501 * identification. 502 */ 503 if (nd_pfn->align != align || nd_pfn->mode != mode) { 504 dev_err(&nd_pfn->dev, 505 "init failed, settings mismatch\n"); 506 dev_dbg(&nd_pfn->dev, "align: %lx:%lx mode: %d:%d\n", 507 nd_pfn->align, align, nd_pfn->mode, 508 mode); 509 return -EINVAL; 510 } 511 } 512 513 if (align > nvdimm_namespace_capacity(ndns)) { 514 dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n", 515 align, nvdimm_namespace_capacity(ndns)); 516 return -EINVAL; 517 } 518 519 /* 520 * These warnings are verbose because they can only trigger in 521 * the case where the physical address alignment of the 522 * namespace has changed since the pfn superblock was 523 * established. 524 */ 525 nsio = to_nd_namespace_io(&ndns->dev); 526 if (offset >= resource_size(&nsio->res)) { 527 dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n", 528 dev_name(&ndns->dev)); 529 return -EBUSY; 530 } 531 532 if ((align && !IS_ALIGNED(nsio->res.start + offset + start_pad, align)) 533 || !IS_ALIGNED(offset, PAGE_SIZE)) { 534 dev_err(&nd_pfn->dev, 535 "bad offset: %#llx dax disabled align: %#lx\n", 536 offset, align); 537 return -ENXIO; 538 } 539 540 return nd_pfn_clear_memmap_errors(nd_pfn); 541 } 542 EXPORT_SYMBOL(nd_pfn_validate); 543 544 int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns) 545 { 546 int rc; 547 struct nd_pfn *nd_pfn; 548 struct device *pfn_dev; 549 struct nd_pfn_sb *pfn_sb; 550 struct nd_region *nd_region = to_nd_region(ndns->dev.parent); 551 552 if (ndns->force_raw) 553 return -ENODEV; 554 555 switch (ndns->claim_class) { 556 case NVDIMM_CCLASS_NONE: 557 case NVDIMM_CCLASS_PFN: 558 break; 559 default: 560 return -ENODEV; 561 } 562 563 nvdimm_bus_lock(&ndns->dev); 564 nd_pfn = nd_pfn_alloc(nd_region); 565 pfn_dev = nd_pfn_devinit(nd_pfn, ndns); 566 nvdimm_bus_unlock(&ndns->dev); 567 if (!pfn_dev) 568 return -ENOMEM; 569 pfn_sb = devm_kmalloc(dev, sizeof(*pfn_sb), GFP_KERNEL); 570 nd_pfn = to_nd_pfn(pfn_dev); 571 nd_pfn->pfn_sb = pfn_sb; 572 rc = nd_pfn_validate(nd_pfn, PFN_SIG); 573 dev_dbg(dev, "pfn: %s\n", rc == 0 ? dev_name(pfn_dev) : "<none>"); 574 if (rc < 0) { 575 nd_detach_ndns(pfn_dev, &nd_pfn->ndns); 576 put_device(pfn_dev); 577 } else 578 __nd_device_register(pfn_dev); 579 580 return rc; 581 } 582 EXPORT_SYMBOL(nd_pfn_probe); 583 584 static u32 info_block_reserve(void) 585 { 586 return ALIGN(SZ_8K, PAGE_SIZE); 587 } 588 589 /* 590 * We hotplug memory at sub-section granularity, pad the reserved area 591 * from the previous section base to the namespace base address. 592 */ 593 static unsigned long init_altmap_base(resource_size_t base) 594 { 595 unsigned long base_pfn = PHYS_PFN(base); 596 597 return SUBSECTION_ALIGN_DOWN(base_pfn); 598 } 599 600 static unsigned long init_altmap_reserve(resource_size_t base) 601 { 602 unsigned long reserve = info_block_reserve() >> PAGE_SHIFT; 603 unsigned long base_pfn = PHYS_PFN(base); 604 605 reserve += base_pfn - SUBSECTION_ALIGN_DOWN(base_pfn); 606 return reserve; 607 } 608 609 static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap) 610 { 611 struct resource *res = &pgmap->res; 612 struct vmem_altmap *altmap = &pgmap->altmap; 613 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb; 614 u64 offset = le64_to_cpu(pfn_sb->dataoff); 615 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad); 616 u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc); 617 u32 reserve = info_block_reserve(); 618 struct nd_namespace_common *ndns = nd_pfn->ndns; 619 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); 620 resource_size_t base = nsio->res.start + start_pad; 621 struct vmem_altmap __altmap = { 622 .base_pfn = init_altmap_base(base), 623 .reserve = init_altmap_reserve(base), 624 }; 625 626 memcpy(res, &nsio->res, sizeof(*res)); 627 res->start += start_pad; 628 res->end -= end_trunc; 629 630 if (nd_pfn->mode == PFN_MODE_RAM) { 631 if (offset < reserve) 632 return -EINVAL; 633 nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns); 634 } else if (nd_pfn->mode == PFN_MODE_PMEM) { 635 nd_pfn->npfns = PHYS_PFN((resource_size(res) - offset)); 636 if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns) 637 dev_info(&nd_pfn->dev, 638 "number of pfns truncated from %lld to %ld\n", 639 le64_to_cpu(nd_pfn->pfn_sb->npfns), 640 nd_pfn->npfns); 641 memcpy(altmap, &__altmap, sizeof(*altmap)); 642 altmap->free = PHYS_PFN(offset - reserve); 643 altmap->alloc = 0; 644 pgmap->flags |= PGMAP_ALTMAP_VALID; 645 } else 646 return -ENXIO; 647 648 return 0; 649 } 650 651 static int nd_pfn_init(struct nd_pfn *nd_pfn) 652 { 653 struct nd_namespace_common *ndns = nd_pfn->ndns; 654 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); 655 resource_size_t start, size; 656 struct nd_region *nd_region; 657 unsigned long npfns, align; 658 struct nd_pfn_sb *pfn_sb; 659 phys_addr_t offset; 660 const char *sig; 661 u64 checksum; 662 int rc; 663 664 pfn_sb = devm_kmalloc(&nd_pfn->dev, sizeof(*pfn_sb), GFP_KERNEL); 665 if (!pfn_sb) 666 return -ENOMEM; 667 668 nd_pfn->pfn_sb = pfn_sb; 669 if (is_nd_dax(&nd_pfn->dev)) 670 sig = DAX_SIG; 671 else 672 sig = PFN_SIG; 673 674 rc = nd_pfn_validate(nd_pfn, sig); 675 if (rc != -ENODEV) 676 return rc; 677 678 /* no info block, do init */; 679 memset(pfn_sb, 0, sizeof(*pfn_sb)); 680 681 nd_region = to_nd_region(nd_pfn->dev.parent); 682 if (nd_region->ro) { 683 dev_info(&nd_pfn->dev, 684 "%s is read-only, unable to init metadata\n", 685 dev_name(&nd_region->dev)); 686 return -ENXIO; 687 } 688 689 /* 690 * Note, we use 64 here for the standard size of struct page, 691 * debugging options may cause it to be larger in which case the 692 * implementation will limit the pfns advertised through 693 * ->direct_access() to those that are included in the memmap. 694 */ 695 start = nsio->res.start; 696 size = resource_size(&nsio->res); 697 npfns = PHYS_PFN(size - SZ_8K); 698 align = max(nd_pfn->align, (1UL << SUBSECTION_SHIFT)); 699 if (nd_pfn->mode == PFN_MODE_PMEM) { 700 /* 701 * The altmap should be padded out to the block size used 702 * when populating the vmemmap. This *should* be equal to 703 * PMD_SIZE for most architectures. 704 */ 705 offset = ALIGN(start + SZ_8K + 64 * npfns, align) - start; 706 } else if (nd_pfn->mode == PFN_MODE_RAM) 707 offset = ALIGN(start + SZ_8K, align) - start; 708 else 709 return -ENXIO; 710 711 if (offset >= size) { 712 dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n", 713 dev_name(&ndns->dev)); 714 return -ENXIO; 715 } 716 717 npfns = PHYS_PFN(size - offset); 718 pfn_sb->mode = cpu_to_le32(nd_pfn->mode); 719 pfn_sb->dataoff = cpu_to_le64(offset); 720 pfn_sb->npfns = cpu_to_le64(npfns); 721 memcpy(pfn_sb->signature, sig, PFN_SIG_LEN); 722 memcpy(pfn_sb->uuid, nd_pfn->uuid, 16); 723 memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16); 724 pfn_sb->version_major = cpu_to_le16(1); 725 pfn_sb->version_minor = cpu_to_le16(3); 726 pfn_sb->align = cpu_to_le32(nd_pfn->align); 727 checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb); 728 pfn_sb->checksum = cpu_to_le64(checksum); 729 730 return nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0); 731 } 732 733 /* 734 * Determine the effective resource range and vmem_altmap from an nd_pfn 735 * instance. 736 */ 737 int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap) 738 { 739 int rc; 740 741 if (!nd_pfn->uuid || !nd_pfn->ndns) 742 return -ENODEV; 743 744 rc = nd_pfn_init(nd_pfn); 745 if (rc) 746 return rc; 747 748 /* we need a valid pfn_sb before we can init a dev_pagemap */ 749 return __nvdimm_setup_pfn(nd_pfn, pgmap); 750 } 751 EXPORT_SYMBOL_GPL(nvdimm_setup_pfn); 752