1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Simple MTD partitioning layer 4 * 5 * Copyright © 2000 Nicolas Pitre <nico@fluxnic.net> 6 * Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de> 7 * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org> 8 */ 9 10 #include <linux/module.h> 11 #include <linux/types.h> 12 #include <linux/kernel.h> 13 #include <linux/slab.h> 14 #include <linux/list.h> 15 #include <linux/kmod.h> 16 #include <linux/mtd/mtd.h> 17 #include <linux/mtd/partitions.h> 18 #include <linux/err.h> 19 #include <linux/of.h> 20 #include <linux/of_platform.h> 21 #include <linux/mtd/concat.h> 22 23 #include "mtdcore.h" 24 25 /* 26 * MTD methods which simply translate the effective address and pass through 27 * to the _real_ device. 28 */ 29 30 static inline void free_partition(struct mtd_info *mtd) 31 { 32 kfree(mtd->name); 33 kfree(mtd); 34 } 35 36 void release_mtd_partition(struct mtd_info *mtd) 37 { 38 WARN_ON(!list_empty(&mtd->part.node)); 39 free_partition(mtd); 40 } 41 42 static struct mtd_info *allocate_partition(struct mtd_info *parent, 43 const struct mtd_partition *part, 44 int partno, uint64_t cur_offset) 45 { 46 struct mtd_info *master = mtd_get_master(parent); 47 int wr_alignment = (parent->flags & MTD_NO_ERASE) ? 48 master->writesize : master->erasesize; 49 u64 parent_size = mtd_is_partition(parent) ? 50 parent->part.size : parent->size; 51 struct mtd_info *child; 52 u32 remainder; 53 char *name; 54 u64 tmp; 55 56 /* allocate the partition structure */ 57 child = kzalloc_obj(*child); 58 name = kstrdup(part->name, GFP_KERNEL); 59 if (!name || !child) { 60 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n", 61 parent->name); 62 kfree(name); 63 kfree(child); 64 return ERR_PTR(-ENOMEM); 65 } 66 67 /* set up the MTD object for this partition */ 68 child->type = parent->type; 69 child->part.flags = parent->flags & ~part->mask_flags; 70 child->part.flags |= part->add_flags; 71 child->flags = child->part.flags; 72 child->part.size = part->size; 73 child->writesize = parent->writesize; 74 child->writebufsize = parent->writebufsize; 75 child->oobsize = parent->oobsize; 76 child->oobavail = parent->oobavail; 77 child->subpage_sft = parent->subpage_sft; 78 79 child->name = name; 80 child->owner = parent->owner; 81 82 /* NOTE: Historically, we didn't arrange MTDs as a tree out of 83 * concern for showing the same data in multiple partitions. 84 * However, it is very useful to have the master node present, 85 * so the MTD_PARTITIONED_MASTER option allows that. The master 86 * will have device nodes etc only if this is set, so make the 87 * parent conditional on that option. Note, this is a way to 88 * distinguish between the parent and its partitions in sysfs. 89 */ 90 child->dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) || mtd_is_partition(parent) ? 91 &parent->dev : parent->dev.parent; 92 child->dev.of_node = part->of_node; 93 child->parent = parent; 94 child->part.offset = part->offset; 95 INIT_LIST_HEAD(&child->partitions); 96 97 if (child->part.offset == MTDPART_OFS_APPEND) 98 child->part.offset = cur_offset; 99 if (child->part.offset == MTDPART_OFS_NXTBLK) { 100 tmp = cur_offset; 101 child->part.offset = cur_offset; 102 remainder = do_div(tmp, wr_alignment); 103 if (remainder) { 104 child->part.offset += wr_alignment - remainder; 105 printk(KERN_NOTICE "Moving partition %d: " 106 "0x%012llx -> 0x%012llx\n", partno, 107 (unsigned long long)cur_offset, 108 child->part.offset); 109 } 110 } 111 if (child->part.offset == MTDPART_OFS_RETAIN) { 112 child->part.offset = cur_offset; 113 if (parent_size - child->part.offset >= child->part.size) { 114 child->part.size = parent_size - child->part.offset - 115 child->part.size; 116 } else { 117 printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n", 118 part->name, parent_size - child->part.offset, 119 child->part.size); 120 /* register to preserve ordering */ 121 goto out_register; 122 } 123 } 124 if (child->part.size == MTDPART_SIZ_FULL) 125 child->part.size = parent_size - child->part.offset; 126 127 printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", 128 child->part.offset, child->part.offset + child->part.size, 129 child->name); 130 131 /* let's do some sanity checks */ 132 if (child->part.offset >= parent_size) { 133 /* let's register it anyway to preserve ordering */ 134 child->part.offset = 0; 135 child->part.size = 0; 136 137 /* Initialize ->erasesize to make add_mtd_device() happy. */ 138 child->erasesize = parent->erasesize; 139 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n", 140 part->name); 141 goto out_register; 142 } 143 if (child->part.offset + child->part.size > parent->size) { 144 child->part.size = parent_size - child->part.offset; 145 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n", 146 part->name, parent->name, child->part.size); 147 } 148 149 if (parent->numeraseregions > 1) { 150 /* Deal with variable erase size stuff */ 151 int i, max = parent->numeraseregions; 152 u64 end = child->part.offset + child->part.size; 153 struct mtd_erase_region_info *regions = parent->eraseregions; 154 155 /* Find the first erase regions which is part of this 156 * partition. */ 157 for (i = 0; i < max && regions[i].offset <= child->part.offset; 158 i++) 159 ; 160 /* The loop searched for the region _behind_ the first one */ 161 if (i > 0) 162 i--; 163 164 /* Pick biggest erasesize */ 165 for (; i < max && regions[i].offset < end; i++) { 166 if (child->erasesize < regions[i].erasesize) 167 child->erasesize = regions[i].erasesize; 168 } 169 BUG_ON(child->erasesize == 0); 170 } else { 171 /* Single erase size */ 172 child->erasesize = master->erasesize; 173 } 174 175 /* 176 * Child erasesize might differ from the parent one if the parent 177 * exposes several regions with different erasesize. Adjust 178 * wr_alignment accordingly. 179 */ 180 if (!(child->flags & MTD_NO_ERASE)) 181 wr_alignment = child->erasesize; 182 183 tmp = mtd_get_master_ofs(child, 0); 184 remainder = do_div(tmp, wr_alignment); 185 if ((child->flags & MTD_WRITEABLE) && remainder) { 186 /* Doesn't start on a boundary of major erase size */ 187 /* FIXME: Let it be writable if it is on a boundary of 188 * _minor_ erase size though */ 189 child->flags &= ~MTD_WRITEABLE; 190 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n", 191 part->name); 192 } 193 194 tmp = mtd_get_master_ofs(child, 0) + child->part.size; 195 remainder = do_div(tmp, wr_alignment); 196 if ((child->flags & MTD_WRITEABLE) && remainder) { 197 child->flags &= ~MTD_WRITEABLE; 198 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n", 199 part->name); 200 } 201 202 child->size = child->part.size; 203 child->ecc_step_size = parent->ecc_step_size; 204 child->ecc_strength = parent->ecc_strength; 205 child->bitflip_threshold = parent->bitflip_threshold; 206 207 if (master->_block_isbad) { 208 uint64_t offs = 0; 209 210 while (offs < child->part.size) { 211 if (mtd_block_isreserved(child, offs)) 212 child->ecc_stats.bbtblocks++; 213 else if (mtd_block_isbad(child, offs)) 214 child->ecc_stats.badblocks++; 215 offs += child->erasesize; 216 } 217 } 218 219 out_register: 220 return child; 221 } 222 223 static ssize_t offset_show(struct device *dev, 224 struct device_attribute *attr, char *buf) 225 { 226 struct mtd_info *mtd = dev_get_drvdata(dev); 227 228 return sysfs_emit(buf, "%lld\n", mtd->part.offset); 229 } 230 static DEVICE_ATTR_RO(offset); /* mtd partition offset */ 231 232 static const struct attribute *mtd_partition_attrs[] = { 233 &dev_attr_offset.attr, 234 NULL 235 }; 236 237 static int mtd_add_partition_attrs(struct mtd_info *new) 238 { 239 int ret = sysfs_create_files(&new->dev.kobj, mtd_partition_attrs); 240 if (ret) 241 printk(KERN_WARNING 242 "mtd: failed to create partition attrs, err=%d\n", ret); 243 return ret; 244 } 245 246 int mtd_add_partition(struct mtd_info *parent, const char *name, 247 long long offset, long long length) 248 { 249 struct mtd_info *master = mtd_get_master(parent); 250 u64 parent_size = mtd_is_partition(parent) ? 251 parent->part.size : parent->size; 252 struct mtd_partition part; 253 struct mtd_info *child; 254 int ret = 0; 255 256 /* the direct offset is expected */ 257 if (offset == MTDPART_OFS_APPEND || 258 offset == MTDPART_OFS_NXTBLK) 259 return -EINVAL; 260 261 if (length == MTDPART_SIZ_FULL) 262 length = parent_size - offset; 263 264 if (length <= 0) 265 return -EINVAL; 266 267 memset(&part, 0, sizeof(part)); 268 part.name = name; 269 part.size = length; 270 part.offset = offset; 271 272 child = allocate_partition(parent, &part, -1, offset); 273 if (IS_ERR(child)) 274 return PTR_ERR(child); 275 276 mutex_lock(&master->master.partitions_lock); 277 list_add_tail(&child->part.node, &parent->partitions); 278 mutex_unlock(&master->master.partitions_lock); 279 280 ret = add_mtd_device(child); 281 if (ret) 282 goto err_remove_part; 283 284 mtd_add_partition_attrs(child); 285 286 return 0; 287 288 err_remove_part: 289 mutex_lock(&master->master.partitions_lock); 290 list_del(&child->part.node); 291 mutex_unlock(&master->master.partitions_lock); 292 293 free_partition(child); 294 295 return ret; 296 } 297 EXPORT_SYMBOL_GPL(mtd_add_partition); 298 299 /** 300 * __mtd_del_partition - delete MTD partition 301 * 302 * @mtd: MTD structure to be deleted 303 * 304 * This function must be called with the partitions mutex locked. 305 */ 306 static int __mtd_del_partition(struct mtd_info *mtd) 307 { 308 struct mtd_info *child, *next; 309 int err; 310 311 list_for_each_entry_safe(child, next, &mtd->partitions, part.node) { 312 err = __mtd_del_partition(child); 313 if (err) 314 return err; 315 } 316 317 sysfs_remove_files(&mtd->dev.kobj, mtd_partition_attrs); 318 319 list_del_init(&mtd->part.node); 320 err = del_mtd_device(mtd); 321 if (err) 322 return err; 323 324 return 0; 325 } 326 327 /* 328 * This function unregisters and destroy all slave MTD objects which are 329 * attached to the given MTD object, recursively. 330 */ 331 static int __del_mtd_partitions(struct mtd_info *mtd) 332 { 333 struct mtd_info *child, *next; 334 int ret, err = 0; 335 336 list_for_each_entry_safe(child, next, &mtd->partitions, part.node) { 337 if (mtd_has_partitions(child)) 338 __del_mtd_partitions(child); 339 340 pr_info("Deleting %s MTD partition\n", child->name); 341 list_del_init(&child->part.node); 342 ret = del_mtd_device(child); 343 if (ret < 0) { 344 pr_err("Error when deleting partition \"%s\" (%d)\n", 345 child->name, ret); 346 err = ret; 347 continue; 348 } 349 } 350 351 return err; 352 } 353 354 int del_mtd_partitions(struct mtd_info *mtd) 355 { 356 struct mtd_info *master = mtd_get_master(mtd); 357 int ret; 358 359 pr_info("Deleting MTD partitions on \"%s\":\n", mtd->name); 360 361 mutex_lock(&master->master.partitions_lock); 362 ret = __del_mtd_partitions(mtd); 363 mutex_unlock(&master->master.partitions_lock); 364 365 return ret; 366 } 367 368 int mtd_del_partition(struct mtd_info *mtd, int partno) 369 { 370 struct mtd_info *child, *master = mtd_get_master(mtd); 371 int ret = -EINVAL; 372 373 mutex_lock(&master->master.partitions_lock); 374 list_for_each_entry(child, &mtd->partitions, part.node) { 375 if (child->index == partno) { 376 ret = __mtd_del_partition(child); 377 break; 378 } 379 } 380 mutex_unlock(&master->master.partitions_lock); 381 382 return ret; 383 } 384 EXPORT_SYMBOL_GPL(mtd_del_partition); 385 386 /* 387 * This function, given a parent MTD object and a partition table, creates 388 * and registers the child MTD objects which are bound to the parent according 389 * to the partition definitions. 390 * 391 * For historical reasons, this function's caller only registers the parent 392 * if the MTD_PARTITIONED_MASTER config option is set. 393 */ 394 395 int add_mtd_partitions(struct mtd_info *parent, 396 const struct mtd_partition *parts, 397 int nbparts) 398 { 399 struct mtd_info *child, *master = mtd_get_master(parent); 400 uint64_t cur_offset = 0; 401 int i, ret; 402 403 printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", 404 nbparts, parent->name); 405 406 for (i = 0; i < nbparts; i++) { 407 child = allocate_partition(parent, parts + i, i, cur_offset); 408 if (IS_ERR(child)) { 409 ret = PTR_ERR(child); 410 goto err_del_partitions; 411 } 412 413 if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) { 414 if (mtd_virt_concat_add(child)) 415 continue; 416 } 417 418 mutex_lock(&master->master.partitions_lock); 419 list_add_tail(&child->part.node, &parent->partitions); 420 mutex_unlock(&master->master.partitions_lock); 421 422 ret = add_mtd_device(child); 423 if (ret) { 424 mutex_lock(&master->master.partitions_lock); 425 list_del(&child->part.node); 426 mutex_unlock(&master->master.partitions_lock); 427 428 free_partition(child); 429 goto err_del_partitions; 430 } 431 432 mtd_add_partition_attrs(child); 433 434 /* Look for subpartitions (skip if no maching parser found) */ 435 ret = parse_mtd_partitions(child, parts[i].types, NULL); 436 if (ret < 0 && ret == -ENOENT) { 437 pr_debug("Skip parsing subpartitions: %d\n", ret); 438 continue; 439 } else if (ret < 0) { 440 pr_err("Failed to parse subpartitions: %d\n", ret); 441 goto err_del_partitions; 442 } 443 444 cur_offset = child->part.offset + child->part.size; 445 } 446 447 return 0; 448 449 err_del_partitions: 450 del_mtd_partitions(master); 451 452 return ret; 453 } 454 455 static DEFINE_SPINLOCK(part_parser_lock); 456 static LIST_HEAD(part_parsers); 457 458 static struct mtd_part_parser *mtd_part_parser_get(const char *name) 459 { 460 struct mtd_part_parser *p, *ret = NULL; 461 462 spin_lock(&part_parser_lock); 463 464 list_for_each_entry(p, &part_parsers, list) 465 if (!strcmp(p->name, name) && try_module_get(p->owner)) { 466 ret = p; 467 break; 468 } 469 470 spin_unlock(&part_parser_lock); 471 472 return ret; 473 } 474 475 static inline void mtd_part_parser_put(const struct mtd_part_parser *p) 476 { 477 module_put(p->owner); 478 } 479 480 /* 481 * Many partition parsers just expected the core to kfree() all their data in 482 * one chunk. Do that by default. 483 */ 484 static void mtd_part_parser_cleanup_default(const struct mtd_partition *pparts, 485 int nr_parts) 486 { 487 kfree(pparts); 488 } 489 490 int __register_mtd_parser(struct mtd_part_parser *p, struct module *owner) 491 { 492 p->owner = owner; 493 494 if (!p->cleanup) 495 p->cleanup = &mtd_part_parser_cleanup_default; 496 497 spin_lock(&part_parser_lock); 498 list_add(&p->list, &part_parsers); 499 spin_unlock(&part_parser_lock); 500 501 return 0; 502 } 503 EXPORT_SYMBOL_GPL(__register_mtd_parser); 504 505 void deregister_mtd_parser(struct mtd_part_parser *p) 506 { 507 spin_lock(&part_parser_lock); 508 list_del(&p->list); 509 spin_unlock(&part_parser_lock); 510 } 511 EXPORT_SYMBOL_GPL(deregister_mtd_parser); 512 513 /* 514 * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you 515 * are changing this array! 516 */ 517 static const char * const default_mtd_part_types[] = { 518 "cmdlinepart", 519 "ofpart", 520 NULL 521 }; 522 523 /* Check DT only when looking for subpartitions. */ 524 static const char * const default_subpartition_types[] = { 525 "ofpart", 526 NULL 527 }; 528 529 static int mtd_part_do_parse(struct mtd_part_parser *parser, 530 struct mtd_info *master, 531 struct mtd_partitions *pparts, 532 struct mtd_part_parser_data *data) 533 { 534 int ret; 535 536 ret = (*parser->parse_fn)(master, &pparts->parts, data); 537 pr_debug("%s: parser %s: %i\n", master->name, parser->name, ret); 538 if (ret <= 0) 539 return ret; 540 541 pr_notice("%d %s partitions found on MTD device %s\n", ret, 542 parser->name, master->name); 543 544 pparts->nr_parts = ret; 545 pparts->parser = parser; 546 547 return ret; 548 } 549 550 /** 551 * mtd_part_get_compatible_parser - find MTD parser by a compatible string 552 * 553 * @compat: compatible string describing partitions in a device tree 554 * 555 * MTD parsers can specify supported partitions by providing a table of 556 * compatibility strings. This function finds a parser that advertises support 557 * for a passed value of "compatible". 558 */ 559 static struct mtd_part_parser *mtd_part_get_compatible_parser(const char *compat) 560 { 561 struct mtd_part_parser *p, *ret = NULL; 562 563 spin_lock(&part_parser_lock); 564 565 list_for_each_entry(p, &part_parsers, list) { 566 const struct of_device_id *matches; 567 568 matches = p->of_match_table; 569 if (!matches) 570 continue; 571 572 for (; matches->compatible[0]; matches++) { 573 if (!strcmp(matches->compatible, compat) && 574 try_module_get(p->owner)) { 575 ret = p; 576 break; 577 } 578 } 579 580 if (ret) 581 break; 582 } 583 584 spin_unlock(&part_parser_lock); 585 586 return ret; 587 } 588 589 static int mtd_part_of_parse(struct mtd_info *master, 590 struct mtd_partitions *pparts) 591 { 592 struct mtd_part_parser *parser; 593 struct device_node *np; 594 struct device_node *child; 595 struct property *prop; 596 struct device *dev; 597 const char *compat; 598 const char *fixed = "fixed-partitions"; 599 int ret, err = 0; 600 601 dev = &master->dev; 602 /* Use parent device (controller) if the top level MTD is not registered */ 603 if (!IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) && !mtd_is_partition(master)) 604 dev = master->dev.parent; 605 606 np = mtd_get_of_node(master); 607 if (mtd_is_partition(master)) 608 of_node_get(np); 609 else 610 np = of_get_child_by_name(np, "partitions"); 611 612 /* 613 * Don't create devices that are added to a bus but will never get 614 * probed. That'll cause fw_devlink to block probing of consumers of 615 * this partition until the partition device is probed. 616 */ 617 for_each_child_of_node(np, child) 618 if (of_device_is_compatible(child, "nvmem-cells")) 619 of_node_set_flag(child, OF_POPULATED); 620 621 of_property_for_each_string(np, "compatible", prop, compat) { 622 parser = mtd_part_get_compatible_parser(compat); 623 if (!parser) 624 continue; 625 ret = mtd_part_do_parse(parser, master, pparts, NULL); 626 if (ret > 0) { 627 of_platform_populate(np, NULL, NULL, dev); 628 of_node_put(np); 629 return ret; 630 } 631 mtd_part_parser_put(parser); 632 if (ret < 0 && !err) 633 err = ret; 634 } 635 of_platform_populate(np, NULL, NULL, dev); 636 of_node_put(np); 637 638 /* 639 * For backward compatibility we have to try the "fixed-partitions" 640 * parser. It supports old DT format with partitions specified as a 641 * direct subnodes of a flash device DT node without any compatibility 642 * specified we could match. 643 */ 644 parser = mtd_part_parser_get(fixed); 645 if (!parser && !request_module("%s", fixed)) 646 parser = mtd_part_parser_get(fixed); 647 if (parser) { 648 ret = mtd_part_do_parse(parser, master, pparts, NULL); 649 if (ret > 0) 650 return ret; 651 mtd_part_parser_put(parser); 652 if (ret < 0 && !err) 653 err = ret; 654 } 655 656 return err; 657 } 658 659 /** 660 * parse_mtd_partitions - parse and register MTD partitions 661 * 662 * @master: the master partition (describes whole MTD device) 663 * @types: names of partition parsers to try or %NULL 664 * @data: MTD partition parser-specific data 665 * 666 * This function tries to find & register partitions on MTD device @master. It 667 * uses MTD partition parsers, specified in @types. However, if @types is %NULL, 668 * then the default list of parsers is used. The default list contains only the 669 * "cmdlinepart" and "ofpart" parsers ATM. 670 * Note: If there are more then one parser in @types, the kernel only takes the 671 * partitions parsed out by the first parser. 672 * 673 * This function may return: 674 * o a negative error code in case of failure 675 * o number of found partitions otherwise 676 */ 677 int parse_mtd_partitions(struct mtd_info *master, const char *const *types, 678 struct mtd_part_parser_data *data) 679 { 680 struct mtd_partitions pparts = { }; 681 struct mtd_part_parser *parser; 682 int ret, err = 0; 683 684 if (!types) 685 types = mtd_is_partition(master) ? default_subpartition_types : 686 default_mtd_part_types; 687 688 for ( ; *types; types++) { 689 /* 690 * ofpart is a special type that means OF partitioning info 691 * should be used. It requires a bit different logic so it is 692 * handled in a separated function. 693 */ 694 if (!strcmp(*types, "ofpart")) { 695 ret = mtd_part_of_parse(master, &pparts); 696 } else { 697 pr_debug("%s: parsing partitions %s\n", master->name, 698 *types); 699 parser = mtd_part_parser_get(*types); 700 if (!parser && !request_module("%s", *types)) 701 parser = mtd_part_parser_get(*types); 702 if (!parser) 703 continue; 704 pr_debug("%s: got parser %s\n", master->name, parser->name); 705 ret = mtd_part_do_parse(parser, master, &pparts, data); 706 if (ret <= 0) 707 mtd_part_parser_put(parser); 708 } 709 /* Found partitions! */ 710 if (ret > 0) { 711 err = add_mtd_partitions(master, pparts.parts, 712 pparts.nr_parts); 713 mtd_part_parser_cleanup(&pparts); 714 return err ? err : pparts.nr_parts; 715 } 716 /* 717 * Stash the first error we see; only report it if no parser 718 * succeeds 719 */ 720 if (ret < 0 && !err) 721 err = ret; 722 } 723 return err; 724 } 725 726 void mtd_part_parser_cleanup(struct mtd_partitions *parts) 727 { 728 const struct mtd_part_parser *parser; 729 730 if (!parts) 731 return; 732 733 parser = parts->parser; 734 if (parser) { 735 if (parser->cleanup) 736 parser->cleanup(parts->parts, parts->nr_parts); 737 738 mtd_part_parser_put(parser); 739 } 740 } 741 742 /* Returns the size of the entire flash chip */ 743 uint64_t mtd_get_device_size(const struct mtd_info *mtd) 744 { 745 struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd); 746 747 return master->size; 748 } 749 EXPORT_SYMBOL_GPL(mtd_get_device_size); 750