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