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