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 child->part.offset = 0; 122 child->part.size = 0; 123 child->erasesize = parent->erasesize; 124 goto out_register; 125 } 126 } 127 if (child->part.size == MTDPART_SIZ_FULL) 128 child->part.size = parent_size - child->part.offset; 129 130 printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", 131 child->part.offset, child->part.offset + child->part.size, 132 child->name); 133 134 /* let's do some sanity checks */ 135 if (child->part.offset >= parent_size) { 136 /* let's register it anyway to preserve ordering */ 137 child->part.offset = 0; 138 child->part.size = 0; 139 140 /* Initialize ->erasesize to make add_mtd_device() happy. */ 141 child->erasesize = parent->erasesize; 142 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n", 143 part->name); 144 goto out_register; 145 } 146 if (child->part.offset + child->part.size > parent->size) { 147 child->part.size = parent_size - child->part.offset; 148 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n", 149 part->name, parent->name, child->part.size); 150 } 151 152 if (parent->numeraseregions > 1) { 153 /* Deal with variable erase size stuff */ 154 int i, max = parent->numeraseregions; 155 u64 end = child->part.offset + child->part.size; 156 struct mtd_erase_region_info *regions = parent->eraseregions; 157 158 /* Find the first erase regions which is part of this 159 * partition. */ 160 for (i = 0; i < max && regions[i].offset <= child->part.offset; 161 i++) 162 ; 163 /* The loop searched for the region _behind_ the first one */ 164 if (i > 0) 165 i--; 166 167 /* Pick biggest erasesize */ 168 for (; i < max && regions[i].offset < end; i++) { 169 if (child->erasesize < regions[i].erasesize) 170 child->erasesize = regions[i].erasesize; 171 } 172 BUG_ON(child->erasesize == 0); 173 } else { 174 /* Single erase size */ 175 child->erasesize = master->erasesize; 176 } 177 178 /* 179 * Child erasesize might differ from the parent one if the parent 180 * exposes several regions with different erasesize. Adjust 181 * wr_alignment accordingly. 182 */ 183 if (!(child->flags & MTD_NO_ERASE)) 184 wr_alignment = child->erasesize; 185 186 tmp = mtd_get_master_ofs(child, 0); 187 remainder = do_div(tmp, wr_alignment); 188 if ((child->flags & MTD_WRITEABLE) && remainder) { 189 /* Doesn't start on a boundary of major erase size */ 190 /* FIXME: Let it be writable if it is on a boundary of 191 * _minor_ erase size though */ 192 child->flags &= ~MTD_WRITEABLE; 193 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n", 194 part->name); 195 } 196 197 tmp = mtd_get_master_ofs(child, 0) + child->part.size; 198 remainder = do_div(tmp, wr_alignment); 199 if ((child->flags & MTD_WRITEABLE) && remainder) { 200 child->flags &= ~MTD_WRITEABLE; 201 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n", 202 part->name); 203 } 204 205 child->size = child->part.size; 206 child->ecc_step_size = parent->ecc_step_size; 207 child->ecc_strength = parent->ecc_strength; 208 child->bitflip_threshold = parent->bitflip_threshold; 209 210 if (master->_block_isbad) { 211 uint64_t offs = 0; 212 213 while (offs < child->part.size) { 214 if (mtd_block_isreserved(child, offs)) 215 child->ecc_stats.bbtblocks++; 216 else if (mtd_block_isbad(child, offs)) 217 child->ecc_stats.badblocks++; 218 offs += child->erasesize; 219 } 220 } 221 222 out_register: 223 return child; 224 } 225 226 static ssize_t offset_show(struct device *dev, 227 struct device_attribute *attr, char *buf) 228 { 229 struct mtd_info *mtd = dev_get_drvdata(dev); 230 231 return sysfs_emit(buf, "%lld\n", mtd->part.offset); 232 } 233 static DEVICE_ATTR_RO(offset); /* mtd partition offset */ 234 235 static const struct attribute *mtd_partition_attrs[] = { 236 &dev_attr_offset.attr, 237 NULL 238 }; 239 240 static int mtd_add_partition_attrs(struct mtd_info *new) 241 { 242 int ret = sysfs_create_files(&new->dev.kobj, mtd_partition_attrs); 243 if (ret) 244 printk(KERN_WARNING 245 "mtd: failed to create partition attrs, err=%d\n", ret); 246 return ret; 247 } 248 249 int mtd_add_partition(struct mtd_info *parent, const char *name, 250 long long offset, long long length) 251 { 252 struct mtd_info *master = mtd_get_master(parent); 253 u64 parent_size = mtd_is_partition(parent) ? 254 parent->part.size : parent->size; 255 struct mtd_partition part; 256 struct mtd_info *child; 257 int ret = 0; 258 259 /* the direct offset is expected */ 260 if (offset == MTDPART_OFS_APPEND || 261 offset == MTDPART_OFS_NXTBLK) 262 return -EINVAL; 263 264 if (length == MTDPART_SIZ_FULL) 265 length = parent_size - offset; 266 267 if (length <= 0) 268 return -EINVAL; 269 270 if (offset < 0 || offset >= (long long)parent_size) 271 return -EINVAL; 272 273 if ((u64)offset + (u64)length > parent_size) 274 return -EINVAL; 275 memset(&part, 0, sizeof(part)); 276 part.name = name; 277 part.size = length; 278 part.offset = offset; 279 280 child = allocate_partition(parent, &part, -1, offset); 281 if (IS_ERR(child)) 282 return PTR_ERR(child); 283 284 mutex_lock(&master->master.partitions_lock); 285 list_add_tail(&child->part.node, &parent->partitions); 286 mutex_unlock(&master->master.partitions_lock); 287 288 ret = add_mtd_device(child); 289 if (ret) 290 goto err_remove_part; 291 292 mtd_add_partition_attrs(child); 293 294 return 0; 295 296 err_remove_part: 297 mutex_lock(&master->master.partitions_lock); 298 list_del(&child->part.node); 299 mutex_unlock(&master->master.partitions_lock); 300 301 free_partition(child); 302 303 return ret; 304 } 305 EXPORT_SYMBOL_GPL(mtd_add_partition); 306 307 /** 308 * __mtd_del_partition - delete MTD partition 309 * 310 * @mtd: MTD structure to be deleted 311 * 312 * This function must be called with the partitions mutex locked. 313 */ 314 static int __mtd_del_partition(struct mtd_info *mtd) 315 { 316 struct mtd_info *child, *next; 317 int err; 318 319 list_for_each_entry_safe(child, next, &mtd->partitions, part.node) { 320 err = __mtd_del_partition(child); 321 if (err) 322 return err; 323 } 324 325 sysfs_remove_files(&mtd->dev.kobj, mtd_partition_attrs); 326 327 list_del_init(&mtd->part.node); 328 err = del_mtd_device(mtd); 329 if (err) 330 return err; 331 332 return 0; 333 } 334 335 /* 336 * This function unregisters and destroy all slave MTD objects which are 337 * attached to the given MTD object, recursively. 338 */ 339 static int __del_mtd_partitions(struct mtd_info *mtd) 340 { 341 struct mtd_info *child, *next; 342 int ret, err = 0; 343 344 list_for_each_entry_safe(child, next, &mtd->partitions, part.node) { 345 if (mtd_has_partitions(child)) 346 __del_mtd_partitions(child); 347 348 pr_info("Deleting %s MTD partition\n", child->name); 349 list_del_init(&child->part.node); 350 ret = del_mtd_device(child); 351 if (ret < 0) { 352 pr_err("Error when deleting partition \"%s\" (%d)\n", 353 child->name, ret); 354 err = ret; 355 continue; 356 } 357 } 358 359 return err; 360 } 361 362 int del_mtd_partitions(struct mtd_info *mtd) 363 { 364 struct mtd_info *master = mtd_get_master(mtd); 365 int ret; 366 367 pr_info("Deleting MTD partitions on \"%s\":\n", mtd->name); 368 369 mutex_lock(&master->master.partitions_lock); 370 ret = __del_mtd_partitions(mtd); 371 mutex_unlock(&master->master.partitions_lock); 372 373 return ret; 374 } 375 376 int mtd_del_partition(struct mtd_info *mtd, int partno) 377 { 378 struct mtd_info *child, *master = mtd_get_master(mtd); 379 int ret = -EINVAL; 380 381 mutex_lock(&master->master.partitions_lock); 382 list_for_each_entry(child, &mtd->partitions, part.node) { 383 if (child->index == partno) { 384 ret = __mtd_del_partition(child); 385 break; 386 } 387 } 388 mutex_unlock(&master->master.partitions_lock); 389 390 return ret; 391 } 392 EXPORT_SYMBOL_GPL(mtd_del_partition); 393 394 /* 395 * This function, given a parent MTD object and a partition table, creates 396 * and registers the child MTD objects which are bound to the parent according 397 * to the partition definitions. 398 * 399 * For historical reasons, this function's caller only registers the parent 400 * if the MTD_PARTITIONED_MASTER config option is set. 401 */ 402 403 int add_mtd_partitions(struct mtd_info *parent, 404 const struct mtd_partition *parts, 405 int nbparts) 406 { 407 struct mtd_info *child, *master = mtd_get_master(parent); 408 uint64_t cur_offset = 0; 409 int i, ret; 410 411 printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", 412 nbparts, parent->name); 413 414 for (i = 0; i < nbparts; i++) { 415 child = allocate_partition(parent, parts + i, i, cur_offset); 416 if (IS_ERR(child)) { 417 ret = PTR_ERR(child); 418 goto err_del_partitions; 419 } 420 421 if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) { 422 if (mtd_virt_concat_add(child)) 423 continue; 424 } 425 426 mutex_lock(&master->master.partitions_lock); 427 list_add_tail(&child->part.node, &parent->partitions); 428 mutex_unlock(&master->master.partitions_lock); 429 430 ret = add_mtd_device(child); 431 if (ret) { 432 mutex_lock(&master->master.partitions_lock); 433 list_del(&child->part.node); 434 mutex_unlock(&master->master.partitions_lock); 435 436 free_partition(child); 437 goto err_del_partitions; 438 } 439 440 mtd_add_partition_attrs(child); 441 442 /* Look for subpartitions (skip if no maching parser found) */ 443 ret = parse_mtd_partitions(child, parts[i].types, NULL); 444 if (ret < 0 && ret == -ENOENT) { 445 pr_debug("Skip parsing subpartitions: %d\n", ret); 446 continue; 447 } else if (ret < 0) { 448 pr_err("Failed to parse subpartitions: %d\n", ret); 449 goto err_del_partitions; 450 } 451 452 cur_offset = child->part.offset + child->part.size; 453 } 454 455 return 0; 456 457 err_del_partitions: 458 del_mtd_partitions(master); 459 460 return ret; 461 } 462 463 static DEFINE_SPINLOCK(part_parser_lock); 464 static LIST_HEAD(part_parsers); 465 466 static struct mtd_part_parser *mtd_part_parser_get(const char *name) 467 { 468 struct mtd_part_parser *p, *ret = NULL; 469 470 spin_lock(&part_parser_lock); 471 472 list_for_each_entry(p, &part_parsers, list) 473 if (!strcmp(p->name, name) && try_module_get(p->owner)) { 474 ret = p; 475 break; 476 } 477 478 spin_unlock(&part_parser_lock); 479 480 return ret; 481 } 482 483 static inline void mtd_part_parser_put(const struct mtd_part_parser *p) 484 { 485 module_put(p->owner); 486 } 487 488 /* 489 * Many partition parsers just expected the core to kfree() all their data in 490 * one chunk. Do that by default. 491 */ 492 static void mtd_part_parser_cleanup_default(const struct mtd_partition *pparts, 493 int nr_parts) 494 { 495 kfree(pparts); 496 } 497 498 int __register_mtd_parser(struct mtd_part_parser *p, struct module *owner) 499 { 500 p->owner = owner; 501 502 if (!p->cleanup) 503 p->cleanup = &mtd_part_parser_cleanup_default; 504 505 spin_lock(&part_parser_lock); 506 list_add(&p->list, &part_parsers); 507 spin_unlock(&part_parser_lock); 508 509 return 0; 510 } 511 EXPORT_SYMBOL_GPL(__register_mtd_parser); 512 513 void deregister_mtd_parser(struct mtd_part_parser *p) 514 { 515 spin_lock(&part_parser_lock); 516 list_del(&p->list); 517 spin_unlock(&part_parser_lock); 518 } 519 EXPORT_SYMBOL_GPL(deregister_mtd_parser); 520 521 /* 522 * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you 523 * are changing this array! 524 */ 525 static const char * const default_mtd_part_types[] = { 526 "cmdlinepart", 527 "ofpart", 528 NULL 529 }; 530 531 /* Check DT only when looking for subpartitions. */ 532 static const char * const default_subpartition_types[] = { 533 "ofpart", 534 NULL 535 }; 536 537 static int mtd_part_do_parse(struct mtd_part_parser *parser, 538 struct mtd_info *master, 539 struct mtd_partitions *pparts, 540 struct mtd_part_parser_data *data) 541 { 542 int ret; 543 544 ret = (*parser->parse_fn)(master, &pparts->parts, data); 545 pr_debug("%s: parser %s: %i\n", master->name, parser->name, ret); 546 if (ret <= 0) 547 return ret; 548 549 pr_notice("%d %s partitions found on MTD device %s\n", ret, 550 parser->name, master->name); 551 552 pparts->nr_parts = ret; 553 pparts->parser = parser; 554 555 return ret; 556 } 557 558 /** 559 * mtd_part_get_compatible_parser - find MTD parser by a compatible string 560 * 561 * @compat: compatible string describing partitions in a device tree 562 * 563 * MTD parsers can specify supported partitions by providing a table of 564 * compatibility strings. This function finds a parser that advertises support 565 * for a passed value of "compatible". 566 */ 567 static struct mtd_part_parser *mtd_part_get_compatible_parser(const char *compat) 568 { 569 struct mtd_part_parser *p, *ret = NULL; 570 571 spin_lock(&part_parser_lock); 572 573 list_for_each_entry(p, &part_parsers, list) { 574 const struct of_device_id *matches; 575 576 matches = p->of_match_table; 577 if (!matches) 578 continue; 579 580 for (; matches->compatible[0]; matches++) { 581 if (!strcmp(matches->compatible, compat) && 582 try_module_get(p->owner)) { 583 ret = p; 584 break; 585 } 586 } 587 588 if (ret) 589 break; 590 } 591 592 spin_unlock(&part_parser_lock); 593 594 return ret; 595 } 596 597 static int mtd_part_of_parse(struct mtd_info *master, 598 struct mtd_partitions *pparts) 599 { 600 struct mtd_part_parser *parser; 601 struct device_node *np; 602 struct device_node *child; 603 struct property *prop; 604 struct device *dev; 605 const char *compat; 606 const char *fixed = "fixed-partitions"; 607 int ret, err = 0; 608 609 dev = &master->dev; 610 /* Use parent device (controller) if the top level MTD is not registered */ 611 if (!IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) && !mtd_is_partition(master)) 612 dev = master->dev.parent; 613 614 np = mtd_get_of_node(master); 615 if (mtd_is_partition(master)) 616 of_node_get(np); 617 else 618 np = of_get_child_by_name(np, "partitions"); 619 620 /* 621 * Don't create devices that are added to a bus but will never get 622 * probed. That'll cause fw_devlink to block probing of consumers of 623 * this partition until the partition device is probed. 624 */ 625 for_each_child_of_node(np, child) 626 if (of_device_is_compatible(child, "nvmem-cells")) 627 of_node_set_flag(child, OF_POPULATED); 628 629 of_property_for_each_string(np, "compatible", prop, compat) { 630 parser = mtd_part_get_compatible_parser(compat); 631 if (!parser) 632 continue; 633 ret = mtd_part_do_parse(parser, master, pparts, NULL); 634 if (ret > 0) { 635 of_platform_populate(np, NULL, NULL, dev); 636 of_node_put(np); 637 return ret; 638 } 639 mtd_part_parser_put(parser); 640 if (ret < 0 && !err) 641 err = ret; 642 } 643 of_platform_populate(np, NULL, NULL, dev); 644 of_node_put(np); 645 646 /* 647 * For backward compatibility we have to try the "fixed-partitions" 648 * parser. It supports old DT format with partitions specified as a 649 * direct subnodes of a flash device DT node without any compatibility 650 * specified we could match. 651 */ 652 parser = mtd_part_parser_get(fixed); 653 if (!parser && !request_module("%s", fixed)) 654 parser = mtd_part_parser_get(fixed); 655 if (parser) { 656 ret = mtd_part_do_parse(parser, master, pparts, NULL); 657 if (ret > 0) 658 return ret; 659 mtd_part_parser_put(parser); 660 if (ret < 0 && !err) 661 err = ret; 662 } 663 664 return err; 665 } 666 667 /** 668 * parse_mtd_partitions - parse and register MTD partitions 669 * 670 * @master: the master partition (describes whole MTD device) 671 * @types: names of partition parsers to try or %NULL 672 * @data: MTD partition parser-specific data 673 * 674 * This function tries to find & register partitions on MTD device @master. It 675 * uses MTD partition parsers, specified in @types. However, if @types is %NULL, 676 * then the default list of parsers is used. The default list contains only the 677 * "cmdlinepart" and "ofpart" parsers ATM. 678 * Note: If there are more then one parser in @types, the kernel only takes the 679 * partitions parsed out by the first parser. 680 * 681 * This function may return: 682 * o a negative error code in case of failure 683 * o number of found partitions otherwise 684 */ 685 int parse_mtd_partitions(struct mtd_info *master, const char *const *types, 686 struct mtd_part_parser_data *data) 687 { 688 struct mtd_partitions pparts = { }; 689 struct mtd_part_parser *parser; 690 int ret, err = 0; 691 692 if (!types) 693 types = mtd_is_partition(master) ? default_subpartition_types : 694 default_mtd_part_types; 695 696 for ( ; *types; types++) { 697 /* 698 * ofpart is a special type that means OF partitioning info 699 * should be used. It requires a bit different logic so it is 700 * handled in a separated function. 701 */ 702 if (!strcmp(*types, "ofpart")) { 703 ret = mtd_part_of_parse(master, &pparts); 704 } else { 705 pr_debug("%s: parsing partitions %s\n", master->name, 706 *types); 707 parser = mtd_part_parser_get(*types); 708 if (!parser && !request_module("%s", *types)) 709 parser = mtd_part_parser_get(*types); 710 if (!parser) 711 continue; 712 pr_debug("%s: got parser %s\n", master->name, parser->name); 713 ret = mtd_part_do_parse(parser, master, &pparts, data); 714 if (ret <= 0) 715 mtd_part_parser_put(parser); 716 } 717 /* Found partitions! */ 718 if (ret > 0) { 719 err = add_mtd_partitions(master, pparts.parts, 720 pparts.nr_parts); 721 mtd_part_parser_cleanup(&pparts); 722 return err ? err : pparts.nr_parts; 723 } 724 /* 725 * Stash the first error we see; only report it if no parser 726 * succeeds 727 */ 728 if (ret < 0 && !err) 729 err = ret; 730 } 731 return err; 732 } 733 734 void mtd_part_parser_cleanup(struct mtd_partitions *parts) 735 { 736 const struct mtd_part_parser *parser; 737 738 if (!parts) 739 return; 740 741 parser = parts->parser; 742 if (parser) { 743 if (parser->cleanup) 744 parser->cleanup(parts->parts, parts->nr_parts); 745 746 mtd_part_parser_put(parser); 747 } 748 } 749 750 /* Returns the size of the entire flash chip */ 751 uint64_t mtd_get_device_size(const struct mtd_info *mtd) 752 { 753 struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd); 754 755 return master->size; 756 } 757 EXPORT_SYMBOL_GPL(mtd_get_device_size); 758