1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * Core registration and callback routines for MTD 4 * drivers and users. 5 * 6 * Copyright �� 1999-2010 David Woodhouse <dwmw2@infradead.org> 7 * Copyright �� 2006 Red Hat UK Limited 8 */ 9 10#include <linux/module.h> 11#include <linux/kernel.h> 12#include <linux/ptrace.h> 13#include <linux/seq_file.h> 14#include <linux/string.h> 15#include <linux/timer.h> 16#include <linux/major.h> 17#include <linux/fs.h> 18#include <linux/err.h> 19#include <linux/ioctl.h> 20#include <linux/init.h> 21#include <linux/of.h> 22#include <linux/proc_fs.h> 23#include <linux/idr.h> 24#include <linux/backing-dev.h> 25#include <linux/gfp.h> 26#include <linux/random.h> 27#include <linux/slab.h> 28#include <linux/reboot.h> 29#include <linux/leds.h> 30#include <linux/debugfs.h> 31#include <linux/nvmem-provider.h> 32#include <linux/root_dev.h> 33#include <linux/error-injection.h> 34 35#include <linux/mtd/mtd.h> 36#include <linux/mtd/partitions.h> 37 38#include "mtdcore.h" 39 40struct backing_dev_info *mtd_bdi; 41 42#ifdef CONFIG_PM_SLEEP 43 44static int mtd_cls_suspend(struct device *dev) 45{ 46 struct mtd_info *mtd = dev_get_drvdata(dev); 47 48 return mtd ? mtd_suspend(mtd) : 0; 49} 50 51static int mtd_cls_resume(struct device *dev) 52{ 53 struct mtd_info *mtd = dev_get_drvdata(dev); 54 55 if (mtd) 56 mtd_resume(mtd); 57 return 0; 58} 59 60static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume); 61#define MTD_CLS_PM_OPS (&mtd_cls_pm_ops) 62#else 63#define MTD_CLS_PM_OPS NULL 64#endif 65 66static struct class mtd_class = { 67 .name = "mtd", 68 .pm = MTD_CLS_PM_OPS, 69}; 70 71static DEFINE_IDR(mtd_idr); 72 73/* These are exported solely for the purpose of mtd_blkdevs.c. You 74 should not use them for _anything_ else */ 75DEFINE_MUTEX(mtd_table_mutex); 76EXPORT_SYMBOL_GPL(mtd_table_mutex); 77 78struct mtd_info *__mtd_next_device(int i) 79{ 80 return idr_get_next(&mtd_idr, &i); 81} 82EXPORT_SYMBOL_GPL(__mtd_next_device); 83 84static LIST_HEAD(mtd_notifiers); 85 86 87#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2) 88 89/* REVISIT once MTD uses the driver model better, whoever allocates 90 * the mtd_info will probably want to use the release() hook... 91 */ 92static void mtd_release(struct device *dev) 93{ 94 struct mtd_info *mtd = dev_get_drvdata(dev); 95 dev_t index = MTD_DEVT(mtd->index); 96 97 idr_remove(&mtd_idr, mtd->index); 98 of_node_put(mtd_get_of_node(mtd)); 99 100 if (mtd_is_partition(mtd)) 101 release_mtd_partition(mtd); 102 103 /* remove /dev/mtdXro node */ 104 device_destroy(&mtd_class, index + 1); 105} 106 107static void mtd_device_release(struct kref *kref) 108{ 109 struct mtd_info *mtd = container_of(kref, struct mtd_info, refcnt); 110 bool is_partition = mtd_is_partition(mtd); 111 112 debugfs_remove_recursive(mtd->dbg.dfs_dir); 113 114 /* Try to remove the NVMEM provider */ 115 nvmem_unregister(mtd->nvmem); 116 117 device_unregister(&mtd->dev); 118 119 /* 120 * Clear dev so mtd can be safely re-registered later if desired. 121 * Should not be done for partition, 122 * as it was already destroyed in device_unregister(). 123 */ 124 if (!is_partition) 125 memset(&mtd->dev, 0, sizeof(mtd->dev)); 126 127 module_put(THIS_MODULE); 128} 129 130#define MTD_DEVICE_ATTR_RO(name) \ 131static DEVICE_ATTR(name, 0444, mtd_##name##_show, NULL) 132 133#define MTD_DEVICE_ATTR_RW(name) \ 134static DEVICE_ATTR(name, 0644, mtd_##name##_show, mtd_##name##_store) 135 136static ssize_t mtd_type_show(struct device *dev, 137 struct device_attribute *attr, char *buf) 138{ 139 struct mtd_info *mtd = dev_get_drvdata(dev); 140 char *type; 141 142 switch (mtd->type) { 143 case MTD_ABSENT: 144 type = "absent"; 145 break; 146 case MTD_RAM: 147 type = "ram"; 148 break; 149 case MTD_ROM: 150 type = "rom"; 151 break; 152 case MTD_NORFLASH: 153 type = "nor"; 154 break; 155 case MTD_NANDFLASH: 156 type = "nand"; 157 break; 158 case MTD_DATAFLASH: 159 type = "dataflash"; 160 break; 161 case MTD_UBIVOLUME: 162 type = "ubi"; 163 break; 164 case MTD_MLCNANDFLASH: 165 type = "mlc-nand"; 166 break; 167 default: 168 type = "unknown"; 169 } 170 171 return sysfs_emit(buf, "%s\n", type); 172} 173MTD_DEVICE_ATTR_RO(type); 174 175static ssize_t mtd_flags_show(struct device *dev, 176 struct device_attribute *attr, char *buf) 177{ 178 struct mtd_info *mtd = dev_get_drvdata(dev); 179 180 return sysfs_emit(buf, "0x%lx\n", (unsigned long)mtd->flags); 181} 182MTD_DEVICE_ATTR_RO(flags); 183 184static ssize_t mtd_size_show(struct device *dev, 185 struct device_attribute *attr, char *buf) 186{ 187 struct mtd_info *mtd = dev_get_drvdata(dev); 188 189 return sysfs_emit(buf, "%llu\n", (unsigned long long)mtd->size); 190} 191MTD_DEVICE_ATTR_RO(size); 192 193static ssize_t mtd_erasesize_show(struct device *dev, 194 struct device_attribute *attr, char *buf) 195{ 196 struct mtd_info *mtd = dev_get_drvdata(dev); 197 198 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->erasesize); 199} 200MTD_DEVICE_ATTR_RO(erasesize); 201 202static ssize_t mtd_writesize_show(struct device *dev, 203 struct device_attribute *attr, char *buf) 204{ 205 struct mtd_info *mtd = dev_get_drvdata(dev); 206 207 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->writesize); 208} 209MTD_DEVICE_ATTR_RO(writesize); 210 211static ssize_t mtd_subpagesize_show(struct device *dev, 212 struct device_attribute *attr, char *buf) 213{ 214 struct mtd_info *mtd = dev_get_drvdata(dev); 215 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft; 216 217 return sysfs_emit(buf, "%u\n", subpagesize); 218} 219MTD_DEVICE_ATTR_RO(subpagesize); 220 221static ssize_t mtd_oobsize_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, "%lu\n", (unsigned long)mtd->oobsize); 227} 228MTD_DEVICE_ATTR_RO(oobsize); 229 230static ssize_t mtd_oobavail_show(struct device *dev, 231 struct device_attribute *attr, char *buf) 232{ 233 struct mtd_info *mtd = dev_get_drvdata(dev); 234 235 return sysfs_emit(buf, "%u\n", mtd->oobavail); 236} 237MTD_DEVICE_ATTR_RO(oobavail); 238 239static ssize_t mtd_numeraseregions_show(struct device *dev, 240 struct device_attribute *attr, char *buf) 241{ 242 struct mtd_info *mtd = dev_get_drvdata(dev); 243 244 return sysfs_emit(buf, "%u\n", mtd->numeraseregions); 245} 246MTD_DEVICE_ATTR_RO(numeraseregions); 247 248static ssize_t mtd_name_show(struct device *dev, 249 struct device_attribute *attr, char *buf) 250{ 251 struct mtd_info *mtd = dev_get_drvdata(dev); 252 253 return sysfs_emit(buf, "%s\n", mtd->name); 254} 255MTD_DEVICE_ATTR_RO(name); 256 257static ssize_t mtd_ecc_strength_show(struct device *dev, 258 struct device_attribute *attr, char *buf) 259{ 260 struct mtd_info *mtd = dev_get_drvdata(dev); 261 262 return sysfs_emit(buf, "%u\n", mtd->ecc_strength); 263} 264MTD_DEVICE_ATTR_RO(ecc_strength); 265 266static ssize_t mtd_bitflip_threshold_show(struct device *dev, 267 struct device_attribute *attr, 268 char *buf) 269{ 270 struct mtd_info *mtd = dev_get_drvdata(dev); 271 272 return sysfs_emit(buf, "%u\n", mtd->bitflip_threshold); 273} 274 275static ssize_t mtd_bitflip_threshold_store(struct device *dev, 276 struct device_attribute *attr, 277 const char *buf, size_t count) 278{ 279 struct mtd_info *mtd = dev_get_drvdata(dev); 280 unsigned int bitflip_threshold; 281 int retval; 282 283 retval = kstrtouint(buf, 0, &bitflip_threshold); 284 if (retval) 285 return retval; 286 287 mtd->bitflip_threshold = bitflip_threshold; 288 return count; 289} 290MTD_DEVICE_ATTR_RW(bitflip_threshold); 291 292static ssize_t mtd_ecc_step_size_show(struct device *dev, 293 struct device_attribute *attr, char *buf) 294{ 295 struct mtd_info *mtd = dev_get_drvdata(dev); 296 297 return sysfs_emit(buf, "%u\n", mtd->ecc_step_size); 298 299} 300MTD_DEVICE_ATTR_RO(ecc_step_size); 301 302static ssize_t mtd_corrected_bits_show(struct device *dev, 303 struct device_attribute *attr, char *buf) 304{ 305 struct mtd_info *mtd = dev_get_drvdata(dev); 306 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats; 307 308 return sysfs_emit(buf, "%u\n", ecc_stats->corrected); 309} 310MTD_DEVICE_ATTR_RO(corrected_bits); /* ecc stats corrected */ 311 312static ssize_t mtd_ecc_failures_show(struct device *dev, 313 struct device_attribute *attr, char *buf) 314{ 315 struct mtd_info *mtd = dev_get_drvdata(dev); 316 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats; 317 318 return sysfs_emit(buf, "%u\n", ecc_stats->failed); 319} 320MTD_DEVICE_ATTR_RO(ecc_failures); /* ecc stats errors */ 321 322static ssize_t mtd_bad_blocks_show(struct device *dev, 323 struct device_attribute *attr, char *buf) 324{ 325 struct mtd_info *mtd = dev_get_drvdata(dev); 326 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats; 327 328 return sysfs_emit(buf, "%u\n", ecc_stats->badblocks); 329} 330MTD_DEVICE_ATTR_RO(bad_blocks); 331 332static ssize_t mtd_bbt_blocks_show(struct device *dev, 333 struct device_attribute *attr, char *buf) 334{ 335 struct mtd_info *mtd = dev_get_drvdata(dev); 336 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats; 337 338 return sysfs_emit(buf, "%u\n", ecc_stats->bbtblocks); 339} 340MTD_DEVICE_ATTR_RO(bbt_blocks); 341 342static struct attribute *mtd_attrs[] = { 343 &dev_attr_type.attr, 344 &dev_attr_flags.attr, 345 &dev_attr_size.attr, 346 &dev_attr_erasesize.attr, 347 &dev_attr_writesize.attr, 348 &dev_attr_subpagesize.attr, 349 &dev_attr_oobsize.attr, 350 &dev_attr_oobavail.attr, 351 &dev_attr_numeraseregions.attr, 352 &dev_attr_name.attr, 353 &dev_attr_ecc_strength.attr, 354 &dev_attr_ecc_step_size.attr, 355 &dev_attr_corrected_bits.attr, 356 &dev_attr_ecc_failures.attr, 357 &dev_attr_bad_blocks.attr, 358 &dev_attr_bbt_blocks.attr, 359 &dev_attr_bitflip_threshold.attr, 360 NULL, 361}; 362ATTRIBUTE_GROUPS(mtd); 363 364static const struct device_type mtd_devtype = { 365 .name = "mtd", 366 .groups = mtd_groups, 367 .release = mtd_release, 368}; 369 370static bool mtd_expert_analysis_mode; 371 372#ifdef CONFIG_DEBUG_FS 373bool mtd_check_expert_analysis_mode(void) 374{ 375 const char *mtd_expert_analysis_warning = 376 "Bad block checks have been entirely disabled.\n" 377 "This is only reserved for post-mortem forensics and debug purposes.\n" 378 "Never enable this mode if you do not know what you are doing!\n"; 379 380 return WARN_ONCE(mtd_expert_analysis_mode, mtd_expert_analysis_warning); 381} 382EXPORT_SYMBOL_GPL(mtd_check_expert_analysis_mode); 383#endif 384 385static struct dentry *dfs_dir_mtd; 386 387static void mtd_debugfs_populate(struct mtd_info *mtd) 388{ 389 struct device *dev = &mtd->dev; 390 391 if (IS_ERR_OR_NULL(dfs_dir_mtd)) 392 return; 393 394 mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(dev), dfs_dir_mtd); 395} 396 397#ifndef CONFIG_MMU 398unsigned mtd_mmap_capabilities(struct mtd_info *mtd) 399{ 400 switch (mtd->type) { 401 case MTD_RAM: 402 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC | 403 NOMMU_MAP_READ | NOMMU_MAP_WRITE; 404 case MTD_ROM: 405 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC | 406 NOMMU_MAP_READ; 407 default: 408 return NOMMU_MAP_COPY; 409 } 410} 411EXPORT_SYMBOL_GPL(mtd_mmap_capabilities); 412#endif 413 414static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state, 415 void *cmd) 416{ 417 struct mtd_info *mtd; 418 419 mtd = container_of(n, struct mtd_info, reboot_notifier); 420 mtd->_reboot(mtd); 421 422 return NOTIFY_DONE; 423} 424 425/** 426 * mtd_wunit_to_pairing_info - get pairing information of a wunit 427 * @mtd: pointer to new MTD device info structure 428 * @wunit: write unit we are interested in 429 * @info: returned pairing information 430 * 431 * Retrieve pairing information associated to the wunit. 432 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be 433 * paired together, and where programming a page may influence the page it is 434 * paired with. 435 * The notion of page is replaced by the term wunit (write-unit) to stay 436 * consistent with the ->writesize field. 437 * 438 * The @wunit argument can be extracted from an absolute offset using 439 * mtd_offset_to_wunit(). @info is filled with the pairing information attached 440 * to @wunit. 441 * 442 * From the pairing info the MTD user can find all the wunits paired with 443 * @wunit using the following loop: 444 * 445 * for (i = 0; i < mtd_pairing_groups(mtd); i++) { 446 * info.pair = i; 447 * mtd_pairing_info_to_wunit(mtd, &info); 448 * ... 449 * } 450 */ 451int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit, 452 struct mtd_pairing_info *info) 453{ 454 struct mtd_info *master = mtd_get_master(mtd); 455 int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master); 456 457 if (wunit < 0 || wunit >= npairs) 458 return -EINVAL; 459 460 if (master->pairing && master->pairing->get_info) 461 return master->pairing->get_info(master, wunit, info); 462 463 info->group = 0; 464 info->pair = wunit; 465 466 return 0; 467} 468EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info); 469 470/** 471 * mtd_pairing_info_to_wunit - get wunit from pairing information 472 * @mtd: pointer to new MTD device info structure 473 * @info: pairing information struct 474 * 475 * Returns a positive number representing the wunit associated to the info 476 * struct, or a negative error code. 477 * 478 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to 479 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info() 480 * doc). 481 * 482 * It can also be used to only program the first page of each pair (i.e. 483 * page attached to group 0), which allows one to use an MLC NAND in 484 * software-emulated SLC mode: 485 * 486 * info.group = 0; 487 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd); 488 * for (info.pair = 0; info.pair < npairs; info.pair++) { 489 * wunit = mtd_pairing_info_to_wunit(mtd, &info); 490 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit), 491 * mtd->writesize, &retlen, buf + (i * mtd->writesize)); 492 * } 493 */ 494int mtd_pairing_info_to_wunit(struct mtd_info *mtd, 495 const struct mtd_pairing_info *info) 496{ 497 struct mtd_info *master = mtd_get_master(mtd); 498 int ngroups = mtd_pairing_groups(master); 499 int npairs = mtd_wunit_per_eb(master) / ngroups; 500 501 if (!info || info->pair < 0 || info->pair >= npairs || 502 info->group < 0 || info->group >= ngroups) 503 return -EINVAL; 504 505 if (master->pairing && master->pairing->get_wunit) 506 return mtd->pairing->get_wunit(master, info); 507 508 return info->pair; 509} 510EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit); 511 512/** 513 * mtd_pairing_groups - get the number of pairing groups 514 * @mtd: pointer to new MTD device info structure 515 * 516 * Returns the number of pairing groups. 517 * 518 * This number is usually equal to the number of bits exposed by a single 519 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit() 520 * to iterate over all pages of a given pair. 521 */ 522int mtd_pairing_groups(struct mtd_info *mtd) 523{ 524 struct mtd_info *master = mtd_get_master(mtd); 525 526 if (!master->pairing || !master->pairing->ngroups) 527 return 1; 528 529 return master->pairing->ngroups; 530} 531EXPORT_SYMBOL_GPL(mtd_pairing_groups); 532 533static int mtd_nvmem_reg_read(void *priv, unsigned int offset, 534 void *val, size_t bytes) 535{ 536 struct mtd_info *mtd = priv; 537 size_t retlen; 538 int err; 539 540 err = mtd_read(mtd, offset, bytes, &retlen, val); 541 if (err && err != -EUCLEAN) 542 return err; 543 544 return retlen == bytes ? 0 : -EIO; 545} 546 547static int mtd_nvmem_add(struct mtd_info *mtd) 548{ 549 struct device_node *node = mtd_get_of_node(mtd); 550 struct nvmem_config config = {}; 551 552 config.id = NVMEM_DEVID_NONE; 553 config.dev = &mtd->dev; 554 config.name = dev_name(&mtd->dev); 555 config.owner = THIS_MODULE; 556 config.add_legacy_fixed_of_cells = of_device_is_compatible(node, "nvmem-cells"); 557 config.reg_read = mtd_nvmem_reg_read; 558 config.size = mtd->size; 559 config.word_size = 1; 560 config.stride = 1; 561 config.read_only = true; 562 config.root_only = true; 563 config.ignore_wp = true; 564 config.priv = mtd; 565 566 mtd->nvmem = nvmem_register(&config); 567 if (IS_ERR(mtd->nvmem)) { 568 /* Just ignore if there is no NVMEM support in the kernel */ 569 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) 570 mtd->nvmem = NULL; 571 else 572 return dev_err_probe(&mtd->dev, PTR_ERR(mtd->nvmem), 573 "Failed to register NVMEM device\n"); 574 } 575 576 return 0; 577} 578 579static void mtd_check_of_node(struct mtd_info *mtd) 580{ 581 struct device_node *partitions, *parent_dn, *mtd_dn = NULL; 582 const char *pname, *prefix = "partition-"; 583 int plen, mtd_name_len, offset, prefix_len; 584 585 /* Check if MTD already has a device node */ 586 if (mtd_get_of_node(mtd)) 587 return; 588 589 if (!mtd_is_partition(mtd)) 590 return; 591 592 parent_dn = of_node_get(mtd_get_of_node(mtd->parent)); 593 if (!parent_dn) 594 return; 595 596 if (mtd_is_partition(mtd->parent)) 597 partitions = of_node_get(parent_dn); 598 else 599 partitions = of_get_child_by_name(parent_dn, "partitions"); 600 if (!partitions) 601 goto exit_parent; 602 603 prefix_len = strlen(prefix); 604 mtd_name_len = strlen(mtd->name); 605 606 /* Search if a partition is defined with the same name */ 607 for_each_child_of_node(partitions, mtd_dn) { 608 /* Skip partition with no/wrong prefix */ 609 if (!of_node_name_prefix(mtd_dn, prefix)) 610 continue; 611 612 /* Label have priority. Check that first */ 613 if (!of_property_read_string(mtd_dn, "label", &pname)) { 614 offset = 0; 615 } else { 616 pname = mtd_dn->name; 617 offset = prefix_len; 618 } 619 620 plen = strlen(pname) - offset; 621 if (plen == mtd_name_len && 622 !strncmp(mtd->name, pname + offset, plen)) { 623 mtd_set_of_node(mtd, mtd_dn); 624 of_node_put(mtd_dn); 625 break; 626 } 627 } 628 629 of_node_put(partitions); 630exit_parent: 631 of_node_put(parent_dn); 632} 633 634/** 635 * add_mtd_device - register an MTD device 636 * @mtd: pointer to new MTD device info structure 637 * 638 * Add a device to the list of MTD devices present in the system, and 639 * notify each currently active MTD 'user' of its arrival. Returns 640 * zero on success or non-zero on failure. 641 */ 642 643int add_mtd_device(struct mtd_info *mtd) 644{ 645 struct device_node *np = mtd_get_of_node(mtd); 646 struct mtd_info *master = mtd_get_master(mtd); 647 struct mtd_notifier *not; 648 int i, error, ofidx; 649 650 /* 651 * May occur, for instance, on buggy drivers which call 652 * mtd_device_parse_register() multiple times on the same master MTD, 653 * especially with CONFIG_MTD_PARTITIONED_MASTER=y. 654 */ 655 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n")) 656 return -EEXIST; 657 658 BUG_ON(mtd->writesize == 0); 659 660 /* 661 * MTD drivers should implement ->_{write,read}() or 662 * ->_{write,read}_oob(), but not both. 663 */ 664 if (WARN_ON((mtd->_write && mtd->_write_oob) || 665 (mtd->_read && mtd->_read_oob))) 666 return -EINVAL; 667 668 if (WARN_ON((!mtd->erasesize || !master->_erase) && 669 !(mtd->flags & MTD_NO_ERASE))) 670 return -EINVAL; 671 672 /* 673 * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the 674 * master is an MLC NAND and has a proper pairing scheme defined. 675 * We also reject masters that implement ->_writev() for now, because 676 * NAND controller drivers don't implement this hook, and adding the 677 * SLC -> MLC address/length conversion to this path is useless if we 678 * don't have a user. 679 */ 680 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION && 681 (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH || 682 !master->pairing || master->_writev)) 683 return -EINVAL; 684 685 mutex_lock(&mtd_table_mutex); 686 687 ofidx = -1; 688 if (np) 689 ofidx = of_alias_get_id(np, "mtd"); 690 if (ofidx >= 0) 691 i = idr_alloc(&mtd_idr, mtd, ofidx, ofidx + 1, GFP_KERNEL); 692 else 693 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL); 694 if (i < 0) { 695 error = i; 696 goto fail_locked; 697 } 698 699 mtd->index = i; 700 kref_init(&mtd->refcnt); 701 702 /* default value if not set by driver */ 703 if (mtd->bitflip_threshold == 0) 704 mtd->bitflip_threshold = mtd->ecc_strength; 705 706 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { 707 int ngroups = mtd_pairing_groups(master); 708 709 mtd->erasesize /= ngroups; 710 mtd->size = (u64)mtd_div_by_eb(mtd->size, master) * 711 mtd->erasesize; 712 } 713 714 if (is_power_of_2(mtd->erasesize)) 715 mtd->erasesize_shift = ffs(mtd->erasesize) - 1; 716 else 717 mtd->erasesize_shift = 0; 718 719 if (is_power_of_2(mtd->writesize)) 720 mtd->writesize_shift = ffs(mtd->writesize) - 1; 721 else 722 mtd->writesize_shift = 0; 723 724 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1; 725 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1; 726 727 /* Some chips always power up locked. Unlock them now */ 728 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) { 729 error = mtd_unlock(mtd, 0, mtd->size); 730 if (error && error != -EOPNOTSUPP) 731 printk(KERN_WARNING 732 "%s: unlock failed, writes may not work\n", 733 mtd->name); 734 /* Ignore unlock failures? */ 735 error = 0; 736 } 737 738 /* Caller should have set dev.parent to match the 739 * physical device, if appropriate. 740 */ 741 mtd->dev.type = &mtd_devtype; 742 mtd->dev.class = &mtd_class; 743 mtd->dev.devt = MTD_DEVT(i); 744 dev_set_name(&mtd->dev, "mtd%d", i); 745 dev_set_drvdata(&mtd->dev, mtd); 746 mtd_check_of_node(mtd); 747 of_node_get(mtd_get_of_node(mtd)); 748 error = device_register(&mtd->dev); 749 if (error) { 750 put_device(&mtd->dev); 751 goto fail_added; 752 } 753 754 /* Add the nvmem provider */ 755 error = mtd_nvmem_add(mtd); 756 if (error) 757 goto fail_nvmem_add; 758 759 mtd_debugfs_populate(mtd); 760 761 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL, 762 "mtd%dro", i); 763 764 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name); 765 /* No need to get a refcount on the module containing 766 the notifier, since we hold the mtd_table_mutex */ 767 list_for_each_entry(not, &mtd_notifiers, list) 768 not->add(mtd); 769 770 mutex_unlock(&mtd_table_mutex); 771 772 if (of_property_read_bool(mtd_get_of_node(mtd), "linux,rootfs")) { 773 if (IS_BUILTIN(CONFIG_MTD)) { 774 pr_info("mtd: setting mtd%d (%s) as root device\n", mtd->index, mtd->name); 775 ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, mtd->index); 776 } else { 777 pr_warn("mtd: can't set mtd%d (%s) as root device - mtd must be builtin\n", 778 mtd->index, mtd->name); 779 } 780 } 781 782 /* We _know_ we aren't being removed, because 783 our caller is still holding us here. So none 784 of this try_ nonsense, and no bitching about it 785 either. :) */ 786 __module_get(THIS_MODULE); 787 return 0; 788 789fail_nvmem_add: 790 device_unregister(&mtd->dev); 791fail_added: 792 of_node_put(mtd_get_of_node(mtd)); 793 idr_remove(&mtd_idr, i); 794fail_locked: 795 mutex_unlock(&mtd_table_mutex); 796 return error; 797} 798 799/** 800 * del_mtd_device - unregister an MTD device 801 * @mtd: pointer to MTD device info structure 802 * 803 * Remove a device from the list of MTD devices present in the system, 804 * and notify each currently active MTD 'user' of its departure. 805 * Returns zero on success or 1 on failure, which currently will happen 806 * if the requested device does not appear to be present in the list. 807 */ 808 809int del_mtd_device(struct mtd_info *mtd) 810{ 811 int ret; 812 struct mtd_notifier *not; 813 814 mutex_lock(&mtd_table_mutex); 815 816 if (idr_find(&mtd_idr, mtd->index) != mtd) { 817 ret = -ENODEV; 818 goto out_error; 819 } 820 821 /* No need to get a refcount on the module containing 822 the notifier, since we hold the mtd_table_mutex */ 823 list_for_each_entry(not, &mtd_notifiers, list) 824 not->remove(mtd); 825 826 kref_put(&mtd->refcnt, mtd_device_release); 827 ret = 0; 828 829out_error: 830 mutex_unlock(&mtd_table_mutex); 831 return ret; 832} 833 834/* 835 * Set a few defaults based on the parent devices, if not provided by the 836 * driver 837 */ 838static void mtd_set_dev_defaults(struct mtd_info *mtd) 839{ 840 if (mtd->dev.parent) { 841 if (!mtd->owner && mtd->dev.parent->driver) 842 mtd->owner = mtd->dev.parent->driver->owner; 843 if (!mtd->name) 844 mtd->name = dev_name(mtd->dev.parent); 845 } else { 846 pr_debug("mtd device won't show a device symlink in sysfs\n"); 847 } 848 849 INIT_LIST_HEAD(&mtd->partitions); 850 mutex_init(&mtd->master.partitions_lock); 851 mutex_init(&mtd->master.chrdev_lock); 852} 853 854static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user) 855{ 856 struct otp_info *info; 857 ssize_t size = 0; 858 unsigned int i; 859 size_t retlen; 860 int ret; 861 862 info = kmalloc(PAGE_SIZE, GFP_KERNEL); 863 if (!info) 864 return -ENOMEM; 865 866 if (is_user) 867 ret = mtd_get_user_prot_info(mtd, PAGE_SIZE, &retlen, info); 868 else 869 ret = mtd_get_fact_prot_info(mtd, PAGE_SIZE, &retlen, info); 870 if (ret) 871 goto err; 872 873 for (i = 0; i < retlen / sizeof(*info); i++) 874 size += info[i].length; 875 876 kfree(info); 877 return size; 878 879err: 880 kfree(info); 881 882 /* ENODATA means there is no OTP region. */ 883 return ret == -ENODATA ? 0 : ret; 884} 885 886static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd, 887 const char *compatible, 888 int size, 889 nvmem_reg_read_t reg_read) 890{ 891 struct nvmem_device *nvmem = NULL; 892 struct nvmem_config config = {}; 893 struct device_node *np; 894 895 /* DT binding is optional */ 896 np = of_get_compatible_child(mtd->dev.of_node, compatible); 897 898 /* OTP nvmem will be registered on the physical device */ 899 config.dev = mtd->dev.parent; 900 config.name = compatible; 901 config.id = NVMEM_DEVID_AUTO; 902 config.owner = THIS_MODULE; 903 config.add_legacy_fixed_of_cells = !mtd_type_is_nand(mtd); 904 config.type = NVMEM_TYPE_OTP; 905 config.root_only = true; 906 config.ignore_wp = true; 907 config.reg_read = reg_read; 908 config.size = size; 909 config.of_node = np; 910 config.priv = mtd; 911 912 nvmem = nvmem_register(&config); 913 /* Just ignore if there is no NVMEM support in the kernel */ 914 if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EOPNOTSUPP) 915 nvmem = NULL; 916 917 of_node_put(np); 918 919 return nvmem; 920} 921 922static int mtd_nvmem_user_otp_reg_read(void *priv, unsigned int offset, 923 void *val, size_t bytes) 924{ 925 struct mtd_info *mtd = priv; 926 size_t retlen; 927 int ret; 928 929 ret = mtd_read_user_prot_reg(mtd, offset, bytes, &retlen, val); 930 if (ret) 931 return ret; 932 933 return retlen == bytes ? 0 : -EIO; 934} 935 936static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset, 937 void *val, size_t bytes) 938{ 939 struct mtd_info *mtd = priv; 940 size_t retlen; 941 int ret; 942 943 ret = mtd_read_fact_prot_reg(mtd, offset, bytes, &retlen, val); 944 if (ret) 945 return ret; 946 947 return retlen == bytes ? 0 : -EIO; 948} 949 950static int mtd_otp_nvmem_add(struct mtd_info *mtd) 951{ 952 struct device *dev = mtd->dev.parent; 953 struct nvmem_device *nvmem; 954 ssize_t size; 955 int err; 956 957 if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) { 958 size = mtd_otp_size(mtd, true); 959 if (size < 0) { 960 err = size; 961 goto err; 962 } 963 964 if (size > 0) { 965 nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size, 966 mtd_nvmem_user_otp_reg_read); 967 if (IS_ERR(nvmem)) { 968 err = PTR_ERR(nvmem); 969 goto err; 970 } 971 mtd->otp_user_nvmem = nvmem; 972 } 973 } 974 975 if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) { 976 size = mtd_otp_size(mtd, false); 977 if (size < 0) { 978 err = size; 979 goto err; 980 } 981 982 if (size > 0) { 983 /* 984 * The factory OTP contains thing such as a unique serial 985 * number and is small, so let's read it out and put it 986 * into the entropy pool. 987 */ 988 void *otp; 989 990 otp = kmalloc(size, GFP_KERNEL); 991 if (!otp) { 992 err = -ENOMEM; 993 goto err; 994 } 995 err = mtd_nvmem_fact_otp_reg_read(mtd, 0, otp, size); 996 if (err < 0) { 997 kfree(otp); 998 goto err; 999 } 1000 add_device_randomness(otp, err); 1001 kfree(otp); 1002 1003 nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size, 1004 mtd_nvmem_fact_otp_reg_read); 1005 if (IS_ERR(nvmem)) { 1006 err = PTR_ERR(nvmem); 1007 goto err; 1008 } 1009 mtd->otp_factory_nvmem = nvmem; 1010 } 1011 } 1012 1013 return 0; 1014 1015err: 1016 nvmem_unregister(mtd->otp_user_nvmem); 1017 /* Don't report error if OTP is not supported. */ 1018 if (err == -EOPNOTSUPP) 1019 return 0; 1020 return dev_err_probe(dev, err, "Failed to register OTP NVMEM device\n"); 1021} 1022 1023/** 1024 * mtd_device_parse_register - parse partitions and register an MTD device. 1025 * 1026 * @mtd: the MTD device to register 1027 * @types: the list of MTD partition probes to try, see 1028 * 'parse_mtd_partitions()' for more information 1029 * @parser_data: MTD partition parser-specific data 1030 * @parts: fallback partition information to register, if parsing fails; 1031 * only valid if %nr_parts > %0 1032 * @nr_parts: the number of partitions in parts, if zero then the full 1033 * MTD device is registered if no partition info is found 1034 * 1035 * This function aggregates MTD partitions parsing (done by 1036 * 'parse_mtd_partitions()') and MTD device and partitions registering. It 1037 * basically follows the most common pattern found in many MTD drivers: 1038 * 1039 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is 1040 * registered first. 1041 * * Then It tries to probe partitions on MTD device @mtd using parsers 1042 * specified in @types (if @types is %NULL, then the default list of parsers 1043 * is used, see 'parse_mtd_partitions()' for more information). If none are 1044 * found this functions tries to fallback to information specified in 1045 * @parts/@nr_parts. 1046 * * If no partitions were found this function just registers the MTD device 1047 * @mtd and exits. 1048 * 1049 * Returns zero in case of success and a negative error code in case of failure. 1050 */ 1051int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types, 1052 struct mtd_part_parser_data *parser_data, 1053 const struct mtd_partition *parts, 1054 int nr_parts) 1055{ 1056 int ret; 1057 1058 mtd_set_dev_defaults(mtd); 1059 1060 ret = mtd_otp_nvmem_add(mtd); 1061 if (ret) 1062 goto out; 1063 1064 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) { 1065 ret = add_mtd_device(mtd); 1066 if (ret) 1067 goto out; 1068 } 1069 1070 /* Prefer parsed partitions over driver-provided fallback */ 1071 ret = parse_mtd_partitions(mtd, types, parser_data); 1072 if (ret == -EPROBE_DEFER) 1073 goto out; 1074 1075 if (ret > 0) 1076 ret = 0; 1077 else if (nr_parts) 1078 ret = add_mtd_partitions(mtd, parts, nr_parts); 1079 else if (!device_is_registered(&mtd->dev)) 1080 ret = add_mtd_device(mtd); 1081 else 1082 ret = 0; 1083 1084 if (ret) 1085 goto out; 1086 1087 /* 1088 * FIXME: some drivers unfortunately call this function more than once. 1089 * So we have to check if we've already assigned the reboot notifier. 1090 * 1091 * Generally, we can make multiple calls work for most cases, but it 1092 * does cause problems with parse_mtd_partitions() above (e.g., 1093 * cmdlineparts will register partitions more than once). 1094 */ 1095 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call, 1096 "MTD already registered\n"); 1097 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) { 1098 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier; 1099 register_reboot_notifier(&mtd->reboot_notifier); 1100 } 1101 1102out: 1103 if (ret) { 1104 nvmem_unregister(mtd->otp_user_nvmem); 1105 nvmem_unregister(mtd->otp_factory_nvmem); 1106 } 1107 1108 if (ret && device_is_registered(&mtd->dev)) 1109 del_mtd_device(mtd); 1110 1111 return ret; 1112} 1113EXPORT_SYMBOL_GPL(mtd_device_parse_register); 1114 1115/** 1116 * mtd_device_unregister - unregister an existing MTD device. 1117 * 1118 * @master: the MTD device to unregister. This will unregister both the master 1119 * and any partitions if registered. 1120 */ 1121int mtd_device_unregister(struct mtd_info *master) 1122{ 1123 int err; 1124 1125 if (master->_reboot) { 1126 unregister_reboot_notifier(&master->reboot_notifier); 1127 memset(&master->reboot_notifier, 0, sizeof(master->reboot_notifier)); 1128 } 1129 1130 nvmem_unregister(master->otp_user_nvmem); 1131 nvmem_unregister(master->otp_factory_nvmem); 1132 1133 err = del_mtd_partitions(master); 1134 if (err) 1135 return err; 1136 1137 if (!device_is_registered(&master->dev)) 1138 return 0; 1139 1140 return del_mtd_device(master); 1141} 1142EXPORT_SYMBOL_GPL(mtd_device_unregister); 1143 1144/** 1145 * register_mtd_user - register a 'user' of MTD devices. 1146 * @new: pointer to notifier info structure 1147 * 1148 * Registers a pair of callbacks function to be called upon addition 1149 * or removal of MTD devices. Causes the 'add' callback to be immediately 1150 * invoked for each MTD device currently present in the system. 1151 */ 1152void register_mtd_user (struct mtd_notifier *new) 1153{ 1154 struct mtd_info *mtd; 1155 1156 mutex_lock(&mtd_table_mutex); 1157 1158 list_add(&new->list, &mtd_notifiers); 1159 1160 __module_get(THIS_MODULE); 1161 1162 mtd_for_each_device(mtd) 1163 new->add(mtd); 1164 1165 mutex_unlock(&mtd_table_mutex); 1166} 1167EXPORT_SYMBOL_GPL(register_mtd_user); 1168 1169/** 1170 * unregister_mtd_user - unregister a 'user' of MTD devices. 1171 * @old: pointer to notifier info structure 1172 * 1173 * Removes a callback function pair from the list of 'users' to be 1174 * notified upon addition or removal of MTD devices. Causes the 1175 * 'remove' callback to be immediately invoked for each MTD device 1176 * currently present in the system. 1177 */ 1178int unregister_mtd_user (struct mtd_notifier *old) 1179{ 1180 struct mtd_info *mtd; 1181 1182 mutex_lock(&mtd_table_mutex); 1183 1184 module_put(THIS_MODULE); 1185 1186 mtd_for_each_device(mtd) 1187 old->remove(mtd); 1188 1189 list_del(&old->list); 1190 mutex_unlock(&mtd_table_mutex); 1191 return 0; 1192} 1193EXPORT_SYMBOL_GPL(unregister_mtd_user); 1194 1195/** 1196 * get_mtd_device - obtain a validated handle for an MTD device 1197 * @mtd: last known address of the required MTD device 1198 * @num: internal device number of the required MTD device 1199 * 1200 * Given a number and NULL address, return the num'th entry in the device 1201 * table, if any. Given an address and num == -1, search the device table 1202 * for a device with that address and return if it's still present. Given 1203 * both, return the num'th driver only if its address matches. Return 1204 * error code if not. 1205 */ 1206struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num) 1207{ 1208 struct mtd_info *ret = NULL, *other; 1209 int err = -ENODEV; 1210 1211 mutex_lock(&mtd_table_mutex); 1212 1213 if (num == -1) { 1214 mtd_for_each_device(other) { 1215 if (other == mtd) { 1216 ret = mtd; 1217 break; 1218 } 1219 } 1220 } else if (num >= 0) { 1221 ret = idr_find(&mtd_idr, num); 1222 if (mtd && mtd != ret) 1223 ret = NULL; 1224 } 1225 1226 if (!ret) { 1227 ret = ERR_PTR(err); 1228 goto out; 1229 } 1230 1231 err = __get_mtd_device(ret); 1232 if (err) 1233 ret = ERR_PTR(err); 1234out: 1235 mutex_unlock(&mtd_table_mutex); 1236 return ret; 1237} 1238EXPORT_SYMBOL_GPL(get_mtd_device); 1239 1240 1241int __get_mtd_device(struct mtd_info *mtd) 1242{ 1243 struct mtd_info *master = mtd_get_master(mtd); 1244 int err; 1245 1246 if (master->_get_device) { 1247 err = master->_get_device(mtd); 1248 if (err) 1249 return err; 1250 } 1251 1252 if (!try_module_get(master->owner)) { 1253 if (master->_put_device) 1254 master->_put_device(master); 1255 return -ENODEV; 1256 } 1257 1258 while (mtd) { 1259 if (mtd != master) 1260 kref_get(&mtd->refcnt); 1261 mtd = mtd->parent; 1262 } 1263 1264 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) 1265 kref_get(&master->refcnt); 1266 1267 return 0; 1268} 1269EXPORT_SYMBOL_GPL(__get_mtd_device); 1270 1271/** 1272 * of_get_mtd_device_by_node - obtain an MTD device associated with a given node 1273 * 1274 * @np: device tree node 1275 */ 1276struct mtd_info *of_get_mtd_device_by_node(struct device_node *np) 1277{ 1278 struct mtd_info *mtd = NULL; 1279 struct mtd_info *tmp; 1280 int err; 1281 1282 mutex_lock(&mtd_table_mutex); 1283 1284 err = -EPROBE_DEFER; 1285 mtd_for_each_device(tmp) { 1286 if (mtd_get_of_node(tmp) == np) { 1287 mtd = tmp; 1288 err = __get_mtd_device(mtd); 1289 break; 1290 } 1291 } 1292 1293 mutex_unlock(&mtd_table_mutex); 1294 1295 return err ? ERR_PTR(err) : mtd; 1296} 1297EXPORT_SYMBOL_GPL(of_get_mtd_device_by_node); 1298 1299/** 1300 * get_mtd_device_nm - obtain a validated handle for an MTD device by 1301 * device name 1302 * @name: MTD device name to open 1303 * 1304 * This function returns MTD device description structure in case of 1305 * success and an error code in case of failure. 1306 */ 1307struct mtd_info *get_mtd_device_nm(const char *name) 1308{ 1309 int err = -ENODEV; 1310 struct mtd_info *mtd = NULL, *other; 1311 1312 mutex_lock(&mtd_table_mutex); 1313 1314 mtd_for_each_device(other) { 1315 if (!strcmp(name, other->name)) { 1316 mtd = other; 1317 break; 1318 } 1319 } 1320 1321 if (!mtd) 1322 goto out_unlock; 1323 1324 err = __get_mtd_device(mtd); 1325 if (err) 1326 goto out_unlock; 1327 1328 mutex_unlock(&mtd_table_mutex); 1329 return mtd; 1330 1331out_unlock: 1332 mutex_unlock(&mtd_table_mutex); 1333 return ERR_PTR(err); 1334} 1335EXPORT_SYMBOL_GPL(get_mtd_device_nm); 1336 1337void put_mtd_device(struct mtd_info *mtd) 1338{ 1339 mutex_lock(&mtd_table_mutex); 1340 __put_mtd_device(mtd); 1341 mutex_unlock(&mtd_table_mutex); 1342 1343} 1344EXPORT_SYMBOL_GPL(put_mtd_device); 1345 1346void __put_mtd_device(struct mtd_info *mtd) 1347{ 1348 struct mtd_info *master = mtd_get_master(mtd); 1349 1350 while (mtd) { 1351 /* kref_put() can relese mtd, so keep a reference mtd->parent */ 1352 struct mtd_info *parent = mtd->parent; 1353 1354 if (mtd != master) 1355 kref_put(&mtd->refcnt, mtd_device_release); 1356 mtd = parent; 1357 } 1358 1359 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) 1360 kref_put(&master->refcnt, mtd_device_release); 1361 1362 module_put(master->owner); 1363 1364 /* must be the last as master can be freed in the _put_device */ 1365 if (master->_put_device) 1366 master->_put_device(master); 1367} 1368EXPORT_SYMBOL_GPL(__put_mtd_device); 1369 1370/* 1371 * Erase is an synchronous operation. Device drivers are epected to return a 1372 * negative error code if the operation failed and update instr->fail_addr 1373 * to point the portion that was not properly erased. 1374 */ 1375int mtd_erase(struct mtd_info *mtd, struct erase_info *instr) 1376{ 1377 struct mtd_info *master = mtd_get_master(mtd); 1378 u64 mst_ofs = mtd_get_master_ofs(mtd, 0); 1379 struct erase_info adjinstr; 1380 int ret; 1381 1382 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN; 1383 adjinstr = *instr; 1384 1385 if (!mtd->erasesize || !master->_erase) 1386 return -ENOTSUPP; 1387 1388 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr) 1389 return -EINVAL; 1390 if (!(mtd->flags & MTD_WRITEABLE)) 1391 return -EROFS; 1392 1393 if (!instr->len) 1394 return 0; 1395 1396 ledtrig_mtd_activity(); 1397 1398 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { 1399 adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) * 1400 master->erasesize; 1401 adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) * 1402 master->erasesize) - 1403 adjinstr.addr; 1404 } 1405 1406 adjinstr.addr += mst_ofs; 1407 1408 ret = master->_erase(master, &adjinstr); 1409 1410 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) { 1411 instr->fail_addr = adjinstr.fail_addr - mst_ofs; 1412 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { 1413 instr->fail_addr = mtd_div_by_eb(instr->fail_addr, 1414 master); 1415 instr->fail_addr *= mtd->erasesize; 1416 } 1417 } 1418 1419 return ret; 1420} 1421EXPORT_SYMBOL_GPL(mtd_erase); 1422ALLOW_ERROR_INJECTION(mtd_erase, ERRNO); 1423 1424/* 1425 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL. 1426 */ 1427int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, 1428 void **virt, resource_size_t *phys) 1429{ 1430 struct mtd_info *master = mtd_get_master(mtd); 1431 1432 *retlen = 0; 1433 *virt = NULL; 1434 if (phys) 1435 *phys = 0; 1436 if (!master->_point) 1437 return -EOPNOTSUPP; 1438 if (from < 0 || from >= mtd->size || len > mtd->size - from) 1439 return -EINVAL; 1440 if (!len) 1441 return 0; 1442 1443 from = mtd_get_master_ofs(mtd, from); 1444 return master->_point(master, from, len, retlen, virt, phys); 1445} 1446EXPORT_SYMBOL_GPL(mtd_point); 1447 1448/* We probably shouldn't allow XIP if the unpoint isn't a NULL */ 1449int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len) 1450{ 1451 struct mtd_info *master = mtd_get_master(mtd); 1452 1453 if (!master->_unpoint) 1454 return -EOPNOTSUPP; 1455 if (from < 0 || from >= mtd->size || len > mtd->size - from) 1456 return -EINVAL; 1457 if (!len) 1458 return 0; 1459 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len); 1460} 1461EXPORT_SYMBOL_GPL(mtd_unpoint); 1462 1463/* 1464 * Allow NOMMU mmap() to directly map the device (if not NULL) 1465 * - return the address to which the offset maps 1466 * - return -ENOSYS to indicate refusal to do the mapping 1467 */ 1468unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len, 1469 unsigned long offset, unsigned long flags) 1470{ 1471 size_t retlen; 1472 void *virt; 1473 int ret; 1474 1475 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL); 1476 if (ret) 1477 return ret; 1478 if (retlen != len) { 1479 mtd_unpoint(mtd, offset, retlen); 1480 return -ENOSYS; 1481 } 1482 return (unsigned long)virt; 1483} 1484EXPORT_SYMBOL_GPL(mtd_get_unmapped_area); 1485 1486static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master, 1487 const struct mtd_ecc_stats *old_stats) 1488{ 1489 struct mtd_ecc_stats diff; 1490 1491 if (master == mtd) 1492 return; 1493 1494 diff = master->ecc_stats; 1495 diff.failed -= old_stats->failed; 1496 diff.corrected -= old_stats->corrected; 1497 1498 while (mtd->parent) { 1499 mtd->ecc_stats.failed += diff.failed; 1500 mtd->ecc_stats.corrected += diff.corrected; 1501 mtd = mtd->parent; 1502 } 1503} 1504 1505int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, 1506 u_char *buf) 1507{ 1508 struct mtd_oob_ops ops = { 1509 .len = len, 1510 .datbuf = buf, 1511 }; 1512 int ret; 1513 1514 ret = mtd_read_oob(mtd, from, &ops); 1515 *retlen = ops.retlen; 1516 1517 WARN_ON_ONCE(*retlen != len && mtd_is_bitflip_or_eccerr(ret)); 1518 1519 return ret; 1520} 1521EXPORT_SYMBOL_GPL(mtd_read); 1522ALLOW_ERROR_INJECTION(mtd_read, ERRNO); 1523 1524int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, 1525 const u_char *buf) 1526{ 1527 struct mtd_oob_ops ops = { 1528 .len = len, 1529 .datbuf = (u8 *)buf, 1530 }; 1531 int ret; 1532 1533 ret = mtd_write_oob(mtd, to, &ops); 1534 *retlen = ops.retlen; 1535 1536 return ret; 1537} 1538EXPORT_SYMBOL_GPL(mtd_write); 1539ALLOW_ERROR_INJECTION(mtd_write, ERRNO); 1540 1541/* 1542 * In blackbox flight recorder like scenarios we want to make successful writes 1543 * in interrupt context. panic_write() is only intended to be called when its 1544 * known the kernel is about to panic and we need the write to succeed. Since 1545 * the kernel is not going to be running for much longer, this function can 1546 * break locks and delay to ensure the write succeeds (but not sleep). 1547 */ 1548int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, 1549 const u_char *buf) 1550{ 1551 struct mtd_info *master = mtd_get_master(mtd); 1552 1553 *retlen = 0; 1554 if (!master->_panic_write) 1555 return -EOPNOTSUPP; 1556 if (to < 0 || to >= mtd->size || len > mtd->size - to) 1557 return -EINVAL; 1558 if (!(mtd->flags & MTD_WRITEABLE)) 1559 return -EROFS; 1560 if (!len) 1561 return 0; 1562 if (!master->oops_panic_write) 1563 master->oops_panic_write = true; 1564 1565 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len, 1566 retlen, buf); 1567} 1568EXPORT_SYMBOL_GPL(mtd_panic_write); 1569 1570static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs, 1571 struct mtd_oob_ops *ops) 1572{ 1573 /* 1574 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving 1575 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in 1576 * this case. 1577 */ 1578 if (!ops->datbuf) 1579 ops->len = 0; 1580 1581 if (!ops->oobbuf) 1582 ops->ooblen = 0; 1583 1584 if (offs < 0 || offs + ops->len > mtd->size) 1585 return -EINVAL; 1586 1587 if (ops->ooblen) { 1588 size_t maxooblen; 1589 1590 if (ops->ooboffs >= mtd_oobavail(mtd, ops)) 1591 return -EINVAL; 1592 1593 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) - 1594 mtd_div_by_ws(offs, mtd)) * 1595 mtd_oobavail(mtd, ops)) - ops->ooboffs; 1596 if (ops->ooblen > maxooblen) 1597 return -EINVAL; 1598 } 1599 1600 return 0; 1601} 1602 1603static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from, 1604 struct mtd_oob_ops *ops) 1605{ 1606 struct mtd_info *master = mtd_get_master(mtd); 1607 int ret; 1608 1609 from = mtd_get_master_ofs(mtd, from); 1610 if (master->_read_oob) 1611 ret = master->_read_oob(master, from, ops); 1612 else 1613 ret = master->_read(master, from, ops->len, &ops->retlen, 1614 ops->datbuf); 1615 1616 return ret; 1617} 1618 1619static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to, 1620 struct mtd_oob_ops *ops) 1621{ 1622 struct mtd_info *master = mtd_get_master(mtd); 1623 int ret; 1624 1625 to = mtd_get_master_ofs(mtd, to); 1626 if (master->_write_oob) 1627 ret = master->_write_oob(master, to, ops); 1628 else 1629 ret = master->_write(master, to, ops->len, &ops->retlen, 1630 ops->datbuf); 1631 1632 return ret; 1633} 1634 1635static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read, 1636 struct mtd_oob_ops *ops) 1637{ 1638 struct mtd_info *master = mtd_get_master(mtd); 1639 int ngroups = mtd_pairing_groups(master); 1640 int npairs = mtd_wunit_per_eb(master) / ngroups; 1641 struct mtd_oob_ops adjops = *ops; 1642 unsigned int wunit, oobavail; 1643 struct mtd_pairing_info info; 1644 int max_bitflips = 0; 1645 u32 ebofs, pageofs; 1646 loff_t base, pos; 1647 1648 ebofs = mtd_mod_by_eb(start, mtd); 1649 base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize; 1650 info.group = 0; 1651 info.pair = mtd_div_by_ws(ebofs, mtd); 1652 pageofs = mtd_mod_by_ws(ebofs, mtd); 1653 oobavail = mtd_oobavail(mtd, ops); 1654 1655 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) { 1656 int ret; 1657 1658 if (info.pair >= npairs) { 1659 info.pair = 0; 1660 base += master->erasesize; 1661 } 1662 1663 wunit = mtd_pairing_info_to_wunit(master, &info); 1664 pos = mtd_wunit_to_offset(mtd, base, wunit); 1665 1666 adjops.len = ops->len - ops->retlen; 1667 if (adjops.len > mtd->writesize - pageofs) 1668 adjops.len = mtd->writesize - pageofs; 1669 1670 adjops.ooblen = ops->ooblen - ops->oobretlen; 1671 if (adjops.ooblen > oobavail - adjops.ooboffs) 1672 adjops.ooblen = oobavail - adjops.ooboffs; 1673 1674 if (read) { 1675 ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops); 1676 if (ret > 0) 1677 max_bitflips = max(max_bitflips, ret); 1678 } else { 1679 ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops); 1680 } 1681 1682 if (ret < 0) 1683 return ret; 1684 1685 max_bitflips = max(max_bitflips, ret); 1686 ops->retlen += adjops.retlen; 1687 ops->oobretlen += adjops.oobretlen; 1688 adjops.datbuf += adjops.retlen; 1689 adjops.oobbuf += adjops.oobretlen; 1690 adjops.ooboffs = 0; 1691 pageofs = 0; 1692 info.pair++; 1693 } 1694 1695 return max_bitflips; 1696} 1697 1698int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops) 1699{ 1700 struct mtd_info *master = mtd_get_master(mtd); 1701 struct mtd_ecc_stats old_stats = master->ecc_stats; 1702 int ret_code; 1703 1704 ops->retlen = ops->oobretlen = 0; 1705 1706 ret_code = mtd_check_oob_ops(mtd, from, ops); 1707 if (ret_code) 1708 return ret_code; 1709 1710 ledtrig_mtd_activity(); 1711 1712 /* Check the validity of a potential fallback on mtd->_read */ 1713 if (!master->_read_oob && (!master->_read || ops->oobbuf)) 1714 return -EOPNOTSUPP; 1715 1716 if (ops->stats) 1717 memset(ops->stats, 0, sizeof(*ops->stats)); 1718 1719 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) 1720 ret_code = mtd_io_emulated_slc(mtd, from, true, ops); 1721 else 1722 ret_code = mtd_read_oob_std(mtd, from, ops); 1723 1724 mtd_update_ecc_stats(mtd, master, &old_stats); 1725 1726 /* 1727 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics 1728 * similar to mtd->_read(), returning a non-negative integer 1729 * representing max bitflips. In other cases, mtd->_read_oob() may 1730 * return -EUCLEAN. In all cases, perform similar logic to mtd_read(). 1731 */ 1732 if (unlikely(ret_code < 0)) 1733 return ret_code; 1734 if (mtd->ecc_strength == 0) 1735 return 0; /* device lacks ecc */ 1736 if (ops->stats) 1737 ops->stats->max_bitflips = ret_code; 1738 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0; 1739} 1740EXPORT_SYMBOL_GPL(mtd_read_oob); 1741 1742int mtd_write_oob(struct mtd_info *mtd, loff_t to, 1743 struct mtd_oob_ops *ops) 1744{ 1745 struct mtd_info *master = mtd_get_master(mtd); 1746 int ret; 1747 1748 ops->retlen = ops->oobretlen = 0; 1749 1750 if (!(mtd->flags & MTD_WRITEABLE)) 1751 return -EROFS; 1752 1753 ret = mtd_check_oob_ops(mtd, to, ops); 1754 if (ret) 1755 return ret; 1756 1757 ledtrig_mtd_activity(); 1758 1759 /* Check the validity of a potential fallback on mtd->_write */ 1760 if (!master->_write_oob && (!master->_write || ops->oobbuf)) 1761 return -EOPNOTSUPP; 1762 1763 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) 1764 return mtd_io_emulated_slc(mtd, to, false, ops); 1765 1766 return mtd_write_oob_std(mtd, to, ops); 1767} 1768EXPORT_SYMBOL_GPL(mtd_write_oob); 1769 1770/** 1771 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section 1772 * @mtd: MTD device structure 1773 * @section: ECC section. Depending on the layout you may have all the ECC 1774 * bytes stored in a single contiguous section, or one section 1775 * per ECC chunk (and sometime several sections for a single ECC 1776 * ECC chunk) 1777 * @oobecc: OOB region struct filled with the appropriate ECC position 1778 * information 1779 * 1780 * This function returns ECC section information in the OOB area. If you want 1781 * to get all the ECC bytes information, then you should call 1782 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE. 1783 * 1784 * Returns zero on success, a negative error code otherwise. 1785 */ 1786int mtd_ooblayout_ecc(struct mtd_info *mtd, int section, 1787 struct mtd_oob_region *oobecc) 1788{ 1789 struct mtd_info *master = mtd_get_master(mtd); 1790 1791 memset(oobecc, 0, sizeof(*oobecc)); 1792 1793 if (!master || section < 0) 1794 return -EINVAL; 1795 1796 if (!master->ooblayout || !master->ooblayout->ecc) 1797 return -ENOTSUPP; 1798 1799 return master->ooblayout->ecc(master, section, oobecc); 1800} 1801EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc); 1802 1803/** 1804 * mtd_ooblayout_free - Get the OOB region definition of a specific free 1805 * section 1806 * @mtd: MTD device structure 1807 * @section: Free section you are interested in. Depending on the layout 1808 * you may have all the free bytes stored in a single contiguous 1809 * section, or one section per ECC chunk plus an extra section 1810 * for the remaining bytes (or other funky layout). 1811 * @oobfree: OOB region struct filled with the appropriate free position 1812 * information 1813 * 1814 * This function returns free bytes position in the OOB area. If you want 1815 * to get all the free bytes information, then you should call 1816 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE. 1817 * 1818 * Returns zero on success, a negative error code otherwise. 1819 */ 1820int mtd_ooblayout_free(struct mtd_info *mtd, int section, 1821 struct mtd_oob_region *oobfree) 1822{ 1823 struct mtd_info *master = mtd_get_master(mtd); 1824 1825 memset(oobfree, 0, sizeof(*oobfree)); 1826 1827 if (!master || section < 0) 1828 return -EINVAL; 1829 1830 if (!master->ooblayout || !master->ooblayout->free) 1831 return -ENOTSUPP; 1832 1833 return master->ooblayout->free(master, section, oobfree); 1834} 1835EXPORT_SYMBOL_GPL(mtd_ooblayout_free); 1836 1837/** 1838 * mtd_ooblayout_find_region - Find the region attached to a specific byte 1839 * @mtd: mtd info structure 1840 * @byte: the byte we are searching for 1841 * @sectionp: pointer where the section id will be stored 1842 * @oobregion: used to retrieve the ECC position 1843 * @iter: iterator function. Should be either mtd_ooblayout_free or 1844 * mtd_ooblayout_ecc depending on the region type you're searching for 1845 * 1846 * This function returns the section id and oobregion information of a 1847 * specific byte. For example, say you want to know where the 4th ECC byte is 1848 * stored, you'll use: 1849 * 1850 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc); 1851 * 1852 * Returns zero on success, a negative error code otherwise. 1853 */ 1854static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte, 1855 int *sectionp, struct mtd_oob_region *oobregion, 1856 int (*iter)(struct mtd_info *, 1857 int section, 1858 struct mtd_oob_region *oobregion)) 1859{ 1860 int pos = 0, ret, section = 0; 1861 1862 memset(oobregion, 0, sizeof(*oobregion)); 1863 1864 while (1) { 1865 ret = iter(mtd, section, oobregion); 1866 if (ret) 1867 return ret; 1868 1869 if (pos + oobregion->length > byte) 1870 break; 1871 1872 pos += oobregion->length; 1873 section++; 1874 } 1875 1876 /* 1877 * Adjust region info to make it start at the beginning at the 1878 * 'start' ECC byte. 1879 */ 1880 oobregion->offset += byte - pos; 1881 oobregion->length -= byte - pos; 1882 *sectionp = section; 1883 1884 return 0; 1885} 1886 1887/** 1888 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific 1889 * ECC byte 1890 * @mtd: mtd info structure 1891 * @eccbyte: the byte we are searching for 1892 * @section: pointer where the section id will be stored 1893 * @oobregion: OOB region information 1894 * 1895 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC 1896 * byte. 1897 * 1898 * Returns zero on success, a negative error code otherwise. 1899 */ 1900int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte, 1901 int *section, 1902 struct mtd_oob_region *oobregion) 1903{ 1904 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion, 1905 mtd_ooblayout_ecc); 1906} 1907EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion); 1908 1909/** 1910 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer 1911 * @mtd: mtd info structure 1912 * @buf: destination buffer to store OOB bytes 1913 * @oobbuf: OOB buffer 1914 * @start: first byte to retrieve 1915 * @nbytes: number of bytes to retrieve 1916 * @iter: section iterator 1917 * 1918 * Extract bytes attached to a specific category (ECC or free) 1919 * from the OOB buffer and copy them into buf. 1920 * 1921 * Returns zero on success, a negative error code otherwise. 1922 */ 1923static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf, 1924 const u8 *oobbuf, int start, int nbytes, 1925 int (*iter)(struct mtd_info *, 1926 int section, 1927 struct mtd_oob_region *oobregion)) 1928{ 1929 struct mtd_oob_region oobregion; 1930 int section, ret; 1931 1932 ret = mtd_ooblayout_find_region(mtd, start, §ion, 1933 &oobregion, iter); 1934 1935 while (!ret) { 1936 int cnt; 1937 1938 cnt = min_t(int, nbytes, oobregion.length); 1939 memcpy(buf, oobbuf + oobregion.offset, cnt); 1940 buf += cnt; 1941 nbytes -= cnt; 1942 1943 if (!nbytes) 1944 break; 1945 1946 ret = iter(mtd, ++section, &oobregion); 1947 } 1948 1949 return ret; 1950} 1951 1952/** 1953 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer 1954 * @mtd: mtd info structure 1955 * @buf: source buffer to get OOB bytes from 1956 * @oobbuf: OOB buffer 1957 * @start: first OOB byte to set 1958 * @nbytes: number of OOB bytes to set 1959 * @iter: section iterator 1960 * 1961 * Fill the OOB buffer with data provided in buf. The category (ECC or free) 1962 * is selected by passing the appropriate iterator. 1963 * 1964 * Returns zero on success, a negative error code otherwise. 1965 */ 1966static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf, 1967 u8 *oobbuf, int start, int nbytes, 1968 int (*iter)(struct mtd_info *, 1969 int section, 1970 struct mtd_oob_region *oobregion)) 1971{ 1972 struct mtd_oob_region oobregion; 1973 int section, ret; 1974 1975 ret = mtd_ooblayout_find_region(mtd, start, §ion, 1976 &oobregion, iter); 1977 1978 while (!ret) { 1979 int cnt; 1980 1981 cnt = min_t(int, nbytes, oobregion.length); 1982 memcpy(oobbuf + oobregion.offset, buf, cnt); 1983 buf += cnt; 1984 nbytes -= cnt; 1985 1986 if (!nbytes) 1987 break; 1988 1989 ret = iter(mtd, ++section, &oobregion); 1990 } 1991 1992 return ret; 1993} 1994 1995/** 1996 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category 1997 * @mtd: mtd info structure 1998 * @iter: category iterator 1999 * 2000 * Count the number of bytes in a given category. 2001 * 2002 * Returns a positive value on success, a negative error code otherwise. 2003 */ 2004static int mtd_ooblayout_count_bytes(struct mtd_info *mtd, 2005 int (*iter)(struct mtd_info *, 2006 int section, 2007 struct mtd_oob_region *oobregion)) 2008{ 2009 struct mtd_oob_region oobregion; 2010 int section = 0, ret, nbytes = 0; 2011 2012 while (1) { 2013 ret = iter(mtd, section++, &oobregion); 2014 if (ret) { 2015 if (ret == -ERANGE) 2016 ret = nbytes; 2017 break; 2018 } 2019 2020 nbytes += oobregion.length; 2021 } 2022 2023 return ret; 2024} 2025 2026/** 2027 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer 2028 * @mtd: mtd info structure 2029 * @eccbuf: destination buffer to store ECC bytes 2030 * @oobbuf: OOB buffer 2031 * @start: first ECC byte to retrieve 2032 * @nbytes: number of ECC bytes to retrieve 2033 * 2034 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes. 2035 * 2036 * Returns zero on success, a negative error code otherwise. 2037 */ 2038int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf, 2039 const u8 *oobbuf, int start, int nbytes) 2040{ 2041 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes, 2042 mtd_ooblayout_ecc); 2043} 2044EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes); 2045 2046/** 2047 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer 2048 * @mtd: mtd info structure 2049 * @eccbuf: source buffer to get ECC bytes from 2050 * @oobbuf: OOB buffer 2051 * @start: first ECC byte to set 2052 * @nbytes: number of ECC bytes to set 2053 * 2054 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes. 2055 * 2056 * Returns zero on success, a negative error code otherwise. 2057 */ 2058int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf, 2059 u8 *oobbuf, int start, int nbytes) 2060{ 2061 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes, 2062 mtd_ooblayout_ecc); 2063} 2064EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes); 2065 2066/** 2067 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer 2068 * @mtd: mtd info structure 2069 * @databuf: destination buffer to store ECC bytes 2070 * @oobbuf: OOB buffer 2071 * @start: first ECC byte to retrieve 2072 * @nbytes: number of ECC bytes to retrieve 2073 * 2074 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes. 2075 * 2076 * Returns zero on success, a negative error code otherwise. 2077 */ 2078int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf, 2079 const u8 *oobbuf, int start, int nbytes) 2080{ 2081 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes, 2082 mtd_ooblayout_free); 2083} 2084EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes); 2085 2086/** 2087 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer 2088 * @mtd: mtd info structure 2089 * @databuf: source buffer to get data bytes from 2090 * @oobbuf: OOB buffer 2091 * @start: first ECC byte to set 2092 * @nbytes: number of ECC bytes to set 2093 * 2094 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes. 2095 * 2096 * Returns zero on success, a negative error code otherwise. 2097 */ 2098int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf, 2099 u8 *oobbuf, int start, int nbytes) 2100{ 2101 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes, 2102 mtd_ooblayout_free); 2103} 2104EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes); 2105 2106/** 2107 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB 2108 * @mtd: mtd info structure 2109 * 2110 * Works like mtd_ooblayout_count_bytes(), except it count free bytes. 2111 * 2112 * Returns zero on success, a negative error code otherwise. 2113 */ 2114int mtd_ooblayout_count_freebytes(struct mtd_info *mtd) 2115{ 2116 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free); 2117} 2118EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes); 2119 2120/** 2121 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB 2122 * @mtd: mtd info structure 2123 * 2124 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes. 2125 * 2126 * Returns zero on success, a negative error code otherwise. 2127 */ 2128int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd) 2129{ 2130 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc); 2131} 2132EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes); 2133 2134/* 2135 * Method to access the protection register area, present in some flash 2136 * devices. The user data is one time programmable but the factory data is read 2137 * only. 2138 */ 2139int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen, 2140 struct otp_info *buf) 2141{ 2142 struct mtd_info *master = mtd_get_master(mtd); 2143 2144 if (!master->_get_fact_prot_info) 2145 return -EOPNOTSUPP; 2146 if (!len) 2147 return 0; 2148 return master->_get_fact_prot_info(master, len, retlen, buf); 2149} 2150EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info); 2151 2152int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len, 2153 size_t *retlen, u_char *buf) 2154{ 2155 struct mtd_info *master = mtd_get_master(mtd); 2156 2157 *retlen = 0; 2158 if (!master->_read_fact_prot_reg) 2159 return -EOPNOTSUPP; 2160 if (!len) 2161 return 0; 2162 return master->_read_fact_prot_reg(master, from, len, retlen, buf); 2163} 2164EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg); 2165 2166int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen, 2167 struct otp_info *buf) 2168{ 2169 struct mtd_info *master = mtd_get_master(mtd); 2170 2171 if (!master->_get_user_prot_info) 2172 return -EOPNOTSUPP; 2173 if (!len) 2174 return 0; 2175 return master->_get_user_prot_info(master, len, retlen, buf); 2176} 2177EXPORT_SYMBOL_GPL(mtd_get_user_prot_info); 2178 2179int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len, 2180 size_t *retlen, u_char *buf) 2181{ 2182 struct mtd_info *master = mtd_get_master(mtd); 2183 2184 *retlen = 0; 2185 if (!master->_read_user_prot_reg) 2186 return -EOPNOTSUPP; 2187 if (!len) 2188 return 0; 2189 return master->_read_user_prot_reg(master, from, len, retlen, buf); 2190} 2191EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg); 2192 2193int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len, 2194 size_t *retlen, const u_char *buf) 2195{ 2196 struct mtd_info *master = mtd_get_master(mtd); 2197 int ret; 2198 2199 *retlen = 0; 2200 if (!master->_write_user_prot_reg) 2201 return -EOPNOTSUPP; 2202 if (!len) 2203 return 0; 2204 ret = master->_write_user_prot_reg(master, to, len, retlen, buf); 2205 if (ret) 2206 return ret; 2207 2208 /* 2209 * If no data could be written at all, we are out of memory and 2210 * must return -ENOSPC. 2211 */ 2212 return (*retlen) ? 0 : -ENOSPC; 2213} 2214EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg); 2215 2216int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len) 2217{ 2218 struct mtd_info *master = mtd_get_master(mtd); 2219 2220 if (!master->_lock_user_prot_reg) 2221 return -EOPNOTSUPP; 2222 if (!len) 2223 return 0; 2224 return master->_lock_user_prot_reg(master, from, len); 2225} 2226EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg); 2227 2228int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len) 2229{ 2230 struct mtd_info *master = mtd_get_master(mtd); 2231 2232 if (!master->_erase_user_prot_reg) 2233 return -EOPNOTSUPP; 2234 if (!len) 2235 return 0; 2236 return master->_erase_user_prot_reg(master, from, len); 2237} 2238EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg); 2239 2240/* Chip-supported device locking */ 2241int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) 2242{ 2243 struct mtd_info *master = mtd_get_master(mtd); 2244 2245 if (!master->_lock) 2246 return -EOPNOTSUPP; 2247 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs) 2248 return -EINVAL; 2249 if (!len) 2250 return 0; 2251 2252 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { 2253 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; 2254 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize; 2255 } 2256 2257 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len); 2258} 2259EXPORT_SYMBOL_GPL(mtd_lock); 2260 2261int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len) 2262{ 2263 struct mtd_info *master = mtd_get_master(mtd); 2264 2265 if (!master->_unlock) 2266 return -EOPNOTSUPP; 2267 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs) 2268 return -EINVAL; 2269 if (!len) 2270 return 0; 2271 2272 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { 2273 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; 2274 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize; 2275 } 2276 2277 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len); 2278} 2279EXPORT_SYMBOL_GPL(mtd_unlock); 2280 2281int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len) 2282{ 2283 struct mtd_info *master = mtd_get_master(mtd); 2284 2285 if (!master->_is_locked) 2286 return -EOPNOTSUPP; 2287 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs) 2288 return -EINVAL; 2289 if (!len) 2290 return 0; 2291 2292 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { 2293 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; 2294 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize; 2295 } 2296 2297 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len); 2298} 2299EXPORT_SYMBOL_GPL(mtd_is_locked); 2300 2301int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs) 2302{ 2303 struct mtd_info *master = mtd_get_master(mtd); 2304 2305 if (ofs < 0 || ofs >= mtd->size) 2306 return -EINVAL; 2307 if (!master->_block_isreserved) 2308 return 0; 2309 2310 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) 2311 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; 2312 2313 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs)); 2314} 2315EXPORT_SYMBOL_GPL(mtd_block_isreserved); 2316 2317int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs) 2318{ 2319 struct mtd_info *master = mtd_get_master(mtd); 2320 2321 if (ofs < 0 || ofs >= mtd->size) 2322 return -EINVAL; 2323 if (!master->_block_isbad) 2324 return 0; 2325 2326 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) 2327 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; 2328 2329 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs)); 2330} 2331EXPORT_SYMBOL_GPL(mtd_block_isbad); 2332 2333int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs) 2334{ 2335 struct mtd_info *master = mtd_get_master(mtd); 2336 int ret; 2337 2338 if (!master->_block_markbad) 2339 return -EOPNOTSUPP; 2340 if (ofs < 0 || ofs >= mtd->size) 2341 return -EINVAL; 2342 if (!(mtd->flags & MTD_WRITEABLE)) 2343 return -EROFS; 2344 2345 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) 2346 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; 2347 2348 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs)); 2349 if (ret) 2350 return ret; 2351 2352 while (mtd->parent) { 2353 mtd->ecc_stats.badblocks++; 2354 mtd = mtd->parent; 2355 } 2356 2357 return 0; 2358} 2359EXPORT_SYMBOL_GPL(mtd_block_markbad); 2360ALLOW_ERROR_INJECTION(mtd_block_markbad, ERRNO); 2361 2362/* 2363 * default_mtd_writev - the default writev method 2364 * @mtd: mtd device description object pointer 2365 * @vecs: the vectors to write 2366 * @count: count of vectors in @vecs 2367 * @to: the MTD device offset to write to 2368 * @retlen: on exit contains the count of bytes written to the MTD device. 2369 * 2370 * This function returns zero in case of success and a negative error code in 2371 * case of failure. 2372 */ 2373static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, 2374 unsigned long count, loff_t to, size_t *retlen) 2375{ 2376 unsigned long i; 2377 size_t totlen = 0, thislen; 2378 int ret = 0; 2379 2380 for (i = 0; i < count; i++) { 2381 if (!vecs[i].iov_len) 2382 continue; 2383 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen, 2384 vecs[i].iov_base); 2385 totlen += thislen; 2386 if (ret || thislen != vecs[i].iov_len) 2387 break; 2388 to += vecs[i].iov_len; 2389 } 2390 *retlen = totlen; 2391 return ret; 2392} 2393 2394/* 2395 * mtd_writev - the vector-based MTD write method 2396 * @mtd: mtd device description object pointer 2397 * @vecs: the vectors to write 2398 * @count: count of vectors in @vecs 2399 * @to: the MTD device offset to write to 2400 * @retlen: on exit contains the count of bytes written to the MTD device. 2401 * 2402 * This function returns zero in case of success and a negative error code in 2403 * case of failure. 2404 */ 2405int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, 2406 unsigned long count, loff_t to, size_t *retlen) 2407{ 2408 struct mtd_info *master = mtd_get_master(mtd); 2409 2410 *retlen = 0; 2411 if (!(mtd->flags & MTD_WRITEABLE)) 2412 return -EROFS; 2413 2414 if (!master->_writev) 2415 return default_mtd_writev(mtd, vecs, count, to, retlen); 2416 2417 return master->_writev(master, vecs, count, 2418 mtd_get_master_ofs(mtd, to), retlen); 2419} 2420EXPORT_SYMBOL_GPL(mtd_writev); 2421 2422/** 2423 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size 2424 * @mtd: mtd device description object pointer 2425 * @size: a pointer to the ideal or maximum size of the allocation, points 2426 * to the actual allocation size on success. 2427 * 2428 * This routine attempts to allocate a contiguous kernel buffer up to 2429 * the specified size, backing off the size of the request exponentially 2430 * until the request succeeds or until the allocation size falls below 2431 * the system page size. This attempts to make sure it does not adversely 2432 * impact system performance, so when allocating more than one page, we 2433 * ask the memory allocator to avoid re-trying, swapping, writing back 2434 * or performing I/O. 2435 * 2436 * Note, this function also makes sure that the allocated buffer is aligned to 2437 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value. 2438 * 2439 * This is called, for example by mtd_{read,write} and jffs2_scan_medium, 2440 * to handle smaller (i.e. degraded) buffer allocations under low- or 2441 * fragmented-memory situations where such reduced allocations, from a 2442 * requested ideal, are allowed. 2443 * 2444 * Returns a pointer to the allocated buffer on success; otherwise, NULL. 2445 */ 2446void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size) 2447{ 2448 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY; 2449 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE); 2450 void *kbuf; 2451 2452 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE); 2453 2454 while (*size > min_alloc) { 2455 kbuf = kmalloc(*size, flags); 2456 if (kbuf) 2457 return kbuf; 2458 2459 *size >>= 1; 2460 *size = ALIGN(*size, mtd->writesize); 2461 } 2462 2463 /* 2464 * For the last resort allocation allow 'kmalloc()' to do all sorts of 2465 * things (write-back, dropping caches, etc) by using GFP_KERNEL. 2466 */ 2467 return kmalloc(*size, GFP_KERNEL); 2468} 2469EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to); 2470 2471#ifdef CONFIG_PROC_FS 2472 2473/*====================================================================*/ 2474/* Support for /proc/mtd */ 2475 2476static int mtd_proc_show(struct seq_file *m, void *v) 2477{ 2478 struct mtd_info *mtd; 2479 2480 seq_puts(m, "dev: size erasesize name\n"); 2481 mutex_lock(&mtd_table_mutex); 2482 mtd_for_each_device(mtd) { 2483 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n", 2484 mtd->index, (unsigned long long)mtd->size, 2485 mtd->erasesize, mtd->name); 2486 } 2487 mutex_unlock(&mtd_table_mutex); 2488 return 0; 2489} 2490#endif /* CONFIG_PROC_FS */ 2491 2492/*====================================================================*/ 2493/* Init code */ 2494 2495static struct backing_dev_info * __init mtd_bdi_init(const char *name) 2496{ 2497 struct backing_dev_info *bdi; 2498 int ret; 2499 2500 bdi = bdi_alloc(NUMA_NO_NODE); 2501 if (!bdi) 2502 return ERR_PTR(-ENOMEM); 2503 bdi->ra_pages = 0; 2504 bdi->io_pages = 0; 2505 2506 /* 2507 * We put '-0' suffix to the name to get the same name format as we 2508 * used to get. Since this is called only once, we get a unique name. 2509 */ 2510 ret = bdi_register(bdi, "%.28s-0", name); 2511 if (ret) 2512 bdi_put(bdi); 2513 2514 return ret ? ERR_PTR(ret) : bdi; 2515} 2516 2517static struct proc_dir_entry *proc_mtd; 2518 2519static int __init init_mtd(void) 2520{ 2521 int ret; 2522 2523 ret = class_register(&mtd_class); 2524 if (ret) 2525 goto err_reg; 2526 2527 mtd_bdi = mtd_bdi_init("mtd"); 2528 if (IS_ERR(mtd_bdi)) { 2529 ret = PTR_ERR(mtd_bdi); 2530 goto err_bdi; 2531 } 2532 2533 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show); 2534 2535 ret = init_mtdchar(); 2536 if (ret) 2537 goto out_procfs; 2538 2539 dfs_dir_mtd = debugfs_create_dir("mtd", NULL); 2540 debugfs_create_bool("expert_analysis_mode", 0600, dfs_dir_mtd, 2541 &mtd_expert_analysis_mode); 2542 2543 return 0; 2544 2545out_procfs: 2546 if (proc_mtd) 2547 remove_proc_entry("mtd", NULL); 2548 bdi_unregister(mtd_bdi); 2549 bdi_put(mtd_bdi); 2550err_bdi: 2551 class_unregister(&mtd_class); 2552err_reg: 2553 pr_err("Error registering mtd class or bdi: %d\n", ret); 2554 return ret; 2555} 2556 2557static void __exit cleanup_mtd(void) 2558{ 2559 debugfs_remove_recursive(dfs_dir_mtd); 2560 cleanup_mtdchar(); 2561 if (proc_mtd) 2562 remove_proc_entry("mtd", NULL); 2563 class_unregister(&mtd_class); 2564 bdi_unregister(mtd_bdi); 2565 bdi_put(mtd_bdi); 2566 idr_destroy(&mtd_idr); 2567} 2568 2569module_init(init_mtd); 2570module_exit(cleanup_mtd); 2571 2572MODULE_LICENSE("GPL"); 2573MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 2574MODULE_DESCRIPTION("Core MTD registration and access routines"); 2575