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 = true; 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 return size; 961 962 if (size > 0) { 963 nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size, 964 mtd_nvmem_user_otp_reg_read); 965 if (IS_ERR(nvmem)) { 966 err = PTR_ERR(nvmem); 967 goto err; 968 } 969 mtd->otp_user_nvmem = nvmem; 970 } 971 } 972 973 if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) { 974 size = mtd_otp_size(mtd, false); 975 if (size < 0) { 976 err = size; 977 goto err; 978 } 979 980 if (size > 0) { 981 /* 982 * The factory OTP contains thing such as a unique serial 983 * number and is small, so let's read it out and put it 984 * into the entropy pool. 985 */ 986 void *otp; 987 988 otp = kmalloc(size, GFP_KERNEL); 989 if (!otp) { 990 err = -ENOMEM; 991 goto err; 992 } 993 err = mtd_nvmem_fact_otp_reg_read(mtd, 0, otp, size); 994 if (err < 0) { 995 kfree(otp); 996 goto err; 997 } 998 add_device_randomness(otp, err); 999 kfree(otp); 1000 1001 nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size, 1002 mtd_nvmem_fact_otp_reg_read); 1003 if (IS_ERR(nvmem)) { 1004 err = PTR_ERR(nvmem); 1005 goto err; 1006 } 1007 mtd->otp_factory_nvmem = nvmem; 1008 } 1009 } 1010 1011 return 0; 1012 1013err: 1014 nvmem_unregister(mtd->otp_user_nvmem); 1015 return dev_err_probe(dev, err, "Failed to register OTP NVMEM device\n"); 1016} 1017 1018/** 1019 * mtd_device_parse_register - parse partitions and register an MTD device. 1020 * 1021 * @mtd: the MTD device to register 1022 * @types: the list of MTD partition probes to try, see 1023 * 'parse_mtd_partitions()' for more information 1024 * @parser_data: MTD partition parser-specific data 1025 * @parts: fallback partition information to register, if parsing fails; 1026 * only valid if %nr_parts > %0 1027 * @nr_parts: the number of partitions in parts, if zero then the full 1028 * MTD device is registered if no partition info is found 1029 * 1030 * This function aggregates MTD partitions parsing (done by 1031 * 'parse_mtd_partitions()') and MTD device and partitions registering. It 1032 * basically follows the most common pattern found in many MTD drivers: 1033 * 1034 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is 1035 * registered first. 1036 * * Then It tries to probe partitions on MTD device @mtd using parsers 1037 * specified in @types (if @types is %NULL, then the default list of parsers 1038 * is used, see 'parse_mtd_partitions()' for more information). If none are 1039 * found this functions tries to fallback to information specified in 1040 * @parts/@nr_parts. 1041 * * If no partitions were found this function just registers the MTD device 1042 * @mtd and exits. 1043 * 1044 * Returns zero in case of success and a negative error code in case of failure. 1045 */ 1046int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types, 1047 struct mtd_part_parser_data *parser_data, 1048 const struct mtd_partition *parts, 1049 int nr_parts) 1050{ 1051 int ret; 1052 1053 mtd_set_dev_defaults(mtd); 1054 1055 ret = mtd_otp_nvmem_add(mtd); 1056 if (ret) 1057 goto out; 1058 1059 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) { 1060 ret = add_mtd_device(mtd); 1061 if (ret) 1062 goto out; 1063 } 1064 1065 /* Prefer parsed partitions over driver-provided fallback */ 1066 ret = parse_mtd_partitions(mtd, types, parser_data); 1067 if (ret == -EPROBE_DEFER) 1068 goto out; 1069 1070 if (ret > 0) 1071 ret = 0; 1072 else if (nr_parts) 1073 ret = add_mtd_partitions(mtd, parts, nr_parts); 1074 else if (!device_is_registered(&mtd->dev)) 1075 ret = add_mtd_device(mtd); 1076 else 1077 ret = 0; 1078 1079 if (ret) 1080 goto out; 1081 1082 /* 1083 * FIXME: some drivers unfortunately call this function more than once. 1084 * So we have to check if we've already assigned the reboot notifier. 1085 * 1086 * Generally, we can make multiple calls work for most cases, but it 1087 * does cause problems with parse_mtd_partitions() above (e.g., 1088 * cmdlineparts will register partitions more than once). 1089 */ 1090 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call, 1091 "MTD already registered\n"); 1092 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) { 1093 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier; 1094 register_reboot_notifier(&mtd->reboot_notifier); 1095 } 1096 1097out: 1098 if (ret) { 1099 nvmem_unregister(mtd->otp_user_nvmem); 1100 nvmem_unregister(mtd->otp_factory_nvmem); 1101 } 1102 1103 if (ret && device_is_registered(&mtd->dev)) 1104 del_mtd_device(mtd); 1105 1106 return ret; 1107} 1108EXPORT_SYMBOL_GPL(mtd_device_parse_register); 1109 1110/** 1111 * mtd_device_unregister - unregister an existing MTD device. 1112 * 1113 * @master: the MTD device to unregister. This will unregister both the master 1114 * and any partitions if registered. 1115 */ 1116int mtd_device_unregister(struct mtd_info *master) 1117{ 1118 int err; 1119 1120 if (master->_reboot) { 1121 unregister_reboot_notifier(&master->reboot_notifier); 1122 memset(&master->reboot_notifier, 0, sizeof(master->reboot_notifier)); 1123 } 1124 1125 nvmem_unregister(master->otp_user_nvmem); 1126 nvmem_unregister(master->otp_factory_nvmem); 1127 1128 err = del_mtd_partitions(master); 1129 if (err) 1130 return err; 1131 1132 if (!device_is_registered(&master->dev)) 1133 return 0; 1134 1135 return del_mtd_device(master); 1136} 1137EXPORT_SYMBOL_GPL(mtd_device_unregister); 1138 1139/** 1140 * register_mtd_user - register a 'user' of MTD devices. 1141 * @new: pointer to notifier info structure 1142 * 1143 * Registers a pair of callbacks function to be called upon addition 1144 * or removal of MTD devices. Causes the 'add' callback to be immediately 1145 * invoked for each MTD device currently present in the system. 1146 */ 1147void register_mtd_user (struct mtd_notifier *new) 1148{ 1149 struct mtd_info *mtd; 1150 1151 mutex_lock(&mtd_table_mutex); 1152 1153 list_add(&new->list, &mtd_notifiers); 1154 1155 __module_get(THIS_MODULE); 1156 1157 mtd_for_each_device(mtd) 1158 new->add(mtd); 1159 1160 mutex_unlock(&mtd_table_mutex); 1161} 1162EXPORT_SYMBOL_GPL(register_mtd_user); 1163 1164/** 1165 * unregister_mtd_user - unregister a 'user' of MTD devices. 1166 * @old: pointer to notifier info structure 1167 * 1168 * Removes a callback function pair from the list of 'users' to be 1169 * notified upon addition or removal of MTD devices. Causes the 1170 * 'remove' callback to be immediately invoked for each MTD device 1171 * currently present in the system. 1172 */ 1173int unregister_mtd_user (struct mtd_notifier *old) 1174{ 1175 struct mtd_info *mtd; 1176 1177 mutex_lock(&mtd_table_mutex); 1178 1179 module_put(THIS_MODULE); 1180 1181 mtd_for_each_device(mtd) 1182 old->remove(mtd); 1183 1184 list_del(&old->list); 1185 mutex_unlock(&mtd_table_mutex); 1186 return 0; 1187} 1188EXPORT_SYMBOL_GPL(unregister_mtd_user); 1189 1190/** 1191 * get_mtd_device - obtain a validated handle for an MTD device 1192 * @mtd: last known address of the required MTD device 1193 * @num: internal device number of the required MTD device 1194 * 1195 * Given a number and NULL address, return the num'th entry in the device 1196 * table, if any. Given an address and num == -1, search the device table 1197 * for a device with that address and return if it's still present. Given 1198 * both, return the num'th driver only if its address matches. Return 1199 * error code if not. 1200 */ 1201struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num) 1202{ 1203 struct mtd_info *ret = NULL, *other; 1204 int err = -ENODEV; 1205 1206 mutex_lock(&mtd_table_mutex); 1207 1208 if (num == -1) { 1209 mtd_for_each_device(other) { 1210 if (other == mtd) { 1211 ret = mtd; 1212 break; 1213 } 1214 } 1215 } else if (num >= 0) { 1216 ret = idr_find(&mtd_idr, num); 1217 if (mtd && mtd != ret) 1218 ret = NULL; 1219 } 1220 1221 if (!ret) { 1222 ret = ERR_PTR(err); 1223 goto out; 1224 } 1225 1226 err = __get_mtd_device(ret); 1227 if (err) 1228 ret = ERR_PTR(err); 1229out: 1230 mutex_unlock(&mtd_table_mutex); 1231 return ret; 1232} 1233EXPORT_SYMBOL_GPL(get_mtd_device); 1234 1235 1236int __get_mtd_device(struct mtd_info *mtd) 1237{ 1238 struct mtd_info *master = mtd_get_master(mtd); 1239 int err; 1240 1241 if (master->_get_device) { 1242 err = master->_get_device(mtd); 1243 if (err) 1244 return err; 1245 } 1246 1247 if (!try_module_get(master->owner)) { 1248 if (master->_put_device) 1249 master->_put_device(master); 1250 return -ENODEV; 1251 } 1252 1253 while (mtd) { 1254 if (mtd != master) 1255 kref_get(&mtd->refcnt); 1256 mtd = mtd->parent; 1257 } 1258 1259 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) 1260 kref_get(&master->refcnt); 1261 1262 return 0; 1263} 1264EXPORT_SYMBOL_GPL(__get_mtd_device); 1265 1266/** 1267 * of_get_mtd_device_by_node - obtain an MTD device associated with a given node 1268 * 1269 * @np: device tree node 1270 */ 1271struct mtd_info *of_get_mtd_device_by_node(struct device_node *np) 1272{ 1273 struct mtd_info *mtd = NULL; 1274 struct mtd_info *tmp; 1275 int err; 1276 1277 mutex_lock(&mtd_table_mutex); 1278 1279 err = -EPROBE_DEFER; 1280 mtd_for_each_device(tmp) { 1281 if (mtd_get_of_node(tmp) == np) { 1282 mtd = tmp; 1283 err = __get_mtd_device(mtd); 1284 break; 1285 } 1286 } 1287 1288 mutex_unlock(&mtd_table_mutex); 1289 1290 return err ? ERR_PTR(err) : mtd; 1291} 1292EXPORT_SYMBOL_GPL(of_get_mtd_device_by_node); 1293 1294/** 1295 * get_mtd_device_nm - obtain a validated handle for an MTD device by 1296 * device name 1297 * @name: MTD device name to open 1298 * 1299 * This function returns MTD device description structure in case of 1300 * success and an error code in case of failure. 1301 */ 1302struct mtd_info *get_mtd_device_nm(const char *name) 1303{ 1304 int err = -ENODEV; 1305 struct mtd_info *mtd = NULL, *other; 1306 1307 mutex_lock(&mtd_table_mutex); 1308 1309 mtd_for_each_device(other) { 1310 if (!strcmp(name, other->name)) { 1311 mtd = other; 1312 break; 1313 } 1314 } 1315 1316 if (!mtd) 1317 goto out_unlock; 1318 1319 err = __get_mtd_device(mtd); 1320 if (err) 1321 goto out_unlock; 1322 1323 mutex_unlock(&mtd_table_mutex); 1324 return mtd; 1325 1326out_unlock: 1327 mutex_unlock(&mtd_table_mutex); 1328 return ERR_PTR(err); 1329} 1330EXPORT_SYMBOL_GPL(get_mtd_device_nm); 1331 1332void put_mtd_device(struct mtd_info *mtd) 1333{ 1334 mutex_lock(&mtd_table_mutex); 1335 __put_mtd_device(mtd); 1336 mutex_unlock(&mtd_table_mutex); 1337 1338} 1339EXPORT_SYMBOL_GPL(put_mtd_device); 1340 1341void __put_mtd_device(struct mtd_info *mtd) 1342{ 1343 struct mtd_info *master = mtd_get_master(mtd); 1344 1345 while (mtd) { 1346 /* kref_put() can relese mtd, so keep a reference mtd->parent */ 1347 struct mtd_info *parent = mtd->parent; 1348 1349 if (mtd != master) 1350 kref_put(&mtd->refcnt, mtd_device_release); 1351 mtd = parent; 1352 } 1353 1354 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) 1355 kref_put(&master->refcnt, mtd_device_release); 1356 1357 module_put(master->owner); 1358 1359 /* must be the last as master can be freed in the _put_device */ 1360 if (master->_put_device) 1361 master->_put_device(master); 1362} 1363EXPORT_SYMBOL_GPL(__put_mtd_device); 1364 1365/* 1366 * Erase is an synchronous operation. Device drivers are epected to return a 1367 * negative error code if the operation failed and update instr->fail_addr 1368 * to point the portion that was not properly erased. 1369 */ 1370int mtd_erase(struct mtd_info *mtd, struct erase_info *instr) 1371{ 1372 struct mtd_info *master = mtd_get_master(mtd); 1373 u64 mst_ofs = mtd_get_master_ofs(mtd, 0); 1374 struct erase_info adjinstr; 1375 int ret; 1376 1377 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN; 1378 adjinstr = *instr; 1379 1380 if (!mtd->erasesize || !master->_erase) 1381 return -ENOTSUPP; 1382 1383 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr) 1384 return -EINVAL; 1385 if (!(mtd->flags & MTD_WRITEABLE)) 1386 return -EROFS; 1387 1388 if (!instr->len) 1389 return 0; 1390 1391 ledtrig_mtd_activity(); 1392 1393 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { 1394 adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) * 1395 master->erasesize; 1396 adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) * 1397 master->erasesize) - 1398 adjinstr.addr; 1399 } 1400 1401 adjinstr.addr += mst_ofs; 1402 1403 ret = master->_erase(master, &adjinstr); 1404 1405 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) { 1406 instr->fail_addr = adjinstr.fail_addr - mst_ofs; 1407 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { 1408 instr->fail_addr = mtd_div_by_eb(instr->fail_addr, 1409 master); 1410 instr->fail_addr *= mtd->erasesize; 1411 } 1412 } 1413 1414 return ret; 1415} 1416EXPORT_SYMBOL_GPL(mtd_erase); 1417ALLOW_ERROR_INJECTION(mtd_erase, ERRNO); 1418 1419/* 1420 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL. 1421 */ 1422int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, 1423 void **virt, resource_size_t *phys) 1424{ 1425 struct mtd_info *master = mtd_get_master(mtd); 1426 1427 *retlen = 0; 1428 *virt = NULL; 1429 if (phys) 1430 *phys = 0; 1431 if (!master->_point) 1432 return -EOPNOTSUPP; 1433 if (from < 0 || from >= mtd->size || len > mtd->size - from) 1434 return -EINVAL; 1435 if (!len) 1436 return 0; 1437 1438 from = mtd_get_master_ofs(mtd, from); 1439 return master->_point(master, from, len, retlen, virt, phys); 1440} 1441EXPORT_SYMBOL_GPL(mtd_point); 1442 1443/* We probably shouldn't allow XIP if the unpoint isn't a NULL */ 1444int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len) 1445{ 1446 struct mtd_info *master = mtd_get_master(mtd); 1447 1448 if (!master->_unpoint) 1449 return -EOPNOTSUPP; 1450 if (from < 0 || from >= mtd->size || len > mtd->size - from) 1451 return -EINVAL; 1452 if (!len) 1453 return 0; 1454 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len); 1455} 1456EXPORT_SYMBOL_GPL(mtd_unpoint); 1457 1458/* 1459 * Allow NOMMU mmap() to directly map the device (if not NULL) 1460 * - return the address to which the offset maps 1461 * - return -ENOSYS to indicate refusal to do the mapping 1462 */ 1463unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len, 1464 unsigned long offset, unsigned long flags) 1465{ 1466 size_t retlen; 1467 void *virt; 1468 int ret; 1469 1470 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL); 1471 if (ret) 1472 return ret; 1473 if (retlen != len) { 1474 mtd_unpoint(mtd, offset, retlen); 1475 return -ENOSYS; 1476 } 1477 return (unsigned long)virt; 1478} 1479EXPORT_SYMBOL_GPL(mtd_get_unmapped_area); 1480 1481static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master, 1482 const struct mtd_ecc_stats *old_stats) 1483{ 1484 struct mtd_ecc_stats diff; 1485 1486 if (master == mtd) 1487 return; 1488 1489 diff = master->ecc_stats; 1490 diff.failed -= old_stats->failed; 1491 diff.corrected -= old_stats->corrected; 1492 1493 while (mtd->parent) { 1494 mtd->ecc_stats.failed += diff.failed; 1495 mtd->ecc_stats.corrected += diff.corrected; 1496 mtd = mtd->parent; 1497 } 1498} 1499 1500int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, 1501 u_char *buf) 1502{ 1503 struct mtd_oob_ops ops = { 1504 .len = len, 1505 .datbuf = buf, 1506 }; 1507 int ret; 1508 1509 ret = mtd_read_oob(mtd, from, &ops); 1510 *retlen = ops.retlen; 1511 1512 WARN_ON_ONCE(*retlen != len && mtd_is_bitflip_or_eccerr(ret)); 1513 1514 return ret; 1515} 1516EXPORT_SYMBOL_GPL(mtd_read); 1517ALLOW_ERROR_INJECTION(mtd_read, ERRNO); 1518 1519int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, 1520 const u_char *buf) 1521{ 1522 struct mtd_oob_ops ops = { 1523 .len = len, 1524 .datbuf = (u8 *)buf, 1525 }; 1526 int ret; 1527 1528 ret = mtd_write_oob(mtd, to, &ops); 1529 *retlen = ops.retlen; 1530 1531 return ret; 1532} 1533EXPORT_SYMBOL_GPL(mtd_write); 1534ALLOW_ERROR_INJECTION(mtd_write, ERRNO); 1535 1536/* 1537 * In blackbox flight recorder like scenarios we want to make successful writes 1538 * in interrupt context. panic_write() is only intended to be called when its 1539 * known the kernel is about to panic and we need the write to succeed. Since 1540 * the kernel is not going to be running for much longer, this function can 1541 * break locks and delay to ensure the write succeeds (but not sleep). 1542 */ 1543int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, 1544 const u_char *buf) 1545{ 1546 struct mtd_info *master = mtd_get_master(mtd); 1547 1548 *retlen = 0; 1549 if (!master->_panic_write) 1550 return -EOPNOTSUPP; 1551 if (to < 0 || to >= mtd->size || len > mtd->size - to) 1552 return -EINVAL; 1553 if (!(mtd->flags & MTD_WRITEABLE)) 1554 return -EROFS; 1555 if (!len) 1556 return 0; 1557 if (!master->oops_panic_write) 1558 master->oops_panic_write = true; 1559 1560 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len, 1561 retlen, buf); 1562} 1563EXPORT_SYMBOL_GPL(mtd_panic_write); 1564 1565static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs, 1566 struct mtd_oob_ops *ops) 1567{ 1568 /* 1569 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving 1570 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in 1571 * this case. 1572 */ 1573 if (!ops->datbuf) 1574 ops->len = 0; 1575 1576 if (!ops->oobbuf) 1577 ops->ooblen = 0; 1578 1579 if (offs < 0 || offs + ops->len > mtd->size) 1580 return -EINVAL; 1581 1582 if (ops->ooblen) { 1583 size_t maxooblen; 1584 1585 if (ops->ooboffs >= mtd_oobavail(mtd, ops)) 1586 return -EINVAL; 1587 1588 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) - 1589 mtd_div_by_ws(offs, mtd)) * 1590 mtd_oobavail(mtd, ops)) - ops->ooboffs; 1591 if (ops->ooblen > maxooblen) 1592 return -EINVAL; 1593 } 1594 1595 return 0; 1596} 1597 1598static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from, 1599 struct mtd_oob_ops *ops) 1600{ 1601 struct mtd_info *master = mtd_get_master(mtd); 1602 int ret; 1603 1604 from = mtd_get_master_ofs(mtd, from); 1605 if (master->_read_oob) 1606 ret = master->_read_oob(master, from, ops); 1607 else 1608 ret = master->_read(master, from, ops->len, &ops->retlen, 1609 ops->datbuf); 1610 1611 return ret; 1612} 1613 1614static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to, 1615 struct mtd_oob_ops *ops) 1616{ 1617 struct mtd_info *master = mtd_get_master(mtd); 1618 int ret; 1619 1620 to = mtd_get_master_ofs(mtd, to); 1621 if (master->_write_oob) 1622 ret = master->_write_oob(master, to, ops); 1623 else 1624 ret = master->_write(master, to, ops->len, &ops->retlen, 1625 ops->datbuf); 1626 1627 return ret; 1628} 1629 1630static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read, 1631 struct mtd_oob_ops *ops) 1632{ 1633 struct mtd_info *master = mtd_get_master(mtd); 1634 int ngroups = mtd_pairing_groups(master); 1635 int npairs = mtd_wunit_per_eb(master) / ngroups; 1636 struct mtd_oob_ops adjops = *ops; 1637 unsigned int wunit, oobavail; 1638 struct mtd_pairing_info info; 1639 int max_bitflips = 0; 1640 u32 ebofs, pageofs; 1641 loff_t base, pos; 1642 1643 ebofs = mtd_mod_by_eb(start, mtd); 1644 base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize; 1645 info.group = 0; 1646 info.pair = mtd_div_by_ws(ebofs, mtd); 1647 pageofs = mtd_mod_by_ws(ebofs, mtd); 1648 oobavail = mtd_oobavail(mtd, ops); 1649 1650 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) { 1651 int ret; 1652 1653 if (info.pair >= npairs) { 1654 info.pair = 0; 1655 base += master->erasesize; 1656 } 1657 1658 wunit = mtd_pairing_info_to_wunit(master, &info); 1659 pos = mtd_wunit_to_offset(mtd, base, wunit); 1660 1661 adjops.len = ops->len - ops->retlen; 1662 if (adjops.len > mtd->writesize - pageofs) 1663 adjops.len = mtd->writesize - pageofs; 1664 1665 adjops.ooblen = ops->ooblen - ops->oobretlen; 1666 if (adjops.ooblen > oobavail - adjops.ooboffs) 1667 adjops.ooblen = oobavail - adjops.ooboffs; 1668 1669 if (read) { 1670 ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops); 1671 if (ret > 0) 1672 max_bitflips = max(max_bitflips, ret); 1673 } else { 1674 ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops); 1675 } 1676 1677 if (ret < 0) 1678 return ret; 1679 1680 max_bitflips = max(max_bitflips, ret); 1681 ops->retlen += adjops.retlen; 1682 ops->oobretlen += adjops.oobretlen; 1683 adjops.datbuf += adjops.retlen; 1684 adjops.oobbuf += adjops.oobretlen; 1685 adjops.ooboffs = 0; 1686 pageofs = 0; 1687 info.pair++; 1688 } 1689 1690 return max_bitflips; 1691} 1692 1693int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops) 1694{ 1695 struct mtd_info *master = mtd_get_master(mtd); 1696 struct mtd_ecc_stats old_stats = master->ecc_stats; 1697 int ret_code; 1698 1699 ops->retlen = ops->oobretlen = 0; 1700 1701 ret_code = mtd_check_oob_ops(mtd, from, ops); 1702 if (ret_code) 1703 return ret_code; 1704 1705 ledtrig_mtd_activity(); 1706 1707 /* Check the validity of a potential fallback on mtd->_read */ 1708 if (!master->_read_oob && (!master->_read || ops->oobbuf)) 1709 return -EOPNOTSUPP; 1710 1711 if (ops->stats) 1712 memset(ops->stats, 0, sizeof(*ops->stats)); 1713 1714 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) 1715 ret_code = mtd_io_emulated_slc(mtd, from, true, ops); 1716 else 1717 ret_code = mtd_read_oob_std(mtd, from, ops); 1718 1719 mtd_update_ecc_stats(mtd, master, &old_stats); 1720 1721 /* 1722 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics 1723 * similar to mtd->_read(), returning a non-negative integer 1724 * representing max bitflips. In other cases, mtd->_read_oob() may 1725 * return -EUCLEAN. In all cases, perform similar logic to mtd_read(). 1726 */ 1727 if (unlikely(ret_code < 0)) 1728 return ret_code; 1729 if (mtd->ecc_strength == 0) 1730 return 0; /* device lacks ecc */ 1731 if (ops->stats) 1732 ops->stats->max_bitflips = ret_code; 1733 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0; 1734} 1735EXPORT_SYMBOL_GPL(mtd_read_oob); 1736 1737int mtd_write_oob(struct mtd_info *mtd, loff_t to, 1738 struct mtd_oob_ops *ops) 1739{ 1740 struct mtd_info *master = mtd_get_master(mtd); 1741 int ret; 1742 1743 ops->retlen = ops->oobretlen = 0; 1744 1745 if (!(mtd->flags & MTD_WRITEABLE)) 1746 return -EROFS; 1747 1748 ret = mtd_check_oob_ops(mtd, to, ops); 1749 if (ret) 1750 return ret; 1751 1752 ledtrig_mtd_activity(); 1753 1754 /* Check the validity of a potential fallback on mtd->_write */ 1755 if (!master->_write_oob && (!master->_write || ops->oobbuf)) 1756 return -EOPNOTSUPP; 1757 1758 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) 1759 return mtd_io_emulated_slc(mtd, to, false, ops); 1760 1761 return mtd_write_oob_std(mtd, to, ops); 1762} 1763EXPORT_SYMBOL_GPL(mtd_write_oob); 1764 1765/** 1766 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section 1767 * @mtd: MTD device structure 1768 * @section: ECC section. Depending on the layout you may have all the ECC 1769 * bytes stored in a single contiguous section, or one section 1770 * per ECC chunk (and sometime several sections for a single ECC 1771 * ECC chunk) 1772 * @oobecc: OOB region struct filled with the appropriate ECC position 1773 * information 1774 * 1775 * This function returns ECC section information in the OOB area. If you want 1776 * to get all the ECC bytes information, then you should call 1777 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE. 1778 * 1779 * Returns zero on success, a negative error code otherwise. 1780 */ 1781int mtd_ooblayout_ecc(struct mtd_info *mtd, int section, 1782 struct mtd_oob_region *oobecc) 1783{ 1784 struct mtd_info *master = mtd_get_master(mtd); 1785 1786 memset(oobecc, 0, sizeof(*oobecc)); 1787 1788 if (!master || section < 0) 1789 return -EINVAL; 1790 1791 if (!master->ooblayout || !master->ooblayout->ecc) 1792 return -ENOTSUPP; 1793 1794 return master->ooblayout->ecc(master, section, oobecc); 1795} 1796EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc); 1797 1798/** 1799 * mtd_ooblayout_free - Get the OOB region definition of a specific free 1800 * section 1801 * @mtd: MTD device structure 1802 * @section: Free section you are interested in. Depending on the layout 1803 * you may have all the free bytes stored in a single contiguous 1804 * section, or one section per ECC chunk plus an extra section 1805 * for the remaining bytes (or other funky layout). 1806 * @oobfree: OOB region struct filled with the appropriate free position 1807 * information 1808 * 1809 * This function returns free bytes position in the OOB area. If you want 1810 * to get all the free bytes information, then you should call 1811 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE. 1812 * 1813 * Returns zero on success, a negative error code otherwise. 1814 */ 1815int mtd_ooblayout_free(struct mtd_info *mtd, int section, 1816 struct mtd_oob_region *oobfree) 1817{ 1818 struct mtd_info *master = mtd_get_master(mtd); 1819 1820 memset(oobfree, 0, sizeof(*oobfree)); 1821 1822 if (!master || section < 0) 1823 return -EINVAL; 1824 1825 if (!master->ooblayout || !master->ooblayout->free) 1826 return -ENOTSUPP; 1827 1828 return master->ooblayout->free(master, section, oobfree); 1829} 1830EXPORT_SYMBOL_GPL(mtd_ooblayout_free); 1831 1832/** 1833 * mtd_ooblayout_find_region - Find the region attached to a specific byte 1834 * @mtd: mtd info structure 1835 * @byte: the byte we are searching for 1836 * @sectionp: pointer where the section id will be stored 1837 * @oobregion: used to retrieve the ECC position 1838 * @iter: iterator function. Should be either mtd_ooblayout_free or 1839 * mtd_ooblayout_ecc depending on the region type you're searching for 1840 * 1841 * This function returns the section id and oobregion information of a 1842 * specific byte. For example, say you want to know where the 4th ECC byte is 1843 * stored, you'll use: 1844 * 1845 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc); 1846 * 1847 * Returns zero on success, a negative error code otherwise. 1848 */ 1849static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte, 1850 int *sectionp, struct mtd_oob_region *oobregion, 1851 int (*iter)(struct mtd_info *, 1852 int section, 1853 struct mtd_oob_region *oobregion)) 1854{ 1855 int pos = 0, ret, section = 0; 1856 1857 memset(oobregion, 0, sizeof(*oobregion)); 1858 1859 while (1) { 1860 ret = iter(mtd, section, oobregion); 1861 if (ret) 1862 return ret; 1863 1864 if (pos + oobregion->length > byte) 1865 break; 1866 1867 pos += oobregion->length; 1868 section++; 1869 } 1870 1871 /* 1872 * Adjust region info to make it start at the beginning at the 1873 * 'start' ECC byte. 1874 */ 1875 oobregion->offset += byte - pos; 1876 oobregion->length -= byte - pos; 1877 *sectionp = section; 1878 1879 return 0; 1880} 1881 1882/** 1883 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific 1884 * ECC byte 1885 * @mtd: mtd info structure 1886 * @eccbyte: the byte we are searching for 1887 * @section: pointer where the section id will be stored 1888 * @oobregion: OOB region information 1889 * 1890 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC 1891 * byte. 1892 * 1893 * Returns zero on success, a negative error code otherwise. 1894 */ 1895int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte, 1896 int *section, 1897 struct mtd_oob_region *oobregion) 1898{ 1899 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion, 1900 mtd_ooblayout_ecc); 1901} 1902EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion); 1903 1904/** 1905 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer 1906 * @mtd: mtd info structure 1907 * @buf: destination buffer to store OOB bytes 1908 * @oobbuf: OOB buffer 1909 * @start: first byte to retrieve 1910 * @nbytes: number of bytes to retrieve 1911 * @iter: section iterator 1912 * 1913 * Extract bytes attached to a specific category (ECC or free) 1914 * from the OOB buffer and copy them into buf. 1915 * 1916 * Returns zero on success, a negative error code otherwise. 1917 */ 1918static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf, 1919 const u8 *oobbuf, int start, int nbytes, 1920 int (*iter)(struct mtd_info *, 1921 int section, 1922 struct mtd_oob_region *oobregion)) 1923{ 1924 struct mtd_oob_region oobregion; 1925 int section, ret; 1926 1927 ret = mtd_ooblayout_find_region(mtd, start, §ion, 1928 &oobregion, iter); 1929 1930 while (!ret) { 1931 int cnt; 1932 1933 cnt = min_t(int, nbytes, oobregion.length); 1934 memcpy(buf, oobbuf + oobregion.offset, cnt); 1935 buf += cnt; 1936 nbytes -= cnt; 1937 1938 if (!nbytes) 1939 break; 1940 1941 ret = iter(mtd, ++section, &oobregion); 1942 } 1943 1944 return ret; 1945} 1946 1947/** 1948 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer 1949 * @mtd: mtd info structure 1950 * @buf: source buffer to get OOB bytes from 1951 * @oobbuf: OOB buffer 1952 * @start: first OOB byte to set 1953 * @nbytes: number of OOB bytes to set 1954 * @iter: section iterator 1955 * 1956 * Fill the OOB buffer with data provided in buf. The category (ECC or free) 1957 * is selected by passing the appropriate iterator. 1958 * 1959 * Returns zero on success, a negative error code otherwise. 1960 */ 1961static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf, 1962 u8 *oobbuf, int start, int nbytes, 1963 int (*iter)(struct mtd_info *, 1964 int section, 1965 struct mtd_oob_region *oobregion)) 1966{ 1967 struct mtd_oob_region oobregion; 1968 int section, ret; 1969 1970 ret = mtd_ooblayout_find_region(mtd, start, §ion, 1971 &oobregion, iter); 1972 1973 while (!ret) { 1974 int cnt; 1975 1976 cnt = min_t(int, nbytes, oobregion.length); 1977 memcpy(oobbuf + oobregion.offset, buf, cnt); 1978 buf += cnt; 1979 nbytes -= cnt; 1980 1981 if (!nbytes) 1982 break; 1983 1984 ret = iter(mtd, ++section, &oobregion); 1985 } 1986 1987 return ret; 1988} 1989 1990/** 1991 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category 1992 * @mtd: mtd info structure 1993 * @iter: category iterator 1994 * 1995 * Count the number of bytes in a given category. 1996 * 1997 * Returns a positive value on success, a negative error code otherwise. 1998 */ 1999static int mtd_ooblayout_count_bytes(struct mtd_info *mtd, 2000 int (*iter)(struct mtd_info *, 2001 int section, 2002 struct mtd_oob_region *oobregion)) 2003{ 2004 struct mtd_oob_region oobregion; 2005 int section = 0, ret, nbytes = 0; 2006 2007 while (1) { 2008 ret = iter(mtd, section++, &oobregion); 2009 if (ret) { 2010 if (ret == -ERANGE) 2011 ret = nbytes; 2012 break; 2013 } 2014 2015 nbytes += oobregion.length; 2016 } 2017 2018 return ret; 2019} 2020 2021/** 2022 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer 2023 * @mtd: mtd info structure 2024 * @eccbuf: destination buffer to store ECC bytes 2025 * @oobbuf: OOB buffer 2026 * @start: first ECC byte to retrieve 2027 * @nbytes: number of ECC bytes to retrieve 2028 * 2029 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes. 2030 * 2031 * Returns zero on success, a negative error code otherwise. 2032 */ 2033int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf, 2034 const u8 *oobbuf, int start, int nbytes) 2035{ 2036 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes, 2037 mtd_ooblayout_ecc); 2038} 2039EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes); 2040 2041/** 2042 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer 2043 * @mtd: mtd info structure 2044 * @eccbuf: source buffer to get ECC bytes from 2045 * @oobbuf: OOB buffer 2046 * @start: first ECC byte to set 2047 * @nbytes: number of ECC bytes to set 2048 * 2049 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes. 2050 * 2051 * Returns zero on success, a negative error code otherwise. 2052 */ 2053int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf, 2054 u8 *oobbuf, int start, int nbytes) 2055{ 2056 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes, 2057 mtd_ooblayout_ecc); 2058} 2059EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes); 2060 2061/** 2062 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer 2063 * @mtd: mtd info structure 2064 * @databuf: destination buffer to store ECC bytes 2065 * @oobbuf: OOB buffer 2066 * @start: first ECC byte to retrieve 2067 * @nbytes: number of ECC bytes to retrieve 2068 * 2069 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes. 2070 * 2071 * Returns zero on success, a negative error code otherwise. 2072 */ 2073int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf, 2074 const u8 *oobbuf, int start, int nbytes) 2075{ 2076 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes, 2077 mtd_ooblayout_free); 2078} 2079EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes); 2080 2081/** 2082 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer 2083 * @mtd: mtd info structure 2084 * @databuf: source buffer to get data bytes from 2085 * @oobbuf: OOB buffer 2086 * @start: first ECC byte to set 2087 * @nbytes: number of ECC bytes to set 2088 * 2089 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes. 2090 * 2091 * Returns zero on success, a negative error code otherwise. 2092 */ 2093int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf, 2094 u8 *oobbuf, int start, int nbytes) 2095{ 2096 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes, 2097 mtd_ooblayout_free); 2098} 2099EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes); 2100 2101/** 2102 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB 2103 * @mtd: mtd info structure 2104 * 2105 * Works like mtd_ooblayout_count_bytes(), except it count free bytes. 2106 * 2107 * Returns zero on success, a negative error code otherwise. 2108 */ 2109int mtd_ooblayout_count_freebytes(struct mtd_info *mtd) 2110{ 2111 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free); 2112} 2113EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes); 2114 2115/** 2116 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB 2117 * @mtd: mtd info structure 2118 * 2119 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes. 2120 * 2121 * Returns zero on success, a negative error code otherwise. 2122 */ 2123int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd) 2124{ 2125 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc); 2126} 2127EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes); 2128 2129/* 2130 * Method to access the protection register area, present in some flash 2131 * devices. The user data is one time programmable but the factory data is read 2132 * only. 2133 */ 2134int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen, 2135 struct otp_info *buf) 2136{ 2137 struct mtd_info *master = mtd_get_master(mtd); 2138 2139 if (!master->_get_fact_prot_info) 2140 return -EOPNOTSUPP; 2141 if (!len) 2142 return 0; 2143 return master->_get_fact_prot_info(master, len, retlen, buf); 2144} 2145EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info); 2146 2147int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len, 2148 size_t *retlen, u_char *buf) 2149{ 2150 struct mtd_info *master = mtd_get_master(mtd); 2151 2152 *retlen = 0; 2153 if (!master->_read_fact_prot_reg) 2154 return -EOPNOTSUPP; 2155 if (!len) 2156 return 0; 2157 return master->_read_fact_prot_reg(master, from, len, retlen, buf); 2158} 2159EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg); 2160 2161int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen, 2162 struct otp_info *buf) 2163{ 2164 struct mtd_info *master = mtd_get_master(mtd); 2165 2166 if (!master->_get_user_prot_info) 2167 return -EOPNOTSUPP; 2168 if (!len) 2169 return 0; 2170 return master->_get_user_prot_info(master, len, retlen, buf); 2171} 2172EXPORT_SYMBOL_GPL(mtd_get_user_prot_info); 2173 2174int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len, 2175 size_t *retlen, u_char *buf) 2176{ 2177 struct mtd_info *master = mtd_get_master(mtd); 2178 2179 *retlen = 0; 2180 if (!master->_read_user_prot_reg) 2181 return -EOPNOTSUPP; 2182 if (!len) 2183 return 0; 2184 return master->_read_user_prot_reg(master, from, len, retlen, buf); 2185} 2186EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg); 2187 2188int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len, 2189 size_t *retlen, const u_char *buf) 2190{ 2191 struct mtd_info *master = mtd_get_master(mtd); 2192 int ret; 2193 2194 *retlen = 0; 2195 if (!master->_write_user_prot_reg) 2196 return -EOPNOTSUPP; 2197 if (!len) 2198 return 0; 2199 ret = master->_write_user_prot_reg(master, to, len, retlen, buf); 2200 if (ret) 2201 return ret; 2202 2203 /* 2204 * If no data could be written at all, we are out of memory and 2205 * must return -ENOSPC. 2206 */ 2207 return (*retlen) ? 0 : -ENOSPC; 2208} 2209EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg); 2210 2211int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len) 2212{ 2213 struct mtd_info *master = mtd_get_master(mtd); 2214 2215 if (!master->_lock_user_prot_reg) 2216 return -EOPNOTSUPP; 2217 if (!len) 2218 return 0; 2219 return master->_lock_user_prot_reg(master, from, len); 2220} 2221EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg); 2222 2223int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len) 2224{ 2225 struct mtd_info *master = mtd_get_master(mtd); 2226 2227 if (!master->_erase_user_prot_reg) 2228 return -EOPNOTSUPP; 2229 if (!len) 2230 return 0; 2231 return master->_erase_user_prot_reg(master, from, len); 2232} 2233EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg); 2234 2235/* Chip-supported device locking */ 2236int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) 2237{ 2238 struct mtd_info *master = mtd_get_master(mtd); 2239 2240 if (!master->_lock) 2241 return -EOPNOTSUPP; 2242 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs) 2243 return -EINVAL; 2244 if (!len) 2245 return 0; 2246 2247 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { 2248 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; 2249 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize; 2250 } 2251 2252 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len); 2253} 2254EXPORT_SYMBOL_GPL(mtd_lock); 2255 2256int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len) 2257{ 2258 struct mtd_info *master = mtd_get_master(mtd); 2259 2260 if (!master->_unlock) 2261 return -EOPNOTSUPP; 2262 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs) 2263 return -EINVAL; 2264 if (!len) 2265 return 0; 2266 2267 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { 2268 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; 2269 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize; 2270 } 2271 2272 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len); 2273} 2274EXPORT_SYMBOL_GPL(mtd_unlock); 2275 2276int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len) 2277{ 2278 struct mtd_info *master = mtd_get_master(mtd); 2279 2280 if (!master->_is_locked) 2281 return -EOPNOTSUPP; 2282 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs) 2283 return -EINVAL; 2284 if (!len) 2285 return 0; 2286 2287 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { 2288 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; 2289 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize; 2290 } 2291 2292 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len); 2293} 2294EXPORT_SYMBOL_GPL(mtd_is_locked); 2295 2296int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs) 2297{ 2298 struct mtd_info *master = mtd_get_master(mtd); 2299 2300 if (ofs < 0 || ofs >= mtd->size) 2301 return -EINVAL; 2302 if (!master->_block_isreserved) 2303 return 0; 2304 2305 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) 2306 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; 2307 2308 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs)); 2309} 2310EXPORT_SYMBOL_GPL(mtd_block_isreserved); 2311 2312int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs) 2313{ 2314 struct mtd_info *master = mtd_get_master(mtd); 2315 2316 if (ofs < 0 || ofs >= mtd->size) 2317 return -EINVAL; 2318 if (!master->_block_isbad) 2319 return 0; 2320 2321 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) 2322 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; 2323 2324 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs)); 2325} 2326EXPORT_SYMBOL_GPL(mtd_block_isbad); 2327 2328int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs) 2329{ 2330 struct mtd_info *master = mtd_get_master(mtd); 2331 int ret; 2332 2333 if (!master->_block_markbad) 2334 return -EOPNOTSUPP; 2335 if (ofs < 0 || ofs >= mtd->size) 2336 return -EINVAL; 2337 if (!(mtd->flags & MTD_WRITEABLE)) 2338 return -EROFS; 2339 2340 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) 2341 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; 2342 2343 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs)); 2344 if (ret) 2345 return ret; 2346 2347 while (mtd->parent) { 2348 mtd->ecc_stats.badblocks++; 2349 mtd = mtd->parent; 2350 } 2351 2352 return 0; 2353} 2354EXPORT_SYMBOL_GPL(mtd_block_markbad); 2355ALLOW_ERROR_INJECTION(mtd_block_markbad, ERRNO); 2356 2357/* 2358 * default_mtd_writev - the default writev method 2359 * @mtd: mtd device description object pointer 2360 * @vecs: the vectors to write 2361 * @count: count of vectors in @vecs 2362 * @to: the MTD device offset to write to 2363 * @retlen: on exit contains the count of bytes written to the MTD device. 2364 * 2365 * This function returns zero in case of success and a negative error code in 2366 * case of failure. 2367 */ 2368static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, 2369 unsigned long count, loff_t to, size_t *retlen) 2370{ 2371 unsigned long i; 2372 size_t totlen = 0, thislen; 2373 int ret = 0; 2374 2375 for (i = 0; i < count; i++) { 2376 if (!vecs[i].iov_len) 2377 continue; 2378 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen, 2379 vecs[i].iov_base); 2380 totlen += thislen; 2381 if (ret || thislen != vecs[i].iov_len) 2382 break; 2383 to += vecs[i].iov_len; 2384 } 2385 *retlen = totlen; 2386 return ret; 2387} 2388 2389/* 2390 * mtd_writev - the vector-based MTD write method 2391 * @mtd: mtd device description object pointer 2392 * @vecs: the vectors to write 2393 * @count: count of vectors in @vecs 2394 * @to: the MTD device offset to write to 2395 * @retlen: on exit contains the count of bytes written to the MTD device. 2396 * 2397 * This function returns zero in case of success and a negative error code in 2398 * case of failure. 2399 */ 2400int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, 2401 unsigned long count, loff_t to, size_t *retlen) 2402{ 2403 struct mtd_info *master = mtd_get_master(mtd); 2404 2405 *retlen = 0; 2406 if (!(mtd->flags & MTD_WRITEABLE)) 2407 return -EROFS; 2408 2409 if (!master->_writev) 2410 return default_mtd_writev(mtd, vecs, count, to, retlen); 2411 2412 return master->_writev(master, vecs, count, 2413 mtd_get_master_ofs(mtd, to), retlen); 2414} 2415EXPORT_SYMBOL_GPL(mtd_writev); 2416 2417/** 2418 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size 2419 * @mtd: mtd device description object pointer 2420 * @size: a pointer to the ideal or maximum size of the allocation, points 2421 * to the actual allocation size on success. 2422 * 2423 * This routine attempts to allocate a contiguous kernel buffer up to 2424 * the specified size, backing off the size of the request exponentially 2425 * until the request succeeds or until the allocation size falls below 2426 * the system page size. This attempts to make sure it does not adversely 2427 * impact system performance, so when allocating more than one page, we 2428 * ask the memory allocator to avoid re-trying, swapping, writing back 2429 * or performing I/O. 2430 * 2431 * Note, this function also makes sure that the allocated buffer is aligned to 2432 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value. 2433 * 2434 * This is called, for example by mtd_{read,write} and jffs2_scan_medium, 2435 * to handle smaller (i.e. degraded) buffer allocations under low- or 2436 * fragmented-memory situations where such reduced allocations, from a 2437 * requested ideal, are allowed. 2438 * 2439 * Returns a pointer to the allocated buffer on success; otherwise, NULL. 2440 */ 2441void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size) 2442{ 2443 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY; 2444 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE); 2445 void *kbuf; 2446 2447 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE); 2448 2449 while (*size > min_alloc) { 2450 kbuf = kmalloc(*size, flags); 2451 if (kbuf) 2452 return kbuf; 2453 2454 *size >>= 1; 2455 *size = ALIGN(*size, mtd->writesize); 2456 } 2457 2458 /* 2459 * For the last resort allocation allow 'kmalloc()' to do all sorts of 2460 * things (write-back, dropping caches, etc) by using GFP_KERNEL. 2461 */ 2462 return kmalloc(*size, GFP_KERNEL); 2463} 2464EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to); 2465 2466#ifdef CONFIG_PROC_FS 2467 2468/*====================================================================*/ 2469/* Support for /proc/mtd */ 2470 2471static int mtd_proc_show(struct seq_file *m, void *v) 2472{ 2473 struct mtd_info *mtd; 2474 2475 seq_puts(m, "dev: size erasesize name\n"); 2476 mutex_lock(&mtd_table_mutex); 2477 mtd_for_each_device(mtd) { 2478 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n", 2479 mtd->index, (unsigned long long)mtd->size, 2480 mtd->erasesize, mtd->name); 2481 } 2482 mutex_unlock(&mtd_table_mutex); 2483 return 0; 2484} 2485#endif /* CONFIG_PROC_FS */ 2486 2487/*====================================================================*/ 2488/* Init code */ 2489 2490static struct backing_dev_info * __init mtd_bdi_init(const char *name) 2491{ 2492 struct backing_dev_info *bdi; 2493 int ret; 2494 2495 bdi = bdi_alloc(NUMA_NO_NODE); 2496 if (!bdi) 2497 return ERR_PTR(-ENOMEM); 2498 bdi->ra_pages = 0; 2499 bdi->io_pages = 0; 2500 2501 /* 2502 * We put '-0' suffix to the name to get the same name format as we 2503 * used to get. Since this is called only once, we get a unique name. 2504 */ 2505 ret = bdi_register(bdi, "%.28s-0", name); 2506 if (ret) 2507 bdi_put(bdi); 2508 2509 return ret ? ERR_PTR(ret) : bdi; 2510} 2511 2512static struct proc_dir_entry *proc_mtd; 2513 2514static int __init init_mtd(void) 2515{ 2516 int ret; 2517 2518 ret = class_register(&mtd_class); 2519 if (ret) 2520 goto err_reg; 2521 2522 mtd_bdi = mtd_bdi_init("mtd"); 2523 if (IS_ERR(mtd_bdi)) { 2524 ret = PTR_ERR(mtd_bdi); 2525 goto err_bdi; 2526 } 2527 2528 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show); 2529 2530 ret = init_mtdchar(); 2531 if (ret) 2532 goto out_procfs; 2533 2534 dfs_dir_mtd = debugfs_create_dir("mtd", NULL); 2535 debugfs_create_bool("expert_analysis_mode", 0600, dfs_dir_mtd, 2536 &mtd_expert_analysis_mode); 2537 2538 return 0; 2539 2540out_procfs: 2541 if (proc_mtd) 2542 remove_proc_entry("mtd", NULL); 2543 bdi_unregister(mtd_bdi); 2544 bdi_put(mtd_bdi); 2545err_bdi: 2546 class_unregister(&mtd_class); 2547err_reg: 2548 pr_err("Error registering mtd class or bdi: %d\n", ret); 2549 return ret; 2550} 2551 2552static void __exit cleanup_mtd(void) 2553{ 2554 debugfs_remove_recursive(dfs_dir_mtd); 2555 cleanup_mtdchar(); 2556 if (proc_mtd) 2557 remove_proc_entry("mtd", NULL); 2558 class_unregister(&mtd_class); 2559 bdi_unregister(mtd_bdi); 2560 bdi_put(mtd_bdi); 2561 idr_destroy(&mtd_idr); 2562} 2563 2564module_init(init_mtd); 2565module_exit(cleanup_mtd); 2566 2567MODULE_LICENSE("GPL"); 2568MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 2569MODULE_DESCRIPTION("Core MTD registration and access routines"); 2570