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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Core registration and callback routines for MTD4 * 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_SLEEP43 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#else63#define MTD_CLS_PM_OPS NULL64#endif65 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. You74 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 allocates90 * 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_FS373bool 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#endif384 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_MMU398unsigned 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#endif413 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 wunit427 * @mtd: pointer to new MTD device info structure428 * @wunit: write unit we are interested in429 * @info: returned pairing information430 *431 * Retrieve pairing information associated to the wunit.432 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be433 * paired together, and where programming a page may influence the page it is434 * paired with.435 * The notion of page is replaced by the term wunit (write-unit) to stay436 * consistent with the ->writesize field.437 *438 * The @wunit argument can be extracted from an absolute offset using439 * mtd_offset_to_wunit(). @info is filled with the pairing information attached440 * to @wunit.441 *442 * From the pairing info the MTD user can find all the wunits paired with443 * @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 information472 * @mtd: pointer to new MTD device info structure473 * @info: pairing information struct474 *475 * Returns a positive number representing the wunit associated to the info476 * struct, or a negative error code.477 *478 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to479 * 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 in484 * 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 groups514 * @mtd: pointer to new MTD device info structure515 *516 * Returns the number of pairing groups.517 *518 * This number is usually equal to the number of bits exposed by a single519 * 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 else572 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 else599 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 device636 * @mtd: pointer to new MTD device info structure637 *638 * Add a device to the list of MTD devices present in the system, and639 * notify each currently active MTD 'user' of its arrival. Returns640 * 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 call652 * 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}() or662 * ->_{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 the674 * master is an MLC NAND and has a proper pairing scheme defined.675 * We also reject masters that implement ->_writev() for now, because676 * NAND controller drivers don't implement this hook, and adding the677 * SLC -> MLC address/length conversion to this path is useless if we678 * 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 else693 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 else717 mtd->erasesize_shift = 0;718 719 if (is_power_of_2(mtd->writesize))720 mtd->writesize_shift = ffs(mtd->writesize) - 1;721 else722 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_WARNING732 "%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 the739 * 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 containing766 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, because783 our caller is still holding us here. So none784 of this try_ nonsense, and no bitching about it785 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 device801 * @mtd: pointer to MTD device info structure802 *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 happen806 * 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 containing822 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 the836 * driver837 */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 else869 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 serial985 * number and is small, so let's read it out and put it986 * 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 register1027 * @types: the list of MTD partition probes to try, see1028 * 'parse_mtd_partitions()' for more information1029 * @parser_data: MTD partition parser-specific data1030 * @parts: fallback partition information to register, if parsing fails;1031 * only valid if %nr_parts > %01032 * @nr_parts: the number of partitions in parts, if zero then the full1033 * MTD device is registered if no partition info is found1034 *1035 * This function aggregates MTD partitions parsing (done by1036 * 'parse_mtd_partitions()') and MTD device and partitions registering. It1037 * 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 is1040 * registered first.1041 * * Then It tries to probe partitions on MTD device @mtd using parsers1042 * specified in @types (if @types is %NULL, then the default list of parsers1043 * is used, see 'parse_mtd_partitions()' for more information). If none are1044 * found this functions tries to fallback to information specified in1045 * @parts/@nr_parts.1046 * * If no partitions were found this function just registers the MTD device1047 * @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 else1082 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 it1092 * 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 master1119 * 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 structure1147 *1148 * Registers a pair of callbacks function to be called upon addition1149 * or removal of MTD devices. Causes the 'add' callback to be immediately1150 * 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 structure1172 *1173 * Removes a callback function pair from the list of 'users' to be1174 * notified upon addition or removal of MTD devices. Causes the1175 * 'remove' callback to be immediately invoked for each MTD device1176 * 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 device1197 * @mtd: last known address of the required MTD device1198 * @num: internal device number of the required MTD device1199 *1200 * Given a number and NULL address, return the num'th entry in the device1201 * table, if any. Given an address and num == -1, search the device table1202 * for a device with that address and return if it's still present. Given1203 * both, return the num'th driver only if its address matches. Return1204 * 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 node1273 *1274 * @np: device tree node1275 */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 by1301 * device name1302 * @name: MTD device name to open1303 *1304 * This function returns MTD device description structure in case of1305 * 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 a1372 * negative error code if the operation failed and update instr->fail_addr1373 * 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 maps1466 * - return -ENOSYS to indicate refusal to do the mapping1467 */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 writes1543 * in interrupt context. panic_write() is only intended to be called when its1544 * known the kernel is about to panic and we need the write to succeed. Since1545 * the kernel is not going to be running for much longer, this function can1546 * 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 leaving1575 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in1576 * 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 else1613 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 else1629 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 else1722 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 semantics1728 * similar to mtd->_read(), returning a non-negative integer1729 * representing max bitflips. In other cases, mtd->_read_oob() may1730 * 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 section1772 * @mtd: MTD device structure1773 * @section: ECC section. Depending on the layout you may have all the ECC1774 * bytes stored in a single contiguous section, or one section1775 * per ECC chunk (and sometime several sections for a single ECC1776 * ECC chunk)1777 * @oobecc: OOB region struct filled with the appropriate ECC position1778 * information1779 *1780 * This function returns ECC section information in the OOB area. If you want1781 * to get all the ECC bytes information, then you should call1782 * 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 free1805 * section1806 * @mtd: MTD device structure1807 * @section: Free section you are interested in. Depending on the layout1808 * you may have all the free bytes stored in a single contiguous1809 * section, or one section per ECC chunk plus an extra section1810 * for the remaining bytes (or other funky layout).1811 * @oobfree: OOB region struct filled with the appropriate free position1812 * information1813 *1814 * This function returns free bytes position in the OOB area. If you want1815 * to get all the free bytes information, then you should call1816 * 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 byte1839 * @mtd: mtd info structure1840 * @byte: the byte we are searching for1841 * @sectionp: pointer where the section id will be stored1842 * @oobregion: used to retrieve the ECC position1843 * @iter: iterator function. Should be either mtd_ooblayout_free or1844 * mtd_ooblayout_ecc depending on the region type you're searching for1845 *1846 * This function returns the section id and oobregion information of a1847 * specific byte. For example, say you want to know where the 4th ECC byte is1848 * 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 the1878 * '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 specific1889 * ECC byte1890 * @mtd: mtd info structure1891 * @eccbyte: the byte we are searching for1892 * @section: pointer where the section id will be stored1893 * @oobregion: OOB region information1894 *1895 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC1896 * 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 buffer1911 * @mtd: mtd info structure1912 * @buf: destination buffer to store OOB bytes1913 * @oobbuf: OOB buffer1914 * @start: first byte to retrieve1915 * @nbytes: number of bytes to retrieve1916 * @iter: section iterator1917 *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 buffer1954 * @mtd: mtd info structure1955 * @buf: source buffer to get OOB bytes from1956 * @oobbuf: OOB buffer1957 * @start: first OOB byte to set1958 * @nbytes: number of OOB bytes to set1959 * @iter: section iterator1960 *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 category1997 * @mtd: mtd info structure1998 * @iter: category iterator1999 *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 buffer2028 * @mtd: mtd info structure2029 * @eccbuf: destination buffer to store ECC bytes2030 * @oobbuf: OOB buffer2031 * @start: first ECC byte to retrieve2032 * @nbytes: number of ECC bytes to retrieve2033 *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 buffer2048 * @mtd: mtd info structure2049 * @eccbuf: source buffer to get ECC bytes from2050 * @oobbuf: OOB buffer2051 * @start: first ECC byte to set2052 * @nbytes: number of ECC bytes to set2053 *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 buffer2068 * @mtd: mtd info structure2069 * @databuf: destination buffer to store ECC bytes2070 * @oobbuf: OOB buffer2071 * @start: first ECC byte to retrieve2072 * @nbytes: number of ECC bytes to retrieve2073 *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 buffer2088 * @mtd: mtd info structure2089 * @databuf: source buffer to get data bytes from2090 * @oobbuf: OOB buffer2091 * @start: first ECC byte to set2092 * @nbytes: number of ECC bytes to set2093 *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 OOB2108 * @mtd: mtd info structure2109 *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 OOB2122 * @mtd: mtd info structure2123 *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 flash2136 * devices. The user data is one time programmable but the factory data is read2137 * 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 and2210 * 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 method2364 * @mtd: mtd device description object pointer2365 * @vecs: the vectors to write2366 * @count: count of vectors in @vecs2367 * @to: the MTD device offset to write to2368 * @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 in2371 * 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 method2396 * @mtd: mtd device description object pointer2397 * @vecs: the vectors to write2398 * @count: count of vectors in @vecs2399 * @to: the MTD device offset to write to2400 * @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 in2403 * 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 size2424 * @mtd: mtd device description object pointer2425 * @size: a pointer to the ideal or maximum size of the allocation, points2426 * to the actual allocation size on success.2427 *2428 * This routine attempts to allocate a contiguous kernel buffer up to2429 * the specified size, backing off the size of the request exponentially2430 * until the request succeeds or until the allocation size falls below2431 * the system page size. This attempts to make sure it does not adversely2432 * impact system performance, so when allocating more than one page, we2433 * ask the memory allocator to avoid re-trying, swapping, writing back2434 * or performing I/O.2435 *2436 * Note, this function also makes sure that the allocated buffer is aligned to2437 * 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- or2441 * fragmented-memory situations where such reduced allocations, from a2442 * 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 of2465 * 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_FS2472 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 we2508 * 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