/* * Core registration and callback routines for MTD * drivers and users. * * Copyright © 1999-2010 David Woodhouse * Copyright © 2006 Red Hat UK Limited * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "mtdcore.h" static struct backing_dev_info mtd_bdi = { }; #ifdef CONFIG_PM_SLEEP static int mtd_cls_suspend(struct device *dev) { struct mtd_info *mtd = dev_get_drvdata(dev); return mtd ? mtd_suspend(mtd) : 0; } static int mtd_cls_resume(struct device *dev) { struct mtd_info *mtd = dev_get_drvdata(dev); if (mtd) mtd_resume(mtd); return 0; } static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume); #define MTD_CLS_PM_OPS (&mtd_cls_pm_ops) #else #define MTD_CLS_PM_OPS NULL #endif static struct class mtd_class = { .name = "mtd", .owner = THIS_MODULE, .pm = MTD_CLS_PM_OPS, }; static DEFINE_IDR(mtd_idr); /* These are exported solely for the purpose of mtd_blkdevs.c. You should not use them for _anything_ else */ DEFINE_MUTEX(mtd_table_mutex); EXPORT_SYMBOL_GPL(mtd_table_mutex); struct mtd_info *__mtd_next_device(int i) { return idr_get_next(&mtd_idr, &i); } EXPORT_SYMBOL_GPL(__mtd_next_device); static LIST_HEAD(mtd_notifiers); #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2) /* REVISIT once MTD uses the driver model better, whoever allocates * the mtd_info will probably want to use the release() hook... */ static void mtd_release(struct device *dev) { struct mtd_info *mtd = dev_get_drvdata(dev); dev_t index = MTD_DEVT(mtd->index); /* remove /dev/mtdXro node */ device_destroy(&mtd_class, index + 1); } static ssize_t mtd_type_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); char *type; switch (mtd->type) { case MTD_ABSENT: type = "absent"; break; case MTD_RAM: type = "ram"; break; case MTD_ROM: type = "rom"; break; case MTD_NORFLASH: type = "nor"; break; case MTD_NANDFLASH: type = "nand"; break; case MTD_DATAFLASH: type = "dataflash"; break; case MTD_UBIVOLUME: type = "ubi"; break; case MTD_MLCNANDFLASH: type = "mlc-nand"; break; default: type = "unknown"; } return snprintf(buf, PAGE_SIZE, "%s\n", type); } static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL); static ssize_t mtd_flags_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags); } static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL); static ssize_t mtd_size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return snprintf(buf, PAGE_SIZE, "%llu\n", (unsigned long long)mtd->size); } static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL); static ssize_t mtd_erasesize_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize); } static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL); static ssize_t mtd_writesize_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize); } static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL); static ssize_t mtd_subpagesize_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft; return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize); } static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL); static ssize_t mtd_oobsize_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize); } static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL); static ssize_t mtd_numeraseregions_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions); } static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show, NULL); static ssize_t mtd_name_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name); } static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL); static ssize_t mtd_ecc_strength_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength); } static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL); static ssize_t mtd_bitflip_threshold_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold); } static ssize_t mtd_bitflip_threshold_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct mtd_info *mtd = dev_get_drvdata(dev); unsigned int bitflip_threshold; int retval; retval = kstrtouint(buf, 0, &bitflip_threshold); if (retval) return retval; mtd->bitflip_threshold = bitflip_threshold; return count; } static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR, mtd_bitflip_threshold_show, mtd_bitflip_threshold_store); static ssize_t mtd_ecc_step_size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size); } static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL); static ssize_t mtd_ecc_stats_corrected_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats; return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected); } static DEVICE_ATTR(corrected_bits, S_IRUGO, mtd_ecc_stats_corrected_show, NULL); static ssize_t mtd_ecc_stats_errors_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats; return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed); } static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL); static ssize_t mtd_badblocks_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats; return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks); } static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL); static ssize_t mtd_bbtblocks_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats; return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks); } static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL); static struct attribute *mtd_attrs[] = { &dev_attr_type.attr, &dev_attr_flags.attr, &dev_attr_size.attr, &dev_attr_erasesize.attr, &dev_attr_writesize.attr, &dev_attr_subpagesize.attr, &dev_attr_oobsize.attr, &dev_attr_numeraseregions.attr, &dev_attr_name.attr, &dev_attr_ecc_strength.attr, &dev_attr_ecc_step_size.attr, &dev_attr_corrected_bits.attr, &dev_attr_ecc_failures.attr, &dev_attr_bad_blocks.attr, &dev_attr_bbt_blocks.attr, &dev_attr_bitflip_threshold.attr, NULL, }; ATTRIBUTE_GROUPS(mtd); static struct device_type mtd_devtype = { .name = "mtd", .groups = mtd_groups, .release = mtd_release, }; #ifndef CONFIG_MMU unsigned mtd_mmap_capabilities(struct mtd_info *mtd) { switch (mtd->type) { case MTD_RAM: return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC | NOMMU_MAP_READ | NOMMU_MAP_WRITE; case MTD_ROM: return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC | NOMMU_MAP_READ; default: return NOMMU_MAP_COPY; } } EXPORT_SYMBOL_GPL(mtd_mmap_capabilities); #endif static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state, void *cmd) { struct mtd_info *mtd; mtd = container_of(n, struct mtd_info, reboot_notifier); mtd->_reboot(mtd); return NOTIFY_DONE; } /** * add_mtd_device - register an MTD device * @mtd: pointer to new MTD device info structure * * Add a device to the list of MTD devices present in the system, and * notify each currently active MTD 'user' of its arrival. Returns * zero on success or 1 on failure, which currently will only happen * if there is insufficient memory or a sysfs error. */ int add_mtd_device(struct mtd_info *mtd) { struct mtd_notifier *not; int i, error; mtd->backing_dev_info = &mtd_bdi; BUG_ON(mtd->writesize == 0); mutex_lock(&mtd_table_mutex); i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL); if (i < 0) goto fail_locked; mtd->index = i; mtd->usecount = 0; /* default value if not set by driver */ if (mtd->bitflip_threshold == 0) mtd->bitflip_threshold = mtd->ecc_strength; if (is_power_of_2(mtd->erasesize)) mtd->erasesize_shift = ffs(mtd->erasesize) - 1; else mtd->erasesize_shift = 0; if (is_power_of_2(mtd->writesize)) mtd->writesize_shift = ffs(mtd->writesize) - 1; else mtd->writesize_shift = 0; mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1; mtd->writesize_mask = (1 << mtd->writesize_shift) - 1; /* Some chips always power up locked. Unlock them now */ if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) { error = mtd_unlock(mtd, 0, mtd->size); if (error && error != -EOPNOTSUPP) printk(KERN_WARNING "%s: unlock failed, writes may not work\n", mtd->name); } /* Caller should have set dev.parent to match the * physical device. */ mtd->dev.type = &mtd_devtype; mtd->dev.class = &mtd_class; mtd->dev.devt = MTD_DEVT(i); dev_set_name(&mtd->dev, "mtd%d", i); dev_set_drvdata(&mtd->dev, mtd); if (device_register(&mtd->dev) != 0) goto fail_added; device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL, "mtd%dro", i); pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name); /* No need to get a refcount on the module containing the notifier, since we hold the mtd_table_mutex */ list_for_each_entry(not, &mtd_notifiers, list) not->add(mtd); mutex_unlock(&mtd_table_mutex); /* We _know_ we aren't being removed, because our caller is still holding us here. So none of this try_ nonsense, and no bitching about it either. :) */ __module_get(THIS_MODULE); return 0; fail_added: idr_remove(&mtd_idr, i); fail_locked: mutex_unlock(&mtd_table_mutex); return 1; } /** * del_mtd_device - unregister an MTD device * @mtd: pointer to MTD device info structure * * Remove a device from the list of MTD devices present in the system, * and notify each currently active MTD 'user' of its departure. * Returns zero on success or 1 on failure, which currently will happen * if the requested device does not appear to be present in the list. */ int del_mtd_device(struct mtd_info *mtd) { int ret; struct mtd_notifier *not; mutex_lock(&mtd_table_mutex); if (idr_find(&mtd_idr, mtd->index) != mtd) { ret = -ENODEV; goto out_error; } /* No need to get a refcount on the module containing the notifier, since we hold the mtd_table_mutex */ list_for_each_entry(not, &mtd_notifiers, list) not->remove(mtd); if (mtd->usecount) { printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n", mtd->index, mtd->name, mtd->usecount); ret = -EBUSY; } else { device_unregister(&mtd->dev); idr_remove(&mtd_idr, mtd->index); module_put(THIS_MODULE); ret = 0; } out_error: mutex_unlock(&mtd_table_mutex); return ret; } static int mtd_add_device_partitions(struct mtd_info *mtd, struct mtd_partition *real_parts, int nbparts) { int ret; if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) { ret = add_mtd_device(mtd); if (ret == 1) return -ENODEV; } if (nbparts > 0) { ret = add_mtd_partitions(mtd, real_parts, nbparts); if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) del_mtd_device(mtd); return ret; } return 0; } /** * mtd_device_parse_register - parse partitions and register an MTD device. * * @mtd: the MTD device to register * @types: the list of MTD partition probes to try, see * 'parse_mtd_partitions()' for more information * @parser_data: MTD partition parser-specific data * @parts: fallback partition information to register, if parsing fails; * only valid if %nr_parts > %0 * @nr_parts: the number of partitions in parts, if zero then the full * MTD device is registered if no partition info is found * * This function aggregates MTD partitions parsing (done by * 'parse_mtd_partitions()') and MTD device and partitions registering. It * basically follows the most common pattern found in many MTD drivers: * * * It first tries to probe partitions on MTD device @mtd using parsers * specified in @types (if @types is %NULL, then the default list of parsers * is used, see 'parse_mtd_partitions()' for more information). If none are * found this functions tries to fallback to information specified in * @parts/@nr_parts. * * If any partitioning info was found, this function registers the found * partitions. If the MTD_PARTITIONED_MASTER option is set, then the device * as a whole is registered first. * * If no partitions were found this function just registers the MTD device * @mtd and exits. * * Returns zero in case of success and a negative error code in case of failure. */ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types, struct mtd_part_parser_data *parser_data, const struct mtd_partition *parts, int nr_parts) { int ret; struct mtd_partition *real_parts = NULL; ret = parse_mtd_partitions(mtd, types, &real_parts, parser_data); if (ret <= 0 && nr_parts && parts) { real_parts = kmemdup(parts, sizeof(*parts) * nr_parts, GFP_KERNEL); if (!real_parts) ret = -ENOMEM; else ret = nr_parts; } if (ret >= 0) ret = mtd_add_device_partitions(mtd, real_parts, ret); /* * FIXME: some drivers unfortunately call this function more than once. * So we have to check if we've already assigned the reboot notifier. * * Generally, we can make multiple calls work for most cases, but it * does cause problems with parse_mtd_partitions() above (e.g., * cmdlineparts will register partitions more than once). */ if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) { mtd->reboot_notifier.notifier_call = mtd_reboot_notifier; register_reboot_notifier(&mtd->reboot_notifier); } kfree(real_parts); return ret; } EXPORT_SYMBOL_GPL(mtd_device_parse_register); /** * mtd_device_unregister - unregister an existing MTD device. * * @master: the MTD device to unregister. This will unregister both the master * and any partitions if registered. */ int mtd_device_unregister(struct mtd_info *master) { int err; if (master->_reboot) unregister_reboot_notifier(&master->reboot_notifier); err = del_mtd_partitions(master); if (err) return err; if (!device_is_registered(&master->dev)) return 0; return del_mtd_device(master); } EXPORT_SYMBOL_GPL(mtd_device_unregister); /** * register_mtd_user - register a 'user' of MTD devices. * @new: pointer to notifier info structure * * Registers a pair of callbacks function to be called upon addition * or removal of MTD devices. Causes the 'add' callback to be immediately * invoked for each MTD device currently present in the system. */ void register_mtd_user (struct mtd_notifier *new) { struct mtd_info *mtd; mutex_lock(&mtd_table_mutex); list_add(&new->list, &mtd_notifiers); __module_get(THIS_MODULE); mtd_for_each_device(mtd) new->add(mtd); mutex_unlock(&mtd_table_mutex); } EXPORT_SYMBOL_GPL(register_mtd_user); /** * unregister_mtd_user - unregister a 'user' of MTD devices. * @old: pointer to notifier info structure * * Removes a callback function pair from the list of 'users' to be * notified upon addition or removal of MTD devices. Causes the * 'remove' callback to be immediately invoked for each MTD device * currently present in the system. */ int unregister_mtd_user (struct mtd_notifier *old) { struct mtd_info *mtd; mutex_lock(&mtd_table_mutex); module_put(THIS_MODULE); mtd_for_each_device(mtd) old->remove(mtd); list_del(&old->list); mutex_unlock(&mtd_table_mutex); return 0; } EXPORT_SYMBOL_GPL(unregister_mtd_user); /** * get_mtd_device - obtain a validated handle for an MTD device * @mtd: last known address of the required MTD device * @num: internal device number of the required MTD device * * Given a number and NULL address, return the num'th entry in the device * table, if any. Given an address and num == -1, search the device table * for a device with that address and return if it's still present. Given * both, return the num'th driver only if its address matches. Return * error code if not. */ struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num) { struct mtd_info *ret = NULL, *other; int err = -ENODEV; mutex_lock(&mtd_table_mutex); if (num == -1) { mtd_for_each_device(other) { if (other == mtd) { ret = mtd; break; } } } else if (num >= 0) { ret = idr_find(&mtd_idr, num); if (mtd && mtd != ret) ret = NULL; } if (!ret) { ret = ERR_PTR(err); goto out; } err = __get_mtd_device(ret); if (err) ret = ERR_PTR(err); out: mutex_unlock(&mtd_table_mutex); return ret; } EXPORT_SYMBOL_GPL(get_mtd_device); int __get_mtd_device(struct mtd_info *mtd) { int err; if (!try_module_get(mtd->owner)) return -ENODEV; if (mtd->_get_device) { err = mtd->_get_device(mtd); if (err) { module_put(mtd->owner); return err; } } mtd->usecount++; return 0; } EXPORT_SYMBOL_GPL(__get_mtd_device); /** * get_mtd_device_nm - obtain a validated handle for an MTD device by * device name * @name: MTD device name to open * * This function returns MTD device description structure in case of * success and an error code in case of failure. */ struct mtd_info *get_mtd_device_nm(const char *name) { int err = -ENODEV; struct mtd_info *mtd = NULL, *other; mutex_lock(&mtd_table_mutex); mtd_for_each_device(other) { if (!strcmp(name, other->name)) { mtd = other; break; } } if (!mtd) goto out_unlock; err = __get_mtd_device(mtd); if (err) goto out_unlock; mutex_unlock(&mtd_table_mutex); return mtd; out_unlock: mutex_unlock(&mtd_table_mutex); return ERR_PTR(err); } EXPORT_SYMBOL_GPL(get_mtd_device_nm); void put_mtd_device(struct mtd_info *mtd) { mutex_lock(&mtd_table_mutex); __put_mtd_device(mtd); mutex_unlock(&mtd_table_mutex); } EXPORT_SYMBOL_GPL(put_mtd_device); void __put_mtd_device(struct mtd_info *mtd) { --mtd->usecount; BUG_ON(mtd->usecount < 0); if (mtd->_put_device) mtd->_put_device(mtd); module_put(mtd->owner); } EXPORT_SYMBOL_GPL(__put_mtd_device); /* * Erase is an asynchronous operation. Device drivers are supposed * to call instr->callback() whenever the operation completes, even * if it completes with a failure. * Callers are supposed to pass a callback function and wait for it * to be called before writing to the block. */ int mtd_erase(struct mtd_info *mtd, struct erase_info *instr) { if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr) return -EINVAL; if (!(mtd->flags & MTD_WRITEABLE)) return -EROFS; instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN; if (!instr->len) { instr->state = MTD_ERASE_DONE; mtd_erase_callback(instr); return 0; } return mtd->_erase(mtd, instr); } EXPORT_SYMBOL_GPL(mtd_erase); /* * This stuff for eXecute-In-Place. phys is optional and may be set to NULL. */ int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, void **virt, resource_size_t *phys) { *retlen = 0; *virt = NULL; if (phys) *phys = 0; if (!mtd->_point) return -EOPNOTSUPP; if (from < 0 || from >= mtd->size || len > mtd->size - from) return -EINVAL; if (!len) return 0; return mtd->_point(mtd, from, len, retlen, virt, phys); } EXPORT_SYMBOL_GPL(mtd_point); /* We probably shouldn't allow XIP if the unpoint isn't a NULL */ int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len) { if (!mtd->_point) return -EOPNOTSUPP; if (from < 0 || from >= mtd->size || len > mtd->size - from) return -EINVAL; if (!len) return 0; return mtd->_unpoint(mtd, from, len); } EXPORT_SYMBOL_GPL(mtd_unpoint); /* * Allow NOMMU mmap() to directly map the device (if not NULL) * - return the address to which the offset maps * - return -ENOSYS to indicate refusal to do the mapping */ unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len, unsigned long offset, unsigned long flags) { if (!mtd->_get_unmapped_area) return -EOPNOTSUPP; if (offset >= mtd->size || len > mtd->size - offset) return -EINVAL; return mtd->_get_unmapped_area(mtd, len, offset, flags); } EXPORT_SYMBOL_GPL(mtd_get_unmapped_area); int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) { int ret_code; *retlen = 0; if (from < 0 || from >= mtd->size || len > mtd->size - from) return -EINVAL; if (!len) return 0; /* * In the absence of an error, drivers return a non-negative integer * representing the maximum number of bitflips that were corrected on * any one ecc region (if applicable; zero otherwise). */ ret_code = mtd->_read(mtd, from, len, retlen, buf); if (unlikely(ret_code < 0)) return ret_code; if (mtd->ecc_strength == 0) return 0; /* device lacks ecc */ return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0; } EXPORT_SYMBOL_GPL(mtd_read); int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf) { *retlen = 0; if (to < 0 || to >= mtd->size || len > mtd->size - to) return -EINVAL; if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE)) return -EROFS; if (!len) return 0; return mtd->_write(mtd, to, len, retlen, buf); } EXPORT_SYMBOL_GPL(mtd_write); /* * In blackbox flight recorder like scenarios we want to make successful writes * in interrupt context. panic_write() is only intended to be called when its * known the kernel is about to panic and we need the write to succeed. Since * the kernel is not going to be running for much longer, this function can * break locks and delay to ensure the write succeeds (but not sleep). */ int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf) { *retlen = 0; if (!mtd->_panic_write) return -EOPNOTSUPP; if (to < 0 || to >= mtd->size || len > mtd->size - to) return -EINVAL; if (!(mtd->flags & MTD_WRITEABLE)) return -EROFS; if (!len) return 0; return mtd->_panic_write(mtd, to, len, retlen, buf); } EXPORT_SYMBOL_GPL(mtd_panic_write); int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops) { int ret_code; ops->retlen = ops->oobretlen = 0; if (!mtd->_read_oob) return -EOPNOTSUPP; /* * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics * similar to mtd->_read(), returning a non-negative integer * representing max bitflips. In other cases, mtd->_read_oob() may * return -EUCLEAN. In all cases, perform similar logic to mtd_read(). */ ret_code = mtd->_read_oob(mtd, from, ops); if (unlikely(ret_code < 0)) return ret_code; if (mtd->ecc_strength == 0) return 0; /* device lacks ecc */ return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0; } EXPORT_SYMBOL_GPL(mtd_read_oob); /* * Method to access the protection register area, present in some flash * devices. The user data is one time programmable but the factory data is read * only. */ int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen, struct otp_info *buf) { if (!mtd->_get_fact_prot_info) return -EOPNOTSUPP; if (!len) return 0; return mtd->_get_fact_prot_info(mtd, len, retlen, buf); } EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info); int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) { *retlen = 0; if (!mtd->_read_fact_prot_reg) return -EOPNOTSUPP; if (!len) return 0; return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf); } EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg); int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen, struct otp_info *buf) { if (!mtd->_get_user_prot_info) return -EOPNOTSUPP; if (!len) return 0; return mtd->_get_user_prot_info(mtd, len, retlen, buf); } EXPORT_SYMBOL_GPL(mtd_get_user_prot_info); int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) { *retlen = 0; if (!mtd->_read_user_prot_reg) return -EOPNOTSUPP; if (!len) return 0; return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf); } EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg); int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, u_char *buf) { int ret; *retlen = 0; if (!mtd->_write_user_prot_reg) return -EOPNOTSUPP; if (!len) return 0; ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf); if (ret) return ret; /* * If no data could be written at all, we are out of memory and * must return -ENOSPC. */ return (*retlen) ? 0 : -ENOSPC; } EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg); int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len) { if (!mtd->_lock_user_prot_reg) return -EOPNOTSUPP; if (!len) return 0; return mtd->_lock_user_prot_reg(mtd, from, len); } EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg); /* Chip-supported device locking */ int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) { if (!mtd->_lock) return -EOPNOTSUPP; if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs) return -EINVAL; if (!len) return 0; return mtd->_lock(mtd, ofs, len); } EXPORT_SYMBOL_GPL(mtd_lock); int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len) { if (!mtd->_unlock) return -EOPNOTSUPP; if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs) return -EINVAL; if (!len) return 0; return mtd->_unlock(mtd, ofs, len); } EXPORT_SYMBOL_GPL(mtd_unlock); int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len) { if (!mtd->_is_locked) return -EOPNOTSUPP; if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs) return -EINVAL; if (!len) return 0; return mtd->_is_locked(mtd, ofs, len); } EXPORT_SYMBOL_GPL(mtd_is_locked); int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs) { if (ofs < 0 || ofs >= mtd->size) return -EINVAL; if (!mtd->_block_isreserved) return 0; return mtd->_block_isreserved(mtd, ofs); } EXPORT_SYMBOL_GPL(mtd_block_isreserved); int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs) { if (ofs < 0 || ofs >= mtd->size) return -EINVAL; if (!mtd->_block_isbad) return 0; return mtd->_block_isbad(mtd, ofs); } EXPORT_SYMBOL_GPL(mtd_block_isbad); int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs) { if (!mtd->_block_markbad) return -EOPNOTSUPP; if (ofs < 0 || ofs >= mtd->size) return -EINVAL; if (!(mtd->flags & MTD_WRITEABLE)) return -EROFS; return mtd->_block_markbad(mtd, ofs); } EXPORT_SYMBOL_GPL(mtd_block_markbad); /* * default_mtd_writev - the default writev method * @mtd: mtd device description object pointer * @vecs: the vectors to write * @count: count of vectors in @vecs * @to: the MTD device offset to write to * @retlen: on exit contains the count of bytes written to the MTD device. * * This function returns zero in case of success and a negative error code in * case of failure. */ static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen) { unsigned long i; size_t totlen = 0, thislen; int ret = 0; for (i = 0; i < count; i++) { if (!vecs[i].iov_len) continue; ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base); totlen += thislen; if (ret || thislen != vecs[i].iov_len) break; to += vecs[i].iov_len; } *retlen = totlen; return ret; } /* * mtd_writev - the vector-based MTD write method * @mtd: mtd device description object pointer * @vecs: the vectors to write * @count: count of vectors in @vecs * @to: the MTD device offset to write to * @retlen: on exit contains the count of bytes written to the MTD device. * * This function returns zero in case of success and a negative error code in * case of failure. */ int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen) { *retlen = 0; if (!(mtd->flags & MTD_WRITEABLE)) return -EROFS; if (!mtd->_writev) return default_mtd_writev(mtd, vecs, count, to, retlen); return mtd->_writev(mtd, vecs, count, to, retlen); } EXPORT_SYMBOL_GPL(mtd_writev); /** * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size * @mtd: mtd device description object pointer * @size: a pointer to the ideal or maximum size of the allocation, points * to the actual allocation size on success. * * This routine attempts to allocate a contiguous kernel buffer up to * the specified size, backing off the size of the request exponentially * until the request succeeds or until the allocation size falls below * the system page size. This attempts to make sure it does not adversely * impact system performance, so when allocating more than one page, we * ask the memory allocator to avoid re-trying, swapping, writing back * or performing I/O. * * Note, this function also makes sure that the allocated buffer is aligned to * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value. * * This is called, for example by mtd_{read,write} and jffs2_scan_medium, * to handle smaller (i.e. degraded) buffer allocations under low- or * fragmented-memory situations where such reduced allocations, from a * requested ideal, are allowed. * * Returns a pointer to the allocated buffer on success; otherwise, NULL. */ void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size) { gfp_t flags = __GFP_NOWARN | __GFP_WAIT | __GFP_NORETRY | __GFP_NO_KSWAPD; size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE); void *kbuf; *size = min_t(size_t, *size, KMALLOC_MAX_SIZE); while (*size > min_alloc) { kbuf = kmalloc(*size, flags); if (kbuf) return kbuf; *size >>= 1; *size = ALIGN(*size, mtd->writesize); } /* * For the last resort allocation allow 'kmalloc()' to do all sorts of * things (write-back, dropping caches, etc) by using GFP_KERNEL. */ return kmalloc(*size, GFP_KERNEL); } EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to); #ifdef CONFIG_PROC_FS /*====================================================================*/ /* Support for /proc/mtd */ static int mtd_proc_show(struct seq_file *m, void *v) { struct mtd_info *mtd; seq_puts(m, "dev: size erasesize name\n"); mutex_lock(&mtd_table_mutex); mtd_for_each_device(mtd) { seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n", mtd->index, (unsigned long long)mtd->size, mtd->erasesize, mtd->name); } mutex_unlock(&mtd_table_mutex); return 0; } static int mtd_proc_open(struct inode *inode, struct file *file) { return single_open(file, mtd_proc_show, NULL); } static const struct file_operations mtd_proc_ops = { .open = mtd_proc_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; #endif /* CONFIG_PROC_FS */ /*====================================================================*/ /* Init code */ static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name) { int ret; ret = bdi_init(bdi); if (!ret) ret = bdi_register(bdi, NULL, "%s", name); if (ret) bdi_destroy(bdi); return ret; } static struct proc_dir_entry *proc_mtd; static int __init init_mtd(void) { int ret; ret = class_register(&mtd_class); if (ret) goto err_reg; ret = mtd_bdi_init(&mtd_bdi, "mtd"); if (ret) goto err_bdi; proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops); ret = init_mtdchar(); if (ret) goto out_procfs; return 0; out_procfs: if (proc_mtd) remove_proc_entry("mtd", NULL); err_bdi: class_unregister(&mtd_class); err_reg: pr_err("Error registering mtd class or bdi: %d\n", ret); return ret; } static void __exit cleanup_mtd(void) { cleanup_mtdchar(); if (proc_mtd) remove_proc_entry("mtd", NULL); class_unregister(&mtd_class); bdi_destroy(&mtd_bdi); } module_init(init_mtd); module_exit(cleanup_mtd); MODULE_LICENSE("GPL"); MODULE_AUTHOR("David Woodhouse "); MODULE_DESCRIPTION("Core MTD registration and access routines");