X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fmtd%2Fmtdcore.c;fp=kernel%2Fdrivers%2Fmtd%2Fmtdcore.c;h=d172195fbd15fcbd947a2bc0780d0f9044cba2fd;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git diff --git a/kernel/drivers/mtd/mtdcore.c b/kernel/drivers/mtd/mtdcore.c new file mode 100644 index 000000000..d172195fb --- /dev/null +++ b/kernel/drivers/mtd/mtdcore.c @@ -0,0 +1,1303 @@ +/* + * 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 = { +}; + +static int mtd_cls_suspend(struct device *dev, pm_message_t state); +static int mtd_cls_resume(struct device *dev); + +static struct class mtd_class = { + .name = "mtd", + .owner = THIS_MODULE, + .suspend = mtd_cls_suspend, + .resume = mtd_cls_resume, +}; + +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 int mtd_cls_suspend(struct device *dev, pm_message_t state) +{ + 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 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");