diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/mtd/mtdcore.c | 2255 |
1 files changed, 2255 insertions, 0 deletions
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c new file mode 100644 index 000000000..b2d88ff90 --- /dev/null +++ b/drivers/mtd/mtdcore.c @@ -0,0 +1,2255 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Core registration and callback routines for MTD + * drivers and users. + * + * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> + * Copyright © 2006 Red Hat UK Limited + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/ptrace.h> +#include <linux/seq_file.h> +#include <linux/string.h> +#include <linux/timer.h> +#include <linux/major.h> +#include <linux/fs.h> +#include <linux/err.h> +#include <linux/ioctl.h> +#include <linux/init.h> +#include <linux/of.h> +#include <linux/proc_fs.h> +#include <linux/idr.h> +#include <linux/backing-dev.h> +#include <linux/gfp.h> +#include <linux/slab.h> +#include <linux/reboot.h> +#include <linux/leds.h> +#include <linux/debugfs.h> +#include <linux/nvmem-provider.h> + +#include <linux/mtd/mtd.h> +#include <linux/mtd/partitions.h> + +#include "mtdcore.h" + +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_oobavail_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->oobavail); +} +static DEVICE_ATTR(oobavail, S_IRUGO, mtd_oobavail_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_oobavail.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 const struct device_type mtd_devtype = { + .name = "mtd", + .groups = mtd_groups, + .release = mtd_release, +}; + +static int mtd_partid_debug_show(struct seq_file *s, void *p) +{ + struct mtd_info *mtd = s->private; + + seq_printf(s, "%s\n", mtd->dbg.partid); + + return 0; +} + +DEFINE_SHOW_ATTRIBUTE(mtd_partid_debug); + +static int mtd_partname_debug_show(struct seq_file *s, void *p) +{ + struct mtd_info *mtd = s->private; + + seq_printf(s, "%s\n", mtd->dbg.partname); + + return 0; +} + +DEFINE_SHOW_ATTRIBUTE(mtd_partname_debug); + +static struct dentry *dfs_dir_mtd; + +static void mtd_debugfs_populate(struct mtd_info *mtd) +{ + struct device *dev = &mtd->dev; + struct dentry *root; + + if (IS_ERR_OR_NULL(dfs_dir_mtd)) + return; + + root = debugfs_create_dir(dev_name(dev), dfs_dir_mtd); + mtd->dbg.dfs_dir = root; + + if (mtd->dbg.partid) + debugfs_create_file("partid", 0400, root, mtd, + &mtd_partid_debug_fops); + + if (mtd->dbg.partname) + debugfs_create_file("partname", 0400, root, mtd, + &mtd_partname_debug_fops); +} + +#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; +} + +/** + * mtd_wunit_to_pairing_info - get pairing information of a wunit + * @mtd: pointer to new MTD device info structure + * @wunit: write unit we are interested in + * @info: returned pairing information + * + * Retrieve pairing information associated to the wunit. + * This is mainly useful when dealing with MLC/TLC NANDs where pages can be + * paired together, and where programming a page may influence the page it is + * paired with. + * The notion of page is replaced by the term wunit (write-unit) to stay + * consistent with the ->writesize field. + * + * The @wunit argument can be extracted from an absolute offset using + * mtd_offset_to_wunit(). @info is filled with the pairing information attached + * to @wunit. + * + * From the pairing info the MTD user can find all the wunits paired with + * @wunit using the following loop: + * + * for (i = 0; i < mtd_pairing_groups(mtd); i++) { + * info.pair = i; + * mtd_pairing_info_to_wunit(mtd, &info); + * ... + * } + */ +int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit, + struct mtd_pairing_info *info) +{ + struct mtd_info *master = mtd_get_master(mtd); + int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master); + + if (wunit < 0 || wunit >= npairs) + return -EINVAL; + + if (master->pairing && master->pairing->get_info) + return master->pairing->get_info(master, wunit, info); + + info->group = 0; + info->pair = wunit; + + return 0; +} +EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info); + +/** + * mtd_pairing_info_to_wunit - get wunit from pairing information + * @mtd: pointer to new MTD device info structure + * @info: pairing information struct + * + * Returns a positive number representing the wunit associated to the info + * struct, or a negative error code. + * + * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to + * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info() + * doc). + * + * It can also be used to only program the first page of each pair (i.e. + * page attached to group 0), which allows one to use an MLC NAND in + * software-emulated SLC mode: + * + * info.group = 0; + * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd); + * for (info.pair = 0; info.pair < npairs; info.pair++) { + * wunit = mtd_pairing_info_to_wunit(mtd, &info); + * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit), + * mtd->writesize, &retlen, buf + (i * mtd->writesize)); + * } + */ +int mtd_pairing_info_to_wunit(struct mtd_info *mtd, + const struct mtd_pairing_info *info) +{ + struct mtd_info *master = mtd_get_master(mtd); + int ngroups = mtd_pairing_groups(master); + int npairs = mtd_wunit_per_eb(master) / ngroups; + + if (!info || info->pair < 0 || info->pair >= npairs || + info->group < 0 || info->group >= ngroups) + return -EINVAL; + + if (master->pairing && master->pairing->get_wunit) + return mtd->pairing->get_wunit(master, info); + + return info->pair; +} +EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit); + +/** + * mtd_pairing_groups - get the number of pairing groups + * @mtd: pointer to new MTD device info structure + * + * Returns the number of pairing groups. + * + * This number is usually equal to the number of bits exposed by a single + * cell, and can be used in conjunction with mtd_pairing_info_to_wunit() + * to iterate over all pages of a given pair. + */ +int mtd_pairing_groups(struct mtd_info *mtd) +{ + struct mtd_info *master = mtd_get_master(mtd); + + if (!master->pairing || !master->pairing->ngroups) + return 1; + + return master->pairing->ngroups; +} +EXPORT_SYMBOL_GPL(mtd_pairing_groups); + +static int mtd_nvmem_reg_read(void *priv, unsigned int offset, + void *val, size_t bytes) +{ + struct mtd_info *mtd = priv; + size_t retlen; + int err; + + err = mtd_read(mtd, offset, bytes, &retlen, val); + if (err && err != -EUCLEAN) + return err; + + return retlen == bytes ? 0 : -EIO; +} + +static int mtd_nvmem_add(struct mtd_info *mtd) +{ + struct nvmem_config config = {}; + + config.id = -1; + config.dev = &mtd->dev; + config.name = dev_name(&mtd->dev); + config.owner = THIS_MODULE; + config.reg_read = mtd_nvmem_reg_read; + config.size = mtd->size; + config.word_size = 1; + config.stride = 1; + config.read_only = true; + config.root_only = true; + config.no_of_node = true; + config.priv = mtd; + + mtd->nvmem = nvmem_register(&config); + if (IS_ERR(mtd->nvmem)) { + /* Just ignore if there is no NVMEM support in the kernel */ + if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) { + mtd->nvmem = NULL; + } else { + dev_err(&mtd->dev, "Failed to register NVMEM device\n"); + return PTR_ERR(mtd->nvmem); + } + } + + return 0; +} + +/** + * 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 non-zero on failure. + */ + +int add_mtd_device(struct mtd_info *mtd) +{ + struct mtd_info *master = mtd_get_master(mtd); + struct mtd_notifier *not; + int i, error; + + /* + * May occur, for instance, on buggy drivers which call + * mtd_device_parse_register() multiple times on the same master MTD, + * especially with CONFIG_MTD_PARTITIONED_MASTER=y. + */ + if (WARN_ONCE(mtd->dev.type, "MTD already registered\n")) + return -EEXIST; + + BUG_ON(mtd->writesize == 0); + + /* + * MTD drivers should implement ->_{write,read}() or + * ->_{write,read}_oob(), but not both. + */ + if (WARN_ON((mtd->_write && mtd->_write_oob) || + (mtd->_read && mtd->_read_oob))) + return -EINVAL; + + if (WARN_ON((!mtd->erasesize || !master->_erase) && + !(mtd->flags & MTD_NO_ERASE))) + return -EINVAL; + + /* + * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the + * master is an MLC NAND and has a proper pairing scheme defined. + * We also reject masters that implement ->_writev() for now, because + * NAND controller drivers don't implement this hook, and adding the + * SLC -> MLC address/length conversion to this path is useless if we + * don't have a user. + */ + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION && + (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH || + !master->pairing || master->_writev)) + return -EINVAL; + + mutex_lock(&mtd_table_mutex); + + i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL); + if (i < 0) { + error = i; + 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 (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { + int ngroups = mtd_pairing_groups(master); + + mtd->erasesize /= ngroups; + mtd->size = (u64)mtd_div_by_eb(mtd->size, master) * + mtd->erasesize; + } + + 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); + /* Ignore unlock failures? */ + error = 0; + } + + /* Caller should have set dev.parent to match the + * physical device, if appropriate. + */ + 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); + of_node_get(mtd_get_of_node(mtd)); + error = device_register(&mtd->dev); + if (error) { + put_device(&mtd->dev); + goto fail_added; + } + + /* Add the nvmem provider */ + error = mtd_nvmem_add(mtd); + if (error) + goto fail_nvmem_add; + + mtd_debugfs_populate(mtd); + + 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_nvmem_add: + device_unregister(&mtd->dev); +fail_added: + of_node_put(mtd_get_of_node(mtd)); + idr_remove(&mtd_idr, i); +fail_locked: + mutex_unlock(&mtd_table_mutex); + return error; +} + +/** + * 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 { + debugfs_remove_recursive(mtd->dbg.dfs_dir); + + /* Try to remove the NVMEM provider */ + if (mtd->nvmem) + nvmem_unregister(mtd->nvmem); + + device_unregister(&mtd->dev); + + idr_remove(&mtd_idr, mtd->index); + of_node_put(mtd_get_of_node(mtd)); + + module_put(THIS_MODULE); + ret = 0; + } + +out_error: + mutex_unlock(&mtd_table_mutex); + return ret; +} + +/* + * Set a few defaults based on the parent devices, if not provided by the + * driver + */ +static void mtd_set_dev_defaults(struct mtd_info *mtd) +{ + if (mtd->dev.parent) { + if (!mtd->owner && mtd->dev.parent->driver) + mtd->owner = mtd->dev.parent->driver->owner; + if (!mtd->name) + mtd->name = dev_name(mtd->dev.parent); + } else { + pr_debug("mtd device won't show a device symlink in sysfs\n"); + } + + INIT_LIST_HEAD(&mtd->partitions); + mutex_init(&mtd->master.partitions_lock); +} + +/** + * 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: + * + * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is + * registered first. + * * Then It 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 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; + + mtd_set_dev_defaults(mtd); + + if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) { + ret = add_mtd_device(mtd); + if (ret) + return ret; + } + + /* Prefer parsed partitions over driver-provided fallback */ + ret = parse_mtd_partitions(mtd, types, parser_data); + if (ret == -EPROBE_DEFER) + goto out; + + if (ret > 0) + ret = 0; + else if (nr_parts) + ret = add_mtd_partitions(mtd, parts, nr_parts); + else if (!device_is_registered(&mtd->dev)) + ret = add_mtd_device(mtd); + else + ret = 0; + + if (ret) + goto out; + + /* + * 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). + */ + WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call, + "MTD already registered\n"); + if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) { + mtd->reboot_notifier.notifier_call = mtd_reboot_notifier; + register_reboot_notifier(&mtd->reboot_notifier); + } + +out: + if (ret && device_is_registered(&mtd->dev)) + del_mtd_device(mtd); + + 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) +{ + struct mtd_info *master = mtd_get_master(mtd); + int err; + + if (!try_module_get(master->owner)) + return -ENODEV; + + if (master->_get_device) { + err = master->_get_device(mtd); + + if (err) { + module_put(master->owner); + return err; + } + } + + master->usecount++; + + while (mtd->parent) { + mtd->usecount++; + mtd = mtd->parent; + } + + 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) +{ + struct mtd_info *master = mtd_get_master(mtd); + + while (mtd->parent) { + --mtd->usecount; + BUG_ON(mtd->usecount < 0); + mtd = mtd->parent; + } + + master->usecount--; + + if (master->_put_device) + master->_put_device(master); + + module_put(master->owner); +} +EXPORT_SYMBOL_GPL(__put_mtd_device); + +/* + * Erase is an synchronous operation. Device drivers are epected to return a + * negative error code if the operation failed and update instr->fail_addr + * to point the portion that was not properly erased. + */ +int mtd_erase(struct mtd_info *mtd, struct erase_info *instr) +{ + struct mtd_info *master = mtd_get_master(mtd); + u64 mst_ofs = mtd_get_master_ofs(mtd, 0); + struct erase_info adjinstr; + int ret; + + instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN; + adjinstr = *instr; + + if (!mtd->erasesize || !master->_erase) + return -ENOTSUPP; + + if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr) + return -EINVAL; + if (!(mtd->flags & MTD_WRITEABLE)) + return -EROFS; + + if (!instr->len) + return 0; + + ledtrig_mtd_activity(); + + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { + adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) * + master->erasesize; + adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) * + master->erasesize) - + adjinstr.addr; + } + + adjinstr.addr += mst_ofs; + + ret = master->_erase(master, &adjinstr); + + if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) { + instr->fail_addr = adjinstr.fail_addr - mst_ofs; + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { + instr->fail_addr = mtd_div_by_eb(instr->fail_addr, + master); + instr->fail_addr *= mtd->erasesize; + } + } + + return ret; +} +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) +{ + struct mtd_info *master = mtd_get_master(mtd); + + *retlen = 0; + *virt = NULL; + if (phys) + *phys = 0; + if (!master->_point) + return -EOPNOTSUPP; + if (from < 0 || from >= mtd->size || len > mtd->size - from) + return -EINVAL; + if (!len) + return 0; + + from = mtd_get_master_ofs(mtd, from); + return master->_point(master, 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) +{ + struct mtd_info *master = mtd_get_master(mtd); + + if (!master->_unpoint) + return -EOPNOTSUPP; + if (from < 0 || from >= mtd->size || len > mtd->size - from) + return -EINVAL; + if (!len) + return 0; + return master->_unpoint(master, mtd_get_master_ofs(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) +{ + size_t retlen; + void *virt; + int ret; + + ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL); + if (ret) + return ret; + if (retlen != len) { + mtd_unpoint(mtd, offset, retlen); + return -ENOSYS; + } + return (unsigned long)virt; +} +EXPORT_SYMBOL_GPL(mtd_get_unmapped_area); + +static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master, + const struct mtd_ecc_stats *old_stats) +{ + struct mtd_ecc_stats diff; + + if (master == mtd) + return; + + diff = master->ecc_stats; + diff.failed -= old_stats->failed; + diff.corrected -= old_stats->corrected; + + while (mtd->parent) { + mtd->ecc_stats.failed += diff.failed; + mtd->ecc_stats.corrected += diff.corrected; + mtd = mtd->parent; + } +} + +int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, + u_char *buf) +{ + struct mtd_oob_ops ops = { + .len = len, + .datbuf = buf, + }; + int ret; + + ret = mtd_read_oob(mtd, from, &ops); + *retlen = ops.retlen; + + return ret; +} +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) +{ + struct mtd_oob_ops ops = { + .len = len, + .datbuf = (u8 *)buf, + }; + int ret; + + ret = mtd_write_oob(mtd, to, &ops); + *retlen = ops.retlen; + + return ret; +} +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) +{ + struct mtd_info *master = mtd_get_master(mtd); + + *retlen = 0; + if (!master->_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; + if (!master->oops_panic_write) + master->oops_panic_write = true; + + return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len, + retlen, buf); +} +EXPORT_SYMBOL_GPL(mtd_panic_write); + +static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs, + struct mtd_oob_ops *ops) +{ + /* + * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving + * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in + * this case. + */ + if (!ops->datbuf) + ops->len = 0; + + if (!ops->oobbuf) + ops->ooblen = 0; + + if (offs < 0 || offs + ops->len > mtd->size) + return -EINVAL; + + if (ops->ooblen) { + size_t maxooblen; + + if (ops->ooboffs >= mtd_oobavail(mtd, ops)) + return -EINVAL; + + maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) - + mtd_div_by_ws(offs, mtd)) * + mtd_oobavail(mtd, ops)) - ops->ooboffs; + if (ops->ooblen > maxooblen) + return -EINVAL; + } + + return 0; +} + +static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from, + struct mtd_oob_ops *ops) +{ + struct mtd_info *master = mtd_get_master(mtd); + int ret; + + from = mtd_get_master_ofs(mtd, from); + if (master->_read_oob) + ret = master->_read_oob(master, from, ops); + else + ret = master->_read(master, from, ops->len, &ops->retlen, + ops->datbuf); + + return ret; +} + +static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to, + struct mtd_oob_ops *ops) +{ + struct mtd_info *master = mtd_get_master(mtd); + int ret; + + to = mtd_get_master_ofs(mtd, to); + if (master->_write_oob) + ret = master->_write_oob(master, to, ops); + else + ret = master->_write(master, to, ops->len, &ops->retlen, + ops->datbuf); + + return ret; +} + +static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read, + struct mtd_oob_ops *ops) +{ + struct mtd_info *master = mtd_get_master(mtd); + int ngroups = mtd_pairing_groups(master); + int npairs = mtd_wunit_per_eb(master) / ngroups; + struct mtd_oob_ops adjops = *ops; + unsigned int wunit, oobavail; + struct mtd_pairing_info info; + int max_bitflips = 0; + u32 ebofs, pageofs; + loff_t base, pos; + + ebofs = mtd_mod_by_eb(start, mtd); + base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize; + info.group = 0; + info.pair = mtd_div_by_ws(ebofs, mtd); + pageofs = mtd_mod_by_ws(ebofs, mtd); + oobavail = mtd_oobavail(mtd, ops); + + while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) { + int ret; + + if (info.pair >= npairs) { + info.pair = 0; + base += master->erasesize; + } + + wunit = mtd_pairing_info_to_wunit(master, &info); + pos = mtd_wunit_to_offset(mtd, base, wunit); + + adjops.len = ops->len - ops->retlen; + if (adjops.len > mtd->writesize - pageofs) + adjops.len = mtd->writesize - pageofs; + + adjops.ooblen = ops->ooblen - ops->oobretlen; + if (adjops.ooblen > oobavail - adjops.ooboffs) + adjops.ooblen = oobavail - adjops.ooboffs; + + if (read) { + ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops); + if (ret > 0) + max_bitflips = max(max_bitflips, ret); + } else { + ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops); + } + + if (ret < 0) + return ret; + + max_bitflips = max(max_bitflips, ret); + ops->retlen += adjops.retlen; + ops->oobretlen += adjops.oobretlen; + adjops.datbuf += adjops.retlen; + adjops.oobbuf += adjops.oobretlen; + adjops.ooboffs = 0; + pageofs = 0; + info.pair++; + } + + return max_bitflips; +} + +int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops) +{ + struct mtd_info *master = mtd_get_master(mtd); + struct mtd_ecc_stats old_stats = master->ecc_stats; + int ret_code; + + ops->retlen = ops->oobretlen = 0; + + ret_code = mtd_check_oob_ops(mtd, from, ops); + if (ret_code) + return ret_code; + + ledtrig_mtd_activity(); + + /* Check the validity of a potential fallback on mtd->_read */ + if (!master->_read_oob && (!master->_read || ops->oobbuf)) + return -EOPNOTSUPP; + + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) + ret_code = mtd_io_emulated_slc(mtd, from, true, ops); + else + ret_code = mtd_read_oob_std(mtd, from, ops); + + mtd_update_ecc_stats(mtd, master, &old_stats); + + /* + * 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(). + */ + 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); + +int mtd_write_oob(struct mtd_info *mtd, loff_t to, + struct mtd_oob_ops *ops) +{ + struct mtd_info *master = mtd_get_master(mtd); + int ret; + + ops->retlen = ops->oobretlen = 0; + + if (!(mtd->flags & MTD_WRITEABLE)) + return -EROFS; + + ret = mtd_check_oob_ops(mtd, to, ops); + if (ret) + return ret; + + ledtrig_mtd_activity(); + + /* Check the validity of a potential fallback on mtd->_write */ + if (!master->_write_oob && (!master->_write || ops->oobbuf)) + return -EOPNOTSUPP; + + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) + return mtd_io_emulated_slc(mtd, to, false, ops); + + return mtd_write_oob_std(mtd, to, ops); +} +EXPORT_SYMBOL_GPL(mtd_write_oob); + +/** + * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section + * @mtd: MTD device structure + * @section: ECC section. Depending on the layout you may have all the ECC + * bytes stored in a single contiguous section, or one section + * per ECC chunk (and sometime several sections for a single ECC + * ECC chunk) + * @oobecc: OOB region struct filled with the appropriate ECC position + * information + * + * This function returns ECC section information in the OOB area. If you want + * to get all the ECC bytes information, then you should call + * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE. + * + * Returns zero on success, a negative error code otherwise. + */ +int mtd_ooblayout_ecc(struct mtd_info *mtd, int section, + struct mtd_oob_region *oobecc) +{ + struct mtd_info *master = mtd_get_master(mtd); + + memset(oobecc, 0, sizeof(*oobecc)); + + if (!master || section < 0) + return -EINVAL; + + if (!master->ooblayout || !master->ooblayout->ecc) + return -ENOTSUPP; + + return master->ooblayout->ecc(master, section, oobecc); +} +EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc); + +/** + * mtd_ooblayout_free - Get the OOB region definition of a specific free + * section + * @mtd: MTD device structure + * @section: Free section you are interested in. Depending on the layout + * you may have all the free bytes stored in a single contiguous + * section, or one section per ECC chunk plus an extra section + * for the remaining bytes (or other funky layout). + * @oobfree: OOB region struct filled with the appropriate free position + * information + * + * This function returns free bytes position in the OOB area. If you want + * to get all the free bytes information, then you should call + * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE. + * + * Returns zero on success, a negative error code otherwise. + */ +int mtd_ooblayout_free(struct mtd_info *mtd, int section, + struct mtd_oob_region *oobfree) +{ + struct mtd_info *master = mtd_get_master(mtd); + + memset(oobfree, 0, sizeof(*oobfree)); + + if (!master || section < 0) + return -EINVAL; + + if (!master->ooblayout || !master->ooblayout->free) + return -ENOTSUPP; + + return master->ooblayout->free(master, section, oobfree); +} +EXPORT_SYMBOL_GPL(mtd_ooblayout_free); + +/** + * mtd_ooblayout_find_region - Find the region attached to a specific byte + * @mtd: mtd info structure + * @byte: the byte we are searching for + * @sectionp: pointer where the section id will be stored + * @oobregion: used to retrieve the ECC position + * @iter: iterator function. Should be either mtd_ooblayout_free or + * mtd_ooblayout_ecc depending on the region type you're searching for + * + * This function returns the section id and oobregion information of a + * specific byte. For example, say you want to know where the 4th ECC byte is + * stored, you'll use: + * + * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc); + * + * Returns zero on success, a negative error code otherwise. + */ +static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte, + int *sectionp, struct mtd_oob_region *oobregion, + int (*iter)(struct mtd_info *, + int section, + struct mtd_oob_region *oobregion)) +{ + int pos = 0, ret, section = 0; + + memset(oobregion, 0, sizeof(*oobregion)); + + while (1) { + ret = iter(mtd, section, oobregion); + if (ret) + return ret; + + if (pos + oobregion->length > byte) + break; + + pos += oobregion->length; + section++; + } + + /* + * Adjust region info to make it start at the beginning at the + * 'start' ECC byte. + */ + oobregion->offset += byte - pos; + oobregion->length -= byte - pos; + *sectionp = section; + + return 0; +} + +/** + * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific + * ECC byte + * @mtd: mtd info structure + * @eccbyte: the byte we are searching for + * @sectionp: pointer where the section id will be stored + * @oobregion: OOB region information + * + * Works like mtd_ooblayout_find_region() except it searches for a specific ECC + * byte. + * + * Returns zero on success, a negative error code otherwise. + */ +int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte, + int *section, + struct mtd_oob_region *oobregion) +{ + return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion, + mtd_ooblayout_ecc); +} +EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion); + +/** + * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer + * @mtd: mtd info structure + * @buf: destination buffer to store OOB bytes + * @oobbuf: OOB buffer + * @start: first byte to retrieve + * @nbytes: number of bytes to retrieve + * @iter: section iterator + * + * Extract bytes attached to a specific category (ECC or free) + * from the OOB buffer and copy them into buf. + * + * Returns zero on success, a negative error code otherwise. + */ +static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf, + const u8 *oobbuf, int start, int nbytes, + int (*iter)(struct mtd_info *, + int section, + struct mtd_oob_region *oobregion)) +{ + struct mtd_oob_region oobregion; + int section, ret; + + ret = mtd_ooblayout_find_region(mtd, start, §ion, + &oobregion, iter); + + while (!ret) { + int cnt; + + cnt = min_t(int, nbytes, oobregion.length); + memcpy(buf, oobbuf + oobregion.offset, cnt); + buf += cnt; + nbytes -= cnt; + + if (!nbytes) + break; + + ret = iter(mtd, ++section, &oobregion); + } + + return ret; +} + +/** + * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer + * @mtd: mtd info structure + * @buf: source buffer to get OOB bytes from + * @oobbuf: OOB buffer + * @start: first OOB byte to set + * @nbytes: number of OOB bytes to set + * @iter: section iterator + * + * Fill the OOB buffer with data provided in buf. The category (ECC or free) + * is selected by passing the appropriate iterator. + * + * Returns zero on success, a negative error code otherwise. + */ +static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf, + u8 *oobbuf, int start, int nbytes, + int (*iter)(struct mtd_info *, + int section, + struct mtd_oob_region *oobregion)) +{ + struct mtd_oob_region oobregion; + int section, ret; + + ret = mtd_ooblayout_find_region(mtd, start, §ion, + &oobregion, iter); + + while (!ret) { + int cnt; + + cnt = min_t(int, nbytes, oobregion.length); + memcpy(oobbuf + oobregion.offset, buf, cnt); + buf += cnt; + nbytes -= cnt; + + if (!nbytes) + break; + + ret = iter(mtd, ++section, &oobregion); + } + + return ret; +} + +/** + * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category + * @mtd: mtd info structure + * @iter: category iterator + * + * Count the number of bytes in a given category. + * + * Returns a positive value on success, a negative error code otherwise. + */ +static int mtd_ooblayout_count_bytes(struct mtd_info *mtd, + int (*iter)(struct mtd_info *, + int section, + struct mtd_oob_region *oobregion)) +{ + struct mtd_oob_region oobregion; + int section = 0, ret, nbytes = 0; + + while (1) { + ret = iter(mtd, section++, &oobregion); + if (ret) { + if (ret == -ERANGE) + ret = nbytes; + break; + } + + nbytes += oobregion.length; + } + + return ret; +} + +/** + * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer + * @mtd: mtd info structure + * @eccbuf: destination buffer to store ECC bytes + * @oobbuf: OOB buffer + * @start: first ECC byte to retrieve + * @nbytes: number of ECC bytes to retrieve + * + * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes. + * + * Returns zero on success, a negative error code otherwise. + */ +int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf, + const u8 *oobbuf, int start, int nbytes) +{ + return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes, + mtd_ooblayout_ecc); +} +EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes); + +/** + * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer + * @mtd: mtd info structure + * @eccbuf: source buffer to get ECC bytes from + * @oobbuf: OOB buffer + * @start: first ECC byte to set + * @nbytes: number of ECC bytes to set + * + * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes. + * + * Returns zero on success, a negative error code otherwise. + */ +int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf, + u8 *oobbuf, int start, int nbytes) +{ + return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes, + mtd_ooblayout_ecc); +} +EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes); + +/** + * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer + * @mtd: mtd info structure + * @databuf: destination buffer to store ECC bytes + * @oobbuf: OOB buffer + * @start: first ECC byte to retrieve + * @nbytes: number of ECC bytes to retrieve + * + * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes. + * + * Returns zero on success, a negative error code otherwise. + */ +int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf, + const u8 *oobbuf, int start, int nbytes) +{ + return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes, + mtd_ooblayout_free); +} +EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes); + +/** + * mtd_ooblayout_set_databytes - set data bytes into the oob buffer + * @mtd: mtd info structure + * @databuf: source buffer to get data bytes from + * @oobbuf: OOB buffer + * @start: first ECC byte to set + * @nbytes: number of ECC bytes to set + * + * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes. + * + * Returns zero on success, a negative error code otherwise. + */ +int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf, + u8 *oobbuf, int start, int nbytes) +{ + return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes, + mtd_ooblayout_free); +} +EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes); + +/** + * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB + * @mtd: mtd info structure + * + * Works like mtd_ooblayout_count_bytes(), except it count free bytes. + * + * Returns zero on success, a negative error code otherwise. + */ +int mtd_ooblayout_count_freebytes(struct mtd_info *mtd) +{ + return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free); +} +EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes); + +/** + * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB + * @mtd: mtd info structure + * + * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes. + * + * Returns zero on success, a negative error code otherwise. + */ +int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd) +{ + return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc); +} +EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes); + +/* + * 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) +{ + struct mtd_info *master = mtd_get_master(mtd); + + if (!master->_get_fact_prot_info) + return -EOPNOTSUPP; + if (!len) + return 0; + return master->_get_fact_prot_info(master, 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) +{ + struct mtd_info *master = mtd_get_master(mtd); + + *retlen = 0; + if (!master->_read_fact_prot_reg) + return -EOPNOTSUPP; + if (!len) + return 0; + return master->_read_fact_prot_reg(master, 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) +{ + struct mtd_info *master = mtd_get_master(mtd); + + if (!master->_get_user_prot_info) + return -EOPNOTSUPP; + if (!len) + return 0; + return master->_get_user_prot_info(master, 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) +{ + struct mtd_info *master = mtd_get_master(mtd); + + *retlen = 0; + if (!master->_read_user_prot_reg) + return -EOPNOTSUPP; + if (!len) + return 0; + return master->_read_user_prot_reg(master, 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) +{ + struct mtd_info *master = mtd_get_master(mtd); + int ret; + + *retlen = 0; + if (!master->_write_user_prot_reg) + return -EOPNOTSUPP; + if (!len) + return 0; + ret = master->_write_user_prot_reg(master, 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) +{ + struct mtd_info *master = mtd_get_master(mtd); + + if (!master->_lock_user_prot_reg) + return -EOPNOTSUPP; + if (!len) + return 0; + return master->_lock_user_prot_reg(master, 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) +{ + struct mtd_info *master = mtd_get_master(mtd); + + if (!master->_lock) + return -EOPNOTSUPP; + if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs) + return -EINVAL; + if (!len) + return 0; + + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { + ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; + len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize; + } + + return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len); +} +EXPORT_SYMBOL_GPL(mtd_lock); + +int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len) +{ + struct mtd_info *master = mtd_get_master(mtd); + + if (!master->_unlock) + return -EOPNOTSUPP; + if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs) + return -EINVAL; + if (!len) + return 0; + + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { + ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; + len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize; + } + + return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len); +} +EXPORT_SYMBOL_GPL(mtd_unlock); + +int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len) +{ + struct mtd_info *master = mtd_get_master(mtd); + + if (!master->_is_locked) + return -EOPNOTSUPP; + if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs) + return -EINVAL; + if (!len) + return 0; + + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) { + ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; + len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize; + } + + return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len); +} +EXPORT_SYMBOL_GPL(mtd_is_locked); + +int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs) +{ + struct mtd_info *master = mtd_get_master(mtd); + + if (ofs < 0 || ofs >= mtd->size) + return -EINVAL; + if (!master->_block_isreserved) + return 0; + + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) + ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; + + return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs)); +} +EXPORT_SYMBOL_GPL(mtd_block_isreserved); + +int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs) +{ + struct mtd_info *master = mtd_get_master(mtd); + + if (ofs < 0 || ofs >= mtd->size) + return -EINVAL; + if (!master->_block_isbad) + return 0; + + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) + ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; + + return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs)); +} +EXPORT_SYMBOL_GPL(mtd_block_isbad); + +int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs) +{ + struct mtd_info *master = mtd_get_master(mtd); + int ret; + + if (!master->_block_markbad) + return -EOPNOTSUPP; + if (ofs < 0 || ofs >= mtd->size) + return -EINVAL; + if (!(mtd->flags & MTD_WRITEABLE)) + return -EROFS; + + if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) + ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize; + + ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs)); + if (ret) + return ret; + + while (mtd->parent) { + mtd->ecc_stats.badblocks++; + mtd = mtd->parent; + } + + return 0; +} +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) +{ + struct mtd_info *master = mtd_get_master(mtd); + + *retlen = 0; + if (!(mtd->flags & MTD_WRITEABLE)) + return -EROFS; + + if (!master->_writev) + return default_mtd_writev(mtd, vecs, count, to, retlen); + + return master->_writev(master, vecs, count, + mtd_get_master_ofs(mtd, 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_DIRECT_RECLAIM | __GFP_NORETRY; + 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; +} +#endif /* CONFIG_PROC_FS */ + +/*====================================================================*/ +/* Init code */ + +static struct backing_dev_info * __init mtd_bdi_init(char *name) +{ + struct backing_dev_info *bdi; + int ret; + + bdi = bdi_alloc(NUMA_NO_NODE); + if (!bdi) + return ERR_PTR(-ENOMEM); + bdi->ra_pages = 0; + bdi->io_pages = 0; + + /* + * We put '-0' suffix to the name to get the same name format as we + * used to get. Since this is called only once, we get a unique name. + */ + ret = bdi_register(bdi, "%.28s-0", name); + if (ret) + bdi_put(bdi); + + return ret ? ERR_PTR(ret) : bdi; +} + +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; + + mtd_bdi = mtd_bdi_init("mtd"); + if (IS_ERR(mtd_bdi)) { + ret = PTR_ERR(mtd_bdi); + goto err_bdi; + } + + proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show); + + ret = init_mtdchar(); + if (ret) + goto out_procfs; + + dfs_dir_mtd = debugfs_create_dir("mtd", NULL); + + return 0; + +out_procfs: + if (proc_mtd) + remove_proc_entry("mtd", NULL); + bdi_put(mtd_bdi); +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) +{ + debugfs_remove_recursive(dfs_dir_mtd); + cleanup_mtdchar(); + if (proc_mtd) + remove_proc_entry("mtd", NULL); + class_unregister(&mtd_class); + bdi_put(mtd_bdi); + idr_destroy(&mtd_idr); +} + +module_init(init_mtd); +module_exit(cleanup_mtd); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); +MODULE_DESCRIPTION("Core MTD registration and access routines"); |