// SPDX-License-Identifier: GPL-2.0-or-later /* * Core registration and callback routines for MTD * drivers and users. * * Copyright © 1999-2010 David Woodhouse * Copyright © 2006 Red Hat UK Limited */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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); } #define MTD_DEVICE_ATTR_RO(name) \ static DEVICE_ATTR(name, 0444, mtd_##name##_show, NULL) #define MTD_DEVICE_ATTR_RW(name) \ static DEVICE_ATTR(name, 0644, mtd_##name##_show, mtd_##name##_store) 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 sysfs_emit(buf, "%s\n", type); } MTD_DEVICE_ATTR_RO(type); static ssize_t mtd_flags_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return sysfs_emit(buf, "0x%lx\n", (unsigned long)mtd->flags); } MTD_DEVICE_ATTR_RO(flags); static ssize_t mtd_size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return sysfs_emit(buf, "%llu\n", (unsigned long long)mtd->size); } MTD_DEVICE_ATTR_RO(size); static ssize_t mtd_erasesize_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->erasesize); } MTD_DEVICE_ATTR_RO(erasesize); static ssize_t mtd_erasesize_minor_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->erasesize_minor); } MTD_DEVICE_ATTR_RO(erasesize_minor); static ssize_t mtd_writesize_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->writesize); } MTD_DEVICE_ATTR_RO(writesize); 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 sysfs_emit(buf, "%u\n", subpagesize); } MTD_DEVICE_ATTR_RO(subpagesize); static ssize_t mtd_oobsize_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->oobsize); } MTD_DEVICE_ATTR_RO(oobsize); static ssize_t mtd_oobavail_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return sysfs_emit(buf, "%u\n", mtd->oobavail); } MTD_DEVICE_ATTR_RO(oobavail); static ssize_t mtd_numeraseregions_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return sysfs_emit(buf, "%u\n", mtd->numeraseregions); } MTD_DEVICE_ATTR_RO(numeraseregions); static ssize_t mtd_name_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return sysfs_emit(buf, "%s\n", mtd->name); } MTD_DEVICE_ATTR_RO(name); 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 sysfs_emit(buf, "%u\n", mtd->ecc_strength); } MTD_DEVICE_ATTR_RO(ecc_strength); 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 sysfs_emit(buf, "%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; } MTD_DEVICE_ATTR_RW(bitflip_threshold); 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 sysfs_emit(buf, "%u\n", mtd->ecc_step_size); } MTD_DEVICE_ATTR_RO(ecc_step_size); static ssize_t mtd_corrected_bits_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 sysfs_emit(buf, "%u\n", ecc_stats->corrected); } MTD_DEVICE_ATTR_RO(corrected_bits); /* ecc stats corrected */ static ssize_t mtd_ecc_failures_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 sysfs_emit(buf, "%u\n", ecc_stats->failed); } MTD_DEVICE_ATTR_RO(ecc_failures); /* ecc stats errors */ static ssize_t mtd_bad_blocks_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 sysfs_emit(buf, "%u\n", ecc_stats->badblocks); } MTD_DEVICE_ATTR_RO(bad_blocks); static ssize_t mtd_bbt_blocks_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 sysfs_emit(buf, "%u\n", ecc_stats->bbtblocks); } MTD_DEVICE_ATTR_RO(bbt_blocks); static struct attribute *mtd_attrs[] = { &dev_attr_type.attr, &dev_attr_flags.attr, &dev_attr_size.attr, &dev_attr_erasesize.attr, &dev_attr_erasesize_minor.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 mtd_info *master = mtd_get_master(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 (master->dbg.partid) debugfs_create_file("partid", 0400, root, master, &mtd_partid_debug_fops); if (master->dbg.partname) debugfs_create_file("partname", 0400, root, master, &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 device_node *node = mtd_get_of_node(mtd); struct nvmem_config config = {}; /* * Do NOT register NVMEM device for any partition that is meant to be * handled by a U-Boot env driver. That would result in associating two * different NVMEM devices with the same OF node. * * An example of unwanted behaviour of above (forwardtrace): * of_get_mac_addr_nvmem() * of_nvmem_cell_get() * __nvmem_device_get() * * We can't have __nvmem_device_get() return "mtdX" NVMEM device instead * of U-Boot env NVMEM device. That would result in failing to find * NVMEM cell. * * This issue seems to affect U-Boot env case only and will go away with * switch to NVMEM layouts. */ if (of_device_is_compatible(node, "u-boot,env") || of_device_is_compatible(node, "u-boot,env-redundant-bool") || of_device_is_compatible(node, "u-boot,env-redundant-count") || of_device_is_compatible(node, "brcm,env")) return 0; config.id = -1; config.dev = &mtd->dev; config.name = dev_name(&mtd->dev); config.owner = THIS_MODULE; config.add_legacy_fixed_of_cells = of_device_is_compatible(node, "nvmem-cells"); 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.ignore_wp = 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; } static void mtd_check_of_node(struct mtd_info *mtd) { struct device_node *partitions, *parent_dn, *mtd_dn = NULL; const char *pname, *prefix = "partition-"; int plen, mtd_name_len, offset, prefix_len; /* Check if MTD already has a device node */ if (mtd_get_of_node(mtd)) return; if (!mtd_is_partition(mtd)) return; parent_dn = of_node_get(mtd_get_of_node(mtd->parent)); if (!parent_dn) return; if (mtd_is_partition(mtd->parent)) partitions = of_node_get(parent_dn); else partitions = of_get_child_by_name(parent_dn, "partitions"); if (!partitions) goto exit_parent; prefix_len = strlen(prefix); mtd_name_len = strlen(mtd->name); /* Search if a partition is defined with the same name */ for_each_child_of_node(partitions, mtd_dn) { /* Skip partition with no/wrong prefix */ if (!of_node_name_prefix(mtd_dn, prefix)) continue; /* Label have priority. Check that first */ if (!of_property_read_string(mtd_dn, "label", &pname)) { offset = 0; } else { pname = mtd_dn->name; offset = prefix_len; } plen = strlen(pname) - offset; if (plen == mtd_name_len && !strncmp(mtd->name, pname + offset, plen)) { mtd_set_of_node(mtd, mtd_dn); break; } } of_node_put(partitions); exit_parent: of_node_put(parent_dn); } /** * 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); mtd_check_of_node(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); if (of_find_property(mtd_get_of_node(mtd), "linux,rootfs", NULL) || (IS_ENABLED(CONFIG_MTD_ROOTFS_ROOT_DEV) && !strcmp(mtd->name, "rootfs") && ROOT_DEV == 0)) { if (IS_BUILTIN(CONFIG_MTD)) { pr_info("mtd: setting mtd%d (%s) as root device\n", mtd->index, mtd->name); ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, mtd->index); } else { pr_warn("mtd: can't set mtd%d (%s) as root device - mtd must be builtin\n", mtd->index, mtd->name); } } /* 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); mutex_init(&mtd->master.chrdev_lock); } static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user) { struct otp_info *info; ssize_t size = 0; unsigned int i; size_t retlen; int ret; info = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!info) return -ENOMEM; if (is_user) ret = mtd_get_user_prot_info(mtd, PAGE_SIZE, &retlen, info); else ret = mtd_get_fact_prot_info(mtd, PAGE_SIZE, &retlen, info); if (ret) goto err; for (i = 0; i < retlen / sizeof(*info); i++) size += info[i].length; kfree(info); return size; err: kfree(info); /* ENODATA means there is no OTP region. */ return ret == -ENODATA ? 0 : ret; } static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd, const char *compatible, int size, nvmem_reg_read_t reg_read) { struct nvmem_device *nvmem = NULL; struct nvmem_config config = {}; struct device_node *np; /* DT binding is optional */ np = of_get_compatible_child(mtd->dev.of_node, compatible); /* OTP nvmem will be registered on the physical device */ config.dev = mtd->dev.parent; config.name = compatible; config.id = NVMEM_DEVID_AUTO; config.owner = THIS_MODULE; config.add_legacy_fixed_of_cells = true; config.type = NVMEM_TYPE_OTP; config.root_only = true; config.ignore_wp = true; config.reg_read = reg_read; config.size = size; config.of_node = np; config.priv = mtd; nvmem = nvmem_register(&config); /* Just ignore if there is no NVMEM support in the kernel */ if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EOPNOTSUPP) nvmem = NULL; of_node_put(np); return nvmem; } static int mtd_nvmem_user_otp_reg_read(void *priv, unsigned int offset, void *val, size_t bytes) { struct mtd_info *mtd = priv; size_t retlen; int ret; ret = mtd_read_user_prot_reg(mtd, offset, bytes, &retlen, val); if (ret) return ret; return retlen == bytes ? 0 : -EIO; } static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset, void *val, size_t bytes) { struct mtd_info *mtd = priv; size_t retlen; int ret; ret = mtd_read_fact_prot_reg(mtd, offset, bytes, &retlen, val); if (ret) return ret; return retlen == bytes ? 0 : -EIO; } static int mtd_otp_nvmem_add(struct mtd_info *mtd) { struct device *dev = mtd->dev.parent; struct nvmem_device *nvmem; ssize_t size; int err; if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) { size = mtd_otp_size(mtd, true); if (size < 0) return size; if (size > 0) { nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size, mtd_nvmem_user_otp_reg_read); if (IS_ERR(nvmem)) { err = PTR_ERR(nvmem); goto err; } mtd->otp_user_nvmem = nvmem; } } if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) { size = mtd_otp_size(mtd, false); if (size < 0) { err = size; goto err; } if (size > 0) { nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size, mtd_nvmem_fact_otp_reg_read); if (IS_ERR(nvmem)) { err = PTR_ERR(nvmem); goto err; } mtd->otp_factory_nvmem = nvmem; } } return 0; err: if (mtd->otp_user_nvmem) nvmem_unregister(mtd->otp_user_nvmem); return dev_err_probe(dev, err, "Failed to register OTP NVMEM device\n"); } /** * 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); ret = mtd_otp_nvmem_add(mtd); if (ret) goto out; if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) { ret = add_mtd_device(mtd); if (ret) goto out; } /* 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); } register_mtd_blktrans_devs(); out: if (ret) { nvmem_unregister(mtd->otp_user_nvmem); nvmem_unregister(mtd->otp_factory_nvmem); } 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); if (master->otp_user_nvmem) nvmem_unregister(master->otp_user_nvmem); if (master->otp_factory_nvmem) nvmem_unregister(master->otp_factory_nvmem); 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); /** * of_get_mtd_device_by_node - obtain an MTD device associated with a given node * * @np: device tree node */ struct mtd_info *of_get_mtd_device_by_node(struct device_node *np) { struct mtd_info *mtd = NULL; struct mtd_info *tmp; int err; mutex_lock(&mtd_table_mutex); err = -EPROBE_DEFER; mtd_for_each_device(tmp) { if (mtd_get_of_node(tmp) == np) { mtd = tmp; err = __get_mtd_device(mtd); break; } } mutex_unlock(&mtd_table_mutex); return err ? ERR_PTR(err) : mtd; } EXPORT_SYMBOL_GPL(of_get_mtd_device_by_node); /** * 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 (ops->stats) memset(ops->stats, 0, sizeof(*ops->stats)); 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 */ if (ops->stats) ops->stats->max_bitflips = ret_code; 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 * @section: 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, const 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); int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len) { struct mtd_info *master = mtd_get_master(mtd); if (!master->_erase_user_prot_reg) return -EOPNOTSUPP; if (!len) return 0; return master->_erase_user_prot_reg(master, from, len); } EXPORT_SYMBOL_GPL(mtd_erase_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(const 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 "); MODULE_DESCRIPTION("Core MTD registration and access routines");