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0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Copyright (c) International Business Machines Corp., 2006
0004  * Copyright (c) Nokia Corporation, 2007
0005  *
0006  * Author: Artem Bityutskiy (Битюцкий Артём),
0007  *         Frank Haverkamp
0008  */
0009 
0010 /*
0011  * This file includes UBI initialization and building of UBI devices.
0012  *
0013  * When UBI is initialized, it attaches all the MTD devices specified as the
0014  * module load parameters or the kernel boot parameters. If MTD devices were
0015  * specified, UBI does not attach any MTD device, but it is possible to do
0016  * later using the "UBI control device".
0017  */
0018 
0019 #include <linux/err.h>
0020 #include <linux/module.h>
0021 #include <linux/moduleparam.h>
0022 #include <linux/stringify.h>
0023 #include <linux/namei.h>
0024 #include <linux/stat.h>
0025 #include <linux/miscdevice.h>
0026 #include <linux/mtd/partitions.h>
0027 #include <linux/log2.h>
0028 #include <linux/kthread.h>
0029 #include <linux/kernel.h>
0030 #include <linux/slab.h>
0031 #include <linux/major.h>
0032 #include "ubi.h"
0033 
0034 /* Maximum length of the 'mtd=' parameter */
0035 #define MTD_PARAM_LEN_MAX 64
0036 
0037 /* Maximum number of comma-separated items in the 'mtd=' parameter */
0038 #define MTD_PARAM_MAX_COUNT 4
0039 
0040 /* Maximum value for the number of bad PEBs per 1024 PEBs */
0041 #define MAX_MTD_UBI_BEB_LIMIT 768
0042 
0043 #ifdef CONFIG_MTD_UBI_MODULE
0044 #define ubi_is_module() 1
0045 #else
0046 #define ubi_is_module() 0
0047 #endif
0048 
0049 /**
0050  * struct mtd_dev_param - MTD device parameter description data structure.
0051  * @name: MTD character device node path, MTD device name, or MTD device number
0052  *        string
0053  * @ubi_num: UBI number
0054  * @vid_hdr_offs: VID header offset
0055  * @max_beb_per1024: maximum expected number of bad PEBs per 1024 PEBs
0056  */
0057 struct mtd_dev_param {
0058     char name[MTD_PARAM_LEN_MAX];
0059     int ubi_num;
0060     int vid_hdr_offs;
0061     int max_beb_per1024;
0062 };
0063 
0064 /* Numbers of elements set in the @mtd_dev_param array */
0065 static int mtd_devs;
0066 
0067 /* MTD devices specification parameters */
0068 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
0069 #ifdef CONFIG_MTD_UBI_FASTMAP
0070 /* UBI module parameter to enable fastmap automatically on non-fastmap images */
0071 static bool fm_autoconvert;
0072 static bool fm_debug;
0073 #endif
0074 
0075 /* Slab cache for wear-leveling entries */
0076 struct kmem_cache *ubi_wl_entry_slab;
0077 
0078 /* UBI control character device */
0079 static struct miscdevice ubi_ctrl_cdev = {
0080     .minor = MISC_DYNAMIC_MINOR,
0081     .name = "ubi_ctrl",
0082     .fops = &ubi_ctrl_cdev_operations,
0083 };
0084 
0085 /* All UBI devices in system */
0086 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
0087 
0088 /* Serializes UBI devices creations and removals */
0089 DEFINE_MUTEX(ubi_devices_mutex);
0090 
0091 /* Protects @ubi_devices and @ubi->ref_count */
0092 static DEFINE_SPINLOCK(ubi_devices_lock);
0093 
0094 /* "Show" method for files in '/<sysfs>/class/ubi/' */
0095 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
0096 static ssize_t version_show(struct class *class, struct class_attribute *attr,
0097                 char *buf)
0098 {
0099     return sprintf(buf, "%d\n", UBI_VERSION);
0100 }
0101 static CLASS_ATTR_RO(version);
0102 
0103 static struct attribute *ubi_class_attrs[] = {
0104     &class_attr_version.attr,
0105     NULL,
0106 };
0107 ATTRIBUTE_GROUPS(ubi_class);
0108 
0109 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
0110 struct class ubi_class = {
0111     .name       = UBI_NAME_STR,
0112     .owner      = THIS_MODULE,
0113     .class_groups   = ubi_class_groups,
0114 };
0115 
0116 static ssize_t dev_attribute_show(struct device *dev,
0117                   struct device_attribute *attr, char *buf);
0118 
0119 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
0120 static struct device_attribute dev_eraseblock_size =
0121     __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
0122 static struct device_attribute dev_avail_eraseblocks =
0123     __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
0124 static struct device_attribute dev_total_eraseblocks =
0125     __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
0126 static struct device_attribute dev_volumes_count =
0127     __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
0128 static struct device_attribute dev_max_ec =
0129     __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
0130 static struct device_attribute dev_reserved_for_bad =
0131     __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
0132 static struct device_attribute dev_bad_peb_count =
0133     __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
0134 static struct device_attribute dev_max_vol_count =
0135     __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
0136 static struct device_attribute dev_min_io_size =
0137     __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
0138 static struct device_attribute dev_bgt_enabled =
0139     __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
0140 static struct device_attribute dev_mtd_num =
0141     __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
0142 static struct device_attribute dev_ro_mode =
0143     __ATTR(ro_mode, S_IRUGO, dev_attribute_show, NULL);
0144 
0145 /**
0146  * ubi_volume_notify - send a volume change notification.
0147  * @ubi: UBI device description object
0148  * @vol: volume description object of the changed volume
0149  * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
0150  *
0151  * This is a helper function which notifies all subscribers about a volume
0152  * change event (creation, removal, re-sizing, re-naming, updating). Returns
0153  * zero in case of success and a negative error code in case of failure.
0154  */
0155 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
0156 {
0157     int ret;
0158     struct ubi_notification nt;
0159 
0160     ubi_do_get_device_info(ubi, &nt.di);
0161     ubi_do_get_volume_info(ubi, vol, &nt.vi);
0162 
0163     switch (ntype) {
0164     case UBI_VOLUME_ADDED:
0165     case UBI_VOLUME_REMOVED:
0166     case UBI_VOLUME_RESIZED:
0167     case UBI_VOLUME_RENAMED:
0168         ret = ubi_update_fastmap(ubi);
0169         if (ret)
0170             ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
0171     }
0172 
0173     return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
0174 }
0175 
0176 /**
0177  * ubi_notify_all - send a notification to all volumes.
0178  * @ubi: UBI device description object
0179  * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
0180  * @nb: the notifier to call
0181  *
0182  * This function walks all volumes of UBI device @ubi and sends the @ntype
0183  * notification for each volume. If @nb is %NULL, then all registered notifiers
0184  * are called, otherwise only the @nb notifier is called. Returns the number of
0185  * sent notifications.
0186  */
0187 int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
0188 {
0189     struct ubi_notification nt;
0190     int i, count = 0;
0191 
0192     ubi_do_get_device_info(ubi, &nt.di);
0193 
0194     mutex_lock(&ubi->device_mutex);
0195     for (i = 0; i < ubi->vtbl_slots; i++) {
0196         /*
0197          * Since the @ubi->device is locked, and we are not going to
0198          * change @ubi->volumes, we do not have to lock
0199          * @ubi->volumes_lock.
0200          */
0201         if (!ubi->volumes[i])
0202             continue;
0203 
0204         ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
0205         if (nb)
0206             nb->notifier_call(nb, ntype, &nt);
0207         else
0208             blocking_notifier_call_chain(&ubi_notifiers, ntype,
0209                              &nt);
0210         count += 1;
0211     }
0212     mutex_unlock(&ubi->device_mutex);
0213 
0214     return count;
0215 }
0216 
0217 /**
0218  * ubi_enumerate_volumes - send "add" notification for all existing volumes.
0219  * @nb: the notifier to call
0220  *
0221  * This function walks all UBI devices and volumes and sends the
0222  * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
0223  * registered notifiers are called, otherwise only the @nb notifier is called.
0224  * Returns the number of sent notifications.
0225  */
0226 int ubi_enumerate_volumes(struct notifier_block *nb)
0227 {
0228     int i, count = 0;
0229 
0230     /*
0231      * Since the @ubi_devices_mutex is locked, and we are not going to
0232      * change @ubi_devices, we do not have to lock @ubi_devices_lock.
0233      */
0234     for (i = 0; i < UBI_MAX_DEVICES; i++) {
0235         struct ubi_device *ubi = ubi_devices[i];
0236 
0237         if (!ubi)
0238             continue;
0239         count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
0240     }
0241 
0242     return count;
0243 }
0244 
0245 /**
0246  * ubi_get_device - get UBI device.
0247  * @ubi_num: UBI device number
0248  *
0249  * This function returns UBI device description object for UBI device number
0250  * @ubi_num, or %NULL if the device does not exist. This function increases the
0251  * device reference count to prevent removal of the device. In other words, the
0252  * device cannot be removed if its reference count is not zero.
0253  */
0254 struct ubi_device *ubi_get_device(int ubi_num)
0255 {
0256     struct ubi_device *ubi;
0257 
0258     spin_lock(&ubi_devices_lock);
0259     ubi = ubi_devices[ubi_num];
0260     if (ubi) {
0261         ubi_assert(ubi->ref_count >= 0);
0262         ubi->ref_count += 1;
0263         get_device(&ubi->dev);
0264     }
0265     spin_unlock(&ubi_devices_lock);
0266 
0267     return ubi;
0268 }
0269 
0270 /**
0271  * ubi_put_device - drop an UBI device reference.
0272  * @ubi: UBI device description object
0273  */
0274 void ubi_put_device(struct ubi_device *ubi)
0275 {
0276     spin_lock(&ubi_devices_lock);
0277     ubi->ref_count -= 1;
0278     put_device(&ubi->dev);
0279     spin_unlock(&ubi_devices_lock);
0280 }
0281 
0282 /**
0283  * ubi_get_by_major - get UBI device by character device major number.
0284  * @major: major number
0285  *
0286  * This function is similar to 'ubi_get_device()', but it searches the device
0287  * by its major number.
0288  */
0289 struct ubi_device *ubi_get_by_major(int major)
0290 {
0291     int i;
0292     struct ubi_device *ubi;
0293 
0294     spin_lock(&ubi_devices_lock);
0295     for (i = 0; i < UBI_MAX_DEVICES; i++) {
0296         ubi = ubi_devices[i];
0297         if (ubi && MAJOR(ubi->cdev.dev) == major) {
0298             ubi_assert(ubi->ref_count >= 0);
0299             ubi->ref_count += 1;
0300             get_device(&ubi->dev);
0301             spin_unlock(&ubi_devices_lock);
0302             return ubi;
0303         }
0304     }
0305     spin_unlock(&ubi_devices_lock);
0306 
0307     return NULL;
0308 }
0309 
0310 /**
0311  * ubi_major2num - get UBI device number by character device major number.
0312  * @major: major number
0313  *
0314  * This function searches UBI device number object by its major number. If UBI
0315  * device was not found, this function returns -ENODEV, otherwise the UBI device
0316  * number is returned.
0317  */
0318 int ubi_major2num(int major)
0319 {
0320     int i, ubi_num = -ENODEV;
0321 
0322     spin_lock(&ubi_devices_lock);
0323     for (i = 0; i < UBI_MAX_DEVICES; i++) {
0324         struct ubi_device *ubi = ubi_devices[i];
0325 
0326         if (ubi && MAJOR(ubi->cdev.dev) == major) {
0327             ubi_num = ubi->ubi_num;
0328             break;
0329         }
0330     }
0331     spin_unlock(&ubi_devices_lock);
0332 
0333     return ubi_num;
0334 }
0335 
0336 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
0337 static ssize_t dev_attribute_show(struct device *dev,
0338                   struct device_attribute *attr, char *buf)
0339 {
0340     ssize_t ret;
0341     struct ubi_device *ubi;
0342 
0343     /*
0344      * The below code looks weird, but it actually makes sense. We get the
0345      * UBI device reference from the contained 'struct ubi_device'. But it
0346      * is unclear if the device was removed or not yet. Indeed, if the
0347      * device was removed before we increased its reference count,
0348      * 'ubi_get_device()' will return -ENODEV and we fail.
0349      *
0350      * Remember, 'struct ubi_device' is freed in the release function, so
0351      * we still can use 'ubi->ubi_num'.
0352      */
0353     ubi = container_of(dev, struct ubi_device, dev);
0354 
0355     if (attr == &dev_eraseblock_size)
0356         ret = sprintf(buf, "%d\n", ubi->leb_size);
0357     else if (attr == &dev_avail_eraseblocks)
0358         ret = sprintf(buf, "%d\n", ubi->avail_pebs);
0359     else if (attr == &dev_total_eraseblocks)
0360         ret = sprintf(buf, "%d\n", ubi->good_peb_count);
0361     else if (attr == &dev_volumes_count)
0362         ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
0363     else if (attr == &dev_max_ec)
0364         ret = sprintf(buf, "%d\n", ubi->max_ec);
0365     else if (attr == &dev_reserved_for_bad)
0366         ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
0367     else if (attr == &dev_bad_peb_count)
0368         ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
0369     else if (attr == &dev_max_vol_count)
0370         ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
0371     else if (attr == &dev_min_io_size)
0372         ret = sprintf(buf, "%d\n", ubi->min_io_size);
0373     else if (attr == &dev_bgt_enabled)
0374         ret = sprintf(buf, "%d\n", ubi->thread_enabled);
0375     else if (attr == &dev_mtd_num)
0376         ret = sprintf(buf, "%d\n", ubi->mtd->index);
0377     else if (attr == &dev_ro_mode)
0378         ret = sprintf(buf, "%d\n", ubi->ro_mode);
0379     else
0380         ret = -EINVAL;
0381 
0382     return ret;
0383 }
0384 
0385 static struct attribute *ubi_dev_attrs[] = {
0386     &dev_eraseblock_size.attr,
0387     &dev_avail_eraseblocks.attr,
0388     &dev_total_eraseblocks.attr,
0389     &dev_volumes_count.attr,
0390     &dev_max_ec.attr,
0391     &dev_reserved_for_bad.attr,
0392     &dev_bad_peb_count.attr,
0393     &dev_max_vol_count.attr,
0394     &dev_min_io_size.attr,
0395     &dev_bgt_enabled.attr,
0396     &dev_mtd_num.attr,
0397     &dev_ro_mode.attr,
0398     NULL
0399 };
0400 ATTRIBUTE_GROUPS(ubi_dev);
0401 
0402 static void dev_release(struct device *dev)
0403 {
0404     struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
0405 
0406     kfree(ubi);
0407 }
0408 
0409 /**
0410  * kill_volumes - destroy all user volumes.
0411  * @ubi: UBI device description object
0412  */
0413 static void kill_volumes(struct ubi_device *ubi)
0414 {
0415     int i;
0416 
0417     for (i = 0; i < ubi->vtbl_slots; i++)
0418         if (ubi->volumes[i])
0419             ubi_free_volume(ubi, ubi->volumes[i]);
0420 }
0421 
0422 /**
0423  * uif_init - initialize user interfaces for an UBI device.
0424  * @ubi: UBI device description object
0425  *
0426  * This function initializes various user interfaces for an UBI device. If the
0427  * initialization fails at an early stage, this function frees all the
0428  * resources it allocated, returns an error.
0429  *
0430  * This function returns zero in case of success and a negative error code in
0431  * case of failure.
0432  */
0433 static int uif_init(struct ubi_device *ubi)
0434 {
0435     int i, err;
0436     dev_t dev;
0437 
0438     sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
0439 
0440     /*
0441      * Major numbers for the UBI character devices are allocated
0442      * dynamically. Major numbers of volume character devices are
0443      * equivalent to ones of the corresponding UBI character device. Minor
0444      * numbers of UBI character devices are 0, while minor numbers of
0445      * volume character devices start from 1. Thus, we allocate one major
0446      * number and ubi->vtbl_slots + 1 minor numbers.
0447      */
0448     err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
0449     if (err) {
0450         ubi_err(ubi, "cannot register UBI character devices");
0451         return err;
0452     }
0453 
0454     ubi->dev.devt = dev;
0455 
0456     ubi_assert(MINOR(dev) == 0);
0457     cdev_init(&ubi->cdev, &ubi_cdev_operations);
0458     dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
0459     ubi->cdev.owner = THIS_MODULE;
0460 
0461     dev_set_name(&ubi->dev, UBI_NAME_STR "%d", ubi->ubi_num);
0462     err = cdev_device_add(&ubi->cdev, &ubi->dev);
0463     if (err)
0464         goto out_unreg;
0465 
0466     for (i = 0; i < ubi->vtbl_slots; i++)
0467         if (ubi->volumes[i]) {
0468             err = ubi_add_volume(ubi, ubi->volumes[i]);
0469             if (err) {
0470                 ubi_err(ubi, "cannot add volume %d", i);
0471                 goto out_volumes;
0472             }
0473         }
0474 
0475     return 0;
0476 
0477 out_volumes:
0478     kill_volumes(ubi);
0479     cdev_device_del(&ubi->cdev, &ubi->dev);
0480 out_unreg:
0481     unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
0482     ubi_err(ubi, "cannot initialize UBI %s, error %d",
0483         ubi->ubi_name, err);
0484     return err;
0485 }
0486 
0487 /**
0488  * uif_close - close user interfaces for an UBI device.
0489  * @ubi: UBI device description object
0490  *
0491  * Note, since this function un-registers UBI volume device objects (@vol->dev),
0492  * the memory allocated voe the volumes is freed as well (in the release
0493  * function).
0494  */
0495 static void uif_close(struct ubi_device *ubi)
0496 {
0497     kill_volumes(ubi);
0498     cdev_device_del(&ubi->cdev, &ubi->dev);
0499     unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
0500 }
0501 
0502 /**
0503  * ubi_free_volumes_from - free volumes from specific index.
0504  * @ubi: UBI device description object
0505  * @from: the start index used for volume free.
0506  */
0507 static void ubi_free_volumes_from(struct ubi_device *ubi, int from)
0508 {
0509     int i;
0510 
0511     for (i = from; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
0512         if (!ubi->volumes[i])
0513             continue;
0514         ubi_eba_replace_table(ubi->volumes[i], NULL);
0515         ubi_fastmap_destroy_checkmap(ubi->volumes[i]);
0516         kfree(ubi->volumes[i]);
0517         ubi->volumes[i] = NULL;
0518     }
0519 }
0520 
0521 /**
0522  * ubi_free_all_volumes - free all volumes.
0523  * @ubi: UBI device description object
0524  */
0525 void ubi_free_all_volumes(struct ubi_device *ubi)
0526 {
0527     ubi_free_volumes_from(ubi, 0);
0528 }
0529 
0530 /**
0531  * ubi_free_internal_volumes - free internal volumes.
0532  * @ubi: UBI device description object
0533  */
0534 void ubi_free_internal_volumes(struct ubi_device *ubi)
0535 {
0536     ubi_free_volumes_from(ubi, ubi->vtbl_slots);
0537 }
0538 
0539 static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
0540 {
0541     int limit, device_pebs;
0542     uint64_t device_size;
0543 
0544     if (!max_beb_per1024) {
0545         /*
0546          * Since max_beb_per1024 has not been set by the user in either
0547          * the cmdline or Kconfig, use mtd_max_bad_blocks to set the
0548          * limit if it is supported by the device.
0549          */
0550         limit = mtd_max_bad_blocks(ubi->mtd, 0, ubi->mtd->size);
0551         if (limit < 0)
0552             return 0;
0553         return limit;
0554     }
0555 
0556     /*
0557      * Here we are using size of the entire flash chip and
0558      * not just the MTD partition size because the maximum
0559      * number of bad eraseblocks is a percentage of the
0560      * whole device and bad eraseblocks are not fairly
0561      * distributed over the flash chip. So the worst case
0562      * is that all the bad eraseblocks of the chip are in
0563      * the MTD partition we are attaching (ubi->mtd).
0564      */
0565     device_size = mtd_get_device_size(ubi->mtd);
0566     device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
0567     limit = mult_frac(device_pebs, max_beb_per1024, 1024);
0568 
0569     /* Round it up */
0570     if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
0571         limit += 1;
0572 
0573     return limit;
0574 }
0575 
0576 /**
0577  * io_init - initialize I/O sub-system for a given UBI device.
0578  * @ubi: UBI device description object
0579  * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
0580  *
0581  * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
0582  * assumed:
0583  *   o EC header is always at offset zero - this cannot be changed;
0584  *   o VID header starts just after the EC header at the closest address
0585  *     aligned to @io->hdrs_min_io_size;
0586  *   o data starts just after the VID header at the closest address aligned to
0587  *     @io->min_io_size
0588  *
0589  * This function returns zero in case of success and a negative error code in
0590  * case of failure.
0591  */
0592 static int io_init(struct ubi_device *ubi, int max_beb_per1024)
0593 {
0594     dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
0595     dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
0596 
0597     if (ubi->mtd->numeraseregions != 0) {
0598         /*
0599          * Some flashes have several erase regions. Different regions
0600          * may have different eraseblock size and other
0601          * characteristics. It looks like mostly multi-region flashes
0602          * have one "main" region and one or more small regions to
0603          * store boot loader code or boot parameters or whatever. I
0604          * guess we should just pick the largest region. But this is
0605          * not implemented.
0606          */
0607         ubi_err(ubi, "multiple regions, not implemented");
0608         return -EINVAL;
0609     }
0610 
0611     if (ubi->vid_hdr_offset < 0)
0612         return -EINVAL;
0613 
0614     /*
0615      * Note, in this implementation we support MTD devices with 0x7FFFFFFF
0616      * physical eraseblocks maximum.
0617      */
0618 
0619     ubi->peb_size   = ubi->mtd->erasesize;
0620     ubi->peb_count  = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
0621     ubi->flash_size = ubi->mtd->size;
0622 
0623     if (mtd_can_have_bb(ubi->mtd)) {
0624         ubi->bad_allowed = 1;
0625         ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
0626     }
0627 
0628     if (ubi->mtd->type == MTD_NORFLASH)
0629         ubi->nor_flash = 1;
0630 
0631     ubi->min_io_size = ubi->mtd->writesize;
0632     ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
0633 
0634     /*
0635      * Make sure minimal I/O unit is power of 2. Note, there is no
0636      * fundamental reason for this assumption. It is just an optimization
0637      * which allows us to avoid costly division operations.
0638      */
0639     if (!is_power_of_2(ubi->min_io_size)) {
0640         ubi_err(ubi, "min. I/O unit (%d) is not power of 2",
0641             ubi->min_io_size);
0642         return -EINVAL;
0643     }
0644 
0645     ubi_assert(ubi->hdrs_min_io_size > 0);
0646     ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
0647     ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
0648 
0649     ubi->max_write_size = ubi->mtd->writebufsize;
0650     /*
0651      * Maximum write size has to be greater or equivalent to min. I/O
0652      * size, and be multiple of min. I/O size.
0653      */
0654     if (ubi->max_write_size < ubi->min_io_size ||
0655         ubi->max_write_size % ubi->min_io_size ||
0656         !is_power_of_2(ubi->max_write_size)) {
0657         ubi_err(ubi, "bad write buffer size %d for %d min. I/O unit",
0658             ubi->max_write_size, ubi->min_io_size);
0659         return -EINVAL;
0660     }
0661 
0662     /* Calculate default aligned sizes of EC and VID headers */
0663     ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
0664     ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
0665 
0666     dbg_gen("min_io_size      %d", ubi->min_io_size);
0667     dbg_gen("max_write_size   %d", ubi->max_write_size);
0668     dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
0669     dbg_gen("ec_hdr_alsize    %d", ubi->ec_hdr_alsize);
0670     dbg_gen("vid_hdr_alsize   %d", ubi->vid_hdr_alsize);
0671 
0672     if (ubi->vid_hdr_offset == 0)
0673         /* Default offset */
0674         ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
0675                       ubi->ec_hdr_alsize;
0676     else {
0677         ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
0678                         ~(ubi->hdrs_min_io_size - 1);
0679         ubi->vid_hdr_shift = ubi->vid_hdr_offset -
0680                         ubi->vid_hdr_aloffset;
0681     }
0682 
0683     /* Similar for the data offset */
0684     ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
0685     ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
0686 
0687     dbg_gen("vid_hdr_offset   %d", ubi->vid_hdr_offset);
0688     dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
0689     dbg_gen("vid_hdr_shift    %d", ubi->vid_hdr_shift);
0690     dbg_gen("leb_start        %d", ubi->leb_start);
0691 
0692     /* The shift must be aligned to 32-bit boundary */
0693     if (ubi->vid_hdr_shift % 4) {
0694         ubi_err(ubi, "unaligned VID header shift %d",
0695             ubi->vid_hdr_shift);
0696         return -EINVAL;
0697     }
0698 
0699     /* Check sanity */
0700     if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
0701         ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
0702         ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
0703         ubi->leb_start & (ubi->min_io_size - 1)) {
0704         ubi_err(ubi, "bad VID header (%d) or data offsets (%d)",
0705             ubi->vid_hdr_offset, ubi->leb_start);
0706         return -EINVAL;
0707     }
0708 
0709     /*
0710      * Set maximum amount of physical erroneous eraseblocks to be 10%.
0711      * Erroneous PEB are those which have read errors.
0712      */
0713     ubi->max_erroneous = ubi->peb_count / 10;
0714     if (ubi->max_erroneous < 16)
0715         ubi->max_erroneous = 16;
0716     dbg_gen("max_erroneous    %d", ubi->max_erroneous);
0717 
0718     /*
0719      * It may happen that EC and VID headers are situated in one minimal
0720      * I/O unit. In this case we can only accept this UBI image in
0721      * read-only mode.
0722      */
0723     if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
0724         ubi_warn(ubi, "EC and VID headers are in the same minimal I/O unit, switch to read-only mode");
0725         ubi->ro_mode = 1;
0726     }
0727 
0728     ubi->leb_size = ubi->peb_size - ubi->leb_start;
0729 
0730     if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
0731         ubi_msg(ubi, "MTD device %d is write-protected, attach in read-only mode",
0732             ubi->mtd->index);
0733         ubi->ro_mode = 1;
0734     }
0735 
0736     /*
0737      * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
0738      * unfortunately, MTD does not provide this information. We should loop
0739      * over all physical eraseblocks and invoke mtd->block_is_bad() for
0740      * each physical eraseblock. So, we leave @ubi->bad_peb_count
0741      * uninitialized so far.
0742      */
0743 
0744     return 0;
0745 }
0746 
0747 /**
0748  * autoresize - re-size the volume which has the "auto-resize" flag set.
0749  * @ubi: UBI device description object
0750  * @vol_id: ID of the volume to re-size
0751  *
0752  * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
0753  * the volume table to the largest possible size. See comments in ubi-header.h
0754  * for more description of the flag. Returns zero in case of success and a
0755  * negative error code in case of failure.
0756  */
0757 static int autoresize(struct ubi_device *ubi, int vol_id)
0758 {
0759     struct ubi_volume_desc desc;
0760     struct ubi_volume *vol = ubi->volumes[vol_id];
0761     int err, old_reserved_pebs = vol->reserved_pebs;
0762 
0763     if (ubi->ro_mode) {
0764         ubi_warn(ubi, "skip auto-resize because of R/O mode");
0765         return 0;
0766     }
0767 
0768     /*
0769      * Clear the auto-resize flag in the volume in-memory copy of the
0770      * volume table, and 'ubi_resize_volume()' will propagate this change
0771      * to the flash.
0772      */
0773     ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
0774 
0775     if (ubi->avail_pebs == 0) {
0776         struct ubi_vtbl_record vtbl_rec;
0777 
0778         /*
0779          * No available PEBs to re-size the volume, clear the flag on
0780          * flash and exit.
0781          */
0782         vtbl_rec = ubi->vtbl[vol_id];
0783         err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
0784         if (err)
0785             ubi_err(ubi, "cannot clean auto-resize flag for volume %d",
0786                 vol_id);
0787     } else {
0788         desc.vol = vol;
0789         err = ubi_resize_volume(&desc,
0790                     old_reserved_pebs + ubi->avail_pebs);
0791         if (err)
0792             ubi_err(ubi, "cannot auto-resize volume %d",
0793                 vol_id);
0794     }
0795 
0796     if (err)
0797         return err;
0798 
0799     ubi_msg(ubi, "volume %d (\"%s\") re-sized from %d to %d LEBs",
0800         vol_id, vol->name, old_reserved_pebs, vol->reserved_pebs);
0801     return 0;
0802 }
0803 
0804 /**
0805  * ubi_attach_mtd_dev - attach an MTD device.
0806  * @mtd: MTD device description object
0807  * @ubi_num: number to assign to the new UBI device
0808  * @vid_hdr_offset: VID header offset
0809  * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
0810  *
0811  * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
0812  * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
0813  * which case this function finds a vacant device number and assigns it
0814  * automatically. Returns the new UBI device number in case of success and a
0815  * negative error code in case of failure.
0816  *
0817  * Note, the invocations of this function has to be serialized by the
0818  * @ubi_devices_mutex.
0819  */
0820 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
0821                int vid_hdr_offset, int max_beb_per1024)
0822 {
0823     struct ubi_device *ubi;
0824     int i, err;
0825 
0826     if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
0827         return -EINVAL;
0828 
0829     if (!max_beb_per1024)
0830         max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
0831 
0832     /*
0833      * Check if we already have the same MTD device attached.
0834      *
0835      * Note, this function assumes that UBI devices creations and deletions
0836      * are serialized, so it does not take the &ubi_devices_lock.
0837      */
0838     for (i = 0; i < UBI_MAX_DEVICES; i++) {
0839         ubi = ubi_devices[i];
0840         if (ubi && mtd->index == ubi->mtd->index) {
0841             pr_err("ubi: mtd%d is already attached to ubi%d\n",
0842                 mtd->index, i);
0843             return -EEXIST;
0844         }
0845     }
0846 
0847     /*
0848      * Make sure this MTD device is not emulated on top of an UBI volume
0849      * already. Well, generally this recursion works fine, but there are
0850      * different problems like the UBI module takes a reference to itself
0851      * by attaching (and thus, opening) the emulated MTD device. This
0852      * results in inability to unload the module. And in general it makes
0853      * no sense to attach emulated MTD devices, so we prohibit this.
0854      */
0855     if (mtd->type == MTD_UBIVOLUME) {
0856         pr_err("ubi: refuse attaching mtd%d - it is already emulated on top of UBI\n",
0857             mtd->index);
0858         return -EINVAL;
0859     }
0860 
0861     /*
0862      * Both UBI and UBIFS have been designed for SLC NAND and NOR flashes.
0863      * MLC NAND is different and needs special care, otherwise UBI or UBIFS
0864      * will die soon and you will lose all your data.
0865      * Relax this rule if the partition we're attaching to operates in SLC
0866      * mode.
0867      */
0868     if (mtd->type == MTD_MLCNANDFLASH &&
0869         !(mtd->flags & MTD_SLC_ON_MLC_EMULATION)) {
0870         pr_err("ubi: refuse attaching mtd%d - MLC NAND is not supported\n",
0871             mtd->index);
0872         return -EINVAL;
0873     }
0874 
0875     if (ubi_num == UBI_DEV_NUM_AUTO) {
0876         /* Search for an empty slot in the @ubi_devices array */
0877         for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
0878             if (!ubi_devices[ubi_num])
0879                 break;
0880         if (ubi_num == UBI_MAX_DEVICES) {
0881             pr_err("ubi: only %d UBI devices may be created\n",
0882                 UBI_MAX_DEVICES);
0883             return -ENFILE;
0884         }
0885     } else {
0886         if (ubi_num >= UBI_MAX_DEVICES)
0887             return -EINVAL;
0888 
0889         /* Make sure ubi_num is not busy */
0890         if (ubi_devices[ubi_num]) {
0891             pr_err("ubi: ubi%i already exists\n", ubi_num);
0892             return -EEXIST;
0893         }
0894     }
0895 
0896     ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
0897     if (!ubi)
0898         return -ENOMEM;
0899 
0900     device_initialize(&ubi->dev);
0901     ubi->dev.release = dev_release;
0902     ubi->dev.class = &ubi_class;
0903     ubi->dev.groups = ubi_dev_groups;
0904 
0905     ubi->mtd = mtd;
0906     ubi->ubi_num = ubi_num;
0907     ubi->vid_hdr_offset = vid_hdr_offset;
0908     ubi->autoresize_vol_id = -1;
0909 
0910 #ifdef CONFIG_MTD_UBI_FASTMAP
0911     ubi->fm_pool.used = ubi->fm_pool.size = 0;
0912     ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
0913 
0914     /*
0915      * fm_pool.max_size is 5% of the total number of PEBs but it's also
0916      * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
0917      */
0918     ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
0919         ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
0920     ubi->fm_pool.max_size = max(ubi->fm_pool.max_size,
0921         UBI_FM_MIN_POOL_SIZE);
0922 
0923     ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;
0924     ubi->fm_disabled = !fm_autoconvert;
0925     if (fm_debug)
0926         ubi_enable_dbg_chk_fastmap(ubi);
0927 
0928     if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
0929         <= UBI_FM_MAX_START) {
0930         ubi_err(ubi, "More than %i PEBs are needed for fastmap, sorry.",
0931             UBI_FM_MAX_START);
0932         ubi->fm_disabled = 1;
0933     }
0934 
0935     ubi_msg(ubi, "default fastmap pool size: %d", ubi->fm_pool.max_size);
0936     ubi_msg(ubi, "default fastmap WL pool size: %d",
0937         ubi->fm_wl_pool.max_size);
0938 #else
0939     ubi->fm_disabled = 1;
0940 #endif
0941     mutex_init(&ubi->buf_mutex);
0942     mutex_init(&ubi->ckvol_mutex);
0943     mutex_init(&ubi->device_mutex);
0944     spin_lock_init(&ubi->volumes_lock);
0945     init_rwsem(&ubi->fm_protect);
0946     init_rwsem(&ubi->fm_eba_sem);
0947 
0948     ubi_msg(ubi, "attaching mtd%d", mtd->index);
0949 
0950     err = io_init(ubi, max_beb_per1024);
0951     if (err)
0952         goto out_free;
0953 
0954     err = -ENOMEM;
0955     ubi->peb_buf = vmalloc(ubi->peb_size);
0956     if (!ubi->peb_buf)
0957         goto out_free;
0958 
0959 #ifdef CONFIG_MTD_UBI_FASTMAP
0960     ubi->fm_size = ubi_calc_fm_size(ubi);
0961     ubi->fm_buf = vzalloc(ubi->fm_size);
0962     if (!ubi->fm_buf)
0963         goto out_free;
0964 #endif
0965     err = ubi_attach(ubi, 0);
0966     if (err) {
0967         ubi_err(ubi, "failed to attach mtd%d, error %d",
0968             mtd->index, err);
0969         goto out_free;
0970     }
0971 
0972     if (ubi->autoresize_vol_id != -1) {
0973         err = autoresize(ubi, ubi->autoresize_vol_id);
0974         if (err)
0975             goto out_detach;
0976     }
0977 
0978     err = uif_init(ubi);
0979     if (err)
0980         goto out_detach;
0981 
0982     err = ubi_debugfs_init_dev(ubi);
0983     if (err)
0984         goto out_uif;
0985 
0986     ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
0987     if (IS_ERR(ubi->bgt_thread)) {
0988         err = PTR_ERR(ubi->bgt_thread);
0989         ubi_err(ubi, "cannot spawn \"%s\", error %d",
0990             ubi->bgt_name, err);
0991         goto out_debugfs;
0992     }
0993 
0994     ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
0995         mtd->index, mtd->name, ubi->flash_size >> 20);
0996     ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
0997         ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
0998     ubi_msg(ubi, "min./max. I/O unit sizes: %d/%d, sub-page size %d",
0999         ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
1000     ubi_msg(ubi, "VID header offset: %d (aligned %d), data offset: %d",
1001         ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
1002     ubi_msg(ubi, "good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
1003         ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
1004     ubi_msg(ubi, "user volume: %d, internal volumes: %d, max. volumes count: %d",
1005         ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
1006         ubi->vtbl_slots);
1007     ubi_msg(ubi, "max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
1008         ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
1009         ubi->image_seq);
1010     ubi_msg(ubi, "available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
1011         ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
1012 
1013     /*
1014      * The below lock makes sure we do not race with 'ubi_thread()' which
1015      * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1016      */
1017     spin_lock(&ubi->wl_lock);
1018     ubi->thread_enabled = 1;
1019     wake_up_process(ubi->bgt_thread);
1020     spin_unlock(&ubi->wl_lock);
1021 
1022     ubi_devices[ubi_num] = ubi;
1023     ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1024     return ubi_num;
1025 
1026 out_debugfs:
1027     ubi_debugfs_exit_dev(ubi);
1028 out_uif:
1029     uif_close(ubi);
1030 out_detach:
1031     ubi_wl_close(ubi);
1032     ubi_free_all_volumes(ubi);
1033     vfree(ubi->vtbl);
1034 out_free:
1035     vfree(ubi->peb_buf);
1036     vfree(ubi->fm_buf);
1037     put_device(&ubi->dev);
1038     return err;
1039 }
1040 
1041 /**
1042  * ubi_detach_mtd_dev - detach an MTD device.
1043  * @ubi_num: UBI device number to detach from
1044  * @anyway: detach MTD even if device reference count is not zero
1045  *
1046  * This function destroys an UBI device number @ubi_num and detaches the
1047  * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1048  * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1049  * exist.
1050  *
1051  * Note, the invocations of this function has to be serialized by the
1052  * @ubi_devices_mutex.
1053  */
1054 int ubi_detach_mtd_dev(int ubi_num, int anyway)
1055 {
1056     struct ubi_device *ubi;
1057 
1058     if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1059         return -EINVAL;
1060 
1061     ubi = ubi_get_device(ubi_num);
1062     if (!ubi)
1063         return -EINVAL;
1064 
1065     spin_lock(&ubi_devices_lock);
1066     put_device(&ubi->dev);
1067     ubi->ref_count -= 1;
1068     if (ubi->ref_count) {
1069         if (!anyway) {
1070             spin_unlock(&ubi_devices_lock);
1071             return -EBUSY;
1072         }
1073         /* This may only happen if there is a bug */
1074         ubi_err(ubi, "%s reference count %d, destroy anyway",
1075             ubi->ubi_name, ubi->ref_count);
1076     }
1077     ubi_devices[ubi_num] = NULL;
1078     spin_unlock(&ubi_devices_lock);
1079 
1080     ubi_assert(ubi_num == ubi->ubi_num);
1081     ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1082     ubi_msg(ubi, "detaching mtd%d", ubi->mtd->index);
1083 #ifdef CONFIG_MTD_UBI_FASTMAP
1084     /* If we don't write a new fastmap at detach time we lose all
1085      * EC updates that have been made since the last written fastmap.
1086      * In case of fastmap debugging we omit the update to simulate an
1087      * unclean shutdown. */
1088     if (!ubi_dbg_chk_fastmap(ubi))
1089         ubi_update_fastmap(ubi);
1090 #endif
1091     /*
1092      * Before freeing anything, we have to stop the background thread to
1093      * prevent it from doing anything on this device while we are freeing.
1094      */
1095     if (ubi->bgt_thread)
1096         kthread_stop(ubi->bgt_thread);
1097 
1098 #ifdef CONFIG_MTD_UBI_FASTMAP
1099     cancel_work_sync(&ubi->fm_work);
1100 #endif
1101     ubi_debugfs_exit_dev(ubi);
1102     uif_close(ubi);
1103 
1104     ubi_wl_close(ubi);
1105     ubi_free_internal_volumes(ubi);
1106     vfree(ubi->vtbl);
1107     vfree(ubi->peb_buf);
1108     vfree(ubi->fm_buf);
1109     ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index);
1110     put_mtd_device(ubi->mtd);
1111     put_device(&ubi->dev);
1112     return 0;
1113 }
1114 
1115 /**
1116  * open_mtd_by_chdev - open an MTD device by its character device node path.
1117  * @mtd_dev: MTD character device node path
1118  *
1119  * This helper function opens an MTD device by its character node device path.
1120  * Returns MTD device description object in case of success and a negative
1121  * error code in case of failure.
1122  */
1123 static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1124 {
1125     int err, minor;
1126     struct path path;
1127     struct kstat stat;
1128 
1129     /* Probably this is an MTD character device node path */
1130     err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1131     if (err)
1132         return ERR_PTR(err);
1133 
1134     err = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
1135     path_put(&path);
1136     if (err)
1137         return ERR_PTR(err);
1138 
1139     /* MTD device number is defined by the major / minor numbers */
1140     if (MAJOR(stat.rdev) != MTD_CHAR_MAJOR || !S_ISCHR(stat.mode))
1141         return ERR_PTR(-EINVAL);
1142 
1143     minor = MINOR(stat.rdev);
1144 
1145     if (minor & 1)
1146         /*
1147          * Just do not think the "/dev/mtdrX" devices support is need,
1148          * so do not support them to avoid doing extra work.
1149          */
1150         return ERR_PTR(-EINVAL);
1151 
1152     return get_mtd_device(NULL, minor / 2);
1153 }
1154 
1155 /**
1156  * open_mtd_device - open MTD device by name, character device path, or number.
1157  * @mtd_dev: name, character device node path, or MTD device device number
1158  *
1159  * This function tries to open and MTD device described by @mtd_dev string,
1160  * which is first treated as ASCII MTD device number, and if it is not true, it
1161  * is treated as MTD device name, and if that is also not true, it is treated
1162  * as MTD character device node path. Returns MTD device description object in
1163  * case of success and a negative error code in case of failure.
1164  */
1165 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1166 {
1167     struct mtd_info *mtd;
1168     int mtd_num;
1169     char *endp;
1170 
1171     mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1172     if (*endp != '\0' || mtd_dev == endp) {
1173         /*
1174          * This does not look like an ASCII integer, probably this is
1175          * MTD device name.
1176          */
1177         mtd = get_mtd_device_nm(mtd_dev);
1178         if (PTR_ERR(mtd) == -ENODEV)
1179             /* Probably this is an MTD character device node path */
1180             mtd = open_mtd_by_chdev(mtd_dev);
1181     } else
1182         mtd = get_mtd_device(NULL, mtd_num);
1183 
1184     return mtd;
1185 }
1186 
1187 static int __init ubi_init(void)
1188 {
1189     int err, i, k;
1190 
1191     /* Ensure that EC and VID headers have correct size */
1192     BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1193     BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1194 
1195     if (mtd_devs > UBI_MAX_DEVICES) {
1196         pr_err("UBI error: too many MTD devices, maximum is %d\n",
1197                UBI_MAX_DEVICES);
1198         return -EINVAL;
1199     }
1200 
1201     /* Create base sysfs directory and sysfs files */
1202     err = class_register(&ubi_class);
1203     if (err < 0)
1204         return err;
1205 
1206     err = misc_register(&ubi_ctrl_cdev);
1207     if (err) {
1208         pr_err("UBI error: cannot register device\n");
1209         goto out;
1210     }
1211 
1212     ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1213                           sizeof(struct ubi_wl_entry),
1214                           0, 0, NULL);
1215     if (!ubi_wl_entry_slab) {
1216         err = -ENOMEM;
1217         goto out_dev_unreg;
1218     }
1219 
1220     err = ubi_debugfs_init();
1221     if (err)
1222         goto out_slab;
1223 
1224 
1225     /* Attach MTD devices */
1226     for (i = 0; i < mtd_devs; i++) {
1227         struct mtd_dev_param *p = &mtd_dev_param[i];
1228         struct mtd_info *mtd;
1229 
1230         cond_resched();
1231 
1232         mtd = open_mtd_device(p->name);
1233         if (IS_ERR(mtd)) {
1234             err = PTR_ERR(mtd);
1235             pr_err("UBI error: cannot open mtd %s, error %d\n",
1236                    p->name, err);
1237             /* See comment below re-ubi_is_module(). */
1238             if (ubi_is_module())
1239                 goto out_detach;
1240             continue;
1241         }
1242 
1243         mutex_lock(&ubi_devices_mutex);
1244         err = ubi_attach_mtd_dev(mtd, p->ubi_num,
1245                      p->vid_hdr_offs, p->max_beb_per1024);
1246         mutex_unlock(&ubi_devices_mutex);
1247         if (err < 0) {
1248             pr_err("UBI error: cannot attach mtd%d\n",
1249                    mtd->index);
1250             put_mtd_device(mtd);
1251 
1252             /*
1253              * Originally UBI stopped initializing on any error.
1254              * However, later on it was found out that this
1255              * behavior is not very good when UBI is compiled into
1256              * the kernel and the MTD devices to attach are passed
1257              * through the command line. Indeed, UBI failure
1258              * stopped whole boot sequence.
1259              *
1260              * To fix this, we changed the behavior for the
1261              * non-module case, but preserved the old behavior for
1262              * the module case, just for compatibility. This is a
1263              * little inconsistent, though.
1264              */
1265             if (ubi_is_module())
1266                 goto out_detach;
1267         }
1268     }
1269 
1270     err = ubiblock_init();
1271     if (err) {
1272         pr_err("UBI error: block: cannot initialize, error %d\n", err);
1273 
1274         /* See comment above re-ubi_is_module(). */
1275         if (ubi_is_module())
1276             goto out_detach;
1277     }
1278 
1279     return 0;
1280 
1281 out_detach:
1282     for (k = 0; k < i; k++)
1283         if (ubi_devices[k]) {
1284             mutex_lock(&ubi_devices_mutex);
1285             ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1286             mutex_unlock(&ubi_devices_mutex);
1287         }
1288     ubi_debugfs_exit();
1289 out_slab:
1290     kmem_cache_destroy(ubi_wl_entry_slab);
1291 out_dev_unreg:
1292     misc_deregister(&ubi_ctrl_cdev);
1293 out:
1294     class_unregister(&ubi_class);
1295     pr_err("UBI error: cannot initialize UBI, error %d\n", err);
1296     return err;
1297 }
1298 late_initcall(ubi_init);
1299 
1300 static void __exit ubi_exit(void)
1301 {
1302     int i;
1303 
1304     ubiblock_exit();
1305 
1306     for (i = 0; i < UBI_MAX_DEVICES; i++)
1307         if (ubi_devices[i]) {
1308             mutex_lock(&ubi_devices_mutex);
1309             ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1310             mutex_unlock(&ubi_devices_mutex);
1311         }
1312     ubi_debugfs_exit();
1313     kmem_cache_destroy(ubi_wl_entry_slab);
1314     misc_deregister(&ubi_ctrl_cdev);
1315     class_unregister(&ubi_class);
1316 }
1317 module_exit(ubi_exit);
1318 
1319 /**
1320  * bytes_str_to_int - convert a number of bytes string into an integer.
1321  * @str: the string to convert
1322  *
1323  * This function returns positive resulting integer in case of success and a
1324  * negative error code in case of failure.
1325  */
1326 static int bytes_str_to_int(const char *str)
1327 {
1328     char *endp;
1329     unsigned long result;
1330 
1331     result = simple_strtoul(str, &endp, 0);
1332     if (str == endp || result >= INT_MAX) {
1333         pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1334         return -EINVAL;
1335     }
1336 
1337     switch (*endp) {
1338     case 'G':
1339         result *= 1024;
1340         fallthrough;
1341     case 'M':
1342         result *= 1024;
1343         fallthrough;
1344     case 'K':
1345         result *= 1024;
1346         break;
1347     case '\0':
1348         break;
1349     default:
1350         pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1351         return -EINVAL;
1352     }
1353 
1354     return result;
1355 }
1356 
1357 /**
1358  * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1359  * @val: the parameter value to parse
1360  * @kp: not used
1361  *
1362  * This function returns zero in case of success and a negative error code in
1363  * case of error.
1364  */
1365 static int ubi_mtd_param_parse(const char *val, const struct kernel_param *kp)
1366 {
1367     int i, len;
1368     struct mtd_dev_param *p;
1369     char buf[MTD_PARAM_LEN_MAX];
1370     char *pbuf = &buf[0];
1371     char *tokens[MTD_PARAM_MAX_COUNT], *token;
1372 
1373     if (!val)
1374         return -EINVAL;
1375 
1376     if (mtd_devs == UBI_MAX_DEVICES) {
1377         pr_err("UBI error: too many parameters, max. is %d\n",
1378                UBI_MAX_DEVICES);
1379         return -EINVAL;
1380     }
1381 
1382     len = strnlen(val, MTD_PARAM_LEN_MAX);
1383     if (len == MTD_PARAM_LEN_MAX) {
1384         pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
1385                val, MTD_PARAM_LEN_MAX);
1386         return -EINVAL;
1387     }
1388 
1389     if (len == 0) {
1390         pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
1391         return 0;
1392     }
1393 
1394     strcpy(buf, val);
1395 
1396     /* Get rid of the final newline */
1397     if (buf[len - 1] == '\n')
1398         buf[len - 1] = '\0';
1399 
1400     for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1401         tokens[i] = strsep(&pbuf, ",");
1402 
1403     if (pbuf) {
1404         pr_err("UBI error: too many arguments at \"%s\"\n", val);
1405         return -EINVAL;
1406     }
1407 
1408     p = &mtd_dev_param[mtd_devs];
1409     strcpy(&p->name[0], tokens[0]);
1410 
1411     token = tokens[1];
1412     if (token) {
1413         p->vid_hdr_offs = bytes_str_to_int(token);
1414 
1415         if (p->vid_hdr_offs < 0)
1416             return p->vid_hdr_offs;
1417     }
1418 
1419     token = tokens[2];
1420     if (token) {
1421         int err = kstrtoint(token, 10, &p->max_beb_per1024);
1422 
1423         if (err) {
1424             pr_err("UBI error: bad value for max_beb_per1024 parameter: %s",
1425                    token);
1426             return -EINVAL;
1427         }
1428     }
1429 
1430     token = tokens[3];
1431     if (token) {
1432         int err = kstrtoint(token, 10, &p->ubi_num);
1433 
1434         if (err) {
1435             pr_err("UBI error: bad value for ubi_num parameter: %s",
1436                    token);
1437             return -EINVAL;
1438         }
1439     } else
1440         p->ubi_num = UBI_DEV_NUM_AUTO;
1441 
1442     mtd_devs += 1;
1443     return 0;
1444 }
1445 
1446 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 0400);
1447 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\n"
1448               "Multiple \"mtd\" parameters may be specified.\n"
1449               "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1450               "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1451               "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1452               __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1453               "Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
1454               "\n"
1455               "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1456               "Example 2: mtd=content,1984 mtd=4 - attach MTD device with name \"content\" using VID header offset 1984, and MTD device number 4 with default VID header offset.\n"
1457               "Example 3: mtd=/dev/mtd1,0,25 - attach MTD device /dev/mtd1 using default VID header offset and reserve 25*nand_size_in_blocks/1024 erase blocks for bad block handling.\n"
1458               "Example 4: mtd=/dev/mtd1,0,0,5 - attach MTD device /dev/mtd1 to UBI 5 and using default values for the other fields.\n"
1459               "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1460 #ifdef CONFIG_MTD_UBI_FASTMAP
1461 module_param(fm_autoconvert, bool, 0644);
1462 MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
1463 module_param(fm_debug, bool, 0);
1464 MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
1465 #endif
1466 MODULE_VERSION(__stringify(UBI_VERSION));
1467 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1468 MODULE_AUTHOR("Artem Bityutskiy");
1469 MODULE_LICENSE("GPL");
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