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      1 /*
      2  * Copyright  International Business Machines Corp., 2006
      3  *
      4  * This program is free software; you can redistribute it and/or modify
      5  * it under the terms of the GNU General Public License as published by
      6  * the Free Software Foundation; either version 2 of the License, or
      7  * (at your option) any later version.
      8  *
      9  * This program is distributed in the hope that it will be useful,
     10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
     12  * the GNU General Public License for more details.
     13  *
     14  * You should have received a copy of the GNU General Public License
     15  * along with this program; if not, write to the Free Software
     16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
     17  *
     18  * Author: Artem Bityutskiy ( )
     19  */
     20 
     21 #ifndef __UBI_USER_H__
     22 #define __UBI_USER_H__
     23 
     24 #include <linux/types.h>
     25 
     26 /*
     27  * UBI device creation (the same as MTD device attachment)
     28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     29  *
     30  * MTD devices may be attached using %UBI_IOCATT ioctl command of the UBI
     31  * control device. The caller has to properly fill and pass
     32  * &struct ubi_attach_req object - UBI will attach the MTD device specified in
     33  * the request and return the newly created UBI device number as the ioctl
     34  * return value.
     35  *
     36  * UBI device deletion (the same as MTD device detachment)
     37  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     38  *
     39  * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI
     40  * control device.
     41  *
     42  * UBI volume creation
     43  * ~~~~~~~~~~~~~~~~~~~
     44  *
     45  * UBI volumes are created via the %UBI_IOCMKVOL ioctl command of UBI character
     46  * device. A &struct ubi_mkvol_req object has to be properly filled and a
     47  * pointer to it has to be passed to the ioctl.
     48  *
     49  * UBI volume deletion
     50  * ~~~~~~~~~~~~~~~~~~~
     51  *
     52  * To delete a volume, the %UBI_IOCRMVOL ioctl command of the UBI character
     53  * device should be used. A pointer to the 32-bit volume ID hast to be passed
     54  * to the ioctl.
     55  *
     56  * UBI volume re-size
     57  * ~~~~~~~~~~~~~~~~~~
     58  *
     59  * To re-size a volume, the %UBI_IOCRSVOL ioctl command of the UBI character
     60  * device should be used. A &struct ubi_rsvol_req object has to be properly
     61  * filled and a pointer to it has to be passed to the ioctl.
     62  *
     63  * UBI volumes re-name
     64  * ~~~~~~~~~~~~~~~~~~~
     65  *
     66  * To re-name several volumes atomically at one go, the %UBI_IOCRNVOL command
     67  * of the UBI character device should be used. A &struct ubi_rnvol_req object
     68  * has to be properly filled and a pointer to it has to be passed to the ioctl.
     69  *
     70  * UBI volume update
     71  * ~~~~~~~~~~~~~~~~~
     72  *
     73  * Volume update should be done via the %UBI_IOCVOLUP ioctl command of the
     74  * corresponding UBI volume character device. A pointer to a 64-bit update
     75  * size should be passed to the ioctl. After this, UBI expects user to write
     76  * this number of bytes to the volume character device. The update is finished
     77  * when the claimed number of bytes is passed. So, the volume update sequence
     78  * is something like:
     79  *
     80  * fd = open("/dev/my_volume");
     81  * ioctl(fd, UBI_IOCVOLUP, &image_size);
     82  * write(fd, buf, image_size);
     83  * close(fd);
     84  *
     85  * Logical eraseblock erase
     86  * ~~~~~~~~~~~~~~~~~~~~~~~~
     87  *
     88  * To erase a logical eraseblock, the %UBI_IOCEBER ioctl command of the
     89  * corresponding UBI volume character device should be used. This command
     90  * unmaps the requested logical eraseblock, makes sure the corresponding
     91  * physical eraseblock is successfully erased, and returns.
     92  *
     93  * Atomic logical eraseblock change
     94  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     95  *
     96  * Atomic logical eraseblock change operation is called using the %UBI_IOCEBCH
     97  * ioctl command of the corresponding UBI volume character device. A pointer to
     98  * a &struct ubi_leb_change_req object has to be passed to the ioctl. Then the
     99  * user is expected to write the requested amount of bytes (similarly to what
    100  * should be done in case of the "volume update" ioctl).
    101  *
    102  * Logical eraseblock map
    103  * ~~~~~~~~~~~~~~~~~~~~~
    104  *
    105  * To map a logical eraseblock to a physical eraseblock, the %UBI_IOCEBMAP
    106  * ioctl command should be used. A pointer to a &struct ubi_map_req object is
    107  * expected to be passed. The ioctl maps the requested logical eraseblock to
    108  * a physical eraseblock and returns.  Only non-mapped logical eraseblocks can
    109  * be mapped. If the logical eraseblock specified in the request is already
    110  * mapped to a physical eraseblock, the ioctl fails and returns error.
    111  *
    112  * Logical eraseblock unmap
    113  * ~~~~~~~~~~~~~~~~~~~~~~~~
    114  *
    115  * To unmap a logical eraseblock to a physical eraseblock, the %UBI_IOCEBUNMAP
    116  * ioctl command should be used. The ioctl unmaps the logical eraseblocks,
    117  * schedules corresponding physical eraseblock for erasure, and returns. Unlike
    118  * the "LEB erase" command, it does not wait for the physical eraseblock being
    119  * erased. Note, the side effect of this is that if an unclean reboot happens
    120  * after the unmap ioctl returns, you may find the LEB mapped again to the same
    121  * physical eraseblock after the UBI is run again.
    122  *
    123  * Check if logical eraseblock is mapped
    124  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    125  *
    126  * To check if a logical eraseblock is mapped to a physical eraseblock, the
    127  * %UBI_IOCEBISMAP ioctl command should be used. It returns %0 if the LEB is
    128  * not mapped, and %1 if it is mapped.
    129  *
    130  * Set an UBI volume property
    131  * ~~~~~~~~~~~~~~~~~~~~~~~~~
    132  *
    133  * To set an UBI volume property the %UBI_IOCSETPROP ioctl command should be
    134  * used. A pointer to a &struct ubi_set_vol_prop_req object is expected to be
    135  * passed. The object describes which property should be set, and to which value
    136  * it should be set.
    137  */
    138 
    139 /*
    140  * When a new UBI volume or UBI device is created, users may either specify the
    141  * volume/device number they want to create or to let UBI automatically assign
    142  * the number using these constants.
    143  */
    144 #define UBI_VOL_NUM_AUTO (-1)
    145 #define UBI_DEV_NUM_AUTO (-1)
    146 
    147 /* Maximum volume name length */
    148 #define UBI_MAX_VOLUME_NAME 127
    149 
    150 /* ioctl commands of UBI character devices */
    151 
    152 #define UBI_IOC_MAGIC 'o'
    153 
    154 /* Create an UBI volume */
    155 #define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req)
    156 /* Remove an UBI volume */
    157 #define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, __s32)
    158 /* Re-size an UBI volume */
    159 #define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req)
    160 /* Re-name volumes */
    161 #define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_req)
    162 
    163 /* ioctl commands of the UBI control character device */
    164 
    165 #define UBI_CTRL_IOC_MAGIC 'o'
    166 
    167 /* Attach an MTD device */
    168 #define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req)
    169 /* Detach an MTD device */
    170 #define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, __s32)
    171 
    172 /* ioctl commands of UBI volume character devices */
    173 
    174 #define UBI_VOL_IOC_MAGIC 'O'
    175 
    176 /* Start UBI volume update */
    177 #define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, __s64)
    178 /* LEB erasure command, used for debugging, disabled by default */
    179 #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, __s32)
    180 /* Atomic LEB change command */
    181 #define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, __s32)
    182 /* Map LEB command */
    183 #define UBI_IOCEBMAP _IOW(UBI_VOL_IOC_MAGIC, 3, struct ubi_map_req)
    184 /* Unmap LEB command */
    185 #define UBI_IOCEBUNMAP _IOW(UBI_VOL_IOC_MAGIC, 4, __s32)
    186 /* Check if LEB is mapped command */
    187 #define UBI_IOCEBISMAP _IOR(UBI_VOL_IOC_MAGIC, 5, __s32)
    188 /* Set an UBI volume property */
    189 #define UBI_IOCSETVOLPROP _IOW(UBI_VOL_IOC_MAGIC, 6, \
    190 			       struct ubi_set_vol_prop_req)
    191 
    192 /* Maximum MTD device name length supported by UBI */
    193 #define MAX_UBI_MTD_NAME_LEN 127
    194 
    195 /* Maximum amount of UBI volumes that can be re-named at one go */
    196 #define UBI_MAX_RNVOL 32
    197 
    198 /*
    199  * UBI data type hint constants.
    200  *
    201  * UBI_LONGTERM: long-term data
    202  * UBI_SHORTTERM: short-term data
    203  * UBI_UNKNOWN: data persistence is unknown
    204  *
    205  * These constants are used when data is written to UBI volumes in order to
    206  * help the UBI wear-leveling unit to find more appropriate physical
    207  * eraseblocks.
    208  */
    209 enum {
    210 	UBI_LONGTERM  = 1,
    211 	UBI_SHORTTERM = 2,
    212 	UBI_UNKNOWN   = 3,
    213 };
    214 
    215 /*
    216  * UBI volume type constants.
    217  *
    218  * @UBI_DYNAMIC_VOLUME: dynamic volume
    219  * @UBI_STATIC_VOLUME:  static volume
    220  */
    221 enum {
    222 	UBI_DYNAMIC_VOLUME = 3,
    223 	UBI_STATIC_VOLUME  = 4,
    224 };
    225 
    226 /*
    227  * UBI set volume property ioctl constants.
    228  *
    229  * @UBI_VOL_PROP_DIRECT_WRITE: allow (any non-zero value) or disallow (value 0)
    230  *                             user to directly write and erase individual
    231  *                             eraseblocks on dynamic volumes
    232  */
    233 enum {
    234 	UBI_VOL_PROP_DIRECT_WRITE = 1,
    235 };
    236 
    237 /**
    238  * struct ubi_attach_req - attach MTD device request.
    239  * @ubi_num: UBI device number to create
    240  * @mtd_num: MTD device number to attach
    241  * @vid_hdr_offset: VID header offset (use defaults if %0)
    242  * @padding: reserved for future, not used, has to be zeroed
    243  *
    244  * This data structure is used to specify MTD device UBI has to attach and the
    245  * parameters it has to use. The number which should be assigned to the new UBI
    246  * device is passed in @ubi_num. UBI may automatically assign the number if
    247  * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in
    248  * @ubi_num.
    249  *
    250  * Most applications should pass %0 in @vid_hdr_offset to make UBI use default
    251  * offset of the VID header within physical eraseblocks. The default offset is
    252  * the next min. I/O unit after the EC header. For example, it will be offset
    253  * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or
    254  * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages.
    255  *
    256  * But in rare cases, if this optimizes things, the VID header may be placed to
    257  * a different offset. For example, the boot-loader might do things faster if
    258  * the VID header sits at the end of the first 2KiB NAND page with 4 sub-pages.
    259  * As the boot-loader would not normally need to read EC headers (unless it
    260  * needs UBI in RW mode), it might be faster to calculate ECC. This is weird
    261  * example, but it real-life example. So, in this example, @vid_hdr_offer would
    262  * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes
    263  * aligned, which is OK, as UBI is clever enough to realize this is 4th
    264  * sub-page of the first page and add needed padding.
    265  */
    266 struct ubi_attach_req {
    267 	__s32 ubi_num;
    268 	__s32 mtd_num;
    269 	__s32 vid_hdr_offset;
    270 	__s8 padding[12];
    271 };
    272 
    273 /**
    274  * struct ubi_mkvol_req - volume description data structure used in
    275  *                        volume creation requests.
    276  * @vol_id: volume number
    277  * @alignment: volume alignment
    278  * @bytes: volume size in bytes
    279  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
    280  * @padding1: reserved for future, not used, has to be zeroed
    281  * @name_len: volume name length
    282  * @padding2: reserved for future, not used, has to be zeroed
    283  * @name: volume name
    284  *
    285  * This structure is used by user-space programs when creating new volumes. The
    286  * @used_bytes field is only necessary when creating static volumes.
    287  *
    288  * The @alignment field specifies the required alignment of the volume logical
    289  * eraseblock. This means, that the size of logical eraseblocks will be aligned
    290  * to this number, i.e.,
    291  *	(UBI device logical eraseblock size) mod (@alignment) = 0.
    292  *
    293  * To put it differently, the logical eraseblock of this volume may be slightly
    294  * shortened in order to make it properly aligned. The alignment has to be
    295  * multiple of the flash minimal input/output unit, or %1 to utilize the entire
    296  * available space of logical eraseblocks.
    297  *
    298  * The @alignment field may be useful, for example, when one wants to maintain
    299  * a block device on top of an UBI volume. In this case, it is desirable to fit
    300  * an integer number of blocks in logical eraseblocks of this UBI volume. With
    301  * alignment it is possible to update this volume using plane UBI volume image
    302  * BLOBs, without caring about how to properly align them.
    303  */
    304 struct ubi_mkvol_req {
    305 	__s32 vol_id;
    306 	__s32 alignment;
    307 	__s64 bytes;
    308 	__s8 vol_type;
    309 	__s8 padding1;
    310 	__s16 name_len;
    311 	__s8 padding2[4];
    312 	char name[UBI_MAX_VOLUME_NAME + 1];
    313 } __attribute__((packed));
    314 
    315 /**
    316  * struct ubi_rsvol_req - a data structure used in volume re-size requests.
    317  * @vol_id: ID of the volume to re-size
    318  * @bytes: new size of the volume in bytes
    319  *
    320  * Re-sizing is possible for both dynamic and static volumes. But while dynamic
    321  * volumes may be re-sized arbitrarily, static volumes cannot be made to be
    322  * smaller than the number of bytes they bear. To arbitrarily shrink a static
    323  * volume, it must be wiped out first (by means of volume update operation with
    324  * zero number of bytes).
    325  */
    326 struct ubi_rsvol_req {
    327 	__s64 bytes;
    328 	__s32 vol_id;
    329 } __attribute__((packed));
    330 
    331 /**
    332  * struct ubi_rnvol_req - volumes re-name request.
    333  * @count: count of volumes to re-name
    334  * @padding1:  reserved for future, not used, has to be zeroed
    335  * @vol_id: ID of the volume to re-name
    336  * @name_len: name length
    337  * @padding2:  reserved for future, not used, has to be zeroed
    338  * @name: new volume name
    339  *
    340  * UBI allows to re-name up to %32 volumes at one go. The count of volumes to
    341  * re-name is specified in the @count field. The ID of the volumes to re-name
    342  * and the new names are specified in the @vol_id and @name fields.
    343  *
    344  * The UBI volume re-name operation is atomic, which means that should power cut
    345  * happen, the volumes will have either old name or new name. So the possible
    346  * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes
    347  * A and B one may create temporary volumes %A1 and %B1 with the new contents,
    348  * then atomically re-name A1->A and B1->B, in which case old %A and %B will
    349  * be removed.
    350  *
    351  * If it is not desirable to remove old A and B, the re-name request has to
    352  * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1
    353  * become A and B, and old A and B will become A1 and B1.
    354  *
    355  * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1
    356  * and B1 become A and B, and old A and B become X and Y.
    357  *
    358  * In other words, in case of re-naming into an existing volume name, the
    359  * existing volume is removed, unless it is re-named as well at the same
    360  * re-name request.
    361  */
    362 struct ubi_rnvol_req {
    363 	__s32 count;
    364 	__s8 padding1[12];
    365 	struct {
    366 		__s32 vol_id;
    367 		__s16 name_len;
    368 		__s8  padding2[2];
    369 		char    name[UBI_MAX_VOLUME_NAME + 1];
    370 	} ents[UBI_MAX_RNVOL];
    371 } __attribute__((packed));
    372 
    373 /**
    374  * struct ubi_leb_change_req - a data structure used in atomic LEB change
    375  *                             requests.
    376  * @lnum: logical eraseblock number to change
    377  * @bytes: how many bytes will be written to the logical eraseblock
    378  * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
    379  * @padding: reserved for future, not used, has to be zeroed
    380  */
    381 struct ubi_leb_change_req {
    382 	__s32 lnum;
    383 	__s32 bytes;
    384 	__s8  dtype;
    385 	__s8  padding[7];
    386 } __attribute__((packed));
    387 
    388 /**
    389  * struct ubi_map_req - a data structure used in map LEB requests.
    390  * @lnum: logical eraseblock number to unmap
    391  * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
    392  * @padding: reserved for future, not used, has to be zeroed
    393  */
    394 struct ubi_map_req {
    395 	__s32 lnum;
    396 	__s8  dtype;
    397 	__s8  padding[3];
    398 } __attribute__((packed));
    399 
    400 
    401 /**
    402  * struct ubi_set_vol_prop_req - a data structure used to set an UBI volume
    403  *                               property.
    404  * @property: property to set (%UBI_VOL_PROP_DIRECT_WRITE)
    405  * @padding: reserved for future, not used, has to be zeroed
    406  * @value: value to set
    407  */
    408 struct ubi_set_vol_prop_req {
    409 	__u8  property;
    410 	__u8  padding[7];
    411 	__u64 value;
    412 }  __attribute__((packed));
    413 
    414 #endif /* __UBI_USER_H__ */
    415