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/*

 * Copyright © International Business Machines Corp., 2006

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See

 * the GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

 *

 * Author: Artem Bityutskiy (Битюцкий Артём)

 */

#ifndef __UBI_USER_H__

#define __UBI_USER_H__

#include <linux/types.h>

/*

 * UBI device creation (the same as MTD device attachment)

 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 *

 * MTD devices may be attached using %UBI_IOCATT ioctl command of the UBI

 * control device. The caller has to properly fill and pass

 * &struct ubi_attach_req object - UBI will attach the MTD device specified in

 * the request and return the newly created UBI device number as the ioctl

 * return value.

 *

 * UBI device deletion (the same as MTD device detachment)

 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 *

 * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI

 * control device.

 *

 * UBI volume creation

 * ~~~~~~~~~~~~~~~~~~~

 *

 * UBI volumes are created via the %UBI_IOCMKVOL ioctl command of UBI character

 * device. A &struct ubi_mkvol_req object has to be properly filled and a

 * pointer to it has to be passed to the ioctl.

 *

 * UBI volume deletion

 * ~~~~~~~~~~~~~~~~~~~

 *

 * To delete a volume, the %UBI_IOCRMVOL ioctl command of the UBI character

 * device should be used. A pointer to the 32-bit volume ID hast to be passed

 * to the ioctl.

 *

 * UBI volume re-size

 * ~~~~~~~~~~~~~~~~~~

 *

 * To re-size a volume, the %UBI_IOCRSVOL ioctl command of the UBI character

 * device should be used. A &struct ubi_rsvol_req object has to be properly

 * filled and a pointer to it has to be passed to the ioctl.

 *

 * UBI volumes re-name

 * ~~~~~~~~~~~~~~~~~~~

 *

 * To re-name several volumes atomically at one go, the %UBI_IOCRNVOL command

 * of the UBI character device should be used. A &struct ubi_rnvol_req object

 * has to be properly filled and a pointer to it has to be passed to the ioctl.

 *

 * UBI volume update

 * ~~~~~~~~~~~~~~~~~

 *

 * Volume update should be done via the %UBI_IOCVOLUP ioctl command of the

 * corresponding UBI volume character device. A pointer to a 64-bit update

 * size should be passed to the ioctl. After this, UBI expects user to write

 * this number of bytes to the volume character device. The update is finished

 * when the claimed number of bytes is passed. So, the volume update sequence

 * is something like:

 *

 * fd = open("/dev/my_volume");

 * ioctl(fd, UBI_IOCVOLUP, &image_size);

 * write(fd, buf, image_size);

 * close(fd);

 *

 * Logical eraseblock erase

 * ~~~~~~~~~~~~~~~~~~~~~~~~

 *

 * To erase a logical eraseblock, the %UBI_IOCEBER ioctl command of the

 * corresponding UBI volume character device should be used. This command

 * unmaps the requested logical eraseblock, makes sure the corresponding

 * physical eraseblock is successfully erased, and returns.

 *

 * Atomic logical eraseblock change

 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 *

 * Atomic logical eraseblock change operation is called using the %UBI_IOCEBCH

 * ioctl command of the corresponding UBI volume character device. A pointer to

 * a &struct ubi_leb_change_req object has to be passed to the ioctl. Then the

 * user is expected to write the requested amount of bytes (similarly to what

 * should be done in case of the "volume update" ioctl).

 *

 * Logical eraseblock map

 * ~~~~~~~~~~~~~~~~~~~~~

 *

 * To map a logical eraseblock to a physical eraseblock, the %UBI_IOCEBMAP

 * ioctl command should be used. A pointer to a &struct ubi_map_req object is

 * expected to be passed. The ioctl maps the requested logical eraseblock to

 * a physical eraseblock and returns.  Only non-mapped logical eraseblocks can

 * be mapped. If the logical eraseblock specified in the request is already

 * mapped to a physical eraseblock, the ioctl fails and returns error.

 *

 * Logical eraseblock unmap

 * ~~~~~~~~~~~~~~~~~~~~~~~~

 *

 * To unmap a logical eraseblock to a physical eraseblock, the %UBI_IOCEBUNMAP

 * ioctl command should be used. The ioctl unmaps the logical eraseblocks,

 * schedules corresponding physical eraseblock for erasure, and returns. Unlike

 * the "LEB erase" command, it does not wait for the physical eraseblock being

 * erased. Note, the side effect of this is that if an unclean reboot happens

 * after the unmap ioctl returns, you may find the LEB mapped again to the same

 * physical eraseblock after the UBI is run again.

 *

 * Check if logical eraseblock is mapped

 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 *

 * To check if a logical eraseblock is mapped to a physical eraseblock, the

 * %UBI_IOCEBISMAP ioctl command should be used. It returns %0 if the LEB is

 * not mapped, and %1 if it is mapped.

 *

 * Set an UBI volume property

 * ~~~~~~~~~~~~~~~~~~~~~~~~~

 *

 * To set an UBI volume property the %UBI_IOCSETPROP ioctl command should be

 * used. A pointer to a &struct ubi_set_vol_prop_req object is expected to be

 * passed. The object describes which property should be set, and to which value

 * it should be set.

 */

/*

 * When a new UBI volume or UBI device is created, users may either specify the

 * volume/device number they want to create or to let UBI automatically assign

 * the number using these constants.

 */

#define UBI_VOL_NUM_AUTO (-1)

#define UBI_DEV_NUM_AUTO (-1)

/* Maximum volume name length */

#define UBI_MAX_VOLUME_NAME 127

/* ioctl commands of UBI character devices */

#define UBI_IOC_MAGIC 'o'

/* Create an UBI volume */

#define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req)

/* Remove an UBI volume */

#define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, __s32)

/* Re-size an UBI volume */

#define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req)

/* Re-name volumes */

#define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_req)

/* ioctl commands of the UBI control character device */

#define UBI_CTRL_IOC_MAGIC 'o'

/* Attach an MTD device */

#define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req)

/* Detach an MTD device */

#define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, __s32)

/* ioctl commands of UBI volume character devices */

#define UBI_VOL_IOC_MAGIC 'O'

/* Start UBI volume update

 * Note: This actually takes a pointer (__s64*), but we can't change

 *       that without breaking the ABI on 32bit systems

 */

#define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, __s64)

/* LEB erasure command, used for debugging, disabled by default */

#define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, __s32)

/* Atomic LEB change command */

#define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, __s32)

/* Map LEB command */

#define UBI_IOCEBMAP _IOW(UBI_VOL_IOC_MAGIC, 3, struct ubi_map_req)

/* Unmap LEB command */

#define UBI_IOCEBUNMAP _IOW(UBI_VOL_IOC_MAGIC, 4, __s32)

/* Check if LEB is mapped command */

#define UBI_IOCEBISMAP _IOR(UBI_VOL_IOC_MAGIC, 5, __s32)

/* Set an UBI volume property */

#define UBI_IOCSETVOLPROP _IOW(UBI_VOL_IOC_MAGIC, 6, \

                               struct ubi_set_vol_prop_req)

/* Maximum MTD device name length supported by UBI */

#define MAX_UBI_MTD_NAME_LEN 127

/* Maximum amount of UBI volumes that can be re-named at one go */

#define UBI_MAX_RNVOL 32

/*

 * UBI volume type constants.

 *

 * @UBI_DYNAMIC_VOLUME: dynamic volume

 * @UBI_STATIC_VOLUME:  static volume

 */

enum {

        UBI_DYNAMIC_VOLUME = 3,

        UBI_STATIC_VOLUME  = 4,

};

/*

 * UBI set volume property ioctl constants.

 *

 * @UBI_VOL_PROP_DIRECT_WRITE: allow (any non-zero value) or disallow (value 0)

 *                             user to directly write and erase individual

 *                             eraseblocks on dynamic volumes

 */

enum {

        UBI_VOL_PROP_DIRECT_WRITE = 1,

};

/**

 * struct ubi_attach_req - attach MTD device request.

 * @ubi_num: UBI device number to create

 * @mtd_num: MTD device number to attach

 * @vid_hdr_offset: VID header offset (use defaults if %0)

 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs

 * @padding: reserved for future, not used, has to be zeroed

 *

 * This data structure is used to specify MTD device UBI has to attach and the

 * parameters it has to use. The number which should be assigned to the new UBI

 * device is passed in @ubi_num. UBI may automatically assign the number if

 * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in

 * @ubi_num.

 *

 * Most applications should pass %0 in @vid_hdr_offset to make UBI use default

 * offset of the VID header within physical eraseblocks. The default offset is

 * the next min. I/O unit after the EC header. For example, it will be offset

 * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or

 * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages.

 *

 * But in rare cases, if this optimizes things, the VID header may be placed to

 * a different offset. For example, the boot-loader might do things faster if

 * the VID header sits at the end of the first 2KiB NAND page with 4 sub-pages.

 * As the boot-loader would not normally need to read EC headers (unless it

 * needs UBI in RW mode), it might be faster to calculate ECC. This is weird

 * example, but it real-life example. So, in this example, @vid_hdr_offer would

 * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes

 * aligned, which is OK, as UBI is clever enough to realize this is 4th

 * sub-page of the first page and add needed padding.

 *

 * The @max_beb_per1024 is the maximum amount of bad PEBs UBI expects on the

 * UBI device per 1024 eraseblocks.  This value is often given in an other form

 * in the NAND datasheet (min NVB i.e. minimal number of valid blocks). The

 * maximum expected bad eraseblocks per 1024 is then:

 *    1024 * (1 - MinNVB / MaxNVB)

 * Which gives 20 for most NAND devices.  This limit is used in order to derive

 * amount of eraseblock UBI reserves for handling new bad blocks. If the device

 * has more bad eraseblocks than this limit, UBI does not reserve any physical

 * eraseblocks for new bad eraseblocks, but attempts to use available

 * eraseblocks (if any). The accepted range is 0-768. If 0 is given, the

 * default kernel value of %CONFIG_MTD_UBI_BEB_LIMIT will be used.

 */

struct ubi_attach_req {

        __s32 ubi_num;

        __s32 mtd_num;

        __s32 vid_hdr_offset;

        __s16 max_beb_per1024;

        __s8 padding[10];

};

/**

 * struct ubi_mkvol_req - volume description data structure used in

 *                        volume creation requests.

 * @vol_id: volume number

 * @alignment: volume alignment

 * @bytes: volume size in bytes

 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)

 * @padding1: reserved for future, not used, has to be zeroed

 * @name_len: volume name length

 * @padding2: reserved for future, not used, has to be zeroed

 * @name: volume name

 *

 * This structure is used by user-space programs when creating new volumes. The

 * @used_bytes field is only necessary when creating static volumes.

 *

 * The @alignment field specifies the required alignment of the volume logical

 * eraseblock. This means, that the size of logical eraseblocks will be aligned

 * to this number, i.e.,

 *      (UBI device logical eraseblock size) mod (@alignment) = 0.

 *

 * To put it differently, the logical eraseblock of this volume may be slightly

 * shortened in order to make it properly aligned. The alignment has to be

 * multiple of the flash minimal input/output unit, or %1 to utilize the entire

 * available space of logical eraseblocks.

 *

 * The @alignment field may be useful, for example, when one wants to maintain

 * a block device on top of an UBI volume. In this case, it is desirable to fit

 * an integer number of blocks in logical eraseblocks of this UBI volume. With

 * alignment it is possible to update this volume using plane UBI volume image

 * BLOBs, without caring about how to properly align them.

 */

struct ubi_mkvol_req {

        __s32 vol_id;

        __s32 alignment;

        __s64 bytes;

        __s8 vol_type;

        __s8 padding1;

        __s16 name_len;

        __s8 padding2[4];

        char name[UBI_MAX_VOLUME_NAME + 1];

} __attribute__((packed));

/**

 * struct ubi_rsvol_req - a data structure used in volume re-size requests.

 * @vol_id: ID of the volume to re-size

 * @bytes: new size of the volume in bytes

 *

 * Re-sizing is possible for both dynamic and static volumes. But while dynamic

 * volumes may be re-sized arbitrarily, static volumes cannot be made to be

 * smaller than the number of bytes they bear. To arbitrarily shrink a static

 * volume, it must be wiped out first (by means of volume update operation with

 * zero number of bytes).

 */

struct ubi_rsvol_req {

        __s64 bytes;

        __s32 vol_id;

} __attribute__((packed));

/**

 * struct ubi_rnvol_req - volumes re-name request.

 * @count: count of volumes to re-name

 * @padding1:  reserved for future, not used, has to be zeroed

 * @vol_id: ID of the volume to re-name

 * @name_len: name length

 * @padding2:  reserved for future, not used, has to be zeroed

 * @name: new volume name

 *

 * UBI allows to re-name up to %32 volumes at one go. The count of volumes to

 * re-name is specified in the @count field. The ID of the volumes to re-name

 * and the new names are specified in the @vol_id and @name fields.

 *

 * The UBI volume re-name operation is atomic, which means that should power cut

 * happen, the volumes will have either old name or new name. So the possible

 * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes

 * A and B one may create temporary volumes %A1 and %B1 with the new contents,

 * then atomically re-name A1->A and B1->B, in which case old %A and %B will

 * be removed.

 *

 * If it is not desirable to remove old A and B, the re-name request has to

 * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1

 * become A and B, and old A and B will become A1 and B1.

 *

 * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1

 * and B1 become A and B, and old A and B become X and Y.

 *

 * In other words, in case of re-naming into an existing volume name, the

 * existing volume is removed, unless it is re-named as well at the same

 * re-name request.

 */

struct ubi_rnvol_req {

        __s32 count;

        __s8 padding1[12];

        struct {

                __s32 vol_id;

                __s16 name_len;

                __s8  padding2[2];

                char    name[UBI_MAX_VOLUME_NAME + 1];

        } ents[UBI_MAX_RNVOL];

} __attribute__((packed));

/**

 * struct ubi_leb_change_req - a data structure used in atomic LEB change

 *                             requests.

 * @lnum: logical eraseblock number to change

 * @bytes: how many bytes will be written to the logical eraseblock

 * @dtype: pass "3" for better compatibility with old kernels

 * @padding: reserved for future, not used, has to be zeroed

 *

 * The @dtype field used to inform UBI about what kind of data will be written

 * to the LEB: long term (value 1), short term (value 2), unknown (value 3).

 * UBI tried to pick a PEB with lower erase counter for short term data and a

 * PEB with higher erase counter for long term data. But this was not really

 * used because users usually do not know this and could easily mislead UBI. We

 * removed this feature in May 2012. UBI currently just ignores the @dtype

 * field. But for better compatibility with older kernels it is recommended to

 * set @dtype to 3 (unknown).

 */

struct ubi_leb_change_req {

        __s32 lnum;

        __s32 bytes;

        __s8  dtype; /* obsolete, do not use! */

        __s8  padding[7];

} __attribute__((packed));

/**

 * struct ubi_map_req - a data structure used in map LEB requests.

 * @dtype: pass "3" for better compatibility with old kernels

 * @lnum: logical eraseblock number to unmap

 * @padding: reserved for future, not used, has to be zeroed

 */

struct ubi_map_req {

        __s32 lnum;

        __s8  dtype; /* obsolete, do not use! */

        __s8  padding[3];

} __attribute__((packed));

/**

 * struct ubi_set_vol_prop_req - a data structure used to set an UBI volume

 *                               property.

 * @property: property to set (%UBI_VOL_PROP_DIRECT_WRITE)

 * @padding: reserved for future, not used, has to be zeroed

 * @value: value to set

 */

struct ubi_set_vol_prop_req {

        __u8  property;

        __u8  padding[7];

        __u64 value;

}  __attribute__((packed));

#endif /* __UBI_USER_H__ */