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linux/include/uapi/mtd/ubi-user.h
Richard Weinberger 663586c0a8 ubi: Expose the bitrot interface 
Using UBI_IOCRPEB and UBI_IOCSPEB userspace can force
reading and scrubbing of PEBs.

In case of bitflips UBI will automatically take action
and move data to a different PEB.
This interface allows a daemon to foster your NAND.

Signed-off-by: Richard Weinberger <richard@nod.at>
2019-02-24 11:40:45 +01:00

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/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
/*
* 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.
*
* Block devices on UBI volumes
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* To create a R/O block device on top of an UBI volume the %UBI_IOCVOLCRBLK
* should be used. A pointer to a &struct ubi_blkcreate_req object is expected
* to be passed, which is not used and reserved for future usage.
*
* Conversely, to remove a block device the %UBI_IOCVOLRMBLK should be used,
* which takes no arguments.
*/
/*
* 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)
/* Read the specified PEB and scrub it if there are bitflips */
#define UBI_IOCRPEB _IOW(UBI_IOC_MAGIC, 4, __s32)
/* Force scrubbing on the specified PEB */
#define UBI_IOCSPEB _IOW(UBI_IOC_MAGIC, 5, __s32)
/* 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)
/* Create a R/O block device on top of an UBI volume */
#define UBI_IOCVOLCRBLK _IOW(UBI_VOL_IOC_MAGIC, 7, struct ubi_blkcreate_req)
/* Remove the R/O block device */
#define UBI_IOCVOLRMBLK _IO(UBI_VOL_IOC_MAGIC, 8)
/* 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];
};
/*
* UBI volume flags.
*
* @UBI_VOL_SKIP_CRC_CHECK_FLG: skip the CRC check done on a static volume at
* open time. Only valid for static volumes and
* should only be used if the volume user has a
* way to verify data integrity
*/
enum {
UBI_VOL_SKIP_CRC_CHECK_FLG = 0x1,
};
#define UBI_VOL_VALID_FLGS (UBI_VOL_SKIP_CRC_CHECK_FLG)
/**
* 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)
* @flags: volume flags (%UBI_VOL_SKIP_CRC_CHECK_FLG)
* @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;
__u8 flags;
__s16 name_len;
__s8 padding2[4];
char name[UBI_MAX_VOLUME_NAME + 1];
} __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;
} __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];
} __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];
} __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];
} __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;
} __packed;
/**
* struct ubi_blkcreate_req - a data structure used in block creation requests.
* @padding: reserved for future, not used, has to be zeroed
*/
struct ubi_blkcreate_req {
__s8 padding[128];
} __packed;
#endif /* __UBI_USER_H__ */
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