diff options
Diffstat (limited to 'include/mtd/ubi-user.h')
| -rw-r--r-- | include/mtd/ubi-user.h | 305 |
1 files changed, 230 insertions, 75 deletions
diff --git a/include/mtd/ubi-user.h b/include/mtd/ubi-user.h index 1ccc06e..c93914a 100644 --- a/include/mtd/ubi-user.h +++ b/include/mtd/ubi-user.h @@ -1,7 +1,7 @@ /* - * Copyright (c) International Business Machines Corp., 2006 + * Copyright © International Business Machines Corp., 2006 * - * SPDX-License-Identifier: GPL-2.0+ + * SPDX-License-Identifier: GPL-2.0+ * * Author: Artem Bityutskiy (Битюцкий Артём) */ @@ -9,6 +9,8 @@ #ifndef __UBI_USER_H__ #define __UBI_USER_H__ +#include <linux/types.h> + /* * UBI device creation (the same as MTD device attachment) * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -28,30 +30,37 @@ * UBI volume creation * ~~~~~~~~~~~~~~~~~~~ * - * UBI volumes are created via the %UBI_IOCMKVOL IOCTL command of UBI character + * 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. + * 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 + * 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. + * to the ioctl. * * UBI volume re-size * ~~~~~~~~~~~~~~~~~~ * - * To re-size a volume, the %UBI_IOCRSVOL IOCTL command of the UBI character + * 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. + * 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 + * 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 + * 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: @@ -61,14 +70,58 @@ * write(fd, buf, image_size); * close(fd); * - * Atomic eraseblock change + * 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 * ~~~~~~~~~~~~~~~~~~~~~~~~ * - * Atomic eraseblock change operation is done via the %UBI_IOCEBCH IOCTL - * command of the corresponding UBI volume character device. A pointer to - * &struct ubi_leb_change_req has to be passed to the IOCTL. Then the user is - * expected to write the requested amount of bytes. This is similar to the - * "volume update" IOCTL. + * 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. */ /* @@ -82,56 +135,56 @@ /* Maximum volume name length */ #define UBI_MAX_VOLUME_NAME 127 -/* IOCTL commands of UBI character devices */ +/* 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, int32_t) +#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 */ +/* 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, int32_t) +#define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, __s32) -/* IOCTL commands of UBI volume character devices */ +/* ioctl commands of UBI volume character devices */ #define UBI_VOL_IOC_MAGIC 'O' -/* Start UBI volume update */ -#define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, int64_t) -/* An eraseblock erasure command, used for debugging, disabled by default */ -#define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, int32_t) -/* An atomic eraseblock change command */ -#define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, int32_t) +/* 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 -/* - * UBI data type hint constants. - * - * UBI_LONGTERM: long-term data - * UBI_SHORTTERM: short-term data - * UBI_UNKNOWN: data persistence is unknown - * - * These constants are used when data is written to UBI volumes in order to - * help the UBI wear-leveling unit to find more appropriate physical - * eraseblocks. - */ -enum { - UBI_LONGTERM = 1, - UBI_SHORTTERM = 2, - UBI_UNKNOWN = 3, -}; +/* Maximum amount of UBI volumes that can be re-named at one go */ +#define UBI_MAX_RNVOL 32 /* * UBI volume type constants. @@ -144,11 +197,23 @@ enum { 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 @@ -164,20 +229,33 @@ enum { * 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. + * 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 { - int32_t ubi_num; - int32_t mtd_num; - int32_t vid_hdr_offset; - uint8_t padding[12]; + __s32 ubi_num; + __s32 mtd_num; + __s32 vid_hdr_offset; + __s16 max_beb_per1024; + __s8 padding[10]; }; /** @@ -212,15 +290,15 @@ struct ubi_attach_req { * BLOBs, without caring about how to properly align them. */ struct ubi_mkvol_req { - int32_t vol_id; - int32_t alignment; - int64_t bytes; - int8_t vol_type; - int8_t padding1; - int16_t name_len; - int8_t padding2[4]; + __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)); +} __packed; /** * struct ubi_rsvol_req - a data structure used in volume re-size requests. @@ -229,28 +307,105 @@ struct ubi_mkvol_req { * * 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 then the number of bytes they bear. To arbitrarily shrink a static + * 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 { - int64_t bytes; - int32_t vol_id; -} __attribute__ ((packed)); + __s64 bytes; + __s32 vol_id; +} __packed; /** - * struct ubi_leb_change_req - a data structure used in atomic logical - * eraseblock change requests. + * 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: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN) + * @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 { - int32_t lnum; - int32_t bytes; - uint8_t dtype; - uint8_t padding[7]; -} __attribute__ ((packed)); + __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; #endif /* __UBI_USER_H__ */ |