#define __UBI_USER_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
* ~~~~~~~~~~~~~~~~~~~
*
* 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 then, 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:
* ioctl(fd, UBI_IOCVOLUP, &image_size);
* write(fd, buf, image_size);
* close(fd);
+ *
+ * Atomic eraseblock change
+ * ~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * 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.
*/
/*
- * When a new volume is created, users may either specify the volume number they
- * want to create or to let UBI automatically assign a volume number using this
- * constant.
+ * 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
#define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, int32_t)
/* 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, int32_t)
/* IOCTL commands of UBI volume character devices */
#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)
+
+/* 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 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,
+};
/*
* UBI volume type constants.
*/
enum {
UBI_DYNAMIC_VOLUME = 3,
- UBI_STATIC_VOLUME = 4
+ UBI_STATIC_VOLUME = 4,
+};
+
+/**
+ * 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)
+ * @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.
+ */
+struct ubi_attach_req {
+ int32_t ubi_num;
+ int32_t mtd_num;
+ int32_t vid_hdr_offset;
+ int8_t padding[12];
};
/**
* struct ubi_mkvol_req - volume description data structure used in
- * volume creation requests.
+ * 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
+ * @padding1: reserved for future, not used, has to be zeroed
* @name_len: volume name length
- * @padding2: reserved for future, not used
+ * @padding2: reserved for future, not used, has to be zeroed
* @name: volume name
*
- * This structure is used by userspace programs when creating new volumes. The
+ * 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
int8_t padding1;
int16_t name_len;
int8_t padding2[4];
- char name[UBI_MAX_VOLUME_NAME+1];
+ char name[UBI_MAX_VOLUME_NAME + 1];
} __attribute__ ((packed));
/**
int32_t 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 {
+ int32_t count;
+ int8_t padding1[12];
+ struct {
+ int32_t vol_id;
+ int16_t name_len;
+ int8_t 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 logical
+ * eraseblock 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)
+ * @padding: reserved for future, not used, has to be zeroed
+ */
+struct ubi_leb_change_req {
+ int32_t lnum;
+ int32_t bytes;
+ int8_t dtype;
+ int8_t padding[7];
+} __attribute__ ((packed));
+
#endif /* __UBI_USER_H__ */
git.openpandora.org / pandora-kernel.git / blobdiff