diff options
Diffstat (limited to 'include/mtd/ubi-user.h')
| -rw-r--r-- | include/mtd/ubi-user.h | 55 |
1 files changed, 32 insertions, 23 deletions
diff --git a/include/mtd/ubi-user.h b/include/mtd/ubi-user.h index 3c4109777aff..723c324590c1 100644 --- a/include/mtd/ubi-user.h +++ b/include/mtd/ubi-user.h @@ -173,7 +173,10 @@ #define UBI_VOL_IOC_MAGIC 'O' -/* Start UBI volume update */ +/* 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) @@ -196,23 +199,6 @@ #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. * * @UBI_DYNAMIC_VOLUME: dynamic volume @@ -239,6 +225,7 @@ enum { * @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 @@ -262,12 +249,25 @@ enum { * 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; - __s8 padding[12]; + __s16 max_beb_per1024; + __s8 padding[10]; }; /** @@ -375,25 +375,34 @@ struct ubi_rnvol_req { * 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 { __s32 lnum; __s32 bytes; - __s8 dtype; + __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 - * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN) * @padding: reserved for future, not used, has to be zeroed */ struct ubi_map_req { __s32 lnum; - __s8 dtype; + __s8 dtype; /* obsolete, do not use! */ __s8 padding[3]; } __packed; |