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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-18 10:50:27 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-18 10:50:27 -0700 |
commit | 8f627a8a881481598c2591c3acc122fb9be7bac4 (patch) | |
tree | 06497d25e30824500aeaf8c736c45b070f121234 /include/linux/mtd | |
parent | fd57ed021990157ee5b3997c3f21c734093a9e23 (diff) | |
parent | 5d630e43284fdb0613e4e7e7dd906f27bc25b6af (diff) |
Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6
* 'linux-next' of git://git.infradead.org/ubifs-2.6: (25 commits)
UBIFS: clean-up commentaries
UBIFS: save 128KiB or more RAM
UBIFS: allocate orphans scan buffer on demand
UBIFS: allocate lpt dump buffer on demand
UBIFS: allocate ltab checking buffer on demand
UBIFS: allocate scanning buffer on demand
UBIFS: allocate dump buffer on demand
UBIFS: do not check data crc by default
UBIFS: simplify UBIFS Kconfig menu
UBIFS: print max. index node size
UBIFS: handle allocation failures in UBIFS write path
UBIFS: use max_write_size during recovery
UBIFS: use max_write_size for write-buffers
UBIFS: introduce write-buffer size field
UBI: incorporate LEB offset information
UBIFS: incorporate maximum write size
UBI: provide LEB offset information
UBI: incorporate maximum write size
UBIFS: fix LEB number in printk
UBIFS: restrict world-writable debugfs files
...
Diffstat (limited to 'include/linux/mtd')
-rw-r--r-- | include/linux/mtd/ubi.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/mtd/ubi.h b/include/linux/mtd/ubi.h index b31bd9e9bca..84854edf443 100644 --- a/include/linux/mtd/ubi.h +++ b/include/linux/mtd/ubi.h @@ -116,18 +116,40 @@ struct ubi_volume_info { * struct ubi_device_info - UBI device description data structure. * @ubi_num: ubi device number * @leb_size: logical eraseblock size on this UBI device + * @leb_start: starting offset of logical eraseblocks within physical + * eraseblocks * @min_io_size: minimal I/O unit size + * @max_write_size: maximum amount of bytes the underlying flash can write at a + * time (MTD write buffer size) * @ro_mode: if this device is in read-only mode * @cdev: UBI character device major and minor numbers * * Note, @leb_size is the logical eraseblock size offered by the UBI device. * Volumes of this UBI device may have smaller logical eraseblock size if their * alignment is not equivalent to %1. + * + * The @max_write_size field describes flash write maximum write unit. For + * example, NOR flash allows for changing individual bytes, so @min_io_size is + * %1. However, it does not mean than NOR flash has to write data byte-by-byte. + * Instead, CFI NOR flashes have a write-buffer of, e.g., 64 bytes, and when + * writing large chunks of data, they write 64-bytes at a time. Obviously, this + * improves write throughput. + * + * Also, the MTD device may have N interleaved (striped) flash chips + * underneath, in which case @min_io_size can be physical min. I/O size of + * single flash chip, while @max_write_size can be N * @min_io_size. + * + * The @max_write_size field is always greater or equivalent to @min_io_size. + * E.g., some NOR flashes may have (@min_io_size = 1, @max_write_size = 64). In + * contrast, NAND flashes usually have @min_io_size = @max_write_size = NAND + * page size. */ struct ubi_device_info { int ubi_num; int leb_size; + int leb_start; int min_io_size; + int max_write_size; int ro_mode; dev_t cdev; }; |