We're missing a lot of important documentation in include/mtd/mtd-abi.h:
* add a simple description of each ioctl (feel free to expand!)
* give full explanations of recently added and modified operations
* explain the usage of "RAW" that appear in different modes and types of
operations
* fix some comment style along the way
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Implement a new ioctl for writing both page data and OOB to flash at the
same time. This ioctl is intended to be a generic interface that can
replace other ioctls (MEMWRITEOOB and MEMWRITEOOB64) and cover the
functionality of several other old ones, e.g., MEMWRITE can:
* write autoplaced OOB instead of using ECCGETLAYOUT (deprecated) and
working around the reserved areas
* write raw (no ECC) OOB instead of using MTDFILEMODE to set the
per-file-descriptor MTD_FILE_MODE_RAW
* write raw (no ECC) data instead of using MTDFILEMODE
(MTD_FILE_MODE_RAW) and using standard character device "write"
This ioctl is especially useful for MLC NAND, which cannot be written
twice (i.e., we cannot successfully write the page data and OOB in two
separate operations). Instead, MEMWRITE can write both in a single
operation.
Note that this ioctl is not affected by the MTD file mode (i.e.,
MTD_FILE_MODE_RAW vs. MTD_FILE_MODE_NORMAL), since it receives its write
mode as an input parameter.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
These modes hold their state only for the life of their file descriptor,
and they overlap functionality with the MTD_OPS_* modes. Particularly,
MTD_MODE_RAW and MTD_OPS_RAW cover the same function: to provide raw
(i.e., without ECC) access to the flash. In fact, although it may not be
clear, MTD_MODE_RAW implied that operations should enable the
MTD_OPS_RAW mode.
Thus, we should be specific on what each mode means. This is a start,
where MTD_FILE_MODE_* actually represents a "file mode," not necessarily
a true global MTD mode.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
These modes are not necessarily for OOB only. Particularly, MTD_OOB_RAW
affected operations on in-band page data as well. To clarify these
options and to emphasize that their effect is applied per-operation, we
change the primary prefix to MTD_OPS_.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
We will want to use the MTD_OOB_{PLACE,AUTO,RAW} modes in user-space
applications through the introduction of new ioctls, so we should make
this enum a shared type.
This enum is now anonymous.
Artem: tweaked the patch.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
This fixes issues with `nanddump -n' and the MEMREADOOB[64] ioctls on
hardware that performs error correction when reading only OOB data. A
driver for such hardware needs to know when we're doing a RAW vs. a
normal write, but mtd_do_read_oob does not pass such information to the
lower layers (e.g., NAND). We should pass MTD_OOB_RAW or MTD_OOB_PLACE
based on the MTD file mode.
For now, most drivers can get away with just setting:
chip->ecc.read_oob_raw = chip->ecc.read_oob
This is done by default; but for systems that behave as described above,
you must supply your own replacement function.
This was tested with nandsim as well as on actual SLC NAND.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Jim Quinlan <jim2101024@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
This fixes issues with `nandwrite -n -o' and the MEMWRITEOOB[64] ioctls
on hardware that writes ECC when writing OOB. The problem arises as
follows: `nandwrite -n' can write page data to flash without applying
ECC, but when used with the `-o' option, ECC is applied (incorrectly),
contrary to the `--noecc' option.
I found that this is the case because my hardware computes and writes
ECC data to flash upon either OOB write or page write. Thus, to support
a proper "no ECC" write, my driver must know when we're performing a raw
OOB write vs. a normal ECC OOB write. However, MTD does not pass any raw
mode information to the write_oob functions. This patch addresses the
problems by:
1) Passing MTD_OOB_RAW down to lower layers, instead of just defaulting
to MTD_OOB_PLACE
2) Handling MTD_OOB_RAW within the NAND layer's `nand_do_write_oob'
3) Adding a new (replaceable) function pointer in struct ecc_ctrl; this
function should support writing OOB without ECC data. Current
hardware often can use the same OOB write function when writing
either with or without ECC
This was tested with nandsim as well as on actual SLC NAND.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Jim Quinlan <jim2101024@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
The code has the check for parts but it called after kmemdup,
kmemdup(parts, sizeof(*parts) * nr_parts,...)
if (!parts)
return -ENOMEM
In fact, we need check parts before safely using it.
and we also need check the real_parts to make sure kmemdup
allocation sucessfully.
Signed-off-by: Jason Liu <jason.hui@linaro.org>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
MEMSETOOBSEL is completely unused and useless. Remove the definition.
Note: it's probably best not to use this ioctl number in the future for
MTD, since that may cause conflicts between old kernels and new user
software (or new kernels and old user software).
Artem: leave a comment about MEMSETOOBSEL.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Previous generations of MTDs all used OOB sizes that were powers of 2,
(e.g., 64, 128). However, newer generations of flash, especially NAND,
use irregular OOB sizes that are not powers of 2 (e.g., 218, 224, 448).
This means we cannot use masks like "mtd->oobsize - 1" to assume that we
will get a proper bitmask for OOB operations.
These masks are really only intended to hide the "page" portion of the
offset, leaving any OOB offset intact, so a masking with the writesize
(which *is* always a power of 2) is valid and makes more sense.
This has been tested for read/write of NAND devices (nanddump/nandwrite)
using nandsim and actual NAND flash.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
This has already been tested with Samsung NAND: K9LAG08U0M
on MX53EVK board, ubi/ubifs has already been tested OK too.
Signed-off-by: Jason Liu <jason.hui@linaro.org>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Convert error handling code to use gotos. At the same time, this adds
calls to kfree and iounmap in a few cases where they were overlooked.
Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Jiandong Zheng <jdzheng@broadcom.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Some messages that were tied to CONFIG_MTD_DEBUG_VERBOSE can now simply
be enabled using dynamic debugging features, if necessary. There's no
need for special debugging functions here.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Brian Norris
Huang Shijie
Jason Liu
Julia Lawall
Michael Hench
Jonghwan Choi
Jan Weitzel