None of the mtd->_erase() implementations work in an asynchronous manner,
so let's simplify MTD users that call mtd_erase(). All they need to do
is check the value returned by mtd_erase() and assume that != 0 means
failure.
Signed-off-by: NBoris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: NRichard Weinberger <richard@nod.at>

Some of the check done in custom ->_read/write_oob() implementation are
already done by the core (in mtd_check_oob_ops()).
Suggested-by: NPeter Pan <peterpansjtu@gmail.com>
[Remove redundant checks done in mtdpart.c]
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: NLadislav Michl <ladis@linux-mips.org>

Some MTD sublayers/drivers are implementing ->_read/write_oob() and
provide dummy wrappers for their ->_read/write() implementations.
Let the core handle this case instead of duplicating the logic.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NMiquel Raynal <miquel.raynal@free-electrons.com>
Tested-by: NLadislav Michl <ladis@linux-mips.org>

part_read() and part_read_oob() were counting ECC failures and
bitflips differently. Adjust part_read_oob() to mimic what is done in
part_read(). This is needed to use ->_read_oob() as a fallback when
when ->_read() is not implemented.

Note that bitflips and ECC failure accounting on MTD partitions is
broken by design, because nothing prevents concurrent accesses to the
underlying master MTD device between the moment we save the stats in a
local variable and the moment master->_read[_oob]() returns. It's not
something that can easily be fixed, so leave it like that for now.
Suggested-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: NLadislav Michl <ladis@linux-mips.org>

It is now unused.
Signed-off-by: NNicolas Pitre <nico@linaro.org>
Reviewed-by: NRichard Weinberger <richard@nod.at>
Acked-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: NChris Brandt <chris.brandt@renesas.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Commit 1eeef2d7 ("mtd: handle partitioning on devices with 0
erasesize") introduced a regression on heterogeneous erase region
devices. Alignment of the partition was tested against the master
eraseblock size which can be bigger than the slave one, thus leading
to some partitions being marked as read-only.

Update wr_alignment to match this slave erasesize after this erasesize
has been determined by picking the biggest erasesize of all the regions
embedded in the MTD partition.
Reported-by: NMathias Thore <Mathias.Thore@infinera.com>
Fixes: 1eeef2d7 ("mtd: handle partitioning on devices with 0 erasesize")
Cc: <stable@vger.kernel.org>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: NMathias Thore <Mathias.Thore@infinera.com>
Reviewed-by: NMathias Thore <Mathias.Thore@infinera.com>

Some recent patches caused churn around this area, and checkpatch
noticed the existing issues.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Some devices have partitions that are kind of containers with extra
subpartitions / volumes instead of e.g. a simple filesystem data. To
support such cases we need to first create normal flash device
partitions and then take care of these special ones.

It's very common case for home routers. Depending on the vendor there
are formats like TRX, Seama, TP-Link, WRGG & more. All of them are used
to embed few partitions into a single one / single firmware file.

Ideally all vendors would use some well documented / standardized format
like UBI (and some probably start doing so), but there are still
countless devices on the market using these poor vendor specific
formats.

This patch extends MTD subsystem by allowing to specify list of parsers
that should be tried for a given partition. Supporting such poor formats
is highly unlikely to be the top priority so these changes try to
minimize maintenance cost to the minimum. It reuses existing code for
these new parsers and just adds a one property and one new function.

This implementation requires setting partition parsers in a flash
parser. A proper change of bcm47xxpart will follow and in the future we
will hopefully also find a solution for doing it with ofpart
("fixed-partitions").
Signed-off-by: NRafał Miłecki <rafal@milecki.pl>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Some flash device partitions can be containers with extra subpartitions
(volumes). All callbacks are already capable of this additional level of
indirection.

This patch makes sure we always display subpartitions using a tree
structure and takes care of deleting subpartitions when parent gets
removed.
Signed-off-by: NRafał Miłecki <rafal@milecki.pl>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This prepares mtd subsystem for the new feature: subpartitions. In some
cases flash device partition can be a container with extra subpartitions
(volumes).

So far there was a flat structure implemented. One master (flash device)
could be partitioned into few partitions. Every partition got its master
and it was enough to get things running.

To support subpartitions we need to store pointer to the parent for each
partition. This is required to implement more natural tree structure and
handle all recursion and offsets calculation.

To make code consistent this patch renamed "master" to the "parent" in
places where we can be dealing with subpartitions.
Signed-off-by: NRafał Miłecki <rafal@milecki.pl>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

When support for sysfs "offset" file was added it missed to update the
del_mtd_partitions function. It deletes partitions just like
mtd_del_partition does so both should also take care of removing sysfs
files.

This change moves sysfs_remove_files call to the shared function to fix
this issue.

Fixes: a62c24d7 ("mtd: part: Add sysfs variable for offset of partition")
Cc: Dan Ehrenberg <dehrenberg@chromium.org>
Signed-off-by: NRafał Miłecki <rafal@milecki.pl>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

There are two similar functions handling deletion. One handles single
partition and another the whole MTD flash device. They share (duplicate)
some code so it makes sense to add a small helper for that part.

Function del_mtd_partitions has been moved a bit to keep all deleting
stuff together.
Signed-off-by: NRafał Miłecki <rafal@milecki.pl>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This code is going to be reused for parsers matched using OF so let's
factor it out to make this easier.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NRafał Miłecki <rafal@milecki.pl>
Acked-by: NBrian Norris <computersforpeace@gmail.com>

erasesize is meaningful for flash devices but for SRAM there is no
concept of an erase block so erasesize is set to 0. When partitioning
these devices instead of ensuring partitions fall on erasesize
boundaries we ensure they fall on writesize boundaries.
Helped-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NChris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The user visible change here is that mtd partitions get an of_node link
in sysfs.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

If implemented, 'max_bad_blocks' returns the maximum number of bad
blocks to reserve for a MTD. An implementation for NAND is coming soon.
Signed-off-by: NJeff Westfahl <jeff.westfahl@ni.com>
Signed-off-by: NZach Brown <zach.brown@ni.com>
Acked-by: NBoris Brezillon <boris.brezillon@free-electron.com>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Kernel source files need not include <linux/kconfig.h> explicitly
because the top Makefile forces to include it with:

  -include $(srctree)/include/linux/kconfig.h

This commit removes explicit includes except the following:

  * arch/s390/include/asm/facilities_src.h
  * tools/testing/radix-tree/linux/kernel.h

These two are used for host programs.

Link: http://lkml.kernel.org/r/1473656164-11929-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If the master device has callbacks for _get/put_device()
and this MTD has slaves a get_mtd_device() call on paritions
will never issue the registered callbacks.
Fix this by propagating _get/put_device() down.
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

MLC and TLC NAND devices are using NAND cells exposing more than one bit,
but instead of attaching all the bits in a given cell to a single NAND
page, each bit is usually attached to a different page. This concept is
called 'page pairing', and has significant impacts on the flash storage
usage.
The main problem showed by these devices is that interrupting a page
program operation may not only corrupt the page we are programming
but also the page it is paired with, hence the need to expose to MTD
users the pairing scheme information.

The pairing APIs allows one to query pairing information attached to a
given page (here called wunit), or the other way around (the wunit
pointed by pairing information).
It also provides several helpers to help the conversion between absolute
offsets and wunits, and query the number of pairing groups.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: NBrian Norris <computersforpeace@gmail.com>

ECC layout definitions are currently exposed using the nand_ecclayout
struct which embeds oobfree and eccpos arrays with predefined size.
This approach was acceptable when NAND chips were providing relatively
small OOB regions, but MLC and TLC now provide OOB regions of several
hundreds of bytes, which implies a non negligible overhead for everybody
even those who only need to support legacy NANDs.

Create an mtd_ooblayout_ops interface providing the same functionality
(expose the ECC and oobfree layout) without the need for this huge
structure.

The mtd->ecclayout is now deprecated and should be replaced by the
equivalent mtd_ooblayout_ops. In the meantime we provide a wrapper around
the ->ecclayout field to ease migration to this new model.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

Use the mtd_set_ecclayout() helper instead of directly assigning the
mtd->ecclayout field.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

Currently, all MTD drivers/sublayers exposing an OOB area are
doing the same kind of test to extract the available OOB size
based on the mtd_info and mtd_oob_ops structures.
Move this common logic into an inline function and make use of it.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Suggested-by: NPriit Laes <plaes@plaes.org>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

If partition parsers need to clean up their resources, we shouldn't
assume that all memory will fit in a single kmalloc() that the caller
can kfree(). We should allow the parser to provide a proper cleanup
routine.

Note that this means we need to keep a hold on the parser's module for a
bit longer, and release it later with mtd_part_parser_put().

Alongside this, define a default callback that we'll automatically use
if the parser doesn't provide one, so we can still retain the old
behavior.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

For some of the core partitioning code, it helps to keep info about the
parsed partition (and who parsed them) together in one place.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The use of kmemdup() complicates the error handling a bit. We don't
actually need to allocate new memory, since this reference is treated as
const, and it is copied into new memory by the partition registration
code anyway. So remove it.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

We're going to reuse put_partition_parser(), so let's fix up the prefix
naming a bit, to hopefully be more consistent. Also make convert to a
true C function instead of a macro.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

We can guard against reorganization of struct mtd_part by using
container_of(). We can also make sure we're using the right pointer
types by making this a static inline function instead of a macro.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This can help eliminate some boilerplate by generating the module_init()
and module_exit() functions, and by automatically assigning the module
owner.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

It's easier to guarantee we've cleared out all unused fields with
memset() than by manually initializing each field.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

Due to wrong assumption in ofpart ofpart fails on Exynos on SPI chips
with no partitions because the subnode containing controller data
confuses the ofpart parser.

Thus compiling in ofpart support automatically fails probing any SPI NOR
flash without partitions on Exynos.

Compiling in a partitioning scheme should not cause probe of otherwise
valid device to fail.

Instead, let's do the following:
 * try parsers until one succeeds
 * if no parser succeeds, report the first error we saw
 * even in the failure case, allow MTD to probe, with fallback
   partitions or no partitions at all -- the master device will still be
   registered

Issue report and comments initially by Michal Suchanek.
Reported-by: NMichal Suchanek <hramrach@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The probe of a mtd device can fail when a partition parser returns
error. The failure due to partition parsing can be quite mysterious when
multiple partitioning schemes are compiled in and any of them can fail
the probe.

Add debug prints which show what parsers were tried and what they
returned.
Signed-off-by: NMichal Suchanek <hramrach@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

If we fail to allocate a partition structure in the middle of the partition
creation process, the already allocated partitions are never removed, which
means they are still present in the partition list and their resources are
never freed.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Cc: stable@vger.kernel.org
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This patch makes MTD dynamic partitioning more flexible by removing
overlap checks for dynamic partitions. I don't see any  particular
reason why overlapping dynamic partitions should be prohibited while
static partitions are allowed to overlap freely.

The checks previously had an off-by-one error, where 'end' should be
one less than what it is currently set at, and adding partitions out of
increasing order will fail. Disabling the checks resolves this issue.
Signed-off-by: NDan Ehrenberg <dehrenberg@chromium.org>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This patch makes a sysfs variable called 'offset' on each partition
which contains the offset in bytes from the beginning of the master
device that the partition starts.
Signed-off-by: NDan Ehrenberg <dehrenberg@chromium.org>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

For many use cases, it helps to have a device node for the entire
MTD device as well as device nodes for the individual partitions.
For example, this allows querying the entire device's properties.
A common idiom is to create an additional partition which spans
over the whole device.

This patch makes a config option, CONFIG_MTD_PARTITIONED_MASTER,
which makes the master partition present even when the device is
partitioned. This isn't turned on by default since it presents
a backwards-incompatible device numbering.

The patch also makes the parent of a partition device be the master,
if the config flag is set, now that the master is a full device.
Signed-off-by: NDan Ehrenberg <dehrenberg@chromium.org>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Since "BDI: Provide backing device capability information [try #3]" the
backing_dev_info structure also provides flags for the kind of mmap
operation available in a nommu environment, which is entirely unrelated
to it's original purpose.

Introduce a new nommu-only file operation to provide this information to
the nommu mmap code instead.  Splitting this from the backing_dev_info
structure allows to remove lots of backing_dev_info instance that aren't
otherwise needed, and entirely gets rid of the concept of providing a
backing_dev_info for a character device.  It also removes the need for
the mtd_inodefs filesystem.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NTejun Heo <tj@kernel.org>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

With the introduction of mtd_block_isreserved(), it's now possible
to fix the bad and reserved block distribution exposed by ecc_stats,
instead of accounting all the bad or reserved blocks as 'bad'.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NPekon Gupta <pekon@ti.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

In addition to mtd_block_isbad(), which checks if a block is bad or
reserved, it's needed to check if a block is reserved only (but not
bad). This commit adds an MTD interface for it, in a similar fashion to
mtd_block_isbad().

While here, fix mtd_block_isbad() so the out-of-bounds checking is done
before the callback check.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NPekon Gupta <pekon@ti.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Signed-off-by: NChristian Riesch <christian.riesch@omicron.at>
Cc: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

register_mtd_parser never fails; hence make it return void.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>