History log of /drivers/mtd/mtdcore.c
Revision Date Author Comments
5e47212831ac565993d21ebd36216d98f2b58f30 22-Jul-2014 Brian Norris <computersforpeace@gmail.com> mtd: remove dead non-char logic

MTD used to allow compiling out character device support. This was
dropped in the following commit, but some of the accompanying logic was
never dropped:

commit 660685d9d1b4730f0b5ca97fa95f272f99c63bce
Author: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Date: Thu Mar 14 13:27:40 2013 +0200

mtd: merge mtdchar module with mtdcore

The weird logic was flagged by Coverity.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
0c2b4e21444d0e274e91fc7db85caddb30988853 22-Jul-2014 Brian Norris <computersforpeace@gmail.com> mtd: correct upper bounds check for mtd_*() APIs

When checking the upper boundary (i.e., whether an address is higher
than the maximum size of the MTD), we should be doing an inclusive check
(greater or equal). For instance, an address of 16MB (0x1000000) on a
16MB device is invalid.

The strengthening of this bounds check is redundant for those which
already have a address+length check and ensure that the length is
non-zero, but let's just fix them all, for completeness.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
8471bb73ba10ed6788b4f1e9b8a0f9dc6bdb05b5 22-May-2014 Ezequiel Garcia <ezequiel.garcia@free-electrons.com> mtd: Introduce mtd_block_isreserved()

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: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Pekon Gupta <pekon@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
990a3af0c20590954be01a95c2c3fcef9360a836 24-Jun-2014 Ezequiel Garcia <ezequiel.garcia@free-electrons.com> mtd: Add sysfs attributes to expose the ECC stats fields

These new sysfs device attributes allow us to retrieve the ECC and bad
block stats by poking a sysfs file, which is often more convenient than
using the ioctl.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Pekon Gupta <pekon@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
9a78bc83b4c31f67202b7b0a77fa25da732f44a3 06-Mar-2014 Christian Riesch <christian.riesch@omicron.at> mtd: Fix the behavior of OTP write if there is not enough room for data

If a write to one time programmable memory (OTP) hits the end of this
memory area, no more data can be written. The count variable in
mtdchar_write() in drivers/mtd/mtdchar.c is not decreased anymore.
We are trapped in the loop forever, mtdchar_write() will never return
in this case.

The desired behavior of a write in such a case is described in [1]:
- Try to write as much data as possible, truncate the write to fit into
the available memory and return the number of bytes that actually
have been written.
- If no data could be written at all, return -ENOSPC.

This patch fixes the behavior of OTP write if there is not enough space
for all data:

1) mtd_write_user_prot_reg() in drivers/mtd/mtdcore.c is modified to
return -ENOSPC if no data could be written at all.
2) mtdchar_write() is modified to handle -ENOSPC correctly. Exit if a
write returned -ENOSPC and yield the correct return value, either
then number of bytes that could be written, or -ENOSPC, if no data
could be written at all.

Furthermore the patch harmonizes the behavior of the OTP memory write
in drivers/mtd/devices/mtd_dataflash.c with the other implementations
and the requirements from [1]. Instead of returning -EINVAL if the data
does not fit into the OTP memory, we try to write as much data as
possible/truncate the write.

[1] http://pubs.opengroup.org/onlinepubs/9699919799/functions/write.html

Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
4b78fc42f3e3f07687dc27efc1153d29e360afa1 28-Jan-2014 Christian Riesch <christian.riesch@omicron.at> mtd: Add a retlen parameter to _get_{fact,user}_prot_info

Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Cc: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
54c738f694ab67a007a43482d1dd7cf956fbb6c3 02-Dec-2013 Axel Lin <axel.lin@ingics.com> mtd: convert to use ATTRIBUTE_GROUPS

Use new ATTRIBUTE_GROUPS macro to declare attribute groups.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
ca5295f48b25ee58fd9de8830fe4016d1d45eb0a 30-Oct-2013 Wei Yongjun <yongjun_wei@trendmicro.com.cn> mtd: remove duplicated include from mtdcore.c

Remove duplicated include.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
f83c3838b9146b891d0405d3a83660e8f6aed02f 13-Oct-2013 Ezequiel Garcia <ezequiel.garcia@free-electrons.com> mtd: Move major number definitions to major.h

This patch moves the char and block major number definitions
to major.h to be with the rest of the major numbers.
While doing this, include major.h in the files that need it.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
f48372465ffdff62a6d75a6f34bc850855fb6470 25-Sep-2013 Huang Shijie <b32955@freescale.com> mtd: add MTD_MLCNANDFLASH case for mtd_type_show()

The current mtd_type_show() misses the MTD_MLCNANDFLASH case.
This patch adds the case for it, and also updates the ABI.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
bf977e3f158dc949fd6e1e4195f80d42232cb5fa 16-Aug-2013 Huang Shijie <b32955@freescale.com> mtd: add a new sys node to show the ecc step size

Add a new sys node to show the ecc step size.
The application then can uses this node to get the ecc step
size.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
02aa2a37636c8fa4fb9322d91be46ff8225b7de0 04-Jul-2013 Kees Cook <keescook@chromium.org> drivers: avoid format string in dev_set_name

Calling dev_set_name with a single paramter causes it to be handled as a
format string. Many callers are passing potentially dynamic string
content, so use "%s" in those cases to avoid any potential accidents,
including wrappers like device_create*() and bdi_register().

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
0d01ff2583086fd532181d2ee16112f5342eb78d 12-Apr-2013 David Howells <dhowells@redhat.com> Include missing linux/slab.h inclusions

Include missing linux/slab.h inclusions where the source file is currently
expecting to get kmalloc() and co. through linux/proc_fs.h.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: linux-s390@vger.kernel.org
cc: sparclinux@vger.kernel.org
cc: linux-efi@vger.kernel.org
cc: linux-mtd@lists.infradead.org
cc: devel@driverdev.osuosl.org
cc: x86@kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
660685d9d1b4730f0b5ca97fa95f272f99c63bce 14-Mar-2013 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: merge mtdchar module with mtdcore

The MTD subsystem has historically tried to be as configurable as possible. The
side-effect of this is that its configuration menu is rather large, and we are
gradually shrinking it. For example, we recently merged partitions support with
the mtdcore.

This patch does the next step - it merges the mtdchar module to mtdcore. And in
this case this is not only about eliminating too fine-grained separation and
simplifying the configuration menu. This is also about eliminating seemingly
useless kernel module.

Indeed, mtdchar is a module that allows user-space making use of MTD devices
via /dev/mtd* character devices. If users do not enable it, they simply cannot
use MTD devices at all. They cannot read or write the flash contents. Is it a
sane and useful setup? I believe not. And everyone just enables mtdchar.

Having mtdchar separate is also a little bit harmful. People sometimes miss the
fact that they need to enable an additional configuration option to have
user-space MTD interfaces, and then they wonder why on earth the kernel does
not allow using the flash? They spend time asking around.

Thus, let's just get rid of this module and make it part of mtd core.

Note, mtdchar had additional configuration option to enable OTP interfaces,
which are present on some flashes. I removed that option as well - it saves a
really tiny amount space.

[dwmw2: Strictly speaking, you can mount file systems on MTD devices just
fine without the mtdchar (or mtdblock) devices; you just can't do
other manipulations directly on the underlying device. But still I
agree that it makes sense to make this unconditional. And Yay! we
get to kill off an instance of checking CONFIG_foo_MODULE, which is
an abomination that should never happen.]

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
93e562141ac58452bcea48718af92cc62a20669d 14-Mar-2013 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: mtdcore: remove few useless #ifdef's

Remove a couple of useles '#ifdef CONFIG_PROC_FS's around procfs functions
which anyway turn into empty function in 'proc_fs.h' file when CONFIG_PROC_FS
is not defined.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
26a4734623e4f06752014336b05cf3ae77158892 11-Mar-2013 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: add 'const' qualifier to a couple of register functions

'mtd_device_parse_register()' and 'parse_mtd_partitions()' functions accept a
an array of character pointers. These functions modify neither the pointers nor
the characters they point to. The characters are actually names of the MTD
parsers.

At the moment, the argument type is 'const char **', which means that only the
names of the parsers are constant. Let's turn the argument type into 'const
char * const *', which means that both names and the pointers which point to
them are constant.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
589e9c4dace6995440c119486919ce95b180dd38 28-Feb-2013 Tejun Heo <tj@kernel.org> mtd: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
caf491916b1c1e939a2c7575efb7a77f11fc9bdf 10-Dec-2012 Linus Torvalds <torvalds@linux-foundation.org> Revert "revert "Revert "mm: remove __GFP_NO_KSWAPD""" and associated damage

This reverts commits a50915394f1fc02c2861d3b7ce7014788aa5066e and
d7c3b937bdf45f0b844400b7bf6fd3ed50bac604.

This is a revert of a revert of a revert. In addition, it reverts the
even older i915 change to stop using the __GFP_NO_KSWAPD flag due to the
original commits in linux-next.

It turns out that the original patch really was bogus, and that the
original revert was the correct thing to do after all. We thought we
had fixed the problem, and then reverted the revert, but the problem
really is fundamental: waking up kswapd simply isn't the right thing to
do, and direct reclaim sometimes simply _is_ the right thing to do.

When certain allocations fail, we simply should try some direct reclaim,
and if that fails, fail the allocation. That's the right thing to do
for THP allocations, which can easily fail, and the GPU allocations want
to do that too.

So starting kswapd is sometimes simply wrong, and removing the flag that
said "don't start kswapd" was a mistake. Let's hope we never revisit
this mistake again - and certainly not this many times ;)

Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
a50915394f1fc02c2861d3b7ce7014788aa5066e 29-Nov-2012 Andrew Morton <akpm@linux-foundation.org> revert "Revert "mm: remove __GFP_NO_KSWAPD""

It apepars that this patch was innocent, and we hope that "mm: avoid
waking kswapd for THP allocations when compaction is deferred or
contended" will fix the final kswapd-spinning cause.

Cc: Zdenek Kabelac <zkabelac@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
82b212f40059bffd6808c07266a942d444d5558a 27-Nov-2012 Mel Gorman <mgorman@suse.de> Revert "mm: remove __GFP_NO_KSWAPD"

With "mm: vmscan: scale number of pages reclaimed by reclaim/compaction
based on failures" reverted, Zdenek Kabelac reported the following

Hmm, so it's just took longer to hit the problem and observe
kswapd0 spinning on my CPU again - it's not as endless like before -
but still it easily eats minutes - it helps to turn off Firefox
or TB (memory hungry apps) so kswapd0 stops soon - and restart
those apps again. (And I still have like >1GB of cached memory)

kswapd0 R running task 0 30 2 0x00000000
Call Trace:
preempt_schedule+0x42/0x60
_raw_spin_unlock+0x55/0x60
put_super+0x31/0x40
drop_super+0x22/0x30
prune_super+0x149/0x1b0
shrink_slab+0xba/0x510

The sysrq+m indicates the system has no swap so it'll never reclaim
anonymous pages as part of reclaim/compaction. That is one part of the
problem but not the root cause as file-backed pages could also be
reclaimed.

The likely underlying problem is that kswapd is woken up or kept awake
for each THP allocation request in the page allocator slow path.

If compaction fails for the requesting process then compaction will be
deferred for a time and direct reclaim is avoided. However, if there
are a storm of THP requests that are simply rejected, it will still be
the the case that kswapd is awake for a prolonged period of time as
pgdat->kswapd_max_order is updated each time. This is noticed by the
main kswapd() loop and it will not call kswapd_try_to_sleep(). Instead
it will loopp, shrinking a small number of pages and calling
shrink_slab() on each iteration.

The temptation is to supply a patch that checks if kswapd was woken for
THP and if so ignore pgdat->kswapd_max_order but it'll be a hack and not
backed up by proper testing. As 3.7 is very close to release and this
is not a bug we should release with, a safer path is to revert "mm:
remove __GFP_NO_KSWAPD" for now and revisit it with the view to ironing
out the balance_pgdat() logic in general.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Zdenek Kabelac <zkabelac@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
c654345924f7cce87bb221b89db91cba890421ba 09-Oct-2012 Rik van Riel <riel@redhat.com> mm: remove __GFP_NO_KSWAPD

When transparent huge pages were introduced, memory compaction and swap
storms were an issue, and the kernel had to be careful to not make THP
allocations cause pageout or compaction.

Now that we have working compaction deferral, kswapd is smart enough to
invoke compaction and the quadratic behaviour around isolate_free_pages
has been fixed, it should be safe to remove __GFP_NO_KSWAPD.

[minchan@kernel.org: Comment fix]
[mgorman@suse.de: Avoid direct reclaim for deferred compaction]
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
e47f68587b8255410e79166cbdecae290ca8a84e 23-Jun-2012 Brian Norris <computersforpeace@gmail.com> mtd: check for max_bitflips in mtd_read_oob()

mtd_read_oob() has some unexpected similarities to mtd_read(). For
instance, when ops->datbuf != NULL, nand_base.c might return max_bitflips;
however, when ops->datbuf == NULL, nand_base's code potentially could
return -EUCLEAN (no in-tree drivers do this yet). In any case where the
driver might return max_bitflips, we should translate this into an
appropriate return code using the bitflip_threshold.

Essentially, mtd_read_oob() duplicates the logic from mtd_read().

This prevents users of mtd_read_oob() from receiving a positive return
value (i.e., from max_bitflips) and interpreting it as an unknown error.

Artem: amend comments.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Mike Dunn <mikedunn@newsguy.com>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
d2d48480d16ab349ae5d4732b4d79ff48b4b4171 23-Jun-2012 Brian Norris <computersforpeace@gmail.com> mtd: move mtd_read_oob() definition out of mtd.h

mtd_read_oob() will be expanded a little, so don't leave it in the header
as a static inline function.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
edbc4540e02c201bdd4f4d498ebb6ed517fd36e2 25-Apr-2012 Mike Dunn <mikedunn@newsguy.com> mtd: driver _read() returns max_bitflips; mtd_read() returns -EUCLEAN

The drivers' _read() method, absent an error, returns a non-negative integer
indicating the maximum number of bit errors that were corrected in any one
region comprising an ecc step. MTD returns -EUCLEAN if this is >=
bitflip_threshold, 0 otherwise. If bitflip_threshold is zero, the comparison is
not made since these devices lack ECC and always return zero in the non-error
case (thanks Brian)¹. Note that this is a subtle change to the driver
interface.

This and the preceding patches in this set were tested with ubi on top of the
nandsim and docg4 devices, running the ubi test io_basic from mtd-utils.

¹ http://lists.infradead.org/pipermail/linux-mtd/2012-March/040468.html

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Ivan Djelic <ivan.djelic@parrot.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
d062d4ede877fcd2ecc4c6262abad09a6f32950a 25-Apr-2012 Mike Dunn <mikedunn@newsguy.com> mtd: bitflip_threshold added to mtd_info and sysfs

An element 'bitflip_threshold' is added to struct mtd_info, and also exposed as
a read/write variable in sysfs. This will be used to determine whether or not
mtd_read() returns -EUCLEAN or 0 (absent a hard error). If the driver leaves it
as zero, mtd will set it to a default value of ecc_strength.

This v2 adds the line that propagates bitflip_threshold from the master to the
partitions - thanks Ivan¹.

¹ http://lists.infradead.org/pipermail/linux-mtd/2012-April/040900.html

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
a9b672e82bca47bf2b37ee869b8095000cf3ca88 25-Apr-2012 Mike Dunn <mikedunn@newsguy.com> mtd: expose ecc_strength through sysfs

ecc_strength element of struct mtd_info is exposed as a read-only variable in
sysfs.

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
3b27dac03972c10980ec5480ad8425fc95aae9ad 09-Feb-2012 Shmulik Ladkani <shmulik.ladkani@gmail.com> mtd: unify initialization of erase_info->fail_addr

Initialization of 'erase_info->fail_addr' to MTD_FAIL_ADDR_UNKNOWN prior
erase operation is duplicated accross several MTD drivers, and also taken
care of by some MTD users as well.

Harmonize it: initialize 'fail_addr' within 'mtd_erase()' interface.

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
de3cac9357b5aa9f9f02520e5f2567b06f3f75a7 08-Feb-2012 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: check for zero length in OTP functions

This patch changes all the OTP functions like 'mtd_get_fact_prot_info()' and
makes them return zero immediately if the input 'len' parameter is 0. This is
not really needed currently, but most of the other functions do this, and it is
just consistent to do the same in the OTP functions.

This patch also moves the OTP functions from the header file to mtdcore.c
because they become a bit too big for being inlined.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
bcb1d238716d138c9e16347fc32b3c1ae006339e 06-Feb-2012 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: move zero length verification to MTD API functions

In many places in drivers we verify for the zero length, but this is very
inconsistent across drivers. This is obviously the right thing to do, though.
This patch moves the check to the MTD API functions instead and removes a lot
of duplication.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
0dd5235f51fb0eb0b8cef3fed35be39b8a06d7bd 08-Feb-2012 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: harmonize mtd_point interface implementation

Some MTD drivers return -EINVAL if the 'phys' parameter is not NULL, trying to
convey that they cannot return the physical address. However, this is not very
logical because they still can return the virtual address ('virt'). But some
drivers (lpddr) just ignore the 'phys' parameter instead, which is a more
logical thing to do.

Let's harmonize this and:

1. Always initialize 'virt' and 'phys' to 'NULL' in 'mtd_point()'.
2. Do not return an error if the physical address cannot be found.

So as a result, all drivers will set 'phys' to 'NULL' if it is not supported.
None of the 'mtd_point()' users use 'phys' anyway, so this should not break
anything. I guess we could also just delete this parameter later.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
834247ec7e281dee839fe4a04bc1bbf0c7395172 05-Feb-2012 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: remove retlen zeroing duplication

The MTD API function now zero the 'retlen' parameter before calling
the driver's method — do not do this again in drivers. This removes
duplicated '*retlen = 0' assignent from the following methods:

'mtd_point()'
'mtd_read()'
'mtd_write()'
'mtd_writev()'
'mtd_panic_write()'

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
664addc248d2fed68d013d26ff2fc796d7134259 03-Feb-2012 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: remove R/O checking duplication

Many drivers check whether the partition is R/O and return -EROFS if yes.
Let's stop having duplicated checks and move them to the API functions
instead.

And again a bit of noise - deleted few too sparse newlines, sorry.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
8273a0c911d8e068297ef70aa7241ee78db4c712 03-Feb-2012 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: add offset and length checks to the API function

Add verification of the offset and length to MTD API functions and verify that
MTD device offset and length are within MTD device size.

The modified API functions are:

'mtd_erase()'
'mtd_point()'
'mtd_unpoint()'
'mtd_get_unmapped_area()'
'mtd_read()'
'mtd_write()'
'mtd_panic_write()'
'mtd_lock()'
'mtd_unlock()'
'mtd_is_locked()'
'mtd_block_isbad()'
'mtd_block_markbad()'

This patch also uninlines these functions and exports in mtdcore.c because they
are not performance-critical and do not have to be inlined.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
3ee5014185b9041fcb27eef34c83487ce77dd9d3 27-Jan-2012 Brian Norris <computersforpeace@gmail.com> mtd: mtdcore: remove unnecessary mtd->resume check

We don't need to to check for mtd->resume before calling mtd_resume().
mtd_resume() should take care of that.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
3c3c10bba1e4ccb75b41442e45c1a072f6cded19 30-Jan-2012 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: add leading underscore to all mtd functions

This patch renames all MTD functions by adding a "_" prefix:

mtd->erase -> mtd->_erase
mtd->read_oob -> mtd->_read_oob
...

The reason is that we are re-working the MTD API and from now on it is
an error to use MTD function pointers directly - we have a corresponding
API call for every pointer. By adding a leading "_" we achieve the following:

1. Make sure we convert every direct pointer users
2. A leading "_" suggests that this interface is internal and it becomes
less likely that people will use them directly
3. Make sure all the out-of-tree modules stop compiling and the owners
spot the big API change and amend them.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
335a5f409ee3960bda6b112b9d1a89d0a4e0a7eb 12-Jan-2012 Fabio Estevam <festevam@gmail.com> mtd: mtdcore: Fix build warning when CONFIG_MTD_CHAR is not defined

Fix the following build warning:

drivers/mtd/mtdcore.c: In function ‘mtd_release’:
drivers/mtd/mtdcore.c:110: warning: unused variable ‘mtd’

This happens when neither CONFIG_MTD_CHAR nor CONFIG_MTD_CHAR_MODULE are defined.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
1a30871fe635d3e92972e6b93e39ff65bb57e52d 16-Jan-2012 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: fix MTD suspend

Commits 3fe4bae88460869a8e553397cd9057a4ee7ca341 and
079c985e7a6f4ce60f931cebfdd5ee3c3 broke MTD suspend in 2 ways:

1. When the '->suspend' method is not present, we return -EOPNOTSUPP, but
the callers of 'mtd_suspend()' expects 0 instead.
2. Checking of the 'mtd' parameter against NULL has been incorrectly removed
in 'mtd_cls_suspend()'.

This patch fixes the breakages. This has been found, analyzed, reported
and tested by Rafael J. Wysocki <rjw@sisk.pl>.

Note, this patch is not needed in the stable tree because it causes a
regression introduced during the v3.3 merge window.

Reported-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
079c985e7a6f4ce60f931cebfdd5ee3c38347e31 30-Dec-2011 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: do not use mtd->suspend and mtd->resume directly

Just call the 'mtd_suspend()' and 'mtd_resume()' - they will do nothing
if the operation is not defined.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
381345652fca688aeaa967c231e5075cf68d05b6 30-Dec-2011 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: do not use mtd->lock, unlock and is_locked directly

Instead, call the corresponding MTD API function which will return
'-EOPNOTSUPP' if the operation is not supported.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
1dbebd32562b3c2caeca35960e5cb00bfcc12900 30-Dec-2011 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: harmonize mtd_writev usage

This patch makes the 'mtd_writev()' function more usable and logical. We first
teach it to fall-back to the 'default_mtd_writev()' function if the MTD driver
does not define its own '->writev()' method. Then we make block2mtd and JFFS2
just 'mtd_writev()' instead of 'default_mtd_writev()' function. This means we
can now stop exporting 'default_mtd_writev()' and instead, export
'mtd_writev()'. This is much cleaner and more logical, as well as allows us to
get read of another direct 'mtd->writev' access in JFFS2.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
33c87b4a2c820316314542ce3f60b8a8c6a96928 30-Dec-2011 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: mtdcore: export symbols cleanup

The mtdcore.c file is a bit inconsistent - some EXPORT_SYMBOL_GPL declarations
follow the corresponding functions, some are placed at the end. This patch
harmonizes the file so that EXPORT_SYMBOL_GPL declarations follow the
corresponding function.

It also removes few extra newlines and trailing white-spaces.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
52b020317f65114eeba2ee2cfa70a51a286f1d8a 30-Dec-2011 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: clean-up the default_mtd_writev function

1. Teach 'mtd_write()' function to return '-EROFS' if the write method
is undefined, and remove the corresponding check from
'default_mtd_writev()'.
2. Do not test 'retlen' for NULL - it cannot be NULL.
3. Few minor coding stile clean-ups.
4. Add a kerneldoc comment

Additionally, minor fixes to the kerneldoc comments of the neighbor function.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
d5de20a9a1c5ad68c07e017d11f6dbb5e289750c 29-Dec-2011 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: kill dev_to_mtd helper

... since it is not needed because the generic 'dev_get_drvdata()' can be
used instead.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
ead995f8d4da1e2f1ef40b0e5f4133fee38a3d3d 23-Dec-2011 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: introduce mtd_resume interface

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
3fe4bae88460869a8e553397cd9057a4ee7ca341 23-Dec-2011 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: introduce mtd_suspend interface

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
b66005cd3e6f104e0a1b6492110c337269b53ec3 23-Dec-2011 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: introduce mtd_unlock interface

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
eda95cbf75193808f62948fb0142ba0901d8bee2 23-Dec-2011 Artem Bityutskiy <artem.bityutskiy@linux.intel.com> mtd: introduce mtd_write interface

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
4d523b60ef9d1953d9e12745ca0ed3e2dc98c189 24-Aug-2011 Jason Liu <jason.hui@linaro.org> mtd: check parts pointer before using it

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>
92394b5c2be774425f255b5c7afbd8b19978fe12 20-Jul-2011 Brian Norris <computersforpeace@gmail.com> mtd: spelling fixes

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
289c05222172b51401dbbb017115655f241d94ab 19-Jul-2011 Brian Norris <computersforpeace@gmail.com> mtd: replace DEBUG() with pr_debug()

Start moving away from the MTD_DEBUG_LEVEL messages. The dynamic
debugging feature is a generic kernel feature that provides more
flexibility.

(See Documentation/dynamic-debug-howto.txt)

Also fix some punctuation, indentation, and capitalization that went
along with the affected lines.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
15c60a508ab3393e68b7ccb3528981ccacf9c0f9 23-Jun-2011 Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> mtd: drop mtd_device_register

mtd_device_register() is a limited version of mtd_device_parse_register.
Replace it with macro calling mtd_device_parse_register().

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
c7975330154af17aecc167b33ca866b6b3d98918 10-Jun-2011 Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> mtd: abstract last MTD partition parser argument

Encapsulate last MTD partition parser argument into a separate
structure. Currently it holds only 'origin' field for RedBoot parser,
but will be extended in future to contain at least device_node for OF
devices.

Amended commentary to make kerneldoc happy

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Artem Bityutskiy <dedekind1@gmail.com>
1c4c215cbdcbfd08183d82b2953591cd00564422 25-Mar-2011 Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> mtd: add new API for handling MTD registration

Lots (nearly all) mtd drivers contain nearly the similar code that
calls parse_mtd_partitions, provides some platform-default values, if
parsing fails, and registers mtd device.

This is an aim to provide single implementation of this scenario:
mtd_device_parse_register() which will handle all this parsing and
defaults.

Artem: amended comments

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
eea72d5fdf59879edb2c6639b0b7cc385e0df646 23-May-2011 Jamie Iles <jamie@jamieiles.com> mtd: remove add_mtd_partitions, add_mtd_device and friends

These symbols are replaced with mtd_device_register() (and removal with
mtd_device_unregister()) for public registration.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
f5671ab3f67a10f7234de21464391c20c1ef8ebb 23-May-2011 Jamie Iles <jamie@jamieiles.com> mtd: introduce mtd_device_(un)register()

To prepare for the removal of add_mtd_device and add_mtd_partitions(),
introduce mtd_device_register(). This will create partitions if they
are supplied or register the whole device if there are no partitions.

Once all drivers are converted to use mtd_device_register(),
add_mtd_device() and add_mtd_partitions() will be made internal only.

v2: move kerneldoc to implementation file and fixup some kerneldoc
warnings.

Artem: tweak comments: remove junk tabs, use dots consistently.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
d5ca51292d899a19882cb9bf8f64079209e688fe 20-May-2011 Wanlong Gao <wanlong.gao@gmail.com> mtd:fix the bad format in the mtdcore.c

Remove the spare spaces in the head of the lines.

Signed-off-by: Wanlong Gao <wanlong.gao@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
52534f2dba5d033c0c33e515faa2767d7e8e986a 17-May-2011 Wanlong Gao <wanlong.gao@gmail.com> mtd: simplify get_mtd_device_nm function

'get_mtd_device_nm()' has a piece of code which equivalent to what
'__get_mtd_device()' does - remove this duplicated code and use
''__get_mtd_device()' instead.

Artem: changed commit message.
Artem: while on it, remove an unnecessary extra empty line

Signed-off-by: Wanlong Gao <wanlong.gao@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
447d9bd82020f159456ee00b011486205205aaa7 13-May-2011 Alexey Dobriyan <adobriyan@gmail.com> mtd: convert to seq_file interface

->read_proc interface is going away, switch to seq_file.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
33b53716bc4b3ff3da2bc41581226424443f9d5a 08-Apr-2011 Grant Erickson <marathon96@gmail.com> mtd: create function to perform large allocations

Introduce a common function to handle large, contiguous kmalloc buffer
allocations by exponentially backing off on the size of the requested
kernel transfer buffer until it succeeds or until the requested
transfer buffer size falls below the page size.

This helps ensure the operation can succeed under low-memory, highly-
fragmented situations albeit somewhat more slowly.

Artem: so this patch solves the problem that the kernel tries to kmalloc too
large buffers, which (a) may fail and does fail - people complain about this,
and (b) slows down the system in case of high memory fragmentation, because
the kernel starts dropping caches, writing back, swapping, etc. But we do not
really have to allocate a lot of memory to do the I/O, we may do this even with
as little as one min. I/O unit (NAND page) of RAM. So the idea of this patch is
that if the user asks to read or write a lot, we try to kmalloc a lot, with GFP
flags which make the kernel _not_ drop caches, etc. If we can allocate it - good,
if not - we try to allocate twice as less, and so on, until we reach the min.
I/O unit size, which is our last resort allocation and use the normal
GFP_KERNEL flag.

Artem: re-write the allocation function so that it makes sure the allocated
buffer is aligned to the min. I/O size of the flash.

Signed-off-by: Grant Erickson <marathon96@gmail.com>
Tested-by: Ben Gardiner <bengardiner@nanometrics.ca>
Tested-by: Stefano Babic <sbabic@denx.de>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
ca91facf6babe548b5386993bb2820b7dc9b743d 12-Jan-2011 H Hartley Sweeten <hartleys@visionengravers.com> mtd: local symbols should be static

The three backing_dev_info symbols are only used in this file and
should be static.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
6ae0185fe201eae0548dace2a84acb5050fc8606 08-Aug-2010 David Woodhouse <David.Woodhouse@intel.com> mtd: Remove obsolete <mtd/compatmac.h> include

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
a1452a3771c4eb85bd779790b040efdc36f4274e 08-Aug-2010 David Woodhouse <David.Woodhouse@intel.com> mtd: Update copyright notices

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
05d71b4625bdadd7c7ae80455e7038e221c76e4d 29-Mar-2010 Tejun Heo <tj@kernel.org> mtd: update gfp/slab.h includes

Implicit slab.h inclusion via percpu.h is about to go away. Make sure
gfp.h or slab.h is included as necessary.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
0661b1ac5d48eb47c8a5948c0554fea25e0895ab 27-Apr-2010 Jens Axboe <jens.axboe@oracle.com> mtd: ensure that bdi entries are properly initialized and registered

They will be holding dirty inodes and be responsible for flushing
them out, so they need to be setup properly.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
a33eb6b91034c95b9b08576f68be170f995b2c7d 27-Apr-2010 Jörn Engel <joern@logfs.org> Move mtd_bdi_*mappable to mtdcore.c

Removes one .h and one .c file that are never used outside of
mtdcore.c.

Signed-off-by: Joern Engel <joern@logfs.org>

Edited to remove on leftover debug define.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
5a0e3ad6af8660be21ca98a971cd00f331318c05 24-Mar-2010 Tejun Heo <tj@kernel.org> include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
75c0b84d41c6f08c0cb083464907005683ef2920 22-Feb-2010 Maxim Levitsky <maximlevitsky@gmail.com> mtd: call the remove notifiers before assuming it is in use

Now that mtd block common layer is prepared for proper hotplug support,
enable it here

Now all users of the mtd device have a chance to put the mtd device
when they are notified to do so, and they have to do so to make hotplug work.

[dwmw2: There's more work to be done to fix hotplug in the general case, but
this is a reasonable start]

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
3bd456576f22acd55fb6c3d3d4261131821f5a3b 22-Feb-2010 Maxim Levitsky <maximlevitsky@gmail.com> mtd: create unlocked versions of {get,put}_mtd_device

Use these only if you know that you already hold mtd_table_mutex

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
b520e412faaaad35641aeedd6059179f9f1b393c 29-Jan-2010 Ben Hutchings <bhutchings@solarflare.com> mtd: Replace static array of devices with an idr structure

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
f1332ba2f23800bb5d52457ac150c568dfb1f3bf 29-Jan-2010 Ben Hutchings <bhutchings@solarflare.com> mtd: Introduce and use iteration macro for reading the MTD device table

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
35016dd7e92cf0eb5ae2e811445dd52320c348d0 03-Nov-2009 Roel Kluin <roel.kluin@gmail.com> mtd: ensure index is positive

The index is signed, make sure it is not negative
when we read the array element.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
a4dbd6740df0872cdf0a86841f75beec8381964d 24-Jun-2009 David Brownell <dbrownell@users.sourceforge.net> driver model: constify attribute groups

Let attribute group vectors be declared "const". We'd
like to let most attribute metadata live in read-only
sections... this is a start.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
fca910883324d437a24d447b08f524fa19261a94 07-Aug-2009 H Hartley Sweeten <hartleys@visionengravers.com> mtd: make few symbols static

Make mtd_group and mtd_groups static since they are only used in this
file.

[Amended by Artem Bityutskiy]

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
6afc4fdb3e94ba60cd566cb878b60c6c01979277 28-Jul-2009 Saeed Bishara <saeed@marvell.com> mtd: fix the conversion from dev to mtd_info

The patch fixes a bug when converting dev to mtd_info by using the
drvdata of the dev, the previous code used
container_of(dev, struct mtd_info, dev), but won't work for the mtdXro
devices as they created without being contained inside mtd_info structure.

Signed-off-by: Saeed Bishara <saeed@marvell.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
15bce40cb3133bcc07d548013df97e4653d363c1 05-Apr-2009 David Woodhouse <David.Woodhouse@intel.com> [MTD] Restore suspend/resume support for mtd devices

This is intended to suspend/resume the _chip_, while we leave board
drivers to handle their own suspend/resume for the controller.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
e7693548950ea5801d5d8b00414aed37033cf972 17-Apr-2009 Artem Bityutskiy <dedekind@infradead.org> mtd: expose subpage size via sysfs

MTD has got sysfs support in 2.6.30-rc1. But subpage size is not
exposed there - do this.

UBI utilities badly need this parameter. At the moment there is
no way to get subpage size - ioctls do not return it. And we
just got sysfs support, so we can easilly extend it with this
additional parameter.

This can be merged late in the development cycle because:
1. sysfs support has been just added - there are no users for
it so far, even.
2. UBI utilities really need this parameter, and it is better
not to delay this.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2fdb11449ca82f4f1907fce4929df4e0bd267c50 12-Apr-2009 Denis V. Lunev <den@openvz.org> mtd: mtd in mtd_release is unused without CONFIG_MTD_CHAR

drivers/mtd/mtdcore.c: In function 'mtd_release':
drivers/mtd/mtdcore.c:51: warning: unused variable 'mtd'

[akpm: make it actually build]
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
45b09076149f1360e15919ca7e004e8d3810a0f7 04-Apr-2009 Kevin Cernekee <kpc.mtd@gmail.com> [MTD] sysfs support should not depend on CONFIG_PROC_FS

Move the driver model init code out of the "#ifdef CONFIG_PROC_FS"
block.

Tested with both values of CONFIG_PROC_FS . Tested with CONFIG_MTD=m .

Issue was reported here: http://lkml.org/lkml/2009/4/4/107

Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
694bb7fc19c6b87e106f4c85a2707072e2f111a0 03-Apr-2009 Kevin Cernekee <kpc.mtd@gmail.com> [MTD] driver model updates (part 2)

1) Add more sysfs attributes: flags, size, erasesize, writesize,
oobsize, numeraseregions, name

2) Move core_initcall() code into init_mtd(). The original approach
does not work if CONFIG_MTD=m .

3) Add device_unregister() in del_mtd_device() so that devices get
removed from sysfs as each driver is unloaded.

Signed-off-by: Kevin Cernekee <kpc.mtd@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
1f24b5a8ecbb2a3c7080f418974d40e3ffedb221 26-Mar-2009 David Brownell <dbrownell@users.sourceforge.net> [MTD] driver model updates

Update driver model support in the MTD framework, so it fits
better into the current udev-based hotplug framework:

- Each mtd_info now has a device node. MTD drivers should set
the dev.parent field to point to the physical device, before
setting up partitions or otherwise declaring MTDs.

- Those device nodes always map to /sys/class/mtdX device nodes,
which no longer depend on MTD_CHARDEV.

- Those mtdX sysfs nodes have a "starter set" of attributes;
it's not yet sufficient to replace /proc/mtd.

- Enabling MTD_CHARDEV provides /sys/class/mtdXro/ nodes and the
/sys/class/mtd*/dev attributes (for udev, mdev, etc).

- Include a MODULE_ALIAS_CHARDEV_MAJOR macro. It'll work with
udev creating the /dev/mtd* nodes, not just a static rootfs.

So the sysfs structure is pretty much what you'd expect, except
that readonly chardev nodes are a bit quirky.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
402d326519c1a4859c527702383f4e60f606ef52 12-Feb-2009 David Howells <dhowells@redhat.com> NOMMU: Present backing device capabilities for MTD chardevs

Present backing device capabilities for MTD character device files to allow
NOMMU mmap to do direct mapping where possible.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Bernd Schmidt <bernd.schmidt@analog.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
69423d99fc182a81f3c5db3eb5c140acc6fc64be 10-Dec-2008 Adrian Hunter <ext-adrian.hunter@nokia.com> [MTD] update internal API to support 64-bit device size

MTD internal API presently uses 32-bit values to represent
device size. This patch updates them to 64-bits but leaves
the external API unchanged. Extending the external API
is a separate issue for several reasons. First, no one
needs it at the moment. Secondly, whether the implementation
is done with IOCTLs, sysfs or both is still debated. Thirdly
external API changes require the internal API to be accepted
first.

Note that although the MTD API will be able to support 64-bit
device sizes, existing drivers do not and are not required
to do so, although NAND base has been updated.

In general, changing from 32-bit to 64-bit values cause little
or no changes to the majority of the code with the following
exceptions:
- printk message formats
- division and modulus of 64-bit values
- NAND base support
- 32-bit local variables used by mtdpart and mtdconcat
- naughtily assuming one structure maps to another
in MEMERASE ioctl

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
71a928c0e52cedc43747c64b96a5f74592ab678f 19-May-2008 Chris Malley <mail@chrismalley.co.uk> [MTD] Use list_for_each_entry[_safe] where appropriate.

Janitorial work to remove temporary pointers and make some functions a bit
more readable.

Signed-off-by: Chris Malley <mail@chrismalley.co.uk>
Reviewed-By: Jörn Engel <joern@logfs.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
59018b6d2acabb114ab58637e6ab95ba424a89d0 20-May-2008 Adrian Bunk <bunk@kernel.org> MTD/JFFS2: remove CVS keywords

Once upon a time, the MTD repository was using CVS.

This patch therefore removes all usages of the no longer updated CVS
keywords from the MTD code.

This also includes code that printed them to the user.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
856613c98c2f864994d5fb33a62b7a468f68ab9b 31-May-2008 matthias@kaehlcke.net <matthias@kaehlcke.net> [MTD] use list_for_each_entry() in del_mtd_device()

Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2606c79759e83fd8b1e45bc99b10e65a1dcf1602 31-May-2008 matthias@kaehlcke.net <matthias@kaehlcke.net> [MTD] use list_for_each_entry() in add_mtd_device()

Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
e619a75ff6201b567a539e787aa9af9bc63a3187 30-Jan-2008 Justin Treon <justin_treon@yahoo.com> [MTD] Unlocking all Intel flash that is locked on power up.

Patch for unlocking all Intel flash that has instant locking on power up.
The patch has been tested on Intel M18, P30 and J3D Strata Flash.
1. The automatic unlocking can be disabled for a particular partition
in the map or the command line.
a. For the bit mask in the map it should look like:
.mask_flags = MTD_POWERUP_LOCK,
b. For the command line parsing it should look like:
mtdparts=0x80000(bootloader)lk
2. This will only unlock parts with instant individual block locking.
Intel parts with legacy unlocking will not be unlocked.

Signed-off-by: Justin Treon <justin_treon@yahoo.com>
Signed-off-by: Jared Hulbert <jaredeh@gmail.com>
Acked-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
356d70f19d949a11320ab626037b2d197a8e8b51 28-May-2007 Ben Dooks <ben-linux@fluff.org> [MTD] mtdcore.c: share syms with mtd_blkdev.c

Fix the sparse warnings generated by the implicit
dependency of mtd_blkdevs.c and mtd_core.c for the
two symbols mtd_table and mtd_table_mutex. This is
done by adding an local header file mtdcore.h to
define these (including the warning about the
non-proliferation of these symbols).

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
cd354f1ae75e6466a7e31b727faede57a1f89ca5 14-Feb-2007 Tim Schmielau <tim@physik3.uni-rostock.de> [PATCH] remove many unneeded #includes of sched.h

After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there. Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.

To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.

Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm. I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).

Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dd36f2673573fc027945d488342f2f70664f0448 29-Nov-2006 David Woodhouse <dwmw2@infradead.org> [MTD] Use EXPORT_SYMBOL_GPL() for exported symbols.

While we're fixing up the newly-added symbol, change the neighbouring ones
too, for consistency and also to reflect the author's interpretation of
the GPL -- which is that _no_ non-GPL modules are permitted. The author
always intended his code to be released under the GPL, and believes that
any new interpretation of 'EXPORT_SYMBOL' as being any different from
'EXPORT_SYMBOL_GPL' is entirely invalid; the GPL requires that _all_
exports have the semantics of the new 'EXPORT_SYMBOL_GPL', which means the
extra four characters are entirely redundant.

But since those four extra characters trigger the check for illegal
modules in a way that just EXPORT_SYMBOL does not, it's useful to change
anyway. This action in no way indicates an admission that there is any
legal distinction between the two states, and in particular does not
indicate that the author believes that non-GPL modules may use symbols
exported with EXPORT_SYMBOL alone.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
9c74034f8fc5d93fbe5656421cbbdc4c76ddda28 11-Oct-2006 Artem Bityutskiy <dedekind@infradead.org> [MTD] return error code from get_mtd_device()

get_mtd_device() returns NULL in case of any failure. Teach it to return an
error code instead. Fix all users as well.

Signed-off-by: Artem Bityutskiy <dedekind@infradead.org>
9fe912cea32aec18f860c95e8574410b5892481b 11-Oct-2006 Artem Bityutskiy <dedekind@infradead.org> [MTD] add get and put methods

This patch adds get_device() and put_device() methods to the MTD description
structure (struct mtd_info). These methods are called by MTD whenever the MTD
device is get or put. They are needed when the underlying driver is something
smarter then just flash chip driver, for example UBI.

Signed-off-by: Artem Bityutskiy <dedekind@infradead.org>
7799308f34d3c3371a319559687c78c0f2506fcf 11-Oct-2006 Artem Bityutskiy <dedekind@infradead.org> [MTD] add get_mtd_device_nm() function

This patch adds one more function to the MTD interface to make it possible to
open MTD devices by their names, not only numbers. This is very handy in many
situations. Also, MTD device number depend on load order and may vary, while
names are fixed.

Signed-off-by: Artem Bityutskiy <dedekind@infradead.org>
187ef15268e638603dea55a91fdfa29feaed6d13 22-Sep-2006 Håvard Skinnemoen <hskinnemoen@atmel.com> [MTD] Unlock NOR flash automatically where necessary

Introduce the MTD_STUPID_LOCK flag which indicates that the flash chip is
always locked after power-up, so all sectors need to be unlocked before it
is usable.

If this flag is set, and the chip provides an unlock() operation,
mtd_add_device will unlock the whole MTD device if it's writeable. This
means that non-writeable partitions will stay locked.

Set MTD_STUPID_LOCK in fixup_use_atmel_lock() so that these chips will work
as expected.

Signed-off-by: Håvard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
6ab3d5624e172c553004ecc862bfeac16d9d68b7 30-Jun-2006 Jörn Engel <joern@wohnheim.fh-wedel.de> Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
783ed81ff39d3f938a6b2efd09fbad96e41e5c1f 14-Jun-2006 Artem B. Bityutskiy <dedekind@sauron.oktetlabs.ru> [MTD] assume mtd->writesize is 1 for NOR flashes

Signed-off-by: Artem B. Bityitskiy
8546ac4f84b252fff078fab1a992c70504147914 25-May-2006 Thomas Gleixner <tglx@cruncher.tec.linutronix.de> [MTD] Remove the only useless readv implementation

Removing readv from struct mtd_info broke block2mtd. Remove the
reference and the useless default implementation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2d2dce0eb650831046316a9cd091ea5257aa7d4b 31-Mar-2006 Pavel Machek <pavel@ucw.cz> [PATCH] Kill ifdefs in mtdcore.c

Kill unneccessary ifdefs in mtdcore.c.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
48b192686dd20cb1576ae1d8ccd17a07971ef24a 31-Mar-2006 Ingo Molnar <mingo@elte.hu> [PATCH] sem2mutex: drivers/mtd/

Semaphore to mutex conversion.

The conversion was generated via scripts, and the result was validated
automatically via a script as well.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
97894cda5773e59bd13e87b72077751099419a9f 07-Nov-2005 Thomas Gleixner <tglx@linutronix.de> [MTD] core: Clean up trailing white spaces

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2c92d755323514a12c367f52027fb1f53328fcd6 11-Aug-2005 Thomas Gleixner <tglx@linutronix.de> [MTD] Remove deprecated power management functions

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
49450795844daba7867cc215f17532cac2c2b284 18-Feb-2005 Artem B. Bityuckiy <dedekind@infradead.org> [MTD] Fix unregister_mtd_user() public function documentation.

Signed-off-by: Artem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 17-Apr-2005 Linus Torvalds <torvalds@ppc970.osdl.org> Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!