Fixed following htmldocs warnings:

  DOCPROC Documentation/DocBook/mtdnand.xml
  Warning(drivers/mtd/nand/nand_base.c:769): No description found for parameter 'page'
  Warning(drivers/mtd/nand/nand_base.c:785): No description found for parameter 'page'
  Warning(drivers/mtd/nand/nand_base.c:824): No description found for parameter 'page'
  Warning(drivers/mtd/nand/nand_base.c:947): No description found for parameter 'page'
  Warning(drivers/mtd/nand/nand_base.c:996): No description found for parameter 'page'
  Warning(drivers/mtd/nand/nand_base.c:1040): No description found for parameter 'page'
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This patch adds the new mode NAND_ECC_HW_OOB_FIRST in the nand code to
support 4-bit ECC on TI DaVinci devices with large page (up to 2KiB) NAND
chips.  This ECC mode is similar to NAND_ECC_HW, with the exception of
read_page API that first reads the OOB area, reads the data in chunks,
feeds the ECC from OOB area to the ECC hw engine and perform any
correction on the data as per the ECC status reported by the engine.

"ECC_HW_OOB_FIRST" name suggested by Thomas Gleixner
Reviewed-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NSneha Narnakaje <nsnehaprabha@ti.com>
Signed-off-by: NSandeep Paulraj <s-paulraj@ti.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This patch adds a new "page" parameter to all NAND read_page/read_page_raw
APIs.  The read_page API for the new mode ECC_HW_OOB_FIRST requires the
page information to send the READOOB command and read the OOB area before
the data area.
Reviewed-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NSneha Narnakaje <nsnehaprabha@ti.com>
Signed-off-by: NSandeep Paulraj <s-paulraj@ti.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This patch allows core driver to choose ECC block size in
sw ecc case.
Signed-off-by: NVimal Singh <vimalsingh@ti.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Correcting debug prints by removing function names from print messages
and using '__func__' macro instead.

Function names were wrong in few places.
Signed-off-by: NVimal Singh <vimalsingh@ti.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Singed-off-by: NVimal Singh <vimalsingh@ti.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Resolve issue noted by Sneha:  when computing oobavail from
the list of free areas in the OOB, don't assume there will
always be an unused slot at the end.  With ECC_HW_SYNDROME
and 4KiB page chips, it's fairly likely there *won't* be one.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: "Narnakaje, Snehaprabha" <nsnehaprabha@ti.com>"
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NSebastian Siewior <bigeasy@linutronix.de>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Impact: Replace and remove risky (non-EXPORTed) API

module_text_address() returns a pointer to the module, which given locking
improvements in module.c, is useless except to test for NULL:

1) If the module can't go away, use __module_text_address.
2) Otherwise, just use is_module_text_address().

Cc: linux-mtd@lists.infradead.org
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Fix incorrect debug messages (*write* not read); someone committed some
cut'n'paste bugs.   There might be more, I only noticed these since I was
looking for nand_read usage and landed in some very wrong functions.

IMO all MTD debugging message framework is goofed, anyway.  It uses
"DEBUG" in a way that's incompatible with usage most everywhere else in
the kernel, and which prevents normal pr_dbg() and dev_dbg() calls from
working right.

[True. It predates those by a long way, and should probably be updated 
to use them. dwmw2]
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The syndrome based page read/write routines store ECC, and possibly other
"OOB" data, right after each chunk of ECC'd data.  With ECC chunk size of
512 bytes and a large page (2KiB) NAND, the layout is:

  data-0 OOB-0 data-1 OOB-1 data-2 OOB-2 data-3 OOB-3 OOB-leftover

Where OOBx is (prepad, ECC, postpad).  However, the current "raw" routines
use a traditional layout -- data OOB, disregarding the prepad and postpad
values -- so when they're used with that type of ECC hardware, those calls
mix up the data and OOB.  Which means, in particular, that bad block
tables won't be found on startup, with data corruption and related chaos
ensuing.

The current syndrome-based drivers in mainline all seem to use one chunk
per page; presumably they haven't noticed such bugs.

Fix this, by adding read/write page_raw_syndrome() routines as siblings of
the existing non-raw routines; "raw" just means to bypass the ECC
computations, not change data and OOB layout.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Delete extra kernel-doc notation for struct fields and function
parameters that don't exist:

Warning(include/linux/mtd/nand.h:428): Excess struct/union/enum/typedef member 'wq' description in 'nand_chip'
Warning(include/linux/mtd/nand.h:428): Excess struct/union/enum/typedef member 'datbuf' description in 'nand_chip'
Warning(include/linux/mtd/nand.h:428): Excess struct/union/enum/typedef member 'oobbuf' description in 'nand_chip'
Warning(include/linux/mtd/nand.h:428): Excess struct/union/enum/typedef member 'oobdirty' description in 'nand_chip'
Warning(include/linux/mtd/nand.h:428): Excess struct/union/enum/typedef member 'data_poi' description in 'nand_chip'
Warning(drivers/mtd/nand/nand_base.c:2527): Excess function parameter 'maxchips' description in 'nand_scan_tail'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

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: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Some chips require a RESET after power-up (e.g. Micron MT29FxGxxxxx).
The first command sent is NAND_CMD_READID.
Issue a NAND_CMD_RESET in nand_scan_ident before reading the device id.
Tested with an MT29F4G08AAC.
Signed-off-by: NKarl Beldan <karl.beldan@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

[Reported by Randy Dunlap]
Signed-off-by: NAlexey Korolev <akorolev@infradead.org>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This patch enables NAND subpage read functionality.
If upper layer drivers are requesting to read non page aligned data NAND
subpage-read functionality reads the only whose ECC regions which include
requested data when original code reads whole page.
This significantly improves performance in many cases.

Here are some digits :

UBI volume mount time
No subpage reads: 5.75 seconds
Subpage read patch: 2.42 seconds

Open/stat time for files on JFFS2 volume:
No subpage read  0m 5.36s
Subpage read     0m 2.88s

Signed-off-by Alexey Korolev <akorolev@infradead.org>
Acked-by: NArtem Bityutskiy <dedekind@infradead.org>
Acked-by: NJörn Engel <joern@logfs.org>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

With modern systems using bus-hold instead of bus pull-up, it can
often lead to erroneous reporting of NAND devices where there are
none. Do a double probe to ensure that the result we got the first
time is repeatable, and if it is not then return that there is no
chip there.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAdrian Bunk <bunk@kernel.org>

Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Some hardware, such as the enhanced local bus controller used on some
mpc83xx chips, does ecc transparently when reading and writing data, rather
than providing a generic calculate/correct mechanism that can be exported to
the nand subsystem.

The subsystem should not BUG() when calculate, correct, or hwctl are
missing, if the methods that call them have been overridden.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Treat any negative return value from a NAND driver's correct() function
as a failure, rather than just -1.
Signed-off-by: NMatt Reimer <mreimer@vpop.net>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

When the erase callback performs some other action on the flash, it's
highly likely to deadlock unless we actually release the chip lock
before calling it.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

The nand_base.c driver implicitly casts the uint32_t
eccpos array to 'int *', which is not only not guaranteed
to be the same sign as the source, but is not guaranteed
to be the same size.

Fix by changing nand_base.c to use uint32_t
referencing the eccpos fields.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

When we mark block bad we have to get chip because this involves
writing to the page's OOB. We hit this bug in UBI - we observed
random obscure crashes when it marks block bad from the background
thread and there is some parallel task which utilizes flash.

This patch also adds a TODO note about BBT table protection which
it seems does not exist.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

replace with working link from nand Kconfig help text
fixes bugzilla 7815
Signed-off-by: Nmaximilian attems <max@stro.at>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

When we mark block bad we have to get chip because this involves
writing to the page's OOB. We hit this bug in UBI - we observed
random obscure crashes when it marks block bad from the background
thread and there is some parallel task which utilizes flash.

This patch also adds a TODO note about BBT table protection which
it seems does not exist.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

The nand_base.c driver implicitly casts the uint32_t
eccpos array to 'int *', which is not only not guaranteed
to be the same sign as the source, but is not guaranteed
to be the same size.

Fix by changing nand_base.c to use uint32_t
referencing the eccpos fields.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Further to the previous patch fixing the calculation of page number,
both branches are using the same result. Clean up the function 
accordingly, calculating it (and also masking with pagemask) only in one 
place.
Signed-off-by: NThomas Knobloch <knobloch@siemens.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

In case that there is no memory based bad block table available the
function nand_block_checkbad() in drivers/mtd/nand/nand_base.c will call
nand_block_bad() directly. When parameter 'getchip' is set to zero,
nand_block_bad() will not right shift the offset to calculate the
correct page number.
Signed-off-by: NThomas Knobloch <knobloch@siemens.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

There is a slight bug in nand_default_block_markbad, where the offset is
cast to an integer, prior to being shifted. This means that on large
offsets, it is incorrectly doing a signed shift & losing bits. Fixed
this by doing the cast after the shift (as is done elsewhere in the code).
Signed-off-by: NAndre Renaud <andre@bluewatersys.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Use the functions in the ecc structure instead of the default ones,
so the override by the board driver is effective also for software ecc
code paths.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

During the MTD rework the oobavail parameter of mtd_info structure has become
private. This is not quite correct in terms of integrity and logic. If we have
means to write to OOB area, then we'd like to know upfront how many bytes out
of OOB are spare per page to be able to adapt to specific cases.
The patch inlined adds the public oobavail parameter.
Signed-off-by: NVitaly Wool <vwool@ru.mvista.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Remove unused and broken mtd->ecctype and mtd->eccsize fields
from struct mtd_info. Do not remove them from userspace API
data structures (don't want to breake userspace) but mark them
as obsolete by a comment. Any userspace program which uses them
should be half-broken anyway, so this is more about saving
data structure size.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Add checks to ensure that out-of-band reads and writes are
not attempted with an invalid offset or length.  Specifically,
the offset must be less than the size of oob for a page
and the length must not go beyond the size of the device.
Additionally the checks must adjust for auto-placement
(MTD_OOB_AUTO) of oob data.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Many SLC NANDs support up to 4 writes at one NAND page. Add support
of this feature.
Signed-off-by: NArtem Bityutskiy <dedekind@infradead.org>

As was discussed between Ricard Wanderlöf, David Woodhouse, Artem 
Bityutskiy and me, the current API for reading/writing OOB is confusing. 

The thing that introduces confusion is the need to specify ops.len 
together with ops.ooblen for reads/writes that concern only OOB not data 
area. So, ops.len is overloaded: when ops.datbuf != NULL it serves to 
specify the length of the data read, and when ops.datbuf == NULL, it 
serves to specify the full OOB read length.

The patch inlined below is the slightly updated version of the previous 
patch serving the same purpose, but with the new Artem's comments taken 
into account.

Artem, BTW, thanks a lot for your valuable input!
Signed-off-by: NVitaly Wool <vwool@ru.mvista.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Add description of 'raw' in comments for
drivers/mtd/nand/nand_base.c::nand_write_page_syndrome() so 'make xmldocs'
will not spew a warning at us.
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When a flash-based BBT is not used, nand_default_mark_blockbad() is supposed
to mark the block bad in the oob. However, it sets the wrong length variable
so that no bad block marker is in fact written. This patch attempts to
rectify that.

(As note, it seems to be that logically, it shouldn't be necessary to set
both length variables, as one appears to be for the main buffer, and
one for the oob buffer, but this is how it is done in several places,
including the code for the mtd character device MEMWRITEOOB and MEMREADOOB
ioctls. I'm not sure if this is a temporary solution during some rework of
the mtd infrastructure, or whether there is a deeper thought here.)
Signed-off-by: NRicard Wanderlöf <ricardw@axis.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>