Unloading the omap2 nand driver missed to release the memory region which will
result in not being able to request it again if one want to load the driver
later on.

This patch fixes following error when loading omap2 module after unloading:
---8<---
~ $ rmmod omap2
~ $ modprobe omap2
[   37.420928] omap2-nand: probe of omap2-nand.0 failed with error -16
~ $
--->8---

This error was introduced in 67ce04bf which
was the first commit of this driver.
Signed-off-by: NAndreas Bießmann <andreas@biessmann.de>
Cc: stable@vger.kernel.org
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Do not kfree() the mtd_info; it is handled in the mtd subsystem and
already freed by nand_release(). Instead kfree() the struct
omap_nand_info allocated in omap_nand_probe which was not freed before.

This patch fixes following error when unloading the omap2 module:

---8<---
~ $ rmmod omap2
------------[ cut here ]------------
kernel BUG at mm/slab.c:3126!
Internal error: Oops - BUG: 0 [#1] PREEMPT ARM
Modules linked in: omap2(-)
CPU: 0    Not tainted  (3.6.0-rc3-00230-g155e36d4-dirty #3)
PC is at cache_free_debugcheck+0x2d4/0x36c
LR is at kfree+0xc8/0x2ac
pc : [<c01125a0>]    lr : [<c0112efc>]    psr: 200d0193
sp : c521fe08  ip : c0e8ef90  fp : c521fe5c
r10: bf0001fc  r9 : c521e000  r8 : c0d99c8c
r7 : c661ebc0  r6 : c065d5a4  r5 : c65c4060  r4 : c78005c0
r3 : 00000000  r2 : 00001000  r1 : c65c4000  r0 : 00000001
Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 10c5387d  Table: 86694019  DAC: 00000015
Process rmmod (pid: 549, stack limit = 0xc521e2f0)
Stack: (0xc521fe08 to 0xc5220000)
fe00:                   c008a874 c00bf44c c515c6d0 200d0193 c65c4860 c515c240
fe20: c521fe3c c521fe30 c008a9c0 c008a854 c521fe5c c65c4860 c78005c0 bf0001fc
fe40: c780ff40 a00d0113 c521e000 00000000 c521fe84 c521fe60 c0112efc c01122d8
fe60: c65c4860 c0673778 c06737ac 00000000 00070013 00000000 c521fe9c c521fe88
fe80: bf0001fc c0112e40 c0673778 bf001ca8 c521feac c521fea0 c02ca11c bf0001ac
fea0: c521fec4 c521feb0 c02c82c4 c02ca100 c0673778 bf001ca8 c521fee4 c521fec8
fec0: c02c8dd8 c02c8250 00000000 bf001ca8 bf001ca8 c0804ee0 c521ff04 c521fee8
fee0: c02c804c c02c8d20 bf001924 00000000 bf001ca8 c521e000 c521ff1c c521ff08
ff00: c02c950c c02c7fbc bf001d48 00000000 c521ff2c c521ff20 c02ca3a4 c02c94b8
ff20: c521ff3c c521ff30 bf001938 c02ca394 c521ffa4 c521ff40 c009beb4 bf001930
ff40: c521ff6c 70616d6f b6fe0032 c0014f84 70616d6f b6fe0032 00000081 60070010
ff60: c521ff84 c521ff70 c008e1f4 c00bf328 0001a004 70616d6f c521ff94 0021ff88
ff80: c008e368 0001a004 70616d6f b6fe0032 00000081 c0015028 00000000 c521ffa8
ffa0: c0014dc0 c009bcd0 0001a004 70616d6f bec2ab38 00000880 bec2ab38 00000880
ffc0: 0001a004 70616d6f b6fe0032 00000081 00000319 00000000 b6fe1000 00000000
ffe0: bec2ab30 bec2ab20 00019f00 b6f539c0 60070010 bec2ab38 aaaaaaaa aaaaaaaa
Backtrace:
[<c01122cc>] (cache_free_debugcheck+0x0/0x36c) from [<c0112efc>] (kfree+0xc8/0x2ac)
[<c0112e34>] (kfree+0x0/0x2ac) from [<bf0001fc>] (omap_nand_remove+0x5c/0x64 [omap2])
[<bf0001a0>] (omap_nand_remove+0x0/0x64 [omap2]) from [<c02ca11c>] (platform_drv_remove+0x28/0x2c)
 r5:bf001ca8 r4:c0673778
[<c02ca0f4>] (platform_drv_remove+0x0/0x2c) from [<c02c82c4>] (__device_release_driver+0x80/0xdc)
[<c02c8244>] (__device_release_driver+0x0/0xdc) from [<c02c8dd8>] (driver_detach+0xc4/0xc8)
 r5:bf001ca8 r4:c0673778
[<c02c8d14>] (driver_detach+0x0/0xc8) from [<c02c804c>] (bus_remove_driver+0x9c/0x104)
 r6:c0804ee0 r5:bf001ca8 r4:bf001ca8 r3:00000000
[<c02c7fb0>] (bus_remove_driver+0x0/0x104) from [<c02c950c>] (driver_unregister+0x60/0x80)
 r6:c521e000 r5:bf001ca8 r4:00000000 r3:bf001924
[<c02c94ac>] (driver_unregister+0x0/0x80) from [<c02ca3a4>] (platform_driver_unregister+0x1c/0x20)
 r5:00000000 r4:bf001d48
[<c02ca388>] (platform_driver_unregister+0x0/0x20) from [<bf001938>] (omap_nand_driver_exit+0x14/0x1c [omap2])
[<bf001924>] (omap_nand_driver_exit+0x0/0x1c [omap2]) from [<c009beb4>] (sys_delete_module+0x1f0/0x2ec)
[<c009bcc4>] (sys_delete_module+0x0/0x2ec) from [<c0014dc0>] (ret_fast_syscall+0x0/0x48)
 r8:c0015028 r7:00000081 r6:b6fe0032 r5:70616d6f r4:0001a004
Code: e1a00005 eb0d9172 e7f001f2 e7f001f2 (e7f001f2)
---[ end trace 6a30b24d8c0cc2ee ]---
Segmentation fault
--->8---

This error was introduced in 67ce04bf which
was the first commit of this driver.
Signed-off-by: NAndreas Bießmann <andreas@biessmann.de>
Cc: stable@vger.kernel.org
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Just as Artem suggested:

"Both UBI and JFFS2 are able to read verify what they wrote already.
There are also MTD tests which do this verification. So I think there
is no reason to keep this in the NAND layer, let alone wasting RAM in
the driver to support this feature. Besides, it does not work for sub-pages
and many drivers have it broken. It hurts more than it provides benefits."

So kill MTD_NAND_VERIFY_WRITE entirely.
Signed-off-by: NHuang Shijie <shijie8@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NPeter Meerwald <p.meerwald@bct-electronic.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Platform data for device drivers should be defined in
include/linux/platform_data/*.h, not in the architecture
and platform specific directories.

This moves such data out of the omap include directories
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NNicolas Pitre <nico@linaro.org>
Acked-by: NTony Lindgren <tony@atomide.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: "Benoît Cousson" <b-cousson@ti.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Omar Ramirez Luna <omar.ramirez@ti.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: Jarkko Nikula <jarkko.nikula@bitmer.com>
Cc: Liam Girdwood <lrg@ti.com>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Jean Pihet <j-pihet@ti.com>
Cc: J Keerthy <j-keerthy@ti.com>
Cc: linux-omap@vger.kernel.org

GPMC platform initialization provides it's clients
with interrupts that can be used through struct
resource. Make use of it for irq mode functionality.

Also now write protect disable is done by GPMC,
hence remove it.
Signed-off-by: NAfzal Mohammed <afzal@ti.com>
Acked-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
[tony@atomide.com: updated to fix new warnings introduced]
Signed-off-by: NTony Lindgren <tony@atomide.com>

gpmc initialization done by platform code now updates struct resource
with the address space alloted for nand. Use this interface to obtain
memory rather than relying on platform data field - phys_base.
Signed-off-by: NAfzal Mohammed <afzal@ti.com>
Acked-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

GPMC platform initialization has been modified to fill NAND
platform data with GPMC NAND register details. As these
registers are accessible in NAND driver itself, configure
NAND in GPMC by itself.

Modified prefetch and ecc functions are logically same as
the corresponding exported symbols from GPMC code.

Note: Verfying that other CS have not yet enabled for
prefetch & ecc has to be incorporated. Currently this
causes no issues as there are no boards that use NAND
on multiple CS. With ongoing GPMC driver migration,
perhaps it would be better to consider NAND connected
on multiple CS as a single peripheral using multiple CS.
This would make handling multiple CS issues easier.
Signed-off-by: NAfzal Mohammed <afzal@ti.com>
Acked-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

The newly added dmaengine support in the omap2 nand driver
potentially causes an undefined return value from the
omap_nand_probe function when dmaengine_slave_config
reports an error. Let's handle this by returning the
same error back to the caller.

Without this patch, building omap2plus_defconfig results in:

drivers/mtd/nand/omap2.c: In function 'omap_nand_probe':
drivers/mtd/nand/omap2.c:1154:6: warning: 'err' may be used uninitialized in this function [-Wuninitialized]
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Grazvydas Ignotas <notasas@gmail.com>

Remove the private DMA API implementation from nand/omap2.c
making it use entirely the DMA engine API.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Add DMA engine support to the OMAP2 NAND driver.  This supplements the
private DMA API implementation contained within this driver, and the
driver can be independently switched at build time between using DMA
engine and the private DMA API.
Tested-by: NGrazvydas Ignotas <notasas@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Two modes are supported: 4-bit and 8-bit error correction.
Note that 4-bit mode is only confirmed to work on OMAP3630 ES 1.x,
x >= 1. The OMAP3 GPMC hardware BCH engine computes remainder
polynomials, it does not provide automatic error location and
correction: this step is implemented using the BCH library.

This implementation only protects page data, there is no support
for protecting user-defined spare area bytes (this could be added
with few modifications); therefore, it cannot be used with YAFFS2
or other similar filesystems that depend on oob storage.

Before being stored to nand flash, hardware BCH ecc is adjusted
so that an erased page has a valid ecc; thus allowing correction of
bitflips in blank pages (also common on 4-bit devices).

BCH correction mode is selected at runtime by setting platform data
parameter 'ecc_opt' to value OMAP_ECC_BCH4_CODE_HW or
OMAP_ECC_BCH8_CODE_HW.

This code has been tested with mtd test modules, UBI and UBIFS on a
BeagleBoard revC3 (OMAP3530 ES3.0 + Micron NAND 256MiB 1,8V 16-bit).
Signed-off-by: NIvan Djelic <ivan.djelic@parrot.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

If a context switch occurs in function omap_wait() just before the
while loop is entered, then upon return from context switch the
timeout may already have elapsed: in that case, status is never
read from NAND device, and omap_wait() returns an error.
This failure has been experimentally observed during stress tests.

This patch ensures a NAND status read is always performed before
returning, as in the generic nand_wait() function.
Signed-off-by: NIvan Djelic <ivan.djelic@parrot.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

If prefetch engine is busy, current code "forgets" to call
dma_unmap_single(), which results in a deadlock later, so add it.
Signed-off-by: NGrazvydas Ignotas <notasas@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Flash device drivers initialize 'ecc_strength' in struct mtd_info, which is the
maximum number of bit errors that can be corrected in one writesize region.

Drivers using the nand interface intitialize 'strength' in struct nand_ecc_ctrl,
which is the maximum number of bit errors that can be corrected in one ecc step.
Nand infrastructure code translates this to 'ecc_strength'.

Also for nand drivers, the nand infrastructure code sets ecc.strength for ecc
modes NAND_ECC_SOFT, NAND_ECC_SOFT_BCH, and NAND_ECC_NONE.  It is set in the
driver for all other modes.
Signed-off-by: NMike Dunn <mikedunn@newsguy.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The first 3 arguments of 'mtd_device_parse_register()' are pointers,
but many callers pass '0' instead of 'NULL'. Fix this globally. Thanks
to coccinelle for making it easy to do with the following semantic patch:

 @@
 expression mtd, types, parser_data, parts, nr_parts;
 @@
 (
 -mtd_device_parse_register(mtd, 0, parser_data, parts, nr_parts)
 +mtd_device_parse_register(mtd, NULL, parser_data, parts, nr_parts)
 |
 -mtd_device_parse_register(mtd, types, 0, parts, nr_parts)
 +mtd_device_parse_register(mtd, types, NULL, parts, nr_parts)
 |
 -mtd_device_parse_register(mtd, types, parser_data, 0, nr_parts)
 +mtd_device_parse_register(mtd, types, parser_data, NULL, nr_parts)
 )
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This patch converts the drivers in drivers/mtd/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

We are cleaning up the implicit presence of module.h that these
drivers are taking advantage of.  Fix them in advance of the
cleanup operation.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@intel.com>

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: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@intel.com>

Replace custom invocations of parse_mtd_partitions and mtd_device_register
with common mtd_device_parse_register call. This would bring: standard
handling of all errors, fallback to default partitions, etc.
Signed-off-by: NDmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Since 'cmdline, NULL' is now a default for parse_mtd_partitions, don't specify
this in every driver, instead pass NULL to force parse_mtd_partitions
to use default.
Signed-off-by: NDmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Convert to mtd_device_register() and remove the CONFIG_MTD_PARTITIONS
preprocessor conditionals as partitioning is always available.
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

When reading/writing a subpage (When HW ECC is not available/enabled)
for number of bytes not aligned to 4, the mis-aligned bytes are handled
first (by cpu copy method) before enabling the Prefetch engine to/from
'p'(start of buffer 'buf'). Then it reads/writes rest of the bytes with
the help of Prefetch engine, if available, or again using cpu copy method.
Currently, reading/writing of rest of bytes, is not done correctly since
its trying to read/write again to/from begining of buffer 'buf',
overwriting the mis-aligned bytes.

Read & write using prefetch engine got broken in commit '2c01946c'.
We never hit a scenario of not getting 'gpmc_prefetch_enable' call
success. So, problem did not get caught up.
Signed-off-by: NKishore Kadiyala <kishore.kadiyala@ti.com>
Signed-off-by: NVimal Singh <vimal.newwork@gmail.com>
Reported-by: NBryan DE FARIA <bdefaria@adeneo-embedded.com>
Cc: stable@kernel.org [2.6.35+]
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

nand_scan calls nand_scan_tail and here we got a ecc.layout and calculate
oobavail for this layout. After calling nand_scan, we change the layout pointer
if OMAP_ECC_HAMMING_CODE_HW_ROMCODE is set. This results in not calcluated
oobavail. Mountig as jffs2 is not possible.

To fix that nand_scan has to split up in nand_scan_ident and nand_scan_tail
setting ecc.layout between these calls. So nand_scan_tail calculates oobvail
for the used layout. This is also done in serveral other platforms.
Signed-off-by: NJan Weitzel <j.weitzel@phytec.de>
Reviewed-by: NVimal Singh <vimal.newwork@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The number of corrected ECC errors should be reported since other MTD
systems make use of this information (such as UBI data scrubbing).
Signed-off-by: NJohn Ogness <john.ogness@linutronix.de>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Since 43cc71ee (platform: prefix MODALIAS
with "platform:"), the platform modalias is prefixed with "platform:".
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org

This patch overrides nand ecc layout and bad block descriptor (for 8-bit
device) to support hw ecc in romcode layout. So as to have in sync with ecc
layout throughout; i.e. x-loader, u-boot and kernel.

This enables to flash x-loader, u-boot, kernel, FS images from kernel itself
and compatiable with other tools.

This patch does not enables this feature by default and need to pass from
board file to enable for any board.
Signed-off-by: NVimal Singh <vimalsingh@ti.com>
Signed-off-by: NSukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

This patch makes it possible to select sw or hw (different layout options)
ecc scheme supported by omap nand driver.
Signed-off-by: NVimal Singh <vimalsingh@ti.com>
Signed-off-by: NSukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

Configure the FIFO THREASHOLD value different for read and write to keep busy
both filling and to drain out of FIFO at reading and writing.
Signed-off-by: NVimal Singh <vimalsingh@ti.com>
Signed-off-by: NSukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

This patch enable prefetch-irq mode for nand transfer(read, write)
Signed-off-by: NVimal Singh <vimalsingh@ti.com>
Signed-off-by: NSukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

nand transfer type (sDMA, Polled, prefetch) can be select from board file,
enabling all transfer type in driver, by default.

this helps in multi-omap build and to select different transfer type for
different board.
Signed-off-by: NSukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

zoom3 and 3630-sdp having the x16 nand device.
This patch configure gpmc as x16 and select the currect function in driver
for polled mode (without prefetch enable) transfer.
Signed-off-by: NSukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

Commit 2c01946c (omap3 nand: cleanup
virtual address usages) wrongly enabled CONFIG_MTD_NAND_OMAP_HWECC
which breaks boards like beagle and pandora that use software ECC
for write.

Boards like beagle and pandora uses sw ecc for write (e.g. binary flushed
from u-boot) and read from kernel.
Signed-off-by: NSukumar Ghorai <s-ghorai@ti.com>
Acked-by: NDavid Woodhouse <David.Woodhouse@intel.com>
[tony@atomide.com: updated comments]
Signed-off-by: NTony Lindgren <tony@atomide.com>

This patch fixes sparse warning for static declaration of variable "use_dma"

drivers/mtd/nand/omap2.c:114:11: warning: symbol 'use_dma' was not declared. Should it be static?
Signed-off-by: NG, Manjunath Kondaiah <manjugk@ti.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Fix build failure from recent interface change and merge.

Tested on OMAP3430.
Signed-off-by: NDaniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch removes direct reference of gpmc address from generic nand platform code.
Nand platform code now uses wrapper functions which are implemented in gpmc module.
Signed-off-by: NSukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

few functions added in gpmc module and to be used by other drivers like NAND.
Signed-off-by: NSukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

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: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

There is a bug in nand prefetch read routine, which comes into effect
only if nand device is a 16-bit device (as we have in zoom boards).
This bug is effective only with below combination of conditions:
1. nand deivce, in use, is a 16 bit device
2. nand driver supports 'subpage' read
3. SW ECC is in use

This was not seen old  kernel (ex: .23), because when, in early days,
we tested this (nand prefetch read in LDP boards) there was no
'subpage read' support.
Later when we had subpage read in (.27) kernel, we had hw ecc enabled
always in our internal tree. So, we missed this bug.

This patch fixes the issue.
Signed-off-by: NVimal Singh <vimalsingh@ti.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>