Replace the default nand_ecclayout definitions for large and small page
devices with the equivalent mtd_ooblayout_ops.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

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

The mtd_ooblayout_xxx() helper functions have been added to avoid direct
accesses to the ecclayout field, and thus ease for future reworks.
Use these helpers in all places where the oobfree[] and eccpos[] arrays
where directly accessed.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

Export the default read/write oob functions (for the standard and syndrome
scheme), so that drivers can use them for their raw implementation and
implement their own functions for the normal oob operation.

This is required if your ECC engine is capable of fixing some of the OOB
data. In this case you have to overload the ->read_oob() and ->write_oob(),
but if you don't specify the ->read/write_oob_raw() functions they are
assigned to the ->read/write_oob() implementation, which is not what you
want.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

There's no reason to BUG() when parameters are being
validated. Drivers can get things wrong, and it's much nicer
to just throw a noisy warn and fail gracefully, than calling
BUG() and throwing the whole system down the drain.
Signed-off-by: NEzequiel Garcia <ezequiel@vanguardiasur.com.ar>
Reviewed-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

Use recently added of_get_nand_ecc_algo for that.
Signed-off-by: NRafał Miłecki <zajec5@gmail.com>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

This commit removes the "nand-disk" LED trigger from the
NAND code.

A trigger with the same name is already available selecting
LEDS_TRIGGER_MTD. Note that "nand-disk" trigger is being
deprecated in favor of the "mtd" trigger.
Signed-off-by: NEzequiel Garcia <ezequiel@vanguardiasur.com.ar>
Acked-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NJacek Anaszewski <j.anaszewski@samsung.com>

The 'getchip' parameter is gone as of commit 9f3e0429 ("mtd: nand:
don't select chip in nand_chip's block_bad op"), so kill the doc with
it.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Acked-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

One of the arguments passed to struct nand_chip's block_bad op is
'getchip', which, if true, is supposed to get and select the nand device,
and later unselect and release the device.

This op is intended to be replaceable by drivers. The drivers shouldn't
be responsible for selecting/unselecting chip. Like other ops, the chip
should already be selected before the block_bad op is called.

Remove the getchip argument from the block_bad op and
nand_block_checkbad. Move the chip selection to nand_block_isbad, since it
is the only caller to nand_block_checkbad which requires chip selection.

Modify nand_block_bad (the default function for the op) such that it
doesn't select the chip.

Remove the getchip argument from the bad_block funcs in cafe_nand,
diskonchip and docg4 drivers.
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

nand_bch_init() requires several arguments which could directly be deduced
from the mtd device. Get rid of those useless parameters.

nand_bch_init() is also requiring the caller to provide a proper eccbytes
value, while this value could be deduced from the ecc.size and
ecc.strength value. Fallback to eccbytes calculation when it is set to 0.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

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

ecclayout->oobavail is just redundant with the mtd->oobavail field.
Moreover, it prevents static const definition of ecc layouts since the
NAND framework is calculating this value based on the ecclayout->oobfree
field.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

In commit b70af9be ("mtd: nand: increase ready wait timeout and
report timeouts"), we increased the likelihood of scheduling during
nand_wait(). This makes us more likely to hit the time_before(...)
condition, since a lot of time may pass before we get scheduled again.

Now, the loop was already buggy, since we don't check if the NAND is
ready after exiting the loop; we simply print out a timeout warning. Fix
this by doing a final status check before printing a timeout message.

This isn't actually a critical bug, since the only effect is a false
warning print. But too many prints never hurt anyone, did they? :)

Side note: perhaps I'm not smart enough, but I'm not sure what the best
policy is for this kind of loop; do we busy loop (i.e., no
cond_resched()) to keep the lowest I/O latency (it's not great if the
resched is delaying Richard's system ~400ms)? Or do we allow
rescheduling, to play nice with the rest of the system (since some
operations can take quite a while)?
Reported-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: NRichard Weinberger <richard@nod.at>
Reviewed-by: NHarvey Hunt <harvey.hunt@imgtec.com>

The default NAND read functions are relying on the underlying controller
driver to correct bitflips, but some of those controllers cannot properly
fix bitflips in erased pages.
Check for bitflips in erased pages in default core functions if the driver
delegated the this check by setting the NAND_ECC_GENERIC_ERASED_CHECK flag.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: NFranklin S Cooper Jr. <fcooper@ti.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Commits such as commit 853f1c58 ("mtd: nand: omap2: show parent
device structure in sysfs") attempt to rely on the core MTD code to set
the MTD name based on the parent device. However, nand_base tries to set
a different default name according to the flash name (e.g., extracted
from the ONFI parameter page), which means NAND drivers will never make
use of the MTD defaults. This is not the intention of commit
853f1c58.

This results in problems when trying to use the cmdline partition
parser, since the MTD name is different than expected. Let's fix this by
providing a default NAND name, where possible.

Note that this is not really a great default name in the long run, since
this means that if there are multiple MTDs attached to the same
controller device, they will have the same name. But that is an existing
issue and requires future work on a better controller vs. flash chip
abstraction to fix properly.

Fixes: 853f1c58 ("mtd: nand: omap2: show parent device structure in sysfs")
Reported-by: NHeiko Schocher <hs@denx.de>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: NHeiko Schocher <hs@denx.de>
Cc: Heiko Schocher <hs@denx.de>
Cc: Frans Klaver <fransklaver@gmail.com>
Cc: <stable@vger.kernel.org>

nand_write_subpage_hwecc causes a crash if the driver did not register
ecc->hwctl or ecc->calculate. Fix this by disabling subpage writes if
ecc->hwctl or ecc->calculate is not provided by the driver.

This behavior was introduced in commit 837a6ba4
"mtd: nand: subpage write support for hardware based ECC schemes".

This fixes a crash with fsl_elbc_nand and maybe others:

Unable to handle kernel paging request for instruction fetch
Faulting instruction address: 0x00000000
Oops: Kernel access of bad area, sig: 11 [#1]
SMP NR_CPUS=2 P1020 RDB
Modules linked in: ath9k ath9k_common pppoe ppp_async option iptable_nat ath9k_hw ath usb_wwan pppox ppp_generic nf_nat_ipv4 nf_conntrack_ipv4 mac80211 ipt_MASQUERADE cfg80211 xt_time xt_tcpudp xt_state xt_quota xt_policy xt_pkttype xt_owner xt_nat xt_multiport xt_mh
CPU: 1 PID: 2161 Comm: ubiformat Not tainted 3.10.26 #6
task: efbc2700 ti: c7950000 task.ti: c7950000
NIP: 00000000 LR: c01a495c CTR: 00000000
REGS: c7951cb0 TRAP: 0400   Not tainted  (3.10.26)
MSR: 00029000 <CE,EE,ME>  CR: 24002028  XER: 00000000

GPR00: c01a4b6c c7951d60 efbc2700 ef84b000 00000001 00000000 000001ff c7800500
GPR08: 00000000 00000000 efae5e40 c01a4ae4 24002022 10023418 c7951e5c c7800500
GPR16: c017b6a8 00000000 0000003f c053404c 00000000 00000004 00000000 00000003
GPR24: 00000010 00000200 ef84b000 c7800d00 c7800000 c7800500 ef84b1c8 00000000
NIP [00000000]   (null)
LR [c01a495c] nand_write_subpage_hwecc+0x74/0x174
Call Trace:
[c7951d60] [c7951d64] 0xc7951d64 (unreliable)
[c7951da0] [c01a4b6c] nand_write_page+0x88/0x198
[c7951dd0] [c01a5f7c] nand_do_write_ops+0x2f4/0x39c
[c7951e40] [c01a61e0] nand_write+0x58/0x84
[c7951e80] [c019e29c] mtdchar_write+0x1dc/0x28c
[c7951ef0] [c00aba84] vfs_write+0xcc/0x1ac
[c7951f10] [c00ac04c] SyS_write+0x4c/0x90
[c7951f40] [c000cd84] ret_from_syscall+0x0/0x3c
 --- Exception: c01 at 0x48050ed8
     LR = 0x100071b8
 Instruction dump:
 XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
 XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
 ---[ end trace 161d3c65a2a15cb8 ]---

Kernel panic - not syncing: Fatal exception

[Brian: editorial note - we've applied a previous fix for the driver in
question (fsl_elbc_nand) long ago:
commit f034d87d ("mtd: eLBC NAND: fix subpage write support")
but this still makes sense, and it could solve issues on some other
unforseen driver.]

Cc: Pekon Gupta <pekon.gupta@gmail.com>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Now that the nand_chip struct directly embeds an mtd_info struct we can
get rid of the ->flash_node field and forward set/get_flash_node requests
to the MTD layer.

As a side effect, we no longer need the mtd_set_of_node() call done in
nand_dt_init().
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

nand_dt_init() function requires 3 arguments where it actually needs one
(dn and mtd can both be retrieved from chip). Drop these parameters.

Testing for dn != NULL inside nand_dt_init() also helps simplifying the
caller code.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

mtd_to_nand() was recently introduced to avoid direct access to the
mtd->priv field. Update core code to use mtd_to_nand().
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

If multiple NAND chips are registered to the same controller, then when
rebooting the system, the first one will grab the controller lock, while
the second will wait forever for the first one to release it. i.e., a
classic deadlock.

This problem was solved for a similar case (suspend/resume) back in
commit 6b0d9a84 ("mtd: nand: fix multi-chip suspend problem"), and
the shutdown state really isn't much different for us, so rather than
adding a new special case to nand_get_device(), we can just overload the
FL_PM_SUSPENDED state.

Now, multiple chips can "get" the same controller lock (preventing
further I/O), while we still allow other chips to pass through
nand_shutdown().

Original report:
http://thread.gmane.org/gmane.linux.drivers.mtd/59726
http://lists.infradead.org/pipermail/linux-mtd/2015-July/059992.html

Fixes: 72ea4036 ("mtd: nand: added nand_shutdown")
Reported-by: NAndrew E. Mileski <andrewm@isoar.ca>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Andrew E. Mileski <andrewm@isoar.ca>
Acked-by: NScott Branden <sbranden@broadcom.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

Used semantic patch with 'make coccicheck MODE=patch COCCI=script.cocci':

---8<----
virtual patch

@@
struct nand_chip c;
struct nand_chip *cp;
@@
(
-(cp)->flash_node
+nand_get_flash_node(cp)
|
-(c).flash_node
+nand_get_flash_node(&c)
)
---8<----
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

We should pass along our flash DT node to the MTD layer, so it can set
up ofpart for us.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

If nand_wait_ready() times out, this is silently ignored, and its
caller will then proceed to read from/write to the chip before it is
ready. This can potentially result in corruption with no indication as
to why.

While a 20ms timeout seems like it should be plenty enough, certain
behaviour can cause it to timeout much earlier than expected. The
situation which prompted this change was that CPU 0, which is
responsible for updating jiffies, was holding interrupts disabled
for a fairly long time while writing to the console during a printk,
causing several jiffies updates to be delayed. If CPU 1 happens to
enter the timeout loop in nand_wait_ready() just before CPU 0 re-
enables interrupts and updates jiffies, CPU 1 will immediately time
out when the delayed jiffies updates are made. The result of this is
that nand_wait_ready() actually waits less time than the NAND chip
would normally take to be ready, and then read_page() proceeds to
read out bad data from the chip.

The situation described above may seem unlikely, but in fact it can be
reproduced almost every boot on the MIPS Creator Ci20.

Therefore, this patch increases the timeout to 400ms. This should be
enough to cover cases where jiffies updates get delayed. In nand_wait()
the timeout was previously chosen based on whether erasing or
programming. This is changed to be 400ms unconditionally as well to
avoid similar problems there. nand_wait() is also slightly refactored
to be consistent with nand_wait{,_status}_ready(). These changes should
have no effect during normal operation.

Debugging this was made more difficult by the misleading comment above
nand_wait_ready() stating "The timeout is caught later" - no timeout was
ever reported, leading me away from the real source of the problem.
Therefore, a pr_warn() is added when a timeout does occur so that it is
easier to pinpoint similar problems in future.
Signed-off-by: NAlex Smith <alex.smith@imgtec.com>
Signed-off-by: NHarvey Hunt <harvey.hunt@imgtec.com>
Reviewed-by: NNiklas Cassel <niklas.cassel@axis.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Niklas Cassel <niklas.cassel@axis.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The ->read_xxx() methods are all passed the page number the NAND controller
is supposed to read, but ->write_xxx() do not have such a parameter.

This is a problem if we want to properly implement data
scrambling/randomization in order to mitigate MLC sensibility to repeated
pattern: to prevent bitflips in adjacent pages in the same block we need
to avoid repeating the same pattern at the same offset in those pages,
hence the randomizer/scrambler engine need to be passed the page value
in order to adapt its seed accordingly.

Moreover, adding the page parameter to the ->write_xxx() methods add some
consistency to the current API.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
CC: Josh Wu <josh.wu@atmel.com>
CC: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
CC: Maxime Ripard <maxime.ripard@free-electrons.com>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: Huang Shijie <shijie.huang@arm.com>
CC: Stefan Agner <stefan@agner.ch>
CC: devel@driverdev.osuosl.org
CC: linux-arm-kernel@lists.infradead.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The ->init_size() hook was introduced to let NAND controller drivers
support NAND devices that could not be described in the nand_ids table.
Since then, the core has added support for extended-id parsing and
full-id description, thus allowing to describe pretty much all existing
NANDs.
Moreover, this hook is not used by any mainline driver, and should not be
used by new drivers, because detecting the NAND chip is not something
controller specific.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Add two helper functions to help NAND controller drivers test whether a
specific NAND region is erased or not.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Use a more descriptive name for the device_node element in struct nand_chip .
This name matches the element name used for device_node property of a flash
in the spi-nor framework.
Signed-off-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

We had an extra tab.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This is an example of why it doesn't make much sense to put this
information here in the first place. I don't really know what purpose it
serves.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

These are already-documented common bindings for NAND chips. Let's
handle them in nand_base.

If NAND controller drivers need to act on this data before bringing up
the NAND chip (e.g., fill out ECC callback functions, change HW modes,
etc.), then they can do so between calling nand_scan_ident() and
nand_scan_tail().
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

As all four bytes are written in any case the memset() is in vain.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

If a NAND device is not really present or pin muxes are not correctly
configured we can lock up the kernel waiting infinitely for NAND_STATUS
to be ready.

This can be easily reproduced on TI's DRA7-evm board by booting it
without NAND support in u-boot and disabling NAND pin muxes in the kernel.

Add timeout when waiting for NAND_CMD_RESET completion. As per ONFi v4.0
tRST can be upto 250ms for EZ-NAND and 5ms for raw NAND.
Signed-off-by: NRoger Quadros <rogerq@ti.com>
Tested-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

We're not initializing the ooblen field. Our users don't care, since
they check that oobbuf == NULL first, but it's good practice to zero
unused fields out.

We can drop the NULL initializations since we're memset()ing the whole
thing.

Noticed by Coverity, CID #200821, #200822
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Coverity noticed that these 'ret' assignments weren't being used. Let's
use them.

Note that nand_lock() and nand_unlock() are still not officially used by
any drivers.

Coverity CIDs #1227054 and #1227037
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Previously, we requested that drivers pass ecc.size and ecc.bytes when
using NAND_ECC_SOFT_BCH. However, a driver is likely to only know the ECC
strength required for its NAND, so each driver would need to perform a
strength-to-bytes calculation.

Avoid duplicating this calculation in each driver by asking drivers to
pass ecc.size and ecc.strength so that the strength-to-bytes calculation
need only be implemented once.

This reverts/generalizes this commit:
    mtd: nand: Base BCH ECC bytes on required strength
Signed-off-by: NAaron Sierra <asierra@xes-inc.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

The MTD API reports -EUCLEAN only if the maximum number of bitflips
found in any ECC block exceeds a certain threshold. This is done to
avoid excessive -EUCLEAN reports to MTD users, which may induce
additional scrubbing of data, even when the ECC algorithm in use is
perfectly capable of handling the bitflips.

This threshold can be controlled by user-space (via sysfs), to allow
users to determine what they are willing to tolerate in their
application. But it still helps to have sane defaults.

In recent discussion [1], it was pointed out that our default threshold
is equal to the correction strength. That means that we won't actually
report any -EUCLEAN (i.e., "bitflips were corrected") errors until there
are almost too many to handle. It was determined that 3/4 of the
correction strength is probably a better default.

[1] http://lists.infradead.org/pipermail/linux-mtd/2015-January/057259.htmlSigned-off-by: NBrian Norris <computersforpeace@gmail.com>
Acked-by: NHuang Shijie <shijie.huang@intel.com>

Commit 7854d3f7 ("mtd: spelling, capitalization, uniformity") added
a correctly spelled line, but failed to remove the wrongly spelled one.
Commit 064a7694 ("mtd: Fix typo mtd/tests") then fixed the spelling
again, but left the duplication.

Fixes: 7854d3f7 ("mtd: spelling, capitalization, uniformity")
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Add nand_shutdown to wait for current nand operations to finish and prevent
further operations by changing the nand flash state to FL_SHUTDOWN.

This is addressing a problem observed during reboot tests using UBIFS
root file system: NAND erase operations that are in progress during
system reboot/shutdown are causing partial erased blocks. Although UBI should
be able to detect and recover from this error, this change will avoid
the creation of partial erased blocks on reboot in the middle of a NAND erase
operation.
Signed-off-by: NScott Branden <sbranden@broadcom.com>
Tested-by: NScott Branden <sbranden@broadcom.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>