mtd: rawnand: remove redundant assignment to variable bbtblocks

The variable bbtblocks is being assigned a value that is never
read. The assignment is redundant and can be removed.

Cleans up clang scan build warning:
drivers/mtd/nand/raw/nand_bbt.c:579:3: warning: Value stored to
'bbtblocks' is never read [deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20240209174019.3933233-1-colin.i.king@gmail.com

mtd: always initialize 'stats' in struct mtd_oob_ops

As the 'stats' field in struct mtd_oob_ops is used in conditional
expressions, ensure it is always zero-initialized in all such structures
to prevent random stack garbage from being interpreted as a pointer.

Strictly speaking, this problem currently only needs to be fixed for
struct mtd_oob_ops structures subsequently passed to mtd_read_oob().
However, this commit goes a step further and makes all instances of
struct mtd_oob_ops in the tree zero-initialized, in hope of preventing
future problems, e.g. if struct mtd_req_stats gets extended with write
statistics at some point.

Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220629125737.14418-3-kernel@kempniu.pl

mtd: Replace the expert mode symbols with a single helper

Reduce the number of exported symbols by replacing:
- mtd_expert_analysis_warning (the error string)
- mtd_expert_analysis_mode (the boolean)
with a single helper:
- mtd_check_expert_analysis_mode

Calling this helper will both check/return the content of the internal
boolean -which is not exported anymore- and as well conditionally
WARN_ONCE() the user, like it was done before.

While on this function, make the error string local to the helper and
set it const. Only export this helper when CONFIG_DEBUG_FS is defined to
limit the growth of the Linux kernel size only for a debug feature on
production kernels.

Mechanically update all the consumers.

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220128113414.1121924-1-miquel.raynal@bootlin.com

mtd: Introduce an expert mode for forensics and debugging purposes

When developping NAND controller drivers or when debugging filesystem
corruptions, it is quite common to need hacking locally into the
MTD/NAND core in order to get access to the content of the bad
blocks. Instead of having multiple implementations out there let's
provide a simple yet effective specific MTD-wide debugfs entry to fully
disable these checks on purpose.

A warning is added to inform the user when this mode gets enabled.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20211118114659.1282855-1-miquel.raynal@bootlin.com

mtd: rawnand: nand_bbt: Skip bad blocks when searching for the BBT in NAND

The blocks containing the bad block table can become bad as well. So
make sure to skip any blocks that are marked bad when searching for the
bad block table.

Otherwise in very rare cases where two BBT blocks wear out it might
happen that an obsolete BBT is used instead of a newer available
version.

This only applies to drivers which make use of a bad block marker in flash.
Other drivers won't be able to identify bad BBT blocks and thus can't skip
these.

Signed-off-by: Stefan Riedmueller <s.riedmueller@phytec.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210625123821.207458-1-s.riedmueller@phytec.de

Revert "mtd: rawnand: bbt: Skip bad blocks when searching for the BBT in NAND"

This reverts commit bd9c9fe2ad04546940f4a9979d679e62cae6aa51.

Since commit bd9c9fe2ad04 ("mtd: rawnand: bbt: Skip bad blocks when
searching for the BBT in NAND") the bad block table cannot be found
on a imx27-phytec-phycard-s-rdk board:

Bad block table not found for chip 0
Bad block table not found for chip 0

Revert it for now, until a better solution can be found.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210419140350.809853-1-festevam@gmail.com

mtd: rawnand: bbt: Skip bad blocks when searching for the BBT in NAND

The blocks containing the bad block table can become bad as well. So
make sure to skip any blocks that are marked bad when searching for the
bad block table.

Otherwise in very rare cases where two BBT blocks wear out it might
happen that an obsolete BBT is used instead of a newer available
version.

Signed-off-by: Stefan Riedmueller <s.riedmueller@phytec.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210325102337.481172-1-s.riedmueller@phytec.de

mtd: rawnand: fix a kernel-doc markup

Some identifiers have different names between their prototypes
and the kernel-doc markup.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/9ed47a57d12c40e73a9b01612ee119d39baa6236.1603469755.git.mchehab+huawei@kernel.org

mtd: rawnand: trivial spelling

The word 'descriptor' is misspelled throughout the tree.

Fix it up accordingly:
decriptors -> descriptors

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200609124610.3445662-5-kieran.bingham+renesas@ideasonboard.com

mtd: rawnand: Fix a memory leak bug

In nand_scan_bbt(), a temporary buffer 'buf' is allocated through
vmalloc(). However, if check_create() fails, 'buf' is not deallocated,
leading to a memory leak bug. To fix this issue, free 'buf' before
returning the error.

Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mtd: rawnand: Support bad block markers in first, second or last page

Currently supported bad block marker positions within the block are:
* in first page only
* in last page only
* in first or second page

Some ESMT NANDs are known to have been shipped by the manufacturer
with bad block markers in the first or last page, instead of the
first or second page.

Also the datasheets for Cypress/Spansion/AMD NANDs claim that the
first, second *and* last page needs to be checked.

Therefore we make it possible to set NAND_BBM_FIRSTPAGE,
NAND_BBM_SECONDPAGE and NAND_BBM_LASTPAGE independently in any
combination.

To simplify the code, the logic to evaluate the flags is moved to a
a new function nand_bbm_get_next_page().

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: nand: Make flags for bad block marker position more granular

To be able to check and set bad block markers in the first and
second page of a block independently of each other, we create
separate flags for both cases.

Previously NAND_BBM_SECONDPAGE meant, that both, the first and the
second page were used. With this patch NAND_BBM_FIRSTPAGE stands for
using the first page and NAND_BBM_SECONDPAGE for using the second
page.

This patch is only for preparation of subsequent changes and does
not implement the logic to actually handle both flags separately.

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Always store info about bad block markers in chip struct

The information about where the manufacturer puts the bad block
markers inside the bad block and in the OOB data is stored in
different places. Let's move this information to nand_chip.options
and nand_chip.badblockpos.

As this chip-specific information is not directly related to the
bad block table (BBT), we also rename the flags to NAND_BBM_*.

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Get rid of chip->numchips

The same information is provided by nanddev_ntargets().

Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>

mtd: rawnand: Get rid of chip->chipsize

The target size can now be returned by nanddev_get_targetsize(). Get
rid of the chip->chipsize field and use this helper instead.

Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Provide a helper to get chip->data_buf

We plan to move cache related fields to a pagecache struct in nand_chip
but some drivers access ->pagebuf directly to invalidate the cache
before they start using ->data_buf.

Let's provide an helper that returns a pointer to ->data_buf after
invalidating the cache.

Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>

mtd: rawnand: fix kernel-doc warnings

Fix kernel-doc warnings in drivers/mtd/nand/raw:

../drivers/mtd/nand/raw/nand_base.c:420: warning: Function parameter or member 'chip' not described in 'nand_fill_oob'
../drivers/mtd/nand/raw/nand_bbt.c:173: warning: Function parameter or member 'this' not described in 'read_bbt'
../drivers/mtd/nand/raw/nand_bbt.c:173: warning: Excess function parameter 'chip' description in 'read_bbt'

Fixes: 0813621ba898a ("mtd: rawnand: Stop passing mtd_info objects to internal functions")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Boris Brezillon <boris.brezillon@bootlin.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: linux-mtd@lists.infradead.org
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>

mtd: rawnand: Reorganize code to avoid forward declarations

Avoid forward declaration of nand_get_device(), nand_do_write_oob()
and nand_update_bbt() by moving functions around.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Tested-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Stop passing mtd_info objects to internal functions

After having reworked the rawnand API to avoid passing mtd_info
objects around, let's do the same for internal functions.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Tested-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Keep all internal stuff private

A lot of things defined in rawnand.h should not be exposed to NAND
controller drivers and should only be shared by core files.

Create the drivers/mtd/nand/raw/internals.h header to store such
definitions, and move all private defs to this header.

Also remove EXPORT_SYMBOLS() on functions that are not supposed to be
exposed.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Deprecate ->block_{bad,markbad}() hooks

Those hooks have been overloaded by some drivers for bad reasons:
either the driver was not fitting in the NAND framework and should
have been an MTD driver (docg4), or it was not properly implementing
the OOB read/write request or had a weird layout where BBM are trashed.
In any case, we should discourage people from overloading those
methods and encourage them to fix their driver instead.

Move the ->block_{bad,markbad}() hooks to the nand_legacy struct to
make it clear.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object nand_erase_nand()

Let's make the raw NAND API consistent by patching all helpers and
hooks to take a nand_chip object instead of an mtd_info one or
remove the mtd_info object when both are passed.

Let's tackle the nand_erase_nand() helper.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object to all nand_xxx_bbt() helpers

Let's make the raw NAND API consistent by patching all helpers and
hooks to take a nand_chip object instead of an mtd_info one or
remove the mtd_info object when both are passed.

Let's tackle the nand_xxx_bbt() helpers.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object to chip->block_xxx() hooks

Let's make the raw NAND API consistent by patching all helpers and
hooks to take a nand_chip object instead of an mtd_info one or
remove the mtd_info object when both are passed.

Let's tackle all chip->block_xxx() hooks at once.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Rename nand_default_bbt() into nand_create_bbt()

Rename nand_default_bbt() into nand_create_bbt() and pass it a nand_chip
object to prepare removal of the chip->scan_bbt() hook.

We add a temporary nand_default_bbt() wrapper which will be dropped
after the removal of ->scan_bbt().

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: nand: move raw NAND related code to the raw/ subdir

As part of the process of sharing more code between different NAND
based devices, we need to move all raw NAND related code to the raw/
subdirectory.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>