Since commit 17799359 ("mtd: nand_bbt:
make nand_scan_bbt() static"), the nand_scan_bbt() function is marked
as static but is still exported using EXPORT_SYMBOL(), which doesn't
make much sense.

This commit gets rid of the useless EXPORT_SYMBOL.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-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>

When using nandsim to simulate a 128K block nand with `overridesize = 1',
the size of mtd device is too small (mtd_size = 4 * block_size) to get the
right length of bbt. Then when creating bbt, kzmalloc() will return
ZERO_SIZE_PTR. This causes a NULL pointer oops when scanning bbt.

[  952.156166] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
[  952.157064] IP: [<ffffffff8148ad4a>] nand_isreserved_bbt+0x2a/0x40
[  952.157064] PGD 0
[  952.157064] Oops: 0000 [#1] SMP
[  952.157064] Modules linked in: nandsim(+) [last unloaded: nandsim]
[  952.157064] CPU: 1 PID: 7103 Comm: modprobe Not tainted 4.2.0-rc3-next-20150724 #4
[  952.157064] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  952.157064] task: ffff88003e24b980 ti: ffff88003d274000 task.ti: ffff88003d274000
[  952.157064] RIP: 0010:[<ffffffff8148ad4a>]  [<ffffffff8148ad4a>] nand_isreserved_bbt+0x2a/0x40
[  952.157064] RSP: 0018:ffff88003d277b90  EFLAGS: 00010246
[  952.157064] RAX: 0000000000000010 RBX: ffff88003d5a1000 RCX: 0000000000000000
[  952.157064] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88003d919000
[  952.157064] RBP: ffff88003d277b98 R08: 0000000000020000 R09: 0000000000000000
[  952.157064] R10: 0000000000000000 R11: 0000000000000195 R12: ffff88003d919000
[  952.157064] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[  952.157064] FS:  00007fada4d07700(0000) GS:ffff88003fd00000(0000) knlGS:0000000000000000
[  952.157064] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  952.157064] CR2: 0000000000000010 CR3: 0000000037924000 CR4: 00000000000006a0
[  952.157064] Stack:
[  952.157064]  ffffffff814851ec ffff88003d277ba8 ffffffff8147e35f ffff88003d277bf8
[  952.157064]  ffffffff814816f3 ffff88003d277c08 ffff88003d277bc8 0000000000000282
[  952.157064]  0000000000000001 0000000000000000 ffff88003d209540 0000000000000001
[  952.157064] Call Trace:
[  952.157064]  [<ffffffff814851ec>] ? nand_block_isreserved+0x1c/0x20
[  952.157064]  [<ffffffff8147e35f>] mtd_block_isreserved+0x1f/0x30
[  952.157064]  [<ffffffff814816f3>] allocate_partition+0x463/0x6a0
[  952.157064]  [<ffffffff81481b3b>] add_mtd_partitions+0x4b/0xe0
[  952.157064]  [<ffffffff8147f14c>] mtd_device_parse_register+0x4c/0xe0
[  952.157064]  [<ffffffffa0013daf>] ns_init_module+0xdaf/0xde4 [nandsim]
[  952.157064]  [<ffffffff8128d7c8>] ? kasprintf+0x38/0x40
[  952.157064]  [<ffffffffa0013000>] ? 0xffffffffa0013000
[  952.157064]  [<ffffffff810002c3>] do_one_initcall+0x83/0x1b0
[  952.157064]  [<ffffffff8113afab>] ? kmem_cache_alloc_trace+0x6b/0x120
[  952.157064]  [<ffffffff8160b503>] do_init_module+0x5c/0x1dd
[  952.157064]  [<ffffffff810aa4db>] load_module+0x1bbb/0x20b0
[  952.157064]  [<ffffffff810a6fc0>] ? __symbol_put+0x30/0x30
[  952.157064]  [<ffffffff810aaac9>] SyS_init_module+0xf9/0x110
[  952.157064]  [<ffffffff810aa9d1>] ? SyS_init_module+0x1/0x110
[  952.157064]  [<ffffffff81615f57>] entry_SYSCALL_64_fastpath+0x12/0x6a
[  952.157064] Code: 00 55 48 8b 87 80 01 00 00 48 89 e5 8b 88 cc 00 00 00 48 8b 80 f0 03 00 00 5d 48 d3 fe 89 f2 83 e6 03 c1 fa 02 8d 0c 36 48 63 d2 <0f> b6 04 10 d3 f8 83 e0 03 3c 02 0f 94 c0 0f b6 c0 c3 0f 1f 40
[  952.157064] RIP  [<ffffffff8148ad4a>] nand_isreserved_bbt+0x2a/0x40
[  952.157064]  RSP <ffff88003d277b90>
[  952.157064] CR2: 0000000000000010
[  952.204010] ---[ end trace 6ca2e1c041fdba36 ]---

This patch gives a smallest length to bbt, 1 byte, which is enough to
represent up to 4 blocks.
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
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>

This statement was written with a cast-to-loff_t to be sure to have a
full 64-bit mask. However, we don't account for the fact that
'1 << this->bbt_erase_shift' might already overflow.

This will not be a problem in practice, since eraseblocks should never
be anywhere near 4GiB. But we can do this for completeness, and quiet
Coverity in the meantime. CID #1226806.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Don't leak this->bbt, and return early if check_create() fails. It helps
to have a single error path to avoid these problems.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

This implementation detail is no longer needed outside of nand_bbt.c.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

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

This follows Chapter 2 of Linux's CodingStyle:
> However, never break user-visible strings such as printk messages,
> because that breaks the ability to grep for them.
Signed-off-by: NRafał Miłecki <zajec5@gmail.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

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: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NPekon Gupta <pekon@ti.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

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

Set, but unused, variable.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

Now that the last user of NAND_BBT_SCANALLPAGES has been removed, let's
kill this peculiar BBT feature flag.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

I removed the last non-nand_base users of this, and we shouldn't have
any more modules that need to access it. It's only non-static to share
between nand_base and nand_bbt.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

NAND_BBT_SCANEMPTY is a strange, badly-supported option with omap as its
single remaining user.

NAND_BBT_SCANEMPTY was likely used by accident in omap2[1]. And anyway,
omap2 doesn't scan the chip for bad blocks (courtesy of
NAND_SKIP_BBTSCAN), and so its use of this option is irrelevant.

This patch drops the NAND_BBT_SCANEMPTY option.

[1] http://lists.infradead.org/pipermail/linux-mtd/2012-July/042902.htmlSigned-off-by: NBrian Norris <computersforpeace@gmail.com>
Cc: Ivan Djelic <ivan.djelic@parrot.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

nand_base.c shouldn't have to know the implementation details of
nand_bbt's in-memory BBT. Specifically, nand_base shouldn't perform the
bit masking and shifting to isolate a BBT entry.

Instead, just move some of the BBT code into a new nand_markbad_bbt()
interface. This interface allows external users (i.e., nand_base) to
mark a single block as bad in the BBT. Then nand_bbt will take care of
modifying the in-memory BBT and updating the flash-based BBT (if
applicable).
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The chip->block_markbad pointer should really only be responsible for
writing a bad block marker for new bad blocks. It should not take care
of BBT-related functionality, nor should it handle bookkeeping of bad
block stats.

This patch refactors the 3 users of the block_markbad interface (plus
the default nand_base implementation) so that the common code is kept in
nand_block_markbad_lowlevel(). It removes some inconsistencies between
the various implementations and should allow for more centralized
improvements in the future.

Because gpmi-nand no longer needs the nand_update_bbt() function, let's
stop exporting it as well.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com> (for gpmi-nand parts)
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Just make 'res' an int.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The parent commit 771c568b ("mtd: nand: add
accessors, macros for in-memory BBT") makes the following comment obsolete:

	/*
	 * Note that numblocks is 2 * (real numblocks) here, see i+=2
	 * below as it makes shifting and masking less painful
	 */

I don't think it ever could have been "less painful" to have to shift an
extra bit (or 2, or 3) at various points in nand_bbt.c (and even
outside, since we leak our in-memory format). But now it is certainly
more painful, since we have nice macros and functions to retrieve the
relevant portions of the BBT.

This patch removes any points where the block number is
doubled/halved/otherwise-shifted, instead representing the block number
in its most natural form: as the actual block number.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

There is an abundance of magic numbers and complicated shifting/masking
logic in the in-memory BBT code which makes the code unnecessary complex
and hard to read.

This patch adds macros to represent the 00b, 01b, 10b, and 11b
memory-BBT magic numbers, as well as two accessor functions for reading
and marking the memory-BBT bitfield for a given block.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

We have only one AG-AND driver and it was not touched since 2005. It looks
like AG-AND was not really make it to mass-production and can be considered
a dead technology.

Along with the AG-AND support, this patch removes the BBT_AUTO_REFRESH feature,
because the only user of this feature is AG-AND. And even though it is
implemented as a generic feature, I prefer to remove it because NAND flashes do
not really need it in this form.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

In nand_bbt.c, a hardcoded value was used instead of the define meant
for that, so we use the define.

There's no functional change.
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

When building MTD_NAND_GPMI_NAND as module, the following error shows up:

ERROR: "nand_update_bbt" [drivers/mtd/nand/gpmi-nand/gpmi_nand.ko] undefined!

Export nand_update_bbt to fix it.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Rename 'len' variable of create_bbt/scan_block_fast/scan_block_full to
'numpages', since it really means number of pages to scan when
searching for the BBM (and not the byte length of the scan).
Signed-off-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
Reviewed-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

None of these scanning functions use MTD_OPS_RAW mode any more, so there's
really nothing 'raw' about them. Rename them to (hopefully) make the code
a little clearer.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

scan_read_raw_oob() is used in only in places where the MTD_OPS_PLACE_OOB mode
is preferable to MTD_OPS_RAW mode, so use MTD_OPS_PLACE_OOB instead.
MTD_OPS_PLACE_OOB provides the same functionality with the potential[1] added
bonus of error correction.

This brings scan_block_full() in line with scan_block_fast() so that they
both read bad block markers with MTD_OPS_PLACE_OOB. This can help in
preventing 0xff markers (in good blocks) from being interpreted as bad
block indicators in the presence of a single bitflip.

Note that ECC error codes (EUCLEAN or EBADMSG) are already silently
ignored in all users of scan_read_raw_oob().

[1] Few  drivers perform proper error correction on OOB data. In those
    cases, the use of MTD_OPS_RAW vs. MTD_OPS_PLACE_OOB is not
    significant.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Some nand_bbt code can be shortened by using memcmp() and memchr_inv().
As an added bonus, there is a possible performance benefit.

Borrowed some code from Akinobu Mita.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The return codes for read_abs_bbts() and search_read_bbts() are always
non-zero, and so don't have much meaning. Just remove them.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Reviewed-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

fix the comment for nand_bbt.c
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This function only returns 0 or -1, so make that clear.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

These descriptors are for BBT's that don't use OOB; the "no_bbt" name doesn't
really make sense.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The code responsible for reading the version of the mirror bbt was
incorrectly using the descriptor of the main bbt.

Pass the mirror bbt descriptor to 'scan_read_raw' when reading the
version of the mirror bbt.
Signed-off-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: stable@vger.kernel.org [v2.6.37+]
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

It seems there is a bug in scan_read_raw_oob() in nand_bbt.c which
should cause wrong functioning of NAND_BBT_SCANALLPAGES option.

Artem: the patch did not apply and I had to amend it a bit.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: stable@kernel.org

Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

These two common macros will be no longer present everywhere.
Call out the include needs of them explicitly where required.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

A portion of the `check_pattern()' function is basically a `memcmp()'.
Since it's possible for `memcmp()' to be optimized for a particular
architecture, we should use it instead.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@intel.com>

Updates to our default function for creating bad block patterns have
broken the "no OOB" feature. The NAND_BBT_NO_OOB option should not be
set while scanning for bad blocks, but we've been passing all BBT
options from nand_chip.bbt_options to the bad block scan. This causes us
to hit the:

	BUG_ON(bd->options & NAND_BBT_NO_OOB);

in create_bbt() when we scan the flash for bad blocks.

Thus, while it can be legal to set NAND_BBT_NO_OOB in a custom badblock
pattern descriptor (presumably with NAND_BBT_CREATE disabled?), we
should not pass it through in our default function.

Also, to help clarify and emphasize that the function creates bad block
patterns only (not, for example, table descriptors for locating
flash-based BBT), I renamed `nand_create_default_bbt_descr' to
`nand_create_badblock_pattern'.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@intel.com>

Because there are so many cases of checking, writing, and re-writing of
the bad block table(s), we might as well wait until the we've settled on
a valid, clean copy of the table. This also prevents us from falsely
incrementing the table version. For example, we may have the following:

  Primary table, with version 0x02
  Mirror table, with version 0x01
  Primary table has uncorrectable ECC errors

If we don't have this fix applied, then we will:

  Choose to read the primary table (higher version)
  Set mirror table version to 0x02
  Read back primary table
  Invalidate table because of ECC errors
  Retry readback operation with mirror table, now version 0x02
  Mirrored table reads cleanly
  Writeback BBT to primary table location (with "version 0x02")

However, the mirrored table shouldn't have a new version number.
Instead, we actually want:

  Choose to read the primary table (higher version)
  Read back primary table
  Invalidate table because of ECC errors
  Retry readback with mirror table (version 0x01)
  Mirrored table reads cleanly
  Set both tables to version 0x01
  Writeback BBT to primary table location (version 0x01)
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@intel.com>