linux-stable.git/drivers/mtd/mtdcore.c, branch v4.0

Merge tag 'for-linus-20150216' of git://git.infradead.org/linux-mtd

2015-02-18T16:01:44+00:00

Pull MTD updates from Brian Norris:
 "NAND:

   - Add new Hisilicon NAND driver for Hip04
   - Add default reboot handler, to ensure all outstanding erase
     transactions complete in time
   - jz4740: convert to use GPIO descriptor API
   - Atmel: add support for sama5d4
   - Change default bitflip threshold to 75% of correction strength
   - Miscellaneous cleanups and bugfixes

  SPI NOR:

   - Freescale QuadSPI:
   - Fix a few probe() and remove() issues
   - Add a MAINTAINERS entry for this driver
   - Tweak transfer size to increase read performance
   - Add suspend/resume support
   - Add Micron quad I/O support
   - ST FSM SPI: miscellaneous fixes

  JFFS2:

   - gracefully handle corrupted 'offset' field found on flash

  Other:

   - bcm47xxpart: add tweaks for a few new devices
   - mtdconcat: set return lengths properly for mtd_write_oob()
   - map_ram: enable use with mtdoops
   - maps: support fallback to ROM/UBI for write-protected NOR flash"

* tag 'for-linus-20150216' of git://git.infradead.org/linux-mtd: (46 commits)
  mtd: hisilicon: && vs & typo
  jffs2: fix handling of corrupted summary length
  mtd: hisilicon: add device tree binding documentation
  mtd: hisilicon: add a new NAND controller driver for hisilicon hip04 Soc
  mtd: avoid registering reboot notifier twice
  mtd: concat: set the return lengths properly
  mtd: kconfig: replace PPC_OF with PPC
  mtd: denali: remove unnecessary stubs
  mtd: nand: remove redundant local variable
  MAINTAINERS: add maintainer entry for FREESCALE QUAD SPI driver
  mtd: fsl-quadspi: improve read performance by increase AHB transfer size
  mtd: fsl-quadspi: Remove unnecessary 'map_failed' label
  mtd: fsl-quadspi: Remove unneeded success/error messages
  mtd: fsl-quadspi: Fix the error paths
  mtd: nand: omap: drop condition with no effect
  mtd: nand: jz4740: Convert to GPIO descriptor API
  mtd: nand: Request strength instead of bytes for soft BCH
  mtd: nand: default bitflip-reporting threshold to 75% of correction strength
  mtd: atmel_nand: introduce a new compatible string for sama5d4 chip
  mtd: atmel_nand: return max bitflips in all sectors in pmecc_correction()
  ...

mtd: avoid registering reboot notifier twice

2015-02-08T06:55:47+00:00

Calling mtd_device_parse_register with the same mtd_info
(e.g. registering several partitions on a single device)
would add the same reboot notifier twice, causing an
infinte loop in notifier_chain_register during boot up.

Signed-off-by: Niklas Cassel 
[Brian: add FIXME comments]
Signed-off-by: Brian Norris 

Signed-off-by: Brian Norris

mtd: export new mtd_mmap_capabilities

2015-01-28T18:09:20+00:00

The recently added mtd_mmap_capabilities can be used from loadable
modules, in particular romfs, but is not exported, so we get

ERROR: "mtd_mmap_capabilities" [fs/romfs/romfs.ko] undefined!

This adds the missing export.

Signed-off-by: Arnd Bergmann 
Fixes: b4caecd48005f ("fs: introduce f_op->mmap_capabilities for nommu mmap support")
Acked-by: Christoph Hellwig 
Acked-by: Brian Norris 
Signed-off-by: Jens Axboe

fs: introduce f_op->mmap_capabilities for nommu mmap support

2015-01-20T21:02:58+00:00

Since "BDI: Provide backing device capability information [try #3]" the
backing_dev_info structure also provides flags for the kind of mmap
operation available in a nommu environment, which is entirely unrelated
to it's original purpose.

Introduce a new nommu-only file operation to provide this information to
the nommu mmap code instead.  Splitting this from the backing_dev_info
structure allows to remove lots of backing_dev_info instance that aren't
otherwise needed, and entirely gets rid of the concept of providing a
backing_dev_info for a character device.  It also removes the need for
the mtd_inodefs filesystem.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Tejun Heo 
Acked-by: Brian Norris 
Signed-off-by: Jens Axboe

mtd: implement common reboot notifier boilerplate

2015-01-08T01:54:22+00:00

cfi_cmdset_000{1,2}.c already implement their own reboot notifiers, and
we're going to add one for NAND. Let's put the boilerplate in one place.

Signed-off-by: Brian Norris 
Tested-by: Scott Branden

mtd: remove dead non-char logic

2014-08-19T18:53:08+00:00

MTD used to allow compiling out character device support. This was
dropped in the following commit, but some of the accompanying logic was
never dropped:

  commit 660685d9d1b4730f0b5ca97fa95f272f99c63bce
  Author: Artem Bityutskiy 
  Date:   Thu Mar 14 13:27:40 2013 +0200

      mtd: merge mtdchar module with mtdcore

The weird logic was flagged by Coverity.

Signed-off-by: Brian Norris 
Cc: Artem Bityutskiy

mtd: correct upper bounds check for mtd_*() APIs

2014-08-19T18:53:07+00:00

When checking the upper boundary (i.e., whether an address is higher
than the maximum size of the MTD), we should be doing an inclusive check
(greater or equal). For instance, an address of 16MB (0x1000000) on a
16MB device is invalid.

The strengthening of this bounds check is redundant for those which
already have a address+length check and ensure that the length is
non-zero, but let's just fix them all, for completeness.

Signed-off-by: Brian Norris

mtd: Introduce mtd_block_isreserved()

2014-07-09T01:38:16+00:00

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: Ezequiel Garcia 
Tested-by: Pekon Gupta 
Signed-off-by: Brian Norris

mtd: Add sysfs attributes to expose the ECC stats fields

2014-07-09T01:37:26+00:00

These new sysfs device attributes allow us to retrieve the ECC and bad
block stats by poking a sysfs file, which is often more convenient than
using the ioctl.

Signed-off-by: Ezequiel Garcia 
Tested-by: Pekon Gupta 
Signed-off-by: Brian Norris

mtd: Fix the behavior of OTP write if there is not enough room for data

2014-03-11T05:42:31+00:00

If a write to one time programmable memory (OTP) hits the end of this
memory area, no more data can be written. The count variable in
mtdchar_write() in drivers/mtd/mtdchar.c is not decreased anymore.
We are trapped in the loop forever, mtdchar_write() will never return
in this case.

The desired behavior of a write in such a case is described in [1]:
- Try to write as much data as possible, truncate the write to fit into
  the available memory and return the number of bytes that actually
  have been written.
- If no data could be written at all, return -ENOSPC.

This patch fixes the behavior of OTP write if there is not enough space
for all data:

1) mtd_write_user_prot_reg() in drivers/mtd/mtdcore.c is modified to
   return -ENOSPC if no data could be written at all.
2) mtdchar_write() is modified to handle -ENOSPC correctly. Exit if a
   write returned -ENOSPC and yield the correct return value, either
   then number of bytes that could be written, or -ENOSPC, if no data
   could be written at all.

Furthermore the patch harmonizes the behavior of the OTP memory write
in drivers/mtd/devices/mtd_dataflash.c with the other implementations
and the requirements from [1]. Instead of returning -EINVAL if the data
does not fit into the OTP memory, we try to write as much data as
possible/truncate the write.

[1] http://pubs.opengroup.org/onlinepubs/9699919799/functions/write.html

Signed-off-by: Christian Riesch 
Signed-off-by: Brian Norris