[PATCH v4 00/35] Allow dynamic allocations during NAND chip identification phase

[miquel.raynal@xxxxxxxxxxx (Miquel Raynal)]

Hello,

This series make a quite deep change in the NAND framework. Until now,
the NAND chip identification phase could be done in two manners from the
controller driver perspective:

1/ Call nand_scan()

  or

1/ Call nand_scan_ident()
2/ Do some controller-dependent configuration
3/ Call nand_scan_tail().

The fact that the identifaction could be split in two operations
involved that in the NAND framework, it was not possible to do any
dynamic allocation without risking a memory leak. What if the core
allocates a structure, then the driver between nand_scan_ident() and
nand_scan_tail() decides it cannot handle the chip and errors out?
The structure allocated by the core is lost: it is a memory leak. One
solution could have been to add a nand_scan_ident_cleanup() function,
but that would mean patching all the drivers anyway to make them call
this function when something fails between nand_scan_ident() and
nand_scan_tail().

To avoid this situation, we migrate all drivers to use nand_scan() in
conjuction with the recently added hooks ->attach_chip() and
->detach_chip() that are part of the nand_controller structure
operations. Drivers that need to tweak their configuration after
nand_scan_ident() should implement it. Any dynamically allocated space
in ->attach_chip() must be freed in the second hook: ->detach_chip().

The ->detach_chip() does not have to be called upon error in the
controller driver probe function. The nand_cleanup() helper already
exists for that and will do the call if needed. Of course, this helper
must be called on error after a successful nand_scan(), just like
before.

Once all drivers not using nand_scan() are migrated, nand_scan_ident()
and nand_scan_tail() are unexported and only available internally.

A previous work [1] removed the ONFI/JEDEC parameter pages and instead
allocated a nand_parameters structure in nand_chip, embedding both
generic entries and ONFI-related ones. The deal was, once dynamic
allocation possible, allocate in nand_scan_ident() the ONFI strcuture
only if actually needed. This is done in the last patches.

This series applies on top of nand/next.

Thank you,
Miqu?l

[1] http://lists.infradead.org/pipermail/linux-mtd/2018-March/079456.html

Changes since v3:
=================
* Constified all the nand_controller_ops structure definitions.
* Fixed a build issue in fsl_elbc.
* Added a patch in the core to prevent executing nand_scan_ident if
  maxchips is NULL.
* Fixed the regression around the model name.
* Used kstrdup to allocate the model.
* The migration from char model[] to const char *model is done in a
  separate patch.

Changes since v2:
=================
* Rebased on top of nand/next.
* Adapted all drivers to declare statically a nand_controller_ops
  structure and assign it in the probe().
* Added the migration of the tegra_nand.c driver.
* Moved brcmnand controller ops affectation in the probe().

Changes since v1:
=================
* Rebased on top of nand/next.
* Light rewording of the cover letter about the possibility to have a
  nand_scan_ident_cleanup() function (just as example of how this series
  could have been done differently).
* Changed the hooks to reside in the nand_hw_ctrl structure instead of
  being part of nand_ecc_ctrl as these hooks are more
  controller-related.


Miquel Raynal (35):
  mtd: rawnand: brcmnand: convert driver to nand_scan()
  mtd: rawnand: cafe: convert driver to nand_scan()
  mtd: rawnand: davinci: convert driver to nand_scan()
  mtd: rawnand: denali: convert to nand_scan()
  mtd: rawnand: fsl_elbc: convert driver to nand_scan()
  mtd: rawnand: fsl_ifc: convert driver to nand_scan()
  mtd: rawnand: fsmc: convert driver to nand_scan()
  mtd: rawnand: gpmi: convert driver to nand_scan()
  mtd: rawnand: hisi504: convert driver to nand_scan()
  mtd: rawnand: jz4780: convert driver to nand_scan()
  mtd: rawnand: lpc32xx_mlc: convert driver to nand_scan()
  mtd: rawnand: lpc32xx_slc: convert driver to nand_scan()
  mtd: rawnand: marvell: convert driver to nand_scan()
  mtd: rawnand: mtk: convert driver to nand_scan()
  mtd: rawnand: mxc: convert driver to nand_scan()
  mtd: rawnand: nandsim: convert driver to nand_scan()
  mtd: rawnand: omap2: convert driver to nand_scan()
  mtd: rawnand: s3c2410: convert driver to nand_scan()
  mtd: rawnand: sh_flctl: move all NAND chip related setup in one
    function
  mtd: rawnand: sh_flctl: convert driver to nand_scan()
  mtd: rawnand: sunxi: convert driver to nand_scan()
  mtd: rawnand: tango: convert driver to nand_scan()
  mtd: rawnand: txx9ndfmc: rename nand controller internal structure
  mtd: rawnand: txx9ndfmc: convert driver to nand_scan()
  mtd: rawnand: vf610: convert driver to nand_scan()
  mtd: rawnand: atmel: convert driver to nand_scan()
  mtd: rawnand: sm_common: convert driver to nand_scan_with_ids()
  mtd: rawnand: allow exiting immediately nand_scan_ident()
  mtd: rawnand: docg4: convert driver to nand_scan()
  mtd: rawnand: qcom: convert driver to nand_scan()
  mtd: rawnand: jz4740: convert driver to nand_scan()
  mtd: rawnand: tegra: convert driver to nand_scan()
  mtd: rawnand: do not export nand_scan_[ident|tail]() anymore
  mtd: rawnand: allocate model parameter dynamically
  mtd: rawnand: allocate dynamically ONFI parameters during detection

 drivers/mtd/nand/raw/atmel/nand-controller.c |  83 ++---
 drivers/mtd/nand/raw/brcmnand/brcmnand.c     |  47 ++-
 drivers/mtd/nand/raw/cafe_nand.c             | 130 ++++---
 drivers/mtd/nand/raw/davinci_nand.c          | 195 +++++-----
 drivers/mtd/nand/raw/denali.c                | 138 +++----
 drivers/mtd/nand/raw/docg4.c                 |  55 +--
 drivers/mtd/nand/raw/fsl_elbc_nand.c         |  19 +-
 drivers/mtd/nand/raw/fsl_ifc_nand.c          |  19 +-
 drivers/mtd/nand/raw/fsmc_nand.c             | 148 ++++----
 drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c   |  56 +--
 drivers/mtd/nand/raw/hisi504_nand.c          |  78 ++--
 drivers/mtd/nand/raw/jz4740_nand.c           |  46 ++-
 drivers/mtd/nand/raw/jz4780_nand.c           |  34 +-
 drivers/mtd/nand/raw/lpc32xx_mlc.c           | 109 +++---
 drivers/mtd/nand/raw/lpc32xx_slc.c           |  77 ++--
 drivers/mtd/nand/raw/marvell_nand.c          | 205 ++++++-----
 drivers/mtd/nand/raw/mtk_nand.c              |  75 ++--
 drivers/mtd/nand/raw/mxc_nand.c              | 136 +++----
 drivers/mtd/nand/raw/nand_base.c             | 132 +++++--
 drivers/mtd/nand/raw/nand_micron.c           |   6 +-
 drivers/mtd/nand/raw/nand_timings.c          |  12 +-
 drivers/mtd/nand/raw/nandsim.c               |  82 +++--
 drivers/mtd/nand/raw/omap2.c                 | 521 +++++++++++++--------------
 drivers/mtd/nand/raw/qcom_nandc.c            |  71 ++--
 drivers/mtd/nand/raw/s3c2410.c               |  30 +-
 drivers/mtd/nand/raw/sh_flctl.c              |  57 ++-
 drivers/mtd/nand/raw/sm_common.c             |  39 +-
 drivers/mtd/nand/raw/sunxi_nand.c            |  43 +--
 drivers/mtd/nand/raw/tango_nand.c            |  40 +-
 drivers/mtd/nand/raw/tegra_nand.c            | 162 +++++----
 drivers/mtd/nand/raw/txx9ndfmc.c             |  35 +-
 drivers/mtd/nand/raw/vf610_nfc.c             | 127 +++----
 include/linux/mtd/rawnand.h                  |  17 +-
 include/linux/mtd/sh_flctl.h                 |   1 +
 34 files changed, 1612 insertions(+), 1413 deletions(-)

-- 
2.14.1