[PATCH v2 0/2] genalloc: add support of multiple gen_pools per device

Vladimir Zapolskiy vladimir_zapolskiy at mentor.com
Thu Jun 18 08:26:02 PDT 2015

This is continuation of development of a proposed earlier
functionality to have multiple gen_pools per device, see
https://lkml.org/lkml/2015/6/8/588 discussion.

The main difference with the originally sent change is that instead of
adding two new interfaces gen_pool_get_named() and
devm_gen_pool_create_named(), it is considered better to change
signatures of the existing exported functions, because
devm_gen_pool_create() may be misused -- it is permitted to create
several gen_pool objects assigned to the same device and
gen_pool_get() returns only the first found object from device devres
data due to missing devres_match helper, fortunately currently
existing genalloc clients are not tainted -- at the moment the sole
user of devm_gen_pool_create() is drivers/misc/sram.c.

The change is split into two parts:
- update gen_pool_get() and devm_gen_pool_create() interfaces
  on client side
- implement proper handling of new gen_pool "name" argument
  and extend of_gen_pool_get() functionality based on it

Both changes are backward compatible in sense of functionality.

The lib/genalloc.c changes are based on two patches from -mm tree:
- http://ozlabs.org/~akpm/mmots/broken-out/genalloc-rename-dev_get_gen_pool-to-gen_pool_get.patch
- http://ozlabs.org/~akpm/mmots/broken-out/genalloc-rename-of_get_named_gen_pool-to-of_gen_pool_get.patch

The client side changes are based on linux-next/master branch.

Changes from v1 to v2:
- addressed Andrew's valuable review comments, namely
-- devm_gen_pool_create() is aware of attempts to register ambiguously
   addressed gen_pool objects and now it returns ERR_PTR() on error,
-- memory management to store gen_pool name literal is done on
   genalloc side,
-- replaced -1 with NUMA_NO_NODE in nid argument description,
- minor updates in of_gen_pool_get() change to respect OF_DYNAMIC
- instead of adding two new functions the existing functions
  gen_pool_get() (at91, imx5m, imx6 and CODA driver clients) and
  devm_gen_pool_create() (sram client) are updated.

Vladimir Zapolskiy (2):
  genalloc: add name arg to gen_pool_get() and devm_gen_pool_create()
  genalloc: add support of multiple gen_pools per device

 arch/arm/mach-at91/pm.c                   |  2 +-
 arch/arm/mach-imx/pm-imx5.c               |  2 +-
 arch/arm/mach-imx/pm-imx6.c               |  2 +-
 drivers/media/platform/coda/coda-common.c |  2 +-
 drivers/misc/sram.c                       |  8 +--
 include/linux/genalloc.h                  |  6 +-
 lib/genalloc.c                            | 99 +++++++++++++++++++++++--------
 7 files changed, 85 insertions(+), 36 deletions(-)


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