[PATCH v3 0/6] reserved-memory regions/CMA in devicetree, again

Marek Szyprowski m.szyprowski at samsung.com
Tue Feb 18 08:37:55 EST 2014

Hi all!

This is yet another update of the second attempt to add basic support
for dynamic allocation of memory reserved regions defined in device

This time I've tried to address all the issues reported by Grant Likely.
The side-effect of it is a complete rewrite of memory reservation code,
which results in added support for for multiple tuples in 'reg' property
and complete support for 'size', 'align' and 'alloc-ranges' properties.

The initial code for this feature were posted here [1], merged as commit
9d8eab7af79cb4ce2de5de39f82c455b1f796963 ("drivers: of: add
initialization code for dma reserved memory") and later reverted by
commit 1931ee143b0ab72924944bc06e363d837ba05063. For more information,
see [2]. Finally a new bindings has been proposed [3] and Josh
Cartwright a few days ago prepared some code which implements those
bindings [4]. This finally pushed me again to find some time to finish
this task and review the code. Josh agreed to give me the ownership of
this series to continue preparing them for mainline inclusion.

For more information please refer to the changlelog below.

[1]: http://lkml.kernel.org/g/1377527959-5080-1-git-send-email-m.szyprowski@samsung.com
[2]: http://lkml.kernel.org/g/1381476448-14548-1-git-send-email-m.szyprowski@samsung.com
[3]: http://lkml.kernel.org/g/20131030134702.19B57C402A0@trevor.secretlab.ca
[4]: http://thread.gmane.org/gmane.linux.documentation/19579


- refactored memory reservation code, created common code to parse reg, size,
  align, alloc-ranges properties
- added support for multiple tuples in 'reg' property
- memory is reserved regardless of presence of the driver for its compatible
- prepared arch specific hooks for memory reservation (defaults use memblock
- removed node matching by string during device initialization
- CMA init code: added checks for required region alignment
- more code cleanup here and there

v2: http://thread.gmane.org/gmane.linux.documentation/19870/
- removed copying of the node name
- split shared-dma-pool handling into separate files (one for CMA and one
  for dma_declare_coherent based implementations) for making the code easier
  to understand
- added support for AMBA devices, changed prototypes to use struct decice
  instead of struct platform_device
- renamed some functions to better match other names used in drivers/of/
- restructured the rest of the code a bit for better readability
- added 'reusable' property to exmaple linux,cma node in documentation
- exclusive dma (dma_coherent) is used for only handling 'shared-dma-pool'
  regions without 'reusable' property and CMA is used only for handling
  'shared-dma-pool' regions with 'reusable' property.

v1: http://thread.gmane.org/gmane.linux.documentation/19579
- initial version prepared by Josh Cartwright


Grant Likely (1):
  of: document bindings for reserved-memory nodes

Josh Cartwright (2):
  drivers: of: implement reserved-memory handling for dma
  drivers: of: implement reserved-memory handling for cma

Marek Szyprowski (3):
  base: dma-contiguous: add dma_contiguous_init_reserved_mem() function
  drivers: of: add initialization code for reserved memory
  ARM: init: add support for reserved memory defined by device tree

 .../bindings/reserved-memory/reserved-memory.txt   |  138 +++++++
 arch/arm/Kconfig                                   |    1 +
 arch/arm/mm/init.c                                 |    3 +
 drivers/base/dma-contiguous.c                      |   70 ++--
 drivers/of/Kconfig                                 |   19 +
 drivers/of/Makefile                                |    3 +
 drivers/of/fdt.c                                   |    2 +
 drivers/of/of_reserved_mem.c                       |  390 ++++++++++++++++++++
 drivers/of/of_reserved_mem_cma.c                   |   68 ++++
 drivers/of/of_reserved_mem_dma.c                   |   65 ++++
 drivers/of/platform.c                              |    7 +
 include/asm-generic/vmlinux.lds.h                  |   11 +
 include/linux/dma-contiguous.h                     |    7 +
 include/linux/of_reserved_mem.h                    |   65 ++++
 14 files changed, 827 insertions(+), 22 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
 create mode 100644 drivers/of/of_reserved_mem.c
 create mode 100644 drivers/of/of_reserved_mem_cma.c
 create mode 100644 drivers/of/of_reserved_mem_dma.c
 create mode 100644 include/linux/of_reserved_mem.h


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