[PATCH RFC 0/4] reserved-memory regions/CMA in devicetree, again

Josh Cartwright joshc at codeaurora.org
Wed Jan 22 13:58:48 EST 2014


Hey Marek-

What is the current status of the reserved-memory/CMA device tree support
series?  It looks like it's stalled out a bit since the revert[2].  Hopefully
this series is a push in the right direction?

---
This set is an adaptation of Marek's original patchset posted here[1],
and then subsequently reverted here[2].  In [3], Grant proposed a new
set of bindings after discussion in Edinburgh.

This is a partially complete implementation of these proposed bindings.

It's functionality is now split into two pieces, the first of which
implements a default/fallback behavior for reserved-memory nodes; that
is, reserved memory nodes describing fixed-address static regions will
be unconditionally reserved, regardless of their intended use.  In
addition, it provides an interface for adding additional reserved-memory
types, using a method similar to CLOCKSOURCE_OF_DECLARE().

The second piece uses the above method to provide support for
reserved-memory nodes whose compatible = "shared-dma-pool".  It makes
use of CMA when available, and when a describing node has the 'reusable'
property.

There is basic support for dynamic allocation of memory reserved
regions, however, noticeably missing is support for additional
restrictions (use of alignment and alloc-ranges properties).

[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

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

Josh Cartwright (1):
  drivers: of: implement reserved-memory handling for dma

Marek Szyprowski (2):
  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   | 137 +++++++++++++++
 arch/arm/mm/init.c                                 |   3 +
 drivers/of/Kconfig                                 |  13 ++
 drivers/of/Makefile                                |   2 +
 drivers/of/of_reserved_mem.c                       | 188 +++++++++++++++++++++
 drivers/of/of_reserved_mem_dma.c                   | 178 +++++++++++++++++++
 drivers/of/platform.c                              |   4 +
 include/asm-generic/vmlinux.lds.h                  |  11 ++
 include/linux/of_reserved_mem.h                    |  61 +++++++
 9 files changed, 597 insertions(+)
 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_dma.c
 create mode 100644 include/linux/of_reserved_mem.h

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