iommu.lists.linux-foundation.org archive mirror
 help / color / mirror / Atom feed
* [RFC 0/3] Introduce memory controller mini-framework
@ 2019-10-15 16:29 Thierry Reding
  2019-10-15 16:29 ` [RFC 1/3] memory: " Thierry Reding
                   ` (2 more replies)
  0 siblings, 3 replies; 7+ messages in thread
From: Thierry Reding @ 2019-10-15 16:29 UTC (permalink / raw)
  To: Arnd Bergmann
  Cc: Will Deacon, Jonathan Hunter, iommu, linux-tegra, Robin Murphy,
	linux-arm-kernel

From: Thierry Reding <treding@nvidia.com>

Hi,

this series proposes the introduction of a mini-framework for memory
controllers. The primary use-case for this right now is to allow for
drivers that depend on the memory controller to defer probe until the
memory controller has been successfully registered.

One example where this is needed is on Tegra186 and later SoCs where
the memory controller needs to program some registers to associate a
stream ID with memory clients. This requires that the IOMMU driver
defers probe until the memory controller has been registered.

This is achieved by providing a trivial memory controller registry that
can be queried.

I haven't written up a full device tree binding for this, but if people
think this is a reasonable proposal, I can flesh things out. Currently I
use something along these lines on Tegra186:

	mc: memory-controller@2c00000 {
		...
		#memory-controller-cells = <0>;
		...
	};

	iommu@12000000 {
		...
		memory-controllers = <&mc>;
		...
	};

Thierry

Thierry Reding (3):
  memory: Introduce memory controller mini-framework
  memory: tegra186: Register as memory controller
  iommu: arm-smmu: Get reference to memory controller

 drivers/iommu/arm-smmu.c          | 12 ++++
 drivers/iommu/arm-smmu.h          |  2 +
 drivers/memory/Makefile           |  1 +
 drivers/memory/core.c             | 99 +++++++++++++++++++++++++++++++
 drivers/memory/tegra/tegra186.c   |  8 ++-
 include/linux/memory-controller.h | 25 ++++++++
 6 files changed, 146 insertions(+), 1 deletion(-)
 create mode 100644 drivers/memory/core.c
 create mode 100644 include/linux/memory-controller.h

-- 
2.23.0

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2019-11-01 19:56 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-15 16:29 [RFC 0/3] Introduce memory controller mini-framework Thierry Reding
2019-10-15 16:29 ` [RFC 1/3] memory: " Thierry Reding
2019-10-31 15:11   ` Dmitry Osipenko
2019-11-01 10:18     ` Thierry Reding
2019-11-01 19:56       ` Dmitry Osipenko
2019-10-15 16:29 ` [RFC 2/3] memory: tegra186: Register as memory controller Thierry Reding
2019-10-15 16:29 ` [RFC 3/3] iommu: arm-smmu: Get reference to " Thierry Reding

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).