[PATCH 0/4] arm64: IOMMU-backed DMA mapping
robin.murphy at arm.com
Wed May 27 07:09:14 PDT 2015
Here's the cleaned-up and nominally ready-to-go IOMMU DMA mapping series,
with (I think) all the outstanding comments addressed. I appreciate
I've probably missed the boat for 4.2, but I'm ever the optimist...
Major changes since RFC:
- Renamed things, shuffled things around, and removed some of the less
useful abstraction for simplicity and clarity.
- Fixed iommu_dma_alloc to handle compound pages and map buffers as
- Filled the API holes like size-aligned allocations and get_sgtable.
- Solved the problem of attching devices to domains before the devices
are created, which confuses IOMMU drivers like the ARM SMMU.
A branch is available at:
In terms of where we go from here, this is more or less what I envisage:
- Get the current functionality merged to unblock arm64 IOMMU work
- Implement proper managed IOMMU domains around this, integrating the
iova_domain into the iommu_domain itself, and getting rid of the
- Find all of the ad-hoc "managed domain" implementations in drivers
currently using the arm_iommu_* functions and convert them to "proper"
- Finally, with the external users taken care of, bring arch/arm over
to the common DMA mapping code.
In the meantime, Laurent's proposal for probe deferral offers hope
that the bus notifier dance may only need to be short-lived, and I'm
hoping to spend some more time on DT-based IOMMU group handling for
platform devices, which should hopefully tie in with default domains
to make the add_device callback mostly redundant.
Robin Murphy (4):
iommu/iova: Avoid over-allocating when size-aligned
iommu: Implement common IOMMU ops for DMA mapping
arm64: Add IOMMU dma_ops
arm64: Hook up IOMMU dma_ops
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/device.h | 3 +
arch/arm64/include/asm/dma-mapping.h | 25 +-
arch/arm64/mm/dma-mapping.c | 357 ++++++++++++++++++++++
drivers/iommu/Kconfig | 7 +
drivers/iommu/Makefile | 1 +
drivers/iommu/dma-iommu.c | 560 +++++++++++++++++++++++++++++++++++
drivers/iommu/intel-iommu.c | 2 +
drivers/iommu/iova.c | 23 +-
include/linux/dma-iommu.h | 94 ++++++
10 files changed, 1051 insertions(+), 22 deletions(-)
create mode 100644 drivers/iommu/dma-iommu.c
create mode 100644 include/linux/dma-iommu.h
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