[PATCH 0/2] iommu: Support reserved-memory regions

Thierry Reding
2019-08-29T11:14:12Z

From: Thierry Reding <treding@nvidia.com>

These two patches implement support for retrieving a list of reserved
regions for a device from its device tree node. These regions are
described by the reserved-memory bindings:

Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt

These reserved memory regions will be used to establish 1:1 mappings.
One case where this is useful is when the Linux kernel wants to take
over the display controller configuration from a bootloader. In order
to ensure that the display controller can keep scanning out from the
framebuffer allocated by the bootloader without faulting after the
IOMMU has been enabled, a 1:1 mapping needs to be established.

Thierry

Thierry Reding (2):
iommu: Implement of_iommu_get_resv_regions()
iommu: dma: Use of_iommu_get_resv_regions()

drivers/iommu/dma-iommu.c | 3 +++
drivers/iommu/of_iommu.c | 39 +++++++++++++++++++++++++++++++++++++++
include/linux/of_iommu.h | 8 ++++++++
3 files changed, 50 insertions(+)

--
2.22.0