Systems such as Apple's M1 and M2 SoCs may have separate IOMMUs
for each PCIe root port. In this case the right IOMMU for a
PCI device behind a particular root port is described by an
"iommu-map" property in the device tree. Parse this property
and use it to find the right IOMMU device for PCI devices.
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Implement translation table support for all the variations of
Apple's DART IOMMU that can be found on Apple's M1 and M2 SoCs.
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Test that the map and unmap operations work for devices that
have DMA translated by an IOMMU and devices that don't have
DMA translated by an IOMMU.
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
In order to support IOMMUs in non-bypass mode we need device ops
to map and unmap DMA memory. The map operation enters a mapping
for a region specified by CPU address and size into the translation
table of the IOMMU and returns a DMA address suitable for
programming the device to do DMA. The unmap operation removes
this mapping from the translation table of the IOMMU.
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
"apple,t8112-dart" uses an incompatible register interface but still
offers the same functionality. This DART is found on the M2 and M1
Pro/Max/Ultra SoCs.
Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Mark Kettenis <kettenis@openbsd.org>
For the purpose of this driver (activating bypass mode) t6000-dart
and t8103-dart are fully compatible.
Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Mark Kettenis <kettenis@openbsd.org>
The DART is an IOMMU that is used on Apple's M1 SoC. This driver
configures the DART such that it operates in bypass mode which is
enough to support DMA for the USB3 ports integrated on the SoC.
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
This uclass is intended to manage IOMMUs on systems where the
IOMMUs are not in bypass mode by default. In that case U-Boot
cannot ignore the IOMMUs if it wants to use devices that need
to do DMA and sit behind such an IOMMU.
This initial IOMMU uclass implementation does not implement and
device ops and is intended for IOMMUs that have a bypass mode
that does not require address translation. Support for IOMMUs
that do require address translation is planned and device ops
will be defined when support for such IOMMUs will be added.
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
