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The Designware PCIe IP in the SynQuacer SoC needs a little help to
appear sane to the OS. Not only does it lack a true root port, and
therefore does not perform any filtering whatsoever of type 0 config
TLPs that are not intended for the link peer, it also has trouble
issuing 64-bit wide MMIO accesses, which are often used on MMIO BARs
with memory semantics (e.g., frame buffers).
So let's create a stage 2 mapping covering the entire physical address
space, and remap some ECAM regions and demote write combine attributes
to device/strongly ordered. This is not a water tight fix, but it does
work around the issues in the majority of cases.
(Note that the ECAM remapping can also be addressed in the SMMU mapping
of the PCIe IP exposed to the CPU, but this is currently under
development, and it does not hurt to have it in two places)
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
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