Implement DT-aware PciHostBridgeDxe.

intel / FdtBusPkg

Device Tree-based Platform Device Driver Development for Tiano UEFI

https://wiki.riseproject.dev/display/HOME/EDK2_00_03+-+FdtBusDxe+support

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Implement DT-aware PciHostBridgeDxe. #12

Closed andreiw closed 6 months ago

andreiw commented 7 months ago

Today FdtBusPkg provides a PciHostBridgeLib (PciHostBridgeLibEcam), for use with MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostBridgeDxe.inf, which is somewhat limited:

Only one RC node is supported.
Not driver-binding based.
No support for non-cache coherent or strange DMA ranges.

See https://github.com/intel/FdtBusPkg/issues/11, https://github.com/intel/FdtBusPkg/issues/2, https://github.com/intel/FdtBusPkg/issues/3, https://github.com/intel/FdtBusPkg/issues/4, https://github.com/intel/FdtBusPkg/issues/5.

andreiw commented 6 months ago

Partially resolved by https://github.com/intel/FdtBusPkg/pull/97/commits/ec866edd1e9952c825b84782b453c8de95729b7b

Uses DT I/O Reg* API to service config space and BAR reads/writes.

Does NOT use the DT I/O DMA API yet.
Supports multiple RCs (first segment seen is set up as the PciLib one for compat... first segment with IO space sets PcdPciIoTranslation).
Does NOT support ResourceAssigned unlike PciHostBridgeDxe
Is simpler (I think?)
The ECAM parts will be factored out into a library, so that the driver may be used with crazy platforms (e.g. Pi 4)

andreiw commented 6 months ago

Now uses DMA API (but does not support non-coherent RCs yet)

https://github.com/intel/FdtBusPkg/pull/101/commits/982ea7265c628b0da439568af5a815f25adc55e5