This is a rebase of the later revisions of [1], but refactored slightly to add a DT method as well. It has all the same advantages of the ACPI method (putting HW quirks in the firmware rather than the kernel) but now applied to a 'pci-host-smc-generic' compatible property which extends the pci-host-generic logic to handle cases where the PCI Config region isn't ECAM compliant. With this in place, and firmware managed clock/phy/etc its possible to run the generic driver on hardware that isn't what one would consider standards compliant PCI root ports. The DT code was tested on the RPi4, where the ACPI/SMC is upstream in TF-A and EDK2. On that platform the PCIe works as expected utilizing the generic host driver rather than the pcie-brcmstb driver. [1] https://lkml.org/lkml/2021/1/4/1255 Jeremy Linton (4): arm64: smccc: Add PCI SMCCCs arm64: PCI: Enable SMC conduit PCI: host-generic: Add firmware managed config ops dt-bindings: PCI: Note the use of pci-host-smc-generic .../bindings/pci/host-generic-pci.yaml | 24 +++- arch/arm64/kernel/pci.c | 109 ++++++++++++++++++ drivers/pci/controller/pci-host-common.c | 34 ++++-- drivers/pci/controller/pci-host-generic.c | 6 + include/linux/arm-smccc.h | 29 +++++ 5 files changed, 186 insertions(+), 16 deletions(-) -- 2.37.1
