On Mon, Aug 21, 2017 at 08:29:04PM +0100, Ard Biesheuvel wrote: > UEFI based systems incorporating a Synopsys Designware PCIe controller > in RC mode will typically configure it before entering the OS. If this > configuration is fully static and ECAM compliant, there is no need to > expose particulars of the device to the OS, and we can simply describe > it as "pci-host-ecam-generic". I *love* the idea of moving more of this to firmware. I spend an incredible amount of time looking at all these native drivers, and *zero* time looking at the ACPI driver (pci_root.c). And it's not like all this code in the native drivers is adding features or performance. It's just extra work for no benefit. I'm assuming there'll be a v2 soon for the kbuild warnings. > However, the Synopsys IP may be synthesized in a way where a quirk is > needed for config space accesses to the first bus. It makes little sense > to instantiate yet another pcie-designware driver that contains all the > low level setup code, but it is also not justified to add quirks handling > to the generic ECAM driver. > > So instead, create a variant of the generic ECAM driver that filters config > space accesses directed at device #1 and up on the first bus. > > Also, add a binding and driver to support the MSI functionality available > in some versions of this IP. This allows the MSI routing to be described > at the DT level rather than hardcoding it in the driver. > > Cc: Leif Lindholm <leif.lindholm@xxxxxxxxxx> > Cc: Graeme Gregory <graeme.gregory@xxxxxxxxxx> > Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > Cc: Jingoo Han <jingoohan1@xxxxxxxxx> > Cc: Joao Pinto <Joao.Pinto@xxxxxxxxxxxx> > Cc: Marc Zyngier <marc.zyngier@xxxxxxx> > > Ard Biesheuvel (3): > pci: designware: add driver for DWC controller in ECAM shift mode > pci: designware: add separate driver for the MSI part of the RC > dt-bindings: designware: add binding for Designware PCIe in ECAM mode > > Documentation/devicetree/bindings/pci/designware-pcie-ecam.txt | 56 +++++ > drivers/pci/dwc/Kconfig | 11 + > drivers/pci/dwc/Makefile | 4 +- > drivers/pci/dwc/pcie-designware-ecam.c | 75 ++++++ > drivers/pci/dwc/pcie-designware-msi.c | 255 ++++++++++++++++++++ > 5 files changed, 400 insertions(+), 1 deletion(-) > create mode 100644 Documentation/devicetree/bindings/pci/designware-pcie-ecam.txt > create mode 100644 drivers/pci/dwc/pcie-designware-ecam.c > create mode 100644 drivers/pci/dwc/pcie-designware-msi.c > > -- > 2.11.0 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
