The PCIe controller in Tegra194 SoC is not completely ECAM-compliant. With the current hardware design limitations in place, ECAM can be enabled only for one controller (C5 controller to be precise) with bus numbers starting from 160 instead of 0. A different approach is taken to avoid this abnormal way of enabling ECAM for just one controller but to enable configuration space access for all the other controllers. In this approach, ops are added through MCFG quirk mechanism which access the configuration spaces by dynamically programming iATU (internal AddressTranslation Unit) to generate respective configuration accesses just like the way it is done in DesignWare core sub-system. To increase the size of ECAM, a device-tree change is pushed in this series to move the IO window from 32-bit PCIe aperture to 64-bit PCIe aperture leaving the entire 32MB of 32-bit aperture for configuration space access. V3: * Pushed a device-tree change in the series to enable more space for ECAM Vidya Sagar (2): arm64: tegra: Re-order PCIe aperture mappings to support ACPI boot PCI: Add MCFG quirks for Tegra194 host controllers arch/arm64/boot/dts/nvidia/tegra194.dtsi | 36 ++++---- drivers/acpi/pci_mcfg.c | 7 ++ drivers/pci/controller/dwc/Kconfig | 3 +- drivers/pci/controller/dwc/Makefile | 2 +- drivers/pci/controller/dwc/pcie-tegra194.c | 102 +++++++++++++++++++++ include/linux/pci-ecam.h | 1 + 6 files changed, 131 insertions(+), 20 deletions(-) -- 2.17.1
