ArmVirtualizationPkg/VirtFdtDxe: parse "pci-host-ecam-generic" properties

ArmVirtualizationPkg/VirtFdtDxe: parse "pci-host-ecam-generic" properties

In the Linux kernel tree,
"Documentation/devicetree/bindings/pci/host-generic-pci.txt" describes the
device tree bindings of a Generic PCI host controller.

Recent QEMU patches from Alexander Graf implement such a controller on the
"virt" machine type of qemu-system-(aarch64|arm):

  pcie@10000000 {
    //
    //                    (devfn<<8, 0, 0)  PCI irq
    //                    ----------------  -------
    interrupt-map-mask = <0x1800 0x0 0x0    0x7>;

    //                                        gic      irq
    //               (devfn<<8, 0, 0)  pin+1  phandle  (type, nr, level)
    //               ----------------  -----  -------- -----------------
    interrupt-map = <   0x0 0x0 0x0    0x1    0x8001   0x0 0x3 0x4
                        0x0 0x0 0x0    0x2    0x8001   0x0 0x4 0x4
                        0x0 0x0 0x0    0x3    0x8001   0x0 0x5 0x4
                        0x0 0x0 0x0    0x4    0x8001   0x0 0x6 0x4
                      0x800 0x0 0x0    0x1    0x8001   0x0 0x4 0x4
                      0x800 0x0 0x0    0x2    0x8001   0x0 0x5 0x4
                      0x800 0x0 0x0    0x3    0x8001   0x0 0x6 0x4
                      0x800 0x0 0x0    0x4    0x8001   0x0 0x3 0x4
                     0x1000 0x0 0x0    0x1    0x8001   0x0 0x5 0x4
                     0x1000 0x0 0x0    0x2    0x8001   0x0 0x6 0x4
                     0x1000 0x0 0x0    0x3    0x8001   0x0 0x3 0x4
                     0x1000 0x0 0x0    0x4    0x8001   0x0 0x4 0x4
                     0x1800 0x0 0x0    0x1    0x8001   0x0 0x6 0x4
                     0x1800 0x0 0x0    0x2    0x8001   0x0 0x3 0x4
                     0x1800 0x0 0x0    0x3    0x8001   0x0 0x4 0x4
                     0x1800 0x0 0x0    0x4    0x8001   0x0 0x5 0x4>;

    #interrupt-cells = <0x1>;

    //
    //                   child base      cpu base
    //        type       address         address         size
    //        ---------  --------------  --------------  --------------
    ranges = <0x1000000  0x0        0x0  0x0 0x3eff0000  0x0    0x10000
              0x2000000  0x0 0x10000000  0x0 0x10000000  0x0 0x2eff0000>;

    //
    //     PCIe config     PCIe config
    //     space base      space size
    //     --------------  -------------
    reg = <0x0 0x3f000000  0x0 0x1000000>;

    //
    // allowed bus numbers; inclusive range
    //
    bus-range = <0x0 0xf>;

    #size-cells = <0x2>;
    #address-cells = <0x3>;
    device_type = "pci";
    compatible = "pci-host-ecam-generic";
  };

Parse those properties of the compatible="pci-host-ecam-generic" node into
PCDs that are relevant for PCI enumeration in edk2:

- gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress controls
  MdePkg/Library/BasePciExpressLib,

- gEfiMdeModulePkgTokenSpaceGuid.PcdPciDisableBusEnumeration controls
  OvmfPkg/AcpiPlatformDxe at this point,

- the rest have been introduced earlier in this patchset, and will control
  PCI range checks and translation.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16894 6f19259b-4bc3-4df7-8a09-765794883524