PCI: xilinx-cpm: Add Versal CPM Root Port driver

Add support for Versal CPM as Root Port.

The Versal ACAP devices include CCIX-PCIe Module (CPM). The integrated
block for CPM along with the integrated bridge can function as PCIe Root
Port.

Bridge error and legacy interrupts in Versal CPM are handled using Versal
CPM specific interrupt line.

[bhelgaas: fold in kerneldoc fix from
https://lore.kernel.org/linux-acpi/20200729201224.26799-7-krzk@kernel.org/]
Link: https://lore.kernel.org/r/1592312214-9347-3-git-send-email-bharat.kumar.gogada@xilinx.comSigned-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>

drivers/pci/controller/Kconfig

@@ -99,6 +99,14 @@ config PCIE_XILINX
 	  Say 'Y' here if you want kernel to support the Xilinx AXI PCIe
 	  Host Bridge driver.
 
+config PCIE_XILINX_CPM
+	bool "Xilinx Versal CPM host bridge support"
+	depends on ARCH_ZYNQMP || COMPILE_TEST
+	select PCI_HOST_COMMON
+	help
+	  Say 'Y' here if you want kernel support for the
+	  Xilinx Versal CPM host bridge.
+
 config PCI_XGENE
 	bool "X-Gene PCIe controller"
 	depends on ARM64 || COMPILE_TEST

drivers/pci/controller/Makefile

@@ -13,6 +13,7 @@ obj-$(CONFIG_PCI_HOST_COMMON) += pci-host-common.o
 obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o
 obj-$(CONFIG_PCIE_XILINX) += pcie-xilinx.o
 obj-$(CONFIG_PCIE_XILINX_NWL) += pcie-xilinx-nwl.o
+obj-$(CONFIG_PCIE_XILINX_CPM) += pcie-xilinx-cpm.o
 obj-$(CONFIG_PCI_V3_SEMI) += pci-v3-semi.o
 obj-$(CONFIG_PCI_XGENE_MSI) += pci-xgene-msi.o
 obj-$(CONFIG_PCI_VERSATILE) += pci-versatile.o