PCI: xilinx-xdma: Add Xilinx XDMA Root Port driver

Add support for Xilinx XDMA Soft IP core as Root Port.

The Zynq UltraScale+ MPSoCs devices support XDMA soft IP module in
programmable logic.

The integrated XDMA Soft IP block has integrated bridge function that
can act as PCIe Root Port.

[kwilczynski: correct indentation and whitespaces, Kconfig help update]
Link: https://lore.kernel.org/linux-pci/[email protected]
Signed-off-by: Thippeswamy Havalige <[email protected]>
Signed-off-by: Bharat Kumar Gogada <[email protected]>
Signed-off-by: Krzysztof Wilczyński <[email protected]>

Author: Thippeswamy Havalige

drivers/pci/controller/Kconfig

@@ -324,6 +324,17 @@ config PCIE_XILINX
 	  Say 'Y' here if you want kernel to support the Xilinx AXI PCIe
 	  Host Bridge driver.
 
+config PCIE_XILINX_DMA_PL
+	bool "Xilinx DMA PL PCIe host bridge support"
+	depends on ARCH_ZYNQMP || COMPILE_TEST
+	depends on PCI_MSI
+	select PCI_HOST_COMMON
+	help
+	  Say 'Y' here if you want kernel support for the Xilinx PL DMA
+	  PCIe host bridge. The controller is a Soft IP which can act as
+	  Root Port. If your system provides Xilinx PCIe host controller
+	  bridge DMA as Soft IP say 'Y'; if you are not sure, say 'N'.
+
 config PCIE_XILINX_NWL
 	bool "Xilinx NWL PCIe controller"
 	depends on ARCH_ZYNQMP || COMPILE_TEST

drivers/pci/controller/Makefile

@@ -17,6 +17,7 @@ obj-$(CONFIG_PCI_HOST_THUNDER_PEM) += pci-thunder-pem.o
 obj-$(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-$(CONFIG_PCIE_XILINX_DMA_PL) += pcie-xilinx-dma-pl.o
 obj-$(CONFIG_PCI_V3_SEMI) += pci-v3-semi.o
 obj-$(CONFIG_PCI_XGENE) += pci-xgene.o
 obj-$(CONFIG_PCI_XGENE_MSI) += pci-xgene-msi.o

drivers/pci/controller/pcie-xilinx-common.h

@@ -19,6 +19,7 @@
 #define XILINX_PCIE_INTR_PME_TO_ACK_RCVD	15
 #define XILINX_PCIE_INTR_INTX			16
 #define XILINX_PCIE_INTR_PM_PME_RCVD		17
+#define XILINX_PCIE_INTR_MSI			17
 #define XILINX_PCIE_INTR_SLV_UNSUPP		20
 #define XILINX_PCIE_INTR_SLV_UNEXP		21
 #define XILINX_PCIE_INTR_SLV_COMPL		22