[PATCH v3 2/2] PCI: Versal CPM: Add support for Versal CPM Root Port driver

Bharat Kumar Gogada
2020-01-13T10:04:21Z

- Adding 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.
- CPM Versal uses GICv3 ITS feature for acheiving assigning MSI/MSI-X
vectors and handling MSI/MSI-X interrupts.
- Bridge error and legacy interrupts in Versal CPM are handled using
Versal CPM specific MISC interrupt line.

Changes v3:
Fix warnings reported.

Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
---
drivers/pci/controller/Kconfig | 8 +
drivers/pci/controller/Makefile | 1 +
drivers/pci/controller/pcie-xilinx-cpm.c | 505 +++++++++++++++++++++++++++++++
3 files changed, 514 insertions(+)
create mode 100644 drivers/pci/controller/pcie-xilinx-cpm.c

diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
index c77069c..eca496d 100644
--- a/drivers/pci/controller/Kconfig
+++ b/drivers/pci/controller/Kconfig
@@ -81,6 +81,14 @@ 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
+ help
+ Say 'Y' here if you want kernel to enable support the
+ Xilinx Versal CPM host Bridge driver.The driver supports
+ MSI/MSI-X interrupts using GICv3 ITS feature.
+
config PCI_XGENE
bool "X-Gene PCIe controller"
depends on ARM64 || COMPILE_TEST
diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
index 3d4f597..6c936e9 100644
--- a/drivers/pci/controller/Makefile
+++ b/drivers/pci/controller/Makefile
@@ -12,6 +12,7 @@ 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
diff --git a/drivers/pci/controller/pcie-xilinx-cpm.c b/drivers/pci/controller/pcie-xilinx-cpm.c
new file mode 100644
index 0000000..88ee93e
--- /dev/null
+++ b/drivers/pci/controller/pcie-xilinx-cpm.c
@@ -0,0 +1,505 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PCIe host controller driver for Xilinx Versal CPM DMA Bridge
+ *
+ * (C) Copyright 2019 - 2020, Xilinx, Inc.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/of_irq.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+
+#include "../pci.h"
+
+/* Register definitions */
+#define XILINX_CPM_PCIE_REG_IDR 0x00000E10
+#define XILINX_CPM_PCIE_REG_IMR 0x00000E14
+#define XILINX_CPM_PCIE_REG_PSCR 0x00000E1C
+#define XILINX_CPM_PCIE_REG_RPSC 0x00000E20
+#define XILINX_CPM_PCIE_REG_RPEFR 0x00000E2C
+#define XILINX_CPM_PCIE_REG_IDRN 0x00000E38
+#define XILINX_CPM_PCIE_REG_IDRN_MASK 0x00000E3C
+#define XILINX_CPM_PCIE_MISC_IR_STATUS 0x00000340
+#define XILINX_CPM_PCIE_MISC_IR_ENABLE 0x00000348
+#define XILINX_CPM_PCIE_MISC_IR_LOCAL BIT(1)
+
+/* Interrupt registers definitions */
+#define XILINX_CPM_PCIE_INTR_LINK_DOWN BIT(0)
+#define XILINX_CPM_PCIE_INTR_HOT_RESET BIT(3)
+#define XILINX_CPM_PCIE_INTR_CFG_TIMEOUT BIT(8)
+#define XILINX_CPM_PCIE_INTR_CORRECTABLE BIT(9)
+#define XILINX_CPM_PCIE_INTR_NONFATAL BIT(10)
+#define XILINX_CPM_PCIE_INTR_FATAL BIT(11)
+#define XILINX_CPM_PCIE_INTR_INTX BIT(16)
+#define XILINX_CPM_PCIE_INTR_MSI BIT(17)
+#define XILINX_CPM_PCIE_INTR_SLV_UNSUPP BIT(20)
+#define XILINX_CPM_PCIE_INTR_SLV_UNEXP BIT(21)
+#define XILINX_CPM_PCIE_INTR_SLV_COMPL BIT(22)
+#define XILINX_CPM_PCIE_INTR_SLV_ERRP BIT(23)
+#define XILINX_CPM_PCIE_INTR_SLV_CMPABT BIT(24)
+#define XILINX_CPM_PCIE_INTR_SLV_ILLBUR BIT(25)
+#define XILINX_CPM_PCIE_INTR_MST_DECERR BIT(26)
+#define XILINX_CPM_PCIE_INTR_MST_SLVERR BIT(27)
+#define XILINX_CPM_PCIE_IMR_ALL_MASK 0x1FF39FF9
+#define XILINX_CPM_PCIE_IDR_ALL_MASK 0xFFFFFFFF
+#define XILINX_CPM_PCIE_IDRN_MASK GENMASK(19, 16)
+#define XILINX_CPM_PCIE_INTR_CFG_PCIE_TIMEOUT BIT(4)
+#define XILINX_CPM_PCIE_INTR_CFG_ERR_POISON BIT(12)
+#define XILINX_CPM_PCIE_INTR_PME_TO_ACK_RCVD BIT(15)
+#define XILINX_CPM_PCIE_INTR_PM_PME_RCVD BIT(17)
+#define XILINX_CPM_PCIE_INTR_SLV_PCIE_TIMEOUT BIT(28)
+#define XILINX_CPM_PCIE_IDRN_SHIFT 16
+
+/* Root Port Error FIFO Read Register definitions */
+#define XILINX_CPM_PCIE_RPEFR_ERR_VALID BIT(18)
+#define XILINX_CPM_PCIE_RPEFR_REQ_ID GENMASK(15, 0)
+#define XILINX_CPM_PCIE_RPEFR_ALL_MASK 0xFFFFFFFF
+
+/* Root Port Status/control Register definitions */
+#define XILINX_CPM_PCIE_REG_RPSC_BEN BIT(0)
+
+/* Phy Status/Control Register definitions */
+#define XILINX_CPM_PCIE_REG_PSCR_LNKUP BIT(11)
+
+/* ECAM definitions */
+#define ECAM_BUS_NUM_SHIFT 20
+#define ECAM_DEV_NUM_SHIFT 12
+
+/**
+ * struct xilinx_cpm_pcie_port - PCIe port information
+ * @reg_base: Bridge Register Base
+ * @cpm_base: CPM SLCR Register Base
+ * @irq: Interrupt number
+ * @root_busno: Root Bus number
+ * @dev: Device pointer
+ * @leg_domain: Legacy IRQ domain pointer
+ * @irq_misc: Legacy and error interrupt number
+ */
+struct xilinx_cpm_pcie_port {
+ void __iomem *reg_base;
+ void __iomem *cpm_base;
+ u32 irq;
+ u8 root_busno;
+ struct device *dev;
+ struct irq_domain *leg_domain;
+ int irq_misc;
+};
+
+static inline u32 pcie_read(struct xilinx_cpm_pcie_port *port, u32 reg)
+{
+ return readl(port->reg_base + reg);
+}
+
+static inline void pcie_write(struct xilinx_cpm_pcie_port *port,
+ u32 val, u32 reg)
+{
+ writel(val, port->reg_base + reg);
+}
+
+static inline bool cpm_pcie_link_up(struct xilinx_cpm_pcie_port *port)
+{
+ return (pcie_read(port, XILINX_CPM_PCIE_REG_PSCR) &
+ XILINX_CPM_PCIE_REG_PSCR_LNKUP) ? 1 : 0;
+}
+
+/**
+ * xilinx_cpm_pcie_clear_err_interrupts - Clear Error Interrupts
+ * @port: PCIe port information
+ */
+static void cpm_pcie_clear_err_interrupts(struct xilinx_cpm_pcie_port *port)
+{
+ unsigned long val = pcie_read(port, XILINX_CPM_PCIE_REG_RPEFR);
+
+ if (val & XILINX_CPM_PCIE_RPEFR_ERR_VALID) {
+ dev_dbg(port->dev, "Requester ID %lu\n",
+ val & XILINX_CPM_PCIE_RPEFR_REQ_ID);
+ pcie_write(port, XILINX_CPM_PCIE_RPEFR_ALL_MASK,
+ XILINX_CPM_PCIE_REG_RPEFR);
+ }
+}
+
+/**
+ * xilinx_cpm_pcie_valid_device - Check if a valid device is present on bus
+ * @bus: PCI Bus structure
+ * @devfn: device/function
+ *
+ * Return: 'true' on success and 'false' if invalid device is found
+ */
+static bool xilinx_cpm_pcie_valid_device(struct pci_bus *bus,
+ unsigned int devfn)
+{
+ struct xilinx_cpm_pcie_port *port = bus->sysdata;
+
+ /* Only one device down on each root port */
+ if (bus->number == port->root_busno && devfn > 0)
+ return false;
+
+ return true;
+}
+
+/**
+ * xilinx_cpm_pcie_map_bus - Get configuration base
+ * @bus: PCI Bus structure
+ * @devfn: Device/function
+ * @where: Offset from base
+ *
+ * Return: Base address of the configuration space needed to be
+ * accessed.
+ */
+static void __iomem *xilinx_cpm_pcie_map_bus(struct pci_bus *bus,
+ unsigned int devfn, int where)
+{
+ struct xilinx_cpm_pcie_port *port = bus->sysdata;
+ int relbus;
+
+ if (!xilinx_cpm_pcie_valid_device(bus, devfn))
+ return NULL;
+
+ relbus = (bus->number << ECAM_BUS_NUM_SHIFT) |
+ (devfn << ECAM_DEV_NUM_SHIFT);
+
+ return port->reg_base + relbus + where;
+}
+
+/* PCIe operations */
+static struct pci_ops xilinx_cpm_pcie_ops = {
+ .map_bus = xilinx_cpm_pcie_map_bus,
+ .read = pci_generic_config_read,
+ .write = pci_generic_config_write,
+};
+
+/**
+ * xilinx_cpm_pcie_intx_map - Set the handler for the INTx and mark IRQ as valid
+ * @domain: IRQ domain
+ * @irq: Virtual IRQ number
+ * @hwirq: HW interrupt number
+ *
+ * Return: Always returns 0.
+ */
+static int xilinx_cpm_pcie_intx_map(struct irq_domain *domain,
+ unsigned int irq, irq_hw_number_t hwirq)
+{
+ irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
+ irq_set_chip_data(irq, domain->host_data);
+ irq_set_status_flags(irq, IRQ_LEVEL);
+
+ return 0;
+}
+
+/* INTx IRQ Domain operations */
+static const struct irq_domain_ops intx_domain_ops = {
+ .map = xilinx_cpm_pcie_intx_map,
+ .xlate = pci_irqd_intx_xlate,
+};
+
+/**
+ * xilinx_cpm_pcie_intr_handler - Interrupt Service Handler
+ * @irq: IRQ number
+ * @data: PCIe port information
+ *
+ * Return: IRQ_HANDLED on success and IRQ_NONE on failure
+ */
+static irqreturn_t xilinx_cpm_pcie_intr_handler(int irq, void *data)
+{
+ struct xilinx_cpm_pcie_port *port =
+ (struct xilinx_cpm_pcie_port *)data;
+ struct device *dev = port->dev;
+ u32 val, mask, status, bit;
+ unsigned long intr_val;
+
+ /* Read interrupt decode and mask registers */
+ val = pcie_read(port, XILINX_CPM_PCIE_REG_IDR);
+ mask = pcie_read(port, XILINX_CPM_PCIE_REG_IMR);
+
+ status = val & mask;
+ if (!status)
+ return IRQ_NONE;
+
+ if (status & XILINX_CPM_PCIE_INTR_LINK_DOWN)
+ dev_warn(dev, "Link Down\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_HOT_RESET)
+ dev_info(dev, "Hot reset\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_CFG_TIMEOUT)
+ dev_warn(dev, "ECAM access timeout\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_CORRECTABLE) {
+ dev_warn(dev, "Correctable error message\n");
+ cpm_pcie_clear_err_interrupts(port);
+ }
+
+ if (status & XILINX_CPM_PCIE_INTR_NONFATAL) {
+ dev_warn(dev, "Non fatal error message\n");
+ cpm_pcie_clear_err_interrupts(port);
+ }
+
+ if (status & XILINX_CPM_PCIE_INTR_FATAL) {
+ dev_warn(dev, "Fatal error message\n");
+ cpm_pcie_clear_err_interrupts(port);
+ }
+
+ if (status & XILINX_CPM_PCIE_INTR_INTX) {
+ /* Handle INTx Interrupt */
+ intr_val = pcie_read(port, XILINX_CPM_PCIE_REG_IDRN);
+ intr_val = intr_val >> XILINX_CPM_PCIE_IDRN_SHIFT;
+
+ for_each_set_bit(bit, &intr_val, PCI_NUM_INTX)
+ generic_handle_irq(irq_find_mapping(port->leg_domain,
+ bit));
+ }
+
+ if (status & XILINX_CPM_PCIE_INTR_SLV_UNSUPP)
+ dev_warn(dev, "Slave unsupported request\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_SLV_UNEXP)
+ dev_warn(dev, "Slave unexpected completion\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_SLV_COMPL)
+ dev_warn(dev, "Slave completion timeout\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_SLV_ERRP)
+ dev_warn(dev, "Slave Error Poison\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_SLV_CMPABT)
+ dev_warn(dev, "Slave Completer Abort\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_SLV_ILLBUR)
+ dev_warn(dev, "Slave Illegal Burst\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_MST_DECERR)
+ dev_warn(dev, "Master decode error\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_MST_SLVERR)
+ dev_warn(dev, "Master slave error\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_CFG_PCIE_TIMEOUT)
+ dev_warn(dev, "PCIe ECAM access timeout\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_CFG_ERR_POISON)
+ dev_warn(dev, "ECAM poisoned completion received\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_PME_TO_ACK_RCVD)
+ dev_warn(dev, "PME_TO_ACK message received\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_PM_PME_RCVD)
+ dev_warn(dev, "PM_PME message received\n");
+
+ if (status & XILINX_CPM_PCIE_INTR_SLV_PCIE_TIMEOUT)
+ dev_warn(dev, "PCIe completion timeout received\n");
+
+ /* Clear the Interrupt Decode register */
+ pcie_write(port, status, XILINX_CPM_PCIE_REG_IDR);
+ val = readl(port->cpm_base + XILINX_CPM_PCIE_MISC_IR_STATUS);
+ if (val)
+ writel(val, port->cpm_base + XILINX_CPM_PCIE_MISC_IR_STATUS);
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * xilinx_cpm_pcie_init_irq_domain - Initialize IRQ domain
+ * @port: PCIe port information
+ *
+ * Return: '0' on success and error value on failure
+ */
+static int xilinx_cpm_pcie_init_irq_domain(struct xilinx_cpm_pcie_port *port)
+{
+ struct device *dev = port->dev;
+ struct device_node *node = dev->of_node;
+ struct device_node *pcie_intc_node;
+
+ /* Setup INTx */
+ pcie_intc_node = of_get_next_child(node, NULL);
+ if (!pcie_intc_node) {
+ dev_err(dev, "No PCIe Intc node found\n");
+ return -EINVAL;
+ }
+
+ port->leg_domain = irq_domain_add_linear(pcie_intc_node, PCI_NUM_INTX,
+ &intx_domain_ops,
+ port);
+ if (!port->leg_domain) {
+ dev_err(dev, "Failed to get a INTx IRQ domain\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+/**
+ * xilinx_cpm_pcie_init_port - Initialize hardware
+ * @port: PCIe port information
+ */
+static void xilinx_cpm_pcie_init_port(struct xilinx_cpm_pcie_port *port)
+{
+ if (cpm_pcie_link_up(port))
+ dev_info(port->dev, "PCIe Link is UP\n");
+ else
+ dev_info(port->dev, "PCIe Link is DOWN\n");
+
+ /* Disable all interrupts */
+ pcie_write(port, ~XILINX_CPM_PCIE_IDR_ALL_MASK,
+ XILINX_CPM_PCIE_REG_IMR);
+
+ /* Clear pending interrupts */
+ pcie_write(port, pcie_read(port, XILINX_CPM_PCIE_REG_IDR) &
+ XILINX_CPM_PCIE_IMR_ALL_MASK,
+ XILINX_CPM_PCIE_REG_IDR);
+
+ /* Enable all interrupts */
+ pcie_write(port, XILINX_CPM_PCIE_IMR_ALL_MASK,
+ XILINX_CPM_PCIE_REG_IMR);
+ pcie_write(port, XILINX_CPM_PCIE_IDRN_MASK,
+ XILINX_CPM_PCIE_REG_IDRN_MASK);
+
+ writel(XILINX_CPM_PCIE_MISC_IR_LOCAL,
+ port->cpm_base + XILINX_CPM_PCIE_MISC_IR_ENABLE);
+ /* Enable the Bridge enable bit */
+ pcie_write(port, pcie_read(port, XILINX_CPM_PCIE_REG_RPSC) |
+ XILINX_CPM_PCIE_REG_RPSC_BEN,
+ XILINX_CPM_PCIE_REG_RPSC);
+}
+
+static int xilinx_cpm_request_misc_irq(struct xilinx_cpm_pcie_port *port)
+{
+ struct device *dev = port->dev;
+ struct platform_device *pdev = to_platform_device(dev);
+ int err;
+
+ port->irq_misc = platform_get_irq_byname(pdev, "misc");
+ if (port->irq_misc <= 0) {
+ dev_err(dev, "Unable to find misc IRQ line\n");
+ return port->irq_misc;
+ }
+ err = devm_request_irq(dev, port->irq_misc,
+ xilinx_cpm_pcie_intr_handler,
+ IRQF_SHARED | IRQF_NO_THREAD,
+ "xilinx-pcie", port);
+ if (err) {
+ dev_err(dev, "unable to request misc IRQ line %d\n",
+ port->irq_misc);
+ return err;
+ }
+
+ return 0;
+}
+
+/**
+ * xilinx_cpm_pcie_parse_dt - Parse Device tree
+ * @port: PCIe port information
+ *
+ * Return: '0' on success and error value on failure
+ */
+static int xilinx_cpm_pcie_parse_dt(struct xilinx_cpm_pcie_port *port)
+{
+ struct device *dev = port->dev;
+ struct resource *res;
+ int err;
+ struct platform_device *pdev = to_platform_device(dev);
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
+ port->reg_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(port->reg_base))
+ return PTR_ERR(port->reg_base);
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+ "cpm_slcr");
+ port->cpm_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(port->cpm_base))
+ return PTR_ERR(port->cpm_base);
+
+ err = xilinx_cpm_request_misc_irq(port);
+ if (err)
+ return err;
+
+ return 0;
+}
+
+/**
+ * xilinx_cpm_pcie_probe - Probe function
+ * @pdev: Platform device pointer
+ *
+ * Return: '0' on success and error value on failure
+ */
+static int xilinx_cpm_pcie_probe(struct platform_device *pdev)
+{
+ struct xilinx_cpm_pcie_port *port;
+ struct device *dev = &pdev->dev;
+ struct pci_bus *bus;
+ struct pci_bus *child;
+ struct pci_host_bridge *bridge;
+ int err;
+
+ bridge = devm_pci_alloc_host_bridge(dev, sizeof(*port));
+ if (!bridge)
+ return -ENODEV;
+
+ port = pci_host_bridge_priv(bridge);
+
+ port->dev = dev;
+
+ err = xilinx_cpm_pcie_parse_dt(port);
+ if (err) {
+ dev_err(dev, "Parsing DT failed\n");
+ return err;
+ }
+
+ xilinx_cpm_pcie_init_port(port);
+
+ err = xilinx_cpm_pcie_init_irq_domain(port);
+ if (err) {
+ dev_err(dev, "Failed creating IRQ Domain\n");
+ return err;
+ }
+
+ err = pci_parse_request_of_pci_ranges(dev, &bridge->windows,
+ &bridge->dma_ranges, NULL);
+ if (err) {
+ dev_err(dev, "Getting bridge resources failed\n");
+ return err;
+ }
+
+ bridge->dev.parent = dev;
+ bridge->sysdata = port;
+ bridge->busnr = port->root_busno;
+ bridge->ops = &xilinx_cpm_pcie_ops;
+ bridge->map_irq = of_irq_parse_and_map_pci;
+ bridge->swizzle_irq = pci_common_swizzle;
+
+ err = pci_scan_root_bus_bridge(bridge);
+ if (err)
+ return err;
+
+ bus = bridge->bus;
+
+ pci_assign_unassigned_bus_resources(bus);
+ list_for_each_entry(child, &bus->children, node)
+ pcie_bus_configure_settings(child);
+ pci_bus_add_devices(bus);
+ return 0;
+}
+
+static const struct of_device_id xilinx_cpm_pcie_of_match[] = {
+ { .compatible = "xlnx,versal-cpm-host-1.00", },
+ {}
+};
+
+static struct platform_driver xilinx_cpm_pcie_driver = {
+ .driver = {
+ .name = "xilinx-cpm-pcie",
+ .of_match_table = xilinx_cpm_pcie_of_match,
+ .suppress_bind_attrs = true,
+ },
+ .probe = xilinx_cpm_pcie_probe,
+};
+
+builtin_platform_driver(xilinx_cpm_pcie_driver);
--
2.7.4