[PATCH v4 0/2] Adding support for Versal CPM as Root Port driver.

[PATCH v4 0/2] Adding support for Versal CPM as Root Port driver.

[Bharat Kumar Gogada]

- 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.
- Versal CPM uses GICv3 ITS feature for 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.

Bharat Kumar Gogada (2):
  PCI: xilinx-cpm: Add device tree binding for Versal CPM host bridge.
  PCI: xilinx-cpm: Add Versal CPM Root Port driver

 .../devicetree/bindings/pci/xilinx-versal-cpm.txt  |  66 +++
 drivers/pci/controller/Kconfig                     |   8 +
 drivers/pci/controller/Makefile                    |   1 +
 drivers/pci/controller/pcie-xilinx-cpm.c           | 506 +++++++++++++++++++++
 4 files changed, 581 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/xilinx-versal-cpm.txt
 create mode 100644 drivers/pci/controller/pcie-xilinx-cpm.c

-- 
2.7.4

[PATCH v4 1/2] PCI: xilinx-cpm: Add device tree binding for Versal CPM host bridge.

[Bharat Kumar Gogada]

Add device tree binding documentation for Versal CPM Root Port driver.

Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
---
 .../devicetree/bindings/pci/xilinx-versal-cpm.txt  | 66 ++++++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/xilinx-versal-cpm.txt

diff --git a/Documentation/devicetree/bindings/pci/xilinx-versal-cpm.txt b/Documentation/devicetree/bindings/pci/xilinx-versal-cpm.txt
new file mode 100644
index 0000000..35f8556
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/xilinx-versal-cpm.txt
@@ -0,0 +1,66 @@
+* Xilinx Versal CPM DMA Root Port Bridge DT description
+
+Required properties:
+- #address-cells: Address representation for root ports, set to <3>
+- #size-cells: Size representation for root ports, set to <2>
+- #interrupt-cells: specifies the number of cells needed to encode an
+	interrupt source. The value must be 1.
+- compatible: Should contain "xlnx,versal-cpm-host-1.00"
+- reg: Should contain configuration space (includes bridge registers) and
+	CPM system level control and status registers, and length
+- reg-names: Must include the following entries:
+	"cfg": configuration space region and bridge registers
+	"cpm_slcr": CPM system level control and status registers
+- interrupts: Should contain AXI PCIe interrupt
+- interrupt-map-mask,
+  interrupt-map: standard PCI properties to define the mapping of the
+	PCI interface to interrupt numbers.
+- ranges: ranges for the PCI memory regions (I/O space region is not
+	supported by hardware)
+	Please refer to the standard PCI bus binding document for a more
+	detailed explanation
+- msi-map: Maps a Requester ID to an MSI controller and associated MSI
+	sideband data
+- interrupt-names: Must include the following entries:
+	"misc": interrupt asserted when legacy or error interrupt is received
+
+Interrupt controller child node
++++++++++++++++++++++++++++++++
+Required properties:
+- interrupt-controller: identifies the node as an interrupt controller
+- #address-cells: specifies the number of cells needed to encode an
+	address. The value must be 0.
+- #interrupt-cells: specifies the number of cells needed to encode an
+	interrupt source. The value must be 1.
+
+
+Refer to the following binding document for more detailed description on
+the use of 'msi-map':
+	 Documentation/devicetree/bindings/pci/pci-msi.txt
+
+Example:
+	pci@fca10000 {
+		#address-cells = <3>;
+		#interrupt-cells = <1>;
+		#size-cells = <2>;
+		compatible = "xlnx,versal-cpm-host-1.00";
+		interrupt-map = <0 0 0 1 &pcie_intc_0 1>,
+				<0 0 0 2 &pcie_intc_0 2>,
+				<0 0 0 3 &pcie_intc_0 3>,
+				<0 0 0 4 &pcie_intc_0 4>;
+		interrupt-map-mask = <0 0 0 7>;
+		interrupt-parent = <&gic>;
+		interrupt-names = "misc";
+		interrupts = <0 72 4>;
+		ranges = <0x02000000 0x00000000 0xE0000000 0x0 0xE0000000 0x00000000 0x10000000>,
+			 <0x43000000 0x00000080 0x00000000 0x00000080 0x00000000 0x00000000 0x80000000>;
+		msi-map = <0x0 &its_gic 0x0 0x10000>;
+		reg = <0x6 0x00000000 0x0 0x1000000>,
+		      <0x0 0xFCA10000 0x0 0x1000>;
+		reg-names = "cfg", "cpm_slcr";
+		pcie_intc_0: pci-interrupt-controller {
+			#address-cells = <0>;
+			#interrupt-cells = <1>;
+			interrupt-controller ;
+		};
+	};
-- 
2.7.4

[PATCH v4 2/2] PCI: xilinx-cpm: Add Versal CPM Root Port driver

[Bharat Kumar Gogada]

- 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.
- CPM Versal uses GICv3 ITS feature for achieving 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 v4:
- change commit subject.
- Remove unnecessary comments and type cast.
- Added comments for CPM block register access using readl/writel.

Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
---
 drivers/pci/controller/Kconfig           |   8 +
 drivers/pci/controller/Makefile          |   1 +
 drivers/pci/controller/pcie-xilinx-cpm.c | 506 +++++++++++++++++++++++++++++++
 3 files changed, 515 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..362f4db 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 support for the
+	  Xilinx Versal CPM host bridge. 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..49ec5c7
--- /dev/null
+++ b/drivers/pci/controller/pcie-xilinx-cpm.c
@@ -0,0 +1,506 @@
+// 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 System Level Control and Status Register(SLCR) 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);
+	}
+}
+
+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 = 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);
+
+	/*
+	 * XILINX_CPM_PCIE_MISC_IR_STATUS register is mapped to
+	 * CPM SLCR block.
+	 */
+	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);
+
+	/*
+	 * XILINX_CPM_PCIE_MISC_IR_ENABLE register is mapped to
+	 * CPM SLCR block.
+	 */
+	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 platform_device *pdev = to_platform_device(dev);
+	struct resource *res;
+	int err;
+
+	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

Re: [PATCH v4 2/2] PCI: xilinx-cpm: Add Versal CPM Root Port driver

[Bjorn Helgaas]

On Tue, Jan 28, 2020 at 06:14:43PM +0530, Bharat Kumar Gogada wrote:
> - 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.
> - CPM Versal uses GICv3 ITS feature for achieving 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 v4:
> - change commit subject.
> - Remove unnecessary comments and type cast.
> - Added comments for CPM block register access using readl/writel.
> 
> Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
> ...

> +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;

This whole *_valid_device() thing is a mess.  We shouldn't need it at
all.  But if we *do* need it, I don't think you should check the
entire devfn because that means you can't attach a multifunction
device.

Several other drivers with similar *_valid_device() implementations
check only PCI_SLOT():

  dw_pcie_valid_device()
  advk_pcie_valid_device()
  pci_dw_valid_device()
  altera_pcie_valid_device()
  mobiveil_pcie_valid_device()
  rockchip_pcie_valid_device()

Even checking just PCI_SLOT() is problematic because I think an ARI
device with more than 8 functions will not work correctly.

What exactly happens if you omit this function, i.e., if we just go
ahead and attempt config accesses when the device is not present?  We
*should* get something like an Unsupported Request completion, and
that *should* be a recoverable error.  Most hardware turns this error
into read data of 0xffffffff.  The OS should be able to figure out
that there's no device there and continue with no ill effects.

> +	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,
> +};

RE: [PATCH v4 2/2] PCI: xilinx-cpm: Add Versal CPM Root Port driver

[Bharat Kumar Gogada]

> Subject: Re: [PATCH v4 2/2] PCI: xilinx-cpm: Add Versal CPM Root Port driver
> 
> On Tue, Jan 28, 2020 at 06:14:43PM +0530, Bharat Kumar Gogada wrote:
> > - 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.
> > - CPM Versal uses GICv3 ITS feature for achieving 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 v4:
> > - change commit subject.
> > - Remove unnecessary comments and type cast.
> > - Added comments for CPM block register access using readl/writel.
> >
> > Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
> > ...
> 
> > +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;
> 
> This whole *_valid_device() thing is a mess.  We shouldn't need it at all.  But if
> we *do* need it, I don't think you should check the entire devfn because that
> means you can't attach a multifunction device.
> 
> Several other drivers with similar *_valid_device() implementations check only
> PCI_SLOT():
> 
>   dw_pcie_valid_device()
>   advk_pcie_valid_device()
>   pci_dw_valid_device()
>   altera_pcie_valid_device()
>   mobiveil_pcie_valid_device()
>   rockchip_pcie_valid_device()
> 
> Even checking just PCI_SLOT() is problematic because I think an ARI device with
> more than 8 functions will not work correctly.
> 
> What exactly happens if you omit this function, i.e., if we just go ahead and
> attempt config accesses when the device is not present?  We
> *should* get something like an Unsupported Request completion, and that
> *should* be a recoverable error.  Most hardware turns this error into read data
> of 0xffffffff.  The OS should be able to figure out that there's no device there
> and continue with no ill effects.
> 
Thanks Bjorn. I did test and I do not see any issue without this. 
Will resend patch with this change.
> > +	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,
> > +};

Regards,
bharat

Re: [PATCH v4 2/2] PCI: xilinx-cpm: Add Versal CPM Root Port driver

[Bjorn Helgaas]

On Wed, Jan 29, 2020 at 11:16:47AM +0000, Bharat Kumar Gogada wrote:
> > Subject: Re: [PATCH v4 2/2] PCI: xilinx-cpm: Add Versal CPM Root Port driver
> > 
> > On Tue, Jan 28, 2020 at 06:14:43PM +0530, Bharat Kumar Gogada wrote:
> > > - 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.
> > > - CPM Versal uses GICv3 ITS feature for achieving 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 v4:
> > > - change commit subject.
> > > - Remove unnecessary comments and type cast.
> > > - Added comments for CPM block register access using readl/writel.
> > >
> > > Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
> > > ...
> > 
> > > +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;
> > 
> > This whole *_valid_device() thing is a mess.  We shouldn't need it at all.  But if
> > we *do* need it, I don't think you should check the entire devfn because that
> > means you can't attach a multifunction device.
> > 
> > Several other drivers with similar *_valid_device() implementations check only
> > PCI_SLOT():
> > 
> >   dw_pcie_valid_device()
> >   advk_pcie_valid_device()
> >   pci_dw_valid_device()
> >   altera_pcie_valid_device()
> >   mobiveil_pcie_valid_device()
> >   rockchip_pcie_valid_device()
> > 
> > Even checking just PCI_SLOT() is problematic because I think an ARI device with
> > more than 8 functions will not work correctly.
> > 
> > What exactly happens if you omit this function, i.e., if we just go ahead and
> > attempt config accesses when the device is not present?  We
> > *should* get something like an Unsupported Request completion, and that
> > *should* be a recoverable error.  Most hardware turns this error into read data
> > of 0xffffffff.  The OS should be able to figure out that there's no device there
> > and continue with no ill effects.
> > 
> Thanks Bjorn. I did test and I do not see any issue without this. 
> Will resend patch with this change.

That's great, thanks for testing that!  I wonder how many other
drivers could just drop that code.

Bjorn

Re: [PATCH v4 0/2] Adding support for Versal CPM as Root Port driver.

[Bjorn Helgaas]

On Tue, Jan 28, 2020 at 06:14:41PM +0530, Bharat Kumar Gogada wrote:
> - 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.
> - Versal CPM uses GICv3 ITS feature for 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.
> 
> Bharat Kumar Gogada (2):
>   PCI: xilinx-cpm: Add device tree binding for Versal CPM host bridge.
>   PCI: xilinx-cpm: Add Versal CPM Root Port driver

Nit for next time: Omit the period at the end of the subject.  No need
to repost just for that.

>  .../devicetree/bindings/pci/xilinx-versal-cpm.txt  |  66 +++
>  drivers/pci/controller/Kconfig                     |   8 +
>  drivers/pci/controller/Makefile                    |   1 +
>  drivers/pci/controller/pcie-xilinx-cpm.c           | 506 +++++++++++++++++++++
>  4 files changed, 581 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pci/xilinx-versal-cpm.txt
>  create mode 100644 drivers/pci/controller/pcie-xilinx-cpm.c
> 
> -- 
> 2.7.4
>