1 files changed, 476 insertions, 0 deletions
diff --git a/drivers/pci/controller/dwc/pcie-amd-mdb.c b/drivers/pci/controller/dwc/pcie-amd-mdb.c
new file mode 100644
index 000000000000..4eb2a4e8189d
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-amd-mdb.c
@@ -0,0 +1,476 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe host controller driver for AMD MDB PCIe Bridge
+ *
+ * Copyright (C) 2024-2025, Advanced Micro Devices, Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/of_device.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/resource.h>
+#include <linux/types.h>
+
+#include "pcie-designware.h"
+
+#define AMD_MDB_TLP_IR_STATUS_MISC		0x4C0
+#define AMD_MDB_TLP_IR_MASK_MISC		0x4C4
+#define AMD_MDB_TLP_IR_ENABLE_MISC		0x4C8
+#define AMD_MDB_TLP_IR_DISABLE_MISC		0x4CC
+
+#define AMD_MDB_TLP_PCIE_INTX_MASK	GENMASK(23, 16)
+
+#define AMD_MDB_PCIE_INTR_INTX_ASSERT(x)	BIT((x) * 2)
+
+/* Interrupt registers definitions. */
+#define AMD_MDB_PCIE_INTR_CMPL_TIMEOUT		15
+#define AMD_MDB_PCIE_INTR_INTX			16
+#define AMD_MDB_PCIE_INTR_PM_PME_RCVD		24
+#define AMD_MDB_PCIE_INTR_PME_TO_ACK_RCVD	25
+#define AMD_MDB_PCIE_INTR_MISC_CORRECTABLE	26
+#define AMD_MDB_PCIE_INTR_NONFATAL		27
+#define AMD_MDB_PCIE_INTR_FATAL			28
+
+#define IMR(x) BIT(AMD_MDB_PCIE_INTR_ ##x)
+#define AMD_MDB_PCIE_IMR_ALL_MASK			\
+	(						\
+		IMR(CMPL_TIMEOUT)	|		\
+		IMR(PM_PME_RCVD)	|		\
+		IMR(PME_TO_ACK_RCVD)	|		\
+		IMR(MISC_CORRECTABLE)	|		\
+		IMR(NONFATAL)		|		\
+		IMR(FATAL)		|		\
+		AMD_MDB_TLP_PCIE_INTX_MASK		\
+	)
+
+/**
+ * struct amd_mdb_pcie - PCIe port information
+ * @pci: DesignWare PCIe controller structure
+ * @slcr: MDB System Level Control and Status Register (SLCR) base
+ * @intx_domain: INTx IRQ domain pointer
+ * @mdb_domain: MDB IRQ domain pointer
+ * @intx_irq: INTx IRQ interrupt number
+ */
+struct amd_mdb_pcie {
+	struct dw_pcie			pci;
+	void __iomem			*slcr;
+	struct irq_domain		*intx_domain;
+	struct irq_domain		*mdb_domain;
+	int				intx_irq;
+};
+
+static const struct dw_pcie_host_ops amd_mdb_pcie_host_ops = {
+};
+
+static void amd_mdb_intx_irq_mask(struct irq_data *data)
+{
+	struct amd_mdb_pcie *pcie = irq_data_get_irq_chip_data(data);
+	struct dw_pcie *pci = &pcie->pci;
+	struct dw_pcie_rp *port = &pci->pp;
+	unsigned long flags;
+	u32 val;
+
+	raw_spin_lock_irqsave(&port->lock, flags);
+	val = FIELD_PREP(AMD_MDB_TLP_PCIE_INTX_MASK,
+			 AMD_MDB_PCIE_INTR_INTX_ASSERT(data->hwirq));
+
+	/*
+	 * Writing '1' to a bit in AMD_MDB_TLP_IR_DISABLE_MISC disables that
+	 * interrupt, writing '0' has no effect.
+	 */
+	writel_relaxed(val, pcie->slcr + AMD_MDB_TLP_IR_DISABLE_MISC);
+	raw_spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void amd_mdb_intx_irq_unmask(struct irq_data *data)
+{
+	struct amd_mdb_pcie *pcie = irq_data_get_irq_chip_data(data);
+	struct dw_pcie *pci = &pcie->pci;
+	struct dw_pcie_rp *port = &pci->pp;
+	unsigned long flags;
+	u32 val;
+
+	raw_spin_lock_irqsave(&port->lock, flags);
+	val = FIELD_PREP(AMD_MDB_TLP_PCIE_INTX_MASK,
+			 AMD_MDB_PCIE_INTR_INTX_ASSERT(data->hwirq));
+
+	/*
+	 * Writing '1' to a bit in AMD_MDB_TLP_IR_ENABLE_MISC enables that
+	 * interrupt, writing '0' has no effect.
+	 */
+	writel_relaxed(val, pcie->slcr + AMD_MDB_TLP_IR_ENABLE_MISC);
+	raw_spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static struct irq_chip amd_mdb_intx_irq_chip = {
+	.name		= "AMD MDB INTx",
+	.irq_mask	= amd_mdb_intx_irq_mask,
+	.irq_unmask	= amd_mdb_intx_irq_unmask,
+};
+
+/**
+ * amd_mdb_pcie_intx_map - Set the handler for the INTx and mark IRQ as valid
+ * @domain: IRQ domain
+ * @irq: Virtual IRQ number
+ * @hwirq: Hardware interrupt number
+ *
+ * Return: Always returns '0'.
+ */
+static int amd_mdb_pcie_intx_map(struct irq_domain *domain,
+				 unsigned int irq, irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler(irq, &amd_mdb_intx_irq_chip,
+				 handle_level_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 amd_intx_domain_ops = {
+	.map = amd_mdb_pcie_intx_map,
+};
+
+static irqreturn_t dw_pcie_rp_intx(int irq, void *args)
+{
+	struct amd_mdb_pcie *pcie = args;
+	unsigned long val;
+	int i, int_status;
+
+	val = readl_relaxed(pcie->slcr + AMD_MDB_TLP_IR_STATUS_MISC);
+	int_status = FIELD_GET(AMD_MDB_TLP_PCIE_INTX_MASK, val);
+
+	for (i = 0; i < PCI_NUM_INTX; i++) {
+		if (int_status & AMD_MDB_PCIE_INTR_INTX_ASSERT(i))
+			generic_handle_domain_irq(pcie->intx_domain, i);
+	}
+
+	return IRQ_HANDLED;
+}
+
+#define _IC(x, s)[AMD_MDB_PCIE_INTR_ ## x] = { __stringify(x), s }
+
+static const struct {
+	const char	*sym;
+	const char	*str;
+} intr_cause[32] = {
+	_IC(CMPL_TIMEOUT,	"Completion timeout"),
+	_IC(PM_PME_RCVD,	"PM_PME message received"),
+	_IC(PME_TO_ACK_RCVD,	"PME_TO_ACK message received"),
+	_IC(MISC_CORRECTABLE,	"Correctable error message"),
+	_IC(NONFATAL,		"Non fatal error message"),
+	_IC(FATAL,		"Fatal error message"),
+};
+
+static void amd_mdb_event_irq_mask(struct irq_data *d)
+{
+	struct amd_mdb_pcie *pcie = irq_data_get_irq_chip_data(d);
+	struct dw_pcie *pci = &pcie->pci;
+	struct dw_pcie_rp *port = &pci->pp;
+	unsigned long flags;
+	u32 val;
+
+	raw_spin_lock_irqsave(&port->lock, flags);
+	val = BIT(d->hwirq);
+	writel_relaxed(val, pcie->slcr + AMD_MDB_TLP_IR_DISABLE_MISC);
+	raw_spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void amd_mdb_event_irq_unmask(struct irq_data *d)
+{
+	struct amd_mdb_pcie *pcie = irq_data_get_irq_chip_data(d);
+	struct dw_pcie *pci = &pcie->pci;
+	struct dw_pcie_rp *port = &pci->pp;
+	unsigned long flags;
+	u32 val;
+
+	raw_spin_lock_irqsave(&port->lock, flags);
+	val = BIT(d->hwirq);
+	writel_relaxed(val, pcie->slcr + AMD_MDB_TLP_IR_ENABLE_MISC);
+	raw_spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static struct irq_chip amd_mdb_event_irq_chip = {
+	.name		= "AMD MDB RC-Event",
+	.irq_mask	= amd_mdb_event_irq_mask,
+	.irq_unmask	= amd_mdb_event_irq_unmask,
+};
+
+static int amd_mdb_pcie_event_map(struct irq_domain *domain,
+				  unsigned int irq, irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler(irq, &amd_mdb_event_irq_chip,
+				 handle_level_irq);
+	irq_set_chip_data(irq, domain->host_data);
+	irq_set_status_flags(irq, IRQ_LEVEL);
+
+	return 0;
+}
+
+static const struct irq_domain_ops event_domain_ops = {
+	.map = amd_mdb_pcie_event_map,
+};
+
+static irqreturn_t amd_mdb_pcie_event(int irq, void *args)
+{
+	struct amd_mdb_pcie *pcie = args;
+	unsigned long val;
+	int i;
+
+	val = readl_relaxed(pcie->slcr + AMD_MDB_TLP_IR_STATUS_MISC);
+	val &= ~readl_relaxed(pcie->slcr + AMD_MDB_TLP_IR_MASK_MISC);
+	for_each_set_bit(i, &val, 32)
+		generic_handle_domain_irq(pcie->mdb_domain, i);
+	writel_relaxed(val, pcie->slcr + AMD_MDB_TLP_IR_STATUS_MISC);
+
+	return IRQ_HANDLED;
+}
+
+static void amd_mdb_pcie_free_irq_domains(struct amd_mdb_pcie *pcie)
+{
+	if (pcie->intx_domain) {
+		irq_domain_remove(pcie->intx_domain);
+		pcie->intx_domain = NULL;
+	}
+
+	if (pcie->mdb_domain) {
+		irq_domain_remove(pcie->mdb_domain);
+		pcie->mdb_domain = NULL;
+	}
+}
+
+static int amd_mdb_pcie_init_port(struct amd_mdb_pcie *pcie)
+{
+	unsigned long val;
+
+	/* Disable all TLP interrupts. */
+	writel_relaxed(AMD_MDB_PCIE_IMR_ALL_MASK,
+		       pcie->slcr + AMD_MDB_TLP_IR_DISABLE_MISC);
+
+	/* Clear pending TLP interrupts. */
+	val = readl_relaxed(pcie->slcr + AMD_MDB_TLP_IR_STATUS_MISC);
+	val &= AMD_MDB_PCIE_IMR_ALL_MASK;
+	writel_relaxed(val, pcie->slcr + AMD_MDB_TLP_IR_STATUS_MISC);
+
+	/* Enable all TLP interrupts. */
+	writel_relaxed(AMD_MDB_PCIE_IMR_ALL_MASK,
+		       pcie->slcr + AMD_MDB_TLP_IR_ENABLE_MISC);
+
+	return 0;
+}
+
+/**
+ * amd_mdb_pcie_init_irq_domains - Initialize IRQ domain
+ * @pcie: PCIe port information
+ * @pdev: Platform device
+ *
+ * Return: Returns '0' on success and error value on failure.
+ */
+static int amd_mdb_pcie_init_irq_domains(struct amd_mdb_pcie *pcie,
+					 struct platform_device *pdev)
+{
+	struct dw_pcie *pci = &pcie->pci;
+	struct dw_pcie_rp *pp = &pci->pp;
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->of_node;
+	struct device_node *pcie_intc_node;
+	int err;
+
+	pcie_intc_node = of_get_next_child(node, NULL);
+	if (!pcie_intc_node) {
+		dev_err(dev, "No PCIe Intc node found\n");
+		return -ENODEV;
+	}
+
+	pcie->mdb_domain = irq_domain_add_linear(pcie_intc_node, 32,
+						 &event_domain_ops, pcie);
+	if (!pcie->mdb_domain) {
+		err = -ENOMEM;
+		dev_err(dev, "Failed to add MDB domain\n");
+		goto out;
+	}
+
+	irq_domain_update_bus_token(pcie->mdb_domain, DOMAIN_BUS_NEXUS);
+
+	pcie->intx_domain = irq_domain_add_linear(pcie_intc_node, PCI_NUM_INTX,
+						  &amd_intx_domain_ops, pcie);
+	if (!pcie->intx_domain) {
+		err = -ENOMEM;
+		dev_err(dev, "Failed to add INTx domain\n");
+		goto mdb_out;
+	}
+
+	of_node_put(pcie_intc_node);
+	irq_domain_update_bus_token(pcie->intx_domain, DOMAIN_BUS_WIRED);
+
+	raw_spin_lock_init(&pp->lock);
+
+	return 0;
+mdb_out:
+	amd_mdb_pcie_free_irq_domains(pcie);
+out:
+	of_node_put(pcie_intc_node);
+	return err;
+}
+
+static irqreturn_t amd_mdb_pcie_intr_handler(int irq, void *args)
+{
+	struct amd_mdb_pcie *pcie = args;
+	struct device *dev;
+	struct irq_data *d;
+
+	dev = pcie->pci.dev;
+
+	/*
+	 * In the future, error reporting will be hooked to the AER subsystem.
+	 * Currently, the driver prints a warning message to the user.
+	 */
+	d = irq_domain_get_irq_data(pcie->mdb_domain, irq);
+	if (intr_cause[d->hwirq].str)
+		dev_warn(dev, "%s\n", intr_cause[d->hwirq].str);
+	else
+		dev_warn_once(dev, "Unknown IRQ %ld\n", d->hwirq);
+
+	return IRQ_HANDLED;
+}
+
+static int amd_mdb_setup_irq(struct amd_mdb_pcie *pcie,
+			     struct platform_device *pdev)
+{
+	struct dw_pcie *pci = &pcie->pci;
+	struct dw_pcie_rp *pp = &pci->pp;
+	struct device *dev = &pdev->dev;
+	int i, irq, err;
+
+	amd_mdb_pcie_init_port(pcie);
+
+	pp->irq = platform_get_irq(pdev, 0);
+	if (pp->irq < 0)
+		return pp->irq;
+
+	for (i = 0; i < ARRAY_SIZE(intr_cause); i++) {
+		if (!intr_cause[i].str)
+			continue;
+
+		irq = irq_create_mapping(pcie->mdb_domain, i);
+		if (!irq) {
+			dev_err(dev, "Failed to map MDB domain interrupt\n");
+			return -ENOMEM;
+		}
+
+		err = devm_request_irq(dev, irq, amd_mdb_pcie_intr_handler,
+				       IRQF_NO_THREAD, intr_cause[i].sym, pcie);
+		if (err) {
+			dev_err(dev, "Failed to request IRQ %d, err=%d\n",
+				irq, err);
+			return err;
+		}
+	}
+
+	pcie->intx_irq = irq_create_mapping(pcie->mdb_domain,
+					    AMD_MDB_PCIE_INTR_INTX);
+	if (!pcie->intx_irq) {
+		dev_err(dev, "Failed to map INTx interrupt\n");
+		return -ENXIO;
+	}
+
+	err = devm_request_irq(dev, pcie->intx_irq, dw_pcie_rp_intx,
+			       IRQF_NO_THREAD, NULL, pcie);
+	if (err) {
+		dev_err(dev, "Failed to request INTx IRQ %d, err=%d\n",
+			irq, err);
+		return err;
+	}
+
+	/* Plug the main event handler. */
+	err = devm_request_irq(dev, pp->irq, amd_mdb_pcie_event, IRQF_NO_THREAD,
+			       "amd_mdb pcie_irq", pcie);
+	if (err) {
+		dev_err(dev, "Failed to request event IRQ %d, err=%d\n",
+			pp->irq, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int amd_mdb_add_pcie_port(struct amd_mdb_pcie *pcie,
+				 struct platform_device *pdev)
+{
+	struct dw_pcie *pci = &pcie->pci;
+	struct dw_pcie_rp *pp = &pci->pp;
+	struct device *dev = &pdev->dev;
+	int err;
+
+	pcie->slcr = devm_platform_ioremap_resource_byname(pdev, "slcr");
+	if (IS_ERR(pcie->slcr))
+		return PTR_ERR(pcie->slcr);
+
+	err = amd_mdb_pcie_init_irq_domains(pcie, pdev);
+	if (err)
+		return err;
+
+	err = amd_mdb_setup_irq(pcie, pdev);
+	if (err) {
+		dev_err(dev, "Failed to set up interrupts, err=%d\n", err);
+		goto out;
+	}
+
+	pp->ops = &amd_mdb_pcie_host_ops;
+
+	err = dw_pcie_host_init(pp);
+	if (err) {
+		dev_err(dev, "Failed to initialize host, err=%d\n", err);
+		goto out;
+	}
+
+	return 0;
+
+out:
+	amd_mdb_pcie_free_irq_domains(pcie);
+	return err;
+}
+
+static int amd_mdb_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct amd_mdb_pcie *pcie;
+	struct dw_pcie *pci;
+
+	pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
+	if (!pcie)
+		return -ENOMEM;
+
+	pci = &pcie->pci;
+	pci->dev = dev;
+
+	platform_set_drvdata(pdev, pcie);
+
+	return amd_mdb_add_pcie_port(pcie, pdev);
+}
+
+static const struct of_device_id amd_mdb_pcie_of_match[] = {
+	{
+		.compatible = "amd,versal2-mdb-host",
+	},
+	{},
+};
+
+static struct platform_driver amd_mdb_pcie_driver = {
+	.driver = {
+		.name	= "amd-mdb-pcie",
+		.of_match_table = amd_mdb_pcie_of_match,
+		.suppress_bind_attrs = true,
+	},
+	.probe = amd_mdb_pcie_probe,
+};
+
+builtin_platform_driver(amd_mdb_pcie_driver);