irqchip/riscv-aplic: Add ACPI support

Add ACPI support in APLIC drivers. Use the mapping created early during
boot to get the details about the APLIC.
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20240812005929.113499-17-sunilvl@ventanamicro.comSigned-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/irqchip/irq-riscv-aplic-direct.c

@@ -4,6 +4,7 @@
  * Copyright (C) 2022 Ventana Micro Systems Inc.
  */
 
+#include <linux/acpi.h>
 #include <linux/bitfield.h>
 #include <linux/bitops.h>
 #include <linux/cpu.h>
@@ -189,17 +190,22 @@ static int aplic_direct_starting_cpu(unsigned int cpu)
 }
 
 static int aplic_direct_parse_parent_hwirq(struct device *dev, u32 index,
-					   u32 *parent_hwirq, unsigned long *parent_hartid)
+					   u32 *parent_hwirq, unsigned long *parent_hartid,
+					   struct aplic_priv *priv)
 {
 	struct of_phandle_args parent;
+	unsigned long hartid;
 	int rc;
 
-	/*
-	 * Currently, only OF fwnode is supported so extend this
-	 * function for ACPI support.
-	 */
-	if (!is_of_node(dev->fwnode))
-		return -EINVAL;
+	if (!is_of_node(dev->fwnode)) {
+		hartid = acpi_rintc_ext_parent_to_hartid(priv->acpi_aplic_id, index);
+		if (hartid == INVALID_HARTID)
+			return -ENODEV;
+
+		*parent_hartid = hartid;
+		*parent_hwirq = RV_IRQ_EXT;
+		return 0;
+	}
 
 	rc = of_irq_parse_one(to_of_node(dev->fwnode), index, &parent);
 	if (rc)
@@ -237,7 +243,7 @@ int aplic_direct_setup(struct device *dev, void __iomem *regs)
 	/* Setup per-CPU IDC and target CPU mask */
 	current_cpu = get_cpu();
 	for (i = 0; i < priv->nr_idcs; i++) {
-		rc = aplic_direct_parse_parent_hwirq(dev, i, &hwirq, &hartid);
+		rc = aplic_direct_parse_parent_hwirq(dev, i, &hwirq, &hartid, priv);
 		if (rc) {
 			dev_warn(dev, "parent irq for IDC%d not found\n", i);
 			continue;

drivers/irqchip/irq-riscv-aplic-main.c

@@ -4,8 +4,10 @@
  * Copyright (C) 2022 Ventana Micro Systems Inc.
  */
 
+#include <linux/acpi.h>
 #include <linux/bitfield.h>
 #include <linux/irqchip/riscv-aplic.h>
+#include <linux/irqchip/riscv-imsic.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
@@ -125,39 +127,50 @@ static void aplic_init_hw_irqs(struct aplic_priv *priv)
 	writel(0, priv->regs + APLIC_DOMAINCFG);
 }
 
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id aplic_acpi_match[] = {
+	{ "RSCV0002", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, aplic_acpi_match);
+
+#endif
+
 int aplic_setup_priv(struct aplic_priv *priv, struct device *dev, void __iomem *regs)
 {
 	struct device_node *np = to_of_node(dev->fwnode);
 	struct of_phandle_args parent;
 	int rc;
 
-	/*
-	 * Currently, only OF fwnode is supported so extend this
-	 * function for ACPI support.
-	 */
-	if (!np)
-		return -EINVAL;
-
 	/* Save device pointer and register base */
 	priv->dev = dev;
 	priv->regs = regs;
 
-	/* Find out number of interrupt sources */
-	rc = of_property_read_u32(np, "riscv,num-sources", &priv->nr_irqs);
-	if (rc) {
-		dev_err(dev, "failed to get number of interrupt sources\n");
-		return rc;
-	}
-
-	/*
-	 * Find out number of IDCs based on parent interrupts
-	 *
-	 * If "msi-parent" property is present then we ignore the
-	 * APLIC IDCs which forces the APLIC driver to use MSI mode.
-	 */
-	if (!of_property_present(np, "msi-parent")) {
-		while (!of_irq_parse_one(np, priv->nr_idcs, &parent))
-			priv->nr_idcs++;
+	if (np) {
+		/* Find out number of interrupt sources */
+		rc = of_property_read_u32(np, "riscv,num-sources", &priv->nr_irqs);
+		if (rc) {
+			dev_err(dev, "failed to get number of interrupt sources\n");
+			return rc;
+		}
+
+		/*
+		 * Find out number of IDCs based on parent interrupts
+		 *
+		 * If "msi-parent" property is present then we ignore the
+		 * APLIC IDCs which forces the APLIC driver to use MSI mode.
+		 */
+		if (!of_property_present(np, "msi-parent")) {
+			while (!of_irq_parse_one(np, priv->nr_idcs, &parent))
+				priv->nr_idcs++;
+		}
+	} else {
+		rc = riscv_acpi_get_gsi_info(dev->fwnode, &priv->gsi_base, &priv->acpi_aplic_id,
+					     &priv->nr_irqs, &priv->nr_idcs);
+		if (rc) {
+			dev_err(dev, "failed to find GSI mapping\n");
+			return rc;
+		}
 	}
 
 	/* Setup initial state APLIC interrupts */
@@ -184,7 +197,11 @@ static int aplic_probe(struct platform_device *pdev)
 	 * If msi-parent property is present then setup APLIC MSI
 	 * mode otherwise setup APLIC direct mode.
 	 */
-	msi_mode = of_property_present(to_of_node(dev->fwnode), "msi-parent");
+	if (is_of_node(dev->fwnode))
+		msi_mode = of_property_present(to_of_node(dev->fwnode), "msi-parent");
+	else
+		msi_mode = imsic_acpi_get_fwnode(NULL) ? 1 : 0;
+
 	if (msi_mode)
 		rc = aplic_msi_setup(dev, regs);
 	else
@@ -192,6 +209,11 @@ static int aplic_probe(struct platform_device *pdev)
 	if (rc)
 		dev_err(dev, "failed to setup APLIC in %s mode\n", msi_mode ? "MSI" : "direct");
 
+#ifdef CONFIG_ACPI
+	if (!acpi_disabled)
+		acpi_dev_clear_dependencies(ACPI_COMPANION(dev));
+#endif
+
 	return rc;
 }
 
@@ -204,6 +226,7 @@ static struct platform_driver aplic_driver = {
 	.driver = {
 		.name		= "riscv-aplic",
 		.of_match_table	= aplic_match,
+		.acpi_match_table = ACPI_PTR(aplic_acpi_match),
 	},
 	.probe = aplic_probe,
 };

drivers/irqchip/irq-riscv-aplic-main.h

@@ -28,6 +28,7 @@ struct aplic_priv {
 	u32			gsi_base;
 	u32			nr_irqs;
 	u32			nr_idcs;
+	u32			acpi_aplic_id;
 	void __iomem		*regs;
 	struct aplic_msicfg	msicfg;
 };

drivers/irqchip/irq-riscv-aplic-msi.c

@@ -175,6 +175,7 @@ static const struct msi_domain_template aplic_msi_template = {
 int aplic_msi_setup(struct device *dev, void __iomem *regs)
 {
 	const struct imsic_global_config *imsic_global;
+	struct irq_domain *msi_domain;
 	struct aplic_priv *priv;
 	struct aplic_msicfg *mc;
 	phys_addr_t pa;
@@ -257,8 +258,14 @@ int aplic_msi_setup(struct device *dev, void __iomem *regs)
 		 * IMSIC and the IMSIC MSI domains are created later through
 		 * the platform driver probing so we set it explicitly here.
 		 */
-		if (is_of_node(dev->fwnode))
+		if (is_of_node(dev->fwnode)) {
 			of_msi_configure(dev, to_of_node(dev->fwnode));
+		} else {
+			msi_domain = irq_find_matching_fwnode(imsic_acpi_get_fwnode(dev),
+							      DOMAIN_BUS_PLATFORM_MSI);
+			if (msi_domain)
+				dev_set_msi_domain(dev, msi_domain);
+		}
 	}
 
 	if (!msi_create_device_irq_domain(dev, MSI_DEFAULT_DOMAIN, &aplic_msi_template,