[RFC PATCH v3 11/17] irqchip: riscv-aplic: Add ACPI support

[Sunil V L <sunilvl@ventanamicro.com>]

Add ACPI support in APLIC drivers. In ACPI, IO devices use Global System
Interrupts (GSI) which is a flat space split across multiple APLICs.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
---
 arch/riscv/include/asm/irq.h             |  6 +++
 drivers/irqchip/irq-riscv-aplic-direct.c | 21 +++++---
 drivers/irqchip/irq-riscv-aplic-main.c   | 64 ++++++++++++++----------
 drivers/irqchip/irq-riscv-aplic-main.h   |  1 +
 drivers/irqchip/irq-riscv-aplic-msi.c    |  9 +++-
 5 files changed, 66 insertions(+), 35 deletions(-)

diff --git a/arch/riscv/include/asm/irq.h b/arch/riscv/include/asm/irq.h
index 232314e5f007..df59192a157d 100644
--- a/arch/riscv/include/asm/irq.h
+++ b/arch/riscv/include/asm/irq.h
@@ -22,6 +22,12 @@
 #define APLIC_PLIC_ID(x) ((x) >> 24)
 #define IDC_CONTEXT_ID(x) ((x) & 0x0000ffff)
 
+#ifdef CONFIG_RISCV_APLIC
+struct fwnode_handle *aplic_get_gsi_domain_id(u32 gsi);
+#else
+static inline struct fwnode_handle *aplic_get_gsi_domain_id(u32 gsi) { return NULL; }
+#endif
+
 int __init acpi_get_intc_index_hartid(u32 index, unsigned long *hartid);
 int acpi_get_ext_intc_parent_hartid(u8 id, u32 idx, unsigned long *hartid);
 void acpi_get_plic_nr_contexts(u8 id, int *nr_contexts);
diff --git a/drivers/irqchip/irq-riscv-aplic-direct.c b/drivers/irqchip/irq-riscv-aplic-direct.c
index 9ed2666bfb5e..3e7a7e092120 100644
--- a/drivers/irqchip/irq-riscv-aplic-direct.c
+++ b/drivers/irqchip/irq-riscv-aplic-direct.c
@@ -4,6 +4,7 @@
  * Copyright (C) 2022 Ventana Micro Systems Inc.
  */
 
+#include <linux/acpi.h>
 #include <linux/bitops.h>
 #include <linux/cpu.h>
 #include <linux/interrupt.h>
@@ -14,6 +15,7 @@
 #include <linux/of_address.h>
 #include <linux/printk.h>
 #include <linux/smp.h>
+#include <asm/acpi.h>
 
 #include "irq-riscv-aplic-main.h"
 
@@ -203,17 +205,20 @@ 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)
+					   unsigned long *parent_hartid,
+					   struct aplic_priv *priv)
 {
 	struct of_phandle_args parent;
 	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)) {
+		rc = acpi_get_ext_intc_parent_hartid(priv->id, index, parent_hartid);
+		if (rc)
+			return rc;
+
+		*parent_hwirq = RV_IRQ_EXT;
+		return 0;
+	}
 
 	rc = of_irq_parse_one(to_of_node(dev->fwnode), index, &parent);
 	if (rc)
@@ -251,7 +256,7 @@ int aplic_direct_setup(struct device *dev, void __iomem *regs)
 
 	/* Setup per-CPU IDC and target CPU mask */
 	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;
diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
index d1b342b66551..31434b3ff690 100644
--- a/drivers/irqchip/irq-riscv-aplic-main.c
+++ b/drivers/irqchip/irq-riscv-aplic-main.c
@@ -4,12 +4,15 @@
  * Copyright (C) 2022 Ventana Micro Systems Inc.
  */
 
+#include <linux/acpi.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
 #include <linux/printk.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/irqchip/riscv-aplic.h>
+#include <linux/irqchip/riscv-imsic.h>
+#include <asm/acpi.h>
 
 #include "irq-riscv-aplic-main.h"
 
@@ -137,38 +140,44 @@ int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
 		     void __iomem *regs)
 {
 	struct of_phandle_args parent;
+	struct acpi_madt_aplic *aplic;
 	int rc;
 
-	/*
-	 * Currently, only OF fwnode is supported so extend this
-	 * function for ACPI support.
-	 */
-	if (!is_of_node(dev->fwnode))
-		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(to_of_node(dev->fwnode),
-					     "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(to_of_node(dev->fwnode), "msi-parent")) {
-		while (!of_irq_parse_one(to_of_node(dev->fwnode),
-					 priv->nr_idcs, &parent))
-			priv->nr_idcs++;
+	if (is_of_node(dev->fwnode)) {
+		/* Find out number of interrupt sources */
+		rc = of_property_read_u32(to_of_node(dev->fwnode),
+					  "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(to_of_node(dev->fwnode), "msi-parent")) {
+			while (!of_irq_parse_one(to_of_node(dev->fwnode),
+						 priv->nr_idcs, &parent))
+				priv->nr_idcs++;
+		}
+	} else {
+		aplic = *(struct acpi_madt_aplic **)dev_get_platdata(dev);
+		if (!aplic) {
+			dev_err(dev, "APLIC platform data is NULL!\n");
+			return -1;
+		}
+		priv->gsi_base = aplic->gsi_base;
+		priv->nr_irqs = aplic->num_sources;
+		priv->nr_idcs = aplic->num_idcs;
+		priv->id = aplic->id;
 	}
 
 	/* Setup initial state APLIC interrupts */
@@ -204,6 +213,9 @@ static int aplic_probe(struct platform_device *pdev)
 	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
diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
index 78267ec58098..dc022e89bc97 100644
--- a/drivers/irqchip/irq-riscv-aplic-main.h
+++ b/drivers/irqchip/irq-riscv-aplic-main.h
@@ -28,6 +28,7 @@ struct aplic_priv {
 	u32			gsi_base;
 	u32			nr_irqs;
 	u32			nr_idcs;
+	u32			id;
 	void __iomem		*regs;
 	struct aplic_msicfg	msicfg;
 };
diff --git a/drivers/irqchip/irq-riscv-aplic-msi.c b/drivers/irqchip/irq-riscv-aplic-msi.c
index 086d00e0429e..03a8ac6554c4 100644
--- a/drivers/irqchip/irq-riscv-aplic-msi.c
+++ b/drivers/irqchip/irq-riscv-aplic-msi.c
@@ -178,6 +178,7 @@ static void aplic_msi_write_msg(struct msi_desc *desc, struct msi_msg *msg)
 int aplic_msi_setup(struct device *dev, void __iomem *regs)
 {
 	const struct imsic_global_config *imsic_global;
+	struct irq_domain *msi_domain;
 	struct irq_domain *irqdomain;
 	struct aplic_priv *priv;
 	struct aplic_msicfg *mc;
@@ -261,8 +262,14 @@ 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);
+		}
 	}
 
 	/* Create irq domain instance for the APLIC MSI-mode */
-- 
2.39.2