irqchip/loongson-liointc: Add ACPI init support

LIOINTC stands for "Legacy I/O Interrupts" that described in Section
11.1 of "Loongson 3A5000 Processor Reference Manual". For more
information please refer Documentation/loongarch/irq-chip-model.rst.

Co-developed-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1658314292-35346-11-git-send-email-lvjianmin@loongson.cn

arch/loongarch/include/asm/irq.h

@@ -105,7 +105,7 @@ struct acpi_madt_lpc_pic;
 
 struct irq_domain *loongarch_cpu_irq_init(void);
 
-struct irq_domain *liointc_acpi_init(struct irq_domain *parent,
+int liointc_acpi_init(struct irq_domain *parent,
 					struct acpi_madt_lio_pic *acpi_liointc);
 struct irq_domain *eiointc_acpi_init(struct irq_domain *parent,
 					struct acpi_madt_eio_pic *acpi_eiointc);
@@ -138,7 +138,7 @@ extern struct acpi_madt_msi_pic *acpi_pchmsi[MAX_IO_PICS];
 extern struct acpi_madt_bio_pic *acpi_pchpic[MAX_IO_PICS];
 
 extern struct irq_domain *cpu_domain;
-extern struct irq_domain *liointc_domain;
+extern struct fwnode_handle *liointc_handle;
 extern struct fwnode_handle *pch_lpc_handle;
 extern struct fwnode_handle *pch_pic_handle[MAX_IO_PICS];
 

arch/loongarch/kernel/irq.c

@@ -26,7 +26,6 @@ DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
 EXPORT_PER_CPU_SYMBOL(irq_stat);
 
 struct irq_domain *cpu_domain;
-struct irq_domain *liointc_domain;
 
 struct acpi_vector_group pch_group[MAX_IO_PICS];
 struct acpi_vector_group msi_group[MAX_IO_PICS];

arch/mips/include/asm/mach-loongson64/irq.h

@@ -9,6 +9,7 @@
 #define NR_IRQS			(NR_IRQS_LEGACY + NR_MIPS_CPU_IRQS + NR_MAX_CHAINED_IRQS + 256)
 #define MAX_IO_PICS		1
 #define MIPS_CPU_IRQ_BASE 	NR_IRQS_LEGACY
+#define GSI_MIN_CPU_IRQ		0
 
 #include <asm/mach-generic/irq.h>
 

drivers/irqchip/irq-loongson-liointc.c

@@ -23,7 +23,7 @@
 #endif
 
 #define LIOINTC_CHIP_IRQ	32
-#define LIOINTC_NUM_PARENT 4
+#define LIOINTC_NUM_PARENT	4
 #define LIOINTC_NUM_CORES	4
 
 #define LIOINTC_INTC_CHIP_START	0x20
@@ -58,6 +58,8 @@ struct liointc_priv {
 	bool				has_lpc_irq_errata;
 };
 
+struct fwnode_handle *liointc_handle;
+
 static void liointc_chained_handle_irq(struct irq_desc *desc)
 {
 	struct liointc_handler_data *handler = irq_desc_get_handler_data(desc);
@@ -153,97 +155,79 @@ static void liointc_resume(struct irq_chip_generic *gc)
 	irq_gc_unlock_irqrestore(gc, flags);
 }
 
-static const char * const parent_names[] = {"int0", "int1", "int2", "int3"};
-static const char * const core_reg_names[] = {"isr0", "isr1", "isr2", "isr3"};
+static int parent_irq[LIOINTC_NUM_PARENT];
+static u32 parent_int_map[LIOINTC_NUM_PARENT];
+static const char *const parent_names[] = {"int0", "int1", "int2", "int3"};
+static const char *const core_reg_names[] = {"isr0", "isr1", "isr2", "isr3"};
 
-static void __iomem *liointc_get_reg_byname(struct device_node *node,
-						const char *name)
+static int liointc_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
+			     const u32 *intspec, unsigned int intsize,
+			     unsigned long *out_hwirq, unsigned int *out_type)
 {
-	int index = of_property_match_string(node, "reg-names", name);
-
-	if (index < 0)
-		return NULL;
-
-	return of_iomap(node, index);
+	if (WARN_ON(intsize < 1))
+		return -EINVAL;
+	*out_hwirq = intspec[0] - GSI_MIN_CPU_IRQ;
+	*out_type = IRQ_TYPE_NONE;
+	return 0;
 }
 
-static int __init liointc_of_init(struct device_node *node,
-				  struct device_node *parent)
+static const struct irq_domain_ops acpi_irq_gc_ops = {
+	.map	= irq_map_generic_chip,
+	.unmap  = irq_unmap_generic_chip,
+	.xlate	= liointc_domain_xlate,
+};
+
+static int liointc_init(phys_addr_t addr, unsigned long size, int revision,
+		struct fwnode_handle *domain_handle, struct device_node *node)
 {
+	int i, err;
+	void __iomem *base;
+	struct irq_chip_type *ct;
 	struct irq_chip_generic *gc;
 	struct irq_domain *domain;
-	struct irq_chip_type *ct;
 	struct liointc_priv *priv;
-	void __iomem *base;
-	u32 of_parent_int_map[LIOINTC_NUM_PARENT];
-	int parent_irq[LIOINTC_NUM_PARENT];
-	bool have_parent = FALSE;
-	int sz, i, err = 0;
 
 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
 
-	if (of_device_is_compatible(node, "loongson,liointc-2.0")) {
-		base = liointc_get_reg_byname(node, "main");
-		if (!base) {
-			err = -ENODEV;
-			goto out_free_priv;
-		}
+	base = ioremap(addr, size);
+	if (!base)
+		goto out_free_priv;
 
-		for (i = 0; i < LIOINTC_NUM_CORES; i++)
-			priv->core_isr[i] = liointc_get_reg_byname(node, core_reg_names[i]);
-		if (!priv->core_isr[0]) {
-			err = -ENODEV;
-			goto out_iounmap_base;
-		}
-	} else {
-		base = of_iomap(node, 0);
-		if (!base) {
-			err = -ENODEV;
-			goto out_free_priv;
-		}
-
-		for (i = 0; i < LIOINTC_NUM_CORES; i++)
-			priv->core_isr[i] = base + LIOINTC_REG_INTC_STATUS;
-	}
-
-	for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
-		parent_irq[i] = of_irq_get_byname(node, parent_names[i]);
-		if (parent_irq[i] > 0)
-			have_parent = TRUE;
-	}
-	if (!have_parent) {
-		err = -ENODEV;
-		goto out_iounmap_isr;
-	}
-
-	sz = of_property_read_variable_u32_array(node,
-						"loongson,parent_int_map",
-						&of_parent_int_map[0],
-						LIOINTC_NUM_PARENT,
-						LIOINTC_NUM_PARENT);
-	if (sz < 4) {
-		pr_err("loongson-liointc: No parent_int_map\n");
-		err = -ENODEV;
-		goto out_iounmap_isr;
-	}
+	for (i = 0; i < LIOINTC_NUM_CORES; i++)
+		priv->core_isr[i] = base + LIOINTC_REG_INTC_STATUS;
 
 	for (i = 0; i < LIOINTC_NUM_PARENT; i++)
-		priv->handler[i].parent_int_map = of_parent_int_map[i];
+		priv->handler[i].parent_int_map = parent_int_map[i];
+
+	if (revision > 1) {
+		for (i = 0; i < LIOINTC_NUM_CORES; i++) {
+			int index = of_property_match_string(node,
+					"reg-names", core_reg_names[i]);
+
+			if (index < 0)
+				return -EINVAL;
+
+			priv->core_isr[i] = of_iomap(node, index);
+		}
+	}
 
 	/* Setup IRQ domain */
-	domain = irq_domain_add_linear(node, 32,
+	if (!acpi_disabled)
+		domain = irq_domain_create_linear(domain_handle, LIOINTC_CHIP_IRQ,
+					&acpi_irq_gc_ops, priv);
+	else
+		domain = irq_domain_create_linear(domain_handle, LIOINTC_CHIP_IRQ,
 					&irq_generic_chip_ops, priv);
 	if (!domain) {
 		pr_err("loongson-liointc: cannot add IRQ domain\n");
-		err = -EINVAL;
-		goto out_iounmap_isr;
+		goto out_iounmap;
 	}
 
-	err = irq_alloc_domain_generic_chips(domain, 32, 1,
-					node->full_name, handle_level_irq,
-					IRQ_NOPROBE, 0, 0);
+	err = irq_alloc_domain_generic_chips(domain, LIOINTC_CHIP_IRQ, 1,
+					(node ? node->full_name : "LIOINTC"),
+					handle_level_irq, 0, IRQ_NOPROBE, 0);
 	if (err) {
 		pr_err("loongson-liointc: unable to register IRQ domain\n");
 		goto out_free_domain;
@@ -299,24 +283,93 @@ static int __init liointc_of_init(struct device_node *node,
 				liointc_chained_handle_irq, &priv->handler[i]);
 	}
 
+	liointc_handle = domain_handle;
 	return 0;
 
 out_free_domain:
 	irq_domain_remove(domain);
-out_iounmap_isr:
-	for (i = 0; i < LIOINTC_NUM_CORES; i++) {
-		if (!priv->core_isr[i])
-			continue;
-		iounmap(priv->core_isr[i]);
-	}
-out_iounmap_base:
+out_iounmap:
 	iounmap(base);
 out_free_priv:
 	kfree(priv);
 
-	return err;
+	return -EINVAL;
+}
+
+#ifdef CONFIG_OF
+
+static int __init liointc_of_init(struct device_node *node,
+				  struct device_node *parent)
+{
+	bool have_parent = FALSE;
+	int sz, i, index, revision, err = 0;
+	struct resource res;
+
+	if (!of_device_is_compatible(node, "loongson,liointc-2.0")) {
+		index = 0;
+		revision = 1;
+	} else {
+		index = of_property_match_string(node, "reg-names", "main");
+		revision = 2;
+	}
+
+	if (of_address_to_resource(node, index, &res))
+		return -EINVAL;
+
+	for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
+		parent_irq[i] = of_irq_get_byname(node, parent_names[i]);
+		if (parent_irq[i] > 0)
+			have_parent = TRUE;
+	}
+	if (!have_parent)
+		return -ENODEV;
+
+	sz = of_property_read_variable_u32_array(node,
+						"loongson,parent_int_map",
+						&parent_int_map[0],
+						LIOINTC_NUM_PARENT,
+						LIOINTC_NUM_PARENT);
+	if (sz < 4) {
+		pr_err("loongson-liointc: No parent_int_map\n");
+		return -ENODEV;
+	}
+
+	err = liointc_init(res.start, resource_size(&res),
+			revision, of_node_to_fwnode(node), node);
+	if (err < 0)
+		return err;
+
+	return 0;
 }
 
 IRQCHIP_DECLARE(loongson_liointc_1_0, "loongson,liointc-1.0", liointc_of_init);
 IRQCHIP_DECLARE(loongson_liointc_1_0a, "loongson,liointc-1.0a", liointc_of_init);
 IRQCHIP_DECLARE(loongson_liointc_2_0, "loongson,liointc-2.0", liointc_of_init);
+
+#endif
+
+#ifdef CONFIG_ACPI
+int __init liointc_acpi_init(struct irq_domain *parent, struct acpi_madt_lio_pic *acpi_liointc)
+{
+	int ret;
+	struct fwnode_handle *domain_handle;
+
+	parent_int_map[0] = acpi_liointc->cascade_map[0];
+	parent_int_map[1] = acpi_liointc->cascade_map[1];
+
+	parent_irq[0] = irq_create_mapping(parent, acpi_liointc->cascade[0]);
+	parent_irq[1] = irq_create_mapping(parent, acpi_liointc->cascade[1]);
+
+	domain_handle = irq_domain_alloc_fwnode((phys_addr_t *)acpi_liointc);
+	if (!domain_handle) {
+		pr_err("Unable to allocate domain handle\n");
+		return -ENOMEM;
+	}
+	ret = liointc_init(acpi_liointc->address, acpi_liointc->size,
+			   1, domain_handle, NULL);
+	if (ret)
+		irq_domain_free_fwnode(domain_handle);
+
+	return ret;
+}
+#endif