irqchip/loongson-pch-pic: Add ACPI init support

PCH-PIC/PCH-MSI stands for "Interrupt Controller" that described in
Section 5 of "Loongson 7A1000 Bridge User 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/1658314292-35346-9-git-send-email-lvjianmin@loongson.cn

arch/loongarch/include/asm/irq.h

@@ -116,8 +116,9 @@ int pch_lpc_acpi_init(struct irq_domain *parent,
 					struct acpi_madt_lpc_pic *acpi_pchlpc);
 struct irq_domain *pch_msi_acpi_init(struct irq_domain *parent,
 					struct acpi_madt_msi_pic *acpi_pchmsi);
-struct irq_domain *pch_pic_acpi_init(struct irq_domain *parent,
+int pch_pic_acpi_init(struct irq_domain *parent,
 					struct acpi_madt_bio_pic *acpi_pchpic);
+int find_pch_pic(u32 gsi);
 
 extern struct acpi_madt_lio_pic *acpi_liointc;
 extern struct acpi_madt_eio_pic *acpi_eiointc[MAX_IO_PICS];
@@ -131,7 +132,7 @@ extern struct irq_domain *cpu_domain;
 extern struct irq_domain *liointc_domain;
 extern struct fwnode_handle *pch_lpc_handle;
 extern struct irq_domain *pch_msi_domain[MAX_IO_PICS];
-extern struct irq_domain *pch_pic_domain[MAX_IO_PICS];
+extern struct fwnode_handle *pch_pic_handle[MAX_IO_PICS];
 
 extern irqreturn_t loongson3_ipi_interrupt(int irq, void *dev);
 

arch/loongarch/kernel/irq.c

@@ -28,7 +28,6 @@ EXPORT_PER_CPU_SYMBOL(irq_stat);
 struct irq_domain *cpu_domain;
 struct irq_domain *liointc_domain;
 struct irq_domain *pch_msi_domain[MAX_IO_PICS];
-struct irq_domain *pch_pic_domain[MAX_IO_PICS];
 
 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

@@ -7,7 +7,7 @@
 #define NR_MIPS_CPU_IRQS	8
 #define NR_MAX_CHAINED_IRQS	40 /* Chained IRQs means those not directly used by devices */
 #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
 
 #include <asm/mach-generic/irq.h>

drivers/irqchip/Kconfig

@@ -574,7 +574,7 @@ config LOONGSON_HTVEC
 
 config LOONGSON_PCH_PIC
 	bool "Loongson PCH PIC Controller"
-	depends on MACH_LOONGSON64 || COMPILE_TEST
+	depends on MACH_LOONGSON64
 	default MACH_LOONGSON64
 	select IRQ_DOMAIN_HIERARCHY
 	select IRQ_FASTEOI_HIERARCHY_HANDLERS

drivers/irqchip/irq-loongson-pch-pic.c

@@ -33,13 +33,40 @@
 #define PIC_REG_IDX(irq_id)	((irq_id) / PIC_COUNT_PER_REG)
 #define PIC_REG_BIT(irq_id)	((irq_id) % PIC_COUNT_PER_REG)
 
+static int nr_pics;
+
 struct pch_pic {
 	void __iomem		*base;
 	struct irq_domain	*pic_domain;
 	u32			ht_vec_base;
 	raw_spinlock_t		pic_lock;
+	u32			vec_count;
+	u32			gsi_base;
 };
 
+static struct pch_pic *pch_pic_priv[MAX_IO_PICS];
+
+struct fwnode_handle *pch_pic_handle[MAX_IO_PICS];
+
+int find_pch_pic(u32 gsi)
+{
+	int i;
+
+	/* Find the PCH_PIC that manages this GSI. */
+	for (i = 0; i < MAX_IO_PICS; i++) {
+		struct pch_pic *priv = pch_pic_priv[i];
+
+		if (!priv)
+			return -1;
+
+		if (gsi >= priv->gsi_base && gsi < (priv->gsi_base + priv->vec_count))
+			return i;
+	}
+
+	pr_err("ERROR: Unable to locate PCH_PIC for GSI %d\n", gsi);
+	return -1;
+}
+
 static void pch_pic_bitset(struct pch_pic *priv, int offset, int bit)
 {
 	u32 reg;
@@ -139,6 +166,28 @@ static struct irq_chip pch_pic_irq_chip = {
 	.irq_set_type		= pch_pic_set_type,
 };
 
+static int pch_pic_domain_translate(struct irq_domain *d,
+					struct irq_fwspec *fwspec,
+					unsigned long *hwirq,
+					unsigned int *type)
+{
+	struct pch_pic *priv = d->host_data;
+	struct device_node *of_node = to_of_node(fwspec->fwnode);
+
+	if (fwspec->param_count < 1)
+		return -EINVAL;
+
+	if (of_node) {
+		*hwirq = fwspec->param[0] + priv->ht_vec_base;
+		*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
+	} else {
+		*hwirq = fwspec->param[0] - priv->gsi_base;
+		*type = IRQ_TYPE_NONE;
+	}
+
+	return 0;
+}
+
 static int pch_pic_alloc(struct irq_domain *domain, unsigned int virq,
 			      unsigned int nr_irqs, void *arg)
 {
@@ -149,13 +198,13 @@ static int pch_pic_alloc(struct irq_domain *domain, unsigned int virq,
 	struct irq_fwspec parent_fwspec;
 	struct pch_pic *priv = domain->host_data;
 
-	err = irq_domain_translate_twocell(domain, fwspec, &hwirq, &type);
+	err = pch_pic_domain_translate(domain, fwspec, &hwirq, &type);
 	if (err)
 		return err;
 
 	parent_fwspec.fwnode = domain->parent->fwnode;
 	parent_fwspec.param_count = 1;
-	parent_fwspec.param[0] = hwirq + priv->ht_vec_base;
+	parent_fwspec.param[0] = hwirq;
 
 	err = irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
 	if (err)
@@ -170,7 +219,7 @@ static int pch_pic_alloc(struct irq_domain *domain, unsigned int virq,
 }
 
 static const struct irq_domain_ops pch_pic_domain_ops = {
-	.translate	= irq_domain_translate_twocell,
+	.translate	= pch_pic_domain_translate,
 	.alloc		= pch_pic_alloc,
 	.free		= irq_domain_free_irqs_parent,
 };
@@ -180,7 +229,7 @@ static void pch_pic_reset(struct pch_pic *priv)
 	int i;
 
 	for (i = 0; i < PIC_COUNT; i++) {
-		/* Write vectored ID */
+		/* Write vector ID */
 		writeb(priv->ht_vec_base + i, priv->base + PCH_INT_HTVEC(i));
 		/* Hardcode route to HT0 Lo */
 		writeb(1, priv->base + PCH_INT_ROUTE(i));
@@ -198,50 +247,37 @@ static void pch_pic_reset(struct pch_pic *priv)
 	}
 }
 
-static int pch_pic_of_init(struct device_node *node,
-				struct device_node *parent)
+static int pch_pic_init(phys_addr_t addr, unsigned long size, int vec_base,
+			struct irq_domain *parent_domain, struct fwnode_handle *domain_handle,
+			u32 gsi_base)
 {
 	struct pch_pic *priv;
-	struct irq_domain *parent_domain;
-	int err;
 
 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
 
 	raw_spin_lock_init(&priv->pic_lock);
-	priv->base = of_iomap(node, 0);
-	if (!priv->base) {
-		err = -ENOMEM;
+	priv->base = ioremap(addr, size);
+	if (!priv->base)
 		goto free_priv;
-	}
 
-	parent_domain = irq_find_host(parent);
-	if (!parent_domain) {
-		pr_err("Failed to find the parent domain\n");
-		err = -ENXIO;
-		goto iounmap_base;
-	}
-
-	if (of_property_read_u32(node, "loongson,pic-base-vec",
-				&priv->ht_vec_base)) {
-		pr_err("Failed to determine pic-base-vec\n");
-		err = -EINVAL;
-		goto iounmap_base;
-	}
+	priv->ht_vec_base = vec_base;
+	priv->vec_count = ((readq(priv->base) >> 48) & 0xff) + 1;
+	priv->gsi_base = gsi_base;
 
 	priv->pic_domain = irq_domain_create_hierarchy(parent_domain, 0,
-						       PIC_COUNT,
-						       of_node_to_fwnode(node),
-						       &pch_pic_domain_ops,
-						       priv);
+						priv->vec_count, domain_handle,
+						&pch_pic_domain_ops, priv);
+
 	if (!priv->pic_domain) {
 		pr_err("Failed to create IRQ domain\n");
-		err = -ENOMEM;
 		goto iounmap_base;
 	}
 
 	pch_pic_reset(priv);
+	pch_pic_handle[nr_pics] = domain_handle;
+	pch_pic_priv[nr_pics++] = priv;
 
 	return 0;
 
@@ -250,7 +286,86 @@ iounmap_base:
 free_priv:
 	kfree(priv);
 
-	return err;
+	return -EINVAL;
+}
+
+#ifdef CONFIG_OF
+
+static int pch_pic_of_init(struct device_node *node,
+				struct device_node *parent)
+{
+	int err, vec_base;
+	struct resource res;
+	struct irq_domain *parent_domain;
+
+	if (of_address_to_resource(node, 0, &res))
+		return -EINVAL;
+
+	parent_domain = irq_find_host(parent);
+	if (!parent_domain) {
+		pr_err("Failed to find the parent domain\n");
+		return -ENXIO;
+	}
+
+	if (of_property_read_u32(node, "loongson,pic-base-vec", &vec_base)) {
+		pr_err("Failed to determine pic-base-vec\n");
+		return -EINVAL;
+	}
+
+	err = pch_pic_init(res.start, resource_size(&res), vec_base,
+				parent_domain, of_node_to_fwnode(node), 0);
+	if (err < 0)
+		return err;
+
+	return 0;
 }
 
 IRQCHIP_DECLARE(pch_pic, "loongson,pch-pic-1.0", pch_pic_of_init);
+
+#endif
+
+#ifdef CONFIG_ACPI
+static int __init
+pch_lpc_parse_madt(union acpi_subtable_headers *header,
+		       const unsigned long end)
+{
+	struct acpi_madt_lpc_pic *pchlpc_entry = (struct acpi_madt_lpc_pic *)header;
+
+	return pch_lpc_acpi_init(pch_pic_priv[0]->pic_domain, pchlpc_entry);
+}
+
+static int __init acpi_cascade_irqdomain_init(void)
+{
+	acpi_table_parse_madt(ACPI_MADT_TYPE_LPC_PIC,
+			      pch_lpc_parse_madt, 0);
+	return 0;
+}
+
+int __init pch_pic_acpi_init(struct irq_domain *parent,
+					struct acpi_madt_bio_pic *acpi_pchpic)
+{
+	int ret, vec_base;
+	struct fwnode_handle *domain_handle;
+
+	vec_base = acpi_pchpic->gsi_base - GSI_MIN_PCH_IRQ;
+
+	domain_handle = irq_domain_alloc_fwnode((phys_addr_t *)acpi_pchpic);
+	if (!domain_handle) {
+		pr_err("Unable to allocate domain handle\n");
+		return -ENOMEM;
+	}
+
+	ret = pch_pic_init(acpi_pchpic->address, acpi_pchpic->size,
+				vec_base, parent, domain_handle, acpi_pchpic->gsi_base);
+
+	if (ret < 0) {
+		irq_domain_free_fwnode(domain_handle);
+		return ret;
+	}
+
+	if (acpi_pchpic->id == 0)
+		acpi_cascade_irqdomain_init();
+
+	return ret;
+}
+#endif