irqchip/loongson-pch-lpc: Extract non-ACPI-related code from ACPI init

A lot of code can be shared between the existing ACPI init flow with the
upcoming OF init flow.

Extract it into a dedicated function.

The re-ordering of parent interrupt allocation requires the architecture
code to reserve legacy interrupts from the dynamic allocation by overriding
arch_dynirq_lower_bound(), otherwise the parent of LPC irqchip will be
allocated in the intended static range of LPC interrupts, which leads to
allocation failure of LPC interrupts.

Co-developed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Link: https://patch.msgid.link/20260321092032.3502701-5-zhengxingda@iscas.ac.cn

1 files changed, 37 insertions, 20 deletions

diff --git a/drivers/irqchip/irq-loongson-pch-lpc.c b/drivers/irqchip/irq-loongson-pch-lpc.c
index 3ad46ec94e3c..2bb6659e9a93 100644
--- a/drivers/irqchip/irq-loongson-pch-lpc.c
+++ b/drivers/irqchip/irq-loongson-pch-lpc.c
@@ -175,13 +175,10 @@ static struct syscore pch_lpc_syscore = {
 	.ops = &pch_lpc_syscore_ops,
 };
 
-int __init pch_lpc_acpi_init(struct irq_domain *parent,
-					struct acpi_madt_lpc_pic *acpi_pchlpc)
+static int __init pch_lpc_init(phys_addr_t addr, unsigned long size,
+			       struct fwnode_handle *irq_handle, int parent_irq)
 {
-	int parent_irq;
 	struct pch_lpc *priv;
-	struct irq_fwspec fwspec;
-	struct fwnode_handle *irq_handle;
 
 	priv = kzalloc_obj(*priv);
 	if (!priv)
@@ -189,7 +186,7 @@ int __init pch_lpc_acpi_init(struct irq_domain *parent,
 
 	raw_spin_lock_init(&priv->lpc_lock);
 
-	priv->base = ioremap(acpi_pchlpc->address, acpi_pchlpc->size);
+	priv->base = ioremap(addr, size);
 	if (!priv->base)
 		goto free_priv;
 
@@ -198,12 +195,6 @@ int __init pch_lpc_acpi_init(struct irq_domain *parent,
 		goto iounmap_base;
 	}
 
-	irq_handle = irq_domain_alloc_named_fwnode("lpcintc");
-	if (!irq_handle) {
-		pr_err("Unable to allocate domain handle\n");
-		goto iounmap_base;
-	}
-
 	/*
 	 * The LPC interrupt controller is a legacy i8259-compatible device,
 	 * which requires a static 1:1 mapping for IRQs 0-15.
@@ -213,15 +204,10 @@ int __init pch_lpc_acpi_init(struct irq_domain *parent,
 						    &pch_lpc_domain_ops, priv);
 	if (!priv->lpc_domain) {
 		pr_err("Failed to create IRQ domain\n");
-		goto free_irq_handle;
+		goto iounmap_base;
 	}
 	pch_lpc_reset(priv);
 
-	fwspec.fwnode = parent->fwnode;
-	fwspec.param[0] = acpi_pchlpc->cascade + GSI_MIN_PCH_IRQ;
-	fwspec.param[1] = IRQ_TYPE_LEVEL_HIGH;
-	fwspec.param_count = 2;
-	parent_irq = irq_create_fwspec_mapping(&fwspec);
 	irq_set_chained_handler_and_data(parent_irq, lpc_irq_dispatch, priv);
 
 	pch_lpc_priv = priv;
@@ -230,8 +216,6 @@ int __init pch_lpc_acpi_init(struct irq_domain *parent,
 
 	return 0;
 
-free_irq_handle:
-	irq_domain_free_fwnode(irq_handle);
 iounmap_base:
 	iounmap(priv->base);
 free_priv:
@@ -239,3 +223,36 @@ free_priv:
 
 	return -ENOMEM;
 }
+
+int __init pch_lpc_acpi_init(struct irq_domain *parent, struct acpi_madt_lpc_pic *acpi_pchlpc)
+{
+	struct fwnode_handle *irq_handle;
+	struct irq_fwspec fwspec;
+	int parent_irq, ret;
+
+	irq_handle = irq_domain_alloc_named_fwnode("lpcintc");
+	if (!irq_handle) {
+		pr_err("Unable to allocate domain handle\n");
+		return -ENOMEM;
+	}
+
+	fwspec.fwnode = parent->fwnode;
+	fwspec.param[0] = acpi_pchlpc->cascade + GSI_MIN_PCH_IRQ;
+	fwspec.param[1] = IRQ_TYPE_LEVEL_HIGH;
+	fwspec.param_count = 2;
+	parent_irq = irq_create_fwspec_mapping(&fwspec);
+	if (parent_irq <= 0) {
+		pr_err("Unable to map LPC parent interrupt\n");
+		irq_domain_free_fwnode(irq_handle);
+		return -ENOMEM;
+	}
+
+	ret = pch_lpc_init(acpi_pchlpc->address, acpi_pchlpc->size, irq_handle, parent_irq);
+	if (ret) {
+		irq_dispose_mapping(parent_irq);
+		irq_domain_free_fwnode(irq_handle);
+		return ret;
+	}
+
+	return 0;
+}