irqchip/loongson-pch-msi: Prepare get_pch_msi_handle() for AVECINTC

On Loongson-3C6000 and higher systems with AVECINTC irqchip, there may
be multiple PCI segments, but only one PCH-MSI irq domain. In this case,
let get_pch_msi_handle() return the first domain handle.

Co-developed-by: Jianmin Lv <[email protected]>
Signed-off-by: Jianmin Lv <[email protected]>
Co-developed-by: Liupu Wang <[email protected]>
Signed-off-by: Liupu Wang <[email protected]>
Co-developed-by: Huacai Chen <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>
Signed-off-by: Tianyang Zhang <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Link: https://lore.kernel.org/all/[email protected]

Author: zhangtianyang-zty

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

@@ -255,17 +255,17 @@ IRQCHIP_DECLARE(pch_msi, "loongson,pch-msi-1.0", pch_msi_of_init);
 #ifdef CONFIG_ACPI
 struct fwnode_handle *get_pch_msi_handle(int pci_segment)
 {
-	int i;
+	if (cpu_has_avecint)
+		return pch_msi_handle[0];
 
-	for (i = 0; i < MAX_IO_PICS; i++) {
+	for (int i = 0; i < MAX_IO_PICS; i++) {
 		if (msi_group[i].pci_segment == pci_segment)
 			return pch_msi_handle[i];
 	}
-	return NULL;
+	return pch_msi_handle[0];
 }
 
-int __init pch_msi_acpi_init(struct irq_domain *parent,
-					struct acpi_madt_msi_pic *acpi_pchmsi)
+int __init pch_msi_acpi_init(struct irq_domain *parent, struct acpi_madt_msi_pic *acpi_pchmsi)
 {
 	int ret;
 	struct fwnode_handle *domain_handle;