irqchip/loongarch-avec: Add multi-nodes topology support

avecintc_init() enables the Advanced Interrupt Controller (AVEC) of
the boot CPU node, but nothing enables the AVEC on secondary nodes.

Move the enablement to the CPU hotplug callback so that secondary nodes get
the AVEC enabled too. In theory enabling it once per node would be
sufficient, but redundant enabling does no hurt, so keep the code simple
and do it unconditionally.

Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Link: https://lore.kernel.org/all/20250111023704.17285-1-zhangtianyang@loongson.cn

Author: zhangtianyang-zty

drivers/irqchip/irq-loongarch-avec.c

@@ -56,6 +56,15 @@ struct avecintc_data {
 	unsigned int		moving;
 };
 
+static inline void avecintc_enable(void)
+{
+	u64 value;
+
+	value = iocsr_read64(LOONGARCH_IOCSR_MISC_FUNC);
+	value |= IOCSR_MISC_FUNC_AVEC_EN;
+	iocsr_write64(value, LOONGARCH_IOCSR_MISC_FUNC);
+}
+
 static inline void avecintc_ack_irq(struct irq_data *d)
 {
 }
@@ -127,6 +136,8 @@ static int avecintc_cpu_online(unsigned int cpu)
 
 	guard(raw_spinlock)(&loongarch_avec.lock);
 
+	avecintc_enable();
+
 	irq_matrix_online(loongarch_avec.vector_matrix);
 
 	pending_list_init(cpu);
@@ -339,7 +350,6 @@ static int __init irq_matrix_init(void)
 static int __init avecintc_init(struct irq_domain *parent)
 {
 	int ret, parent_irq;
-	unsigned long value;
 
 	raw_spin_lock_init(&loongarch_avec.lock);
 
@@ -378,9 +388,7 @@ static int __init avecintc_init(struct irq_domain *parent)
 				  "irqchip/loongarch/avecintc:starting",
 				  avecintc_cpu_online, avecintc_cpu_offline);
 #endif
-	value = iocsr_read64(LOONGARCH_IOCSR_MISC_FUNC);
-	value |= IOCSR_MISC_FUNC_AVEC_EN;
-	iocsr_write64(value, LOONGARCH_IOCSR_MISC_FUNC);
+	avecintc_enable();
 
 	return ret;