[PATCH] LoongArch: Don't disable EIOINTC master core

[Huacai Chen]

This patch fix a CPU hotplug issue. The EIOINTC master core (the first
core of an EIOINTC node) should not be disabled at runtime, since it has
the responsibility of dispatching I/O interrupts.

Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
 arch/loongarch/kernel/smp.c            | 9 +++++++++
 drivers/irqchip/irq-loongson-eiointc.c | 5 +++++
 2 files changed, 14 insertions(+)

diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c
index 09743103d9b3..54901716f8de 100644
--- a/arch/loongarch/kernel/smp.c
+++ b/arch/loongarch/kernel/smp.c
@@ -242,9 +242,18 @@ void loongson3_smp_finish(void)
 
 static bool io_master(int cpu)
 {
+	int i, node, master;
+
 	if (cpu == 0)
 		return true;
 
+	for (i = 1; i < loongson_sysconf.nr_io_pics; i++) {
+		node = eiointc_get_node(i);
+		master = cpu_number_map(node * CORES_PER_EIO_NODE);
+		if (cpu == master)
+			return true;
+	}
+
 	return false;
 }
 
diff --git a/drivers/irqchip/irq-loongson-eiointc.c b/drivers/irqchip/irq-loongson-eiointc.c
index 170dbc96c7d3..6c99a2ff95f5 100644
--- a/drivers/irqchip/irq-loongson-eiointc.c
+++ b/drivers/irqchip/irq-loongson-eiointc.c
@@ -56,6 +56,11 @@ static void eiointc_enable(void)
 	iocsr_write64(misc, LOONGARCH_IOCSR_MISC_FUNC);
 }
 
+int eiointc_get_node(int id)
+{
+	return eiointc_priv[id]->node;
+}
+
 static int cpu_to_eio_node(int cpu)
 {
 	return cpu_logical_map(cpu) / CORES_PER_EIO_NODE;
-- 
2.31.1