LoongArch: Add machine_kexec_mask_interrupts() implementation

Commit 863a320 ("LoongArch: Mask all interrupts during
kexec/kdump") is backported to LTS branches, but they lack a generic
machine_kexec_mask_interrupts() implementation, so add an arch-specific
one.

Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: chenhuacai

arch/loongarch/kernel/machine_kexec.c

@@ -136,6 +136,28 @@ void kexec_reboot(void)
 	BUG();
 }
 
+static void machine_kexec_mask_interrupts(void)
+{
+	unsigned int i;
+	struct irq_desc *desc;
+
+	for_each_irq_desc(i, desc) {
+		struct irq_chip *chip;
+
+		chip = irq_desc_get_chip(desc);
+		if (!chip)
+			continue;
+
+		if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
+			chip->irq_eoi(&desc->irq_data);
+
+		if (chip->irq_mask)
+			chip->irq_mask(&desc->irq_data);
+
+		if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
+			chip->irq_disable(&desc->irq_data);
+	}
+}
 
 #ifdef CONFIG_SMP
 static void kexec_shutdown_secondary(void *regs)