drivers/irqchip: xtensa-mx: fix mask and unmask

xtensa_irq_mask and xtensa_irq_unmask don't do the right thing when
called for the first two external IRQs. Treat these IRQs as per-CPU
IRQs.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
diff --git a/drivers/irqchip/irq-xtensa-mx.c b/drivers/irqchip/irq-xtensa-mx.c
index 0bd3fe3..2793333 100644
--- a/drivers/irqchip/irq-xtensa-mx.c
+++ b/drivers/irqchip/irq-xtensa-mx.c
@@ -71,14 +71,17 @@ static void xtensa_mx_irq_mask(struct irq_data *d)
 	unsigned int mask = 1u << d->hwirq;
 
 	if (mask & (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
-				XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
-		set_er(1u << (xtensa_get_ext_irq_no(d->hwirq) -
-					HW_IRQ_MX_BASE), MIENG);
-	} else {
-		mask = __this_cpu_read(cached_irq_mask) & ~mask;
-		__this_cpu_write(cached_irq_mask, mask);
-		xtensa_set_sr(mask, intenable);
+		    XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
+		unsigned int ext_irq = xtensa_get_ext_irq_no(d->hwirq);
+
+		if (ext_irq >= HW_IRQ_MX_BASE) {
+			set_er(1u << (ext_irq - HW_IRQ_MX_BASE), MIENG);
+			return;
+		}
 	}
+	mask = __this_cpu_read(cached_irq_mask) & ~mask;
+	__this_cpu_write(cached_irq_mask, mask);
+	xtensa_set_sr(mask, intenable);
 }
 
 static void xtensa_mx_irq_unmask(struct irq_data *d)
@@ -86,14 +89,17 @@ static void xtensa_mx_irq_unmask(struct irq_data *d)
 	unsigned int mask = 1u << d->hwirq;
 
 	if (mask & (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
-				XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
-		set_er(1u << (xtensa_get_ext_irq_no(d->hwirq) -
-					HW_IRQ_MX_BASE), MIENGSET);
-	} else {
-		mask |= __this_cpu_read(cached_irq_mask);
-		__this_cpu_write(cached_irq_mask, mask);
-		xtensa_set_sr(mask, intenable);
+		    XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
+		unsigned int ext_irq = xtensa_get_ext_irq_no(d->hwirq);
+
+		if (ext_irq >= HW_IRQ_MX_BASE) {
+			set_er(1u << (ext_irq - HW_IRQ_MX_BASE), MIENGSET);
+			return;
+		}
 	}
+	mask |= __this_cpu_read(cached_irq_mask);
+	__this_cpu_write(cached_irq_mask, mask);
+	xtensa_set_sr(mask, intenable);
 }
 
 static void xtensa_mx_irq_enable(struct irq_data *d)