diff --git a/arch/mips/sibyte/sb1250/irq.c b/arch/mips/sibyte/sb1250/irq.c
index b9f1ff420fefae35b8297f1ae05a1c18cb08edaf..589537bfcc3d11b3cc66cc26db44e450492b0734 100644
--- a/arch/mips/sibyte/sb1250/irq.c
+++ b/arch/mips/sibyte/sb1250/irq.c
@@ -53,7 +53,7 @@ static void disable_sb1250_irq(unsigned int irq);
 static unsigned int startup_sb1250_irq(unsigned int irq);
 static void ack_sb1250_irq(unsigned int irq);
 #ifdef CONFIG_SMP
-static void sb1250_set_affinity(unsigned int irq, unsigned long mask);
+static void sb1250_set_affinity(unsigned int irq, cpumask_t mask);
 #endif
 
 #ifdef CONFIG_SIBYTE_HAS_LDT
@@ -117,23 +117,16 @@ void sb1250_unmask_irq(int cpu, int irq)
 }
 
 #ifdef CONFIG_SMP
-static void sb1250_set_affinity(unsigned int irq, unsigned long mask)
+static void sb1250_set_affinity(unsigned int irq, cpumask_t mask)
 {
 	int i = 0, old_cpu, cpu, int_on;
 	u64 cur_ints;
 	irq_desc_t *desc = irq_desc + irq;
 	unsigned long flags;
 
-	while (mask) {
-		if (mask & 1) {
-			mask >>= 1;
-			break;
-		}
-		mask >>= 1;
-		i++;
-	}
+	i = first_cpu(mask);
 
-	if (mask) {
+	if (cpus_weight(mask) > 1) {
 		printk("attempted to set irq affinity for irq %d to multiple CPUs\n", irq);
 		return;
 	}