1 files changed, 4 insertions, 2 deletions

diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index 6eba6fd8a8ec..8ac2097f13d4 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -196,7 +196,7 @@ asmlinkage void do_softirq(void)
  * ext_int_hash[index] is the list head for all external interrupts that hash
  * to this index.
  */
-static struct hlist_head ext_int_hash[256];
+static struct hlist_head ext_int_hash[32] ____cacheline_aligned;
 
 struct ext_int_info {
         ext_int_handler_t handler;
@@ -210,7 +210,9 @@ static DEFINE_SPINLOCK(ext_int_hash_lock);
 
 static inline int ext_hash(u16 code)
 {
-        return (code + (code >> 9)) & 0xff;
+        BUILD_BUG_ON(!is_power_of_2(ARRAY_SIZE(ext_int_hash)));
+
+        return (code + (code >> 9)) & (ARRAY_SIZE(ext_int_hash) - 1);
 }
 
 int register_external_interrupt(u16 code, ext_int_handler_t handler)