+ u32 curval;
+ int i;
+
+ /*
+ * This will fail and we want it. Some arch implementations do
+ * runtime detection of the futex_atomic_cmpxchg_inatomic()
+ * functionality. We want to know that before we call in any
+ * of the complex code paths. Also we want to prevent
+ * registration of robust lists in that case. NULL is
+ * guaranteed to fault and we get -EFAULT on functional
+ * implementation, the non functional ones will return
+ * -ENOSYS.
+ */
+ curval = cmpxchg_futex_value_locked(NULL, 0, 0);
+ if (curval == -EFAULT)
+ futex_cmpxchg_enabled = 1;
+
+ for (i = 0; i < ARRAY_SIZE(futex_queues); i++) {
+ plist_head_init(&futex_queues[i].chain, &futex_queues[i].lock);
+ spin_lock_init(&futex_queues[i].lock);
+ }