return;
}
ACCESS_ONCE(prev->next) = node;
- smp_wmb();
- /* Wait until the lock holder passes the lock down */
- while (!ACCESS_ONCE(node->locked))
+ /*
+ * Wait until the lock holder passes the lock down.
+ * Using smp_load_acquire() provides a memory barrier that
+ * ensures subsequent operations happen after the lock is acquired.
+ */
+ while (!(smp_load_acquire(&node->locked)))
arch_mutex_cpu_relax();
}
while (!(next = ACCESS_ONCE(node->next)))
arch_mutex_cpu_relax();
}
- ACCESS_ONCE(next->locked) = 1;
- smp_wmb();
+ /*
+ * Pass lock to next waiter.
+ * smp_store_release() provides a memory barrier to ensure
+ * all operations in the critical section has been completed
+ * before unlocking.
+ */
+ smp_store_release(&next->locked, 1);
}
/*