Merge branch 'devel'

[palacios.git] / kitten / kernel / waitq.c

diff --git a/kitten/kernel/waitq.c b/kitten/kernel/waitq.c
new file mode 100644 (file)
index 0000000..80f5de9
--- /dev/null
+++ b/kitten/kernel/waitq.c
@@ -0,0 +1,89 @@
+#include <lwk/kernel.h>
+#include <lwk/waitq.h>
+#include <lwk/sched.h>
+
+void
+waitq_init(waitq_t *waitq)
+{
+       spin_lock_init(&waitq->lock);
+       list_head_init(&waitq->waitq);
+}
+
+void
+waitq_init_entry(waitq_entry_t *entry, struct task_struct *task)
+{
+       entry->task = task;
+       list_head_init(&entry->link);
+}
+
+bool
+waitq_active(waitq_t *waitq)
+{
+       bool active;
+       unsigned long irqstate;
+
+       spin_lock_irqsave(&waitq->lock, irqstate);
+       active = !list_empty(&waitq->waitq);
+       spin_unlock_irqrestore(&waitq->lock, irqstate);
+
+       return active;
+}
+
+void
+waitq_add_entry(waitq_t *waitq, waitq_entry_t *entry)
+{
+       unsigned long irqstate;
+
+       spin_lock_irqsave(&waitq->lock, irqstate);
+       BUG_ON(!list_empty(&entry->link));
+       list_add(&entry->link, &waitq->waitq);
+       spin_unlock_irqrestore(&waitq->lock, irqstate);
+}
+
+void
+waitq_remove_entry(waitq_t *waitq, waitq_entry_t *entry)
+{
+       unsigned long irqstate;
+
+       spin_lock_irqsave(&waitq->lock, irqstate);
+       BUG_ON(list_empty(&entry->link));
+       list_del_init(&entry->link);
+       spin_unlock_irqrestore(&waitq->lock, irqstate);
+}
+
+void
+waitq_prepare_to_wait(waitq_t *waitq, waitq_entry_t *entry, taskstate_t state)
+{
+       unsigned long irqstate;
+
+       spin_lock_irqsave(&waitq->lock, irqstate);
+       if (list_empty(&entry->link))
+               list_add(&entry->link, &waitq->waitq);
+       set_mb(entry->task->state, state);
+       spin_unlock_irqrestore(&waitq->lock, irqstate);
+}
+
+void
+waitq_finish_wait(waitq_t *waitq, waitq_entry_t *entry)
+{
+       set_mb(entry->task->state, TASKSTATE_READY);
+       waitq_remove_entry(waitq, entry);
+}
+
+void
+waitq_wakeup(waitq_t *waitq)
+{
+       unsigned long irqstate;
+       struct list_head *tmp;
+       waitq_entry_t *entry;
+
+       spin_lock_irqsave(&waitq->lock, irqstate);
+       list_for_each(tmp, &waitq->waitq) {
+               entry  = list_entry(tmp, waitq_entry_t, link);
+               sched_wakeup_task(
+                       entry->task,
+                       (TASKSTATE_UNINTERRUPTIBLE | TASKSTATE_INTERRUPTIBLE)
+               );
+       }
+       spin_unlock_irqrestore(&waitq->lock, irqstate);
+}