Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / kernel / power / autosleep.c

diff --git a/kernel/kernel/power/autosleep.c b/kernel/kernel/power/autosleep.c
new file mode 100644 (file)
index 0000000..9012ecf
--- /dev/null
+++ b/kernel/kernel/power/autosleep.c
@@ -0,0 +1,128 @@
+/*
+ * kernel/power/autosleep.c
+ *
+ * Opportunistic sleep support.
+ *
+ * Copyright (C) 2012 Rafael J. Wysocki <rjw@sisk.pl>
+ */
+
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/pm_wakeup.h>
+
+#include "power.h"
+
+static suspend_state_t autosleep_state;
+static struct workqueue_struct *autosleep_wq;
+/*
+ * Note: it is only safe to mutex_lock(&autosleep_lock) if a wakeup_source
+ * is active, otherwise a deadlock with try_to_suspend() is possible.
+ * Alternatively mutex_lock_interruptible() can be used.  This will then fail
+ * if an auto_sleep cycle tries to freeze processes.
+ */
+static DEFINE_MUTEX(autosleep_lock);
+static struct wakeup_source *autosleep_ws;
+
+static void try_to_suspend(struct work_struct *work)
+{
+       unsigned int initial_count, final_count;
+
+       if (!pm_get_wakeup_count(&initial_count, true))
+               goto out;
+
+       mutex_lock(&autosleep_lock);
+
+       if (!pm_save_wakeup_count(initial_count) ||
+               system_state != SYSTEM_RUNNING) {
+               mutex_unlock(&autosleep_lock);
+               goto out;
+       }
+
+       if (autosleep_state == PM_SUSPEND_ON) {
+               mutex_unlock(&autosleep_lock);
+               return;
+       }
+       if (autosleep_state >= PM_SUSPEND_MAX)
+               hibernate();
+       else
+               pm_suspend(autosleep_state);
+
+       mutex_unlock(&autosleep_lock);
+
+       if (!pm_get_wakeup_count(&final_count, false))
+               goto out;
+
+       /*
+        * If the wakeup occured for an unknown reason, wait to prevent the
+        * system from trying to suspend and waking up in a tight loop.
+        */
+       if (final_count == initial_count)
+               schedule_timeout_uninterruptible(HZ / 2);
+
+ out:
+       queue_up_suspend_work();
+}
+
+static DECLARE_WORK(suspend_work, try_to_suspend);
+
+void queue_up_suspend_work(void)
+{
+       if (autosleep_state > PM_SUSPEND_ON)
+               queue_work(autosleep_wq, &suspend_work);
+}
+
+suspend_state_t pm_autosleep_state(void)
+{
+       return autosleep_state;
+}
+
+int pm_autosleep_lock(void)
+{
+       return mutex_lock_interruptible(&autosleep_lock);
+}
+
+void pm_autosleep_unlock(void)
+{
+       mutex_unlock(&autosleep_lock);
+}
+
+int pm_autosleep_set_state(suspend_state_t state)
+{
+
+#ifndef CONFIG_HIBERNATION
+       if (state >= PM_SUSPEND_MAX)
+               return -EINVAL;
+#endif
+
+       __pm_stay_awake(autosleep_ws);
+
+       mutex_lock(&autosleep_lock);
+
+       autosleep_state = state;
+
+       __pm_relax(autosleep_ws);
+
+       if (state > PM_SUSPEND_ON) {
+               pm_wakep_autosleep_enabled(true);
+               queue_up_suspend_work();
+       } else {
+               pm_wakep_autosleep_enabled(false);
+       }
+
+       mutex_unlock(&autosleep_lock);
+       return 0;
+}
+
+int __init pm_autosleep_init(void)
+{
+       autosleep_ws = wakeup_source_register("autosleep");
+       if (!autosleep_ws)
+               return -ENOMEM;
+
+       autosleep_wq = alloc_ordered_workqueue("autosleep", 0);
+       if (autosleep_wq)
+               return 0;
+
+       wakeup_source_unregister(autosleep_ws);
+       return -ENOMEM;
+}