Merge tag 'pm-for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:

 - Implementation of opportunistic suspend (autosleep) and user space
   interface for manipulating wakeup sources.

 - Hibernate updates from Bojan Smojver and Minho Ban.

 - Updates of the runtime PM core and generic PM domains framework
   related to PM QoS.

 - Assorted fixes.

* tag 'pm-for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (25 commits)
  epoll: Fix user space breakage related to EPOLLWAKEUP
  PM / Domains: Make it possible to add devices to inactive domains
  PM / Hibernate: Use get_gendisk to verify partition if resume_file is integer format
  PM / Domains: Fix computation of maximum domain off time
  PM / Domains: Fix link checking when add subdomain
  PM / Sleep: User space wakeup sources garbage collector Kconfig option
  PM / Sleep: Make the limit of user space wakeup sources configurable
  PM / Documentation: suspend-and-cpuhotplug.txt: Fix typo
  PM / Domains: Cache device stop and domain power off governor results, v3
  PM / Domains: Make device removal more straightforward
  PM / Sleep: Fix a mistake in a conditional in autosleep_store()
  epoll: Add a flag, EPOLLWAKEUP, to prevent suspend while epoll events are ready
  PM / QoS: Create device constraints objects on notifier registration
  PM / Runtime: Remove device fields related to suspend time, v2
  PM / Domains: Rework default domain power off governor function, v2
  PM / Domains: Rework default device stop governor function, v2
  PM / Sleep: Add user space interface for manipulating wakeup sources, v3
  PM / Sleep: Add "prevent autosleep time" statistics to wakeup sources
  PM / Sleep: Implement opportunistic sleep, v2
  PM / Sleep: Add wakeup_source_activate and wakeup_source_deactivate tracepoints
  ...

1 files changed, 127 insertions, 0 deletions

diff --git a/kernel/power/autosleep.c b/kernel/power/autosleep.c
new file mode 100644
index 00000000000..ca304046d9e
--- /dev/null
+++ b/kernel/power/autosleep.c
@@ -0,0 +1,127 @@
+/*
+ * 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)) {
+		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 (!work_pending(&suspend_work) && 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;
+}