PM / Wakeup: Introduce wakeup source objects and event statistics (v3)

Introduce struct wakeup_source for representing system wakeup sources
within the kernel and for collecting statistics related to them.
Make the recently introduced helper functions pm_wakeup_event(),
pm_stay_awake() and pm_relax() use struct wakeup_source objects
internally, so that wakeup statistics associated with wakeup devices
can be collected and reported in a consistent way (the definition of
pm_relax() is changed, which is harmless, because this function is
not called directly by anyone yet).  Introduce new wakeup-related
sysfs device attributes in /sys/devices/.../power for reporting the
device wakeup statistics.

Change the global wakeup events counters event_count and
events_in_progress into atomic variables, so that it is not necessary
to acquire a global spinlock in pm_wakeup_event(), pm_stay_awake()
and pm_relax(), which should allow us to avoid lock contention in
these functions on SMP systems with many wakeup devices.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 70 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power
index 6123c523bfd7..6bb2dd3c3a71 100644
--- a/Documentation/ABI/testing/sysfs-devices-power
+++ b/Documentation/ABI/testing/sysfs-devices-power
@@ -77,3 +77,73 @@ Description:
                 devices this attribute is set to "enabled" by bus type code or
                 device drivers and in that cases it should be safe to leave the
                 default value.
+
+What:           /sys/devices/.../power/wakeup_count
+Date:           September 2010
+Contact:        Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+                The /sys/devices/.../wakeup_count attribute contains the number
+                of signaled wakeup events associated with the device.  This
+                attribute is read-only.  If the device is not enabled to wake up
+                the system from sleep states, this attribute is empty.
+
+What:           /sys/devices/.../power/wakeup_active_count
+Date:           September 2010
+Contact:        Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+                The /sys/devices/.../wakeup_active_count attribute contains the
+                number of times the processing of wakeup events associated with
+                the device was completed (at the kernel level).  This attribute
+                is read-only.  If the device is not enabled to wake up the
+                system from sleep states, this attribute is empty.
+
+What:           /sys/devices/.../power/wakeup_hit_count
+Date:           September 2010
+Contact:        Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+                The /sys/devices/.../wakeup_hit_count attribute contains the
+                number of times the processing of a wakeup event associated with
+                the device might prevent the system from entering a sleep state.
+                This attribute is read-only.  If the device is not enabled to
+                wake up the system from sleep states, this attribute is empty.
+
+What:           /sys/devices/.../power/wakeup_active
+Date:           September 2010
+Contact:        Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+                The /sys/devices/.../wakeup_active attribute contains either 1,
+                or 0, depending on whether or not a wakeup event associated with
+                the device is being processed (1).  This attribute is read-only.
+                If the device is not enabled to wake up the system from sleep
+                states, this attribute is empty.
+
+What:           /sys/devices/.../power/wakeup_total_time_ms
+Date:           September 2010
+Contact:        Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+                The /sys/devices/.../wakeup_total_time_ms attribute contains
+                the total time of processing wakeup events associated with the
+                device, in milliseconds.  This attribute is read-only.  If the
+                device is not enabled to wake up the system from sleep states,
+                this attribute is empty.
+
+What:           /sys/devices/.../power/wakeup_max_time_ms
+Date:           September 2010
+Contact:        Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+                The /sys/devices/.../wakeup_max_time_ms attribute contains
+                the maximum time of processing a single wakeup event associated
+                with the device, in milliseconds.  This attribute is read-only.
+                If the device is not enabled to wake up the system from sleep
+                states, this attribute is empty.
+
+What:           /sys/devices/.../power/wakeup_last_time_ms
+Date:           September 2010
+Contact:        Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+                The /sys/devices/.../wakeup_last_time_ms attribute contains
+                the value of the monotonic clock corresponding to the time of
+                signaling the last wakeup event associated with the device, in
+                milliseconds.  This attribute is read-only.  If the device is
+                not enabled to wake up the system from sleep states, this
+                attribute is empty.