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, 119 insertions, 2 deletions

diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index e56b4388fe61..8859780817e1 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -210,11 +210,122 @@ static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store);
 static ssize_t wakeup_count_show(struct device *dev,
                                 struct device_attribute *attr, char *buf)
 {
-        return sprintf(buf, "%lu\n", dev->power.wakeup_count);
+        unsigned long count = 0;
+        bool enabled = false;
+
+        spin_lock_irq(&dev->power.lock);
+        if (dev->power.wakeup) {
+                count = dev->power.wakeup->event_count;
+                enabled = true;
+        }
+        spin_unlock_irq(&dev->power.lock);
+        return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
 }
 
 static DEVICE_ATTR(wakeup_count, 0444, wakeup_count_show, NULL);
-#endif
+
+static ssize_t wakeup_active_count_show(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        unsigned long count = 0;
+        bool enabled = false;
+
+        spin_lock_irq(&dev->power.lock);
+        if (dev->power.wakeup) {
+                count = dev->power.wakeup->active_count;
+                enabled = true;
+        }
+        spin_unlock_irq(&dev->power.lock);
+        return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR(wakeup_active_count, 0444, wakeup_active_count_show, NULL);
+
+static ssize_t wakeup_hit_count_show(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        unsigned long count = 0;
+        bool enabled = false;
+
+        spin_lock_irq(&dev->power.lock);
+        if (dev->power.wakeup) {
+                count = dev->power.wakeup->hit_count;
+                enabled = true;
+        }
+        spin_unlock_irq(&dev->power.lock);
+        return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR(wakeup_hit_count, 0444, wakeup_hit_count_show, NULL);
+
+static ssize_t wakeup_active_show(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        unsigned int active = 0;
+        bool enabled = false;
+
+        spin_lock_irq(&dev->power.lock);
+        if (dev->power.wakeup) {
+                active = dev->power.wakeup->active;
+                enabled = true;
+        }
+        spin_unlock_irq(&dev->power.lock);
+        return enabled ? sprintf(buf, "%u\n", active) : sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR(wakeup_active, 0444, wakeup_active_show, NULL);
+
+static ssize_t wakeup_total_time_show(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        s64 msec = 0;
+        bool enabled = false;
+
+        spin_lock_irq(&dev->power.lock);
+        if (dev->power.wakeup) {
+                msec = ktime_to_ms(dev->power.wakeup->total_time);
+                enabled = true;
+        }
+        spin_unlock_irq(&dev->power.lock);
+        return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR(wakeup_total_time_ms, 0444, wakeup_total_time_show, NULL);
+
+static ssize_t wakeup_max_time_show(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        s64 msec = 0;
+        bool enabled = false;
+
+        spin_lock_irq(&dev->power.lock);
+        if (dev->power.wakeup) {
+                msec = ktime_to_ms(dev->power.wakeup->max_time);
+                enabled = true;
+        }
+        spin_unlock_irq(&dev->power.lock);
+        return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR(wakeup_max_time_ms, 0444, wakeup_max_time_show, NULL);
+
+static ssize_t wakeup_last_time_show(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        s64 msec = 0;
+        bool enabled = false;
+
+        spin_lock_irq(&dev->power.lock);
+        if (dev->power.wakeup) {
+                msec = ktime_to_ms(dev->power.wakeup->last_time);
+                enabled = true;
+        }
+        spin_unlock_irq(&dev->power.lock);
+        return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR(wakeup_last_time_ms, 0444, wakeup_last_time_show, NULL);
+#endif /* CONFIG_PM_SLEEP */
 
 #ifdef CONFIG_PM_ADVANCED_DEBUG
 #ifdef CONFIG_PM_RUNTIME
@@ -288,6 +399,12 @@ static struct attribute * power_attrs[] = {
         &dev_attr_wakeup.attr,
 #ifdef CONFIG_PM_SLEEP
         &dev_attr_wakeup_count.attr,
+        &dev_attr_wakeup_active_count.attr,
+        &dev_attr_wakeup_hit_count.attr,
+        &dev_attr_wakeup_active.attr,
+        &dev_attr_wakeup_total_time_ms.attr,
+        &dev_attr_wakeup_max_time_ms.attr,
+        &dev_attr_wakeup_last_time_ms.attr,
 #endif
 #ifdef CONFIG_PM_ADVANCED_DEBUG
         &dev_attr_async.attr,