PM / Runtime: Combine runtime PM entry points

This patch (as1424) combines the various public entry points for the
runtime PM routines into three simple functions: one for idle, one for
suspend, and one for resume.  A new bitflag specifies whether or not
to increment or decrement the usage_count field.

The new entry points are named __pm_runtime_idle,
__pm_runtime_suspend, and __pm_runtime_resume, to reflect that they
are trampolines.  Simultaneously, the corresponding internal routines
are renamed to rpm_idle, rpm_suspend, and rpm_resume.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

drivers/base/power/runtime.c

@@ -11,7 +11,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/jiffies.h>
 
-static int __pm_runtime_resume(struct device *dev, int rpmflags);
+static int rpm_resume(struct device *dev, int rpmflags);
 
 /**
  * update_pm_runtime_accounting - Update the time accounting of power states
@@ -107,7 +107,7 @@ static int rpm_check_suspend_allowed(struct device *dev)
 
 
 /**
- * __pm_runtime_idle - Notify device bus type if the device can be suspended.
+ * rpm_idle - Notify device bus type if the device can be suspended.
  * @dev: Device to notify the bus type about.
  * @rpmflags: Flag bits.
  *
@@ -118,7 +118,7 @@ static int rpm_check_suspend_allowed(struct device *dev)
  *
  * This function must be called under dev->power.lock with interrupts disabled.
  */
-static int __pm_runtime_idle(struct device *dev, int rpmflags)
+static int rpm_idle(struct device *dev, int rpmflags)
 	__releases(&dev->power.lock) __acquires(&dev->power.lock)
 {
 	int retval;
@@ -189,23 +189,7 @@ static int __pm_runtime_idle(struct device *dev, int rpmflags)
 }
 
 /**
- * pm_runtime_idle - Notify device bus type if the device can be suspended.
- * @dev: Device to notify the bus type about.
- */
-int pm_runtime_idle(struct device *dev)
-{
-	int retval;
-
-	spin_lock_irq(&dev->power.lock);
-	retval = __pm_runtime_idle(dev, 0);
-	spin_unlock_irq(&dev->power.lock);
-
-	return retval;
-}
-EXPORT_SYMBOL_GPL(pm_runtime_idle);
-
-/**
- * __pm_runtime_suspend - Carry out run-time suspend of given device.
+ * rpm_suspend - Carry out run-time suspend of given device.
  * @dev: Device to suspend.
  * @rpmflags: Flag bits.
  *
@@ -220,7 +204,7 @@ EXPORT_SYMBOL_GPL(pm_runtime_idle);
  *
  * This function must be called under dev->power.lock with interrupts disabled.
  */
-static int __pm_runtime_suspend(struct device *dev, int rpmflags)
+static int rpm_suspend(struct device *dev, int rpmflags)
 	__releases(&dev->power.lock) __acquires(&dev->power.lock)
 {
 	struct device *parent = NULL;
@@ -332,13 +316,13 @@ static int __pm_runtime_suspend(struct device *dev, int rpmflags)
 	wake_up_all(&dev->power.wait_queue);
 
 	if (dev->power.deferred_resume) {
-		__pm_runtime_resume(dev, 0);
+		rpm_resume(dev, 0);
 		retval = -EAGAIN;
 		goto out;
 	}
 
 	if (notify)
-		__pm_runtime_idle(dev, 0);
+		rpm_idle(dev, 0);
 
 	if (parent && !parent->power.ignore_children) {
 		spin_unlock_irq(&dev->power.lock);
@@ -355,23 +339,7 @@ static int __pm_runtime_suspend(struct device *dev, int rpmflags)
 }
 
 /**
- * pm_runtime_suspend - Carry out run-time suspend of given device.
- * @dev: Device to suspend.
- */
-int pm_runtime_suspend(struct device *dev)
-{
-	int retval;
-
-	spin_lock_irq(&dev->power.lock);
-	retval = __pm_runtime_suspend(dev, 0);
-	spin_unlock_irq(&dev->power.lock);
-
-	return retval;
-}
-EXPORT_SYMBOL_GPL(pm_runtime_suspend);
-
-/**
- * __pm_runtime_resume - Carry out run-time resume of given device.
+ * rpm_resume - Carry out run-time resume of given device.
  * @dev: Device to resume.
  * @rpmflags: Flag bits.
  *
@@ -387,7 +355,7 @@ EXPORT_SYMBOL_GPL(pm_runtime_suspend);
  *
  * This function must be called under dev->power.lock with interrupts disabled.
  */
-static int __pm_runtime_resume(struct device *dev, int rpmflags)
+static int rpm_resume(struct device *dev, int rpmflags)
 	__releases(&dev->power.lock) __acquires(&dev->power.lock)
 {
 	struct device *parent = NULL;
@@ -469,7 +437,7 @@ static int __pm_runtime_resume(struct device *dev, int rpmflags)
 		 */
 		if (!parent->power.disable_depth
 		    && !parent->power.ignore_children) {
-			__pm_runtime_resume(parent, 0);
+			rpm_resume(parent, 0);
 			if (parent->power.runtime_status != RPM_ACTIVE)
 				retval = -EBUSY;
 		}
@@ -521,7 +489,7 @@ static int __pm_runtime_resume(struct device *dev, int rpmflags)
 	wake_up_all(&dev->power.wait_queue);
 
 	if (!retval)
-		__pm_runtime_idle(dev, RPM_ASYNC);
+		rpm_idle(dev, RPM_ASYNC);
 
  out:
 	if (parent) {
@@ -537,22 +505,6 @@ static int __pm_runtime_resume(struct device *dev, int rpmflags)
 	return retval;
 }
 
-/**
- * pm_runtime_resume - Carry out run-time resume of given device.
- * @dev: Device to suspend.
- */
-int pm_runtime_resume(struct device *dev)
-{
-	int retval;
-
-	spin_lock_irq(&dev->power.lock);
-	retval = __pm_runtime_resume(dev, 0);
-	spin_unlock_irq(&dev->power.lock);
-
-	return retval;
-}
-EXPORT_SYMBOL_GPL(pm_runtime_resume);
-
 /**
  * pm_runtime_work - Universal run-time PM work function.
  * @work: Work structure used for scheduling the execution of this function.
@@ -578,13 +530,13 @@ static void pm_runtime_work(struct work_struct *work)
 	case RPM_REQ_NONE:
 		break;
 	case RPM_REQ_IDLE:
-		__pm_runtime_idle(dev, RPM_NOWAIT);
+		rpm_idle(dev, RPM_NOWAIT);
 		break;
 	case RPM_REQ_SUSPEND:
-		__pm_runtime_suspend(dev, RPM_NOWAIT);
+		rpm_suspend(dev, RPM_NOWAIT);
 		break;
 	case RPM_REQ_RESUME:
-		__pm_runtime_resume(dev, RPM_NOWAIT);
+		rpm_resume(dev, RPM_NOWAIT);
 		break;
 	}
 
@@ -592,23 +544,6 @@ static void pm_runtime_work(struct work_struct *work)
 	spin_unlock_irq(&dev->power.lock);
 }
 
-/**
- * pm_request_idle - Submit an idle notification request for given device.
- * @dev: Device to handle.
- */
-int pm_request_idle(struct device *dev)
-{
-	unsigned long flags;
-	int retval;
-
-	spin_lock_irqsave(&dev->power.lock, flags);
-	retval = __pm_runtime_idle(dev, RPM_ASYNC);
-	spin_unlock_irqrestore(&dev->power.lock, flags);
-
-	return retval;
-}
-EXPORT_SYMBOL_GPL(pm_request_idle);
-
 /**
  * pm_suspend_timer_fn - Timer function for pm_schedule_suspend().
  * @data: Device pointer passed by pm_schedule_suspend().
@@ -627,7 +562,7 @@ static void pm_suspend_timer_fn(unsigned long data)
 	/* If 'expire' is after 'jiffies' we've been called too early. */
 	if (expires > 0 && !time_after(expires, jiffies)) {
 		dev->power.timer_expires = 0;
-		__pm_runtime_suspend(dev, RPM_ASYNC);
+		rpm_suspend(dev, RPM_ASYNC);
 	}
 
 	spin_unlock_irqrestore(&dev->power.lock, flags);
@@ -646,7 +581,7 @@ int pm_schedule_suspend(struct device *dev, unsigned int delay)
 	spin_lock_irqsave(&dev->power.lock, flags);
 
 	if (!delay) {
-		retval = __pm_runtime_suspend(dev, RPM_ASYNC);
+		retval = rpm_suspend(dev, RPM_ASYNC);
 		goto out;
 	}
 
@@ -669,62 +604,81 @@ int pm_schedule_suspend(struct device *dev, unsigned int delay)
 EXPORT_SYMBOL_GPL(pm_schedule_suspend);
 
 /**
- * pm_request_resume - Submit a resume request for given device.
- * @dev: Device to resume.
+ * __pm_runtime_idle - Entry point for run-time idle operations.
+ * @dev: Device to send idle notification for.
+ * @rpmflags: Flag bits.
+ *
+ * If the RPM_GET_PUT flag is set, decrement the device's usage count and
+ * return immediately if it is larger than zero.  Then carry out an idle
+ * notification, either synchronous or asynchronous.
+ *
+ * This routine may be called in atomic context if the RPM_ASYNC flag is set.
  */
-int pm_request_resume(struct device *dev)
+int __pm_runtime_idle(struct device *dev, int rpmflags)
 {
 	unsigned long flags;
 	int retval;
 
+	if (rpmflags & RPM_GET_PUT) {
+		if (!atomic_dec_and_test(&dev->power.usage_count))
+			return 0;
+	}
+
 	spin_lock_irqsave(&dev->power.lock, flags);
-	retval = __pm_runtime_resume(dev, RPM_ASYNC);
+	retval = rpm_idle(dev, rpmflags);
 	spin_unlock_irqrestore(&dev->power.lock, flags);
 
 	return retval;
 }
-EXPORT_SYMBOL_GPL(pm_request_resume);
+EXPORT_SYMBOL_GPL(__pm_runtime_idle);
 
 /**
- * __pm_runtime_get - Reference count a device and wake it up, if necessary.
- * @dev: Device to handle.
+ * __pm_runtime_suspend - Entry point for run-time put/suspend operations.
+ * @dev: Device to suspend.
  * @rpmflags: Flag bits.
  *
- * Increment the usage count of the device and resume it or submit a resume
- * request for it, depending on the RPM_ASYNC flag bit.
+ * Carry out a suspend, either synchronous or asynchronous.
+ *
+ * This routine may be called in atomic context if the RPM_ASYNC flag is set.
  */
-int __pm_runtime_get(struct device *dev, int rpmflags)
+int __pm_runtime_suspend(struct device *dev, int rpmflags)
 {
+	unsigned long flags;
 	int retval;
 
-	atomic_inc(&dev->power.usage_count);
-	retval = (rpmflags & RPM_ASYNC) ?
-	    pm_request_resume(dev) : pm_runtime_resume(dev);
+	spin_lock_irqsave(&dev->power.lock, flags);
+	retval = rpm_suspend(dev, rpmflags);
+	spin_unlock_irqrestore(&dev->power.lock, flags);
 
 	return retval;
 }
-EXPORT_SYMBOL_GPL(__pm_runtime_get);
+EXPORT_SYMBOL_GPL(__pm_runtime_suspend);
 
 /**
- * __pm_runtime_put - Decrement the device's usage counter and notify its bus.
- * @dev: Device to handle.
+ * __pm_runtime_resume - Entry point for run-time resume operations.
+ * @dev: Device to resume.
  * @rpmflags: Flag bits.
  *
- * Decrement the usage count of the device and if it reaches zero, carry out a
- * synchronous idle notification or submit an idle notification request for it,
- * depending on the RPM_ASYNC flag bit.
+ * If the RPM_GET_PUT flag is set, increment the device's usage count.  Then
+ * carry out a resume, either synchronous or asynchronous.
+ *
+ * This routine may be called in atomic context if the RPM_ASYNC flag is set.
  */
-int __pm_runtime_put(struct device *dev, int rpmflags)
+int __pm_runtime_resume(struct device *dev, int rpmflags)
 {
-	int retval = 0;
+	unsigned long flags;
+	int retval;
 
-	if (atomic_dec_and_test(&dev->power.usage_count))
-		retval = (rpmflags & RPM_ASYNC) ?
-		    pm_request_idle(dev) : pm_runtime_idle(dev);
+	if (rpmflags & RPM_GET_PUT)
+		atomic_inc(&dev->power.usage_count);
+
+	spin_lock_irqsave(&dev->power.lock, flags);
+	retval = rpm_resume(dev, rpmflags);
+	spin_unlock_irqrestore(&dev->power.lock, flags);
 
 	return retval;
 }
-EXPORT_SYMBOL_GPL(__pm_runtime_put);
+EXPORT_SYMBOL_GPL(__pm_runtime_resume);
 
 /**
  * __pm_runtime_set_status - Set run-time PM status of a device.
@@ -875,7 +829,7 @@ int pm_runtime_barrier(struct device *dev)
 
 	if (dev->power.request_pending
 	    && dev->power.request == RPM_REQ_RESUME) {
-		__pm_runtime_resume(dev, 0);
+		rpm_resume(dev, 0);
 		retval = 1;
 	}
 
@@ -924,7 +878,7 @@ void __pm_runtime_disable(struct device *dev, bool check_resume)
 		 */
 		pm_runtime_get_noresume(dev);
 
-		__pm_runtime_resume(dev, 0);
+		rpm_resume(dev, 0);
 
 		pm_runtime_put_noidle(dev);
 	}
@@ -972,7 +926,7 @@ void pm_runtime_forbid(struct device *dev)
 
 	dev->power.runtime_auto = false;
 	atomic_inc(&dev->power.usage_count);
-	__pm_runtime_resume(dev, 0);
+	rpm_resume(dev, 0);
 
  out:
 	spin_unlock_irq(&dev->power.lock);
@@ -993,7 +947,7 @@ void pm_runtime_allow(struct device *dev)
 
 	dev->power.runtime_auto = true;
 	if (atomic_dec_and_test(&dev->power.usage_count))
-		__pm_runtime_idle(dev, 0);
+		rpm_idle(dev, 0);
 
  out:
 	spin_unlock_irq(&dev->power.lock);

include/linux/pm_runtime.h

@@ -16,19 +16,17 @@
 #define RPM_ASYNC		0x01	/* Request is asynchronous */
 #define RPM_NOWAIT		0x02	/* Don't wait for concurrent
 					    state change */
+#define RPM_GET_PUT		0x04	/* Increment/decrement the
+					    usage_count */
 
 #ifdef CONFIG_PM_RUNTIME
 
 extern struct workqueue_struct *pm_wq;
 
-extern int pm_runtime_idle(struct device *dev);
-extern int pm_runtime_suspend(struct device *dev);
-extern int pm_runtime_resume(struct device *dev);
-extern int pm_request_idle(struct device *dev);
+extern int __pm_runtime_idle(struct device *dev, int rpmflags);
+extern int __pm_runtime_suspend(struct device *dev, int rpmflags);
+extern int __pm_runtime_resume(struct device *dev, int rpmflags);
 extern int pm_schedule_suspend(struct device *dev, unsigned int delay);
-extern int pm_request_resume(struct device *dev);
-extern int __pm_runtime_get(struct device *dev, int rpmflags);
-extern int __pm_runtime_put(struct device *dev, int rpmflags);
 extern int __pm_runtime_set_status(struct device *dev, unsigned int status);
 extern int pm_runtime_barrier(struct device *dev);
 extern void pm_runtime_enable(struct device *dev);
@@ -77,19 +75,22 @@ static inline bool pm_runtime_suspended(struct device *dev)
 
 #else /* !CONFIG_PM_RUNTIME */
 
-static inline int pm_runtime_idle(struct device *dev) { return -ENOSYS; }
-static inline int pm_runtime_suspend(struct device *dev) { return -ENOSYS; }
-static inline int pm_runtime_resume(struct device *dev) { return 0; }
-static inline int pm_request_idle(struct device *dev) { return -ENOSYS; }
+static inline int __pm_runtime_idle(struct device *dev, int rpmflags)
+{
+	return -ENOSYS;
+}
+static inline int __pm_runtime_suspend(struct device *dev, int rpmflags)
+{
+	return -ENOSYS;
+}
+static inline int __pm_runtime_resume(struct device *dev, int rpmflags)
+{
+	return 1;
+}
 static inline int pm_schedule_suspend(struct device *dev, unsigned int delay)
 {
 	return -ENOSYS;
 }
-static inline int pm_request_resume(struct device *dev) { return 0; }
-static inline int __pm_runtime_get(struct device *dev, int rpmflags)
-					{ return 1; }
-static inline int __pm_runtime_put(struct device *dev, int rpmflags)
-					{ return 0; }
 static inline int __pm_runtime_set_status(struct device *dev,
 					    unsigned int status) { return 0; }
 static inline int pm_runtime_barrier(struct device *dev) { return 0; }
@@ -112,24 +113,49 @@ static inline int pm_generic_runtime_resume(struct device *dev) { return 0; }
 
 #endif /* !CONFIG_PM_RUNTIME */
 
+static inline int pm_runtime_idle(struct device *dev)
+{
+	return __pm_runtime_idle(dev, 0);
+}
+
+static inline int pm_runtime_suspend(struct device *dev)
+{
+	return __pm_runtime_suspend(dev, 0);
+}
+
+static inline int pm_runtime_resume(struct device *dev)
+{
+	return __pm_runtime_resume(dev, 0);
+}
+
+static inline int pm_request_idle(struct device *dev)
+{
+	return __pm_runtime_idle(dev, RPM_ASYNC);
+}
+
+static inline int pm_request_resume(struct device *dev)
+{
+	return __pm_runtime_resume(dev, RPM_ASYNC);
+}
+
 static inline int pm_runtime_get(struct device *dev)
 {
-	return __pm_runtime_get(dev, RPM_ASYNC);
+	return __pm_runtime_resume(dev, RPM_GET_PUT | RPM_ASYNC);
 }
 
 static inline int pm_runtime_get_sync(struct device *dev)
 {
-	return __pm_runtime_get(dev, 0);
+	return __pm_runtime_resume(dev, RPM_GET_PUT);
 }
 
 static inline int pm_runtime_put(struct device *dev)
 {
-	return __pm_runtime_put(dev, RPM_ASYNC);
+	return __pm_runtime_idle(dev, RPM_GET_PUT | RPM_ASYNC);
 }
 
 static inline int pm_runtime_put_sync(struct device *dev)
 {
-	return __pm_runtime_put(dev, 0);
+	return __pm_runtime_idle(dev, RPM_GET_PUT);
 }
 
 static inline int pm_runtime_set_active(struct device *dev)