PM / core: Split dpm_suspend_noirq() and dpm_resume_noirq()

Put the device interrupts disabling and enabling as well as
cpuidle_pause() and cpuidle_resume() called during the "noirq"
stages of system suspend into separate functions to allow the
core suspend-to-idle code to be optimized (later).

The only functional difference this makes is that debug facilities
and diagnostic tools will not include the above operations into the
"noirq" device suspend/resume duration measurements.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/base/power/main.c

@@ -598,14 +598,7 @@ static void async_resume_noirq(void *data, async_cookie_t cookie)
 	put_device(dev);
 }
 
-/**
- * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
- * @state: PM transition of the system being carried out.
- *
- * Call the "noirq" resume handlers for all devices in dpm_noirq_list and
- * enable device drivers to receive interrupts.
- */
-void dpm_resume_noirq(pm_message_t state)
+void dpm_noirq_resume_devices(pm_message_t state)
 {
 	struct device *dev;
 	ktime_t starttime = ktime_get();
@@ -651,10 +644,27 @@ void dpm_resume_noirq(pm_message_t state)
 	mutex_unlock(&dpm_list_mtx);
 	async_synchronize_full();
 	dpm_show_time(starttime, state, "noirq");
+	trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
+}
+
+void dpm_noirq_end(void)
+{
 	resume_device_irqs();
 	device_wakeup_disarm_wake_irqs();
 	cpuidle_resume();
-	trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
+}
+
+/**
+ * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
+ * @state: PM transition of the system being carried out.
+ *
+ * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
+ * allow device drivers' interrupt handlers to be called.
+ */
+void dpm_resume_noirq(pm_message_t state)
+{
+	dpm_noirq_resume_devices(state);
+	dpm_noirq_end();
 }
 
 /**
@@ -1154,22 +1164,19 @@ static int device_suspend_noirq(struct device *dev)
 	return __device_suspend_noirq(dev, pm_transition, false);
 }
 
-/**
- * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
- * @state: PM transition of the system being carried out.
- *
- * Prevent device drivers from receiving interrupts and call the "noirq" suspend
- * handlers for all non-sysdev devices.
- */
-int dpm_suspend_noirq(pm_message_t state)
+void dpm_noirq_begin(void)
+{
+	cpuidle_pause();
+	device_wakeup_arm_wake_irqs();
+	suspend_device_irqs();
+}
+
+int dpm_noirq_suspend_devices(pm_message_t state)
 {
 	ktime_t starttime = ktime_get();
 	int error = 0;
 
 	trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
-	cpuidle_pause();
-	device_wakeup_arm_wake_irqs();
-	suspend_device_irqs();
 	mutex_lock(&dpm_list_mtx);
 	pm_transition = state;
 	async_error = 0;
@@ -1204,7 +1211,6 @@ int dpm_suspend_noirq(pm_message_t state)
 	if (error) {
 		suspend_stats.failed_suspend_noirq++;
 		dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
-		dpm_resume_noirq(resume_event(state));
 	} else {
 		dpm_show_time(starttime, state, "noirq");
 	}
@@ -1212,6 +1218,25 @@ int dpm_suspend_noirq(pm_message_t state)
 	return error;
 }
 
+/**
+ * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
+ * @state: PM transition of the system being carried out.
+ *
+ * Prevent device drivers' interrupt handlers from being called and invoke
+ * "noirq" suspend callbacks for all non-sysdev devices.
+ */
+int dpm_suspend_noirq(pm_message_t state)
+{
+	int ret;
+
+	dpm_noirq_begin();
+	ret = dpm_noirq_suspend_devices(state);
+	if (ret)
+		dpm_resume_noirq(resume_event(state));
+
+	return ret;
+}
+
 /**
  * device_suspend_late - Execute a "late suspend" callback for given device.
  * @dev: Device to handle.

include/linux/pm.h

@@ -689,6 +689,8 @@ struct dev_pm_domain {
 extern void device_pm_lock(void);
 extern void dpm_resume_start(pm_message_t state);
 extern void dpm_resume_end(pm_message_t state);
+extern void dpm_noirq_resume_devices(pm_message_t state);
+extern void dpm_noirq_end(void);
 extern void dpm_resume_noirq(pm_message_t state);
 extern void dpm_resume_early(pm_message_t state);
 extern void dpm_resume(pm_message_t state);
@@ -697,6 +699,8 @@ extern void dpm_complete(pm_message_t state);
 extern void device_pm_unlock(void);
 extern int dpm_suspend_end(pm_message_t state);
 extern int dpm_suspend_start(pm_message_t state);
+extern void dpm_noirq_begin(void);
+extern int dpm_noirq_suspend_devices(pm_message_t state);
 extern int dpm_suspend_noirq(pm_message_t state);
 extern int dpm_suspend_late(pm_message_t state);
 extern int dpm_suspend(pm_message_t state);