ACPI / PM: Revork the handling of ACPI device wakeup notifications

Since ACPI wakeup GPEs are going to be enabled during system suspend
as well as for runtime wakeup by a subsequent patch and the same
notify handlers will be used in both cases, rework the ACPI device
wakeup notification framework so that the part specific to physical
devices is always run asynchronously from the PM workqueue.  This
prevents runtime resume callbacks for those devices from being
run during system suspend and resume which may not be appropriate,
among other things.

Also make ACPI device wakeup notification handling a bit more robust
agaist subsequent removal of ACPI device objects, whould that ever
happen, and create a wakeup source object for each ACPI device
configured for wakeup so that wakeup notifications for those
devices can wake up the system from the "freeze" sleep state.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

2 files changed, 59 insertions, 23 deletions

diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index 49a5127..366de0b 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -367,29 +367,61 @@ EXPORT_SYMBOL(acpi_bus_power_manageable);
 #ifdef CONFIG_PM
 static DEFINE_MUTEX(acpi_pm_notifier_lock);
 
+static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
+{
+	struct acpi_device *adev;
+
+	if (val != ACPI_NOTIFY_DEVICE_WAKE)
+		return;
+
+	adev = acpi_bus_get_acpi_device(handle);
+	if (!adev)
+		return;
+
+	mutex_lock(&acpi_pm_notifier_lock);
+
+	if (adev->wakeup.flags.notifier_present) {
+		__pm_wakeup_event(adev->wakeup.ws, 0);
+		if (adev->wakeup.context.work.func)
+			queue_pm_work(&adev->wakeup.context.work);
+	}
+
+	mutex_unlock(&acpi_pm_notifier_lock);
+
+	acpi_bus_put_acpi_device(adev);
+}
+
 /**
- * acpi_add_pm_notifier - Register PM notifier for given ACPI device.
- * @adev: ACPI device to add the notifier for.
- * @context: Context information to pass to the notifier routine.
+ * acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
+ * @adev: ACPI device to add the notify handler for.
+ * @dev: Device to generate a wakeup event for while handling the notification.
+ * @work_func: Work function to execute when handling the notification.
  *
  * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
  * PM wakeup events.  For example, wakeup events may be generated for bridges
  * if one of the devices below the bridge is signaling wakeup, even if the
  * bridge itself doesn't have a wakeup GPE associated with it.
  */
-acpi_status acpi_add_pm_notifier(struct acpi_device *adev,
-				 acpi_notify_handler handler, void *context)
+acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
+				 void (*work_func)(struct work_struct *work))
 {
 	acpi_status status = AE_ALREADY_EXISTS;
 
+	if (!dev && !work_func)
+		return AE_BAD_PARAMETER;
+
 	mutex_lock(&acpi_pm_notifier_lock);
 
 	if (adev->wakeup.flags.notifier_present)
 		goto out;
 
-	status = acpi_install_notify_handler(adev->handle,
-					     ACPI_SYSTEM_NOTIFY,
-					     handler, context);
+	adev->wakeup.ws = wakeup_source_register(dev_name(&adev->dev));
+	adev->wakeup.context.dev = dev;
+	if (work_func)
+		INIT_WORK(&adev->wakeup.context.work, work_func);
+
+	status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
+					     acpi_pm_notify_handler, NULL);
 	if (ACPI_FAILURE(status))
 		goto out;
 
@@ -404,8 +436,7 @@ acpi_status acpi_add_pm_notifier(struct acpi_device *adev,
  * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
  * @adev: ACPI device to remove the notifier from.
  */
-acpi_status acpi_remove_pm_notifier(struct acpi_device *adev,
-				    acpi_notify_handler handler)
+acpi_status acpi_remove_pm_notifier(struct acpi_device *adev)
 {
 	acpi_status status = AE_BAD_PARAMETER;
 
@@ -416,10 +447,17 @@ acpi_status acpi_remove_pm_notifier(struct acpi_device *adev,
 
 	status = acpi_remove_notify_handler(adev->handle,
 					    ACPI_SYSTEM_NOTIFY,
-					    handler);
+					    acpi_pm_notify_handler);
 	if (ACPI_FAILURE(status))
 		goto out;
 
+	if (adev->wakeup.context.work.func) {
+		cancel_work_sync(&adev->wakeup.context.work);
+		adev->wakeup.context.work.func = NULL;
+	}
+	adev->wakeup.context.dev = NULL;
+	wakeup_source_unregister(adev->wakeup.ws);
+
 	adev->wakeup.flags.notifier_present = false;
 
  out:
@@ -602,16 +640,15 @@ EXPORT_SYMBOL(acpi_pm_device_sleep_state);
 
 #ifdef CONFIG_PM_RUNTIME
 /**
- * acpi_wakeup_device - Wakeup notification handler for ACPI devices.
- * @handle: ACPI handle of the device the notification is for.
- * @event: Type of the signaled event.
- * @context: Device corresponding to @handle.
+ * acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
+ * @work: Work item to handle.
  */
-static void acpi_wakeup_device(acpi_handle handle, u32 event, void *context)
+static void acpi_pm_notify_work_func(struct work_struct *work)
 {
-	struct device *dev = context;
+	struct device *dev;
 
-	if (event == ACPI_NOTIFY_DEVICE_WAKE && dev) {
+	dev = container_of(work, struct acpi_device_wakeup_context, work)->dev;
+	if (dev) {
 		pm_wakeup_event(dev, 0);
 		pm_runtime_resume(dev);
 	}
@@ -677,8 +714,7 @@ int acpi_pm_device_run_wake(struct device *phys_dev, bool enable)
 }
 EXPORT_SYMBOL(acpi_pm_device_run_wake);
 #else
-static inline void acpi_wakeup_device(acpi_handle handle, u32 event,
-				      void *context) {}
+static inline void acpi_pm_notify_work_func(struct work_struct *work) {}
 #endif /* CONFIG_PM_RUNTIME */
 
 #ifdef CONFIG_PM_SLEEP
@@ -1048,7 +1084,7 @@ int acpi_dev_pm_attach(struct device *dev, bool power_on)
 	if (dev->pm_domain)
 		return -EEXIST;
 
-	acpi_add_pm_notifier(adev, acpi_wakeup_device, dev);
+	acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
 	dev->pm_domain = &acpi_general_pm_domain;
 	if (power_on) {
 		acpi_dev_pm_full_power(adev);
@@ -1076,7 +1112,7 @@ void acpi_dev_pm_detach(struct device *dev, bool power_off)
 
 	if (adev && dev->pm_domain == &acpi_general_pm_domain) {
 		dev->pm_domain = NULL;
-		acpi_remove_pm_notifier(adev, acpi_wakeup_device);
+		acpi_remove_pm_notifier(adev);
 		if (power_off) {
 			/*
 			 * If the device's PM QoS resume latency limit or flags
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index d388f13..e6ae603 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -593,7 +593,7 @@ static int acpi_pci_root_add(struct acpi_device *device,
 	if (no_aspm)
 		pcie_no_aspm();
 
-	pci_acpi_add_bus_pm_notifier(device, root->bus);
+	pci_acpi_add_bus_pm_notifier(device);
 	if (device->wakeup.flags.run_wake)
 		device_set_run_wake(root->bus->bridge, true);