[PATCH] acpi bridge hotadd: Allow ACPI .add and .start operations to be done independently

Create new interfaces to recursively add an acpi namespace object to the acpi
device list, and recursively start the namespace object. This is needed for
ACPI based hotplug of a root bridge hierarchy where the add operation must be
performed first and the start operation must be performed separately after the
hot-plugged devices have been properly configured.

Signed-off-by: Rajesh Shah <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/acpi/container.c

···
 		return_VALUE(-ENODEV);
 	}
 
-	result = acpi_bus_scan(*device);
+	result = acpi_bus_start(*device);
 
 	return_VALUE(result);
 }

drivers/acpi/processor_core.c

···
 		return_VALUE(-ENODEV);
 	}
 
-	acpi_bus_scan(*device);
+	acpi_bus_start(*device);
 
 	pr = acpi_driver_data(*device);
 	if (!pr)

drivers/acpi/scan.c

···
 	 * upon possible configuration and currently allocated resources.
 	 */
 
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Driver successfully bound to device\n"));
+	return_VALUE(0);
+}
+
+int
+acpi_start_single_object (
+		struct acpi_device *device)
+{
+	int result = 0;
+	struct acpi_driver *driver;
+
+	ACPI_FUNCTION_TRACE("acpi_start_single_object");
+
+	if (!(driver = device->driver))
+		return_VALUE(0);
+
 	if (driver->ops.start) {
 		result = driver->ops.start(device);
 		if (result && driver->ops.remove)
 			driver->ops.remove(device, ACPI_BUS_REMOVAL_NORMAL);
-		return_VALUE(result);
 	}
 
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Driver successfully bound to device\n"));
-
-	if (driver->ops.scan) {
-		driver->ops.scan(device);
-	}
-
-	return_VALUE(0);
+	return_VALUE(result);
 }
 
 static int acpi_driver_attach(struct acpi_driver * drv)
···
 
 		if (!acpi_bus_match(dev, drv)) {
 			if (!acpi_bus_driver_init(dev, drv)) {
+				acpi_start_single_object(dev);
 				atomic_inc(&drv->references);
 				count++;
 				ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
···
 }
 
 
-int
-acpi_bus_add (
+static int
+acpi_add_single_object (
 	struct acpi_device	**child,
 	struct acpi_device	*parent,
 	acpi_handle		handle,
···
 	int			result = 0;
 	struct acpi_device	*device = NULL;
 
-	ACPI_FUNCTION_TRACE("acpi_bus_add");
+	ACPI_FUNCTION_TRACE("acpi_add_single_object");
 
 	if (!child)
 		return_VALUE(-EINVAL);
···
 	 *
 	 * TBD: Assumes LDM provides driver hot-plug capability.
 	 */
-	acpi_bus_find_driver(device);
+	result = acpi_bus_find_driver(device);
 
 end:
 	if (!result)
···
 
 	return_VALUE(result);
 }
-EXPORT_SYMBOL(acpi_bus_add);
 
 
-int acpi_bus_scan (struct acpi_device	*start)
+static int acpi_bus_scan (struct acpi_device	*start,
+		struct acpi_bus_ops *ops)
 {
 	acpi_status		status = AE_OK;
 	struct acpi_device	*parent = NULL;
···
 			continue;
 		}
 
-		status = acpi_bus_add(&child, parent, chandle, type);
-		if (ACPI_FAILURE(status))
-			continue;
+		if (ops->acpi_op_add)
+			status = acpi_add_single_object(&child, parent,
+					chandle, type);
+		 else
+			status = acpi_bus_get_device(chandle, &child);
+
+		 if (ACPI_FAILURE(status))
+			 continue;
+
+		if (ops->acpi_op_start) {
+			status = acpi_start_single_object(child);
+			if (ACPI_FAILURE(status))
+				continue;
+		}
 
 		/*
 		 * If the device is present, enabled, and functioning then
···
 
 	return_VALUE(0);
 }
-EXPORT_SYMBOL(acpi_bus_scan);
 
+int
+acpi_bus_add (
+	struct acpi_device	**child,
+	struct acpi_device	*parent,
+	acpi_handle		handle,
+	int			type)
+{
+	int result;
+	struct acpi_bus_ops ops;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_add");
+
+	result = acpi_add_single_object(child, parent, handle, type);
+	if (!result) {
+		memset(&ops, 0, sizeof(ops));
+		ops.acpi_op_add = 1;
+		result = acpi_bus_scan(*child, &ops);
+	}
+	return_VALUE(result);
+}
+EXPORT_SYMBOL(acpi_bus_add);
+
+int
+acpi_bus_start (
+	struct acpi_device *device)
+{
+	int result;
+	struct acpi_bus_ops ops;
+
+	ACPI_FUNCTION_TRACE("acpi_bus_start");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	result = acpi_start_single_object(device);
+	if (!result) {
+		memset(&ops, 0, sizeof(ops));
+		ops.acpi_op_start = 1;
+		result = acpi_bus_scan(device, &ops);
+	}
+	return_VALUE(result);
+}
+EXPORT_SYMBOL(acpi_bus_start);
 
 static int
 acpi_bus_trim(struct acpi_device	*start,
···
 	/*
 	 * Enumerate all fixed-feature devices.
 	 */
-	if (acpi_fadt.pwr_button == 0)
-		result = acpi_bus_add(&device, acpi_root, 
+	if (acpi_fadt.pwr_button == 0) {
+		result = acpi_add_single_object(&device, acpi_root,
 			NULL, ACPI_BUS_TYPE_POWER_BUTTON);
+		if (!result)
+			result = acpi_start_single_object(device);
+	}
 
-	if (acpi_fadt.sleep_button == 0)
-		result = acpi_bus_add(&device, acpi_root, 
+	if (acpi_fadt.sleep_button == 0) {
+		result = acpi_add_single_object(&device, acpi_root,
 			NULL, ACPI_BUS_TYPE_SLEEP_BUTTON);
+		if (!result)
+			result = acpi_start_single_object(device);
+	}
 
 	return_VALUE(result);
 }
···
 static int __init acpi_scan_init(void)
 {
 	int result;
+	struct acpi_bus_ops ops;
 
 	ACPI_FUNCTION_TRACE("acpi_scan_init");
 
···
 	/*
 	 * Create the root device in the bus's device tree
 	 */
-	result = acpi_bus_add(&acpi_root, NULL, ACPI_ROOT_OBJECT, 
+	result = acpi_add_single_object(&acpi_root, NULL, ACPI_ROOT_OBJECT,
 		ACPI_BUS_TYPE_SYSTEM);
 	if (result)
 		goto Done;
+
+	result = acpi_start_single_object(acpi_root);
 
 	/*
 	 * Enumerate devices in the ACPI namespace.
 	 */
 	result = acpi_bus_scan_fixed(acpi_root);
-	if (!result) 
-		result = acpi_bus_scan(acpi_root);
+	if (!result) {
+		memset(&ops, 0, sizeof(ops));
+		ops.acpi_op_add = 1;
+		ops.acpi_op_start = 1;
+		result = acpi_bus_scan(acpi_root, &ops);
+	}
 
 	if (result)
 		acpi_device_unregister(acpi_root, ACPI_BUS_REMOVAL_NORMAL);

include/acpi/acpi_bus.h

···
 typedef int (*acpi_op_match)	(struct acpi_device *device,
 				 struct acpi_driver *driver);
 
+struct acpi_bus_ops {
+	u32 			acpi_op_add:1;
+	u32			acpi_op_remove:1;
+	u32			acpi_op_lock:1;
+	u32			acpi_op_start:1;
+	u32			acpi_op_stop:1;
+	u32			acpi_op_suspend:1;
+	u32			acpi_op_resume:1;
+	u32			acpi_op_scan:1;
+	u32			acpi_op_bind:1;
+	u32			acpi_op_unbind:1;
+	u32			acpi_op_match:1;
+	u32			reserved:21;
+};
+
 struct acpi_device_ops {
 	acpi_op_add		add;
 	acpi_op_remove		remove;
···
 int acpi_bus_receive_event (struct acpi_bus_event *event);
 int acpi_bus_register_driver (struct acpi_driver *driver);
 int acpi_bus_unregister_driver (struct acpi_driver *driver);
-int acpi_bus_scan (struct acpi_device *start);
 int acpi_bus_add (struct acpi_device **child, struct acpi_device *parent,
 		acpi_handle handle, int type);
+int acpi_bus_start (struct acpi_device *device);
 
 
 int acpi_match_ids (struct acpi_device	*device, char	*ids);