[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 <rajesh.shah@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 103 insertions, 27 deletions

diff --git a/drivers/acpi/container.c b/drivers/acpi/container.c
index 5a0adbf..97013dd 100644
--- a/drivers/acpi/container.c
+++ b/drivers/acpi/container.c
@@ -153,7 +153,7 @@ container_device_add(struct acpi_device **device, acpi_handle handle)
 		return_VALUE(-ENODEV);
 	}
 
-	result = acpi_bus_scan(*device);
+	result = acpi_bus_start(*device);
 
 	return_VALUE(result);
 }
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index f477874..76156ac 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -723,7 +723,7 @@ int acpi_processor_device_add(
 		return_VALUE(-ENODEV);
 	}
 
-	acpi_bus_scan(*device);
+	acpi_bus_start(*device);
 
 	pr = acpi_driver_data(*device);
 	if (!pr)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index e858855..337d49b 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -553,20 +553,29 @@ acpi_bus_driver_init (
 	 * 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)
@@ -586,6 +595,7 @@ 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",
@@ -1009,8 +1019,8 @@ acpi_bus_remove (
 }
 
 
-int
-acpi_bus_add (
+static int
+acpi_add_single_object (
 	struct acpi_device	**child,
 	struct acpi_device	*parent,
 	acpi_handle		handle,
@@ -1019,7 +1029,7 @@ acpi_bus_add (
 	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);
@@ -1140,7 +1150,7 @@ acpi_bus_add (
 	 *
 	 * TBD: Assumes LDM provides driver hot-plug capability.
 	 */
-	acpi_bus_find_driver(device);
+	result = acpi_bus_find_driver(device);
 
 end:
 	if (!result)
@@ -1153,10 +1163,10 @@ end:
 
 	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;
@@ -1229,9 +1239,20 @@ int acpi_bus_scan (struct acpi_device	*start)
 			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
@@ -1257,8 +1278,50 @@ int acpi_bus_scan (struct acpi_device	*start)
 
 	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,
@@ -1331,13 +1394,19 @@ acpi_bus_scan_fixed (
 	/*
 	 * 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);
 }
@@ -1346,6 +1415,7 @@ acpi_bus_scan_fixed (
 static int __init acpi_scan_init(void)
 {
 	int result;
+	struct acpi_bus_ops ops;
 
 	ACPI_FUNCTION_TRACE("acpi_scan_init");
 
@@ -1357,17 +1427,23 @@ static int __init acpi_scan_init(void)
 	/*
 	 * 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);