Index: test/drivers/acpi/Kconfig
===================================================================
--- test.orig/drivers/acpi/Kconfig
+++ test/drivers/acpi/Kconfig
@@ -350,9 +350,8 @@ config ACPI_CONTAINER
 	  the module will be called container.
 
 config ACPI_HOTPLUG_MEMORY
-	tristate "Memory Hotplug"
+	bool "Memory Hotplug"
 	depends on MEMORY_HOTPLUG
-	default n
 	help
 	  This driver supports ACPI memory hotplug.  The driver
 	  fields notifications on ACPI memory devices (PNP0C80),
Index: test/drivers/acpi/acpi_memhotplug.c
===================================================================
--- test.orig/drivers/acpi/acpi_memhotplug.c
+++ test/drivers/acpi/acpi_memhotplug.c
@@ -1,5 +1,7 @@
 /*
- * Copyright (C) 2004 Intel Corporation <naveen.b.s@intel.com>
+ * Copyright (C) 2004, 2013 Intel Corporation
+ * Author: Naveen B S <naveen.b.s@intel.com>
+ * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  *
  * All rights reserved.
  *
@@ -25,14 +27,10 @@
  * ranges.
  */
 
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/types.h>
-#include <linux/memory_hotplug.h>
-#include <linux/slab.h>
 #include <linux/acpi.h>
-#include <acpi/acpi_drivers.h>
+#include <linux/memory_hotplug.h>
+
+#include "internal.h"
 
 #define ACPI_MEMORY_DEVICE_CLASS		"memory"
 #define ACPI_MEMORY_DEVICE_HID			"PNP0C80"
@@ -44,32 +42,28 @@
 #define 	PREFIX		"ACPI:memory_hp:"
 
 ACPI_MODULE_NAME("acpi_memhotplug");
-MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
-MODULE_DESCRIPTION("Hotplug Mem Driver");
-MODULE_LICENSE("GPL");
 
 /* Memory Device States */
 #define MEMORY_INVALID_STATE	0
 #define MEMORY_POWER_ON_STATE	1
 #define MEMORY_POWER_OFF_STATE	2
 
-static int acpi_memory_device_add(struct acpi_device *device);
-static int acpi_memory_device_remove(struct acpi_device *device);
+static int acpi_memory_device_add(struct acpi_device *device,
+				  const struct acpi_device_id *not_used);
+static void acpi_memory_device_remove(struct acpi_device *device);
 
 static const struct acpi_device_id memory_device_ids[] = {
 	{ACPI_MEMORY_DEVICE_HID, 0},
 	{"", 0},
 };
-MODULE_DEVICE_TABLE(acpi, memory_device_ids);
 
-static struct acpi_driver acpi_memory_device_driver = {
-	.name = "acpi_memhotplug",
-	.class = ACPI_MEMORY_DEVICE_CLASS,
+static struct acpi_scan_handler memory_device_handler = {
 	.ids = memory_device_ids,
-	.ops = {
-		.add = acpi_memory_device_add,
-		.remove = acpi_memory_device_remove,
-		},
+	.attach = acpi_memory_device_add,
+	.detach = acpi_memory_device_remove,
+	.hotplug = {
+		.enabled = true,
+	},
 };
 
 struct acpi_memory_info {
@@ -153,48 +147,6 @@ acpi_memory_get_device_resources(struct
 	return 0;
 }
 
-static int acpi_memory_get_device(acpi_handle handle,
-				  struct acpi_memory_device **mem_device)
-{
-	struct acpi_device *device = NULL;
-	int result = 0;
-
-	acpi_scan_lock_acquire();
-
-	acpi_bus_get_device(handle, &device);
-	if (device)
-		goto end;
-
-	/*
-	 * Now add the notified device.  This creates the acpi_device
-	 * and invokes .add function
-	 */
-	result = acpi_bus_scan(handle);
-	if (result) {
-		acpi_handle_warn(handle, "ACPI namespace scan failed\n");
-		result = -EINVAL;
-		goto out;
-	}
-	result = acpi_bus_get_device(handle, &device);
-	if (result) {
-		acpi_handle_warn(handle, "Missing device object\n");
-		result = -EINVAL;
-		goto out;
-	}
-
- end:
-	*mem_device = acpi_driver_data(device);
-	if (!(*mem_device)) {
-		dev_err(&device->dev, "driver data not found\n");
-		result = -ENODEV;
-		goto out;
-	}
-
- out:
-	acpi_scan_lock_release();
-	return result;
-}
-
 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 {
 	unsigned long long current_status;
@@ -306,95 +258,21 @@ static int acpi_memory_remove_memory(str
 	return result;
 }
 
-static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
-{
-	struct acpi_memory_device *mem_device;
-	struct acpi_device *device;
-	struct acpi_eject_event *ej_event = NULL;
-	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
-	acpi_status status;
-
-	switch (event) {
-	case ACPI_NOTIFY_BUS_CHECK:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "\nReceived BUS CHECK notification for device\n"));
-		/* Fall Through */
-	case ACPI_NOTIFY_DEVICE_CHECK:
-		if (event == ACPI_NOTIFY_DEVICE_CHECK)
-			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-					  "\nReceived DEVICE CHECK notification for device\n"));
-		if (acpi_memory_get_device(handle, &mem_device)) {
-			acpi_handle_err(handle, "Cannot find driver data\n");
-			break;
-		}
-
-		ost_code = ACPI_OST_SC_SUCCESS;
-		break;
-
-	case ACPI_NOTIFY_EJECT_REQUEST:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "\nReceived EJECT REQUEST notification for device\n"));
-
-		status = AE_ERROR;
-		acpi_scan_lock_acquire();
-
-		if (acpi_bus_get_device(handle, &device)) {
-			acpi_handle_err(handle, "Device doesn't exist\n");
-			goto unlock;
-		}
-		mem_device = acpi_driver_data(device);
-		if (!mem_device) {
-			acpi_handle_err(handle, "Driver Data is NULL\n");
-			goto unlock;
-		}
-
-		ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
-		if (!ej_event) {
-			pr_err(PREFIX "No memory, dropping EJECT\n");
-			goto unlock;
-		}
-
-		get_device(&device->dev);
-		ej_event->device = device;
-		ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
-		/* The eject is carried out asynchronously. */
-		status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
-						 ej_event);
-		if (ACPI_FAILURE(status)) {
-			put_device(&device->dev);
-			kfree(ej_event);
-		}
-
- unlock:
-		acpi_scan_lock_release();
-		if (ACPI_SUCCESS(status))
-			return;
-	default:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "Unsupported event [0x%x]\n", event));
-
-		/* non-hotplug event; possibly handled by other handler */
-		return;
-	}
-
-	/* Inform firmware that the hotplug operation has completed */
-	(void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
-}
-
 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
 {
 	if (!mem_device)
 		return;
 
 	acpi_memory_free_device_resources(mem_device);
+	mem_device->device->driver_data = NULL;
 	kfree(mem_device);
 }
 
-static int acpi_memory_device_add(struct acpi_device *device)
+static int acpi_memory_device_add(struct acpi_device *device,
+				  const struct acpi_device_id *not_used)
 {
+	struct acpi_memory_device *mem_device;
 	int result;
-	struct acpi_memory_device *mem_device = NULL;
-
 
 	if (!device)
 		return -EINVAL;
@@ -419,147 +297,36 @@ static int acpi_memory_device_add(struct
 	/* Set the device state */
 	mem_device->state = MEMORY_POWER_ON_STATE;
 
-	pr_debug("%s\n", acpi_device_name(device));
+	result = acpi_memory_check_device(mem_device);
+	if (result) {
+		acpi_memory_device_free(mem_device);
+		return 0;
+	}
 
-	if (!acpi_memory_check_device(mem_device)) {
-		/* call add_memory func */
-		result = acpi_memory_enable_device(mem_device);
-		if (result) {
-			dev_err(&device->dev,
-				"Error in acpi_memory_enable_device\n");
-			acpi_memory_device_free(mem_device);
-		}
+	result = acpi_memory_enable_device(mem_device);
+	if (result) {
+		dev_err(&device->dev, "acpi_memory_enable_device() error\n");
+		acpi_memory_device_free(mem_device);
+		return -ENODEV;
 	}
-	return result;
+
+	dev_dbg(&device->dev, "Memory device configured by ACPI\n");
+	return 1;
 }
 
-static int acpi_memory_device_remove(struct acpi_device *device)
+static void acpi_memory_device_remove(struct acpi_device *device)
 {
-	struct acpi_memory_device *mem_device = NULL;
-	int result;
+	struct acpi_memory_device *mem_device;
 
 	if (!device || !acpi_driver_data(device))
-		return -EINVAL;
+		return;
 
 	mem_device = acpi_driver_data(device);
-
-	result = acpi_memory_remove_memory(mem_device);
-	if (result)
-		return result;
-
+	acpi_memory_remove_memory(mem_device);
 	acpi_memory_device_free(mem_device);
-
-	return 0;
-}
-
-/*
- * Helper function to check for memory device
- */
-static acpi_status is_memory_device(acpi_handle handle)
-{
-	char *hardware_id;
-	acpi_status status;
-	struct acpi_device_info *info;
-
-	status = acpi_get_object_info(handle, &info);
-	if (ACPI_FAILURE(status))
-		return status;
-
-	if (!(info->valid & ACPI_VALID_HID)) {
-		kfree(info);
-		return AE_ERROR;
-	}
-
-	hardware_id = info->hardware_id.string;
-	if ((hardware_id == NULL) ||
-	    (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
-		status = AE_ERROR;
-
-	kfree(info);
-	return status;
-}
-
-static acpi_status
-acpi_memory_register_notify_handler(acpi_handle handle,
-				    u32 level, void *ctxt, void **retv)
-{
-	acpi_status status;
-
-
-	status = is_memory_device(handle);
-	if (ACPI_FAILURE(status))
-		return AE_OK;	/* continue */
-
-	status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
-					     acpi_memory_device_notify, NULL);
-	/* continue */
-	return AE_OK;
-}
-
-static acpi_status
-acpi_memory_deregister_notify_handler(acpi_handle handle,
-				      u32 level, void *ctxt, void **retv)
-{
-	acpi_status status;
-
-
-	status = is_memory_device(handle);
-	if (ACPI_FAILURE(status))
-		return AE_OK;	/* continue */
-
-	status = acpi_remove_notify_handler(handle,
-					    ACPI_SYSTEM_NOTIFY,
-					    acpi_memory_device_notify);
-
-	return AE_OK;	/* continue */
-}
-
-static int __init acpi_memory_device_init(void)
-{
-	int result;
-	acpi_status status;
-
-
-	result = acpi_bus_register_driver(&acpi_memory_device_driver);
-
-	if (result < 0)
-		return -ENODEV;
-
-	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
-				     ACPI_UINT32_MAX,
-				     acpi_memory_register_notify_handler, NULL,
-				     NULL, NULL);
-
-	if (ACPI_FAILURE(status)) {
-		ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
-		acpi_bus_unregister_driver(&acpi_memory_device_driver);
-		return -ENODEV;
-	}
-
-	return 0;
 }
 
-static void __exit acpi_memory_device_exit(void)
+void __init acpi_memory_hotplug_init(void)
 {
-	acpi_status status;
-
-
-	/*
-	 * Adding this to un-install notification handlers for all the device
-	 * handles.
-	 */
-	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
-				     ACPI_UINT32_MAX,
-				     acpi_memory_deregister_notify_handler, NULL,
-				     NULL, NULL);
-
-	if (ACPI_FAILURE(status))
-		ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
-
-	acpi_bus_unregister_driver(&acpi_memory_device_driver);
-
-	return;
+	acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
 }
-
-module_init(acpi_memory_device_init);
-module_exit(acpi_memory_device_exit);
Index: test/drivers/acpi/internal.h
===================================================================
--- test.orig/drivers/acpi/internal.h
+++ test/drivers/acpi/internal.h
@@ -35,6 +35,11 @@ void acpi_container_init(void);
 #else
 static inline void acpi_container_init(void) {}
 #endif
+#ifdef CONFIG_ACPI_HOTPLUG_MEMORY
+void acpi_memory_hotplug_init(void);
+#else
+static inline void acpi_memory_hotplug_init(void) {}
+#endif
 
 void acpi_sysfs_add_hotplug_profile(struct acpi_hotplug_profile *hotplug,
 				    const char *name);
Index: test/drivers/acpi/scan.c
===================================================================
--- test.orig/drivers/acpi/scan.c
+++ test/drivers/acpi/scan.c
@@ -2025,6 +2025,7 @@ int __init acpi_scan_init(void)
 	acpi_platform_init();
 	acpi_csrt_init();
 	acpi_container_init();
+	acpi_memory_hotplug_init();
 
 	mutex_lock(&acpi_scan_lock);
 	/*
