[mirror_ubuntu-bionic-kernel.git] / drivers / acpi / acpi_memhotplug.c

/*
 * Copyright (C) 2004 Intel Corporation <naveen.b.s@intel.com>
 *
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *
 * ACPI based HotPlug driver that supports Memory Hotplug
 * This driver fields notifications from firmare for memory add
 * and remove operations and alerts the VM of the affected memory
 * ranges.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/memory_hotplug.h>
#include <acpi/acpi_drivers.h>

#define ACPI_MEMORY_DEVICE_COMPONENT		0x08000000UL
#define ACPI_MEMORY_DEVICE_CLASS		"memory"
#define ACPI_MEMORY_DEVICE_HID			"PNP0C80"
#define ACPI_MEMORY_DEVICE_DRIVER_NAME		"Hotplug Mem Driver"
#define ACPI_MEMORY_DEVICE_NAME			"Hotplug Mem Device"

#define _COMPONENT		ACPI_MEMORY_DEVICE_COMPONENT

ACPI_MODULE_NAME("acpi_memory")
    MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
MODULE_DESCRIPTION(ACPI_MEMORY_DEVICE_DRIVER_NAME);
MODULE_LICENSE("GPL");

/* ACPI _STA method values */
#define ACPI_MEMORY_STA_PRESENT		(0x00000001UL)
#define ACPI_MEMORY_STA_ENABLED		(0x00000002UL)
#define ACPI_MEMORY_STA_FUNCTIONAL	(0x00000008UL)

/* 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, int type);
static int acpi_memory_device_start(struct acpi_device *device);

static struct acpi_driver acpi_memory_device_driver = {
	.name = ACPI_MEMORY_DEVICE_DRIVER_NAME,
	.class = ACPI_MEMORY_DEVICE_CLASS,
	.ids = ACPI_MEMORY_DEVICE_HID,
	.ops = {
		.add = acpi_memory_device_add,
		.remove = acpi_memory_device_remove,
		.start = acpi_memory_device_start,
		},
};

struct acpi_memory_info {
	struct list_head list;
	u64 start_addr;		/* Memory Range start physical addr */
	u64 length;		/* Memory Range length */
	unsigned short caching;	/* memory cache attribute */
	unsigned short write_protect;	/* memory read/write attribute */
	unsigned int enabled:1;
};

struct acpi_memory_device {
	struct acpi_device * device;
	unsigned int state;	/* State of the memory device */
	struct list_head res_list;
};

static acpi_status
acpi_memory_get_resource(struct acpi_resource *resource, void *context)
{
	struct acpi_memory_device *mem_device = context;
	struct acpi_resource_address64 address64;
	struct acpi_memory_info *info, *new;
	acpi_status status;

	status = acpi_resource_to_address64(resource, &address64);
	if (ACPI_FAILURE(status) ||
	    (address64.resource_type != ACPI_MEMORY_RANGE))
		return AE_OK;

	list_for_each_entry(info, &mem_device->res_list, list) {
		/* Can we combine the resource range information? */
		if ((info->caching == address64.info.mem.caching) &&
		    (info->write_protect == address64.info.mem.write_protect) &&
		    (info->start_addr + info->length == address64.minimum)) {
			info->length += address64.address_length;
			return AE_OK;
		}
	}

	new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
	if (!new)
		return AE_ERROR;

	INIT_LIST_HEAD(&new->list);
	new->caching = address64.info.mem.caching;
	new->write_protect = address64.info.mem.write_protect;
	new->start_addr = address64.minimum;
	new->length = address64.address_length;
	list_add_tail(&new->list, &mem_device->res_list);

	return AE_OK;
}

static int
acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
{
	acpi_status status;
	struct acpi_memory_info *info, *n;


	if (!list_empty(&mem_device->res_list))
		return 0;

	status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
				     acpi_memory_get_resource, mem_device);
	if (ACPI_FAILURE(status)) {
		list_for_each_entry_safe(info, n, &mem_device->res_list, list)
			kfree(info);
		INIT_LIST_HEAD(&mem_device->res_list);
		return -EINVAL;
	}

	return 0;
}

static int
acpi_memory_get_device(acpi_handle handle,
		       struct acpi_memory_device **mem_device)
{
	acpi_status status;
	acpi_handle phandle;
	struct acpi_device *device = NULL;
	struct acpi_device *pdevice = NULL;


	if (!acpi_bus_get_device(handle, &device) && device)
		goto end;

	status = acpi_get_parent(handle, &phandle);
	if (ACPI_FAILURE(status)) {
		ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
		return -EINVAL;
	}

	/* Get the parent device */
	status = acpi_bus_get_device(phandle, &pdevice);
	if (ACPI_FAILURE(status)) {
		ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
		return -EINVAL;
	}

	/*
	 * Now add the notified device.  This creates the acpi_device
	 * and invokes .add function
	 */
	status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
	if (ACPI_FAILURE(status)) {
		ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
		return -EINVAL;
	}

      end:
	*mem_device = acpi_driver_data(device);
	if (!(*mem_device)) {
		printk(KERN_ERR "\n driver data not found");
		return -ENODEV;
	}

	return 0;
}

static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
{
	unsigned long current_status;


	/* Get device present/absent information from the _STA */
	if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
					       NULL, &current_status)))
		return -ENODEV;
	/*
	 * Check for device status. Device should be
	 * present/enabled/functioning.
	 */
	if (!((current_status & ACPI_MEMORY_STA_PRESENT)
	      && (current_status & ACPI_MEMORY_STA_ENABLED)
	      && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
		return -ENODEV;

	return 0;
}

static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
{
	int result, num_enabled = 0;
	struct acpi_memory_info *info;
	int node;


	/* Get the range from the _CRS */
	result = acpi_memory_get_device_resources(mem_device);
	if (result) {
		printk(KERN_ERR PREFIX "get_device_resources failed\n");
		mem_device->state = MEMORY_INVALID_STATE;
		return result;
	}

	node = acpi_get_node(mem_device->device->handle);
	/*
	 * Tell the VM there is more memory here...
	 * Note: Assume that this function returns zero on success
	 * We don't have memory-hot-add rollback function,now.
	 * (i.e. memory-hot-remove function)
	 */
	list_for_each_entry(info, &mem_device->res_list, list) {
		if (info->enabled) { /* just sanity check...*/
			num_enabled++;
			continue;
		}
		result = add_memory(node, info->start_addr, info->length);
		if (result)
			continue;
		info->enabled = 1;
		num_enabled++;
	}
	if (!num_enabled) {
		printk(KERN_ERR PREFIX "add_memory failed\n");
		mem_device->state = MEMORY_INVALID_STATE;
		return -EINVAL;
	}

	return result;
}

static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
{
	acpi_status status;
	struct acpi_object_list arg_list;
	union acpi_object arg;
	unsigned long current_status;


	/* Issue the _EJ0 command */
	arg_list.count = 1;
	arg_list.pointer = &arg;
	arg.type = ACPI_TYPE_INTEGER;
	arg.integer.value = 1;
	status = acpi_evaluate_object(mem_device->device->handle,
				      "_EJ0", &arg_list, NULL);
	/* Return on _EJ0 failure */
	if (ACPI_FAILURE(status)) {
		ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
		return -ENODEV;
	}

	/* Evalute _STA to check if the device is disabled */
	status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
				       NULL, &current_status);
	if (ACPI_FAILURE(status))
		return -ENODEV;

	/* Check for device status.  Device should be disabled */
	if (current_status & ACPI_MEMORY_STA_ENABLED)
		return -EINVAL;

	return 0;
}

static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
{
	int result;
	struct acpi_memory_info *info, *n;


	/*
	 * Ask the VM to offline this memory range.
	 * Note: Assume that this function returns zero on success
	 */
	list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
		if (info->enabled) {
			result = remove_memory(info->start_addr, info->length);
			if (result)
				return result;
		}
		kfree(info);
	}

	/* Power-off and eject the device */
	result = acpi_memory_powerdown_device(mem_device);
	if (result) {
		/* Set the status of the device to invalid */
		mem_device->state = MEMORY_INVALID_STATE;
		return result;
	}

	mem_device->state = MEMORY_POWER_OFF_STATE;
	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;


	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)) {
			printk(KERN_ERR PREFIX "Cannot find driver data\n");
			return;
		}

		if (!acpi_memory_check_device(mem_device)) {
			if (acpi_memory_enable_device(mem_device))
				printk(KERN_ERR PREFIX
					    "Cannot enable memory device\n");
		}
		break;
	case ACPI_NOTIFY_EJECT_REQUEST:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				  "\nReceived EJECT REQUEST notification for device\n"));

		if (acpi_bus_get_device(handle, &device)) {
			printk(KERN_ERR PREFIX "Device doesn't exist\n");
			break;
		}
		mem_device = acpi_driver_data(device);
		if (!mem_device) {
			printk(KERN_ERR PREFIX "Driver Data is NULL\n");
			break;
		}

		/*
		 * Currently disabling memory device from kernel mode
		 * TBD: Can also be disabled from user mode scripts
		 * TBD: Can also be disabled by Callback registration
		 *      with generic sysfs driver
		 */
		if (acpi_memory_disable_device(mem_device))
			printk(KERN_ERR PREFIX
				    "Disable memory device\n");
		/*
		 * TBD: Invoke acpi_bus_remove to cleanup data structures
		 */
		break;
	default:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				  "Unsupported event [0x%x]\n", event));
		break;
	}

	return;
}

static int acpi_memory_device_add(struct acpi_device *device)
{
	int result;
	struct acpi_memory_device *mem_device = NULL;


	if (!device)
		return -EINVAL;

	mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
	if (!mem_device)
		return -ENOMEM;
	memset(mem_device, 0, sizeof(struct acpi_memory_device));

	INIT_LIST_HEAD(&mem_device->res_list);
	mem_device->device = device;
	sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
	sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
	acpi_driver_data(device) = mem_device;

	/* Get the range from the _CRS */
	result = acpi_memory_get_device_resources(mem_device);
	if (result) {
		kfree(mem_device);
		return result;
	}

	/* Set the device state */
	mem_device->state = MEMORY_POWER_ON_STATE;

	printk(KERN_INFO "%s \n", acpi_device_name(device));

	return result;
}

static int acpi_memory_device_remove(struct acpi_device *device, int type)
{
	struct acpi_memory_device *mem_device = NULL;


	if (!device || !acpi_driver_data(device))
		return -EINVAL;

	mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
	kfree(mem_device);

	return 0;
}

static int acpi_memory_device_start (struct acpi_device *device)
{
	struct acpi_memory_device *mem_device;
	int result = 0;

	mem_device = acpi_driver_data(device);

	if (!acpi_memory_check_device(mem_device)) {
		/* call add_memory func */
		result = acpi_memory_enable_device(mem_device);
		if (result)
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
				"Error in acpi_memory_enable_device\n"));
	}
	return result;
}

/*
 * Helper function to check for memory device
 */
static acpi_status is_memory_device(acpi_handle handle)
{
	char *hardware_id;
	acpi_status status;
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	struct acpi_device_info *info;


	status = acpi_get_object_info(handle, &buffer);
	if (ACPI_FAILURE(status))
		return status;

	info = buffer.pointer;
	if (!(info->valid & ACPI_VALID_HID)) {
		kfree(buffer.pointer);
		return AE_ERROR;
	}

	hardware_id = info->hardware_id.value;
	if ((hardware_id == NULL) ||
	    (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
		status = AE_ERROR;

	kfree(buffer.pointer);
	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)){
		ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
		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)){
		ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
		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);

	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)
{
	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);

	if (ACPI_FAILURE(status))
		ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));

	acpi_bus_unregister_driver(&acpi_memory_device_driver);

	return;
}

module_init(acpi_memory_device_init);
module_exit(acpi_memory_device_exit);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright (C) 2004 Intel Corporation <naveen.b.s@intel.com>
	3	*
	4	* All rights reserved.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or (at
	9	* your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful, but
	12	* WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
	14	* NON INFRINGEMENT. See the GNU General Public License for more
	15	* details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to the Free Software
	19	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	20	*
	21	*
	22	* ACPI based HotPlug driver that supports Memory Hotplug
	23	* This driver fields notifications from firmare for memory add
	24	* and remove operations and alerts the VM of the affected memory
	25	* ranges.
	26	*/
	27
	28	#include <linux/kernel.h>
	29	#include <linux/module.h>
	30	#include <linux/init.h>
	31	#include <linux/types.h>
	32	#include <linux/memory_hotplug.h>
	33	#include <acpi/acpi_drivers.h>
	34
1da177e4 LT	35	#define ACPI_MEMORY_DEVICE_COMPONENT 0x08000000UL
	36	#define ACPI_MEMORY_DEVICE_CLASS "memory"
	37	#define ACPI_MEMORY_DEVICE_HID "PNP0C80"
	38	#define ACPI_MEMORY_DEVICE_DRIVER_NAME "Hotplug Mem Driver"
	39	#define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
	40
	41	#define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT
	42
4be44fcd LB	43	ACPI_MODULE_NAME("acpi_memory")
4be44fcd LB	44	MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
1da177e4 LT	45	MODULE_DESCRIPTION(ACPI_MEMORY_DEVICE_DRIVER_NAME);
	46	MODULE_LICENSE("GPL");
	47
	48	/* ACPI _STA method values */
	49	#define ACPI_MEMORY_STA_PRESENT (0x00000001UL)
	50	#define ACPI_MEMORY_STA_ENABLED (0x00000002UL)
	51	#define ACPI_MEMORY_STA_FUNCTIONAL (0x00000008UL)
	52
	53	/* Memory Device States */
	54	#define MEMORY_INVALID_STATE 0
	55	#define MEMORY_POWER_ON_STATE 1
	56	#define MEMORY_POWER_OFF_STATE 2
	57
4be44fcd LB	58	static int acpi_memory_device_add(struct acpi_device *device);
4be44fcd LB	59	static int acpi_memory_device_remove(struct acpi_device *device, int type);
1f425994	60	static int acpi_memory_device_start(struct acpi_device *device);
1da177e4 LT	61
1da177e4 LT	62	static struct acpi_driver acpi_memory_device_driver = {
4be44fcd LB	63	.name = ACPI_MEMORY_DEVICE_DRIVER_NAME,
	64	.class = ACPI_MEMORY_DEVICE_CLASS,
	65	.ids = ACPI_MEMORY_DEVICE_HID,
	66	.ops = {
	67	.add = acpi_memory_device_add,
	68	.remove = acpi_memory_device_remove,
1f425994	69	.start = acpi_memory_device_start,
4be44fcd	70	},
1da177e4 LT	71	};
1da177e4 LT	72
9ac02398 KH	73	struct acpi_memory_info {
	74	struct list_head list;
	75	u64 start_addr; /* Memory Range start physical addr */
	76	u64 length; /* Memory Range length */
	77	unsigned short caching; /* memory cache attribute */
	78	unsigned short write_protect; /* memory read/write attribute */
	79	unsigned int enabled:1;
	80	};
	81
1da177e4	82	struct acpi_memory_device {
3b74863d	83	struct acpi_device * device;
4be44fcd	84	unsigned int state; /* State of the memory device */
9ac02398	85	struct list_head res_list;
1da177e4 LT	86	};
1da177e4 LT	87
9ac02398 KH	88	static acpi_status
	89	acpi_memory_get_resource(struct acpi_resource resource, void context)
	90	{
	91	struct acpi_memory_device *mem_device = context;
	92	struct acpi_resource_address64 address64;
	93	struct acpi_memory_info info, new;
	94	acpi_status status;
	95
	96	status = acpi_resource_to_address64(resource, &address64);
	97	if (ACPI_FAILURE(status) \|\|
	98	(address64.resource_type != ACPI_MEMORY_RANGE))
	99	return AE_OK;
	100
	101	list_for_each_entry(info, &mem_device->res_list, list) {
	102	/* Can we combine the resource range information? */
	103	if ((info->caching == address64.info.mem.caching) &&
	104	(info->write_protect == address64.info.mem.write_protect) &&
	105	(info->start_addr + info->length == address64.minimum)) {
	106	info->length += address64.address_length;
	107	return AE_OK;
	108	}
	109	}
	110
	111	new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
	112	if (!new)
	113	return AE_ERROR;
	114
	115	INIT_LIST_HEAD(&new->list);
	116	new->caching = address64.info.mem.caching;
	117	new->write_protect = address64.info.mem.write_protect;
	118	new->start_addr = address64.minimum;
	119	new->length = address64.address_length;
	120	list_add_tail(&new->list, &mem_device->res_list);
	121
	122	return AE_OK;
	123	}
	124
1da177e4 LT	125	static int
	126	acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
	127	{
	128	acpi_status status;
9ac02398	129	struct acpi_memory_info info, n;
1da177e4	130
1da177e4	131
5d2870fa KH	132	if (!list_empty(&mem_device->res_list))
	133	return 0;
	134
b8632785	135	status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
9ac02398 KH	136	acpi_memory_get_resource, mem_device);
	137	if (ACPI_FAILURE(status)) {
	138	list_for_each_entry_safe(info, n, &mem_device->res_list, list)
	139	kfree(info);
5d2870fa	140	INIT_LIST_HEAD(&mem_device->res_list);
d550d98d	141	return -EINVAL;
1da177e4 LT	142	}
1da177e4 LT	143
d550d98d	144	return 0;
1da177e4 LT	145	}
	146
	147	static int
	148	acpi_memory_get_device(acpi_handle handle,
4be44fcd	149	struct acpi_memory_device **mem_device)
1da177e4 LT	150	{
	151	acpi_status status;
	152	acpi_handle phandle;
	153	struct acpi_device *device = NULL;
	154	struct acpi_device *pdevice = NULL;
	155
1da177e4 LT	156
	157	if (!acpi_bus_get_device(handle, &device) && device)
	158	goto end;
	159
	160	status = acpi_get_parent(handle, &phandle);
	161	if (ACPI_FAILURE(status)) {
a6fc6720	162	ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
d550d98d	163	return -EINVAL;
1da177e4 LT	164	}
	165
	166	/* Get the parent device */
	167	status = acpi_bus_get_device(phandle, &pdevice);
	168	if (ACPI_FAILURE(status)) {
a6fc6720	169	ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
d550d98d	170	return -EINVAL;
1da177e4 LT	171	}
	172
	173	/*
	174	* Now add the notified device. This creates the acpi_device
	175	* and invokes .add function
	176	*/
	177	status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
	178	if (ACPI_FAILURE(status)) {
a6fc6720	179	ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
d550d98d	180	return -EINVAL;
1da177e4 LT	181	}
1da177e4 LT	182
4be44fcd	183	end:
1da177e4 LT	184	*mem_device = acpi_driver_data(device);
1da177e4 LT	185	if (!(*mem_device)) {
4be44fcd	186	printk(KERN_ERR "\n driver data not found");
d550d98d	187	return -ENODEV;
1da177e4 LT	188	}
1da177e4 LT	189
d550d98d	190	return 0;
1da177e4 LT	191	}
1da177e4 LT	192
4be44fcd	193	static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
1da177e4 LT	194	{
	195	unsigned long current_status;
	196
1da177e4 LT	197
1da177e4 LT	198	/* Get device present/absent information from the _STA */
b8632785	199	if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
4be44fcd	200	NULL, &current_status)))
d550d98d	201	return -ENODEV;
1da177e4 LT	202	/*
	203	* Check for device status. Device should be
	204	* present/enabled/functioning.
	205	*/
	206	if (!((current_status & ACPI_MEMORY_STA_PRESENT)
4be44fcd LB	207	&& (current_status & ACPI_MEMORY_STA_ENABLED)
4be44fcd LB	208	&& (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
d550d98d	209	return -ENODEV;
1da177e4	210
d550d98d	211	return 0;
1da177e4 LT	212	}
1da177e4 LT	213
4be44fcd	214	static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
1da177e4	215	{
9ac02398 KH	216	int result, num_enabled = 0;
9ac02398 KH	217	struct acpi_memory_info *info;
1e3590e2	218	int node;
1da177e4	219
1da177e4 LT	220
	221	/* Get the range from the _CRS */
	222	result = acpi_memory_get_device_resources(mem_device);
	223	if (result) {
6468463a	224	printk(KERN_ERR PREFIX "get_device_resources failed\n");
1da177e4 LT	225	mem_device->state = MEMORY_INVALID_STATE;
	226	return result;
	227	}
	228
b8632785	229	node = acpi_get_node(mem_device->device->handle);
1da177e4 LT	230	/*
	231	* Tell the VM there is more memory here...
	232	* Note: Assume that this function returns zero on success
9ac02398 KH	233	* We don't have memory-hot-add rollback function,now.
9ac02398 KH	234	* (i.e. memory-hot-remove function)
1da177e4	235	*/
9ac02398	236	list_for_each_entry(info, &mem_device->res_list, list) {
fa25d8d6	237	if (info->enabled) { /* just sanity check...*/
dd56a8e3 YG	238	num_enabled++;
	239	continue;
	240	}
bc02af93	241	result = add_memory(node, info->start_addr, info->length);
9ac02398 KH	242	if (result)
	243	continue;
	244	info->enabled = 1;
	245	num_enabled++;
	246	}
	247	if (!num_enabled) {
0a1f1ab8	248	printk(KERN_ERR PREFIX "add_memory failed\n");
1da177e4	249	mem_device->state = MEMORY_INVALID_STATE;
9ac02398	250	return -EINVAL;
1da177e4 LT	251	}
	252
	253	return result;
	254	}
	255
4be44fcd	256	static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
1da177e4 LT	257	{
1da177e4 LT	258	acpi_status status;
4be44fcd	259	struct acpi_object_list arg_list;
1da177e4 LT	260	union acpi_object arg;
	261	unsigned long current_status;
	262
1da177e4 LT	263
	264	/* Issue the _EJ0 command */
	265	arg_list.count = 1;
	266	arg_list.pointer = &arg;
	267	arg.type = ACPI_TYPE_INTEGER;
	268	arg.integer.value = 1;
b8632785	269	status = acpi_evaluate_object(mem_device->device->handle,
4be44fcd	270	"_EJ0", &arg_list, NULL);
1da177e4 LT	271	/* Return on _EJ0 failure */
1da177e4 LT	272	if (ACPI_FAILURE(status)) {
a6fc6720	273	ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
d550d98d	274	return -ENODEV;
1da177e4 LT	275	}
	276
	277	/* Evalute _STA to check if the device is disabled */
b8632785	278	status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
4be44fcd	279	NULL, &current_status);
1da177e4	280	if (ACPI_FAILURE(status))
d550d98d	281	return -ENODEV;
1da177e4 LT	282
	283	/* Check for device status. Device should be disabled */
	284	if (current_status & ACPI_MEMORY_STA_ENABLED)
d550d98d	285	return -EINVAL;
1da177e4	286
d550d98d	287	return 0;
1da177e4 LT	288	}
1da177e4 LT	289
4be44fcd	290	static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
1da177e4 LT	291	{
1da177e4 LT	292	int result;
9ac02398	293	struct acpi_memory_info info, n;
1da177e4	294
1da177e4 LT	295
	296	/*
	297	* Ask the VM to offline this memory range.
	298	* Note: Assume that this function returns zero on success
	299	*/
9ac02398 KH	300	list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
	301	if (info->enabled) {
	302	result = remove_memory(info->start_addr, info->length);
	303	if (result)
	304	return result;
	305	}
	306	kfree(info);
1da177e4 LT	307	}
	308
	309	/* Power-off and eject the device */
	310	result = acpi_memory_powerdown_device(mem_device);
	311	if (result) {
1da177e4 LT	312	/* Set the status of the device to invalid */
	313	mem_device->state = MEMORY_INVALID_STATE;
	314	return result;
	315	}
	316
	317	mem_device->state = MEMORY_POWER_OFF_STATE;
	318	return result;
	319	}
	320
4be44fcd	321	static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
1da177e4 LT	322	{
	323	struct acpi_memory_device *mem_device;
	324	struct acpi_device *device;
	325
1da177e4 LT	326
	327	switch (event) {
	328	case ACPI_NOTIFY_BUS_CHECK:
	329	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd	330	"\nReceived BUS CHECK notification for device\n"));
1da177e4 LT	331	/* Fall Through */
	332	case ACPI_NOTIFY_DEVICE_CHECK:
	333	if (event == ACPI_NOTIFY_DEVICE_CHECK)
	334	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd	335	"\nReceived DEVICE CHECK notification for device\n"));
1da177e4	336	if (acpi_memory_get_device(handle, &mem_device)) {
6468463a	337	printk(KERN_ERR PREFIX "Cannot find driver data\n");
d550d98d	338	return;
1da177e4 LT	339	}
	340
	341	if (!acpi_memory_check_device(mem_device)) {
	342	if (acpi_memory_enable_device(mem_device))
6468463a LB	343	printk(KERN_ERR PREFIX
6468463a LB	344	"Cannot enable memory device\n");
1da177e4 LT	345	}
	346	break;
	347	case ACPI_NOTIFY_EJECT_REQUEST:
	348	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd	349	"\nReceived EJECT REQUEST notification for device\n"));
1da177e4 LT	350
1da177e4 LT	351	if (acpi_bus_get_device(handle, &device)) {
6468463a	352	printk(KERN_ERR PREFIX "Device doesn't exist\n");
1da177e4 LT	353	break;
	354	}
	355	mem_device = acpi_driver_data(device);
	356	if (!mem_device) {
6468463a	357	printk(KERN_ERR PREFIX "Driver Data is NULL\n");
1da177e4 LT	358	break;
	359	}
	360
	361	/*
	362	* Currently disabling memory device from kernel mode
	363	* TBD: Can also be disabled from user mode scripts
	364	* TBD: Can also be disabled by Callback registration
4be44fcd	365	* with generic sysfs driver
1da177e4 LT	366	*/
1da177e4 LT	367	if (acpi_memory_disable_device(mem_device))
6468463a LB	368	printk(KERN_ERR PREFIX
6468463a LB	369	"Disable memory device\n");
1da177e4 LT	370	/*
	371	* TBD: Invoke acpi_bus_remove to cleanup data structures
	372	*/
	373	break;
	374	default:
	375	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd	376	"Unsupported event [0x%x]\n", event));
1da177e4 LT	377	break;
	378	}
	379
d550d98d	380	return;
1da177e4 LT	381	}
1da177e4 LT	382
4be44fcd	383	static int acpi_memory_device_add(struct acpi_device *device)
1da177e4 LT	384	{
	385	int result;
	386	struct acpi_memory_device *mem_device = NULL;
	387
1da177e4 LT	388
1da177e4 LT	389	if (!device)
d550d98d	390	return -EINVAL;
1da177e4 LT	391
	392	mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
	393	if (!mem_device)
d550d98d	394	return -ENOMEM;
1da177e4 LT	395	memset(mem_device, 0, sizeof(struct acpi_memory_device));
1da177e4 LT	396
9ac02398	397	INIT_LIST_HEAD(&mem_device->res_list);
3b74863d	398	mem_device->device = device;
1da177e4 LT	399	sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
	400	sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
	401	acpi_driver_data(device) = mem_device;
	402
	403	/* Get the range from the _CRS */
	404	result = acpi_memory_get_device_resources(mem_device);
	405	if (result) {
	406	kfree(mem_device);
d550d98d	407	return result;
1da177e4 LT	408	}
	409
	410	/* Set the device state */
	411	mem_device->state = MEMORY_POWER_ON_STATE;
	412
	413	printk(KERN_INFO "%s \n", acpi_device_name(device));
	414
d550d98d	415	return result;
1da177e4 LT	416	}
1da177e4 LT	417
4be44fcd	418	static int acpi_memory_device_remove(struct acpi_device *device, int type)
1da177e4 LT	419	{
	420	struct acpi_memory_device *mem_device = NULL;
	421
1da177e4 LT	422
1da177e4 LT	423	if (!device \|\| !acpi_driver_data(device))
d550d98d	424	return -EINVAL;
1da177e4	425
4be44fcd	426	mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
1da177e4 LT	427	kfree(mem_device);
1da177e4 LT	428
d550d98d	429	return 0;
1da177e4 LT	430	}
1da177e4 LT	431
1f425994 YG	432	static int acpi_memory_device_start (struct acpi_device *device)
	433	{
	434	struct acpi_memory_device *mem_device;
	435	int result = 0;
	436
1f425994 YG	437	mem_device = acpi_driver_data(device);
	438
	439	if (!acpi_memory_check_device(mem_device)) {
	440	/* call add_memory func */
	441	result = acpi_memory_enable_device(mem_device);
	442	if (result)
	443	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	444	"Error in acpi_memory_enable_device\n"));
	445	}
d120cfb5	446	return result;
1f425994 YG	447	}
1f425994 YG	448
1da177e4 LT	449	/*
	450	* Helper function to check for memory device
	451	*/
4be44fcd	452	static acpi_status is_memory_device(acpi_handle handle)
1da177e4 LT	453	{
	454	char *hardware_id;
	455	acpi_status status;
4be44fcd	456	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1da177e4 LT	457	struct acpi_device_info *info;
1da177e4 LT	458
1da177e4 LT	459
	460	status = acpi_get_object_info(handle, &buffer);
	461	if (ACPI_FAILURE(status))
d550d98d	462	return status;
1da177e4 LT	463
	464	info = buffer.pointer;
	465	if (!(info->valid & ACPI_VALID_HID)) {
02438d87	466	kfree(buffer.pointer);
d550d98d	467	return AE_ERROR;
1da177e4 LT	468	}
	469
	470	hardware_id = info->hardware_id.value;
	471	if ((hardware_id == NULL) \|\|
4be44fcd	472	(strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
1da177e4 LT	473	status = AE_ERROR;
1da177e4 LT	474
02438d87	475	kfree(buffer.pointer);
d550d98d	476	return status;
1da177e4 LT	477	}
	478
	479	static acpi_status
4be44fcd LB	480	acpi_memory_register_notify_handler(acpi_handle handle,
4be44fcd LB	481	u32 level, void ctxt, void *retv)
1da177e4 LT	482	{
	483	acpi_status status;
	484
1da177e4 LT	485
1da177e4 LT	486	status = is_memory_device(handle);
a6fc6720 TR	487	if (ACPI_FAILURE(status)){
a6fc6720 TR	488	ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
d550d98d	489	return AE_OK; /* continue */
a6fc6720	490	}
1da177e4 LT	491
1da177e4 LT	492	status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
4be44fcd	493	acpi_memory_device_notify, NULL);
a6fc6720	494	/* continue */
d550d98d	495	return AE_OK;
1da177e4 LT	496	}
	497
	498	static acpi_status
4be44fcd LB	499	acpi_memory_deregister_notify_handler(acpi_handle handle,
4be44fcd LB	500	u32 level, void ctxt, void *retv)
1da177e4 LT	501	{
	502	acpi_status status;
	503
1da177e4 LT	504
1da177e4 LT	505	status = is_memory_device(handle);
a6fc6720 TR	506	if (ACPI_FAILURE(status)){
a6fc6720 TR	507	ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
d550d98d	508	return AE_OK; /* continue */
a6fc6720	509	}
1da177e4 LT	510
1da177e4 LT	511	status = acpi_remove_notify_handler(handle,
4be44fcd LB	512	ACPI_SYSTEM_NOTIFY,
4be44fcd LB	513	acpi_memory_device_notify);
1da177e4	514
d550d98d	515	return AE_OK; /* continue */
1da177e4 LT	516	}
1da177e4 LT	517
4be44fcd	518	static int __init acpi_memory_device_init(void)
1da177e4 LT	519	{
	520	int result;
	521	acpi_status status;
	522
1da177e4 LT	523
	524	result = acpi_bus_register_driver(&acpi_memory_device_driver);
	525
	526	if (result < 0)
d550d98d	527	return -ENODEV;
1da177e4 LT	528
1da177e4 LT	529	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
4be44fcd LB	530	ACPI_UINT32_MAX,
	531	acpi_memory_register_notify_handler,
	532	NULL, NULL);
1da177e4	533
4be44fcd	534	if (ACPI_FAILURE(status)) {
a6fc6720	535	ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
1da177e4	536	acpi_bus_unregister_driver(&acpi_memory_device_driver);
d550d98d	537	return -ENODEV;
4be44fcd	538	}
1da177e4	539
d550d98d	540	return 0;
1da177e4 LT	541	}
1da177e4 LT	542
4be44fcd	543	static void __exit acpi_memory_device_exit(void)
1da177e4 LT	544	{
	545	acpi_status status;
	546
1da177e4 LT	547
	548	/*
	549	* Adding this to un-install notification handlers for all the device
	550	* handles.
	551	*/
	552	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
4be44fcd LB	553	ACPI_UINT32_MAX,
	554	acpi_memory_deregister_notify_handler,
	555	NULL, NULL);
1da177e4	556
4be44fcd	557	if (ACPI_FAILURE(status))
a6fc6720	558	ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
1da177e4 LT	559
	560	acpi_bus_unregister_driver(&acpi_memory_device_driver);
	561
d550d98d	562	return;
1da177e4 LT	563	}
	564
	565	module_init(acpi_memory_device_init);
	566	module_exit(acpi_memory_device_exit);