[linux-block.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_NAME			"Hotplug Mem Device"

#define _COMPONENT		ACPI_MEMORY_DEVICE_COMPONENT

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

static struct acpi_driver acpi_memory_device_driver = {
	.name = "acpi_memhotplug",
	.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 int acpi_hotmem_initialized;

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_STA_DEVICE_PRESENT)
	      && (current_status & ACPI_STA_DEVICE_ENABLED)
	      && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
		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;
		}

		if (node < 0)
			node = memory_add_physaddr_to_nid(info->start_addr);

		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_STA_DEVICE_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 = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
	if (!mem_device)
		return -ENOMEM;

	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_DEBUG "%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 = 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;

	/*
	 * Early boot code has recognized memory area by EFI/E820.
	 * If DSDT shows these memory devices on boot, hotplug is not necessary
	 * for them. So, it just returns until completion of this driver's
	 * start up.
	 */
	if (!acpi_hotmem_initialized)
		return 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))
		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);

	if (ACPI_FAILURE(status)) {
		ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
		acpi_bus_unregister_driver(&acpi_memory_device_driver);
		return -ENODEV;
	}

	acpi_hotmem_initialized = 1;
	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"
1da177e4 LT	38	#define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
	39
	40	#define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT
	41
f52fd66d LB	42	ACPI_MODULE_NAME("acpi_memhotplug");
f52fd66d LB	43	MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
7cda93e0	44	MODULE_DESCRIPTION("Hotplug Mem Driver");
1da177e4 LT	45	MODULE_LICENSE("GPL");
1da177e4 LT	46
1da177e4 LT	47	/* Memory Device States */
	48	#define MEMORY_INVALID_STATE 0
	49	#define MEMORY_POWER_ON_STATE 1
	50	#define MEMORY_POWER_OFF_STATE 2
	51
4be44fcd LB	52	static int acpi_memory_device_add(struct acpi_device *device);
4be44fcd LB	53	static int acpi_memory_device_remove(struct acpi_device *device, int type);
1f425994	54	static int acpi_memory_device_start(struct acpi_device *device);
1da177e4 LT	55
1da177e4 LT	56	static struct acpi_driver acpi_memory_device_driver = {
c2b6705b	57	.name = "acpi_memhotplug",
4be44fcd LB	58	.class = ACPI_MEMORY_DEVICE_CLASS,
	59	.ids = ACPI_MEMORY_DEVICE_HID,
	60	.ops = {
	61	.add = acpi_memory_device_add,
	62	.remove = acpi_memory_device_remove,
1f425994	63	.start = acpi_memory_device_start,
4be44fcd	64	},
1da177e4 LT	65	};
1da177e4 LT	66
9ac02398 KH	67	struct acpi_memory_info {
	68	struct list_head list;
	69	u64 start_addr; /* Memory Range start physical addr */
	70	u64 length; /* Memory Range length */
	71	unsigned short caching; /* memory cache attribute */
	72	unsigned short write_protect; /* memory read/write attribute */
	73	unsigned int enabled:1;
	74	};
	75
1da177e4	76	struct acpi_memory_device {
3b74863d	77	struct acpi_device * device;
4be44fcd	78	unsigned int state; /* State of the memory device */
9ac02398	79	struct list_head res_list;
1da177e4 LT	80	};
1da177e4 LT	81
887b9593 YG	82	static int acpi_hotmem_initialized;
887b9593 YG	83
9ac02398 KH	84	static acpi_status
	85	acpi_memory_get_resource(struct acpi_resource resource, void context)
	86	{
	87	struct acpi_memory_device *mem_device = context;
	88	struct acpi_resource_address64 address64;
	89	struct acpi_memory_info info, new;
	90	acpi_status status;
	91
	92	status = acpi_resource_to_address64(resource, &address64);
	93	if (ACPI_FAILURE(status) \|\|
	94	(address64.resource_type != ACPI_MEMORY_RANGE))
	95	return AE_OK;
	96
	97	list_for_each_entry(info, &mem_device->res_list, list) {
	98	/* Can we combine the resource range information? */
	99	if ((info->caching == address64.info.mem.caching) &&
	100	(info->write_protect == address64.info.mem.write_protect) &&
	101	(info->start_addr + info->length == address64.minimum)) {
	102	info->length += address64.address_length;
	103	return AE_OK;
	104	}
	105	}
	106
	107	new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
	108	if (!new)
	109	return AE_ERROR;
	110
	111	INIT_LIST_HEAD(&new->list);
	112	new->caching = address64.info.mem.caching;
	113	new->write_protect = address64.info.mem.write_protect;
	114	new->start_addr = address64.minimum;
	115	new->length = address64.address_length;
	116	list_add_tail(&new->list, &mem_device->res_list);
	117
	118	return AE_OK;
	119	}
	120
1da177e4 LT	121	static int
	122	acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
	123	{
	124	acpi_status status;
9ac02398	125	struct acpi_memory_info info, n;
1da177e4	126
1da177e4	127
5d2870fa KH	128	if (!list_empty(&mem_device->res_list))
	129	return 0;
	130
b8632785	131	status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
9ac02398 KH	132	acpi_memory_get_resource, mem_device);
	133	if (ACPI_FAILURE(status)) {
	134	list_for_each_entry_safe(info, n, &mem_device->res_list, list)
	135	kfree(info);
5d2870fa	136	INIT_LIST_HEAD(&mem_device->res_list);
d550d98d	137	return -EINVAL;
1da177e4 LT	138	}
1da177e4 LT	139
d550d98d	140	return 0;
1da177e4 LT	141	}
	142
	143	static int
	144	acpi_memory_get_device(acpi_handle handle,
4be44fcd	145	struct acpi_memory_device **mem_device)
1da177e4 LT	146	{
	147	acpi_status status;
	148	acpi_handle phandle;
	149	struct acpi_device *device = NULL;
	150	struct acpi_device *pdevice = NULL;
	151
1da177e4 LT	152
	153	if (!acpi_bus_get_device(handle, &device) && device)
	154	goto end;
	155
	156	status = acpi_get_parent(handle, &phandle);
	157	if (ACPI_FAILURE(status)) {
a6fc6720	158	ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
d550d98d	159	return -EINVAL;
1da177e4 LT	160	}
	161
	162	/* Get the parent device */
	163	status = acpi_bus_get_device(phandle, &pdevice);
	164	if (ACPI_FAILURE(status)) {
a6fc6720	165	ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
d550d98d	166	return -EINVAL;
1da177e4 LT	167	}
	168
	169	/*
	170	* Now add the notified device. This creates the acpi_device
	171	* and invokes .add function
	172	*/
	173	status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
	174	if (ACPI_FAILURE(status)) {
a6fc6720	175	ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
d550d98d	176	return -EINVAL;
1da177e4 LT	177	}
1da177e4 LT	178
4be44fcd	179	end:
1da177e4 LT	180	*mem_device = acpi_driver_data(device);
1da177e4 LT	181	if (!(*mem_device)) {
4be44fcd	182	printk(KERN_ERR "\n driver data not found");
d550d98d	183	return -ENODEV;
1da177e4 LT	184	}
1da177e4 LT	185
d550d98d	186	return 0;
1da177e4 LT	187	}
1da177e4 LT	188
4be44fcd	189	static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
1da177e4 LT	190	{
	191	unsigned long current_status;
	192
1da177e4 LT	193
1da177e4 LT	194	/* Get device present/absent information from the _STA */
b8632785	195	if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
4be44fcd	196	NULL, &current_status)))
d550d98d	197	return -ENODEV;
1da177e4 LT	198	/*
	199	* Check for device status. Device should be
	200	* present/enabled/functioning.
	201	*/
a0bd4ac4 BH	202	if (!((current_status & ACPI_STA_DEVICE_PRESENT)
	203	&& (current_status & ACPI_STA_DEVICE_ENABLED)
	204	&& (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
d550d98d	205	return -ENODEV;
1da177e4	206
d550d98d	207	return 0;
1da177e4 LT	208	}
1da177e4 LT	209
4be44fcd	210	static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
1da177e4	211	{
9ac02398 KH	212	int result, num_enabled = 0;
9ac02398 KH	213	struct acpi_memory_info *info;
1e3590e2	214	int node;
1da177e4	215
1da177e4 LT	216
	217	/* Get the range from the _CRS */
	218	result = acpi_memory_get_device_resources(mem_device);
	219	if (result) {
6468463a	220	printk(KERN_ERR PREFIX "get_device_resources failed\n");
1da177e4 LT	221	mem_device->state = MEMORY_INVALID_STATE;
	222	return result;
	223	}
	224
b8632785	225	node = acpi_get_node(mem_device->device->handle);
1da177e4 LT	226	/*
	227	* Tell the VM there is more memory here...
	228	* Note: Assume that this function returns zero on success
9ac02398 KH	229	* We don't have memory-hot-add rollback function,now.
9ac02398 KH	230	* (i.e. memory-hot-remove function)
1da177e4	231	*/
9ac02398	232	list_for_each_entry(info, &mem_device->res_list, list) {
fa25d8d6	233	if (info->enabled) { /* just sanity check...*/
dd56a8e3 YG	234	num_enabled++;
	235	continue;
	236	}
8c2676a5 KM	237
	238	if (node < 0)
	239	node = memory_add_physaddr_to_nid(info->start_addr);
	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
1da177e4 LT	283	/* Check for device status. Device should be disabled */
a0bd4ac4	284	if (current_status & ACPI_STA_DEVICE_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	391
36bcbec7	392	mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
1da177e4	393	if (!mem_device)
d550d98d	394	return -ENOMEM;
1da177e4	395
9ac02398	396	INIT_LIST_HEAD(&mem_device->res_list);
3b74863d	397	mem_device->device = device;
1da177e4 LT	398	sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
	399	sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
	400	acpi_driver_data(device) = mem_device;
	401
	402	/* Get the range from the _CRS */
	403	result = acpi_memory_get_device_resources(mem_device);
	404	if (result) {
	405	kfree(mem_device);
d550d98d	406	return result;
1da177e4 LT	407	}
	408
	409	/* Set the device state */
	410	mem_device->state = MEMORY_POWER_ON_STATE;
	411
6cbe44cd	412	printk(KERN_DEBUG "%s \n", acpi_device_name(device));
1da177e4	413
d550d98d	414	return result;
1da177e4 LT	415	}
1da177e4 LT	416
4be44fcd	417	static int acpi_memory_device_remove(struct acpi_device *device, int type)
1da177e4 LT	418	{
	419	struct acpi_memory_device *mem_device = NULL;
	420
1da177e4 LT	421
1da177e4 LT	422	if (!device \|\| !acpi_driver_data(device))
d550d98d	423	return -EINVAL;
1da177e4	424
50dd0969	425	mem_device = acpi_driver_data(device);
1da177e4 LT	426	kfree(mem_device);
1da177e4 LT	427
d550d98d	428	return 0;
1da177e4 LT	429	}
1da177e4 LT	430
1f425994 YG	431	static int acpi_memory_device_start (struct acpi_device *device)
	432	{
	433	struct acpi_memory_device *mem_device;
	434	int result = 0;
	435
887b9593 YG	436	/*
	437	* Early boot code has recognized memory area by EFI/E820.
	438	* If DSDT shows these memory devices on boot, hotplug is not necessary
	439	* for them. So, it just returns until completion of this driver's
	440	* start up.
	441	*/
	442	if (!acpi_hotmem_initialized)
	443	return 0;
	444
1f425994 YG	445	mem_device = acpi_driver_data(device);
	446
	447	if (!acpi_memory_check_device(mem_device)) {
	448	/* call add_memory func */
	449	result = acpi_memory_enable_device(mem_device);
	450	if (result)
	451	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	452	"Error in acpi_memory_enable_device\n"));
	453	}
d120cfb5	454	return result;
1f425994 YG	455	}
1f425994 YG	456
1da177e4 LT	457	/*
	458	* Helper function to check for memory device
	459	*/
4be44fcd	460	static acpi_status is_memory_device(acpi_handle handle)
1da177e4 LT	461	{
	462	char *hardware_id;
	463	acpi_status status;
4be44fcd	464	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1da177e4 LT	465	struct acpi_device_info *info;
1da177e4 LT	466
1da177e4 LT	467
	468	status = acpi_get_object_info(handle, &buffer);
	469	if (ACPI_FAILURE(status))
d550d98d	470	return status;
1da177e4 LT	471
	472	info = buffer.pointer;
	473	if (!(info->valid & ACPI_VALID_HID)) {
02438d87	474	kfree(buffer.pointer);
d550d98d	475	return AE_ERROR;
1da177e4 LT	476	}
	477
	478	hardware_id = info->hardware_id.value;
	479	if ((hardware_id == NULL) \|\|
4be44fcd	480	(strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
1da177e4 LT	481	status = AE_ERROR;
1da177e4 LT	482
02438d87	483	kfree(buffer.pointer);
d550d98d	484	return status;
1da177e4 LT	485	}
	486
	487	static acpi_status
4be44fcd LB	488	acpi_memory_register_notify_handler(acpi_handle handle,
4be44fcd LB	489	u32 level, void ctxt, void *retv)
1da177e4 LT	490	{
	491	acpi_status status;
	492
1da177e4 LT	493
1da177e4 LT	494	status = is_memory_device(handle);
07dd4855	495	if (ACPI_FAILURE(status))
d550d98d	496	return AE_OK; /* continue */
1da177e4 LT	497
1da177e4 LT	498	status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
4be44fcd	499	acpi_memory_device_notify, NULL);
a6fc6720	500	/* continue */
d550d98d	501	return AE_OK;
1da177e4 LT	502	}
	503
	504	static acpi_status
4be44fcd LB	505	acpi_memory_deregister_notify_handler(acpi_handle handle,
4be44fcd LB	506	u32 level, void ctxt, void *retv)
1da177e4 LT	507	{
	508	acpi_status status;
	509
1da177e4 LT	510
1da177e4 LT	511	status = is_memory_device(handle);
07dd4855	512	if (ACPI_FAILURE(status))
d550d98d	513	return AE_OK; /* continue */
1da177e4 LT	514
1da177e4 LT	515	status = acpi_remove_notify_handler(handle,
4be44fcd LB	516	ACPI_SYSTEM_NOTIFY,
4be44fcd LB	517	acpi_memory_device_notify);
1da177e4	518
d550d98d	519	return AE_OK; /* continue */
1da177e4 LT	520	}
1da177e4 LT	521
4be44fcd	522	static int __init acpi_memory_device_init(void)
1da177e4 LT	523	{
	524	int result;
	525	acpi_status status;
	526
1da177e4 LT	527
	528	result = acpi_bus_register_driver(&acpi_memory_device_driver);
	529
	530	if (result < 0)
d550d98d	531	return -ENODEV;
1da177e4 LT	532
1da177e4 LT	533	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
4be44fcd LB	534	ACPI_UINT32_MAX,
	535	acpi_memory_register_notify_handler,
	536	NULL, NULL);
1da177e4	537
4be44fcd	538	if (ACPI_FAILURE(status)) {
a6fc6720	539	ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
1da177e4	540	acpi_bus_unregister_driver(&acpi_memory_device_driver);
d550d98d	541	return -ENODEV;
4be44fcd	542	}
1da177e4	543
887b9593	544	acpi_hotmem_initialized = 1;
d550d98d	545	return 0;
1da177e4 LT	546	}
1da177e4 LT	547
4be44fcd	548	static void __exit acpi_memory_device_exit(void)
1da177e4 LT	549	{
	550	acpi_status status;
	551
1da177e4 LT	552
	553	/*
	554	* Adding this to un-install notification handlers for all the device
	555	* handles.
	556	*/
	557	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
4be44fcd LB	558	ACPI_UINT32_MAX,
	559	acpi_memory_deregister_notify_handler,
	560	NULL, NULL);
1da177e4	561
4be44fcd	562	if (ACPI_FAILURE(status))
a6fc6720	563	ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
1da177e4 LT	564
	565	acpi_bus_unregister_driver(&acpi_memory_device_driver);
	566
d550d98d	567	return;
1da177e4 LT	568	}
	569
	570	module_init(acpi_memory_device_init);
	571	module_exit(acpi_memory_device_exit);