[GitHub/mt8127/android_kernel_alcatel_ttab.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 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,
		},
};

struct acpi_memory_device {
	acpi_handle handle;
	unsigned int state;	/* State of the memory device */
	unsigned short caching;	/* memory cache attribute */
	unsigned short write_protect;	/* memory read/write attribute */
	u64 start_addr;		/* Memory Range start physical addr */
	u64 length;		/* Memory Range length */
};

static int
acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
{
	acpi_status status;
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	struct acpi_resource *resource = NULL;
	struct acpi_resource_address64 address64;


	/* Get the range from the _CRS */
	status = acpi_get_current_resources(mem_device->handle, &buffer);
	if (ACPI_FAILURE(status))
		return -EINVAL;

	resource = (struct acpi_resource *)buffer.pointer;
	status = acpi_resource_to_address64(resource, &address64);
	if (ACPI_SUCCESS(status)) {
		if (address64.resource_type == ACPI_MEMORY_RANGE) {
			/* Populate the structure */
			mem_device->caching = address64.info.mem.caching;
			mem_device->write_protect =
			    address64.info.mem.write_protect;
			mem_device->start_addr = address64.minimum;
			mem_device->length = address64.address_length;
		}
	}

	acpi_os_free(buffer.pointer);
	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->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;


	/* 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;
	}

	/*
	 * Tell the VM there is more memory here...
	 * Note: Assume that this function returns zero on success
	 */
	result = add_memory(mem_device->start_addr, mem_device->length);
	if (result) {
		printk(KERN_ERR PREFIX "add_memory failed\n");
		mem_device->state = MEMORY_INVALID_STATE;
		return result;
	}

	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->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->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;
	u64 start = mem_device->start_addr;
	u64 len = mem_device->length;


	/*
	 * Ask the VM to offline this memory range.
	 * Note: Assume that this function returns zero on success
	 */
	result = remove_memory(start, len);
	if (result)
		return result;

	/* 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));

	mem_device->handle = device->handle;
	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;
}

/*
 * 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)) {
		acpi_os_free(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;

	acpi_os_free(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);
1da177e4 LT	60
1da177e4 LT	61	static struct acpi_driver acpi_memory_device_driver = {
4be44fcd LB	62	.name = ACPI_MEMORY_DEVICE_DRIVER_NAME,
	63	.class = ACPI_MEMORY_DEVICE_CLASS,
	64	.ids = ACPI_MEMORY_DEVICE_HID,
	65	.ops = {
	66	.add = acpi_memory_device_add,
	67	.remove = acpi_memory_device_remove,
	68	},
1da177e4 LT	69	};
	70
	71	struct acpi_memory_device {
	72	acpi_handle handle;
4be44fcd	73	unsigned int state; /* State of the memory device */
3963f008 KH	74	unsigned short caching; /* memory cache attribute */
3963f008 KH	75	unsigned short write_protect; /* memory read/write attribute */
4be44fcd	76	u64 start_addr; /* Memory Range start physical addr */
459c7266	77	u64 length; /* Memory Range length */
1da177e4 LT	78	};
1da177e4 LT	79
1da177e4 LT	80	static int
	81	acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
	82	{
	83	acpi_status status;
4be44fcd	84	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1da177e4 LT	85	struct acpi_resource *resource = NULL;
	86	struct acpi_resource_address64 address64;
	87
1da177e4 LT	88
	89	/* Get the range from the _CRS */
	90	status = acpi_get_current_resources(mem_device->handle, &buffer);
	91	if (ACPI_FAILURE(status))
d550d98d	92	return -EINVAL;
1da177e4	93
4be44fcd	94	resource = (struct acpi_resource *)buffer.pointer;
1da177e4 LT	95	status = acpi_resource_to_address64(resource, &address64);
	96	if (ACPI_SUCCESS(status)) {
	97	if (address64.resource_type == ACPI_MEMORY_RANGE) {
	98	/* Populate the structure */
459c7266	99	mem_device->caching = address64.info.mem.caching;
3963f008 KH	100	mem_device->write_protect =
3963f008 KH	101	address64.info.mem.write_protect;
50eca3eb	102	mem_device->start_addr = address64.minimum;
459c7266	103	mem_device->length = address64.address_length;
1da177e4 LT	104	}
	105	}
	106
	107	acpi_os_free(buffer.pointer);
d550d98d	108	return 0;
1da177e4 LT	109	}
	110
	111	static int
	112	acpi_memory_get_device(acpi_handle handle,
4be44fcd	113	struct acpi_memory_device **mem_device)
1da177e4 LT	114	{
	115	acpi_status status;
	116	acpi_handle phandle;
	117	struct acpi_device *device = NULL;
	118	struct acpi_device *pdevice = NULL;
	119
1da177e4 LT	120
	121	if (!acpi_bus_get_device(handle, &device) && device)
	122	goto end;
	123
	124	status = acpi_get_parent(handle, &phandle);
	125	if (ACPI_FAILURE(status)) {
a6fc6720	126	ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
d550d98d	127	return -EINVAL;
1da177e4 LT	128	}
	129
	130	/* Get the parent device */
	131	status = acpi_bus_get_device(phandle, &pdevice);
	132	if (ACPI_FAILURE(status)) {
a6fc6720	133	ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
d550d98d	134	return -EINVAL;
1da177e4 LT	135	}
	136
	137	/*
	138	* Now add the notified device. This creates the acpi_device
	139	* and invokes .add function
	140	*/
	141	status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
	142	if (ACPI_FAILURE(status)) {
a6fc6720	143	ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
d550d98d	144	return -EINVAL;
1da177e4 LT	145	}
1da177e4 LT	146
4be44fcd	147	end:
1da177e4 LT	148	*mem_device = acpi_driver_data(device);
1da177e4 LT	149	if (!(*mem_device)) {
4be44fcd	150	printk(KERN_ERR "\n driver data not found");
d550d98d	151	return -ENODEV;
1da177e4 LT	152	}
1da177e4 LT	153
d550d98d	154	return 0;
1da177e4 LT	155	}
1da177e4 LT	156
4be44fcd	157	static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
1da177e4 LT	158	{
	159	unsigned long current_status;
	160
1da177e4 LT	161
	162	/* Get device present/absent information from the _STA */
	163	if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
4be44fcd	164	NULL, &current_status)))
d550d98d	165	return -ENODEV;
1da177e4 LT	166	/*
	167	* Check for device status. Device should be
	168	* present/enabled/functioning.
	169	*/
	170	if (!((current_status & ACPI_MEMORY_STA_PRESENT)
4be44fcd LB	171	&& (current_status & ACPI_MEMORY_STA_ENABLED)
4be44fcd LB	172	&& (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
d550d98d	173	return -ENODEV;
1da177e4	174
d550d98d	175	return 0;
1da177e4 LT	176	}
1da177e4 LT	177
4be44fcd	178	static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
1da177e4 LT	179	{
	180	int result;
	181
1da177e4 LT	182
	183	/* Get the range from the _CRS */
	184	result = acpi_memory_get_device_resources(mem_device);
	185	if (result) {
6468463a	186	printk(KERN_ERR PREFIX "get_device_resources failed\n");
1da177e4 LT	187	mem_device->state = MEMORY_INVALID_STATE;
	188	return result;
	189	}
	190
	191	/*
	192	* Tell the VM there is more memory here...
	193	* Note: Assume that this function returns zero on success
	194	*/
459c7266	195	result = add_memory(mem_device->start_addr, mem_device->length);
1da177e4	196	if (result) {
6468463a	197	printk(KERN_ERR PREFIX "add_memory failed\n");
1da177e4 LT	198	mem_device->state = MEMORY_INVALID_STATE;
	199	return result;
	200	}
	201
	202	return result;
	203	}
	204
4be44fcd	205	static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
1da177e4 LT	206	{
1da177e4 LT	207	acpi_status status;
4be44fcd	208	struct acpi_object_list arg_list;
1da177e4 LT	209	union acpi_object arg;
	210	unsigned long current_status;
	211
1da177e4 LT	212
	213	/* Issue the _EJ0 command */
	214	arg_list.count = 1;
	215	arg_list.pointer = &arg;
	216	arg.type = ACPI_TYPE_INTEGER;
	217	arg.integer.value = 1;
	218	status = acpi_evaluate_object(mem_device->handle,
4be44fcd	219	"_EJ0", &arg_list, NULL);
1da177e4 LT	220	/* Return on _EJ0 failure */
1da177e4 LT	221	if (ACPI_FAILURE(status)) {
a6fc6720	222	ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
d550d98d	223	return -ENODEV;
1da177e4 LT	224	}
	225
	226	/* Evalute _STA to check if the device is disabled */
	227	status = acpi_evaluate_integer(mem_device->handle, "_STA",
4be44fcd	228	NULL, &current_status);
1da177e4	229	if (ACPI_FAILURE(status))
d550d98d	230	return -ENODEV;
1da177e4 LT	231
	232	/* Check for device status. Device should be disabled */
	233	if (current_status & ACPI_MEMORY_STA_ENABLED)
d550d98d	234	return -EINVAL;
1da177e4	235
d550d98d	236	return 0;
1da177e4 LT	237	}
1da177e4 LT	238
4be44fcd	239	static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
1da177e4 LT	240	{
	241	int result;
	242	u64 start = mem_device->start_addr;
459c7266	243	u64 len = mem_device->length;
1da177e4	244
1da177e4 LT	245
	246	/*
	247	* Ask the VM to offline this memory range.
	248	* Note: Assume that this function returns zero on success
	249	*/
0b0acbec	250	result = remove_memory(start, len);
a6fc6720	251	if (result)
d550d98d	252	return result;
1da177e4 LT	253
	254	/* Power-off and eject the device */
	255	result = acpi_memory_powerdown_device(mem_device);
	256	if (result) {
1da177e4 LT	257	/* Set the status of the device to invalid */
	258	mem_device->state = MEMORY_INVALID_STATE;
	259	return result;
	260	}
	261
	262	mem_device->state = MEMORY_POWER_OFF_STATE;
	263	return result;
	264	}
	265
4be44fcd	266	static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
1da177e4 LT	267	{
	268	struct acpi_memory_device *mem_device;
	269	struct acpi_device *device;
	270
1da177e4 LT	271
	272	switch (event) {
	273	case ACPI_NOTIFY_BUS_CHECK:
	274	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd	275	"\nReceived BUS CHECK notification for device\n"));
1da177e4 LT	276	/* Fall Through */
	277	case ACPI_NOTIFY_DEVICE_CHECK:
	278	if (event == ACPI_NOTIFY_DEVICE_CHECK)
	279	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd	280	"\nReceived DEVICE CHECK notification for device\n"));
1da177e4	281	if (acpi_memory_get_device(handle, &mem_device)) {
6468463a	282	printk(KERN_ERR PREFIX "Cannot find driver data\n");
d550d98d	283	return;
1da177e4 LT	284	}
	285
	286	if (!acpi_memory_check_device(mem_device)) {
	287	if (acpi_memory_enable_device(mem_device))
6468463a LB	288	printk(KERN_ERR PREFIX
6468463a LB	289	"Cannot enable memory device\n");
1da177e4 LT	290	}
	291	break;
	292	case ACPI_NOTIFY_EJECT_REQUEST:
	293	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd	294	"\nReceived EJECT REQUEST notification for device\n"));
1da177e4 LT	295
1da177e4 LT	296	if (acpi_bus_get_device(handle, &device)) {
6468463a	297	printk(KERN_ERR PREFIX "Device doesn't exist\n");
1da177e4 LT	298	break;
	299	}
	300	mem_device = acpi_driver_data(device);
	301	if (!mem_device) {
6468463a	302	printk(KERN_ERR PREFIX "Driver Data is NULL\n");
1da177e4 LT	303	break;
	304	}
	305
	306	/*
	307	* Currently disabling memory device from kernel mode
	308	* TBD: Can also be disabled from user mode scripts
	309	* TBD: Can also be disabled by Callback registration
4be44fcd	310	* with generic sysfs driver
1da177e4 LT	311	*/
1da177e4 LT	312	if (acpi_memory_disable_device(mem_device))
6468463a LB	313	printk(KERN_ERR PREFIX
6468463a LB	314	"Disable memory device\n");
1da177e4 LT	315	/*
	316	* TBD: Invoke acpi_bus_remove to cleanup data structures
	317	*/
	318	break;
	319	default:
	320	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
4be44fcd	321	"Unsupported event [0x%x]\n", event));
1da177e4 LT	322	break;
	323	}
	324
d550d98d	325	return;
1da177e4 LT	326	}
1da177e4 LT	327
4be44fcd	328	static int acpi_memory_device_add(struct acpi_device *device)
1da177e4 LT	329	{
	330	int result;
	331	struct acpi_memory_device *mem_device = NULL;
	332
1da177e4 LT	333
1da177e4 LT	334	if (!device)
d550d98d	335	return -EINVAL;
1da177e4 LT	336
	337	mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
	338	if (!mem_device)
d550d98d	339	return -ENOMEM;
1da177e4 LT	340	memset(mem_device, 0, sizeof(struct acpi_memory_device));
	341
	342	mem_device->handle = device->handle;
	343	sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
	344	sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
	345	acpi_driver_data(device) = mem_device;
	346
	347	/* Get the range from the _CRS */
	348	result = acpi_memory_get_device_resources(mem_device);
	349	if (result) {
	350	kfree(mem_device);
d550d98d	351	return result;
1da177e4 LT	352	}
	353
	354	/* Set the device state */
	355	mem_device->state = MEMORY_POWER_ON_STATE;
	356
	357	printk(KERN_INFO "%s \n", acpi_device_name(device));
	358
d550d98d	359	return result;
1da177e4 LT	360	}
1da177e4 LT	361
4be44fcd	362	static int acpi_memory_device_remove(struct acpi_device *device, int type)
1da177e4 LT	363	{
	364	struct acpi_memory_device *mem_device = NULL;
	365
1da177e4 LT	366
1da177e4 LT	367	if (!device \|\| !acpi_driver_data(device))
d550d98d	368	return -EINVAL;
1da177e4	369
4be44fcd	370	mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
1da177e4 LT	371	kfree(mem_device);
1da177e4 LT	372
d550d98d	373	return 0;
1da177e4 LT	374	}
	375
	376	/*
	377	* Helper function to check for memory device
	378	*/
4be44fcd	379	static acpi_status is_memory_device(acpi_handle handle)
1da177e4 LT	380	{
	381	char *hardware_id;
	382	acpi_status status;
4be44fcd	383	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1da177e4 LT	384	struct acpi_device_info *info;
1da177e4 LT	385
1da177e4 LT	386
	387	status = acpi_get_object_info(handle, &buffer);
	388	if (ACPI_FAILURE(status))
d550d98d	389	return status;
1da177e4 LT	390
	391	info = buffer.pointer;
	392	if (!(info->valid & ACPI_VALID_HID)) {
	393	acpi_os_free(buffer.pointer);
d550d98d	394	return AE_ERROR;
1da177e4 LT	395	}
	396
	397	hardware_id = info->hardware_id.value;
	398	if ((hardware_id == NULL) \|\|
4be44fcd	399	(strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
1da177e4 LT	400	status = AE_ERROR;
	401
	402	acpi_os_free(buffer.pointer);
d550d98d	403	return status;
1da177e4 LT	404	}
	405
	406	static acpi_status
4be44fcd LB	407	acpi_memory_register_notify_handler(acpi_handle handle,
4be44fcd LB	408	u32 level, void ctxt, void *retv)
1da177e4 LT	409	{
	410	acpi_status status;
	411
1da177e4 LT	412
1da177e4 LT	413	status = is_memory_device(handle);
a6fc6720 TR	414	if (ACPI_FAILURE(status)){
a6fc6720 TR	415	ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
d550d98d	416	return AE_OK; /* continue */
a6fc6720	417	}
1da177e4 LT	418
1da177e4 LT	419	status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
4be44fcd	420	acpi_memory_device_notify, NULL);
a6fc6720	421	/* continue */
d550d98d	422	return AE_OK;
1da177e4 LT	423	}
	424
	425	static acpi_status
4be44fcd LB	426	acpi_memory_deregister_notify_handler(acpi_handle handle,
4be44fcd LB	427	u32 level, void ctxt, void *retv)
1da177e4 LT	428	{
	429	acpi_status status;
	430
1da177e4 LT	431
1da177e4 LT	432	status = is_memory_device(handle);
a6fc6720 TR	433	if (ACPI_FAILURE(status)){
a6fc6720 TR	434	ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
d550d98d	435	return AE_OK; /* continue */
a6fc6720	436	}
1da177e4 LT	437
1da177e4 LT	438	status = acpi_remove_notify_handler(handle,
4be44fcd LB	439	ACPI_SYSTEM_NOTIFY,
4be44fcd LB	440	acpi_memory_device_notify);
1da177e4	441
d550d98d	442	return AE_OK; /* continue */
1da177e4 LT	443	}
1da177e4 LT	444
4be44fcd	445	static int __init acpi_memory_device_init(void)
1da177e4 LT	446	{
	447	int result;
	448	acpi_status status;
	449
1da177e4 LT	450
	451	result = acpi_bus_register_driver(&acpi_memory_device_driver);
	452
	453	if (result < 0)
d550d98d	454	return -ENODEV;
1da177e4 LT	455
1da177e4 LT	456	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
4be44fcd LB	457	ACPI_UINT32_MAX,
	458	acpi_memory_register_notify_handler,
	459	NULL, NULL);
1da177e4	460
4be44fcd	461	if (ACPI_FAILURE(status)) {
a6fc6720	462	ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
1da177e4	463	acpi_bus_unregister_driver(&acpi_memory_device_driver);
d550d98d	464	return -ENODEV;
4be44fcd	465	}
1da177e4	466
d550d98d	467	return 0;
1da177e4 LT	468	}
1da177e4 LT	469
4be44fcd	470	static void __exit acpi_memory_device_exit(void)
1da177e4 LT	471	{
	472	acpi_status status;
	473
1da177e4 LT	474
	475	/*
	476	* Adding this to un-install notification handlers for all the device
	477	* handles.
	478	*/
	479	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
4be44fcd LB	480	ACPI_UINT32_MAX,
	481	acpi_memory_deregister_notify_handler,
	482	NULL, NULL);
1da177e4	483
4be44fcd	484	if (ACPI_FAILURE(status))
a6fc6720	485	ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
1da177e4 LT	486
	487	acpi_bus_unregister_driver(&acpi_memory_device_driver);
	488
d550d98d	489	return;
1da177e4 LT	490	}
	491
	492	module_init(acpi_memory_device_init);
	493	module_exit(acpi_memory_device_exit);