path: root/drivers/acpi/bus.c

/*
 *  acpi_bus.c - ACPI Bus Driver ($Revision: 80 $)
 *
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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.  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.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/proc_fs.h>
#include <linux/acpi.h>
#include <linux/slab.h>
#ifdef CONFIG_X86
#include <asm/mpspec.h>
#endif
#include <linux/pci.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#include <acpi/apei.h>
#include <linux/dmi.h>
#include <linux/suspend.h>

#include "internal.h"

#define _COMPONENT		ACPI_BUS_COMPONENT
ACPI_MODULE_NAME("bus");

struct acpi_device *acpi_root;
struct proc_dir_entry *acpi_root_dir;
EXPORT_SYMBOL(acpi_root_dir);

#define STRUCT_TO_INT(s)	(*((int*)&s))


#ifdef CONFIG_X86
static int set_copy_dsdt(const struct dmi_system_id *id)
{
	printk(KERN_NOTICE "%s detected - "
		"force copy of DSDT to local memory\n", id->ident);
	acpi_gbl_copy_dsdt_locally = 1;
	return 0;
}

static struct dmi_system_id dsdt_dmi_table[] __initdata = {
	/*
	 * Invoke DSDT corruption work-around on all Toshiba Satellite.
	 * https://bugzilla.kernel.org/show_bug.cgi?id=14679
	 */
	{
	 .callback = set_copy_dsdt,
	 .ident = "TOSHIBA Satellite",
	 .matches = {
		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
		DMI_MATCH(DMI_PRODUCT_NAME, "Satellite"),
		},
	},
	{}
};
#else
static struct dmi_system_id dsdt_dmi_table[] __initdata = {
	{}
};
#endif

/* --------------------------------------------------------------------------
                                Device Management
   -------------------------------------------------------------------------- */

int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
{
	acpi_status status = AE_OK;


	if (!device)
		return -EINVAL;

	/* TBD: Support fixed-feature devices */

	status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
	if (ACPI_FAILURE(status) || !*device) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
				  handle));
		return -ENODEV;
	}

	return 0;
}

EXPORT_SYMBOL(acpi_bus_get_device);

acpi_status acpi_bus_get_status_handle(acpi_handle handle,
				       unsigned long long *sta)
{
	acpi_status status;

	status = acpi_evaluate_integer(handle, "_STA", NULL, sta);
	if (ACPI_SUCCESS(status))
		return AE_OK;

	if (status == AE_NOT_FOUND) {
		*sta = ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
		       ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
		return AE_OK;
	}
	return status;
}

int acpi_bus_get_status(struct acpi_device *device)
{
	acpi_status status;
	unsigned long long sta;

	status = acpi_bus_get_status_handle(device->handle, &sta);
	if (ACPI_FAILURE(status))
		return -ENODEV;

	STRUCT_TO_INT(device->status) = (int) sta;

	if (device->status.functional && !device->status.present) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "
		       "functional but not present;\n",
			device->pnp.bus_id,
			(u32) STRUCT_TO_INT(device->status)));
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
			  device->pnp.bus_id,
			  (u32) STRUCT_TO_INT(device->status)));
	return 0;
}
EXPORT_SYMBOL(acpi_bus_get_status);

void acpi_bus_private_data_handler(acpi_handle handle,
				   void *context)
{
	return;
}
EXPORT_SYMBOL(acpi_bus_private_data_handler);

int acpi_bus_get_private_data(acpi_handle handle, void **data)
{
	acpi_status status = AE_OK;

	if (!*data)
		return -EINVAL;

	status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
	if (ACPI_FAILURE(status) || !*data) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
				handle));
		return -ENODEV;
	}

	return 0;
}
EXPORT_SYMBOL(acpi_bus_get_private_data);

/* --------------------------------------------------------------------------
                                 Power Management
   -------------------------------------------------------------------------- */

/**
 * acpi_power_state_string - String representation of ACPI device power state.
 * @state: ACPI device power state to return the string representation of.
 */
const char *acpi_power_state_string(int state)
{
	switch (state) {
	case ACPI_STATE_D0:
		return "D0";
	case ACPI_STATE_D1:
		return "D1";
	case ACPI_STATE_D2:
		return "D2";
	case ACPI_STATE_D3_HOT:
		return "D3hot";
	case ACPI_STATE_D3_COLD:
		return "D3";
	default:
		return "(unknown)";
	}
}

/**
 * acpi_device_get_power - Get power state of an ACPI device.
 * @device: Device to get the power state of.
 * @state: Place to store the power state of the device.
 *
 * This function does not update the device's power.state field, but it may
 * update its parent's power.state field (when the parent's power state is
 * unknown and the device's power state turns out to be D0).
 */
int acpi_device_get_power(struct acpi_device *device, int *state)
{
	int result = ACPI_STATE_UNKNOWN;

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

	if (!device->flags.power_manageable) {
		/* TBD: Non-recursive algorithm for walking up hierarchy. */
		*state = device->parent ?
			device->parent->power.state : ACPI_STATE_D0;
		goto out;
	}

	/*
	 * Get the device's power state either directly (via _PSC) or
	 * indirectly (via power resources).
	 */
	if (device->power.flags.explicit_get) {
		unsigned long long psc;
		acpi_status status = acpi_evaluate_integer(device->handle,
							   "_PSC", NULL, &psc);
		if (ACPI_FAILURE(status))
			return -ENODEV;

		result = psc;
	}
	/* The test below covers ACPI_STATE_UNKNOWN too. */
	if (result <= ACPI_STATE_D2) {
	  ; /* Do nothing. */
	} else if (device->power.flags.power_resources) {
		int error = acpi_power_get_inferred_state(device, &result);
		if (error)
			return error;
	} else if (result == ACPI_STATE_D3_HOT) {
		result = ACPI_STATE_D3;
	}

	/*
	 * If we were unsure about the device parent's power state up to this
	 * point, the fact that the device is in D0 implies that the parent has
	 * to be in D0 too.
	 */
	if (device->parent && device->parent->power.state == ACPI_STATE_UNKNOWN
	    && result == ACPI_STATE_D0)
		device->parent->power.state = ACPI_STATE_D0;

	*state = result;

 out:
	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",
			  device->pnp.bus_id, acpi_power_state_string(*state)));

	return 0;
}


/**
 * acpi_device_set_power - Set power state of an ACPI device.
 * @device: Device to set the power state of.
 * @state: New power state to set.
 *
 * Callers must ensure that the device is power manageable before using this
 * function.
 */
int acpi_device_set_power(struct acpi_device *device, int state)
{
	int result = 0;
	acpi_status status = AE_OK;
	char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };
	bool cut_power = false;

	if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
		return -EINVAL;

	/* Make sure this is a valid target state */

	if (state == device->power.state) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at %s\n",
				  acpi_power_state_string(state)));
		return 0;
	}

	if (!device->power.states[state].flags.valid) {
		printk(KERN_WARNING PREFIX "Device does not support %s\n",
		       acpi_power_state_string(state));
		return -ENODEV;
	}
	if (device->parent && (state < device->parent->power.state)) {
		printk(KERN_WARNING PREFIX
			      "Cannot set device to a higher-powered"
			      " state than parent\n");
		return -ENODEV;
	}

	/* For D3cold we should first transition into D3hot. */
	if (state == ACPI_STATE_D3_COLD
	    && device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible) {
		state = ACPI_STATE_D3_HOT;
		object_name[3] = '3';
		cut_power = true;
	}

	/*
	 * Transition Power
	 * ----------------
	 * On transitions to a high-powered state we first apply power (via
	 * power resources) then evalute _PSx.  Conversly for transitions to
	 * a lower-powered state.
	 */
	if (state < device->power.state) {
		if (device->power.state >= ACPI_STATE_D3_HOT &&
		    state != ACPI_STATE_D0) {
			printk(KERN_WARNING PREFIX
			      "Cannot transition to non-D0 state from D3\n");
			return -ENODEV;
		}
		if (device->power.flags.power_resources) {
			result = acpi_power_transition(device, state);
			if (result)
				goto end;
		}
		if (device->power.states[state].flags.explicit_set) {
			status = acpi_evaluate_object(device->handle,
						      object_name, NULL, NULL);
			if (ACPI_FAILURE(status)) {
				result = -ENODEV;
				goto end;
			}
		}
	} else {
		if (device->power.states[state].flags.explicit_set) {
			status = acpi_evaluate_object(device->handle,
						      object_name, NULL, NULL);
			if (ACPI_FAILURE(status)) {
				result = -ENODEV;
				goto end;
			}
		}
		if (device->power.flags.power_resources) {
			result = acpi_power_transition(device, state);
			if (result)
				goto end;
		}
	}

	if (cut_power)
		result = acpi_power_transition(device, ACPI_STATE_D3_COLD);

      end:
	if (result)
		printk(KERN_WARNING PREFIX
			      "Device [%s] failed to transition to %s\n",
			      device->pnp.bus_id,
			      acpi_power_state_string(state));
	else {
		device->power.state = state;
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				  "Device [%s] transitioned to %s\n",
				  device->pnp.bus_id,
				  acpi_power_state_string(state)));
	}

	return result;
}
EXPORT_SYMBOL(acpi_device_set_power);


int acpi_bus_set_power(acpi_handle handle, int state)
{
	struct acpi_device *device;
	int result;

	result = acpi_bus_get_device(handle, &device);
	if (result)
		return result;

	if (!device->flags.power_manageable) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				"Device [%s] is not power manageable\n",
				dev_name(&device->dev)));
		return -ENODEV;
	}

	return acpi_device_set_power(device, state);
}
EXPORT_SYMBOL(acpi_bus_set_power);


int acpi_bus_init_power(struct acpi_device *device)
{
	int state;
	int result;

	if (!device)
		return -EINVAL;

	device->power.state = ACPI_STATE_UNKNOWN;

	result = acpi_device_get_power(device, &state);
	if (result)
		return result;

	if (device->power.flags.power_resources)
		result = acpi_power_on_resources(device, state);

	if (!result)
		device->power.state = state;

	return result;
}


int acpi_bus_update_power(acpi_handle handle, int *state_p)
{
	struct acpi_device *device;
	int state;
	int result;

	result = acpi_bus_get_device(handle, &device);
	if (result)
		return result;

	result = acpi_device_get_power(device, &state);
	if (result)
		return result;

	result = acpi_device_set_power(device, state);
	if (!result && state_p)
		*state_p = state;

	return result;
}
EXPORT_SYMBOL_GPL(acpi_bus_update_power);


bool acpi_bus_power_manageable(acpi_handle handle)
{
	struct acpi_device *device;
	int result;

	result = acpi_bus_get_device(handle, &device);
	return result ? false : device->flags.power_manageable;
}

EXPORT_SYMBOL(acpi_bus_power_manageable);

bool acpi_bus_can_wakeup(acpi_handle handle)
{
	struct acpi_device *device;
	int result;

	result = acpi_bus_get_device(handle, &device);
	return result ? false : device->wakeup.flags.valid;
}

EXPORT_SYMBOL(acpi_bus_can_wakeup);

static void acpi_print_osc_error(acpi_handle handle,
	struct acpi_osc_context *context, char *error)
{
	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER};
	int i;

	if (ACPI_FAILURE(acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer)))
		printk(KERN_DEBUG "%s\n", error);
	else {
		printk(KERN_DEBUG "%s:%s\n", (char *)buffer.pointer, error);
		kfree(buffer.pointer);
	}
	printk(KERN_DEBUG"_OSC request data:");
	for (i = 0; i < context->cap.length; i += sizeof(u32))
		printk("%x ", *((u32 *)(context->cap.pointer + i)));
	printk("\n");
}

static acpi_status acpi_str_to_uuid(char *str, u8 *uuid)
{
	int i;
	static int opc_map_to_uuid[16] = {6, 4, 2, 0, 11, 9, 16, 14, 19, 21,
		24, 26, 28, 30, 32, 34};

	if (strlen(str) != 36)
		return AE_BAD_PARAMETER;
	for (i = 0; i < 36; i++) {
		if (i == 8 || i == 13 || i == 18 || i == 23) {
			if (str[i] != '-')
				return AE_BAD_PARAMETER;
		} else if (!isxdigit(str[i]))
			return AE_BAD_PARAMETER;
	}
	for (i = 0; i < 16; i++) {
		uuid[i] = hex_to_bin(str[opc_map_to_uuid[i]]) << 4;
		uuid[i] |= hex_to_bin(str[opc_map_to_uuid[i] + 1]);
	}
	return AE_OK;
}

acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
{
	acpi_status status;
	struct acpi_object_list input;
	union acpi_object in_params[4];
	union acpi_object *out_obj;
	u8 uuid[16];
	u32 errors;
	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};

	if (!context)
		return AE_ERROR;
	if (ACPI_FAILURE(acpi_str_to_uuid(context->uuid_str, uuid)))
		return AE_ERROR;
	context->ret.length = ACPI_ALLOCATE_BUFFER;
	context->ret.pointer = NULL;

	/* Setting up input parameters */
	input.count = 4;
	input.pointer = in_params;
	in_params[0].type 		= ACPI_TYPE_BUFFER;
	in_params[0].buffer.length 	= 16;
	in_params[0].buffer.pointer	= uuid;
	in_params[1].type 		= ACPI_TYPE_INTEGER;
	in_params[1].integer.value 	= context->rev;
	in_params[2].type 		= ACPI_TYPE_INTEGER;
	in_params[2].integer.value	= context->cap.length/sizeof(u32);
	in_params[3].type		= ACPI_TYPE_BUFFER;
	in_params[3].buffer.length 	= context->cap.length;
	in_params[3].buffer.pointer 	= context->cap.pointer;

	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
	if (ACPI_FAILURE(status))
		return status;

	if (!output.length)
		return AE_NULL_OBJECT;

	out_obj = output.pointer;
	if (out_obj->type != ACPI_TYPE_BUFFER
		|| out_obj->buffer.length != context->cap.length) {
		acpi_print_osc_error(handle, context,
			"_OSC evaluation returned wrong type");
		status = AE_TYPE;
		goto out_kfree;
	}
	/* Need to ignore the bit0 in result code */
	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
	if (errors) {
		if (errors & OSC_REQUEST_ERROR)
			acpi_print_osc_error(handle, context,
				"_OSC request failed");
		if (errors & OSC_INVALID_UUID_ERROR)
			acpi_print_osc_error(handle, context,
				"_OSC invalid UUID");
		if (errors & OSC_INVALID_REVISION_ERROR)
			acpi_print_osc_error(handle, context,
				"_OSC invalid revision");
		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
			if (((u32 *)context->cap.pointer)[OSC_QUERY_TYPE]
			    & OSC_QUERY_ENABLE)
				goto out_success;
			status = AE_SUPPORT;
			goto out_kfree;
		}
		status = AE_ERROR;
		goto out_kfree;
	}
out_success:
	context->ret.length = out_obj->buffer.length;
	context->ret.pointer = kmalloc(context->ret.length, GFP_KERNEL);
	if (!context->ret.pointer) {
		status =  AE_NO_MEMORY;
		goto out_kfree;
	}
	memcpy(context->ret.pointer, out_obj->buffer.pointer,
		context->ret.length);
	status =  AE_OK;

out_kfree:
	kfree(output.pointer);
	if (status != AE_OK)
		context->ret.pointer = NULL;
	return status;
}
EXPORT_SYMBOL(acpi_run_osc);

bool osc_sb_apei_support_acked;
static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48";
static void acpi_bus_osc_support(void)
{
	u32 capbuf[2];
	struct acpi_osc_context context = {
		.uuid_str = sb_uuid_str,
		.rev = 1,
		.cap.length = 8,
		.cap.pointer = capbuf,
	};
	acpi_handle handle;

	capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
	capbuf[OSC_SUPPORT_TYPE] = OSC_SB_PR3_SUPPORT; /* _PR3 is in use */
#if defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR) ||\
			defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR_MODULE)
	capbuf[OSC_SUPPORT_TYPE] |= OSC_SB_PAD_SUPPORT;
#endif

#if defined(CONFIG_ACPI_PROCESSOR) || defined(CONFIG_ACPI_PROCESSOR_MODULE)
	capbuf[OSC_SUPPORT_TYPE] |= OSC_SB_PPC_OST_SUPPORT;
#endif

#ifdef ACPI_HOTPLUG_OST
	capbuf[OSC_SUPPORT_TYPE] |= OSC_SB_HOTPLUG_OST_SUPPORT;
#endif

	if (!ghes_disable)
		capbuf[OSC_SUPPORT_TYPE] |= OSC_SB_APEI_SUPPORT;
	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
		return;
	if (ACPI_SUCCESS(acpi_run_osc(handle, &context))) {
		u32 *capbuf_ret = context.ret.pointer;
		if (context.ret.length > OSC_SUPPORT_TYPE)
			osc_sb_apei_support_acked =
				capbuf_ret[OSC_SUPPORT_TYPE] & OSC_SB_APEI_SUPPORT;
		kfree(context.ret.pointer);
	}
	/* do we need to check other returned cap? Sounds no */
}

/* --------------------------------------------------------------------------
                                Event Management
   -------------------------------------------------------------------------- */

#ifdef CONFIG_ACPI_PROC_EVENT
static DEFINE_SPINLOCK(acpi_bus_event_lock);

LIST_HEAD(acpi_bus_event_list);
DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);

extern int event_is_open;

int acpi_bus_generate_proc_event4(const char *device_class, const char *bus_id, u8 type, int data)
{
	struct acpi_bus_event *event;
	unsigned long flags = 0;

	/* drop event on the floor if no one's listening */
	if (!event_is_open)
		return 0;

	event = kzalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
	if (!event)
		return -ENOMEM;

	strcpy(event->device_class, device_class);
	strcpy(event->bus_id, bus_id);
	event->type = type;
	event->data = data;

	spin_lock_irqsave(&acpi_bus_event_lock, flags);
	list_add_tail(&event->node, &acpi_bus_event_list);
	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);

	wake_up_interruptible(&acpi_bus_event_queue);

	return 0;

}

EXPORT_SYMBOL_GPL(acpi_bus_generate_proc_event4);

int acpi_bus_generate_proc_event(struct acpi_device *device, u8 type, int data)
{
	if (!device)
		return -EINVAL;
	return acpi_bus_generate_proc_event4(device->pnp.device_class,
					     device->pnp.bus_id, type, data);
}

EXPORT_SYMBOL(acpi_bus_generate_proc_event);

int acpi_bus_receive_event(struct acpi_bus_event *event)
{
	unsigned long flags = 0;
	struct acpi_bus_event *entry = NULL;

	DECLARE_WAITQUEUE(wait, current);


	if (!event)
		return -EINVAL;

	if (list_empty(&acpi_bus_event_list)) {

		set_current_state(TASK_INTERRUPTIBLE);
		add_wait_queue(&acpi_bus_event_queue, &wait);

		if (list_empty(&acpi_bus_event_list))
			schedule();

		remove_wait_queue(&acpi_bus_event_queue, &wait);
		set_current_state(TASK_RUNNING);

		if (signal_pending(current))
			return -ERESTARTSYS;
	}

	spin_lock_irqsave(&acpi_bus_event_lock, flags);
	if (!list_empty(&acpi_bus_event_list)) {
		entry = list_entry(acpi_bus_event_list.next,
				   struct acpi_bus_event, node);
		list_del(&entry->node);
	}
	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);

	if (!entry)
		return -ENODEV;

	memcpy(event, entry, sizeof(struct acpi_bus_event));

	kfree(entry);

	return 0;
}

#endif	/* CONFIG_ACPI_PROC_EVENT */

/* --------------------------------------------------------------------------
                             Notification Handling
   -------------------------------------------------------------------------- */

static void acpi_bus_check_device(acpi_handle handle)
{
	struct acpi_device *device;
	acpi_status status;
	struct acpi_device_status old_status;

	if (acpi_bus_get_device(handle, &device))
		return;
	if (!device)
		return;

	old_status = device->status;

	/*
	 * Make sure this device's parent is present before we go about
	 * messing with the device.
	 */
	if (device->parent && !device->parent->status.present) {
		device->status = device->parent->status;
		return;
	}

	status = acpi_bus_get_status(device);
	if (ACPI_FAILURE(status))
		return;

	if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
		return;

	/*
	 * Device Insertion/Removal
	 */
	if ((device->status.present) && !(old_status.present)) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
		/* TBD: Handle device insertion */
	} else if (!(device->status.present) && (old_status.present)) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device removal detected\n"));
		/* TBD: Handle device removal */
	}
}

static void acpi_bus_check_scope(acpi_handle handle)
{
	/* Status Change? */
	acpi_bus_check_device(handle);

	/*
	 * TBD: Enumerate child devices within this device's scope and
	 *       run acpi_bus_check_device()'s on them.
	 */
}

static BLOCKING_NOTIFIER_HEAD(acpi_bus_notify_list);
int register_acpi_bus_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_register(&acpi_bus_notify_list, nb);
}
EXPORT_SYMBOL_GPL(register_acpi_bus_notifier);

void unregister_acpi_bus_notifier(struct notifier_block *nb)
{
	blocking_notifier_chain_unregister(&acpi_bus_notify_list, nb);
}
EXPORT_SYMBOL_GPL(unregister_acpi_bus_notifier);

/**
 * acpi_bus_notify
 * ---------------
 * Callback for all 'system-level' device notifications (values 0x00-0x7F).
 */
static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
{
	struct acpi_device *device = NULL;
	struct acpi_driver *driver;

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Notification %#02x to handle %p\n",
			  type, handle));

	blocking_notifier_call_chain(&acpi_bus_notify_list,
		type, (void *)handle);

	switch (type) {

	case ACPI_NOTIFY_BUS_CHECK:
		acpi_bus_check_scope(handle);
		/*
		 * TBD: We'll need to outsource certain events to non-ACPI
		 *      drivers via the device manager (device.c).
		 */
		break;

	case ACPI_NOTIFY_DEVICE_CHECK:
		acpi_bus_check_device(handle);
		/*
		 * TBD: We'll need to outsource certain events to non-ACPI
		 *      drivers via the device manager (device.c).
		 */
		break;

	case ACPI_NOTIFY_DEVICE_WAKE:
		/* TBD */
		break;

	case ACPI_NOTIFY_EJECT_REQUEST:
		/* TBD */
		break;

	case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
		/* TBD: Exactly what does 'light' mean? */
		break;

	case ACPI_NOTIFY_FREQUENCY_MISMATCH:
		/* TBD */
		break;

	case ACPI_NOTIFY_BUS_MODE_MISMATCH:
		/* TBD */
		break;

	case ACPI_NOTIFY_POWER_FAULT:
		/* TBD */
		break;

	default:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				  "Received unknown/unsupported notification [%08x]\n",
				  type));
		break;
	}

	acpi_bus_get_device(handle, &device);
	if (device) {
		driver = device->driver;
		if (driver && driver->ops.notify &&
		    (driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
			driver->ops.notify(device, type);
	}
}

/* --------------------------------------------------------------------------
                             Initialization/Cleanup
   -------------------------------------------------------------------------- */

static int __init acpi_bus_init_irq(void)
{
	acpi_status status = AE_OK;
	union acpi_object arg = { ACPI_TYPE_INTEGER };
	struct acpi_object_list arg_list = { 1, &arg };
	char *message = NULL;


	/*
	 * Let the system know what interrupt model we are using by
	 * evaluating the \_PIC object, if exists.
	 */

	switch (acpi_irq_model) {
	case ACPI_IRQ_MODEL_PIC:
		message = "PIC";
		break;
	case ACPI_IRQ_MODEL_IOAPIC:
		message = "IOAPIC";
		break;
	case ACPI_IRQ_MODEL_IOSAPIC:
		message = "IOSAPIC";
		break;
	case ACPI_IRQ_MODEL_PLATFORM:
		message = "platform specific model";
		break;
	default:
		printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
		return -ENODEV;
	}

	printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);

	arg.integer.value = acpi_irq_model;

	status = acpi_evaluate_object(NULL, "\\_PIC", &arg_list, NULL);
	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
		return -ENODEV;
	}

	return 0;
}

u8 acpi_gbl_permanent_mmap;


void __init acpi_early_init(void)
{
	acpi_status status = AE_OK;

	if (acpi_disabled)
		return;

	printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);

	/* enable workarounds, unless strict ACPI spec. compliance */
	if (!acpi_strict)
		acpi_gbl_enable_interpreter_slack = TRUE;

	acpi_gbl_permanent_mmap = 1;

	/*
	 * If the machine falls into the DMI check table,
	 * DSDT will be copied to memory
	 */
	dmi_check_system(dsdt_dmi_table);

	status = acpi_reallocate_root_table();
	if (ACPI_FAILURE(status)) {
		printk(KERN_ERR PREFIX
		       "Unable to reallocate ACPI tables\n");
		goto error0;
	}

	status = acpi_initialize_subsystem();
	if (ACPI_FAILURE(status)) {
		printk(KERN_ERR PREFIX
		       "Unable to initialize the ACPI Interpreter\n");
		goto error0;
	}

	status = acpi_load_tables();
	if (ACPI_FAILURE(status)) {
		printk(KERN_ERR PREFIX
		       "Unable to load the System Description Tables\n");
		goto error0;
	}

#ifdef CONFIG_X86
	if (!acpi_ioapic) {
		/* compatible (0) means level (3) */
		if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
			acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
			acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
		}
		/* Set PIC-mode SCI trigger type */
		acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
					 (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
	} else {
		/*
		 * now that acpi_gbl_FADT is initialized,
		 * update it with result from INT_SRC_OVR parsing
		 */
		acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
	}
#endif

	status = acpi_enable_subsystem(~ACPI_NO_ACPI_ENABLE);
	if (ACPI_FAILURE(status)) {
		printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
		goto error0;
	}

	return;

      error0:
	disable_acpi();
	return;
}

static int __init acpi_bus_init(void)
{
	int result = 0;
	acpi_status status = AE_OK;
	extern acpi_status acpi_os_initialize1(void);

	acpi_os_initialize1();

	status = acpi_enable_subsystem(ACPI_NO_ACPI_ENABLE);
	if (ACPI_FAILURE(status)) {
		printk(KERN_ERR PREFIX
		       "Unable to start the ACPI Interpreter\n");
		goto error1;
	}

	/*
	 * ACPI 2.0 requires the EC driver to be loaded and work before
	 * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
	 * is called).
	 *
	 * This is accomplished by looking for the ECDT table, and getting
	 * the EC parameters out of that.
	 */
	status = acpi_ec_ecdt_probe();
	/* Ignore result. Not having an ECDT is not fatal. */

	status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
	if (ACPI_FAILURE(status)) {
		printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
		goto error1;
	}

	/*
	 * _OSC method may exist in module level code,
	 * so it must be run after ACPI_FULL_INITIALIZATION
	 */
	acpi_bus_osc_support();

	/*
	 * _PDC control method may load dynamic SSDT tables,
	 * and we need to install the table handler before that.
	 */
	acpi_sysfs_init();

	acpi_early_processor_set_pdc();

	/*
	 * Maybe EC region is required at bus_scan/acpi_get_devices. So it
	 * is necessary to enable it as early as possible.
	 */
	acpi_boot_ec_enable();

	printk(KERN_INFO PREFIX "Interpreter enabled\n");

	/* Initialize sleep structures */
	acpi_sleep_init();

	/*
	 * Get the system interrupt model and evaluate \_PIC.
	 */
	result = acpi_bus_init_irq();
	if (result)
		goto error1;

	/*
	 * Register the for all standard device notifications.
	 */
	status =
	    acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
					&acpi_bus_notify, NULL);
	if (ACPI_FAILURE(status)) {
		printk(KERN_ERR PREFIX
		       "Unable to register for device notifications\n");
		goto error1;
	}

	/*
	 * Create the top ACPI proc directory
	 */
	acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);

	return 0;

	/* Mimic structured exception handling */
      error1:
	acpi_terminate();
	return -ENODEV;
}

struct kobject *acpi_kobj;
EXPORT_SYMBOL_GPL(acpi_kobj);

static int __init acpi_init(void)
{
	int result;

	if (acpi_disabled) {
		printk(KERN_INFO PREFIX "Interpreter disabled.\n");
		return -ENODEV;
	}

	acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
	if (!acpi_kobj) {
		printk(KERN_WARNING "%s: kset create error\n", __func__);
		acpi_kobj = NULL;
	}

	init_acpi_device_notify();
	result = acpi_bus_init();
	if (result) {
		disable_acpi();
		return result;
	}

	pci_mmcfg_late_init();
	acpi_scan_init();
	acpi_ec_init();
	acpi_debugfs_init();
	acpi_sleep_proc_init();
	acpi_wakeup_device_init();
	return 0;
}

subsys_initcall(acpi_init);