drivers/acpi/pci_root.c - kernel/msm-4.9 - Gitiles

 /*
  *  pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
  *
  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
  *  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/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/proc_fs.h>
 #include <linux/spinlock.h>
 #include <linux/pm.h>
 #include <linux/pci.h>
 #include <linux/pci-acpi.h>
 #include <linux/acpi.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>

 #define _COMPONENT		ACPI_PCI_COMPONENT
 ACPI_MODULE_NAME("pci_root");
 #define ACPI_PCI_ROOT_CLASS		"pci_bridge"
 #define ACPI_PCI_ROOT_DEVICE_NAME	"PCI Root Bridge"
 static int acpi_pci_root_add(struct acpi_device *device);
 static int acpi_pci_root_remove(struct acpi_device *device, int type);
 static int acpi_pci_root_start(struct acpi_device *device);

 static struct acpi_device_id root_device_ids[] = {
 	{"PNP0A03", 0},
 	{"", 0},
 };
 MODULE_DEVICE_TABLE(acpi, root_device_ids);

 static struct acpi_driver acpi_pci_root_driver = {
 	.name = "pci_root",
 	.class = ACPI_PCI_ROOT_CLASS,
 	.ids = root_device_ids,
 	.ops = {
 		.add = acpi_pci_root_add,
 		.remove = acpi_pci_root_remove,
 		.start = acpi_pci_root_start,
 		},
 };

 static LIST_HEAD(acpi_pci_roots);

 static struct acpi_pci_driver *sub_driver;
 static DEFINE_MUTEX(osc_lock);

 int acpi_pci_register_driver(struct acpi_pci_driver *driver)
 {
 	int n = 0;
 	struct acpi_pci_root *root;

 	struct acpi_pci_driver **pptr = &sub_driver;
 	while (*pptr)
 		pptr = &(*pptr)->next;
 	*pptr = driver;

 	if (!driver->add)
 		return 0;

 	list_for_each_entry(root, &acpi_pci_roots, node) {
 		driver->add(root->device->handle);
 		n++;
 	}

 	return n;
 }

 EXPORT_SYMBOL(acpi_pci_register_driver);

 void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
 {
 	struct acpi_pci_root *root;

 	struct acpi_pci_driver **pptr = &sub_driver;
 	while (*pptr) {
 		if (*pptr == driver)
 			break;
 		pptr = &(*pptr)->next;
 	}
 	BUG_ON(!*pptr);
 	*pptr = (*pptr)->next;

 	if (!driver->remove)
 		return;

 	list_for_each_entry(root, &acpi_pci_roots, node)
 		driver->remove(root->device->handle);
 }

 EXPORT_SYMBOL(acpi_pci_unregister_driver);

 acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
 {
 	struct acpi_pci_root *root;

 	list_for_each_entry(root, &acpi_pci_roots, node)
 		if ((root->segment == (u16) seg) && (root->bus_nr == (u16) bus))
 			return root->device->handle;
 	return NULL;
 }

 EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);

 /**
  * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
  * @handle - the ACPI CA node in question.
  *
  * Note: we could make this API take a struct acpi_device * instead, but
  * for now, it's more convenient to operate on an acpi_handle.
  */
 int acpi_is_root_bridge(acpi_handle handle)
 {
 	int ret;
 	struct acpi_device *device;

 	ret = acpi_bus_get_device(handle, &device);
 	if (ret)
 		return 0;

 	ret = acpi_match_device_ids(device, root_device_ids);
 	if (ret)
 		return 0;
 	else
 		return 1;
 }
 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);

 static acpi_status
 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
 {
 	int *busnr = data;
 	struct acpi_resource_address64 address;

 	if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
 	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
 	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
 		return AE_OK;

 	acpi_resource_to_address64(resource, &address);
 	if ((address.address_length > 0) &&
 	    (address.resource_type == ACPI_BUS_NUMBER_RANGE))
 		*busnr = address.minimum;

 	return AE_OK;
 }

 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
 					     unsigned long long *bus)
 {
 	acpi_status status;
 	int busnum;

 	busnum = -1;
 	status =
 	    acpi_walk_resources(handle, METHOD_NAME__CRS,
 				get_root_bridge_busnr_callback, &busnum);
 	if (ACPI_FAILURE(status))
 		return status;
 	/* Check if we really get a bus number from _CRS */
 	if (busnum == -1)
 		return AE_ERROR;
 	*bus = busnum;
 	return AE_OK;
 }

 static void acpi_pci_bridge_scan(struct acpi_device *device)
 {
 	int status;
 	struct acpi_device *child = NULL;

 	if (device->flags.bus_address)
 		if (device->parent && device->parent->ops.bind) {
 			status = device->parent->ops.bind(device);
 			if (!status) {
 				list_for_each_entry(child, &device->children, node)
 					acpi_pci_bridge_scan(child);
 			}
 		}
 }

 static u8 OSC_UUID[16] = {0x5B, 0x4D, 0xDB, 0x33, 0xF7, 0x1F, 0x1C, 0x40,
 			  0x96, 0x57, 0x74, 0x41, 0xC0, 0x3D, 0xD7, 0x66};

 static acpi_status acpi_pci_run_osc(acpi_handle handle,
 				    const u32 *capbuf, u32 *retval)
 {
 	acpi_status status;
 	struct acpi_object_list input;
 	union acpi_object in_params[4];
 	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
 	union acpi_object *out_obj;
 	u32 errors;

 	/* 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	= OSC_UUID;
 	in_params[1].type 		= ACPI_TYPE_INTEGER;
 	in_params[1].integer.value 	= 1;
 	in_params[2].type 		= ACPI_TYPE_INTEGER;
 	in_params[2].integer.value	= 3;
 	in_params[3].type		= ACPI_TYPE_BUFFER;
 	in_params[3].buffer.length 	= 12;
 	in_params[3].buffer.pointer 	= (u8 *)capbuf;

 	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) {
 		printk(KERN_DEBUG "_OSC evaluation returned wrong type\n");
 		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)
 			printk(KERN_DEBUG "_OSC request failed\n");
 		if (errors & OSC_INVALID_UUID_ERROR)
 			printk(KERN_DEBUG "_OSC invalid UUID\n");
 		if (errors & OSC_INVALID_REVISION_ERROR)
 			printk(KERN_DEBUG "_OSC invalid revision\n");
 		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
 			if (capbuf[OSC_QUERY_TYPE] & OSC_QUERY_ENABLE)
 				goto out_success;
 			printk(KERN_DEBUG
 			       "Firmware did not grant requested _OSC control\n");
 			status = AE_SUPPORT;
 			goto out_kfree;
 		}
 		status = AE_ERROR;
 		goto out_kfree;
 	}
 out_success:
 	*retval = *((u32 *)(out_obj->buffer.pointer + 8));
 	status = AE_OK;

 out_kfree:
 	kfree(output.pointer);
 	return status;
 }

 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, u32 flags)
 {
 	acpi_status status;
 	u32 support_set, result, capbuf[3];

 	/* do _OSC query for all possible controls */
 	support_set = root->osc_support_set | (flags & OSC_SUPPORT_MASKS);
 	capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
 	capbuf[OSC_SUPPORT_TYPE] = support_set;
 	capbuf[OSC_CONTROL_TYPE] = OSC_CONTROL_MASKS;

 	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
 	if (ACPI_SUCCESS(status)) {
 		root->osc_support_set = support_set;
 		root->osc_control_qry = result;
 		root->osc_queried = 1;
 	}
 	return status;
 }

 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
 {
 	acpi_status status;
 	acpi_handle tmp;

 	status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
 	if (ACPI_FAILURE(status))
 		return status;
 	mutex_lock(&osc_lock);
 	status = acpi_pci_query_osc(root, flags);
 	mutex_unlock(&osc_lock);
 	return status;
 }

 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 {
 	struct acpi_pci_root *root;

 	list_for_each_entry(root, &acpi_pci_roots, node) {
 		if (root->device->handle == handle)
 			return root;
 	}
 	return NULL;
 }
 EXPORT_SYMBOL_GPL(acpi_pci_find_root);

 struct acpi_handle_node {
 	struct list_head node;
 	acpi_handle handle;
 };

 /**
  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
  * @handle: the handle in question
  *
  * Given an ACPI CA handle, the desired PCI device is located in the
  * list of PCI devices.
  *
  * If the device is found, its reference count is increased and this
  * function returns a pointer to its data structure.  The caller must
  * decrement the reference count by calling pci_dev_put().
  * If no device is found, %NULL is returned.
  */
 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
 {
 	int dev, fn;
 	unsigned long long adr;
 	acpi_status status;
 	acpi_handle phandle;
 	struct pci_bus *pbus;
 	struct pci_dev *pdev = NULL;
 	struct acpi_handle_node *node, *tmp;
 	struct acpi_pci_root *root;
 	LIST_HEAD(device_list);

 	/*
 	 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
 	 */
 	phandle = handle;
 	while (!acpi_is_root_bridge(phandle)) {
 		node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
 		if (!node)
 			goto out;

 		INIT_LIST_HEAD(&node->node);
 		node->handle = phandle;
 		list_add(&node->node, &device_list);

 		status = acpi_get_parent(phandle, &phandle);
 		if (ACPI_FAILURE(status))
 			goto out;
 	}

 	root = acpi_pci_find_root(phandle);
 	if (!root)
 		goto out;

 	pbus = root->bus;

 	/*
 	 * Now, walk back down the PCI device tree until we return to our
 	 * original handle. Assumes that everything between the PCI root
 	 * bridge and the device we're looking for must be a P2P bridge.
 	 */
 	list_for_each_entry(node, &device_list, node) {
 		acpi_handle hnd = node->handle;
 		status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
 		if (ACPI_FAILURE(status))
 			goto out;
 		dev = (adr >> 16) & 0xffff;
 		fn  = adr & 0xffff;

 		pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
 		if (!pdev || hnd == handle)
 			break;

 		pbus = pdev->subordinate;
 		pci_dev_put(pdev);
 	}
 out:
 	list_for_each_entry_safe(node, tmp, &device_list, node)
 		kfree(node);

 	return pdev;
 }
 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);

 /**
  * acpi_pci_osc_control_set - commit requested control to Firmware
  * @handle: acpi_handle for the target ACPI object
  * @flags: driver's requested control bits
  *
  * Attempt to take control from Firmware on requested control bits.
  **/
 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags)
 {
 	acpi_status status;
 	u32 control_req, result, capbuf[3];
 	acpi_handle tmp;
 	struct acpi_pci_root *root;

 	status = acpi_get_handle(handle, "_OSC", &tmp);
 	if (ACPI_FAILURE(status))
 		return status;

 	control_req = (flags & OSC_CONTROL_MASKS);
 	if (!control_req)
 		return AE_TYPE;

 	root = acpi_pci_find_root(handle);
 	if (!root)
 		return AE_NOT_EXIST;

 	mutex_lock(&osc_lock);
 	/* No need to evaluate _OSC if the control was already granted. */
 	if ((root->osc_control_set & control_req) == control_req)
 		goto out;

 	/* Need to query controls first before requesting them */
 	if (!root->osc_queried) {
 		status = acpi_pci_query_osc(root, root->osc_support_set);
 		if (ACPI_FAILURE(status))
 			goto out;
 	}
 	if ((root->osc_control_qry & control_req) != control_req) {
 		printk(KERN_DEBUG
 		       "Firmware did not grant requested _OSC control\n");
 		status = AE_SUPPORT;
 		goto out;
 	}

 	capbuf[OSC_QUERY_TYPE] = 0;
 	capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
 	capbuf[OSC_CONTROL_TYPE] = root->osc_control_set | control_req;
 	status = acpi_pci_run_osc(handle, capbuf, &result);
 	if (ACPI_SUCCESS(status))
 		root->osc_control_set = result;
 out:
 	mutex_unlock(&osc_lock);
 	return status;
 }
 EXPORT_SYMBOL(acpi_pci_osc_control_set);

 static int __devinit acpi_pci_root_add(struct acpi_device *device)
 {
 	unsigned long long segment, bus;
 	acpi_status status;
 	int result;
 	struct acpi_pci_root *root;
 	acpi_handle handle;
 	struct acpi_device *child;
 	u32 flags, base_flags;

 	segment = 0;
 	status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
 				       &segment);
 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 		printk(KERN_ERR PREFIX "can't evaluate _SEG\n");
 		return -ENODEV;
 	}

 	/* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 	bus = 0;
 	status = try_get_root_bridge_busnr(device->handle, &bus);
 	if (ACPI_FAILURE(status)) {
 		status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN,					       NULL, &bus);
 		if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 			printk(KERN_ERR PREFIX
 			     "no bus number in _CRS and can't evaluate _BBN\n");
 			return -ENODEV;
 		}
 	}

 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 	if (!root)
 		return -ENOMEM;

 	INIT_LIST_HEAD(&root->node);
 	root->device = device;
 	root->segment = segment & 0xFFFF;
 	root->bus_nr = bus & 0xFF;
 	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 	device->driver_data = root;

 	/*
 	 * All supported architectures that use ACPI have support for
 	 * PCI domains, so we indicate this in _OSC support capabilities.
 	 */
 	flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 	acpi_pci_osc_support(root, flags);

 	/*
 	 * TBD: Need PCI interface for enumeration/configuration of roots.
 	 */

 	/* TBD: Locking */
 	list_add_tail(&root->node, &acpi_pci_roots);

 	printk(KERN_INFO PREFIX "%s [%s] (%04x:%02x)\n",
 	       acpi_device_name(device), acpi_device_bid(device),
 	       root->segment, root->bus_nr);

 	/*
 	 * Scan the Root Bridge
 	 * --------------------
 	 * Must do this prior to any attempt to bind the root device, as the
 	 * PCI namespace does not get created until this call is made (and
 	 * thus the root bridge's pci_dev does not exist).
 	 */
 	root->bus = pci_acpi_scan_root(device, segment, bus);
 	if (!root->bus) {
 		printk(KERN_ERR PREFIX
 			    "Bus %04x:%02x not present in PCI namespace\n",
 			    root->segment, root->bus_nr);
 		result = -ENODEV;
 		goto end;
 	}

 	/*
 	 * Attach ACPI-PCI Context
 	 * -----------------------
 	 * Thus binding the ACPI and PCI devices.
 	 */
 	result = acpi_pci_bind_root(device);
 	if (result)
 		goto end;

 	/*
 	 * PCI Routing Table
 	 * -----------------
 	 * Evaluate and parse _PRT, if exists.
 	 */
 	status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
 	if (ACPI_SUCCESS(status))
 		result = acpi_pci_irq_add_prt(device->handle, root->bus);

 	/*
 	 * Scan and bind all _ADR-Based Devices
 	 */
 	list_for_each_entry(child, &device->children, node)
 		acpi_pci_bridge_scan(child);

 	/* Indicate support for various _OSC capabilities. */
 	if (pci_ext_cfg_avail(root->bus->self))
 		flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
 	if (pcie_aspm_enabled())
 		flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
 			OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
 	if (pci_msi_enabled())
 		flags |= OSC_MSI_SUPPORT;
 	if (flags != base_flags)
 		acpi_pci_osc_support(root, flags);

 	return 0;

 end:
 	if (!list_empty(&root->node))
 		list_del(&root->node);
 	kfree(root);
 	return result;
 }

 static int acpi_pci_root_start(struct acpi_device *device)
 {
 	struct acpi_pci_root *root = acpi_driver_data(device);

 	pci_bus_add_devices(root->bus);
 	return 0;
 }

 static int acpi_pci_root_remove(struct acpi_device *device, int type)
 {
 	struct acpi_pci_root *root = acpi_driver_data(device);

 	kfree(root);
 	return 0;
 }

 static int __init acpi_pci_root_init(void)
 {
 	if (acpi_pci_disabled)
 		return 0;

 	if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
 		return -ENODEV;

 	return 0;
 }

 subsys_initcall(acpi_pci_root_init);
	/*
	* pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
	*
	* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
	* 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/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/types.h>
	#include <linux/proc_fs.h>
	#include <linux/spinlock.h>
	#include <linux/pm.h>
	#include <linux/pci.h>
	#include <linux/pci-acpi.h>
	#include <linux/acpi.h>
	#include <acpi/acpi_bus.h>
	#include <acpi/acpi_drivers.h>

	#define _COMPONENT ACPI_PCI_COMPONENT
	ACPI_MODULE_NAME("pci_root");
	#define ACPI_PCI_ROOT_CLASS "pci_bridge"
	#define ACPI_PCI_ROOT_DEVICE_NAME "PCI Root Bridge"
	static int acpi_pci_root_add(struct acpi_device *device);
	static int acpi_pci_root_remove(struct acpi_device *device, int type);
	static int acpi_pci_root_start(struct acpi_device *device);

	static struct acpi_device_id root_device_ids[] = {
	{"PNP0A03", 0},
	{"", 0},
	};
	MODULE_DEVICE_TABLE(acpi, root_device_ids);

	static struct acpi_driver acpi_pci_root_driver = {
	.name = "pci_root",
	.class = ACPI_PCI_ROOT_CLASS,
	.ids = root_device_ids,
	.ops = {
	.add = acpi_pci_root_add,
	.remove = acpi_pci_root_remove,
	.start = acpi_pci_root_start,
	},
	};

	static LIST_HEAD(acpi_pci_roots);

	static struct acpi_pci_driver *sub_driver;
	static DEFINE_MUTEX(osc_lock);

	int acpi_pci_register_driver(struct acpi_pci_driver *driver)
	{
	int n = 0;
	struct acpi_pci_root *root;

	struct acpi_pci_driver **pptr = &sub_driver;
	while (*pptr)
	pptr = &(*pptr)->next;
	*pptr = driver;

	if (!driver->add)
	return 0;

	list_for_each_entry(root, &acpi_pci_roots, node) {
	driver->add(root->device->handle);
	n++;
	}

	return n;
	}

	EXPORT_SYMBOL(acpi_pci_register_driver);

	void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
	{
	struct acpi_pci_root *root;

	struct acpi_pci_driver **pptr = &sub_driver;
	while (*pptr) {
	if (*pptr == driver)
	break;
	pptr = &(*pptr)->next;
	}
	BUG_ON(!*pptr);
	pptr = (pptr)->next;

	if (!driver->remove)
	return;

	list_for_each_entry(root, &acpi_pci_roots, node)
	driver->remove(root->device->handle);
	}

	EXPORT_SYMBOL(acpi_pci_unregister_driver);

	acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
	{
	struct acpi_pci_root *root;

	list_for_each_entry(root, &acpi_pci_roots, node)
	if ((root->segment == (u16) seg) && (root->bus_nr == (u16) bus))
	return root->device->handle;
	return NULL;
	}

	EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);

	/**
	* acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
	* @handle - the ACPI CA node in question.
	*
	* Note: we could make this API take a struct acpi_device * instead, but
	* for now, it's more convenient to operate on an acpi_handle.
	*/
	int acpi_is_root_bridge(acpi_handle handle)
	{
	int ret;
	struct acpi_device *device;

	ret = acpi_bus_get_device(handle, &device);
	if (ret)
	return 0;

	ret = acpi_match_device_ids(device, root_device_ids);
	if (ret)
	return 0;
	else
	return 1;
	}
	EXPORT_SYMBOL_GPL(acpi_is_root_bridge);

	static acpi_status
	get_root_bridge_busnr_callback(struct acpi_resource resource, void data)
	{
	int *busnr = data;
	struct acpi_resource_address64 address;

	if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
	resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
	resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
	return AE_OK;

	acpi_resource_to_address64(resource, &address);
	if ((address.address_length > 0) &&
	(address.resource_type == ACPI_BUS_NUMBER_RANGE))
	*busnr = address.minimum;

	return AE_OK;
	}

	static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
	unsigned long long *bus)
	{
	acpi_status status;
	int busnum;

	busnum = -1;
	status =
	acpi_walk_resources(handle, METHOD_NAME__CRS,
	get_root_bridge_busnr_callback, &busnum);
	if (ACPI_FAILURE(status))
	return status;
	/* Check if we really get a bus number from _CRS */
	if (busnum == -1)
	return AE_ERROR;
	*bus = busnum;
	return AE_OK;
	}

	static void acpi_pci_bridge_scan(struct acpi_device *device)
	{
	int status;
	struct acpi_device *child = NULL;

	if (device->flags.bus_address)
	if (device->parent && device->parent->ops.bind) {
	status = device->parent->ops.bind(device);
	if (!status) {
	list_for_each_entry(child, &device->children, node)
	acpi_pci_bridge_scan(child);
	}
	}
	}

	static u8 OSC_UUID[16] = {0x5B, 0x4D, 0xDB, 0x33, 0xF7, 0x1F, 0x1C, 0x40,
	0x96, 0x57, 0x74, 0x41, 0xC0, 0x3D, 0xD7, 0x66};

	static acpi_status acpi_pci_run_osc(acpi_handle handle,
	const u32 capbuf, u32 retval)
	{
	acpi_status status;
	struct acpi_object_list input;
	union acpi_object in_params[4];
	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
	union acpi_object *out_obj;
	u32 errors;

	/* 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 = OSC_UUID;
	in_params[1].type = ACPI_TYPE_INTEGER;
	in_params[1].integer.value = 1;
	in_params[2].type = ACPI_TYPE_INTEGER;
	in_params[2].integer.value = 3;
	in_params[3].type = ACPI_TYPE_BUFFER;
	in_params[3].buffer.length = 12;
	in_params[3].buffer.pointer = (u8 *)capbuf;

	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) {
	printk(KERN_DEBUG "_OSC evaluation returned wrong type\n");
	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)
	printk(KERN_DEBUG "_OSC request failed\n");
	if (errors & OSC_INVALID_UUID_ERROR)
	printk(KERN_DEBUG "_OSC invalid UUID\n");
	if (errors & OSC_INVALID_REVISION_ERROR)
	printk(KERN_DEBUG "_OSC invalid revision\n");
	if (errors & OSC_CAPABILITIES_MASK_ERROR) {
	if (capbuf[OSC_QUERY_TYPE] & OSC_QUERY_ENABLE)
	goto out_success;
	printk(KERN_DEBUG
	"Firmware did not grant requested _OSC control\n");
	status = AE_SUPPORT;
	goto out_kfree;
	}
	status = AE_ERROR;
	goto out_kfree;
	}
	out_success:
	retval = ((u32 *)(out_obj->buffer.pointer + 8));
	status = AE_OK;

	out_kfree:
	kfree(output.pointer);
	return status;
	}

	static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, u32 flags)
	{
	acpi_status status;
	u32 support_set, result, capbuf[3];

	/* do _OSC query for all possible controls */
	support_set = root->osc_support_set \| (flags & OSC_SUPPORT_MASKS);
	capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
	capbuf[OSC_SUPPORT_TYPE] = support_set;
	capbuf[OSC_CONTROL_TYPE] = OSC_CONTROL_MASKS;

	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
	if (ACPI_SUCCESS(status)) {
	root->osc_support_set = support_set;
	root->osc_control_qry = result;
	root->osc_queried = 1;
	}
	return status;
	}

	static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
	{
	acpi_status status;
	acpi_handle tmp;

	status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
	if (ACPI_FAILURE(status))
	return status;
	mutex_lock(&osc_lock);
	status = acpi_pci_query_osc(root, flags);
	mutex_unlock(&osc_lock);
	return status;
	}

	struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
	{
	struct acpi_pci_root *root;

	list_for_each_entry(root, &acpi_pci_roots, node) {
	if (root->device->handle == handle)
	return root;
	}
	return NULL;
	}
	EXPORT_SYMBOL_GPL(acpi_pci_find_root);

	struct acpi_handle_node {
	struct list_head node;
	acpi_handle handle;
	};

	/**
	* acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
	* @handle: the handle in question
	*
	* Given an ACPI CA handle, the desired PCI device is located in the
	* list of PCI devices.
	*
	* If the device is found, its reference count is increased and this
	* function returns a pointer to its data structure. The caller must
	* decrement the reference count by calling pci_dev_put().
	* If no device is found, %NULL is returned.
	*/
	struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
	{
	int dev, fn;
	unsigned long long adr;
	acpi_status status;
	acpi_handle phandle;
	struct pci_bus *pbus;
	struct pci_dev *pdev = NULL;
	struct acpi_handle_node node, tmp;
	struct acpi_pci_root *root;
	LIST_HEAD(device_list);

	/*
	* Walk up the ACPI CA namespace until we reach a PCI root bridge.
	*/
	phandle = handle;
	while (!acpi_is_root_bridge(phandle)) {
	node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
	if (!node)
	goto out;

	INIT_LIST_HEAD(&node->node);
	node->handle = phandle;
	list_add(&node->node, &device_list);

	status = acpi_get_parent(phandle, &phandle);
	if (ACPI_FAILURE(status))
	goto out;
	}

	root = acpi_pci_find_root(phandle);
	if (!root)
	goto out;

	pbus = root->bus;

	/*
	* Now, walk back down the PCI device tree until we return to our
	* original handle. Assumes that everything between the PCI root
	* bridge and the device we're looking for must be a P2P bridge.
	*/
	list_for_each_entry(node, &device_list, node) {
	acpi_handle hnd = node->handle;
	status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
	if (ACPI_FAILURE(status))
	goto out;
	dev = (adr >> 16) & 0xffff;
	fn = adr & 0xffff;

	pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
	if (!pdev \|\| hnd == handle)
	break;

	pbus = pdev->subordinate;
	pci_dev_put(pdev);
	}
	out:
	list_for_each_entry_safe(node, tmp, &device_list, node)
	kfree(node);

	return pdev;
	}
	EXPORT_SYMBOL_GPL(acpi_get_pci_dev);

	/**
	* acpi_pci_osc_control_set - commit requested control to Firmware
	* @handle: acpi_handle for the target ACPI object
	* @flags: driver's requested control bits
	*
	* Attempt to take control from Firmware on requested control bits.
	**/
	acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags)
	{
	acpi_status status;
	u32 control_req, result, capbuf[3];
	acpi_handle tmp;
	struct acpi_pci_root *root;

	status = acpi_get_handle(handle, "_OSC", &tmp);
	if (ACPI_FAILURE(status))
	return status;

	control_req = (flags & OSC_CONTROL_MASKS);
	if (!control_req)
	return AE_TYPE;

	root = acpi_pci_find_root(handle);
	if (!root)
	return AE_NOT_EXIST;

	mutex_lock(&osc_lock);
	/* No need to evaluate _OSC if the control was already granted. */
	if ((root->osc_control_set & control_req) == control_req)
	goto out;

	/* Need to query controls first before requesting them */
	if (!root->osc_queried) {
	status = acpi_pci_query_osc(root, root->osc_support_set);
	if (ACPI_FAILURE(status))
	goto out;
	}
	if ((root->osc_control_qry & control_req) != control_req) {
	printk(KERN_DEBUG
	"Firmware did not grant requested _OSC control\n");
	status = AE_SUPPORT;
	goto out;
	}

	capbuf[OSC_QUERY_TYPE] = 0;
	capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
	capbuf[OSC_CONTROL_TYPE] = root->osc_control_set \| control_req;
	status = acpi_pci_run_osc(handle, capbuf, &result);
	if (ACPI_SUCCESS(status))
	root->osc_control_set = result;
	out:
	mutex_unlock(&osc_lock);
	return status;
	}
	EXPORT_SYMBOL(acpi_pci_osc_control_set);

	static int __devinit acpi_pci_root_add(struct acpi_device *device)
	{
	unsigned long long segment, bus;
	acpi_status status;
	int result;
	struct acpi_pci_root *root;
	acpi_handle handle;
	struct acpi_device *child;
	u32 flags, base_flags;

	segment = 0;
	status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
	&segment);
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
	printk(KERN_ERR PREFIX "can't evaluate _SEG\n");
	return -ENODEV;
	}

	/* Check _CRS first, then _BBN. If no _BBN, default to zero. */
	bus = 0;
	status = try_get_root_bridge_busnr(device->handle, &bus);
	if (ACPI_FAILURE(status)) {
	status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN, NULL, &bus);
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
	printk(KERN_ERR PREFIX
	"no bus number in _CRS and can't evaluate _BBN\n");
	return -ENODEV;
	}
	}

	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
	if (!root)
	return -ENOMEM;

	INIT_LIST_HEAD(&root->node);
	root->device = device;
	root->segment = segment & 0xFFFF;
	root->bus_nr = bus & 0xFF;
	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
	device->driver_data = root;

	/*
	* All supported architectures that use ACPI have support for
	* PCI domains, so we indicate this in _OSC support capabilities.
	*/
	flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
	acpi_pci_osc_support(root, flags);

	/*
	* TBD: Need PCI interface for enumeration/configuration of roots.
	*/

	/* TBD: Locking */
	list_add_tail(&root->node, &acpi_pci_roots);

	printk(KERN_INFO PREFIX "%s [%s] (%04x:%02x)\n",
	acpi_device_name(device), acpi_device_bid(device),
	root->segment, root->bus_nr);

	/*
	* Scan the Root Bridge
	* --------------------
	* Must do this prior to any attempt to bind the root device, as the
	* PCI namespace does not get created until this call is made (and
	* thus the root bridge's pci_dev does not exist).
	*/
	root->bus = pci_acpi_scan_root(device, segment, bus);
	if (!root->bus) {
	printk(KERN_ERR PREFIX
	"Bus %04x:%02x not present in PCI namespace\n",
	root->segment, root->bus_nr);
	result = -ENODEV;
	goto end;
	}

	/*
	* Attach ACPI-PCI Context
	* -----------------------
	* Thus binding the ACPI and PCI devices.
	*/
	result = acpi_pci_bind_root(device);
	if (result)
	goto end;

	/*
	* PCI Routing Table
	* -----------------
	* Evaluate and parse _PRT, if exists.
	*/
	status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
	if (ACPI_SUCCESS(status))
	result = acpi_pci_irq_add_prt(device->handle, root->bus);

	/*
	* Scan and bind all _ADR-Based Devices
	*/
	list_for_each_entry(child, &device->children, node)
	acpi_pci_bridge_scan(child);

	/* Indicate support for various _OSC capabilities. */
	if (pci_ext_cfg_avail(root->bus->self))
	flags \|= OSC_EXT_PCI_CONFIG_SUPPORT;
	if (pcie_aspm_enabled())
	flags \|= OSC_ACTIVE_STATE_PWR_SUPPORT \|
	OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
	if (pci_msi_enabled())
	flags \|= OSC_MSI_SUPPORT;
	if (flags != base_flags)
	acpi_pci_osc_support(root, flags);

	return 0;

	end:
	if (!list_empty(&root->node))
	list_del(&root->node);
	kfree(root);
	return result;
	}

	static int acpi_pci_root_start(struct acpi_device *device)
	{
	struct acpi_pci_root *root = acpi_driver_data(device);

	pci_bus_add_devices(root->bus);
	return 0;
	}

	static int acpi_pci_root_remove(struct acpi_device *device, int type)
	{
	struct acpi_pci_root *root = acpi_driver_data(device);

	kfree(root);
	return 0;
	}

	static int __init acpi_pci_root_init(void)
	{
	if (acpi_pci_disabled)
	return 0;

	if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
	return -ENODEV;

	return 0;
	}

	subsys_initcall(acpi_pci_root_init);