1 files changed, 221 insertions, 247 deletions

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 7aff6312ce7..d388f13d48b 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -27,7 +27,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/types.h>
-#include <linux/spinlock.h>
+#include <linux/mutex.h>
 #include <linux/pm.h>
 #include <linux/pm_runtime.h>
 #include <linux/pci.h>
@@ -35,105 +35,46 @@
 #include <linux/pci-aspm.h>
 #include <linux/acpi.h>
 #include <linux/slab.h>
-#include <acpi/acpi_bus.h>
-#include <acpi/acpi_drivers.h>
-#include <acpi/apei.h>
+#include <acpi/apei.h>	/* for acpi_hest_init() */
 
-#define PREFIX "ACPI: "
+#include "internal.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 int acpi_pci_root_add(struct acpi_device *device,
+			     const struct acpi_device_id *not_used);
+static void acpi_pci_root_remove(struct acpi_device *device);
 
-#define ACPI_PCIE_REQ_SUPPORT (OSC_EXT_PCI_CONFIG_SUPPORT \
-				| OSC_ACTIVE_STATE_PWR_SUPPORT \
-				| OSC_CLOCK_PWR_CAPABILITY_SUPPORT \
-				| OSC_MSI_SUPPORT)
+static int acpi_pci_root_scan_dependent(struct acpi_device *adev)
+{
+	acpiphp_check_host_bridge(adev);
+	return 0;
+}
+
+#define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \
+				| OSC_PCI_ASPM_SUPPORT \
+				| OSC_PCI_CLOCK_PM_SUPPORT \
+				| OSC_PCI_MSI_SUPPORT)
 
 static const 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,
+static struct acpi_scan_handler pci_root_handler = {
 	.ids = root_device_ids,
-	.ops = {
-		.add = acpi_pci_root_add,
-		.remove = acpi_pci_root_remove,
-		.start = acpi_pci_root_start,
-		},
+	.attach = acpi_pci_root_add,
+	.detach = acpi_pci_root_remove,
+	.hotplug = {
+		.enabled = true,
+		.scan_dependent = acpi_pci_root_scan_dependent,
+	},
 };
 
-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->secondary.start == (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.
@@ -163,13 +104,12 @@ get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
 {
 	struct resource *res = data;
 	struct acpi_resource_address64 address;
+	acpi_status status;
 
-	if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
-	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
-	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
+	status = acpi_resource_to_address64(resource, &address);
+	if (ACPI_FAILURE(status))
 		return AE_OK;
 
-	acpi_resource_to_address64(resource, &address);
 	if ((address.address_length > 0) &&
 	    (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
 		res->start = address.minimum;
@@ -195,19 +135,53 @@ static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
 	return AE_OK;
 }
 
-static void acpi_pci_bridge_scan(struct acpi_device *device)
+struct pci_osc_bit_struct {
+	u32 bit;
+	char *desc;
+};
+
+static struct pci_osc_bit_struct pci_osc_support_bit[] = {
+	{ OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },
+	{ OSC_PCI_ASPM_SUPPORT, "ASPM" },
+	{ OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
+	{ OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
+	{ OSC_PCI_MSI_SUPPORT, "MSI" },
+};
+
+static struct pci_osc_bit_struct pci_osc_control_bit[] = {
+	{ OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },
+	{ OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },
+	{ OSC_PCI_EXPRESS_PME_CONTROL, "PME" },
+	{ OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
+	{ OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
+};
+
+static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
+			    struct pci_osc_bit_struct *table, int size)
+{
+	char buf[80];
+	int i, len = 0;
+	struct pci_osc_bit_struct *entry;
+
+	buf[0] = '\0';
+	for (i = 0, entry = table; i < size; i++, entry++)
+		if (word & entry->bit)
+			len += snprintf(buf + len, sizeof(buf) - len, "%s%s",
+					len ? " " : "", entry->desc);
+
+	dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
+}
+
+static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
 {
-	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);
-			}
-		}
+	decode_osc_bits(root, msg, word, pci_osc_support_bit,
+			ARRAY_SIZE(pci_osc_support_bit));
+}
+
+static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
+{
+	decode_osc_bits(root, msg, word, pci_osc_control_bit,
+			ARRAY_SIZE(pci_osc_control_bit));
 }
 
 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
@@ -241,14 +215,14 @@ static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
 	support &= OSC_PCI_SUPPORT_MASKS;
 	support |= root->osc_support_set;
 
-	capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
-	capbuf[OSC_SUPPORT_TYPE] = support;
+	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
+	capbuf[OSC_SUPPORT_DWORD] = support;
 	if (control) {
 		*control &= OSC_PCI_CONTROL_MASKS;
-		capbuf[OSC_CONTROL_TYPE] = *control | root->osc_control_set;
+		capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
 	} else {
-		/* Run _OSC query for all possible controls. */
-		capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS;
+		/* Run _OSC query only with existing controls. */
+		capbuf[OSC_CONTROL_DWORD] = root->osc_control_set;
 	}
 
 	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
@@ -263,11 +237,7 @@ static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
 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, NULL);
 	mutex_unlock(&osc_lock);
@@ -277,12 +247,15 @@ static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 {
 	struct acpi_pci_root *root;
+	struct acpi_device *device;
 
-	list_for_each_entry(root, &acpi_pci_roots, node) {
-		if (root->device->handle == handle)
-			return root;
-	}
-	return NULL;
+	if (acpi_bus_get_device(handle, &device) ||
+	    acpi_match_device_ids(device, root_device_ids))
+		return NULL;
+
+	root = acpi_driver_data(device);
+
+	return root;
 }
 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
 
@@ -396,9 +369,8 @@ EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 {
 	struct acpi_pci_root *root;
-	acpi_status status;
+	acpi_status status = AE_OK;
 	u32 ctrl, capbuf[3];
-	acpi_handle tmp;
 
 	if (!mask)
 		return AE_BAD_PARAMETER;
@@ -411,10 +383,6 @@ acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 	if (!root)
 		return AE_NOT_EXIST;
 
-	status = acpi_get_handle(handle, "_OSC", &tmp);
-	if (ACPI_FAILURE(status))
-		return status;
-
 	mutex_lock(&osc_lock);
 
 	*mask = ctrl | root->osc_control_set;
@@ -429,17 +397,21 @@ acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 			goto out;
 		if (ctrl == *mask)
 			break;
+		decode_osc_control(root, "platform does not support",
+				   ctrl & ~(*mask));
 		ctrl = *mask;
 	}
 
 	if ((ctrl & req) != req) {
+		decode_osc_control(root, "not requesting control; platform does not support",
+				   req & ~(ctrl));
 		status = AE_SUPPORT;
 		goto out;
 	}
 
-	capbuf[OSC_QUERY_TYPE] = 0;
-	capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
-	capbuf[OSC_CONTROL_TYPE] = ctrl;
+	capbuf[OSC_QUERY_DWORD] = 0;
+	capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
+	capbuf[OSC_CONTROL_DWORD] = ctrl;
 	status = acpi_pci_run_osc(handle, capbuf, mask);
 	if (ACPI_SUCCESS(status))
 		root->osc_control_set = *mask;
@@ -449,32 +421,113 @@ out:
 }
 EXPORT_SYMBOL(acpi_pci_osc_control_set);
 
-static int __devinit acpi_pci_root_add(struct acpi_device *device)
+static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
+				 int *clear_aspm)
+{
+	u32 support, control, requested;
+	acpi_status status;
+	struct acpi_device *device = root->device;
+	acpi_handle handle = device->handle;
+
+	/*
+	 * All supported architectures that use ACPI have support for
+	 * PCI domains, so we indicate this in _OSC support capabilities.
+	 */
+	support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
+	if (pci_ext_cfg_avail())
+		support |= OSC_PCI_EXT_CONFIG_SUPPORT;
+	if (pcie_aspm_support_enabled())
+		support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
+	if (pci_msi_enabled())
+		support |= OSC_PCI_MSI_SUPPORT;
+
+	decode_osc_support(root, "OS supports", support);
+	status = acpi_pci_osc_support(root, support);
+	if (ACPI_FAILURE(status)) {
+		dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
+			 acpi_format_exception(status));
+		*no_aspm = 1;
+		return;
+	}
+
+	if (pcie_ports_disabled) {
+		dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
+		return;
+	}
+
+	if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
+		decode_osc_support(root, "not requesting OS control; OS requires",
+				   ACPI_PCIE_REQ_SUPPORT);
+		return;
+	}
+
+	control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
+		| OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
+		| OSC_PCI_EXPRESS_PME_CONTROL;
+
+	if (pci_aer_available()) {
+		if (aer_acpi_firmware_first())
+			dev_info(&device->dev,
+				 "PCIe AER handled by firmware\n");
+		else
+			control |= OSC_PCI_EXPRESS_AER_CONTROL;
+	}
+
+	requested = control;
+	status = acpi_pci_osc_control_set(handle, &control,
+					  OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
+	if (ACPI_SUCCESS(status)) {
+		decode_osc_control(root, "OS now controls", control);
+		if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
+			/*
+			 * We have ASPM control, but the FADT indicates
+			 * that it's unsupported. Clear it.
+			 */
+			*clear_aspm = 1;
+		}
+	} else {
+		decode_osc_control(root, "OS requested", requested);
+		decode_osc_control(root, "platform willing to grant", control);
+		dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
+			acpi_format_exception(status));
+
+		/*
+		 * We want to disable ASPM here, but aspm_disabled
+		 * needs to remain in its state from boot so that we
+		 * properly handle PCIe 1.1 devices.  So we set this
+		 * flag here, to defer the action until after the ACPI
+		 * root scan.
+		 */
+		*no_aspm = 1;
+	}
+}
+
+static int acpi_pci_root_add(struct acpi_device *device,
+			     const struct acpi_device_id *not_used)
 {
 	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;
+	acpi_handle handle = device->handle;
+	int no_aspm = 0, clear_aspm = 0;
 
 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 	if (!root)
 		return -ENOMEM;
 
 	segment = 0;
-	status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
+	status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
 				       &segment);
 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
-		printk(KERN_ERR PREFIX "can't evaluate _SEG\n");
+		dev_err(&device->dev,  "can't evaluate _SEG\n");
 		result = -ENODEV;
 		goto end;
 	}
 
 	/* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 	root->secondary.flags = IORESOURCE_BUS;
-	status = try_get_root_bridge_busnr(device->handle, &root->secondary);
+	status = try_get_root_bridge_busnr(handle, &root->secondary);
 	if (ACPI_FAILURE(status)) {
 		/*
 		 * We need both the start and end of the downstream bus range
@@ -483,185 +536,106 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 		 * can do is assume [_BBN-0xFF] or [0-0xFF].
 		 */
 		root->secondary.end = 0xFF;
-		printk(KERN_WARNING FW_BUG PREFIX
-		       "no secondary bus range in _CRS\n");
-		status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN,
+		dev_warn(&device->dev,
+			 FW_BUG "no secondary bus range in _CRS\n");
+		status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
 					       NULL, &bus);
 		if (ACPI_SUCCESS(status))
 			root->secondary.start = bus;
 		else if (status == AE_NOT_FOUND)
 			root->secondary.start = 0;
 		else {
-			printk(KERN_ERR PREFIX "can't evaluate _BBN\n");
+			dev_err(&device->dev, "can't evaluate _BBN\n");
 			result = -ENODEV;
 			goto end;
 		}
 	}
 
-	INIT_LIST_HEAD(&root->node);
 	root->device = device;
 	root->segment = segment & 0xFFFF;
 	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);
+	pr_info(PREFIX "%s [%s] (domain %04x %pR)\n",
+	       acpi_device_name(device), acpi_device_bid(device),
+	       root->segment, &root->secondary);
+
+	root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
+
+	negotiate_os_control(root, &no_aspm, &clear_aspm);
 
 	/*
 	 * 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] (domain %04x %pR)\n",
-	       acpi_device_name(device), acpi_device_bid(device),
-	       root->segment, &root->secondary);
-
 	/*
 	 * 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 
+	 * 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(root);
 	if (!root->bus) {
-		printk(KERN_ERR PREFIX
-			    "Bus %04x:%02x not present in PCI namespace\n",
-			    root->segment, (unsigned int)root->secondary.start);
+		dev_err(&device->dev,
+			"Bus %04x:%02x not present in PCI namespace\n",
+			root->segment, (unsigned int)root->secondary.start);
+		device->driver_data = NULL;
 		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_support_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);
-
-	if (!pcie_ports_disabled
-	    && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) {
-		flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL
-			| OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
-			| OSC_PCI_EXPRESS_PME_CONTROL;
-
-		if (pci_aer_available()) {
-			if (aer_acpi_firmware_first())
-				dev_dbg(root->bus->bridge,
-					"PCIe errors handled by BIOS.\n");
-			else
-				flags |= OSC_PCI_EXPRESS_AER_CONTROL;
-		}
-
-		dev_info(root->bus->bridge,
-			"Requesting ACPI _OSC control (0x%02x)\n", flags);
-
-		status = acpi_pci_osc_control_set(device->handle, &flags,
-					OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
-		if (ACPI_SUCCESS(status)) {
-			dev_info(root->bus->bridge,
-				"ACPI _OSC control (0x%02x) granted\n", flags);
-			if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
-				/*
-				 * We have ASPM control, but the FADT indicates
-				 * that it's unsupported. Clear it.
-				 */
-				pcie_clear_aspm(root->bus);
-			}
-		} else {
-			dev_info(root->bus->bridge,
-				"ACPI _OSC request failed (%s), "
-				"returned control mask: 0x%02x\n",
-				acpi_format_exception(status), flags);
-			pr_info("ACPI _OSC control for PCIe not granted, "
-				"disabling ASPM\n");
-			pcie_no_aspm();
-		}
-	} else {
-		dev_info(root->bus->bridge,
-			 "Unable to request _OSC control "
-			 "(_OSC support mask: 0x%02x)\n", flags);
+	if (clear_aspm) {
+		dev_info(&device->dev, "Disabling ASPM (FADT indicates it is unsupported)\n");
+		pcie_clear_aspm(root->bus);
 	}
+	if (no_aspm)
+		pcie_no_aspm();
 
 	pci_acpi_add_bus_pm_notifier(device, root->bus);
 	if (device->wakeup.flags.run_wake)
 		device_set_run_wake(root->bus->bridge, true);
 
-	return 0;
+	if (system_state != SYSTEM_BOOTING) {
+		pcibios_resource_survey_bus(root->bus);
+		pci_assign_unassigned_root_bus_resources(root->bus);
+	}
+
+	pci_lock_rescan_remove();
+	pci_bus_add_devices(root->bus);
+	pci_unlock_rescan_remove();
+	return 1;
 
 end:
-	if (!list_empty(&root->node))
-		list_del(&root->node);
 	kfree(root);
 	return result;
 }
 
-static int acpi_pci_root_start(struct acpi_device *device)
+static void acpi_pci_root_remove(struct acpi_device *device)
 {
 	struct acpi_pci_root *root = acpi_driver_data(device);
 
-	pci_bus_add_devices(root->bus);
-	return 0;
-}
+	pci_lock_rescan_remove();
 
-static int acpi_pci_root_remove(struct acpi_device *device, int type)
-{
-	struct acpi_pci_root *root = acpi_driver_data(device);
+	pci_stop_root_bus(root->bus);
 
 	device_set_run_wake(root->bus->bridge, false);
 	pci_acpi_remove_bus_pm_notifier(device);
 
+	pci_remove_root_bus(root->bus);
+
+	pci_unlock_rescan_remove();
+
 	kfree(root);
-	return 0;
 }
 
-static int __init acpi_pci_root_init(void)
+void __init acpi_pci_root_init(void)
 {
 	acpi_hest_init();
-
 	if (acpi_pci_disabled)
-		return 0;
+		return;
 
 	pci_acpi_crs_quirks();
-	if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
-		return -ENODEV;
-
-	return 0;
+	acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
 }
-
-subsys_initcall(acpi_pci_root_init);