1 files changed, 505 insertions, 258 deletions

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index c3fed31166b..d388f13d48b 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -27,368 +27,615 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/types.h>
-#include <linux/proc_fs.h>
-#include <linux/spinlock.h>
+#include <linux/mutex.h>
 #include <linux/pm.h>
+#include <linux/pm_runtime.h>
 #include <linux/pci.h>
+#include <linux/pci-acpi.h>
+#include <linux/pci-aspm.h>
 #include <linux/acpi.h>
-#include <acpi/acpi_bus.h>
-#include <acpi/acpi_drivers.h>
+#include <linux/slab.h>
+#include <acpi/apei.h>	/* for acpi_hest_init() */
+
+#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);
+
+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 struct acpi_device_id root_device_ids[] = {
+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,
+	},
 };
 
-struct acpi_pci_root {
-	struct list_head node;
-	struct acpi_device * device;
-	struct acpi_pci_id id;
-	struct pci_bus *bus;
-};
-
-static LIST_HEAD(acpi_pci_roots);
+static DEFINE_MUTEX(osc_lock);
 
-static struct acpi_pci_driver *sub_driver;
-
-int acpi_pci_register_driver(struct acpi_pci_driver *driver)
+/**
+ * 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 n = 0;
-	struct list_head *entry;
+	int ret;
+	struct acpi_device *device;
 
-	struct acpi_pci_driver **pptr = &sub_driver;
-	while (*pptr)
-		pptr = &(*pptr)->next;
-	*pptr = driver;
+	ret = acpi_bus_get_device(handle, &device);
+	if (ret)
+		return 0;
 
-	if (!driver->add)
+	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)
+{
+	struct resource *res = data;
+	struct acpi_resource_address64 address;
+	acpi_status status;
+
+	status = acpi_resource_to_address64(resource, &address);
+	if (ACPI_FAILURE(status))
+		return AE_OK;
 
-	list_for_each(entry, &acpi_pci_roots) {
-		struct acpi_pci_root *root;
-		root = list_entry(entry, struct acpi_pci_root, node);
-		driver->add(root->device->handle);
-		n++;
+	if ((address.address_length > 0) &&
+	    (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
+		res->start = address.minimum;
+		res->end = address.minimum + address.address_length - 1;
 	}
 
-	return n;
+	return AE_OK;
 }
 
-EXPORT_SYMBOL(acpi_pci_register_driver);
-
-void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
+static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
+					     struct resource *res)
 {
-	struct list_head *entry;
+	acpi_status status;
 
-	struct acpi_pci_driver **pptr = &sub_driver;
-	while (*pptr) {
-		if (*pptr == driver)
-			break;
-		pptr = &(*pptr)->next;
-	}
-	BUG_ON(!*pptr);
-	*pptr = (*pptr)->next;
+	res->start = -1;
+	status =
+	    acpi_walk_resources(handle, METHOD_NAME__CRS,
+				get_root_bridge_busnr_callback, res);
+	if (ACPI_FAILURE(status))
+		return status;
+	if (res->start == -1)
+		return AE_ERROR;
+	return AE_OK;
+}
 
-	if (!driver->remove)
-		return;
+struct pci_osc_bit_struct {
+	u32 bit;
+	char *desc;
+};
 
-	list_for_each(entry, &acpi_pci_roots) {
-		struct acpi_pci_root *root;
-		root = list_entry(entry, struct acpi_pci_root, node);
-		driver->remove(root->device->handle);
-	}
+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);
 }
 
-EXPORT_SYMBOL(acpi_pci_unregister_driver);
+static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
+{
+	decode_osc_bits(root, msg, word, pci_osc_support_bit,
+			ARRAY_SIZE(pci_osc_support_bit));
+}
 
-acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
+static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
 {
-	struct acpi_pci_root *tmp;
-	
-	list_for_each_entry(tmp, &acpi_pci_roots, node) {
-		if ((tmp->id.segment == (u16) seg) && (tmp->id.bus == (u16) bus))
-			return tmp->device->handle;
-	}
-	return NULL;		
+	decode_osc_bits(root, msg, word, pci_osc_control_bit,
+			ARRAY_SIZE(pci_osc_control_bit));
 }
 
-EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
+static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
 
-static acpi_status
-get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
+static acpi_status acpi_pci_run_osc(acpi_handle handle,
+				    const u32 *capbuf, u32 *retval)
 {
-	int *busnr = data;
-	struct acpi_resource_address64 address;
+	struct acpi_osc_context context = {
+		.uuid_str = pci_osc_uuid_str,
+		.rev = 1,
+		.cap.length = 12,
+		.cap.pointer = (void *)capbuf,
+	};
+	acpi_status status;
 
-	if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
-	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
-	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
-		return AE_OK;
+	status = acpi_run_osc(handle, &context);
+	if (ACPI_SUCCESS(status)) {
+		*retval = *((u32 *)(context.ret.pointer + 8));
+		kfree(context.ret.pointer);
+	}
+	return status;
+}
 
-	acpi_resource_to_address64(resource, &address);
-	if ((address.address_length > 0) &&
-	    (address.resource_type == ACPI_BUS_NUMBER_RANGE))
-		*busnr = address.minimum;
+static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
+					u32 support,
+					u32 *control)
+{
+	acpi_status status;
+	u32 result, capbuf[3];
+
+	support &= OSC_PCI_SUPPORT_MASKS;
+	support |= root->osc_support_set;
+
+	capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
+	capbuf[OSC_SUPPORT_DWORD] = support;
+	if (control) {
+		*control &= OSC_PCI_CONTROL_MASKS;
+		capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
+	} else {
+		/* Run _OSC query only with existing controls. */
+		capbuf[OSC_CONTROL_DWORD] = root->osc_control_set;
+	}
 
-	return AE_OK;
+	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
+	if (ACPI_SUCCESS(status)) {
+		root->osc_support_set = support;
+		if (control)
+			*control = result;
+	}
+	return status;
 }
 
-static acpi_status try_get_root_bridge_busnr(acpi_handle handle, int *busnum)
+static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
 {
 	acpi_status status;
 
-	*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;
-	return AE_OK;
+	mutex_lock(&osc_lock);
+	status = acpi_pci_query_osc(root, flags, NULL);
+	mutex_unlock(&osc_lock);
+	return status;
+}
+
+struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
+{
+	struct acpi_pci_root *root;
+	struct acpi_device *device;
+
+	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);
 
-static void acpi_pci_bridge_scan(struct acpi_device *device)
+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 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);
-			}
+	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);
+
+		/*
+		 * This function may be called for a non-PCI device that has a
+		 * PCI parent (eg. a disk under a PCI SATA controller).  In that
+		 * case pdev->subordinate will be NULL for the parent.
+		 */
+		if (!pbus) {
+			dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
+			pdev = NULL;
+			break;
 		}
+	}
+out:
+	list_for_each_entry_safe(node, tmp, &device_list, node)
+		kfree(node);
+
+	return pdev;
 }
+EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 
-static int __devinit acpi_pci_root_add(struct acpi_device *device)
+/**
+ * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
+ * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
+ * @mask: Mask of _OSC bits to request control of, place to store control mask.
+ * @req: Mask of _OSC bits the control of is essential to the caller.
+ *
+ * Run _OSC query for @mask and if that is successful, compare the returned
+ * mask of control bits with @req.  If all of the @req bits are set in the
+ * returned mask, run _OSC request for it.
+ *
+ * The variable at the @mask address may be modified regardless of whether or
+ * not the function returns success.  On success it will contain the mask of
+ * _OSC bits the BIOS has granted control of, but its contents are meaningless
+ * on failure.
+ **/
+acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 {
-	int result = 0;
-	struct acpi_pci_root *root = NULL;
-	struct acpi_pci_root *tmp;
+	struct acpi_pci_root *root;
 	acpi_status status = AE_OK;
-	unsigned long value = 0;
-	acpi_handle handle = NULL;
-	struct acpi_device *child;
+	u32 ctrl, capbuf[3];
 
+	if (!mask)
+		return AE_BAD_PARAMETER;
 
-	if (!device)
-		return -EINVAL;
+	ctrl = *mask & OSC_PCI_CONTROL_MASKS;
+	if ((ctrl & req) != req)
+		return AE_TYPE;
 
-	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
+	root = acpi_pci_find_root(handle);
 	if (!root)
-		return -ENOMEM;
-	INIT_LIST_HEAD(&root->node);
+		return AE_NOT_EXIST;
 
-	root->device = device;
-	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
-	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
-	acpi_driver_data(device) = root;
+	mutex_lock(&osc_lock);
 
-	device->ops.bind = acpi_pci_bind;
+	*mask = ctrl | root->osc_control_set;
+	/* No need to evaluate _OSC if the control was already granted. */
+	if ((root->osc_control_set & ctrl) == ctrl)
+		goto out;
 
-	/* 
-	 * Segment
-	 * -------
-	 * Obtained via _SEG, if exists, otherwise assumed to be zero (0).
-	 */
-	status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
-				       &value);
-	switch (status) {
-	case AE_OK:
-		root->id.segment = (u16) value;
-		break;
-	case AE_NOT_FOUND:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "Assuming segment 0 (no _SEG)\n"));
-		root->id.segment = 0;
-		break;
-	default:
-		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SEG"));
-		result = -ENODEV;
-		goto end;
+	/* Need to check the available controls bits before requesting them. */
+	while (*mask) {
+		status = acpi_pci_query_osc(root, root->osc_support_set, mask);
+		if (ACPI_FAILURE(status))
+			goto out;
+		if (ctrl == *mask)
+			break;
+		decode_osc_control(root, "platform does not support",
+				   ctrl & ~(*mask));
+		ctrl = *mask;
 	}
 
-	/* 
-	 * Bus
-	 * ---
-	 * Obtained via _BBN, if exists, otherwise assumed to be zero (0).
+	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_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;
+out:
+	mutex_unlock(&osc_lock);
+	return status;
+}
+EXPORT_SYMBOL(acpi_pci_osc_control_set);
+
+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.
 	 */
-	status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN, NULL,
-				       &value);
-	switch (status) {
-	case AE_OK:
-		root->id.bus = (u16) value;
-		break;
-	case AE_NOT_FOUND:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Assuming bus 0 (no _BBN)\n"));
-		root->id.bus = 0;
-		break;
-	default:
-		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BBN"));
+	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 = 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(handle, METHOD_NAME__SEG, NULL,
+				       &segment);
+	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+		dev_err(&device->dev,  "can't evaluate _SEG\n");
 		result = -ENODEV;
 		goto end;
 	}
 
-	/* Some systems have wrong _BBN */
-	list_for_each_entry(tmp, &acpi_pci_roots, node) {
-		if ((tmp->id.segment == root->id.segment)
-		    && (tmp->id.bus == root->id.bus)) {
-			int bus = 0;
-			acpi_status status;
-
-			printk(KERN_ERR PREFIX
-				    "Wrong _BBN value, reboot"
-				    " and use option 'pci=noacpi'\n");
-
-			status = try_get_root_bridge_busnr(device->handle, &bus);
-			if (ACPI_FAILURE(status))
-				break;
-			if (bus != root->id.bus) {
-				printk(KERN_INFO PREFIX
-				       "PCI _CRS %d overrides _BBN 0\n", bus);
-				root->id.bus = bus;
-			}
-			break;
+	/* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
+	root->secondary.flags = IORESOURCE_BUS;
+	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
+		 * to interpret _CBA (MMCONFIG base address), so it really is
+		 * supposed to be in _CRS.  If we don't find it there, all we
+		 * can do is assume [_BBN-0xFF] or [0-0xFF].
+		 */
+		root->secondary.end = 0xFF;
+		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 {
+			dev_err(&device->dev, "can't evaluate _BBN\n");
+			result = -ENODEV;
+			goto end;
 		}
 	}
-	/*
-	 * Device & Function
-	 * -----------------
-	 * Obtained from _ADR (which has already been evaluated for us).
-	 */
-	root->id.device = device->pnp.bus_address >> 16;
-	root->id.function = device->pnp.bus_address & 0xFFFF;
+
+	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;
+
+	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] (%04x:%02x)\n",
-	       acpi_device_name(device), acpi_device_bid(device),
-	       root->id.segment, root->id.bus);
-
 	/*
 	 * 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(device, root->id.segment, root->id.bus);
+	root->bus = pci_acpi_scan_root(root);
 	if (!root->bus) {
-		printk(KERN_ERR PREFIX
-			    "Bus %04x:%02x not present in PCI namespace\n",
-			    root->id.segment, root->id.bus);
+		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, &root->id, root->bus);
-	if (result)
-		goto end;
+	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 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->id.segment,
-					      root->id.bus);
+	pci_acpi_add_bus_pm_notifier(device, root->bus);
+	if (device->wakeup.flags.run_wake)
+		device_set_run_wake(root->bus->bridge, true);
 
-	/*
-	 * Scan and bind all _ADR-Based Devices
-	 */
-	list_for_each_entry(child, &device->children, node)
-		acpi_pci_bridge_scan(child);
-
-      end:
-	if (result) {
-		if (!list_empty(&root->node))
-			list_del(&root->node);
-		kfree(root);
+	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:
+	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;
+	struct acpi_pci_root *root = acpi_driver_data(device);
 
+	pci_lock_rescan_remove();
 
-	list_for_each_entry(root, &acpi_pci_roots, node) {
-		if (root->device == device) {
-			pci_bus_add_devices(root->bus);
-			return 0;
-		}
-	}
-	return -ENODEV;
-}
+	pci_stop_root_bus(root->bus);
 
-static int acpi_pci_root_remove(struct acpi_device *device, int type)
-{
-	struct acpi_pci_root *root = NULL;
+	device_set_run_wake(root->bus->bridge, false);
+	pci_acpi_remove_bus_pm_notifier(device);
 
+	pci_remove_root_bus(root->bus);
 
-	if (!device || !acpi_driver_data(device))
-		return -EINVAL;
-
-	root = acpi_driver_data(device);
+	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;
-
-	/* DEBUG:
-	   acpi_dbg_layer = ACPI_PCI_COMPONENT;
-	   acpi_dbg_level = 0xFFFFFFFF;
-	 */
-
-	if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
-		return -ENODEV;
+		return;
 
-	return 0;
+	pci_acpi_crs_quirks();
+	acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
 }
-
-subsys_initcall(acpi_pci_root_init);