diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c
index 7cc3be9fa7c6..d20db9e48014 100644
--- a/arch/ia64/pci/pci.c
+++ b/arch/ia64/pci/pci.c
@@ -115,29 +115,12 @@ struct pci_ops pci_root_ops = {
 	.write = pci_write,
 };
 
-/* Called by ACPI when it finds a new root bus.  */
-
-static struct pci_controller *alloc_pci_controller(int seg)
-{
-	struct pci_controller *controller;
-
-	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
-	if (!controller)
-		return NULL;
-
-	controller->segment = seg;
-	return controller;
-}
-
 struct pci_root_info {
+	struct pci_controller controller;
 	struct acpi_device *bridge;
-	struct pci_controller *controller;
 	struct list_head resources;
-	struct resource *res;
-	resource_size_t *res_offset;
-	unsigned int res_num;
 	struct list_head io_resources;
-	char *name;
+	char name[16];
 };
 
 static unsigned int
@@ -168,11 +151,11 @@ new_space (u64 phys_base, int sparse)
 	return i;
 }
 
-static u64 add_io_space(struct pci_root_info *info,
-			struct acpi_resource_address64 *addr)
+static int add_io_space(struct device *dev, struct pci_root_info *info,
+			struct resource_entry *entry)
 {
 	struct iospace_resource *iospace;
-	struct resource *resource;
+	struct resource *resource, *res = entry->res;
 	char *name;
 	unsigned long base, min, max, base_port;
 	unsigned int sparse = 0, space_nr, len;
@@ -180,27 +163,24 @@ static u64 add_io_space(struct pci_root_info *info,
 	len = strlen(info->name) + 32;
 	iospace = kzalloc(sizeof(*iospace) + len, GFP_KERNEL);
 	if (!iospace) {
-		dev_err(&info->bridge->dev,
-				"PCI: No memory for %s I/O port space\n",
-				info->name);
-		goto out;
+		dev_err(dev, "PCI: No memory for %s I/O port space\n",
+			info->name);
+		return -ENOMEM;
 	}
 
-	name = (char *)(iospace + 1);
-
-	min = addr->address.minimum;
-	max = min + addr->address.address_length - 1;
-	if (addr->info.io.translation_type == ACPI_SPARSE_TRANSLATION)
+	if (res->flags & IORESOURCE_IO_SPARSE)
 		sparse = 1;
-
-	space_nr = new_space(addr->address.translation_offset, sparse);
+	space_nr = new_space(entry->offset, sparse);
 	if (space_nr == ~0)
 		goto free_resource;
 
+	name = (char *)(iospace + 1);
+	min = res->start - entry->offset;
+	max = res->end - entry->offset;
 	base = __pa(io_space[space_nr].mmio_base);
 	base_port = IO_SPACE_BASE(space_nr);
 	snprintf(name, len, "%s I/O Ports %08lx-%08lx", info->name,
-		base_port + min, base_port + max);
+		 base_port + min, base_port + max);
 
 	/*
 	 * The SDM guarantees the legacy 0-64K space is sparse, but if the
@@ -216,153 +196,195 @@ static u64 add_io_space(struct pci_root_info *info,
 	resource->start = base + (sparse ? IO_SPACE_SPARSE_ENCODING(min) : min);
 	resource->end   = base + (sparse ? IO_SPACE_SPARSE_ENCODING(max) : max);
 	if (insert_resource(&iomem_resource, resource)) {
-		dev_err(&info->bridge->dev,
-				"can't allocate host bridge io space resource  %pR\n",
-				resource);
+		dev_err(dev,
+			"can't allocate host bridge io space resource  %pR\n",
+			resource);
 		goto free_resource;
 	}
 
+	entry->offset = base_port;
+	res->start = min + base_port;
+	res->end = max + base_port;
 	list_add_tail(&iospace->list, &info->io_resources);
-	return base_port;
+
+	return 0;
 
 free_resource:
 	kfree(iospace);
-out:
-	return ~0;
+	return -ENOSPC;
+}
+
+/*
+ * An IO port or MMIO resource assigned to a PCI host bridge may be
+ * consumed by the host bridge itself or available to its child
+ * bus/devices. The ACPI specification defines a bit (Producer/Consumer)
+ * to tell whether the resource is consumed by the host bridge itself,
+ * but firmware hasn't used that bit consistently, so we can't rely on it.
+ *
+ * On x86 and IA64 platforms, all IO port and MMIO resources are assumed
+ * to be available to child bus/devices except one special case:
+ *     IO port [0xCF8-0xCFF] is consumed by the host bridge itself
+ *     to access PCI configuration space.
+ *
+ * So explicitly filter out PCI CFG IO ports[0xCF8-0xCFF].
+ */
+static bool resource_is_pcicfg_ioport(struct resource *res)
+{
+	return (res->flags & IORESOURCE_IO) &&
+		res->start == 0xCF8 && res->end == 0xCFF;
 }
 
-static acpi_status resource_to_window(struct acpi_resource *resource,
-				      struct acpi_resource_address64 *addr)
+static int
+probe_pci_root_info(struct pci_root_info *info, struct acpi_device *device,
+		    int busnum, int domain)
 {
-	acpi_status status;
+	int ret;
+	struct list_head *list = &info->resources;
+	struct resource_entry *entry, *tmp;
 
-	/*
-	 * We're only interested in _CRS descriptors that are
-	 *	- address space descriptors for memory or I/O space
-	 *	- non-zero size
-	 */
-	status = acpi_resource_to_address64(resource, addr);
-	if (ACPI_SUCCESS(status) &&
-	    (addr->resource_type == ACPI_MEMORY_RANGE ||
-	     addr->resource_type == ACPI_IO_RANGE) &&
-	    addr->address.address_length)
-		return AE_OK;
-
-	return AE_ERROR;
-}
-
-static acpi_status count_window(struct acpi_resource *resource, void *data)
-{
-	unsigned int *windows = (unsigned int *) data;
-	struct acpi_resource_address64 addr;
-	acpi_status status;
-
-	status = resource_to_window(resource, &addr);
-	if (ACPI_SUCCESS(status))
-		(*windows)++;
-
-	return AE_OK;
-}
-
-static acpi_status add_window(struct acpi_resource *res, void *data)
-{
-	struct pci_root_info *info = data;
-	struct resource *resource;
-	struct acpi_resource_address64 addr;
-	acpi_status status;
-	unsigned long flags, offset = 0;
-	struct resource *root;
-
-	/* Return AE_OK for non-window resources to keep scanning for more */
-	status = resource_to_window(res, &addr);
-	if (!ACPI_SUCCESS(status))
-		return AE_OK;
-
-	if (addr.resource_type == ACPI_MEMORY_RANGE) {
-		flags = IORESOURCE_MEM;
-		root = &iomem_resource;
-		offset = addr.address.translation_offset;
-	} else if (addr.resource_type == ACPI_IO_RANGE) {
-		flags = IORESOURCE_IO;
-		root = &ioport_resource;
-		offset = add_io_space(info, &addr);
-		if (offset == ~0)
-			return AE_OK;
-	} else
-		return AE_OK;
-
-	resource = &info->res[info->res_num];
-	resource->name = info->name;
-	resource->flags = flags;
-	resource->start = addr.address.minimum + offset;
-	resource->end = resource->start + addr.address.address_length - 1;
-	info->res_offset[info->res_num] = offset;
-
-	if (insert_resource(root, resource)) {
-		dev_err(&info->bridge->dev,
-			"can't allocate host bridge window %pR\n",
-			resource);
-	} else {
-		if (offset)
-			dev_info(&info->bridge->dev, "host bridge window %pR "
-				 "(PCI address [%#llx-%#llx])\n",
-				 resource,
-				 resource->start - offset,
-				 resource->end - offset);
-		else
-			dev_info(&info->bridge->dev,
-				 "host bridge window %pR\n", resource);
-	}
-	/* HP's firmware has a hack to work around a Windows bug.
-	 * Ignore these tiny memory ranges */
-	if (!((resource->flags & IORESOURCE_MEM) &&
-	      (resource->end - resource->start < 16)))
-		pci_add_resource_offset(&info->resources, resource,
-					info->res_offset[info->res_num]);
+	ret = acpi_dev_get_resources(device, list,
+				     acpi_dev_filter_resource_type_cb,
+				     (void *)(IORESOURCE_IO | IORESOURCE_MEM));
+	if (ret < 0)
+		dev_warn(&device->dev,
+			 "failed to parse _CRS method, error code %d\n", ret);
+	else if (ret == 0)
+		dev_dbg(&device->dev,
+			"no IO and memory resources present in _CRS\n");
+	else
+		resource_list_for_each_entry_safe(entry, tmp, list) {
+			if ((entry->res->flags & IORESOURCE_DISABLED) ||
+			    resource_is_pcicfg_ioport(entry->res))
+				resource_list_destroy_entry(entry);
+			else
+				entry->res->name = info->name;
+		}
 
-	info->res_num++;
-	return AE_OK;
+	return ret;
 }
 
-static void free_pci_root_info_res(struct pci_root_info *info)
-{
-	struct iospace_resource *iospace, *tmp;
+static void validate_resources(struct device *dev, struct list_head *resources,
+			       unsigned long type)
+{
+	LIST_HEAD(list);
+	struct resource *res1, *res2, *root = NULL;
+	struct resource_entry *tmp, *entry, *entry2;
+
+	BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0);
+	root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource;
+
+	list_splice_init(resources, &list);
+	resource_list_for_each_entry_safe(entry, tmp, &list) {
+		bool free = false;
+		resource_size_t end;
+
+		res1 = entry->res;
+		if (!(res1->flags & type))
+			goto next;
+
+		/* Exclude non-addressable range or non-addressable portion */
+		end = min(res1->end, root->end);
+		if (end <= res1->start) {
+			dev_info(dev, "host bridge window %pR (ignored, not CPU addressable)\n",
+				 res1);
+			free = true;
+			goto next;
+		} else if (res1->end != end) {
+			dev_info(dev, "host bridge window %pR ([%#llx-%#llx] ignored, not CPU addressable)\n",
+				 res1, (unsigned long long)end + 1,
+				 (unsigned long long)res1->end);
+			res1->end = end;
+		}
 
-	list_for_each_entry_safe(iospace, tmp, &info->io_resources, list)
-		kfree(iospace);
+		resource_list_for_each_entry(entry2, resources) {
+			res2 = entry2->res;
+			if (!(res2->flags & type))
+				continue;
+
+			/*
+			 * I don't like throwing away windows because then
+			 * our resources no longer match the ACPI _CRS, but
+			 * the kernel resource tree doesn't allow overlaps.
+			 */
+			if (resource_overlaps(res1, res2)) {
+				res2->start = min(res1->start, res2->start);
+				res2->end = max(res1->end, res2->end);
+				dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n",
+					 res2, res1);
+				free = true;
+				goto next;
+			}
+		}
 
-	kfree(info->name);
-	kfree(info->res);
-	info->res = NULL;
-	kfree(info->res_offset);
-	info->res_offset = NULL;
-	info->res_num = 0;
-	kfree(info->controller);
-	info->controller = NULL;
+next:
+		resource_list_del(entry);
+		if (free)
+			resource_list_free_entry(entry);
+		else
+			resource_list_add_tail(entry, resources);
+	}
+}
+
+static void add_resources(struct pci_root_info *info, struct device *dev)
+{
+	struct resource_entry *entry, *tmp;
+	struct resource *res, *conflict, *root = NULL;
+	struct list_head *list = &info->resources;
+
+	validate_resources(dev, list, IORESOURCE_MEM);
+	validate_resources(dev, list, IORESOURCE_IO);
+
+	resource_list_for_each_entry_safe(entry, tmp, list) {
+		res = entry->res;
+		if (res->flags & IORESOURCE_MEM) {
+			root = &iomem_resource;
+			/*
+			 * HP's firmware has a hack to work around a Windows
+			 * bug. Ignore these tiny memory ranges.
+			 */
+			if (resource_size(res) <= 16) {
+				resource_list_destroy_entry(entry);
+				continue;
+			}
+		} else if (res->flags & IORESOURCE_IO) {
+			root = &ioport_resource;
+			if (add_io_space(&info->bridge->dev, info, entry)) {
+				resource_list_destroy_entry(entry);
+				continue;
+			}
+		} else {
+			BUG_ON(res);
+		}
+
+		conflict = insert_resource_conflict(root, res);
+		if (conflict) {
+			dev_info(dev,
+				 "ignoring host bridge window %pR (conflicts with %s %pR)\n",
+				 res, conflict->name, conflict);
+			resource_list_destroy_entry(entry);
+		}
+	}
 }
 
 static void __release_pci_root_info(struct pci_root_info *info)
 {
-	int i;
 	struct resource *res;
-	struct iospace_resource *iospace;
+	struct iospace_resource *iospace, *tmp;
+	struct resource_entry *entry, *tentry;
 
-	list_for_each_entry(iospace, &info->io_resources, list)
+	list_for_each_entry_safe(iospace, tmp, &info->io_resources, list) {
 		release_resource(&iospace->res);
+		kfree(iospace);
+	}
 
-	for (i = 0; i < info->res_num; i++) {
-		res = &info->res[i];
-
-		if (!res->parent)
-			continue;
-
-		if (!(res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
-			continue;
-
-		release_resource(res);
+	resource_list_for_each_entry_safe(entry, tentry, &info->resources) {
+		res = entry->res;
+		if (res->parent &&
+		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
+			release_resource(res);
+		resource_list_destroy_entry(entry);
 	}
 
-	free_pci_root_info_res(info);
 	kfree(info);
 }
 
@@ -373,99 +395,49 @@ static void release_pci_root_info(struct pci_host_bridge *bridge)
 	__release_pci_root_info(info);
 }
 
-static int
-probe_pci_root_info(struct pci_root_info *info, struct acpi_device *device,
-		int busnum, int domain)
-{
-	char *name;
-
-	name = kmalloc(16, GFP_KERNEL);
-	if (!name)
-		return -ENOMEM;
-
-	sprintf(name, "PCI Bus %04x:%02x", domain, busnum);
-	info->bridge = device;
-	info->name = name;
-
-	acpi_walk_resources(device->handle, METHOD_NAME__CRS, count_window,
-			&info->res_num);
-	if (info->res_num) {
-		info->res =
-			kzalloc_node(sizeof(*info->res) * info->res_num,
-				     GFP_KERNEL, info->controller->node);
-		if (!info->res) {
-			kfree(name);
-			return -ENOMEM;
-		}
-
-		info->res_offset =
-			kzalloc_node(sizeof(*info->res_offset) * info->res_num,
-					GFP_KERNEL, info->controller->node);
-		if (!info->res_offset) {
-			kfree(name);
-			kfree(info->res);
-			info->res = NULL;
-			return -ENOMEM;
-		}
-
-		info->res_num = 0;
-		acpi_walk_resources(device->handle, METHOD_NAME__CRS,
-			add_window, info);
-	} else
-		kfree(name);
-
-	return 0;
-}
-
 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 {
 	struct acpi_device *device = root->device;
 	int domain = root->segment;
 	int bus = root->secondary.start;
-	struct pci_controller *controller;
-	struct pci_root_info *info = NULL;
-	int busnum = root->secondary.start;
+	struct pci_root_info *info;
 	struct pci_bus *pbus;
 	int ret;
 
-	controller = alloc_pci_controller(domain);
-	if (!controller)
-		return NULL;
-
-	controller->companion = device;
-	controller->node = acpi_get_node(device->handle);
-
 	info = kzalloc(sizeof(*info), GFP_KERNEL);
 	if (!info) {
 		dev_err(&device->dev,
-				"pci_bus %04x:%02x: ignored (out of memory)\n",
-				domain, busnum);
-		kfree(controller);
+			"pci_bus %04x:%02x: ignored (out of memory)\n",
+			domain, bus);
 		return NULL;
 	}
 
-	info->controller = controller;
-	INIT_LIST_HEAD(&info->io_resources);
+	info->controller.segment = domain;
+	info->controller.companion = device;
+	info->controller.node = acpi_get_node(device->handle);
+	info->bridge = device;
 	INIT_LIST_HEAD(&info->resources);
+	INIT_LIST_HEAD(&info->io_resources);
+	snprintf(info->name, sizeof(info->name),
+		 "PCI Bus %04x:%02x", domain, bus);
 
-	ret = probe_pci_root_info(info, device, busnum, domain);
-	if (ret) {
-		kfree(info->controller);
+	ret = probe_pci_root_info(info, device, bus, domain);
+	if (ret <= 0) {
 		kfree(info);
 		return NULL;
 	}
-	/* insert busn resource at first */
+	add_resources(info, &info->bridge->dev);
 	pci_add_resource(&info->resources, &root->secondary);
+
 	/*
 	 * See arch/x86/pci/acpi.c.
 	 * The desired pci bus might already be scanned in a quirk. We
 	 * should handle the case here, but it appears that IA64 hasn't
 	 * such quirk. So we just ignore the case now.
 	 */
-	pbus = pci_create_root_bus(NULL, bus, &pci_root_ops, controller,
-				   &info->resources);
+	pbus = pci_create_root_bus(NULL, bus, &pci_root_ops,
+				   &info->controller, &info->resources);
 	if (!pbus) {
-		pci_free_resource_list(&info->resources);
 		__release_pci_root_info(info);
 		return NULL;
 	}
