diff --git a/arch/ia64/hp/common/sba_iommu.c b/arch/ia64/hp/common/sba_iommu.c
index a6d6190..78e4444 100644
--- a/arch/ia64/hp/common/sba_iommu.c
+++ b/arch/ia64/hp/common/sba_iommu.c
@@ -1981,7 +1981,7 @@ sba_connect_bus(struct pci_bus *bus)
 	if (PCI_CONTROLLER(bus)->iommu)
 		return;
 
-	handle = acpi_device_handle(PCI_CONTROLLER(bus)->companion);
+	handle = acpi_device_handle(ACPI_COMPANION(bus->bridge));
 	if (!handle)
 		return;
 
diff --git a/arch/ia64/include/asm/pci.h b/arch/ia64/include/asm/pci.h
index 07039d1..5050748 100644
--- a/arch/ia64/include/asm/pci.h
+++ b/arch/ia64/include/asm/pci.h
@@ -65,7 +65,6 @@ extern int pci_mmap_legacy_page_range(struct pci_bus *bus,
 #define pci_legacy_write platform_pci_legacy_write
 
 struct pci_controller {
-	struct acpi_device *companion;
 	void *iommu;
 	int segment;
 	int node;		/* nearest node with memory or NUMA_NO_NODE for global allocation */
diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c
index 8f6ac2f..978d6af 100644
--- a/arch/ia64/pci/pci.c
+++ b/arch/ia64/pci/pci.c
@@ -301,28 +301,12 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 	}
 
 	info->controller.segment = root->segment;
-	info->controller.companion = device;
 	info->controller.node = acpi_get_node(device->handle);
 	INIT_LIST_HEAD(&info->io_resources);
 	return acpi_pci_root_create(root, &pci_acpi_root_ops,
 				    &info->common, &info->controller);
 }
 
-int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
-{
-	/*
-	 * We pass NULL as parent to pci_create_root_bus(), so if it is not NULL
-	 * here, pci_create_root_bus() has been called by someone else and
-	 * sysdata is likely to be different from what we expect.  Let it go in
-	 * that case.
-	 */
-	if (!bridge->dev.parent) {
-		struct pci_controller *controller = bridge->bus->sysdata;
-		ACPI_COMPANION_SET(&bridge->dev, controller->companion);
-	}
-	return 0;
-}
-
 void pcibios_fixup_device_resources(struct pci_dev *dev)
 {
 	int idx;
diff --git a/arch/ia64/sn/kernel/io_acpi_init.c b/arch/ia64/sn/kernel/io_acpi_init.c
index 0640739..bcfddc2 100644
--- a/arch/ia64/sn/kernel/io_acpi_init.c
+++ b/arch/ia64/sn/kernel/io_acpi_init.c
@@ -132,7 +132,7 @@ sn_get_bussoft_ptr(struct pci_bus *bus)
 	struct acpi_resource_vendor_typed *vendor;
 
 
-	handle = acpi_device_handle(PCI_CONTROLLER(bus)->companion);
+	handle = acpi_device_handle(ACPI_COMPANION(bus->bridge));
 	status = acpi_get_vendor_resource(handle, METHOD_NAME__CRS,
 					  &sn_uuid, &buffer);
 	if (ACPI_FAILURE(status)) {
@@ -360,7 +360,7 @@ sn_acpi_get_pcidev_info(struct pci_dev *dev, struct pcidev_info **pcidev_info,
 	acpi_status status;
 	struct acpi_buffer name_buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 
-	rootbus_handle = acpi_device_handle(PCI_CONTROLLER(dev)->companion);
+	rootbus_handle = acpi_device_handle(ACPI_COMPANION(dev->bus->bridge));
         status = acpi_evaluate_integer(rootbus_handle, METHOD_NAME__SEG, NULL,
                                        &segment);
         if (ACPI_SUCCESS(status)) {
diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
index 4625943..a98c022 100644
--- a/arch/x86/include/asm/pci.h
+++ b/arch/x86/include/asm/pci.h
@@ -14,9 +14,6 @@
 struct pci_sysdata {
 	int		domain;		/* PCI domain */
 	int		node;		/* NUMA node */
-#ifdef CONFIG_ACPI
-	struct acpi_device *companion;	/* ACPI companion device */
-#endif
 #ifdef CONFIG_X86_64
 	void		*iommu;		/* IOMMU private data */
 #endif
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 8e89921..d5086d1 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -341,7 +341,6 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 		struct pci_sysdata sd = {
 			.domain = domain,
 			.node = node,
-			.companion = root->device
 		};
 
 		memcpy(bus->sysdata, &sd, sizeof(sd));
@@ -356,7 +355,6 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 		else {
 			info->sd.domain = domain;
 			info->sd.node = node;
-			info->sd.companion = root->device;
 			bus = acpi_pci_root_create(root, &acpi_pci_root_ops,
 						   &info->common, &info->sd);
 		}
@@ -374,21 +372,6 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 	return bus;
 }
 
-int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
-{
-	/*
-	 * We pass NULL as parent to pci_create_root_bus(), so if it is not NULL
-	 * here, pci_create_root_bus() has been called by someone else and
-	 * sysdata is likely to be different from what we expect.  Let it go in
-	 * that case.
-	 */
-	if (!bridge->dev.parent) {
-		struct pci_sysdata *sd = bridge->bus->sysdata;
-		ACPI_COMPANION_SET(&bridge->dev, sd->companion);
-	}
-	return 0;
-}
-
 int __init pci_acpi_init(void)
 {
 	struct pci_dev *dev = NULL;
