[RFC 00/15] PCI: turn some __weak functions into callbacks

@@ -23,13 +23,6 @@
 #define CARDBUS_LATENCY_TIMER	176	/* secondary latency timer */
 #define CARDBUS_RESERVE_BUSNR	3
 
-static struct resource busn_resource = {
-	.name	= "PCI busn",
-	.start	= 0,
-	.end	= 255,
-	.flags	= IORESOURCE_BUS,
-};
-
 /* Ugh.  Need to stop exporting this to modules. */
 LIST_HEAD(pci_root_buses);
 EXPORT_SYMBOL(pci_root_buses);

@@ -3060,53 +3053,64 @@ EXPORT_SYMBOL(pci_scan_root_bus_bridge);
 struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
 		struct pci_ops *ops, void *sysdata, struct list_head *resources)
 {
-	struct resource_entry *window;
-	bool found = false;
-	struct pci_bus *b;
-	int max;
-
-	resource_list_for_each_entry(window, resources)
-		if (window->res->flags & IORESOURCE_BUS) {
-			found = true;
-			break;
-		}
+	struct pci_host_bridge *bridge;
+	int error;
 
-	b = pci_create_root_bus(parent, bus, ops, sysdata, resources);
-	if (!b)
+	bridge = pci_alloc_host_bridge(0);
+	if (!bridge)
 		return NULL;
 
-	if (!found) {
-		dev_info(&b->dev,
-		 "No busn resource found for root bus, will use [bus %02x-ff]\n",
-			bus);
-		pci_bus_insert_busn_res(b, bus, 255);
-	}
+	list_splice_init(resources, &bridge->windows);
+	bridge->dev.parent = parent;
+	bridge->sysdata = sysdata;
+	bridge->busnr = bus;
+	bridge->ops = ops;
 
-	max = pci_scan_child_bus(b);
+	error = pci_scan_root_bus_bridge(bridge);
+	if (error < 0)
+		goto err_out;
 
-	if (!found)
-		pci_bus_update_busn_res_end(b, max);
+	return bridge->bus;
 
-	return b;
+err_out:
+	kfree(bridge);
+	return NULL;
 }
 EXPORT_SYMBOL(pci_scan_root_bus);
 
+static struct resource busn_resource = {
+	.name	= "PCI busn",
+	.start	= 0,
+	.end	= 255,
+	.flags	= IORESOURCE_BUS,
+};
+
 struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops,
 					void *sysdata)
 {
-	LIST_HEAD(resources);
-	struct pci_bus *b;
+	struct pci_host_bridge *bridge;
+	int error;
 
-	pci_add_resource(&resources, &ioport_resource);
-	pci_add_resource(&resources, &iomem_resource);
-	pci_add_resource(&resources, &busn_resource);
-	b = pci_create_root_bus(NULL, bus, ops, sysdata, &resources);
-	if (b) {
-		pci_scan_child_bus(b);
-	} else {
-		pci_free_resource_list(&resources);
-	}
-	return b;
+	bridge = pci_alloc_host_bridge(0);
+	if (!bridge)
+		goto err;
+
+	pci_add_resource(&bridge->windows, &ioport_resource);
+	pci_add_resource(&bridge->windows, &iomem_resource);
+	pci_add_resource(&bridge->windows, &busn_resource);
+	bridge->sysdata = sysdata;
+	bridge->busnr = bus;
+	bridge->ops = ops;
+
+	error = pci_scan_root_bus_bridge(bridge);
+	if (error < 0)
+		goto err;
+
+	return bridge->bus;
+
+err:
+	pci_free_host_bridge(bridge);
+	return NULL;
 }
 EXPORT_SYMBOL(pci_scan_bus);
 

@@ -191,14 +191,4 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 	return bus;
 }
 
-void pcibios_add_bus(struct pci_bus *bus)
-{
-	acpi_pci_add_bus(bus);
-}
-
-void pcibios_remove_bus(struct pci_bus *bus)
-{
-	acpi_pci_remove_bus(bus);
-}
-
 #endif

@@ -367,16 +367,6 @@ void pcibios_fixup_bus(struct pci_bus *b)
 	platform_pci_fixup_bus(b);
 }
 
-void pcibios_add_bus(struct pci_bus *bus)
-{
-	acpi_pci_add_bus(bus);
-}
-
-void pcibios_remove_bus(struct pci_bus *bus)
-{
-	acpi_pci_remove_bus(bus);
-}
-
 void pcibios_set_master (struct pci_dev *dev)
 {
 	/* No special bus mastering setup handling */

@@ -769,7 +769,7 @@ static void zpci_free_domain(struct zpci_dev *zdev)
 	spin_unlock(&zpci_domain_lock);
 }
 
-void pcibios_remove_bus(struct pci_bus *bus)
+static void zpci_remove_bus(struct pci_bus *bus)
 {
 	struct zpci_dev *zdev = get_zdev_by_bus(bus);
 

@@ -801,6 +801,7 @@ static struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
 	bridge->sysdata = sysdata;
 	bridge->busnr = bus;
 	bridge->ops = ops;
+	bridge->remove_bus = zpci_remove_bus;
 
 	error = pci_scan_root_bus_bridge(bridge);
 	if (error < 0)

@@ -168,16 +168,6 @@ void pcibios_fixup_bus(struct pci_bus *b)
 		pcibios_fixup_device_resources(dev);
 }
 
-void pcibios_add_bus(struct pci_bus *bus)
-{
-	acpi_pci_add_bus(bus);
-}
-
-void pcibios_remove_bus(struct pci_bus *bus)
-{
-	acpi_pci_remove_bus(bus);
-}
-
 /*
  * Only use DMI information to set this if nothing was passed
  * on the kernel command line (which was parsed earlier).

@@ -911,6 +911,8 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
 	bridge->busnr = busnum;
 	bridge->ops = ops->pci_ops;
 	bridge->prepare = acpi_pci_root_bridge_prepare;
+	bridge->add_bus = acpi_pci_add_bus;
+	bridge->remove_bus = acpi_pci_remove_bus;
 	pci_set_host_bridge_release(bridge, acpi_pci_root_release_info,
 				    info);
 

@@ -2905,12 +2905,20 @@ unsigned int pci_scan_child_bus(struct pci_bus *bus)
 }
 EXPORT_SYMBOL_GPL(pci_scan_child_bus);
 
-void __weak pcibios_add_bus(struct pci_bus *bus)
+void pcibios_add_bus(struct pci_bus *bus)
 {
+	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
+
+	if (bridge->add_bus)
+		bridge->add_bus(bus);
 }
 
-void __weak pcibios_remove_bus(struct pci_bus *bus)
+void pcibios_remove_bus(struct pci_bus *bus)
 {
+	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
+
+	if (bridge->remove_bus)
+		bridge->remove_bus(bus);
 }
 
 int pci_host_probe(struct pci_host_bridge *bridge)

@@ -479,6 +479,8 @@ struct pci_host_bridge {
 	void (*bus_add_device)(struct pci_dev *pdev);
 	int (*alloc_irq)(struct pci_dev *);
 	int (*free_irq)(struct pci_dev *);
+	void (*add_bus)(struct pci_bus *);
+	void (*remove_bus)(struct pci_bus *);
 	void		*release_data;
 	struct msi_controller *msi;
 	unsigned int	ignore_reset_delay:1;	/* For entire hierarchy */

@@ -270,12 +270,6 @@ int pcibios_sriov_disable(struct pci_dev *pdev)
 
 #endif /* CONFIG_PCI_IOV */
 
-void pcibios_bus_add_device(struct pci_dev *pdev)
-{
-	if (ppc_md.pcibios_bus_add_device)
-		ppc_md.pcibios_bus_add_device(pdev);
-}
-
 static resource_size_t pcibios_io_size(const struct pci_controller *hose)
 {
 #ifdef CONFIG_PPC64

@@ -1617,6 +1611,7 @@ void pcibios_scan_phb(struct pci_controller *hose)
 	hose->busn.flags = IORESOURCE_BUS;
 	pci_add_resource(&bridge->windows, &hose->busn);
 
+	bridge->bus_add_device = ppc_md->pcibios_bus_add_device;
 	bridge->dev.parent = hose->parent;
 	bridge->sysdata = hose;
 	bridge->busnr = hose->first_busno;

@@ -65,6 +65,7 @@ static void pcibios_scanbus(struct pci_channel *hose)
 	bridge->ops = hose->pci_ops;
 	bridge->swizzle_irq = pci_common_swizzle;
 	bridge->map_irq = pcibios_map_platform_irq;
+	bridge->bus_add_device = hose->bus_add_device;
 
 	ret = pci_scan_root_bus_bridge(bridge);
 	if (ret) {

@@ -122,6 +122,7 @@ extern struct pci_ops sh7786_pci_ops;
 	.reg_base	= start,					\
 	.mem_offset	= 0,						\
 	.io_offset	= 0,						\
+	.bus_add_device = sh7786_pci_bus_add_device,			\
 }
 
 static struct pci_channel sh7786_pci_channels[] = {

@@ -488,7 +489,7 @@ int pcibios_map_platform_irq(const struct pci_dev *pdev, u8 slot, u8 pin)
         return evt2irq(0xae0);
 }
 
-void pcibios_bus_add_device(struct pci_dev *pdev)
+static void sh7786_pci_bus_add_device(struct pci_dev *pdev)
 {
 	pdev->dev.dma_pfn_offset = dma_pfn_offset;
 }

@@ -35,6 +35,8 @@ struct pci_channel {
 	/* Optional error handling */
 	struct timer_list	err_timer, serr_timer;
 	unsigned int		err_irq, serr_irq;
+
+	void (*bus_add_device)(struct pci_dev *pdev);
 };
 
 /* arch/sh/drivers/pci/pci.c */

@@ -299,7 +299,13 @@ bool pci_bus_clip_resource(struct pci_dev *dev, int idx)
 
 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
 
-void __weak pcibios_bus_add_device(struct pci_dev *pdev) { }
+static void pcibios_bus_add_device(struct pci_dev *pdev)
+{
+	struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus);
+
+	if (bridge->bus_add_device)
+		bridge->bus_add_device(pdev);
+}
 
 /**
  * pci_bus_add_device - start driver for a single device

@@ -475,6 +475,7 @@ struct pci_host_bridge {
 	u8 (*swizzle_irq)(struct pci_dev *, u8 *); /* Platform IRQ swizzler */
 	int (*map_irq)(const struct pci_dev *, u8, u8);
 	void (*release_fn)(struct pci_host_bridge *);
+	void (*bus_add_device)(struct pci_dev *pdev);
 	void		*release_data;
 	struct msi_controller *msi;
 	unsigned int	ignore_reset_delay:1;	/* For entire hierarchy */

@@ -880,7 +881,6 @@ extern struct list_head pci_root_buses;	/* List of all known PCI buses */
 int no_pci_devices(void);
 
 void pcibios_resource_survey_bus(struct pci_bus *bus);
-void pcibios_bus_add_device(struct pci_dev *pdev);
 void pcibios_add_bus(struct pci_bus *bus);
 void pcibios_remove_bus(struct pci_bus *bus);
 void pcibios_fixup_bus(struct pci_bus *);

@@ -443,40 +443,12 @@ static int pcifront_scan_bus(struct pcifront_device *pdev,
 	return 0;
 }
 
-static struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
-		struct pci_ops *ops, void *sysdata, struct list_head *resources)
-{
-	struct pci_host_bridge *bridge;
-	int error;
-
-	bridge = pci_alloc_host_bridge(0);
-	if (!bridge)
-		return NULL;
-
-	list_splice_init(resources, &bridge->windows);
-	bridge->dev.parent = parent;
-	bridge->sysdata = sysdata;
-	bridge->busnr = bus;
-	bridge->ops = ops;
-
-	error = pci_scan_root_bus_bridge(bridge);
-	if (error < 0)
-		goto err_out;
-
-	return bridge->bus;
-
-err_out:
-	kfree(bridge);
-	return NULL;
-}
-
 static int pcifront_scan_root(struct pcifront_device *pdev,
 				 unsigned int domain, unsigned int bus)
 {
-	struct pci_bus *b;
-	LIST_HEAD(resources);
 	struct pcifront_sd *sd = NULL;
 	struct pci_bus_entry *bus_entry = NULL;
+	struct pci_host_bridge *bridge;
 	int err = 0;
 	static struct resource busn_res = {
 		.start = 0,

@@ -498,50 +470,55 @@ static int pcifront_scan_root(struct pcifront_device *pdev,
 	dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n",
 		 domain, bus);
 
+	bridge = pci_alloc_host_bridge(sizeof(*sd));
+	if (!bridge)
+		return -ENOMEM;
+
 	bus_entry = kzalloc(sizeof(*bus_entry), GFP_KERNEL);
-	sd = kzalloc(sizeof(*sd), GFP_KERNEL);
-	if (!bus_entry || !sd) {
+	sd = pci_host_bridge_priv(bridge);
+	if (!bus_entry) {
 		err = -ENOMEM;
 		goto err_out;
 	}
-	pci_add_resource(&resources, &ioport_resource);
-	pci_add_resource(&resources, &iomem_resource);
-	pci_add_resource(&resources, &busn_res);
+	pci_add_resource(&bridge->windows, &ioport_resource);
+	pci_add_resource(&bridge->windows, &iomem_resource);
+	pci_add_resource(&bridge->windows, &busn_res);
 	pcifront_init_sd(sd, domain, bus, pdev);
+	bridge->dev.parent = &pdev->xdev->dev;
+	bridge->sysdata = sd;
+	bridge->busnr = bus;
+	bridge->ops = &pcifront_bus_ops;
 
 	pci_lock_rescan_remove();
 
-	b = pci_scan_root_bus(&pdev->xdev->dev, bus,
-				  &pcifront_bus_ops, sd, &resources);
-	if (!b) {
+	err = pci_scan_root_bus_bridge(bridge);
+	if (err < 0) {
 		dev_err(&pdev->xdev->dev,
 			"Error creating PCI Frontend Bus!\n");
-		err = -ENOMEM;
 		pci_unlock_rescan_remove();
-		pci_free_resource_list(&resources);
 		goto err_out;
 	}
 
-	bus_entry->bus = b;
+	bus_entry->bus = bridge->bus;
 
 	list_add(&bus_entry->list, &pdev->root_buses);
 
 	/* pci_scan_root_bus skips devices which do not have a
 	* devfn==0. The pcifront_scan_bus enumerates all devfn. */
-	err = pcifront_scan_bus(pdev, domain, bus, b);
+	err = pcifront_scan_bus(pdev, domain, bus, bridge->bus);
 
 	/* Claim resources before going "live" with our devices */
-	pci_walk_bus(b, pcifront_claim_resource, pdev);
+	pci_walk_bus(bridge->bus, pcifront_claim_resource, pdev);
 
 	/* Create SysFS and notify udev of the devices. Aka: "going live" */
-	pci_bus_add_devices(b);
+	pci_bus_add_devices(bridge->bus);
 
 	pci_unlock_rescan_remove();
 	return err;
 
 err_out:
+	pci_free_host_bridge(bridge);
 	kfree(bus_entry);
-	kfree(sd);
 
 	return err;
 }

@@ -605,8 +582,6 @@ static void pcifront_free_roots(struct pcifront_device *pdev)
 
 		free_root_bus_devs(bus_entry->bus);
 
-		kfree(bus_entry->bus->sysdata);
-
 		device_unregister(bus_entry->bus->bridge);
 		pci_remove_bus(bus_entry->bus);
 

@@ -1587,6 +1587,34 @@ struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus)
 	return of_node_get(hose->dn);
 }
 
+static struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
+		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+{
+	int error;
+	struct pci_host_bridge *bridge;
+
+	bridge = pci_alloc_host_bridge(0);
+	if (!bridge)
+		return NULL;
+
+	bridge->dev.parent = parent;
+
+	list_splice_init(resources, &bridge->windows);
+	bridge->sysdata = sysdata;
+	bridge->busnr = bus;
+	bridge->ops = ops;
+
+	error = pci_register_host_bridge(bridge);
+	if (error < 0)
+		goto err_out;
+
+	return bridge->bus;
+
+err_out:
+	kfree(bridge);
+	return NULL;
+}
+
 /**
  * pci_scan_phb - Given a pci_controller, setup and scan the PCI bus
  * @hose: Pointer to the PCI host controller instance structure

@@ -691,6 +691,34 @@ static void pci_claim_bus_resources(struct pci_bus *bus)
 		pci_claim_bus_resources(child_bus);
 }
 
+static struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
+		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+{
+	int error;
+	struct pci_host_bridge *bridge;
+
+	bridge = pci_alloc_host_bridge(0);
+	if (!bridge)
+		return NULL;
+
+	bridge->dev.parent = parent;
+
+	list_splice_init(resources, &bridge->windows);
+	bridge->sysdata = sysdata;
+	bridge->busnr = bus;
+	bridge->ops = ops;
+
+	error = pci_register_host_bridge(bridge);
+	if (error < 0)
+		goto err_out;
+
+	return bridge->bus;
+
+err_out:
+	kfree(bridge);
+	return NULL;
+}
+
 struct pci_bus *pci_scan_one_pbm(struct pci_pbm_info *pbm,
 				 struct device *parent)
 {

@@ -873,6 +873,34 @@ static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
 	__acpi_pci_root_release_info(bridge->release_data);
 }
 
+static struct pci_bus *acpi_pci_create_root_bus(struct device *parent, int bus,
+		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+{
+	int error;
+	struct pci_host_bridge *bridge;
+
+	bridge = pci_alloc_host_bridge(0);
+	if (!bridge)
+		return NULL;
+
+	bridge->dev.parent = parent;
+
+	list_splice_init(resources, &bridge->windows);
+	bridge->sysdata = sysdata;
+	bridge->busnr = bus;
+	bridge->ops = ops;
+
+	error = pci_register_host_bridge(bridge);
+	if (error < 0)
+		goto err_out;
+
+	return bridge->bus;
+
+err_out:
+	kfree(bridge);
+	return NULL;
+}
+
 struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
 				     struct acpi_pci_root_ops *ops,
 				     struct acpi_pci_root_info *info,

@@ -902,7 +930,7 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
 
 	pci_acpi_root_add_resources(info);
 	pci_add_resource(&info->resources, &root->secondary);
-	bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
+	bus = acpi_pci_create_root_bus(NULL, busnum, ops->pci_ops,
 				  sysdata, &info->resources);
 	if (!bus)
 		goto out_release_info;

@@ -882,6 +882,34 @@ static const char *cujo_vers[] = {
 
 void ccio_cujo20_fixup(struct parisc_device *dev, u32 iovp);
 
+static struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
+		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+{
+	int error;
+	struct pci_host_bridge *bridge;
+
+	bridge = pci_alloc_host_bridge(0);
+	if (!bridge)
+		return NULL;
+
+	bridge->dev.parent = parent;
+
+	list_splice_init(resources, &bridge->windows);
+	bridge->sysdata = sysdata;
+	bridge->busnr = bus;
+	bridge->ops = ops;
+
+	error = pci_register_host_bridge(bridge);
+	if (error < 0)
+		goto err_out;
+
+	return bridge->bus;
+
+err_out:
+	kfree(bridge);
+	return NULL;
+}
+
 /*
 ** Determine if dino should claim this chip (return 0) or not (return 1).
 ** If so, initialize the chip appropriately (card-mode vs bridge mode).

@@ -1464,6 +1464,34 @@ lba_hw_init(struct lba_device *d)
  */
 static unsigned int lba_next_bus = 0;
 
+static struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
+		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+{
+	int error;
+	struct pci_host_bridge *bridge;
+
+	bridge = pci_alloc_host_bridge(0);
+	if (!bridge)
+		return NULL;
+
+	bridge->dev.parent = parent;
+
+	list_splice_init(resources, &bridge->windows);
+	bridge->sysdata = sysdata;
+	bridge->busnr = bus;
+	bridge->ops = ops;
+
+	error = pci_register_host_bridge(bridge);
+	if (error < 0)
+		goto err_out;
+
+	return bridge->bus;
+
+err_out:
+	kfree(bridge);
+	return NULL;
+}
+
 /*
  * Determine if lba should claim this chip (return 0) or not (return 1).
  * If so, initialize the chip and tell other partners in crime they

@@ -1457,6 +1457,34 @@ static void prepopulate_bars(struct hv_pcibus_device *hbus)
 	spin_unlock_irqrestore(&hbus->device_list_lock, flags);
 }
 
+static struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
+		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+{
+	int error;
+	struct pci_host_bridge *bridge;
+
+	bridge = pci_alloc_host_bridge(0);
+	if (!bridge)
+		return NULL;
+
+	bridge->dev.parent = parent;
+
+	list_splice_init(resources, &bridge->windows);
+	bridge->sysdata = sysdata;
+	bridge->busnr = bus;
+	bridge->ops = ops;
+
+	error = pci_register_host_bridge(bridge);
+	if (error < 0)
+		goto err_out;
+
+	return bridge->bus;
+
+err_out:
+	kfree(bridge);
+	return NULL;
+}
+
 /**
  * create_root_hv_pci_bus() - Expose a new root PCI bus
  * @hbus:	Root PCI bus, as understood by this driver

@@ -579,6 +579,34 @@ static int vmd_find_free_domain(void)
 	return domain + 1;
 }
 
+static struct pci_bus *vmd_create_root_bus(struct device *parent, int bus,
+		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+{
+	int error;
+	struct pci_host_bridge *bridge;
+
+	bridge = pci_alloc_host_bridge(0);
+	if (!bridge)
+		return NULL;
+
+	bridge->dev.parent = parent;
+
+	list_splice_init(resources, &bridge->windows);
+	bridge->sysdata = sysdata;
+	bridge->busnr = bus;
+	bridge->ops = ops;
+
+	error = pci_register_host_bridge(bridge);
+	if (error < 0)
+		goto err_out;
+
+	return bridge->bus;
+
+err_out:
+	kfree(bridge);
+	return NULL;
+}
+
 static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 {
 	struct pci_sysdata *sd = &vmd->sysdata;

@@ -705,7 +733,7 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 	pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);
 	pci_add_resource_offset(&resources, &vmd->resources[2], offset[1]);
 
-	vmd->bus = pci_create_root_bus(&vmd->dev->dev, busn_start, &vmd_ops,
+	vmd->bus = vmd_create_root_bus(&vmd->dev->dev, busn_start, &vmd_ops,
 				       sd, &resources);
 	if (!vmd->bus) {
 		pci_free_resource_list(&resources);

@@ -2909,35 +2909,6 @@ void __weak pcibios_remove_bus(struct pci_bus *bus)
 {
 }
 
-struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
-		struct pci_ops *ops, void *sysdata, struct list_head *resources)
-{
-	int error;
-	struct pci_host_bridge *bridge;
-
-	bridge = pci_alloc_host_bridge(0);
-	if (!bridge)
-		return NULL;
-
-	bridge->dev.parent = parent;
-
-	list_splice_init(resources, &bridge->windows);
-	bridge->sysdata = sysdata;
-	bridge->busnr = bus;
-	bridge->ops = ops;
-
-	error = pci_register_host_bridge(bridge);
-	if (error < 0)
-		goto err_out;
-
-	return bridge->bus;
-
-err_out:
-	kfree(bridge);
-	return NULL;
-}
-EXPORT_SYMBOL_GPL(pci_create_root_bus);
-
 int pci_host_probe(struct pci_host_bridge *bridge)
 {
 	struct pci_bus *bus, *child;

@@ -905,9 +905,6 @@ void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
 void pcibios_scan_specific_bus(int busn);
 struct pci_bus *pci_find_bus(int domain, int busnr);
 void pci_bus_add_devices(const struct pci_bus *bus);
-struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
-				    struct pci_ops *ops, void *sysdata,
-				    struct list_head *resources);
 int pci_host_probe(struct pci_host_bridge *bridge);
 int pci_register_host_bridge(struct pci_host_bridge *);
 int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax);

@@ -762,7 +762,29 @@ static void pci_set_bus_msi_domain(struct pci_bus *bus)
 	dev_set_msi_domain(&bus->dev, d);
 }
 
-static int pci_register_host_bridge(struct pci_host_bridge *bridge)
+/*
+ * pci_register_host_bridge() - Register a host bridge without scanning
+ *
+ * @bridge: a newly allocated host bridge structure
+ *
+ * This is the core part of bringing up a new PCI host bridge,
+ * before we scan for attached devices and register them as
+ * pci_dev.
+ *
+ * For the most part, this is an implementation detail of the
+ * pci_host_probe() interface, which brings up the entire bus,
+ * bus some older platforms still call it directly and manually
+ * scan for devices.
+ *
+ * If your driver uses this, try to convert it to using
+ * pci_host_probe() instead.
+ *
+ * Return: zero on suggess, or a negative error code.
+ * Note: after pci_register_host_bridge() successfully returns,
+ * the pci_host_bridge device is alive in driver core, and must
+ * not be freed directly.
+ */
+int pci_register_host_bridge(struct pci_host_bridge *bridge)
 {
 	struct device *parent = bridge->dev.parent;
 	struct resource_entry *window, *n;

@@ -877,6 +899,7 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
 	kfree(bus);
 	return err;
 }
+EXPORT_SYMBOL_GPL(pci_register_host_bridge);
 
 static bool pci_bridge_child_ext_cfg_accessible(struct pci_dev *bridge)
 {

@@ -909,6 +909,7 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 				    struct pci_ops *ops, void *sysdata,
 				    struct list_head *resources);
 int pci_host_probe(struct pci_host_bridge *bridge);
+int pci_register_host_bridge(struct pci_host_bridge *);
 int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax);
 int pci_bus_update_busn_res_end(struct pci_bus *b, int busmax);
 void pci_bus_release_busn_res(struct pci_bus *b);

@@ -691,70 +691,50 @@ static void pci_claim_bus_resources(struct pci_bus *bus)
 		pci_claim_bus_resources(child_bus);
 }
 
-static struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
-		struct pci_ops *ops, void *sysdata, struct list_head *resources)
+struct pci_bus *pci_scan_one_pbm(struct pci_pbm_info *pbm,
+				 struct device *parent)
 {
-	int error;
+	struct device_node *node = pbm->op->dev.of_node;
 	struct pci_host_bridge *bridge;
+	int ret;
 
 	bridge = pci_alloc_host_bridge(0);
 	if (!bridge)
 		return NULL;
 
 	bridge->dev.parent = parent;
+	bridge->sysdata = pbm;
+	bridge->busnr = pbm->pci_first_busno;
+	bridge->ops = pbm->pci_ops;
 
-	list_splice_init(resources, &bridge->windows);
-	bridge->sysdata = sysdata;
-	bridge->busnr = bus;
-	bridge->ops = ops;
-
-	error = pci_register_host_bridge(bridge);
-	if (error < 0)
-		goto err_out;
-
-	return bridge->bus;
-
-err_out:
-	kfree(bridge);
-	return NULL;
-}
-
-struct pci_bus *pci_scan_one_pbm(struct pci_pbm_info *pbm,
-				 struct device *parent)
-{
-	LIST_HEAD(resources);
-	struct device_node *node = pbm->op->dev.of_node;
-	struct pci_bus *bus;
-
-	printk("PCI: Scanning PBM %s\n", node->full_name);
-
-	pci_add_resource_offset(&resources, &pbm->io_space,
+	pci_add_resource_offset(&bridge->windows, &pbm->io_space,
 				pbm->io_offset);
-	pci_add_resource_offset(&resources, &pbm->mem_space,
+	pci_add_resource_offset(&bridge->windows, &pbm->mem_space,
 				pbm->mem_offset);
 	if (pbm->mem64_space.flags)
-		pci_add_resource_offset(&resources, &pbm->mem64_space,
+		pci_add_resource_offset(&bridge->windows, &pbm->mem64_space,
 					pbm->mem64_offset);
 	pbm->busn.start = pbm->pci_first_busno;
 	pbm->busn.end	= pbm->pci_last_busno;
 	pbm->busn.flags	= IORESOURCE_BUS;
-	pci_add_resource(&resources, &pbm->busn);
-	bus = pci_create_root_bus(parent, pbm->pci_first_busno, pbm->pci_ops,
-				  pbm, &resources);
-	if (!bus) {
+	pci_add_resource(&bridge->windows, &pbm->busn);
+
+	printk("PCI: Scanning PBM %s\n", node->full_name);
+	ret = pci_register_host_bridge(bridge);
+	if (!ret) {
 		printk(KERN_ERR "Failed to create bus for %s\n",
 		       node->full_name);
-		pci_free_resource_list(&resources);
+		pci_free_host_bridge(bridge);
 		return NULL;
 	}
 
-	pci_of_scan_bus(pbm, node, bus);
-	pci_bus_register_of_sysfs(bus);
+	pci_of_scan_bus(pbm, node, bridge->bus);
+	pci_bus_register_of_sysfs(bridge->bus);
 
-	pci_claim_bus_resources(bus);
+	pci_claim_bus_resources(bridge->bus);
 
-	pci_bus_add_devices(bus);
-	return bus;
+	pci_bus_add_devices(bridge->bus);
+	return bridge->bus;
 }
 
 int pcibios_enable_device(struct pci_dev *dev, int mask)

@@ -51,8 +51,11 @@ struct pci_controller_ops {
 
 /*
  * Structure of a PCI controller (host bridge)
+ * Some members here are duplicated in struct pci_host_bridge
+ * and should be moved there.
  */
 struct pci_controller {
+	struct pci_host_bridge *bridge;
 	struct pci_bus *bus;
 	char is_dynamic;
 #ifdef CONFIG_PPC64

@@ -1587,81 +1587,63 @@ struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus)
 	return of_node_get(hose->dn);
 }
 
-static struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
-		struct pci_ops *ops, void *sysdata, struct list_head *resources)
-{
-	int error;
-	struct pci_host_bridge *bridge;
-
-	bridge = pci_alloc_host_bridge(0);
-	if (!bridge)
-		return NULL;
-
-	bridge->dev.parent = parent;
-
-	list_splice_init(resources, &bridge->windows);
-	bridge->sysdata = sysdata;
-	bridge->busnr = bus;
-	bridge->ops = ops;
-
-	error = pci_register_host_bridge(bridge);
-	if (error < 0)
-		goto err_out;
-
-	return bridge->bus;
-
-err_out:
-	kfree(bridge);
-	return NULL;
-}
-
 /**
  * pci_scan_phb - Given a pci_controller, setup and scan the PCI bus
  * @hose: Pointer to the PCI host controller instance structure
  */
 void pcibios_scan_phb(struct pci_controller *hose)
 {
-	LIST_HEAD(resources);
-	struct pci_bus *bus;
 	struct device_node *node = hose->dn;
 	int mode;
+	struct pci_host_bridge *bridge;
+	int error;
 
 	pr_debug("PCI: Scanning PHB %pOF\n", node);
 
+	/* The allocation should ideally be done in pcibios_alloc_controller(),
+	 * but pci_alloc_host_bridge() requires slab to work first */
+	bridge = pci_alloc_host_bridge(0);
+	if (!bridge)
+		return;
+
 	/* Get some IO space for the new PHB */
 	pcibios_setup_phb_io_space(hose);
 
 	/* Wire up PHB bus resources */
-	pcibios_setup_phb_resources(hose, &resources);
+	pcibios_setup_phb_resources(hose, &bridge->windows);
 
 	hose->busn.start = hose->first_busno;
 	hose->busn.end	 = hose->last_busno;
 	hose->busn.flags = IORESOURCE_BUS;
-	pci_add_resource(&resources, &hose->busn);
+	pci_add_resource(&bridge->windows, &hose->busn);
+
+	bridge->dev.parent = hose->parent;
+	bridge->sysdata = hose;
+	bridge->busnr = hose->first_busno;
+	bridge->ops = hose->ops;
 
-	/* Create an empty bus for the toplevel */
-	bus = pci_create_root_bus(hose->parent, hose->first_busno,
-				  hose->ops, hose, &resources);
-	if (bus == NULL) {
+	error = pci_register_host_bridge(bridge);
+	if (error < 0) {
 		pr_err("Failed to create bus for PCI domain %04x\n",
 			hose->global_number);
-		pci_free_resource_list(&resources);
+		pci_free_host_bridge(bridge);
 		return;
 	}
-	hose->bus = bus;
+	hose->bridge = bridge;
+	hose->bus = bridge->bus;
 
 	/* Get probe mode and perform scan */
 	mode = PCI_PROBE_NORMAL;
 	if (node && hose->controller_ops.probe_mode)
-		mode = hose->controller_ops.probe_mode(bus);
+		mode = hose->controller_ops.probe_mode(bridge->bus);
 	pr_debug("    probe mode: %d\n", mode);
 	if (mode == PCI_PROBE_DEVTREE)
-		of_scan_bus(node, bus);
+		of_scan_bus(node, bridge->bus);
 
 	if (mode == PCI_PROBE_NORMAL) {
-		pci_bus_update_busn_res_end(bus, 255);
-		hose->last_busno = pci_scan_child_bus(bus);
-		pci_bus_update_busn_res_end(bus, hose->last_busno);
+		pci_bus_update_busn_res_end(bridge->bus, 255);
+		hose->last_busno = pci_scan_child_bus(bridge->bus);
+		pci_bus_update_busn_res_end(bridge->bus, hose->last_busno);
 	}
 
 	/* Platform gets a chance to do some global fixups before