Merge branch 'pci/jiang-bus-lock-v3' into next

* pci/jiang-bus-lock-v3:
  PCI: Return early on allocation failures to unindent mainline code
  PCI: Simplify IOV implementation and fix reference count races
  PCI: Drop redundant setting of bus->is_added in virtfn_add_bus()
  unicore32/PCI: Remove redundant call of pci_bus_add_devices()
  m68k/PCI: Remove redundant call of pci_bus_add_devices()
  PCI: Rename pci_release_bus_bridge_dev() to pci_release_host_bridge_dev()
  PCI: Fix refcount issue in pci_create_root_bus() error recovery path
  ia64/PCI: Clean up pci_scan_root_bus() usage
  PCI: Convert alloc_pci_dev(void) to pci_alloc_dev(bus)
  PCI: Introduce pci_alloc_dev(struct pci_bus*) to replace alloc_pci_dev()
  PCI: Introduce pci_bus_{get|put}() to manage PCI bus reference count

Conflicts:
	drivers/pci/probe.c

arch/ia64/sn/kernel/io_init.c

@@ -326,16 +326,7 @@ sn_pci_controller_fixup(int segment, int busnum, struct pci_bus *bus)
 	bus = pci_scan_root_bus(NULL, busnum, &pci_root_ops, controller,
 				&resources);
  	if (bus == NULL)
- 		goto error_return; /* error, or bus already scanned */
-
-	bus->sysdata = controller;
-
-	return;
-
-error_return:
-
-	kfree(controller);
-	return;
+		kfree(controller);
 }
 
 /*

arch/m68k/platform/coldfire/pci.c

@@ -320,7 +320,6 @@ static int __init mcf_pci_init(void)
 	pci_bus_size_bridges(rootbus);
 	pci_bus_assign_resources(rootbus);
 	pci_enable_bridges(rootbus);
-	pci_bus_add_devices(rootbus);
 	return 0;
 }
 

arch/powerpc/kernel/pci_of_scan.c

@@ -128,7 +128,7 @@ struct pci_dev *of_create_pci_dev(struct device_node *node,
 	const char *type;
 	struct pci_slot *slot;
 
-	dev = alloc_pci_dev();
+	dev = pci_alloc_dev(bus);
 	if (!dev)
 		return NULL;
 	type = of_get_property(node, "device_type", NULL);
@@ -137,7 +137,6 @@ struct pci_dev *of_create_pci_dev(struct device_node *node,
 
 	pr_debug("    create device, devfn: %x, type: %s\n", devfn, type);
 
-	dev->bus = bus;
 	dev->dev.of_node = of_node_get(node);
 	dev->dev.parent = bus->bridge;
 	dev->dev.bus = &pci_bus_type;

arch/sparc/kernel/pci.c

@@ -254,7 +254,7 @@ static struct pci_dev *of_create_pci_dev(struct pci_pbm_info *pbm,
 	const char *type;
 	u32 class;
 
-	dev = alloc_pci_dev();
+	dev = pci_alloc_dev(bus);
 	if (!dev)
 		return NULL;
 
@@ -281,7 +281,6 @@ static struct pci_dev *of_create_pci_dev(struct pci_pbm_info *pbm,
 		printk("    create device, devfn: %x, type: %s\n",
 		       devfn, type);
 
-	dev->bus = bus;
 	dev->sysdata = node;
 	dev->dev.parent = bus->bridge;
 	dev->dev.bus = &pci_bus_type;

arch/unicore32/kernel/pci.c

@@ -277,11 +277,6 @@ static int __init pci_common_init(void)
 		pci_bus_assign_resources(puv3_bus);
 	}
 
-	/*
-	 * Tell drivers about devices found.
-	 */
-	pci_bus_add_devices(puv3_bus);
-
 	return 0;
 }
 subsys_initcall(pci_common_init);

drivers/char/agp/alpha-agp.c

@@ -174,7 +174,7 @@ alpha_core_agp_setup(void)
 	/*
 	 * Build a fake pci_dev struct
 	 */
-	pdev = alloc_pci_dev();
+	pdev = pci_alloc_dev(NULL);
 	if (!pdev)
 		return -ENOMEM;
 	pdev->vendor = 0xffff;

drivers/char/agp/parisc-agp.c

@@ -333,7 +333,7 @@ parisc_agp_setup(void __iomem *ioc_hpa, void __iomem *lba_hpa)
 	struct agp_bridge_data *bridge;
 	int error = 0;
 
-	fake_bridge_dev = alloc_pci_dev();
+	fake_bridge_dev = pci_alloc_dev(NULL);
 	if (!fake_bridge_dev) {
 		error = -ENOMEM;
 		goto fail;

drivers/pci/bus.c

@@ -283,6 +283,21 @@ void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
 }
 EXPORT_SYMBOL_GPL(pci_walk_bus);
 
+struct pci_bus *pci_bus_get(struct pci_bus *bus)
+{
+	if (bus)
+		get_device(&bus->dev);
+	return bus;
+}
+EXPORT_SYMBOL(pci_bus_get);
+
+void pci_bus_put(struct pci_bus *bus)
+{
+	if (bus)
+		put_device(&bus->dev);
+}
+EXPORT_SYMBOL(pci_bus_put);
+
 EXPORT_SYMBOL(pci_bus_alloc_resource);
 EXPORT_SYMBOL_GPL(pci_bus_add_device);
 EXPORT_SYMBOL(pci_bus_add_devices);

drivers/pci/iov.c

@@ -47,46 +47,36 @@ static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
 		return NULL;
 
 	pci_bus_insert_busn_res(child, busnr, busnr);
-	bus->is_added = 1;
 
 	return child;
 }
 
-static void virtfn_remove_bus(struct pci_bus *bus, int busnr)
+static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
 {
-	struct pci_bus *child;
-
-	if (bus->number == busnr)
-		return;
-
-	child = pci_find_bus(pci_domain_nr(bus), busnr);
-	BUG_ON(!child);
-
-	if (list_empty(&child->devices))
-		pci_remove_bus(child);
+	if (physbus != virtbus && list_empty(&virtbus->devices))
+		pci_remove_bus(virtbus);
 }
 
 static int virtfn_add(struct pci_dev *dev, int id, int reset)
 {
 	int i;
-	int rc;
+	int rc = -ENOMEM;
 	u64 size;
 	char buf[VIRTFN_ID_LEN];
 	struct pci_dev *virtfn;
 	struct resource *res;
 	struct pci_sriov *iov = dev->sriov;
+	struct pci_bus *bus;
 
-	virtfn = alloc_pci_dev();
+	mutex_lock(&iov->dev->sriov->lock);
+	bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id));
+	if (!bus)
+		goto failed;
+
+	virtfn = pci_alloc_dev(bus);
 	if (!virtfn)
-		return -ENOMEM;
+		goto failed0;
 
-	mutex_lock(&iov->dev->sriov->lock);
-	virtfn->bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id));
-	if (!virtfn->bus) {
-		kfree(virtfn);
-		mutex_unlock(&iov->dev->sriov->lock);
-		return -ENOMEM;
-	}
 	virtfn->devfn = virtfn_devfn(dev, id);
 	virtfn->vendor = dev->vendor;
 	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
@@ -134,7 +124,9 @@ static int virtfn_add(struct pci_dev *dev, int id, int reset)
 	pci_dev_put(dev);
 	mutex_lock(&iov->dev->sriov->lock);
 	pci_stop_and_remove_bus_device(virtfn);
-	virtfn_remove_bus(dev->bus, virtfn_bus(dev, id));
+failed0:
+	virtfn_remove_bus(dev->bus, bus);
+failed:
 	mutex_unlock(&iov->dev->sriov->lock);
 
 	return rc;
@@ -143,20 +135,15 @@ static int virtfn_add(struct pci_dev *dev, int id, int reset)
 static void virtfn_remove(struct pci_dev *dev, int id, int reset)
 {
 	char buf[VIRTFN_ID_LEN];
-	struct pci_bus *bus;
 	struct pci_dev *virtfn;
 	struct pci_sriov *iov = dev->sriov;
 
-	bus = pci_find_bus(pci_domain_nr(dev->bus), virtfn_bus(dev, id));
-	if (!bus)
-		return;
-
-	virtfn = pci_get_slot(bus, virtfn_devfn(dev, id));
+	virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
+					     virtfn_bus(dev, id),
+					     virtfn_devfn(dev, id));
 	if (!virtfn)
 		return;
 
-	pci_dev_put(virtfn);
-
 	if (reset) {
 		device_release_driver(&virtfn->dev);
 		__pci_reset_function(virtfn);
@@ -174,9 +161,11 @@ static void virtfn_remove(struct pci_dev *dev, int id, int reset)
 
 	mutex_lock(&iov->dev->sriov->lock);
 	pci_stop_and_remove_bus_device(virtfn);
-	virtfn_remove_bus(dev->bus, virtfn_bus(dev, id));
+	virtfn_remove_bus(dev->bus, virtfn->bus);
 	mutex_unlock(&iov->dev->sriov->lock);
 
+	/* balance pci_get_domain_bus_and_slot() */
+	pci_dev_put(virtfn);
 	pci_dev_put(dev);
 }
 
@@ -333,13 +322,14 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 		if (!pdev)
 			return -ENODEV;
 
-		pci_dev_put(pdev);
-
-		if (!pdev->is_physfn)
+		if (!pdev->is_physfn) {
+			pci_dev_put(pdev);
 			return -ENODEV;
+		}
 
 		rc = sysfs_create_link(&dev->dev.kobj,
 					&pdev->dev.kobj, "dep_link");
+		pci_dev_put(pdev);
 		if (rc)
 			return rc;
 	}

drivers/pci/probe.c

@@ -470,33 +470,46 @@ void pci_read_bridge_bases(struct pci_bus *child)
 	}
 }
 
-static struct pci_bus * pci_alloc_bus(void)
+static struct pci_bus *pci_alloc_bus(void)
 {
 	struct pci_bus *b;
 
 	b = kzalloc(sizeof(*b), GFP_KERNEL);
-	if (b) {
-		INIT_LIST_HEAD(&b->node);
-		INIT_LIST_HEAD(&b->children);
-		INIT_LIST_HEAD(&b->devices);
-		INIT_LIST_HEAD(&b->slots);
-		INIT_LIST_HEAD(&b->resources);
-		b->max_bus_speed = PCI_SPEED_UNKNOWN;
-		b->cur_bus_speed = PCI_SPEED_UNKNOWN;
-	}
+	if (!b)
+		return NULL;
+
+	INIT_LIST_HEAD(&b->node);
+	INIT_LIST_HEAD(&b->children);
+	INIT_LIST_HEAD(&b->devices);
+	INIT_LIST_HEAD(&b->slots);
+	INIT_LIST_HEAD(&b->resources);
+	b->max_bus_speed = PCI_SPEED_UNKNOWN;
+	b->cur_bus_speed = PCI_SPEED_UNKNOWN;
 	return b;
 }
 
+static void pci_release_host_bridge_dev(struct device *dev)
+{
+	struct pci_host_bridge *bridge = to_pci_host_bridge(dev);
+
+	if (bridge->release_fn)
+		bridge->release_fn(bridge);
+
+	pci_free_resource_list(&bridge->windows);
+
+	kfree(bridge);
+}
+
 static struct pci_host_bridge *pci_alloc_host_bridge(struct pci_bus *b)
 {
 	struct pci_host_bridge *bridge;
 
 	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
-	if (bridge) {
-		INIT_LIST_HEAD(&bridge->windows);
-		bridge->bus = b;
-	}
+	if (!bridge)
+		return NULL;
 
+	INIT_LIST_HEAD(&bridge->windows);
+	bridge->bus = b;
 	return bridge;
 }
 
@@ -1152,6 +1165,7 @@ static void pci_release_dev(struct device *dev)
 	pci_release_capabilities(pci_dev);
 	pci_release_of_node(pci_dev);
 	pcibios_release_device(pci_dev);
+	pci_bus_put(pci_dev->bus);
 	kfree(pci_dev);
 }
 
@@ -1208,19 +1222,7 @@ int pci_cfg_space_size(struct pci_dev *dev)
 	return PCI_CFG_SPACE_SIZE;
 }
 
-static void pci_release_bus_bridge_dev(struct device *dev)
-{
-	struct pci_host_bridge *bridge = to_pci_host_bridge(dev);
-
-	if (bridge->release_fn)
-		bridge->release_fn(bridge);
-
-	pci_free_resource_list(&bridge->windows);
-
-	kfree(bridge);
-}
-
-struct pci_dev *alloc_pci_dev(void)
+struct pci_dev *pci_alloc_dev(struct pci_bus *bus)
 {
 	struct pci_dev *dev;
 
@@ -1230,9 +1232,16 @@ struct pci_dev *alloc_pci_dev(void)
 
 	INIT_LIST_HEAD(&dev->bus_list);
 	dev->dev.type = &pci_dev_type;
+	dev->bus = pci_bus_get(bus);
 
 	return dev;
 }
+EXPORT_SYMBOL(pci_alloc_dev);
+
+struct pci_dev *alloc_pci_dev(void)
+{
+	return pci_alloc_dev(NULL);
+}
 EXPORT_SYMBOL(alloc_pci_dev);
 
 bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l,
@@ -1283,18 +1292,18 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
 	if (!pci_bus_read_dev_vendor_id(bus, devfn, &l, 60*1000))
 		return NULL;
 
-	dev = alloc_pci_dev();
+	dev = pci_alloc_dev(bus);
 	if (!dev)
 		return NULL;
 
-	dev->bus = bus;
 	dev->devfn = devfn;
 	dev->vendor = l & 0xffff;
 	dev->device = (l >> 16) & 0xffff;
 
 	pci_set_of_node(dev);
 
 	if (pci_setup_device(dev)) {
+		pci_bus_put(dev->bus);
 		kfree(dev);
 		return NULL;
 	}
@@ -1720,15 +1729,19 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 		goto err_out;
 
 	bridge->dev.parent = parent;
-	bridge->dev.release = pci_release_bus_bridge_dev;
+	bridge->dev.release = pci_release_host_bridge_dev;
 	dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus);
 	error = pcibios_root_bridge_prepare(bridge);
-	if (error)
-		goto bridge_dev_reg_err;
+	if (error) {
+		kfree(bridge);
+		goto err_out;
+	}
 
 	error = device_register(&bridge->dev);
-	if (error)
-		goto bridge_dev_reg_err;
+	if (error) {
+		put_device(&bridge->dev);
+		goto err_out;
+	}
 	b->bridge = get_device(&bridge->dev);
 	device_enable_async_suspend(b->bridge);
 	pci_set_bus_of_node(b);
@@ -1784,8 +1797,6 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 class_dev_reg_err:
 	put_device(&bridge->dev);
 	device_unregister(&bridge->dev);
-bridge_dev_reg_err:
-	kfree(bridge);
 err_out:
 	kfree(b);
 	return NULL;