1 files changed, 38 insertions, 28 deletions

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 281d90f19c7..b494066ef32 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1295,7 +1295,7 @@ static void pci_init_capabilities(struct pci_dev *dev)
 	pci_vpd_pci22_init(dev);
 
 	/* Alternative Routing-ID Forwarding */
-	pci_enable_ari(dev);
+	pci_configure_ari(dev);
 
 	/* Single Root I/O Virtualization */
 	pci_iov_init(dev);
@@ -1371,31 +1371,31 @@ struct pci_dev *__ref pci_scan_single_device(struct pci_bus *bus, int devfn)
 }
 EXPORT_SYMBOL(pci_scan_single_device);
 
-static unsigned next_ari_fn(struct pci_dev *dev, unsigned fn)
+static unsigned next_fn(struct pci_bus *bus, struct pci_dev *dev, unsigned fn)
 {
-	u16 cap;
-	unsigned pos, next_fn;
+	int pos;
+	u16 cap = 0;
+	unsigned next_fn;
 
-	if (!dev)
-		return 0;
+	if (pci_ari_enabled(bus)) {
+		if (!dev)
+			return 0;
+		pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
+		if (!pos)
+			return 0;
 
-	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
-	if (!pos)
-		return 0;
-	pci_read_config_word(dev, pos + 4, &cap);
-	next_fn = cap >> 8;
-	if (next_fn <= fn)
-		return 0;
-	return next_fn;
-}
+		pci_read_config_word(dev, pos + PCI_ARI_CAP, &cap);
+		next_fn = PCI_ARI_CAP_NFN(cap);
+		if (next_fn <= fn)
+			return 0;	/* protect against malformed list */
 
-static unsigned next_trad_fn(struct pci_dev *dev, unsigned fn)
-{
-	return (fn + 1) % 8;
-}
+		return next_fn;
+	}
+
+	/* dev may be NULL for non-contiguous multifunction devices */
+	if (!dev || dev->multifunction)
+		return (fn + 1) % 8;
 
-static unsigned no_next_fn(struct pci_dev *dev, unsigned fn)
-{
 	return 0;
 }
 
@@ -1428,7 +1428,6 @@ int pci_scan_slot(struct pci_bus *bus, int devfn)
 {
 	unsigned fn, nr = 0;
 	struct pci_dev *dev;
-	unsigned (*next_fn)(struct pci_dev *, unsigned) = no_next_fn;
 
 	if (only_one_child(bus) && (devfn > 0))
 		return 0; /* Already scanned the entire slot */
@@ -1439,12 +1438,7 @@ int pci_scan_slot(struct pci_bus *bus, int devfn)
 	if (!dev->is_added)
 		nr++;
 
-	if (pci_ari_enabled(bus))
-		next_fn = next_ari_fn;
-	else if (dev->multifunction)
-		next_fn = next_trad_fn;
-
-	for (fn = next_fn(dev, 0); fn > 0; fn = next_fn(dev, fn)) {
+	for (fn = next_fn(bus, dev, 0); fn > 0; fn = next_fn(bus, dev, fn)) {
 		dev = pci_scan_single_device(bus, devfn + fn);
 		if (dev) {
 			if (!dev->is_added)
@@ -1655,6 +1649,18 @@ unsigned int pci_scan_child_bus(struct pci_bus *bus)
 	return max;
 }
 
+/**
+ * pcibios_root_bridge_prepare - Platform-specific host bridge setup.
+ * @bridge: Host bridge to set up.
+ *
+ * Default empty implementation.  Replace with an architecture-specific setup
+ * routine, if necessary.
+ */
+int __weak pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
+{
+	return 0;
+}
+
 struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 		struct pci_ops *ops, void *sysdata, struct list_head *resources)
 {
@@ -1688,6 +1694,10 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 	bridge->dev.parent = parent;
 	bridge->dev.release = pci_release_bus_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;
+
 	error = device_register(&bridge->dev);
 	if (error)
 		goto bridge_dev_reg_err;