PCI: Assign resources on a per-bus basis

Previously, we did resource assignment globally.  This patch splits up
pci_assign_unassigned_resources() so assignment is done for each root bus
in turn.  We check each root bus individually to see whether it needs any
reassignment, and if it does, we assign resources for just that bus.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/setup-bus.c

@@ -1315,21 +1315,6 @@ static int __init pci_bus_get_depth(struct pci_bus *bus)
 
 	return depth;
 }
-static int __init pci_get_max_depth(void)
-{
-	int depth = 0;
-	struct pci_bus *bus;
-
-	list_for_each_entry(bus, &pci_root_buses, node) {
-		int ret;
-
-		ret = pci_bus_get_depth(bus);
-		if (ret > depth)
-			depth = ret;
-	}
-
-	return depth;
-}
 
 /*
  * -1: undefined, will auto detect later
@@ -1410,10 +1395,9 @@ static enum enable_type __init pci_realloc_detect(struct pci_bus *bus,
  * second  and later try will clear small leaf bridge res
  * will stop till to the max  deepth if can not find good one
  */
-void __init
-pci_assign_unassigned_resources(void)
+static void __init
+pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
 {
-	struct pci_bus *bus;
 	LIST_HEAD(realloc_head); /* list of resources that
 					want additional resources */
 	struct list_head *add_list = NULL;
@@ -1424,17 +1408,17 @@ pci_assign_unassigned_resources(void)
 	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
 				  IORESOURCE_PREFETCH;
 	int pci_try_num = 1;
-	enum enable_type enable_local = pci_realloc_enable;
-
-	list_for_each_entry(bus, &pci_root_buses, node)
-		enable_local = pci_realloc_detect(bus, enable_local);
+	enum enable_type enable_local;
 
+	/* don't realloc if asked to do so */
+	enable_local = pci_realloc_detect(bus, pci_realloc_enable);
 	if (pci_realloc_enabled(enable_local)) {
-		int max_depth = pci_get_max_depth();
+		int max_depth = pci_bus_get_depth(bus);
 
 		pci_try_num = max_depth + 1;
-		printk(KERN_DEBUG "PCI: max bus depth: %d pci_try_num: %d\n",
-			 max_depth, pci_try_num);
+		dev_printk(KERN_DEBUG, &bus->dev,
+			   "max bus depth: %d pci_try_num: %d\n",
+			   max_depth, pci_try_num);
 	}
 
 again:
@@ -1446,12 +1430,10 @@ again:
 		add_list = &realloc_head;
 	/* Depth first, calculate sizes and alignments of all
 	   subordinate buses. */
-	list_for_each_entry(bus, &pci_root_buses, node)
-		__pci_bus_size_bridges(bus, add_list);
+	__pci_bus_size_bridges(bus, add_list);
 
 	/* Depth last, allocate resources and update the hardware. */
-	list_for_each_entry(bus, &pci_root_buses, node)
-		__pci_bus_assign_resources(bus, add_list, &fail_head);
+	__pci_bus_assign_resources(bus, add_list, &fail_head);
 	if (add_list)
 		BUG_ON(!list_empty(add_list));
 	tried_times++;
@@ -1462,16 +1444,16 @@ again:
 
 	if (tried_times >= pci_try_num) {
 		if (enable_local == undefined)
-			printk(KERN_INFO "Some PCI device resources are unassigned, try booting with pci=realloc\n");
+			dev_info(&bus->dev, "Some PCI device resources are unassigned, try booting with pci=realloc\n");
 		else if (enable_local == auto_enabled)
-			printk(KERN_INFO "Automatically enabled pci realloc, if you have problem, try booting with pci=realloc=off\n");
+			dev_info(&bus->dev, "Automatically enabled pci realloc, if you have problem, try booting with pci=realloc=off\n");
 
 		free_list(&fail_head);
 		goto enable_and_dump;
 	}
 
-	printk(KERN_DEBUG "PCI: No. %d try to assign unassigned res\n",
-			 tried_times + 1);
+	dev_printk(KERN_DEBUG, &bus->dev,
+		   "No. %d try to assign unassigned res\n", tried_times + 1);
 
 	/* third times and later will not check if it is leaf */
 	if ((tried_times + 1) > 2)
@@ -1502,12 +1484,18 @@ again:
 
 enable_and_dump:
 	/* Depth last, update the hardware. */
-	list_for_each_entry(bus, &pci_root_buses, node)
-		pci_enable_bridges(bus);
+	pci_enable_bridges(bus);
 
 	/* dump the resource on buses */
-	list_for_each_entry(bus, &pci_root_buses, node)
-		pci_bus_dump_resources(bus);
+	pci_bus_dump_resources(bus);
+}
+
+void __init pci_assign_unassigned_resources(void)
+{
+	struct pci_bus *root_bus;
+
+	list_for_each_entry(root_bus, &pci_root_buses, node)
+		pci_assign_unassigned_root_bus_resources(root_bus);
 }
 
 void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)