diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index a94ecc1..89d0a6a 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -33,6 +33,7 @@ struct resource_list_x {
 	struct pci_dev *dev;
 	resource_size_t start;
 	resource_size_t end;
+	resource_size_t add_size;
 	unsigned long flags;
 };
 
@@ -46,8 +47,18 @@ struct resource_list_x {
 	(head)->next = NULL;				\
 } while (0)
 
-static void add_to_failed_list(struct resource_list_x *head,
-				 struct pci_dev *dev, struct resource *res)
+/**
+ * add_to_list() - add a new resource tracker to the list
+ * @head:	Head of the list
+ * @dev:	device corresponding to which the resource
+ *		belongs
+ * @res:	The resource to be tracked
+ * @add_size:	additional size to be optionally added
+ *              to the resource
+ */
+static void add_to_list(struct resource_list_x *head,
+		 struct pci_dev *dev, struct resource *res,
+		 resource_size_t add_size)
 {
 	struct resource_list_x *list = head;
 	struct resource_list_x *ln = list->next;
@@ -55,7 +66,7 @@ static void add_to_failed_list(struct resource_list_x *head,
 
 	tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
 	if (!tmp) {
-		pr_warning("add_to_failed_list: kmalloc() failed!\n");
+		pr_warning("add_to_list: kmalloc() failed!\n");
 		return;
 	}
 
@@ -65,9 +76,16 @@ static void add_to_failed_list(struct resource_list_x *head,
 	tmp->start = res->start;
 	tmp->end = res->end;
 	tmp->flags = res->flags;
+	tmp->add_size = add_size;
 	list->next = tmp;
 }
 
+static void add_to_failed_list(struct resource_list_x *head,
+				struct pci_dev *dev, struct resource *res)
+{
+	add_to_list(head, dev, res, 0);
+}
+
 static void __dev_sort_resources(struct pci_dev *dev,
 				 struct resource_list *head)
 {
@@ -95,18 +113,81 @@ static inline void reset_resource(struct resource *res)
 	res->flags = 0;
 }
 
-static void __assign_resources_sorted(struct resource_list *head,
-				 struct resource_list_x *fail_head)
+/**
+ * adjust_resources_sorted() - satisfy any additional resource requests
+ *
+ * @add_head : head of the list tracking requests requiring additional
+ *             resources
+ * @head     : head of the list tracking requests with allocated
+ *             resources
+ *
+ * Walk through each element of the add_head and try to procure
+ * additional resources for the element, provided the element
+ * is in the head list.
+ */
+static void adjust_resources_sorted(struct resource_list_x *add_head,
+		struct resource_list *head)
 {
 	struct resource *res;
-	struct resource_list *list, *tmp;
+	struct resource_list_x *list, *tmp, *prev;
+	struct resource_list *hlist;
+	resource_size_t add_size;
 	int idx;
 
-	for (list = head->next; list;) {
+	prev = add_head;
+	for (list = add_head->next; list;) {
 		res = list->res;
+		/* skip resource that has been reset */
+		if (!res->flags)
+			goto out;
+
+		/* skip this resource if not found in head list */
+		for (hlist = head->next; hlist && hlist->res != res;
+				hlist = hlist->next);
+		if (!hlist) { /* just skip */
+			prev = list;
+			list = list->next;
+			continue;
+		}
+
 		idx = res - &list->dev->resource[0];
+		add_size=list->add_size;
+		if (!resource_size(res) && add_size) {
+			 res->end = res->start + add_size - 1;
+			 if(pci_assign_resource(list->dev, idx))
+				reset_resource(res);
+		} else if (add_size) {
+			adjust_resource(res, res->start,
+				resource_size(res) + add_size);
+		}
+out:
+		tmp = list;
+		prev->next = list = list->next;
+		kfree(tmp);
+	}
+}
+
+/**
+ * assign_requested_resources_sorted() - satisfy resource requests
+ *
+ * @head : head of the list tracking requests for resources
+ * @failed_list : head of the list tracking requests that could
+ *		not be allocated
+ *
+ * Satisfy resource requests of each element in the list. Add
+ * requests that could not satisfied to the failed_list.
+ */
+static void assign_requested_resources_sorted(struct resource_list *head,
+				 struct resource_list_x *fail_head)
+{
+	struct resource *res;
+	struct resource_list *list;
+	int idx;
 
-		if (pci_assign_resource(list->dev, idx)) {
+	for (list = head->next; list; list = list->next) {
+		res = list->res;
+		idx = res - &list->dev->resource[0];
+		if (resource_size(res) && pci_assign_resource(list->dev, idx)) {
 			if (fail_head && !pci_is_root_bus(list->dev->bus)) {
 				/*
 				 * if the failed res is for ROM BAR, and it will
@@ -118,12 +199,23 @@ static void __assign_resources_sorted(struct resource_list *head,
 			}
 			reset_resource(res);
 		}
-		tmp = list;
-		list = list->next;
-		kfree(tmp);
 	}
 }
 
+static void __assign_resources_sorted(struct resource_list *head,
+				 struct resource_list_x *add_head,
+				 struct resource_list_x *fail_head)
+{
+	/* Satisfy the must-have resource requests */
+	assign_requested_resources_sorted(head, fail_head);
+
+	/* Try to satisfy any additional nice-to-have resource
+		requests */
+	if (add_head)
+		adjust_resources_sorted(add_head, head);
+	free_list(resource_list, head);
+}
+
 static void pdev_assign_resources_sorted(struct pci_dev *dev,
 				 struct resource_list_x *fail_head)
 {
@@ -131,11 +223,12 @@ static void pdev_assign_resources_sorted(struct pci_dev *dev,
 
 	head.next = NULL;
 	__dev_sort_resources(dev, &head);
-	__assign_resources_sorted(&head, fail_head);
+	__assign_resources_sorted(&head, NULL, fail_head);
 
 }
 
 static void pbus_assign_resources_sorted(const struct pci_bus *bus,
+					 struct resource_list_x *add_head,
 					 struct resource_list_x *fail_head)
 {
 	struct pci_dev *dev;
@@ -145,7 +238,7 @@ static void pbus_assign_resources_sorted(const struct pci_bus *bus,
 	list_for_each_entry(dev, &bus->devices, bus_list)
 		__dev_sort_resources(dev, &head);
 
-	__assign_resources_sorted(&head, fail_head);
+	__assign_resources_sorted(&head, add_head, fail_head);
 }
 
 void pci_setup_cardbus(struct pci_bus *bus)
@@ -443,15 +536,25 @@ static resource_size_t calculate_memsize(resource_size_t size,
 	return size;
 }
 
-/* Sizing the IO windows of the PCI-PCI bridge is trivial,
-   since these windows have 4K granularity and the IO ranges
-   of non-bridge PCI devices are limited to 256 bytes.
-   We must be careful with the ISA aliasing though. */
-static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size)
+/**
+ * pbus_size_io() - size the io window of a given bus
+ *
+ * @bus : the bus
+ * @min_size : the minimum io window that must to be allocated
+ * @add_size : additional optional io window
+ * @add_head : track the additional io window on this list
+ *
+ * Sizing the IO windows of the PCI-PCI bridge is trivial,
+ * since these windows have 4K granularity and the IO ranges
+ * of non-bridge PCI devices are limited to 256 bytes.
+ * We must be careful with the ISA aliasing though.
+ */
+static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
+		resource_size_t add_size, struct resource_list_x *add_head)
 {
 	struct pci_dev *dev;
 	struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO);
-	unsigned long size = 0, size1 = 0;
+	unsigned long size = 0, size0 = 0, size1 = 0;
 
 	if (!b_res)
  		return;
@@ -474,9 +577,12 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size)
 				size1 += r_size;
 		}
 	}
-	size = calculate_iosize(size, min_size, size1,
+	size0 = calculate_iosize(size, min_size, size1,
+			resource_size(b_res), 4096);
+	size1 = !add_size? size0:
+		calculate_iosize(size, min_size+add_size, size1,
 			resource_size(b_res), 4096);
-	if (!size) {
+	if (!size0 && !size1) {
 		if (b_res->start || b_res->end)
 			dev_info(&bus->self->dev, "disabling bridge window "
 				 "%pR to [bus %02x-%02x] (unused)\n", b_res,
@@ -486,17 +592,30 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size)
 	}
 	/* Alignment of the IO window is always 4K */
 	b_res->start = 4096;
-	b_res->end = b_res->start + size - 1;
+	b_res->end = b_res->start + size0 - 1;
 	b_res->flags |= IORESOURCE_STARTALIGN;
+	if (size1 > size0 && add_head)
+		add_to_list(add_head, bus->self, b_res, size1-size0);
 }
 
-/* Calculate the size of the bus and minimal alignment which
-   guarantees that all child resources fit in this size. */
+/**
+ * pbus_size_mem() - size the memory window of a given bus
+ *
+ * @bus : the bus
+ * @min_size : the minimum memory window that must to be allocated
+ * @add_size : additional optional memory window
+ * @add_head : track the additional memory window on this list
+ *
+ * Calculate the size of the bus and minimal alignment which
+ * guarantees that all child resources fit in this size.
+ */
 static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
-			 unsigned long type, resource_size_t min_size)
+			 unsigned long type, resource_size_t min_size,
+			resource_size_t add_size,
+			struct resource_list_x *add_head)
 {
 	struct pci_dev *dev;
-	resource_size_t min_align, align, size;
+	resource_size_t min_align, align, size, size0, size1;
 	resource_size_t aligns[12];	/* Alignments from 1Mb to 2Gb */
 	int order, max_order;
 	struct resource *b_res = find_free_bus_resource(bus, type);
@@ -557,8 +676,11 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
 			min_align = align1 >> 1;
 		align += aligns[order];
 	}
-	size = calculate_memsize(size, min_size, 0, resource_size(b_res), align);
-	if (!size) {
+	size0 = calculate_memsize(size, min_size, 0, resource_size(b_res), align);
+	size1 = !add_size ? size :
+		calculate_memsize(size, min_size+add_size, 0,
+				resource_size(b_res), align);
+	if (!size0 && !size1) {
 		if (b_res->start || b_res->end)
 			dev_info(&bus->self->dev, "disabling bridge window "
 				 "%pR to [bus %02x-%02x] (unused)\n", b_res,
@@ -567,9 +689,10 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
 		return 1;
 	}
 	b_res->start = min_align;
-	b_res->end = size + min_align - 1;
-	b_res->flags |= IORESOURCE_STARTALIGN;
-	b_res->flags |= mem64_mask;
+	b_res->end = size0 + min_align - 1;
+	b_res->flags |= IORESOURCE_STARTALIGN | mem64_mask;
+	if (size1 > size0 && add_head)
+		add_to_list(add_head, bus->self, b_res, size1-size0);
 	return 1;
 }
 
@@ -622,11 +745,12 @@ static void pci_bus_size_cardbus(struct pci_bus *bus)
 	}
 }
 
-void __ref pci_bus_size_bridges(struct pci_bus *bus)
+void __ref __pci_bus_size_bridges(struct pci_bus *bus,
+			struct resource_list_x *add_head)
 {
 	struct pci_dev *dev;
 	unsigned long mask, prefmask;
-	resource_size_t min_mem_size = 0, min_io_size = 0;
+	resource_size_t additional_mem_size = 0, additional_io_size = 0;
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		struct pci_bus *b = dev->subordinate;
@@ -640,7 +764,7 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus)
 
 		case PCI_CLASS_BRIDGE_PCI:
 		default:
-			pci_bus_size_bridges(b);
+			__pci_bus_size_bridges(b, add_head);
 			break;
 		}
 	}
@@ -657,11 +781,14 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus)
 	case PCI_CLASS_BRIDGE_PCI:
 		pci_bridge_check_ranges(bus);
 		if (bus->self->is_hotplug_bridge) {
-			min_io_size  = pci_hotplug_io_size;
-			min_mem_size = pci_hotplug_mem_size;
+			additional_io_size  = pci_hotplug_io_size;
+			additional_mem_size = pci_hotplug_mem_size;
 		}
+		/*
+		 * Follow thru
+		 */
 	default:
-		pbus_size_io(bus, min_io_size);
+		pbus_size_io(bus, 0, additional_io_size, add_head);
 		/* If the bridge supports prefetchable range, size it
 		   separately. If it doesn't, or its prefetchable window
 		   has already been allocated by arch code, try
@@ -669,30 +796,36 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus)
 		   resources. */
 		mask = IORESOURCE_MEM;
 		prefmask = IORESOURCE_MEM | IORESOURCE_PREFETCH;
-		if (pbus_size_mem(bus, prefmask, prefmask, min_mem_size))
+		if (pbus_size_mem(bus, prefmask, prefmask, 0, additional_mem_size, add_head))
 			mask = prefmask; /* Success, size non-prefetch only. */
 		else
-			min_mem_size += min_mem_size;
-		pbus_size_mem(bus, mask, IORESOURCE_MEM, min_mem_size);
+			additional_mem_size += additional_mem_size;
+		pbus_size_mem(bus, mask, IORESOURCE_MEM, 0, additional_mem_size, add_head);
 		break;
 	}
 }
+
+void __ref pci_bus_size_bridges(struct pci_bus *bus)
+{
+	__pci_bus_size_bridges(bus, NULL);
+}
 EXPORT_SYMBOL(pci_bus_size_bridges);
 
 static void __ref __pci_bus_assign_resources(const struct pci_bus *bus,
+					 struct resource_list_x *add_head,
 					 struct resource_list_x *fail_head)
 {
 	struct pci_bus *b;
 	struct pci_dev *dev;
 
-	pbus_assign_resources_sorted(bus, fail_head);
+	pbus_assign_resources_sorted(bus, add_head, fail_head);
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		b = dev->subordinate;
 		if (!b)
 			continue;
 
-		__pci_bus_assign_resources(b, fail_head);
+		__pci_bus_assign_resources(b, add_head, fail_head);
 
 		switch (dev->class >> 8) {
 		case PCI_CLASS_BRIDGE_PCI:
@@ -714,7 +847,7 @@ static void __ref __pci_bus_assign_resources(const struct pci_bus *bus,
 
 void __ref pci_bus_assign_resources(const struct pci_bus *bus)
 {
-	__pci_bus_assign_resources(bus, NULL);
+	__pci_bus_assign_resources(bus, NULL, NULL);
 }
 EXPORT_SYMBOL(pci_bus_assign_resources);
 
@@ -729,7 +862,7 @@ static void __ref __pci_bridge_assign_resources(const struct pci_dev *bridge,
 	if (!b)
 		return;
 
-	__pci_bus_assign_resources(b, fail_head);
+	__pci_bus_assign_resources(b, NULL, fail_head);
 
 	switch (bridge->class >> 8) {
 	case PCI_CLASS_BRIDGE_PCI:
@@ -862,17 +995,21 @@ void __init
 pci_assign_unassigned_resources(void)
 {
 	struct pci_bus *bus;
-
+	struct resource_list_x add_list; /* list of resources that
+					want additional resources */
+	add_list.next = NULL;
 	/* Depth first, calculate sizes and alignments of all
 	   subordinate buses. */
 	list_for_each_entry(bus, &pci_root_buses, node) {
-		pci_bus_size_bridges(bus);
+		__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);
+		__pci_bus_assign_resources(bus, &add_list, NULL);
 		pci_enable_bridges(bus);
 	}
+	BUG_ON(add_list.next);
 
 	/* dump the resource on buses */
 	list_for_each_entry(bus, &pci_root_buses, node) {
