diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c
index 89f957c..64aff52 100644
--- a/arch/ia64/pci/pci.c
+++ b/arch/ia64/pci/pci.c
@@ -320,9 +320,9 @@ static __devinit acpi_status add_window(struct acpi_resource *res, void *data)
 static void __devinit
 pcibios_setup_root_windows(struct pci_bus *bus, struct pci_controller *ctrl)
 {
-	int i, j;
+	int i;
 
-	j = 0;
+	pci_bus_remove_resources(bus);
 	for (i = 0; i < ctrl->windows; i++) {
 		struct resource *res = &ctrl->window[i].resource;
 		/* HP's firmware has a hack to work around a Windows bug.
@@ -330,13 +330,7 @@ pcibios_setup_root_windows(struct pci_bus *bus, struct pci_controller *ctrl)
 		if ((res->flags & IORESOURCE_MEM) &&
 		    (res->end - res->start < 16))
 			continue;
-		if (j >= PCI_BUS_NUM_RESOURCES) {
-			dev_warn(&bus->dev,
-				 "ignoring host bridge window %pR (no space)\n",
-				 res);
-			continue;
-		}
-		bus->resource[j++] = res;
+		pci_bus_add_resource(bus, res, 0);
 	}
 }
 
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 959e548..a2f8cdb 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -45,20 +45,6 @@ count_resource(struct acpi_resource *acpi_res, void *data)
 	return AE_OK;
 }
 
-static int
-bus_has_transparent_bridge(struct pci_bus *bus)
-{
-	struct pci_dev *dev;
-
-	list_for_each_entry(dev, &bus->devices, bus_list) {
-		u16 class = dev->class >> 8;
-
-		if (class == PCI_CLASS_BRIDGE_PCI && dev->transparent)
-			return true;
-	}
-	return false;
-}
-
 static void
 align_resource(struct acpi_device *bridge, struct resource *res)
 {
@@ -92,12 +78,8 @@ setup_resource(struct acpi_resource *acpi_res, void *data)
 	acpi_status status;
 	unsigned long flags;
 	struct resource *root;
-	int max_root_bus_resources = PCI_BUS_NUM_RESOURCES;
 	u64 start, end;
 
-	if (bus_has_transparent_bridge(info->bus))
-		max_root_bus_resources -= 3;
-
 	status = resource_to_addr(acpi_res, &addr);
 	if (!ACPI_SUCCESS(status))
 		return AE_OK;
@@ -115,15 +97,6 @@ setup_resource(struct acpi_resource *acpi_res, void *data)
 
 	start = addr.minimum + addr.translation_offset;
 	end = start + addr.address_length - 1;
-	if (info->res_num >= max_root_bus_resources) {
-		if (pci_probe & PCI_USE__CRS)
-			printk(KERN_WARNING "PCI: Failed to allocate "
-			       "0x%lx-0x%lx from %s for %s due to _CRS "
-			       "returning more than %d resource descriptors\n",
-			       (unsigned long) start, (unsigned long) end,
-			       root->name, info->name, max_root_bus_resources);
-		return AE_OK;
-	}
 
 	res = &info->res[info->res_num];
 	res->name = info->name;
@@ -143,7 +116,7 @@ setup_resource(struct acpi_resource *acpi_res, void *data)
 		dev_err(&info->bridge->dev,
 			"can't allocate host bridge window %pR\n", res);
 	} else {
-		info->bus->resource[info->res_num] = res;
+		pci_bus_add_resource(info->bus, res, 0);
 		info->res_num++;
 		if (addr.translation_offset)
 			dev_info(&info->bridge->dev, "host bridge window %pR "
@@ -164,7 +137,9 @@ get_current_resources(struct acpi_device *device, int busnum,
 	struct pci_root_info info;
 	size_t size;
 
-	if (!(pci_probe & PCI_USE__CRS))
+	if (pci_probe & PCI_USE__CRS)
+		pci_bus_remove_resources(bus);
+	else
 		dev_info(&device->dev,
 			 "ignoring host bridge windows from ACPI; "
 			 "boot with \"pci=use_crs\" to use them\n");
diff --git a/arch/x86/pci/bus_numa.c b/arch/x86/pci/bus_numa.c
index f939d60..12d54ff 100644
--- a/arch/x86/pci/bus_numa.c
+++ b/arch/x86/pci/bus_numa.c
@@ -36,13 +36,14 @@ void x86_pci_root_bus_res_quirks(struct pci_bus *b)
 	printk(KERN_DEBUG "PCI: peer root bus %02x res updated from pci conf\n",
 			b->number);
 
+	pci_bus_remove_resources(b);
 	info = &pci_root_info[i];
 	for (j = 0; j < info->res_num; j++) {
 		struct resource *res;
 		struct resource *root;
 
 		res = &info->res[j];
-		b->resource[j] = res;
+		pci_bus_add_resource(b, res, 0);
 		if (res->flags & IORESOURCE_IO)
 			root = &ioport_resource;
 		else
diff --git a/arch/x86/pci/bus_numa.h b/arch/x86/pci/bus_numa.h
index adbc23f..731b64e 100644
--- a/arch/x86/pci/bus_numa.h
+++ b/arch/x86/pci/bus_numa.h
@@ -2,8 +2,7 @@
 
 /*
  * sub bus (transparent) will use entres from 3 to store extra from
- * root, so need to make sure we have enough slot there, Should we
- * increase PCI_BUS_NUM_RESOURCES?
+ * root, so need to make sure we have enough slot there.
  */
 #define RES_NUM 16
 struct pci_root_info {
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index e75d219..712250f 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -17,6 +17,52 @@
 
 #include "pci.h"
 
+void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
+			  unsigned int flags)
+{
+	struct pci_bus_resource *bus_res;
+
+	bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
+	if (!bus_res) {
+		dev_err(&bus->dev, "can't add %pR resource\n", res);
+		return;
+	}
+
+	bus_res->res = res;
+	bus_res->flags = flags;
+	list_add_tail(&bus_res->list, &bus->resources);
+}
+
+struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
+{
+	struct pci_bus_resource *bus_res;
+
+	if (n < PCI_BRIDGE_RESOURCE_NUM)
+		return bus->resource[n];
+
+	n -= PCI_BRIDGE_RESOURCE_NUM;
+	list_for_each_entry(bus_res, &bus->resources, list) {
+		if (n-- == 0)
+			return bus_res->res;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(pci_bus_resource_n);
+
+void pci_bus_remove_resources(struct pci_bus *bus)
+{
+	struct pci_bus_resource *bus_res, *tmp;
+	int i;
+
+	for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
+		bus->resource[i] = 0;
+
+	list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
+		list_del(&bus_res->list);
+		kfree(bus_res);
+	}
+}
+
 /**
  * pci_bus_alloc_resource - allocate a resource from a parent bus
  * @bus: PCI bus
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 70c4ed2..270d069 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -89,6 +89,7 @@ static void release_pcibus_dev(struct device *dev)
 
 	if (pci_bus->bridge)
 		put_device(pci_bus->bridge);
+	pci_bus_remove_resources(pci_bus);
 	kfree(pci_bus);
 }
 
@@ -394,6 +395,7 @@ static void __devinit pci_read_bridge_mmio_pref(struct pci_bus *child)
 void __devinit pci_read_bridge_bases(struct pci_bus *child)
 {
 	struct pci_dev *dev = child->self;
+	struct resource *res;
 	int i;
 
 	if (pci_is_root_bus(child))	/* It's a host bus, nothing to read */
@@ -403,17 +405,23 @@ void __devinit pci_read_bridge_bases(struct pci_bus *child)
 		 child->secondary, child->subordinate,
 		 dev->transparent ? " (subtractive decode)" : "");
 
+	pci_bus_remove_resources(child);
+	for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
+		child->resource[i] = &dev->resource[PCI_BRIDGE_RESOURCES+i];
+
 	pci_read_bridge_io(child);
 	pci_read_bridge_mmio(child);
 	pci_read_bridge_mmio_pref(child);
 
 	if (dev->transparent) {
-		for (i = 3; i < PCI_BUS_NUM_RESOURCES; i++) {
-			child->resource[i] = child->parent->resource[i - 3];
-			if (child->resource[i])
+		pci_bus_for_each_resource(child->parent, res, i) {
+			if (res) {
+				pci_bus_add_resource(child, res,
+						     PCI_SUBTRACTIVE_DECODE);
 				dev_printk(KERN_DEBUG, &dev->dev,
 					   "  bridge window %pR (subtractive decode)\n",
-					   child->resource[i]);
+					   res);
+			}
 		}
 	}
 }
@@ -428,6 +436,7 @@ static struct pci_bus * pci_alloc_bus(void)
 		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;
 	}
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8891d3b..2af5eab 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -363,9 +363,26 @@ static inline void pci_add_saved_cap(struct pci_dev *pci_dev,
 	hlist_add_head(&new_cap->next, &pci_dev->saved_cap_space);
 }
 
-#ifndef PCI_BUS_NUM_RESOURCES
-#define PCI_BUS_NUM_RESOURCES	16
-#endif
+/*
+ * The first PCI_BRIDGE_RESOURCE_NUM PCI bus resources (those that correspond
+ * to P2P or CardBus bridge windows) go in a table.  Additional ones (for
+ * buses below host bridges or subtractive decode bridges) go in the list.
+ * Use pci_bus_for_each_resource() to iterate through all the resources.
+ */
+
+/*
+ * PCI_SUBTRACTIVE_DECODE means the bridge forwards the window implicitly
+ * and there's no way to program the bridge with the details of the window.
+ * This does not apply to ACPI _CRS windows, even with the _DEC subtractive-
+ * decode bit set, because they are explicit and can be programmed with _SRS.
+ */
+#define PCI_SUBTRACTIVE_DECODE	0x1
+
+struct pci_bus_resource {
+	struct list_head list;
+	struct resource *res;
+	unsigned int flags;
+};
 
 #define PCI_REGION_FLAG_MASK	0x0fU	/* These bits of resource flags tell us the PCI region flags */
 
@@ -376,8 +393,8 @@ struct pci_bus {
 	struct list_head devices;	/* list of devices on this bus */
 	struct pci_dev	*self;		/* bridge device as seen by parent */
 	struct list_head slots;		/* list of slots on this bus */
-	struct resource	*resource[PCI_BUS_NUM_RESOURCES];
-					/* address space routed to this bus */
+	struct resource *resource[PCI_BRIDGE_RESOURCE_NUM];
+	struct list_head resources;	/* address space routed to this bus */
 
 	struct pci_ops	*ops;		/* configuration access functions */
 	void		*sysdata;	/* hook for sys-specific extension */
@@ -828,8 +845,14 @@ int pci_request_selected_regions_exclusive(struct pci_dev *, int, const char *);
 void pci_release_selected_regions(struct pci_dev *, int);
 
 /* drivers/pci/bus.c */
+void pci_bus_add_resource(struct pci_bus *bus, struct resource *res, unsigned int flags);
+struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n);
+void pci_bus_remove_resources(struct pci_bus *bus);
+
 #define pci_bus_for_each_resource(bus, res, i)				\
-	for (i = 0; res = bus->resource[i], i < PCI_BUS_NUM_RESOURCES; i++)
+	for (i = 0;							\
+	    (res = pci_bus_resource_n(bus, i)) || i < PCI_BRIDGE_RESOURCE_NUM; \
+	     i++)
 
 int __must_check pci_bus_alloc_resource(struct pci_bus *bus,
 			struct resource *res, resource_size_t size,
