PCI: Convert maintaining FW-assigned BIOS BAR values to a list of temporary entries

index 51a9095..ad8c4ae 100644
@@ -164,15 +164,18 @@ static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
 	resource_size_t start, end;
 	int ret = 0;
 
-	if (res->flags & IORESOURCE_IO)
-		root = &ioport_resource;
-	else
-		root = &iomem_resource;
-
 	start = res->start;
 	end = res->end;
 	res->start = dev->fw_addr[resno];
 	res->end = res->start + size - 1;
+
+	root = pci_find_parent_resource(dev, res);
+	if (!root)
+		if (res->flags & IORESOURCE_IO)
+			root = &ioport_resource;
+		else
+			root = &iomem_resource;
+
 	dev_info(&dev->dev, "BAR %d: trying firmware assignment %pR\n",
 		 resno, res);
 	conflict = request_resource_conflict(root, res);

index ad8c4ae..ab45c11 100644
@@ -26,6 +26,79 @@
 #include "pci.h"
 
 
+/*
+ * This list of dynamic mappings is for temporarly maintaining
+ * original BIOS BAR addresses for possbile reinstatement.
+ */
+struct pci_fwaddrmap {
+	struct list_head list;
+	struct pci_dev *dev;
+	resource_size_t fw_addr[DEVICE_COUNT_RESOURCE];
+	unsigned long refcount;
+};
+
+static LIST_HEAD(pci_fwaddrmappings);
+static DEFINE_SPINLOCK(pci_fwaddrmap_lock);
+
+/* Must be called with 'pci_fwaddrmap_lock' lock held. */
+static struct pci_fwaddrmap *pci_fwaddrmap_lookup(struct pci_dev *dev)
+{
+	struct pci_fwaddrmap *map;
+
+	list_for_each_entry(map, &pci_fwaddrmappings, list)
+		if (map->dev == dev)
+			return map;
+
+	return NULL;
+}
+
+void pci_save_fw_addr(struct pci_dev *dev, int idx, resource_size_t fw_addr)
+{
+	unsigned long flags;
+	struct pci_fwaddrmap *map;
+
+	spin_lock_irqsave(&pci_fwaddrmap_lock, flags);
+	map = pci_fwaddrmap_lookup(dev);
+	if (!map) {
+		spin_unlock_irqrestore(&pci_fwaddrmap_lock, flags);
+		map = kzalloc(sizeof(*map), GFP_KERNEL);
+		if (!map)
+			return;
+
+		INIT_LIST_HEAD(&map->list);
+		map->dev = dev;
+		map->fw_addr[idx] = fw_addr;
+
+		spin_lock_irqsave(&pci_fwaddrmap_lock, flags);
+		list_add_tail(&map->list, &pci_fwaddrmappings);
+	} else {
+		map->fw_addr[idx] = fw_addr;
+	}
+	map->refcount++;
+	spin_unlock_irqrestore(&pci_fwaddrmap_lock, flags);
+}
+
+static resource_size_t pci_retrieve_fw_addr(struct pci_dev *dev, int idx)
+{
+	unsigned long flags;
+	resource_size_t fw_addr = 0;
+	struct pci_fwaddrmap *map;
+
+	spin_lock_irqsave(&pci_fwaddrmap_lock, flags);
+	map = pci_fwaddrmap_lookup(dev);
+	if (map) {
+		fw_addr = map->fw_addr[idx];
+
+		if (!--map->refcount) {
+			list_del(&map->list);
+			kfree(map);
+		}
+	}
+	spin_unlock_irqrestore(&pci_fwaddrmap_lock, flags);
+
+	return fw_addr;
+}
+
 void pci_update_resource(struct pci_dev *dev, int resno)
 {
 	struct pci_bus_region region;

index 84225c7..14f2492 100644
@@ -889,6 +889,7 @@ ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void
 int pci_vpd_truncate(struct pci_dev *dev, size_t size);
 
 /* Helper functions for low-level code (drivers/pci/setup-[bus,res].c) */
+void pci_save_fw_addr(struct pci_dev *dev, int idx, resource_size_t fw_addr);
 void pci_bus_assign_resources(const struct pci_bus *bus);
 void pci_bus_size_bridges(struct pci_bus *bus);
 int pci_claim_resource(struct pci_dev *, int);

index 494f2e7..99ba108 100644
@@ -181,7 +181,7 @@ static void __init pcibios_allocate_resources(int pass)
 					idx, r, disabled, pass);
 				if (pci_claim_resource(dev, idx) < 0) {
 					/* We'll assign a new address later */
-					dev->fw_addr[idx] = r->start;
+					pci_save_fw_addr(dev, idx, r->start);
 					r->end -= r->start;
 					r->start = 0;
 				}

index ab45c11..7e4711e 100644
@@ -231,7 +231,7 @@ static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
 }
 
 static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev, 
-		int resno, resource_size_t size)
+		int resno, resource_size_t fw_addr, resource_size_t size)
 {
 	struct resource *root, *conflict;
 	resource_size_t start, end;

@@ -239,7 +239,7 @@ static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
 
 	start = res->start;
 	end = res->end;
-	res->start = dev->fw_addr[resno];
+	res->start = fw_addr;
 	res->end = res->start + size - 1;
 
 	root = pci_find_parent_resource(dev, res);

@@ -322,7 +322,7 @@ int pci_reassign_resource(struct pci_dev *dev, int resno, resource_size_t addsiz
 int pci_assign_resource(struct pci_dev *dev, int resno)
 {
 	struct resource *res = dev->resource + resno;
-	resource_size_t align, size;
+	resource_size_t align, fw_addr, size;
 	struct pci_bus *bus;
 	int ret;
 

@@ -342,8 +342,12 @@ int pci_assign_resource(struct pci_dev *dev, int resno)
 	 * where firmware left it.  That at least has a chance of
 	 * working, which is better than just leaving it disabled.
 	 */
-	if (ret < 0 && dev->fw_addr[resno])
-		ret = pci_revert_fw_address(res, dev, resno, size);
+	if (ret < 0) {
+		fw_addr = pci_retrieve_fw_addr(dev, resno);
+		if (fw_addr)
+			ret = pci_revert_fw_address(res, dev, resno, fw_addr,
+						    size);
+	}
 
 	if (!ret) {
 		res->flags &= ~IORESOURCE_STARTALIGN;

index 14f2492..5a5d2fc 100644
@@ -299,7 +299,6 @@ struct pci_dev {
 	 */
 	unsigned int	irq;
 	struct resource resource[DEVICE_COUNT_RESOURCE]; /* I/O and memory regions + expansion ROMs */
-	resource_size_t	fw_addr[DEVICE_COUNT_RESOURCE]; /* FW-assigned addr */
 
 	/* These fields are used by common fixups */
 	unsigned int	transparent:1;	/* Transparent PCI bridge */