1 files changed, 100 insertions, 36 deletions

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 522e25d725ba..7ec2ee3fe909 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -2372,18 +2372,16 @@ EXPORT_SYMBOL_GPL(pci_assign_unassigned_bridge_resources);
  * release it when possible. If the bridge window contains assigned
  * resources, it cannot be released.
  */
-int pbus_reassign_bridge_resources(struct pci_bus *bus, struct resource *res)
+static int pbus_reassign_bridge_resources(struct pci_bus *bus, struct resource *res,
+					  struct list_head *saved)
 {
 	unsigned long type = res->flags;
 	struct pci_dev_resource *dev_res;
-	struct pci_dev *bridge;
-	LIST_HEAD(saved);
+	struct pci_dev *bridge = NULL;
 	LIST_HEAD(added);
 	LIST_HEAD(failed);
 	unsigned int i;
-	int ret;
-
-	down_read(&pci_bus_sem);
+	int ret = 0;
 
 	while (!pci_is_root_bus(bus)) {
 		bridge = bus->self;
@@ -2395,9 +2393,9 @@ int pbus_reassign_bridge_resources(struct pci_bus *bus, struct resource *res)
 
 		/* Ignore BARs which are still in use */
 		if (!res->child) {
-			ret = add_to_list(&saved, bridge, res, 0, 0);
+			ret = add_to_list(saved, bridge, res, 0, 0);
 			if (ret)
-				goto cleanup;
+				return ret;
 
 			pci_release_resource(bridge, i);
 		} else {
@@ -2411,10 +2409,8 @@ int pbus_reassign_bridge_resources(struct pci_bus *bus, struct resource *res)
 		bus = bus->parent;
 	}
 
-	if (list_empty(&saved)) {
-		up_read(&pci_bus_sem);
+	if (!bridge)
 		return -ENOENT;
-	}
 
 	__pci_bus_size_bridges(bridge->subordinate, &added);
 	__pci_bridge_assign_resources(bridge, &added, &failed);
@@ -2422,54 +2418,122 @@ int pbus_reassign_bridge_resources(struct pci_bus *bus, struct resource *res)
 		free_list(&added);
 
 	if (!list_empty(&failed)) {
-		if (pci_required_resource_failed(&failed, type)) {
+		if (pci_required_resource_failed(&failed, type))
 			ret = -ENOSPC;
-			goto cleanup;
-		}
-		/* Only resources with unrelated types failed (again) */
 		free_list(&failed);
+		if (ret)
+			return ret;
+
+		/* Only resources with unrelated types failed (again) */
 	}
 
-	list_for_each_entry(dev_res, &saved, list) {
+	list_for_each_entry(dev_res, saved, list) {
+		struct pci_dev *dev = dev_res->dev;
+
 		/* Skip the bridge we just assigned resources for */
-		if (bridge == dev_res->dev)
+		if (bridge == dev)
+			continue;
+
+		if (!dev->subordinate)
 			continue;
 
-		bridge = dev_res->dev;
-		pci_setup_bridge(bridge->subordinate);
+		pci_setup_bridge(dev->subordinate);
 	}
 
-	free_list(&saved);
-	up_read(&pci_bus_sem);
 	return 0;
+}
 
-cleanup:
-	/* Restore size and flags */
-	list_for_each_entry(dev_res, &failed, list)
-		restore_dev_resource(dev_res);
-	free_list(&failed);
+int pci_do_resource_release_and_resize(struct pci_dev *pdev, int resno, int size,
+				       int exclude_bars)
+{
+	struct resource *res = pci_resource_n(pdev, resno);
+	struct pci_dev_resource *dev_res;
+	struct pci_bus *bus = pdev->bus;
+	struct resource *b_win, *r;
+	LIST_HEAD(saved);
+	unsigned int i;
+	int old, ret;
+
+	b_win = pbus_select_window(bus, res);
+	if (!b_win)
+		return -EINVAL;
+
+	old = pci_rebar_get_current_size(pdev, resno);
+	if (old < 0)
+		return old;
+
+	ret = pci_rebar_set_size(pdev, resno, size);
+	if (ret)
+		return ret;
+
+	pci_dev_for_each_resource(pdev, r, i) {
+		if (i >= PCI_BRIDGE_RESOURCES)
+			break;
+
+		if (exclude_bars & BIT(i))
+			continue;
+
+		if (b_win != pbus_select_window(bus, r))
+			continue;
+
+		ret = add_to_list(&saved, pdev, r, 0, 0);
+		if (ret)
+			goto restore;
+		pci_release_resource(pdev, i);
+	}
+
+	pci_resize_resource_set_size(pdev, resno, size);
+
+	if (!bus->self)
+		goto out;
+
+	down_read(&pci_bus_sem);
+	ret = pbus_reassign_bridge_resources(bus, res, &saved);
+	if (ret)
+		goto restore;
+
+out:
+	up_read(&pci_bus_sem);
+	free_list(&saved);
+	return ret;
+
+restore:
+	/*
+	 * Revert to the old configuration.
+	 *
+	 * BAR Size must be restored first because it affects the read-only
+	 * bits in BAR (the old address might not be restorable otherwise
+	 * due to low address bits).
+	 */
+	pci_rebar_set_size(pdev, resno, old);
 
-	/* Revert to the old configuration */
 	list_for_each_entry(dev_res, &saved, list) {
 		struct resource *res = dev_res->res;
+		struct pci_dev *dev = dev_res->dev;
 
-		bridge = dev_res->dev;
-		i = pci_resource_num(bridge, res);
+		i = pci_resource_num(dev, res);
 
 		if (res->parent) {
 			release_child_resources(res);
-			pci_release_resource(bridge, i);
+			pci_release_resource(dev, i);
 		}
 
 		restore_dev_resource(dev_res);
 
-		pci_claim_resource(bridge, i);
-		pci_setup_bridge(bridge->subordinate);
-	}
-	free_list(&saved);
-	up_read(&pci_bus_sem);
+		if (pci_claim_resource(dev, i))
+			continue;
 
-	return ret;
+		if (i < PCI_BRIDGE_RESOURCES) {
+			const char *res_name = pci_resource_name(dev, i);
+
+			pci_update_resource(dev, i);
+			pci_info(dev, "%s %pR: old value restored\n",
+				 res_name, res);
+		}
+		if (dev->subordinate)
+			pci_setup_bridge(dev->subordinate);
+	}
+	goto out;
 }
 
 void pci_assign_unassigned_bus_resources(struct pci_bus *bus)