PCI: Consolidate assignment loop next round preparation

pci_assign_unassigned_root_bus_resources() and
pci_assign_unassigned_bridge_resources() have a loop that may perform
several rounds to assign resources. The code to prepare for the next round
is identical.

Consolidate the code that prepares for the next assignment round into
pci_prepare_next_assign_round().

Link: https://lore.kernel.org/r/20241216175632.4175-17-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Xiaochun Lee <lixc17@lenovo.com>

1 files changed, 42 insertions, 62 deletions

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index badfecd599d8..41f1d5129cac 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -2134,6 +2134,45 @@ pci_root_bus_distribute_available_resources(struct pci_bus *bus,
 	}
 }
 
+static void pci_prepare_next_assign_round(struct list_head *fail_head,
+					  int tried_times,
+					  enum release_type rel_type)
+{
+	struct pci_dev_resource *fail_res;
+
+	pr_info("PCI: No. %d try to assign unassigned res\n", tried_times + 1);
+
+	/*
+	 * Try to release leaf bridge's resources that aren't big
+	 * enough to contain child device resources.
+	 */
+	list_for_each_entry(fail_res, fail_head, list) {
+		pci_bus_release_bridge_resources(fail_res->dev->bus,
+						 fail_res->flags & PCI_RES_TYPE_MASK,
+						 rel_type);
+	}
+
+	/* Restore size and flags */
+	list_for_each_entry(fail_res, fail_head, list) {
+		struct resource *res = fail_res->res;
+		struct pci_dev *dev = fail_res->dev;
+		int idx = pci_resource_num(dev, res);
+
+		res->start = fail_res->start;
+		res->end = fail_res->end;
+		res->flags = fail_res->flags;
+
+		if (!pci_is_bridge(dev))
+			continue;
+
+		if (idx >= PCI_BRIDGE_RESOURCES &&
+		    idx <= PCI_BRIDGE_RESOURCE_END)
+			res->flags = 0;
+	}
+
+	free_list(fail_head);
+}
+
 /*
  * First try will not touch PCI bridge res.
  * Second and later try will clear small leaf bridge res.
@@ -2147,7 +2186,6 @@ void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
 	int tried_times = 0;
 	enum release_type rel_type = leaf_only;
 	LIST_HEAD(fail_head);
-	struct pci_dev_resource *fail_res;
 	int pci_try_num = 1;
 	enum enable_type enable_local;
 
@@ -2198,40 +2236,11 @@ void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
 			break;
 		}
 
-		dev_info(&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)
 			rel_type = whole_subtree;
 
-		/*
-		 * Try to release leaf bridge's resources that doesn't fit
-		 * resource of child device under that bridge.
-		 */
-		list_for_each_entry(fail_res, &fail_head, list) {
-			pci_bus_release_bridge_resources(fail_res->dev->bus,
-							 fail_res->flags & PCI_RES_TYPE_MASK,
-							 rel_type);
-		}
-
-		/* Restore size and flags */
-		list_for_each_entry(fail_res, &fail_head, list) {
-			struct resource *res = fail_res->res;
-			int idx;
-
-			res->start = fail_res->start;
-			res->end = fail_res->end;
-			res->flags = fail_res->flags;
-
-			if (pci_is_bridge(fail_res->dev)) {
-				idx = pci_resource_num(fail_res->dev, res);
-				if (idx >= PCI_BRIDGE_RESOURCES &&
-				    idx <= PCI_BRIDGE_RESOURCE_END)
-					res->flags = 0;
-			}
-		}
-		free_list(&fail_head);
+		pci_prepare_next_assign_round(&fail_head, tried_times, rel_type);
 	}
 
 	pci_bus_dump_resources(bus);
@@ -2257,7 +2266,6 @@ void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
 	LIST_HEAD(add_list);
 	int tried_times = 0;
 	LIST_HEAD(fail_head);
-	struct pci_dev_resource *fail_res;
 	int ret;
 
 	while (1) {
@@ -2283,36 +2291,8 @@ void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
 			break;
 		}
 
-		printk(KERN_DEBUG "PCI: No. %d try to assign unassigned res\n",
-				 tried_times + 1);
-
-		/*
-		 * Try to release leaf bridge's resources that aren't big
-		 * enough to contain child device resources.
-		 */
-		list_for_each_entry(fail_res, &fail_head, list) {
-			pci_bus_release_bridge_resources(fail_res->dev->bus,
-							 fail_res->flags & PCI_RES_TYPE_MASK,
-							 whole_subtree);
-		}
-
-		/* Restore size and flags */
-		list_for_each_entry(fail_res, &fail_head, list) {
-			struct resource *res = fail_res->res;
-			int idx;
-
-			res->start = fail_res->start;
-			res->end = fail_res->end;
-			res->flags = fail_res->flags;
-
-			if (pci_is_bridge(fail_res->dev)) {
-				idx = pci_resource_num(fail_res->dev, res);
-				if (idx >= PCI_BRIDGE_RESOURCES &&
-				    idx <= PCI_BRIDGE_RESOURCE_END)
-					res->flags = 0;
-			}
-		}
-		free_list(&fail_head);
+		pci_prepare_next_assign_round(&fail_head, tried_times,
+					      whole_subtree);
 	}
 
 	ret = pci_reenable_device(bridge);