PCI: Pass bridge window to pci_bus_release_bridge_resources()

pci_bus_release_bridge_resources() takes type, which is converted into a
bridge window resource in pci_bridge_release_resources().

Find out the correct bridge window for resource whose assignment failed.
Pass that bridge window to pci_bus_release_bridge_resources() instead of
passing the type. When recursing to subordinate, check which bridge windows
have to be released and recurse for each.

For now, use pbus_select_window_for_type() instead of pbus_select_window()
because non-bridge window resources still have their flags reset which
destroys the type information from the struct resource. The struct
pci_dev_resource holds a copy of the flags which are used instead.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-24-ilpo.jarvinen@linux.intel.com

Author: ij-intel

drivers/pci/setup-bus.c

@@ -1800,51 +1800,24 @@ static void __pci_bridge_assign_resources(const struct pci_dev *bridge,
 }
 
 static void pci_bridge_release_resources(struct pci_bus *bus,
-					 unsigned long type)
+					 struct resource *b_win)
 {
 	struct pci_dev *dev = bus->self;
-	struct resource *r;
-	struct resource *b_res;
 	int idx, ret;
 
-	b_res = &dev->resource[PCI_BRIDGE_RESOURCES];
-
-	/*
-	 * 1. If IO port assignment fails, release bridge IO port.
-	 * 2. If non pref MMIO assignment fails, release bridge nonpref MMIO.
-	 * 3. If 64bit pref MMIO assignment fails, and bridge pref is 64bit,
-	 *    release bridge pref MMIO.
-	 * 4. If pref MMIO assignment fails, and bridge pref is 32bit,
-	 *    release bridge pref MMIO.
-	 * 5. If pref MMIO assignment fails, and bridge pref is not
-	 *    assigned, release bridge nonpref MMIO.
-	 */
-	if (type & IORESOURCE_IO)
-		idx = 0;
-	else if (!(type & IORESOURCE_PREFETCH))
-		idx = 1;
-	else if ((type & IORESOURCE_MEM_64) &&
-		 (b_res[2].flags & IORESOURCE_MEM_64))
-		idx = 2;
-	else if (!(b_res[2].flags & IORESOURCE_MEM_64) &&
-		 (b_res[2].flags & IORESOURCE_PREFETCH))
-		idx = 2;
-	else
-		idx = 1;
-
-	r = &b_res[idx];
-
-	if (!r->parent)
+	if (!b_win->parent)
 		return;
 
+	idx = pci_resource_num(dev, b_win);
+
 	/* If there are children, release them all */
-	release_child_resources(r);
+	release_child_resources(b_win);
 
-	ret = pci_release_resource(dev, PCI_BRIDGE_RESOURCES + idx);
+	ret = pci_release_resource(dev, idx);
 	if (ret)
 		return;
 
-	pci_setup_one_bridge_window(dev, PCI_BRIDGE_RESOURCES + idx);
+	pci_setup_one_bridge_window(dev, idx);
 }
 
 enum release_type {
@@ -1857,14 +1830,16 @@ enum release_type {
  * a larger window later.
  */
 static void pci_bus_release_bridge_resources(struct pci_bus *bus,
-					     unsigned long type,
+					     struct resource *b_win,
 					     enum release_type rel_type)
 {
 	struct pci_dev *dev;
 	bool is_leaf_bridge = true;
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		struct pci_bus *b = dev->subordinate;
+		struct resource *res;
+
 		if (!b)
 			continue;
 
@@ -1873,9 +1848,15 @@ static void pci_bus_release_bridge_resources(struct pci_bus *bus,
 		if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
 			continue;
 
-		if (rel_type == whole_subtree)
-			pci_bus_release_bridge_resources(b, type,
-						 whole_subtree);
+		if (rel_type != whole_subtree)
+			continue;
+
+		pci_bus_for_each_resource(b, res) {
+			if (res->parent != b_win)
+				continue;
+
+			pci_bus_release_bridge_resources(b, res, whole_subtree);
+		}
 	}
 
 	if (pci_is_root_bus(bus))
@@ -1885,7 +1866,7 @@ static void pci_bus_release_bridge_resources(struct pci_bus *bus,
 		return;
 
 	if ((rel_type == whole_subtree) || is_leaf_bridge)
-		pci_bridge_release_resources(bus, type);
+		pci_bridge_release_resources(bus, b_win);
 }
 
 static void pci_bus_dump_res(struct pci_bus *bus)
@@ -2282,9 +2263,13 @@ static void pci_prepare_next_assign_round(struct list_head *fail_head,
 	 * 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);
+		struct pci_bus *bus = fail_res->dev->bus;
+		struct resource *b_win;
+
+		b_win = pbus_select_window_for_type(bus, fail_res->flags);
+		if (!b_win)
+			continue;
+		pci_bus_release_bridge_resources(bus, b_win, rel_type);
 	}
 
 	/* Restore size and flags */