mn10300/PCI: Clip bridge windows to fit in upstream windows

Every PCI-PCI bridge window should fit inside an upstream bridge window
because orphaned address space is unreachable from the primary side of the
upstream bridge. If we inherit invalid bridge windows that overlap an
upstream window from firmware, clip them to fit and update the bridge
accordingly.

[bhelgaas: changelog]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=85491
Reported-by: Marek Kordik <[e-mail]>
Fixes: 5b28541552ef ("PCI: Restrict 64-bit prefetchable bridge windows to 64-bit resources")
Signed-off-by: Yinghai Lu <[e-mail]>
Signed-off-by: Bjorn Helgaas <[e-mail]>
CC: David Howells <[e-mail]>
CC: Koichi Yasutake <[e-mail]>
CC: [e-mail]

arch/mn10300/unit-asb2305/pci-asb2305.c

···
 				if (!r->flags)
 					continue;
 				if (!r->start ||
-				    pci_claim_resource(dev, idx) < 0) {
+				    pci_claim_bridge_resource(dev, idx) < 0) {
 					printk(KERN_ERR "PCI:"
 					       " Cannot allocate resource"
 					       " region %d of bridge %s\n",

arch/mn10300/unit-asb2305/pci.c

···
 	return -ENODEV;
 }
 
-static int is_valid_resource(struct pci_dev *dev, int idx)
-{
-	unsigned int i, type_mask = IORESOURCE_IO | IORESOURCE_MEM;
-	struct resource *devr = &dev->resource[idx], *busr;
-
-	if (dev->bus) {
-		pci_bus_for_each_resource(dev->bus, busr, i) {
-			if (!busr || (busr->flags ^ devr->flags) & type_mask)
-				continue;
-
-			if (devr->start &&
-			    devr->start >= busr->start &&
-			    devr->end <= busr->end)
-				return 1;
-		}
-	}
-
-	return 0;
-}
-
 static void pcibios_fixup_device_resources(struct pci_dev *dev)
 {
-	int limit, i;
+	int idx;
 
-	if (dev->bus->number != 0)
+	if (!dev->bus)
 		return;
 
-	limit = (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) ?
-		PCI_BRIDGE_RESOURCES : PCI_NUM_RESOURCES;
+	for (idx = 0; idx < PCI_BRIDGE_RESOURCES; idx++) {
+		struct resource *r = &dev->resource[idx];
 
-	for (i = 0; i < limit; i++) {
-		if (!dev->resource[i].flags)
+		if (!r->flags || r->parent || !r->start)
 			continue;
 
-		if (is_valid_resource(dev, i))
-			pci_claim_resource(dev, i);
+		pci_claim_resource(dev, idx);
+	}
+}
+
+static void pcibios_fixup_bridge_resources(struct pci_dev *dev)
+{
+	int idx;
+
+	if (!dev->bus)
+		return;
+
+	for (idx = PCI_BRIDGE_RESOURCES; idx < PCI_NUM_RESOURCES; idx++) {
+		struct resource *r = &dev->resource[idx];
+
+		if (!r->flags || r->parent || !r->start)
+			continue;
+
+		pci_claim_bridge_resource(dev, idx);
 	}
 }
 
···
 
 	if (bus->self) {
 		pci_read_bridge_bases(bus);
-		pcibios_fixup_device_resources(bus->self);
+		pcibios_fixup_bridge_resources(bus->self);
 	}
 
 	list_for_each_entry(dev, &bus->devices, bus_list)