ia64/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 <kordikmarek@gmail.com>
Fixes: 5b28541552ef ("PCI: Restrict 64-bit prefetchable bridge windows to 64-bit resources")
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Tony Luck <tony.luck@intel.com>
CC: Fenghua Yu <fenghua.yu@intel.com>
CC: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
CC: linux-ia64@vger.kernel.org

arch/ia64/pci/pci.c

@@ -487,45 +487,39 @@ int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
 	return 0;
 }
 
-static int is_valid_resource(struct pci_dev *dev, int idx)
+void pcibios_fixup_device_resources(struct pci_dev *dev)
 {
-	unsigned int i, type_mask = IORESOURCE_IO | IORESOURCE_MEM;
-	struct resource *devr = &dev->resource[idx], *busr;
+	int idx;
 
 	if (!dev->bus)
-		return 0;
-
-	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;
-}
+		return;
 
-static void pcibios_fixup_resources(struct pci_dev *dev, int start, int limit)
-{
-	int i;
+	for (idx = 0; idx < PCI_BRIDGE_RESOURCES; idx++) {
+		struct resource *r = &dev->resource[idx];
 
-	for (i = start; 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);
-	}
-}
 
-void pcibios_fixup_device_resources(struct pci_dev *dev)
-{
-	pcibios_fixup_resources(dev, 0, PCI_BRIDGE_RESOURCES);
+		pci_claim_resource(dev, idx);
+	}
 }
 EXPORT_SYMBOL_GPL(pcibios_fixup_device_resources);
 
 static void pcibios_fixup_bridge_resources(struct pci_dev *dev)
 {
-	pcibios_fixup_resources(dev, PCI_BRIDGE_RESOURCES, PCI_NUM_RESOURCES);
+	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);
+	}
 }
 
 /*