1 files changed, 40 insertions, 4 deletions

diff --git a/drivers/of/address.c b/drivers/of/address.c
index 327a57410797..afdb78299f61 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -295,14 +295,50 @@ struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
 }
 EXPORT_SYMBOL_GPL(of_pci_range_parser_one);
 
-void of_pci_range_to_resource(struct of_pci_range *range,
-			      struct device_node *np, struct resource *res)
+/*
+ * of_pci_range_to_resource - Create a resource from an of_pci_range
+ * @range:	the PCI range that describes the resource
+ * @np:		device node where the range belongs to
+ * @res:	pointer to a valid resource that will be updated to
+ *              reflect the values contained in the range.
+ *
+ * Returns EINVAL if the range cannot be converted to resource.
+ *
+ * Note that if the range is an IO range, the resource will be converted
+ * using pci_address_to_pio() which can fail if it is called too early or
+ * if the range cannot be matched to any host bridge IO space (our case here).
+ * To guard against that we try to register the IO range first.
+ * If that fails we know that pci_address_to_pio() will do too.
+ */
+int of_pci_range_to_resource(struct of_pci_range *range,
+			     struct device_node *np, struct resource *res)
 {
+	int err;
 	res->flags = range->flags;
-	res->start = range->cpu_addr;
-	res->end = range->cpu_addr + range->size - 1;
 	res->parent = res->child = res->sibling = NULL;
 	res->name = np->full_name;
+
+	if (res->flags & IORESOURCE_IO) {
+		unsigned long port;
+		err = pci_register_io_range(range->cpu_addr, range->size);
+		if (err)
+			goto invalid_range;
+		port = pci_address_to_pio(range->cpu_addr);
+		if (port == (unsigned long)-1) {
+			err = -EINVAL;
+			goto invalid_range;
+		}
+		res->start = port;
+	} else {
+		res->start = range->cpu_addr;
+	}
+	res->end = res->start + range->size - 1;
+	return 0;
+
+invalid_range:
+	res->start = (resource_size_t)OF_BAD_ADDR;
+	res->end = (resource_size_t)OF_BAD_ADDR;
+	return err;
 }
 #endif /* CONFIG_PCI */