PCI: Clean up resource allocation in devm_of_pci_get_host_bridge_resources()

Instead of first allocating and then freeing memory for struct resource in
case we cannot parse a PCI resource from the device tree, work against a
local struct and kmemdup() it when we decide to go with it.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index d088c91..f8686c4 100644 (file)
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -266,7 +266,7 @@ int devm_of_pci_get_host_bridge_resources(struct device *dev,
                        struct list_head *resources, resource_size_t *io_base)
 {
        struct device_node *dev_node = dev->of_node;
-       struct resource *res;
+       struct resource *res, tmp_res;
        struct resource *bus_range;
        struct of_pci_range range;
        struct of_pci_range_parser parser;
@@ -320,18 +320,16 @@ int devm_of_pci_get_host_bridge_resources(struct device *dev,
                if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
                        continue;
 
-               res = devm_kzalloc(dev, sizeof(struct resource), GFP_KERNEL);
+               err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
+               if (err)
+                       continue;
+
+               res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
                if (!res) {
                        err = -ENOMEM;
                        goto failed;
                }
 
-               err = of_pci_range_to_resource(&range, dev_node, res);
-               if (err) {
-                       devm_kfree(dev, res);
-                       continue;
-               }
-
                if (resource_type(res) == IORESOURCE_IO) {
                        if (!io_base) {
                                dev_err(dev, "I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n",