x86/PCI: add host bridge resource release for _CRS path

1. Allocate pci_root_info instead of using stack.  We need to pass around
   info for release function.
2. Add release_pci_root_info
3. Set x86 host bridge release function to make sure root bridge
   related resources get freed during root bus removal.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 51 insertions, 12 deletions

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index a858c1d9af53..2b74a161d215 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -315,11 +315,40 @@ static void add_resources(struct pci_root_info *info,
         }
 }
 
-static void free_pci_root_info(struct pci_root_info *info)
+static void free_pci_root_info_res(struct pci_root_info *info)
 {
         kfree(info->name);
         kfree(info->res);
-        memset(info, 0, sizeof(struct pci_root_info));
+        info->res = NULL;
+        info->res_num = 0;
+}
+
+static void __release_pci_root_info(struct pci_root_info *info)
+{
+        int i;
+        struct resource *res;
+
+        for (i = 0; i < info->res_num; i++) {
+                res = &info->res[i];
+
+                if (!res->parent)
+                        continue;
+
+                if (!(res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
+                        continue;
+
+                release_resource(res);
+        }
+
+        free_pci_root_info_res(info);
+
+        kfree(info);
+}
+static void release_pci_root_info(struct pci_host_bridge *bridge)
+{
+        struct pci_root_info *info = bridge->release_data;
+
+        __release_pci_root_info(info);
 }
 
 static void
@@ -352,7 +381,7 @@ probe_pci_root_info(struct pci_root_info *info, struct acpi_device *device,
 struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
 {
         struct acpi_device *device = root->device;
-        struct pci_root_info info;
+        struct pci_root_info *info = NULL;
         int domain = root->segment;
         int busnum = root->secondary.start;
         LIST_HEAD(resources);
@@ -397,7 +426,13 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
 
         sd->domain = domain;
         sd->node = node;
-        memset(&info, 0, sizeof(struct pci_root_info));
+        info = kzalloc(sizeof(*info), GFP_KERNEL);
+        if (!info) {
+                kfree(sd);
+                printk(KERN_WARNING "pci_bus %04x:%02x: "
+                       "ignored (out of memory)\n", domain, busnum);
+                return NULL;
+        }
         /*
          * Maybe the desired pci bus has been already scanned. In such case
          * it is unnecessary to scan the pci bus with the given domain,busnum.
@@ -409,29 +444,33 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
                  * be replaced by sd.
                  */
                 memcpy(bus->sysdata, sd, sizeof(*sd));
+                kfree(info);
                 kfree(sd);
         } else {
-                probe_pci_root_info(&info, device, busnum, domain);
+                probe_pci_root_info(info, device, busnum, domain);
 
                 /*
                  * _CRS with no apertures is normal, so only fall back to
                  * defaults or native bridge info if we're ignoring _CRS.
                  */
                 if (pci_use_crs)
-                        add_resources(&info, &resources);
+                        add_resources(info, &resources);
                 else {
-                        free_pci_root_info(&info);
+                        free_pci_root_info_res(info);
                         x86_pci_root_bus_resources(busnum, &resources);
                 }
+
                 bus = pci_create_root_bus(NULL, busnum, &pci_root_ops, sd,
                                           &resources);
-                if (bus)
+                if (bus) {
                         bus->subordinate = pci_scan_child_bus(bus);
-                else
+                        pci_set_host_bridge_release(
+                                to_pci_host_bridge(bus->bridge),
+                                release_pci_root_info, info);
+                } else {
                         pci_free_resource_list(&resources);
-
-                if (!bus && pci_use_crs)
-                        free_pci_root_info(&info);
+                        __release_pci_root_info(info);
+                }
         }
 
         /* After the PCI-E bus has been walked and all devices discovered,