PCI/ACPI: Protect acpi_pci_roots list with mutex

Use mutex to protect acpi_pci_roots list against PCI host bridge
hotplug operations.

[bhelgaas: s/struct acpi_handle *handle/acpi_handle handle/]
Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 2868a9ff6d07209a82d2d0985bbfbe0a0e67677c..e1bdcc700cbbd6518b9d7a1082b621b0fb1c1658 100644 (file)
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -112,12 +112,17 @@ EXPORT_SYMBOL(acpi_pci_unregister_driver);
 acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
 {
        struct acpi_pci_root *root;
+       acpi_handle handle = NULL;
        
+       mutex_lock(&acpi_pci_root_lock);
        list_for_each_entry(root, &acpi_pci_roots, node)
                if ((root->segment == (u16) seg) &&
-                   (root->secondary.start == (u16) bus))
-                       return root->device->handle;
-       return NULL;            
+                   (root->secondary.start == (u16) bus)) {
+                       handle = root->device->handle;
+                       break;
+               }
+       mutex_unlock(&acpi_pci_root_lock);
+       return handle;
 }
 
 EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
@@ -506,8 +511,9 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
         * TBD: Need PCI interface for enumeration/configuration of roots.
         */
 
-       /* TBD: Locking */
+       mutex_lock(&acpi_pci_root_lock);
        list_add_tail(&root->node, &acpi_pci_roots);
+       mutex_unlock(&acpi_pci_root_lock);
 
        printk(KERN_INFO PREFIX "%s [%s] (domain %04x %pR)\n",
               acpi_device_name(device), acpi_device_bid(device),
@@ -526,7 +532,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
                            "Bus %04x:%02x not present in PCI namespace\n",
                            root->segment, (unsigned int)root->secondary.start);
                result = -ENODEV;
-               goto end;
+               goto out_del_root;
        }
 
        /*
@@ -536,7 +542,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
         */
        result = acpi_pci_bind_root(device);
        if (result)
-               goto end;
+               goto out_del_root;
 
        /*
         * PCI Routing Table
@@ -614,9 +620,11 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 
        return 0;
 
+out_del_root:
+       mutex_lock(&acpi_pci_root_lock);
+       list_del(&root->node);
+       mutex_unlock(&acpi_pci_root_lock);
 end:
-       if (!list_empty(&root->node))
-               list_del(&root->node);
        kfree(root);
        return result;
 }
@@ -646,11 +654,12 @@ static int acpi_pci_root_remove(struct acpi_device *device, int type)
        list_for_each_entry(driver, &acpi_pci_drivers, node)
                if (driver->remove)
                        driver->remove(root);
-       mutex_unlock(&acpi_pci_root_lock);
 
        device_set_run_wake(root->bus->bridge, false);
        pci_acpi_remove_bus_pm_notifier(device);
 
+       list_del(&root->node);
+       mutex_unlock(&acpi_pci_root_lock);
        kfree(root);
        return 0;
 }