1 files changed, 130 insertions, 0 deletions

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index bf5108ad4d63..417487a201fb 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -655,3 +655,133 @@ int __init acpi_pci_root_init(void)
 
         return 0;
 }
+/* Support root bridge hotplug */
+
+static void handle_root_bridge_insertion(acpi_handle handle)
+{
+        struct acpi_device *device;
+
+        if (!acpi_bus_get_device(handle, &device)) {
+                printk(KERN_DEBUG "acpi device exists...\n");
+                return;
+        }
+
+        if (acpi_bus_scan(handle))
+                printk(KERN_ERR "cannot add bridge to acpi list\n");
+}
+
+static void handle_root_bridge_removal(struct acpi_device *device)
+{
+        struct acpi_eject_event *ej_event;
+
+        ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
+        if (!ej_event) {
+                /* Inform firmware the hot-remove operation has error */
+                (void) acpi_evaluate_hotplug_ost(device->handle,
+                                        ACPI_NOTIFY_EJECT_REQUEST,
+                                        ACPI_OST_SC_NON_SPECIFIC_FAILURE,
+                                        NULL);
+                return;
+        }
+
+        ej_event->device = device;
+        ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
+
+        acpi_bus_hot_remove_device(ej_event);
+}
+
+static void _handle_hotplug_event_root(struct work_struct *work)
+{
+        struct acpi_pci_root *root;
+        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER };
+        struct acpi_hp_work *hp_work;
+        acpi_handle handle;
+        u32 type;
+
+        hp_work = container_of(work, struct acpi_hp_work, work);
+        handle = hp_work->handle;
+        type = hp_work->type;
+
+        root = acpi_pci_find_root(handle);
+
+        acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
+
+        switch (type) {
+        case ACPI_NOTIFY_BUS_CHECK:
+                /* bus enumerate */
+                printk(KERN_DEBUG "%s: Bus check notify on %s\n", __func__,
+                                 (char *)buffer.pointer);
+                if (!root)
+                        handle_root_bridge_insertion(handle);
+
+                break;
+
+        case ACPI_NOTIFY_DEVICE_CHECK:
+                /* device check */
+                printk(KERN_DEBUG "%s: Device check notify on %s\n", __func__,
+                                 (char *)buffer.pointer);
+                if (!root)
+                        handle_root_bridge_insertion(handle);
+                break;
+
+        case ACPI_NOTIFY_EJECT_REQUEST:
+                /* request device eject */
+                printk(KERN_DEBUG "%s: Device eject notify on %s\n", __func__,
+                                 (char *)buffer.pointer);
+                if (root)
+                        handle_root_bridge_removal(root->device);
+                break;
+        default:
+                printk(KERN_WARNING "notify_handler: unknown event type 0x%x for %s\n",
+                                 type, (char *)buffer.pointer);
+                break;
+        }
+
+        kfree(hp_work); /* allocated in handle_hotplug_event_bridge */
+        kfree(buffer.pointer);
+}
+
+static void handle_hotplug_event_root(acpi_handle handle, u32 type,
+                                        void *context)
+{
+        alloc_acpi_hp_work(handle, type, context,
+                                _handle_hotplug_event_root);
+}
+
+static acpi_status __init
+find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
+{
+        acpi_status status;
+        char objname[64];
+        struct acpi_buffer buffer = { .length = sizeof(objname),
+                                      .pointer = objname };
+        int *count = (int *)context;
+
+        if (!acpi_is_root_bridge(handle))
+                return AE_OK;
+
+        (*count)++;
+
+        acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
+
+        status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+                                        handle_hotplug_event_root, NULL);
+        if (ACPI_FAILURE(status))
+                printk(KERN_DEBUG "acpi root: %s notify handler is not installed, exit status: %u\n",
+                                  objname, (unsigned int)status);
+        else
+                printk(KERN_DEBUG "acpi root: %s notify handler is installed\n",
+                                 objname);
+
+        return AE_OK;
+}
+
+void __init acpi_pci_root_hp_init(void)
+{
+        int num = 0;
+
+        acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+                ACPI_UINT32_MAX, find_root_bridges, NULL, &num, NULL);
+
+        printk(KERN_DEBUG "Found %d acpi root devices\n", num);
+}