ACPI: Remove the arguments of acpi_bus_add() that are not used

Notice that acpi_bus_add() uses only 2 of its 4 arguments and
redefine its header to match the body.  Update all of its callers as
necessary and observe that this leads to quite a number of removed
lines of code (Linus will like that).

Add a kerneldoc comment documenting acpi_bus_add() and wonder how
its callers make wrong assumptions about the second argument (make
note to self to take care of that later).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Toshi Kani <toshi.kani@hp.com>

5 files changed, 26 insertions, 80 deletions

diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index eb30e5ab4cab..d0a7da704d49 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -157,34 +157,17 @@ static int
 acpi_memory_get_device(acpi_handle handle,
                        struct acpi_memory_device **mem_device)
 {
-        acpi_status status;
-        acpi_handle phandle;
         struct acpi_device *device = NULL;
-        struct acpi_device *pdevice = NULL;
         int result;
 
-
         if (!acpi_bus_get_device(handle, &device) && device)
                 goto end;
 
-        status = acpi_get_parent(handle, &phandle);
-        if (ACPI_FAILURE(status)) {
-                ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
-                return -EINVAL;
-        }
-
-        /* Get the parent device */
-        result = acpi_bus_get_device(phandle, &pdevice);
-        if (result) {
-                acpi_handle_warn(phandle, "Cannot get acpi bus device\n");
-                return -EINVAL;
-        }
-
         /*
          * Now add the notified device.  This creates the acpi_device
          * and invokes .add function
          */
-        result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
+        result = acpi_bus_add(handle, &device);
         if (result) {
                 acpi_handle_warn(handle, "Cannot add acpi bus\n");
                 return -EINVAL;
diff --git a/drivers/acpi/container.c b/drivers/acpi/container.c
index 98b85e3e4781..0688f83bc436 100644
--- a/drivers/acpi/container.c
+++ b/drivers/acpi/container.c
@@ -135,20 +135,6 @@ static int acpi_container_remove(struct acpi_device *device, int type)
         return status;
 }
 
-static int container_device_add(struct acpi_device **device, acpi_handle handle)
-{
-        acpi_handle phandle;
-        struct acpi_device *pdev;
-
-        if (acpi_get_parent(handle, &phandle))
-                return -ENODEV;
-
-        if (acpi_bus_get_device(phandle, &pdev))
-                return -ENODEV;
-
-        return acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_DEVICE);
-}
-
 static void container_notify_cb(acpi_handle handle, u32 type, void *context)
 {
         struct acpi_device *device = NULL;
@@ -180,7 +166,7 @@ static void container_notify_cb(acpi_handle handle, u32 type, void *context)
                 if (!ACPI_FAILURE(status) || device)
                         break;
 
-                result = container_device_add(&device, handle);
+                result = acpi_bus_add(handle, &device);
                 if (result) {
                         acpi_handle_warn(handle, "Failed to add container\n");
                         break;
diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index f32bd47b35e0..ff30582d2e1d 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -310,8 +310,6 @@ static int dock_present(struct dock_station *ds)
 static struct acpi_device * dock_create_acpi_device(acpi_handle handle)
 {
         struct acpi_device *device;
-        struct acpi_device *parent_device;
-        acpi_handle parent;
         int ret;
 
         if (acpi_bus_get_device(handle, &device)) {
@@ -319,16 +317,9 @@ static struct acpi_device * dock_create_acpi_device(acpi_handle handle)
                  * no device created for this object,
                  * so we should create one.
                  */
-                acpi_get_parent(handle, &parent);
-                if (acpi_bus_get_device(parent, &parent_device))
-                        parent_device = NULL;
-
-                ret = acpi_bus_add(&device, parent_device, handle,
-                        ACPI_BUS_TYPE_DEVICE);
-                if (ret) {
+                ret = acpi_bus_add(handle, &device);
+                if (ret)
                         pr_debug("error adding bus, %x\n", -ret);
-                        return NULL;
-                }
         }
         return device;
 }
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index e83311bf1ebd..18b292e12b38 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -677,28 +677,6 @@ static int is_processor_present(acpi_handle handle)
         return 0;
 }
 
-static
-int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
-{
-        acpi_handle phandle;
-        struct acpi_device *pdev;
-
-
-        if (acpi_get_parent(handle, &phandle)) {
-                return -ENODEV;
-        }
-
-        if (acpi_bus_get_device(phandle, &pdev)) {
-                return -ENODEV;
-        }
-
-        if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR)) {
-                return -ENODEV;
-        }
-
-        return 0;
-}
-
 static void acpi_processor_hotplug_notify(acpi_handle handle,
                                           u32 event, void *data)
 {
@@ -721,7 +699,7 @@ static void acpi_processor_hotplug_notify(acpi_handle handle,
                 if (!acpi_bus_get_device(handle, &device))
                         break;
 
-                result = acpi_processor_device_add(handle, &device);
+                result = acpi_bus_add(handle, &device);
                 if (result) {
                         acpi_handle_err(handle, "Unable to add the device\n");
                         break;
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 6321cab4e5ff..25095bf57bba 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1650,25 +1650,33 @@ static int acpi_bus_scan(acpi_handle handle, bool start,
         return ret;
 }
 
-/*
- * acpi_bus_add
+/**
+ * acpi_bus_add - Add ACPI device node objects in a given namespace scope.
+ * @handle: Root of the namespace scope to scan.
+ * @ret: Location to store a return struct acpi_device pointer.
+ *
+ * Scan a given ACPI tree (probably recently hot-plugged) and create and add
+ * found devices.
  *
- * scan a given ACPI tree and (probably recently hot-plugged)
- * create and add found devices.
+ * If no devices were found, -ENODEV is returned, but it does not mean that
+ * there has been a real error.  There just have been no suitable ACPI objects
+ * in the table trunk from which the kernel could create a device and add an
+ * appropriate driver.
  *
- * If no devices were found -ENODEV is returned which does not
- * mean that this is a real error, there just have been no suitable
- * ACPI objects in the table trunk from which the kernel could create
- * a device and add an appropriate driver.
+ * If 0 is returned, the memory location pointed to by @ret will be populated
+ * with a pointer to a struct acpi_device created while scanning the namespace.
+ * If @handle corresponds to a device node, that will be a pointer to the struct
+ * acpi_device object corresponding to @handle.  Otherwise, it will be a pointer
+ * to a struct acpi_device corresponding to one of its descendants.
+ *
+ * If an error code is returned, NULL will be stored in the memory location
+ * pointed to by @ret.
  */
-
-int
-acpi_bus_add(struct acpi_device **child,
-             struct acpi_device *parent, acpi_handle handle, int type)
+int acpi_bus_add(acpi_handle handle, struct acpi_device **ret)
 {
         int err;
 
-        err = acpi_bus_scan(handle, false, child);
+        err = acpi_bus_scan(handle, false, ret);
         if (err)
                 return err;