ACPI / dock / PCI: Drop ACPI dock notifier chain

The only user of the ACPI dock notifier chain is the ACPI-based PCI
hotplug (acpiphp) driver that uses it to carry out post-dock fixups
needed by some systems with broken _DCK.  However, it is not
necessary to use a separate notifier chain for that, as it can be
simply replaced with a new callback in struct acpi_dock_ops.

For this reason, add a new .fixup() callback to struct acpi_dock_ops
and make hotplug_dock_devices() execute it for all dock devices with
hotplug operations registered.  Accordingly, make acpiphp point that
callback to the function carrying out the post-dock fixups and
do not register a separate dock notifier for each device
registering dock operations.  Finally, drop the ACPI dock notifier
chain that has no more users.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

4 files changed, 30 insertions, 65 deletions

diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index 3e20b13fa272..c89a9c3b48b4 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -51,8 +51,6 @@ MODULE_PARM_DESC(immediate_undock, "1 (default) will cause the driver to "
         " the driver to wait for userspace to write the undock sysfs file "
         " before undocking");
 
-static struct atomic_notifier_head dock_notifier_list;
-
 static const struct acpi_device_id dock_device_ids[] = {
         {"LNXDOCK", 0},
         {"", 0},
@@ -89,6 +87,12 @@ struct dock_dependent_device {
 #define DOCK_EVENT      3
 #define UNDOCK_EVENT    2
 
+enum dock_callback_type {
+        DOCK_CALL_HANDLER,
+        DOCK_CALL_FIXUP,
+        DOCK_CALL_UEVENT,
+};
+
 /*****************************************************************************
  *                         Dock Dependent device functions                   *
  *****************************************************************************/
@@ -179,7 +183,7 @@ static void dock_release_hotplug(struct dock_dependent_device *dd)
 }
 
 static void dock_hotplug_event(struct dock_dependent_device *dd, u32 event,
-                               bool uevent)
+                               enum dock_callback_type cb_type)
 {
         acpi_notify_handler cb = NULL;
         bool run = false;
@@ -189,8 +193,18 @@ static void dock_hotplug_event(struct dock_dependent_device *dd, u32 event,
         if (dd->hp_context) {
                 run = true;
                 dd->hp_refcount++;
-                if (dd->hp_ops)
-                        cb = uevent ? dd->hp_ops->uevent : dd->hp_ops->handler;
+                if (dd->hp_ops) {
+                        switch (cb_type) {
+                        case DOCK_CALL_FIXUP:
+                                cb = dd->hp_ops->fixup;
+                                break;
+                        case DOCK_CALL_UEVENT:
+                                cb = dd->hp_ops->uevent;
+                                break;
+                        default:
+                                cb = dd->hp_ops->handler;
+                        }
+                }
         }
 
         mutex_unlock(&hotplug_lock);
@@ -372,9 +386,13 @@ static void hotplug_dock_devices(struct dock_station *ds, u32 event)
 {
         struct dock_dependent_device *dd;
 
+        /* Call driver specific post-dock fixups. */
+        list_for_each_entry(dd, &ds->dependent_devices, list)
+                dock_hotplug_event(dd, event, DOCK_CALL_FIXUP);
+
         /* Call driver specific hotplug functions. */
         list_for_each_entry(dd, &ds->dependent_devices, list)
-                dock_hotplug_event(dd, event, false);
+                dock_hotplug_event(dd, event, DOCK_CALL_HANDLER);
 
         /*
          * Now make sure that an acpi_device is created for each dependent
@@ -405,7 +423,7 @@ static void dock_event(struct dock_station *ds, u32 event, int num)
                 kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
 
         list_for_each_entry(dd, &ds->dependent_devices, list)
-                dock_hotplug_event(dd, event, true);
+                dock_hotplug_event(dd, event, DOCK_CALL_UEVENT);
 
         if (num != DOCK_EVENT)
                 kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
@@ -488,37 +506,6 @@ static int dock_in_progress(struct dock_station *ds)
 }
 
 /**
- * register_dock_notifier - add yourself to the dock notifier list
- * @nb: the callers notifier block
- *
- * If a driver wishes to be notified about dock events, they can
- * use this function to put a notifier block on the dock notifier list.
- * this notifier call chain will be called after a dock event, but
- * before hotplugging any new devices.
- */
-int register_dock_notifier(struct notifier_block *nb)
-{
-        if (!dock_station_count)
-                return -ENODEV;
-
-        return atomic_notifier_chain_register(&dock_notifier_list, nb);
-}
-EXPORT_SYMBOL_GPL(register_dock_notifier);
-
-/**
- * unregister_dock_notifier - remove yourself from the dock notifier list
- * @nb: the callers notifier block
- */
-void unregister_dock_notifier(struct notifier_block *nb)
-{
-        if (!dock_station_count)
-                return;
-
-        atomic_notifier_chain_unregister(&dock_notifier_list, nb);
-}
-EXPORT_SYMBOL_GPL(unregister_dock_notifier);
-
-/**
  * register_hotplug_dock_device - register a hotplug function
  * @handle: the handle of the device
  * @ops: handlers to call after docking
@@ -658,8 +645,6 @@ static void dock_notify(struct dock_station *ds, u32 event)
                                 complete_dock(ds);
                                 break;
                         }
-                        atomic_notifier_call_chain(&dock_notifier_list,
-                                                   event, NULL);
                         hotplug_dock_devices(ds, event);
                         complete_dock(ds);
                         dock_event(ds, event, DOCK_EVENT);
@@ -945,7 +930,6 @@ void __init acpi_dock_init(void)
                 return;
         }
 
-        ATOMIC_INIT_NOTIFIER_HEAD(&dock_notifier_list);
         pr_info(PREFIX "%s: %d docks/bays found\n",
                 ACPI_DOCK_DRIVER_DESCRIPTION, dock_station_count);
 }
diff --git a/drivers/pci/hotplug/acpiphp.h b/drivers/pci/hotplug/acpiphp.h
index 6fdd49c6f0b9..6c781edabcc6 100644
--- a/drivers/pci/hotplug/acpiphp.h
+++ b/drivers/pci/hotplug/acpiphp.h
@@ -122,7 +122,6 @@ struct acpiphp_func {
         struct acpiphp_slot *slot;      /* parent */
 
         struct list_head sibling;
-        struct notifier_block nb;
         acpi_handle     handle;
 
         u8              function;       /* pci function# */
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index a0a7133a1d12..8bfad0dc29ab 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -119,15 +119,14 @@ static void free_bridge(struct kref *kref)
  * TBD - figure out a way to only call fixups for
  * systems that require them.
  */
-static int post_dock_fixups(struct notifier_block *nb, unsigned long val,
-        void *v)
+static void post_dock_fixups(acpi_handle not_used, u32 event, void *data)
 {
-        struct acpiphp_func *func = container_of(nb, struct acpiphp_func, nb);
+        struct acpiphp_func *func = data;
         struct pci_bus *bus = func->slot->bridge->pci_bus;
         u32 buses;
 
         if (!bus->self)
-                return  NOTIFY_OK;
+                return;
 
         /* fixup bad _DCK function that rewrites
          * secondary bridge on slot
@@ -143,11 +142,11 @@ static int post_dock_fixups(struct notifier_block *nb, unsigned long val,
                         | ((unsigned int)(bus->busn_res.end) << 16);
                 pci_write_config_dword(bus->self, PCI_PRIMARY_BUS, buses);
         }
-        return NOTIFY_OK;
 }
 
 
 static const struct acpi_dock_ops acpiphp_dock_ops = {
+        .fixup = post_dock_fixups,
         .handler = hotplug_event_func,
 };
 
@@ -315,14 +314,6 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
                         &acpiphp_dock_ops, newfunc,
                         acpiphp_dock_init, acpiphp_dock_release))
                         dbg("failed to register dock device\n");
-
-                /* we need to be notified when dock events happen
-                 * outside of the hotplug operation, since we may
-                 * need to do fixups before we can hotplug.
-                 */
-                newfunc->nb.notifier_call = post_dock_fixups;
-                if (register_dock_notifier(&newfunc->nb))
-                        dbg("failed to register a dock notifier");
         }
 
         /* install notify handler */
@@ -472,7 +463,6 @@ static void cleanup_bridge(struct acpiphp_bridge *bridge)
                 list_for_each_entry(func, &slot->funcs, sibling) {
                         if (is_dock_device(func->handle)) {
                                 unregister_hotplug_dock_device(func->handle);
-                                unregister_dock_notifier(&func->nb);
                         }
                         if (!(func->flags & FUNC_HAS_DCK)) {
                                 status = acpi_remove_notify_handler(func->handle,
diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h
index 0cf85786ed21..1cedfcb1bd88 100644
--- a/include/acpi/acpi_drivers.h
+++ b/include/acpi/acpi_drivers.h
@@ -113,14 +113,13 @@ void pci_acpi_crs_quirks(void);
                                   Dock Station
   -------------------------------------------------------------------------- */
 struct acpi_dock_ops {
+        acpi_notify_handler fixup;
         acpi_notify_handler handler;
         acpi_notify_handler uevent;
 };
 
 #ifdef CONFIG_ACPI_DOCK
 extern int is_dock_device(acpi_handle handle);
-extern int register_dock_notifier(struct notifier_block *nb);
-extern void unregister_dock_notifier(struct notifier_block *nb);
 extern int register_hotplug_dock_device(acpi_handle handle,
                                         const struct acpi_dock_ops *ops,
                                         void *context,
@@ -132,13 +131,6 @@ static inline int is_dock_device(acpi_handle handle)
 {
         return 0;
 }
-static inline int register_dock_notifier(struct notifier_block *nb)
-{
-        return -ENODEV;
-}
-static inline void unregister_dock_notifier(struct notifier_block *nb)
-{
-}
 static inline int register_hotplug_dock_device(acpi_handle handle,
                                                const struct acpi_dock_ops *ops,
                                                void *context,