Changes in uspace/srv/devman/main.c [80a96d2:7beb220] in mainline

File:

• uspace/srv/devman/main.c (modified) (32 diffs)

uspace/srv/devman/main.c

@@ -65 +65 @@
 static dev_tree_t device_tree;
 
-static int init_running_drv(void *drv);
-
 /** Register running driver. */
-static driver_t *devman_driver_register(ipc_callid_t callid, ipc_call_t *call)
-{
+static driver_t *devman_driver_register(void)
+{
+        ipc_call_t icall;
+        ipc_callid_t iid;
         driver_t *driver = NULL;
+
+        log_msg(LVL_DEBUG, "devman_driver_register");
+        
+        iid = async_get_call(&icall);
+        if (IPC_GET_IMETHOD(icall) != DEVMAN_DRIVER_REGISTER) {
+                async_answer_0(iid, EREFUSED);
+                return NULL;
+        }
+        
         char *drv_name = NULL;
-
-        log_msg(LVL_DEBUG, "devman_driver_register");
         
         /* Get driver name. */
         int rc = async_data_write_accept((void **) &drv_name, true, 0, 0, 0, 0);
         if (rc != EOK) {
-                async_answer_0(callid, rc);
+                async_answer_0(iid, rc);
                 return NULL;
         }
@@ -91 +98 @@
                 free(drv_name);
                 drv_name = NULL;
-                async_answer_0(callid, ENOENT);
+                async_answer_0(iid, ENOENT);
                 return NULL;
         }
@@ -105 +112 @@
                     driver->name);
                 fibril_mutex_unlock(&driver->driver_mutex);
-                async_answer_0(callid, EEXISTS);
+                async_answer_0(iid, EEXISTS);
                 return NULL;
         }
@@ -127 +134 @@
         log_msg(LVL_DEBUG, "Creating connection to the `%s' driver.",
             driver->name);
-        driver->sess = async_callback_receive(EXCHANGE_PARALLEL);
+        driver->sess = async_callback_receive(EXCHANGE_SERIALIZE);
         if (!driver->sess) {
                 fibril_mutex_unlock(&driver->driver_mutex);
-                async_answer_0(callid, ENOTSUP);
+                async_answer_0(iid, ENOTSUP);
                 return NULL;
         }
-        /* FIXME: Work around problem with callback sessions */
-        async_sess_args_set(driver->sess, DRIVER_DEVMAN, 0, 0);
+        
+        fibril_mutex_unlock(&driver->driver_mutex);
         
         log_msg(LVL_NOTE,
             "The `%s' driver was successfully registered as running.",
             driver->name);
+        
+        async_answer_0(iid, EOK);
+        
+        return driver;
+}
+
+/** Receive device match ID from the device's parent driver and add it to the
+ * list of devices match ids.
+ *
+ * @param match_ids     The list of the device's match ids.
+ * @return              Zero on success, negative error code otherwise.
+ */
+static int devman_receive_match_id(match_id_list_t *match_ids)
+{
+        match_id_t *match_id = create_match_id();
+        ipc_callid_t callid;
+        ipc_call_t call;
+        int rc = 0;
+        
+        callid = async_get_call(&call);
+        if (DEVMAN_ADD_MATCH_ID != IPC_GET_IMETHOD(call)) {
+                log_msg(LVL_ERROR, 
+                    "Invalid protocol when trying to receive match id.");
+                async_answer_0(callid, EINVAL); 
+                delete_match_id(match_id);
+                return EINVAL;
+        }
+        
+        if (match_id == NULL) {
+                log_msg(LVL_ERROR, "Failed to allocate match id.");
+                async_answer_0(callid, ENOMEM);
+                return ENOMEM;
+        }
+        
+        async_answer_0(callid, EOK);
+        
+        match_id->score = IPC_GET_ARG1(call);
+        
+        char *match_id_str;
+        rc = async_data_write_accept((void **) &match_id_str, true, 0, 0, 0, 0);
+        match_id->id = match_id_str;
+        if (rc != EOK) {
+                delete_match_id(match_id);
+                log_msg(LVL_ERROR, "Failed to receive match id string: %s.",
+                    str_error(rc));
+                return rc;
+        }
+        
+        list_append(&match_id->link, &match_ids->ids);
+        
+        log_msg(LVL_DEBUG, "Received match id `%s', score %d.",
+            match_id->id, match_id->score);
+        return rc;
+}
+
+/** Receive device match IDs from the device's parent driver and add them to the
+ * list of devices match ids.
+ *
+ * @param match_count   The number of device's match ids to be received.
+ * @param match_ids     The list of the device's match ids.
+ * @return              Zero on success, negative error code otherwise.
+ */
+static int devman_receive_match_ids(sysarg_t match_count,
+    match_id_list_t *match_ids)
+{
+        int ret = EOK;
+        size_t i;
+        
+        for (i = 0; i < match_count; i++) {
+                if (EOK != (ret = devman_receive_match_id(match_ids)))
+                        return ret;
+        }
+        return ret;
+}
+
+static int assign_driver_fibril(void *arg)
+{
+        dev_node_t *dev_node = (dev_node_t *) arg;
+        assign_driver(dev_node, &drivers_list, &device_tree);
+        return EOK;
+}
+
+/** Handle function registration.
+ *
+ * Child devices are registered by their parent's device driver.
+ */
+static void devman_add_function(ipc_callid_t callid, ipc_call_t *call)
+{
+        fun_type_t ftype = (fun_type_t) IPC_GET_ARG1(*call);
+        devman_handle_t dev_handle = IPC_GET_ARG2(*call);
+        sysarg_t match_count = IPC_GET_ARG3(*call);
+        dev_tree_t *tree = &device_tree;
+        
+        fibril_rwlock_write_lock(&tree->rwlock);
+
+        dev_node_t *dev = NULL;
+        dev_node_t *pdev = find_dev_node_no_lock(&device_tree, dev_handle);
+        
+        if (pdev == NULL) {
+                fibril_rwlock_write_unlock(&tree->rwlock);
+                async_answer_0(callid, ENOENT);
+                return;
+        }
+        
+        if (ftype != fun_inner && ftype != fun_exposed) {
+                /* Unknown function type */
+                log_msg(LVL_ERROR, 
+                    "Unknown function type %d provided by driver.",
+                    (int) ftype);
+
+                fibril_rwlock_write_unlock(&tree->rwlock);
+                async_answer_0(callid, EINVAL);
+                return;
+        }
+        
+        char *fun_name = NULL;
+        int rc = async_data_write_accept((void **)&fun_name, true, 0, 0, 0, 0);
+        if (rc != EOK) {
+                fibril_rwlock_write_unlock(&tree->rwlock);
+                async_answer_0(callid, rc);
+                return;
+        }
+        
+        /* Check that function with same name is not there already. */
+        if (find_fun_node_in_device(pdev, fun_name) != NULL) {
+                fibril_rwlock_write_unlock(&tree->rwlock);
+                async_answer_0(callid, EEXISTS);
+                printf(NAME ": Warning, driver tried to register `%s' twice.\n",
+                    fun_name);
+                free(fun_name);
+                return;
+        }
+        
+        fun_node_t *fun = create_fun_node();
+        fun->ftype = ftype;
+        
+        if (!insert_fun_node(&device_tree, fun, fun_name, pdev)) {
+                fibril_rwlock_write_unlock(&tree->rwlock);
+                delete_fun_node(fun);
+                async_answer_0(callid, ENOMEM);
+                return;
+        }
+
+        if (ftype == fun_inner) {
+                dev = create_dev_node();
+                if (dev == NULL) {
+                        fibril_rwlock_write_unlock(&tree->rwlock);
+                        delete_fun_node(fun);
+                        async_answer_0(callid, ENOMEM);
+                        return;
+                }
+
+                insert_dev_node(tree, dev, fun);
+        }
+
+        fibril_rwlock_write_unlock(&tree->rwlock);
+        
+        log_msg(LVL_DEBUG, "devman_add_function(fun=\"%s\")", fun->pathname);
+        
+        devman_receive_match_ids(match_count, &fun->match_ids);
+
+        if (ftype == fun_inner) {
+                assert(dev != NULL);
+                /*
+                 * Try to find a suitable driver and assign it to the device.  We do
+                 * not want to block the current fibril that is used for processing
+                 * incoming calls: we will launch a separate fibril to handle the
+                 * driver assigning. That is because assign_driver can actually include
+                 * task spawning which could take some time.
+                 */
+                fid_t assign_fibril = fibril_create(assign_driver_fibril, dev);
+                if (assign_fibril == 0) {
+                        /*
+                         * Fallback in case we are out of memory.
+                         * Probably not needed as we will die soon anyway ;-).
+                         */
+                        (void) assign_driver_fibril(fun);
+                } else {
+                        fibril_add_ready(assign_fibril);
+                }
+        } else {
+                loc_register_tree_function(fun, tree);
+        }
+        
+        /* Return device handle to parent's driver. */
+        async_answer_1(callid, EOK, fun->handle);
+}
+
+static void devman_add_function_to_cat(ipc_callid_t callid, ipc_call_t *call)
+{
+        devman_handle_t handle = IPC_GET_ARG1(*call);
+        category_id_t cat_id;
+        int rc;
+        
+        /* Get category name. */
+        char *cat_name;
+        rc = async_data_write_accept((void **) &cat_name, true,
+            0, 0, 0, 0);
+        if (rc != EOK) {
+                async_answer_0(callid, rc);
+                return;
+        }       
+        
+        fun_node_t *fun = find_fun_node(&device_tree, handle);
+        if (fun == NULL) {
+                async_answer_0(callid, ENOENT);
+                return;
+        }
+        
+        rc = loc_category_get_id(cat_name, &cat_id, IPC_FLAG_BLOCKING);
+        if (rc == EOK) {
+                loc_service_add_to_cat(fun->service_id, cat_id);
+        } else {
+                log_msg(LVL_ERROR, "Failed adding function `%s' to category "
+                    "`%s'.", fun->pathname, cat_name);
+        }
+        
+        log_msg(LVL_NOTE, "Function `%s' added to category `%s'.",
+            fun->pathname, cat_name);
+
+        async_answer_0(callid, EOK);
+}
+
+/** Remove function. */
+static void devman_remove_function(ipc_callid_t callid, ipc_call_t *call)
+{
+        devman_handle_t fun_handle = IPC_GET_ARG1(*call);
+        dev_tree_t *tree = &device_tree;
+        int rc;
+        
+        fibril_rwlock_write_lock(&tree->rwlock);
+        
+        fun_node_t *fun = find_fun_node_no_lock(&device_tree, fun_handle);
+        if (fun == NULL) {
+                fibril_rwlock_write_unlock(&tree->rwlock);
+                async_answer_0(callid, ENOENT);
+                return;
+        }
+        
+        log_msg(LVL_DEBUG, "devman_remove_function(fun='%s')", fun->pathname);
+        
+        if (fun->ftype == fun_inner) {
+                /* Handle possible descendants */
+                /* TODO */
+                log_msg(LVL_WARN, "devman_remove_function(): not handling "
+                    "descendants\n");
+        } else {
+                /* Unregister from location service */
+                rc = loc_service_unregister(fun->service_id);
+                if (rc != EOK) {
+                        log_msg(LVL_ERROR, "Failed unregistering tree service.");
+                        fibril_rwlock_write_unlock(&tree->rwlock);
+                        async_answer_0(callid, EIO);
+                        return;
+                }
+        }
+        
+        remove_fun_node(&device_tree, fun);
+        fibril_rwlock_write_unlock(&tree->rwlock);
+        delete_fun_node(fun);
+        
+        log_msg(LVL_DEBUG, "devman_remove_function() succeeded.");
+        async_answer_0(callid, EOK);
+}
+
+/** Initialize driver which has registered itself as running and ready.
+ *
+ * The initialization is done in a separate fibril to avoid deadlocks (if the
+ * driver needed to be served by devman during the driver's initialization).
+ */
+static int init_running_drv(void *drv)
+{
+        driver_t *driver = (driver_t *) drv;
+        
+        initialize_running_driver(driver, &device_tree);
+        log_msg(LVL_DEBUG, "The `%s` driver was successfully initialized.",
+            driver->name);
+        return 0;
+}
+
+/** Function for handling connections from a driver to the device manager. */
+static void devman_connection_driver(ipc_callid_t iid, ipc_call_t *icall)
+{
+        /* Accept the connection. */
+        async_answer_0(iid, EOK);
+        
+        driver_t *driver = devman_driver_register();
+        if (driver == NULL)
+                return;
         
         /*
@@ -149 +445 @@
                 log_msg(LVL_ERROR, "Failed to create initialization fibril " \
                     "for driver `%s'.", driver->name);
-                fibril_mutex_unlock(&driver->driver_mutex);
-                async_answer_0(callid, ENOMEM);
-                return NULL;
-        }
-        
+                return;
+        }
         fibril_add_ready(fid);
-        fibril_mutex_unlock(&driver->driver_mutex);
-        
-        async_answer_0(callid, EOK);
-        return driver;
-}
-
-/** Receive device match ID from the device's parent driver and add it to the
- * list of devices match ids.
- *
- * @param match_ids     The list of the device's match ids.
- * @return              Zero on success, negative error code otherwise.
- */
-static int devman_receive_match_id(match_id_list_t *match_ids)
-{
-        match_id_t *match_id = create_match_id();
-        ipc_callid_t callid;
-        ipc_call_t call;
-        int rc = 0;
-        
-        callid = async_get_call(&call);
-        if (DEVMAN_ADD_MATCH_ID != IPC_GET_IMETHOD(call)) {
-                log_msg(LVL_ERROR, 
-                    "Invalid protocol when trying to receive match id.");
-                async_answer_0(callid, EINVAL); 
-                delete_match_id(match_id);
-                return EINVAL;
-        }
-        
-        if (match_id == NULL) {
-                log_msg(LVL_ERROR, "Failed to allocate match id.");
-                async_answer_0(callid, ENOMEM);
-                return ENOMEM;
-        }
-        
-        async_answer_0(callid, EOK);
-        
-        match_id->score = IPC_GET_ARG1(call);
-        
-        char *match_id_str;
-        rc = async_data_write_accept((void **) &match_id_str, true, 0, 0, 0, 0);
-        match_id->id = match_id_str;
-        if (rc != EOK) {
-                delete_match_id(match_id);
-                log_msg(LVL_ERROR, "Failed to receive match id string: %s.",
-                    str_error(rc));
-                return rc;
-        }
-        
-        list_append(&match_id->link, &match_ids->ids);
-        
-        log_msg(LVL_DEBUG, "Received match id `%s', score %d.",
-            match_id->id, match_id->score);
-        return rc;
-}
-
-/** Receive device match IDs from the device's parent driver and add them to the
- * list of devices match ids.
- *
- * @param match_count   The number of device's match ids to be received.
- * @param match_ids     The list of the device's match ids.
- * @return              Zero on success, negative error code otherwise.
- */
-static int devman_receive_match_ids(sysarg_t match_count,
-    match_id_list_t *match_ids)
-{
-        int ret = EOK;
-        size_t i;
-        
-        for (i = 0; i < match_count; i++) {
-                if (EOK != (ret = devman_receive_match_id(match_ids)))
-                        return ret;
-        }
-        return ret;
-}
-
-static int assign_driver_fibril(void *arg)
-{
-        dev_node_t *dev_node = (dev_node_t *) arg;
-        assign_driver(dev_node, &drivers_list, &device_tree);
-
-        /* Delete one reference we got from the caller. */
-        dev_del_ref(dev_node);
-        return EOK;
-}
-
-static int online_function(fun_node_t *fun)
-{
-        dev_node_t *dev;
-        
-        fibril_rwlock_write_lock(&device_tree.rwlock);
-
-        if (fun->state == FUN_ON_LINE) {
-                fibril_rwlock_write_unlock(&device_tree.rwlock);
-                log_msg(LVL_WARN, "Function %s is already on line.",
-                    fun->pathname);
-                return EOK;
-        }
-        
-        if (fun->ftype == fun_inner) {
-                dev = create_dev_node();
-                if (dev == NULL) {
-                        fibril_rwlock_write_unlock(&device_tree.rwlock);
-                        return ENOMEM;
-                }
-
-                insert_dev_node(&device_tree, dev, fun);
-                dev_add_ref(dev);
-        }
-        
-        log_msg(LVL_DEBUG, "devman_add_function(fun=\"%s\")", fun->pathname);
-        
-        if (fun->ftype == fun_inner) {
-                dev = fun->child;
-                assert(dev != NULL);
-                
-                /* Give one reference over to assign_driver_fibril(). */
-                dev_add_ref(dev);
-                /*
-                 * Try to find a suitable driver and assign it to the device.  We do
-                 * not want to block the current fibril that is used for processing
-                 * incoming calls: we will launch a separate fibril to handle the
-                 * driver assigning. That is because assign_driver can actually include
-                 * task spawning which could take some time.
-                 */
-                fid_t assign_fibril = fibril_create(assign_driver_fibril, dev);
-                if (assign_fibril == 0) {
-                        log_msg(LVL_ERROR, "Failed to create fibril for "
-                            "assigning driver.");
-                        /* XXX Cleanup */
-                        fibril_rwlock_write_unlock(&device_tree.rwlock);
-                        return ENOMEM;
-                }
-                fibril_add_ready(assign_fibril);
-        } else {
-                loc_register_tree_function(fun, &device_tree);
-        }
-        
-        fibril_rwlock_write_unlock(&device_tree.rwlock);
-        
-        return EOK;
-}
-
-static int offline_function(fun_node_t *fun)
-{
-        int rc;
-        
-        fibril_rwlock_write_lock(&device_tree.rwlock);
-        
-        if (fun->state == FUN_OFF_LINE) {
-                fibril_rwlock_write_unlock(&device_tree.rwlock);
-                log_msg(LVL_WARN, "Function %s is already off line.",
-                    fun->pathname);
-                return EOK;
-        }
-        
-        if (fun->ftype == fun_inner) {
-                log_msg(LVL_DEBUG, "Offlining inner function %s.",
-                    fun->pathname);
-                
-                if (fun->child != NULL) {
-                        dev_node_t *dev = fun->child;
-                        device_state_t dev_state;
-                        
-                        dev_add_ref(dev);
-                        dev_state = dev->state;
-                        
-                        fibril_rwlock_write_unlock(&device_tree.rwlock);
-
-                        /* If device is owned by driver, ask driver to give it up. */
-                        if (dev_state == DEVICE_USABLE) {
-                                rc = driver_dev_remove(&device_tree, dev);
-                                if (rc != EOK) {
-                                        dev_del_ref(dev);
-                                        return ENOTSUP;
-                                }
-                        }
-                        
-                        /* Verify that driver removed all functions */
-                        fibril_rwlock_read_lock(&device_tree.rwlock);
-                        if (!list_empty(&dev->functions)) {
-                                fibril_rwlock_read_unlock(&device_tree.rwlock);
-                                dev_del_ref(dev);
-                                return EIO;
-                        }
-                        
-                        driver_t *driver = dev->drv;
-                        fibril_rwlock_read_unlock(&device_tree.rwlock);
-                        
-                        if (driver)
-                                detach_driver(&device_tree, dev);
-                        
-                        fibril_rwlock_write_lock(&device_tree.rwlock);
-                        remove_dev_node(&device_tree, dev);
-                        
-                        /* Delete ref created when node was inserted */
-                        dev_del_ref(dev);
-                        /* Delete ref created by dev_add_ref(dev) above */
-                        dev_del_ref(dev);
-                }
-        } else {
-                /* Unregister from location service */
-                rc = loc_service_unregister(fun->service_id);
-                if (rc != EOK) {
-                        fibril_rwlock_write_unlock(&device_tree.rwlock);
-                        log_msg(LVL_ERROR, "Failed unregistering tree service.");
-                        return EIO;
-                }
-                
-                fun->service_id = 0;
-        }
-        
-        fun->state = FUN_OFF_LINE;
-        fibril_rwlock_write_unlock(&device_tree.rwlock);
-        
-        return EOK;
-}
-
-/** Handle function registration.
- *
- * Child devices are registered by their parent's device driver.
- */
-static void devman_add_function(ipc_callid_t callid, ipc_call_t *call)
-{
-        fun_type_t ftype = (fun_type_t) IPC_GET_ARG1(*call);
-        devman_handle_t dev_handle = IPC_GET_ARG2(*call);
-        sysarg_t match_count = IPC_GET_ARG3(*call);
-        dev_tree_t *tree = &device_tree;
-        
-        dev_node_t *pdev = find_dev_node(&device_tree, dev_handle);
-        if (pdev == NULL) {
-                async_answer_0(callid, ENOENT);
-                return;
-        }
-        
-        if (ftype != fun_inner && ftype != fun_exposed) {
-                /* Unknown function type */
-                log_msg(LVL_ERROR, 
-                    "Unknown function type %d provided by driver.",
-                    (int) ftype);
-
-                dev_del_ref(pdev);
-                async_answer_0(callid, EINVAL);
-                return;
-        }
-        
-        char *fun_name = NULL;
-        int rc = async_data_write_accept((void **)&fun_name, true, 0, 0, 0, 0);
-        if (rc != EOK) {
-                dev_del_ref(pdev);
-                async_answer_0(callid, rc);
-                return;
-        }
-        
-        fibril_rwlock_write_lock(&tree->rwlock);
-        
-        /* Check device state */
-        if (pdev->state == DEVICE_REMOVED) {
-                fibril_rwlock_write_unlock(&tree->rwlock);
-                dev_del_ref(pdev);
-                async_answer_0(callid, ENOENT);
-                return;
-        }
-        
-        /* Check that function with same name is not there already. */
-        if (find_fun_node_in_device(tree, pdev, fun_name) != NULL) {
-                fibril_rwlock_write_unlock(&tree->rwlock);
-                dev_del_ref(pdev);
-                async_answer_0(callid, EEXISTS);
-                printf(NAME ": Warning, driver tried to register `%s' twice.\n",
-                    fun_name);
-                free(fun_name);
-                return;
-        }
-        
-        fun_node_t *fun = create_fun_node();
-        fun_add_ref(fun);
-        fun->ftype = ftype;
-        
-        if (!insert_fun_node(&device_tree, fun, fun_name, pdev)) {
-                fibril_rwlock_write_unlock(&tree->rwlock);
-                dev_del_ref(pdev);
-                delete_fun_node(fun);
-                async_answer_0(callid, ENOMEM);
-                return;
-        }
-        
-        fibril_rwlock_write_unlock(&tree->rwlock);
-        dev_del_ref(pdev);
-        
-        devman_receive_match_ids(match_count, &fun->match_ids);
-        
-        rc = online_function(fun);
-        if (rc != EOK) {
-                /* XXX clean up */
-                async_answer_0(callid, rc);
-                return;
-        }
-        
-        /* Return device handle to parent's driver. */
-        async_answer_1(callid, EOK, fun->handle);
-}
-
-static void devman_add_function_to_cat(ipc_callid_t callid, ipc_call_t *call)
-{
-        devman_handle_t handle = IPC_GET_ARG1(*call);
-        category_id_t cat_id;
-        int rc;
-        
-        /* Get category name. */
-        char *cat_name;
-        rc = async_data_write_accept((void **) &cat_name, true,
-            0, 0, 0, 0);
-        if (rc != EOK) {
-                async_answer_0(callid, rc);
-                return;
-        }
-        
-        fun_node_t *fun = find_fun_node(&device_tree, handle);
-        if (fun == NULL) {
-                async_answer_0(callid, ENOENT);
-                return;
-        }
-        
-        fibril_rwlock_read_lock(&device_tree.rwlock);
-        
-        /* Check function state */
-        if (fun->state == FUN_REMOVED) {
-                fibril_rwlock_read_unlock(&device_tree.rwlock);
-                async_answer_0(callid, ENOENT);
-                return;
-        }
-        
-        rc = loc_category_get_id(cat_name, &cat_id, IPC_FLAG_BLOCKING);
-        if (rc == EOK) {
-                loc_service_add_to_cat(fun->service_id, cat_id);
-        } else {
-                log_msg(LVL_ERROR, "Failed adding function `%s' to category "
-                    "`%s'.", fun->pathname, cat_name);
-        }
-        
-        log_msg(LVL_NOTE, "Function `%s' added to category `%s'.",
-            fun->pathname, cat_name);
-
-        fibril_rwlock_read_unlock(&device_tree.rwlock);
-        fun_del_ref(fun);
-
-        async_answer_0(callid, EOK);
-}
-
-/** Online function by driver request.
- *
- */
-static void devman_drv_fun_online(ipc_callid_t iid, ipc_call_t *icall,
-    driver_t *drv)
-{
-        fun_node_t *fun;
-        int rc;
-        
-        log_msg(LVL_DEBUG, "devman_drv_fun_online()");
-        
-        fun = find_fun_node(&device_tree, IPC_GET_ARG1(*icall));
-        if (fun == NULL) {
-                async_answer_0(iid, ENOENT);
-                return;
-        }
-        
-        fibril_rwlock_read_lock(&device_tree.rwlock);
-        if (fun->dev == NULL || fun->dev->drv != drv) {
-                fibril_rwlock_read_unlock(&device_tree.rwlock);
-                fun_del_ref(fun);
-                async_answer_0(iid, ENOENT);
-                return;
-        }
-        fibril_rwlock_read_unlock(&device_tree.rwlock);
-        
-        rc = online_function(fun);
-        if (rc != EOK) {
-                fun_del_ref(fun);
-                async_answer_0(iid, (sysarg_t) rc);
-                return;
-        }
-        
-        fun_del_ref(fun);
-        
-        async_answer_0(iid, (sysarg_t) EOK);
-}
-
-
-/** Offline function by driver request.
- *
- */
-static void devman_drv_fun_offline(ipc_callid_t iid, ipc_call_t *icall,
-    driver_t *drv)
-{
-        fun_node_t *fun;
-        int rc;
-
-        fun = find_fun_node(&device_tree, IPC_GET_ARG1(*icall));
-        if (fun == NULL) {
-                async_answer_0(iid, ENOENT);
-                return;
-        }
-        
-        fibril_rwlock_write_lock(&device_tree.rwlock);
-        if (fun->dev == NULL || fun->dev->drv != drv) {
-                fun_del_ref(fun);
-                async_answer_0(iid, ENOENT);
-                return;
-        }
-        fibril_rwlock_write_unlock(&device_tree.rwlock);
-        
-        rc = offline_function(fun);
-        if (rc != EOK) {
-                fun_del_ref(fun);
-                async_answer_0(iid, (sysarg_t) rc);
-                return;
-        }
-        
-        fun_del_ref(fun);
-        async_answer_0(iid, (sysarg_t) EOK);
-}
-
-/** Remove function. */
-static void devman_remove_function(ipc_callid_t callid, ipc_call_t *call)
-{
-        devman_handle_t fun_handle = IPC_GET_ARG1(*call);
-        dev_tree_t *tree = &device_tree;
-        int rc;
-        
-        fun_node_t *fun = find_fun_node(&device_tree, fun_handle);
-        if (fun == NULL) {
-                async_answer_0(callid, ENOENT);
-                return;
-        }
-        
-        fibril_rwlock_write_lock(&tree->rwlock);
-        
-        log_msg(LVL_DEBUG, "devman_remove_function(fun='%s')", fun->pathname);
-        
-        /* Check function state */
-        if (fun->state == FUN_REMOVED) {
-                fibril_rwlock_write_unlock(&tree->rwlock);
-                async_answer_0(callid, ENOENT);
-                return;
-        }
-        
-        if (fun->ftype == fun_inner) {
-                /* This is a surprise removal. Handle possible descendants */
-                if (fun->child != NULL) {
-                        dev_node_t *dev = fun->child;
-                        device_state_t dev_state;
-                        int gone_rc;
-                        
-                        dev_add_ref(dev);
-                        dev_state = dev->state;
-                        
-                        fibril_rwlock_write_unlock(&device_tree.rwlock);
-                        
-                        /* If device is owned by driver, inform driver it is gone. */
-                        if (dev_state == DEVICE_USABLE)
-                                gone_rc = driver_dev_gone(&device_tree, dev);
-                        else
-                                gone_rc = EOK;
-                        
-                        fibril_rwlock_read_lock(&device_tree.rwlock);
-                        
-                        /* Verify that driver succeeded and removed all functions */
-                        if (gone_rc != EOK || !list_empty(&dev->functions)) {
-                                log_msg(LVL_ERROR, "Driver did not remove "
-                                    "functions for device that is gone. "
-                                    "Device node is now defunct.");
-                                
-                                /*
-                                 * Not much we can do but mark the device
-                                 * node as having invalid state. This
-                                 * is a driver bug.
-                                 */
-                                dev->state = DEVICE_INVALID;
-                                fibril_rwlock_read_unlock(&device_tree.rwlock);
-                                dev_del_ref(dev);
-                                return;
-                        }
-                        
-                        driver_t *driver = dev->drv;
-                        fibril_rwlock_read_unlock(&device_tree.rwlock);
-                        
-                        if (driver)
-                                detach_driver(&device_tree, dev);
-                        
-                        fibril_rwlock_write_lock(&device_tree.rwlock);
-                        remove_dev_node(&device_tree, dev);
-                        
-                        /* Delete ref created when node was inserted */
-                        dev_del_ref(dev);
-                        /* Delete ref created by dev_add_ref(dev) above */
-                        dev_del_ref(dev);
-                }
-        } else {
-                if (fun->service_id != 0) {
-                        /* Unregister from location service */
-                        rc = loc_service_unregister(fun->service_id);
-                        if (rc != EOK) {
-                                log_msg(LVL_ERROR, "Failed unregistering tree "
-                                    "service.");
-                                fibril_rwlock_write_unlock(&tree->rwlock);
-                                fun_del_ref(fun);
-                                async_answer_0(callid, EIO);
-                                return;
-                        }
-                }
-        }
-        
-        remove_fun_node(&device_tree, fun);
-        fibril_rwlock_write_unlock(&tree->rwlock);
-        
-        /* Delete ref added when inserting function into tree */
-        fun_del_ref(fun);
-        /* Delete ref added above when looking up function */
-        fun_del_ref(fun);
-        
-        log_msg(LVL_DEBUG, "devman_remove_function() succeeded.");
-        async_answer_0(callid, EOK);
-}
-
-/** Initialize driver which has registered itself as running and ready.
- *
- * The initialization is done in a separate fibril to avoid deadlocks (if the
- * driver needed to be served by devman during the driver's initialization).
- */
-static int init_running_drv(void *drv)
-{
-        driver_t *driver = (driver_t *) drv;
-        
-        initialize_running_driver(driver, &device_tree);
-        log_msg(LVL_DEBUG, "The `%s` driver was successfully initialized.",
-            driver->name);
-        return 0;
-}
-
-/** Function for handling connections from a driver to the device manager. */
-static void devman_connection_driver(ipc_callid_t iid, ipc_call_t *icall)
-{
-        client_t *client;
-        driver_t *driver;
-        
-        /* Accept the connection. */
-        async_answer_0(iid, EOK);
-        
-        client = async_get_client_data();
-        if (client == NULL) {
-                log_msg(LVL_ERROR, "Failed to allocate client data.");
-                return;
-        }
         
         while (true) {
@@ -716 +456 @@
                         break;
                 
-                if (IPC_GET_IMETHOD(call) != DEVMAN_DRIVER_REGISTER) {
-                        fibril_mutex_lock(&client->mutex);
-                        driver = client->driver;
-                        fibril_mutex_unlock(&client->mutex);
-                        if (driver == NULL) {
-                                /* First call must be to DEVMAN_DRIVER_REGISTER */
-                                async_answer_0(callid, ENOTSUP);
-                                continue;
-                        }
-                }
-                
                 switch (IPC_GET_IMETHOD(call)) {
-                case DEVMAN_DRIVER_REGISTER:
-                        fibril_mutex_lock(&client->mutex);
-                        if (client->driver != NULL) {
-                                fibril_mutex_unlock(&client->mutex);
-                                async_answer_0(callid, EINVAL);
-                                continue;
-                        }
-                        client->driver = devman_driver_register(callid, &call);
-                        fibril_mutex_unlock(&client->mutex);
-                        break;
                 case DEVMAN_ADD_FUNCTION:
                         devman_add_function(callid, &call);
@@ -744 +463 @@
                         devman_add_function_to_cat(callid, &call);
                         break;
-                case DEVMAN_DRV_FUN_ONLINE:
-                        devman_drv_fun_online(callid, &call, driver);
-                        break;
-                case DEVMAN_DRV_FUN_OFFLINE:
-                        devman_drv_fun_offline(callid, &call, driver);
-                        break;
                 case DEVMAN_REMOVE_FUNCTION:
                         devman_remove_function(callid, &call);
                         break;
                 default:
-                        async_answer_0(callid, EINVAL);
+                        async_answer_0(callid, EINVAL); 
                         break;
                 }
@@ -765 +478 @@
 {
         char *pathname;
-        devman_handle_t handle;
         
         int rc = async_data_write_accept((void **) &pathname, true, 0, 0, 0, 0);
@@ -782 +494 @@
         }
 
-        fibril_rwlock_read_lock(&device_tree.rwlock);
-
-        /* Check function state */
-        if (fun->state == FUN_REMOVED) {
-                fibril_rwlock_read_unlock(&device_tree.rwlock);
-                async_answer_0(iid, ENOENT);
-                return;
-        }
-        handle = fun->handle;
-
-        fibril_rwlock_read_unlock(&device_tree.rwlock);
-
-        /* Delete reference created above by find_fun_node_by_path() */
-        fun_del_ref(fun);
-
-        async_answer_1(iid, EOK, handle);
+        async_answer_1(iid, EOK, fun->handle);
 }
 
@@ -815 +512 @@
         if (!async_data_read_receive(&data_callid, &data_len)) {
                 async_answer_0(iid, EINVAL);
-                fun_del_ref(fun);
                 return;
         }
@@ -823 +519 @@
                 async_answer_0(data_callid, ENOMEM);
                 async_answer_0(iid, ENOMEM);
-                fun_del_ref(fun);
-                return;
-        }
-
-        fibril_rwlock_read_lock(&device_tree.rwlock);
-
-        /* Check function state */
-        if (fun->state == FUN_REMOVED) {
-                fibril_rwlock_read_unlock(&device_tree.rwlock);
-                free(buffer);
-
-                async_answer_0(data_callid, ENOENT);
-                async_answer_0(iid, ENOENT);
-                fun_del_ref(fun);
                 return;
         }
@@ -848 +530 @@
         async_answer_0(iid, EOK);
 
-        fibril_rwlock_read_unlock(&device_tree.rwlock);
-        fun_del_ref(fun);
         free(buffer);
 }
@@ -869 +549 @@
         if (!async_data_read_receive(&data_callid, &data_len)) {
                 async_answer_0(iid, EINVAL);
-                fun_del_ref(fun);
                 return;
         }
@@ -877 +556 @@
                 async_answer_0(data_callid, ENOMEM);
                 async_answer_0(iid, ENOMEM);
-                fun_del_ref(fun);
-                return;
-        }
-        
-        fibril_rwlock_read_lock(&device_tree.rwlock);
-        
-        /* Check function state */
-        if (fun->state == FUN_REMOVED) {
-                fibril_rwlock_read_unlock(&device_tree.rwlock);
-                free(buffer);
-
-                async_answer_0(data_callid, ENOENT);
-                async_answer_0(iid, ENOENT);
-                fun_del_ref(fun);
-                return;
-        }
-        
+                return;
+        }
+
         size_t sent_length = str_size(fun->pathname);
         if (sent_length > data_len) {
@@ -902 +567 @@
         async_answer_0(iid, EOK);
 
-        fibril_rwlock_read_unlock(&device_tree.rwlock);
-        fun_del_ref(fun);
         free(buffer);
 }
@@ -924 +587 @@
         dev_node_t *dev = find_dev_node_no_lock(&device_tree,
             IPC_GET_ARG1(*icall));
-        if (dev == NULL || dev->state == DEVICE_REMOVED) {
+        if (dev == NULL) {
                 fibril_rwlock_read_unlock(&device_tree.rwlock);
                 async_answer_0(callid, ENOENT);
@@ -963 +626 @@
         fibril_rwlock_read_lock(&device_tree.rwlock);
         
-        fun = find_fun_node_no_lock(&device_tree, IPC_GET_ARG1(*icall));
-        if (fun == NULL || fun->state == FUN_REMOVED) {
+        fun = find_fun_node(&device_tree, IPC_GET_ARG1(*icall));
+        if (fun == NULL) {
                 fibril_rwlock_read_unlock(&device_tree.rwlock);
                 async_answer_0(iid, ENOENT);
@@ -981 +644 @@
 }
 
-/** Online function.
- *
- * Send a request to online a function to the responsible driver.
- * The driver may offline other functions if necessary (i.e. if the state
- * of this function is linked to state of another function somehow).
- */
-static void devman_fun_online(ipc_callid_t iid, ipc_call_t *icall)
-{
-        fun_node_t *fun;
-        int rc;
-
-        fun = find_fun_node(&device_tree, IPC_GET_ARG1(*icall));
-        if (fun == NULL) {
-                async_answer_0(iid, ENOENT);
-                return;
-        }
-        
-        rc = driver_fun_online(&device_tree, fun);
-        fun_del_ref(fun);
-        
-        async_answer_0(iid, (sysarg_t) rc);
-}
-
-/** Offline function.
- *
- * Send a request to offline a function to the responsible driver. As
- * a result the subtree rooted at that function should be cleanly
- * detatched. The driver may offline other functions if necessary
- * (i.e. if the state of this function is linked to state of another
- * function somehow).
- */
-static void devman_fun_offline(ipc_callid_t iid, ipc_call_t *icall)
-{
-        fun_node_t *fun;
-        int rc;
-
-        fun = find_fun_node(&device_tree, IPC_GET_ARG1(*icall));
-        if (fun == NULL) {
-                async_answer_0(iid, ENOENT);
-                return;
-        }
-        
-        rc = driver_fun_offline(&device_tree, fun);
-        fun_del_ref(fun);
-        
-        async_answer_0(iid, (sysarg_t) rc);
-}
-
 /** Find handle for the function instance identified by its service ID. */
 static void devman_fun_sid_to_handle(ipc_callid_t iid, ipc_call_t *icall)
@@ -1041 +656 @@
         }
 
-        fibril_rwlock_read_lock(&device_tree.rwlock);
-
-        /* Check function state */
-        if (fun->state == FUN_REMOVED) {
-                fibril_rwlock_read_unlock(&device_tree.rwlock);
-                async_answer_0(iid, ENOENT);
-                return;
-        }
-
         async_answer_1(iid, EOK, fun->handle);
-        fibril_rwlock_read_unlock(&device_tree.rwlock);
-        fun_del_ref(fun);
 }
 
@@ -1084 +688 @@
                         devman_fun_get_path(callid, &call);
                         break;
-                case DEVMAN_FUN_ONLINE:
-                        devman_fun_online(callid, &call);
-                        break;
-                case DEVMAN_FUN_OFFLINE:
-                        devman_fun_offline(callid, &call);
-                        break;
                 case DEVMAN_FUN_SID_TO_HANDLE:
                         devman_fun_sid_to_handle(callid, &call);
@@ -1110 +708 @@
         if (fun == NULL)
                 dev = find_dev_node(&device_tree, handle);
-        else {
-                fibril_rwlock_read_lock(&device_tree.rwlock);
+        else
                 dev = fun->dev;
-                if (dev != NULL)
-                        dev_add_ref(dev);
-                fibril_rwlock_read_unlock(&device_tree.rwlock);
-        }
 
         /*
@@ -1128 +721 @@
                     "function with handle %" PRIun " was found.", handle);
                 async_answer_0(iid, ENOENT);
-                goto cleanup;
+                return;
         }
 
@@ -1136 +729 @@
                     handle);
                 async_answer_0(iid, ENOENT);
-                goto cleanup;
+                return;
         }
         
         driver_t *driver = NULL;
-        
-        fibril_rwlock_read_lock(&device_tree.rwlock);
         
         if (drv_to_parent) {
@@ -1156 +747 @@
         }
         
-        fibril_rwlock_read_unlock(&device_tree.rwlock);
-        
         if (driver == NULL) {
                 log_msg(LVL_ERROR, "IPC forwarding refused - " \
                     "the device %" PRIun " is not in usable state.", handle);
                 async_answer_0(iid, ENOENT);
-                goto cleanup;
+                return;
         }
         
@@ -1175 +764 @@
                     "Could not forward to driver `%s'.", driver->name);
                 async_answer_0(iid, EINVAL);
-                goto cleanup;
+                return;
         }
 
@@ -1191 +780 @@
         async_forward_fast(iid, exch, method, fwd_h, 0, IPC_FF_NONE);
         async_exchange_end(exch);
-
-cleanup:
-        if (dev != NULL)
-                dev_del_ref(dev);
-        if (fun != NULL)
-                fun_del_ref(fun);
 }
 
@@ -1206 +789 @@
         fun_node_t *fun;
         dev_node_t *dev;
-        devman_handle_t handle;
-        driver_t *driver;
 
         fun = find_loc_tree_function(&device_tree, service_id);
         
-        fibril_rwlock_read_lock(&device_tree.rwlock);
-        
-        if (fun == NULL || fun->dev == NULL || fun->dev->drv == NULL) {
+        if (fun == NULL || fun->dev->drv == NULL) {
                 log_msg(LVL_WARN, "devman_connection_loc(): function "
                     "not found.\n");
-                fibril_rwlock_read_unlock(&device_tree.rwlock);
                 async_answer_0(iid, ENOENT);
                 return;
@@ -1222 +800 @@
         
         dev = fun->dev;
-        driver = dev->drv;
-        handle = fun->handle;
-        
-        fibril_rwlock_read_unlock(&device_tree.rwlock);
-        
-        async_exch_t *exch = async_exchange_begin(driver->sess);
-        async_forward_fast(iid, exch, DRIVER_CLIENT, handle, 0,
+        
+        async_exch_t *exch = async_exchange_begin(dev->drv->sess);
+        async_forward_fast(iid, exch, DRIVER_CLIENT, fun->handle, 0,
             IPC_FF_NONE);
         async_exchange_end(exch);
@@ -1234 +808 @@
         log_msg(LVL_DEBUG,
             "Forwarding loc service request for `%s' function to driver `%s'.",
-            fun->pathname, driver->name);
-
-        fun_del_ref(fun);
+            fun->pathname, dev->drv->name);
 }
 
@@ -1242 +814 @@
 static void devman_connection(ipc_callid_t iid, ipc_call_t *icall, void *arg)
 {
-        /* Select port. */
+        /* Select interface. */
         switch ((sysarg_t) (IPC_GET_ARG1(*icall))) {
         case DEVMAN_DRIVER:
@@ -1268 +840 @@
 }
 
-static void *devman_client_data_create(void)
-{
-        client_t *client;
-        
-        client = calloc(1, sizeof(client_t));
-        if (client == NULL)
-                return NULL;
-        
-        fibril_mutex_initialize(&client->mutex);
-        return client;
-}
-
-static void devman_client_data_destroy(void *data)
-{
-        free(data);
-}
-
 /** Initialize device manager internal structures. */
 static bool devman_init(void)
@@ -1331 +886 @@
         }
         
-        /* Set handlers for incoming connections. */
-        async_set_client_data_constructor(devman_client_data_create);
-        async_set_client_data_destructor(devman_client_data_destroy);
+        /* Set a handler of incomming connections. */
         async_set_client_connection(devman_connection);