source: mainline/uspace/srv/devman/drv_conn.c

/*
 * Copyright (c) 2025 Jiri Svoboda
 * Copyright (c) 2010 Lenka Trochtova
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @addtogroup devman
 * @{
 */

/** @file
 */

#include <assert.h>
#include <ipc/services.h>
#include <ns.h>
#include <async.h>
#include <stdio.h>
#include <errno.h>
#include <str_error.h>
#include <stdbool.h>
#include <fibril_synch.h>
#include <stdlib.h>
#include <str.h>
#include <io/log.h>
#include <ipc/devman.h>
#include <loc.h>

#include "client_conn.h"
#include "dev.h"
#include "devman.h"
#include "devtree.h"
#include "driver.h"
#include "drv_conn.h"
#include "fun.h"
#include "loc.h"
#include "main.h"

static errno_t init_running_drv(void *drv);

/** Register running driver. */
static driver_t *devman_driver_register(ipc_call_t *call)
{
        driver_t *driver = NULL;
        char *drv_name = NULL;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "devman_driver_register");

        /* Get driver name. */
        errno_t rc = async_data_write_accept((void **) &drv_name, true, 0, 0, 0, 0);
        if (rc != EOK) {
                async_answer_0(call, rc);
                return NULL;
        }

        log_msg(LOG_DEFAULT, LVL_DEBUG, "The `%s' driver is trying to register.",
            drv_name);

        /* Find driver structure. */
        driver = driver_find_by_name(&drivers_list, drv_name);
        if (driver == NULL) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "No driver named `%s' was found.", drv_name);
                free(drv_name);
                drv_name = NULL;
                async_answer_0(call, ENOENT);
                return NULL;
        }

        free(drv_name);
        drv_name = NULL;

        fibril_mutex_lock(&driver->driver_mutex);

        if (driver->sess) {
                /* We already have a connection to the driver. */
                log_msg(LOG_DEFAULT, LVL_ERROR, "Driver '%s' already started.\n",
                    driver->name);
                fibril_mutex_unlock(&driver->driver_mutex);
                async_answer_0(call, EEXIST);
                return NULL;
        }

        switch (driver->state) {
        case DRIVER_NOT_STARTED:
                /* Somebody started the driver manually. */
                log_msg(LOG_DEFAULT, LVL_NOTE, "Driver '%s' started manually.\n",
                    driver->name);
                driver->state = DRIVER_STARTING;
                break;
        case DRIVER_STARTING:
                /* The expected case */
                break;
        case DRIVER_RUNNING:
                /* Should not happen since we do not have a connected session */
                assert(false);
        }

        /* Create connection to the driver. */
        log_msg(LOG_DEFAULT, LVL_DEBUG, "Creating connection to the `%s' driver.",
            driver->name);
        driver->sess = async_callback_receive(EXCHANGE_PARALLEL);
        if (!driver->sess) {
                fibril_mutex_unlock(&driver->driver_mutex);
                async_answer_0(call, ENOTSUP);
                return NULL;
        }
        /* FIXME: Work around problem with callback sessions */
        async_sess_args_set(driver->sess, INTERFACE_DDF_DEVMAN, 0, 0);

        log_msg(LOG_DEFAULT, LVL_NOTE,
            "The `%s' driver was successfully registered as running.",
            driver->name);

        /*
         * Initialize the driver as running (e.g. pass assigned devices to it)
         * in a separate fibril; the separate fibril is used to enable the
         * driver to use devman service during the driver's initialization.
         */
        fid_t fid = fibril_create(init_running_drv, driver);
        if (fid == 0) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed to create initialization fibril "
                    "for driver `%s'.", driver->name);
                fibril_mutex_unlock(&driver->driver_mutex);
                async_answer_0(call, ENOMEM);
                return NULL;
        }

        fibril_add_ready(fid);
        fibril_mutex_unlock(&driver->driver_mutex);

        async_answer_0(call, 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, error code otherwise.
 */
static errno_t devman_receive_match_id(match_id_list_t *match_ids)
{
        match_id_t *match_id = create_match_id();
        ipc_call_t call;
        errno_t rc = 0;

        async_get_call(&call);
        if (DEVMAN_ADD_MATCH_ID != ipc_get_imethod(&call)) {
                log_msg(LOG_DEFAULT, LVL_ERROR,
                    "Invalid protocol when trying to receive match id.");
                async_answer_0(&call, EINVAL);
                delete_match_id(match_id);
                return EINVAL;
        }

        if (match_id == NULL) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed to allocate match id.");
                async_answer_0(&call, ENOMEM);
                return ENOMEM;
        }

        async_answer_0(&call, 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(LOG_DEFAULT, LVL_ERROR, "Failed to receive match id string: %s.",
                    str_error(rc));
                return rc;
        }

        list_append(&match_id->link, &match_ids->ids);

        log_msg(LOG_DEFAULT, 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, error code otherwise.
 */
static errno_t devman_receive_match_ids(sysarg_t match_count,
    match_id_list_t *match_ids)
{
        errno_t 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;
}

/** Handle function registration.
 *
 * Child devices are registered by their parent's device driver.
 */
static void devman_add_function(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(call, ENOENT);
                return;
        }

        if (ftype != fun_inner && ftype != fun_exposed) {
                /* Unknown function type */
                log_msg(LOG_DEFAULT, LVL_ERROR,
                    "Unknown function type %d provided by driver.",
                    (int) ftype);

                dev_del_ref(pdev);
                async_answer_0(call, EINVAL);
                return;
        }

        char *fun_name = NULL;
        errno_t rc = async_data_write_accept((void **) &fun_name, true, 0, 0, 0, 0);
        if (rc != EOK) {
                dev_del_ref(pdev);
                async_answer_0(call, 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(call, ENOENT);
                return;
        }

        /* Check that function with same name is not there already. */
        fun_node_t *tfun = find_fun_node_in_device(tree, pdev, fun_name);
        if (tfun) {
                fun_del_ref(tfun);      /* drop the new unwanted reference */
                fibril_rwlock_write_unlock(&tree->rwlock);
                dev_del_ref(pdev);
                async_answer_0(call, EEXIST);
                printf(NAME ": Warning, driver tried to register `%s' twice.\n",
                    fun_name);
                free(fun_name);
                return;
        }

        fun_node_t *fun = create_fun_node();
        /*
         * Hold a temporary reference while we work with fun. The reference from
         * create_fun_node() moves to the device tree.
         */
        fun_add_ref(fun);
        fun->ftype = ftype;

        /*
         * We can lock the function here even when holding the tree because
         * we know it cannot be held by anyone else yet.
         */
        fun_busy_lock(fun);

        if (!insert_fun_node(&device_tree, fun, fun_name, pdev)) {
                fibril_rwlock_write_unlock(&tree->rwlock);
                dev_del_ref(pdev);
                fun_busy_unlock(fun);
                fun_del_ref(fun);
                fun_del_ref(fun);       /* fun is destroyed */
                async_answer_0(call, ENOMEM);
                return;
        }

        fibril_rwlock_write_unlock(&tree->rwlock);
        dev_del_ref(pdev);

        devman_receive_match_ids(match_count, &fun->match_ids);

        rc = fun_online(fun);
        if (rc != EOK) {
                /* XXX Set some failed state? */
                fun_busy_unlock(fun);
                fun_del_ref(fun);
                async_answer_0(call, rc);
                return;
        }

        fun_busy_unlock(fun);
        fun_del_ref(fun);

        /* Return device handle to parent's driver. */
        async_answer_1(call, EOK, fun->handle);
}

static void devman_add_function_to_cat(ipc_call_t *call)
{
        devman_handle_t handle = ipc_get_arg1(call);
        category_id_t cat_id;
        errno_t 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(call, rc);
                return;
        }

        fun_node_t *fun = find_fun_node(&device_tree, handle);
        if (fun == NULL) {
                async_answer_0(call, 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(call, ENOENT);
                return;
        }

        rc = loc_category_get_id(cat_name, &cat_id, IPC_FLAG_BLOCKING);
        if (rc == EOK)
                rc = loc_service_add_to_cat(devman_srv, fun->service_id, cat_id);
        if (rc == EOK) {
                log_msg(LOG_DEFAULT, LVL_NOTE, "Function `%s' added to category `%s'.",
                    fun->pathname, cat_name);
        } else {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed adding function `%s' to category "
                    "`%s'.", fun->pathname, cat_name);
        }

        fibril_rwlock_read_unlock(&device_tree.rwlock);
        fun_del_ref(fun);

        async_answer_0(call, rc);
}

/** Online function by driver request.
 *
 */
static void devman_drv_fun_online(ipc_call_t *icall, driver_t *drv)
{
        fun_node_t *fun;
        errno_t rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "devman_drv_fun_online()");

        fun = find_fun_node(&device_tree, ipc_get_arg1(icall));
        if (fun == NULL) {
                async_answer_0(icall, ENOENT);
                return;
        }

        fun_busy_lock(fun);

        fibril_rwlock_read_lock(&device_tree.rwlock);
        if (fun->dev == NULL || fun->dev->drv != drv) {
                fibril_rwlock_read_unlock(&device_tree.rwlock);
                fun_busy_unlock(fun);
                fun_del_ref(fun);
                async_answer_0(icall, ENOENT);
                return;
        }
        fibril_rwlock_read_unlock(&device_tree.rwlock);

        rc = fun_online(fun);
        if (rc != EOK) {
                fun_busy_unlock(fun);
                fun_del_ref(fun);
                async_answer_0(icall, rc);
                return;
        }

        fun_busy_unlock(fun);
        fun_del_ref(fun);

        async_answer_0(icall, EOK);
}

/** Offline function by driver request.
 *
 */
static void devman_drv_fun_offline(ipc_call_t *icall, driver_t *drv)
{
        fun_node_t *fun;
        errno_t rc;

        fun = find_fun_node(&device_tree, ipc_get_arg1(icall));
        if (fun == NULL) {
                async_answer_0(icall, ENOENT);
                return;
        }

        fun_busy_lock(fun);

        fibril_rwlock_write_lock(&device_tree.rwlock);
        if (fun->dev == NULL || fun->dev->drv != drv) {
                fun_busy_unlock(fun);
                fun_del_ref(fun);
                async_answer_0(icall, ENOENT);
                return;
        }
        fibril_rwlock_write_unlock(&device_tree.rwlock);

        rc = fun_offline(fun);
        if (rc != EOK) {
                fun_busy_unlock(fun);
                fun_del_ref(fun);
                async_answer_0(icall, rc);
                return;
        }

        fun_busy_unlock(fun);
        fun_del_ref(fun);
        async_answer_0(icall, EOK);
}

/** Quiesce function by driver request.
 *
 */
static void devman_drv_fun_quiesce(ipc_call_t *icall, driver_t *drv)
{
        fun_node_t *fun;
        errno_t rc;

        fun = find_fun_node(&device_tree, ipc_get_arg1(icall));
        if (fun == NULL) {
                async_answer_0(icall, ENOENT);
                return;
        }

        fun_busy_lock(fun);

        fibril_rwlock_write_lock(&device_tree.rwlock);
        if (fun->dev == NULL || fun->dev->drv != drv) {
                fun_busy_unlock(fun);
                fun_del_ref(fun);
                async_answer_0(icall, ENOENT);
                return;
        }
        fibril_rwlock_write_unlock(&device_tree.rwlock);

        rc = fun_quiesce(fun);
        if (rc != EOK) {
                fun_busy_unlock(fun);
                fun_del_ref(fun);
                async_answer_0(icall, rc);
                return;
        }

        fun_busy_unlock(fun);
        fun_del_ref(fun);
        async_answer_0(icall, EOK);
}

/** Wait for function to become stable.
 *
 */
static void devman_drv_fun_wait_stable(ipc_call_t *icall, driver_t *drv)
{
        fun_node_t *fun;
        dev_node_t *dev;

        fibril_rwlock_read_lock(&device_tree.rwlock);

        fun = find_fun_node(&device_tree, ipc_get_arg1(icall));
        if (fun == NULL) {
                fibril_rwlock_read_unlock(&device_tree.rwlock);
                async_answer_0(icall, ENOENT);
                return;
        }

        if (fun->child == NULL) {
                fibril_rwlock_read_unlock(&device_tree.rwlock);
                fun_del_ref(fun);
                async_answer_0(icall, EOK);
                return;
        }

        dev = fun->child;
        dev_add_ref(dev);

        fibril_rwlock_read_unlock(&device_tree.rwlock);

        dev_wait_stable(dev);
        dev_del_ref(dev);

        async_answer_0(icall, EOK);
}

/** Remove function. */
static void devman_remove_function(ipc_call_t *call)
{
        devman_handle_t fun_handle = ipc_get_arg1(call);
        dev_tree_t *tree = &device_tree;
        errno_t rc;

        fun_node_t *fun = find_fun_node(&device_tree, fun_handle);
        if (fun == NULL) {
                async_answer_0(call, ENOENT);
                return;
        }

        fun_busy_lock(fun);

        fibril_rwlock_write_lock(&tree->rwlock);

        log_msg(LOG_DEFAULT, LVL_DEBUG, "devman_remove_function(fun='%s')", fun->pathname);

        /* Check function state */
        if (fun->state == FUN_REMOVED) {
                fibril_rwlock_write_unlock(&tree->rwlock);
                fun_busy_unlock(fun);
                fun_del_ref(fun);
                async_answer_0(call, 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;
                        errno_t 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(LOG_DEFAULT, 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);
                                if (gone_rc == EOK)
                                        gone_rc = ENOTSUP;
                                fun_busy_unlock(fun);
                                fun_del_ref(fun);
                                async_answer_0(call, gone_rc);
                                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_unregister_tree_function(fun, &device_tree);
                        if (rc != EOK) {
                                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed unregistering tree "
                                    "service.");
                                fibril_rwlock_write_unlock(&tree->rwlock);
                                fun_busy_unlock(fun);
                                fun_del_ref(fun);
                                async_answer_0(call, EIO);
                                return;
                        }
                }
        }

        remove_fun_node(&device_tree, fun);
        fibril_rwlock_write_unlock(&tree->rwlock);
        fun_busy_unlock(fun);

        /* 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(LOG_DEFAULT, LVL_DEBUG, "devman_remove_function() succeeded.");
        async_answer_0(call, 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 errno_t init_running_drv(void *drv)
{
        driver_t *driver = (driver_t *) drv;

        initialize_running_driver(driver, &device_tree);
        log_msg(LOG_DEFAULT, LVL_DEBUG, "The `%s` driver was successfully initialized.",
            driver->name);
        return 0;
}

/** Function for handling connections from a driver to the device manager. */
void devman_connection_driver(ipc_call_t *icall, void *arg)
{
        client_t *client;
        driver_t *driver = NULL;

        /* Accept the connection. */
        async_accept_0(icall);

        client = async_get_client_data();
        if (client == NULL) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed to allocate client data.");
                return;
        }

        while (true) {
                ipc_call_t call;
                async_get_call(&call);

                if (!ipc_get_imethod(&call)) {
                        async_answer_0(&call, EOK);
                        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(&call, 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(&call, EINVAL);
                                continue;
                        }
                        client->driver = devman_driver_register(&call);
                        fibril_mutex_unlock(&client->mutex);
                        break;
                case DEVMAN_ADD_FUNCTION:
                        devman_add_function(&call);
                        break;
                case DEVMAN_ADD_DEVICE_TO_CATEGORY:
                        devman_add_function_to_cat(&call);
                        break;
                case DEVMAN_DRV_FUN_ONLINE:
                        devman_drv_fun_online(&call, driver);
                        break;
                case DEVMAN_DRV_FUN_OFFLINE:
                        devman_drv_fun_offline(&call, driver);
                        break;
                case DEVMAN_DRV_FUN_QUIESCE:
                        devman_drv_fun_quiesce(&call, driver);
                        break;
                case DEVMAN_DRV_FUN_WAIT_STABLE:
                        devman_drv_fun_wait_stable(&call, driver);
                        break;
                case DEVMAN_REMOVE_FUNCTION:
                        devman_remove_function(&call);
                        break;
                default:
                        async_answer_0(&call, EINVAL);
                        break;
                }
        }
}

/** @}
 */