source: mainline/uspace/srv/devman/driver.c@ a60e90b

/*
 * 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
 * @{
 */

#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <io/log.h>
#include <ipc/driver.h>
#include <loc.h>
#include <str_error.h>
#include <stdio.h>

#include "dev.h"
#include "devman.h"
#include "driver.h"
#include "match.h"

/**
 * Initialize the list of device driver's.
 *
 * @param drv_list the list of device driver's.
 *
 */
void init_driver_list(driver_list_t *drv_list)
{
        assert(drv_list != NULL);
        
        list_initialize(&drv_list->drivers);
        fibril_mutex_initialize(&drv_list->drivers_mutex);
}

/** Allocate and initialize a new driver structure.
 *
 * @return      Driver structure.
 */
driver_t *create_driver(void)
{
        driver_t *res = malloc(sizeof(driver_t));
        if (res != NULL)
                init_driver(res);
        return res;
}

/** Add a driver to the list of drivers.
 *
 * @param drivers_list  List of drivers.
 * @param drv           Driver structure.
 */
void add_driver(driver_list_t *drivers_list, driver_t *drv)
{
        fibril_mutex_lock(&drivers_list->drivers_mutex);
        list_prepend(&drv->drivers, &drivers_list->drivers);
        fibril_mutex_unlock(&drivers_list->drivers_mutex);

        log_msg(LOG_DEFAULT, LVL_NOTE, "Driver `%s' was added to the list of available "
            "drivers.", drv->name);
}

/**
 * Get information about a driver.
 *
 * Each driver has its own directory in the base directory.
 * The name of the driver's directory is the same as the name of the driver.
 * The driver's directory contains driver's binary (named as the driver without
 * extension) and the configuration file with match ids for device-to-driver
 *  matching (named as the driver with a special extension).
 *
 * This function searches for the driver's directory and containing
 * configuration files. If all the files needed are found, they are parsed and
 * the information about the driver is stored in the driver's structure.
 *
 * @param base_path     The base directory, in which we look for driver's
 *                      subdirectory.
 * @param name          The name of the driver.
 * @param drv           The driver structure to fill information in.
 *
 * @return              True on success, false otherwise.
 */
bool get_driver_info(const char *base_path, const char *name, driver_t *drv)
{
        log_msg(LOG_DEFAULT, LVL_DEBUG, "get_driver_info(base_path=\"%s\", name=\"%s\")",
            base_path, name);
        
        assert(base_path != NULL && name != NULL && drv != NULL);
        
        bool suc = false;
        char *match_path = NULL;
        size_t name_size = 0;
        
        /* Read the list of match ids from the driver's configuration file. */
        match_path = get_abs_path(base_path, name, MATCH_EXT);
        if (match_path == NULL)
                goto cleanup;
        
        if (!read_match_ids(match_path, &drv->match_ids))
                goto cleanup;
        
        /* Allocate and fill driver's name. */
        name_size = str_size(name) + 1;
        drv->name = malloc(name_size);
        if (drv->name == NULL)
                goto cleanup;
        str_cpy(drv->name, name_size, name);
        
        /* Initialize path with driver's binary. */
        drv->binary_path = get_abs_path(base_path, name, "");
        if (drv->binary_path == NULL)
                goto cleanup;
        
        /* Check whether the driver's binary exists. */
        struct stat s;
        if (stat(drv->binary_path, &s) == ENOENT) { /* FIXME!! */
                log_msg(LOG_DEFAULT, LVL_ERROR, "Driver not found at path `%s'.",
                    drv->binary_path);
                goto cleanup;
        }
        
        suc = true;
        
cleanup:
        if (!suc) {
                free(drv->binary_path);
                free(drv->name);
                /* Set the driver structure to the default state. */
                init_driver(drv);
        }
        
        free(match_path);
        
        return suc;
}

/** Lookup drivers in the directory.
 *
 * @param drivers_list  The list of available drivers.
 * @param dir_path      The path to the directory where we search for drivers.
 * @return              Number of drivers which were found.
 */
int lookup_available_drivers(driver_list_t *drivers_list, const char *dir_path)
{
        log_msg(LOG_DEFAULT, LVL_DEBUG, "lookup_available_drivers(dir=\"%s\")", dir_path);
        
        int drv_cnt = 0;
        DIR *dir = NULL;
        struct dirent *diren;

        dir = opendir(dir_path);
        
        if (dir != NULL) {
                driver_t *drv = create_driver();
                while ((diren = readdir(dir))) {
                        if (get_driver_info(dir_path, diren->d_name, drv)) {
                                add_driver(drivers_list, drv);
                                drv_cnt++;
                                drv = create_driver();
                        }
                }
                delete_driver(drv);
                closedir(dir);
        }
        
        return drv_cnt;
}

/** Lookup the best matching driver for the specified device in the list of
 * drivers.
 *
 * A match between a device and a driver is found if one of the driver's match
 * ids match one of the device's match ids. The score of the match is the
 * product of the driver's and device's score associated with the matching id.
 * The best matching driver for a device is the driver with the highest score
 * of the match between the device and the driver.
 *
 * @param drivers_list  The list of drivers, where we look for the driver
 *                      suitable for handling the device.
 * @param node          The device node structure of the device.
 * @return              The best matching driver or NULL if no matching driver
 *                      is found.
 */
driver_t *find_best_match_driver(driver_list_t *drivers_list, dev_node_t *node)
{
        driver_t *best_drv = NULL, *drv = NULL;
        int best_score = 0, score = 0;
        
        fibril_mutex_lock(&drivers_list->drivers_mutex);
        
        list_foreach(drivers_list->drivers, link) {
                drv = list_get_instance(link, driver_t, drivers);
                score = get_match_score(drv, node);
                if (score > best_score) {
                        best_score = score;
                        best_drv = drv;
                }
        }
        
        fibril_mutex_unlock(&drivers_list->drivers_mutex);
        
        return best_drv;
}

/** Assign a driver to a device.
 *
 * @param tree          Device tree
 * @param node          The device's node in the device tree.
 * @param drv           The driver.
 */
void attach_driver(dev_tree_t *tree, dev_node_t *dev, driver_t *drv)
{
        log_msg(LOG_DEFAULT, LVL_DEBUG, "attach_driver(dev=\"%s\",drv=\"%s\")",
            dev->pfun->pathname, drv->name);
        
        fibril_mutex_lock(&drv->driver_mutex);
        fibril_rwlock_write_lock(&tree->rwlock);
        
        dev->drv = drv;
        list_append(&dev->driver_devices, &drv->devices);
        
        fibril_rwlock_write_unlock(&tree->rwlock);
        fibril_mutex_unlock(&drv->driver_mutex);
}

/** Detach driver from device.
 *
 * @param tree          Device tree
 * @param node          The device's node in the device tree.
 * @param drv           The driver.
 */
void detach_driver(dev_tree_t *tree, dev_node_t *dev)
{
        driver_t *drv = dev->drv;
        
        assert(drv != NULL);
        
        log_msg(LOG_DEFAULT, LVL_DEBUG, "detach_driver(dev=\"%s\",drv=\"%s\")",
            dev->pfun->pathname, drv->name);
        
        fibril_mutex_lock(&drv->driver_mutex);
        fibril_rwlock_write_lock(&tree->rwlock);
        
        dev->drv = NULL;
        list_remove(&dev->driver_devices);
        
        fibril_rwlock_write_unlock(&tree->rwlock);
        fibril_mutex_unlock(&drv->driver_mutex);
}

/** Start a driver
 *
 * @param drv           The driver's structure.
 * @return              True if the driver's task is successfully spawned, false
 *                      otherwise.
 */
bool start_driver(driver_t *drv)
{
        int rc;

        assert(fibril_mutex_is_locked(&drv->driver_mutex));
        
        log_msg(LOG_DEFAULT, LVL_DEBUG, "start_driver(drv=\"%s\")", drv->name);
        
        rc = task_spawnl(NULL, drv->binary_path, drv->binary_path, NULL);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Spawning driver `%s' (%s) failed: %s.",
                    drv->name, drv->binary_path, str_error(rc));
                return false;
        }
        
        drv->state = DRIVER_STARTING;
        return true;
}

/** Find device driver in the list of device drivers.
 *
 * @param drv_list      The list of device drivers.
 * @param drv_name      The name of the device driver which is searched.
 * @return              The device driver of the specified name, if it is in the
 *                      list, NULL otherwise.
 */
driver_t *find_driver(driver_list_t *drv_list, const char *drv_name)
{
        driver_t *res = NULL;
        driver_t *drv = NULL;
        
        fibril_mutex_lock(&drv_list->drivers_mutex);
        
        list_foreach(drv_list->drivers, link) {
                drv = list_get_instance(link, driver_t, drivers);
                if (str_cmp(drv->name, drv_name) == 0) {
                        res = drv;
                        break;
                }
        }
        
        fibril_mutex_unlock(&drv_list->drivers_mutex);
        
        return res;
}

/** Notify driver about the devices to which it was assigned.
 *
 * @param driver        The driver to which the devices are passed.
 */
static void pass_devices_to_driver(driver_t *driver, dev_tree_t *tree)
{
        dev_node_t *dev;
        link_t *link;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "pass_devices_to_driver(driver=\"%s\")",
            driver->name);

        fibril_mutex_lock(&driver->driver_mutex);

        /*
         * Go through devices list as long as there is some device
         * that has not been passed to the driver.
         */
        link = driver->devices.head.next;
        while (link != &driver->devices.head) {
                dev = list_get_instance(link, dev_node_t, driver_devices);
                fibril_rwlock_write_lock(&tree->rwlock);
                
                if (dev->passed_to_driver) {
                        fibril_rwlock_write_unlock(&tree->rwlock);
                        link = link->next;
                        continue;
                }

                log_msg(LOG_DEFAULT, LVL_DEBUG, "pass_devices_to_driver: dev->refcnt=%d\n",
                    (int)atomic_get(&dev->refcnt));
                dev_add_ref(dev);

                /*
                 * Unlock to avoid deadlock when adding device
                 * handled by itself.
                 */
                fibril_mutex_unlock(&driver->driver_mutex);
                fibril_rwlock_write_unlock(&tree->rwlock);

                add_device(driver, dev, tree);

                dev_del_ref(dev);

                /*
                 * Lock again as we will work with driver's
                 * structure.
                 */
                fibril_mutex_lock(&driver->driver_mutex);

                /*
                 * Restart the cycle to go through all devices again.
                 */
                link = driver->devices.head.next;
        }

        /*
         * Once we passed all devices to the driver, we need to mark the
         * driver as running.
         * It is vital to do it here and inside critical section.
         *
         * If we would change the state earlier, other devices added to
         * the driver would be added to the device list and started
         * immediately and possibly started here as well.
         */
        log_msg(LOG_DEFAULT, LVL_DEBUG, "Driver `%s' enters running state.", driver->name);
        driver->state = DRIVER_RUNNING;

        fibril_mutex_unlock(&driver->driver_mutex);
}

/** Finish the initialization of a driver after it has succesfully started
 * and after it has registered itself by the device manager.
 *
 * Pass devices formerly matched to the driver to the driver and remember the
 * driver is running and fully functional now.
 *
 * @param driver        The driver which registered itself as running by the
 *                      device manager.
 */
void initialize_running_driver(driver_t *driver, dev_tree_t *tree)
{
        log_msg(LOG_DEFAULT, LVL_DEBUG, "initialize_running_driver(driver=\"%s\")",
            driver->name);
        
        /*
         * Pass devices which have been already assigned to the driver to the
         * driver.
         */
        pass_devices_to_driver(driver, tree);
}

/** Initialize device driver structure.
 *
 * @param drv           The device driver structure.
 */
void init_driver(driver_t *drv)
{
        assert(drv != NULL);

        memset(drv, 0, sizeof(driver_t));
        list_initialize(&drv->match_ids.ids);
        list_initialize(&drv->devices);
        fibril_mutex_initialize(&drv->driver_mutex);
        drv->sess = NULL;
}

/** Device driver structure clean-up.
 *
 * @param drv           The device driver structure.
 */
void clean_driver(driver_t *drv)
{
        assert(drv != NULL);

        free(drv->name);
        free(drv->binary_path);

        clean_match_ids(&drv->match_ids);

        init_driver(drv);
}

/** Delete device driver structure.
 *
 * @param drv           The device driver structure.
 */
void delete_driver(driver_t *drv)
{
        assert(drv != NULL);
        
        clean_driver(drv);
        free(drv);
}

/** Find suitable driver for a device and assign the driver to it.
 *
 * @param node          The device node of the device in the device tree.
 * @param drivers_list  The list of available drivers.
 * @return              True if the suitable driver is found and
 *                      successfully assigned to the device, false otherwise.
 */
bool assign_driver(dev_node_t *dev, driver_list_t *drivers_list,
    dev_tree_t *tree)
{
        assert(dev != NULL);
        assert(drivers_list != NULL);
        assert(tree != NULL);
        
        /*
         * Find the driver which is the most suitable for handling this device.
         */
        driver_t *drv = find_best_match_driver(drivers_list, dev);
        if (drv == NULL) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "No driver found for device `%s'.",
                    dev->pfun->pathname);
                return false;
        }
        
        /* Attach the driver to the device. */
        attach_driver(tree, dev, drv);
        
        fibril_mutex_lock(&drv->driver_mutex);
        if (drv->state == DRIVER_NOT_STARTED) {
                /* Start the driver. */
                start_driver(drv);
        }
        bool is_running = drv->state == DRIVER_RUNNING;
        fibril_mutex_unlock(&drv->driver_mutex);

        /* Notify the driver about the new device. */
        if (is_running)
                add_device(drv, dev, tree);
        
        fibril_mutex_lock(&drv->driver_mutex);
        fibril_mutex_unlock(&drv->driver_mutex);

        fibril_rwlock_write_lock(&tree->rwlock);
        if (dev->pfun != NULL) {
                dev->pfun->state = FUN_ON_LINE;
        }
        fibril_rwlock_write_unlock(&tree->rwlock);
        return true;
}

/** Pass a device to running driver.
 *
 * @param drv           The driver's structure.
 * @param node          The device's node in the device tree.
 */
void add_device(driver_t *drv, dev_node_t *dev, dev_tree_t *tree)
{
        /*
         * We do not expect to have driver's mutex locked as we do not
         * access any structures that would affect driver_t.
         */
        log_msg(LOG_DEFAULT, LVL_DEBUG, "add_device(drv=\"%s\", dev=\"%s\")",
            drv->name, dev->pfun->name);
        
        /* Send the device to the driver. */
        devman_handle_t parent_handle;
        if (dev->pfun) {
                parent_handle = dev->pfun->handle;
        } else {
                parent_handle = 0;
        }
        
        async_exch_t *exch = async_exchange_begin(drv->sess);
        
        ipc_call_t answer;
        aid_t req = async_send_2(exch, DRIVER_DEV_ADD, dev->handle,
            parent_handle, &answer);
        
        /* Send the device name to the driver. */
        sysarg_t rc = async_data_write_start(exch, dev->pfun->name,
            str_size(dev->pfun->name) + 1);
        
        async_exchange_end(exch);
        
        if (rc != EOK) {
                /* TODO handle error */
        }

        /* Wait for answer from the driver. */
        async_wait_for(req, &rc);

        switch(rc) {
        case EOK:
                dev->state = DEVICE_USABLE;
                break;
        case ENOENT:
                dev->state = DEVICE_NOT_PRESENT;
                break;
        default:
                dev->state = DEVICE_INVALID;
                break;
        }
        
        dev->passed_to_driver = true;

        return;
}

int driver_dev_remove(dev_tree_t *tree, dev_node_t *dev)
{
        async_exch_t *exch;
        sysarg_t retval;
        driver_t *drv;
        devman_handle_t handle;
        
        assert(dev != NULL);
        
        log_msg(LOG_DEFAULT, LVL_DEBUG, "driver_dev_remove(%p)", dev);
        
        fibril_rwlock_read_lock(&tree->rwlock);
        drv = dev->drv;
        handle = dev->handle;
        fibril_rwlock_read_unlock(&tree->rwlock);
        
        exch = async_exchange_begin(drv->sess);
        retval = async_req_1_0(exch, DRIVER_DEV_REMOVE, handle);
        async_exchange_end(exch);
        
        return retval;
}

int driver_dev_gone(dev_tree_t *tree, dev_node_t *dev)
{
        async_exch_t *exch;
        sysarg_t retval;
        driver_t *drv;
        devman_handle_t handle;
        
        assert(dev != NULL);
        
        log_msg(LOG_DEFAULT, LVL_DEBUG, "driver_dev_gone(%p)", dev);
        
        fibril_rwlock_read_lock(&tree->rwlock);
        drv = dev->drv;
        handle = dev->handle;
        fibril_rwlock_read_unlock(&tree->rwlock);
        
        exch = async_exchange_begin(drv->sess);
        retval = async_req_1_0(exch, DRIVER_DEV_GONE, handle);
        async_exchange_end(exch);
        
        return retval;
}

int driver_fun_online(dev_tree_t *tree, fun_node_t *fun)
{
        async_exch_t *exch;
        sysarg_t retval;
        driver_t *drv;
        devman_handle_t handle;
        
        log_msg(LOG_DEFAULT, LVL_DEBUG, "driver_fun_online(%p)", fun);

        fibril_rwlock_read_lock(&tree->rwlock);
        
        if (fun->dev == NULL) {
                /* XXX root function? */
                fibril_rwlock_read_unlock(&tree->rwlock);
                return EINVAL;
        }
        
        drv = fun->dev->drv;
        handle = fun->handle;
        fibril_rwlock_read_unlock(&tree->rwlock);
        
        exch = async_exchange_begin(drv->sess);
        retval = async_req_1_0(exch, DRIVER_FUN_ONLINE, handle);
        loc_exchange_end(exch);
        
        return retval;
}

int driver_fun_offline(dev_tree_t *tree, fun_node_t *fun)
{
        async_exch_t *exch;
        sysarg_t retval;
        driver_t *drv;
        devman_handle_t handle;
        
        log_msg(LOG_DEFAULT, LVL_DEBUG, "driver_fun_offline(%p)", fun);

        fibril_rwlock_read_lock(&tree->rwlock);
        if (fun->dev == NULL) {
                /* XXX root function? */
                fibril_rwlock_read_unlock(&tree->rwlock);
                return EINVAL;
        }
        
        drv = fun->dev->drv;
        handle = fun->handle;
        fibril_rwlock_read_unlock(&tree->rwlock);
        
        exch = async_exchange_begin(drv->sess);
        retval = async_req_1_0(exch, DRIVER_FUN_OFFLINE, handle);
        loc_exchange_end(exch);
        
        return retval;

}

/** @}
 */