Changeset 4006447 in mainline for uspace/srv

Timestamp:

2010-12-06T20:03:54Z (15 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

c0bd08d

Parents:

b38dfd8 (diff), 463e734 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge from lp:~vojtech-horky/helenos/ddf-fixes.

Location:

uspace/srv/devman

Files:

• devman.c (modified) (12 diffs)
• devman.h (modified) (1 diff)
• main.c (modified) (3 diffs)
• match.c (modified) (2 diffs)

uspace/srv/devman/devman.c

@@ -508 +508 @@
 /** Notify driver about the devices to which it was assigned.
  *
- * The driver's mutex must be locked.
- *
  * @param driver        The driver to which the devices are passed.
  */
@@ -518 +516 @@
         int phone;
 
-        printf(NAME ": pass_devices_to_driver\n");
-
-        phone = ipc_connect_me_to(driver->phone, DRIVER_DEVMAN, 0, 0);
-        if (phone > 0) {
-                
+        printf(NAME ": pass_devices_to_driver(`%s')\n", driver->name);
+
+        fibril_mutex_lock(&driver->driver_mutex);
+
+        phone = async_connect_me_to(driver->phone, DRIVER_DEVMAN, 0, 0);
+
+        if (phone < 0) {
+                fibril_mutex_unlock(&driver->driver_mutex);
+                return;
+        }
+
+        /*
+         * Go through devices list as long as there is some device
+         * that has not been passed to the driver.
+         */
+        link = driver->devices.next;
+        while (link != &driver->devices) {
+                dev = list_get_instance(link, node_t, driver_devices);
+                if (dev->passed_to_driver) {
+                        link = link->next;
+                        continue;
+                }
+
+                /*
+                 * We remove the device from the list to allow safe adding
+                 * of new devices (no one will touch our item this way).
+                 */
+                list_remove(link);
+
+                /*
+                 * Unlock to avoid deadlock when adding device
+                 * handled by itself.
+                 */
+                fibril_mutex_unlock(&driver->driver_mutex);
+
+                add_device(phone, driver, dev, tree);
+
+                /*
+                 * Lock again as we will work with driver's
+                 * structure.
+                 */
+                fibril_mutex_lock(&driver->driver_mutex);
+
+                /*
+                 * Insert the device back.
+                 * The order is not relevant here so no harm is done
+                 * (actually, the order would be preserved in most cases).
+                 */
+                list_append(link, &driver->devices);
+
+                /*
+                 * Restart the cycle to go through all devices again.
+                 */
                 link = driver->devices.next;
-                while (link != &driver->devices) {
-                        dev = list_get_instance(link, node_t, driver_devices);
-                        add_device(phone, driver, dev, tree);
-                        link = link->next;
-                }
-                
-                ipc_hangup(phone);
-        }
+        }
+
+        ipc_hangup(phone);
+
+        /*
+         * 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.
+         */
+        printf(NAME ": driver %s goes into running state.\n", driver->name);
+        driver->state = DRIVER_RUNNING;
+
+        fibril_mutex_unlock(&driver->driver_mutex);
 }
 
@@ -545 +600 @@
 void initialize_running_driver(driver_t *driver, dev_tree_t *tree)
 {
-        printf(NAME ": initialize_running_driver\n");
-        fibril_mutex_lock(&driver->driver_mutex);
+        printf(NAME ": initialize_running_driver (`%s')\n", driver->name);
         
         /*
@@ -553 +607 @@
          */
         pass_devices_to_driver(driver, tree);
-        
-        /* Change driver's state to running. */
-        driver->state = DRIVER_RUNNING;
-        
-        fibril_mutex_unlock(&driver->driver_mutex);
 }
 
@@ -629 +678 @@
 }
 
+static FIBRIL_MUTEX_INITIALIZE(add_device_guard);
 
 /** Pass a device to running driver.
@@ -637 +687 @@
 void add_device(int phone, driver_t *drv, node_t *node, dev_tree_t *tree)
 {
-        printf(NAME ": add_device\n");
+        fibril_mutex_lock(&add_device_guard);
+
+        /*
+         * We do not expect to have driver's mutex locked as we do not
+         * access any structures that would affect driver_t.
+         */
+        printf(NAME ": add_device (driver `%s', device `%s')\n", drv->name,
+            node->name);
         
         ipcarg_t rc;
@@ -643 +700 @@
         
         /* Send the device to the driver. */
-        aid_t req = async_send_1(phone, DRIVER_ADD_DEVICE, node->handle,
-            &answer);
+        devman_handle_t parent_handle;
+        if (node->parent) {
+                parent_handle = node->parent->handle;
+        } else {
+                parent_handle = 0;
+        }
+
+        aid_t req = async_send_2(phone, DRIVER_ADD_DEVICE, node->handle,
+            parent_handle, &answer);
         
         /* Send the device's name to the driver. */
@@ -652 +716 @@
                 /* TODO handle error */
         }
-        
+
         /* Wait for answer from the driver. */
         async_wait_for(req, &rc);
+
+        fibril_mutex_unlock(&add_device_guard);
+
         switch(rc) {
         case EOK:
@@ -667 +734 @@
         }
         
+        node->passed_to_driver = true;
+
         return;
 }
@@ -692 +761 @@
         attach_driver(node, drv);
         
+        fibril_mutex_lock(&drv->driver_mutex);
         if (drv->state == DRIVER_NOT_STARTED) {
                 /* Start the driver. */
                 start_driver(drv);
         }
-        
-        if (drv->state == DRIVER_RUNNING) {
+        bool is_running = drv->state == DRIVER_RUNNING;
+        fibril_mutex_unlock(&drv->driver_mutex);
+
+        if (is_running) {
                 /* Notify the driver about the new device. */
-                int phone = ipc_connect_me_to(drv->phone, DRIVER_DEVMAN, 0, 0);
+                int phone = async_connect_me_to(drv->phone, DRIVER_DEVMAN, 0, 0);
                 if (phone > 0) {
                         add_device(phone, drv, node, tree);
@@ -861 +933 @@
         node->name = dev_name;
         if (!set_dev_path(node, parent)) {
-                fibril_rwlock_write_unlock(&tree->rwlock);
                 return false;
         }
@@ -1083 +1154 @@
         while (link != &class_list->classes) {
                 cl = list_get_instance(link, dev_class_t, link);
-                if (str_cmp(cl->name, class_name) == 0)
+                if (str_cmp(cl->name, class_name) == 0) {
                         return cl;
+                }
+                link = link->next;
         }
         

uspace/srv/devman/devman.h

@@ -168 +168 @@
          */
         link_t devmap_link;
+
+        /**
+         * Whether this device was already passed to the driver.
+         */
+        bool passed_to_driver;
 };
 

uspace/srv/devman/main.c

@@ -197 +197 @@
 }
 
+static int assign_driver_fibril(void *arg)
+{
+        node_t *node = (node_t *) arg;
+        assign_driver(node, &drivers_list, &device_tree);
+        return EOK;
+}
+
 /** Handle child device registration.
  *
@@ -237 +244 @@
         
         devman_receive_match_ids(match_count, &node->match_ids);
-        
+
+        /*
+         * 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, node);
+        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(node);
+        } else {
+                fibril_add_ready(assign_fibril);
+        }
+
         /* Return device handle to parent's driver. */
         ipc_answer_1(callid, EOK, node->handle);
-        
-        /* Try to find suitable driver and assign it to the device. */
-        assign_driver(node, &drivers_list, &device_tree);
 }
 
@@ -297 +319 @@
         printf(NAME ": device '%s' added to class '%s', class name '%s' was "
             "asigned to it\n", dev->pathname, class_name, class_info->dev_name);
-        
+
         ipc_answer_0(callid, EOK);
 }

uspace/srv/devman/match.c

@@ -35 +35 @@
 #include "devman.h"
 
+/** Compute compound score of driver and device.
+ *
+ * @param driver Match id of the driver.
+ * @param device Match id of the device.
+ * @return Compound score.
+ * @retval 0 No match at all.
+ */
+static int compute_match_score(match_id_t *driver, match_id_t *device)
+{
+        if (str_cmp(driver->id, device->id) == 0) {
+                /*
+                 * The strings match, return the product of their scores.
+                 */
+                return driver->score * device->score;
+        } else {
+                /*
+                 * Different strings, return zero.
+                 */
+                return 0;
+        }
+}
+
 int get_match_score(driver_t *drv, node_t *dev)
 {
@@ -43 +65 @@
                 return 0;
         
+        /*
+         * Go through all pairs, return the highest score obtained.
+         */
+        int highest_score = 0;
+        
         link_t *drv_link = drv->match_ids.ids.next;
-        link_t *dev_link = dev->match_ids.ids.next;
-        
-        match_id_t *drv_id = list_get_instance(drv_link, match_id_t, link);
-        match_id_t *dev_id = list_get_instance(dev_link, match_id_t, link);
-        
-        int score_next_drv = 0;
-        int score_next_dev = 0;
-        
-        do {
-                match_id_t *tmp_ma_id;
-        
-                if (str_cmp(drv_id->id, dev_id->id) == 0) {
-                        /*
-                         * We found a match.
-                         * Return the score of the match.
-                         */
-                        return drv_id->score * dev_id->score;
+        while (drv_link != drv_head) {
+                link_t *dev_link = dev_head->next;
+                while (dev_link != dev_head) {
+                        match_id_t *drv_id = list_get_instance(drv_link, match_id_t, link);
+                        match_id_t *dev_id = list_get_instance(dev_link, match_id_t, link);
+                        
+                        int score = compute_match_score(drv_id, dev_id);
+                        if (score > highest_score) {
+                                highest_score = score;
+                        }
+
+                        dev_link = dev_link->next;
                 }
                 
-                /*
-                 * Compute the next score we get, if we advance in the driver's
-                 * list of match ids.
-                 */
-                if (drv_link->next != drv_head) {
-                        tmp_ma_id = list_get_instance(drv_link->next,
-                            match_id_t, link);
-                        score_next_drv = dev_id->score * tmp_ma_id->score;
-                } else {
-                        score_next_drv = 0;
-                }
-                
-                /*
-                 * Compute the next score we get, if we advance in the device's
-                 * list of match ids.
-                 */
-                if (dev_link->next != dev_head) {
-                        tmp_ma_id = list_get_instance(dev_link->next,
-                            match_id_t, link);
-                        score_next_dev = drv_id->score * tmp_ma_id->score;
-                } else {
-                        score_next_dev = 0;
-                }
-                
-                /*
-                 * Advance in one of the two lists, so we get the next highest
-                 * score.
-                 */
-                if (score_next_drv > score_next_dev) {
-                        drv_link = drv_link->next;
-                        drv_id = list_get_instance(drv_link, match_id_t, link);
-                } else {
-                        dev_link = dev_link->next;
-                        dev_id = list_get_instance(dev_link, match_id_t, link);
-                }
-                
-        } while (drv_link->next != drv_head && dev_link->next != dev_head);
+                drv_link = drv_link->next;
+        }
         
-        return 0;
+        return highest_score;
 }