Changeset 9306cd7 in mainline for kernel/generic/src/ipc/irq.c

Timestamp:

2017-09-03T18:14:15Z (7 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

3422fb6

Parents:

4d6629f

Message:

Make IRQ subscribe/unsubscribe thread safe again

File:

• kernel/generic/src/ipc/irq.c (modified) (5 diffs)

kernel/generic/src/ipc/irq.c

@@ -329 +329 @@
         cap_t *cap = cap_get_current(handle, CAP_TYPE_ALLOCATED);
         assert(cap);
-        cap->type = CAP_TYPE_IRQ;
-
+        
         irq_t *irq = &cap->irq;
         irq_initialize(irq);
@@ -344 +343 @@
         /*
          * Enlist the IRQ structure in the uspace IRQ hash table and the
-         * answerbox's list.
+         * answerbox's list and make the IRQ capability valid.
          */
         irq_spinlock_lock(&irq_uspace_hash_table_lock, true);
@@ -350 +349 @@
         irq_spinlock_lock(&box->irq_lock, false);
         
+        cap->type = CAP_TYPE_IRQ;
         hash_table_insert(&irq_uspace_hash_table, key, &irq->link);
         list_append(&irq->notif_cfg.link, &box->irq_list);
@@ -370 +370 @@
 int ipc_irq_unsubscribe(answerbox_t *box, int handle)
 {
+        irq_spinlock_lock(&TASK->lock, true);
         cap_t *cap = cap_get_current(handle, CAP_TYPE_IRQ);
-        if (!cap)
+        if (!cap) {
+                irq_spinlock_unlock(&TASK->lock, true);
                 return ENOENT;
+        }
+        cap->type = CAP_TYPE_ALLOCATED;
+        irq_spinlock_unlock(&TASK->lock, true);
+        
         irq_t *irq = &cap->irq;
-
+        
         irq_spinlock_lock(&irq_uspace_hash_table_lock, true);
         irq_spinlock_lock(&irq->lock, false);
@@ -398 +404 @@
         
         return EOK;
-}
-
-/** Disconnect all IRQ notifications from an answerbox.
- *
- * This function is effective because the answerbox contains list of all irq_t
- * structures that are subscribed to send notifications to it.
- *
- * @param box Answerbox for which we want to carry out the cleanup.
- *
- */
-void ipc_irq_cleanup(answerbox_t *box)
-{
-loop:
-        irq_spinlock_lock(&irq_uspace_hash_table_lock, true);
-        irq_spinlock_lock(&box->irq_lock, false);
-        
-        while (!list_empty(&box->irq_list)) {
-                DEADLOCK_PROBE_INIT(p_irqlock);
-                
-                irq_t *irq = list_get_instance(list_first(&box->irq_list), irq_t,
-                    notif_cfg.link);
-                
-                if (!irq_spinlock_trylock(&irq->lock)) {
-                        /*
-                         * Avoid deadlock by trying again.
-                         */
-                        irq_spinlock_unlock(&box->irq_lock, false);
-                        irq_spinlock_unlock(&irq_uspace_hash_table_lock, true);
-                        DEADLOCK_PROBE(p_irqlock, DEADLOCK_THRESHOLD);
-                        goto loop;
-                }
-                
-                assert(irq->notif_cfg.answerbox == box);
-                
-                /* Unlist from the answerbox. */
-                list_remove(&irq->notif_cfg.link);
-                
-                /* Remove from the hash table. */
-                hash_table_remove_item(&irq_uspace_hash_table, &irq->link);
-                
-                /*
-                 * Release both locks so that we can free the IRQ code.
-                 */
-                irq_spinlock_unlock(&box->irq_lock, false);
-                irq_spinlock_unlock(&irq_uspace_hash_table_lock, true);
-                
-                code_free(irq->notif_cfg.code);
-                
-                // XXX: what to do about the irq capability? The task is in
-                // clean-up anyway.
-                
-                /* Reacquire both locks before taking another round. */
-                irq_spinlock_lock(&irq_uspace_hash_table_lock, true);
-                irq_spinlock_lock(&box->irq_lock, false);
-        }
-        
-        irq_spinlock_unlock(&box->irq_lock, false);
-        irq_spinlock_unlock(&irq_uspace_hash_table_lock, true);
 }