Changeset b14e35f2 in mainline for kernel/generic/src/ipc/irq.c

Timestamp:

2006-10-17T21:20:00Z (18 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

fb8335c

Parents:

4874c2d

Message:

Implement efficient IPC notification cleanup.

File:

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

kernel/generic/src/ipc/irq.c

@@ -177 +177 @@
         if (irq) {
                 if (irq->notif_cfg.answerbox == box) {
+                        code_free(irq->notif_cfg.code);
                         irq->notif_cfg.notify = false;
                         irq->notif_cfg.answerbox = NULL;
@@ -182 +183 @@
                         irq->notif_cfg.method = 0;
                         irq->notif_cfg.counter = 0;
-                        code_free(irq->notif_cfg.code);
+
+                        spinlock_lock(&box->irq_lock);
+                        list_remove(&irq->notif_cfg.link);
+                        spinlock_unlock(&box->irq_lock);
+                        
                         spinlock_unlock(&irq->lock);
                 }
@@ -199 +204 @@
  * @return EBADMEM, ENOENT or EEXISTS on failure or 0 on success.
  */
-int
-ipc_irq_register(answerbox_t *box, inr_t inr, devno_t devno, unative_t method, irq_code_t *ucode)
+int ipc_irq_register(answerbox_t *box, inr_t inr, devno_t devno, unative_t method, irq_code_t *ucode)
 {
         ipl_t ipl;
@@ -233 +237 @@
         irq->notif_cfg.code = code;
         irq->notif_cfg.counter = 0;
+
+        spinlock_lock(&box->irq_lock);
+        list_append(&irq->notif_cfg.link, &box->irq_head);
+        spinlock_unlock(&box->irq_lock);
+
         spinlock_unlock(&irq->lock);
         interrupts_restore(ipl);
@@ -311 +320 @@
 /** Disconnect all IRQ notifications from an answerbox.
  *
+ * This function is effective because the answerbox contains
+ * list of all irq_t structures that are registered to
+ * send notifications to it.
+ *
  * @param box Answerbox for which we want to carry out the cleanup.
  */
 void ipc_irq_cleanup(answerbox_t *box)
 {
-        /* TODO */
+        ipl_t ipl;
+        
+loop:
+        ipl = interrupts_disable();
+        spinlock_lock(&box->irq_lock);
+        
+        while (box->irq_head.next != &box->irq_head) {
+                link_t *cur = box->irq_head.next;
+                irq_t *irq;
+                
+                irq = list_get_instance(cur, irq_t, notif_cfg.link);
+                if (!spinlock_trylock(&irq->lock)) {
+                        /*
+                         * Avoid deadlock by trying again.
+                         */
+                        spinlock_unlock(&box->irq_lock);
+                        interrupts_restore(ipl);
+                        goto loop;
+                }
+                
+                ASSERT(irq->notif_cfg.answerbox == box);
+                
+                list_remove(&irq->notif_cfg.link);
+                
+                /*
+                 * Don't forget to free any top-half pseudocode.
+                 */
+                code_free(irq->notif_cfg.code);
+                
+                irq->notif_cfg.notify = false;
+                irq->notif_cfg.answerbox = NULL;
+                irq->notif_cfg.code = NULL;
+                irq->notif_cfg.method = 0;
+                irq->notif_cfg.counter = 0;
+
+                spinlock_unlock(&irq->lock);
+        }
+        
+        spinlock_unlock(&box->irq_lock);
+        interrupts_restore(ipl);
 }