WebSVN – HelenOS – Diff – /trunk/kernel/generic/src/ipc/ipc.c

 /** @file
  */
 /* Lock ordering
+ *
- * First the answerbox, then the phone
+ * First the answerbox, then the phone.
  */
 #include <synch/spinlock.h>
 #include <synch/waitq.h>
 #include <synch/synch.h>
 #include <print.h>
 #include <proc/thread.h>
 #include <arch/interrupt.h>
 #include <ipc/irq.h>
-/* Open channel that is assigned automatically to new tasks */
+/** Open channel that is assigned automatically to new tasks */
 answerbox_t *ipc_phone_0 = NULL;
 static slab_cache_t *ipc_call_slab;
-/* Initialize new call */
+/** Initialize a call structure.
+ *
+ * @param call      Call structure to be initialized.
+ */
 static void _ipc_call_init(call_t *call)
+{
-    memsetb((uintptr_t)call, sizeof(*call), 0);
+    memsetb((uintptr_t) call, sizeof(*call), 0);
     call->callerbox = &TASK->answerbox;
     call->sender = TASK;
+}
-/** Allocate & initialize call structure
+/** Allocate and initialize a call structure.
+ *
- * The call is initialized, so that the reply will be directed
+ * The call is initialized, so that the reply will be directed to
- * to TASK->answerbox
+ * TASK->answerbox.
+ *
+ * @param flags     Parameters for slab_alloc (e.g FRAME_ATOMIC).
+ *
- * @param flags Parameters for slab_alloc (ATOMIC, etc.)
+ * @return      If flags permit it, return NULL, or initialized kernel
+ *          call structure.
  */
-call_t * ipc_call_alloc(int flags)
+call_t *ipc_call_alloc(int flags)
+{
     call_t *call;
     call = slab_alloc(ipc_call_slab, flags);
     _ipc_call_init(call);
     return call;
+}
-/** Initialize allocated call */
+/** Initialize a statically allocated call structure.
+ *
+ * @param call      Statically allocated kernel call structure to be
+ *          initialized.
+ */
 void ipc_call_static_init(call_t *call)
+{
     _ipc_call_init(call);
     call->flags |= IPC_CALL_STATIC_ALLOC;
+}
-/** Deallocate call stracuture */
+/** Deallocate a call stracuture.
+ *
+ * @param call      Call structure to be freed.
+ */
 void ipc_call_free(call_t *call)
+{
+    ASSERT(!(call->flags & IPC_CALL_STATIC_ALLOC));
     slab_free(ipc_call_slab, call);
+}
-/** Initialize answerbox structure
+/** Initialize an answerbox structure.
+ *
+ * @param box       Answerbox structure to be initialized.
  */
 void ipc_answerbox_init(answerbox_t *box)
+{
     spinlock_initialize(&box->lock, "ipc_box_lock");
     spinlock_initialize(&box->irq_lock, "ipc_box_irqlock");
     list_initialize(&box->irq_notifs);
     list_initialize(&box->irq_head);
     box->task = TASK;
+}
-/** Connect phone to answerbox */
+/** Connect a phone to an answerbox.
+ *
+ * @param phone     Initialized phone structure.
+ * @param box       Initialized answerbox structure.
+ */
 void ipc_phone_connect(phone_t *phone, answerbox_t *box)
+{
     spinlock_lock(&phone->lock);
     phone->state = IPC_PHONE_CONNECTED;
     spinlock_unlock(&box->lock);
     spinlock_unlock(&phone->lock);
+}
+/** Initialize a phone structure.
+ *
-/** Initialize phone structure and connect phone to answerbox
+ * @param phone     Phone structure to be initialized.
  */
 void ipc_phone_init(phone_t *phone)
+{
     spinlock_initialize(&phone->lock, "phone_lock");
     phone->callee = NULL;
     phone->state = IPC_PHONE_FREE;
     atomic_set(&phone->active_calls, 0);
+}
-/** Helper function to facilitate synchronous calls */
+/** Helper function to facilitate synchronous calls.
+ *
+ * @param phone     Destination kernel phone structure.
+ * @param request   Call structure with request.
+ */
 void ipc_call_sync(phone_t *phone, call_t *request)
+{
     answerbox_t sync_box;
     ipc_answerbox_init(&sync_box);
-    /* We will receive data on special box */
+    /* We will receive data in a special box. */
     request->callerbox = &sync_box;
     ipc_call(phone, request);
     ipc_wait_for_call(&sync_box, SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE);
+}
-/** Answer message that was not dispatched and is not entered in
+/** Answer a message which was not dispatched and is not listed in any queue.
- * any queue
+ *
+ * @param call      Call structure to be answered.
  */
 static void _ipc_answer_free_call(call_t *call)
+{
     answerbox_t *callerbox = call->callerbox;
     list_append(&call->link, &callerbox->answers);
     spinlock_unlock(&callerbox->lock);
     waitq_wakeup(&callerbox->wq, WAKEUP_FIRST);
+}
-/** Answer message, that is in callee queue
+/** Answer a message which is in a callee queue.
+ *
- * @param box Answerbox that is answering the message
+ * @param box       Answerbox that is answering the message.
- * @param call Modified request that is being sent back
+ * @param call      Modified request that is being sent back.
  */
 void ipc_answer(answerbox_t *box, call_t *call)
+{
     /* Remove from active box */
     spinlock_lock(&box->lock);
     spinlock_unlock(&box->lock);
     /* Send back answer */
     _ipc_answer_free_call(call);
+}
-/** Simulate sending back a message
+/** Simulate sending back a message.
+ *
  * Most errors are better handled by forming a normal backward
  * message and sending it as a normal answer.
+ *
+ * @param phone     Phone structure the call should appear to come from.
+ * @param call      Call structure to be answered.
+ * @param err       Return value to be used for the answer.
  */
 void ipc_backsend_err(phone_t *phone, call_t *call, unative_t err)
+{
     call->data.phone = phone;
     atomic_inc(&phone->active_calls);
     IPC_SET_RETVAL(call->data, err);
     _ipc_answer_free_call(call);
+}
-/* Unsafe unchecking ipc_call */
+/** Unsafe unchecking version of ipc_call.
+ *
+ * @param phone     Phone structure the call comes from.
+ * @param box       Destination answerbox structure.
+ */
 static void _ipc_call(phone_t *phone, answerbox_t *box, call_t *call)
+{
-    if (! (call->flags & IPC_CALL_FORWARDED)) {
+    if (!(call->flags & IPC_CALL_FORWARDED)) {
         atomic_inc(&phone->active_calls);
         call->data.phone = phone;
+    }
     spinlock_lock(&box->lock);
     list_append(&call->link, &box->calls);
     spinlock_unlock(&box->lock);
     waitq_wakeup(&box->wq, WAKEUP_FIRST);
+}
-/** Send a asynchronous request using phone to answerbox
+/** Send an asynchronous request using a phone to an answerbox.
+ *
+ * @param phone     Phone structure the call comes from and which is
+ *          connected to the destination answerbox.
+ * @param call      Call structure with request.
+ *
- * @param phone Phone connected to answerbox.
+ * @return      Return 0 on success, ENOENT on error.
- * @param call Structure representing the call.
  */
 int ipc_call(phone_t *phone, call_t *call)
+{
     answerbox_t *box;
     spinlock_unlock(&phone->lock);
     return 0;
+}
-/** Disconnect phone from answerbox
+/** Disconnect phone from answerbox.
+ *
- * This call leaves the phone in HUNGUP state. The change to 'free' is done
+ * This call leaves the phone in the HUNGUP state. The change to 'free' is done
  * lazily later.
+ *
- * @param phone Phone to be hung up
+ * @param phone     Phone structure to be hung up.
+ *
+ * @return      Return 0 if the phone is disconnected.
- * @return 0 - phone disconnected, -1 - the phone was already disconnected
+ *          Return -1 if the phone was already disconnected.
  */
 int ipc_phone_hangup(phone_t *phone)
+{
     answerbox_t *box;
     call_t *call;
     spinlock_lock(&phone->lock);
-    if (phone->state == IPC_PHONE_FREE || phone->state ==IPC_PHONE_HUNGUP \
+    if (phone->state == IPC_PHONE_FREE || phone->state == IPC_PHONE_HUNGUP ||
-        || phone->state == IPC_PHONE_CONNECTING) {
+        phone->state == IPC_PHONE_CONNECTING) {
         spinlock_unlock(&phone->lock);
         return -1;
+    }
     box = phone->callee;
     if (phone->state != IPC_PHONE_SLAMMED) {
     spinlock_unlock(&phone->lock);
     return 0;
+}
-/** Forwards call from one answerbox to a new one
+/** Forwards call from one answerbox to another one.
+ *
- * @param call Call to be redirected.
+ * @param call      Call structure to be redirected.
- * @param newphone Phone to target answerbox.
+ * @param newphone  Phone structure to target answerbox.
- * @param oldbox Old answerbox
+ * @param oldbox    Old answerbox structure.
+ *
- * @return 0 on forward ok, error code, if there was error
+ * @return      Return 0 if forwarding succeeded or an error code if
+ *          there was error.
+ *
- * - the return value serves only as an information for the forwarder,
+ * The return value serves only as an information for the forwarder,
- *   the original caller is notified automatically with EFORWARD
+ * the original caller is notified automatically with EFORWARD.
  */
 int ipc_forward(call_t *call, phone_t *newphone, answerbox_t *oldbox)
+{
     spinlock_lock(&oldbox->lock);
     list_remove(&call->link);
     return ipc_call(newphone, call);
+}
-/** Wait for phone call
+/** Wait for a phone call.
+ *
- * @param box Answerbox expecting the call.
+ * @param box       Answerbox expecting the call.
- * @param usec Timeout in microseconds. See documentation for waitq_sleep_timeout() for
+ * @param usec      Timeout in microseconds. See documentation for
- *         decription of its special meaning.
+ *          waitq_sleep_timeout() for decription of its special
+ *          meaning.
- * @param flags Select mode of sleep operation. See documentation for waitq_sleep_timeout()i
+ * @param flags     Select mode of sleep operation. See documentation for
- *      for description of its special meaning.
+ *          waitq_sleep_timeout() for description of its special
+ *          meaning.
- * @return Recived message address
+ * @return      Recived call structure or NULL.
+ *
- * - to distinguish between call and answer, look at call->flags
+ * To distinguish between a call and an answer, have a look at call->flags.
  */
-call_t * ipc_wait_for_call(answerbox_t *box, uint32_t usec, int flags)
+call_t *ipc_wait_for_call(answerbox_t *box, uint32_t usec, int flags)
+{
     call_t *request;
     ipl_t ipl;
     int rc;
+    }
     spinlock_unlock(&box->lock);
     return request;
+}
-/** Answer all calls from list with EHANGUP msg */
+/** Answer all calls from list with EHANGUP answer.
+ *
+ * @param lst       Head of the list to be cleaned up.
+ */
 static void ipc_cleanup_call_list(link_t *lst)
+{
     call_t *call;
     while (!list_empty(lst)) {
         IPC_SET_RETVAL(call->data, EHANGUP);
         _ipc_answer_free_call(call);
+    }
+}
-/** Cleans up all IPC communication of the current task
+/** Cleans up all IPC communication of the current task.
+ *
  * Note: ipc_hangup sets returning answerbox to TASK->answerbox, you
- * have to change it as well if you want to cleanup other current then current.
+ * have to change it as well if you want to cleanup other tasks than TASK.
  */
 void ipc_cleanup(void)
+{
     int i;
     call_t *call;
     phone_t *phone;
     DEADLOCK_PROBE_INIT(p_phonelck);
     /* Disconnect all our phones ('ipc_phone_hangup') */
-    for (i=0;i < IPC_MAX_PHONES; i++)
+    for (i = 0; i < IPC_MAX_PHONES; i++)
         ipc_phone_hangup(&TASK->phones[i]);
     /* Disconnect all connected irqs */
     ipc_irq_cleanup(&TASK->answerbox);
     /* Wait for all async answers to arrive */
     while (1) {
         /* Go through all phones, until all are FREE... */
         /* Locking not needed, no one else should modify
          * it, when we are in cleanup */
-        for (i=0;i < IPC_MAX_PHONES; i++) {
+        for (i = 0; i < IPC_MAX_PHONES; i++) {
-            if (TASK->phones[i].state == IPC_PHONE_HUNGUP && \
+            if (TASK->phones[i].state == IPC_PHONE_HUNGUP &&
                 atomic_get(&TASK->phones[i].active_calls) == 0)
                 TASK->phones[i].state = IPC_PHONE_FREE;
             /* Just for sure, we might have had some
              * IPC_PHONE_CONNECTING phones */
+        }
         /* Voila, got into cleanup */
         if (i == IPC_MAX_PHONES)
             break;
-        call = ipc_wait_for_call(&TASK->answerbox, SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE);
+        call = ipc_wait_for_call(&TASK->answerbox, SYNCH_NO_TIMEOUT,
+            SYNCH_FLAGS_NONE);
-        ASSERT((call->flags & IPC_CALL_ANSWERED) || (call->flags & IPC_CALL_NOTIF));
+        ASSERT((call->flags & IPC_CALL_ANSWERED) ||
+            (call->flags & IPC_CALL_NOTIF));
-        ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
+        ASSERT(!(call->flags & IPC_CALL_STATIC_ALLOC));
         atomic_dec(&TASK->active_calls);
         ipc_call_free(call);
+    }
+}
 /** Initilize IPC subsystem */
 void ipc_init(void)
+{
-    ipc_call_slab = slab_cache_create("ipc_call", sizeof(call_t), 0, NULL, NULL, 0);
+    ipc_call_slab = slab_cache_create("ipc_call", sizeof(call_t), 0, NULL,
+        NULL, 0);
+}
-/** Kconsole - list answerbox contents */
+/** List answerbox contents.
+ *
+ * @param taskid    Task ID.
+ */
 void ipc_print_task(task_id_t taskid)
+{
     task_t *task;
     int i;
     call_t *call;
     if (!task)
         return;
     /* Print opened phones & details */
     printf("PHONE:\n");
-    for (i=0; i < IPC_MAX_PHONES;i++) {
+    for (i = 0; i < IPC_MAX_PHONES; i++) {
         spinlock_lock(&task->phones[i].lock);
         if (task->phones[i].state != IPC_PHONE_FREE) {
-            printf("%d: ",i);
+            printf("%d: ", i);
             switch (task->phones[i].state) {
             case IPC_PHONE_CONNECTING:
                 printf("connecting ");
                 break;
             case IPC_PHONE_CONNECTED:

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/ipc/ipc.c – Rev 2310 → 2471