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  1. /*
  2.  * Copyright (c) 2008 Jiri Svoboda
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup genericipc
  30.  * @{
  31.  */
  32. /** @file
  33.  */
  34.  
  35. #include <synch/synch.h>
  36. #include <synch/spinlock.h>
  37. #include <synch/mutex.h>
  38. #include <ipc/ipc.h>
  39. #include <ipc/ipcrsc.h>
  40. #include <arch.h>
  41. #include <errno.h>
  42. #include <debug.h>
  43. #include <udebug/udebug_ipc.h>
  44. #include <ipc/kbox.h>
  45. #include <print.h>
  46.  
  47. void ipc_kbox_cleanup(void)
  48. {
  49.     ipl_t ipl;
  50.     bool have_kb_thread;
  51.  
  52.     /*
  53.      * Only hold kb.cleanup_lock while setting kb.finished -
  54.      * this is enough.
  55.      */
  56.     mutex_lock(&TASK->kb.cleanup_lock);
  57.     TASK->kb.finished = true;
  58.     mutex_unlock(&TASK->kb.cleanup_lock);
  59.  
  60.     have_kb_thread = (TASK->kb.thread != NULL);
  61.  
  62.     /*
  63.      * From now on nobody will try to connect phones or attach
  64.      * kbox threads
  65.      */
  66.  
  67.     /*
  68.      * Disconnect all phones connected to our kbox. Passing true for
  69.      * notify_box causes a HANGUP message to be inserted for each
  70.      * disconnected phone. This ensures the kbox thread is going to
  71.      * wake up and terminate.
  72.      */
  73.     ipc_answerbox_slam_phones(&TASK->kb.box, have_kb_thread);
  74.  
  75.     /*
  76.      * If the task was being debugged, clean up debugging session.
  77.      * This is necessarry as slamming the phones won't force
  78.      * kbox thread to clean it up since sender != debugger.
  79.      */
  80.     ipl = interrupts_disable();
  81.     spinlock_lock(&TASK->lock);
  82.     udebug_task_cleanup(TASK);
  83.     spinlock_unlock(&TASK->lock);
  84.     interrupts_restore(ipl);
  85.    
  86.     if (have_kb_thread) {
  87.         LOG("Join kb.thread.");
  88.         thread_join(TASK->kb.thread);
  89.         thread_detach(TASK->kb.thread);
  90.         LOG("...join done.");
  91.         TASK->kb.thread = NULL;
  92.     }
  93.  
  94.     /* Answer all messages in 'calls' and 'dispatched_calls' queues. */
  95.     spinlock_lock(&TASK->kb.box.lock);
  96.     ipc_cleanup_call_list(&TASK->kb.box.dispatched_calls);
  97.     ipc_cleanup_call_list(&TASK->kb.box.calls);
  98.     spinlock_unlock(&TASK->kb.box.lock);
  99. }
  100.  
  101. /** Handle hangup message in kbox.
  102.  *
  103.  * @param call  The IPC_M_PHONE_HUNGUP call structure.
  104.  * @param last  Output, the function stores @c true here if
  105.  *      this was the last phone, @c false otherwise.
  106.  **/
  107. static void kbox_proc_phone_hungup(call_t *call, bool *last)
  108. {
  109.     ipl_t ipl;
  110.  
  111.     /* Was it our debugger, who hung up? */
  112.     if (call->sender == TASK->udebug.debugger) {
  113.         /* Terminate debugging session (if any). */
  114.         LOG("Terminate debugging session.");
  115.         ipl = interrupts_disable();
  116.         spinlock_lock(&TASK->lock);
  117.         udebug_task_cleanup(TASK);
  118.         spinlock_unlock(&TASK->lock);
  119.         interrupts_restore(ipl);
  120.     } else {
  121.         LOG("Was not debugger.");
  122.     }
  123.  
  124.     LOG("Continue with hangup message.");
  125.     IPC_SET_RETVAL(call->data, 0);
  126.     ipc_answer(&TASK->kb.box, call);
  127.  
  128.     ipl = interrupts_disable();
  129.     spinlock_lock(&TASK->lock);
  130.     spinlock_lock(&TASK->kb.box.lock);
  131.     if (list_empty(&TASK->kb.box.connected_phones)) {
  132.         /*
  133.          * Last phone has been disconnected. Detach this thread so it
  134.          * gets freed and signal to the caller.
  135.          */
  136.  
  137.         /* Only detach kbox thread unless already terminating. */
  138.         mutex_lock(&TASK->kb.cleanup_lock);
  139.         if (&TASK->kb.finished == false) {
  140.             /* Detach kbox thread so it gets freed from memory. */
  141.             thread_detach(TASK->kb.thread);
  142.             TASK->kb.thread = NULL;
  143.         }
  144.         mutex_unlock(&TASK->kb.cleanup_lock);
  145.  
  146.         LOG("Phone list is empty.");
  147.         *last = true;
  148.     } else {
  149.         *last = false;
  150.     }
  151.  
  152.     spinlock_unlock(&TASK->kb.box.lock);
  153.     spinlock_unlock(&TASK->lock);
  154.     interrupts_restore(ipl);
  155. }
  156.  
  157. /** Implementing function for the kbox thread.
  158.  *
  159.  * This function listens for debug requests. It terminates
  160.  * when all phones are disconnected from the kbox.
  161.  *
  162.  * @param arg   Ignored.
  163.  */
  164. static void kbox_thread_proc(void *arg)
  165. {
  166.     call_t *call;
  167.     bool done;
  168.  
  169.     (void)arg;
  170.     LOG("Starting.");
  171.     done = false;
  172.  
  173.     while (!done) {
  174.         call = ipc_wait_for_call(&TASK->kb.box, SYNCH_NO_TIMEOUT,
  175.             SYNCH_FLAGS_NONE);
  176.  
  177.         if (call == NULL)
  178.             continue;   /* Try again. */
  179.  
  180.         switch (IPC_GET_METHOD(call->data)) {
  181.  
  182.         case IPC_M_DEBUG_ALL:
  183.             /* Handle debug call. */
  184.             udebug_call_receive(call);
  185.             break;
  186.  
  187.         case IPC_M_PHONE_HUNGUP:
  188.             /*
  189.              * Process the hangup call. If this was the last
  190.              * phone, done will be set to true and the
  191.              * while loop will terminate.
  192.              */
  193.             kbox_proc_phone_hungup(call, &done);
  194.             break;
  195.  
  196.         default:
  197.             /* Ignore */
  198.             break;
  199.         }
  200.     }
  201.  
  202.     LOG("Exiting.");
  203. }
  204.  
  205.  
  206. /**
  207.  * Connect phone to a task kernel-box specified by id.
  208.  *
  209.  * Note that this is not completely atomic. For optimisation reasons, the task
  210.  * might start cleaning up kbox after the phone has been connected and before
  211.  * a kbox thread has been created. This must be taken into account in the
  212.  * cleanup code.
  213.  *
  214.  * @return      Phone id on success, or negative error code.
  215.  */
  216. int ipc_connect_kbox(task_id_t taskid)
  217. {
  218.     int newphid;
  219.     task_t *ta;
  220.     thread_t *kb_thread;
  221.     ipl_t ipl;
  222.  
  223.     ipl = interrupts_disable();
  224.     spinlock_lock(&tasks_lock);
  225.  
  226.     ta = task_find_by_id(taskid);
  227.     if (ta == NULL) {
  228.         spinlock_unlock(&tasks_lock);
  229.         interrupts_restore(ipl);
  230.         return ENOENT;
  231.     }
  232.  
  233.     atomic_inc(&ta->refcount);
  234.  
  235.     spinlock_unlock(&tasks_lock);
  236.     interrupts_restore(ipl);
  237.  
  238.     mutex_lock(&ta->kb.cleanup_lock);
  239.  
  240.     if (atomic_predec(&ta->refcount) == 0) {
  241.         mutex_unlock(&ta->kb.cleanup_lock);
  242.         task_destroy(ta);
  243.         return ENOENT;
  244.     }
  245.  
  246.     if (ta->kb.finished != false) {
  247.         mutex_unlock(&ta->kb.cleanup_lock);
  248.         return EINVAL;
  249.     }
  250.  
  251.     newphid = phone_alloc();
  252.     if (newphid < 0) {
  253.         mutex_unlock(&ta->kb.cleanup_lock);
  254.         return ELIMIT;
  255.     }
  256.  
  257.     /* Connect the newly allocated phone to the kbox */
  258.     ipc_phone_connect(&TASK->phones[newphid], &ta->kb.box);
  259.  
  260.     if (ta->kb.thread != NULL) {
  261.         mutex_unlock(&ta->kb.cleanup_lock);
  262.         return newphid;
  263.     }
  264.  
  265.     /* Create a kbox thread */
  266.     kb_thread = thread_create(kbox_thread_proc, NULL, ta, 0,
  267.         "kbox", false);
  268.     if (!kb_thread) {
  269.         mutex_unlock(&ta->kb.cleanup_lock);
  270.         return ENOMEM;
  271.     }
  272.  
  273.     ta->kb.thread = kb_thread;
  274.     thread_ready(kb_thread);
  275.  
  276.     mutex_unlock(&ta->kb.cleanup_lock);
  277.  
  278.     return newphid;
  279. }
  280.  
  281. /** @}
  282.  */
  283.