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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..\n");
  88.         thread_join(TASK->kb.thread);
  89.         thread_detach(TASK->kb.thread);
  90.         LOG("join done\n");
  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.     LOG("kbox_proc_phone_hungup()\n");
  112.  
  113.     /* Was it our debugger, who hung up? */
  114.     if (call->sender == TASK->udebug.debugger) {
  115.         /* Terminate debugging session (if any). */
  116.         LOG("kbox: terminate debug session\n");
  117.         ipl = interrupts_disable();
  118.         spinlock_lock(&TASK->lock);
  119.         udebug_task_cleanup(TASK);
  120.         spinlock_unlock(&TASK->lock);
  121.         interrupts_restore(ipl);
  122.     } else {
  123.         LOG("kbox: was not debugger\n");
  124.     }
  125.  
  126.     LOG("kbox: continue with hangup message\n");
  127.     IPC_SET_RETVAL(call->data, 0);
  128.     ipc_answer(&TASK->kb.box, call);
  129.  
  130.     ipl = interrupts_disable();
  131.     spinlock_lock(&TASK->lock);
  132.     spinlock_lock(&TASK->kb.box.lock);
  133.     if (list_empty(&TASK->kb.box.connected_phones)) {
  134.         /*
  135.          * Last phone has been disconnected. Detach this thread so it
  136.          * gets freed and signal to the caller.
  137.          */
  138.  
  139.         /* Only detach kbox thread unless already terminating. */
  140.         mutex_lock(&TASK->kb.cleanup_lock);
  141.         if (&TASK->kb.finished == false) {
  142.             /* Detach kbox thread so it gets freed from memory. */
  143.             thread_detach(TASK->kb.thread);
  144.             TASK->kb.thread = NULL;
  145.         }
  146.         mutex_unlock(&TASK->kb.cleanup_lock);
  147.  
  148.         LOG("phone list is empty\n");
  149.         *last = true;
  150.     } else {
  151.         *last = false;
  152.     }
  153.  
  154.     spinlock_unlock(&TASK->kb.box.lock);
  155.     spinlock_unlock(&TASK->lock);
  156.     interrupts_restore(ipl);
  157. }
  158.  
  159. /** Implementing function for the kbox thread.
  160.  *
  161.  * This function listens for debug requests. It terminates
  162.  * when all phones are disconnected from the kbox.
  163.  *
  164.  * @param arg   Ignored.
  165.  */
  166. static void kbox_thread_proc(void *arg)
  167. {
  168.     call_t *call;
  169.     bool done;
  170.  
  171.     (void)arg;
  172.     LOG("kbox_thread_proc()\n");
  173.     done = false;
  174.  
  175.     while (!done) {
  176.         call = ipc_wait_for_call(&TASK->kb.box, SYNCH_NO_TIMEOUT,
  177.             SYNCH_FLAGS_NONE);
  178.  
  179.         if (call == NULL)
  180.             continue;   /* Try again. */
  181.  
  182.         switch (IPC_GET_METHOD(call->data)) {
  183.  
  184.         case IPC_M_DEBUG_ALL:
  185.             /* Handle debug call. */
  186.             udebug_call_receive(call);
  187.             break;
  188.  
  189.         case IPC_M_PHONE_HUNGUP:
  190.             /*
  191.              * Process the hangup call. If this was the last
  192.              * phone, done will be set to true and the
  193.              * while loop will terminate.
  194.              */
  195.             kbox_proc_phone_hungup(call, &done);
  196.             break;
  197.  
  198.         default:
  199.             /* Ignore */
  200.             break;
  201.         }
  202.     }
  203.  
  204.     LOG("kbox: finished\n");
  205. }
  206.  
  207.  
  208. /**
  209.  * Connect phone to a task kernel-box specified by id.
  210.  *
  211.  * Note that this is not completely atomic. For optimisation reasons, the task
  212.  * might start cleaning up kbox after the phone has been connected and before
  213.  * a kbox thread has been created. This must be taken into account in the
  214.  * cleanup code.
  215.  *
  216.  * @return      Phone id on success, or negative error code.
  217.  */
  218. int ipc_connect_kbox(task_id_t taskid)
  219. {
  220.     int newphid;
  221.     task_t *ta;
  222.     thread_t *kb_thread;
  223.     ipl_t ipl;
  224.  
  225.     ipl = interrupts_disable();
  226.     spinlock_lock(&tasks_lock);
  227.  
  228.     ta = task_find_by_id(taskid);
  229.     if (ta == NULL) {
  230.         spinlock_unlock(&tasks_lock);
  231.         interrupts_restore(ipl);
  232.         return ENOENT;
  233.     }
  234.  
  235.     atomic_inc(&ta->refcount);
  236.  
  237.     spinlock_unlock(&tasks_lock);
  238.     interrupts_restore(ipl);
  239.  
  240.     mutex_lock(&ta->kb.cleanup_lock);
  241.  
  242.     if (atomic_predec(&ta->refcount) == 0) {
  243.         mutex_unlock(&ta->kb.cleanup_lock);
  244.         task_destroy(ta);
  245.         return ENOENT;
  246.     }
  247.  
  248.     if (ta->kb.finished != false) {
  249.         mutex_unlock(&ta->kb.cleanup_lock);
  250.         return EINVAL;
  251.     }
  252.  
  253.     newphid = phone_alloc();
  254.     if (newphid < 0) {
  255.         mutex_unlock(&ta->kb.cleanup_lock);
  256.         return ELIMIT;
  257.     }
  258.  
  259.     /* Connect the newly allocated phone to the kbox */
  260.     ipc_phone_connect(&TASK->phones[newphid], &ta->kb.box);
  261.  
  262.     if (ta->kb.thread != NULL) {
  263.         mutex_unlock(&ta->kb.cleanup_lock);
  264.         return newphid;
  265.     }
  266.  
  267.     /* Create a kbox thread */
  268.     kb_thread = thread_create(kbox_thread_proc, NULL, ta, 0,
  269.         "kbox", false);
  270.     if (!kb_thread) {
  271.         mutex_unlock(&ta->kb.cleanup_lock);
  272.         return ENOMEM;
  273.     }
  274.  
  275.     ta->kb.thread = kb_thread;
  276.     thread_ready(kb_thread);
  277.  
  278.     mutex_unlock(&ta->kb.cleanup_lock);
  279.  
  280.     return newphid;
  281. }
  282.  
  283. /** @}
  284.  */
  285.