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  1. /*
  2.  * Copyright (c) 2006 Ondrej Palkovsky
  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. /* Lock ordering
  36.  *
  37.  * First the answerbox, then the phone.
  38.  */
  39.  
  40. #include <synch/spinlock.h>
  41. #include <synch/waitq.h>
  42. #include <synch/synch.h>
  43. #include <ipc/ipc.h>
  44. #include <errno.h>
  45. #include <mm/slab.h>
  46. #include <arch.h>
  47. #include <proc/task.h>
  48. #include <memstr.h>
  49. #include <debug.h>
  50.  
  51. #include <print.h>
  52. #include <console/klog.h>
  53. #include <proc/thread.h>
  54. #include <arch/interrupt.h>
  55. #include <ipc/irq.h>
  56.  
  57. /** Open channel that is assigned automatically to new tasks */
  58. answerbox_t *ipc_phone_0 = NULL;
  59.  
  60. static slab_cache_t *ipc_call_slab;
  61.  
  62. /** Initialize a call structure.
  63.  *
  64.  * @param call      Call structure to be initialized.
  65.  */
  66. static void _ipc_call_init(call_t *call)
  67. {
  68.     memsetb((uintptr_t) call, sizeof(*call), 0);
  69.     call->callerbox = &TASK->answerbox;
  70.     call->sender = TASK;
  71.     call->buffer = NULL;
  72. }
  73.  
  74. /** Allocate and initialize a call structure.
  75.  *
  76.  * The call is initialized, so that the reply will be directed to
  77.  * TASK->answerbox.
  78.  *
  79.  * @param flags     Parameters for slab_alloc (e.g FRAME_ATOMIC).
  80.  *
  81.  * @return      If flags permit it, return NULL, or initialized kernel
  82.  *          call structure.
  83.  */
  84. call_t *ipc_call_alloc(int flags)
  85. {
  86.     call_t *call;
  87.  
  88.     call = slab_alloc(ipc_call_slab, flags);
  89.     _ipc_call_init(call);
  90.  
  91.     return call;
  92. }
  93.  
  94. /** Initialize a statically allocated call structure.
  95.  *
  96.  * @param call      Statically allocated kernel call structure to be
  97.  *          initialized.
  98.  */
  99. void ipc_call_static_init(call_t *call)
  100. {
  101.     _ipc_call_init(call);
  102.     call->flags |= IPC_CALL_STATIC_ALLOC;
  103. }
  104.  
  105. /** Deallocate a call structure.
  106.  *
  107.  * @param call      Call structure to be freed.
  108.  */
  109. void ipc_call_free(call_t *call)
  110. {
  111.     ASSERT(!(call->flags & IPC_CALL_STATIC_ALLOC));
  112.     /* Check to see if we have data in the IPC_M_DATA_SEND buffer. */
  113.     if (call->buffer)
  114.         free(call->buffer);
  115.     slab_free(ipc_call_slab, call);
  116. }
  117.  
  118. /** Initialize an answerbox structure.
  119.  *
  120.  * @param box       Answerbox structure to be initialized.
  121.  * @param task      Task to which the answerbox belongs.
  122.  */
  123. void ipc_answerbox_init(answerbox_t *box, task_t *task)
  124. {
  125.     spinlock_initialize(&box->lock, "ipc_box_lock");
  126.     spinlock_initialize(&box->irq_lock, "ipc_box_irqlock");
  127.     waitq_initialize(&box->wq);
  128.     list_initialize(&box->connected_phones);
  129.     list_initialize(&box->calls);
  130.     list_initialize(&box->dispatched_calls);
  131.     list_initialize(&box->answers);
  132.     list_initialize(&box->irq_notifs);
  133.     list_initialize(&box->irq_head);
  134.     box->task = task;
  135. }
  136.  
  137. /** Connect a phone to an answerbox.
  138.  *
  139.  * @param phone     Initialized phone structure.
  140.  * @param box       Initialized answerbox structure.
  141.  */
  142. void ipc_phone_connect(phone_t *phone, answerbox_t *box)
  143. {
  144.     spinlock_lock(&phone->lock);
  145.  
  146.     phone->state = IPC_PHONE_CONNECTED;
  147.     phone->callee = box;
  148.  
  149.     spinlock_lock(&box->lock);
  150.     list_append(&phone->link, &box->connected_phones);
  151.     spinlock_unlock(&box->lock);
  152.  
  153.     spinlock_unlock(&phone->lock);
  154. }
  155.  
  156. /** Initialize a phone structure.
  157.  *
  158.  * @param phone     Phone structure to be initialized.
  159.  */
  160. void ipc_phone_init(phone_t *phone)
  161. {
  162.     spinlock_initialize(&phone->lock, "phone_lock");
  163.     phone->callee = NULL;
  164.     phone->state = IPC_PHONE_FREE;
  165.     atomic_set(&phone->active_calls, 0);
  166. }
  167.  
  168. /** Helper function to facilitate synchronous calls.
  169.  *
  170.  * @param phone     Destination kernel phone structure.
  171.  * @param request   Call structure with request.
  172.  */
  173. void ipc_call_sync(phone_t *phone, call_t *request)
  174. {
  175.     answerbox_t sync_box;
  176.  
  177.     ipc_answerbox_init(&sync_box, TASK);
  178.  
  179.     /* We will receive data in a special box. */
  180.     request->callerbox = &sync_box;
  181.  
  182.     ipc_call(phone, request);
  183.     ipc_wait_for_call(&sync_box, SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE);
  184. }
  185.  
  186. /** Answer a message which was not dispatched and is not listed in any queue.
  187.  *
  188.  * @param call      Call structure to be answered.
  189.  */
  190. static void _ipc_answer_free_call(call_t *call)
  191. {
  192.     answerbox_t *callerbox = call->callerbox;
  193.  
  194.     call->flags |= IPC_CALL_ANSWERED;
  195.  
  196.     spinlock_lock(&callerbox->lock);
  197.     list_append(&call->link, &callerbox->answers);
  198.     spinlock_unlock(&callerbox->lock);
  199.     waitq_wakeup(&callerbox->wq, WAKEUP_FIRST);
  200. }
  201.  
  202. /** Answer a message which is in a callee queue.
  203.  *
  204.  * @param box       Answerbox that is answering the message.
  205.  * @param call      Modified request that is being sent back.
  206.  */
  207. void ipc_answer(answerbox_t *box, call_t *call)
  208. {
  209.     /* Remove from active box */
  210.     spinlock_lock(&box->lock);
  211.     list_remove(&call->link);
  212.     spinlock_unlock(&box->lock);
  213.     /* Send back answer */
  214.     _ipc_answer_free_call(call);
  215. }
  216.  
  217. /** Simulate sending back a message.
  218.  *
  219.  * Most errors are better handled by forming a normal backward
  220.  * message and sending it as a normal answer.
  221.  *
  222.  * @param phone     Phone structure the call should appear to come from.
  223.  * @param call      Call structure to be answered.
  224.  * @param err       Return value to be used for the answer.
  225.  */
  226. void ipc_backsend_err(phone_t *phone, call_t *call, unative_t err)
  227. {
  228.     call->data.phone = phone;
  229.     atomic_inc(&phone->active_calls);
  230.     IPC_SET_RETVAL(call->data, err);
  231.     _ipc_answer_free_call(call);
  232. }
  233.  
  234. /** Unsafe unchecking version of ipc_call.
  235.  *
  236.  * @param phone     Phone structure the call comes from.
  237.  * @param box       Destination answerbox structure.
  238.  * @param call      Call structure with request.
  239.  */
  240. static void _ipc_call(phone_t *phone, answerbox_t *box, call_t *call)
  241. {
  242.     if (!(call->flags & IPC_CALL_FORWARDED)) {
  243.         atomic_inc(&phone->active_calls);
  244.         call->data.phone = phone;
  245.     }
  246.  
  247.     spinlock_lock(&box->lock);
  248.     list_append(&call->link, &box->calls);
  249.     spinlock_unlock(&box->lock);
  250.     waitq_wakeup(&box->wq, WAKEUP_FIRST);
  251. }
  252.  
  253. /** Send an asynchronous request using a phone to an answerbox.
  254.  *
  255.  * @param phone     Phone structure the call comes from and which is
  256.  *          connected to the destination answerbox.
  257.  * @param call      Call structure with request.
  258.  *
  259.  * @return      Return 0 on success, ENOENT on error.
  260.  */
  261. int ipc_call(phone_t *phone, call_t *call)
  262. {
  263.     answerbox_t *box;
  264.  
  265.     spinlock_lock(&phone->lock);
  266.     if (phone->state != IPC_PHONE_CONNECTED) {
  267.         spinlock_unlock(&phone->lock);
  268.         if (call->flags & IPC_CALL_FORWARDED) {
  269.             IPC_SET_RETVAL(call->data, EFORWARD);
  270.             _ipc_answer_free_call(call);
  271.         } else {
  272.             if (phone->state == IPC_PHONE_HUNGUP)
  273.                 ipc_backsend_err(phone, call, EHANGUP);
  274.             else
  275.                 ipc_backsend_err(phone, call, ENOENT);
  276.         }
  277.         return ENOENT;
  278.     }
  279.     box = phone->callee;
  280.     _ipc_call(phone, box, call);
  281.    
  282.     spinlock_unlock(&phone->lock);
  283.     return 0;
  284. }
  285.  
  286. /** Disconnect phone from answerbox.
  287.  *
  288.  * This call leaves the phone in the HUNGUP state. The change to 'free' is done
  289.  * lazily later.
  290.  *
  291.  * @param phone     Phone structure to be hung up.
  292.  *              
  293.  * @return      Return 0 if the phone is disconnected.
  294.  *          Return -1 if the phone was already disconnected.
  295.  */
  296. int ipc_phone_hangup(phone_t *phone)
  297. {
  298.     answerbox_t *box;
  299.     call_t *call;
  300.    
  301.     spinlock_lock(&phone->lock);
  302.     if (phone->state == IPC_PHONE_FREE ||
  303.         phone->state == IPC_PHONE_HUNGUP ||
  304.         phone->state == IPC_PHONE_CONNECTING) {
  305.         spinlock_unlock(&phone->lock);
  306.         return -1;
  307.     }
  308.     box = phone->callee;
  309.     if (phone->state != IPC_PHONE_SLAMMED) {
  310.         /* Remove myself from answerbox */
  311.         spinlock_lock(&box->lock);
  312.         list_remove(&phone->link);
  313.         spinlock_unlock(&box->lock);
  314.  
  315.         if (phone->state != IPC_PHONE_SLAMMED) {
  316.             call = ipc_call_alloc(0);
  317.             IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
  318.             call->flags |= IPC_CALL_DISCARD_ANSWER;
  319.             _ipc_call(phone, box, call);
  320.         }
  321.     }
  322.  
  323.     phone->state = IPC_PHONE_HUNGUP;
  324.     spinlock_unlock(&phone->lock);
  325.  
  326.     return 0;
  327. }
  328.  
  329. /** Forwards call from one answerbox to another one.
  330.  *
  331.  * @param call      Call structure to be redirected.
  332.  * @param newphone  Phone structure to target answerbox.
  333.  * @param oldbox    Old answerbox structure.
  334.  * @param mode      Flags that specify mode of the forward operation.
  335.  *
  336.  * @return      Return 0 if forwarding succeeded or an error code if
  337.  *          there was error.
  338.  *
  339.  * The return value serves only as an information for the forwarder,
  340.  * the original caller is notified automatically with EFORWARD.
  341.  */
  342. int ipc_forward(call_t *call, phone_t *newphone, answerbox_t *oldbox, int mode)
  343. {
  344.     spinlock_lock(&oldbox->lock);
  345.     list_remove(&call->link);
  346.     spinlock_unlock(&oldbox->lock);
  347.  
  348.     if (mode & IPC_FF_ROUTE_FROM_ME)
  349.         call->data.phone = newphone;
  350.  
  351.     return ipc_call(newphone, call);
  352. }
  353.  
  354.  
  355. /** Wait for a phone call.
  356.  *
  357.  * @param box       Answerbox expecting the call.
  358.  * @param usec      Timeout in microseconds. See documentation for
  359.  *          waitq_sleep_timeout() for decription of its special
  360.  *          meaning.
  361.  * @param flags     Select mode of sleep operation. See documentation for
  362.  *          waitq_sleep_timeout() for description of its special
  363.  *          meaning.
  364.  * @return      Recived call structure or NULL.
  365.  *
  366.  * To distinguish between a call and an answer, have a look at call->flags.
  367.  */
  368. call_t *ipc_wait_for_call(answerbox_t *box, uint32_t usec, int flags)
  369. {
  370.     call_t *request;
  371.     ipl_t ipl;
  372.     int rc;
  373.  
  374. restart:
  375.     rc = waitq_sleep_timeout(&box->wq, usec, flags);
  376.     if (SYNCH_FAILED(rc))
  377.         return NULL;
  378.    
  379.     spinlock_lock(&box->lock);
  380.     if (!list_empty(&box->irq_notifs)) {
  381.         ipl = interrupts_disable();
  382.         spinlock_lock(&box->irq_lock);
  383.  
  384.         request = list_get_instance(box->irq_notifs.next, call_t, link);
  385.         list_remove(&request->link);
  386.  
  387.         spinlock_unlock(&box->irq_lock);
  388.         interrupts_restore(ipl);
  389.     } else if (!list_empty(&box->answers)) {
  390.         /* Handle asynchronous answers */
  391.         request = list_get_instance(box->answers.next, call_t, link);
  392.         list_remove(&request->link);
  393.         atomic_dec(&request->data.phone->active_calls);
  394.     } else if (!list_empty(&box->calls)) {
  395.         /* Handle requests */
  396.         request = list_get_instance(box->calls.next, call_t, link);
  397.         list_remove(&request->link);
  398.         /* Append request to dispatch queue */
  399.         list_append(&request->link, &box->dispatched_calls);
  400.     } else {
  401.         /* This can happen regularly after ipc_cleanup */
  402.         spinlock_unlock(&box->lock);
  403.         goto restart;
  404.     }
  405.     spinlock_unlock(&box->lock);
  406.     return request;
  407. }
  408.  
  409. /** Answer all calls from list with EHANGUP answer.
  410.  *
  411.  * @param lst       Head of the list to be cleaned up.
  412.  */
  413. static void ipc_cleanup_call_list(link_t *lst)
  414. {
  415.     call_t *call;
  416.  
  417.     while (!list_empty(lst)) {
  418.         call = list_get_instance(lst->next, call_t, link);
  419.         if (call->buffer)
  420.             free(call->buffer);
  421.         list_remove(&call->link);
  422.  
  423.         IPC_SET_RETVAL(call->data, EHANGUP);
  424.         _ipc_answer_free_call(call);
  425.     }
  426. }
  427.  
  428. /** Disconnects all phones connected to an answerbox.
  429.  *
  430.  * @param box       Answerbox to disconnect phones from.
  431.  * @param notify_box    If true, the answerbox will get a hangup message for
  432.  *          each disconnected phone.
  433.  */
  434. static void ipc_answerbox_slam_phones(answerbox_t *box, bool notify_box)
  435. {
  436.     phone_t *phone;
  437.     DEADLOCK_PROBE_INIT(p_phonelck);
  438.     ipl_t ipl;
  439.     call_t *call;
  440.  
  441.     call = ipc_call_alloc(0);
  442.  
  443.     /* Disconnect all phones connected to our answerbox */
  444. restart_phones:
  445.     ipl = interrupts_disable();
  446.     spinlock_lock(&box->lock);
  447.     while (!list_empty(&box->connected_phones)) {
  448.         phone = list_get_instance(box->connected_phones.next,
  449.             phone_t, link);
  450.         if (!spinlock_trylock(&phone->lock)) {
  451.             spinlock_unlock(&box->lock);
  452.             interrupts_restore(ipl);
  453.             DEADLOCK_PROBE(p_phonelck, DEADLOCK_THRESHOLD);
  454.             goto restart_phones;
  455.         }
  456.        
  457.         /* Disconnect phone */
  458.         ASSERT(phone->state == IPC_PHONE_CONNECTED);
  459.  
  460.         list_remove(&phone->link);
  461.         phone->state = IPC_PHONE_SLAMMED;
  462.  
  463.         if (notify_box) {
  464.             spinlock_unlock(&phone->lock);
  465.             spinlock_unlock(&box->lock);
  466.             interrupts_restore(ipl);
  467.  
  468.             /*
  469.              * Send one message to the answerbox for each
  470.              * phone. Used to make sure the kbox thread
  471.              * wakes up after the last phone has been
  472.              * disconnected.
  473.              */
  474.             IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
  475.             call->flags |= IPC_CALL_DISCARD_ANSWER;
  476.             _ipc_call(phone, box, call);
  477.  
  478.             /* Allocate another call in advance */
  479.             call = ipc_call_alloc(0);
  480.  
  481.             /* Must start again */
  482.             goto restart_phones;
  483.         }
  484.  
  485.         spinlock_unlock(&phone->lock);
  486.     }
  487.  
  488.     spinlock_unlock(&box->lock);
  489.     interrupts_restore(ipl);
  490.  
  491.     /* Free unused call */
  492.     if (call) ipc_call_free(call);
  493. }
  494.  
  495. static void ipc_kbox_cleanup()
  496. {
  497.     ipl_t ipl;
  498.     bool have_kb_thread;
  499.  
  500.     /* Only hold kb_cleanup_lock while setting kb_finished - this is enough */
  501.     ipl = interrupts_disable();
  502.     spinlock_lock(&TASK->kb_cleanup_lock);
  503.  
  504.     TASK->kb_finished = true;
  505.  
  506.     spinlock_unlock(&TASK->kb_cleanup_lock);
  507.     interrupts_restore(ipl);
  508.  
  509.     have_kb_thread = (TASK->kb_thread != NULL);
  510.  
  511.     /* From now on nobody will try to connect phones or attach kbox threads */
  512.  
  513.     /*
  514.      * Disconnect all phones connected to our kbox. Passing true for
  515.      * notify_box causes a HANGUP message to be inserted for each
  516.      * disconnected phone. This ensures the kbox thread is going to
  517.      * wake up and terminate.
  518.      */
  519.     ipc_answerbox_slam_phones(&TASK->kernel_box, have_kb_thread);
  520.    
  521.     /* TODO: Wait for kbox thread to terminate */
  522.     if (have_kb_thread) {
  523.         klog_printf("ipc_kbox_cleanup - wait for kbox thread to finish");
  524.         waitq_sleep(&TASK->kb_thread_shutdown_wq);
  525.     }
  526.  
  527.     /* Answer all messages in 'calls' and 'dispatched_calls' queues */
  528.     spinlock_lock(&TASK->kernel_box.lock);
  529.     ipc_cleanup_call_list(&TASK->kernel_box.dispatched_calls);
  530.     ipc_cleanup_call_list(&TASK->kernel_box.calls);
  531.     spinlock_unlock(&TASK->kernel_box.lock);
  532. }
  533.  
  534.  
  535. /** Cleans up all IPC communication of the current task.
  536.  *
  537.  * Note: ipc_hangup sets returning answerbox to TASK->answerbox, you
  538.  * have to change it as well if you want to cleanup other tasks than TASK.
  539.  */
  540. void ipc_cleanup(void)
  541. {
  542.     int i;
  543.     call_t *call;
  544.  
  545.     /* Disconnect all our phones ('ipc_phone_hangup') */
  546.     for (i = 0; i < IPC_MAX_PHONES; i++)
  547.         ipc_phone_hangup(&TASK->phones[i]);
  548.  
  549.     /* Disconnect all connected irqs */
  550.     ipc_irq_cleanup(&TASK->answerbox);
  551.  
  552.     /* Disconnect all phones connected to our regular answerbox */
  553.     ipc_answerbox_slam_phones(&TASK->answerbox, false);
  554.  
  555.     /* Clean up kbox thread and communications */
  556.     ipc_kbox_cleanup();
  557.  
  558.     /* Answer all messages in 'calls' and 'dispatched_calls' queues */
  559.     spinlock_lock(&TASK->answerbox.lock);
  560.     ipc_cleanup_call_list(&TASK->answerbox.dispatched_calls);
  561.     ipc_cleanup_call_list(&TASK->answerbox.calls);
  562.     spinlock_unlock(&TASK->answerbox.lock);
  563.    
  564.     /* Wait for all async answers to arrive */
  565.     while (1) {
  566.         /* Go through all phones, until all are FREE... */
  567.         /* Locking not needed, no one else should modify
  568.          * it, when we are in cleanup */
  569.         for (i = 0; i < IPC_MAX_PHONES; i++) {
  570.             if (TASK->phones[i].state == IPC_PHONE_HUNGUP &&
  571.                 atomic_get(&TASK->phones[i].active_calls) == 0)
  572.                 TASK->phones[i].state = IPC_PHONE_FREE;
  573.            
  574.             /* Just for sure, we might have had some
  575.              * IPC_PHONE_CONNECTING phones */
  576.             if (TASK->phones[i].state == IPC_PHONE_CONNECTED)
  577.                 ipc_phone_hangup(&TASK->phones[i]);
  578.             /* If the hangup succeeded, it has sent a HANGUP
  579.              * message, the IPC is now in HUNGUP state, we
  580.              * wait for the reply to come */
  581.            
  582.             if (TASK->phones[i].state != IPC_PHONE_FREE)
  583.                 break;
  584.         }
  585.         /* Voila, got into cleanup */
  586.         if (i == IPC_MAX_PHONES)
  587.             break;
  588.        
  589.         call = ipc_wait_for_call(&TASK->answerbox, SYNCH_NO_TIMEOUT,
  590.             SYNCH_FLAGS_NONE);
  591.         ASSERT((call->flags & IPC_CALL_ANSWERED) ||
  592.             (call->flags & IPC_CALL_NOTIF));
  593.         ASSERT(!(call->flags & IPC_CALL_STATIC_ALLOC));
  594.        
  595.         atomic_dec(&TASK->active_calls);
  596.         ipc_call_free(call);
  597.     }
  598. }
  599.  
  600.  
  601. /** Initilize IPC subsystem */
  602. void ipc_init(void)
  603. {
  604.     ipc_call_slab = slab_cache_create("ipc_call", sizeof(call_t), 0, NULL,
  605.         NULL, 0);
  606. }
  607.  
  608.  
  609. /** List answerbox contents.
  610.  *
  611.  * @param taskid    Task ID.
  612.  */
  613. void ipc_print_task(task_id_t taskid)
  614. {
  615.     task_t *task;
  616.     int i;
  617.     call_t *call;
  618.     link_t *tmp;
  619.    
  620.     spinlock_lock(&tasks_lock);
  621.     task = task_find_by_id(taskid);
  622.     if (task)
  623.         spinlock_lock(&task->lock);
  624.     spinlock_unlock(&tasks_lock);
  625.     if (!task)
  626.         return;
  627.  
  628.     /* Print opened phones & details */
  629.     printf("PHONE:\n");
  630.     for (i = 0; i < IPC_MAX_PHONES; i++) {
  631.         spinlock_lock(&task->phones[i].lock);
  632.         if (task->phones[i].state != IPC_PHONE_FREE) {
  633.             printf("%d: ", i);
  634.             switch (task->phones[i].state) {
  635.             case IPC_PHONE_CONNECTING:
  636.                 printf("connecting ");
  637.                 break;
  638.             case IPC_PHONE_CONNECTED:
  639.                 printf("connected to: %p ",
  640.                        task->phones[i].callee);
  641.                 break;
  642.             case IPC_PHONE_SLAMMED:
  643.                 printf("slammed by: %p ",
  644.                        task->phones[i].callee);
  645.                 break;
  646.             case IPC_PHONE_HUNGUP:
  647.                 printf("hung up - was: %p ",
  648.                        task->phones[i].callee);
  649.                 break;
  650.             default:
  651.                 break;
  652.             }
  653.             printf("active: %d\n",
  654.                 atomic_get(&task->phones[i].active_calls));
  655.         }
  656.         spinlock_unlock(&task->phones[i].lock);
  657.     }
  658.  
  659.  
  660.     /* Print answerbox - calls */
  661.     spinlock_lock(&task->answerbox.lock);
  662.     printf("ABOX - CALLS:\n");
  663.     for (tmp = task->answerbox.calls.next; tmp != &task->answerbox.calls;
  664.         tmp = tmp->next) {
  665.         call = list_get_instance(tmp, call_t, link);
  666.         printf("Callid: %p Srctask:%llu M:%d A1:%d A2:%d A3:%d "
  667.             "A4:%d A5:%d Flags:%x\n", call, call->sender->taskid,
  668.             IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
  669.             IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data),
  670.             IPC_GET_ARG4(call->data), IPC_GET_ARG5(call->data),
  671.             call->flags);
  672.     }
  673.     /* Print answerbox - calls */
  674.     printf("ABOX - DISPATCHED CALLS:\n");
  675.     for (tmp=task->answerbox.dispatched_calls.next;
  676.          tmp != &task->answerbox.dispatched_calls;
  677.          tmp = tmp->next) {
  678.         call = list_get_instance(tmp, call_t, link);
  679.         printf("Callid: %p Srctask:%llu M:%d A1:%d A2:%d A3:%d "
  680.             "A4:%d A5:%d Flags:%x\n", call, call->sender->taskid,
  681.             IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
  682.             IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data),
  683.             IPC_GET_ARG4(call->data), IPC_GET_ARG5(call->data),
  684.             call->flags);
  685.     }
  686.     /* Print answerbox - calls */
  687.     printf("ABOX - ANSWERS:\n");
  688.     for (tmp = task->answerbox.answers.next; tmp != &task->answerbox.answers;
  689.         tmp = tmp->next) {
  690.         call = list_get_instance(tmp, call_t, link);
  691.         printf("Callid:%p M:%d A1:%d A2:%d A3:%d A4:%d A5:%d Flags:%x\n",
  692.             call, IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
  693.             IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data),
  694.             IPC_GET_ARG4(call->data), IPC_GET_ARG5(call->data),
  695.             call->flags);
  696.     }
  697.  
  698.     spinlock_unlock(&task->answerbox.lock);
  699.     spinlock_unlock(&task->lock);
  700. }
  701.  
  702. #include <ipc/ipcrsc.h>
  703. #include <console/klog.h>
  704. #include <udebug/udebug_ipc.h>
  705.  
  706. static void kbox_thread_proc(void *arg)
  707. {
  708.     call_t *call;
  709.     int method;
  710.     bool done;
  711.     ipl_t ipl;
  712.  
  713.     (void)arg;
  714.     klog_printf("kbox_thread_proc()");
  715.     done = false;
  716.  
  717.     while (!done) {
  718.         klog_printf("kbox: wait for call");
  719.         call = ipc_wait_for_call(&TASK->kernel_box, SYNCH_NO_TIMEOUT,
  720.             SYNCH_FLAGS_NONE);
  721.  
  722.         if (call != NULL) {
  723.             method = IPC_GET_METHOD(call->data);
  724.  
  725.             if (method == IPC_M_DEBUG_ALL) {
  726.                 udebug_call_receive(call);
  727.             }
  728.  
  729.             if (method == IPC_M_PHONE_HUNGUP) {
  730.                 klog_printf("kbox: handle hangup message");
  731.  
  732.                 /* Was it our debugger, who hung up? */
  733.                 if (call->sender == TASK->debugger) {
  734.                     /* Terminate debugging session (if any) */
  735.                     klog_printf("kbox: terminate debug session");
  736.                     ipl = interrupts_disable();
  737.                     spinlock_lock(&TASK->lock);
  738.                     udebug_task_cleanup(TASK);
  739.                     spinlock_unlock(&TASK->lock);
  740.                     interrupts_restore(ipl);
  741.                 } else {
  742.                     klog_printf("kbox: was not debugger");
  743.                 }
  744.  
  745.                 klog_printf("kbox: continue with hangup message");
  746.                 IPC_SET_RETVAL(call->data, 0);
  747.                 ipc_answer(&TASK->kernel_box, call);
  748.  
  749.                 ipl = interrupts_disable();
  750.                 spinlock_lock(&TASK->lock);
  751.                 spinlock_lock(&TASK->answerbox.lock);
  752.                 if (list_empty(&TASK->answerbox.connected_phones)) {
  753.                     /* Last phone has been disconnected */
  754.                     TASK->kb_thread = NULL;
  755.                     done = true;
  756.                     klog_printf("phone list is empty");
  757.                 }
  758.                 spinlock_unlock(&TASK->answerbox.lock);
  759.                 spinlock_unlock(&TASK->lock);
  760.                 interrupts_restore(ipl);
  761.             }
  762.         }
  763.     }
  764.  
  765.     klog_printf("kbox: done, waking up possible shutdown routine");
  766.     waitq_wakeup(&TASK->kb_thread_shutdown_wq, WAKEUP_ALL);
  767.     klog_printf("kbox: finished");
  768. }
  769.  
  770.  
  771. /**
  772.  * Connect phone to a task kernel-box specified by id.
  773.  *
  774.  * Note that this is not completely atomic. For optimisation reasons,
  775.  * The task might start cleaning up kbox after the phone has been connected
  776.  * and before a kbox thread has been created. This must be taken into account
  777.  * in the cleanup code.
  778.  *
  779.  * @return      Phone id on success, or negative error code.
  780.  */
  781. int ipc_connect_kbox(task_id_t taskid)
  782. {
  783.     int newphid;
  784.     task_t *ta;
  785.     thread_t *kb_thread;
  786.     ipl_t ipl;
  787.     bool had_kb_thread;
  788.  
  789.     newphid = phone_alloc();
  790.     if (newphid < 0)
  791.         return ELIMIT;
  792.  
  793.     ipl = interrupts_disable();
  794.     spinlock_lock(&tasks_lock);
  795.  
  796.     ta = task_find_by_id(taskid);
  797.     if (ta == NULL) {
  798.         spinlock_unlock(&tasks_lock);
  799.         interrupts_restore(ipl);
  800.         return ENOENT;
  801.     }
  802.  
  803.     spinlock_lock(&ta->kb_cleanup_lock);
  804.     spinlock_unlock(&tasks_lock);
  805.  
  806.     /*
  807.      * Only ta->kb_cleanup_lock left. Since we checked the value
  808.      * of ta->kb_finished, this suffices to ensure the task's exitence.
  809.      * (And that it didn't start kbox cleanup yet). It also ensures
  810.      * mutual exclusion with other threads running this function.
  811.      */
  812.  
  813.     if (ta->kb_finished != false) {
  814.         spinlock_unlock(&ta->kb_cleanup_lock);
  815.         interrupts_restore(ipl);
  816.         return EINVAL;
  817.     }
  818.  
  819.     /* Connect the newly allocated phone to the kbox */
  820.     ipc_phone_connect(&TASK->phones[newphid], &ta->kernel_box);
  821.  
  822.     had_kb_thread = (ta->kb_thread != NULL);
  823.    
  824.     /*
  825.      * Release all locks. This is an optimisation, that makes
  826.      * unnecessary thread creation very unlikely.
  827.      */
  828.     spinlock_unlock(&ta->kb_cleanup_lock);
  829.     interrupts_restore(ipl);
  830.  
  831.     /* Create a kbox thread */
  832.  
  833.     kb_thread = thread_create(kbox_thread_proc,
  834.         NULL, ta, THREAD_FLAG_NOATTACH, "kbox", false);
  835.     if (!kb_thread)
  836.         return ENOMEM;
  837.  
  838.     /*
  839.      * It might happen that someone else has attached a kbox thread.
  840.      * in the meantime. Also, the task might have gone or shut down.
  841.      * Let's try from the beginning.
  842.      */
  843.  
  844.     ipl = interrupts_disable();
  845.     spinlock_lock(&tasks_lock);
  846.  
  847.     ta = task_find_by_id(taskid);
  848.     if (ta == NULL) {
  849.         spinlock_unlock(&tasks_lock);
  850.         return ENOENT;
  851.     }
  852.  
  853.     spinlock_lock(&ta->kb_cleanup_lock);
  854.     spinlock_unlock(&tasks_lock);
  855.  
  856.     if (ta->kb_finished != false || ta->kb_thread != NULL) {
  857.         spinlock_unlock(&ta->kb_cleanup_lock);
  858.         interrupts_restore(ipl);
  859.  
  860.         /*
  861.          * Release the allocated thread struct. This won't
  862.          * happen too often, only if two CPUs raced for
  863.          * connecting to the kbox.
  864.          */
  865.         thread_unattached_free(kb_thread);
  866.         return EINVAL;
  867.     }
  868.  
  869.     /* Attach thread */
  870.     ta->kb_thread = kb_thread;
  871.     thread_attach(kb_thread, ta);
  872.  
  873.     thread_detach(kb_thread);
  874.     thread_ready(kb_thread);
  875.  
  876.     spinlock_unlock(&ta->kb_cleanup_lock);
  877.     interrupts_restore(ipl);
  878.  
  879.     return newphid;
  880. }
  881.  
  882. /** @}
  883.  */
  884.