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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. /* Lock ordering
  30.  *
  31.  * First the answerbox, then the phone
  32.  */
  33.  
  34. #include <synch/spinlock.h>
  35. #include <synch/waitq.h>
  36. #include <synch/synch.h>
  37. #include <ipc/ipc.h>
  38. #include <errno.h>
  39. #include <mm/slab.h>
  40. #include <arch.h>
  41. #include <proc/task.h>
  42. #include <memstr.h>
  43. #include <debug.h>
  44.  
  45. #include <print.h>
  46. #include <proc/thread.h>
  47. #include <arch/interrupt.h>
  48. #include <ipc/irq.h>
  49.  
  50. /* Open channel that is assigned automatically to new tasks */
  51. answerbox_t *ipc_phone_0 = NULL;
  52.  
  53. static slab_cache_t *ipc_call_slab;
  54.  
  55. /* Initialize new call */
  56. static void _ipc_call_init(call_t *call)
  57. {
  58.     memsetb((__address)call, sizeof(*call), 0);
  59.     call->callerbox = &TASK->answerbox;
  60.     call->sender = TASK;
  61. }
  62.  
  63. /** Allocate & initialize call structure
  64.  *
  65.  * The call is initialized, so that the reply will be directed
  66.  * to TASK->answerbox
  67.  *
  68.  * @param flags Parameters for slab_alloc (ATOMIC, etc.)
  69.  */
  70. call_t * ipc_call_alloc(int flags)
  71. {
  72.     call_t *call;
  73.  
  74.     call = slab_alloc(ipc_call_slab, flags);
  75.     _ipc_call_init(call);
  76.  
  77.     return call;
  78. }
  79.  
  80. /** Initialize allocated call */
  81. void ipc_call_static_init(call_t *call)
  82. {
  83.     _ipc_call_init(call);
  84.     call->flags |= IPC_CALL_STATIC_ALLOC;
  85. }
  86.  
  87. /** Deallocate call stracuture */
  88. void ipc_call_free(call_t *call)
  89. {
  90.     slab_free(ipc_call_slab, call);
  91. }
  92.  
  93. /** Initialize answerbox structure
  94.  */
  95. void ipc_answerbox_init(answerbox_t *box)
  96. {
  97.     spinlock_initialize(&box->lock, "ipc_box_lock");
  98.     spinlock_initialize(&box->irq_lock, "ipc_box_irqlock");
  99.     waitq_initialize(&box->wq);
  100.     list_initialize(&box->connected_phones);
  101.     list_initialize(&box->calls);
  102.     list_initialize(&box->dispatched_calls);
  103.     list_initialize(&box->answers);
  104.     list_initialize(&box->irq_notifs);
  105.     box->task = TASK;
  106. }
  107.  
  108. /** Connect phone to answerbox */
  109. void ipc_phone_connect(phone_t *phone, answerbox_t *box)
  110. {
  111.     spinlock_lock(&phone->lock);
  112.  
  113.     phone->state = IPC_PHONE_CONNECTED;
  114.     phone->callee = box;
  115.  
  116.     spinlock_lock(&box->lock);
  117.     list_append(&phone->link, &box->connected_phones);
  118.     spinlock_unlock(&box->lock);
  119.  
  120.     spinlock_unlock(&phone->lock);
  121. }
  122.  
  123. /** Initialize phone structure and connect phone to answerbox
  124.  */
  125. void ipc_phone_init(phone_t *phone)
  126. {
  127.     spinlock_initialize(&phone->lock, "phone_lock");
  128.     phone->callee = NULL;
  129.     phone->state = IPC_PHONE_FREE;
  130.     atomic_set(&phone->active_calls, 0);
  131. }
  132.  
  133. /** Helper function to facilitate synchronous calls */
  134. void ipc_call_sync(phone_t *phone, call_t *request)
  135. {
  136.     answerbox_t sync_box;
  137.  
  138.     ipc_answerbox_init(&sync_box);
  139.  
  140.     /* We will receive data on special box */
  141.     request->callerbox = &sync_box;
  142.  
  143.     ipc_call(phone, request);
  144.     ipc_wait_for_call(&sync_box, SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE);
  145. }
  146.  
  147. /** Answer message that was not dispatched and is not entered in
  148.  * any queue
  149.  */
  150. static void _ipc_answer_free_call(call_t *call)
  151. {
  152.     answerbox_t *callerbox = call->callerbox;
  153.  
  154.     call->flags |= IPC_CALL_ANSWERED;
  155.  
  156.     spinlock_lock(&callerbox->lock);
  157.     list_append(&call->link, &callerbox->answers);
  158.     spinlock_unlock(&callerbox->lock);
  159.     waitq_wakeup(&callerbox->wq, 0);
  160. }
  161.  
  162. /** Answer message, that is in callee queue
  163.  *
  164.  * @param box Answerbox that is answering the message
  165.  * @param call Modified request that is being sent back
  166.  */
  167. void ipc_answer(answerbox_t *box, call_t *call)
  168. {
  169.     /* Remove from active box */
  170.     spinlock_lock(&box->lock);
  171.     list_remove(&call->link);
  172.     spinlock_unlock(&box->lock);
  173.     /* Send back answer */
  174.     _ipc_answer_free_call(call);
  175. }
  176.  
  177. /** Simulate sending back a message
  178.  *
  179.  * Most errors are better handled by forming a normal backward
  180.  * message and sending it as a normal answer.
  181.  */
  182. void ipc_backsend_err(phone_t *phone, call_t *call, __native err)
  183. {
  184.     call->data.phone = phone;
  185.     atomic_inc(&phone->active_calls);
  186.     IPC_SET_RETVAL(call->data, err);
  187.     _ipc_answer_free_call(call);
  188. }
  189.  
  190. /* Unsafe unchecking ipc_call */
  191. static void _ipc_call(phone_t *phone, answerbox_t *box, call_t *call)
  192. {
  193.     if (! (call->flags & IPC_CALL_FORWARDED)) {
  194.         atomic_inc(&phone->active_calls);
  195.         call->data.phone = phone;
  196.     }
  197.  
  198.     spinlock_lock(&box->lock);
  199.     list_append(&call->link, &box->calls);
  200.     spinlock_unlock(&box->lock);
  201.     waitq_wakeup(&box->wq, 0);
  202. }
  203.  
  204. /** Send a asynchronous request using phone to answerbox
  205.  *
  206.  * @param phone Phone connected to answerbox
  207.  * @param request Request to be sent
  208.  */
  209. int ipc_call(phone_t *phone, call_t *call)
  210. {
  211.     answerbox_t *box;
  212.  
  213.     spinlock_lock(&phone->lock);
  214.     if (phone->state != IPC_PHONE_CONNECTED) {
  215.         spinlock_unlock(&phone->lock);
  216.         if (call->flags & IPC_CALL_FORWARDED) {
  217.             IPC_SET_RETVAL(call->data, EFORWARD);
  218.             _ipc_answer_free_call(call);
  219.         } else {
  220.             if (phone->state == IPC_PHONE_HUNGUP)
  221.                 ipc_backsend_err(phone, call, EHANGUP);
  222.             else
  223.                 ipc_backsend_err(phone, call, ENOENT);
  224.         }
  225.         return ENOENT;
  226.     }
  227.     box = phone->callee;
  228.     _ipc_call(phone, box, call);
  229.    
  230.     spinlock_unlock(&phone->lock);
  231.     return 0;
  232. }
  233.  
  234. /** Disconnect phone from answerbox
  235.  *
  236.  * This call leaves the phone in HUNGUP state. The change to 'free' is done
  237.  * lazily later.
  238.  *
  239.  * @param phone Phone to be hung up
  240.  *              
  241.  * @return 0 - phone disconnected, -1 - the phone was already disconnected
  242.  */
  243. int ipc_phone_hangup(phone_t *phone)
  244. {
  245.     answerbox_t *box;
  246.     call_t *call;
  247.    
  248.     spinlock_lock(&phone->lock);
  249.     if (phone->state == IPC_PHONE_FREE || phone->state ==IPC_PHONE_HUNGUP \
  250.         || phone->state == IPC_PHONE_CONNECTING) {
  251.         spinlock_unlock(&phone->lock);
  252.         return -1;
  253.     }
  254.     box = phone->callee;
  255.     if (phone->state != IPC_PHONE_SLAMMED) {
  256.         /* Remove myself from answerbox */
  257.         spinlock_lock(&box->lock);
  258.         list_remove(&phone->link);
  259.         spinlock_unlock(&box->lock);
  260.  
  261.         if (phone->state != IPC_PHONE_SLAMMED) {
  262.             call = ipc_call_alloc(0);
  263.             IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
  264.             call->flags |= IPC_CALL_DISCARD_ANSWER;
  265.             _ipc_call(phone, box, call);
  266.         }
  267.     }
  268.  
  269.     phone->state = IPC_PHONE_HUNGUP;
  270.     spinlock_unlock(&phone->lock);
  271.  
  272.     return 0;
  273. }
  274.  
  275. /** Forwards call from one answerbox to a new one
  276.  *
  277.  * @param call Call to be redirected.
  278.  * @param newphone Phone to target answerbox.
  279.  * @param oldbox Old answerbox
  280.  * @return 0 on forward ok, error code, if there was error
  281.  *
  282.  * - the return value serves only as an information for the forwarder,
  283.  *   the original caller is notified automatically with EFORWARD
  284.  */
  285. int ipc_forward(call_t *call, phone_t *newphone, answerbox_t *oldbox)
  286. {
  287.     spinlock_lock(&oldbox->lock);
  288.     list_remove(&call->link);
  289.     spinlock_unlock(&oldbox->lock);
  290.  
  291.     return ipc_call(newphone, call);
  292. }
  293.  
  294.  
  295. /** Wait for phone call
  296.  *
  297.  * @param box Answerbox expecting the call.
  298.  * @param usec Timeout in microseconds. See documentation for waitq_sleep_timeout() for
  299.  *         decription of its special meaning.
  300.  * @param flags Select mode of sleep operation. See documentation for waitq_sleep_timeout()i
  301.  *      for description of its special meaning.
  302.  * @return Recived message address
  303.  * - to distinguish between call and answer, look at call->flags
  304.  */
  305. call_t * ipc_wait_for_call(answerbox_t *box, __u32 usec, int flags)
  306. {
  307.     call_t *request;
  308.     ipl_t ipl;
  309.     int rc;
  310.  
  311. restart:
  312.     rc = waitq_sleep_timeout(&box->wq, usec, flags);
  313.     if (SYNCH_FAILED(rc))
  314.         return NULL;
  315.    
  316.     spinlock_lock(&box->lock);
  317.     if (!list_empty(&box->irq_notifs)) {
  318.         ipl = interrupts_disable();
  319.         spinlock_lock(&box->irq_lock);
  320.  
  321.         request = list_get_instance(box->irq_notifs.next, call_t, link);
  322.         list_remove(&request->link);
  323.  
  324.         spinlock_unlock(&box->irq_lock);
  325.         interrupts_restore(ipl);
  326.     } else if (!list_empty(&box->answers)) {
  327.         /* Handle asynchronous answers */
  328.         request = list_get_instance(box->answers.next, call_t, link);
  329.         list_remove(&request->link);
  330.         atomic_dec(&request->data.phone->active_calls);
  331.     } else if (!list_empty(&box->calls)) {
  332.         /* Handle requests */
  333.         request = list_get_instance(box->calls.next, call_t, link);
  334.         list_remove(&request->link);
  335.         /* Append request to dispatch queue */
  336.         list_append(&request->link, &box->dispatched_calls);
  337.     } else {
  338.         /* This can happen regularly after ipc_cleanup */
  339.         spinlock_unlock(&box->lock);
  340.         goto restart;
  341.     }
  342.     spinlock_unlock(&box->lock);
  343.     return request;
  344. }
  345.  
  346. /** Answer all calls from list with EHANGUP msg */
  347. static void ipc_cleanup_call_list(link_t *lst)
  348. {
  349.     call_t *call;
  350.  
  351.     while (!list_empty(lst)) {
  352.         call = list_get_instance(lst->next, call_t, link);
  353.         list_remove(&call->link);
  354.  
  355.         IPC_SET_RETVAL(call->data, EHANGUP);
  356.         _ipc_answer_free_call(call);
  357.     }
  358. }
  359.  
  360. /** Cleans up all IPC communication of the current task
  361.  *
  362.  * Note: ipc_hangup sets returning answerbox to TASK->answerbox, you
  363.  * have to change it as well if you want to cleanup other current then current.
  364.  */
  365. void ipc_cleanup(void)
  366. {
  367.     int i;
  368.     call_t *call;
  369.     phone_t *phone;
  370.  
  371.     /* Disconnect all our phones ('ipc_phone_hangup') */
  372.     for (i=0;i < IPC_MAX_PHONES; i++)
  373.         ipc_phone_hangup(&TASK->phones[i]);
  374.  
  375.     /* Disconnect all connected irqs */
  376.     ipc_irq_cleanup(&TASK->answerbox);
  377.  
  378.     /* Disconnect all phones connected to our answerbox */
  379. restart_phones:
  380.     spinlock_lock(&TASK->answerbox.lock);
  381.     while (!list_empty(&TASK->answerbox.connected_phones)) {
  382.         phone = list_get_instance(TASK->answerbox.connected_phones.next,
  383.                       phone_t, link);
  384.         if (! spinlock_trylock(&phone->lock)) {
  385.             spinlock_unlock(&TASK->answerbox.lock);
  386.             goto restart_phones;
  387.         }
  388.        
  389.         /* Disconnect phone */
  390.         ASSERT(phone->state == IPC_PHONE_CONNECTED);
  391.         phone->state = IPC_PHONE_SLAMMED;
  392.         list_remove(&phone->link);
  393.  
  394.         spinlock_unlock(&phone->lock);
  395.     }
  396.  
  397.     /* Answer all messages in 'calls' and 'dispatched_calls' queues */
  398.     ipc_cleanup_call_list(&TASK->answerbox.dispatched_calls);
  399.     ipc_cleanup_call_list(&TASK->answerbox.calls);
  400.     spinlock_unlock(&TASK->answerbox.lock);
  401.    
  402.     /* Wait for all async answers to arrive */
  403.     while (1) {
  404.         /* Go through all phones, until all are FREE... */
  405.         /* Locking not needed, no one else should modify
  406.          * it, when we are in cleanup */
  407.         for (i=0;i < IPC_MAX_PHONES; i++) {
  408.             if (TASK->phones[i].state == IPC_PHONE_HUNGUP && \
  409.                 atomic_get(&TASK->phones[i].active_calls) == 0)
  410.                 TASK->phones[i].state = IPC_PHONE_FREE;
  411.            
  412.             /* Just for sure, we might have had some
  413.              * IPC_PHONE_CONNECTING phones */
  414.             if (TASK->phones[i].state == IPC_PHONE_CONNECTED)
  415.                 ipc_phone_hangup(&TASK->phones[i]);
  416.             /* If the hangup succeeded, it has sent a HANGUP
  417.              * message, the IPC is now in HUNGUP state, we
  418.              * wait for the reply to come */
  419.            
  420.             if (TASK->phones[i].state != IPC_PHONE_FREE)
  421.                 break;
  422.         }
  423.         /* Voila, got into cleanup */
  424.         if (i == IPC_MAX_PHONES)
  425.             break;
  426.        
  427.         call = ipc_wait_for_call(&TASK->answerbox, SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE);
  428.         ASSERT((call->flags & IPC_CALL_ANSWERED) || (call->flags & IPC_CALL_NOTIF));
  429.         ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
  430.        
  431.         atomic_dec(&TASK->active_calls);
  432.         ipc_call_free(call);
  433.     }
  434. }
  435.  
  436.  
  437. /** Initilize ipc subsystem */
  438. void ipc_init(void)
  439. {
  440.     ipc_call_slab = slab_cache_create("ipc_call",
  441.                       sizeof(call_t),
  442.                       0,
  443.                       NULL, NULL, 0);
  444.     ipc_irq_make_table(IRQ_COUNT);
  445. }
  446.  
  447.  
  448. /** Kconsole - list answerbox contents */
  449. void ipc_print_task(task_id_t taskid)
  450. {
  451.     task_t *task;
  452.     int i;
  453.     call_t *call;
  454.     link_t *tmp;
  455.    
  456.     spinlock_lock(&tasks_lock);
  457.     task = task_find_by_id(taskid);
  458.     if (task)
  459.         spinlock_lock(&task->lock);
  460.     spinlock_unlock(&tasks_lock);
  461.     if (!task)
  462.         return;
  463.  
  464.     /* Print opened phones & details */
  465.     printf("PHONE:\n");
  466.     for (i=0; i < IPC_MAX_PHONES;i++) {
  467.         spinlock_lock(&task->phones[i].lock);
  468.         if (task->phones[i].state != IPC_PHONE_FREE) {
  469.             printf("%d: ",i);
  470.             switch (task->phones[i].state) {
  471.             case IPC_PHONE_CONNECTING:
  472.                 printf("connecting ");
  473.                 break;
  474.             case IPC_PHONE_CONNECTED:
  475.                 printf("connected to: %P ",
  476.                        task->phones[i].callee);
  477.                 break;
  478.             case IPC_PHONE_SLAMMED:
  479.                 printf("slammed by: %P ",
  480.                        task->phones[i].callee);
  481.                 break;
  482.             case IPC_PHONE_HUNGUP:
  483.                 printf("hung up - was: %P ",
  484.                        task->phones[i].callee);
  485.                 break;
  486.             default:
  487.                 break;
  488.             }
  489.             printf("active: %d\n", atomic_get(&task->phones[i].active_calls));
  490.         }
  491.         spinlock_unlock(&task->phones[i].lock);
  492.     }
  493.  
  494.  
  495.     /* Print answerbox - calls */
  496.     spinlock_lock(&task->answerbox.lock);
  497.     printf("ABOX - CALLS:\n");
  498.     for (tmp=task->answerbox.calls.next; tmp != &task->answerbox.calls;tmp = tmp->next) {
  499.         call = list_get_instance(tmp, call_t, link);
  500.         printf("Callid: %P Srctask:%lld M:%d A1:%d A2:%d A3:%d Flags:%x\n",call,
  501.                call->sender->taskid, IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
  502.                IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data), call->flags);
  503.     }
  504.     /* Print answerbox - calls */
  505.     printf("ABOX - DISPATCHED CALLS:\n");
  506.     for (tmp=task->answerbox.dispatched_calls.next;
  507.          tmp != &task->answerbox.dispatched_calls;
  508.          tmp = tmp->next) {
  509.         call = list_get_instance(tmp, call_t, link);
  510.         printf("Callid: %P Srctask:%lld M:%d A1:%d A2:%d A3:%d Flags:%x\n",call,
  511.                call->sender->taskid, IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
  512.                IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data), call->flags);
  513.     }
  514.     /* Print answerbox - calls */
  515.     printf("ABOX - ANSWERS:\n");
  516.     for (tmp=task->answerbox.answers.next; tmp != &task->answerbox.answers; tmp = tmp->next) {
  517.         call = list_get_instance(tmp, call_t, link);
  518.         printf("Callid:%P M:%d A1:%d A2:%d A3:%d Flags:%x\n",call,
  519.                IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
  520.                IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data), call->flags);
  521.     }
  522.  
  523.     spinlock_unlock(&task->answerbox.lock);
  524.     spinlock_unlock(&task->lock);
  525. }
  526.