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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 <ipc/ipc.h>
  37. #include <errno.h>
  38. #include <mm/slab.h>
  39. #include <arch.h>
  40. #include <proc/task.h>
  41. #include <memstr.h>
  42. #include <debug.h>
  43.  
  44. #include <print.h>
  45. #include <proc/thread.h>
  46. #include <arch/interrupt.h>
  47. #include <ipc/irq.h>
  48.  
  49. /* Open channel that is assigned automatically to new tasks */
  50. answerbox_t *ipc_phone_0 = NULL;
  51.  
  52. static slab_cache_t *ipc_call_slab;
  53.  
  54. /* Initialize new call */
  55. static void _ipc_call_init(call_t *call)
  56. {
  57.     memsetb((__address)call, sizeof(*call), 0);
  58.     call->callerbox = &TASK->answerbox;
  59.     call->sender = TASK;
  60. }
  61.  
  62. /** Allocate & initialize call structure
  63.  *
  64.  * The call is initialized, so that the reply will be directed
  65.  * to TASK->answerbox
  66.  *
  67.  * @param flags Parameters for slab_alloc (ATOMIC, etc.)
  68.  */
  69. call_t * ipc_call_alloc(int flags)
  70. {
  71.     call_t *call;
  72.  
  73.     call = slab_alloc(ipc_call_slab, flags);
  74.     _ipc_call_init(call);
  75.  
  76.     return call;
  77. }
  78.  
  79. /** Initialize allocated call */
  80. void ipc_call_static_init(call_t *call)
  81. {
  82.     _ipc_call_init(call);
  83.     call->flags |= IPC_CALL_STATIC_ALLOC;
  84. }
  85.  
  86. /** Deallocate call stracuture */
  87. void ipc_call_free(call_t *call)
  88. {
  89.     slab_free(ipc_call_slab, call);
  90. }
  91.  
  92. /** Initialize answerbox structure
  93.  */
  94. void ipc_answerbox_init(answerbox_t *box)
  95. {
  96.     spinlock_initialize(&box->lock, "ipc_box_lock");
  97.     spinlock_initialize(&box->irq_lock, "ipc_box_irqlock");
  98.     waitq_initialize(&box->wq);
  99.     list_initialize(&box->connected_phones);
  100.     list_initialize(&box->calls);
  101.     list_initialize(&box->dispatched_calls);
  102.     list_initialize(&box->answers);
  103.     list_initialize(&box->irq_notifs);
  104.     box->task = TASK;
  105. }
  106.  
  107. /** Connect phone to answerbox */
  108. void ipc_phone_connect(phone_t *phone, answerbox_t *box)
  109. {
  110.     spinlock_lock(&phone->lock);
  111.  
  112.     ASSERT(!phone->callee);
  113.     phone->busy = IPC_BUSY_CONNECTED;
  114.     phone->callee = box;
  115.  
  116.     spinlock_lock(&box->lock);
  117.     list_append(&phone->list, &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->busy = IPC_BUSY_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, 0);
  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->list, &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->list);
  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.     if (phone->busy == IPC_BUSY_CONNECTED)
  187.         IPC_SET_RETVAL(call->data, EHANGUP);
  188.     else
  189.         IPC_SET_RETVAL(call->data, ENOENT);
  190.  
  191.     _ipc_answer_free_call(call);
  192. }
  193.  
  194. /* Unsafe unchecking ipc_call */
  195. static void _ipc_call(phone_t *phone, answerbox_t *box, call_t *call)
  196. {
  197.     if (! (call->flags & IPC_CALL_FORWARDED)) {
  198.         atomic_inc(&phone->active_calls);
  199.         call->data.phone = phone;
  200.     }
  201.  
  202.     spinlock_lock(&box->lock);
  203.     list_append(&call->list, &box->calls);
  204.     spinlock_unlock(&box->lock);
  205.     waitq_wakeup(&box->wq, 0);
  206. }
  207.  
  208. /** Send a asynchronous request using phone to answerbox
  209.  *
  210.  * @param phone Phone connected to answerbox
  211.  * @param request Request to be sent
  212.  */
  213. int ipc_call(phone_t *phone, call_t *call)
  214. {
  215.     answerbox_t *box;
  216.  
  217.     spinlock_lock(&phone->lock);
  218.  
  219.     box = phone->callee;
  220.     if (!box) {
  221.         /* Trying to send over disconnected phone */
  222.         spinlock_unlock(&phone->lock);
  223.         if (call->flags & IPC_CALL_FORWARDED) {
  224.             IPC_SET_RETVAL(call->data, EFORWARD);
  225.             _ipc_answer_free_call(call);
  226.         } else { /* Simulate sending back a message */
  227.             if (phone->busy == IPC_BUSY_CONNECTED)
  228.                 ipc_backsend_err(phone, call, EHANGUP);
  229.             else
  230.                 ipc_backsend_err(phone, call, ENOENT);
  231.         }
  232.  
  233.         return ENOENT;
  234.     }
  235.     _ipc_call(phone, box, call);
  236.    
  237.     spinlock_unlock(&phone->lock);
  238.     return 0;
  239. }
  240.  
  241. /** Disconnect phone from answerbox
  242.  *
  243.  * It is allowed to call disconnect on already disconnected phone
  244.  *
  245.  * @return 0 - phone disconnected, -1 - the phone was already disconnected
  246.  */
  247. int ipc_phone_hangup(phone_t *phone)
  248. {
  249.     answerbox_t *box;
  250.     call_t *call;
  251.    
  252.     spinlock_lock(&phone->lock);
  253.     box = phone->callee;
  254.     if (!box) {
  255.         if (phone->busy == IPC_BUSY_CONNECTING) {
  256.             spinlock_unlock(&phone->lock);
  257.             return -1;
  258.         }
  259.         /* Already disconnected phone */
  260.         phone->busy = IPC_BUSY_FREE;
  261.         spinlock_unlock(&phone->lock);
  262.         return 0;
  263.     }
  264.  
  265.     spinlock_lock(&box->lock);
  266.     list_remove(&phone->list);
  267.     phone->callee = NULL;
  268.     spinlock_unlock(&box->lock);
  269.  
  270.     call = ipc_call_alloc(0);
  271.     IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
  272.     call->flags |= IPC_CALL_DISCARD_ANSWER;
  273.     _ipc_call(phone, box, call);
  274.  
  275.     phone->busy = IPC_BUSY_FREE;
  276.  
  277.     spinlock_unlock(&phone->lock);
  278.  
  279.     return 0;
  280. }
  281.  
  282. /** Forwards call from one answerbox to a new one
  283.  *
  284.  * @param call Call to be redirected.
  285.  * @param newphone Phone to target answerbox.
  286.  * @param oldbox Old answerbox
  287.  * @return 0 on forward ok, error code, if there was error
  288.  *
  289.  * - the return value serves only as an information for the forwarder,
  290.  *   the original caller is notified automatically with EFORWARD
  291.  */
  292. int ipc_forward(call_t *call, phone_t *newphone, answerbox_t *oldbox)
  293. {
  294.     spinlock_lock(&oldbox->lock);
  295.     list_remove(&call->list);
  296.     spinlock_unlock(&oldbox->lock);
  297.  
  298.     return ipc_call(newphone, call);
  299. }
  300.  
  301.  
  302. /** Wait for phone call
  303.  *
  304.  * @return Recived message address
  305.  * - to distinguish between call and answer, look at call->flags
  306.  */
  307. call_t * ipc_wait_for_call(answerbox_t *box, int flags)
  308. {
  309.     call_t *request;
  310.     ipl_t ipl;
  311.  
  312. restart:      
  313.     if (flags & IPC_WAIT_NONBLOCKING) {
  314.         if (waitq_sleep_timeout(&box->wq,0,1) == ESYNCH_WOULD_BLOCK)
  315.             return NULL;
  316.     } else
  317.         waitq_sleep(&box->wq);
  318.    
  319.     spinlock_lock(&box->lock);
  320.     if (!list_empty(&box->irq_notifs)) {
  321.         ipl = interrupts_disable();
  322.         spinlock_lock(&box->irq_lock);
  323.  
  324.         request = list_get_instance(box->irq_notifs.next, call_t, list);
  325.         list_remove(&request->list);
  326.  
  327.         spinlock_unlock(&box->irq_lock);
  328.         interrupts_restore(ipl);
  329.     } else if (!list_empty(&box->answers)) {
  330.         /* Handle asynchronous answers */
  331.         request = list_get_instance(box->answers.next, call_t, list);
  332.         list_remove(&request->list);
  333.         atomic_dec(&request->data.phone->active_calls);
  334.     } else if (!list_empty(&box->calls)) {
  335.         /* Handle requests */
  336.         request = list_get_instance(box->calls.next, call_t, list);
  337.         list_remove(&request->list);
  338.         /* Append request to dispatch queue */
  339.         list_append(&request->list, &box->dispatched_calls);
  340.     } else {
  341.         /* This can happen regularly after ipc_cleanup, remove
  342.          * the warning in the future when the IPC is
  343.          * more debugged */
  344.         printf("WARNING: Spurious IPC wakeup.\n");
  345.         spinlock_unlock(&box->lock);
  346.         goto restart;
  347.     }
  348.     spinlock_unlock(&box->lock);
  349.     return request;
  350. }
  351.  
  352. /** Answer all calls from list with EHANGUP msg */
  353. static void ipc_cleanup_call_list(link_t *lst)
  354. {
  355.     call_t *call;
  356.  
  357.     while (!list_empty(lst)) {
  358.         call = list_get_instance(lst->next, call_t, list);
  359.         list_remove(&call->list);
  360.  
  361.         IPC_SET_RETVAL(call->data, EHANGUP);
  362.         _ipc_answer_free_call(call);
  363.     }
  364. }
  365.  
  366. /** Cleans up all IPC communication of the given task
  367.  *
  368.  *
  369.  */
  370. void ipc_cleanup(task_t *task)
  371. {
  372.     int i;
  373.     call_t *call;
  374.     phone_t *phone;
  375.    
  376.     /* Disconnect all our phones ('ipc_phone_hangup') */
  377.     for (i=0;i < IPC_MAX_PHONES; i++)
  378.         ipc_phone_hangup(&task->phones[i]);
  379.  
  380.     /* Disconnect all connected irqs */
  381.     ipc_irq_cleanup(&task->answerbox);
  382.  
  383.     /* Disconnect all phones connected to our answerbox */
  384. restart_phones:
  385.     spinlock_lock(&task->answerbox.lock);
  386.     while (!list_empty(&task->answerbox.connected_phones)) {
  387.         phone = list_get_instance(task->answerbox.connected_phones.next,
  388.                       phone_t,
  389.                       list);
  390.         if (! spinlock_trylock(&phone->lock)) {
  391.             spinlock_unlock(&task->answerbox.lock);
  392.             goto restart_phones;
  393.         }
  394.        
  395.         /* Disconnect phone */
  396.         phone->callee = NULL;
  397.         list_remove(&phone->list);
  398.  
  399.         spinlock_unlock(&phone->lock);
  400.     }
  401.  
  402.     /* Answer all messages in 'calls' and 'dispatched_calls' queues */
  403.     spinlock_lock(&task->answerbox.lock);
  404.     ipc_cleanup_call_list(&task->answerbox.dispatched_calls);
  405.     ipc_cleanup_call_list(&task->answerbox.calls);
  406.     spinlock_unlock(&task->answerbox.lock);
  407.    
  408.     /* Wait for all async answers to arrive */
  409.     while (atomic_get(&task->active_calls)) {
  410.         call = ipc_wait_for_call(&task->answerbox, 0);
  411.         ASSERT((call->flags & IPC_CALL_ANSWERED) || (call->flags & IPC_CALL_NOTIF));
  412.         ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
  413.        
  414.         atomic_dec(&task->active_calls);
  415.         ipc_call_free(call);
  416.     }
  417. }
  418.  
  419.  
  420. /** Initilize ipc subsystem */
  421. void ipc_init(void)
  422. {
  423.     ipc_call_slab = slab_cache_create("ipc_call",
  424.                       sizeof(call_t),
  425.                       0,
  426.                       NULL, NULL, 0);
  427.     ipc_irq_make_table(IRQ_COUNT);
  428. }
  429.  
  430.