generic/src/ipc/ipc.c

   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         ASSERT(!phone->callee);
 114         phone->busy = IPC_BUSY_CONNECTED;
 115         phone->callee = box;
 116
 117         spinlock_lock(&box->lock);
 118         list_append(&phone->list, &box->connected_phones);
 119         spinlock_unlock(&box->lock);
 120
 121         spinlock_unlock(&phone->lock);
 122 }
 123
 124 /** Initialize phone structure and connect phone to answerbox
 125  */
 126 void ipc_phone_init(phone_t *phone)
 127 {
 128         spinlock_initialize(&phone->lock, "phone_lock");
 129         phone->callee = NULL;
 130         phone->busy = IPC_BUSY_FREE;
 131         atomic_set(&phone->active_calls, 0);
 132 }
 133
 134 /** Helper function to facilitate synchronous calls */
 135 void ipc_call_sync(phone_t *phone, call_t *request)
 136 {
 137         answerbox_t sync_box;
 138
 139         ipc_answerbox_init(&sync_box);
 140
 141         /* We will receive data on special box */
 142         request->callerbox = &sync_box;
 143
 144         ipc_call(phone, request);
 145         ipc_wait_for_call(&sync_box, SYNCH_NO_TIMEOUT, SYNCH_BLOCKING);
 146 }
 147
 148 /** Answer message that was not dispatched and is not entered in
 149  * any queue
 150  */
 151 static void _ipc_answer_free_call(call_t *call)
 152 {
 153         answerbox_t *callerbox = call->callerbox;
 154
 155         call->flags |= IPC_CALL_ANSWERED;
 156
 157         spinlock_lock(&callerbox->lock);
 158         list_append(&call->list, &callerbox->answers);
 159         spinlock_unlock(&callerbox->lock);
 160         waitq_wakeup(&callerbox->wq, 0);
 161 }
 162
 163 /** Answer message, that is in callee queue
 164  *
 165  * @param box Answerbox that is answering the message
 166  * @param call Modified request that is being sent back
 167  */
 168 void ipc_answer(answerbox_t *box, call_t *call)
 169 {
 170         /* Remove from active box */
 171         spinlock_lock(&box->lock);
 172         list_remove(&call->list);
 173         spinlock_unlock(&box->lock);
 174         /* Send back answer */
 175         _ipc_answer_free_call(call);
 176 }
 177
 178 /** Simulate sending back a message
 179  *
 180  * Most errors are better handled by forming a normal backward
 181  * message and sending it as a normal answer.
 182  */
 183 void ipc_backsend_err(phone_t *phone, call_t *call, __native err)
 184 {
 185         call->data.phone = phone;
 186         atomic_inc(&phone->active_calls);
 187         if (phone->busy == IPC_BUSY_CONNECTED)
 188                 IPC_SET_RETVAL(call->data, EHANGUP);
 189         else
 190                 IPC_SET_RETVAL(call->data, ENOENT);
 191
 192         _ipc_answer_free_call(call);
 193 }
 194
 195 /* Unsafe unchecking ipc_call */
 196 static void _ipc_call(phone_t *phone, answerbox_t *box, call_t *call)
 197 {
 198         if (! (call->flags & IPC_CALL_FORWARDED)) {
 199                 atomic_inc(&phone->active_calls);
 200                 call->data.phone = phone;
 201         }
 202
 203         spinlock_lock(&box->lock);
 204         list_append(&call->list, &box->calls);
 205         spinlock_unlock(&box->lock);
 206         waitq_wakeup(&box->wq, 0);
 207 }
 208
 209 /** Send a asynchronous request using phone to answerbox
 210  *
 211  * @param phone Phone connected to answerbox
 212  * @param request Request to be sent
 213  */
 214 int ipc_call(phone_t *phone, call_t *call)
 215 {
 216         answerbox_t *box;
 217
 218         spinlock_lock(&phone->lock);
 219
 220         box = phone->callee;
 221         if (!box) {
 222                 /* Trying to send over disconnected phone */
 223                 spinlock_unlock(&phone->lock);
 224                 if (call->flags & IPC_CALL_FORWARDED) {
 225                         IPC_SET_RETVAL(call->data, EFORWARD);
 226                         _ipc_answer_free_call(call);
 227                 } else { /* Simulate sending back a message */
 228                         if (phone->busy == IPC_BUSY_CONNECTED)
 229                                 ipc_backsend_err(phone, call, EHANGUP);
 230                         else
 231                                 ipc_backsend_err(phone, call, ENOENT);
 232                 }
 233
 234                 return ENOENT;
 235         }
 236         _ipc_call(phone, box, call);
 237
 238         spinlock_unlock(&phone->lock);
 239         return 0;
 240 }
 241
 242 /** Disconnect phone from answerbox
 243  *
 244  * It is allowed to call disconnect on already disconnected phone
 245  *
 246  * @return 0 - phone disconnected, -1 - the phone was already disconnected
 247  */
 248 int ipc_phone_hangup(phone_t *phone)
 249 {
 250         answerbox_t *box;
 251         call_t *call;
 252
 253         spinlock_lock(&phone->lock);
 254         box = phone->callee;
 255         if (!box) {
 256                 if (phone->busy == IPC_BUSY_CONNECTING) {
 257                         spinlock_unlock(&phone->lock);
 258                         return -1;
 259                 }
 260                 /* Already disconnected phone */
 261                 phone->busy = IPC_BUSY_FREE;
 262                 spinlock_unlock(&phone->lock);
 263                 return 0;
 264         }
 265
 266         spinlock_lock(&box->lock);
 267         list_remove(&phone->list);
 268         phone->callee = NULL;
 269         spinlock_unlock(&box->lock);
 270
 271         call = ipc_call_alloc(0);
 272         IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
 273         call->flags |= IPC_CALL_DISCARD_ANSWER;
 274         _ipc_call(phone, box, call);
 275
 276         phone->busy = IPC_BUSY_FREE;
 277
 278         spinlock_unlock(&phone->lock);
 279
 280         return 0;
 281 }
 282
 283 /** Forwards call from one answerbox to a new one
 284  *
 285  * @param call Call to be redirected.
 286  * @param newphone Phone to target answerbox.
 287  * @param oldbox Old answerbox
 288  * @return 0 on forward ok, error code, if there was error
 289  *
 290  * - the return value serves only as an information for the forwarder,
 291  *   the original caller is notified automatically with EFORWARD
 292  */
 293 int ipc_forward(call_t *call, phone_t *newphone, answerbox_t *oldbox)
 294 {
 295         spinlock_lock(&oldbox->lock);
 296         list_remove(&call->list);
 297         spinlock_unlock(&oldbox->lock);
 298
 299         return ipc_call(newphone, call);
 300 }
 301
 302
 303 /** Wait for phone call
 304  *
 305  * @param box Answerbox expecting the call.
 306  * @param usec Timeout in microseconds. See documentation for waitq_sleep_timeout() for
 307  *             decription of its special meaning.
 308  * @param nonblocking Blocking vs. non-blocking operation mode switch. See documentation
 309  *                    for waitq_sleep_timeout() for description of its special meaning.
 310  * @return Recived message address
 311  * - to distinguish between call and answer, look at call->flags
 312  */
 313 call_t * ipc_wait_for_call(answerbox_t *box, __u32 usec, int nonblocking)
 314 {
 315         call_t *request;
 316         ipl_t ipl;
 317         int rc;
 318
 319 restart:
 320         rc = waitq_sleep_timeout(&box->wq, usec, nonblocking);
 321         if (SYNCH_FAILED(rc))
 322                 return NULL;
 323
 324         spinlock_lock(&box->lock);
 325         if (!list_empty(&box->irq_notifs)) {
 326                 ipl = interrupts_disable();
 327                 spinlock_lock(&box->irq_lock);
 328
 329                 request = list_get_instance(box->irq_notifs.next, call_t, list);
 330                 list_remove(&request->list);
 331
 332                 spinlock_unlock(&box->irq_lock);
 333                 interrupts_restore(ipl);
 334         } else if (!list_empty(&box->answers)) {
 335                 /* Handle asynchronous answers */
 336                 request = list_get_instance(box->answers.next, call_t, list);
 337                 list_remove(&request->list);
 338                 atomic_dec(&request->data.phone->active_calls);
 339         } else if (!list_empty(&box->calls)) {
 340                 /* Handle requests */
 341                 request = list_get_instance(box->calls.next, call_t, list);
 342                 list_remove(&request->list);
 343                 /* Append request to dispatch queue */
 344                 list_append(&request->list, &box->dispatched_calls);
 345         } else {
 346                 /* This can happen regularly after ipc_cleanup, remove
 347                  * the warning in the future when the IPC is
 348                  * more debugged */
 349                 printf("WARNING: Spurious IPC wakeup.\n");
 350                 spinlock_unlock(&box->lock);
 351                 goto restart;
 352         }
 353         spinlock_unlock(&box->lock);
 354         return request;
 355 }
 356
 357 /** Answer all calls from list with EHANGUP msg */
 358 static void ipc_cleanup_call_list(link_t *lst)
 359 {
 360         call_t *call;
 361
 362         while (!list_empty(lst)) {
 363                 call = list_get_instance(lst->next, call_t, list);
 364                 list_remove(&call->list);
 365
 366                 IPC_SET_RETVAL(call->data, EHANGUP);
 367                 _ipc_answer_free_call(call);
 368         }
 369 }
 370
 371 /** Cleans up all IPC communication of the given task
 372  *
 373  *
 374  */
 375 void ipc_cleanup(task_t *task)
 376 {
 377         int i;
 378         call_t *call;
 379         phone_t *phone;
 380
 381         /* Disconnect all our phones ('ipc_phone_hangup') */
 382         for (i=0;i < IPC_MAX_PHONES; i++)
 383                 ipc_phone_hangup(&task->phones[i]);
 384
 385         /* Disconnect all connected irqs */
 386         ipc_irq_cleanup(&task->answerbox);
 387
 388         /* Disconnect all phones connected to our answerbox */
 389 restart_phones:
 390         spinlock_lock(&task->answerbox.lock);
 391         while (!list_empty(&task->answerbox.connected_phones)) {
 392                 phone = list_get_instance(task->answerbox.connected_phones.next,
 393                                           phone_t,
 394                                           list);
 395                 if (! spinlock_trylock(&phone->lock)) {
 396                         spinlock_unlock(&task->answerbox.lock);
 397                         goto restart_phones;
 398                 }
 399
 400                 /* Disconnect phone */
 401                 phone->callee = NULL;
 402                 list_remove(&phone->list);
 403
 404                 spinlock_unlock(&phone->lock);
 405         }
 406
 407         /* Answer all messages in 'calls' and 'dispatched_calls' queues */
 408         spinlock_lock(&task->answerbox.lock);
 409         ipc_cleanup_call_list(&task->answerbox.dispatched_calls);
 410         ipc_cleanup_call_list(&task->answerbox.calls);
 411         spinlock_unlock(&task->answerbox.lock);
 412
 413         /* Wait for all async answers to arrive */
 414         while (atomic_get(&task->active_calls)) {
 415                 call = ipc_wait_for_call(&task->answerbox, SYNCH_NO_TIMEOUT, SYNCH_BLOCKING);
 416                 ASSERT((call->flags & IPC_CALL_ANSWERED) || (call->flags & IPC_CALL_NOTIF));
 417                 ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
 418
 419                 atomic_dec(&task->active_calls);
 420                 ipc_call_free(call);
 421         }
 422 }
 423
 424
 425 /** Initilize ipc subsystem */
 426 void ipc_init(void)
 427 {
 428         ipc_call_slab = slab_cache_create("ipc_call",
 429                                           sizeof(call_t),
 430                                           0,
 431                                           NULL, NULL, 0);
 432         ipc_irq_make_table(IRQ_COUNT);
 433 }
 434